Researchers have identified a batch of genes that not only prevent cancer but slow the aging process in worms, and say they are now looking to see if the genes have the same properties in humans.
Many of the genes in the worms are already known to have counterparts in humans, and the team at the University of California, San Francisco, say they hope to better understand some of the processes that cause both aging and cancer. Drugs that mimic the effects of these genes might help people both avoid cancer and also live longer, they wrote in an issue of the journal Nature Genetics.
Biologist Cynthia Kenyon is perhaps best known for discovering that a change in just one gene, called daf-2, could double the life span of small roundworms called Caenorhabditis elegans.
She and graduate student Julie Pinkston-Gosse screened as many genes as they could that were affected by daf-2. They looked at 734 in total, and found that 29 of them either stimulated tumor growth or suppressed it. Some caused cell proliferation—which goes haywire to help a tumor grow and spread—while others initiated a programmed suicide process called apoptosis, used by the body to destroy faulty cells, including tumor cells.
"About half of these genes also affected normal aging, thereby linking these two processes mechanistically," the two researchers wrote.
"There is a widely held view that any mechanism that slows aging would probably stimulate tumor growth," Kenyon said in a statement. "But we found many genes that increase life span, but slow tumor growth. Humans have versions of many of these genes, so this work may lead to treatments that keep us youthful and cancer-free much longer than normal."
The genes that stimulated tumor growth also accelerated aging, Kenyon found. The genes that prevented tumor growth slowed down the aging process and extended life span in the worms.
Kenyon said the findings strengthen theories that the controls of life span and cancer have deep, common roots.
Small creatures that researchers work on, such as the C. elegans roundworm, often share genes with humans, and these genes often underlie key biological processes.
Reuters, October 15, 2007