ECHS1, epidermal growth factor, and low-glucose conditions promote the invasion and metastasis of hepatocellular carcinoma cells

Objective To investigate the expression of key enzymes associated with energy metabolism in hepatocellular carcinoma ( HCC) tissue, as well as the roles of short-chain enoyl-CoA hydratase 1 ( ECHS1) , AMP-activated protein kinase ( AMPK) , fatty acid synthase ( FAS) , acetyl-CoA carboxylase ( ACC) , and low-glucose conditions in the development and progression of HCC. Methods A total of 32 HCC patients who underwent surgical resection in 175 Hospital of PLA from June 2015 to June 2016 were enrolled. HCC tissue and adjacent tissue samples were collected, and immunohistochemistry was used to measure the expression of key enzymes associated with energy metabolism in HCC tissue samples with different degrees of tumor differentiation and adjacent tissues, including FAS, ACC, and AMPK.Two groups of hepatoma cells were established. Hepatoma Huh7-plv and HepG2-PU6 cells transfected with blank control plasmids were established as control group, and hepatoma cells transfected with small interfering RNA ( siRNA) ( Huh7-siECHS1 and HepG2-siECHS1 cells) were established as experimental group. A Transwell chamber assay was used to observe the effect of ECHS1, low-glucose condition, and EGF on the invasion ability of hepatoma cells. The t-test was used for comparison of continuous data between groups, and the chi-square test was used for comparison of categorical data between groups. Results Immunohistochemistry showed that compared with the adjacent tissue samples, the HCC tissue samples had a significant higher proportion of ACC-or AMPKβ-positive cells ( ACC-positive cells:21/11 vs 7/25, χ2= 12. 44, P < 0. 05; AMPKβ-positive cells: 31/1 vs 26/6, χ2= 4. 68, P < 0. 05) . The Transwell chamber assay showed that compared with the corresponding hepatoma cells treated by ECHS1 interference ( Huh7-siECHS1-N, HepG2-siECHS1-N, Huh7-siECHS1-N-EGF, and HepG2-siECHS1-N-EGF) , the hepatoma cells cultured under normal conditions ( Huh7-plv-N and HepG2-PU6-N) and with the addition of EGF ( Huh7-plv-N-EGF and HepG2-PU6-N-EGF) had a significantly higher number of invasive cells ( t = 6. 93, 6. 51, 7. 55, and 4. 93, all P < 0. 05) ; compared with the corresponding hepatoma cells treated by ECHS1 interference ( Huh7-siECHS1-LowGlu, HepG2-siECHS1-LowGlu, Huh7-siECHS1-LowGlu-EGF, and HepG2-siECHS1-LowGlu-EGF) , the hepatoma cells cultured under low-glucose conditions ( Huh7-plv-LowGlu and HepG2-PU6-LowGlu) and with the addition of EGF ( Huh7-plv-LowGlu-EGF and HepG2-PU6-LowGlu-EGF) had a significantly higher number of invasive cells ( t= 9. 52, 5. 80, 20. 52, and 8. 80, all P < 0. 05) . Under different conditions, hepatoma Huh7 and HepG2 cells had a significant reduction in invasion ability after ECHS1 interference. Compared with the hepatoma cells cultured under normal conditions ( Huh7-plv-N and HepG2-PU6-N) , the hepatoma cells cultured with the addition of EGF ( Huh7-plv-N-EGF and HepG2-PU6-N-EGF) had a significant increase in the number of cells passing through the Transwell chamber ( t = 4. 44 and 3. 17, both P < 0. 05) . Compared with the hepatoma cells cultured under normal conditions, the hepatoma cells cultured under low-glucose conditions ( Huh7-plv-LowGlu and HepG2-PU6-LowGlu) had an increase in the number of invasive cells ( both P > 0. 05) . Conclusion ECHS1 and EGF can significantly enhance the invasion and metastasis of hepatoma cells, and low-glucose conditions can also promote the invasion of hepatoma cells.