MiR-4282 inhibits proliferation, invasion and metastasis of human breast cancer by targeting Myc.

OBJECTIVE: To investigate the expression and role of MicroRNA 4282 (miR-4282) in the development of breast cancer. MATERIALS AND METHODS: In situ hybridization was performed to investigate the expression of miR-4282 in human breast cancer tissues. Cell lines stably over-expressed miR-4282 were established by lentivirus transfection. The effects of miR-4282 on the biological behavior of breast cancer cells were then explored in vitro. RESULTS: The results showed that miR-4282 was down-regulated in human breast cancer tissues and was particularly in invasive and metastatic tumors. In addition, the expression of miR-4282 was related to the occurrence of metastasis and the clinical grade of breast cancer. Recovery of miR-4282 expression in the cell could inhibit the proliferation of breast cancer cells, blocked G1-S phase and promoted breast cancer cell apoptosis, inhibited breast cancer cell migration and invasion. Besides, miR-4282 also significantly enhanced the sensitivity of breast cancer cells to paclitaxel. The results of bioinformatics analysis combined with qRT-PCR and Western blot demonstrated that Myc might be the target gene of miR-4282 in breast cancer. CONCLUSIONS: miR-4282 inhibited the occurrence and development of breast cancer by regulating Myc, which made it a new target for clinical diagnosis and treatment of breast cancer.