Abstract: ［Abstract］ Objective To explore the expression of Deubiquitinase 3 （DUB3） in different human prostate cancer cell lines and the effect on cell proliferation， migration and epithelial?mesenchymal transition in prostate cancer. Methods Western Blot and quantitative RT?PCR were performed to detect the protein and mRNA expression of DUB3 in prostate cancer cell lines and normal prostate epithelial cell line. Then， PC?3 cells were transiently transfected with siRNA for DUB3 silencing， and MTS and Transwell were performed to measure the cell proliferation and migration. Finally， we used Western Blot to investigate the relationship between DUB3 and Snail1. Results The results of Western Blot and qRT?PCR showed that both the protein and mRNA levels of DUB3 were obviously higher in prostate cancer cell lines than in normal prostate epithelial cell line （P<0.05）|After DUB3 was inhibited by siRNA， the cell proliferation and cell migration of PC?3 were both obviously decreased （P<0.05）. Furthermore，the expression of Snail1 in prostate cancer cells was also downregulated. Conclusion DUB3 is overexpressed in prostate cancer and promotes cells proliferation and migration. Importantly， DUB3 may facilitate EMT in prostate cancer by deubiquitination of Snail1. USP3 is expected to be a candidate target for prostate cancer treatment.

Key words: ubiquitination, deubiquitinase 3, prostate cancer, epithelial?mesenchymal transition

摘要： ［摘要］ 目的 探讨去泛素化酶3在人不同前列腺癌细胞株中与前列腺癌组织中的表达，以及去泛素化酶3对前列腺癌细胞增殖、迁移和上皮间质化的影响。方法 采用Western Blot法和实时荧光定量PCR法，分别检测去泛素化酶3在前列腺癌细胞株和正常前列腺上皮细胞株中的蛋白和mRNA水平。以前列腺癌细胞株PC?3为研究对象，通过瞬时转染siRNA抑制去泛素化酶3的表达，然后采用MTS法和Transwell法分别检测PC?3细胞增殖和迁移能力的变化，最后通过Western Blot法明确去泛素化酶3在前列腺癌细胞中对上皮间质化关键因子Snail1的调控作用。结果 Western Blot法和实时荧光定量PCR均显示去泛素化酶3在前列腺癌细胞中的蛋白和mRNA水平高于正常前列腺细胞株（P<0.05）；通过siRNA抑制去泛素化酶3的表达后，PC?3细胞的增殖能力和迁移能力均明显减弱（P<0.05），而且Snail1的表达也同时下降。结论 去泛素化酶3在前列腺癌中高表达，具有促进前列腺癌细胞增殖和迁移的作用，并且通过对Snail1去泛素化，可能具有增强前列腺癌细胞上皮间质化的能力，有望成为前列腺癌治疗的新靶点。

关键词: 去泛素化酶3, 泛素化, 前列腺癌, 上皮间质化