Li Xiao-Yu, Luo Qi-Feng, Wei Chuan-Kui, Li Deng-Feng, Fang Lin
Department of Breast and Thyroid Surgery, Shanghai Tenth People's Hospital, Tongji University Shanghai, 200072, China.
Int J Clin Exp Pathol. 2013 Dec 15;7(1):92-100. eCollection 2014.
CDK8 is a cyclin-dependent kinase (CDK) member of the mediator complex that couples transcriptional regulators to the basal transcriptional machinery, and it has been investigated for possible tumor promoting functions. However, it is unclear whether CDK8 is involved in breast tumor cells growth. The aim of this study was to determine whether the suppression of CDK8 by small interfering RNA (siRNA) inhibits the growth of human breast cancer cell.
CDK8-siRNA transfection was used to silencing the CDK8 gene in established breast cancer cell line, MDA-MB-231 and MCF-7, successful transfection being confirmed by Real-time PCR and could be shown by Western Blotting. CDK8 deletion caused significant decline in cell proliferation was observed in breast cancer cell lines as investigated by MTS assay, the number and size of the colonies formed were also significantly reduced in the absence of CDK8. Furthermore, transwell test were conducted to explore the migration of breast cancer cells. Moreover CDK8 gene knockdown arrested cell cycle.
CDK8 mRNA expression was reduced after transfection with CDK8-siRNA, and protein expression had a similar trend. Transfection of CDK8-siRNA suppressed breast cancer cells proliferation and migration; meanwhile the cells were arrested at G0/G1 phase.
CDK8 plays an essential role in breast cancer progression, which might inhibit the proliferation and migration in breast cancer cells.
CDK8是中介体复合物的一种细胞周期蛋白依赖性激酶（CDK）成员，它将转录调节因子与基础转录机制偶联起来，并且其促肿瘤功能已得到研究。然而，CDK8是否参与乳腺肿瘤细胞的生长尚不清楚。本研究的目的是确定小干扰RNA（siRNA）抑制CDK8是否会抑制人乳腺癌细胞的生长。
采用CDK8-siRNA转染在已建立的乳腺癌细胞系MDA-MB-231和MCF-7中沉默CDK8基因，通过实时PCR确认成功转染，并通过蛋白质印迹法显示。通过MTS测定法研究发现，在乳腺癌细胞系中观察到CDK8缺失导致细胞增殖显著下降，在没有CDK8的情况下形成的集落数量和大小也显著减少。此外，进行Transwell试验以探究乳腺癌细胞的迁移。而且CDK8基因敲低使细胞周期停滞。
用CDK8-siRNA转染后，CDK8 mRNA表达降低，蛋白质表达也有类似趋势。CDK8-siRNA转染抑制了乳腺癌细胞的增殖和迁移；同时细胞停滞在G0/G1期。
CDK8在乳腺癌进展中起重要作用，可能抑制乳腺癌细胞的增殖和迁移。
