The overall aim of these studies is to develop an understanding of the role of sexually transmitted viruses in the development of human tumors. The persistence of herpes simplex virus, cytomegalovirus and papilloma virus nucleic acid sequences will be examined by in situ and Southern blot hybridization, using cloned viral DNA sequences as probes. Monoclonal antibodies prepared against viral-specific proteins will be used to detect viral polypeptides in sectioned tumor tissues and by immunoprecipitation. The relationship of the viruses to various stages in progression of neoplasia in human cancer will be studied, with particular reference to the role of viral and/or cellular genes in the initiation, promotion and maintenance of the neoplastic phenotype. The human tumors of major interest in this context are carcinoma of the cervix, vulva and anus and Kaposi's sarcoma. An extensive analysis of the minimum region of viral DNA needed to induce transformation in vitro will be conducted and models of the mechanism of transformation will be tested. The possibility that HSV, CMV and/or HPV might act in a synergistic manner will be tested by conducting in vitro transfection experiments in rodent and human cells and comparing the frequency of focus formation and the cell line characteristics of transformants isolated following single or multiple transfections. We will continue experiments aimed at isolating cellular oncogenes from the in vitro transformants and from human urogentital and Kaposi tumors by transfection of NIH 3T3 cells and other cells competent for uptake of transfected DNA.
