m6A修饰和功能相关蛋白调控肾透明细胞癌发生发展的机制研究

Renal cell carcinoma (RCC) is one of the most common malignant tumors of the urinary system. The most common histological type is clear cell renal cell carcinoma (ccRCC), which accounts for 75–80% of RCC. Many patients are found metastasis in diagnosis or recurrences/metastases after surgery. RCC initiation and progression are driven by a series of genetic and epigenetic alterations such as 5mC/5hmC in DNA and m6A in RNA that cause either activation of oncogenes, or inactivation of tumor suppressor genes. Our previous research has found that 5hmC was globally lost in kidney cancer as an independent prognostic marker for kidney cancer. Little is known about the distribution and function of m6A in RCC. Here, we focus on how m6A related proteins influences ccRCC through the regulation of m6A modification. We plan to use MeRIP-seq to enrich m6A-specific regions of RNA and to achieve next generation sequencing. Until now, we have established several MeRIP-seq and transcriptome libraries for 3 ccRCC and adjacent tissues. By integrating multiple technologies ranging from molecular cell biology, biochemistry to transcriptome and bioinformatics, we aim to explore mechanisms how m6A related proteins regulate mRNA processing and metabolism in ccRCC, by then search for the epigenetic abnormalities, key genes and sites, providing the new insights into the diagnosis and treatment to ccRCC.

肾细胞癌又名肾癌，是泌尿系统最常见的恶性肿瘤之一。肾透明细胞癌是其主要病理类型，约占肾癌的75-80%。许多患者在诊断时已发现转移，术后易发生复发或转移。肾癌的发生发展受到遗传和表观遗传的协同调控，包括5mC、5hmC、m6A等。实验室前期研究发现5hmC在肾癌中显著下降且与肾癌发生发展及预后密切相关，提高5hmC可抑制肾癌。但关于m6A修饰对肾癌的调控目前并不十分清楚。本课题将主要从蛋白质和RNA层面研究m6A修饰和功能相关蛋白在肾透明细胞癌中的调控作用。目前我们已熟练掌握富集含有m6A特异区域的MeRIP-seq技术及生物信息分析方法。构建完成了3例肾透明细胞癌及癌旁组织的MeRIP-seq文库。本项目拟整合分子、细胞、生化、和生物信息等交叉技术研究m6A修饰和功能相关蛋白调控肾透明细胞癌发生发展的动态规律，寻找其调控的关键靶基因及位点，为肾癌的诊断和治疗提供理论基础和科学依据。

肾癌被列为全球10大癌症之一，我国肾癌发病率成递增趋势。约70%-85%肾癌为肾透明细胞癌。大部分患者在就诊时已处于中晚期。约有15%的进展期肾癌患者合并发生癌栓。目前肾癌是泌尿系统肿瘤中致死率最高的肿瘤。虽然已发现多种治疗靶点，但其对于不同患者敏感性不一，同时极易产生耐药性。因此对于肾癌发生发展的多角度解析有助于提供更多的治疗相关思路和方案。本项目主要以肾癌为研究对象，系统解析了肾癌RNA甲基化表观层面和单细胞转录组层面的分子机制。首先针对RNA表观遗传修饰层面，利用公共数据结合生物功能实验系统鉴定发现RNA甲基化酶METTL3在肾癌发生发展中的促进作用。同时结合MeRIP-seq测序及生物信息分析进一步鉴定到下游潜在调控因子ABCD1。该基因蛋白表达变化受到m6A修饰的调控影响。此外，针对晚期肾癌易长癌栓的特征，我们利用单细胞转录组分析发现肾癌原发肿瘤和癌栓之间存在显著差异。癌栓组织中胞外基质相关通路更加活跃；原发组织中，免疫抑制基因表达更高。组织驻留型CD8+T细胞在癌栓组织中更加富集，提示免疫治疗可能对其更加有效。该项目的整体有效推进为肾癌的精准诊治提供了理论基础和潜在靶标。