Liu Huancai, Chen Yanchun, Zhou Fenghua, Jie Linlin, Pu Leidong, Ju Jie, Li Fengjie, Dai Zhigang, Wang Xin, Zhou Shuanhu
Department of Orthopedics, Clinical College, Weifang Medical University Weifang, Shandong, P.R. China.
Department of Histology and Embryology, Weifang Medical University Weifang, Shandong, P.R. China.
Int J Clin Exp Pathol. 2014 Jul 15;7(8):4795-805. eCollection 2014.
Osteosarcoma (OS) is the most common primary malignant bone tumor that has poor prognosis. Molecular mechanisms underlying disease progression remain largely unknown. Sox9, one of the Sox family transcription factors, is closely associated with the development of a variety of malignant tumors. This study investigates the expression of Sox9, Wnt1 and Fzd1 in human osteosarcoma tissues and cells and the role of Sox9 in the proliferation of human osteosarcoma cells. Immunohistochemical analyses for Sox9, Wnt1, Fzd1, and Ki-67 proteins were performed in human primary osteosarcoma tissues from 48 patients. The small interfering RNA (siRNA) of Sox9 was transfected into human osteosarcoma MG63 cells. At 24 and 48 h after transfection with Sox9 siRNA, the expression of Wnt1 and Fzd1 was analyzed by RT-qPCR, Western blot, and immunofluorescence techniques. Cell proliferation was assayed by CCK-8 method, and Ki-67 protein expression was analyzed by Western blot. Results showed that the expressions of Sox9, Wnt1, Fzd1, and Ki-67 proteins in human osteosarcoma tissues were higher than those in the adjacent non-cancerous tissues. Hyperexpressions of Sox9, Wnt1, Fzd1, and Ki-67 proteins occurred more frequently in human osteosarcoma tissues with an advanced clinical stage (IIb/III). Sox9 siRNA reduced both mRNA and protein expression levels of Wnt1 and Fzd1, which result in the distinct inhibition of MG63 cell proliferation. Our study suggests that Sox9 siRNA inhibits the proliferation capability of human osteosarcoma cells by down-regulating the expression of Wnt1 and its receptor Fzd1, which may provide new gene targets for the clinical treatment of osteosarcoma.
骨肉瘤（OS）是最常见的原发性恶性骨肿瘤，预后较差。疾病进展的分子机制在很大程度上仍不清楚。Sox9是Sox家族转录因子之一，与多种恶性肿瘤的发生发展密切相关。本研究调查了Sox9、Wnt1和Fzd1在人骨肉瘤组织和细胞中的表达以及Sox9在人骨肉瘤细胞增殖中的作用。对48例患者的人原发性骨肉瘤组织进行了Sox9、Wnt1、Fzd1和Ki-67蛋白的免疫组织化学分析。将Sox9的小干扰RNA（siRNA）转染到人骨肉瘤MG63细胞中。在用Sox9 siRNA转染后24小时和48小时，通过RT-qPCR、蛋白质免疫印迹和免疫荧光技术分析Wnt1和Fzd1的表达。采用CCK-8法检测细胞增殖，并通过蛋白质免疫印迹分析Ki-67蛋白表达。结果显示，人骨肉瘤组织中Sox9、Wnt1、Fzd1和Ki-67蛋白的表达高于相邻的非癌组织。Sox9、Wnt1、Fzd1和Ki-67蛋白的高表达在临床分期较晚（IIb/III期）的人骨肉瘤组织中更常见。Sox9 siRNA降低了Wnt1和Fzd1的mRNA和蛋白表达水平，从而显著抑制了MG63细胞的增殖。我们的研究表明，Sox9 siRNA通过下调Wnt1及其受体Fzd1的表达来抑制人骨肉瘤细胞的增殖能力，这可能为骨肉瘤的临床治疗提供新的基因靶点。
