Contact: Will Sansom, (210) 567-2579

Shou-Jiang (S.J.) Gao, Ph.D., is the H-E-B Distinguished Chair for Cancer Research at the Health Science Center and directs the tumor virology program at the Greehey Children’s Cancer Research Institute.
Printer Friendly Format

SAN ANTONIO (Jan. 19, 2009) — Some people with AIDS get deadly forms of cancer and others don’t. Researchers at The University of Texas Health Science Center at San Antonio are studying a tiny molecule that appears to regulate the replication of a cancer-causing virus in AIDS patients. Like a thermostat fine-tunes temperature, this molecule fine-tunes the amount of virus in cells.

The virus, known as Kaposi’s sarcoma-associated herpesvirus, is linked to a number of malignant cancers seen in AIDS patients, including the most common and deadly one, Kaposi’s sarcoma, which represents 20 to 40 percent of all cancers in some parts of AIDS-riddled Africa.

The research is published in a recent edition of Nature Cell Biology.

The molecule in question is a type of microRNA, a snippet of RNA, that carries out orders from DNA, the genetic blueprint in cells. The study shows that the microRNA regulates the production of the cancer-causing virus. The microRNA either slows down the production of the virus, allowing it to hide in the body and evade the immune system, or speeds up replication as the virus mounts an offensive, said Shou-Jiang (S.J.) Gao, Ph.D., the H-E-B Distinguished Chair for Cancer Research at the Health Science Center.

“Almost every herpesvirus makes multiple microRNAs,” said Dr. Gao, a professor in the School of Medicine and the Graduate School of Biomedical Sciences at the Health Science Center. He heads the tumor virology program at the university’s Greehey Children’s Cancer Research Institute.

“We have barely scratched the surface about how they affect viral replication and infect cells,” he continued. “Our paper is the first to use a genetic approach to show that a microRNA regulates the viral lifecycle of Kaposi’s sarcoma-associated herpesvirus.”

The viral microRNA influences NF-κB, a protein complex that plays a crucial role in the immune response to inflammation, Dr. Gao added. The NF-κB connection is intriguing because the inflammatory activities of this protein complex are very important for cancer progression and spread, Dr. Gao said. Up to one-fifth of cancers are caused by viral infections.

Dr. Gao is also a virology researcher for the Cancer Therapy & Research Center at the UT Health Science Center. Study investigators include Drs. Xiufen Lei, Zhiqiang Bai, Jianping Xie, Fengchun Ye and Changil Kim. Dr. Yufei Huang from The University of Texas at San Antonio is a collaborator.

# # #