Cell aging is the biggest risk factor for cancer

Researchers at the Beatson Institute, Glasgow, working under the guidance of Professor Peter Adams, have found that in old age, the cause of the development of malignant tumors may be not so much mutations as the loss of aging cells of the mechanism that causes them to stop dividing.

The process of physiological aging of the cell is characterized by the cessation of division and entry into the resting phase. The authors' complete sequencing of the genome of aging human cells cultured in the laboratory revealed changes in the nature of DNA methylation characteristic of physiological aging.

Methylation is one of the most important epigenetic mechanisms (mechanisms of DNA modification by attaching various chemical residues) and consists in attaching methyl residues to certain nucleotide bases, which provides stimulation or suppression of the expression of certain genes.

It turned out that aging cells are characterized by a decrease in the level of methylation of various regions of chromosomes. However, there is a moderate increase in the level of methylation of the central zones of chromosomes, including a number of genes, methylation and suppression of activity of which is considered to be involved in cell malignancy.

An interesting fact is that the methylation profile of cells that have entered the path of physiological aging is very similar to the methylation profile of cancer cells. Based on this observation, scientists have suggested that if the mechanism that ensures the termination of the division of aging cells fails, these epigenetic changes can contribute to malignancy.

It is well known that aging is the most important risk factor for most types of cancer, but we know very little about the causes of this. This study revealed characteristics associated with physiological aging that distance aging cells from normal and bring them closer to malignant. This, at least in part, explains the increasing risk of developing tumors with age.

Further study of the revealed pattern will allow specialists to better understand the fundamental processes involved in the development of malignant tumors and develop new approaches to their prevention and treatment.

Article by Cruickshanks HA et al. Senescent cells harbour features of the cancer epigenome is published in the journal Nature Cell Biology.

Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Cancer Research UK:
Ageing cells could be ticking cancer time bomb.

04.12.2013