February 22, 2009

Stem Cells: the basic 2

Pros and Cons of Embryonic and Adult Stem Cells

There are significant medical and scientific differences between embryonic and adult stem cell research and therapy. Here is a comparison between the two types, including some of the advantages and disadvantages of each.

Embryonic Stem Cell Advantages
1. Flexible, appear to have the potential to make any cell
2. Immortal, one ES cell line can potentially provide an endless supply of cells with defined characteristics
3. Availability, embryos from in vitro fertilization clinics
Embryonic Stem Cell Disadvantages
1. Difficult to differentiate uniformly and homogeneously into a target tissue
2. Immunogenic, ES cells from a random embryo donor are likely to be rejected after transplantation
3. Tumorigenic, capable of forming tumors or promoting tumor formation
4. Destructive, destruction of developing human life
Adult Stem Cell Advantages
1. Flexibility, special adult-type stem cells from bone marrow and from umbilical cord have been isolated recently which appear to be as flexible as the embryonic type
2. Inducibility, already somewhat specialized, inducement may be simpler
3. Not immunogenic, recipients who receive the products of their own stem cells will not experience immune rejection
4. Availability, Relative ease of procurement, some adult stem cells are easy to harvest (skin, muscle, marrow, fat), while others may be more difficult to obtain (brain stem cells). Umbilical and placental stem cells are likely to be readily available
5. Non-tumorigenic, tend not to form tumors
6. No harm done to the donor
Adult Stem Cell Disadvantages
1. Limited quantity, can sometimes be difficult to obtain in large numbers
2. Finite, may not live as long as ES cells in culture
3. Less flexible (with the exception of #1 above), may be more difficult to reprogram to form other tissue types
Adult stem cells are a “natural” solution. They naturally exist in our bodies, and they provide a natural repair mechanism for many tissues of our bodies. They belong in the microenvironment of an adult body, while embryonic stem cells belong in the microenvironment of the early embryo, not in an adult body, where they tend to cause tumors and immune system reactions. Most importantly, adult stem cells have already been successfully used in human therapies for many years. As of this moment, NO therapies in humans have ever been successfully carried out using embryonic stem cells. New therapies using adult type stem cells, on the other hand, are being developed all the time. Here are but a few of the many examples of success stories using adult stem cells.
Cancers: Brain Cancer , Retinoblastoma, Ovarian Cancer , Skin Cancer: Merkel Cell Carcinoma, Testicular Cancer, Tumors abdominal organs Lymphoma, Non-Hodgkin’s lymphoma, Hodgkin’s Disease, Acute Lymphoblastic Leukemia, Acute Myelogenous Leukemia, Chronic Myelogenous Leukemia, Juvenile Myelomonocytic Leukemia, Chronic Myelomonocytic Leukemia, Angioimmunoblastic Lymphadenopathy , Multiple Myeloma, Myelodysplasia, Breast Cancer, Neuroblastoma, Renal Cell Carcinoma, Sarcoma, Ewing’s Sarcoma, Waldenstrom’s macroglobulinemia, Hemophagocytic lymphohistiocytosis. POEMS syndrome, Myelofibrosis. Auto-Immune Diseases: Diabetes Type I (Juvenile), SLE, Sjogren’s Syndrome, Myasthenia, Autoimmune Thrombocytopenia, Scleromyxedema, Scleroderma, Crohn’s Disease, Behcet’s Disease, Rheumatoid Arthritis, Juvenile Arthritis, Multiple Sclerosis, Idiopatic Polychondritis, Systemic Vasculitis, Alopecia Universalis, Buerger’s Disease. Cardiovascular: Acute Heart Damage, Chronic Coronary Artery Disease. Ocular: Corneal regeneration. Immunodeficiencies: Severe Combined Immunodeficiency Syndrome SCID, X-linked Lymphoproliferative Syndrome, X-linked Hyper-immunoglobulin M Syndrome. Neural Degenerative Diseases and Injuries: Parkinson’s Disease, Spinal Cord Injury, Stroke Damage. Anemias and Other Blood Conditions: Sickle Cell Anemia, Sideroblastic Anemia, Aplastic Anemia, Red Cell Aplasia, Amegakaryocytic Thrombocytopenia, Thalassemia, Primary Amyloidosis, Diamond Blackfan Anemia, Fanconi’s Anemia, Chronic Epstein-Barr Infection. Wounds and Injuries: Limb Gangrene, Surface Wound Healing, Jawbone Replacement, Skull Bone Repair. Other Metabolic Disorders: Hurler’s Syndrome, Osteogenesis Imperfecta, Krabbe’s Leukodystrophy, Osteopetrosis, Cerebral X-Linked Adrenoleukodystrophy. Liver Disease: Chronic Liver Failure, Liver Cirrhosis. Bladder Disease: End-Stage Bladder Disease.

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