To investigate the effect of long non-coding RNA GIHCG (lncRNA GIHCG) on the malignant phenotype of non-small cell lung cancer (NSCLC).

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression levels of lncRNA GIHCG in the tumor tissues and the adjacent normal tissues of 50 patients with NSCLC, respectively. LncRNA GIHCG expression levels in human normal bronchial epithelial cell line 16HBE and NSCLC cell lines A549, H1299, H1650, and H2087 were also detected. Two small interfering RNAs (siRNA-1 and siRNA-2) were designed according to the lncRNA GIHCG sequence. Both the siRNAs were transfected respectively into A549 and H1299 cells. Then the cells were separately divided into four groups: siRNA-1 transfection group, siRNA-2 transfection group, the negative control group, and the blank control group. After transfection for 48 h, the cell proliferation activity was investigated with CCK8 array. Transwell assay was applied to detect the cell invasion ability and flow cytometry was used to detect the cell cycle changes in each group. All the data were statistically analyzed with SPSS 16.0. The measurement data conforming to the normal distribution were shown as mean±standard deviation (mean±SD), and the comparison between two groups was performed by independent sample t test. The one-way analysis of variance (ANOVA) was used to determine whether there were any statistically significant differences in comparing multiple groups and the least significant difference (LSD) was used to further analyze the difference between two groups after ANOVA test.

The qRT-PCR results showed that the expression level of lncRNA GIHCG in the lung cancer tissues was significantly higher than that of the adjacent normal tissues, and the expression levels of lncRNA GIHCG in the NSCLC cell lines A549, H1299, H1650 and H2087 were all significantly higher than the expression level of GIHCG in 16HBE cells (P<0.05). After transfection for 48 h, compared with the blank control group and the negative control group, the survival rates of cells in the siRNA-1 transfection group and the siRNA-2 transfection group were significantly decreased. Correspondingly, the number of transmembrane cells was significantly reduced. The proportion of cells in G0/G1 phase was significantly increased, and the number of cells in the S phase was decreased, with statistically significant difference between them. However, the G2/M phase cells were the same proportion in different treatments. The difference between the negative control group and the blank control group had no statistical significant difference.

lncRNA GIHCG is highly expressed in the NSCLC tissues and the cell lines. Therefore, silencing the expression of lncRNA GIHCG can significantly inhibit the biological phenotype of malignant NSCLC.