Targeting the MICAL2 signaling axis in pancreatic cancer

项目摘要/摘要 胰腺导管腺癌(PDAC)迫切需要新的治疗方法，因为 目前的化疗方案无法控制大多数患者的疾病。辨别小说 我们比较了手术切除的肿瘤和正常胰腺的表观遗传学特征 使用组蛋白-3赖氨酸-27乙酰化(H3K27ac)。这项分析揭示了超级增强子区域是“热- 斑点“，用于转录因子结合。PDAC组织的超级增强子图谱显示了一种独特的景观 与正常胰腺相比。在映射到MICAL2的高度乙酰化的增强子中 吉恩。MICAL2酶是一种黄素单加氧酶，它调节核肌动蛋白的动态，导致 肌钙蛋白相关转录因子-A和血清反应因子对转录的下游调控。 作为一种在人类疾病中被成功抑制的酶，我们认为MICAL2代表 这是胰腺癌治疗的一个令人兴奋且可能易于处理的靶点。 我们研究了人和小鼠胰腺癌细胞系和有机物，以及几个独立的 数据集，并确认MICAL2在PDAC中过表达，并且它的过度表达导致 预后。此外，我们已经生成了稳健的初步数据，表明MICAL2的丢失导致 关键的细胞周期调节因子下调，这会减缓细胞增殖，并导致G1和G2/M期的停滞。 此外，MICAL2的沉默抑制了体外的克隆形成和细胞迁移，这些都是关键的表型 晚期疾病。重要的是，这些表型在体内是保守的，其中MICAL2的丢失 小鼠或人的PDAC细胞显著抑制肿瘤的生长，以及转移到肝脏和肺的扩散。 最后，MICAL2似乎促进了对吉西他滨的耐药性，吉西他滨是一种常见的PDAC化疗药物。 我们收集的证据有力地表明，在PDAC中以MICAL2计划为目标 治疗效果很好。为了验证我们的假设，我们的目标是确定MICAL2的抑制如何影响 PDAC对细胞毒治疗的反应及MICAL2抑制对PDAC细胞的外源性影响 模特们。为了实现这一点，我们将使用正交方法来定义以下潜在的好处和结果 MICAL2瞄准。我们将利用我们广泛的临床前建模专业知识来评估细胞内在和 MICAL2抑制的外在效应。我们将定义促进化疗耐药的MICAL2依赖程序 并评估新的药物组合以克服这些计划。重要的是，我们将彻查 我们治疗方法的潜在毒性。这些研究的结果将加深我们对 MICAL2生物学，从而为MICAL2导向疗法的开发和测试提供信息 胰腺癌。

PROJECT SUMMARY/ABSTRACT There is a critical need for novel therapeutic approaches for pancreatic ductal adenocarcinoma (PDAC) as the current chemotherapeutic regimens fail to control the disease for a majority of patients. To identify novel regulators of PDAC we compared the epigenetic landscape of surgically resected tumors to normal pancreas using histone-3 lysine-27 acetylation (H3K27ac). This analysis revealed super-enhancer regions which are “hot- spots” for transcription factor binding. Super-enhancer profiling of PDAC tissue revealed a distinctive landscape compared to that of normal pancreas. Amongst the most highly acetylated enhancers mapped to the MICAL2 gene. The MICAL2 enzyme is a flavin monooxygenase that regulates nuclear actin dynamics resulting in downstream modulation of transcription by myocardin-related transcription factor-A and serum response factor. As an enzyme whose class has been successfully inhibited in human disease, we believe MICAL2 represents an exciting and potentially tractable target for pancreatic cancer therapy. We examined human and murine pancreatic cancer cell lines and organoids as well as several independent datasets and confirmed that MICAL2 is overexpressed in PDAC and that its overexpression confers a poor prognosis. In addition, we have generated robust preliminary data demonstrating that loss of MICAL2 results in downregulation of key cell cycle regulators which slows proliferation and causes stalling in G1 and G2/M phases. Furthermore, silencing of MICAL2 inhibits colony formation and cell migration in vitro which are key phenotypes of advanced disease. Importantly, these phenotypes are conserved in vivo, where the loss of MICAL2 in either mouse or human PDAC cells markedly inhibits tumor growth, as well as metastatic spread to both liver and lung. Finally, MICAL2 appears to promote chemoresistance to gemcitabine, a common PDAC chemotherapeutic. The evidence we have gathered strongly suggests that targeting the MICAL2 program in PDAC will be therapeutically effective. To validate our hypothesis, our goals are to determine how inhibition of MICAL2 impacts PDAC response to cytotoxic therapies and to define the cell extrinsic effects of MICAL2 inhibition in PDAC models. To accomplish this, we will use orthogonal approaches to define the potential benefits and outcomes of MICAL2 targeting. We will leverage our extensive pre-clinical modeling expertise to assess cell intrinsic and extrinsic effects of MICAL2 inhibition. We will define MICAL2 dependent programs that promote chemoresistance and assess novel drug combinations to overcome these programs. Importantly, we will thoroughly investigate the potential toxicity of our therapeutic approach. The findings from these studies will enhance our understanding of MICAL2 biology and thereby serve to inform the development and testing of MICAL2-directed therapies in pancreatic cancer.