Tumor-associated mesenchymal stem/stromal cells in tumor microenvironment and carcinogenesis.

Mesenchymal stem/stromal cells (MSCs) possess significant potential in regenerative medicine, attributed to their inherent capacity for site-specific homing to inflammatory regions, diverse differentiation abilities, and immunomodulatory functions. Tumors represent a substantial threat to human health, and therapeutic options remain limited. The inherent ability of MSCs to migrate towards tumor sites has been extensively utilized in cancer therapies. However, MSCs have shown ambiguous effects on tumors and contribute to the tumor microenvironment by trans-differentiation into different stromal cell types. Tumor-associated MSCs (TA-MSCs), derived from various tumor tissues, have been identified for their role in promoting tumor progression by interacting with tumor cells and other stromal components. As integral components of the tumor stroma, TA-MSCs provide a novel perspective for elucidating the mechanisms underlying malignancy. This review enhances our comprehension of TA-MSCs in solid tumors by summarizing evidence on their existence, differences from normal MSCs, heterogeneity, and roles in tumor initiation and progression. Furthermore, this review underscores the potential clinical implications of TA-MSCs for tumor diagnosis, prognosis prediction, and therapy.