毛酸浆内酯通过抑制STAT3诱导人乳腺癌MCF-7细胞凋亡

Physapubescin induced human breast cancer MCF-7 cells apoptosis by inhibiting STAT3

[目的]旨在探讨信号转导和转录激活因子3(STAT3)在毛酸浆内酯(PPB)诱导人乳腺癌MCF-7细胞凋亡中发挥的作用。[方法]采用荧光染色法分析PPB诱导MCF-7细胞凋亡;使用生物信息学方法预测PPB抗乳腺癌的潜在机制;采用噻唑蓝(MTT)法考察STAT3抑制剂S3I-201以及STAT3小干扰RNA(siRNA)对PPB抑制MCF-7细胞生长的作用;采用蛋白免疫印迹(Western Blot)法考察PPB单独处理或STAT3 siRNA预处理后对MCF-7细胞中STAT3、B淋巴细胞瘤-2(Bcl-2)、Bcl-2相关X蛋白(Bax)、半胱氨酸天冬氨酸蛋白酶8(Caspase8)、半胱氨酸天冬氨酸蛋白酶9(Caspase9)、细胞色素c(Cytochrome c)以及多聚ADP核糖聚合酶(PARP)蛋白表达的影响。[结果]MCF-7细胞经PPB作用后凋亡形态特征明显,凋亡比例上升;生物信息学结果显示PPB与乳腺癌疾病的共同靶点STAT3在乳腺癌组织中高表达,单基因GSEA结果提示STAT3高表达与凋亡信号通路呈负相关;Western Blot法检测结果显示PPB能够抑制STAT3的磷酸化;S3I-201抑制剂或siRNA敲降STAT3均能进一步促进PPB抑制MCF-7细胞生长;此外,敲降STAT3进一步增加PPB对促凋亡蛋白Bax、Cytochrome c、裂解的Caspase8(Cleaved-Caspase8)、裂解的Caspase9(Cleaved-Caspase9)以及裂解的PARP(Cleaved-PARP)的促进作用,并增加PPB对抗凋亡蛋白Bcl-2的抑制作用。[结论]PPB通过抑制STAT3诱导人乳腺癌MCF-7细胞凋亡。

[Objective]This study determined the role of signal transducer and activator of transcription 3(STAT3)in Physapubescin(PPB)induced apoptosis in the human breast cancer MCF-7 cells.[Methods]The fluorescent stain technology was used to analyze that PPB induced MCF-7 cells apoptosis.The potential mechanisms of PPB against breast cancer were predicted by bioinformatics analysis.The MTT assay was used to investigate the effects of STAT3 inhibitor S3I-201 and STAT3 small interfering RNA(siRNA)on the inhibition of MCF-7 cell growth by PPB.The effects of PPB alone or pretreatment with STAT3 siRNA on the expression of STAT3,B-cell lymphoma-2(Bcl-2),Bcl-2 Associated X protein(Bax),Caspase8,Caspase9,Cytochrome c and poly polymerase(PARP)proteins in MCF-7 cells were detected by Western Blot.[Results]The apoptotic morphology of MCF-7 cells was distinctly characterized by the effect of PPB,and the apoptosis ratio was significantly increased.The bioinformatics analysis showed that STAT3,a common target of PPB and breast cancer disease,was highly expressed in breast cancer tissues,and single-gene GSEA results suggested that high STAT3 expression was negatively correlated with the apoptotic signaling pathway.The results of Western Blot showed that PPB could inhibit STAT3 phosphorylation.The S3I-201 inhibitor or STAT3 siRNA could further promote PPB to inhibit MCF-7 cell growth.In addition,knockdown of STAT3 further increased the up-regulation of PPB on the pro-apoptotic proteins Bax,Cytochrome c,Cleaved-Caspase8,Cleaved-Caspase9,and Cleaved-PARP,meanwhile the inhibitory effect of PPB on the expression of anti-apoptotic protein Bcl-2 was enhanced by treatment with STAT3 siRNA.[Conclusion]PPB induced human breast cancer MCF-7 cells apoptosis by inhibiting STAT3.