LINC00355 inhibits apoptosis and promotes proliferation of gastric cancer cells by regulating Wnt/ß-catenin signaling pathway.

ABSTRACT

OBJECTIVE: To study the expression and biological functions of long intergenic non-protein coding ribonucleic acid 00355 (LINC00355) in gastric cancer (GC), and to explore its potential mechanism of action. PATIENTS AND METHODS: The relative expression level of LINC00355 in 48 cases of GC tissues, the corresponding paracancerous tissues, and GC cells was determined using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and the interference efficiency of small interfering (si)-LINC00355 was detected via qRT-PCR. After knock-down of LINC00355, methyl thiazolyl tetrazolium (MTT) and 5-ethynyl-2'-deoxyuridine (EdU) assays were performed to detect the changes in the proliferation ability of GC cells, and the changes in the GC cell cycle distribution and apoptosis rate were examined by flow cytometry. Besides, Western blotting was conducted to verify the changes in the downstream signaling pathway of LINC00355. RESULTS: Among 48 cases of GC tissues, there were 42 (87.5%) cases of LINC00355 expression up-regulation, and 6 (12.5%) cases of LINC00355 expression down-regulation. The qRT-PCR results revealed that the expression of LINC00355 was raised in 4 kinds of GC cells. After interference with LINC00355 expression, the MTT assay results indicated that the cell proliferation ability was inhibited, consistent with the EdU assay results. After LINC00355 was knocked down in GC cells, GC cells in experiment group had a higher apoptosis rate than those in si-NC group and arrested in the gap 0 (G0)/G1 phase. Moreover, it was found through Western blotting that the expressions of the molecular markers in the downstream wingless-INT (Wnt)/ß-catenin signaling pathway were downregulated after interference with the expression of LINC00355. CONCLUSIONS: LINC0035 exhibits an up-regulated expression in GC and regulates the Wnt/ß-catenin signaling pathway to promote proliferation and inhibit apoptosis.