A new look at cancer
Cancer as an atavism?
Cancer is one of the most frightening diagnoses for patients, and for scientists it is a mystery and a real challenge. In search of the true nature of malignant cell degeneration, researchers put forward and test various hypotheses, including that cancer occurs when very ancient natural cellular functions are restored.
Article by Lineweaver et al. Cancer progression as a sequence of atavistic reversals is published in the journal BioEssays.
Among the causes of cancer, a decisive role is traditionally assigned to random mutations, as a result of which cells with an altered genetic program get out of control of the body and aggressively divide, seizing the living space.
However, researchers from the Australian National University and the University of Arizona hold a different point of view. Ten years ago, they hypothesized that cancer, in fact, we inherited from distant ancestors, i.e. it is an atavism. Such, for example, as the teeth of a chicken or the tail of a human baby. The genetic programs responsible for the appearance of such signs are usually inactive, but under certain circumstances they can "wake up".
In the case of cancer cells, scientists believe that their atavism is a return to the behavior characteristic of unicellular or very simple multicellular organisms without a clear cellular specialization. Colonies of such creatures at the dawn of multicellular life could indeed resemble tumors of modern animals both in appearance and behavior. And when truly complex organisms appeared on Earth about 600 million years ago, nature did not give them new molecular "instructions", but simply corrected the existing ones.
Moreover, this hereditary base is still being successfully used: such genetic programs are actively working during embryo development and tissue regeneration. In adults, they can turn on by mistake, and these changes in gene activity will allow the "wrong" cells to successfully reproduce, resist therapy and metastasize.
Scientists have not only put forward a hypothesis, but are also working to confirm it using the method of genomic philostratigraphy. Using this approach, it is possible to estimate the date of appearance of genes based on the study of genes similar in structure to other species. That is, about the same way geologists date rock formations.
According to researchers, with malignant degeneration, cells do not just return to the "primitive" quasi-cellular state. The genetic stages of this transformation seem to repeat, but in reverse order, the most important evolutionary events: the appearance of eukaryotes (organisms with a decorated nucleus), oxidative phosphorylation (the aerobic stage of cellular respiration) and adaptive immunity.
If it is confirmed that the stages of cancer development correlate with the stages of the emergence of cellular specialization in the process of evolution, this will be convincing evidence that the disease is the result of the awakening of ancient genetic mechanisms dormant in every healthy cell.
Portal "Eternal youth" http://vechnayamolodost.ru