Development of a Diagnostic Panel of Methylated MicroRNA Markers for Head and Neck Cancer

Abstract

Objectives:

Early detection of head and neck squamous cell carcinoma (HNSCC) improves long-term survival. More than half of patients with HNSCC present with locoregional or metastatic disease at the time of diagnosis. MicroRNAs are promising markers for early detection, as they are stable, tissue-specific, and known to be involved in processes critical for tumor development and progression. Methylated miRNA sequences have already been studied in early detection of lung and gastrointestinal (GI) cancers.

Methods:

Genomic DNA was extracted from 30 SCC samples, 24 samples of grossly normal adjacent mucosa from those tumor patients, and 8 samples from normal controls (no cancer). The gDNA was treated with bisulfate to identify methylation patterns, and quantitative polymerase chain reaction was run for 6 miRNA markers (9-1, 9-3, 124-1, 124-2, 124-3, 137) to determine the level of expression in each sample.

Results:

Overall expression of each marker was significantly higher in the tumor group when compared to the controls (P < 0.001) and the adjacent mucosa (P < 0.001). Using the expression levels within the controls as a baseline, a positive cut-off value was determined for each marker to create 100% specificity. The sensitivity of each individual marker ranged from 60-76%, but when used in combination as a diagnostic panel, the sensitivity increased to 90%.

Conclusions:

We have successfully created a diagnostic panel of methylated microRNA markers that demonstrated 90% sensitivity and 100% specificity in the detection of HNSCC. This panel is currently being tested on saliva, blood, and tissue samples of tumor-positive and tumor-negative (control) patients as part of a larger early detection clinical study.