Pancreatic Cancer-Derived Exosomes Promote the Proliferation, Invasion, and Metastasis of Pancreatic Cancer by the miR-3960/TFAP2A Axis

BACKGROUND: The microRNAs (miRNAs) in cancer-derived exosomes have the ability to change tumor microenvironment. This study aims to investigate the role of miRNA in cancer-derived exosomes in pancreatic cancer (PC). METHODS: Based on the analysis of PC-derived and healthy exosomes by bioinformatics analysis and quantitative real-time PCR validation, the miR-3960 was identified to be the most significantly different miRNA, and TFAP2A proved as its potential target gene. Besides, the exosomes were isolated from PANC-1 cells and identified. After that, PANC-1 cells were treated with the isolated exosomes or transfected with miR-3960 mimics or si-TFAP2A, the effect of PC-derived exosomes, as well as the miR-3960/TFAP2A axis in PC cells, were assessed by the CCK-8, EDU staining, Transwell, cell colony formation, and flow cytometry assays. Furthermore, the effects of exosomes and the miR-3960/TFAP2A axis on PC tumor growth were observed in tumor-bearing mice by the measurement of tumor weight and volume, and hematoxylin-eosin staining. Moreover, the expressions of TFAP2A/PTEN/AKT signaling proteins were detected by Western blot. RESULTS: PC-derived exosomes were isolated successfully and proved to have promotion effects on the proliferation, metastasis, and invasion of PC cells both in vitro and tumor growth in vivo. Also, the PC-derived exosomes upregulated the TFAP2A, Bcl-2, and p-AKT/AKT protein levels, and inhibited PTEN and Bax levels and PANC-1 cell apoptosis. Overexpression of miR-3960 antagonized the promotion effect of exosomes on PC cells and the TFAP2A/PTEN/AKT signaling pathway, inhibiting the growth of tumors. Besides, si-TFAP2A enhanced the inhibitory effect of miR-3960 in PC. CONCLUSION: MiR-3960 antagonizes the promotion effect of tumor-derived exosomes on the proliferation, invasion, and metastasis of PC via suppressing TFAP2A.