Curcumin derivative C085 inhibits proliferation of K562/G01 cells and activity of Bcr-Abl kinase in vitro / 中国药理学通报

ABSTRACT

Aim To find new kinase inhibitors that o-vercome the imatinib resistance in the treatment of chronic myeloid leukemia ( CML ) by synthesizing C085, a novel derivative of curcumin , and testing its activities against wild-type( WT) and imatinib-resistant mutant Abl kinases , as well as in imatinib-resistant CML cells in vitro.Methods Cell proliferation and apoptosis were examined using MTT assay and flow cy-tometry, respectively;Kinase activity was measured u-sing Kinase-Glo Luminescent Kinase Assay Platform in recombinant WT and mutant ( Q252H, Y253F, and T315I) Abl kinases.The phosphorylation levels of Bcr-Abl initiated signaling proteins were analyzed using Western blotting .Colony forming units ( CFU ) growth was used to test the effects of C 085 on human leukemia progenitor/stem cells.Results C085 suppressed the growth of imatinib-resistant K562/G01 cells and po-tently inhibited both WT and mutant ( Q252H, Y253F, and T315I) Abl kinase activities in a non-ATP com-petitive manner with the values of IC 50 at low nanomole levels.C085 dose-dependently down-regulated Bcr-Abl kinase activity in K562/G01 cells as judged by auto-phosphorylation and Stat 5 , Crkl phosphorylation , and inhibited the phosphorylation of downstream targets Raf,Mek and Erk with protein content reducing .C085 could directly impact mitochondrial PT hole and make it open, which prevents the activation of caspase cas-cade reaction and induces the apoptosis .Furthermore, C085 significantly suppressed CFU growth , implicating that C085 could inhibit human leukemia progenitor/stem cells.Conclusion C085 may inhibit K562/G01 cells through inhibiting Bcr-Abl kinase activity and down-regulating the downstream signal proteins .Di-rectly acting on mitochondrial PT hole and then activa-ting apoptosis-associated proteins are also involved in the pro-apoptotic effect of C085.C085 is a promising compound for the treatment of CML patients with Bcr-Abl kinase domain mutations that confer imatinib re-sistance .