Microarray expression profile analysis of long non-coding RNAs in human gastric cardiac adenocarcinoma

Long noncoding RNAs (lncRNAs) are pervasively transcribed and have been shown to regulate key biological processes that maintain normal cellular functions. Abnormal regulation of these lncRNAs can promote tumorigenesis through resulting aberrant cellular essential functions. however, the roles of lncRNAs played in the development of gastric cardiac adenocarcinoma (GCA) remain unknown. With this work we aimed to show the expression profile of lncRNAs in GCA tissues compared with paired adjacent noncancerous tissue using microarray analysis in order to interrogate potential carcinogenesis molecular mechanisms of GCA from lncRNA level.

In this study, total RNA was isolated from 15 pairs of GCA tissue, cancerous and non-cancerous, and hybridized to arraystar lncRNA V2.0 chips containing probes representing 33,000 lncRNA genes. Quantitative real-time polymerase chain reaction (PCR) was used to validate 6 up-regulated and 6 down-regulated lncRNAs. Bioinformatic analysis including gene ontology(GO) analysis, pathway analysis and network analysis was done for further investigation.

Pathway analysis indicated that 8 pathways corresponded to downregulated transcripts and that 20 pathways corresponded to up-regulated transcripts (p-value cut-off is 0.05). GO analysis showed that the highest enriched GOs targeted by up-regulated transcripts were tissue homeostasis and the highest esenriched GOs targeted by the downregulated transcripts were tissue homeostasis.

Our study is the first to interrogate differentially expressed lncRNAs in human GCA tissues and indicates that lncRNAs may be used as novel candidate biomarkers for the clinical diagnosis of GCA and potential targets for further therapy.