Читать книгу The SAGE Encyclopedia of Stem Cell Research - Группа авторов - Страница 140

Greater attention and controversy regarding stem cell therapy has mostly been in connection with embryonic stem cells, which are often difficult to procure and harvest. However, adult stem cells have recently been found to be applicable for therapeutic purposes, and a number of studies in this vein have followed confirming their therapeutic efficacy. Adult stem cells have been used to replace aging and damaged cells as they are present throughout the adult body, particularly in the bone marrow and blood, from which they can be harvested easily. The blood stem cells have been used in the treatment of leukemia and other cancers. However, owing to aggressive radiation or immune suppression so as to kill the cancer cells, the death rate is alarmingly high. Such treatment is thus regarded as extremely dangerous in cases of life-threatening diseases. It was estimated in a review by Burt et al. that the death rate was nearly 13 percent in patients who received aggressive bone marrow suppressing treatments.

While less aggressive treatments, such as non-myeloablative transplant, accounted for less than 1 percent of deaths. In cases of cancer, the best result is achieved with the use of less aggressive treatments that kill the cancer and are followed by transplantation of the highly purified blood adult stem cells. This approach has been tried in the treatment of a number of diseases, including cardiovascular ailments. However, the most important application of blood adult stem cells has been in the treatment of leukemia. Adult stem cells that have permanently settled within their niche in the bone marrow can be remobilized with the application of cytokines, such as leukocyte stimulating growth factors. It has been demonstrated that the granulocyte colony stimulating factor (GCSF) is the most commonly used stem cell mobilizing pharmaceutical agent. Such hematopoietic stem cells, when leaving their niche from the bone marrow for a small time interval, can be collected from the peripheral blood. The technique has now replaced surgical bone marrow harvesting in many clinical settings as it offers a similar quality of bone marrow stem cell collection but is less invasive for the donors. Such ease of bone marrow stem cell collection means that the stem cells can be used easily for therapeutic purposes in the necessary amounts.

Therefore, significant advances have been made in the field of blood adult stem cell isolation and the application of these stem cells for therapeutic purposes. A number of ongoing clinical trials point toward their successful implementation in the treatment of different, complicated diseases.

Syed Feroj Ahmed

CSIR–Indian Institute of Chemical Biology

See Also: Blood Adult Stem Cell: Development and Regeneration Potential; Blood Adult Stem Cell: Existing or Potential Regenerative Medicine Strategies; Leukemia and Lymphoma Cancer Stem Cells.