PT - JOURNAL ARTICLE AU - Indira Jutooru AU - Gayathri Chadalapaka AU - Maen Abdelrahim AU - Md. Riyaz Basha AU - Ismael Samudio AU - Marina Konopleva AU - Michael Andreeff AU - Stephen H. Safe TI - Methyl 2-Cyano-3,12-dioxooleana-1,9-dien-28-oate (CDDO-Me) Decreases Specificity Protein (Sp) Transcription Factors and Inhibits Pancreatic Tumor Growth: Role of MicroRNA-27a AID - 10.1124/mol.110.064451 DP - 2010 Jan 01 TA - Molecular Pharmacology PG - mol.110.064451 4099 - http://molpharm.aspetjournals.org/content/early/2010/05/20/mol.110.064451.short 4100 - http://molpharm.aspetjournals.org/content/early/2010/05/20/mol.110.064451.full AB - The anticancer agent 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid (CDDO) and its methyl ester (CDDO-Me) typically induce a broad spectrum of growth inhibitory, proapototic and antiangiogenic responses. Treatment of Panc1, Panc28 and L3.6pL pancreatic cancer cells with low μM concentrations of CDDO or CDDO-Me resulted in growth inhibition, induction of apoptosis, and downregulation of cyclin D1, survivin, vascular endothelial growth factor (VEGF) and its receptor (VEGFR2). RNA interference studies indicate that these repressed genes are regulated by specificity protein (Sp) transcription factors Sp1, Sp3 and Sp4, and western blot analysis of lysates from pancreatic cancer cells treated with CDDO and CDDO-Me shows for the first time that both compounds decreased expression of Sp1, Sp3 and Sp4. Moreover, CDDO-Me (7.5 mg/kg/day) also inhibited pancreatic human L3.6pL tumor growth and downregulated Sp1, Sp3 and Sp4 in tumors using an orthotopic pancreatic cancer model. CDDO-Me also induced reactive oxygen species (ROS) and decreased mitochondrial membrane potential (MMP) in Panc1 and L3.6pL cells, and cotreatment with antioxidants (glutathione and dithiothreitol) blocked formation of ROS, reversed the loss of MMP, and also inhibited downregulation of Sp1, Sp3 and Sp4. Repression of Sp and Sp-dependent genes by CDDO-Me was due to downregulation of microRNA-27a and induction of ZBTB10, an Sp repressor, and these responses were also reversed by antioxidants. Thus, the anticancer activity of CDDO-Me is due, in part, to activation of ROS which in turn targets the microRNA-27a:ZBTB10-Sp transcription factor axis. This results in decreased expression of Sp-regulated genes, growth inhibition, induction of apoptosis, and antiangiogenic responses.The American Society for Pharmacology and Experimental Therapeutics