Abstract: Objective To explore the signal Crosstalk between glioma cells and human brain microvascular endothelial cells(HBMECs)and its effects on the proliferation and invasion of glioma cells. Methods HBMECs were divided into four groups: the control group was cultured with conventional endothelial cell medium(ECM); the vascular endothelial growth factor(VEGF)group was cultured with ECM treated with VEGF₁₆₅(50 ng/mL); U87MG co-culture group was co-cultured with U87MG cells; U251 co-culture group was co-cultured with U251 cells. Then ElISA was performed to detect the effects of glioma cells and VEGF on the secretion of CXCL8. The glioma cells(U87MG/U251)were divided into four groups: the control group was cultured with conventional DMEM; U87MG/U251+HBMEC group was co-cultured with HBMECs, U87MG/U251+HBMEC+rhCXCL8 group was co-cultured with HBMECs in DMEM containing rhCXCL8(50 ng/mL, Akt pathway agonist), U87MG/U251+HBMEC+ LY29400 group were co-cultured with HBMECs in DMEM containing LY294002(1 μmol/L, Akt pathway inhibitor). Then Western blotting, CCK-8 and Transwell assays were performed to examine the effects of HBMECs and secretion of CXCL8 on the proliferation and invasion of glioma cells and expression of Akt. Results The secretion of CXCL8 in the VEGF group, U87MG co-culture group and U251 co-culture group were significantly increased compared with that in the control group(P<0.05), which indicated that glioma cells and VEGF could promote the secretion of CXCL8. Compared with the control group, the U87MG/U251+HBMEC group had elevated P-Akt, proliferation and invasion(P<0.05); exposure to CXCL8 further increased P-Akt, proliferation and invasion(P<0.01), whereas exposure to LY294002 suppressed P-Akt(P<0.01), which indicated that HBMECs could activate Akt signaling pathway by secreting CXCL8, and promote the proliferation and invasion of glioma cells. Conclusion There is a crosstalk of VEGF-CXCL8-Akt signal network between glioma cells and HBMECs, which might play an important role in the proliferation and invasion of glioma cells.

Key words: Glioma, Human brain microvascular endothelial cells, Crosstalk, Vascular endothelial growth factor, CXCL8, Akt