SNHG8 is identified as a key regulator of epstein-barr virus(EBV)--associated gastric cancer by an integrative analysis of IncRNA and mRNA expression

The Epstein-Barr virus (EBV) is associated with a variety of cancers, including gastric cancer, which has one of the highest mortality rates of all human cancers. Long non-coding RNAs (IncRNAs) have been suggested to have important causal roles in gastric cancer. However, the interaction between IncRNAs and EBV has not yet been studied. To this end, we sequenced 11,311 IncRNAs and 144,826 protein-coding transcripts from four types of tissue: one non-EBV-infected gastric carcinoma (EBVnGC) and its adjacent normal tissue, and one EBV-associated gastric carcinoma (EBVaGC) and its adjacent normal tissue. Five IncRNAs showed EBVaGCspecific expression; of those, one (SNHG8) was validated using real-time PCR in an independent cohort with 88 paired gastric cancer and adjacent tissue samples. To explore the functions of SNHG8, we identified its mRNA targets on the IncRNA-mRNA co-expression network of the Illumina Body Map, which contains the RNA sequencing data of mRNAs and IncRNAs from 16 normal human tissues. SNHG8 IncRNA was found to affect several gastric cancer-specific pathways and target genes of EBV. Our results reveal the intertwined tumorigenesis mechanisms of IncRNA and EBV and identify SNHG8 as a highly possible candidate biomarker and drug target of gastric cancer.