CDKL1在内质网应激介导的口腔鳞状细胞癌HCPT耐药中的分子机制

10-hydroxycamptothecin (HCPT) is widely used in clinical treatment of various malignancies including oral squamous cell carcinoma (OSCC). However, the development of primary resistance to HCPT in some cancer cells limits its clinical application. How to predict the sensitivity of HCPT in an individual patient and overcome resistance to HCPT is an urgent problem that needs to be addressed in clinical medicine. The applicant confirmed in previous work that CDKL1 plays a key role in HCPT resistance of OSCC cells and is involved in HCPT-mediated cell apoptosis, the mechanism of which is regulated by the pathways of endoplasmic reticulum (ER) stress response. On this basis this project intends to study the expression levels of CDKL1 protein in OSCC specimens from patients with different drug sensitivity profiles. Combined with the expression levels of ER stress response markers, we will explore the correlation of CDKL1-mediated balance between cytoprotective and apoptotic responses and HCPT sensitivity in OSCC, so as to understand the clinical significance of CDKL1. Furthermore, we will use deep-sequencing technology and analysis of signalling pathways to establish a comprehensive signaling network modulated by CDKL1. More importantly, we will identify the key molecular combined to CDKL1 protein and the binding sites on CDKL1 protein from the view point of protein-protein interactions. Thereafter, we will reveal the molecular mechanism by which CDKL1 modulates the ER stress response in the process of HCPT resistance of OSCC cells.

羟基喜树碱（HCPT）广泛应用于口腔鳞状细胞癌的临床治疗，但存在原发耐药现象，如何个体化地预测口腔鳞癌对HCPT的敏感性以及逆转耐药是临床上需要迫切解决的重要转化医学命题。申请者在前期工作中证实CDKL1是口腔鳞癌细胞对HCPT原发耐药的关键分子，参与HCPT介导肿瘤细胞凋亡的核心环节，其作用机制可通过内质网应激性反应途径调控。本项目拟在此基础上研究口腔鳞癌不同药物敏感性病人标本中CDKL1蛋白的表达水平，结合内质网应激反应的标记蛋白，证实CDKL1介导的细胞保护反应和凋亡反应之间的平衡与口腔鳞癌HCPT敏感性及预后的相关性，明确其临床意义。并通过mRNA水平的深度测序技术和蛋白水平信号通路分析，建立起CDKL1调控下的信号通路和网络认识；从蛋白-蛋白相互作用的角度鉴定与CDKL1结合的分子及结合位点，由此揭示CDKL1在口腔鳞癌HCPT耐药中调节内质网应激的深入分子机制。

羟基喜树碱（HCPT）广泛应用于口腔鳞状细胞癌的临床治疗，但存在原发耐药现象，如何个体化地预测口腔鳞癌对HCPT的敏感性以及逆转耐药是临床上需要迫切解决的重要转化医学命题。本课题以口腔鳞状细胞癌细胞系为研究对象，筛选出其HCPT耐药株，通过mRNA表达谱芯片分析发现CDKL1、PP5、NLK、KLF8、SK1等5个可能与口腔鳞状细胞癌HCPT耐药相关的基因，通过研究发现，CDKL1通过抑制IRE1表达以及促进IRE1和GRP78/BIP相互作用，抑制内质网应激，从而调控口腔鳞状细胞癌对HCPT的耐药性；PP5通过抑制p38和JNK信号通路，促进细胞增殖，进而调控口腔鳞状细胞癌对HCPT的耐药性；NLK、KLF8和SKA1在HCPT耐药细胞系中高表达，敲除NLK、KLF8和SKA1可明显抑制口腔鳞癌细胞增殖和克隆形成能力，提示NLK、KLF8和SKA1在口腔鳞状细胞癌对HCPT耐药中可能发挥着重要的调控作用，本研究的发现有助于进一步理解口腔鳞状细胞癌HCPT耐药的分子机制，为临床上预测口腔鳞癌对HCPT的耐药性以及开展口腔鳞状细胞癌的精准化疗具有重要指导意义。此外，项目组对SKA1在腺样囊性癌发生发展中的作用和机制进行了探讨，发现腺样囊性癌中SKA1高表达，并且与肿瘤的临床分期有相关性，SKA1通过调控CDK4、cyclin D1、N-cadherin、MMP-9等细胞增殖、迁移和侵袭相关蛋白，调控腺样囊性癌细胞增殖、迁移和侵袭。项目资助已发表SCI收录论文6篇，待发表2篇。培养博士研究生3名，其中1名已经取得博士学位，2名在读。项目投入经费70万元，支出59.3845万元，各项支出基本与预算相符。剩余经费10.6155万元，剩余经费计划用于本项目研究后续支出。