Curcumin exerts inhibitory effects on undifferentiated nasopharyngeal carcinoma by inhibiting the expression of miR-125a-5p

Curcumin suppresses proliferation, migration, invasion, metastasis and angiogenesis and induces apoptosis by regulating multiple signalling pathways and miRNAs in a wide variety of human malignancies. miRNAs play crucial roles in various steps of carcinogenesis in nasopharyngeal carcinoma (NPC); thus, they could serve as critical therapeutic targets for NPC treatment. Curcumin could provide a novel strategy to block or induce specific miRNAs for miRNA-based gene therapies. Nevertheless, there are no reports to date on the miRNAs regulated by curcumin in NPC. In the present study, we have carried out an miRNA microarray to identify the miRNAs regulated by curcumin in NPC. Curcumin treatment down-regulated the expression of hsa-miR-125a-5p, hsa-miR-574-3p and hsa-miR-210 as determined by miRNA microarray analysis and qPCR (real-time quantitative reverse transcription-PCR). Forced expression of miR-125a-5p enhanced proliferation, migration and invasion of HONE1 cells. Primary NPC exhibited a significantly higher expression level of miR-125a-5p than healthy controls. miR-125a-5p inhibited the expression of tumour protein 53 (TP53), and curcumin treatment up-regulated the expression of TP53. Taken together, these results indicate that curcumin exerted inhibitory effects on NPC by inhibiting the expression of miR-125a-5p and, subsequently, enhancing the expression of TP53. Curcumin could provide a novel strategy to block miR-125a-5p for miRNA-based gene therapies in NPC.