奚小荔?周浩雄?杨碧兰?吴斌?杨逸冬

【摘要】目的 研究富含亮氨酸的重復序列蛋白1（LRRC1）通过巨盘状蛋白1（DLG1）/Yes相关蛋白（YAP）信号通路调节肝癌细胞增殖的机制。方法 在原发性肝细胞癌患者的癌灶组织及配对癌旁组织中，检测LRRC1的表达水平。使用小干扰RNA（siRNA）抑制HepG2及Huh7中LRRC1的表达后，检测细胞增殖能力及YAP、细胞周期蛋白D1（Cyclin D1）和细胞周期蛋白依赖性激酶4（CDK4）表达水平。通过共聚焦显微镜，定位HepG2细胞中LRRC1与DLG1分布。结果 肝细胞癌患者癌灶中LRRC1表达量较癌旁组织升高。siRNA 抑制HepG2及Huh7细胞中LRRC1基因表达后，细胞增殖能力受到抑制，YAP、Cyclin D1及CDK4表达水平下降。镜下发现HepG2细胞中LRRC1与DLG1均主要分布于细胞膜内侧面，两者分布位置高度重叠。结论 LRRC1通过DLG1/YAP信号通路调控细胞周期，促进肝癌细胞增殖。

【关键词】肝细胞癌;富含亮氨酸的重复序列蛋白1;巨盘状蛋白1;细胞周期;增殖

LRRC1 promotes proliferation of hepatocellular carcinoma cells via DLG1/YAP signaling pathway Xi Xiaoli， Zhou Haoxiong， Yang Bilan， Wu Bin， Yang Yidong. Department of Gastroenterology， the Third Affiliated Hospital of Sun Yat-sen University， Guangzhou 510630， China

Corresponding author， Yang Yidong， E-mail： yangyd6@ mail. sysu. edu. cn

【Abstract】Objective To investigate the mechanism of leucine-rich repeat-containing protein 1 （LRRC1） in regulating the proliferation of hepatocellular carcinoma （HCC） cells through the discs large MAGUK scaffold protein 1/Yes associated transcriptional regulator （DLG1/YAP） signaling pathway. Methods The expression levels of LRRC1 protein in the cancer tissues and paired adjacent tissues of HCC patients were detected by Western blot and immunohistochemistry. After down-regulating the expression levels of LRRC1 protein by using small interfering RNA （siRNA） in liver cancer cell lines HepG2 and Huh7， cell proliferation ability was detected by cell counting kit-8 （CCK-8 kit） for three times. The expression levels of YAP protein， Cyclin D1 and cyclin dependent kinase 4 （CDK4） were detected by Western blot. Finally， the distribution of LRRC1 and DLG1 proteins expressed in HepG2 cells was located by immunofluorescence under confocal microscope. Results The expression level of LRRC1 protein in the cancer tissues of HCC patients was significantly higher than that in the paired adjacent tissues. After down-regulating the expression levels of LRRC1 protein in both HepG2 and Huh7 cell lines by siRNA， the cell proliferation ability was significantly inhibited， and the expression levels of YAP protein， Cyclin D1 and CDK4 were down-regulated. Confocal microscope demonstrated that LRRC1 and DLG1 proteins were mainly distributed on the inner surface of HepG2 cell membrane. The distribution patterns of them were highly overlapped. Conclusions LRRC1 can regulate the cell cycle through the DLG1/YAP signaling pathway， thereby promoting the proliferation of HCC cells.

【Key words】Hepatocellular carcinoma;Leucine-rich repeat-containing protein 1;

Discs large MAGUK scaffold protein 1;Cell cycle;Proliferation

肝细胞癌是肝癌最主要的病理分型，具有高发病率及高病死率的特点，但是，肝细胞癌的具体分子发病机制尚不明确。既往研究显示，肝细胞癌与其他上皮来源的恶性肿瘤类似，组织结构改变以及细胞极性丢失是导致肝细胞癌发生、发展的重要机制，而极性蛋白LAP家族具有维持组织正常结构和细胞极性的重要功能，其功能异常或者异常表达参与了多种肿瘤的发生、发展[1]。富含亮氨酸的重复序列蛋白1（LRRC1）是一种524个氨基酸的蛋白，也称为LANO蛋白，其属于LAP蛋白家族[2]。研究显示，LRRC1在肝癌中具有促进癌细胞增殖的作用，但未对其具体分子机制进行进一步研究[3]。……