[Expression of cellular oncogenes during hepatocarcinogenesis in rats].
With RNA-DNA hybridization techniques, the mRNA expression of c-Ha-ras, c-Ki-ras, N-ras, and c-fos oncogenes in rat liver with neoplastic nodules or hepatocellular carcinoma induced by DENA was found to be higher than that in normal liver. No significant difference of c-myc expression was observed between normal liver and liver with neoplastic nodules or hepatocellular carcinoma. In the initiation stage of hepatocarcinogenesis in DENA+AAF+PH+PB and AAF+PH+PB model systems, the expression of c-myc increased markedly, and that of N-ras was remarkably stimulated under the action of AAF. It appears that a cooperative action between the c-myc and N-ras oncogenes was involved in the initiation of hepatocarcinogenesis. In the promotion stage, the expression of c-myc and N-ras returned to a normal level. The expression of c-fos decreased progressively in both the initiation and promotion stages, while that of c-Ha-ras and c-Ki-ras was not much changed. The significance of these results is briefly discussed.
Li
S
S
Institute of Basic Medical Sciences, Beijing.
D015073:2-Acetylaminofluorene; D000818:Animals; D002273:Carcinogens; D004052:Diethylnitrosamine; D015972:Gene Expression Regulation, Neoplastic; D011905:Genes, ras; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology; D008297:Male; D010634:Phenobarbital; D051381:Rats; D011919:Rats, Inbred Strains
D002273:Carcinogens; D004052:Diethylnitrosamine; D015073:2-Acetylaminofluorene; D010634:Phenobarbital