中文摘要：

目的观察食管鳞癌组织中Polo样激酶1（PLKl）的表达变化，及其对食管癌细胞侵袭迁移能力的影响。方法采用免疫组化sP法检测80例食管鳞癌及癌旁组织中的PLKl，分析其与食管鳞癌临床病理参数及患者生存期的关系。将对数生长期的人食管癌EC9706细胞分为两组，观察组转染PLKlsiRNA，对照组转染ScrambledsiRNA；用Transwell小室观察两组食管癌细胞侵袭及迁移能力，Westernblot法检测两组食管癌细胞中的PLKl、MMP-2、MMP-9。结果食管鳞癌组织中PLKl阳性表达53例（66．3％），癌旁组织中PLKl阳性表达27例（33．7％）；两者比较，P〈0．05。PLKl表达与食管鳞癌淋巴结转移及临床分期有关（P均〈0．05）。PLKl阴性者5年生存率为62％，高于PLKl阳性者的39％（P〈0．05）。多因素Cox回归分析显示，临床分期、淋巴结转移、病理分级、PLKl表达均为食管癌预后的独立危险因素。观察组EC9706侵袭迁移个数分别为（120±6）、（269±8）个／HP，对照组分别为（468±11）、（7804-12）个／HP；两组比较，P均〈0．05。观察组EC9706中PLKl、MMP-2、MMP-9灰度比值分别为0．1±0．03、0．40±0．02、0．87±0．05，对照组分别为0．96±0．05、0．98±0．07、0．89±0．06；两组PLKl、MMP-2灰度比值比较，P均〈0．05。结论食管鳞癌组织中PLKl表达增加，其在食管鳞癌的发生发展中起重要作用；敲降PLKl表达可降低食管癌细胞的侵袭迁移能力，该作用与MMP一2的表达下调有关。

英文摘要：

Objective To investigate the expression of PLK1 protein in esophageal squamous cell carcinoma （ESCC） and explore its effects on invasion and migration of ESCC cells. Methods Immunohistochemical staining method of SP was used to examine 80 samples of ESCC. The effects of PLK1 on invasion and migration of EC9706 cells was detected after PLK1 knockdown. Results Positive expression of PLK1 in 53 （66.3%） ESCC tissues was found, negative expression was 27 （33.7%）. Significant different was found between ESCC tissues and normal tissues in PLK1 expression （ P 〈 0.05）. Its level was significantly associated with lymph node metastasis and clinical stage （ all P 〈 0.05）. No correlation was found between PLK1 expression and tumor differentiation. Significant correlation was found between PLK1 expression and prognosis of patients. Multivariate analysis showed the clinical stage, lymph node metastasis and PLK1 expression were the independent prognosis factor, respectively（ all P 〈 0.01 ）. The invasion and migration ability of EC9706 ceils decreased significantly after PLK1 knockdown（P 〈0.01 ）. The expression of MMP-2 decreased after PLK1 knockdown. Conclusion PLK1 may play an important role in ESCC and thus be the potential gene therapy target for ESCC.