Role of Hypoxia in Shaping the Tumor Stroma in Pancreatic Cancer

缺氧在胰腺癌肿瘤基质塑造中的作用

• 批准号: 10629558
• 负责人: Kyoung Eun Lee
• 金额: $ 42.88万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2028-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10629558
• 关键词: 3-Dimensional; Area; Blood Vessels; CCL2 gene; CD8-Positive T-Lymphocytes; Cells; Clinical; Coculture Techniques; Data; Disease; Disease Progression; Exclusion; Extracellular Matrix; Fibroblasts; Goals; Human; Hypoxia; Hypoxia Inducible Factor; Immune; In Vitro; Infiltration; Inflammatory; Knowledge; LIF gene; Macrophage; Malignant Neoplasms; Malignant neoplasm of pancreas; Mediating; Mus; Myelogenous; Neoplasm Transplantation; Outcome; Oxygen; Pancreatic Ductal Adenocarcinoma; Phenotype; Reaction; Regulation; Role; Shapes; Stress; Stromal Cells; Survival Rate; System; T cell infiltration; T-Lymphocyte; Tars; Testing; cancer cell; cancer type; coping; cytokine; density; design; experience; insight; mouse model; neoplastic cell; normoxia; novel therapeutic intervention; pancreatic cancer cells; rapid growth; recruit; response; targeted treatment; therapy resistant; tumor; tumor growth; tumor hypoxia; tumor progression; tumor-immune system interactions

ABSTRACT Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest and most aggressive cancer types, and thus new treatment strategies are urgently needed. Pancreatic cancer cells are surrounded by a dense stroma consisting of extracellular matrix and noncancerous cells, including fibroblasts and immune cells. Interactions between tumor cells and the associated stroma are critical for tumor progression and resistance to therapy. Due to the unusually low vascular density of PDAC, both the tumor and stromal cells experience hypoxia, a condition of insufficient oxygen availability. To cope with hypoxic stress, both the tumor and stromal compartments undergo adaptive changes primarily mediated by hypoxia-inducible factor 1ɑ and 2ɑ (HIF1ɑ and HIF2ɑ). Although PDAC is known to be severely hypoxic and hypoxia predicts poor clinical outcome, the effects of hypoxia and stromal HIF activation on tumor-stroma interactions in PDAC are not fully understood. Based on our preliminary observation that inflammatory fibroblasts and macrophages are preferentially located in hypoxic tumor regions whereas CD8+ T cells are largely excluded from hypoxic regions in PDAC, we hypothesize that hypoxia drives an immunosuppressive microenvironment by promoting an inflammatory fibroblast phenotype and in turn modulating infiltration and function of macrophages and CD8+ T cells. In Specific Aim 1, we will determine how hypoxia and HIFs regulate an inflammatory fibroblast phenotype in PDAC using a three- dimensional (3D) coculture system of pancreatic tumor cells and fibroblasts and exposing the coculture to either hypoxia or normoxia, as well as using mouse models lacking fibroblast expression of HIF1ɑ or HIF2ɑ. In Specific Aim 2, we will define how hypoxia-induced fibroblast-secreted factors and macrophage-intrinsic hypoxic responses regulate macrophage recruitment and function in PDAC by treating macrophages with conditioned media derived from 3D tumor cell-fibroblast cocultures under hypoxia, and using mouse models lacking myeloid expression of HIF1ɑ or HIF2ɑ. In Specific Aim 3, we will determine how macrophages and fibroblasts contribute to CD8+ T cell exclusion in hypoxic tumor niches by depleting macrophages or blocking a factor secreted from fibroblasts in syngeneic orthotopic transplanted tumors, injecting a hypoxia probe into mice, and assessing CD8+ T cell infiltration and activation in hypoxic and normoxic tumor regions. Together, the proposed studies will provide new knowledge on hypoxic regulation of the tumor-stroma crosstalk and inform the optimal design of stroma-targeting therapeutic strategies for PDAC.

摘要 胰腺导管腺癌(PDAC)仍然是最致命和最具侵袭性的癌症类型之一， 因此，迫切需要新的治疗策略。胰腺癌细胞周围有致密的间质。 由细胞外基质和非癌细胞组成，包括成纤维细胞和免疫细胞。互动 肿瘤细胞和相关间质之间的相互作用对肿瘤进展和耐药起关键作用。到期 由于PDAC的血管密度异常低，肿瘤和间质细胞都经历了缺氧，这是一种情况 氧气供应不足。为了应对低氧应激，肿瘤和间质间隔 主要由缺氧诱导因子1ɑ和2ɑ(HIF1ɑ和HIF2ɑ)介导的适应性改变。 虽然众所周知，PDAC严重缺氧，而且缺氧预示着不良的临床结果，但 在PDAC中，缺氧和间质HIF激活对肿瘤-间质相互作用的影响尚不完全清楚。基于 低氧时炎性成纤维细胞和巨噬细胞优先分布的初步观察 肿瘤区域虽然CD8+T细胞基本上被排除在PDAC的缺氧区之外，但我们假设 低氧通过促进炎性成纤维细胞表型来驱动免疫抑制微环境 进而调节巨噬细胞和CD8+T细胞的浸润和功能。在具体目标1中，我们将 用三种方法确定低氧和HIF如何调节PDAC中的炎性成纤维细胞表型 胰腺肿瘤细胞与成纤维细胞的三维共培养体系 低氧或常氧，以及使用HIF1ɑ或HIF2ɑ缺乏成纤维细胞表达的小鼠模型。具体而言 目的2，我们将明确低氧诱导成纤维细胞分泌因子和巨噬细胞内源性低氧 反应调节巨噬细胞在PDAC中的募集和功能 来自3D肿瘤细胞-成纤维细胞在低氧条件下共培养的培养液，并使用缺乏髓系的小鼠模型 HIF1ɑ或HIF2ɑ的表达。在特定的目标3中，我们将确定巨噬细胞和成纤维细胞如何发挥作用。 通过耗尽巨噬细胞或阻断CD8+T细胞分泌的因子在缺氧性肿瘤壁龛中排斥CD8+T细胞 同基因原位移植瘤中的成纤维细胞，向小鼠体内注射低氧探针，并评估CD8+ T细胞在缺氧区和常氧区的浸润和活化。总而言之，拟议的研究将 提供低氧调节肿瘤-间质串扰的新知识，并为优化设计提供信息。 PDAC的间质靶向治疗策略。