Wang Tao, Liu Zi, Shi Fan, Wang Jiquan
Department of Radiaton Oncology, First Hospital of Xi'an Jiaotong University, Xi'an, 710061, China.
Mol Cell Biochem. 2016 Feb;413(1-2):179-87. doi: 10.1007/s11010-015-2651-4. Epub 2016 Jan 28.
The prolyl isomerase Pin1, which is frequently highly expressed in many different cancers, can directly regulate cell proliferation and the cell cycle. However, the role of Pin1 in chemo-resistance remains to be elucidated in cervical cancer. The purpose of the present study was to investigate the role of Pin1 in the chemo-resistance of cervical cancer. The cisplatin resistance was assessed using the MTT assay. Pin1, FoxM1, β-catenin, Cyclin D1, and c-myc expression levels were detected by RT-qPCR or Western blot. The results showed that Pin1 expression displayed a similar expression pattern with the resistance to cisplatin in five cervical cell lines. Knockdown of Pin1 significantly increased the sensitivity to cisplatin in HeLa cells, while Pin1 overexpression decreased the sensitivity to cisplatin in Me180 cells. Knockdown of Pin1 significantly down-regulated FoxM1 expression in HeLa cells, while Pin1 overexpression showed a contrary effect in Me180 cells. Besides, overexpression of Pin1 markedly increased the protein expression of β-catenin and its target genes cyclin D1 and c-myc. FoxM1 siRNA remarkably reversed the promotory effect of pcDNA-Pin1(+) on β-catenin and its target genes cyclin D1 and c-myc in Me180 cells. Furthermore, we also found that FoxM1 siRNA and IWP-2 markedly decreased cell viability, and IWP-2 decreased cell viability to the maximum extent in the Me180 cells co-transfected with pcDNA-Pin1(+) and FoxM1 siRNA. Taken together, these data suggest that Pin1 contributes to cisplatin resistance, partly by up-regulating FoxM1 and Wnt/β-catenin signaling pathway involved in cervical cancer.
脯氨酰异构酶Pin1在许多不同癌症中常常高表达,它可直接调控细胞增殖和细胞周期。然而,Pin1在宫颈癌化疗耐药中的作用仍有待阐明。本研究的目的是探讨Pin1在宫颈癌化疗耐药中的作用。采用MTT法评估顺铂耐药性。通过RT-qPCR或蛋白质印迹法检测Pin1、FoxM1、β-连环蛋白、细胞周期蛋白D1和c-myc的表达水平。结果显示,在5种宫颈癌细胞系中,Pin1表达与顺铂耐药呈现相似的表达模式。敲低Pin1可显著增加HeLa细胞对顺铂的敏感性,而Pin1过表达则降低Me180细胞对顺铂的敏感性。敲低Pin1可显著下调HeLa细胞中FoxM1的表达,而Pin1过表达在Me180细胞中则呈现相反的作用。此外,Pin1过表达显著增加β-连环蛋白及其靶基因细胞周期蛋白D1和c-myc的蛋白表达。FoxM1 siRNA可显著逆转pcDNA-Pin1(+)对Me180细胞中β-连环蛋白及其靶基因细胞周期蛋白D1和c-myc的促进作用。此外,我们还发现,FoxM1 siRNA和IWP-2可显著降低细胞活力,在共转染pcDNA-Pin1(+)和FoxM1 siRNA的Me180细胞中,IWP-2对细胞活力的降低作用最大。综上所述,这些数据表明,Pin1通过上调参与宫颈癌的FoxM1和Wnt/β-连环蛋白信号通路,部分促进了顺铂耐药。