[Possible mechanisms of the transforming and tumorigenic effects of DNA-containing animal viruses].

The literature devoted to oncogenic action of DNA-containing animal viruses and their role in the development of human neoplasias are reviewed. The regularities of persistence and expression of genetic material of DNA-containing viruses in transformed and tumor cells are comprehensively analyzed. The mechanisms of recombination of cellular and viral DNA during cell transformation as well as the specificity of integration of viral DNA into the host genome are considered. The functions and mechanisms of transforming and tumorigenic action of the products of oncogens of DNA-containing viruses of different groups are discussed. The data on the cell transformation by some DNA-containing viruses without oncogene expression are represented. The mechanism of cell transformation by DNA-containing viruses related to the activation of cellular oncogens is discussed.