Metabolic regulation of FOLFIRINOX acquired resistance in pancreatic cancer

项目概述：早期系统性播散，局部侵袭异常，诊断较晚，不充分 对现有化疗的反应导致胰腺导管腺癌预后不良 (PDAC)患者。虽然胰腺肿瘤通常对化疗的内在反应性较低，但大多数 在治疗过程中获得抗药性。因此，迫切需要了解 治疗获得性抵抗的机制和确定新的治疗方法/治疗 能显著提高患者存活率的药物组合。我们已经证明了新陈代谢 重新编程为消除获得性耐药性和改进治疗提供了一个有针对性的脆弱性 PDAC中的响应。治疗抵抗既取决于肿瘤细胞的内在机制，也取决于代谢 肿瘤细胞与肿瘤微环境之间的信号串扰。我们没有偏见的初步数据 多种人PDAC患者来源的异种移植模型确定了肽基精氨酸脱亚氨酶1(PADI1)是 与患者预后不良显著相关的TOP上调基因。瓜氨酸化或脱亚胺 精氨酸残基产生正电荷的损失，增加氨基酸的质量和酸度 侧链，翻译后修饰导致蛋白质-蛋白质相互作用、信号和 转录反应。我们注意到PADI1在人PDAC肿瘤和细胞系中的强阳性表达，以及 与患者生存的相关性。抑制PADI活性或PADI1基因敲除显著改善 PDAC细胞系和有机物对FOLFIRINOX治疗成分的反应性。PADI1表达 PDAC肿瘤也显示与糖酵解表型和低氧基因显著相关 签名，显示了与氧化磷酸化的相互关系。我们还进行了不偏不倚的 CRISPR筛选并确定了可能有效地与药物共同靶向的新的代谢易损性 抑制PADI1下游代谢途径。PADI的表达也与脑组织的重编程有关 微环境中的免疫和非免疫基质。因此，拟议的项目1将检验该假设 如果靶向PADI1或下游代谢重新编程将消除耐药性的发展 设置为PDAC中的FOLFIRINOX。我们还将探讨PDAC间质重塑的机制基础。 肿瘤和间质重编程导致获得性FOLFIRINOX耐药。我们建议 有三个具体的目的来检验这一假设。目标1将研究靶向PADI1下游的有效性 消除对FOLFIRINOX治疗抵抗的间质重塑途径和相关机制。 目标2将确定肿瘤细胞内部代谢重新编程的机制，该机制也会进入间质 由PADI1重新编程。目标3将研究靶向目标1和2中确定的通路的有效性 在PDX模型中，并利用人体组织标本确定临床相关性。这些研究将提供 针对PDAC中获得性FOLFIRINOX耐药性的新见解和机会。

Project Summary: Early systemic dissemination, extraordinary local invasion, late diagnosis, and inadequate response to the existing chemotherapy contribute to poor prognosis for pancreatic ductal adenocarcinoma (PDAC) patients. While pancreatic tumors generally show a low intrinsic response to chemotherapies, most acquire resistance over the course of the treatment. Hence, there is an urgent need to understand the mechanisms contributing to acquired resistance to therapies and to identify novel therapies/therapeutic combinations that would significantly improve survival in patients. We have demonstrated that metabolic reprogramming presents a targetable vulnerability for abrogating acquired resistance and improving the therapy response in PDAC. The therapy resistance depends on both tumor cell-intrinsic mechanisms and a metabolic and signaling crosstalk between tumor cells and tumor microenvironment. Our unbiased preliminary data with multiple human PDAC patient-derived xenograft models identified peptidyl arginine deiminase 1 (PADI1) as the top upregulated gene that correlated significantly with poor patient prognosis. Citrullination or deimination of arginine residues produces a loss of a positive charge, increasing the mass and the acidity of the amino acid side chain, and the post-translational modification results in altered protein-protein interactions, signaling, and transcriptional responses. We noted robust expression of PADI1 in human PDAC tumors and cell lines and a correlation with patient survival. Inhibiting PADI activity or PADI1 knockdown significantly improved the responsiveness of PDAC cell lines and organoids to components of FOLFIRINOX therapy. PADI1 expressing PDAC tumors also demonstrated a significant correlation with the glycolytic phenotype and hypoxia gene signature, showing a reciprocal relationship with oxidative phosphorylation. We also performed an unbiased CRISPR screen and identified novel metabolic vulnerabilities that may be efficacious for co-targeting with agents inhibiting PADI1 downstream metabolic pathways. PADI expression also correlated with the reprogramming of immune and non-immune stroma in the microenvironment. Hence, the proposed project 1 will test the hypothesis if targeting PADI1 or downstream metabolic reprogramming will abrogate the development of resistance to FOLFIRINOX in PDAC. We will also investigate the mechanistic basis of stromal remodeling in PDAC tumors and the stromal reprogramming that contributes to acquired FOLFIRINOX resistance. We propose three specific aims to test the hypothesis. Aim 1 will investigate the efficacy of targeting PADI1 downstream pathways and associated mechanisms of stromal remodeling for abrogating resistance to FOLFIRINOX therapy. Aim 2 will determine the mechanism of tumor-cell intrinsic metabolic reprogramming that also feeds into stromal reprogramming by PADI1. Aim 3 will investigate the efficacy of targeting the pathways identified in Aims 1 and 2 in PDX models and determine clinical correlates utilizing human tissue specimens. These studies will provide novel insights and opportunities to target acquired FOLFIRINOX resistance in PDAC.