Background: Keratinocyte growth factor (KGF) is a member of the fibroblast growth factor (FGF) family. KGF is a stromally derived, paracrine growth factor specifically mitogenic for a variety of epithelial cells. The KGF receptor (KGFR), which is a splice variant of the FGF receptor-2 (FGFR-2)/bek gene, is expressed only in epithelial cells. In this study, the expression of mRNAs encoding KGF, KGFR, and FGFR-2 in endometrial adenocarcinoma and in carcinosarcoma tissues was examined and the expression of the same mRNAs was compared with cycling endometrium.
Methods: Specimens of tumor tissue were collected from 14 women with well differentiated endometrial adenocarcinoma and from 4 women with carcinosarcoma. All samples were obtained at the primary surgery before 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 using 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 endometrial adenocarcinoma tissue compared with cycling endometrial tissues, whereas no difference was found between carcinosarcoma tissue and cycling endometrium. The relative level of KGFR mRNA in endometrial adenocarcinoma did not differ from that in cycling endometrium, but was significantly higher compared with carcinosarcomas. No differences were observed in FGFR-2 mRNA expression between cycling endometrium and tumor tissues.
Conclusions: To the authors' knowledge, this study demonstrates for the first time the expression of KGF, KGFR, and FGFR-2 mRNAs in endometrial adenocarcinoma and in carcinosarcoma tissues. The relative level of KGF mRNA expression in adenocarcinoma tissue is decreased compared with that in cycling endometrium. The change in epithelial/stromal cell prominence between cycling endometrium and adenocarcinoma tissue may account for the difference in KGF expression but does not explain why KGF receptor expression in same tissues remains unchanged. The impact of altered KGF expression for endometrial tumorigenesis is still unknown.