Abstract B064: Anti-phospho-estrogen receptor alpha (Ser305), clone 124.9.4, is a potential clinical antibody marker for tamoxifen-resistant breast cancer

Abstract

Abstract Resistance to tamoxifen is one of the major challenges in breast cancer treatment. Different mechanisms related to tamoxifen sensitivity have been widely investigated, including the phosphorylation of ERα. It has been shown experimentally that phosphorylation of estrogen receptor alpha at serine 305 (ERαS305-P) by protein kinase A (PKA) leads to an activation of ERα and to transcription of ERα-responsive gene after tamoxifen treatment [EMBO J 26:3534-3544][EMBO J 21:5437-5447], leading to tamoxifen resistance. More recently, clinical studies also show that ERαS305-P may be a good biomarker to identify patients unlikely to respond to tamoxifen [J Pathol 217:372-379][Breast Cancer Res Treat 125(1):1-12]. Here we developed and validated a rabbit monoclonal anti-phospho-estrogen receptor alpha (Ser305) antibody, EMD Millipore 05-922R., with immunohistochemistry (IHC) validation on different breast cancer patient samples and other non-breast cancer tissue micro array (TMA) samples. Citation Format: Wayne Speckmann, Robert Brockett, Chun Yang, Alejandra Solache. Anti-phospho-estrogen receptor alpha (Ser305), clone 124.9.4, is a potential clinical antibody marker for tamoxifen-resistant breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr B064.