OVEREXPRESSION OF THE MET HGF RECEPTOR IN OVARIAN-CANCER

The MET oncogene encodes the receptor for Hepatocyte Growth Factor/Sca tter Factor, a unique growth factor that induces not only proliferatio n of epithelial cells, but also cell motility and invasiveness. DNA le vel and expression of the Met/HGF receptor gene were examined with Sou thern- and Western-blot analyses, respectively, in human ovary, benign ovarian tumors and epithelial ovarian carcinomas. The Met/ HGF recept or was detectable in the surface epithelium of normal ovary. The level of expression was unchanged in benign ovarian tumors of various origi ns. Fourteen out of 67 malignant carcinomas (20%) showed a 3- to 10-fo ld increase in expression. in 5 additional cases the Met/HGF protein w as overexpressed over 50-fold. This represents a total of 28% of cases . Overexpression was not associated with MET gene amplification. Overe xpressing tumors belonged to different histotypic variants, but showed a well-differentiated phenotype. Clinically, overexpression was assoc iated with disease at any pathologic stage, but was significantly corr elated with premenopausal status of patients. These data suggest that expression of the Met/HGF receptor may add a selective growth advantag e to a narrow subset of differentiated ovarian cancers in premenopausa l patients. (C) 1994 Wiley-Liss, Inc.