Abstract Pancreatic Ductal Adenocarcinoma (PDAC) remains one of the deadliest solid malignancies, with only 13% of patients surviving beyond five years. This dismal prognosis is largely attributed to the metastatic nature of the disease and its resistance to both cytotoxic and immune-based therapies. The treatment-refractory nature of PDAC has been linked to its tumor microenvironment, characterized by a dense fibrotic stroma and impaired immune surveillance. Cancer-associated fibroblasts (CAFs) and the extracellular matrix (ECM) are prominent components of the PDAC stroma. However, CAFs are functionally and phenotypically heterogeneous and thus can harbor both pro- and anti-tumorigenic effects. PDAC contains several subpopulations of CAFs, including 1) antigen-presenting fibroblasts (apCAFs), 2) inflammatory fibroblasts (iCAFs), and 3) myofibroblasts (myCAFs). Although heterogeneity in CAF phenotypes has been investigated, it remains unclear whether CAF subtypes differ in their metabolic profiles and how this metabolic diversity impacts the fibroinflammatory microenvironment of PDAC. Recently, we identified a subset of myofibroblasts in PDAC that have undergone senescence, which we termed “senescent CAFs” (senCAFs). Using a genetic mouse model of spontaneous PDAC with inducible senescent cell depletion LSL-KRASG12D; p53flox; p48-CRE; INK-ATTAC (KPPC-IA), we demonstrated that senCAFs support tumor growth by inducing fibrosis and compromising anti-tumor immunity. In this study, we aimed to determine whether senescence in CAFs is accompanied by metabolic reprogramming and if these metabolic changes are required for the profibrotic property of senCAFs. To address this, we first assessed the architecture of the ECM deposited by senescent fibroblasts using immunofluorescence imaging and found that the collagen fibers deposited by senescent fibroblasts are thicker compared to those from non-senescent fibroblasts. Moreover, transcriptomic and metabolomic analysis on senescent and non-senescent fibroblasts showed an increase in glycolysis and impaired tricarboxylic acid (TCA) cycle flux and mitochondrial function in the senescent fibroblasts. Interestingly, these metabolic changes associated with senescence in fibroblasts led to the accumulation of cellular α-ketoglutarate, a key metabolite required for prolyl 4-hydroxylase and lysyl hydroxylase-dependent collagen hydroxylation and subsequent triple-helix formation. Transcriptomic analysis also revealed high gene expression of collagen prolyl 4-hydroxylase (P4ha2, P4ha3 Part 1 (Regular Abstracts) ; 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86 (7 Suppl): Abstract nr 6806.
Sen et al. (Fri,) studied this question.