Non-Small Cell Lung Cancer Treatment (PDQ)Health …

By Uncategorized

General Information About Non-Small Cell Lung Cancer (NSCLC)

NSCLC is any type of epithelial lung cancer other than small cell lung cancer (SCLC). The most common types of NSCLC are squamous cell carcinoma, large cell carcinoma, and adenocarcinoma, but there are several other types that occur less frequently, and all types can occur in unusual histologic variants. Although NSCLCs are associated with cigarette smoke, adenocarcinomas may be found in patients who have never smoked. As a class, NSCLCs are relatively insensitive to chemotherapy and radiation therapy compared with SCLC. Patients with resectable disease may be cured by surgery or surgery followed by chemotherapy. Local control can be achieved with radiation therapy in a large number of patients with unresectable disease, but cure is seen only in a small number of patients. Patients with locally advanced unresectable disease may achieve long-term survival with radiation therapy combined with chemotherapy. Patients with advanced metastatic disease may achieve improved survival and palliation of symptoms with chemotherapy, targeted agents, and other supportive measures.

Estimated new cases and deaths from lung cancer (NSCLC and SCLC combined) in the United States in 2016:[1]

Lung cancer is the leading cause of cancer-related mortality in the United States.[1] The 5-year relative survival rate from 1995 to 2001 for patients with lung cancer was 15.7%. The 5-year relative survival rate varies markedly depending on the stage at diagnosis, from 49% to 16% to 2% for patients with local, regional, and distant-stage disease, respectively.[2]

NSCLC arises from the epithelial cells of the lung of the central bronchi to terminal alveoli. The histological type of NSCLC correlates with site of origin, reflecting the variation in respiratory tract epithelium of the bronchi to alveoli. Squamous cell carcinoma usually starts near a central bronchus. Adenocarcinoma and bronchioloalveolar carcinoma usually originate in peripheral lung tissue.

Anatomy of the respiratory system.

Smoking-related lung carcinogenesis is a multistep process. Squamous cell carcinoma and adenocarcinoma have defined premalignant precursor lesions. Before becoming invasive, lung epithelium may undergo morphological changes that include the following:

Dysplasia and carcinoma in situ are considered the principal premalignant lesions because they are more likely to progress to invasive cancer and less likely to spontaneously regress.

In addition, after resection of a lung cancer, there is a 1% to 2% risk per patient per year that a second lung cancer will occur.[3]

NSCLC is a heterogeneous aggregate of histologies. The most common histologies include the following:

These histologies are often classified together because approaches to diagnosis, staging, prognosis, and treatment are similar.

Increasing age is the most important risk factor for most cancers. Other risk factors for lung cancer include:

The single most important risk factor for the development of lung cancer is smoking. For smokers, the risk for lung cancer is on average tenfold higher than in lifetime nonsmokers (defined as a person who has smoked <100 cigarettes in his or her lifetime). The risk increases with the quantity of cigarettes, duration of smoking, and starting age.

Smoking cessation results in a decrease in precancerous lesions and a reduction in the risk of developing lung cancer. Former smokers continue to have an elevated risk for lung cancer for years after quitting. Asbestos exposure may exert a synergistic effect of cigarette smoking on the lung cancer risk.[19]

A significant number of patients cured of their smoking-related lung cancer may develop a second malignancy. In the Lung Cancer Study Group trial of 907 patients with stage T1, N0 resected tumors, the rate was 1.8% per year for nonpulmonary second cancers and 1.6% per year for new lung cancers.[20] Other studies have reported even higher risks of second tumors in long-term survivors, including rates of 10% for second lung cancers and 20% for all second cancers.[21]

Because of the persistent risk of developing second lung cancers in former smokers, various chemoprevention strategies have been evaluated in randomized control trials. None of the phase III trials with the agents beta carotene, retinol, 13-cis-retinoic acid, [alpha]-tocopherol, N-acetylcysteine, or acetylsalicylic acid has demonstrated beneficial, reproducible results.[18,22-25][Level of evidence: 1iiA] Chemoprevention of second primary cancers of the upper aerodigestive tract is undergoing clinical evaluation in patients with early-stage lung cancer.

Refer to the PDQ summaries on Lung Cancer Prevention and Smoking in Cancer Care for more information.

In patients considered at high risk for developing lung cancer, the only screening modality for early detection that has been shown to alter mortality is low-dose helical computed tomography (CT) scanning.[26] Studies of lung cancer screening with chest radiography and sputum cytology have failed to demonstrate that screening lowers lung cancer mortality rates.

(Refer to the Screening by low-dose helical computed tomography subsection in the PDQ summary on Lung Cancer Screening for more information.)

Lung cancer may present with symptoms or be found incidentally on chest imaging. Symptoms and signs may result from the location of the primary local invasion or compression of adjacent thoracic structures, distant metastases, or paraneoplastic phenomena. The most common symptoms at presentation are worsening cough or chest pain. Other presenting symptoms include the following:

Symptoms may result from local invasion or compression of adjacent thoracic structures such as compression involving the esophagus causing dysphagia, compression involving the laryngeal nerves causing hoarseness, or compression involving the superior vena cava causing facial edema and distension of the superficial veins of the head and neck. Symptoms from distant metastases may also be present and include neurological defect or personality change from brain metastases or pain from bone metastases. Infrequently, patients may present with symptoms and signs of paraneoplastic diseases such as hypertrophic osteoarthropathy with digital clubbing or hypercalcemia from parathyroid hormone-related protein. Physical examination may identify enlarged supraclavicular lymphadenopathy, pleural effusion or lobar collapse, unresolved pneumonia, or signs of associated disease such as chronic obstructive pulmonary disease or pulmonary fibrosis.

Investigations of patients with suspected NSCLC focus on confirming the diagnosis and determining the extent of the disease. Treatment options for patients are determined by histology, stage, and general health and comorbidities of the patient.

The procedures used to determine the presence of cancer include the following:

Before a patient begins lung cancer treatment, an experienced lung cancer pathologist must review the pathologic material. This is critical because SCLC, which responds well to chemotherapy and is generally not treated surgically, can be confused on microscopic examination with NSCLC.[27] Immunohistochemistry and electron microscopy are invaluable techniques for diagnosis and subclassification, but most lung tumors can be classified by light microscopic criteria.

(Refer to the Staging Evaluation section of this summary for more information on tests and procedures used for staging.)

The identification of mutations in lung cancer has led to the development of molecularly targeted therapy to improve the survival of subsets of patients with metastatic disease.[28] In particular, subsets of adenocarcinoma now can be defined by specific mutations in genes encoding components of the epidermal growth factor receptor (EGFR) and downstream mitogen-activated protein kinases (MAPK) and phosphatidylinositol 3-kinases (PI3K) signaling pathways. These mutations may define mechanisms of drug sensitivity and primary or acquired resistance to kinase inhibitors.

Other genetic abnormalities of potential relevance to treatment decisions include translocations involving the anaplastic lymphoma kinase (ALK)-tyrosine kinase receptor, which are sensitive to ALK inhibitors, and amplification of MET (mesenchymal epithelial transition factor), which encodes the hepatocyte growth factor receptor. MET amplification has been associated with secondary resistance to EGFR tyrosine kinase inhibitors.

Multiple studies have attempted to identify the prognostic importance of a variety of clinicopathologic factors.[21,29-32] Factors that have correlated with adverse prognosis include the following:

For patients with inoperable disease, prognosis is adversely affected by poor performance status and weight loss of more than 10%. These patients have been excluded from clinical trials evaluating aggressive multimodality interventions.

In multiple retrospective analyses of clinical trial data, advanced age alone has not been shown to influence response or survival with therapy.[47]

Refer to the separate treatment sections for each stage of NSCLC in this summary for more information about prognosis.

Because treatment is not satisfactory for almost all patients with NSCLC, eligible patients should be considered for clinical trials. Information about ongoing clinical trials is available from the NCI website.

Other PDQ summaries containing information related to lung cancer include the following:

Malignant non-small cell epithelial tumors of the lung are classified by the World Health Organization (WHO)/International Association for the Study of Lung Cancer (IASLC). There are three main subtypes of non-small cell lung cancer (NSCLC), including the following:

There are numerous additional subtypes of decreasing frequency.[1]

Most squamous cell carcinomas of the lung are located centrally, in the larger bronchi of the lung. Squamous cell carcinomas are linked more strongly with smoking than other forms of NSCLC. The incidence of squamous cell carcinoma of the lung has been decreasing in recent years.

Adenocarcinoma is now the most common histologic subtype in many countries, and subclassification of adenocarcinoma is important. One of the biggest problems with lung adenocarcinomas is the frequent histologic heterogeneity. In fact, mixtures of adenocarcinoma histologic subtypes are more common than tumors consisting purely of a single pattern of acinar, papillary, bronchioloalveolar, and solid adenocarcinoma with mucin formation.

Criteria for the diagnosis of bronchioloalveolar carcinoma have varied widely in the past. The current WHO/IASLC definition is much more restrictive than that previously used by many pathologists because it is limited to only noninvasive tumors.

If stromal, vascular, or pleural invasion are identified in an adenocarcinoma that has an extensive bronchioloalveolar carcinoma component, the classification would be an adenocarcinoma of mixed subtype with predominant bronchioloalveolar pattern and a focal acinar, solid, or papillary pattern, depending on which pattern is seen in the invasive component. However, the future of bronchioloalveolar carcinoma as a distinct clinical entity is unclear; a multidisciplinary expert panel representing the IASLC, the American Thoracic Society, and the European Respiratory Society proposed a major revision of the classification of adenocarcinomas in 2011 that entails a reclassification of what was called bronchioloalveolar carcinoma into newly defined histologic subgroups.

The following variants of adenocarcinoma are recognized in the WHO/IASLC classification:

In addition to the general category of large cell carcinoma, several uncommon variants are recognized in the WHO/IASLC classification, including the following:

Basaloid carcinoma is also recognized as a variant of squamous cell carcinoma, and rarely, adenocarcinomas may have a basaloid pattern; however, in tumors without either of these features, they are regarded as a variant of large cell carcinoma.

LCNEC is recognized as a histologically high-grade non-small cell carcinoma. It has a very poor prognosis similar to that of small cell lung cancer (SCLC). Atypical carcinoid is recognized as an intermediate-grade neuroendocrine tumor with a prognosis that falls between typical carcinoid and high-grade SCLC and LCNEC.

Neuroendocrine differentiation can be demonstrated by immunohistochemistry or electron microscopy in 10% to 20% of common NSCLCs that do not have any neuroendocrine morphology. These tumors are not formally recognized within the WHO/IASLC classification scheme because the clinical and therapeutic significance of neuroendocrine differentiation in NSCLC is not firmly established. These tumors are referred to collectively as NSCLC with neuroendocrine differentiation.

This is a group of rare tumors. Spindle cell carcinomas and giant cell carcinomas comprise only 0.4% of all lung malignancies, and carcinosarcomas comprise only 0.1% of all lung malignancies. In addition, this group of tumors reflects a continuum in histologic heterogeneity as well as epithelial and mesenchymal differentiation. On the basis of clinical and molecular data, biphasic pulmonary blastoma is regarded as part of the spectrum of carcinomas with pleomorphic, sarcomatoid, or sarcomatous elements.

The identification of mutations in lung cancer has led to the development of molecularly targeted therapy to improve the survival of subsets of patients with metastatic disease.[2] In particular, subsets of adenocarcinoma now can be defined by specific mutations in genes encoding components of the epidermal growth factor receptor (EGFR) and downstream mitogen-activated protein kinases (MAPK) and phosphatidylinositol 3-kinases (PI3K) signaling pathways. These mutations may define mechanisms of drug sensitivity and primary or acquired resistance to kinase inhibitors. Other mutations of potential relevance to treatment decisions include:

These mutations are mutually exclusive, except for those involving PI3KCA and BRAF mutations, EGFR mutations, or ALK translocations.[3,4]

EGFR and ALK mutations predominate in adenocarcinomas that develop in nonsmokers, and KRAS and BRAF mutations are more common in smokers or former smokers. EGFR mutations strongly predict the improved response rate and progression-free survival of EGFR inhibitors. In a set of 2,142 lung adenocarcinoma specimens from patients treated at Memorial Sloan Kettering Cancer Center, EGFR exon 19 deletions and L858R were found in 15% of tumors from former smokers (181 of 1,218; 95% confidence interval [CI], 1317), 6% from current smokers (20 of 344; 95% CI, 49), and 52% from never-smokers (302 of 580; 95% CI, 4856; P < .001 for ever- vs. never-smokers).[5]

Fusions of ALK with EML4 genes form translocation products that occur in ranges from 3% to 7% in unselected NSCLC and are responsive to pharmacological inhibition of ALK by agents such as crizotinib. Sensitizing fusions of ALK with other genes have also been reported. Other mutations that occur in less than 5% of NSCLC tumors include:

BRAF mutations are mutually exclusive of EGFR and KRAS mutations. Somatic mutations in MAP2K1 (also known as MEK) have been identified in 1% of NSCLC. MET oncogene encodes hepatocyte growth factor receptor. Amplification of this gene has been associated with secondary resistance to EGFR tyrosine kinase inhibitors.

In non-small cell lung cancer (NSCLC), the determination of stage is important in terms of therapeutic and prognostic implications. Careful initial diagnostic evaluation to define the location and to determine the extent of primary and metastatic tumor involvement is critical for the appropriate care of patients.

In general, symptoms, physical signs, laboratory findings, or perceived risk of distant metastasis lead to an evaluation for distant metastatic disease. Additional tests such as bone scans and computed tomography (CT)/magnetic resonance imaging (MRI) of the brain may be performed if initial assessments suggest metastases or if patients with stage III disease are under consideration for aggressive local and combined modality treatments.

Stage has a critical role in the selection of therapy. The stage of disease is based on a combination of clinical factors and pathological factors.[1] The distinction between clinical stage and pathological stage should be considered when evaluating reports of survival outcome.

Procedures used to determine staging include the following:

Procedures used to obtain tissue samples include bronchoscopy, mediastinoscopy, or anterior mediastinotomy. Pathological staging of NSCLC requires the following:

Prognostic and treatment decisions are based on some of the following factors:

At diagnosis, patients with NSCLC can be divided into the following three groups that reflect both the extent of the disease and the treatment approach:

Surgical staging of the mediastinum is considered standard if accurate evaluation of the nodal status is needed to determine therapy.

Accurate staging of the mediastinal lymph nodes provides important prognostic information.

Evidence (nodal status):

CT scanning is primarily used for determining the size of the tumor. The CT scan should extend inferiorly to include the liver and adrenal glands. MRI scans of the thorax and upper abdomen do not appear to yield advantages over CT scans.[4]

Evidence (CT scan):

The wider availability and use of FDG-PET scanning for staging has modified the approach to staging mediastinal lymph nodes and distant metastases.

Randomized trials evaluating the utility of FDG-PET scanning in potentially resectable NSCLC report conflicting results in terms of the relative reduction in the number of noncurative thoracotomies.

Although the current evidence is conflicting, FDG-PET scanning may improve results of early-stage lung cancer by identifying patients who have evidence of metastatic disease that is beyond the scope of surgical resection and that is not evident by standard preoperative staging procedures.

Evidence (FDG-PET scan):

Decision analyses demonstrate that FDG-PET scanning may reduce the overall costs of medical care by identifying patients with falsely negative CT scans in the mediastinum or otherwise undetected sites of metastases.[9-11] Studies concluded that the money saved by forgoing mediastinoscopy in FDG-PET-positive mediastinal lesions was not justified because of the unacceptably high number of false-positive results.[9-11] A randomized study found that the addition of FDG-PET scanning to conventional staging was associated with significantly fewer thoracotomies.[12] A second randomized trial evaluating the impact of FDG-PET scanning on clinical management found that FDG-PET scanning provided additional information regarding appropriate stage but did not lead to significantly fewer thoracotomies.[13]

The combination of CT imaging and FDG-PET scanning has greater sensitivity and specificity than CT imaging alone.[14]

Evidence (CT/FDG-PET scan):

For patients with clinically operable NSCLC, the recommendation is for a biopsy of mediastinal lymph nodes that were found to be larger than 1 cm in shortest transverse axis on chest CT scan or were found to be positive on FDG-PET scan. Negative FDG-PET scanning does not preclude biopsy of radiographically enlarged mediastinal lymph nodes. Mediastinoscopy is necessary for the detection of cancer in mediastinal lymph nodes when the results of the CT scan and FDG-PET scan do not corroborate each other.

Patients at risk for brain metastases may be staged with CT or MRI scans. One study randomly assigned 332 patients with potentially operable NSCLC and no neurological symptoms to brain CT or MRI imaging to detect occult brain metastasis before lung surgery. MRI showed a trend towards a higher preoperative detection rate than CT scan (P = .069), with an overall detection rate of approximately 7% from pretreatment to 12 months after surgery.[17] Patients with stage I or stage II disease had a detection rate of 4% (i.e., eight detections out of 200 patients); however, individuals with stage III disease had a detection rate of 11.4% (i.e., 15 detections out of 132 patients). The mean maximal diameter of the brain metastases was significantly smaller in the MRI group. Whether the improved detection rate of MRI translates into improved outcome remains unknown. Not all patients are able to tolerate MRI, and for these patients contrast-enhanced CT scan is a reasonable substitute.

Numerous nonrandomized, prospective, and retrospective studies have demonstrated that FDG-PET scanning seems to offer diagnostic advantages over conventional imaging in staging distant metastatic disease; however, standard FDG-PET scans have limitations. FDG-PET scans may not extend below the pelvis and may not detect bone metastases in the long bones of the lower extremities. Because the metabolic tracer used in FDG-PET scanning accumulates in the brain and urinary tract, FDG-PET scanning is not reliable for detection of metastases in these sites.[17]

The Revised International System for Staging Lung Cancer, based on information from a clinical database of more than 5,000 patients, was adopted in 2010 by the American Joint Committee on Cancer (AJCC) and the Union Internationale Contre le Cancer.[18,19] These revisions provide greater prognostic specificity for patient groups; however, the correlation between stage and prognosis predates the widespread availability of PET imaging.

Summary of Changes

This staging system is now recommended for the classification of both NSCLC and small cell lung carcinomas and for carcinoid tumors of the lung.[19]

The T (primary tumor) classifications have been redefined as follows:[19]

No changes have been made to the N (regional lymph nodes) classification. However, a new international lymph node map defining the anatomical boundaries for lymph node stations has been developed.

The M (distant metastasis) classifications have been redefined as follows:

The AJCC has designated staging by TNM classification to define NSCLC.[19]

In non-small cell lung cancer (NSCLC), results of standard treatment are poor except for the most localized cancers. All newly diagnosed patients with NSCLC are potential candidates for studies evaluating new forms of treatment.

Surgery is the most potentially curative therapeutic option for this disease. Postoperative chemotherapy may provide an additional benefit to patients with resected NSCLC. Radiation therapy combined with chemotherapy can produce a cure in a small number of patients and can provide palliation in most patients. Prophylactic cranial irradiation (PCI) may reduce the incidence of brain metastases, but there is no evidence of a survival benefit and the effect of PCI on quality of life is not known.[1,2] In patients with advanced-stage disease, chemotherapy or epidermal growth factor receptor (EGFR) kinase inhibitors offer modest improvements in median survival, though overall survival is poor.[3,4]

Chemotherapy has produced short-term improvement in disease-related symptoms in patients with advanced NSCLC. Several clinical trials have attempted to assess the impact of chemotherapy on tumor-related symptoms and quality of life. In total, these studies suggest that tumor-related symptoms may be controlled by chemotherapy without adversely affecting overall quality of life;[5,6] however, the impact of chemotherapy on quality of life requires more study. In general, medically fit elderly patients with good performance status obtain the same benefits from treatment as younger patients.

The identification of mutations in lung cancer has led to the development of molecularly targeted therapy to improve the survival of subsets of patients with metastatic disease.[7] In particular, genetic abnormalities in EGFR, MAPK, and PI3K signaling pathways in subsets of NSCLC may define mechanisms of drug sensitivity and primary or acquired resistance to kinase inhibitors. EGFR mutations strongly predict the improved response rate and progression-free survival of inhibitors of EGFR. Fusions of ALK with EML4 and other genes form translocation products that occur in ranges from 3% to 7% in unselected NSCLC and are responsive to pharmacological inhibition of ALK by agents such as crizotinib. MET oncogene encodes hepatocyte growth factor receptor. Amplification of this gene has been associated with secondary resistance to EGFR tyrosine kinase inhibitors.

The standard treatment options for each stage of NSCLC are presented in Table 11.

In addition to the standard treatment options presented in Table 11, treatment options under clinical evaluation include the following:

Several small series have reported that reduction in fluorodeoxyglucose-positron emission tomography (FDG-PET) after chemotherapy, radiation therapy, or chemoradiation therapy correlates with pathological complete response and favorable prognosis.[8-15] Studies have used different timing of assessments, FDG-PET parameters, and cutpoints to define FDG-PET response. Reduction in maximum standardized uptake value (SUV) of higher than 80% predicted for complete pathological response with a sensitivity of 90%, specificity of 100%, and accuracy of 96%.[16] Median survival after resection was greater for patients with tumor SUV values of lower than 4 (56 months vs. 19 months).[15] Patients with complete metabolic response following radiation therapy were reported to have median survivals of 31 months versus 11 months.[17]

FDG-PET may be more sensitive and specific than computed tomography (CT) scan in assessing response to induction therapy. Optimal timing of imaging remains to be defined; however, one study suggests that greater sensitivity and specificity of FDG-PET is achieved if repeat imaging is delayed until 30 days after radiation therapy.[16]

There is no clear role for routine posttreatment PET-CT scans.[18][Level of evidence: 3iiA]

Evidence (surveillance imaging after radiation therapy with or without chemotherapy):

Check the list of NCI-supported cancer clinical trials that are now accepting patients with non-small cell lung cancer. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI website.

In occult lung cancer, a diagnostic evaluation often includes chest x-ray and selective bronchoscopy with close follow-up (e.g., computed tomography scan), when needed, to define the site and nature of the primary tumor; tumors discovered in this fashion are generally early stage and curable by surgery.

After discovery of the primary tumor, treatment involves establishing the stage of the tumor. Therapy is identical to that recommended for other non-small cell lung cancer (NSCLC) patients with similar stage disease.

Standard treatment options for occult NSCLC include the following:

Check the list of NCI-supported cancer clinical trials that are now accepting patients with occult non-small cell lung cancer. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI website.

Stage 0 non-small cell lung cancer (NSCLC) frequently progresses to invasive cancer.[1-3] Patients may be offered surveillance bronchoscopies and, if lesions are detected, potentially curative therapies.

Standard treatment options for stage 0 NSCLC include the following:

Segmentectomy or wedge resection are used to preserve maximum normal pulmonary tissue since patients with stage 0 NSCLC are at a high risk for second lung cancers. Because these tumors are by definition noninvasive and incapable of metastasizing, they should be curable with surgical resection; however, such lesions, when identified, are often centrally located and may require a lobectomy.

Patients with central lesions may be candidates for curative endobronchial therapy. Endobronchial therapies that preserve lung function include photodynamic therapy, electrocautery, cryotherapy, and Nd-YAG laser therapy.[3-6]

More:
Non-Small Cell Lung Cancer Treatment (PDQ)Health ...

Types of Treatment: Stem Cell Transplant – National Cancer …

By Stem Cell Treatment

Stem cell transplants are procedures that restore blood-forming stem cells in people who have had theirs destroyed by the very high doses of chemotherapy or radiation therapy that are used to treat certain cancers.

Blood-forming stem cells are important because they grow into different types of blood cells. The main types of blood cells are:

You need all three types of blood cells to be healthy.

In a stem cell transplant, you receive healthy blood-forming stem cells through a needle in your vein. Once they enter your bloodstream, the stem cells travel to the bone marrow, where they take the place of the cells that were destroyed by treatment. The blood-forming stem cells that are used in transplants can come from the bone marrow, bloodstream, or umbilical cord. Transplants can be:

To reduce possible side effects and improve the chances that an allogeneic transplant will work, the donors blood-forming stem cells must match yours in certain ways. To learn more about how blood-forming stem cells are matched, see Blood-Forming Stem Cell Transplants.

Stem cell transplants do not usually work against cancer directly. Instead, they help you recover your ability to produce stem cells after treatment with very high doses of radiation therapy, chemotherapy, or both.

However, in multiple myeloma and some types of leukemia, the stem cell transplant may work against cancer directly. This happens because of an effect called graft-versus-tumor that can occur after allogeneic transplants. Graft-versus-tumor occurs when white blood cells from your donor (the graft) attack any cancer cells that remain in your body (the tumor) after high-dose treatments. This effect improves the success of the treatments.

Stem cell transplants are most often used to help people with leukemia and lymphoma. They may also be used for neuroblastoma and multiple myeloma.

Stem cell transplants for other types of cancer are being studied in clinical trials, which are research studies involving people. To find a study that may be an option for you, see Find a Clinical Trial.

The high doses of cancer treatment that you have before a stem cell transplant can cause problems such as bleeding and an increased risk of infection. Talk with your doctor or nurse about other side effects that you might have and how serious they might be. For more information about side effects and how to manage them, see the section on side effects.

If you have an allogeneic transplant, you might develop a serious problem called graft-versus-host disease. Graft-versus-host disease can occur when white blood cells from your donor (the graft) recognize cells in your body (the host) as foreign and attack them. This problem can cause damage to your skin, liver, intestines, and many other organs. It can occur a few weeks after the transplant or much later. Graft-versus-host disease can be treated with steroids or other drugs that suppress your immune system.

The closer your donors blood-forming stem cells match yours, the less likely you are to have graft-versus-host disease. Your doctor may also try to prevent it by giving you drugs to suppress your immune system.

Stem cells transplants are complicated procedures that are very expensive. Most insurance plans cover some of the costs of transplants for certain types of cancer. Talk with your health plan about which services it will pay for. Talking with the business office where you go for treatment may help you understand all the costs involved.

To learn about groups that may be able to provide financial help, go to the National Cancer Institute database, Organizations that Offer Support Services and search "financial assistance." Or call toll-free 1-800-4-CANCER (1-800-422-6237) for information about groups that may be able to help.

When you need an allogeneic stem cell transplant, you will need to go to a hospital that has a specialized transplant center. The National Marrow Donor Program maintains a list of transplant centers in the United States that can help you find a transplant center.

Unless you live near a transplant center, you may need to travel from home for your treatment. You might need to stay in the hospital during your transplant, you may be able to have it as an outpatient, or you may need to be in the hospital only part of the time. When you are not in the hospital, you will need to stay in a hotel or apartment nearby. Many transplant centers can assist with finding nearby housing.

A stem cell transplant can take a few months to complete. The process begins with treatment of high doses of chemotherapy, radiation therapy, or a combination of the two. This treatment goes on for a week or two. Once you have finished, you will have a few days to rest.

Next, you will receive the blood-forming stem cells. The stem cells will be given to you through an IV catheter. This process is like receiving a blood transfusion. It takes 1 to 5 hours to receive all the stem cells.

After receiving the stem cells, you begin the recovery phase. During this time, you wait for the blood cells you received to start making new blood cells.

Even after your blood counts return to normal, it takes much longer for your immune system to fully recoverseveral months for autologous transplants and 1 to 2 years for allogeneic or syngeneic transplants.

Stem cell transplants affect people in different ways. How you feel depends on:

Since people respond to stem cell transplants in different ways, your doctor or nurses cannot know for sure how the procedure will make you feel.

Doctors will follow the progress of the new blood cells by checking your blood counts often. As the newly transplanted stem cells produce blood cells, your blood counts will go up.

The high-dose treatments that you have before a stem cell transplant can cause side effects that make it hard to eat, such as mouth sores and nausea. Tell your doctor or nurse if you have trouble eating while you are receiving treatment. You might also find it helpful to speak with a dietitian. For more information about coping with eating problems see the booklet Eating Hints or the section on side effects.

Whether or not you can work during a stem cell transplant may depend on the type of job you have. The process of a stem cell transplant, with the high-dose treatments, the transplant, and recovery, can take weeks or months. You will be in and out of the hospital during this time. Even when you are not in the hospital, sometimes you will need to stay near it, rather than staying in your own home. So, if your job allows, you may want to arrange to work remotely part-time.

Many employers are required by law to change your work schedule to meet your needs during cancer treatment. Talk with your employer about ways to adjust your work during treatment. You can learn more about these laws by talking with a social worker.

Visit link:
Types of Treatment: Stem Cell Transplant - National Cancer ...

CIRM Alpha Stem Cell Clinic – UCSD Stem Cell Program

By Stem Cell Clinics

Mission

The mission of the UC San Diego CIRM Alpha Stem Cell Clinic is to accelerate the design of innovative stem cell research to advance the testing and delivery of safe and effective stem cell-based therapies in regenerative medicine.

For more information, please visit the CIRM Alpha Stem Cell Clinic page on the UC San Diego Health website.

We are one of three alpha clinics in a network designated by theCalifornia Institute for Regenerative Medicine (CIRM), the states stem cell agency. The UC San Diego CIRM Alpha Stem Cell Clinic is the cell therapy arm ofSanford Stem Cell Clinical Center at UC San Diego Health.We specialize in early phase, first-in-human trials.

The Alpha Stem Cell Clinics are intended to create the long-term, networked infrastructure needed to launch and conduct numerous, extensive clinical trials of stem cell-based drugs and therapies in humans, including those developed by independent California-based investigators and companies. These trials are requisite before any new drug or treatment can be approved for clinical use.

The clinics will emphasize public education to raise awareness and understanding of stem cell science. This will combat stem cell tourism and the marketing of unproven, unregulated and potentially dangerous therapies. The clinics will also help establish sustainable business models for future, approved stem cell treatments.

See how we're improving the consent process by deploying enhanced electronic consent tablets.

An Overview of the UC San Diego CIRM Alpha Stem Cell Clinic

alphastemcellclinic@ucsd.edu

1-844-317-STEM (7836)

Excerpt from:
CIRM Alpha Stem Cell Clinic - UCSD Stem Cell Program

Treatment Abroad | Canadian Stem Cell Foundation

By Stem Cell Clinics

The scientific discoveries and innovations surrounding the potential of stem cell science have led to great enthusiasm about the benefits it could bring people.

The dark side of that enthusiasm is the hype, exaggerated publicity and inaccurate claims in the interest of financial gain.

People may develop unrealistic expectations of the benefits available from stem cell research and the speed with which they will be achieved.

Unfortunately, there will always be individuals and companies eager to take advantage of the necessary lag between research and clinical applications to offer the promise of so-called cures and therapies.

Many of these treatments are not based on sound scientific evidence, for example, this 2008 Stem Cell Network-funded study of the online marketing of 19 stem cell clinics found that the clinics claims of safe, effective and routine therapies were not substantiated by published evidence.

Patients considering these therapies are encouraged to review the information available at Closer look at stem cells, a website created by the International Society of Stem Cell Research. Other statements on experimental therapies have been published by the German Stem Cell Network North Rhine Westphaliaand the National Stem Cell Foundation of Australia.

Prof. Timothy Caulfield addresses the problem of websitesmarketing unproven stem cell therapies. Find out more here.

Read more from the original source:
Treatment Abroad | Canadian Stem Cell Foundation

Induced Pluripotent Stem Cells Market 2016: Hepatocytes …

By Induced Pluripotent Stem Cells

Pluripotent stem cells are embryonic stem cells that have the potential to form all adult cell types and help in repairing of damaged tissues in the human body. An Induced pluripotent stem cells, or iPSCs, are taken from any tissue (usually skin or blood) from a child or an adult and is genetically modified to behave like pluripotent stem cells or embryonic stem cells.

iPSCs market is in emerging state mainly due to its ability to make any cell or tissue the body might need to encounter wide range of diseases like diabetes, spinal cord injury, leukaemia or heart disease, these cells can potentially be customized to provide a perfect genetic match for any patient. Furthermore, these cells are very useful in understanding the earliest stage of human development and offer the opportunity to create customized, rejection-proof cells and tissues for transplantation. Also, government and private sectors are increasing funding and growing industry that focuses on different research work related to iPSCs and people are getting more aware about the stem cells through different organisations. However, factors such as high cost associated with the reprograming of cells, ethical issues and lengthy processes are impeding the market growth. Low efficiency, potential tumor risk and incomplete programming are added factors limiting iPSCs market growth.

Request a Brochure of This Report, here: http://www.intenseresearch.com/market-analysis/world-induced-pluripotent-stem-cells-market-opportunities-and.html#request-sample

The world iPSCs market has been segmented based on derived cell type, application, end-user and geography. Based on derived cell type, the market is segmented into hepatocytes, fibroblasts, keratinocytes, amniotic cells and others. Based on application, the market is segmented into academic research, drug development and toxicity testing and regenerative medicine. Based on end-user, the market is segmented into hospitals and research laboratories. The market is analyzed on the basis of four regions, namely, North America, Europe, Asia-Pacific, and LAMEA.

Product launch, collaboration & merger, and acquisition are the key strategies adopted by market players. Healthcare giant such as Fujifilm Holding Corporation has acquired Cellular Dynamics International, Inc. in March 2015 creating a high growth in iPSCs market. Also, Juno Therapeutics and Fate Therapeutics collaborated to improve the products market.

Do Inquiry Before Purchasing Report: http://www.intenseresearch.com/market-analysis/world-induced-pluripotent-stem-cells-market-opportunities-and.html#inquiry-for-buying

Comprehensive competitive analysis and profiles of major market players such as Fujifilm Holding Corporation, Astellas Pharma Inc., Fate Therapeutics, Inc., Bristol-Myers Squibb Company, ViaCyte, Inc., Celgene Corporation, Aastrom Biosciences, Inc., Acelity Holdings, Inc., StemCells, Inc., Japan Tissue Engineering Co., Ltd. and Organogenesis Inc. is also provided in this report.

KEY MARKET BENEFITS:

INDUCED PLURIPOTENT STEM CELLS MARKET SEGMENT:

The world iPSCs market is segmented as follows:

By Derived Cell Type

By Application

By End-User

By Geography

About Intense Research

Intense Research provides a range of marketing and business research solutions designed for our clients specific needs based on our expert resources. The business scopes of Intense Research cover more than 30 industries includsing energy, new materials, transportation, daily consumer goods, chemicals, etc. We provide our clients with one-stop solution for all the research requirements.

Contact Us:

Joel John 3422 SW 15 Street, Suit #8138, Deerfield Beach, Florida 33442, United States Tel: +1-386-310-3803 GMT Tel: +49-322 210 92714 USA/Canada Toll Free No. 1-855-465-4651 Email: sales@intenseresearch.com Web: http://www.intenseresearch.com/

Excerpt from:
Induced Pluripotent Stem Cells Market 2016: Hepatocytes ...

World Induced Pluripotent Stem Cells Market – Opportunities …

By Induced Pluripotent Stem Cells

Country Name

-- Select Country -- Andorra United Arab Emirates Afghanistan Antigua and Barbuda Anguilla Albania Armenia Angola Antarctica Argentina American Samoa Austria Australia Aruba land Islands Azerbaijan Bosnia and Herzegovina Barbados Bangladesh Belgium Burkina Faso Bulgaria Bahrain Burundi Benin Saint Barthlemy Bermuda Brunei Darussalam Bolivia Caribbean Netherlands Brazil Bahamas Bhutan Bouvet Island Botswana Belarus Belize Canada Cocos (Keeling) Islands Congo, Democratic Republic of Central African Republic Congo Switzerland Cte d'Ivoire Cook Islands Chile Cameroon China Colombia Costa Rica Cuba Cape Verde Curaao Christmas Island Cyprus Czech Republic Germany Djibouti Denmark Dominica Dominican Republic Algeria Ecuador Estonia Egypt Western Sahara Eritrea Spain Ethiopia Finland Fiji Falkland Islands Micronesia, Federated States of Faroe Islands France Gabon United Kingdom Grenada Georgia French Guiana Guernsey Ghana Gibraltar Greenland Gambia Guinea Guadeloupe Equatorial Guinea Greece South Georgia and the South Sandwich Islands Guatemala Guam Guinea-Bissau Guyana Hong Kong Heard and McDonald Islands Honduras Croatia Haiti Hungary Indonesia Ireland Israel Isle of Man India British Indian Ocean Territory Iraq Iran Iceland Italy Jersey Jamaica Jordan Japan Kenya Kyrgyzstan Cambodia Kiribati Comoros Saint Kitts and Nevis North Korea South Korea Kuwait Cayman Islands Kazakhstan Lao People's Democratic Republic Lebanon Saint Lucia Liechtenstein Sri Lanka Liberia Lesotho Lithuania Luxembourg Latvia Libya Morocco Monaco Moldova Montenegro Saint-Martin (France) Madagascar Marshall Islands Macedonia Mali Myanmar Mongolia Macau Northern Mariana Islands Martinique Mauritania Montserrat Malta Mauritius Maldives Malawi Mexico Malaysia Mozambique Namibia New Caledonia Niger Norfolk Island Nigeria Nicaragua The Netherlands Norway Nepal Nauru Niue New Zealand Oman Panama Peru French Polynesia Papua New Guinea Philippines Pakistan Poland St. Pierre and Miquelon Pitcairn Puerto Rico Palestine, State of Portugal Palau Paraguay Qatar Runion Romania Serbia Russian Federation Rwanda Saudi Arabia Solomon Islands Seychelles Sudan Sweden Singapore Saint Helena Slovenia Svalbard and Jan Mayen Islands Slovakia Sierra Leone San Marino Senegal Somalia Suriname South Sudan Sao Tome and Principe El Salvador Sint Maarten (Dutch part) Syria Swaziland Turks and Caicos Islands Chad French Southern Territories Togo Thailand Tajikistan Tokelau Timor-Leste Turkmenistan Tunisia Tonga Turkey Trinidad and Tobago Tuvalu Taiwan Tanzania Ukraine Uganda United States Minor Outlying Islands United States Uruguay Uzbekistan Vatican Saint Vincent and the Grenadines Venezuela Virgin Islands (British) Virgin Islands (U.S.) Vietnam Vanuatu Wallis and Futuna Islands Samoa Yemen Mayotte South Africa Zambia Zimbabwe Country name is required

Read more here:
World Induced Pluripotent Stem Cells Market - Opportunities ...

Frequently Asked Questions (FAQs) | stemcells.nih.gov

By Stem Cell Doctors

For FAQs on Research and Policy Questions, Cell Line Availability and the Registry, and Subclones and Modified hESC Lines: please see the "Stem Cell Policy Q & A."

What are stem cells?

Stem cells are cells that have the potential to develop into some or many different cell types in the body, depending on whether they are multipotent or pluripotent. Serving as a sort of repair system, they can theoretically divide without limit to replenish other cells for as long as the person or animal is still alive. When a stem cell divides, each "daughter" cell has the potential to either remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell.

For a discussion of the different kinds of stem cells, such as embryonic stem cells, adult stem cells, or induced pluripotent stem cells, see Stem Cell Basics.

What classes of stem cells are there?

Stem cells may be pluripotent or multipotent.

Where do stem cells come from?

There are several sources of stem cells. Pluripotent stem cells can be isolated from human embryos that are a few days old. Cells from these embryos can be used to create pluripotent stem cell "lines" cell cultures that can be grown indefinitely in the laboratory. Pluripotent stem cell lines have also been developed from fetal tissue (older than 8 weeks of development).

In late 2007, scientists identified conditions that would allow some specialized adult human cells to be reprogrammed genetically to assume a stem cell-like state. These stem cells are called induced pluripotent stem cells (iPSCs). IPSCs are adult cells that have been genetically reprogrammed to an embryonic stem celllike state by being forced to express genes and factors important for maintaining the defining properties of embryonic stem cells. Although these cells meet the defining criteria for pluripotent stem cells, it is not known if iPSCs and embryonic stem cells differ in clinically significant ways. Mouse iPSCs were first reported in 2006, and human iPSCs were first reported in late 2007. Mouse iPSCs demonstrate important characteristics of pluripotent stem cells, including expressing stem cell markers, forming tumors containing cells from all three germ layers, and being able to contribute to many different tissues when injected into mouse embryos at a very early stage in development. Human iPSCs also express stem cell markers and are capable of generating cells characteristic of all three germ layers.

Although additional research is needed, iPSCs are already useful tools for drug development and modeling of diseases, and scientists hope to use them in transplantation medicine. Viruses are currently used to introduce the reprogramming factors into adult cells, and this process must be carefully controlled and tested before the technique can lead to useful treatments for humans. In animal studies, the virus used to introduce the stem cell factors sometimes causes cancers. Researchers are currently investigating non-viral delivery strategies.

Non-embryonic (including adult and umbilical cord blood) stem cells have been identified in many organs and tissues. Typically there is a very small number of multipotent stem cells in each tissue, and these cells have a limited capacity for proliferation, thus making it difficult to generate large quantities of these cells in the laboratory. Stem cells are thought to reside in a specific area of each tissue (called a "stem cell niche") where they may remain quiescent (non-dividing) for many years until they are activated by a normal need for more cells, or by disease or tissue injury. These cells are also called somatic stem cells.

Why do scientists want to use stem cell lines?

Once a stem cell line is established from a cell in the body, it is essentially immortal, no matter how it was derived. That is, the researcher using the line will not have to go through the rigorous procedure necessary to isolate stem cells again. Once established, a cell line can be grown in the laboratory indefinitely and cells may be frozen for storage or distribution to other researchers.

Stem cell lines grown in the lab provide scientists with the opportunity to "engineer" them for use in transplantation or treatment of diseases. For example, before scientists can use any type of tissue, organ, or cell for transplantation, they must overcome attempts by a patient's immune system to reject the transplant. In the future, scientists may be able to modify human stem cell lines in the laboratory by using gene therapy or other techniques to overcome this immune rejection. Scientists might also be able to replace damaged genes or add new genes to stem cells in order to give them characteristics that can ultimately treat diseases.

Why are doctors and scientists so excited about human embryonic stem cells?

Stem cells have potential in many different areas of health and medical research. To start with, studying stem cells will help us to understand how they transform into the dazzling array of specialized cells that make us what we are. Some of the most serious medical conditions, such as cancer and birth defects, are due to problems that occur somewhere in this process. A better understanding of normal cell development will allow us to understand and perhaps correct the errors that cause these medical conditions.

Another potential application of stem cells is making cells and tissues for medical therapies. Today, donated organs and tissues are often used to replace those that are diseased or destroyed. Unfortunately, the number of people needing a transplant far exceeds the number of organs available for transplantation. Pluripotent stem cells offer the possibility of a renewable source of replacement cells and tissues to treat a myriad of diseases, conditions, and disabilities including Parkinson's disease, amyotrophic lateral sclerosis, spinal cord injury, burns, heart disease, diabetes, and arthritis.

Have human embryonic stem cells been used successfully to treat any human diseases yet?

Stem cell research offers hope for treating many human diseases. Click here to read a description of the current status of stem cells and human disease therapies.

What will be the best type of stem cell to use for therapy?

Pluripotent stem cells, while having great therapeutic potential, face formidable technical challenges. First, scientists must learn how to control their development into all the different types of cells in the body. Second, the cells now available for research are likely to be rejected by a patient's immune system. Another serious consideration is that the idea of using stem cells from human embryos or human fetal tissue troubles many people on ethical grounds.

Until recently, there was little evidence that multipotent adult stem cells could change course and provide the flexibility that researchers need in order to address all the medical diseases and disorders they would like to. New findings in animals, however, suggest that even after a stem cell has begun to specialize, it may be more flexible than previously thought.

There are currently several limitations to using traditional adult stem cells. Although many different kinds of multipotent stem cells have been identified, adult stem cells that could give rise to all cell and tissue types have not yet been found. Adult stem cells are often present in only minute quantities and can therefore be difficult to isolate and purify. There is also evidence that they may not have the same capacity to multiply as embryonic stem cells do. Finally, adult stem cells may contain more DNA abnormalitiescaused by sunlight, toxins, and errors in making more DNA copies during the course of a lifetime. These potential weaknesses might limit the usefulness of adult stem cells.

It is now possible to reprogram adult somatic cells to become like embryonic stem cells (induced pluripotent stem cells, iPSCs) through the introduction of embryonic genes. Thus, a source of cells can be generated that are specific to the donor, thereby increasing the chance of compatibility if such cells were to be used for tissue regeneration. However, like embryonic stem cells, determination of the methods by which iPSCs can be completely and reproducibly committed to appropriate cell lineages is still under investigation. Since they are derived from adult cells, iPSCs may also suffer DNA abnormalities, as described in the previous paragraph.

I have Parkinson's Disease. Is there a clinical trial that I can participate in that uses stem cells as therapy?

The public may search a database of NIH-sponsored clinical trials at http://www.clinicaltrials.gov. Enter the search terms of interest (in this case, Parkinson's Disease and stem cells) to search for applicable clinical trials.

Where can I donate umbilical cord stem cells?

NIH cannot accept donated umbilical cord stem cells from the general public. The National Marrow Donor Program maintains a Web page on donating cord blood at http://bethematch.org/support-the-cause/donate-cord-blood/how-to-donate-cord-blood/.

Read the original here:
Frequently Asked Questions (FAQs) | stemcells.nih.gov

Stem Cell Basics IV. | stemcells.nih.gov

By Somatic Stem Cells

An adult stem cell is thought to be an undifferentiated cell, found among differentiated cells in a tissue or organ. The adult stem cell can renew itself and can differentiate to yield some or all of the major specialized cell types of the tissue or organ. The primary roles of adult stem cells in a living organism are to maintain and repair the tissue in which they are found. Scientists also use the term somatic stem cell instead of adult stem cell, where somatic refers to cells of the body (not the germ cells, sperm or eggs). Unlike embryonic stem cells, which are defined by their origin (cells from the preimplantation-stage embryo), the origin of adult stem cells in some mature tissues is still under investigation.

Research on adult stem cells has generated a great deal of excitement. Scientists have found adult stem cells in many more tissues than they once thought possible. This finding has led researchers and clinicians to ask whether adult stem cells could be used for transplants. In fact, adult hematopoietic, or blood-forming, stem cells from bone marrow have been used in transplants for more than 40 years. Scientists now have evidence that stem cells exist in the brain and the heart, two locations where adult stem cells were not at firstexpected to reside. If the differentiation of adult stem cells can be controlled in the laboratory, these cells may become the basis of transplantation-based therapies.

The history of research on adult stem cells began more than 60 years ago. In the 1950s, researchers discovered that the bone marrow contains at least two kinds of stem cells. One population, called hematopoietic stem cells, forms all the types of blood cells in the body. A second population, called bone marrow stromal stem cells (also called mesenchymal stem cells, or skeletal stem cells by some), were discovered a few years later. These non-hematopoietic stem cells make up a small proportion of the stromal cell population in the bone marrow and can generate bone, cartilage, and fat cells that support the formation of blood and fibrous connective tissue.

In the 1960s, scientists who were studying rats discovered two regions of the brain that contained dividing cells that ultimately become nerve cells. Despite these reports, most scientists believed that the adult brain could not generate new nerve cells. It was not until the 1990s that scientists agreed that the adult brain does contain stem cells that are able to generate the brain's three major cell typesastrocytes and oligodendrocytes, which are non-neuronal cells, and neurons, or nerve cells.

Adult stem cells have been identified in many organs and tissues, including brain, bone marrow, peripheral blood, blood vessels, skeletal muscle, skin, teeth, heart, gut, liver, ovarian epithelium, and testis. They are thought to reside in a specific area of each tissue (called a "stem cell niche"). In many tissues, current evidence suggests that some types of stem cells are pericytes, cells that compose the outermost layer of small blood vessels. Stem cells may remain quiescent (non-dividing) for long periods of time until they are activated by a normal need for more cells to maintain tissues, or by disease or tissue injury.

Typically, there is a very small number of stem cells in each tissue and, once removed from the body, their capacity to divide is limited, making generation of large quantities of stem cells difficult. Scientists in many laboratories are trying to find better ways to grow large quantities of adult stem cells in cell culture and to manipulate them to generate specific cell types so they can be used to treat injury or disease. Some examples of potential treatments include regenerating bone using cells derived from bone marrow stroma, developing insulin-producing cells for type1 diabetes, and repairing damaged heart muscle following a heart attack with cardiac muscle cells.

Scientists often use one or more of the following methods to identify adult stem cells: (1) label the cells in a living tissue with molecular markers and then determine the specialized cell types they generate; (2) remove the cells from a living animal, label them in cell culture, and transplant them back into another animal to determine whether the cells replace (or "repopulate") their tissue of origin.

Importantly, scientists must demonstrate that a single adult stem cell can generate a line of genetically identical cells that then gives rise to all the appropriate differentiated cell types of the tissue. To confirm experimentally that a putative adult stem cell is indeed a stem cell, scientists tend to show either that the cell can give rise to these genetically identical cells in culture, and/or that a purified population of these candidate stem cells can repopulate or reform the tissue after transplant into an animal.

As indicated above, scientists have reported that adult stem cells occur in many tissues and that they enter normal differentiation pathways to form the specialized cell types of the tissue in which they reside.

Normal differentiation pathways of adult stem cells. In a living animal, adult stem cells are available to divide for a long period, when needed, and can give rise to mature cell types that have characteristic shapes and specialized structures and functions of a particular tissue. The following are examples of differentiation pathways of adult stem cells (Figure 2) that have been demonstrated in vitro or in vivo.

Figure 2. Hematopoietic and stromal stem cell differentiation. Click here for larger image. ( 2008 Terese Winslow)

Transdifferentiation. A number of experiments have reported that certain adult stem cell types can differentiate into cell types seen in organs or tissues other than those expected from the cells' predicted lineage (i.e., brain stem cells that differentiate into blood cells or blood-forming cells that differentiate into cardiac muscle cells, and so forth). This reported phenomenon is called transdifferentiation.

Although isolated instances of transdifferentiation have been observed in some vertebrate species, whether this phenomenon actually occurs in humans is under debate by the scientific community. Instead of transdifferentiation, the observed instances may involve fusion of a donor cell with a recipient cell. Another possibility is that transplanted stem cells are secreting factors that encourage the recipient's own stem cells to begin the repair process. Even when transdifferentiation has been detected, only a very small percentage of cells undergo the process.

In a variation of transdifferentiation experiments, scientists have recently demonstrated that certain adult cell types can be "reprogrammed" into other cell types in vivo using a well-controlled process of genetic modification (see Section VI for a discussion of the principles of reprogramming). This strategy may offer a way to reprogram available cells into other cell types that have been lost or damaged due to disease. For example, one recent experiment shows how pancreatic beta cells, the insulin-producing cells that are lost or damaged in diabetes, could possibly be created by reprogramming other pancreatic cells. By "re-starting" expression of three critical beta cell genes in differentiated adult pancreatic exocrine cells, researchers were able to create beta cell-like cells that can secrete insulin. The reprogrammed cells were similar to beta cells in appearance, size, and shape; expressed genes characteristic of beta cells; and were able to partially restore blood sugar regulation in mice whose own beta cells had been chemically destroyed. While not transdifferentiation by definition, this method for reprogramming adult cells may be used as a model for directly reprogramming other adult cell types.

In addition to reprogramming cells to become a specific cell type, it is now possible to reprogram adult somatic cells to become like embryonic stem cells (induced pluripotent stem cells, iPSCs) through the introduction of embryonic genes. Thus, a source of cells can be generated that are specific to the donor, thereby increasing the chance of compatibility if such cells were to be used for tissue regeneration. However, like embryonic stem cells, determination of the methods by which iPSCs can be completely and reproducibly committed to appropriate cell lineages is still under investigation.

Many important questions about adult stem cells remain to be answered. They include:

Previous|IV. What are adult stem cells?|Next

Continued here:
Stem Cell Basics IV. | stemcells.nih.gov

Glossary | stemcells.nih.gov

By Somatic Stem Cells

Adult stem cellSee somatic stem cell.

AstrocyteA type of supporting (glial) cell found in the nervous system.

BlastocoelThe fluid-filled cavity inside the blastocyst, an early, preimplantation stage of the developing embryo.

BlastocystApreimplantationembryo consisting of a sphere made up of an outer layer of cells (thetrophoblast), a fluid-filled cavity (theblastocoel), and a cluster of cells on the interior (theinner cell mass).

Bone marrow stromal cellsA population of cells found in bone marrow that are different from blood cells.

Bone marrow stromal stem cells (skeletal stem cells)A multipotent subset of bone marrow stromal cells able to form bone, cartilage, stromal cells that support blood formation, fat, and fibrous tissue.

Cell-based therapiesTreatment in which stem cells are induced to differentiate into the specific cell type required to repair damaged or destroyed cells or tissues.

Cell cultureGrowth of cells in vitro in an artificial medium for research.

Cell divisionMethod by which a single cell divides to create two cells. There are two main types of cell division depending on what happens to the chromosomes: mitosis and meiosis.

ChromosomeA structure consisting of DNA and regulatory proteins found in the nucleus of the cell. The DNA in the nucleus is usually divided up among several chromosomes.The number of chromosomes in the nucleus varies depending on the species of the organism. Humans have 46 chromosomes.

Clone (v) To generate identical copies of a region of a DNA molecule or to generate genetically identical copies of a cell, or organism; (n) The identical molecule, cell, or organism that results from the cloning process.

CloningSee Clone.

Cord blood stem cellsSee Umbilical cord blood stem cells.

Culture mediumThe liquid that covers cells in a culture dish and contains nutrients to nourish and support the cells. Culture medium may also include growth factors added to produce desired changes in the cells.

DifferentiationThe process whereby an unspecialized embryonic cell acquires the features of a specialized cell such as a heart, liver, or muscle cell. Differentiation is controlled by the interaction of a cell's genes with the physical and chemical conditions outside the cell, usually through signaling pathways involving proteins embedded in the cell surface.

Directed differentiationThe manipulation of stem cell culture conditions to induce differentiation into a particular cell type.

DNADeoxyribonucleic acid, a chemical found primarily in the nucleus of cells. DNA carries the instructions or blueprint for making all the structures and materials the body needs to function. DNA consists of both genes and non-gene DNA in between the genes.

EctodermThe outermost germ layer of cells derived from the inner cell mass of the blastocyst; gives rise to the nervous system, sensory organs, skin, and related structures.

EmbryoIn humans, the developing organism from the time of fertilization until the end of the eighth week of gestation, when it is called a fetus.

Embryoid bodiesRounded collections of cells that arise when embryonic stem cells are cultured in suspension. Embryoid bodies contain cell types derived from all threegerm layers.

Embryonic germ cellsPluripotent stem cells that are derived from early germ cells (those that would become sperm and eggs). Embryonic germ cells are thought to have properties similar to embryonic stem cells.

Embryonic stem cellsPrimitive (undifferentiated) cells that are derived from preimplantation-stageembryos, are capable of dividing without differentiating for a prolonged period in culture, and are known to develop into cells and tissues of the three primary germ layers.

Embryonic stem cell lineEmbryonic stem cells, which have been cultured under in vitro conditions that allow proliferation without differentiation for months to years.

EndodermThe innermost layer of the cells derived from the inner cell mass of the blastocyst; it gives rise to lungs, other respiratory structures, and digestive organs, or generally "the gut."

EnucleatedHaving had its nucleus removed.

EpigeneticThe process by which regulatory proteins can turn genes on or off in a way that can be passed on during cell division.

Feeder layerCells used in co-culture to maintain pluripotent stem cells. For human embryonic stem cell culture, typical feeder layers include mouse embryonic fibroblasts (MEFs) or human embryonic fibroblasts that have been treated to prevent them from dividing.

FertilizationThe joining of the male gamete (sperm) and the female gamete (egg).

FetusIn humans, the developing human from approximately eight weeks after conception until the time of its birth.

GameteAn egg (in the female) or sperm (in the male) cell. See also Somatic cell.

GastrulationThe process in which cells proliferate and migrate within the embryo to transform the inner cell mass of the blastocyst stage into an embryo containing all three primary germ layers.

GeneA functional unit of heredity that is a segment of DNA found on chromosomes in the nucleus of a cell. Genes direct the formation of an enzyme or other protein.

Germ layersAfter the blastocyst stage of embryonic development, the inner cell mass of the blastocyst goes through gastrulation, a period when the inner cell mass becomes organized into three distinct cell layers, called germ layers. The three layers are the ectoderm, the mesoderm, and the endoderm.

Hematopoietic stem cellA stem cell that gives rise to all red and white blood cells and platelets.

Human embryonic stem cell (hESC)A type of pluripotent stem cell derived from early stage human embryos, up to and including the blastocyststage. hESCs are capable of dividing without differentiating for a prolonged period in culture and are known to develop into cells and tissues of the three primary germ layers.

Induced pluripotent stem cell (iPSC)A type of pluripotent stem cell, similar to an embryonic stem cell, formed by the introduction of certain embryonic genes into a somatic cell.

In vitroLatin for "in glass;" in a laboratory dish or test tube; an artificial environment.

In vitro fertilizationA technique that unites the egg and sperm in a laboratory instead of inside the female body.

Inner cell mass (ICM)The cluster of cells inside the blastocyst. These cells give rise to the embryo and ultimately the fetus. The ICM may be used to generate embryonic stem cells.

Long-term self-renewalThe ability of stem cells to replicate themselves by dividing into the same non-specialized cell type over long periods (many months to years) depending on the specific type of stem cell.

MeiosisThe type of cell division a diploid germ cell undergoes to produce gametes (sperm or eggs) that will carry half the normal chromosome number. This is to ensure that when fertilization occurs, the fertilized egg will carry the normal number of chromosomes rather than causing aneuploidy (an abnormal number of chromosomes).

Mesenchymal stem cellsA term that is currently used to define non-blood adult stem cells from a variety of tissues, although it is not clear that mesenchymal stem cells from different tissues are the same.

MesodermMiddle layer of a group of cells derived from the inner cell mass of the blastocyst; it gives rise to bone, muscle, connective tissue, kidneys, and related structures.

MicroenvironmentThe molecules and compounds such as nutrients and growth factors in the fluid surrounding a cell in an organism or in the laboratory, which play an important role in determining the characteristics of the cell.

MitosisThe type of cell division that allows a population of cells to increase its numbers or to maintain its numbers. The number of chromosomes in each daughter cell remains the same in this type of cell division.

MultipotentHaving the ability to develop into more than one cell type of the body. See also pluripotent and totipotent.

Neural stem cellA stem cell found in adult neural tissue that can give rise to neurons and glial (supporting) cells. Examples of glial cells include astrocytes and oligodendrocytes.

NeuronsNerve cells, the principal functional units of the nervous system. A neuron consists of a cell body and its processesan axon and one or more dendrites. Neurons transmit information to other neurons or cells by releasing neurotransmitters at synapses.

OligodendrocyteA supporting cell that provides insulation to nerve cells by forming a myelin sheath (a fatty layer) around axons.

ParthenogenesisThe artificial activation of an egg in the absence of a sperm; the egg begins to divide as if it has been fertilized.

PassageIn cell culture, the process in which cells are disassociated, washed, and seeded into new culture vessels after a round of cell growth and proliferation. The number of passages a line of cultured cells has gone through is an indication of its age and expected stability.

PluripotentThe state of a single cell that is capable of differentiating into all tissues of an organism, but not alone capable of sustaining full organismal development.

Scientists demonstrate pluripotency by providing evidence of stable developmental potential, even after prolonged culture, to form derivatives of all three embryonic germ layers from the progeny of a single cell and to generate a teratoma after injection into an immunosuppressed mouse.

Polar bodyA polar body is a structure produced when an early egg cell, or oogonium, undergoes meiosis. In the first meiosis, the oogonium divides its chromosomes evenly between the two cells but divides its cytoplasm unequally. One cell retains most of the cytoplasm, while the other gets almost none, leaving it very small. This smaller cell is called the first polar body. The first polar body usually degenerates. The ovum, or larger cell, then divides again, producing a second polar body with half the amount of chromosomes but almost no cytoplasm. The second polar body splits off and remains adjacent to the large cell, or oocyte, until it (the second polar body) degenerates. Only one large functional oocyte, or egg, is produced at the end of meiosis.

PreimplantationWith regard to an embryo, preimplantation means that the embryo has not yet implanted in the wall of the uterus. Human embryonic stem cells are derived from preimplantation-stage embryos fertilized outside a woman's body (in vitro).

ProliferationExpansion of the number of cells by the continuous division of single cells into two identical daughter cells.

Regenerative medicineA field of medicine devoted to treatments in which stem cells are induced to differentiate into the specific cell type required to repair damaged or destroyed cell populations or tissues. (See also cell-based therapies).

Reproductive cloningThe process of using somatic cell nuclear transfer (SCNT) to produce a normal, full grown organism (e.g., animal) genetically identical to the organism (animal) that donated the somatic cell nucleus. In mammals, this would require implanting the resulting embryo in a uterus where it would undergo normal development to become a live independent being. The firstmammal to be created by reproductive cloning was Dolly the sheep, born at the Roslin Institute in Scotland in 1996. See also Somatic cell nuclear transfer (SCNT).

SignalsInternal and external factors that control changes in cell structure and function. They can be chemical or physical in nature.

Somatic cellAny body cell other than gametes (egg or sperm); sometimes referred to as "adult" cells. See also Gamete.

Somatic cell nuclear transfer (SCNT)A technique that combines an enucleated egg and the nucleus of a somatic cell to make an embryo. SCNT can be used for therapeutic or reproductive purposes, but the initial stage that combines an enucleated egg and a somatic cell nucleus is the same. See also therapeutic cloning and reproductive cloning.

Somatic (adult) stem cellA relatively rare undifferentiated cell found in many organs and differentiated tissues with a limited capacity for both self renewal (in the laboratory) and differentiation. Such cells vary in their differentiation capacity, but it is usually limited to cell types in the organ of origin. This is an active area of investigation.

Stem cellsCells with the ability to divide for indefinite periods in culture and to give rise to specialized cells.

Stromal cellsConnective tissue cells found in virtually every organ. In bone marrow, stromal cells support blood formation.

SubculturingTransferring cultured cells, with or without dilution, from one culture vessel to another.

Surface markersProteins on the outside surface of a cell that are unique to certain cell types and that can be visualized using antibodies or other detection methods.

TeratomaA multi-layered benign tumor that grows from pluripotent cells injected into mice with a dysfunctional immune system. Scientists test whether they have established a human embryonic stem cell (hESC) line by injecting putative stem cells into such mice and verifying that the resulting teratomas contain cells derived from all three embryonic germ layers.

Therapeutic cloningThe process of using somatic cell nuclear transfer (SCNT) to produce cells that exactly match a patient. By combining a patient's somatic cell nucleus and an enucleated egg, a scientist may harvest embryonic stem cells from the resulting embryo that can be used to generate tissues that match a patient's body. This means the tissues created are unlikely to be rejected by the patient's immune system. See also Somatic cell nuclear transfer (SCNT).

TotipotentThe state of a cell that is capable of giving rise to all types of differentiated cells found in an organism, as well as the supporting extra-embryonic structures of the placenta. A single totipotent cell could, by division in utero, reproduce the whole organism. (See also Pluripotent and Multipotent).

TransdifferentiationThe process by which stem cells from one tissue differentiate into cells of another tissue.

TrophoblastThe outer cell layer of the blastocyst. It is responsible for implantation and develops into the extraembryonic tissues, including the placenta, and controls the exchange of oxygen and metabolites between mother and embryo.

Umbilical cord blood stem cellsStem cells collected from the umbilical cord at birth that can produce all of the blood cells in the body. Cord blood is currently used to treat patients who have undergone chemotherapy to destroy their bone marrow due to cancer or other blood-related disorders.

UndifferentiatedA cell that has not yet developed into a specialized cell type.

View post:
Glossary | stemcells.nih.gov

Stem Cell Basics III. | stemcells.nih.gov

By Embryonic Stem Cells

Embryonic stem cells, as their name suggests, are derived from embryos. Most embryonic stem cells are derived from embryos that develop from eggs that have been fertilized in vitroin an in vitro fertilization clinicand then donated for research purposes with informed consent of the donors. They are not derived from eggs fertilized in a woman's body.

Growing cells in the laboratory is known as cell culture. Human embryonic stem cells (hESCs) aregenerated by transferringcells from a preimplantation-stage embryointo a plastic laboratory culture dish that contains a nutrient broth known as culture medium. The cells divide and spread over the surface of the dish. In the original protocol, the inner surface of the culture dish was coated with mouse embryonic skin cellsspecially treated so they will not divide. This coating layer of cells is called a feeder layer. The mouse cells in the bottom of the culture dish provide the cells a sticky surface to which they can attach. Also, the feeder cells release nutrients into the culture medium. Researchers have nowdevised ways to grow embryonic stem cells without mouse feeder cells. This is a significant scientific advance because of the risk that viruses or other macromolecules in the mouse cells may be transmitted to the human cells.

The process of generating an embryonic stem cell line is somewhat inefficient, so lines are not produced each time cells from the preimplantation-stage embryo are placed into a culture dish. However, if the plated cells survive, divide and multiply enough to crowd the dish, they are removed gently and plated into several fresh culture dishes. The process of re-plating or subculturing the cells is repeated many times and for many months. Each cycle of subculturing the cells is referred to as a passage. Once the cell line is established, the original cells yield millions of embryonic stem cells. Embryonic stem cells that have proliferated in cell culture for six or more months without differentiating, are pluripotent, and appear genetically normal are referred to as an embryonic stem cell line. At any stage in the process, batches of cells can be frozen and shipped to other laboratories for further culture and experimentation.

At various points during the process of generating embryonic stem cell lines, scientists test the cells to see whether they exhibit the fundamental properties that make them embryonic stem cells. This process is called characterization.

Scientists who study human embryonic stem cells have not yet agreed on a standard battery of tests that measure the cells' fundamental properties. However, laboratories that grow human embryonic stem cell lines use several kinds of tests, including:

As long as the embryonic stem cells in culture are grown under appropriate conditions, they can remain undifferentiated (unspecialized). But if cells are allowed to clump together to form embryoid bodies, they begin to differentiate spontaneously. They can form muscle cells, nerve cells, and many other cell types. Although spontaneous differentiation is a good indication that a culture of embryonic stem cells is healthy, the process is uncontrolled and therefore an inefficient strategy to produce cultures of specific cell types.

So, to generate cultures of specific types of differentiated cellsheart muscle cells, blood cells, or nerve cells, for examplescientists try to control the differentiation of embryonic stem cells. They change the chemical composition of the culture medium, alter the surface of the culture dish, or modify the cells by inserting specific genes. Through years of experimentation, scientists have established some basic protocols or "recipes" for the directed differentiation of embryonic stem cells into some specific cell types (Figure 1). (For additional examples of directed differentiation of embryonic stem cells, refer to the 2006 NIH stem cell report.)

Figure 1. Directed differentiation of mouse embryonic stem cells. Click here for larger image. ( 2008 Terese Winslow)

If scientists can reliably direct the differentiation of embryonic stem cells into specific cell types, they may be able to use the resulting, differentiated cells to treat certain diseases in the future. Diseases that might be treated by transplanting cells generated from human embryonic stem cells include diabetes, traumatic spinal cord injury, Duchenne's muscular dystrophy, heart disease, and vision and hearing loss.

Previous|III. What are embryonic stem cells?|Next

Read more:
Stem Cell Basics III. | stemcells.nih.gov