RETRACTED: The Potential Therapeutic Role of Exosomal MicroRNA-520b Derived from Normal Fibroblasts in Pancreatic Cancer (Retracted article. See vol. 29, pg. 217, 2022)

Pancreatic cancer (PC) remains a major health concern, with conventional cancer treatments exerting little influence on the disease course. MicroRNA-520b (miR-520b) functions as a tumor suppressor in several types of human cancers, whereas its anti-tumor property in the context of PC is still fundamental. The aim of this study is to identify the potential therapeutic role of miR-520b, transferred by exosomes, derived from normal fibroblasts (NFs) in PC progression. A gain-of-function study was performed to examine the roles of miR-520b in PC cell line SW1990, which suggested that miR-520b served as a tumor suppressor in PC. In order to confirm the role of exosomal miR-520b, exosomes were isolated from NF culture medium and cocultured with SW1990 cells. During the coculture experiments, we disrupted exosome secretion and upregulated exosomal miR-520b. The in vitro coculture studies revealed that miR-520b was transferred from NF-derived exosomes to PC cells and thereby suppressed PC cell proliferation, invasion, migration, and stimulated apoptosis. Furthermore, inhibited tumor growth and live metastasis upon elevated miR-520b in exosomes were observed in vivo. Conjointly, our study demonstrates that NF-derived exosomal miR-520b impedes the progression of PC, which contributes to a novel, therapeutic role of exosomal miR-520b for treating PC.