Abstract: 【Abstract】 Objective To evaluate the effect of laser irradiation on related growth factors in and apoptosis of in vitro cultured infantile hemangioma endothelial cells. Methods Cultured infantile hemangioma endothelial cells were divided into 3 groups: intense pulsed light （IPL） group irradiated with IPL at a dose of 23 J/cm2 for 1 session, laser group irradiated with 1 064-nm Nd:YAG laser at a dose of 90 J/cm2 for 1 session, control group receiving no irradiation. On days 1, 3 and 7 after irradiation, RT-PCR was performed to measure the mRNA expression of vascular endothelial growth factor （VEGF）, VEGF receptor 2 （VEGFR-2） and basic fibroblast growth factor （bFGF）, and Western blot analysis to determine VEGFR-2 protein expression, enzyme-linked immunosorbent assay to detect the levels of VEGF and bFGF in the culture supernatant, and flow cytometry to detect cell apoptosis. Results Compared with the control group, the laser group showed significantly decreased mRNA expression of VEGF （0.363 ± 0.021 vs. 1.000 ± 0.023, P < 0.001）, VEGFR-2 （0.483 ± 0.017 vs. 1.001 ± 0.031, P = 0.001） and bFGF （0.402 ± 0.040 vs. 1.000 ± 0.004, P < 0.001）, decreased VEGFR-2 protein expression （0.332 ± 0.055 vs. 0.768 ± 0.096, P < 0.05）, decreased levels of VEGF （69.389 ± 24.179 ng/L vs. 334.506 ± 13.084 ng/L, P < 0.001） and bFGF （2.386 ± 0.151 ng/L vs. 9.165 ± 0.232 ng/L, P < 0.001） in the culture supernatant, but significantly increased apoptosis rate （18.413% ± 2.654% vs. 4.300% ± 0.036%, P < 0.01） on day 7 after irradiation. Compared with the control group, the IPL group also showed significantly decreased mRNA expression of VEGF （0.436 ± 0.041 vs. 1.000 ± 0.023, P < 0.05）, VEGFR-2 （0.493 ± 0.037 vs. 1.001 ± 0.031, P < 0.05） and bFGF （0.490 ± 0.044 vs. 1.000 ± 0.004, P < 0.05）, decreased VEGFR-2 protein expression （0.406 ± 0.037 vs. 0.768 ± 0.096, P < 0.05）, decreased levels of VEGF （128.858 ± 6.063 ng/L vs. 334.506 ± 13.084 ng/L, P < 0.001） and bFGF （2.723 ± 0.471 ng/L vs. 9.165 ± 0.232 ng/L, P < 0.001） in the culture supernatant, but significantly increased apoptosis rate （16.597% ± 1.877% vs. 4.300% ± 0.036%, P < 0.01） on day 7 after irradiation. Conclusion The 1 064-nm Nd:YAG laser may exert a therapeutic effect on hemangioma by inhibiting hemangioma endothelial cells via regulating key factors on the VEGF/VEGFR-2 signaling pathway and cell apoptosis.

Key words: Hemangioma, Laser therapy, Vascular endothelial growth factors, Fibroblast growth factors, Apoptosis