溴结构域蛋白4影响胃癌恶性生物学行为的机制研究

Mechanism of 4-bromo-domain Proteins Affect the Malignant Behavior of Gastric Cancer

目的探讨溴结构域蛋白4(bromodomain-containing Protein4,BRD4)影响胃癌细胞恶性生物学行为的潜在分子机制。方法在胃癌细胞HGC27和AGS中使用BRD4抑制剂JQ1,通过免疫印迹实验(western blot,WB)检测BRD4及c-MYC的蛋白水平改变,采用细胞活性测定(CCK-8)实验检测细胞增殖情况。运用shRNA构建BRD4敲减的稳定胃癌细胞HGC27和AGS,通过Western Blot验证BRD4的敲减效率,采用流式细胞术检测细胞凋亡,采用Transwell实验分析侵袭转移等恶性生物学行为。结果在胃癌细胞HGC27和AGS中,BRD4抑制剂JQ1可显著下调c-MYC的蛋白水平,且具有一定的浓度依赖性;JQ1分别与5-氟尿嘧啶(5-FU)、顺铂(cisplatin)、紫杉醇(paclitaxel)三种抗肿瘤化疗药物联合使用,明显抑制了胃癌细胞的增殖能力,且具有一定的时间、浓度依赖性。此外,敲减BRD4可促进胃癌细胞凋亡,抑制胃癌细胞的侵袭转移能力。结论BRD4在胃癌的增殖及侵袭转移等恶性进程中起到了重要的作用,有望成为胃癌临床治疗的潜在靶点。

Objective To explore the potential molecular mechanism of bromodomain protein 4(BRD4)affecting the malignant biological behavior of gastric cancer cells.Methods The BRD4 inhibitor JQ1 was used in gastric cancer cells HGC27 and AGS and the protein levels of BRD4 and c-MYC were detected by Western Blot.The cell proliferation was detected by cell viability assay(CCK-8).The gastric cancer cells HGC27 and AGS were constructed by shRNA and the knockdown efficiency of BRD4 was verified by Western Blot.The apoptosis was detected by flow cytometry.Transwell experiments were used to analyze the malignant biological behaviors such as invasion and migration.Results In gastric cancer cells HGC27 and AGS,BRD4 inhibitor JQ1 significantly downregulated the protein level of c-MYC in a concentration-dependent manner;JQ1 was associated with 5-fluorouracil(5-FU)and Cisplatin,respectively.Paclitaxel combined with three anti-tumor chemotherapeutic drugs significantly inhibited the proliferation of gastric cancer cells in a time-and concentration-dependent manner.In addition,knockdown of BRD4 can promote gastric cancer cell apoptosis and inhibit the invasion and metastasis of gastric cancer cells.Conclusion BRD4 plays an important role in the malignant process of gastric cancer proliferation,invasion and metastasis,and it is expected to become a potential target for clinical treatment of gastric cancer.