Circulating miRNA is a novel marker for head and neck squamous cell carcinoma

The aim of the study is to investigate the alteration of plasma miRNA in head and neck squamous cell carcinoma (HNSCC). Altered microRNAs (miRNAs) expression has been found in many cancers, including lung cancer, breast cancer, prostate cancer, bladder cancer and colorectal cancer. Many recent studies have demonstrated that aberrant plasma miRNAs were also found in various types of cancers. However the alteration of plasma expression in HNSCC remains unclear. In this present study, the expression profiles of ten miRNAs, let-7a, miR-21, miR26b, miR-34c, miR-99a, miR-133a, miR-137, miR-184, miR-194a, and miR-375, in plasma from 50 patients and 36 healthy subjects were evaluated using real-time quantitative polymerase chain reaction (PCR). Our results demonstrated that the expression level of miR-21 was significantly up-regulated in plasma samples obtained from HNSCC patients (p < 0.01) than those from healthy subjects, which were in consistent with our finding in HNSCC tissues. A 7.7-fold increase of miR-21 in cancerous parts when compared to their non-cancerous counterparts (p < 0.0001) was observed in HNSCC tissues. In addition, the expression levels of miR-21 and miR-26b were both reduced in post-operative HNSCC patients with good prognosis. In contrast, the concentration of plasma miR-21 and miR-26b stayed high after tumor removal in the expired cases. Our study suggests that detecting circulating miR-21 and miR-26b pre- and post-operatively might provide a novel tumor marker for HNSCC.