Bits of 'junk' RNA aid master tumor-suppr...( Little-known bits of RNA help master...)

Little-known bits of RNA help master tumor-suppressor gene do its job, U-M cancer researchers find

Three micro RNA genes appear to be key partners of protective gene p53; their loss is linked to common type of lung cancer

ANN ARBOR, Mich. Scientists have shown in literally thousands of studies that the p53 gene deserves its reputation as the guardian of the genome. It calls to action an army of other genes in the setting of varied cell stresses, permitting repair of damaged DNA or promoting cell death when the cell damage is too great. A key net effect of p53s action is to prevent development of cancerous cells.

Now, University of Michigan Medical School scientists provide the most thorough evidence yet that p53 also regulates a trio of genes from the realm of so-called junk genes the roughly 97 percent of a cells genetic material whose function is only beginning to be understood.

The study shows that in the junk lies treasure, in terms of critical knowledge about how normal cells stifle cancer or succumb to it, says Guido Bommer, M.D., the lead author of results, published in a recent issue of the journal Current Biology.

The findings in the study offer new insights into specific mechanisms by which the expression of hundreds to thousands of genes and proteins is altered in the roughly 50 percent of cancers that carry mutations in the p53 tumor suppressor gene, says Eric Fearon, M.D., Ph.D., senior author of the study and deputy director of the U-M Comprehensive Cancer Center. Scientists continue to mine for details of what goes wrong when p53 is defective and cannot perform its tumor-fighting duties.

The U-M study is one of four recent studies from labs around the world showing that p53 normally gets support from members of a small family of micro RNA genes. The studies are part of a larger effort to understand the function of micro RNA (miRNA for short).

Scientists have long known the im
'/>"/>