Long non‐coding RNA LGALS8‐AS1 facilitates PLAGL2‐mediated malignant phenotypes in gastric cancer

Abstract

Background Great progress has been made in studying the function of long non‐coding RNA (lncRNA) in various tumors, including gastric cancer (GC). However, there are still numerous lncRNAs that have not yet been studied and explored for their roles in GC, and their important functions need to be further revealed. Methods Through analyzing The Cancer Genome Atlas (TCGA) database combined with bioinformatics survival tools, a novel GC‐related lncRNA LGALS8‐AS1 was identified. A quantitative real‐time polymerase chain reaction and a series of in vitro or in vivo cell functional experiments were performed to determine the expression and the role of LGALS8‐AS1/miR‐138‐5p/PLAGL2 in GC. Results LGALS8‐AS1 was remarkably upregulated and correlated with the unfavorable prognosis in GC. Higher expression of LGALS8‐AS1 was positively associated with higher lymph node metastasis rate, as well as larger tumor size. In addition, a series of cell functional experiments revealed that LGALS8‐AS1 could facilitate GC cell proliferation, migration and metastasis in vitro or in vivo. A deeper mechanism exploration revealed that LGALS8‐AS1 could function as the miR‐138‐5p molecular sponge and upregulate the PLAGL2 expression, thereby promoting the cell proliferation, migration and metastasis in GC. Conclusions In brief, we revealed the tumor promoting role of the LGALS8‐AS1/miR‐138‐5p/PLAGL2 molecular signaling axis in GC, and our findings provide enlightenment for further understanding of the mechanism of tumorigenesis and development of GC, making LGALS8‐AS1 a possible new diagnostic or therapeutic target for GC.