Abstract 4549: Expression and localization of progesterone receptor membrane component 1 and 2 in normal and malignant endometrial cells

Abstract

Abstract Recently, two progesterone receptor membrane components (PGRMC) have been identified. PGRMC-1 protein has been shown to be overexpressed in breast, colon, and thyroid cancers, whereas far less is known about PGRMC2. The purpose of this study was to assess the expression, localization and hormonal regulation of PGRMC-1 and PGRMC-2 in normal and malignant endometrial tissues and cell lines. Immunohistochemical analysis showed a high expression of PGRMC-1 in normal tissues and a stage dependent decrease was observed in endometrial cancer tissues. A progressive decrease of PGRMC-2 expression was evident in endometrial cancer tissues but was not as marked as in PGRMC-1. Dual immunofluorescent confocal microscopy demonstrated colocalization of PGRMC-1 and PGRMC-2 in the cytoplasm and nucleus of endometrial cancer (Ishikawa and ACI-126) cells. Of significance, in normal epithelial endometrial (NEE) cells PGRMC-2 was predominantly localized in the membrane, whereas PGRMC-1 showed cytoplasmic and nuclear expression. Treatment of cancer cells with progesterone (P4) translocated both PGRMCs to the nucleus, while in normal cells PGRMC-1, but not PGRMC2 was translocated to the nucleus of cells. The results suggest that expression of PGRMCs is regulated by P4 and the dynamic pattern of PGRMC1 and PGRMC2 expression in normal and malignant cells implicate their role in tumorigenesis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4549. doi:10.1158/1538-7445.AM2011-4549