EFFECTS OF HEPATOCYTE GROWTH-FACTOR ON DIFFERENTIATION AND CMET RECEPTOR EXPRESSION IN THE PROMYELOCYTIC HL-60 CELL-LINE

Aim-To determine the effects of hepatocyte growth factor (HGF) on myel oid cell differentiation and cMET expression using the promyelocytic H L60 cell line. Methods-HL60 cells cultured with purified recombinant H GF, dimethyl sulphoxide (DMSO), or 12-O tetradecanoylphorbol-13-acetat e (TPA) were immunostained for the differentiation markers, human neut rophil elastase (HNE), cathepsin B, MAC387, or the receptor for hepato cyte growth factor (cMET). Results-HGF treated cells were positive on staining for cathepsin B and MAC387, but were negative for HNE, indica ting monocytic differentiation. HGF treated cells had the morphology o f monocytes but continued to divide at the same rate as control cells and remained non-adherent. DMSO treated cells were positive for HNE an d cell numbers were reduced, confirming myeloid differentiation. TPA t reated cells were positive for cathepsin B and MAC387, cell numbers we re reduced, and the cells became adherent, confirming terminal monocyt ic differentiation. Untreated HL60 cells were weakly positive for cMET at the start of the culture period and expression increased after 72 hours. Cells treated with HGF, DMSO, or TPA were also positive for cME T. Conclusions-These data suggest that HGF induced partial monocytic d ifferentiation in HL60 cells. In addition, expression of cMET by HL60 cells occurs at an early stage in myelomonocytic cells and is maintain ed after differentiation along either the myeloid or monocytic pathway s.