The true statement about stem cells include?
|A||They divide to form different cell lines|
|B||They are used in gene therapy|
|C||Option A,B is right|
|D||They are present in peripheral circulation|
|E||They are incapable of division|
Stem cells: "Ideal target for gene therapy approach"
1. Stem cell replacement involves the administration of pluripotent renewable cells to organs irreversibly damaged by disease. The disciplines of gene and cell therapy are now converging, offering unique opportunity to translate new knowledge of genetics and stem cell biology into the clinical setting.
2. The use of stem cell therapy addresses several of the shortcoming of gene therapy, including the need to express genes in specific types of host cells, such as erythrocytes or neurons, and the need to regulate gene expression in response to physiological signals.
3. Characteristics of Stem cells
a. Stem cells are the undifferentiated progenitors that can develop into highly specialized cells that form the various organs. Q
b. Stem cells vary in their replicative capacity and in their differentiation potential. Q
c. Stem cells are self-renewing while at the same time generating daughter cells that are more differentiated.
d. The expression of telomerase, an enzyme critical for maintaining the telomeres, is consistent with the self-renewing feature of stem cells. Q
4. Classification of stem cells
a. Totipotent stem cells:
i. Can form a placenta and can develop into a complete embryo
ii. e.g. the cells derived from the first few division of the fertilized oocyte
b. Pluripotent stem cells
i. capable of forming tissues derived from all three major germline layers endoderm, mesoderm, and ectoderm. i.e. contribute to all tissues
ii. ego cells derived from the inner cell mass of the blastocyst (= Embryonic stem cells).
c. Multipotent stem cells:
i. are the progenitors of cells in particular tissues
ii. give rise to multiple cell types characteristic of a particular tissue
iii. Tissues such as BM, skin, GIT, and Liver have tremendous regenerative potential and continuously renew their cell population.
[The term oval cell is often used to refer to stem cells in the liver, but other pluripotent cells also appear capable of liver regeneration]