越来越多的证据(主要来自实验研究)表明,二甲双胍通过诱导细胞凋亡和抑制癌细胞的生长和增殖而具有抗癌特性。然而,它对负责组蛋白乙酰化状态的酶的影响,在致癌过程中起着关键作用,尚不清楚。因此,我们研究的目的是评估二甲双胍对组蛋白乙酰转移酶(HAT)的影响(即,p300/CBP相关因子(PCAF),p300和CBP)和组蛋白脱乙酰酶(HDAC)(即,人胰腺癌(PC)细胞系中的SIRT-1,1.2B4和PANC-1)。细胞暴露于二甲双胍,HAT抑制剂(HATi),或HATi与二甲双胍的组合24、48或72小时。使用MTT测定确定细胞活力,用膜联蛋白V-Cy3凋亡检测试剂盒测定早期凋亡细胞的百分比。还评估了胱天蛋白酶-9活性。SIRT-1,PCAF,使用RT-PCR和蛋白质印迹方法在mRNA和蛋白质水平上确定p300和CBP表达,分别。我们的结果表明,二甲双胍对caspase-9的反应增加,表明它诱导了1.2B4和PANC-1细胞的凋亡死亡。当单独使用HATi或HATi与二甲双胍的组合治疗时,早期凋亡中的细胞数量和caspase-9的活性降低,与单独的二甲双胍相比。此外,二甲双胍,一个HATI,HATi与二甲双胍的组合也修饰了SIRT-1,PCAF的mRNA表达,CBP,p300然而,二甲双胍没有改变1.2B4细胞中研究基因的表达。Westernblot分析结果显示二甲双胍可降低1.2B4和PANC-1细胞中PCAF的蛋白表达。因此,PCAF可能参与了二甲双胍介导的PC细胞凋亡。
Accumulating evidence (mainly from experimental research) suggests that metformin possesses anticancer properties through the induction of apoptosis and inhibition of the growth and proliferation of cancer cells. However, its effect on the enzymes responsible for histone acetylation status, which plays a key role in carcinogenesis, remains unclear. Therefore, the aim of our study was to evaluate the impact of metformin on histone acetyltransferases (HATs) (i.e., p300/CBP-associated factor (PCAF), p300, and CBP) and on histone deacetylases (HDACs) (i.e., SIRT-1 in human pancreatic cancer (PC) cell lines, 1.2B4, and PANC-1). The cells were exposed to metformin, an HAT inhibitor (HATi), or a combination of an HATi with metformin for 24, 48, or 72 h. Cell viability was determined using an MTT assay, and the percentage of early apoptotic cells was determined with an Annexin V-Cy3 Apoptosis Detection Assay Kit. Caspase-9 activity was also assessed. SIRT-1, PCAF, p300, and CBP expression were determined at the mRNA and protein levels using RT-PCR and Western blotting methods, respectively. Our results reveal an increase in caspase-9 in response to the metformin, indicating that it induced the apoptotic death of both 1.2B4 and PANC-1 cells. The number of cells in early apoptosis and the activity of caspase-9 decreased when treated with an HATi alone or a combination of an HATi with metformin, as compared to metformin alone. Moreover, metformin, an HATi, and a combination of an HATi with metformin also modified the mRNA expression of SIRT-1, PCAF, CBP, and p300. However, metformin did not change the expression of the studied genes in 1.2B4 cells. The results of the Western blot analysis showed that metformin diminished the protein expression of PCAF in both the 1.2B4 and PANC-1 cells. Hence, it appears possible that PCAF may be involved in the metformin-mediated apoptosis of PC cells.