Targeting the MICAL2 signaling axis in pancreatic cancer

项目总结/摘要 对于胰腺导管腺癌（PDAC）的新治疗方法存在迫切需要，因为胰腺导管腺癌（PDAC）的治疗方法是有效的。 目前的化疗方案不能控制大多数患者的疾病。鉴定新 我们比较了手术切除的肿瘤和正常胰腺的表观遗传景观， 使用组蛋白-3赖氨酸-27乙酰化（H3 K27 ac）。这项分析揭示了超级增强子区域，它们是“热- 转录因子结合的“斑点”。PDAC组织的超级增强子分析揭示了一个独特的景观 与正常胰腺相比。在定位于MICAL 2的最高度乙酰化的增强子中， 基因MICAL 2酶是一种黄素单加氧酶，其调节核肌动蛋白动力学，导致 通过心肌蛋白相关转录因子-A和血清应答因子对转录的下游调节。 作为一种在人类疾病中已被成功抑制的酶，我们认为MICAL 2代表了 胰腺癌治疗的一个令人兴奋的和潜在的易处理的目标。 我们检查了人类和小鼠胰腺癌细胞系和类器官以及几个独立的 数据集，并证实MICAL 2在PDAC中过表达，并且其过表达赋予了差的 预后此外，我们已经产生了强有力的初步数据，表明MICAL 2的丢失导致 下调关键细胞周期调节因子，减缓增殖并导致G1和G2/M期停滞。 此外，MICAL 2的沉默抑制体外集落形成和细胞迁移，这是关键表型 晚期疾病。重要的是，这些表型在体内是保守的，其中MICAL 2在任一种细胞中的丢失都是可能的。 小鼠或人PDAC细胞显著抑制肿瘤生长以及转移性扩散至肝和肺。 最后，MICAL 2似乎促进对吉西他滨（一种常见的PDAC化疗剂）的化学抗性。 我们收集到的证据有力地表明，在PDAC中针对MICAL 2计划将是 治疗有效。为了验证我们的假设，我们的目标是确定抑制MICAL 2如何影响 PDAC对细胞毒性治疗的反应，并确定PDAC中MICAL 2抑制的细胞外在效应 模型为了实现这一点，我们将使用正交方法来定义潜在的好处和结果， MICAL 2定位。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 MICAL 2抑制的外在效应。我们将定义MICAL 2依赖的程序，促进化疗耐药性 并评估新的药物组合来克服这些程序。重要的是，我们会彻底调查 我们治疗方法的潜在毒性这些研究的结果将加强我们对 的MICAL 2生物学，从而为开发和测试MICAL 2导向的治疗提供信息， 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.