中文摘要：

目的：通过比较不同人前列腺癌细胞系在SCID鼠皮下成瘤特性，鉴定前列腺癌细胞系及其皮下肿瘤上皮、间质标志蛋白的表达情况，探讨前列腺癌细胞系成瘤过程与上皮-间质转化（EMT）之间关系。方法：将DU145、Tsu、PC3和LNCaP4种人前列腺癌细胞系分别接种于SCID鼠皮下，比较其成瘤特性；用Western印迹法鉴定人前列腺癌细胞系及其相应皮下肿瘤钙粘蛋白、波形纤维蛋白的表达，并比较其成瘤前后的区别，探讨上皮间质转化与成瘤的关系。结果：EMT阳性细胞（DU145和Tsu）成瘤率、成瘤速度高于EMT阴性细胞（PC3和LNCaP），4种细胞系成瘤的上皮性的标志蛋白钙粘蛋白表达出现不同变化：DU145表达下调，PC3、LNCaP表达缺失，Tsu表达上调，共同特点是间质性的标志蛋白波形纤维蛋白表达消失。结论：EMT阳性细胞成瘤能力高于EMT阴性细胞，皮下肿瘤的形成过程中的确存在间质-上皮转化（MET）现象。

英文摘要：

Objective ： To identify the differences in the expression of epithelial or mesenchymal standard proteins between prostate cancer cell lines and tumors, and to investigate the relationship between the process of the prostate cancer cell line forming subcu- taneous tumors and epithelial-mesenchymal transition （EMT） by comparing the characteristics of different prostate cell lines forming subcutaneous tumors in SCID mice. Methods： We constructed prostate cancer models in male SCID mice by subcutaneous injection of 4 human prostate cancer cell lines DU145, Tsu, PC3 and LNCaP, and compared the characteristics of tumor formation. We used Western blot to detect the expressions of E-cadherin and Vimentin in the cancer cell lines and subcutaneous tumors, observed their differences before and after tumor formation, and explore the relationship between EMT and tumor formation. Results ： The EMT positive cells DU145 and Tsu showed a higher rate and speed of tumor formation than the EMT negative ones PC3 and LNCaP. The expression of E-cadherin was down-regulated in DU145, up-regulated in Tsu, and absent in PC3 and LNCaP. Conclusion ： EMT positive cells have a stronger ability of forming tumors than EMT negative cells, and mesenchymal-epithelial transition does exist in subcutaneous tumor formation.