中文摘要：

目的探讨fibulin-5表达在膀胱尿路上皮癌中的影响作用。方法经尿道切除获取膀胱尿路上皮癌标本20例，其中低级别（G1和G2）13例、高级别（G3）7例。蛋白质印迹法检测fibulin-5在膀胱尿路上皮癌和正常膀胱黏膜组织中的表达。将PCR扩增的fibulin-5eDNA克隆到pMD-19T载体中，构建p-EGFP—fibulin-5质粒。脂质体介导法将p-EGFP—fibulin-5质粒转染到人膀胱癌5637细胞株内，流式细胞仪分选，经G418筛选形成稳定的表达克隆。Boyden小室法检测未转染、转染空载体和转染fibulin-5的膀胱癌细胞迁移和侵袭能力。结果正常膀胱黏膜、低级别和高级别膀胱尿路上皮癌组织中fibulin-5蛋白相对表达量分别为1．16±0．28、0．57±0．32和0．44±0．42。与正常膀胱黏膜相比，膀胱癌组织中fibulin-5蛋白表达显著下调（P〈0．01），低级别和高级别癌之间差异无统计学意义（P〉0．05）。转染成功的膀胱癌5637细胞显示绿色荧光。未转染、转染空载体和转染{ibulin-5的膀胱癌细胞的迁移细胞数分别为136．9±5．7、139．3±7．7和127．6±3．1，侵袭细胞数分别为31．7±4．7、31．5±4．8和8．0±3．1。转染fibulin-5后膀胱癌细胞侵袭力明显降低（P〈0．01），其迁移力虽低于对照组但差异无统计学意义（P〉0，05）。结论Fibulin-5蛋白表达减少可能是膀胱癌发生和发展的机制之一，过表达fibulin-5可以抑制膀胱癌细胞侵袭力。

英文摘要：

Objective To study the role of fibulin-5 in urothelial carcinoma of bladder. Methods Fibulin-5 expression was detected in bladder cancer tissues （13 cases of G1 and G2 , 7 cases of Gs ） and normal bladder mucosa samples by Western blotting assay. Fibulin-5 cDNA was amplified by PCR and cloned into pMD-19T simple vector. The pMD-19T-Fibulin-5 vector was digested by restriction endonucleases XhoI and EcoRI to generate a XhoI-Fibulin5-EcoRI fragment that was then ligated into the identical sites in p-EGFP-N1 plasmid to synthesize p-EGFP-Fibulin-5 plasmid. The p-EGFP- Fibulin-5 plasmid was finally transfected into bladder cancer cell line 5637. The migration and invasion of untransfected, vector-transfected and fibulin-5-transfected bladder cancer cells were measured by Boyden chamber assay. Results Compared to 1.16-0.28 in the normal control, the expression of fibulin-5 protein in low grade and high grade tumors were 0. 57±0. 32 and 0.44±0.42（P〈0.01, respectively）. However, the difference between low grade and high grade tumors was not statistically significant （P〉0.05）. The successfully transfected bladder cancer cells demonstrated green fluorescent light. The migrated cell number of fibulin-5-transfected cells was 127.6 ±3. 1 compared with 139.3±7.7 for vector-transfeeted cells and 136.9±5.7 for untransfected cells （P〉0.05, respectively）. In contrast, the invaded cell number of fibulin-5-transfected cells was 8.0± 3.1 compared with 31.5±4.8 for vector-transfected cells and 31.7±4.7 for untransfected cells （P〈0.01, respectively）. Conclusion Fibuliw5 is down-regulated in urothelial carcinoma of bladder and acts as a tumor suppressor gene by inhibiting the invasion of bladder cancer cells.