DISTINCT PATTERNS OF EXPRESSION OF KERATINOCYTE GROWTH-FACTOR AND ITSRECEPTOR IN ENDOMETRIAL CARCINOMA

BACKGROUND. Keratinocyte growth factor (KGF) is a member of the fibrob last growth factor (FGF) family. KGF is a stromally derived, paracrine growth factor specifically mitogenic for a variety of epithelial cell s. The KGF receptor (KGFR), which is a splice variant of the FGF recep tor-2 (FGFR-2)/bek gene, is expressed only in epithelial cells. In thi s study, the expression of mRNAs encoding KGF, KGFR, and FGFR-2 in end ometrial adenocarcinoma and in carcinosarcoma tissues was examined and the expression of the same mRNAs was compared with cycling endometriu m. METHODS. Specimens of tumor tissue were collected from 14 women wit h well differentiated endometrial adenocarcinoma and from 4 women with carcinosarcoma. All samples were obtained at the primary surgery befo re any treatment was initiated. In addition, endometrial tissues from 19 premenopausal women with normal menstrual cycles were examined The expression of specific mRNAs in the endometrial samples was assessed u sing quantitative reverse transcriptase polymerase chain reaction. The results were analyzed by the nonparametric Kruskal-Wallis statistic. RESULTS. The KGF mRNA expression was significantly lower in endometria l adenocarcinoma tissue compared with cycling endometrial tissues, whe reas no difference was found between carcinosarcoma tissue and cycling endometrium. The relative level of KGFR mRNA in endometrial adenocarc inoma did not differ from that in cycling endometrium, but was signifi cantly higher compared with carcinosarcomas. No differences were obser ved in FGFR-2 mRNA expression between cycling endometrium and tumor ti ssues. CONCLUSIONS. To the authors' knowledge, this study demonstrates for the first time the expression of KGF, KGFR, and FGFR-2 mRNAs in e ndometrial adenocarcinoma and in carcinosarcoma tissues. The relative level of KGF mRNA expression in adenocarcinoma tissue is decreased com pared with that in cycling endometrium. The change in epithelial/strom al cell prominence between cycling endometrium and adenocarcinoma tiss ue may account for the difference in KGF expression but does not expla in why KGF receptor expression in same tissues remains unchanged. The impact of altered KGF expression for endometrial tumorigenesis is stil l unknown. (C) 1997 American Cancer Society.