harnessing HIV protein to cause cancer cells to self-destruct

[Lani]

HIV Protein Helps Prompt Cancer Cell Apoptosis

By David Douglas

NEW YORK (Reuters Health) Feb 27 - A peptide derived from the HIV-1 TAT protein and the pro-apoptotic Bcl-2 family member Bim induces extensive apoptosis in cancer cells, according to Missouri-based researchers.

This work "is just the beginning of what is turning out to be a very promising approach to cancer therapy," senior investigator Dr. William G. Hawkins told Reuters Health. By employing an HIV protein to deliver a cancer drug, he added, "we are just capitalizing on strategies that nature developed."

In the January issue of the Annals of Surgical Oncology, Dr. Hawkins and colleagues at Washington University School of Medicine, St. Louis note that this TAT-Bim construct induced apoptosis in a dose-dependent fashion in pancreatic cancer, lymphoma and melanoma cell lines. Radiation augmented the apoptotic effect.

In mouse models of pancreatic cancer and melanoma, TAT-Bim led to tumor stability and even regression in some animals, and tumors grow more slowly than in controls. After 40 days, 80% of mice given TAT-Bim were alive compared to 20% of controls.

Apoptotic processes are critical targets for the development of anti-cancer therapeutics, the researchers point out. "We are optimistic that the multi-disciplinary collaboration initiated with this project will continue to produce novel and interesting approaches to cancer therapy," Dr. Hawkins said.

Ann Surg Oncol 2007.