Oncogenic microRNA-27a is a target for anticancer agent methyl 2-cyano-3,11-dioxo-18beta-olean-1,12-dien-30-oate in colon cancer cells

Abstract

Methyl 2-cyano-3,11-dioxo-18beta-olean-1,12-dien-30-oate (CDODA-Me) is a synthetic derivative of glycyrrhetinic acid, a triterpenoid phytochemical found in licorice extracts. CDODA-Me inhibited growth of RKO and SW480 colon cancer cells and this was accompanied by decreased expression of Sp1, Sp3 and Sp4 protein and mRNA and several Sp-dependent genes including survivin, vascular endothelial growth factor (VEGF), and VEGF receptor 1 (VEGFR1 or Flt-1). CDODA-Me also induced apoptosis, arrested RKO and SW480 cells at G(2)/M, and inhibited tumor growth in athymic nude mice bearing RKO cells as xenografts. CDODA-Me decreased expression of microRNA-27a (miR-27a), and this was accompanied by increased expression of 2 miR-27a-regulated mRNAs, namely ZBTB10 (an Sp repressor) and Myt-1 which catalyzes phosphorylation of cdc2 to inhibit progression of cells through G(2)/M. Both CDODA-Me and antisense miR-27a induced comparable responses in RKO and SW480 cells, suggesting that the potent anticarcinogenic activity of CDODA-Me is due to repression of oncogenic miR-27a.