EXPRESSION OF PROLACTIN RECEPTORS IN HUMAN OSTEOSARCOMA CELLS

The expression of prolactin receptor (PRL-R) mRNA was demonstrated by reverse transcription-polymerase chain reaction (RT-PCR) combined with Southern analysis in total RNA extracts from two human osteosarcoma c ell lines (MG-63 and Saos-2). The level of PRL-R transcript was signif icantly enhanced in cells cultured in the presence of 1,25-(OH)(2) vit aminD(3) (10(-7)M) and to a lesser extent in the presence of dexametha sone (10(-6)M). This first demonstration of PRL-R gene expression in o steoblastlike cells supports the hypothesis of a direct action of prol actin in bone cells, which is further strongly suggested by the stimul atory effect of 1,25-(OH)(2) vitaminD(3) and dexamethasone on PRL-R mR NA level in these cells. (C) 1996 Academic Press, Inc.