Abstract 1631: Protection of colon carcinogenesis by estrogen receptor-beta may involve regulation of angiogenesis and invasion specific signaling molecules

Abstract

Abstract Estrogen receptor-beta (ERα) has been suggested to exert anti-tumorigenic effects in the colon. However, its mechanism of action in colon cancer remains unclear. Previously, we demonstrated that azoxymethane (AOM) treated ERα knockout (≥ERKO) mice showed a significantly higher incidence of colonic precancerous lesions compared to AOM-treated WT mice. These results were associated with a decrease in apoptosis and loss of crypt organization in the colonic epithelium of αERKO mice. In the present study, we investigated whether ERα deficiency would also correlate with a higher incidence of colonic tumors. For this, αERKO and WT mice were injected subcutaneously with AOM (10mg/kg) once a week, for six weeks. Forty weeks after the beginning of the study, mice were sacrificed and colonic sections were collected for histopathology, RNA, and protein expression analysis. Evaluation of hematoxylin and eosin sections from each group showed that αERKO mice developed higher number of colonic adenomas (1.40 ± 0.40) than WT mice (0.33 ± 0.21) (p < 0.05). Furthermore, Mouse Cancer PathwayFinder Superarray revealed a greater than two-fold increase of angiogenesis and invasion specific signaling molecules in ERα-deficient tumors compared to WT ones. These findings highlight the importance of ERα against colon carcinogenesis progression. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1631. doi:1538-7445.AM2012-1631