Abstract: ObjectiveTo detect the expression of long noncoding RNAs （lncRNAs） in gastric cancer and analyze its function. MethodsRNASeq data of 34 paired gastric cancer and normal adjacent tissues were downloaded from the website of the Cancer Genome Atlas （TCGA）. Subread and featureCounts were used to analyze the data. The expression of mRNAs and lncRNAs was obtained. EdgeR was utilized to identify the differentially expressed lncRNAs between gastric cancer and normal adjacent tissues. The mRNAs coexpressed with the differentially expressed lncRNAs were identified and subjected to Gene Ontology （GO） and Kyoto Encyclopedia of Genes and Genomes （KEGG） analysis. ResultsOne thousand three hundred and fortyfive lncRNAs were differentially expressed between gastric cancer and normal adjacent tissues. Among these lncRNAs， 758 lncRNAs were upregulated and 587 lncRNAs were downregulated in gastric cancer. Coexpression analysis showed that 1045 coding genes were correlated with lncRNAs. The GO biological process terms associated with coexpressed mRNAs included mitotic nuclear division， cell division， DNA replication， etc. The KEGG pathways involved cell cycle， cell adhesion molecules， etc. ConclusionThe expression of lncRNAs in gastric cancer changes significantly compared with normal adjacent tissues， suggesting lncRNAs may play important roles in development and progression of gastric cancer.

Key words: Gastric cancer, Long noncoding RNA（lncRNA）, RNASeq