OCDRA1负向调控PERK在口腔鳞状细胞癌HCPT耐药中的分子机制

Hydroxycamptothecin (HCPT) is widely used in the treatment of oral squamous cell carcinoma (OSCC), but primary drug resistance is common. In th grant from the National Natural Science Foundation of China (NSFC grant No. 81272958), the candidate investigate the menchanism of CDKL1 in mediating endoplasmic reticulum stress-induced apoptosis and HCPT resistance. The present grant still focused on How to predict the sensitivity of OSCC to HCPT and reverse the drug resistance individually. We screened an named long non-coding RNAs OCDRA1 which is highly expressed in cells that exhibits primary resistance to HCPT. Combining bioinformatic and experimental analyses, we proposes that OCDRA1 negatively regulate double-stranded RNA-activated protein kinase-like endoplasmic reticulum kinase (PERK)-mediated HCPT resistance resulted in the endoplasmic reticulum stress-induced apoptosis by bioinformatics analysis. As there is no report on the effect of OCDRA1 in drug resistant to HCPT, the present study is to explore the relevance of the high expression of OCDRA1 on OSCC primary drug resistance, long-term survival and prognosis, to reveal the molecular mechanism of OCDRA1 negatively regulates downstream targets of the PERK-mediated endoplasmic reticulum stress apoptosis, to enhance the sensitivity of OSCC to HCPT and reverse the drug resistance.

羟基喜树碱（HCPT）广泛用于口腔鳞癌的治疗，但存在原发耐药现象。申请人在前一项NSFC基金面上项目(申请号81272958)，就CDKL1经由内质网应激性凋亡通路调控HCPT耐药的分子机制进行了研究。本课题继续立足于如何个体化预测口腔鳞癌对HCPT的敏感性及逆转耐药的转化医学命题，从表观遗传学角度，筛选到在原发耐药细胞中高表达的长链非编码RNA，并将其命名为 OCDRA1。生物信息学分析结合预实验结果，我们提出OCDRA1可能通过负向调控双链RNA依赖的蛋白激酶样内质网激酶 (PERK)介导HCPT的耐药，进而影响内质网应激性凋亡。关于OCDRA1在HCPT耐药中的功能尚未有相关研究，本课题拟研究OCDRA1高表达与口腔鳞癌原发耐药、生存和预后的相关性，揭示OCDRA1负向调节PERK介导内质网应激性凋亡的下游靶标及耐药的分子机制，为提高口腔鳞癌对HCPT的敏感性及逆转耐药提供科学依据。

口腔鳞状细胞癌(oral squamous cell carcinoma，OSCC)是最常见的口腔颌面部的恶性肿瘤，化学治疗能提高晚期OSCC的治疗效果。羟基喜树碱（hydroxycamptothecine, HCPT）目前已应用于OSCC的临床治疗，有临床报道，总有效率在70%左右。但OSCC对HCPT存在原发耐药现象，如何个体化地预测OSCC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，通过基因测序发现lncRNA OCDRA1在耐药株中高表达，并且发现其通过抑制PERK转录，下调PERK表达，抑制内质网应激，进而诱导OSCC对HCPT耐药。此外我们发现CDKL1可通过抑制内质网应激介导OSCC对HCPT耐药，而上调CDKL1苏素化能够逆转CDKL1对内质网应激的抑制作用。本研究的发现有助于进一步理解OSCC HCPT耐药的分子机制，为临床上预测OSCC对HCPT的耐药性以及开展OSCC的精准化疗具有重要指导意义。我们还就OSCC放疗抵抗进行了相关研究，放射线照射导致Sp1苏素化，进而增加Sp1蛋白稳定性且促进Sp1结合PTEN启动子，下调PTEN，进而导致放疗耐受。受本项目资助，已发表SCI论文5篇，培养博士研究生6名，其中2名已取得博士学位，4名在读。项目投入经费72.00万元，支出36.106845万元。剩余经费35.893155万元，剩余经费将用于本项目研究后续支出。