A new study has found that the gene BRAF is frequently mutated in melanomas that develop on areas of the skin that are intermittently exposed to the sun. In contrast, BRAF mutations in melanomas on chronically sun-damaged skin and skin unexposed to the sun are rare. The discovery "strongly suggests distinct genetic pathways leading to melanoma," say study authors Janet L. Maldonado and Boris Bastian, M.D., of the University of California at San Francisco, and their colleagues, who looked at 115 patients with primary invasive melanomas. "The frequent occurrence of BRAF mutations in the most common type of melanoma raises the possibility that specific BRAF inhibitors may be useful therapeutic agents for this type of disease," they write.
Contact: Jennifer O'Brien, UCSF, 415-476-2557, firstname.lastname@example.org.
Bladder Cancers Marked by Defective Checkpoint Function
Both p53-dependent and p53-independent cell cycle checkpoints, which help to maintain genetic stability, are frequently defective in bladder cancer cell lines, a new study has found. Compared with normal human uroepithelial cells, bladder cancer cell lines had severely attenuated checkpoint function, report Sharon C. Doherty, Ph.D., of the University of Ulster in Northern Ireland, William K. Kaufmann, Ph.D., of the Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, and their colleagues. "These functional defects in the bladder [cell] lines suggest that cell cycle checkpoints may represent barriers to bladder carcinogenesis," they write.
Contact: Dianne Shaw, Lineberger Comprehensive Cancer Center, 919-966-5905; fax: 919-966-8030, email@example.com.
Once-Daily Antibiotic More Effective in Children with Neutropenia