Creb1 Modulates Glut1 Expression Through Pcreb1 And Affects Glucose Transport In Glioma Cells

Objective: This study investigates how cAMP-responsive element binding protein 1 (CREB1) regulates the glucose transporter protein (GLUT1) expression through pCREB1 and affects glucose transport in glioma cells.Methods: Human glioma cell line was cultured in vitro and the expression of CREB1 and GLUT1 in the human glioma cell line was detected using the immunohistochemical method. To analyse the expression of GLUT1 and glucose transport in glioma cells, the cells were divided into a normal cell group (without any treatment), negative transfer group (negative transfection control group) and siCREB1 group (down-regulated CREB1 expression). The expression of GLUT1 mRNA and protein and glucose transport in the three groups was detected through the real-time quantitative PCR assay and western blot method. Human glioma cell lines were treated with pCREB1 inhibitors or activators and divided into an inhibitor group and an activator group. Normal cells were used as a control and real-time quantitative PCR and western blot assays were used to detect GLUT1 mRNA and protein expression levels and glucose transporters in three groups of cells.Results: Compared with normal cell lines, both CREB1 and GLUT1 showed high expression in human glioma cell lines. Compared with normal cells and the negative transfection group, the expression of GLUT1 mRNA and protein in the siCREB1 group significantly decreased (P<0.05), as did the glucose absorption of the siCREB1 group (P<0.05). Compared with the normal cell group, expression of GLUT1 mRNA and protein in the inhibitor group markedly decreased (P<0.05), whereas in the activator group, it increased (P<0.05). Finally, compared with the normal cell group, the glucose absorption of the inhibitor group significantly decreased and that of the activator group remarkably increased (P<0.05).Conclusion: Both CREB1 and GLUT1 are highly expressed in human glioma cells. Phosphorylation of CREB1 can affect GLUT1 expression and glucose transport in cells. This suggests that the effect of CREB1 on glucose transport in glioma cells is related to the regulation of GLUT1 expression through pCREB1.