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

关键词:  人乳腺癌MCF-7细胞  毛酸浆内酯  细胞凋亡  信号转导和转录激活因子3

Key words:  human breast cancer MCF-7 cell  Physapubescin  apoptosis  TAT3

摘要:

[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。

Abstract:

[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.