1. ITGB2-mediated metabolic switch in CAFs promotes OSCC proliferation by oxidation of NADH in mitochondrial oxidative phosphorylation system
- Author
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Qingang Hu, Liang Ding, Yanhong Ni, Yuxian Song, Xihu Yang, Yingchun Dong, Mengxiang Zhao, Xiaoxin Zhang, Sheng Chen, and Yue Jing
- Subjects
0301 basic medicine ,Male ,cancer associated fibroblasts ,Medicine (miscellaneous) ,Oxidative Phosphorylation ,0302 clinical medicine ,Cancer-Associated Fibroblasts ,Tumor Microenvironment ,Warburg Effect, Oncologic ,Glycolysis ,ITGB2 ,Pharmacology, Toxicology and Pharmaceutics (miscellaneous) ,Chemistry ,Middle Aged ,Metformin ,Progression-Free Survival ,Mitochondria ,Up-Regulation ,oral squamous cell carcinoma ,Chemotherapy, Adjuvant ,030220 oncology & carcinogenesis ,Female ,Mouth Neoplasms ,Oxidation-Reduction ,Research Paper ,Oxidative phosphorylation ,03 medical and health sciences ,Cell Line, Tumor ,oxidative phosphorylation system ,Humans ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Cell Proliferation ,Tumor microenvironment ,lactate ,Electron Transport Complex I ,Cell growth ,Squamous Cell Carcinoma of Head and Neck ,Mouth Mucosa ,Computational Biology ,NAD ,Xenograft Model Antitumor Assays ,Coculture Techniques ,stomatognathic diseases ,030104 developmental biology ,Cell culture ,CD18 Antigens ,NADH ,Cancer research ,Follow-Up Studies - Abstract
Objectives: Integrins, the coordinator of extracellular and intracellular signaling, are often found to be aberrant in tumors and can reshape the tumor microenvironment. Although previous studies showed that integrin beta 2 (ITGB2) is important for host defense, its expression profile and role in tumors, especially in cancer associated fibroblasts (CAFs) are still unknown. Methods: Immunofluorescence stain and fluorescence activated cell sorting were used to analyze the ITGB2 expression profile in oral squamous cell carcinoma (OSCC). RT-PCR and western blot were used to compare ITGB2 expression in normal fibroblasts (NFs) and cancer associated fibroblasts (CAFs). Clinical data and function-based experiments were used to investigate the promoting tumor growth ability of ITGB2 expressing CAFs. Enhanced glycolysis activity was identified by using bioinformatics analyses and GC/MS assays. MCT1 knockdown OSCC cell lines were constructed to explore the pro-proliferative mechanisms of ITGB2 expressing CAFs in multiple in vitro and in vivo assays. Results: We found that CAFs exhibited significantly higher ITGB2 expression than the matched NFs. In addition, higher ITGB2 expression in CAFs was correlated with higher TNM stages and more Ki67+ tumor cells, indicating its ability to promote OSCC proliferation. Further, co-culture assay demonstrated that ITGB2-mediated lactate release in CAFs promoted OSCC cell proliferation. Mechanically, ITGB2 regulated PI3K/AKT/mTOR pathways to enhance glycolysis activity in CAFs. Accordingly, lactate derived from ITGB2-expressing CAFs was absorbed and metabolized in OSCC to generate NADH, which was then oxidized in the mitochondrial oxidative phosphorylation system (OXPHOS) to produce ATP. Notably, inhibiting the OXPHOS system with metformin delayed the proliferative capacity of OSCC cells cultured in the ITGB2-expressing CAFs medium. Conclusions: Our study uncovered the ITGB2high pro-tumoral CAFs that activated the PI3K/AKT/mTOR axis to promote tumor proliferation in OSCC by NADH oxidation in the mitochondrial oxidative phosphorylation system.
- Published
- 2020