CERNA1通过BCL2L10和LINC00578提高耐药卵巢癌顺铂敏感性的分子机制研究

Ovarian cancer patients tend to develop into drug-resistance, which makes the mortality rate of ovarian cancer to be the first place in gynecological malignant tumors. Preliminary experiments showed that, with the development of drug resistance, the expression of CERNA1 decreased in ovarian cancer. CERNA1 overexpression promoted cell apoptosis and increased the sensitivity of cisplatin-resistant ovarian cancer. In addition, it enhanced the expression of BCL2L10 and LINC00578. BCL2L10 is an apoptotic facilitator of ovarian cancer. LINC00578 also could increase the cisplatin sensitivity. Small molecular ABO induced CERNA1 expression and reversed the drug resistance. Based on these results and the latest literatures, we intend to confirm the following hypothesis from clinical specimens, in vitro cell models and animal experiments: small molecules ABO enhances the cisplatin sensitivity of drug-resistant ovarian cancer by activating CERNA1 expression; CERNA1 promotes the expression of BCL2L10 and LINC00578 through binding with DNMT1/DNMT3B ; BCL2L10 directly promotes apoptosis and enhances the sensitivity of drug-resistant ovarian cancer; LINC00578 promotes apoptosis by reducing the protein level of BCL2 and then increases the cisplatin sensitivity. Therefore, by proving this hypothesis, we will provide new evidences for elucidating the role and mechanism of CERNA1 in cisplatin sensitization of drug-resistant ovarian cancer and provide new targets and clues for drug design of drug-resistant ovarian cancer therapy.

卵巢癌患者往往发展为化疗耐药，使其死亡率居妇科恶性肿瘤首位。预实验表明：CERNA1的表达随卵巢癌耐药而降低，过表达后促进细胞凋亡且提高顺铂敏感性，同时增加BCL2L10和LINC00578的表达。BCL2L10是一个卵巢癌凋亡促进因子，LINC00578也可提高细胞顺铂敏感性。小分子ABO诱导CERNA1表达且逆转铂耐药性。我们拟从临床标本、细胞模型和动物实验证明以下假设：小分子ABO通过激活CERNA1表达提高耐药卵巢癌的顺铂敏感性；CERNA1与DNMT1/3B结合促进BCL2L10和LINC00578的表达；BCL2L10直接促进细胞凋亡提高耐药卵巢癌敏感性；LINC00578通过SSB降低BCL2的蛋白水平，进而促进细胞凋亡提高顺铂敏感性。本项目为阐明CERNA1在耐药卵巢癌顺铂增敏中的功能和作用机制提供新证据，为研发卵巢癌化疗增敏的药物设计提供新的靶点和思路，具有实际应用前景。

在人类的转录组中，除了之前鉴定的21,000个蛋白编码基因外，大约还有9,000个小RNA，10,000~32,000长非编码RNA（lncRNA）和11,000个假基因。越来越多的研究表明，长非编码RNA能够参与表观遗传调控。本研究以小分子化合物ABO为工具，发现了一个调控细胞凋亡的长非编码RNA-LOC100129973（NCBI上更名为CERNA1）。lncRNA以组织特异性模式表达，分布在特定的亚细胞位置，其多种调控机制取决于其亚细胞位置。首次在ABO（6-氨基-2,3-二氢-3-羟甲基-1,4-苯并恶嗪）中发现，能缓解血清和FGF-2饥饿诱导的人脐静脉内皮细胞（HUVECs）凋亡。CERNA1具有隔离miR-4707-5p和miR-4767的诱饵活性，可促进API5和BCL2L12的表达，可缓解血清和FGF-2饥饿诱导的人脐静脉内皮细胞(HUVECs)凋亡。然而，没有关于CERNA1在任何肿瘤中的报道。lncRNA CERNA1作为miRNA海绵，主要位于HUVECs的细胞质中。我们首次阐述了核CERNA1在OC中的作用及其分子调控机制。研究发现无论是在OC组织还是OC细胞中，CERNA1的表达都较低，这预示着OC中的预后作用较差。与HUVECs不同，CERNA1几乎完全分布在OC细胞的细胞核中。核CERNA1诱导BCL2L10 (OC肿瘤抑制因子)表达，通过诱骗影响DNMT1调控BCL2L10的启动子从而诱导细胞凋亡，降低顺铂耐药性。这些结果表明，CERNA1可能是一个可以提高OC患者对化疗的敏感性的有研究意义的治疗靶点；本研究对DNA甲基化基因与肿瘤耐药之间的潜在关系，对于深入阐明甲基化基因对耐药的调控作用机制及提高预后具有的理论指导意义