Human bone marrow mesenchymal stem cell-derived exosomes containing microRNA-425 promote migration, invasion and lung metastasis by down-regulating CPEB1

OBJECTIVE: Bone marrow mesenchymal stem cell-derived exosomes (BMSC-Exos) could mediate the malignancy of tumor cells by transmitting targeted cargo. Therein, this study intends to explore the function of BMSC-Exos transmitting microRNA-425 (miR-425)/cytoplasmic polyadenylation binding protein 1 (CPEB1) in lung cancer growth. METHODS: miR-425 and CPEB1 levels in cancer tissues and cells were measured. BMSCs and their exosomes were collected and identified. After intervention with BMSC-Exos, miR-425 or CPEB1, invasion and migration of A549 and NCI-H1299 cells in vitro, and lung metastasis of A549 cells in vivo were observed. The relationship between miR-425 and CPEB1 was verified. RESULTS: miR-425 was highly expressed while CPEB1 was lowly expressed in lung cancer tissues of patients. CPEB1 was the direct target of miR-425. Down-regulating miR-425 or up-regulating CPEB1 decreased cell invasion and migration ability of A549 and NCI-H1299 cells, as well as decreased the number of lung metastasis lesions in vivo. After co-culture with BMSC-Exos, A549 and NCI-H1299 cells showed promoted migration and invasion in vitro and A549 cells demonstrated increased lung metastasis in vivo. Down-regulated miR-425 or up-regulated CPEB1 reversed the promotion of BMSC-Exos on lung cancer cell invasion, migration and lung metastasis. CONCLUSION: BMSC-Exos could deliver miR-425 to inhibit CPEB1 expression in lung cancer cells, thereby promoting the malignant biological properties of lung cancer cells and their metastasis in vivo.