Loss of motility-related protein 1 (MRP1/CD9) and integrin alpha 3 expression in endometrial cancers

Background. MRP1/CD9 and integrin alpha3 have played crucial roles in cell adhesion, motility, and signaling events. The loss of MRP1/CD9 and integrin alpha3 has been involved in tumor growth and metastasis of cancer cells. T he aim of the current study was to clarify the clinical significance of MRP 1/CD9 and integrin alpha3 in endometrial cancer. Methods. The expression of MRPI/CD9 and integrin alpha3 from the same tissu e sample were examined immunohistochemically in 15 patients with normal end ometrium and in 56 patients with uterine endometrioid adenocarcinoma. Disea se-free survival curves were estimated using the Kaplan-Meier method and an alyzed by the log-rank test between the positive and reduced expression sta tuses of both MRP1/CD9 and integrin alpha3. These expressions and clinicopa thologic variables were analyzed univariately and multivariately. Results. In normal endometrium, MRP/CD9 was expressed at the cell membrane of cell contact sites, and the expression of integrin alpha3 was detected a lso at the cell membrane of cell contact sites and at borders of stromal ti ssues. In patients with endometrioid adenocarcinoma, 17 cases showed reduce d expression of MRP1/CD9, and 20 cases had reduced expression of integrin a lpha3. Fourteen cases indicated a reduced expression of both MRP1/CD9 and i ntegrin alpha3. Each reduced expression of MRP1/CD9 or integrin alpha3 was significantly correlated with histologic grade and metastasis. Multivariate analysis using the Cox regression model disclosed that age at surgery, met astasis, and expression status of MRP1/CD9 were significant prognostic fact ors for disease-free survival. Conclusions. These findings suggested that the analysis for the expression statuses of MRP1/CD9 and integrin alpha3 may provide important information on the clinical behavior of endometrial cancer. Cancer 2001;92;542-8. (C) 2 001 American Cancer Society.