Small-RNA high-throughput sequencing of head-and-neck cancer with or without human papilloma virus etiology

HPV positive head and neck cancer (HNC) are thought to have different etiology from HPV-unrelated HNC. There are indications that HPV positive HNC have better survival and that treatment options could be optimized in this set of tumours. In this study, we sought to evaluate miRNA profiles in the different groups of HNC based on cancer subsite (oral or oropharyngeal) and HPV presence (positive/negative; based on both viral DNA and RNA presence) all in comparison with normal tonsillar tissue from approximately aged subjects. From 61 enrolled patients, 22 were selected for NGS small RNA sequencing using Illumina small RNA library preparation kits and sequencing reagents on Nextseq 500 machine. Only samples with RIN >= 7 were included. manufacturers protocol was followed for library preparation. Indexing was done with indexes 1-22, and final libraries were normalizes to same amount after QBit measurement. Sequencing was done on Nextseq 500 machine and subsequent analyisis in Basespace (illumina). Raw fastq files were subsequently additionally trimmed of adapter sequences using FastQc Basespace app and differential expression evaluated with SmallRNA app. Customized plots were obtained after importing SmallRNA app calculated counts to DeSeq2 package in R and reanalysis therein.