Alcohol consumption has been implicated in the pathogenesis of head and neck squamous cell carcinoma (HNSCC), although its mechanism is poorly understood. Recent advances in the identification and understanding of long non-coding RNAs (lncRNAs) have indicated that these molecules have a profound effect on numerous biological processes, including tumorigenesis and oncogenesis. The present authors hypothesize that alcohol-mediated dysregulation of lncRNAs is a key event in HNSCC pathogenesis. An in silico differential expression analysis utilizing RNA sequencing (RNA-seq) data from 34 HNSCC patients, which included alcohol drinkers and non-alcohol drinkers, identified a panel of lncRNAs that were dysregulated due to alcohol consumption. Normal oral keratinocytes were then exposed to ethanol and acetaldehyde to validate the RNA-seq results. Two lncRNAs that were differentially expressed due to alcohol consumption were identified from RNA-seq analysis of the clinical data: lnc-PSD4-1 and lnc-NETO-1. Oral keratinocytes exposed to alcohol and acetaldehyde demonstrated dysregulation of these two lncRNAs, thus validating the results of RNA-seq analysis. In addition, low expression of the lnc-PSD4-1 isoform, lnc-PSD4-1:14, exhibited a strong correlation with high survival rates in a Cox proportional hazards regression model. Therefore, these lncRNAs may play a key role in the early pathogenesis of HNSCC, since they are dysregulated in both clinical data and in vitro experiments mimicking the effects of alcohol use.
Keywords: RNA-seq; acetaldehyde; alcohol; epigenetics; head and neck squamous cell carcinoma; long non-coding RNAs.