Identify SNPs and Polymorphisms Involved in the Development of Prostate Cancer

该项目的目的是进行转化研究，以开发新的药物，和/或治疗方法，似乎在前列腺癌中具有抗肿瘤活性，并开发前列腺癌患者的分子图谱，以制定个性化的治疗计划。为了实现这一目标，我们已经广泛参与了解前列腺癌生物学的努力。目前，我们正试图将与前列腺癌和治疗反应相关的生物学变量（例如，重要的多态性标记物和微血管计数）联系起来。分子药理学科的一个早期成就是首次证实了氟他胺停药的治疗效果，以及同时抑制肾上腺的活性增强。据推测，与氟他胺相关的临床改善是雄激素受体的配体结合区域内存在突变的结果。我们仍然有兴趣在基因组水平上分析可能使个体易患前列腺癌风险增加的遗传变异的候选基因。我们已经完成了与内皮抑素（COL18A1，无统计学差异）自然产生相关的基因分析，一个直接参与从胆固醇合成睾酮的基因（CYP17，结果表明其多态性与雄激素非依赖型前列腺癌患者的总生存率相关），一个参与睾酮毒性代谢分解的基因（CYP1B1，观察到与生存率降低相关），药物代谢（CYP3A4和5，研究的遗传变异不太可能对癌症患者CYP3A的表型活性有重要的功能意义），以及参与细胞转运和偶联的基因（UGT1A9，功能变异在高加索人中很少见，在伊立替康方案中可能临床上不显著）。由SLCO1B3编码的有机阴离子转运体OATP1B3参与类固醇激素的转运。然而，它在睾酮摄取和前列腺癌进展中的作用尚不清楚。通过测序在NCI-60肿瘤细胞中评估SLCO1B3基因型，而在转染野生型（WT）， 334G和699A SLCO1B3变体的Cos-7细胞中分析睾酮转运。荧光显微镜检测ooatp1b3在前列腺组织中的表达，并检测患者SLCO1B3单倍型与生存的关系。我们最近的研究表明，与正常或良性增生组织相比，前列腺癌过度表达OATP1B3，常见的SLCO1B3 GG/AA单倍型与前列腺癌患者睾酮转运受损和生存率提高有关。此外，对其他基因（SRD5A1&2、LOX、CYP19、ER）的分析已经显示出初步证据，表明它们可能在不同的完成阶段发挥重要作用。最近，在筛选前列腺癌患者的DNA与设计用于筛选参与代谢和药物转运的基因的基因芯片后，发现了其他感兴趣的多态性基因。这些重要的基因将被添加到前列腺癌分子指纹的持续目标中。结合我们的候选基因分析研究，我们也使用生理学研究和观察来帮助阐明前列腺癌的生物学。为了研究沙利度胺如何赋予其生存益处，我们在人类前列腺癌异种移植模型中评估了沙利度胺和化疗药物联合治疗对循环内皮细胞（CECs）和祖细胞（cceps）的影响。静脉注射多西他赛后不久，凋亡/死亡CEC水平升高，加入沙利度胺后，凋亡/死亡CEC水平进一步升高，说明沙利度胺增强了多西他赛对肿瘤血管内皮细胞的细胞毒性。本研究表明，沙利度胺增加了凋亡/死亡的CECs，增强了多西他赛对肿瘤血管内皮细胞的细胞毒性，证实了其在联合抗癌治疗中的体内抗血管生成特性。此外，我们发现治疗早期凋亡/死亡CEC水平升高与后期抗肿瘤疗效之间存在相关性，提示凋亡/死亡CEC水平可作为早期预测肿瘤对抗血管生成治疗反应的标志物。在最近的另一项研究中，研究了前列腺存活肿瘤在转移性雄激素非依赖型前列腺癌（AIPC）患者中的意义。临床病理特征，包括随访，40名男性转移性AIPC接受前列腺活检评估。前列腺活检显示40例患者中有19例（48%）肿瘤存活。在接受放射治疗的18例患者中，9例（50%）在研究期间活检呈阴性。活检阳性肿瘤患者既往放射治疗史与总生存率无关（p=0.84）。此外，在这40例患者中，活检阳性或阴性状态与总生存期（OS）之间没有统计学意义上的显著关联（p=0.39），活检阴性患者的中位OS为19.6个月，活检阳性患者的中位OS为19.8个月。这些观察结果得出的结论是，在有转移性AIPC的病例中，约有一半的患者进行了前列腺活检，结果发现了肿瘤。既往放射治疗史与前列腺活检阴性无关。前列腺活检阴性似乎对预后没有影响。该项目的一些总体目标是：(a)更好地了解重要的雄激素调节基因多态性与前列腺癌风险之间的关系；(b)评估这些多态性和血清激素浓度对非那雄胺作为前列腺癌化学预防剂使用的影响。最近完成的前列腺癌预防试验（PCPT）调查了使用类固醇5 α -还原酶抑制剂非那雄胺在七年治疗期间预防前列腺癌。通过长期合作，我们获得了参与这项研究的18800名男性的组织样本。我们目前正在关注与前列腺癌风险相关的激素相关因素，这可能有助于解释PCPT的发现（即，腺癌的总体发生率降低，但非那雄胺治疗组的高级别疾病患病率增加）。我们假设，与具有野生型等位基因的男性相比，具有积极影响雄激素水平的基因多态性的男性患前列腺癌和高级别疾病的风险更高。此外，长期暴露于非那雄胺可能导致躯体改变，增加血清睾酮水平和潜在有害的睾酮分解产物。目前正在评估AR、SRD5A2和HSD3B2基因的多态性变异是否与前列腺癌活检检测的风险相关。我们正在通过激光捕获显微解剖和直接核苷酸测序来识别AR中的体细胞改变[摘要截断为7800个字符]

The purpose of this project is to perform translational research to develop new agents, and/or therapeutic maneuvers, that appear to have antitumor activity in prostate cancer, and to develop molecular profiles of patients with prostate cancer to tailor an individualized treatment plan. To achieve this goal, we have become extensively involved in the efforts to understand the biology of prostate cancer. Currently, we are attempting to correlate biological variables associated with prostate cancer and response to therapy (e.g., important polymorphic markers, and microvessel counts). One early achievement by the Molecular Pharmacology Section was to report the first confirmation of the therapeutic efficacy of flutamide withdrawal, as well as the enhanced activity of simultaneous adrenal suppression. It has been hypothesized that the clinical improvement associated with flutamide is a result of the presence of a mutation within the ligand-binding domain of the androgen receptor. We remain interested in analyzing candidate genes at the genomic level for genetic variations that may predispose individuals to increased risk of prostate cancer. We have completed the analysis of genes involved in the natural production of endostatin (COL18A1, no statistical difference), a gene directly involved in the synthesis of testosterone from cholesterol (CYP17, the results suggest that the polymorphism is associated with overall survival in patients with androgen independent prostate cancer), a gene involved in the toxic metabolic breakdown of testosterone (CYP1B1, an association with decreased survival was observed), drug metabolism (CYP3A4 &5, the studied genetic variants are unlikely to have an important functional significance to phenotypic CYP3A activity in patients with cancer), and a gene involved in cellular transport and conjugation (UGT1A9, functional variants are rare in Caucasians and likely to be clinically insignificant in irinotecan regimens). The organic anion transporter OATP1B3, encoded by SLCO1B3, is involved in the transport of steroid hormones. However, its role in testosterone uptake and progression of prostate cancer is unknown. SLCO1B3 genotype was assessed in the NCI-60 panel of tumor cells by sequencing, while testosterone transport was analyzed in Cos-7 cells transfected with wild-type (WT), 334G and 699A SLCO1B3 variants. OATP1B3 expression in prostatic tissues was examined by fluorescence microscopy and the relationship between SLCO1B3 haplotypes and survival was examined in patients. Our recent study showed that prostate cancer over-expresses OATP1B3 compared to normal or benign hyperplastic tissue, and the common SLCO1B3 GG/AA haplotype is associated with impaired testosterone transport and improved survival in patients with prostate cancer. Furthermore, the analysis of other genes (SRD5A1&2, LOX, CYP19, ER) which have shown preliminary evidence that suggests that they may play important roles are ongoing and at various stages of completion. Other polymorphic containing genes of interest have been recently identified after screening the DNA from patients with prostate cancer against a gene chip designed to screen genes involved in metabolism and drug transport. These important genes will be added to the ongoing goal of a molecular fingerprint of prostate cancer. In association with our candidate gene analysis studies, we are also using physiological studies and observations to help elucidate the biology of prostate cancer. To investigate how thalidomide confers its survival benefit, we assessed its effect on circulating endothelial cells (CECs) and progenitors (CEPs) in a combination therapy of thalidomide and chemotherapy drugs in a human prostate cancer xenograft model. An increased level of apoptotic/dead CEC was observed shortly after the intravenous injection of docetaxel, and the addition of thalidomide further increased the apoptotic/dead CEC level, demonstrating that thalidomide enhances the cytotoxicity of docetaxel against tumor vascular endothelial cells. This study demonstrated that thalidomide increased the apoptotic/dead CECs and enhanced the cytotoxicity of docetaxel against tumor vascular endothelial cells, confirming its anti-angiogenic property in vivo in combinational anti-cancer treatments. In addition, we discovered a correlation between the increased apoptotic/dead CEC levels early into the treatment and anti-tumor efficacy later, suggesting apoptotic/dead CEC level could be used as a marker at an early stage to predict tumor response to anti-angiogenic therapies. In another recent study the significance of viable tumor in the prostate in patients with metastatic androgen independent prostate cancer (AIPC) was studied. Clinicopathological features, including follow-up, of 40 men with metastatic AIPC who underwent a biopsy of the prostate were evaluated. Prostate biopsies performed revealed viable tumor in 19 of 40 patients (48%). Of the 18 patients who had received radiation treatment, 9 (50%) had negative on-study biopsy. Previous history of radiation therapy was not associated with overall survival in patients with biopsy positive tumors (p=0.84). Also, there was no statistically significant association between positive or negative biopsy status and overall survival (OS) in these 40 patients (p=0.39), with similar median OS of 19.6 months for biopsy negative and 19.8 months for biopsy positive patients, respectively. These observations lead to the conclusion that performing prostate biopsies at the time of documented metastatic AIPC yielded tumor in about half of the cases. Prior history of radiation treatment was not associated with a negative prostate biopsy. A negative prostate biopsy does not appear to have an impact on prognosis. Some of the overall goals of this project are: (a) to better understand associations between important androgen regulatory gene polymorphisms and prostate cancer risk and (b) to evaluate the effects of these polymorphisms and serum hormone concentrations on the use of finasteride as a chemopreventive agent for prostate cancer. The recently completed Prostate Cancer Prevention Trial (PCPT) investigated the prevention of prostate cancer using the steroid 5 alpha-reductase inhibitor finasteride over a seven year treatment period. Through a longstanding collaboration we have access to tissue samples of the 18,800 men enrolled in this study. We are currently focusing on hormone-related factors that are associated with prostate cancer risk, which may help explain the findings of the PCPT (i.e., decreased overall occurrence of adenocarcinoma, but increased prevalence of high-grade disease in the finasteride treatment arm). We hypothesize that men with polymorphisms within genes that positively impact androgen levels will have a higher risk of developing prostate cancer and high grade disease than those with the wild-type alleles. In addition, long-term exposure to finasteride may select for somatic alterations and increase serum levels of testosterone and potentially harmful testosterone breakdown products. The evaluation of whether the polymorphic variations in the AR, SRD5A2 and HSD3B2 genes are associated with the risk of biopsy-detected prostate cancer in the PCPT are underway. We are identifying by laser-capture microdissection and direct nucleotide sequencing somatic alterations in the AR [summary truncated at 7800 characters]