The effect of knockdown of CaMKIIα on the CDDO-Me induced apoptosis in human ESCC cells. A. Percentages of specific cell populations showed in dot plots and apoptotic cells showed in bar graphs for the silencing of CaMKIIα in Ec109 and KYSE30 cells with or without 0.5 μM CDDO-Me treatment for 24 hours. B. Representative blots of bcl-2, bax, and cleaved caspase-3 for the proteinlysate samples, which were prepared from Ec109 and KYSE30 cells treated with CaMKIIα siRNAs or 0.5 μM CDDO-Me for 24 hours. Abbreviation: CaMKIIα, calcium/calmodulin-dependent protein kinase type II subunit alapha; CDDO-Me, methyl ester of 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid; ESCC, esophageal squamous cell carcinoma; bcl-2, B-cell lymphoma-2; bax, bcl-2 associated X protein; siRNA , small interfering RNA.