Therapeutic Targeting of The Long Noncoding RNA SCHLAP1 in Aggressive Prostate Cancer

前列腺癌(PCA)是美国男性的主要死亡原因。几乎所有这些死亡都是由于 化疗耐药和转移扩散的演变。因此，开发新的代理商是一种迫切的、尚未得到满足的需求。 治疗耐药的转移性前列腺癌。与长非编码RNA(LncRNA)相关的第二染色体位点 与前列腺癌1(SChLAP1)相关的RNA已被确定为与前列腺癌特异性死亡率和 来自多个数据集的转移和长期随访。SChLAP1的敲除/过表达相关 伴随着前转移表型的变化，如侵袭和集落形成。瞄准这一关键的蜂窝 然而，调控因子及其在促进PCa治疗抵抗和转移中的作用机制一直难以捉摸 还没有完全阐明。例如，SChLAP1与SWI/SNF复合体之间的相互作用 在一些研究中与前列腺癌进展有关，但在另一些研究中没有。关于分子的这种认识上的差距 SChLAP1的功能阻止了SChLAP1的有效治疗靶向。我们团队和其他人最近的工作是 揭示了SChLAP1内的复杂RNA结构以及定位于高结构的蛋白质结合区 以及转录的灵长类保守区。这些关于功能性RNA结构的令人信服的证据结合在一起 随着SChLAP1可作为尿液和血液中的生物标记物，靶向LncRNA SChLAP1成为一种有前景的靶向 男性侵袭性前列腺癌的精准医学治疗方法。 拟议工作的总体目标是：1)确定和表征蛋白质相互作用因子和 对SChLAP1致癌活性至关重要的染色质结合位点和2)验证最近发现的类药物配体 筛选作为靶向SChLAP1结构区域的工具分子，包括抑制这些相互作用和 SChLAP1驱动的表型。中心假设是SChLAP1的机制涉及与 蛋白质和染色质，靶向这些相互作用将抑制SChLAP1驱动的表型并揭示 治疗转移性、难治性前列腺癌的新治疗途径。在目标1中，无偏测序和质量 基于光谱的方法将识别细胞中与SChLAP1结合的染色质区域和蛋白质，以及这些 相互作用将在一系列表型分析中进行询问，以评估它们在癌细胞增殖中的作用。 生存、迁移/侵袭，以及对标准护理激素治疗的抵抗。在目标2中，保守的配体 SChLAP1亚结构将在表型分析中得到验证，它们对分子相互作用的影响将是 被审问了。这项工作的预期成果如下：1)对目标的全面生物学洞察 SchLAP1的分子间相互作用和2)抑制SchLAP1：蛋白质的小分子的鉴定 PCA中的相互作用和随后的表型。这项工作将为未来的R01提案奠定基础，重点放在 靶向SChLAP1小分子的体内验证研究及外切体液的研制 SChLAP1的活组织检查，最终目标是产生一种基于精确医学的策略，用于积极和 治疗难治性前列腺癌，同时也有助于将LncRNA靶向建立为肿瘤学的治疗范例。

Prostate cancer (PCa) is a leading cause of death among American men. Nearly all of these deaths are due to the evolution of therapy resistance and metastatic spread. As such, there is an urgent, unmet need to develop new agents to treat therapy-resistant, metastatic PCa. The long noncoding RNA (lncRNA) Second Chromosome Locus Associated with Prostate 1 (SChLAP1) has been identified as the top RNA associated with prostate cancer-specific mortality and metastasis from multiple datasets with long-term follow up. Knockdown/overexpression of SChLAP1 is associated with changes to pro-metastatic phenotypes, such as invasion and colony formation. Targeting this critical cellular regulator has been elusive, however, and its mechanism of action in promoting PCa therapy resistance and metastasis has not been fully elucidated. For example, an interaction between SChLAP1 and the SWI/SNF complex has been implicated in PCa progression in some studies, but not in others. This gap in knowledge regarding the molecular function of SChLAP1 prevents effective therapeutic targeting of SChLAP1. Recent work by our team and others has revealed a complex RNA architecture within SChLAP1 as well as protein binding regions localized to highly structured and primate-conserved regions of the transcript. This compelling evidence for functional RNA structures, combined with the availability of SChLAP1 as a biomarker in urine and blood, renders targeting of lncRNA SChLAP1 a promising precision medicine-based treatment approach for men with aggressive PCa. The overall objectives of the proposed work are to: 1) identify and characterize protein interactors and chromatin-binding sites critical to SChLAP1 oncogenic activity and 2) validate drug-like ligands identified in recent screens as tool molecules for targeting structured regions of SChLAP1, including inhibition of these interactions and SChLAP1-driven phenotypes. The central hypothesis is that the mechanism of SChLAP1 involves interactions with both protein and chromatin, and that targeting these interactions will inhibit SChLAP1-driven phenotypes and reveal novel therapeutic avenues to treat metastatic, treatment-resistant PCa. In Aim 1, unbiased sequencing and mass spectrometry-based approaches will identify chromatin regions and proteins bound by SChLAP1 in cells, and these interactions will be interrogated in an array of phenotypic assays to evaluate their role in proliferation, cancer cell survival, migration/invasion, and resistance to standard-of-care hormone therapy. In Aim 2, ligands of conserved SChLAP1 substructures will be validated in phenotypic assays, and their effects on molecular interactions will be interrogated. Expected outcomes of this work will be as follows: 1) comprehensive biological insight into targetable intermolecular interactions for SChLAP1 and 2) identification of small molecules that inhibit SChLAP1:protein interactions and subsequent phenotypes in PCa. This work will set the stage for a future R01 proposal focused on in vivo validation studies for small molecules targeting SChLAP1 and the development of an exosome-based liquid biopsy for SChLAP1, with the ultimate goal of yielding a precision medicine-based strategy for aggressive and treatment-resistant PCa while also helping to establish lncRNA targeting as a therapeutic paradigm in oncology.