BACKGROUND: Long non-coding RNAs (LncRNAs) could potentially function as diagnostic markers for gastric carcinoma. Nevertheless, the expression profile and biological feature of LncRNAs in early gastric cancer (EGC) remains to be explored.

MATERIAL AND METHODS: LncRNA expression microarray analysis was performed on 6 paired EGC tissues. One deregulated LncRNA, LOC389332, was validated using a quantitative reverse-transcription polymerase chain reaction (qRT-PCR) assay using independent tissue samples and cell lines. The Cell Counting Kit-8 (CCK-8) assay and wound healing assay were conducted to evaluate its influences on the proliferation and migration of gastric cancer cells. LncRNA expression microarray and gene ontology (GO) analysis were also performed on the LOC389332 knockdown cell line model to explore the molecular feature of LOC389332 in gastric carcinoma.

RESULTS: The LncRNA expression profiling showed that 72 LncRNAs were significantly differentially expressed in EGC tissues. The results in the validation phase revealed that LOC389332 was remarkably overexpressed in gastric carcinoma tissues, precancerous lesions, and gastric cancer cells. Functional study showed that knockdown of LOC389332 expression could inhibit cell proliferation and migration. LncRNA expression microarray on the LOC389332 knockdown cell line model revealed that 393 mRNAs were differentially expressed. The GO enrichment analysis indicated that the downregulated genes were mainly associated with cell membrane function, signal transmission process, and cell adhesion process.

CONCLUSIONS: The LncRNA expression profile between EGC and gastritis tissues was significantly different. LOC389332 was potential non-coding oncogenes in gastric cancer, and it may perform its function through altering cell membrane function, signal transmission, and cell adhesion.

Keywords: RNA Interference, Cluster Analysis, Down-Regulation, gastritis, gene ontology, Precancerous Conditions, RNA, Messenger