U.S. studies with worms may extend human life, help fight cancer

William Atkins
Tuesday, 16 October 2007 19:12

Science - Health

University of California researchers have found that naturally occurring processes within cells in “Caenorhabditis elegans” worms could possibly be applied to humans to slow the aging process and, in the process, protect against cancer.               

The study “DAF-16/FOXO Targets Genes that Regulate Tumor Growth in Caenorhabditis elegans” was reported on October 14, 2007, in the journal Nature Genetics by University of California (San Francisco)  biologist Cynthia Kenyon and graduate student Julie Pinkston-Gosse, of the university’s Department of Biochemistry and Biophysics.

The Kenyon study is based on earlier studies also performed by Kenyon that show the key to life longevity and cancer elimination is the genes DAF-2 (a receptor that identifies receptors for insulin and a protein for growth) and DAF-16 (a protein that controls when other genes are activated). (DAF is short for Diaminofluorescein.)

One of the most important of these studies is the one published in 1993 the journal Nature, which is called “A C. elegans mutant that lives twice as long as wild type” (366 (6454), 461-464 (1993) by Kenyon, along with Jean Chang, Erin Gensch, Adam Rudner, and Ramon Tabtiang. In this 1993 study, Kenyon found one gene could double the lifespan of the C. elegans worm.

The DAF-2 gene regulates reproductive development, aging, and other important processes within the C. elegans worms. DAF-16 is required for DAF-2 to effectively control lifespan and cancer control.

This newest study concentrates on identifying these two genes and their relationship with other specific genes that may also be controlled by DAF-16 with respect to cancer and lifespan.

Her results using RNA interference (RNAi, which is a mechanism using ribonucleic acid [RNA] to regulate genes) found 29 genes that work with DAF-2 and DAF-16 to either promote or restrict tumor cell growth. Those that minimize tumor cell growth also seem to lengthen the life spans of the worms. The scientists found that the insulin receptor DAF-2 works with the transcription factor DAF-16 to promote life longevity and fight tumor growth.

Kenyon said about her newest finding, “This is very exciting. There is a widely held view that any mechanism that slows aging would probably stimulate tumor growth. But we found many genes that increase lifespan, 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."