TSA可能通过抑制APE1BER功能增强顺铂的肺腺癌细胞毒性

Trichostatin A enhances cisplatin-induced cytotoxicity through inhibiting base excision repair of AP endonuclease in lung adenocarcinoma cells

目的探讨曲古抑菌素A(trichostatin A,TSA)对顺铂诱导的细胞毒性的影响。方法给予0、250、500 nmol/L TSA预处理A549细胞24 h后,分别联合0、5、10、15μmol/L顺铂处理A549细胞24 h后,通过0、0.5、1、2μmol/L APE1 InhibitorⅢ调控APE1 BER功能,应用CCK-8方法检测细胞增殖率,AP内切酶活性实验检测APE1 BER功能,通过流式细胞仪检测细胞凋亡水平,immunoblot检测γ-H2AX表达水平。结果 TSA联合顺铂处理A549细胞明显增强顺铂的细胞增殖抑制,并促进顺铂诱导的细胞凋亡;随着TSA浓度的升高APE1内切酶活性逐渐减弱,TSA联合顺铂促进顺铂诱导的γ-H2AX表达;利用inhibitorⅢ抑制APE1内切酶活性,促进顺铂诱导细胞增殖抑制和凋亡水平。结论TSA可能通过抑制APE1BER功能增强顺铂诱导的细胞毒性反应。

Objective To determine the effect of trichostatin A （TSA） on the cytotoxicity induced by cisplatin in lung adenocarcinoma A549 cells. Methods After the A549 cells were pretreated with TSA at 0, 250 and 500 nmol/L for 24 h, the cells were treated by cisplatin at 0, 5, 10 and 15 μmol/L for another 24 h. CCK-8 assay and flow cytometry were used to detect cell proliferation and apoptosis respectively. The effect of AP endonuclease （APE1） Inhibitor 11 （0, 0.5, 1 and 2 μmoL/L） was determined by AP endonuclease activity assay for the activity of base excision repair （BER）. The expression of γ-H2AX was measured by immunoblotting. Results TSA enhances the inhibitory effect of cisplatin on cell proliferation and its promoting effect on cell apoptosis. With the increased of TSA dose, the BER activity of APE1 was gradually decreased. TSA also improved the expression of γ-H2AX induced by cisplatin. APE1 inhibitor 11 suppressed the activity of endonuclease, and enhanced the cell proliferation and apoptosis induced by cisplatin. Conclusion TSA enhances cytotoxicity response caused by cisplatin through inhibiting the BER activity of APE1.