Elevated protein lactylation promotes immunosuppressive microenvironment and therapeutic resistance in pancreatic ductal adenocarcinoma
Kang Sun, … , Xueli Bai, Tingbo Liang
Kang Sun, … , Xueli Bai, Tingbo Liang
Published January 30, 2025
Citation Information: J Clin Invest. 2025;135(7):e187024. https://doi.org/10.1172/JCI187024.
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Research Article Immunology Oncology

Elevated protein lactylation promotes immunosuppressive microenvironment and therapeutic resistance in pancreatic ductal adenocarcinoma

Abstract

Metabolic reprogramming shapes the tumor microenvironment (TME) and may lead to immunotherapy resistance in pancreatic ductal adenocarcinoma (PDAC). Elucidating the impact of pancreatic cancer cell metabolism in the TME is essential to therapeutic interventions. “Immune cold” PDAC is characterized by elevated lactate levels resulting from tumor cell metabolism, abundance of protumor macrophages, and reduced cytotoxic T cells in the TME. Analysis of fluorine-18 fluorodeoxyglucose (18F-FDG) uptake in patients showed that increased global protein lactylation in PDAC correlates with worse clinical outcomes in immunotherapy. Inhibition of lactate production in pancreatic tumors via glycolysis or mutant-KRAS inhibition reshaped the TME, thereby increasing their sensitivity to immune checkpoint blockade (ICB) therapy. In pancreatic tumor cells, lactate induces K63 lactylation of endosulfine α (ENSA-K63la), a crucial step that triggers STAT3/CCL2 signaling. Consequently, elevated CCL2 secreted by tumor cells facilitates tumor-associated macrophage (TAM) recruitment to the TME. High levels of lactate also drive transcriptional reprogramming in TAMs via ENSA-STAT3 signaling, promoting an immunosuppressive environment. Targeting ENSA-K63la or CCL2 enhances the efficacy of ICB therapy in murine and humanized pancreatic tumor models. In conclusion, elevated lactylation reshapes the TME and promotes immunotherapy resistance in PDAC. A therapeutic approach targeting ENSA-K63la or CCL2 has shown promise in sensitizing pancreatic cancer immunotherapy.

Authors

Kang Sun, Xiaozhen Zhang, Jiatao Shi, Jinyan Huang, Sicheng Wang, Xiang Li, Haixiang Lin, Danyang Zhao, Mao Ye, Sirui Zhang, Li Qiu, Minqi Yang, Chuyang Liao, Lihong He, Mengyi Lao, Jinyuan Song, Na Lu, Yongtao Ji, Hanshen Yang, Lingyue Liu, Xinyuan Liu, Yan Chen, Shicheng Yao, Qianhe Xu, Jieru Lin, Yan Mao, Jingxing Zhou, Xiao Zhi, Ke Sun, Xiongbin Lu, Xueli Bai, Tingbo Liang

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Figure 4

ENSA K63 lactylation upregulates STAT3/CCL2 signaling via PP2A and SRC.

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ENSA K63 lactylation upregulates STAT3/CCL2 signaling via PP2A and SRC. ...
(A) Volcano map of the RNA-Seq analysis. Top 1,000 upregulated genes were deconvoluted to reveal related transcriptional factors using Metascape. (B) Protein expression analysis of KPC cells treated with 2-DG (10 mM, 24 hours) or NALA (40 mM, 24 hours). (C) Relative Ccl2 mRNA expression is shown with 3 technical replicates. KPC cells were treated with STAT3-IN-11 (1 μM, 24 hours) or NALA (40 mM, 24 hours). (D) Protein expression analysis of KPC cells treated with A-485 (EP300 inhibitor, 1 μM, 24 hours) or NALA (40 mM, 24 hours). (E) Protein expression and immunoprecipitation-immunoblotting analyses of KPC cells treated with 2-DG (10 mM, 24 hours) or NALA (40 mM, 24 hours). Anti-FLAG antibody was used to immunoprecipitate ENSA-FLAG proteins. (F) Protein expression analysis of Ensa-NC and Ensa-KO KPC cells treated with 2-DG (10 mM, 24 hours) or NALA (40 mM, 24 hours). (G) Protein expression analysis of each Ensa-KO KPC cell line overexpressing ENSA-NC, ENSA-WT-FLAG, ENSA-K40R-FLAG, ENSA-K56R-FLAG, ENSA-K63R-FLAG, ENSA-K74R-FLAG, or ENSA-K80R-FLAG. (H) Mass spectrum analysis revealed that ENSA is lactylated at K63 site. (I) Relative Ccl2 mRNA expression of each Ensa-KO KPC cell line overexpressing vector control, ENSA-WT, or ENSA-K63R is shown. (J) Protein expression and immunoprecipitation-immunoblotting analyses of KPC-HA-PPP2R2D cell line treated with 2-DG (10 mM, 24 hours) or NALA (40 mM, 24 hours). Anti-HA antibody was used to immunoprecipitate HA-PPP2R2D proteins. (K) Protein expression and immunoprecipitation-immunoblotting analysis of KPC-HA-PPP2CA cell line treated with 2-DG (10 mM, 24 hours) or NALA (40 mM, 24 hours). Anti-HA antibody was used to immunoprecipitate HA-PPP2CA proteins. (L) Protein expression analysis of each KPC cell line overexpressing vector (control), SRC-WT, SRC-S12A, or SRC-S12D. (M) SRC-pS12-specific activity of PP2A phosphatase. SRC-pS12 cell-penetrating peptide (HLYVSPWGG-SKPKDApSQRRRSL) was incubated with KPC cells treated with 2-DG (10 mM, 24 hours) or NALA (40 mM, 24 hours). (N) Protein expression analysis of KPC and PANC-1 cells treated with 2-DG (10 mM, 24 hours) or NALA (40 mM, 24 hours).