Scientists at the University of Pittsburgh Cancer Institute have begun to uncover how the virus that causes most Merkel cell carcinoma（癌） -- a rare and aggressive skin cancer -- operates, meaning that a rational chemotherapeutic target for this cancer could be developed in the near future. Patrick Moore, M.D., M.P.H., an American Cancer Society professor in the laboratory of Yuan Chang and Patrick Moore at the University of Pittsburgh Cancer Institute in Pittsburgh, Pa., presented these study results at the Second AACR International Conference on Frontiers in Basic Cancer Research, held here Sept. 14-18, 2011.

Merkel cell carcinoma is a rare and highly aggressive cancer, the incidence of which has increased fourfold during the last 20 years, particularly in immunosuppressed populations, according to Moore.

"Unfortunately, Merkel cell carcinoma is difficult to treat and clinical trials of chemotherapeutics have been disappointing in affecting clinical course and survival," he said. "Discovery of the molecular cause for this cancer provides opportunities to directly target the cellular pathways that are perturbed by the virus."

In 2008, Moore and colleagues discovered Merkel cell polyomavirus (MCV), the virus that causes most Merkel cell carcinoma. Polyoma refers to the ability of some members of this family to produce multiple tumors in animal models. Their laboratory previously discovered the herpes virus that causes Kaposi's sarcoma, cancer that commonly occurs in patients with AIDS.

"MCV is the first polyomavirus to be consistently associated with human cancer, and is believed to cause 80 percent of Merkel cell carcinoma," Moore said.