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/cm 2 for 1 session, laser group irradiated with 1 064-nm Nd:YAG laser at a dose of 90 J/cm 2 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.
ABSTRACT
AIMS: The present study aimed to investigate the effects of laser irradiation on the growth factors and cell apoptosis of in vitro cultured infant hemangioma endothelial cells. MAIN METHODS: Endothelial cells of infant hemangioma were cultured in vitro and irradiated using a variable pulse width 1064â¯nm Nd:YAG laser and intense pulsed light (IPL), the expression of VEGF, VEGFR-2, bFGF and their mRNAs before and after irradiation were measured by ELISA, western blot, RT-PCR and flow cytometry, and changes in the apoptotic rate of endothelial cells in hemangioma were monitored. KEY FINDINGS: The mRNA and protein expressions of VEGF, VEGFR-2, bFGF in hemangioma endothelial cells were inhibited by both Nd:YAG laser and ILP compared to the control cells. The apoptotic rates of hemangioma endothelial cells were also decreased after both laser irradiation treatments in comparison to the blank group. The differences were statistically significant. SIGNIFICANCE: Laser irradiation treats hemangioma not only through a selective photothermal mechanism, but also through cytokine signaling pathways.
