Abstract 939: Chemoprevention of familial adenomatous polyposis by EM011 in the ApcMin/+ mouse model

Abstract

Abstract Abstract Germline mutation of the tumor suppressor gene, adenomatous polyposis coli (APC), is responsible for familial adenomatous polyposis (FAP) with nearly 100% risk for colon cancer at an early age. Although FAP is involved in only 1% of all colon cancer cases, over 80% of sporadic cancers harbor somatic mutations of APC. We show here that 9-bro-noscapine (EM011), a rationally-designed synthetic derivative of a natural non-toxic tubulin-binding alkaloid−noscapine, that reduces the dynamics of microtubules, causes a reversible G2/M arrest in wild type mouse embryonic fibroblasts (MEFs), but an aberrant exit from a brief mitotic block, followed by apoptosis in MEFs isolated from ApcMin/+ mice. Furthermore, both β-catenin levels and activity fell to half the original levels with a concomitant reduction of cell proliferation-inducing cyclin D1, c-Myc, and induction of cytostatic protein p21 prior to caspase-3 activation. Additionally, we show a statistically significant reduction in the number of newly emerging intestinal polyps (to 35% compared with untreated mice) as well as the mean size of polyps (to 42% compared with untreated mice) in EM011-treated ApcMin/+ mice as compared to their sham-treated control littermates. The remaining polyps in the EM011 treated group of ApcMin/+ mice showed evidence of elevated apoptosis as revealed by immunohistochemistry. We failed to detect any evidence of histopathological and hematological toxicities following EM011 treatment. Taken together, our data are persuasive that a clinical trial of EM011 is possible for the prevention/amelioration of polyposis in FAP patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 939.