Molecular Mechanisms of a Male-Specific Positive Feedback Loop in Liver Cancer

肝细胞癌（HCC）是一种致命的癌症，影响更多的退伍军人比一般美国人 人口风险因素包括肝炎病毒感染、肥胖、衰老、酒精/药物滥用、有毒物质暴露， 遗传/表观遗传倾向，共同促进基因突变，细胞增殖和信号传导 通路功能障碍导致癌症值得注意的是，男性在HCC中的受影响程度是女性的3至6倍。 HCC的男性优势一直是医学领域的一个长期谜团。男性性激素 雄激素及其受体，雄激素受体（AR），加剧致癌过程，包括促进 肝炎病毒复制，癌基因和信号通路的激活，以及抑制肿瘤抑制因子 活动，从而在肝癌中发挥男性偏好。因此，人们对抗雄激素有着重大的兴趣， 在临床领域中作为HCC治疗的治疗剂。重要的是，我们已经检测到 在选定的HCC样本中，检测组成型活性AR变体，例如AR-V7。由于这些AR变体在 在前列腺癌转移进展中的作用，在HCC中的检测表明它们也可以发挥作用， 肝癌的致癌功能。此外，我们还发现了一个男性特有的正反馈回路， 其中男性特异性癌基因TSPY相互作用并放大靶基因的AR和AR-V7反式激活， 包括其自身的基因，分别以配体依赖性和非依赖性的方式，从而潜在地影响 抗雄激素治疗肝癌的有效性。TSPY是性腺母细胞瘤基因座的基因 (GBY)在Y染色体上。它是一种细胞周期调节剂，其功能障碍促进细胞增殖， 肿瘤发生TSPY阳性的HCC患者的生存率低于阴性的HCC患者， AR/AR-V7的位置提示预后不良。因此，了解这种雄性动物的行为机制- AR/AR-V7与Y染色体TSPY基因在肝癌发生过程中的特异性正反馈环， 为在诊断、预后和临床试验中的转化应用提供科学基础。 抗雄激素作为治疗HCC的治疗剂。 该项目的重点是男性特异性正反馈环的协同和致癌功能， AR/AR-V7和TSPY在肝癌发生中的3个特定目标。第一，TSPY、AR的表达模式 将分析配对的HCC肿瘤/非肿瘤RNA样品和病理标本中的AR-V7， 证实这种雄性特异性正反馈回路的存在，并评估它们的表达是否 包括细胞学位置的模式可用作患者的诊断和预后标记。 第二，将研究Y定位的TSPY的AR和AR-V7转录激活的机制。 使用流体动力学转染策略的HCC细胞和小鼠肝脏。第三，TSPY的致癌功能， 将通过对整个小鼠的肝脏进行稳定的流体动力学转染来研究HCC中的AR和AR-V7。他们的 将在正常条件和致瘤倾向下评价诱导肝肿瘤发生的能力。 对它们在肝癌发生中的协同作用机制的全球观点将被描述 用转录组和顺式组分析差异基因表达，靶基因偏好， 与细胞生长、增殖相关的癌基因、肿瘤抑制因子和信号通路的失调 和肿瘤发生。我们将使用由此产生的动物模型来评估抗雄激素药物作为治疗 HCC治疗这项拟议中的研究将为男性的分子机制提供重要的见解， 性激素受体AR/AR-V7和与Y染色体定位的癌基因TSPY的协同作用， 男性特异性正反馈环在肝癌发生中的作用该项目的成功将提供科学的 在开发基于AR/AR-V7和TSPY的诊断、预后和 肝癌的临床管理的治疗策略，并将大大有利于卫生保健提供给 易患或患有肝癌的退伍军人。

Hepatocellular carcinoma (HCC) is a deadly cancer that affects more Veterans than the general American population. Risk factors include hepatitis virus infection, obesity, aging, alcohol/drug abuses, toxic exposure, and genetic/epigenetic predisposition, which collectively promote genetic mutations, cell proliferation and signaling pathway dysfunctions, leading to cancer. Significantly, men are affected 3 to 6 times higher than women in HCC. The male predominance in HCC has been a long-standing enigma in the medical field. The male sex hormone androgen and its receptor, androgen receptor (AR), exacerbate the oncogenic processes, including promotion of hepatitis viral replication, activation of oncogenes and signaling pathways, and repressing tumor suppressor activities, thereby exerting male preference in liver cancer. Hence, there are significant interests in antiandrogens as therapeutics in treatments of HCC in the clinical field. Importantly, we have detected the expression of constitutively active AR variants, e.g. AR-V7, in selected HCC specimens. Since these AR variants play important roles in metastatic advances in prostate cancer, their detection in HCC suggests that they could also exert oncogenic functions in liver cancer. Furthermore, we have identified a male-specific positive feedback loop, in which a male-specific oncogene TSPY interacts and amplifies AR and AR-V7 transactivation of target genes, including its own gene, in ligand-dependent and independent manners respectively, thereby potentially affecting the effectiveness of antiandrogen therapeutics for HCC patients. TSPY is the gene for the gonadoblastoma locus (GBY) on the Y chromosome. It is a cell cycle regulator, dysfunction of which promotes cell proliferation and oncogenesis. TSPY-positive HCC patients have worse survival rate than the negative ones while nuclear locations of AR/AR-V7 signify poor prognosis. Hence, understanding the mechanisms of actions of this male- specific positive feedback loop between AR/AR-V7 and the Y-located TSPY gene in hepatocarcinogenesis will provide the scientific foundation for translational applications in diagnosis, prognosis and clinical trials of antiandrogens as therapeutics in treatments of HCC. The project focuses on the synergistic and oncogenic functions of the male-specific positive feedback loop of AR/AR-V7 and TSPY in hepatocarcinogenesis under 3 specific aims. First, the expression patterns of TSPY, AR and AR-V7 in paired HCC tumor/non-tumor RNA samples and pathological specimens will be analyzed to substantiate the existence of such male-specific positive feedback loop and to evaluate if their expression patterns, including cytological locations, can be used as diagnostic and prognostic signatures for the patients. Second, the mechanisms of AR and AR-V7 transcriptional activation of the Y-located TSPY will be studied in HCC cells and mouse livers using hydrodynamic transfection strategy. Third, the oncogenic functions of TSPY, AR, and AR-V7 in HCC will be studied by stable hydrodynamic transfection to the livers of whole mice. Their ability to induce hepatic oncogenesis will be evaluated under normal conditions and tumorigenic predisposition. The global views on the mechanisms of their synergistic actions in hepatocarcinogenesis will be characterized with transcriptome and cistrome analyses in terms of differential gene expression, target gene preferences, and dysregulation of oncogenes, tumor suppressors and signaling pathways associated with cell growth, proliferation and tumorigenesis. We will use the resulting animal models to evaluate antiandrogen drugs as therapeutics in HCC treatments. The proposed research will provide critical insights on the molecular mechanisms of the male sex hormone receptor AR/AR-V7 and synergistic actions with the Y chromosome-located oncogene TSPY in the male-specific positive feedback loop in hepatocarcinogenesis. Success of the project will provide the scientific basis for translational applications in development of AR/AR-V7 and TSPY-based diagnosis, prognosis and therapeutic strategies in clinical management of HCC; and will greatly benefit the health care delivery to the Veterans predisposed to or suffering from liver cancer.