BRD4抑制剂通过靶向BTK杀伤ABC-DLBCL细胞(英文)  

BRD4 inhibitors kill ABC-DLBCL cells by targeting BTK

作　　者：范志伟 吴圆圆[1] FAN Zhi-wei;WU Yuan-yuan(Laboratory of Basic Medicine,School of Medicine,Nantong University,Nantong 226001,China)

机构地区：[1]南通大学医学院基础医学研究室,江苏南通226001

出　　处：《中国病理生理杂志》2022年第12期2164-2174,共11页Chinese Journal of Pathophysiology

基　　金：the Jiangsu Provincial University Natural Science Research Project of China(No.19KJB310012)。

摘　　要：目的:研究含布罗莫结构域蛋白4(BRD4)抑制剂JQ1和I-BET-762对活化B细胞样弥漫大B细胞淋巴瘤(ABC-DLBCL)的杀伤作用及其分子机制。方法:以不同浓度的BRD4抑制剂JQ1和I-BET-762及布鲁顿酪氨酸激酶(BTK)抑制剂依鲁替尼(ibrutinib)处理ABC-DLBCL细胞,CCK-8法检测细胞活力,PI染色检测细胞凋亡,real-time PCR检测B细胞受体(BCR)/核因子κB(NFκB)信号通路BTK、磷脂酶Cγ(PLCγ)、LYN、SYK、白细胞介素6(IL-6)、蛋白激酶Cβ(PKCβ)、黏膜相关淋巴样组织淋巴瘤易位蛋白1(MALT1)等分子及转录因子MYC和RELA的m RNA表达,Western blot检测BTK、PLCγ、MYC和RELA的蛋白表达;通过生物信息学分析ABC-DLBCL细胞系HBL-1和生发中心B细胞样弥漫大B细胞淋巴瘤(GCB-DLBCL)细胞系Ly1中的BTK基因是否受超级增强子调控。结果:与Burkit淋巴瘤细胞系Raji和GCB-DLBCL细胞系BJAB相比,ABC-DLBCL细胞系HBL-1和Ly10对BRD4抑制剂JQ1更加敏感,JQ1能够抑制BCR/NFκB靶分子IL-6的表达。另一种BRD4抑制剂I-BET-762同样具有杀伤ABC-DLBCL细胞的作用。进一步机制研究发现,JQ1和I-BET-762能明显抑制BCR/NFκB信号通路关键分子BTK,而对其它分子影响较小。生物信息学分析显示,BTK基因附近无超级增强子,但JQ1处理可显著抑制BRD4结合到BTK基因区。有意思的是,BRD4抑制剂对耐ibrutinib的SU-DHL-2细胞也具有较强的杀伤作用。结论:BRD4抑制剂通过抑制BTK对ABC-DLBCL细胞有显著杀伤作用,与BCR信号通路抑制剂联合应用效果更为显著。JQ1或可用于治疗耐BTK抑制剂ibrutinib的ABC-DLBCL。AIM:To investigate the effect of bromodomain-containing protein 4(BRD4)inhibitors on the viability and apoptosis of activated B cell-like diffuse large B-cell lymphoma(ABC-DLBCL)cells and the molecular mechanism.METHODS:The ABC-DLBCL cells were treated with BRD4 inhibitors JQ1 and I-BET-762,and Bruton tyrosine kinase(BTK)inhibitor ibrutinib.The viability and death of the cells were determined by CCK-8 assay and PI staining,respectively.The m RNA levels of BTK,phospholipase Cγ(PLCγ),LYN,SYK,interleukin-6(IL-6),MYC,protein kinase Cβ(PKCβ),mucosa-associated lymphoid tissue lymphoma translocation protein 1(MALT1),MYC and RELA were detected by real-time PCR.The protein levels of BTK,PLCγ,MYC and RELA were determined by Western blot.Superenhancer around BTK gene was revealed by bioinformatics analysis.RESULTS:The ABC-DLBCL cells were sensitive to BRD4/super-enhancer inhibitors such as JQ1 and I-BET-762.Both JQ1 and I-BET-762 inhibited the chronic active B-cell receptor(BCR)/nuclear factorκB(NFκB)signaling through reducing the transcription of BTK,but they had minimal effect on other components in BCR/NFκB signaling.Interestingly,there was no super-enhancer around BTK gene,and the inhibitory effect of JQ1 was likely due to disruption of BRD4 binding within BTK gene.Inhibition of BRD4 had synergic effect with BTK inhibitor ibrutinib.Moreover,inhibition of BRD4 induced significant cell death in ibrutinib-resistant ABCDLBCL cells.CONCLUSION:Inhibitors of BRD4 induce ABC-DLBCL cell death via blocking BCR/NFκB signaling and has synergic effect with BTK inhibitor.Inhibition of BRD4 might be a promising strategy for treatment of ABC-DLBCL,especially ibrutinib-resistant ABC-DLBCL.

关 键 词：活化B细胞样弥漫大B细胞淋巴瘤 含布罗莫结构域蛋白4 布鲁顿酪氨酸激酶 超级增强子 BCR/NFκB信号通路 

分 类 号：R733.4[医药卫生—肿瘤] R730.23[医药卫生—临床医学]