Molecular Mechanisms of Large Oncosome-Induced Prostate Cancer Progression and Metastasis

摘要 前列腺癌是男性最常见的肿瘤之一。尽管最近取得了进展，这种疾病仍然无法治愈 一旦出现对去势治疗的抵抗。肿瘤进展是由改变的分子介导的 癌细胞和周围环境之间的交流，起源于原发部位。但 调节基质对肿瘤的反应，最终促进PC进展的机制是 仍然大部分未知。我们的实验室发现了一种新型的肿瘤源性细胞外囊泡（EV）， 被称为“大癌小体”（LO），可以携带更丰富的分子货物，这是不同的，更有效地 比外泌体携带的生物活性更强。这一建议的理由来自我们对以下问题的初步观察： 患者循环中LO丰度与PC进展相关。我们的功能数据表明， LO可以激活成纤维细胞中的致癌信号传导，成纤维细胞通过激活MYC和SPI 1以及通过激活MYC和SPI 1来响应LO摄取。 诱导促进血管生成和刺激肿瘤生长的转录程序。的首要目标 本项目旨在确定LO在PC进展和转移中的功能作用。我们假设LO 在功能上将正常前列腺相关成纤维细胞（NAF）重编程为由MYC驱动的表型， SPI 1激活。这些结果强烈表明，肿瘤源性LO可能激活细胞间反应， 这种细胞外囊泡亚型的特异性。我们的假设将通过三个具体目标进行检验：目标1： 研究LO诱导的成纤维细胞活化在PC进展中的作用。目标2：找到证据表明，LO- 诱导的转录程序在具有临床显著疾病的PC患者中是活跃的。目标3：测试LO是否 和/或源自PC患者和PDX样本的Exo促进去势抵抗性和/或骨转移。 我们将使用互补的体外和动物原位模型的组合，以及重点 涉及基因组编辑、分子条形码和Cre-Lox报告基因体内系统的方法。我们的研究将 确定体外LO诱导的转录程序是否驱动体内肿瘤进展和转移。 此外，我们将确定是否也可以在患者标本中识别这种转录程序， 表明肿瘤进展。最后，我们的研究将为LO诱导肿瘤转移的能力提供证据。 惰性PC细胞。

Abstract Prostate cancer (PC) is one of the most frequent tumors in men. Despite recent progress, the disease is still incurable once resistance to castration therapy occurs. Tumor progression is strongly mediated by altered molecular exchanges between cancer cells and the surrounding milieu that originate at the primary sites. However, the mechanisms regulating the response of the stroma to the tumor, which ultimately promote PC progression are still largely unknown. Our laboratory discovered a new type of tumor-derived extracellular vesicle (EV), which are referred to as “large oncosomes” (LO), can harbor more abundant molecular cargo that is distinct and more potently bioactive than that carried by exosomes. The rationale for this proposal derives from our preliminary observations in patients that LO abundance in the circulation correlates with PC progression. Our functional data demonstrate that LO can activate oncogenic signaling in fibroblasts, which respond to LO uptake by activating MYC and SPI1 and by induce a transcriptional program that promotes angiogenesis and stimulates tumor growth. The overarching goal of this project is to determine the functional role of LO in PC progression and metastasis. We hypothesize that LO functionally reprogram normal prostate-associated fibroblasts (NAF) toward a phenotype that is driven by MYC and SPI1 activation. These results strongly suggest that tumor-derived LO might activate intercellular responses that are specific to this subtype of extracellular vesicle. Our hypothesis will be tested with three Specific Aims: Aim 1: To investigate the role of LO-induced fibroblast activation in PC progression. Aim 2: To find evidence that the LO- induced transcriptional program is active in PC patients with clinically significant disease. Aim 3: To test if LO and/or Exo derived from PC patient and PDX specimens promote castration resistance and/or bone metastasis. We will use a combination of complementary in vitro and animal orthotopic models as well as focused approaches involving genome editing, molecular barcodes, and a Cre-Lox reporter in vivo system. Our study will determine if the transcriptional program induced by LO in vitro drives tumor progression and metastasis in vivo. Additionally we will determine if this transcriptional program can also be identified in patient specimens and if it indicative of tumor progression. Finally, our study will provide evidence for LO abilities to induce metastasis of indolent PC cells.