Mutations that prolong the life span of worms also suppress tumor formation, report Julie Pinkston, Cynthia Kenyon, and colleagues (University of California, San Francisco).
Mutations in the gld-1 gene of Caenorhabditis elegans cause germ cells to proliferate uncontrollably, giving rise to lethal tumors. In most organisms, tumor susceptability increases with age, so Pinkston et al. were interested in how mutations that increase the life span of C. elegans might affect gld-1 mutant worms.
Four different mutations that each promote longevity also suppressed tumorigenesis. When gld-1 worms carried mutations in daf-2, eat-2, isp-1, or clk-1 genes, the proliferation rate of germ line tumor cells was dramatically reduced. Remarkably, however, none of these mutations affected the proliferation rate of germ cells in worms without the gld-1 mutation.
Mutations in daf-2 interfere with insulin signaling, eat-2 mutations restrict calorie intake, and isp-1 and clk-1 mutations impair mitochondrial activity....
