A novel long noncoding RNA-LOWEG is low expressed in gastric cancer and acts as a tumor suppressor by inhibiting cell invasion.

PURPOSE: Long noncoding RNA (lncRNA) have been reported to be involved in the development of multiple cancers. The aim of this study was to report the identification of lncRNA-CTD-2108O9.1, which we have named lncRNA low expressed in gastric cancer (lncRNA-LOWEG), and investigate its role in cancer development.

METHODS: Total RNA was extracted from the tissues of 94 patients with GC, one normal gastric epithelial cell line and four GC cell lines. Expression levels of lncRNA-LOWEG were determined by real-time PCR. Moreover, CCK-8 proliferation assay, transwell cell invasion assay and flow cytometry were performed to study the effects of lncRNA-LOWEG on SGC-7901 cell proliferation, cell invasion and cell cycle progression. Lastly, western blot and real-time PCR were used to verify the potential target genes of lncRNA-LOWEG.

RESULTS: Significantly reduced expression of lncRNA-LOWEG was found in gastric cancer tissues and cell lines (SGC-7901, AGS, BGC-823 and HG-27) compared with patient-matched nontumorous adjacent tissues (P < 0.01) or the normal gastric cell line GES-1 (P < 0.05). Moreover, the transwell assay showed that the number of cells capable of passing through the Matrigel was significantly reduced after lncRNA-LOWEG transfection (P < 0.05). However, lncRNA-LOWEG overexpression did not significantly influence cell proliferation (P > 0.05) and cell cycle progression (P > 0.05). Lastly, western blot and real-time PCR analysis suggested that lncRNA-LOWEG is positively correlated with the expression of leukemia inhibitory factor receptor (LIFR) gene at the translational level.

CONCLUSIONS: LncRNA-LOWEG is a tumor suppressor that inhibits GC cell invasion. And LIFR gene is up-regulated by lncRNA-LOWEG.