Polyphenol tri-vanillic ester 13c inhibits P-JAK2V617F and Bcr-Abl oncokinase expression in correlation with STAT3/STAT5 inactivation and apoptosis induction in human leukemia cells.

Constitutive activity of kinases has been reported in many types of cancers, so that inhibition of "onco-kinases" became a validated anti-cancer strategy. We found that the polyphenol 13c, a tri-vanillate derivative, inhibited kinase phosphorylation in leukemia cells. P-JAK2, P-Src and P-PI3Kp85 inhibition occurred independently of phosphatase involvement in JAK2V617F expressing HEL cells while 13c inhibited Bcr-Abl expression without inhibition of phosphorylation in chronic myelogenous leukemia cell lines (K562, MEG-01). In correlation with kinase inhibition, 13c abolished constitutive P-STAT3/P-STAT5 expression, down-regulated Mcl-1 and c-Myc gene expression and induced apoptosis. Altogether, polyphenol 13c displays potential antitumor activities by affecting onco-kinases and STAT activities.