Longevity gene may also predict better outcome for breast cancer patients.

2004 MAY 6 - (NewsRx.com & NewsRx.net) -- A gene known to promote longevity in animals has now been discovered to encode a tumor suppressor - a protein that helps prevent cancer, according to a study by a team of scientists from The University of Texas M.D. Anderson Cancer Center.

The new gene, which was inactivated in two-thirds of patients studied, presents a potent new target for breast cancer therapy, the researchers say.

In a study published in the April 16, 2004, issue of the journal Cell, scientists described how the presence of the protein, named Forkhead box class O3 (FOXO3), is associated with better outcomes for breast cancer patients. Conversely, if FOXO3 was inactivated, patients had worse outcomes.

"This is a very good prognostic marker for breast-cancer patient outcome," said Mien-Chie Hung, PhD, the co-principal investigator of the study. "In addition, these proteins provide new targets for cancer therapy and prevention."

The research team, which was a collaboration between the laboratories of Mickey C.-T. Hu, PhD, and Hung, both of the Department of Molecular and Cellular Oncology at M.D. Anderson, demonstrated that FOXO3 is inactivated in many cancer patients by an enzyme called IKK and determined that IKK is an oncoprotein, a protein that can induce cancer.

"We have uncovered two important events and put them together in one story," said Hung. "This research has identified an important new tumor-suppressor protein and a new oncogene that provide targets for cancer therapy. Previously, these proteins had been suspected to be involved in cancer, but there was no direct evidence for that."

The IKK oncoprotein belongs to a family of enzymes called kinases. Researchers have shown that blocking certain kinases can be an effective way to block cancer. New generation cancer drugs such as Gleevec, which has been effective in treating leukemia patients, work by zeroing in and inactivating a kinase molecule. Such targeted therapies are designed to kill cancer cells while avoiding serious damage to other, non-cancerous cells.