RNA-Seq analysis of peripheral blood mononuclear cells reveals unique transcriptional signatures associated with radiotherapy response of nasopharyngeal carcinoma and prognosis of head and neck cancer.

Radiotherapy is the main treatment for nasopharyngeal carcinoma (NPC); however, radioresistance limits the therapeutic efficacy and prognosis of patients with NPC. Here, we plan to identify the genes involved in radiotherapy response. Peripheral blood mononuclear cells (PBMC) from three paired NPC patients with pre-radiotherapy and post-radiotherapy were extracted. Next-generation deep sequencing was then performed to identify the PBMCs transcripts profiles in response to radiotherapy. Data of gene chip GSE48501 was obtained from Gene Expression Omnibus (GEO) database. The gene integration of differentially expressed genes identified from RNA-Seq data and gene chip was performed using "RobustRankAggreg" package. RNA-Seq data from 44 normal and 519 Head and neck squamous cell carcinoma (HNSCC) tissues (downloaded from TCGA) was integrated into the analysis to further support our study. Cox regression was used to identify risk factors impacting survival. Total of 45 genes were identified to be associated with radiotherapy response. Significantly enriched Gene Ontology (GO) terms and pathways were enriched. Univariate and multivariate analysis suggested the dysregulated genes, CHAC2, CLEC9A, GNG10, JCHAIN, KLRB1, NOG, OLR1, PRELID2, SYT1, VWCE, ZNF443 were associated with survival in HNSCC patients. Our data provide an overview of the profiles of radiotherapy-associated genes, which will facilitate future investigations into the function of radiotherapy resistance.