OPA1增强子区域突变在肺鳞癌发生中的功能及机制研究

Lung cancer is one of the most common malignant tumors worldwide, with squamous cell carcinoma accounting for about 40%. Recently, based on the development of next-generation sequencing (NGS) technology and bioinformatics, partial studies of lung squamous cell carcinoma have identified significantly mutated genes (SMGs) in exome region. It is worth noting that, the exome accounts for only about 2% of the genome, whereas the more extensive non-coding region has not been delved deeper. For the whole human genome, there are approximately 80% of the non-coding region playing biochemical functions through functional elements, including promoters, enhancers, suppressors and the others. At present, it is believed that mutations in enhancers are more specific to the tumor type. Therefore, based on targeted-sequencing, we intend to verify significantly somatic mutations in the non-coding regulatory region and the driver gene OPA1, which was identified by our previous study through whole-genome sequencing (WGS) technology. Besides, subsequent functional annotation and mechanism studies provide the basis for identifying the pathogenic mutation, with a new direction for the mechanism in lung squamous cell carcinoma.

肺癌（Lung cancer）是最为常见的恶性肿瘤之一，其中肺鳞癌约占40%左右。近年来，新一代测序技术（NGS）的发展和生物信息方法学的建立，已经初步鉴定出肺鳞癌外显子区中的多个显著突变基因（SMGs）。值得关注的是，外显子编码区仅占到整个基因组的2%左右，更为广漠的非编码区尚未深入研究。人类基因组中约80%的非编码区域可能通过功能元件发挥生物学功能，包括启动子、增强子和抑制子等，目前研究认为增强子区突变更具有肿瘤特异性。因此，本课题拟采用捕获测序验证前期肺鳞癌全基因组测序（WGS）技术筛选出的非编码区显著突变增强子及调控的靶基因OPA1；针对候选功能性突变位点及OPA1进行后续功能学及机制研究，为肺鳞癌的病因机制研究提供分子生物学依据，对肺鳞癌的综合防治具有重要意义。

肺癌是最为常见的恶性肿瘤之一，其中肺鳞癌约占40%左右。新一代测序技术（NGS）已经初步鉴定出肺鳞癌外显子区中的多个显著突变基因（SMGs）。然而，外显子编码区仅占到整个基因组的2%左右，更为广漠的非编码区尚未深入研究。人类基因组中约80%的非编码区域可能通过功能元件发挥生物学功能，包括启动子、增强子和抑制子等，目前研究认为增强子区突变更具有肿瘤特异性。因此，本课题拟基于前期肺鳞癌全基因组测序（WGS）技术筛选出的非编码区显著突变增强子及调控的靶基因OPA1；针对候选功能性突变位点及OPA1进行后续功能学及机制研究。本研究整合了35个肺鳞癌的WGS数据，并在位于OPA1上游约662kb的非编码区确定了3个体细胞突变。染色体构象捕获实验(3C)显示，该区域作为一个OPA1增强子(eOPA1)区域，可以与OPA1启动子物理并列并顺式调节其转录。敲除OPA1可降低肺鳞癌细胞系的增殖和迁移能力。此外，OPA1缺失损害线粒体动力学，导致线粒体形态异常、嵴肿胀和线粒体自噬。随后，线粒体融合的失调阻碍了支持细胞代谢活性的线粒体功能。最后，线粒体形态紊乱加速细胞色素C从嵴释放，引起周期阻滞和细胞凋亡。综上所述，这些结果揭示了eOPA1和OPA1蛋白突变在肺鳞癌发展中的关键作用，这突出了非编码突变对癌症发展的贡献。