[Integration of carcinogenic viruses in the genome of in-vitro cultured human fibroblasts].

Avian sarcoma viruses are known for inducing no transformation of human diploid fibroblasts. Nevertheless, we show that the Rous sarcoma virus can infect and transform some human fibroblastic cell lines, replicate and express viral proteins, integrate into the host genome and prevent expression of MHC class I antigens on cell membranes. Cell transformation happens together with important and significant abnormalities of the cell karyotype and proviral integration is most often close to the c-src oncogene on chromosomes 1 and 20.