BRD4在鳞状细胞癌中的表达及其对鳞状细胞癌细胞增殖和侵袭的影响

Expression of BRD4 in squamous cell carcinoma and its effects on cell proliferation and invasion ability

目的探讨溴含蛋白质4（BRD4）在鳞状细胞癌（简称鳞癌）组织和细胞中的表达，并研究其表达下调对鳞癌细胞增殖和侵袭的影响。方法采用免疫组织化学EnVision法检测食管鳞癌组织及正常食管鳞状上皮组织中BRD4蛋白的表达，Western blot检测不同鳞癌细胞和正常鳞状上皮细胞中BRD4蛋白的表达。将BRD4siRNA和对照siRNA转染鳞癌Eca109细胞，实验分为3组：未处理组、对照siRNA组和BRD4siRNA组，利用Western blot检测3组鳞癌Eca109细胞中BRD4蛋白的表达。利用CCK8检测3组细胞的增殖能力，采用Transwell小室检测3组细胞的侵袭能力．最后采用Western blot检测3组细胞中基质金属蛋白酶（MMP）2和MMP9的表达。结果BRD4蛋白在鳞癌组织中表达的阳性率显著高于正常鳞状上皮组织，4株鳞癌细胞中BRD4的表达均高于正常食管鳞状上皮细胞Het-1A。BRD4siRNA能显著下调鳞癌Eca109细胞中BRD4蛋白的表达，其表达下调能显著抑制鳞癌Eca109细胞的增殖和侵袭能力（均P〈0．05），并下调MMP2和MMP9的表达。结论BRD4与鳞癌细胞的增殖和侵袭密切相关，因而可能成为鳞癌潜在的治疗靶点。

Objective To investigate the expression of BRD4 in squamous cell carcinoma （SCC） tissues and cells, and the effects of its expression on cell proliferation and invasion ability. Methods hnmunohistochemistry was used to detect BRD4 protein expression in SCC tissues and paired nornlal esophageal squamous epithelial tissues. The expression of BRD4 protein was detected in different SCC cell lines and normal esophageal squamous epithelial cells by Western blot. BRD4 siRNA and control siRNA were used to transfect SCC Ecal09 cells, and experiments were divided into three groups： untreated group, control siRNA group and BRD4 siRNA group. Western blot was employed to investigate the expression of BRD4 protein in the three groups of SCC Ecal09 cells. CCK-8 kit was utilized to detect cell proliferation ability, and Transwell chamber was used to examine cell invasion ability. Finally, Western blot was used to detect the expression of MMP2 and MMP9 proteins. Results The positive rate of BRD4 protein expression in SCC tissues was significantly higher than that of normal squamous epithelial tissues. The expression of BRD4 protein in 4 SCC cell lines was higher than that in normal esophageal cell Het-lA. BRD4 siRNA obviously downregulated the expression of BRD4 protein in Ecal09 cells, and its downregulation contributed to the suppression of cell proliferation and invasion ability in Ecal09 cells （all P〈0. 05） , coupled with the decreases of MMP2 and MMP9 proteins. Conclusion BRD4 may be closely associated with the proliferation and invasion of SCC, and it thus may be a potential therapeutic target for SCC.