MiR-24 functions as a tumor suppressor in nasopharyngeal carcinoma through targeting FSCN1.

BACKGROUND: Increasing evidence indicates that the dysregulation of miRNAs expression is involved in the tumorigenesis by acting as tumor suppressors or oncogenes. However, no study investigates the function and mechanisms of miR-24 in nasopharyngeal carcinoma (NPC).

METHODS: Quantitative RT-PCR, MTT, colony formation, soft-agar, wound healing, Transwell migration and invasion assays, and xenograft tumor growth and lung metastasis models were performed to test the expression levels and functions of miR-24 in NPC. Luciferase reporter assay, quantitative RT-PCR, Western blotting, and immunohistochemistry were used to identify and verify the target of miR-24.

RESULTS: The results showed that MiR-24 was obviously downregulated in NPC cell lines and tissue samples (P < 0.05). Ectopic expression of miR-24 inhibited the cell viability, proliferation, migration, and invasion in vitro (all P < 0.05), and suppressed the xenograft tumor growth and lung metastasis formation in vivo (all P < 0.05). Fascin homologue 1 (FSCN1) was verified as a direct target of miR-24, and silencing FSCN1 expression with small interfering RNA inhibited NPC cell proliferation and invasion (all P < 0.05).

CONCLUSIONS: Overall, miR-24 acts as a novel tumor suppressor in the development and progression of NPC through targeting FSCN1, which providing new insight into the mechanisms of NPC carcinogenesis and suggesting the possibility of miR-24 as a therapeutic target.