极性蛋白PARD3对结直肠癌转移的影响

Effect of PARD3 on metastasis of colorectal cancer

目的观察极性蛋白PARD3在结直肠癌转移中的作用。方法应用免疫组织化学和Western blot检测38例结直肠癌组织标本中PARD3的表达，探讨PARD3与临床病理特征的相关性。实时定量反转录聚合酶链反应（RT-qPCR）和Western blot分别检测结直肠癌细胞中PARD3中的表达。通过RNA干扰技术敲除PARD3后，检测上皮-间充质转化（EMT）相关蛋白表达变化及Transwell实验检测细胞迁移能力的改变。结果结直肠癌组织中PARD3表达水平明显低于正常切缘组织（0.33±0.03比0.47±0.03）。PARD3低表达与患者性别、年龄及肿瘤浸润程度无明显相关（P＝0.209、0.405、1.000），而与淋巴结转移明显相关（P＝0.013）。PARD3在结直肠癌细胞株中均表达，其中SW620和LoVo中PARD3表达水明显低于其他结直肠癌细胞。SW480和LoVo细胞敲除PARD3后，E-钙黏蛋白（E-cadherin）表达降低，N-钙黏蛋白（N-cadherin）和波形蛋白（Vimentin）表达升高。Transwell实验显示小干扰RNA（siRNA）转染组中细胞穿过膜的数量明显多于对照组（214.00±35.93比66.00±13.45、521.00±26.27比146.00±23.29）。 结论PARD3表达下调促进结直肠癌转移。

ObjectiveTo observe the effect of PARD3 of the metastasis of colorectal cancer. MethodsImmunohistochemistry and Western blotting were performed to verify the expression of PARD3 in 38 cases of colorectal cancer tissues and the relationship between PARD3 and clinical features was analyzed. The expression of PARD3 in colorectal cancer cell lines was examined by real-time quantitative reverse transcriptase-polymerase chain reaction （RT-qPCR） and Western blotting. With the knockdown of PARD3 by specific small interfering RNA （siRNA）, the alternation of epithelial-mesenchymal transition （EMT） relative proteins was observed and the ability of migration was measured by the Transwell assay. ResultsThe expression of PARD3 in colorectal cancer tissues was significantly lower than that in the corresponding normal tissues （0.33±0.03 vs. 0.47±0.03）. The PARD3 expression was not obviously correlated with gender, age and tumor invasion depth （P=0.209, 0.405, 1.000）, but significantly correlated with lymph node metastasis （P=0.013）. PARD3 could be detected in all colorectal cancer cell lines and the expression level in SW620 and LoVo was significantly lower than that in other cell lines. After knockdown of PARD3 in SW480 and LoVo cells, the E-cadherin level decreased coincidengtly, and N-cadherin and Vimentin increased. Transwell assay revealed that the number of penetrating cells in the siPARD3 group was significantly more than that in siControl group （214.00±35.93 vs. 66.00±13.45, and 521.00±26.27 vs. 146.00±23.29）. ConclusionDown-regulated expression of PARD3 promotes the metastasis of colorectal cancer.