TGF BETA SIGNAL TRANSDUCTION IN PROSTATE CANCER

转化生长因子-β（TGF-β）是一种负调节因子， 通过其抑制细胞增殖的能力抑制上皮细胞生长，和/或 诱导细胞凋亡。 拟议研究的长期目标是 确定TGF-β信号通路的失调， 生物信号通过其传播， 在前列腺癌的发生和发展中的作用。 我们建议 使用人前列腺肿瘤发生细胞模型系统LNCaP细胞， 系，其中TGF-β受体II型功能的特异性丧失， 导致对TGF-β缺乏反应。 具体目标1、 LNCaP前列腺癌细胞将用质粒转染 编码R-II基因，以建立过度 TGF-β受体II的表达和肿瘤的发生行为 这些细胞。 这些研究的结果将表明， 通过过表达恢复LNCaP细胞中的TGF-β敏感性 功能性R-II受体，导致恶性肿瘤的逆转。 在 具体目标2使用R-II受体过表达克隆，我们将 研究潜在的下游效应物， 信号传导/转导TGF-β的抗增殖和凋亡 方面的影响. 细胞周期蛋白依赖性激酶抑制因子p21的表达 WAF 1/Cip 1和p27 Kip 1和p16将在TGF-β 敏感的前列腺癌细胞，用外源性TGF-β 1处理后， 通过北方和西方的分析，以确定是否 这些潜在的TGF-β凋亡效应物的失调， 信号发生在转录后或翻译后水平。 在 特异性Aim 3、PCR和基因测序技术将用于 筛选R-II受体基因突变的发生， 影响前列腺癌细胞系中的受体结构和功能 对TGF-β弱敏感。 这些研究的结果将 在确定功能失调的TGF-β机制是否 在前列腺癌发展中具有重要意义， 进展，通过其表达的丧失或遗传改变， 跨膜受体R-I和R-II基因以及跨膜受体R-I和R-II基因的失调， 下游效应物，其表达TGF-β细胞凋亡信号。

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.