Stem cells are one of the fascinating areas for research in biology today. Vigorous research on stem cells is adding new information to the scientific body of knowledge everyday.
Researchers have now added key evidence to claims that some types of cancer originate with defects in stem cells. The study reveals that if molecules crucial to the functioning of these stem cells are not placed in the right locations within stem cells before they divide, it can result in deadly tumors.
Cells in the very early embryo have no specific function assigned to them and can perform any type of work. Soon, however, they begin differentiating into more specific types, finally becoming specialized cells like neurons, blood, or muscle.
As this continues, the cells should stop dividing and ought to be embedded in particular tissues. If this does not happen for reasons not yet understood why, the result can be a growth in the form of cancer. A lot of similarities infact exist between the stem cells and tumor cells in the sense that they undergo rapid cell division and closely resemble each other in their properties.
Specialized cells may die through age or injuries, so the body keeps stocks of stem cells on hand to generate replacements. Usually the stem cell divides into two types: one that is just like the parent, which is kept to maintain the stock, and another that differentiates. This process is controlled by genetic events that happen before the cell division.
For example, when primary nerve cell called the neuroblast was genetically disturbed, tumor cells rather than normal nerve cells were subsequently produced. When these altered cells were transplanted into flies, the results were swift and dramatic. The tissue containing the altered cells grew to 100 times its initial size; cells invaded other tissues, and death followed.
What is all the more alarming is that the tumor became immortal, capable of propagation, generation after generation, with similar effects. The study proves that specific genes in stem cells - those that control the fate of daughter cells - are crucial. If such genes are disrupted, the new cells may no longer be able to control their reproduction, and this could lead to cancer.
This finding calls for new lines of investigation to explore into the relationship between stem cells and tumors in other model organisms and humans.