EpCAM和HDAC6在前列腺癌中的表达及其对前列腺癌细胞迁移的影响

Expression of EpCAM and HDAC6 in prostate cancer and their effects on cell migration

目的探讨上皮细胞黏附分子(epithelial cell adhesion molecule,EpCAM)和组蛋白去乙酰化酶6(histone deacetylase,HDAC6)蛋白在前列腺癌及癌旁良性组织中的表达及与前列腺癌临床病理特征的关系,并分析两蛋白之间的相关性。探讨沉默EpCAM对前列腺癌细胞迁移及上皮-间质转化(epithelial-mesenchymal transition,EMT)的影响。方法利用TIMER和UALCAN数据库分析EpCAM和HDAC6 mRNA在各种癌症中的表达情况及在前列腺癌和正常前列腺组织中的表达差异。采用免疫组化法观察EpCAM和HDAC6蛋白在前列腺癌和癌旁良性组织中的表达情况,分析两者间的相关性及与前列腺癌临床病理特征的关系。通过体外实验检测沉默EpCAM蛋白对前列腺癌细胞迁移能力的影响。Western blot实验检测前列腺癌细胞中EMT相关蛋白的表达。结果数据库分析结果显示,EpCAM和HDAC6 mRNA在前列腺癌中均呈高表达,且与前列腺癌Gleason评分和淋巴结转移相关。前列腺癌组织中EpCAM蛋白高表达率高于癌旁良性组织(62.61%vs 21.62%,P<0.001)。EpCAM蛋白高表达与肿瘤大小及浸润程度、Gleason评分和WHO/ISUP预后分级分组有关(P均<0.05)。前列腺癌组织中HDAC6蛋白高表达率高于癌旁良性组织(81.74%vs 43.24%,P<0.001),其表达与WHO/ISUP预后分级分组具有一定相关性(P=0.05),但差异无统计学意义。Starbase数据库检索结果显示,前列腺癌组织中EpCAM与HDAC6 mRNA的表达呈正相关(r=0.206,P=3.44e-06)。Spearman秩相关检验显示,前列腺癌组织中EpCAM与HDAC6蛋白表达呈正相关(r=0.454,P<0.001)。si-EpCAM转染DU-145前列腺癌细胞后,EpCAM和HDAC6蛋白表达减少;与si-NC组相比,si-EpCAM组的迁移、侵袭能力明显下调(P<0.001),EMT相关蛋白E-cadherin表达上调,vimentin表达下调。结论前列腺癌组织中EpCAM和HDAC6高表达与肿瘤的发生、发展和恶性程度有关。沉默EpCAM表达可抑制HDAC6表达,抑制DU145细胞侵袭能力,逆转EMT进程,EpCAM和HDAC6可作为前列腺癌诊断和判断预后的潜在标志物。

Purpose To observe the expression of epithelial cell adhesion molecule(EpCAM)and histone deacetylase(HDAC6)proteins in prostate cancer and benign tissue adjacent to cancer,to examine the relationship between the expression of EpCAM and HDAC6 proteins and clinicopathological characteristics and to investigate the impact of EpCAM silencing on prostate cancer cell migration and epithelia-mesenchymal transition(EMT).Methods The expression levels of EpCAM and HDAC6 mRNAs in different types of cancers were analyzed using TIMER and UALCAN database retrieval.The expression levels of EpCAM and HDAC6 proteins were observed in prostate cancer and benign tissue adjacent to cancer through immunohistochemical staining.The correlation between these two proteins was also analyzed.The impact of silencing EpCAM protein on the migration ability of prostate cancer cells was verified through cell scratch and migration experiments.The influence of EpCAM on EMT in prostate cancer cells was confirmed using Western blot analysis.Results The database analysis revealed that the expression of EpCAM and HDAC6 mRNAs was higher in prostate cancer compared to normal prostate tissue.This expression was found to be associated with the Gleason score and lymph node metastasis.Immunohistochemical staining results demonstrated that the positive expression rate of EpCAM protein in prostate cancer tissue was 62.61%,which was significantly higher than that in benign tissue adjacent to cancer(21.62%,P<0.001).The high expression of EpCAM protein in prostate cancer was correlated with tumor size,infiltration,Gleason score,and WHO/ISUP grade(all P<0.05),but not with age,PSA,and lymph node metastasis.Similarly,the positive expression rate of HDAC6 protein in prostate cancer tissue was 81.74%,which was significantly higher than that in benign tissue adjacent to cancer(43.24%,P<0.001).However,there was no significant correlation with age,tumor size,infiltration,Gleason score,PSA,and lymph node metastasis.The starbase data retrieval results indicated a positive correlation between EpCAM and HDAC6 mRNAs expression in prostate cancer tissues(r=0.206,P=3.44e-06).A positive correlation between EpCAM and HDAC6 proteins expression in prostate cancer tissue was observed through the Spearman rank correlation test(r=0.454,P<0.001).Following si-EpCAM transfection into DU-145 prostate cancer cells,the expression of EpCAM and HDAC6 proteins decreased.The si-EpCAM group exhibited a significant downregulation in migration and invasion ability compared to the si-NC group(P<0.001).Additionally,the expression of the EMT related protein E-cadherin was upregulated,while the expression of vimentin was downregulated.Conclusion The higher expression level of EpCAM and HDAC6 proteins in prostate cancer tissues suggests a relationship with the occurrence,development,and degree of malignancy.Silencing the expression of EpCAM protein in prostate cancer cells also reduces the expression of HDAC6 protein,inhibits DU145 cell migration and reverses EMT progression.EpCAM and HDAC6 have the potential to serve as markers for diagnosis and prognosis of prostate cancer.