RNAi Screens Seek Cancer Genes

© 2004 National Academies of Science

Mutant Caenorhabditis elegans strain NL1832 shows increased double-strand DNA breakage (DSB). To explore the synthetic-lethal effects of RNA interference, researchers nourished these nematodes on bacteria that express various RNA vectors. For genes that presumably protect against DSB, RNAi knockdowns killed the mutant worms, lowering their brood sizes (bottom panel) compared to those of wild-type N2 worms exposed to the same vectors (top panel). (From G. van Haaften et al., Proc Natl Acad Sci, 101:12992-6, 2004.)

RNA interference (RNAi) is fast becoming an essential tool for academic and industrial labs searching for genes that promote or inhibit cancer. Munich-based Xantos Biomedicine, for example, once relied on cDNA overexpression, a decades-old approach, to identify novel genes with tumor-suppressor phenotypes. But the small five-year-old company is now supplementing its gain-of-function, high-throughput cDNA technology with loss-of-function RNAi. "I don't see any really stringent advantage of one versus the ...