肿瘤坏死因子α及其受体基因多态性与结外鼻型NK/T细胞淋巴瘤的相关性研究

Extranodal NK/T-cell lymphoma, nasal type (ENKTCL-N) is a kind of lymphoma with distinct clinicopathological and biological characteristics, and has poor prognosis. ENKTCL-N is prevalent in China and rare in West countries, being the most common extranodal lymphoma except diffuse large B-cell lymphoma. The mechanism for the pathogenesis of ENKTCL-N is unclear up to now. Our previous study on detecting two fresh tissues by whole exsome sequencing show that the mutation of tumor necrosis factor (TNF)-α and its receptors (TNFR) is an important abnormality of ENKTCL-N. Recent researches show that TNF-α can stimulate tumor cell proliferation, migration and angiogenesis, resulting in tumorigenesis. The correlation of TNF-α-308 gene polymorphism in promoter region with tumorigenesis has been a research focus at home and abroad. But there have no reports of gene polymorphism of TNF-α and TNFR in NK-cell lymphomas. Therefore, this research is designed to detect TNF-αand TNFR gene polymorphism in a large sample of ENKTCL-N, and to analyze the correlation of these gene polymorphisms with protein expression, cancer susceptibility and the clinicopathological parameters of ENKTCL-N, and to study on the TNF-α and mutant TNFR function in tumor cells. This study will show us the biological significance of TNF-α in the pathogenesis of ENKTCL-N and provide an experimental basis for the biological behavior, treatmentand prognostication.

结外鼻型NK/T细胞淋巴瘤（ENKTCL-N）是一组具有特殊临床病理表现和生物学行为的肿瘤，预后较差。该肿瘤是我国最常见的结外非B细胞淋巴瘤，而在西方国家少见。目前该肿瘤发生发展的分子机制仍不清楚。本课题组采用全外显子组测序对2例该肿瘤标本进行检测，发现TNF-α及其受体基因发生了突变。目前认为，TNF-α能促进肿瘤的发生，其启动子区308位点多态性与肿瘤的相关性一直是国内外的研究热点。但至今为止，国内外尚未见到TNF-α及其受体基因多态性与ENKTCL-N相关性的报道。因此，本课题将检测一组ENKTCL-N石蜡组织中TNF-α及其受体基因多态性情况，并分析基因多态性与蛋白表达、肿瘤易感性以及临床病理指标和预后之间的关系，探讨该基因多态性在该肿瘤发病中的生物学意义，研究TNF-α在该肿瘤细胞中的功能，以及TNFR突变型所导致的功能改变，为该肿瘤生物学行为判断以及治疗和预后提供更可靠的依据。

本课题分为四部分：（1）完成ENKTL-N石蜡包埋肿瘤组织样本和正常人群外周血对照样本的收集和DNA提取工作，并且检测了样本中TNF-α和TNFR2基因的多态性情况。（2）发现TNF-α基因的rs361525位点与ENKTL-N的易感性相关，该位点的突变型增加该肿瘤的易感性。（3）发现TNFR2编码基因的rs1061622和rs5746026位点的多态性与ENKTL-N的易感性相关，rs1061622位点的突变型降低肿瘤易感性，而rs5746026位点的突变型增加肿瘤易感性。（4）构建候选基因的野生型和突变型真核表达质粒，转染细胞，检测信号通路关键分子的表达情况，发现196位突变TNFR2可减少NF-κB的活化，而232位突变TNFR2可增加NF-κB的活化，为进一步研究其分子机制奠定了基础。.本课题按时完成，在该课题的资助下，正在撰写SCI论文2篇。