OSTC突变通过调控JAK-STAT信号通路促进宫颈癌化疗耐药的发生及其分子机制的研究

Chemotherapy resistance is an important cause of tumor recurrence and poor prognosis. In recent years, chemotherapy combined with molecular targeted therapy has become a research hotspot in cancer therapy. We used the whole exome sequencing to detect a new high-frequency mutation gene-OSTC (16.7%) in the Chinese patients with cervical cancer chemotherapy resistance, and confirmed in vitro that the down-regulation of OSTC expression mediates cisplatin resistance in cervical cancer cells. Further analysis found that OSTC has the function of negatively regulating the JAK-STAT signaling pathway. Based on previous findings, this research will further explore the role of OSTC mutations in cervical cancer and the molecular mechanism that mediates chemoresistance. On the one hand, the use of co-immunoprecipitation, GST pull down and other techniques will help us to find the key protein interact with OSTC in the JAK-STAT pathway. On the other hand, in animal models to verify the effect of OSTC mutations on cisplatin resistance in cervical cancer. Combined with in vitro and in vivo models and clinical validation to analyze the molecular mechanism of chemotherapy resistance mediated by OSTC mutation in cervical cancer, to clarify the key factors and the potential signaling pathway regulated by OSTC. In this study,we aim to find new targets for targeted therapy in cervical cancer, and lay a theoretical foundation for improving the treatment of cervical cancer and the prognosis of cervical cancer patients in China.

化疗耐药是影响宫颈癌治疗效果的主要原因，近年来化疗联合分子靶向治疗成为宫颈癌治疗的新策略。申请者前期运用WES首次在汉族宫颈癌患者中发现了新的高频突变基因OSTC，并验证了OSTC与宫颈癌铂类耐药密切相关，在OSTC下调/过表达的宫颈癌细胞模型中验证了OSTC对宫颈癌细胞生物学行为的影响，运用GSEA分析和cDNA芯片技术发现OSTC具有负向调控JAK-STAT信号通路的功能。本项目拟在此基础上，运用免疫共沉淀、GST pull down等技术寻找JAK-STAT通路中与OSTC作用的关键蛋白，进一步阐明OSTC调控JAK-STAT通路促进宫颈癌化疗耐药的分子机制，通过建立动物模型，在体内验证OSTC在宫颈癌顺铂耐药中的分子机制，探索以OSTC为靶点改善宫颈癌治疗效果的可能性，为提高我国宫颈癌治疗水平和改善我国宫颈癌患者预后奠定理论基础。

宫颈癌严重危害我国女性的生命健康，化疗耐药是影响肿瘤治疗效果的重要原因。基因突变和/或信号通路的异常激活与肿瘤化疗耐药的发生密切相关，通过联合分子靶向治疗提高化疗敏感性已成为一种新兴的肿瘤治疗策略。本课题组前期运用全基因组外显子测序(WES)技术首次在中国人群中发现了两个与宫颈癌化疗耐药相关的高频突变基因——OSTC和PRKD2，通过构建稳筛的宫颈癌细胞系验证OSTC和PRKD2基因下调后的生物学效应，运用RNA测序寻找基因下调后调控的信号通路，在宫颈癌临床标本和宫颈癌细胞中进一步验证，结果显示OSTC缺失突变通过调控JAK-STAT信号通路促进宫颈癌化疗耐药；PRKD2下调通过调控TP53/CDKN1A信号通路增强宫颈癌化疗敏感性。本课题明确阐明了新发现的高频突变基因OSTC及PRKD2调控宫颈癌化疗耐药的作用机制，为化疗联合分子靶向治疗提高宫颈癌治疗效果奠定了理论基础。课题组将进一步探索通过小分子抑制剂等方式靶向干预，以增强化疗药物敏感性的可行性，具有广阔的应用前景。