miR-16 targets fibroblast growth factor 2 to inhibit NPC cell proliferation and invasion via PI3K/AKT and MAPK signaling pathways

Dysregulation of miRNAs has been shown to contribute to the carcinogenesis and progression of nasopharyngeal carcinoma (NPC). Our previous microarray data showed that miR-16 expression is significantly decreased in archived NPC tissues. Here, we confirmed that miR-16 was reduced in NPC cell lines and freshly-frozen samples. Ectopic expression of miR-16 suppressed NPC cell proliferation, migration, and invasion in vitro and inhibited tumor growth and metastatic colonization in the lung in vivo. Furthermore, fibroblast growth factor 2 (FGF2) was identified as a direct target of miR-16, and both phosphoinositide-3- kinase/AKT (PI3K/AKT) and mitogen-activated protein kinase (MAPK) signaling pathways were repressed after miR-16 overexpression. In addition, the restoration of FGF2 reversed the suppressive effects of miR-16. Together, these results indicated that miR-16 suppresses NPC carcinogenesis and progression by targeting FGF2, thereby representing a potential target for miRNA-based therapy for NPC in the future.