The Reporter: June 1997, Vol.8, No.3
RESEARCH NOTES
Gene Involved in Three Cancers Identified

Columbia researchers, in collaboration with Cold Spring Harbor Laboratory, have identified a new tumor suppressor gene, known as P-TEN, involved in a large percentage of brain, breast, and prostate cancers. The newly discovered tumor suppressor gene is one of more than a dozen known to be involved in a large variety of cancers. The discovery could lead to better tests for early detection and more effective treatments.

Dr. Ramon Parsons, P&S assistant professor of pathology and of medicine, was senior author of a report on the finding in a March issue of the journal Science. "Although initially mutated in breast cancer, we found mutations of P-TEN in brain and prostate cancer and expect to find mutations in other cancers as well," he says. Unlike mutations of genes such as hMSH2 and BRCA1, which are found in hereditary predispositions to cancer, most P-TEN mutations are found in the more common sporadic cancers. More than 80 percent of all cases of cancer are sporadic.

"Discoveries such as this are rapidly filling in the missing pieces of the cancer puzzle. This discovery represents one of the first genes to be implicated in aggressive and generally fatal brain tumors, a type of cancer in which we desperately need clues that the P-TEN gene may offer," says Dr. Richard Klausner, director of the National Cancer Institute.

Some evidence suggests that loss of P-TEN affects the way a benign tumor becomes malignant. "We identified 20 mutations of P-TEN in advanced brain, breast, and prostate cancers," says Dr. Parsons. "Based on our finding, it may someday be possible to test people for mutations of P-TEN, which would give an early warning of cancer danger. P-TEN may also allow us to identify drugs to better treat cancer overall." Although this discovery shows great promise, Dr. Parsons cautions that it is not likely to have an impact on patient care for many years.