Transforming growth factor-β1 enhances glycolysis and promotes epithelial mesenchymal transition, cell migration and invasion of tongue squamous cell carcinoma

Abstract

Objective To investigate the influence of transforming growth factor-β1 (TGF-β1) on glycolysis, inducing epithelial mesenchymal transition (EMT) , cell migration and invasion of tongue squamous cell carcinoma (TSCC) . Methods TSCC SCC9 cells were treated with 10 ng/mL TGF-β1 for 1, 2 and 3 days and the cell supernatant was collected to detect changes in glucose and lactate. Western blot was used to detect the expression of glycolysis key enzymes following 1, 2, 3 days of treatment of TGF-β1. TSCC SCC9 cells were treated with 10 ng/mL TGF-β1 for 2, 4, 6 days, and the morphology of the cells was observed under inverted microscope. Western blot was used to detect the expression of E-cadherin, Vimentin, Snail and Slug following 2, 4, 6 days of treatment of TGF-β1. Transwell chamber was performed to detect cell migration and invasion. Statistical analysis was performed with SPSS 13.0 software. Results Under the TGF-β1 induction, the glucose uptake (34.1 ± 1.2, 47.1 ± 2.3) of SCC9 cells was significantly higher than that in the control group, and both showed statistically significant difference (t2 d= 17.941, P2 d= 0.003; t3 d= 24.430, P3 d= 0.002) . The lactic acid production (46.4 ± 1.0, 60.2 ± 2.0) in SCC9 cells was significantly higher than that in the control group, and both showed statistically significant difference (t2 d= 50.230, P2 d= 0.005; t3 d= 26.883, P3 d= 0.004) . The expression level of HK2 (1.21 ± 0.04, 1.30±0.06) in TGF-β1 treatment group was higher than control group, and both showed statistically significant difference (t2 d= 6.111, P2 d= 0.026; t3 d= 6.423, P3 d= 0.023) ; the expression level of PKM2 (1.048±0.002, 1.071±0.010) in TGF-β1 treatment group showed no significant difference compared with the control group, and both showed no statistically significant difference (t2 d= 20.693, P2 d= 0.072; t3 d= 9.875, P3 d= 0.081) ; the expression level of PFKP (0.820±0.010, 0.839±0.036) in TGF-β1 treatment group was higher than control group, and both showed statistically significant difference (t2 d= 21.829, P2 d= 0.020; t3 d= 9.853, P3 d= 0.022) ; The expression level of GLUT1 (0.503 ± 0.007, 0.589 ± 0.019) in TGF-β1 treatment group was higher than control group, and both showed statistically significant difference (t2 d= 30.693, P2 d= 0.015; t3 d= 21.173, P3 d= 0.012) . Under the TGF-β1 induction, the morphology of TSCC SCC9 cells changed from pebble to long spindle shape compared with the control group; The expression level of E-cadherin (0.69 ± 0.03, 0.67 ± 0.04, 0.65 ± 0.04) in TGF-β1 treatment group was lower than control group, and both showed statistically significant difference (t2 d= 7.187, P2 d= 0.019; t4 d= 6.631, P4 d= 0.022; t6 d= 6.690, P6 d= 0.022) ; The expression level of Vimentin (1.089 ± 0.134, 0.706 ± 0.025, 0.620 ± 0.010) in TGF-β1 treatment group was higher than control group, and both showed statistically significant difference (t2 d= 6.948, P2 d= 0.020; t4 d= 16.710, P4 d= 0.004; t6 d= 6.157, P6 d= 0.025) ; The expression level of snail (1.14 ± 0.17) in TGF-β1 treatment group was higher than control group (0.77 ± 0.10) , and both showed statistically significant difference (t= 3.794, P= 0.014) ; The expression level of slug (1.85 ± 0.11) in TGF-β1 treatment group was higher than control group (0.93 ± 0.02) , and both showed statistically significant difference (t= 15.385, P= 0.015) . The cell migration ability of SCC9 cell (45.7 ± 11.6) was increased under TGF-β1 treatment compared with control group (20.0 ± 2.0; t= 4.529, P= 0.017) ; The cell invasion ability of SCC9 cell (58.7 ± 5.0) was increased under TGF-β1 treatment compared with control group (22.3 ± 1.5; t= 15.571, P= 0.015) . Conclusion TGF-β1 enhances glycolysis and promotes EMT, cell migration and invasion of tongue squamous cell carcinoma. Key words: Tongue; Carcinoma, squamous cell; Transforming growth factor beta1; Glycolysis; Epithelial-mesenchymal transition; Cell migration assays; Neoplasm invasiveness