RNA结合蛋白QKI-5表达对人头颈鳞癌细胞株的影响

Effects of RNA-binding protein quaking 5 on proliferation and cell cycle of head and neck cancer cell lines

目的研究QKI-5对人头颈鳞癌细胞株的生长抑制作用。方法采用Western blot和免疫组化方法检测人头颈鳞癌临床组织样本中的QKI-5的蛋白表达情况。常规培养舌鳞癌SCC15细胞、舌鳞癌SCC25细胞和头颈鳞癌PCI13细胞,以5×104/ml的密度种植细胞。采用Western blot和反转录聚合酶链反应(RT-PCR)检测三种头颈鳞癌细胞株中的QKI-5的蛋白和mRNA表达情况。采用病毒介导QKI-5在SCC25细胞中过表达和在PCI13细胞中沉默QKI-5。采用MTT法和流式细胞法检测SCC25细胞中过表达QKI-5和在PCI13细胞中沉默QKI-5的细胞增殖和凋亡情况。采用Western blot方法检测SCC25细胞中过表达QKI-5和PCI13细胞中沉默QKI-5中细胞周期蛋白D1(Cyclin D1)、CDK4、P27、PARP-cleaved蛋白的表达情况。结果 SCC15和SCC25细胞中QKI-5的蛋白和mRNA表达水平较低,而PCI13细胞中的QKI-5蛋白和mRNA表达水平较高。采用病毒介导的QKI-5过表达后,SCC25细胞中QKI-5的蛋白和mRNA水平显著增加。采用病毒介导的QKI-5沉默后,PCI13细胞中QKI-5的蛋白和mRNA水平显著减少。SCC25细胞中过表达QKI-5后,细胞增殖减少(P<0.05),细胞多停留在G0/G1期,而凋亡增加,同时Cyclin D1和CDK4表达水平下调(P<0.05),P27和PAPR-clevead蛋白表达水平上调(P<0.05)。PCI13细胞中的QKI-5被沉默后,细胞增殖增加(P<0.05),细胞多进入S期,而凋亡减少,同时Cyclin D1和CDK4表达水平上调(P<0.05),P27和PARP-cleaved表达水平下调(P<0.05)。结论 QKI-5的表达可对人头颈鳞癌细胞增殖产生抑制作用。

Objective To study the inhibition of QKI-5 on human head and neck cancer cell lines in vitro. Methods Western blot and immunohistochemistry were performed to detect the expression of QKI-5 in the human tongue squamous-cell carcinoma samples. Head and neck cancer cells line PCI13 and tongue squamous cell carcinoma cells lines SCC15 and SCC25 were cultured by the density of 5 × 10^4/ ml. Western blot and RT-PCR were used to detect the expression levels of protein and mRNA of QKI-5 in the three cell lines. Using viral to mediate QKI-5 overexpressing in SCC25 cells and silencing in PCI13 cells. MTT method and flow cytometry assay were conducted to detect the proliferation and apoptosis of SCC25 cells with QKI-5 overexpressing and PCI13 cells with QKI-5silencing. Western blot was used for the detection of cyclin D1, CDK4, P27, and PARP-cleaved in SCC25 cells with QKI-5 overexpressing and PCI13 cells with QKI-5 silencing. Results The RNA and protein expression levels of QKI-5 were relatively low in SCC15 and SCC25 cells, while in which the PCI13 cells was higher. Protein and RNA levels of QKI-5 increased significantly after viral mediated overexpression in SCC25 cells, and which were decreased significantly after virus mediated QKI-5silencing in PCI13 cells. After overexpression of QKI-5 in SCC25 cells, the proliferation of SCC25 decreased, and most cells stayed in the G0/ G1 phase, while cell apoptosis increased（P〈0.05）, the expression level of cyclin D1 and CDK4 decreased（P〈0.05） and the expression level of P27 and PAPR-cleaved increased（P〈0.05）. After QKI-5 silencing in PCI13 cells, the cell proliferation of PCI13 increased（P〈0.05）, most cells went into S phase, while apoptosis decreased, and the expression level increased in cyclin D1 and CDK4（P〈0.05）, and decreased in P27 and PARP-cleaved（P〈0.05）.Conclusions QKI-5 could inhibit the proliferation of head and neck cancer cells.