mortalin蛋白在宫颈鳞癌中的表达及其对肿瘤转移能力的影响

Mortalin expression in cervical squamous-cell carcinoma and its effect on tumor metastasis

目的:探讨寿命蛋白(mortalin)在子宫颈鳞癌组织中过表达的临床病理学意义及其与子宫颈鳞癌转移之间的关系。方法:应用免疫荧光染色在人子宫颈鳞癌SiHa细胞系中检测mortalin的定位情况,并采用免疫组化EnVision法检测mortalin在59例正常宫颈上皮组织和93例子宫颈鳞癌组织中的表达,分析mortalin表达与子宫颈鳞癌患者临床病理特征之间的关系;通过MTT实验筛选mortalin抑制剂MKT-077作用浓度及时间后,抑制SiHa细胞中mortalin表达并进行细胞划痕及迁移实验,Western blot检测参与上皮-间充质转化(EMT)相关蛋白的表达。结果:免疫荧光结果显示,mortalin定位于子宫颈鳞癌SiHa细胞质中。免疫组化结果表明,mortalin在子宫颈鳞癌组织中表达的阳性率和强阳性率分别为89.2%(83/93)和62.4%(58/93),显著高于正常宫颈上皮组织(23.7%和5.1%,P<0.01);mortalin表达水平与子宫颈鳞癌患者肿瘤组织学分级、临床分期及淋巴结转移密切相关(P<0.05)。通过MKT-077抑制SiHa细胞中mortalin的表达后,细胞划痕及迁移实验结果显示SiHa细胞的迁移能力下调,Western blot结果表明E-cadherin的表达明显上调,vimentin及Snail的表达明显下调(P<0.05)。结论:mortalin的表达水平与子宫颈鳞癌的发生发展及转移密切相关,该蛋白有望成为子宫颈癌患者预后评估的分子指标。

AIM:To investigate the significance of mortalin expression in clinical pathology of cervical squamous-cell carcinoma.METHODS:Immunofluorescence staining was used to detect the location of mortalin in human cervical squamous-cell carcinoma SiHa cells.The protein expression of mortalin was detected in 59 cases of normal cervical epithelial tissues and 93 cases of cervical squamous-cell carcinoma tissues by immunohistochemical staining,and its correlation with clinicopathological features of cervical squamous-cell carcinoma was also analyzed.MTT assay was used to evaluate the optimal concentration and dosing time of mortalin inhibitor MKT-077.After the protein expression of mortalin in SiHa cells was inhibited,wound-healing and migration assays were performed.The protein expression of epithelial-mesenchymal transition(EMT)-related molecules was determined by Western blot.RESULTS:Immunofluorescence staining showed that mortalin was located in the cytoplasm of SiHa cells.The positive rate and strongly positive rate of mortalin in the cervical squamous-cell carcinoma patients were 88.7%(55/62)and 61.3%(38/62),respectively,and they were significantly higher than those in normal cervical epithelial tissues(23.7%and 5.1%,P<0.01).Additionally,mortalin expression was statistically correlated with the histological grade,clinical stage and lymph node metastasis.After inhibiting the expression of mortalin in the SiHa cells by MKT-077,the results of wound-healing and migration assays showed that the migration ability of SiHa cells was down-regulated.The protein expression of E-cadherin was up-regulated,and vimentin and Snail were significantly down-regulated.CONCLUSION:Mortalin over-expression is an effective biomarker for prediction of malignant potential and poor prognosis of cervical squamous-cell carcinoma.