Can stem cells become cancerous?
Researchers at the Johns Hopkins University (the USA) after numerous medical trials revealed that the number of dividing stem cells is one of the main factors that determine cancer. The tissues of the body are constantly updated due to the presence of stem cells. Each tissue has different stem cells. For example, blood has one type of stem cells, skin has the other type, etc. Not only the composition of these cells differs, but also the speed and the number of their divisions. In 65% of cases development of cancer depends on the rate of division of stem cells. This rule works for all types of tissues, without exception.
The most common tumors are found in the bones of the head, pelvis and forearm, which are characterized by the lowest activity of stem cells. Most often stem cells divide in the colon and rectum. Tumors in these organs are ones of the most common.
Most of the normal, differentiated cells that make up the tissues or organs do not live too long (except, for example, neurons). Therefore, even if they accumulate a lot of potentially oncogenic mutations, the disease does not start: the cell will die earlier than cancer will provoke. Stem cells, in the contrast, live long, divide more often and can be developed into a tumor. The more cases of dividing a stem cell, the more chances that the oncogenic mutation will appear.
From a practical point of view, new data should help in the diagnostics and prevention of cancer. It should be noted, however, that analyzing the statistics of tumors and the rate of cell division in 31 tissues, the scientists did not take into account breast cancer and prostate cancer. The problem is in lack of reliable information about the activity of stem cells in the lacteal and prostate gland. However, this is the problem researchers are going to solve in the nearest future, because breast and prostate tumors, are among the most common ones.