In a study published in the April 16, 2004, issue of the journal Cell, scientists describe 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, Ph.D., 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, Ph.D., 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," says 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. S
Contact: Nancy Jensen
University of Texas M. D. Anderson Cancer Center