OBJECTIVETo examine the expression level of miR-24 in the plasma of nasopharyngeal carcinoma (NPC) patients and investigate the clinical significance of miR-24 in NPC development.

METHODSBlood samples were from 217 NPC patients admitted in our Department between December, 2007 and June, 2011, with those from 73 patients with chronic purulent otitis media or chronic sinusitis as control. The follow-up data of all the patients were reviewed and the expression of miR-24 in the plasma was examined by qRT-PCR. The correlation of miR-24 expression with clinical staging of NPC was analyzed, and miR-24 levels before and after the treatment were compared.

RESULTSCompared with the control group, the NPC patients showed significantly up-regulated level of miR-24 in the plasma (P<0.001). Plasma miR-24 level differed significantly among patients with different T stages (P=0.007) and was negatively correlated with the N stages (P=0.028) and plasma EBV-DNA (P=0.048). The expression levels of miR-24 were significantly reduced after treatment in the NPC patients and were significantly lowered in patients without relapse or metastasis (P=0.001).

CONCLUSIONPlasma miR-24 may serve as a novel molecular biomarker for early diagnosis and prognosis of NPC.