细胞周期相关转录因子Cks1调控UbcH10促进胶质瘤染色体不稳的机制研究

Our previous work has demonstrated that expression of spindle assembly checkpoint protein UbcH10 correlates positively with the pathological grade of glioma. Overexpression of UbcH10 in glioma cells may override the checkpoint, induce immature segregation of chromosomes, and thus lead to chromosome instability of glioma cells. Knockdown of Cks1 expression in glioma cells via RNA interference may inhibit the growth rate of glioma cells and induce G2/M arrest of the cell cycle. In addition, our study suggested that Cks1, a cell cycle related transcription factor, is a potential transcription regulator of UbcH10 gene and Cks1 may compromise the mitotic checkpoint function and promote chromosome instability via inducing UbcH10 expression in glioma cells. The above-mentioned work has now been partly published in Brain Research, Journal of Cancer Research and Clinical Oncology and Journal of Surgical Oncology. In this study, firstly, the regulatory mechanisms of UbcH10 biosynthesis mediated by Cks1 were investigated by using luciferase reporter assay and ChIP assay. Secondly, the mechanisms of chromosome instability mediated by Cks1 via inducing UbcH10 expression were investigated by using RNA interference and chromosome karyotyping analysis. Finally, in vivo study and retrospective clinical study were employed to verify the regulatory mechanisms of Cks1 on UbcH10 biosynthesis and the association with chromosome instability. These results may demonstrate the mechanisms of chromosome instability mediated by Cks1 via inducing UbcH10 expression and may offer potential therapeutic targets for the molecular intervention of chromosome instability.

前期研究发现UbcH10表达与胶质瘤恶性程度密切相关，其可通过终止G2/M检验点促进染色体不稳；敲减UbcH10表达，可抑制胶质瘤细胞增殖并阻滞于G2/M期。此外，研究提示转录因子Cks1可能通过调控UbcH10表达促进胶质瘤染色体不稳。上述结果已发表于Brain Research、Journal of Cancer Research and Clinical Oncology、Journal of Surgical Oncology等杂志。本课题拟应用荧光素酶活性检测、ChIP等方法，探讨Cks1对UbcH10的转录调控作用，通过RNA干扰、染色体谱分析等试验，研究Cks1通过UbcH10促进染色体不稳的机制，并应用体内试验验证Cks1对UbcH10的调控及与染色体不稳的关联。研究有望阐明Cks1通过UbcH10促进染色体不稳的机制，可能为胶质瘤染色体不稳的分子干预提供潜在治疗靶点。

胶质瘤是成人中枢神经系统最常见的恶性肿瘤。前期研究中发现UbcH10表达与胶质瘤的恶性程度密切相关，其可通过G2/M期检验点促进染色体不稳；敲减UbcH10表达后，可抑制胶质瘤细胞增殖并使细胞周期阻滞的G2/M期。我们又发现转录因子调控蛋白Cks1可能通过UbcH10的表达促进胶质瘤染色体不稳。本次研究采用临床胶质瘤样本分析Cks1表达水平与胶质瘤恶性级别的关系；选取U87、U251细胞系研究Cks1对胶质瘤细胞的增殖、凋亡及周期的作用；探索Cks1与UbcH10的具体调控关系；动物实验验证Cks1对肿瘤形成的影响作用；结合临床指标分析Cks1与胶质瘤患者预后及生存关联。我们在研究中发现敲减Cks1后胶质瘤细胞出现增殖能力下降，细胞凋亡增加，细胞周期阻滞在G2/M期。染色体核型分析发现过表达Cks1后，胶质瘤细胞的异常染色体数目、延迟染色体数目及着丝粒数目比例增加；Cks1与UbcH10存在上下游调控关系，初步确定Cks1可能通过UbcH10促进胶质瘤染色体不稳。