title: Expression of retroviral sequences and oncogenes in murine hepatocellular tumors.
abstract: The expression of endogenous retroviral sequences and of three cellular oncogenes was examined in three hepatocellular adenomas and in four carcinomas induced in male C57BL/6JDp X C3Hf/Dp F1 (hereafter called B6C3F1) mice by a single dose of nitrosodiethylamine, in five carcinomas that arose spontaneously in male C3Hf mice, and in the livers of normal age-matched control mice. In all of these adenomas and carcinomas, there was increased expression of Moloney murine leukemia virus- and intracisternal A particle-related sequences. The retrovirus-like VL30 sequence was expressed at significant levels in the normal liver of these mice and increased expression of this sequence was found in only 4 of the 12 tumors examined. Expression of endogenous mouse mammary tumor virus-related sequences was not detected in the normal livers or in any of the liver tumors. With respect to cellular oncogenes, increased expression of c-myc was seen in all of the B6C3F1 tumors. Two of five normal liver samples and all of the tumors of the C3Hf mice displayed significant expression of c-myc. There was a slight increase in expression of c-Ha-ras in some of the tumors. Increased expression of c-fos was found in only 1 of the 12 tumors. Taken together, these studies indicate that both carcinogen-induced and spontaneous liver tumor formation in mice is associated with abnormalities in the expression of endogenous retrovirus-related DNA sequences and also specific cellular oncogenes.
mesh_terms: D000818:Animals; D001483:Base Sequence; D007426:Genes, Intracisternal A-Particle; D005814:Genes, Viral; D008099:Liver / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000235:genetics* / Q000473:pathology; D008297:Male; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics; D051379:Mice; D008815:Mice, Inbred Strains; D009857:Oncogenes; D012367:RNA, Viral / Q000032:analysis; D012190:Retroviridae / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D012367:RNA, Viral