转录因子SP1调控肝细胞癌中三元基序家族蛋白7基因表达的机制  

Mechanism of Transcription Factor SP1 Regulates Expression of Tripartite Motif-containing Protein 7 in Hepatocellular Carcinoma

作　　者：樊昌宇 丁涵 徐乙冉 咸蕊 闫凤娟 FAN Chang-Yu;DING Han;XU Yi-Ran;XIAN Rui;YAN Feng-Juan(Department of Biochemistry and Molecular Biology,School of Life Science,Jiangsu Normal University,Xuzhou 221116,Jiangsu,China)

机构地区：[1]江苏师范大学生命科学学院生物化学与分子生物学教研室,江苏徐州221116

出　　处：《中国生物化学与分子生物学报》2023年第9期1314-1321,共8页Chinese Journal of Biochemistry and Molecular Biology

基　　金：徐州市青年科技人才项目(No.KC21054);江苏省高等学校基础科学(自然科学)研究项目(No.23KJB180008);国家自然科学基金项目(No.81800521)资助。

摘　　要：三元基序家族蛋白7(tripartite motif-containing protein 7,TRIM7)作为E3泛素连接酶TRIM家族的成员,在免疫调控、代谢等生理过程中发挥重要调控作用。此外,TRIM7的异常表达与肝细胞癌(hepatocellular carcinoma,HCC)的发生发展密切相关并呈现出复杂的调控作用,但其在HCC中的表达调控机制尚不清楚。本研究首先利用多种在线数据库分析发现,TRIM7在HCC中高表达,并且TRIM7高表达的肝细胞癌患者预后较差;利用UCSC、JASPAR数据库分析预测TRIM7基因启动子区的转录因子结合位点。结果显示,TRIM7启动子上含有4个特异性蛋白1(specificity protein 1,SP1)转录因子结合位点。本研究利用双荧光素酶报告实验、ChIP-PCR方法检测发现,SP1通过直接结合在TRIM7启动子上的SP1结合位点,从而正调控TRIM7启动子驱动的转录活性。RT-qPCR、Western印迹检测结果进一步显示,过表达SP1在mRNA和蛋白质水平均上调TRIM7基因的表达(P<0.01),且利用SP1抑制剂Mithramycin A处理能够逆转SP1对TRIM7基因表达的调控作用(P<0.01)。总之,本研究初步揭示了TRIM7在肝细胞癌中高表达的调控机制,为深入研究该基因功能以及早期诊断、靶向治疗提供重要的理论依据。Tripartite motif containing protein 7(TRIM7),as a member of the E3 ubiquitin ligase TRIM family,plays an important regulatory role in immune regulation,metabolism and other physiological processes.The aberrant expression of TRIM7 is closely related to the development and progression of hepatocellular carcinoma(HCC)and it shows a complex regulatory role.However,the regulatory mechanism for the expression of TRIM7 in HCC remains unknown.In this study,multiple online databases were used to analyze the expression of TRIM7 in HCC and data indicated that TRIM7 expression was upregulated in HCC and correlated to poor prognosis.Subsequently,the transcription factor binding sites in the TRIM7 promoter region were analyzed using UCSC and JASPAR databases,and the results showed that TRIM7 promoter contains four SP1 binding sites.In this work,we demonstrated that SP1 could directly bind to its binding sites in TRIM7 promoter and positively regulate the transcriptional activity driven by the TRIM7 promoter using dual luciferase reporter experiments and the ChIP-PCR method.Moreover,our results also showed SP1 overexpression upregulated the expression of TRIM7 at both mRNA and pro-tein levels(P<0.01),and SP1 inhibitor,mithramycin A,could reverse the activated effect of SP1 on TRIM7 expression(P<0.01).In conclusion,this study preliminarily reveals the regulatory mechanism of TRIM7 upregulation in HCC,which provides an important theoretical basis for further study of the gene function,early diagnosis and targeted therapy.

关 键 词：肝细胞癌 转录调控 启动子 三元基序家族蛋白7 特异性蛋白1 

分 类 号：Q7[生物学—分子生物学]