ABT-263 induced A431 cell apoptosis and its effect on AKT downstream signaling pathway / 中国职业医学

ABSTRACT

OBJECTIVE: To investigate the effect of ABT-263,an anti-apoptotic protein inhibitor,on human cutaneous squamous cell carcinoma A431 cells,and to explore its molecular mechanisms. METHODS: i) Total protein was extracted from human immortalized epidermal cells( Ha Ca T cells) and A431 cells in logarithmic growth phase. The protein expression of B-cell lymphoma-2( BCL-2) and BCL2-like 1( BCL-XL) was detected by Western blotting. ii) The A431 cells were treated with ABT-263( inhibitor group) and dimethyl sulfoxide( control group) at a concentration of 50 μmol/L for 4 and 9 hours. The morphological changes of the cells were examined by transmission electron microscopy. iii) The A431 cells were treated with 0,10,25,40,and 50 μmol/L of ABT-263 for 24 hours,and the cell viability was determined by CCK-8 assay. iv) The A431 cells were treated with different doses of ABT-263,and the expression of cleaved Caspase-3, cleaved poly( ADP-ribose) polymerase-1( PARP-1), phosphorylated protein kinase B [p AKT(ser473)],phosphorylated glycogen synthase kinase-3β(p GSK3β) and phosphorylated histone H2 AX(γH2 AX) was detected by Western blot. RESULTS: The relative expression of BCL-2 and BCL-XL in A431 cells were higher than those in Ha Ca T cells( P < 0. 01). Transmission electron microscopy results showed that A431 cells in inhibitor group gradually changed from normal morphology to apoptotic morphology,showing loss of microvilli,increased nuclear chromatin density and aggregation around the nuclear membrane,and nuclear fragmentation. The cell viability of A431 cells in 10,25,40 and 50 μmol/L groups were lower than those in control group( P < 0. 05). The relative expression of cleaved Caspase-3 and cleaved PARP-1 in A431 cells in 10,30 and 50 μmol/L groups were higher than those in control group( P < 0. 05).The relative expression of p AKT( ser473) and p GSK3β in A431 cells in 10,25,40 and 50 μmol/L groups were lower than those of the control group( P < 0. 05) and γH2 AX protein expression was higher than that of the control group( P <0. 05). A431 cell viability and p GSK3β protein expression decreased with the increase of inhibitor dosage( P < 0. 01).The relative expression of cleaved Caspase-3 and γH2 AX protein increased with the increase of inhibitor dosage( P <0. 01),showing dose-effect relationship. CONCLUSION: ABT-263 can induce apoptosis of A431 cells through mitochondria pathway and induce the inactivation of AKT/GSK3β pathway,which can promote the apoptosis of A431 cells with a doseeffect relationship.