Gene amplification

Gene or DNA amplification is the increase in the number of copies of a particular piece of DNA. A tumor cell amplifies or copies segments of DNA aberrantly, as a result of cellular signals and sometimes due to damage caused by environmental effects. They may also have their use in medicine as diagnostic techniques, polymerase chain reaction.

The result of this process is the production of several copies of the genes that are found in a region of the chromosome instead of only one, this phenomenon occurs naturally during the life cycle of some insects and amphibians, but in the In the case of mammals, it constitutes an unplanned event that can be caused by genetic instability in the cell that is generally associated with advanced stages of tumor malignancy, although it also appears in benign tumors.

Sometimes when the level of amplification is high, so many copies of the amplified region are produced that the copies can form their own pseudochromosomes called tiny or miniature double chromosomes that together with the presence of abnormal chromosome banding serve as identification of gene amplification under the microscope.

Tiny double chromosomes are small minichromosomes lacking centromeres, formed from copies of the DNA region; and abnormal chromosome banding is due to the fact that the region of DNA that was amplified remains on the chromosome so it is transmitted in a stable manner during cell division, unlike tiny double chromosomes.

This process is common in cancer cells, if an oncogene is included in the amplified region, the resulting overexpression of that gene can cause uncontrolled growth, in addition to contributing to drug resistance in cancer treatment.