Identify SNPs and Polymorphisms Involved in the Development of Prostate Cancer

鉴定参与前列腺癌发展的 SNP 和多态性

• 批准号: 8937742
• 负责人: William Douglas Figg
• 金额: $ 77.42万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8937742
• 关键词: 5 Alpha-Reductase Inhibitor; 8q24; Adenocarcinoma; Adrenal Glands; Aftercare; Age; Alleles; Androgen Receptor; Androgens; Base Sequence; Benign; Biochemical; Biological; Biological Markers; Biological Testing; Biology; Biopsy; CAG repeat; Candidate Disease Gene; Castration; Chemopreventive Agent; Clinical; Collaborations; Conflict (Psychology); Constitutional; DNA; DU145; Data; Development; Diffusion; Disease; Enrollment; Enzymes; Epithelium; Evaluation; Exposure to; Finasteride; Flutamide; Frequencies; Future; Genes; Genetic Polymorphism; Genetic Variation; Genome; Genomics; Goals; Haplotypes; Harvest; High Prevalence; Hormones; Hyperplasia; Individual; LNCaP; Laboratories; Ligand Binding Domain; Literature; Liver; MYC gene; Malignant neoplasm of prostate; Mediating; Meta-Analysis; Metabolism; Metastatic Prostate Cancer; Microsatellite Repeats; Modeling; Molecular; Molecular Profiling; Mus; Mutation; New Agents; Odds Ratio; Oncogenes; Organic Anion Transporters; PC3 cell line; Patients; Pharmacogenomics; Placebos; Polymorphic Microsatellite Marker; Preclinical Drug Evaluation; Prevalence; Prostate Cancer Prevention Trial; Protein Isoforms; Publishing; Race; Recurrence; Regulator Genes; Reporting; Research; Resistance; Review Literature; Risk; Risk Factors; Robin bird; SRD5A2 gene; Sampling; Serum; Single Nucleotide Polymorphism; Somatic Mutation; Steroids; System; TMPRSS2 gene; Testing; Testosterone; Tetanus Helper Peptide; Therapeutic; Time; Tissue Sample; Tissues; Translational Research; Treatment Efficacy; Variant; Withdrawal; Xenograft Model; arm; cancer risk; cancer type; castration resistant prostate cancer; high risk; improved; inhibitor/antagonist; laser capture microdissection; men; overexpression; prostate cancer prevention; research study; response; risk variant; steroid hormone; treatment duration; treatment planning; tumor; uptake

We are conducting translational research to develop new agents and/or therapeutic maneuvers that appear to have antitumor activity in prostate cancer (CaP), and to develop molecular profiles of patients with CaP to tailor an individualized treatment plan. We are extensively involved in the efforts to understand the biology of CaP and to correlate biological variables associated with CaP and response to therapy. We reported the first confirmation of the therapeutic efficacy of flutamide withdrawal and 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 have analyzed candidate genes at the genomic level for genetic variations that may predispose individuals to increased risk of prostate cancer. Biomarker discovery for CaP is an ongoing effort in our laboratory and we have focused on the identification of single nucleotide polymorphisms (SNPs) involved in CaP progression. We use a candidate gene approach which uses a panel of 96 SNPs (identified from prior studies and published literature) from over thirty genes and using DNA samples from subjects with metastatic disease or without biochemical recurrence for over 5 years after treatment. Constitutional DNA from men who were biochemical recurrence free after treatment of their CaP identified from the San Antonio center for Biomarkers Of risk for prostate cancer (SABOR) are being provided by our research collaborator, Dr. Robin Leach. These samples are compared to the constitutional DNA from men with documented metastatic prostate cancer identified from patients treated at the NCI. Only one SNP, rs7311358 in the SLC01B3 gene, showed statistically significant results after adjusting for age and multiple testing. For men under the age of 60, there was an increased risk of metastatic disease with an odds ratio of 12.25 (p=0.002). Future experiments will saturate the polymorphic markers around this gene to identify more important SNPs and give focus for biochemical and molecular biological testing. The organic anion transporter OATP1B3, encoded by SLCO1B3, is involved in the transport of steroid hormones. We have shown that prostate cancer overexpresses 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 CaP. We found that a polymorphism in this transporter increases testosterone import is associated with a shorter time to androgen independence in patients with CaP who are treated with ADT. We are currently ascertaining whether OATP1B3-mediated hormone uptake is significant over diffusion using an MDCK transwell model that is transduced with a tet-inducible SLCO1B3 expression system. We are also currently harvesting tumors from castrated and uncastrated mouse xenograft models to determine if SLCO1B3 expression is related to intratumoral testosterone concentrations and the expression of androgen-receptor-mediated genes. Finally, we are currently conducting a drug screen to identify potential OATP1B3 inhibitors that may have clinical utility in the prostate cancer setting. Our preliminary data indicate quite strongly that OATP1B3 is significantly involved in tumoral androgen accumulation, and this uptake may be a driver of progression in castration resistant prostate cancer. Moreover, our data demonstrate that OATP1B3-dependent uptake can be targeted by specific inhibitors. OATP1B3 is expressed de novo in prostate cancer as two isoforms: liver-type (lt) and cancer type (ct). Studies are underway to characterize the molecular expression of each type and how they are differentially modulated in castration sensitive tumors (LNCaP and 22Rv1) versus castration resistant tumors (PC3 and DU145). The Prostate Cancer Prevention Trial (PCPT) investigated the prevention of prostate cancer using the steroid 5 alpha-reductase inhibitor finasteride over a 7-year treatment period. Through a longstanding collaboration, we have access to the tissue samples of 18,800 men enrolled in this study. The overall goals of this project are: a) to better understand associations between important androgen regulatory gene polymorphisms and CaP risk; and b) to evaluate the effects of these polymorphisms and serum hormone concentrations on the use of finasteride as a chemopreventive agent for CaP. Our focus is on hormone-related factors that are associated with 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 hypothesized that men with polymorphisms within genes that positively impact androgen levels will have a higher risk of developing CaP and high-grade disease than those with the wild-type alleles. Long-term exposure to finasteride may select for somatic alterations and increase serum levels of testosterone and potentially harmful testosterone breakdown products. Evaluation of whether the polymorphic variations in the AR, SRD5A2 and HSD3B2 genes are associated with the risk of biopsy-detected CaP in the PCPT is underway. We identified, by laser-capture microdissection and direct nucleotide sequencing, somatic alterations in AR and HSD3B2 that may have been selected for by long-term exposure to finasteride. We are also determining whether prostate cancer somatic mutations of these genes differ with regard to their prevalence between the placebo and finasteride arms, and among PIA, HGPIN, prostate cancer and normal epithelium. These findings will help define a pharmacogenomic profile to identify men that are most likely to benefit from treatment with 5 alpha-reductase inhibitors. We found that finasteride concentrations and genes involved in regulating its metabolism and target enzyme are associated with prostate cancer risk. We also found that AR CAG repeats are not associated with TMPRSS2:ETS formation in prostate cancer. Furthermore, we investigated racial disparities in the association between variants on 8q24 and prostate cancer and demonstrated that recent studies implicate SNPs within the 8q24 region as a risk factor for CaP. New developments suggest that 8q24 encodes regulators of the nearby MYC gene, a known oncogene. We performed meta-analyses, stratified by race, of seven SNPs and one microsatellite marker previously identified as risk loci on the 8q24 region of the genome. We reviewed the literature examining the possible associations between these polymorphisms and clinicopathological features of CaP. The results of the meta-analyses indicate that rs6983267, rs1447295, rs6983561, rs7837688, rs16901979, and DG8S737 are significantly associated with a higher risk for CaP for at least one race, whereas the variants rs13254738 and rs7000448 are not. The degree of association and frequency of the causative allele varied among men of different races. Though several studies have demonstrated an association between certain 8q24 SNPs and clinicopathological features of the disease, review of this topic revealed conflicting results.

我们正在进行转化研究，以开发似乎对前列腺癌 (CaP) 具有抗肿瘤活性的新药物和/或治疗策略，并开发 CaP 患者的分子谱以定制个体化治疗计划。我们广泛参与了解 CaP 生物学以及关联与 CaP 相关的生物变量和治疗反应的努力。我们首次证实了氟他胺戒断的治疗效果以及同时肾上腺抑制的增强活性。据推测，与氟他胺相关的临床改善是雄激素受体配体结合域内存在突变的结果。我们在基因组水平上分析了候选基因的遗传变异，这些变异可能使个体患前列腺癌的风险增加。 CaP 生物标志物的发现是我们实验室的一项持续努力，我们重点关注与 CaP 进展相关的单核苷酸多态性 (SNP) 的鉴定。我们使用候选基因方法，该方法使用来自 30 多个基因的 96 个 SNP（从之前的研究和已发表的文献中鉴定），并使用来自患有转移性疾病或治疗后 5 年以上没有生化复发的受试者的 DNA 样本。我们的研究合作者 Robin Leach 博士提供了圣安东尼奥前列腺癌风险生物标志物 (SABOR) 中心鉴定出的经 CaP 治疗后未出现生化复发的男性的体质 DNA。将这些样本与经 NCI 治疗的患有转移性前列腺癌的男性的组成 DNA 进行比较。在调整年龄和多次测试后，只有一个 SNP（SLC01B3 基因中的 rs7311358）显示出具有统计学意义的结果。对于 60 岁以下的男性，转移性疾病的风险增加，优势比为 12.25 (p=0.002)。未来的实验将饱和该基因周围的多态性标记，以识别更重要的 SNP，并重点关注生化和分子生物学测试。由 SLCO1B3 编码的有机阴离子转运蛋白 OATP1B3 参与类固醇激素的转运。我们已经证明，与正常或良性增生组织相比，前列腺癌过度表达 OATP1B3，并且常见的 SLCO1B3 GG/AA 单倍型与睾酮转运受损和 CaP 患者生存率提高相关。我们发现，这种转运蛋白的多态性增加了睾酮的输入，与接受 ADT 治疗的 CaP 患者实现雄激素独立的时间较短有关。我们目前正在使用 MDCK transwell 模型确定 OATP1B3 介导的激素摄取是否在扩散过程中显着，该模型是用 tet 诱导的 SLCO1B3 表达系统转导的。我们目前还从阉割和未阉割的小鼠异种移植模型中收获肿瘤，以确定 SLCO1B3 表达是否与瘤内睾酮浓度和雄激素受体介导的基因表达相关。最后，我们目前正在进行药物筛选，以确定可能在前列腺癌治疗中具有临床用途的潜在 OATP1B3 抑制剂。我们的初步数据强烈表明，OATP1B3 显着参与肿瘤雄激素积累，并且这种摄取可能是去势抵抗性前列腺癌进展的驱动因素。此外，我们的数据表明特定抑制剂可以靶向 OATP1B3 依赖性摄取。 OATP1B3 在前列腺癌中从头表达为两种亚型：肝型 (lt) 和癌症型 (ct)。目前正在进行研究来表征每种类型的分子表达以及它们在去势敏感肿瘤（LNCaP 和 22Rv1）与去势抵抗性肿瘤（PC3 和 DU145）中的差异调节方式。前列腺癌预防试验 (PCPT) 研究了在 7 年的治疗期内使用类固醇 5 α 还原酶抑制剂非那雄胺预防前列腺癌的情况。通过长期合作，我们获得了参与这项研究的 18,800 名男性的组织样本。该项目的总体目标是： a) 更好地了解重要的雄激素调节基因多态性与 CaP 风险之​​间的关联； b) 评估这些多态性和血清激素浓度对使用非那雄胺作为 CaP 化学预防剂的影响。我们的重点是与癌症风险相关的激素相关因素，这可能有助于解释 PCPT 的发现（即非那雄胺治疗组中腺癌的总体发生率降低，但高级别疾病的患病率增加）。我们假设，与具有野生型等位基因的男性相比，具有对雄激素水平产生积极影响的基因多态性的男性患 CaP 和重度疾病的风险更高。长期接触非那雄胺可能会导致体细胞改变，并增加睾酮和潜在有害睾酮分解产物的血清水平。目前正在评估 AR、SRD5A2 和 HSD3B2 基因的多态性变异是否与 PCPT 中活检检测到的 CaP 风险相关。我们通过激光捕获显微切割和直接核苷酸测序确定了 AR 和 HSD3B2 的体细胞改变，这些改变可能是由于长期接触非那雄胺而选择的。我们还在确定这些基因的前列腺癌体细胞突变在安慰剂组和非那雄胺组之间以及 PIA、HGPIN、前列腺癌和正常上皮之间的患病率是否存在差异。这些发现将有助于定义药物基因组学概况，以确定最有可能从 5 α-还原酶抑制剂治疗中受益的男性。我们发现非那雄胺浓度以及参与调节其代谢和靶酶的基因与前列腺癌风险相关。我们还发现 AR CAG 重复序列与前列腺癌中 TMPRSS2:ETS 的形成无关。此外，我们调查了 8q24 变异与前列腺癌之间关联的种族差异，并证明最近的研究表明 8q24 区域内的 SNP 是 CaP 的危险因素。新进展表明 8q24 编码附近 MYC 基因（一种已知的癌基因）的调节因子。我们对先前确定为基因组 8q24 区域风险位点的 7 个 SNP 和 1 个微卫星标记进行了按种族分层的荟萃分析。我们回顾了研究这些多态性与 CaP 临床病理特征之间可能关联的文献。荟萃分析的结果表明，rs6983267、rs1447295、rs6983561、rs7837688、rs16901979和DG8S737与至少一个种族的CaP较高风险显着相关，而变异rs13254738和rs7000448则不然。不同种族的男性中致病等位基因的关联程度和频率各不相同。尽管多项研究已经证明某些 8q24 SNP 与该疾病的临床病理特征之间存在关联，但对该主题的回顾却揭示了相互矛盾的结果。