Theoretical basis of cancer stem cell theory

By | January 4, 2012

Theory of the theoretical basis of cancer stem cells, cancer cells compared with normal cells in the poorly differentiated state. The unlimited proliferative capacity of cells, according to developmental biology point of view there are two possible sources: the organization to differentiate into mature cells, immature cells (dedifferentiation); tissue stem cells within the abnormal (dysdiff eren tia tion).
Although there have been evidence that some tumors may be derived from stem cells, but not sure they are derived from stem cells in vivo existence of these cells, another explanation is that the daughter cells had divided once again activate the stem cell procedure, that the result of dedifferentiation. Studies have marked the rat mature hepatocytes, and then given carcinogenic agent, several weeks later found that these cells expressed markers of precancerous cell surface markers. That lesions are caused by the dedifferentiation of mature cells. In gastric cancer and a similar study of thyroid cancer cells to differentiation is also experimental evidence.
Theoretical basis of cancer stem cell theory, unlimited proliferation of tumor cells, reminiscent of the characteristics of stem cell self-renewal. However, the two are different. First, stem cells have feedback mechanisms regulate self-renewal. The mechanism of a certain number of mature cells respond and control the rate of cell division; in tumor cells, this mechanism does not exist. Second, advanced tumor cells did not differentiate into mature cells the ability to explain the differentiation program exception. This has the normal differentiation program of stem cells are different. Finally, the tumor cells prone to replication errors, and normal stem cells to develop mechanisms to prevent this phenomenon.
Theoretical basis of cancer stem cell theory, however, view the following support cancer stem cell theory. First, stem cells and tumor cells were continuous proliferation. Stem cells have the ability to have self-renewal; and mature cells into tumor cells to regain the ability to be relatively easy. Second, tumor formation is a long process, cells can not occur within the short-lived. A normal cell into a transformed cell mutation occurred many times at least, it will take years or decades. Skin and intestinal mucosa in this area, the old cells die and are constantly out of the body. These fast updates organizations, including the blood system is precisely the high incidence of tumor site. Therefore, stem cells may be the only long-term presence of cells and the accumulation of several mutations in the generation of tumors. Third, the characteristics of stem cells to keep dividing, but also increased access to opportunities for the proliferation of errors.

Leave a Reply

Your email address will not be published. Required fields are marked *