Proteomic analysis of migrasomes derived from IL-6 amplifier-induced human breast cancer cells

Migrasomes are extracellular vesicles secreted by migrating cells that mediate intercellular communication and contribute to inflammation and cancer progression. We have previously demonstrated that IL-6 expression is induced in cells that have taken up migrasomes derived from IL-6 amplifier activated cells, suggesting that migrasomes are involved in the propagation of inflammation. However, the molecular changes occurring within migrasomes upon IL-6 amplifier remain unknown. In this study, migrasome-enriched samples were extracted from IL-6 amplification-induced human breast cancer MDA-MB-231 cells by ultracentrifugation, and comparative proteomics analysis was performed. Shotgun proteomics detected a total of 1984 proteins, of which 1339 were detected under all conditions. In the cytokine-stimulated migrasomes, 330 proteins up-regulated and 149 proteins down-regulated compared to starvation condition. Changes associated with IL-6 amplification included the IL-6 pathway kinase JAK1, proteins involved in vesicular transport, and SNARE family members syntaxin-3 and syntaxin-4. After immunostaining, the fluorescence of JAK1 in migrasomes under stimulation condition was approximately 1.5-fold higher than those under starvation condition, consistent with the proteomic result. Furthermore, functional enrichment analysis revealed enhanced expression of pathways related to oxidative phosphorylation, endoplasmic reticulum protein processing, and cell organization. These findings indicate that IL-6 amplifier activation is associated with coordinated changes in migrasome proteins, including those involved in inflammatory signaling and trafficking. This study provides a proteomic understanding of migrasome-mediated inflammatory communication in the tumor microenvironment.