PO.CL05.10 · 临床研究
药理学性抑制wtIDH1可重塑PDAC免疫格局并改善检查点阻断疗效
Pharmacologic wtIDH1 inhibition remodels the PDAC immune landscape and improves checkpoint blockade efficacy
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
引言：胰腺导管腺癌（PDAC）仍是最致命的人类恶性肿瘤之一，五年生存率不足3%。其侵袭性生物学特性、早期转移和对治疗的深度耐药，部分是由致密的、免疫抑制性的肿瘤微环境（TME）所驱动。尽管代谢抑制剂在选定的分子亚型中已显示出前景，但靶向野生型肿瘤代谢弱点的治疗潜力研究较少。我们早期的工作发现，AG-120（Ivosidenib，一种FDA批准的突变型IDH1抑制剂）在PDAC典型的营养受限条件下也能抑制野生型IDH1（wtIDH1）。在此，我们研究wtIDH1抑制如何同时破坏肿瘤代谢并重塑免疫微环境。
方法：将Miapaca-2、Panc-1和KPC细胞培养于低葡萄糖（2.5 mM）和低镁（0.08 mM）培养基中以模拟PDAC代谢应激。使用Titer-Glo、PicoGreen和集落形成实验测定细胞活力。通过DCFDA和MitoSOX利用荧光和流式细胞术定量细胞质活性氧和线粒体ROS。通过CellTrace和BrdU掺入评估增殖和细胞周期调控。使用原位和同基因小鼠模型评估治疗疗效、免疫细胞浸润以及与抗PD-1治疗的协同作用。
结果：wtIDH1抑制显著减少细胞增殖，损害DNA合成，并升高线粒体和胞质ROS，导致凋亡。在体内，Ivosidenib增加了CD45+免疫细胞的浸润，包括CD4+和CD8+中央记忆T细胞，并增强了M1样巨噬细胞群，同时降低了PD-L1表达。治疗组减少了M2样单核细胞，并将TME推向炎症性、抗肿瘤状态。与抗PD-1的联合治疗改善了生存，并通过强劲的中央记忆和效应记忆T细胞扩增，在肿瘤再攻击时提供了保护。
结论：wtIDH1抑制通过损害肿瘤代谢和促进免疫激活，在PDAC中提供双重益处。这种代谢-免疫重编程为将wtIDH1抑制剂与现有免疫疗法相结合提供了充分的理论依据。
查看英文原文 English abstract
Introduction: Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal human malignancies, with a five-year survival rate under 3%. Its aggressive biology, early metastasis, and profound resistance to therapy are driven in part by a dense, immunosuppressive tumor microenvironment (TME). Although metabolic inhibitors have shown promise in selecting molecular subtypes, the therapeutic potential of targeting metabolic vulnerabilities in wild-type tumors is less explored. Our earlier work identified that AG-120 (Ivosidenib), an FDA-approved inhibitor of mutant IDH1, also inhibits wild-type IDH1 (wtIDH1) under nutrient-restricted conditions typical of PDAC. Here, we investigate how wtIDH1 inhibition simultaneously disrupts tumor metabolism and reshapes the immune microenvironment.
Methods: Miapaca-2, Panc-1, and KPC cells were cultured in low-glucose (2.5 mM) and low-magnesium (0.08 mM) media to simulate PDAC metabolic stress. Cell viability was measured using Titer-Glo, PicoGreen, and colony-formation assays. Cytoplasmic reactive oxygen species and mitochondrial ROS were quantified via DCFDA and MitoSOX using fluorescence and flow cytometry. Proliferation and cell-cycle regulation were evaluated by CellTrace and BrdU incorporation. Orthotopic and syngeneic mouse models were used to assess therapeutic efficacy, immune-cell infiltration, and synergy with anti-PD-1 therapy.
Results: wtIDH1 inhibition significantly reduced cell proliferation, impaired DNA synthesis, and elevated mitochondrial and cytosolic ROS, leading to apoptosis. In vivo, Ivosidenib increased infiltration of CD45⁺ immune cells, including CD4⁺ and CD8+ central-memory T cells, and enhanced M1-like macrophage populations with reduced PD-L1 expression. Treatment group decreased M2-like monocytes and shifting the TME toward an inflammatory, anti-tumor state. Combination therapy with anti-PD-1 improved survival and conferred protection upon tumor rechallenge through robust central- and effector-memory T-cell expansion.
Conclusion: wtIDH1 inhibition offers a dual benefit in PDAC by impairing tumor metabolism and promoting immune activation. This metabolic-immune reprogramming provides a strong rationale for combining wtIDH1 inhibitors with existing immunotherapies.
利益披露 Disclosure
P. Sunita, None..
S. Pattanayak, None..
M. Zarei, None.