PO.ET06.02 · 实验与分子治疗
通过腺嘌呤碱基编辑对胰腺导管腺癌进行等位基因特异性的PARP抑制增敏
Allele-specific sensitization of pancreatic ductal adenocarcinoma to PARP inhibition via adenine base editing
该海报暂无可下载的资料
AACR 官方页面
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
合成致死代表了肿瘤学中一种有前景的治疗范式，尤其对于携带BRCA1/2突变的胰腺导管腺癌（PDAC）患者，这类患者对奥拉帕利（olaparib）等PARP抑制剂（PARPi）表现出更高的敏感性。然而，该策略更广泛的应用受到PDAC中与BRCA缺失相平行的同源重组缺陷（HRD）发生率有限的制约。为解决这一问题，我们采用SpRY介导的腺嘌呤碱基编辑（ABE），在正常胰腺上皮（HPNE）细胞系和PDAC细胞系（包括KRAS-G12D突变型（PANC-1）和野生型（BxPC-3）模型）中筛选HR相关基因的等位基因特异性突变。这些编辑后的细胞接受三种递增剂量的奥拉帕利处理。随后基于斜率的活力降低分析鉴定出若干可特异性使PDAC细胞对PARPi增敏的突变。引人注目的是，NBN-X突变在KRAS野生型BxPC-3细胞中赋予了强效的奥拉帕利超敏感性，而PALB2-Y和RAD50-Z突变相比正常HPNE对照显著增强了KRAS-G12D突变型PANC-1细胞中的奥拉帕利疗效。在机制上，NBN-X变体通过破坏MYC驱动的同源重组（HR）修复使非KRAS突变型PDAC增敏。相反，RAD50-Z变体与KRAS驱动的HR抑制协同以增强PARPi疗效。这些等位基因特异性效应经过功能验证，显示奥拉帕利IC50最多降低4.1倍、凋亡增加2.5倍。至关重要的是，这种强效增敏具有高度肿瘤特异性，在体外和体内均较传统BRCA突变模型产生显著改善的安全性特征。基于这些发现，我们正在利用虚拟筛选和AI驱动的药物设计来开发能够模拟我们所鉴定突变诱导的PARPi超敏感性的小分子。这些先导化合物将被推进至复杂的PDAC模型中进行评估，包括患者来源异种移植物（PDX）和基因工程小鼠。我们的结果突显了一种个体化PDAC PARPi治疗的新策略，并提示可能显著扩大的治疗窗，从而改善这一侵袭性疾病患者的预后。
查看英文原文 English abstract
Synthetic lethality represents a promising therapeutic paradigm in oncology, particularly for pancreatic ductal adenocarcinoma (PDAC) patients with BRCA1/2 mutations, who demonstrate increased sensitivity to PARP inhibitors (PARPi) like olaparib. However, the broader application of this strategy is constrained by the limited incidence of homologous recombination deficiency (HRD) in PDAC that parallels BRCA loss. To address this, we employed SpRY-mediated adenine base editing (ABE) to screen for allele-specific mutations in HR-related genes across normal pancreatic epithelial (HPNE) and PDAC cell lines, including both KRAS-G12D mutant (PANC-1) and wild-type (BxPC-3) models. These edited cells were subjected to olaparib treatment at three escalating doses. A subsequent slope-based analysis of viability reduction identified several mutations that specifically sensitized PDAC cells to PARPi. Strikingly, the NBN-X mutation conferred robust olaparib hypersensitivity in KRAS-wild-type BxPC-3 cells, while PALB2-Y and RAD50-Z mutations markedly enhanced olaparib efficacy in KRAS-G12D mutant PANC-1 cells compared to normal HPNE controls. Mechanistically, the NBN-X variant sensitizes non-KRAS mutant PDAC by disrupting MYC-driven homologous recombination (HR) repair. In contrast, the RAD50-Z variant synergizes with KRAS-driven suppression of HR to potentiate PARPi efficacy. These allele-specific effects were functionally validated, demonstrating up to a 4.1-fold decrease in olaparib IC50 and a 2.5-fold increase in apoptosis. Critically, this potent sensitization was highly tumor-specific, yielding a significantly improved safety profile over conventional BRCA-mutant models both in vitro and in vivo. Leveraging these findings, we are using virtual screening and AI-driven drug design to develop small molecules that mimic the PARPi-hypersensitivity induced by our identified mutations. These lead compounds will be advanced for evaluation in sophisticated PDAC models, including patient-derived xenografts (PDX) and genetically engineered mice. Our results highlight a novel strategy for personalizing PARPi therapy in PDAC and suggest a substantially expanded therapeutic window that could improve outcomes for patients with this aggressive disease.
利益披露 Disclosure
J. Zhang, None.