Caveolin-2 is regulated by BRD4 and contributes to cell growth in pancreatic cancer
Caveolin-2 is regulated by BRD4 and contributes to cell growth in pancreatic cancer
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Caveolin-2 受 BRD4 调节并有助于胰腺癌细胞生长
DOI：
10.1186/s12935-020-1135-0
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发表时间：
2020-02-18
影响因子：
5.8
通讯作者：
Wang, Liwei
中科院分区：
文献类型：
--
作者：
Jiao, Feng;Han, Ting;Wang, Liwei
背景蛋白质的溴结构域和末端外结构域（BET）家族，特别是BRD 4在表观遗传调控中起着重要作用，对细胞的生存至关重要，也是有希望的抗癌靶点。本研究旨在分析BRD 4对胰腺癌细胞生长和进展的影响及其新的机制。方法采用Western blotting、免疫组化和真实的时间PCR方法检测76例胰腺癌组织及癌旁组织中BRD 4的表达。分析其与胰腺癌患者临床病理特征及预后的关系。采用集落形成实验和磺酰罗丹明B实验检测BRD 4对细胞增殖的影响。通过Transwell测定确定迁移和侵袭，并在裸鼠中验证BRD 4对皮下肿瘤形成的作用。流式细胞仪检测细胞周期。通过RNA测序、染色质免疫沉淀和双荧光素酶报告基因分析，阐明BRD 4的潜在下游靶点及相关分子机制。生物学结果表明，BRD 4在体内外均具有促癌作用，促进细胞增殖、迁移和侵袭。进一步通过RNA测序，选择小窝蛋白-2作为BRD 4的下游基因。Caveolin-2过表达可部分逆转BRD 4敲低引起的细胞生长能力下降，但不影响细胞的迁移和侵袭。染色质免疫沉淀实验和双荧光素酶报告基因实验表明BRD 4可以与caveolin-2的启动子区结合，上调caveolin-2的表达。临床数据进一步表明BRD 4和小窝蛋白-2表达之间正相关。BRD 4（高）/小窝蛋白-2（高）与胰腺癌患者的总生存期较短相关。多变量分析表明，BRD 4和小窝蛋白-2是独立的factors.ConclusionsOur研究结果揭示了致癌作用的BRD 4在胰腺癌和阐明一种可能的机制，BRD 4和小窝蛋白-2的行为，以增强细胞生长。通过开发BET抑制剂靶向BRD 4-小窝蛋白-2相互作用将是胰腺癌的治疗策略。
BackgroundThe bromodomain and extra-terminal domain (BET) family of proteins, especially BRD4 play an important role in epigenetic regulation, and are essential for cell survival and also are promising anticancer targets. This study aims to analyze the effect of BRD4 on the cell growth and progression of pancreatic cancer and novel mechanisms involved.MethodsExpression of BRD4 in pancreatic cancer and paired adjacent noncancerous tissues from 76 patients was analyzed by western blotting, immunohistochemistry, and real time PCR. Its correlation with the clinicopathological characteristics and prognosis of pancreatic cancer patients was analyzed. The effects of BRD4 on the cell proliferation were detected by colony formation assay and sulforhodamine B assay. Migration and invasion were determined by Transwell assays, and the effect of BRD4 on subcutaneous tumor formation was verified in nude mice. Cell cycle analysis was detected by flow cytometry. The potential downstream targets of BRD4 and related molecular mechanisms were clarified by RNA sequencing, chromatin immunoprecipitation and dual luciferase reporter assay.ResultsBRD4 was overexpressed in pancreatic cancer. Biological results showed that BRD4 functioned as tumor promoter, facilitated cell proliferation, migration and invasion in vitro and in vivo. Further, caveolin-2 was selected as the downstream gene of BRD4 by RNA sequencing. Caveolin-2 overexpression can partially reverse the decreased cell growth ability caused by BRD4 knockdown, but did not affect cell migration and invasion. Chromatin immunoprecipitation assay and dual luciferase reporter assay revealed BRD4 could bind to the promoter region of caveolin-2 and upregulate caveolin-2 expression. Clinical data further indicated a positive correlation between BRD4 and caveolin-2 expression. BRD4 (high)/caveolin-2 (high) correlated with shorter overall survival of patients with pancreatic cancer. Multivariate analysis revealed that both BRD4 and caveolin-2 were independent factors.ConclusionsOur findings reveal the oncogenic effects of BRD4 in pancreatic cancer and elucidate a possible mechanism by which BRD4 and caveolin-2 act to enhance cell growth. Targeting the BRD4-caveolin-2 interaction by development of BET inhibitors will be a therapeutic strategy for pancreatic cancer.