Cancer Study Explores Role of 2 Proteins

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DECEMBER 18, 2008

Cancer Study Explores Role of 2 Proteins
By DAVID ARMSTRONG
WSJ

Ovarian-cancer patients who have low levels of two proteins die much sooner than women with high levels of the proteins, a finding that researchers say is a major development in the search for new treatments for the often deadly and hard-to-detect disease. The proteins identified by researchers at the M.D. Anderson Cancer Center in Houston play a key role in two types of RNA interference, which is the mechanism by which genes are turned on or off. By targeting that process, researchers hope they will be able to silence the cancer-causing genes. In addition, measuring protein levels may eventually allow doctors to better tailor treatment plans.

In a study published in this week's New England Journal of Medicine, the Anderson researchers said women with high levels of proteins known as Dicer and Drosha survived four times as long -- or eight years -- as women who had low levels of the proteins. The researchers said it is likely that low levels of the proteins allow some genes to continue functioning when they should be silenced. The study was funded with grants from the National Cancer Institute as well as several foundations.

Researchers at Anderson are already working on RNA-interference-based cancer therapies, said Anil Sood, the senior author of the New England journal study. "We think this is an attractive alternative because we can shut off the gene of interest," he said. Dr. Sood said the medical center hoped to get approval to begin testing an RNAi therapy on humans in the next year. It typically takes several years for a new therapy to win Food and Drug Administration approval. Dr. Sood said a private company has an option to license the technology.

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Ovarian cancer is hard to detect and primarily strikes older women. Current treatment options include surgery, chemotherapy and radiation treatment. An estimated 21,650 new cases of ovarian cancer are expected this year and 15,520 women are expected to die from the disease in 2008, according to the American Cancer Society. It is the leading killer among cancers of the female reproductive system. The Anderson researchers also tested the protein levels in a smaller group of lung- and breast-cancer patients and found that low levels of the Dicer protein also affected survival rates.

http://online.wsj.com/article/SB122954538976015271.html (subscription)