1. PD-L1 regulates tumor proliferation and T-cell function in NF2-associated meningiomas.
- Author
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Wang Y, Zhang C, Yan M, Ma X, Song L, Wang B, Li P, and Liu P
- Subjects
- Humans, Animals, Mice, Male, Female, Neurofibromin 2 metabolism, Neurofibromin 2 genetics, Cell Line, Tumor, Middle Aged, Mice, Nude, Apoptosis drug effects, Apoptosis physiology, Meningioma metabolism, Meningioma immunology, Meningioma pathology, B7-H1 Antigen metabolism, Cell Proliferation drug effects, Cell Proliferation physiology, Meningeal Neoplasms metabolism, Meningeal Neoplasms pathology, Meningeal Neoplasms immunology, T-Lymphocytes metabolism, T-Lymphocytes drug effects, Neurofibromatosis 2 metabolism
- Abstract
Introduction: Programmed death-ligand 1 (PD-L1) expression is an immune evasion mechanism that has been demonstrated in many tumors and is commonly associated with a poor prognosis. Over the years, anti-PD-L1 agents have gained attention as novel anticancer therapeutics that induce durable tumor regression in numerous malignancies. They may be a new treatment choice for neurofibromatosis type 2 (NF2) patients., Aims: The aims of this study were to detect the expression of PD-L1 in NF2-associated meningiomas, explore the effect of PD-L1 downregulation on tumor cell characteristics and T-cell functions, and investigate the possible pathways that regulate PD-L1 expression to further dissect the possible mechanism of immune suppression in NF2 tumors and to provide new treatment options for NF2 patients., Results: PD-L1 is heterogeneously expressed in NF2-associated meningiomas. After PD-L1 knockdown in NF2-associated meningioma cells, tumor cell proliferation was significantly inhibited, and the apoptosis rate was elevated. When T cells were cocultured with siPD-L1-transfected NF2-associated meningioma cells, the expression of CD69 on both CD4
+ and CD8+ T cells was partly reversed, and the capacity of CD8+ T cells to kill siPD-L1-transfected tumor cells was partly restored. Results also showed that the PI3K-AKT-mTOR pathway regulates PD-L1 expression, and the mTOR inhibitor rapamycin rapidly and persistently suppresses PD-L1 expression. In vivo experimental results suggested that anti-PD-L1 antibody may have a synergetic effect with the mTOR inhibitor in reducing tumor cell proliferation and that reduced PD-L1 expression could contribute to antitumor efficacy., Conclusions: Targeting PD-L1 could be helpful for restoring the function of tumor-infiltrating lymphocytes and inducing apoptosis to inhibit tumor proliferation in NF2-associated meningiomas. Dissecting the mechanisms of the PD-L1-driven tumorigenesis of NF2-associated meningioma will help to improve our understanding of the mechanisms underlying tumor progression and could facilitate further refinement of current therapies to improve the treatment of NF2 patients., (© 2024 The Author(s). CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)- Published
- 2024
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