Prostatic Differentiation and Sex Hormone Metabolism

描述(由申请人提供)：性激素环境和组织氧化剂状态的年龄相关性变化被认为是人类前列腺癌(PCa)发展的内源性风险因素。我们先前证明，用睾酮(T)和雌二醇(E2)同时治疗Noble(NBL)大鼠16周会导致上皮异常增生，这是一种非常类似于人类前列腺上皮内瘤变(PIN)的增殖性病变，仅发生在所有治疗大鼠的前列腺背外侧(DP/LP)，而不是腹侧前列腺(VP)。在接受治疗的大鼠的LP中，也出现了类似于与人类增生性炎性萎缩(PIA)相关的炎症反应，PIA据称是PIN和PCa的前驱。联合激素方案治疗NBL大鼠的时间越长，在所有动物的DLP中前列腺癌的发生率就越高。 我们现在证明，1)除了诱导异型增生/瘤变外，T+E2还可引起高催乳素血症并引起脂蛋白的炎症反应，2)它可直接在处理大鼠的DPS/LP的上皮细胞中引起氧化应激(OS)相关的损伤，3)T+E2在大鼠DP/LP中的诱导异型增生的作用可被垂体催乳素(PRL)释放抑制剂溴隐亭(BR)部分阻断，或可完全被联合治疗：1C1182,780(ICI)，一种抑制局部雌激素作用和全身性高催乳素血症的抗雌激素。这两种联合治疗还消除了：高催乳素血症引起的T+E2治疗大鼠LP中的炎症；4)使用低密度基因表达谱芯片，我们确定并验证了LP中与异型增生诱导相关的独特分子变化；以及5)我们开发了一种前列腺器官培养系统，该系统在无血清条件下保留了上皮-间质结构，以确定组织对单独或联合激素补充剂的反应。T，5α-双氢睾酮(DHT)、催乳素(PRL)和雌二醇(E_2)对VP、LP和DP诱导的外植体具有不同的促增殖和促异型增殖作用。综上所述，我们的数据表明，雄激素、雌激素以及催乳素在异型增生的发生中起作用，这可能是该模型中PCa发生的原因，并增加了OS和/或炎症可能证实这一过程的可能性。基于这些发现，我们假设1，DHT，E2和PRL单独或联合作用，通过：不同和协同的分子途径，可以通过全面的基因图谱研究，加上动物模型和器官培养系统中的平行验证，以及在人类细胞系和人类标本中的功能研究，来促进大鼠前列腺的早期肿瘤转化。该项目的目标是：1)确定在DP(无炎症但与OS相关)和LP(与炎症和OS相关)中与异常增生演变相关的独特转录本；2)确定与据称的异常增生诱导作用相关的转录本：T+E2和T+PRL，以描绘两者之间是否存在差异；3)确定与每种激素刺激相关的基因集。在不同的前列腺叶之间的叶特异性、OS和炎症之间，4)识别与癌前和恶变的特定阶段相关的基因，以及5)测试选定的基因或通路在人类细胞系中的功能，并验证它们在人类前列腺癌标本中的表达。这些研究的数据有望揭示早期前列腺癌发生的潜在机制。

DESCRIPTION (provided by applicant): Age-dependent alterations in sex hormone milieu and tissue oxidant status are believed to be endogenous risk factors for the development of prostate cancer (PCa) in humans. We previously demonstrated that simultaneous treatment of Noble (NBL) rats with testosterone (T) and estradiol-17beta (E2) for 16 weeks induced epithelial dysplasia, a proliferative lesion that closely resembles human prostatic intraepithelial neoplasia (PIN), exclusively in the dorsolateral prostate (DP/LP), but not in the ventral prostate (VP), of all treated rats. In the LP of the treated rats, an inflammatory response similar to one that associates with human proliferative inflammatory atrophy (PIA), a purported precursor to PIN and PCa, also develops. Longer treatment of NBL rats with the combined hormone regimen causes a high incidence of prostatic adenocarcinoma in the DLPs of all treated animals. We now showed that, 1) in addition to induction of dysplasia/neoplasia, T+E2 induced hyperprolactinemia and attended inflammation in the LPs, 2) it caused oxidative stress (OS)-related damages directly in the epithelia of DPs/LPs of the treated rats, 3) the T+E2 dysplasia-inducing action in rat DP/LP was partially blocked by co-treatment with bromocriptin (Br), an inhibitor of pituitary prolactin (PRL) release, or completely inhibited by co-treatment: with 1C1182,780 (ICI), an antiestrogen that inhibits both local estrogen action and systemic hyperprolactinemia. The two co-treatments also eliminated the: hyperprolactinemia-induced inflammation in the LPs of T+E2-treated rats, 4) using a low density microarray for gene profiling we identified and validated' unique molecular changes in the LP that are associated with dysplasia induction, and 5) we have developed a prostate organ culture system that preserves epithelial-stromal architecture under serum-free condition to define tissue responsiveness to individual or combined hormone supplements. T, 5alpha-dihydrotestosterone (DHT), PRL and E2 were shown to exert different proliferation- and dysplasia-promoting actions on explants established from the VP, LP and DP. Taken together, our data suggest that androgen, estrogen as well as PRL are responsible for the genesis of dysplasia which likely contribute to PCa development in this model and raise the possibility that OS and/or inflammatory may corroborate this process. Based on these findings we hypothesize that 1, DHT, E2 and PRL, singularly or in combination, contribute to early neoplastic transformation of the rat prostate, via: distinct and synergistic molecular pathways, which are definable by a comprehensive gene profiling study, coupled with parallel validations in the animal model and in the organ culture system, as well as functional studies in human cell lines and human specimens. The Aims of this: project are: 1) To determine the unique transcriptomes that are associated with evolution of dysplasia in the DP (free of inflammation but associate with OS) and that in the LP (associated with inflammation and OS), 2) To identify the transcriptomes associated with the purported dysplasia-inducing action: of T+E2 and of T+ PRL in order to delineate if a difference exists between the two, 3) to identify sets of genes associated with each hormonal stimulation. lobe-specificity, OS and inflammation among the various prostatic lobes, 4) to identify the genes associated with specific stages of premalignant and malignant transformation, and 5) to test the functionality of selected genes or pathways in human cell lines and validate their expression in human PCa specimens. Data from these studies are expected to uncover the underlying mechanisms of early prostate carcinogenesis.