Metabolic regulation of FOLFIRINOX acquired resistance in pancreatic cancer

项目总结：早期全身播散，异常局部侵袭，晚期诊断， 对现有化疗的反应导致胰腺导管腺癌预后不良 （PDAC）患者。虽然胰腺肿瘤通常显示出对化疗的低内在反应，但大多数胰腺肿瘤都是化疗的结果。 在治疗过程中获得抵抗力。因此，迫切需要了解 有助于获得性耐药性的机制，并确定新的疗法/治疗 联合用药可以显著提高患者的生存率。我们已经证明代谢 重编程为消除获得性耐药性和改善治疗提供了一个有针对性的弱点， PDAC中的响应。治疗抗性取决于肿瘤细胞内在机制和代谢调节机制。 以及肿瘤细胞和肿瘤微环境之间的信号串扰。我们的无偏见的初步数据， 多个人PDAC患者来源的异种移植物模型鉴定肽基精氨酸脱亚胺酶1（PADI 1）为 top上调基因与患者预后不良显著相关。瓜氨酸或脱亚氨基化 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，并且翻译后修饰导致改变的蛋白质-蛋白质相互作用，信号传导， 转录反应。我们注意到PADI1在人PDAC肿瘤和细胞系中的强表达， 与患者生存率的相关性。抑制PADI活性或PADI 1敲低显著改善了PADI的表达。 PDAC细胞系和类器官对FOLFIRINOX治疗组分的反应性。PADI1表达 糖酵解表型和缺氧基因也与PDAC肿瘤有显著相关性 签名，显示与氧化磷酸化的相互关系。我们还进行了一个无偏见的 CRISPR筛选并鉴定了可能有效用于与药物共靶向的新代谢脆弱性 抑制PADI1下游代谢途径。PADI的表达也与细胞的重编程有关。 微环境中的免疫和非免疫基质。因此，拟议的项目1将检验假设 如果靶向PADI1或下游代谢重编程将消除耐药性的发展， PDAC中的FOLFIRINOX。我们还将研究PDAC中基质重塑的机制基础 肿瘤和间质重编程导致获得性FOLFIRINOX耐药。我们提出 三个具体目标来检验假设。目的1将研究靶向PADI 1下游的功效 间质重塑的途径和相关机制，以消除对FOLFIRINOX治疗的耐药性。 目的2将确定肿瘤细胞内在代谢重编程的机制，这种机制也会进入基质， 由PADI1重新编程。目标3将研究目标1和2中确定的靶向途径的有效性 在PDX模型中，并利用人体组织样本确定临床相关性。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.