Mechanism of nerve growth factor and its receptor regulating glioma cell Warburg effect on promoting metastasis

Abstract:

Objective：To investigate the mechanism of action of nerve growth factor （NGF） and its receptor in regulating Warburg ef－fect and promoting metastasis of glioma cells. Methods：Western blot and RT-qPCR were used to measure the protein and mRNA ex－pression of NGF and TrkA in three glioma cell lines. U251 cells were divided into control group and NGF group（treated with 50 μg/L NGF）. CCK-8 assay was used to measure cell viability；flow cytometry after PI staining was used to observe the change in cell cycle；Transwell chamber was used to measure cell invasion ability；Western blot was used to measure the expression of TrkA，AKT，PI3K，phosphofructokinase（PFK），and pyruvate kinase M2（PKM2）. The levels of glucose uptake，lactic acid，and cell oxygen consumption were measured. U251 cells were divided into control group，AKT inhibitor group，and NGF group. The cells in the control group were given routine treatment，those in the AKT inhibitor group were pretreated with AKT inhibitor and then treated with 50 μg/L NGF，and those in the NGF group were treated with 50 μg/L NGF. The above tests were also performed. Results：Glioma cells had significantly higher levels of NGF and TrkA than glial cells，and U251 glioma cells had the highest levels. U251 cells showed a significant increase in cell viability after NGF intervention. Compared with the control group，the NGF group had a signifi－cantly higher number of cells in G2 phase，a significantly higher number of invasive cells，and significantly higher protein expression of TrkA，AKT，and PI3K，as well as significantly lower expression of the metabolic enzymes PFK and PKM2. There were significant differences between the NGF group and the control group in the levels of glucose uptake，lactic acid，and oxygen consumption. After AKT signal suppression，the NGF group had significantly higher cell viability and number of cells in G2 phase than the control group and the AKT inhibitor group. Compared with the control group and the AKT inhibitor group，the NGF group had significantly higher number of invasive cells and protein expression of TrkA，AKT，and PI3K，as well as significantly lower expression of the metabolic enzymes PFK and PKM2. There were significant differences in the levels of glucose uptake，lactic acid，and oxygen consumption between the NGF group and the control group/AKT inhibitor group. Conclusion：NGF can promote Warburg effect and metastasis of glioma cells through the TrkA-PI3K/AKT signaling pathway.