Gastric cancer (GC) is one of the most common malignant
tumor types worldwide. Long non-coding RNAs (lncRNAs) have important epigenetic effects, including altering the proliferation and
metastasis of malignant
tumors. We used gene chip technology to search for lncRNAs that were differentially expressed in GC and metastatic lymph node tissues compared with adjacent normal tissues. The
lncRNA Loc490 and the
RNA-binding protein Quaking (QKI) were downregulated in GC tissues and
lymph node metastases compared with normal tissues, and the levels of these two genes correlated positively with one another. Loc490 expression correlated negatively with
lymph node metastasis and vein/nerve invasion, while it correlated positively with overall and disease-free survival. In vitro, Loc490 post-translationally enhanced the expression of QKI and suppressed the expression of epithelial-mesenchymal transition-related molecules. Overexpression of Loc490 inhibited GC cell proliferation, invasion and
metastasis and exerted strong antitumor effects in vivo, while silencing of QKI antagonized these effects. A potential binding site between Loc490 and QKI was detected through bioinformatics analysis and confirmed through
RNA immunoprecipitation and mutant analyses. Our results suggest that
lncRNA Loc490 inhibits GC cell proliferation and
metastasis by upregulating
RNA-binding protein QKI.