What role do they play in the development of cancer?
Telomeres can also play an essential role in the development of cancer. More often, however, the cause of cancer is a mutation within the DNA strand. However, shortening plays a role in the development of cancer as it does in aging.
In the context of shorter telomeres, it is more likely that cancer can develop. The reason for this is that the part of the DNA double strand that codes for proteins and contains genes is more likely to be attacked. The risk factor for this is the presence of short telomeres from birth.
In addition, low levels of the enzyme telomerase and the shelterine-protein complex increase the probability of this happening. Telomeres also play an important role in pre-existing cancer. During the degeneration of the cells, increased cell growth and cell division occurs. This leads to a faster shortening of the telomeres, which makes further degeneration more likely. The cell tries to react to this by various mechanisms, but this is rarely successful in cancer cells.
What is a telomerase?
Telomerase is an enzyme that occurs in every human cell, but is not detectable in all cells. The telomerase shows a particularly high activity in the following cells: It is mainly found in the cell nucleus, since this is where it acts. The main task of the enzyme is to minimize the base loss of the telomeres of the DNA at the end of the chromosomes during replication.
This is essential, since otherwise a relatively high loss of DNA during each cell division leads to a reduced life span of the cells due to structural reasons. For this purpose, it is one of the few enzymes that have the function of reverse transcriptase. This means that it can generate a new DNA strand from an RNA strand, which is actually a copy of the DNA.
The remaining enzymes in the human body do not have this function. Instead, the telomerase exists to a small section of RNA, which serves as a template for the new section of DNA. The enzyme uses the fact that a sequence occurs repeatedly on the telomeres.
The base sequence of the RNA is complementary to this repeating sequence. The new DNA strand is added to the end of the telomere.
- Cells of the bone marrow
- Stem cells
- Germ line cells (precursors of sperm and oocytes)
- Embryonic cells
