TGF BETA SIGNAL TRANSDUCTION IN PROSTATE CANCER

转化生长因子-β(TGF-β)是一种负性调节因子 上皮细胞通过抑制细胞增殖和/或 诱导细胞凋亡。拟议研究的长期目标是 确定是否放松对转化生长因子-β信号通路的调控， 通过它传播生物信号，起到了重要的作用 在前列腺癌的发生和发展中的作用。我们建议 使用人类前列腺癌发生细胞模型系统，LNCaP细胞 转化生长因子-β受体II型功能的特异性丧失系 对转化生长因子-β缺乏责任感。在具体目标1中， LNCaP前列腺癌细胞将被转染一种质粒 编码R-II基因，以建立超过 转化生长因子-β受体II的表达与人肝癌的致瘤行为 这些细胞。这些研究的结果将表明 过表达恢复LNCaP细胞对转化生长因子-β的敏感性 功能的R-II受体，导致恶性肿瘤的逆转。在……里面 特定目标2使用R-II受体过表达克隆，我们将 调查潜在的下游效应器，这些效应器对 转化生长因子-β抗增殖和凋亡的信号转导 效果。细胞周期蛋白依赖性激酶抑制因子p21的表达 WAF1/Cip1和p27Kip1和p16将在转化生长因子-β中进行检测 外源性转化生长因子-2处理敏感的前列腺癌细胞 贝塔，通过北方和西方的分析，以确定是否 这些潜在的转化生长因子-β凋亡效应因子的解除调控 信号发生在转录后或翻译后水平。在……里面 将使用特定的Aim3、聚合酶链式反应和基因测序技术 筛查R-II受体基因突变的发生 对前列腺癌细胞系受体结构和功能的影响 对转化生长因子-β不敏感的人。这些研究的结果将 在确定功能失调的转化生长因子-β机制是否起关键作用 在前列腺癌的发生和发展中具有重要意义 进展，通过其表达的丧失或基因改变 跨膜受体R-I和R-II基因与细胞的去调节 转导转化生长因子-β细胞凋亡信号的下游效应器。

Transforming growth factor-beta (TGF-beta), is a negative regulator of epithelial cell growth via its ability to inhibit cell proliferation and/or induce apoptosis. The long term goal of the proposed studies is to determine whether deregulation of the TGF-beta signaling pathway, through which the biological signal is propagated, plays a significant role in initiation and progression of prostate cancer. We propose to use a human prostate tumorigenesis cell model system, the LNCaP cell line, in which specific loss of TGF-beta receptor type II function, is responsible for lack of responsivity to TGF-beta. In Specific Aim 1, the LNCaP prostate cancer cells will be transfected with a plasmid encoding the R-II gene, to establish the relationship between over expression of TGF-beta receptor II and the tumorigenic behavior of these cells. Results from these studies will indicate whether restoration of TGF-beta sensitivity in LNCaP cells by over expression of a functional R-II receptor, leads to reversion of malignancy. In Specific Aim 2 using R-II receptor overexpressing clones, we will investigate the potential downstream effectors that are essential for signaling/transducing the TGF-beta's antiproliferative and apoptotic effects. The expression of the cyclin-dependent kinase inhibitors, p21 WAF1/Cip1 and p27Kip1 and p16 will be examined in TGF-beta sensitive prostate cancer cells, after treatment with exogenous TGF- beta, by Northern and Western analysis, to determine whether deregulation of these potential effectors of the TGF-beta apoptotic signal occurs at a post-transcriptional or post-translational level. In Specific Aim3, PCR and genetic sequencing techniques will be used to screen for the occurrence of mutations in the R-II receptor gene, that affect the receptor structure and function in prostate cancer cell lines that are weakly sensitive to TGF-beta. Results from these studies will be critical in identifying whether a dysfunctional TGF-beta mechanism is of major significance in prostate cancer development and progression, via loss of expression or genetic alterations of its transmembrane receptors R-I and R-II genes and deregulation of the downstream effectors that transduce TGF-beta apopoptic signal.