Washington, June 14: Researchers have found a precise molecular mechanism that helps trigger the "stop growing" response of cells. Earlier, the same group of scientists had had shown that by locking cancer cells into a permanent state in which they remain alive but can no longer proliferate, cellular senescence (growing old) contributes to successful outcomes following cancer therapy.
It is believed that the discovery will ultimately lead to ways to harness it for treating cancer. The findings have been published in the June 13 issue of the journal `Cell`.


The researchers found that cellular senescence involves the tight packaging of specific regions of chromosomal DNA into an inactive or silent architecture called `heterochromatin`.

The study provides a detailed view for the first time as to how the tumour suppressor `Rb` establishes regions of specialized DNA architecture in the cell. Because such architecture is extremely stable, the research may explain the irreversibility of the senescent state, namely, why cells rarely if ever start growing again once they senesce. The researchers studied a form of cultured human cells called `IMR-90 cells`, which are commonly used to study cellular senescence. Bureau Report