磷酸酶PRL-3参与前列腺癌细胞侵袭及转移的分子机制研究

项目名称： 磷酸酶PRL-3参与前列腺癌细胞侵袭及转移的分子机制研究

项目编号： No.30872583

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 生物科学

项目作者： 袁建林

作者单位： 中国人民解放军第四军医大学

项目金额： 29万元

中文摘要： PRL-3是PRL磷酸酶家族成员。有研究表明PRL-3的高表达与多种肿瘤的预后不良密切相关，功能学研究证据显示PRL-3 参与肿瘤细胞的侵袭与转移，但其在前列腺癌中的生物学功能及作用机制还未可知。在本研究中，我们的免疫组织化学染色结果显示PRL-3的高表达与前列腺癌的去分化程度呈正相关。在细胞学实验中，利用慢病毒介导表达靶向PRL-3的shRNA在前列腺癌细胞PC-3中下调该基因的表达水平。Boyden小室实验结果显示抑制PRL-3的表达能够显著抑制PC-3前列癌细胞的运动及侵袭能力。实时定量PCR和明胶酶谱实验结果显示下调PRL-3的表达抑制了基质金属蛋白酶2、7和9的表达及活性。机制分析数据结果显示：AKT去磷酸化可能是PRL-3低表达前列腺癌细胞中MMPs活性降低的主要原因，而更进一的AKT恢复实验验证了这一机制的真实性。综上所述，本研究第一次证实了PRL-3在前列腺癌中的表达模式与肿瘤分化程度的相关性。并证明PRL-3可能通过维持AKT的丝氨酸磷酸化状态。使其发挥上调MMPs表达，促进肿瘤侵袭和转移的生物学功能。而负向调解PRL-3在前列腺癌细胞中的表达能够抑制肿瘤细胞的转移。

中文关键词： 肝再生磷酸酶-3; 前列腺癌; 侵袭与转移; 基质金属蛋白酶

英文摘要： PRL-3/PTP4A3 is one of PRL （phosphatase of regenerating liver） family members, which functions as a tyrosine phosphatase. A high level expression of PRL-3 has been reported to be closely correlated with poor prognosis of multiple malignant diseases. Accumulating evidence demonstrates that PRL-3 is involved in invasion and metastasis of many types of cancer cells. Here, to determine the role of PRL-3 in the invasive properties of prostate cancer cells, we explored a lentivirus-mediated delivery system to stably knockdown PRL-3 expression using RNA interference (RNAi) technology in PC-3 prostate cancer cells which has a high level expression of PRL-3. The Boyden chamber assay was performed to evaluate the migration and invasion ability of PC-3 cells in vitro. qRT-PCR and Gelatin zymography were employed to determine the effect of PRL-3 on alteration of MMP-2, MMP-7 and MMP-9 in PC-3 cells. Our results showed that significant downregulation of PRL-3 led to dramatic reduction of the migration and invasion ability in prostate cancer cells. Moreover，the mechanistic analysis showed that downregulation of PRL-3 resulted in dephosphorylation of Akt, which played an important role in decreased expression of MMP-2, MMP-7 and MMP-9 in cancer cells. Collectively, our study for the first time demonstrates that PRL-3 functions as a metastasis-promoter in prostate cancer cells. And Akt signaling pathway-mediated regulation of matrix metalloproteinases plays a critical role in PRL-3's effect on migration and invasion in prostate cancer cells. These results suggest that PRL-3 could be a potential target for anti-metastasis of human prostate cancer cells.

英文关键词： PRL-3; prostate cancer; invasion and migration; MMPs