Influence of Exosomes on Tumorigenic Behavior in Triple-Negative Breast Cancer Cells through STAT3 Inhibition in Autophagy.
OBJECTIVES The prime aim of this research was to evaluate the effect of exosomes on the tumorigenic behavior of TNBC via the autophagic process. MATERIALS AND METHODS TNBC cell lines, MDA-MB-231 and HCC1806 cells, and non-TNBC cell line, MCF-7 cells, were utilized in this study. Cells were maintained in the presence of isolated exosomes, after characterization, before and after the downregulation of the STAT3 signaling pathway. The cell cycle and apoptosis were analyzed using flow cytometry. Moreover, to evaluate overall autophagic flux, LC3B levels were measured by ELISA, and the expression of autophagy-related genes, Beclin-1, ATG16L, ATG5, and RAB24, was analyzed using qRT-PCR. RESULTS The results of this study may suggest that TNBC-derived exosomes play a central role in the tumorigenic behavior of breast cancer by manipulating the autophagic machinery. CONCLUSION Accordingly, it may be concluded that the potentiation of the aggressive behavior of TNBC cells by exosomes could be autophagy-dependent, while that in NTNBC cells is autophagy-independent.