摘要目的 探讨P21活化激酶1(PAK1)在膀胱癌组织中的表达和其对膀胱癌细胞侵袭能力的生物学影响.方法 免疫组化法检测2009年1月至2012年12月在复旦大学附属金山医院手术获取的54份膀胱癌组织蜡块和12份正常膀胱组织蜡块中PAK1的表达情况,实时荧光定量PCR、Western印迹实验验证PAK1在膀胱癌细胞系和正常膀胱上皮细胞系中的表达差异.构建PAK1基因沉默的膀胱癌5637细胞稳定株,Transwell法检测PAK1基因沉默的膀胱癌5637细胞迁移及侵袭能力的改变.结果 PAK1在膀胱癌组织的表达明显高于正常膀胱上皮组织(28/54比1/12,P＜0.05),其高表达与高级别病理分级、淋巴转移以及肿瘤直径等呈正相关(均P＜0.05).膀胱癌细胞系T24、5637中PAK1的mRNA和蛋白水平明显高于正常膀胱上皮细胞系SV-HUC-1,PCR和Westem印迹实验证实PAK1-短发夹RNA (shRNA)对膀胱癌5637细胞中PAK1表达抑制效果理想,迁移和侵袭实验证实PAK1基因沉默的膀胱癌5637细胞穿过小室数目较对照组减少.结论 膀胱癌组织中PAK1高表达是一个重要特征,与膀胱癌细胞迁移及侵袭能力有关,其调控的分子机制有待进一步深入研究.

abstractsObjective To investigate the expression of p21-activated kinase 1 (PAK1) in bladder cancer and its biological influence on invasion ability of bladder cancer cells.Methods A total of 54 paraffin-embedded bladder cancer tissue samples and 12 normal bladder tissue specimens were retrieved in Jinshan Hospital Mfiliated to Fudan University between January 2009 and December 2012.The expression of PAK1 in these tissues was detected by immunohistochemical staining.The PAK1 mRNA and protein levels were measured in bladder cancer cell lines and human normal bladder epithelial cell line using real-time,fluorescence-based quantitative polymerase chain reaction (RT-PCR) and Western blot,respectively.A stable PAK1 gene silencing bladder cancer cell strain 5637 were successfully constructed.After treatment with PAK1 RNA interference(RNAi),the ability of migration and invasion of the 5637 cell was evaluated using a Transwell system.Results The expression of PAK1 proteins was significantly higher in bladder cancer tissues than in normal bladder tissues (28/54 vs 1/12,P ＜ 0.05).The overexpression of PAK1 was positively correlated with high histological grade,lymph node metastasis,and tumor size (all P ＜ 0.05).The mRNA level and protein level of PAK1 was much higher in bladder cancer cell lines T24,5637 than human normal urothelial cell line SV-HUC-1.PCR and Western blot showed satisfactory inhibitory effect of PAK1 short hairpin RNA (shRNA) on PAK1 expression in 5637 bladder cancer cells.The number of PAK1 RNAi-treated 5637 cells traversed the membrane was decreased compared with the control group in migration and invasion assays.Conclusions Overexpression of PAK1 in bladder cancer tissues may be an important feature of bladder cancer and related with the metastasis and invasion of bladder cancer.The molecular mechanisms involved in regulation of PAK1 expression needs further research.