RESPONSIVENESS OF AN SV40-IMMORTALIZED HEPATOCYTE CELL-LINE TO GROWTH-HORMONE

The response of an SV40-immortalized hepatocyte cell line (CWSV-1) der ived from adult male rat hepatocytes to human growth hormone (hGH) was investigated. CWSV-1 cells, which have been characterized extensively , retain certain differentiated functions of normal liver (Woodworth a nd Isom, Mol Cell Biol 7: 3740-3748, 1987). This cell line consists of tightly associated polygonal, mononucleated cells that grow as monola yers. These cells showed no significant morphological changes with the addition of hGH. Northern blot analysis showed that continuous treatm ent of the CWSV-1 cells with hGH induced the expression of insulin-lik e growth factor I (IGF-I) and 5 alpha-reductase RNAs. In addition, con tinuous exposure to hGH resulted in the induction of expression of the growth hormone receptor/growth hormone binding protein (GHR/GHBP) gen es. This study indicates that the CWSV-1 cells may serve as a valuable in vitro model system for studying the signaling pathway of GH.