Role of mesenchymal stem cells in modulating cytokine networks and immune checkpoints in gastric cancer therapy.

Gastric cancer (GC) remains a leading cause of cancer-related mortality worldwide, driven by a complex tumor microenvironment (TME) that promotes disease progression and therapeutic resistance. This review explores the pivotal roles of mesenchymal stem cells (MSCs), cytokines, and immune checkpoint inhibitors (ICIs) in shaping the immunosuppressive GC TME, with emphasis on their interaction and implications for immunotherapy. MSCs secrete cytokines such as IL-6, TGF-β, and IL-10, fostering an immunosuppressive milieu that enables tumor growth, immune evasion, and resistance to ICIs. We synthesize current knowledge on how MSC-derived cytokines regulate immune checkpoint expression, suppress anti-tumor immunity, and contribute to TME heterogeneity. Additionally, we discuss therapeutic strategies targeting MSC-cytokine-immune checkpoint interactions to enhance ICI efficacy and improve clinical outcomes. Emerging approaches including MSC reprogramming, exosome-based therapies, and multi-omics technologies are highlighted as promising avenues to decipher TME complexity and develop personalized immunotherapies. By elucidating mechanisms of MSC-mediated immune modulation in GC, this review aims to inspire novel strategies to overcome therapeutic resistance in this challenging disease.