Effect of alanine-glyoxylate aminotransferase 2-like 1 on proliferation, apoptosis and cell-division cycle of human hepatoma cell lines 97H and HCCLM3

Abstract

Objective To investigate the effect of alanine-glyoxylate aminotransferase 2-like 1 (AGXT2L1) on the proliferation, apoptosis and cell-division cycle of hepatoma cells. Methods Real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) was used to detect the expression of AGXT2L1 in 97H, HCCLM3 and LO2 cells. The siRNA targeting AGXT2L1 was designed, synthetized and transfected into 97H and HCCLM3 cells to construct AGXT2L1 knockdown group, and the efficiency of knockdown was validated by RT-qPCR. The cell proliferation of each group at 0, 12, 24, 48, 72 and 96 h was tested by cell counting kit-8 (CCK-8) assay. Cell cycle assay was applied to detect the distribution of cells in G1, S and G2 phases. The TdT-mediated dUTP nick end labeling (TUNEL) assay was used to detect the apoptosis rate of cells in each group. Results The expression of AGXT2L1 in 97H and HCCLM3 cells was significantly higher than that in normal liver cells (1 350.04±91.36, 1 710.64±92.34, t97H=25.574, P<0.01; tHCCLM3=32.068, P<0.01). The AGXT2L1 expression level in 97H and HCCLM3 cells was decreased significantly after transfection with AGXT2L1-siRNA (0.19±0.04 vs. 1.10±0.04, t97H =-28.722, P<0.01; 0.20±0.01 vs. 0.93±0.09, tHCCLM3=-13.887, P<0.01). The CCK-8 assay showed that proliferation rate of 97H and HCCLM3 cells decreased significantly after knocking down AGXT2L1 (0.71±0.01 vs. 0.95±0.12, t97H=-31.243, P<0.01; 0.67±0.13 vs. 0.87±0.17, tHCCLM3=-17.083, P<0.01). After transfection of AGXT2L1-siRAN into cells, the cell cycle assay showed that the ratio of S phase cells was lower than that in the control group [(13.45±1.20)% vs. (18.73±0.28)%, t97H=-7.451, P<0.01; (15.26±0.52)% vs. (20.45±1.08)%, tHCCLM3=-7.483, P<0.01], and the ratio of G2 phase cells was lower than that in the control group [(16.90±0.54)% vs. (19.99±0.54)%, t97H=-6.992, P<0.01; (16.23±0.28)% vs. (23.36±0.39)%, tHCCLM3=-25.720, P<0.01]. The knockdown of AGXT2L1 could inhibit the transformation of 97H and HCCLM3 cells from G1 to S phase and inhibit the proliferation of human hepatoma cells. Compared with the control group, after the knockdown of AGXT2L1, the apoptosis rate of 97H and HCCLM3 cells was increased [(13.06±1.86)% vs. (1.06±0.75)%, t97H=14.673, P<0.01; (14.41±2.21)% vs. (0.80±0.32)%, tHCCLM3=14.947, P<0.01]. Conclusion The knockdown of AGXT2L1 can inhibit the proliferation of 97H and HCCLM3 cells and promote apoptosis. Key words: Carcinoma, hepatocellular; Alanine-glyoxylate aminotransferase 2-like 1; Proliferation; Apoptosis