Abstract 1668: Induction of Autophagy by a novel agent promotes the growth arrest in breast cancer cells.

Abstract

Abstract Breast cancer is a highly complex disease due to its heterogeneity in nature; that often impedes the current therapeutic options. Autophagy is a catabolic process which plays a vital role in both progressions as well as in the treatment of cancer. In fact, the role of autophagy in cancer is still unclear. Our lab is focusing on small molecules, which may induce autophagy that may result in growth arrest in breast cancer cells. In our preliminary screening studies, we have identified a small molecule, Nimocinol Acetate (NA) which induces autophagy that resulted in inhibition of growth of estrogen-positive (MCF-7) and estrogen-negative (MDA-MB-231) breast cancer cells. Molecular analysis showed the significant induction of LC-3B and ATG-3 in NA treated cells as compared to other autophagy-regulators like Atg5, Atg7, Atg12, and beclin-1, which convey the importance of ATG3 and LC3B markers in induction of autophagy. The immunofluorescence analysis confirmed the formation of acidic autophagic vesicles upon NA treatment. To further ascertain the involvement of lysosomes and autophagosomes, we specifically blocked ATG-3 and LC-3B expression by siRNA and then subjected to immunofluorescence assay. The observed results confirmed the contribution and activation of these two molecules is required for the induction of autophagy. Interestingly, no significant changes were obseverved either in the cell cycle regulation or in induction of apoptosis, which revealed that the activation of autophagy may be responsible for NA mediated growth inhibition in breast cancer cells. Currently, we are planning to conduct xenograft studies, which may suggest the in vivo efficacy and pharmacokinetic potential of NA. The present study concludes that NA could be a potential agent either alone or in combination with other chemotherapeutic agents with a novel strategy to combat breast cancer. Citation Format: Ramadevi Subramani Reddy, Pallab Pahari, Chendil Damodaran. Induction of Autophagy by a novel agent promotes the growth arrest in breast cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1668. doi:10.1158/1538-7445.AM2013-1668