Some skin cancer may be mediated by primary cili...(ut primary cilia the hyped-up Smoothened...)

"The cilium doesn't appear to just turn on or turn off Hedgehog signaling," Reiter said. "It does both -- providing both an accelerator and a brake for tumor growth. If cancer is a run-away car, some mutations cause cancer by opening up the throttle. Others promote cancer by cutting the brake line. The cilium houses both the gas and brake pedals for Hedgehog signaling. "

Targeting primary cilia with drugs may neutralize the effect of these mutations either by boosting cilia function when Gli is hyper-active, or inactivating cilia when mutated Smoothened poses a threat, Reiter said.

"Understanding the molecular machinery that goes awry in cancer should help scientists design new drugs to specifically block the effects of that broken machinery," Reiter said.

Reiter's team studied each of the two over-active, tumor-inducing mutant proteins in the skin of mice. As expected, the mutated proteins promoted tumor growth similar to human basal cell carcinoma. They then removed the cilia in those cells to reveal the effect on tumor growth.

Primary cilia are normally disassembled before each cell division, and then the daughter cells reconstitute them. Since cancer disrupts normal cell growth, many scientists had thought that cancer cells might not have cilia at all.

"The role that cilia play in some cancers gives us another target for anti-cancer therapies," Reiter said.

'/>"/>