Yan Guoxin, Zou Ronghai, Chen Zhenggang, Fan Bing, Wang Zhaoyan, Wang Ying, Yin Xiaonan, Zhang Dong, Tong Lei, Yang Fang, Jiang Weina, Fu Wensheng, Zheng Jiwei, Bergo Martin O, Dalin Martin, Zheng Jiawei, Chen Shulan, Zhou Jianhua
Acta Biochim Biophys Sin (Shanghai). 2014 Aug;46(8):682-90. doi: 10.1093/abbs/gmu051.
Ras homolog gene family member A (RhoA) has been identified as a critical regulator of tumor aggressive behavior. In this study, we assessed the role of RhoA in the mechanisms underlying growth, migration, and invasion of squamous cell carcinoma of tongue (TSCC). Stable RhoA knockdown of TSCC cell lines SCC-4 and CAL27 were achieved using Lentiviral transfection. The effects of RhoA depletion on cell migration, invasion, and cell proliferation were determined. The possible underlying mechanism of RhoA depletion on TSCC cell line was also evaluated by determining the expression of Galectin-3 (Gal-3), β-catenin, and matrix metalloproteinase-9 (MMP-9) in vivo. Meanwhile, the underlying mechanism of TSCC growth was studied by analysis of cyclin D1/2, p21CIP1/WAF1, and p27Kip1 protein levels. Immunohistochemical assessments were performed to further prove the alteration of Gal-3 and β-catenin expression. We found that, in mice injected with human TSCC cells in the tongue, RhoA levels were higher in primary tumors and metastasized lymph nodes compared with those in the normal tissues. Silencing of RhoA significantly reduced the tumor growth, decreased the levels of Gal-3, β-catenin, MMP-9, and cyclin D1/2, and increased the levels of p21CIP1/WAF1 and p27Kip1. In vitro, RhoA knockdown also led to inhibition of cell migration, invasion, and proliferation. Our data suggest that RhoA plays a significant role in TSCC progression by regulating cell migration and invasion through Wnt/β-catenin signaling pathway and cell proliferation through cell cycle regulation, respectively. RhoA might be a novel therapeutic target of TSCC.
Ras同源基因家族成员A（RhoA）已被确定为肿瘤侵袭性行为的关键调节因子。在本研究中，我们评估了RhoA在舌鳞状细胞癌（TSCC）生长、迁移和侵袭机制中的作用。使用慢病毒转染实现了TSCC细胞系SCC - 4和CAL27的RhoA稳定敲低。确定了RhoA缺失对细胞迁移、侵袭和细胞增殖的影响。还通过测定体内半乳糖凝集素-3（Gal-3）、β-连环蛋白和基质金属蛋白酶-9（MMP-9）的表达来评估RhoA缺失对TSCC细胞系的潜在机制。同时，通过分析细胞周期蛋白D1/2、p21CIP1/WAF1和p27Kip1蛋白水平来研究TSCC生长的潜在机制。进行免疫组织化学评估以进一步证明Gal-3和β-连环蛋白表达的改变。我们发现，在舌部注射人TSCC细胞的小鼠中，与正常组织相比，原发性肿瘤和转移淋巴结中的RhoA水平更高。RhoA的沉默显著降低了肿瘤生长，降低了Gal-3、β-连环蛋白、MMP-9和细胞周期蛋白D1/2的水平，并增加了p21CIP1/WAF1和p27Kip1的水平。在体外，RhoA敲低也导致细胞迁移、侵袭和增殖受到抑制。我们的数据表明，RhoA通过分别通过Wnt/β-连环蛋白信号通路调节细胞迁移和侵袭以及通过细胞周期调节细胞增殖，在TSCC进展中发挥重要作用。RhoA可能是TSCC的一个新的治疗靶点。
