CDO1在口腔黏膜癌前损害上皮干性异常与逆转中的调控作用与机制研究

Dysregulated stemness of oral mucosa epithelium cells contributes to uncontrolled proliferation and initiation of OPL and OSCC. Recent studies have shown that overexpression of cysteine dioxygenase 1 (CDO1) contributed the progression of several human cancers. However, the role of CDO1 in the development of OPL and OSCC has not been investigated yet. Our preliminary data indicates that CDO1 expression was up-regulated in OPL tissues, compared to normal oral mucosa. And CDO1 was required for the proliferation and stemness maintenance of OPL-derived keratinocytes. Thus, we hypothesized that inhibition of CDO1 may suppress the dysregulated stemness and proliferation, and reverse the conversion to OSCC of OPL. To address the hypothesis, we planned to access the role of CDO1 in regulation of proliferation and stemness in OPL-derived keratinocytes. To elucidate the underlying mechanism, we would also like to investigate the effect of CDO1 on gene expression profiling and Cystenine-H2S metabolism, and the interaction between CDO1 and SOX2, a master transcription factor of stemness maintenance. Finally, we would analyze the correlation between CDO1 up-regulation and the development of OSCC from OPL. This study holds promise to provide a novel target for gene therapies of OPL and OSCC.

上皮细胞干性失衡是口腔黏膜癌前损害(OPL)发生发展的核心，通过基因重编辑恢复其干性，是防治癌前损害的新思路(Cell 2014)。申请人研究发现，半胱氨酸双氧化酶1(CDO1)具调控干细胞分化功能(Sci Rep 2015)；为OPL上皮维持其异常干性所必需，SOX2参与此过程。但其在OPL上皮干性异常与逆转中调控的精细机制及临床价值急待深入阐明。本课题拟从临床获得OPL的实时研究材料，利用过表达和CRISPR/Cas9基因敲除技术，验证CDO1在口腔黏膜上皮干性调控中的功能；运用RNA-seq等技术从半胱氨酸-H2S代谢、与SOX2交互作用、相关新分子3个方面详细阐明其分子机制；再通过OPL病例追踪，进一步验证CDO1与OPL癌变的相关性，成果有助于阐明OPL发生发展的机制，更重要的是，有助于利用OPL模型，评估针对异常干性重编程，诱导其分化，从而发挥防治策略的有效性和可行性。

口腔黏膜癌前损害（OPL）是口腔鳞癌发生发展的重要阶段。本项目前期基础研究结果提示，CDO1具调控干细胞分化功能，为OPL上皮维持其异常干性所必需。在资助期间，我们按照研究计划，通过敲降和过表达CDO1，进一步证实了CDO1为OPL上皮细胞的维持干性所必需；通过研究CDO1代谢产物对上皮干细胞的影响，基本明确CDO1通过调控H2S代谢水平调节上皮干细胞增殖和SOX2表达水平；明确了调控CDO1、SOX2和干性的新分子——AFF4；通过临床队列研究明确了其在头颈鳞癌中表达的临床意义和预后相关性。综上所诉，本项目从干性调控的转录机制、信号通路、代谢调控等多个层次展开了研究，这些研究成果基本阐明了AFF4-CDO1-SOX2在口腔黏膜癌变发生发展的机制，为以AFF4-CDO1-SOX2为靶点的治疗打下了基础。