Viral gene studies at Cornell University's College of Veterinary Medicine aim to learn how some fish fight skin cancer and how retroviruses function in the development and regression of tumors.

Supported by a three-year, $270,000 grant from the American Cancer Society (ACS), James W. Casey, Ph.D., associate professor of microbiology and immunology, is leading an investigation of a complex retrovirus called walleye dermal sarcoma virus (WDSV) and the tumors it causes on the skin of the fish. Casey, along with microbiology and immunology professors Paul R. Bowser and Donald Holzschu and Volker M. Vogt of the Section of Biochemistry, Cell and Molecular Biology, are investigating the mechanisms by which certain fish tumors grow and regress on a seasonal basis. "The kind of tumor regression we see in walleyes is unique to poikilotherms -- or cold-blooded animals -- and WDSV is of particular interest because an understanding of this process may help explain how other cancer-related retroviruses and the immune systems of their hosts interact," said Casey, a specialist in molecular virology.

The ACS study at Cornell will focus on viral genes and infectious particles during tumor induction and regression in cell cultures as well as in fingerling walleyes and older fish with naturally-induced tumors. By the time the fish virus study is completed in 1998, the research team of virologists and fish pathologtists hope to know more about how processes such as superinfection, viremia and immune responses are related to cancer in other animals, including humans.