黄芩素通过调控糖酵解及谷氨酰胺代谢抑制肝癌细胞能量代谢

Baicalein Inhibiting the Energy Metabolism of Hepatoma Cells by Regulating Glycolysis and Glutamine Metabolism

目的:探讨黄芩素对肝癌细胞能量代谢能力的影响及机制。方法:不同人肝癌细胞SMMC-7721、HepG2中给予不同浓度的黄芩素,通过检测细胞ATP含量、乳酸含量、谷氨酰胺代谢评价黄芩素对肝癌细胞增殖及能量代谢的影响,同时分别采用siRNA干扰己糖激酶2(HK2)及溶质载体家族1A5(SLC1A5)表达后,考察黄芩素对肝癌细胞增殖及能量代谢能力的影响。结果:黄芩素可以浓度、时间依赖性的抑制肝癌细胞活力,SMMC-7721细胞24,48,72 h处理后的半数抑制浓度(IC_(50))分别为26.07,20.9,18.7μmol·L^(-1),HepG2细胞24,48,72 h处理后的IC_(50)分别为27.8,24.5,22.6μmol·L^(-1)。与对照组比较,20μmol·L^(-1)黄芩素可明显降低SMMC-7721和HepG2细胞对葡萄糖的消耗及乳酸含量(P<0.05),同时显著降低SMMC-7721和HepG2细胞中谷氨酰胺含量(P<0.05)。与敲除HK2的肝癌细胞联合培养72 h后,与对照组比较,20μmol·L^(-1)黄芩素仍可降低细胞能量代谢水平(P<0.05),但对肝癌细胞的糖酵解能力无显著影响。与敲除SLC1A5后的肝癌细胞联合培养72 h后,与对照组比较,20μmol·L^(-1)黄芩素能显著降低肝癌细胞的能量代谢及糖酵解能力(P<0.05)。在无谷氨酰胺环境下,20μmol·L^(-1)黄芩素对于敲除HK2肝癌细胞的能量代谢调节作用与siRNA HK2组无显著差异。结论:黄芩素可抑制肝癌细胞的增殖,降低肝癌细胞的能量代谢水平,其作用机制与其同时参与肝癌细胞糖酵解及谷氨酰胺代谢相关。

Objective: To investigate the effects and mechanism of baicalein on the energy metabolism of hepatocellular carcinoma cells. Methods: Different concentrations of baicalein were given to different human hepatoma cells SMMC-7721 and HepG2. The effects of baicalein on the proliferation and energy metabolism of hepatocellular carcinoma cells were evaluated by detecting ATP content, lactate content and glutamine metabolism, Meanwhile, siRNA interference with hexokinase 2(HK2) and solute carrier family 1 A5(SLC1 A5) were used respectively, to investigate the effects of baicalein on the proliferation and energy metabolism of hepatocellular carcinoma cells. Results: Baicalein inhibited hepatocellular carcinoma cells activity in a concentration and time-dependent manner, the half maximal inhibitory concentration( IC_(50)) of SMMC-7721 and HepG2 cells was 26.07, 20.9 and 18.7 μmol·L^(-1), and 27.8, 24.5 and 22.6 μmol·L^(-1)respectively for 24, 48 and 72 h. Compared with the control group, 20 μmol·L^(-1)baicalein significantly reduced the glucose consumption and lactic acid content of SMMC-7721 and HepG2 cells(P<0.05), at the same time, the content of glutamine in SMMC-7721 and HepG2 cells was significantly decreased(P<0.05). The effect of baicalein on the glycolysis ability of hepatocellular carcinoma cells disappeared after co-cultured with HK2 knockout hepatocellular carcinoma cells for 72 h. However, compared with that of the normal control group, the energy metabolism of hepatocellular carcinoma cells was still inhibited(P<0.05). Furthermore, it had no significant effect on the glycolysis ability of hepatoma cells. When baicalein was combined with SLC1 A5 knockout hepatocellular carcinoma cells for 72 h, compared with the normal control group, 20 μmol·L^(-1)baicalein could significantly reduce the energy metabolism and glycolysis ability of hepatocellular carcinoma cells(P<0.05). However, when baicalein was combined with siRNA HK2 cells without glutamine, there were no significant differences in energy metabolism and glycolysis between 20 μmol·L^(-1)baicalein group and siRNA HK2 group. Conclusion: Baicalein can inhibit the proliferation and reduce the energy metabolism of hepatocellular carcinoma cells. Its mechanism is related to its involvement in glycolysis and glutamine metabolism of hepatocellular carcinoma cells.