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Study on identification and application of a novel cancer-associated gene PCA-1 in human prostate carcinoma

新型癌相关基因PCA-1的鉴定及在人前列腺癌中的应用研究

基本信息

批准号：
16390109
负责人：
KONISHI Noboru
金额：
$ 4.8万
依托单位：
Nara Medical University School of Medicine
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16390109/
关键词：
prostate carcinoma PCA-1 differential display phosphorylation signal transduction

项目摘要

The incidence of prostate cancer has increased recently in Japan. Although there is much information relating to molecular events underlying the etiology of prostate cancer, it is still unclear as to how these genetic alterations occur in the tumorigenesis. For potential gene markers for prostate carcinoma, we have molecularly identified genes showing differential expression between prostate cancers and normal tissues using fluorescent differential display (FDD) analysis. We identified a gene, designated prostate cancer antigen-1 (PCA-1), which shows high mRNA expression in prostate cancer. Database analysis of the deduced amino acid sequence of PCA-1 indicated high similarity to Escherichia coli AlkB, a DNA alkylation damage repair enzyme. By immunohistochemistry, PCA-1 was expressed in a high number of both prostate cancer samples and in the atypical cells within high-grade prostatic intraepithelial neoplasias, but not in benign prostatic hyperplasia or normal adjacent tissues.Ubiquitylation and degradation of FLICE-like inhibitory protein (FLIP) was found to be increased and FLIP-dependent Raf-1/extracellular stress-regulated kinase (ERK)/cyclin D1 signal was inhibited by siRNA gene silencing of endogenous PCA-1, resulting in suppression of epidermal growth factor (EGF)-induced cell growth in the human prostate cancer cell line, DU145. FLIP-dependent signaling from PCA-1 was also apparent on paclitaxel stimulation, and apoptosis was enhanced by PCA-1 knock down through down-regulation of Raf-1/ERK. In LNCaP cells with poor endogenous PCA-1 and FLIP, overexpression of PCA-1 promoted EGF-induced cell growth, while attenuating paclitaxel-induced apoptosis through enhanced FLIP/Raf-1 signaling. Both effects were canceled by silencing of FLIP with siRNA. Taken together, the results indicate that PCA-1 is an essential upstream element in FLIP-dependent Raf-1 signaling, playing a critical role in survival of prostate cancer cells.

前列腺癌的发病率最近在日本有所上升。虽然有很多关于前列腺癌病因学的分子事件的信息，但这些遗传改变在肿瘤发生中是如何发生的仍然不清楚。对于前列腺癌的潜在基因标记物，我们使用荧光差异显示（FDD）分析从分子水平鉴定了前列腺癌和正常组织之间差异表达的基因。我们鉴定了一种基因，称为前列腺癌抗原-1（PCA-1），其在前列腺癌中显示高mRNA表达。PCA-1的氨基酸序列与大肠杆菌AlkB（一种DNA烷基化损伤修复酶）的氨基酸序列高度相似。通过免疫组织化学，PCA-1在大量前列腺癌样本和高度前列腺上皮内瘤变中的非典型细胞中表达，而在良性前列腺增生或正常前列腺组织中则无此现象。FLICE样抑制蛋白（FLIP）的泛素化和降解增加，FLIP依赖性Raf-1/细胞外应激调节激酶（ERK）/通过内源性PCA-1的siRNA基因沉默抑制细胞周期蛋白D1信号，从而抑制人前列腺癌细胞系DU 145中表皮生长因子（EGF）诱导的细胞生长。来自PCA-1的FLIP依赖性信号传导在紫杉醇刺激下也是明显的，并且通过下调Raf-1/ERK而通过PCA-1敲低来增强凋亡。在内源性PCA-1和FLIP表达不足的LNCaP细胞中，PCA-1的过表达促进EGF诱导的细胞生长，同时通过增强FLIP/Raf-1信号转导减弱紫杉醇诱导的细胞凋亡。通过用siRNA沉默FLIP来消除这两种效应。综上所述，结果表明PCA-1是FLIP依赖性Raf-1信号传导的重要上游元件，在前列腺癌细胞的存活中起着关键作用。