[摘要] 目的：探讨具有IQ 结构域的GTP 激酶活化蛋白1（Ras GTPase-activating-like protein, IQGAP1）在食管鳞状细胞癌（esophageal squamous cell carcinoma，ESCC）组织与细胞中的表达及其对TE-2 细胞增殖及侵袭能力的影响。方法: 收集2015 年1 月至2016 年12 月郑州大学附属肿瘤医院125 例ESCC手术切除的癌及癌旁组织标本，以及ESCC细胞系TE-2、TE-3、ECA109 和正常食管上皮细胞株Het-1A。用免疫组化染色法检测癌组织中IQGAP1 的表达，分析其表达水平与临床病理特征的关系；用qPCR和Western blotting 检测ESCC细胞中IQGAP1 mRNA和蛋白的表达。用si-IQGAP1（阳性转染组）、si-CTRL（阴性对照组）质粒转染TE-2 细胞，用MTT法、Transwell 小室法和Western blotting 分别检测沉默IQGAP1 对TE-2 细胞增殖、侵袭能力以及上皮钙黏蛋白和神经钙黏蛋白表达的影响。结果: IQGAP1 在ESCC组织中的阳性表达率明显高于癌旁组织（P<0.05），其高表达与肿瘤分期和分级密切相关（均P<0.05）；IQGAP1 mRNA和蛋白在TE-2、TE-3、ECA109 细胞中表达水平显著高于Het-1A细胞（均P<0.05）。沉默IQGAP1 后，与阴性对照组和空白组比较，阳性转染组TE-2 细胞中IQGAP1 mRNA及蛋白的表达水平明显下降（均P<0.05）；细胞的增殖和侵袭能力显著降低（均P<0.05），上皮钙黏蛋白表达水平升高（P<0.05），神经钙黏蛋白表达水平下降（P<0.05）。结论: IQGAP1 在ESCC组织中高表达，敲减IQGAP1 可抑制ESCC细胞的增殖和侵袭能力，其在ESCC的发生发展过程中起重要的作用。

[Abstract] Objective: To explore the expression of IQGAP1 (Ras GTPase-activating-like protein containing IQ domain) in esophageal squamous cell carcinoma (ESCC) tissues and cell lines and its effect on the proliferation and invasion of TE-2 cell. Methods: Totally 125 pairs of cancer tissues and para-cancerous tissues from ESCC patients, who underwent surgical resection in Affiliated Tumor Hospital of Zhengzhou University from January 2015 to December 2016, were included in this study; in addition, ESCC cell lines (TE-2, TE-3, ECA109) and normal esophageal epithelial cell line Het-1A were also collected. The expression of IQGAP1 was detected by immunohistochemical staining and its relationship with cliniopathological features was also analyzed. IQGAP1 mRNA and protein expressions in ESCC cell lines were detected by Real-time quantitative PCR (qPCR) and Western blotting, respectively. TE-2 cells were transfected with si-IQGAP1 (positive transfection group) and si-CTRL (negative control group) plasmids, and the effects of IQGAP1 silencing on the proliferation and invasion of TE-2 cells were detected by MTT and Transwell assay. The expressions of E-cadherin and Ncadherin were detected by Western blotting. Results: The positive expression rate of IQGAP1 in ESCC tissues was significantly higher than that in para-cancerous tissues (P<0.05), which was closely related to tumor stage and histologic grade (all P<0.05). The mRNA and protein expressions of IQGAP1 in TE-2, TE-3 and ECA109 cells were significantly higher than those in Het-1A cells (all P<0.05). After IQGAP1 was silenced, compared with the negative control group and the blank group, the expression of IQGAP1 mRNA and protein in the positive transfection group significantly decreased (all P<0.05); the proliferation and invasiveness of TE-2 cells significantly decreased (all P<0.05); E-cardherin was up-regulated while N-cardherin was down-regulated (all P<0.05) in the positive interference group. Conclusion: IQGAP1 is highly expressed in ESCC tissues, and si-IQGAP1 can inhibit the proliferation and invasion of TE-2 cells, which plays an important role in the occurrence and development of ESCC.

河南省医学科技攻关计划资助项目（No.201702246）