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, jobrien@pubaff.ucsf.edu.
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, dgs@med.unc.edu.
Once-Daily Antibiotic More Effective in Children with Neutropenia
A single daily dose of the antibiotic tobramycin may be more effective and less damaging to the kidneys than the traditional three daily doses in children with fever and neutropenia (reduced white blood cell count) who are undergoing stem cell transplantation, according to a study of 60 children randomly assigned to the two regimens. Lillian Sung, M.D., of the Hospital for Sick Children in Toronto, and her colleagues, conclude that "once-daily dosing with tobramycin should be adopted for children with febrile neutropenia, including children who are undergoing stem cell transplantation."
Contact: Laura Greer, Hospital for Sick Children, 416-813-5046, laura.greer@sickkids.ca.
Titles of additional articles appearing in the December 17 JNCI:
- Interaction of retroviral Tax oncoproteins with tristetraprolin and regulation of tumor necrosis factor-alpha expression, Luc Willems, Universitaire des Sciences Agronomiques de Gembloux, Gembloux, Belgium, et al.
- Effect of epidermal growth factor receptor inhibitor on development of estrogen receptor–negative mammary tumors: http://www.eurekalert.org/emb_releases/2003-12/jotn-ods121103.php
- Adjuvant chemotherapy followed by goserelin versus either modality alone for premenopausal lymph node–negative breast cancer: A randomized trial: http://www.eurekalert.org/emb_releases/2003-12/jotn-sst121103.php
Note: The Journal of the National Cancer Institute is published by Oxford University Press and is not affiliated with the National Cancer Institute. Attribution to the Journal of the National Cancer Institute is requested in all news coverage. Visit the Journal online at http://jncicancerspectrum.oupjournals.org/.
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JNCI Journal of the National Cancer Institute