Thyroid cancer-derived exosomal SPP1 promotes tumor progression by driving macrophage M2 polarization through the CD44/JAK2/STAT3 signaling pathway

Abstract Background: While secreted phosphoprotein 1 (SPP1) drives macrophage M2 polarization and cancer progression in multiple malignancies, its role in thyroid cancer remains poorly understand. This study investigated the roles and mechanisms of thyroid cancer-derived exosomal SPP1 in regulating macrophage M2 polarization and malignant progression in thyroid cancer. Methods: SPP1 protein expression in thyroid cancer tissues and cell lines was assessed. Exosomes from TPC1 cells were isolated and characterized for SPP1 expression. THP-1 cell-differentiated M0 macrophages were treated with unmodified