The human papillomavirus (HPV) allows infected cervical and head and neck cancer cells to maintain internal molecular conditions that make the cancers resistant to therapy and more likely to grow and spread, resulting in a poor prognosis for patients, researchers with UCLA's Jonsson Cancer Center found.
Virtually all human cancers experience a state called intratumoral hypoxia, or a low amount of oxygen within the tumor. In the UCLA study, researchers showed that the HPV-positive cancers adapted to and took advantage of the hypoxic environment by expressing a protein that activates a cell signaling pathway that helps the cancers survive, grow and spread.
The study is published in the Nov. 4, 2008 issue of the journal Cancer Cell.
The research, done on cells in culture and in animal models, may lead to the development of new therapies that target the cell signaling pathway, thereby interrupting ability of the cancer cells to thrive, said Dr. Matthew Rettig, senior author of the study and a researcher at UCLA's Jonsson Comprehensive Cancer Center.
"There is potential for therapeutic intervention based on this finding," said Rettig, an associate professor of urology and medicine.
The finding is crucial because 90 to 98 percent of cervical cancers are caused by HPV. Cervical cancer is the second most common cancer in women worldwide, with more than 500,000 cases diagnosed annually. In all, 200,000 women die from cervical cancer every year. In oral cavity and pharynx cancers, the HPV virus is linked to about 20 to 40 percent of cases, caused by sexual behavior. About 400,000 cases of head and neck cancer are diagnosed worldwide each year, and more than half of those patients die of the disease.
In those cases where the cancer is HPV-positive, which number in the hundreds of thousands, the virus will make the disease more aggressive and deadly. Finding a way to stop the virus from prompting the cance
|Contact: Kim Irwin|
University of California - Los Angeles