选择性剪接基因RBFOX1在食管鳞癌中的研究  

Research of the alternative splicing gene RBFOX1 in esophageal squamous cell carcinoma

作　　者：邓家营 赵快乐[1] 

机构地区：[1]复旦大学附属肿瘤医院放疗科复旦大学上海医学院肿瘤学系,上海200032

出　　处：《中国癌症杂志》2015年第6期401-408,共8页China Oncology

基　　金：国家自然科学基金资助项目(21172043)

摘　　要：背景与目的:选择性剪接是基因表达中的重要调控机制,异常的剪接可导致细胞周期异常、癌基因转录因子激活及抑癌基因转录因子失活;异常剪接与肿瘤发生、发展息息相关。DNA甲基化是表观遗传修饰的重要组成部分,基因启动子的异常甲基化可导致基因沉默,抑癌基因和DNA修复基因的高甲基化参与多种肿瘤的发生;另外DNA甲基化还是选择性剪接的关键参数,DNA异常甲基化影响选择性剪接的平衡。本研究通过对食管鳞癌组织标本中RBFOX1(RNA binding protein,fox-1 homolog 1)选择性剪接基因的甲基化水平和表达进行检测,探讨其临床应用价值。方法:在149例配对的食管鳞癌及癌旁组织中,运用Mass ARRAY对RBFOX1基因的甲基化水平进行检测,并从同一批样品中选取42对组织采用RT-PCR进行RBFOX1基因的mRNA表达分析,统计甲基化水平与食管鳞癌主要临床病理特征的关系。结果:在食管鳞癌组织标本中,RBFOX1的甲基化水平为41.8%,明显低于对应癌旁组织的68.3%。差异有统计学意义(P<0.01);RBFOX1的甲基化水平与患者的性别、年龄、吸烟、饮酒以及肿瘤的分化、分期等无明显相关。依据癌组织中甲基化水平阈值(33.6%)=Mean(癌旁组织)-2.5SD(标准差),将研究对象分为两组,低于阈值的一组定义为组1,高于阈值的为组2。组1和组2的5年总体生存率(overall survival,OS)为57.0%和35.7%。差异无统计学意义(P=0.06)。组1和组2的5年无进展生存率(progression-free survival,PFS)为48.7%和28.9%。差异有统计学意义(P=0.03)。多因素分析结果显示仅TNM分期为生存的独立预测因子。结论:选择性剪接基因RBFOX1在食管鳞癌组织中的甲基化水平和表达水平均低于癌旁组织,RBFOX1启动子区的甲基化水平不能作为生存分析的预测因子。Background and purpose： Alternative splicing is an important regulation mechanism of gene expression. Aberrant alternative splicing is associated with dysregulation of the cell cycle, activation of oncogenes and inactivation of the tumor suppressor genes. Thus, it is closely correlated with the pathogenesis and progression of various tumors. DNA methylation is an important part of epigenetic phenomena. Aberrant methylation of the gene promoter can result in gene silencing. Hypermethylation of tumor suppressor genes and DNA repair genes correlates with the onset of many different cancers. Additionally, DNA methylation acts as a pivotal factor for alternative splicing. Aberrant methylation disrupts the stabilization of the alternative splicing. This study investigated the promoter methylation and expression of RNA binding protein, fox-1 homolog 1（RBFOX1） gene in esophageal squamous cell carcinoma（ESCC）, and to elucidate its role in ESCC. Methods： Mass ARRAY approach and RT-PCR were used respectively to examine the methylation level of RBFOX1 gene and its expression at mRNA level in tumors and corresponding adjacent normal tissues. The correlation between methylation level and clinicopathological features was analyzed. Results： RBFOX1 methylation level and mRNA expression in tumor tissues were signifi cantly lower than those in corresponding adjacent normal tissues（41.8% vs 68.3%, P〈0.01）. No significant correlation was observed between methylation level and clinicopathological features. The cut-off（33.6%） was calculated as the mean of the normal samples to which we applied 2.5 SD. According to the cut-off value, the object of the study was divided into two groups. The methylation level lower than the cut-off was defi ned as group 1; methylation level higher than the cut-off was defi ned as group 2. The 5-year overall survival rates of the two groups were 57.0% and 35.7%, respectively（P=0.06）; 5-year progression-free survival rates were 48.7% and 28.9%, respectively（P=0.03）. However,

关 键 词：食管鳞癌 选择性剪接 甲基化 表达 RBFOX1 

分 类 号：R735.1[医药卫生—肿瘤]