The Mechanisms Governing Antileukemic Action Of BCL-2Inhibitor Of ABT-737Alone And Enhanced Cytotoxicity Of ABT-737Plus HHT In AML Cell (Kasumi-1)

Objective:1、To observe the anti-proliferative and pro-apoptotic effects of ABT-737onKasumi-1cell line and explore the underlying mechanisms.2、To observe the interaction of HHT and ABT-737in Kasumi-1cell andinvestigate the underlying mechanisms.Methods:1、The human AML Kasumi-1cell line was incubated conventionally, and thecells in logarithmic growth phase were used to perform study.2、CCK-8assay was employed to evaluate the effects of ABT-737on theproliferative inhibition of Kasumi-1cells after treated by various concentrations ofABT-737for24~72h.3、AnnexinV-FITC/PI staining was employed to examine the apoptosis ofKasumi-1cells incubating in various concentration of ABT-737for24h.4、Western blot method was used to detect the PARP、BCL-2、BAX proteinexpression of Kasumi-1cells which is treated by various concentrations of ABT-737for24h.5、The proliferative and apoptotic rate were examined with HHT alone, ABT-737alone and HHT plus ABT-737exposure to Kasumi-1cell for24h via CCK-8andAnnexinV-FITC/PI staining respectively. The interaction of HHT and ABT-737wasfurther analysed.6、qRT-PCR and Western blot methods were used to analyze the level of MCL-1mRNA and protein in Kasumi-1cell after treated with HHT alone, ABT-737aloneand cotreatment of both for24h.Results：1、ABT-737inhibited the proliferation of Kasumi-1cellssin dose-dependentmanner within0.625~10umol/L（P<0.05）. Within24~72h, ABT737caused thetime-dependent inhibition of proliferation in Kasumi-1cells.2、ABT-737treatment at the dose of0.625~10umol/L for24h cause the concentration-dose apoptosis of Kasumi-1cells (P<0.01).3、ABT-737treatment of Kasumi-1cells for24h caused cleavage of PARPsignificantly in concentration-dependent fashion..4、ABT-737induced cell apoptosis of Kasumi-1cell via suppressing BCL-2and upregulaing BAX.5、Compared with ABT (0.635umol/L) or HHT (36nmol/L) alone, HHT plusABT-737markedly inhibited the proliferation of Kasumi-1cell. The interactionanalysis indicated the additive effect.6、The apoptosis rate triggered by HHT plus ABT-737was markedly higher thanthat of HHT or ABT-737treatment alone. the MCL-1level was upregulated byABT-737treatment alone, while was downregulated by HHT treatment alone. HHT incombination with ABT-737substantially inhibited the level MCL-1compared withABT-737or HHT alone..Conclusion：1、 ABT-737exerted antiproliferative and proapoptotic activity againstKasumi-1cell in concentration-dependent manner.2、The proappototic effect of ABT-737on Kasumi-1cell was attributed todownregulation of BCL-2and upregulation of BAX.3、HHT augumented the antileukemic action of ABT-737against Kasumi-1cell.4、The additive effect of HHT plus ABT-737on Kasumi-1cell was ascribed toinhibiting MCL-1by HHT which was induced by ABT-737.