Researchers identify how to switch off cancer cell genes

Medicine & Health / Cancer

A new study led by researchers at the University of Southern California (USC) identifies how genes are silenced in cancer cells through distinct changes in the density of nucleosomes within the cells.

The findings, published in the Nov. 13 issue of the journal Cancer Cell, will enable researchers to explore new therapies to switch the genes back on and may lead to novel treatments for human cancers, says study lead author Peter A. Jones, Ph.D., D.Sc., director of the USC/Norris Comprehensive Cancer Center and Distinguished Professor at the Keck School of Medicine of USC.

"The study shows for the first time exactly how genes get shut down in cancer cells," Jones says. "It identifies what the target looks like so that new therapies can be designed to turn them back on."

The study showed that silencing of transcription start sites in some cancer cells involves distinct changes in nucleosomal occupancy'or the density of nucleosomes'in the cell. Researchers found that three nucleosomes, almost completely absent from the start site in normal cells, are present in the methylated and silenced promoter, suggesting that epigenetic silencing may be accomplished by the stable placement of nucleosomes into previously vacant positions.

DNA cytosine methylation'the addition of a group of specific chemicals to a stretch of DNA that can lock or silence a gene'may ultimately lead to silencing by enabling the stable presence of nucleosomes at the start sites of cancer-related genes, the study suggests.

"We believe these findings will contribute to the development of cancer therapies," Jones says. "We were surprised to find how rigid the inactive structure is, and how rapidly it can be dissolved by drug treatment."

Source: University of Southern California

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Posted by Nikola 11/12/07 13:11

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Thank you USC.

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Posted by Simonsez 11/12/07 14:21

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Epigenetics is the wave of the future.

Part of a grand wave, I should say.

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Posted by Argiod 11/13/07 05:07

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Wave of the future, yes... the far future, if the FDA regulations have anything to do with it. You know there'll be a decade or so of trials first on animals; then another decade on human trials; then, if we're lucky, it will be released for clinical use until someone finds out it causes death or disfigurement under some rare, exotic circumstances; then they'll be sued blind until it's taken off the market... At least, that seems to be the common path of new drugs and treatments these days... I've lost count of how many companies Attorney James G. Sokolove is running against various drug manufacturers; but they seem to be keeping his greens fees paid in full...