Expression of long chain non coding RNA gastric cancer-associated transcript 3 in hepatocellular carcinoma and its effect on biological characteristics of HepG2 cells

Objective To investigate the expression of long chain non coding RNA (lncRNA) gastric cancer-associated transcript 3 (GACAT3) in hepatocellular carcinoma and its effect on proliferation, invasion and migration of HepG2 cells and its potential mechanism. Methods real-time quantitative polymerase chain reaction (Real-time PCR) was used to detect the differential expression of lncRNA GACAT3 in liver cancer tissue, adjacent tissues, PLC/PRF/5, Hep3B, HepG2 cell lines and normal liver cells THLE-3. Negative control small interfering RNA (siRNA) and lncRNA GACAT3 siRNA were transfected into HepG2 cells, after 48 h, Real-time PCR was used to detect the expression of lncRNA GACAT3 in transfected cells. Methyl thiazol tetrazolium (MTT) assay was used to detect cell proliferation in each group at 24, 48 and 72 h. The cell migration and invasion were detected by cell scratches experiments and Transwell assay, and the expression of Wnt/β-catenin signaling pathway protein was detected by Western blotting. Results The expression of lncRNA GACAT3 in hepatocellular carcinoma tissues (3.10±1.93) was significantly higher than that in adjacent tissues (1.02±0.59, t=8.086, P<0.01); The expression of lncRNA GACAT3 in PLC/PRF/5 (1.92±0.21, t=7.074, P<0.01), Hep3B (2.42±0.25, t=9.327, P<0.01) and HepG2 cells(2.96±0.31, t=10.582, P<0.01) were significantly higher than that in normal liver cells THLE-3 (0.97±0.10). Compared with the silencing control group (1.03±0.11), the expression of lncRNA GACAT3 in the GACAT3 group (0.16±0.02) was significantly decreased (t=13.478, P<0.01). Cell proliferation was significantly reduced at 48 h and 72 h (P<0.01). Scratch healing rate and migratory and invasive ability were significantly decreased (P<0.01). The expression of Wnt/β-catenin signaling pathway protein β-catenin (0.15±0.02) and its downstream proteins c-Myc (0.22±0.02) and Cyclin D1 (0.21±0.02) were significantly lower than that of the silencing control group(0.81±0.08, t=13.863; 0.65±0.07, t=9.731; 0.78±0.08, t=10.230; P all<0.01). The expression of p-β-catenin protein (0.75±0.08) was significantly higher than that of the silencing control group (0.27±0.03, t=11.972, P<0.01). Conclusion LncRNA GACAT3 is highly expressed in hepatocellular carcinoma. Silencing LncRNA GACAT3 can inhibit the proliferation, migration and invasion of hepatocellular carcinoma cells, and its mechanism may be related to the inhibition of Wnt/β-catenin signaling pathway. Key words: Long chain non coding RNA gastric cancer-associated transcript 3; Hepatocellular carcinoma; HepG2; Wnt/β-catenin signaling pathway