Photodynamic therapy (PDT) is considered an effective alternative for the treatment of port-wine stains (PWS) using hemoporfin (hematoporphyrin monomethyl ether, HMME), a novel photosensitizer with better efficacy and lower recurrence. Vascular endothelial growth factor (VEGF) plays an important role in the development of PWS. Therefore, we conducted this study to investigate the effect of HMME-PDT on VEGF expression. Human vascular endothelial cells (HUVECs) were treated with different doses of HMME and irradiated with 410-nm light emitting-diode (LED) light. To assess cell viability, CCK-8 assays were performed. At 48 h after PDT, the expression of VEGF/VEGF receptor (VEGFR) mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR). Measurement of VEGF protein was carried out using western blotting assays. Cell viability was significantly inhibited after HMME-PDT and was dose-dependent within a certain range. HMME-PDT decreased secretion of VEGF 48 h after irradiation in HUVECs as compared to controls. The downregulation of VEGF and VEGFR mRNA as well as VEGF protein expression was more significant in the high HMME concentration group (4 μg/mL) than in the lower concentration group (2 μg/mL). Our outcomes provide evidence, that HMME-PDT can downregulate VEGF expression in cultured HUVECs and may explain the efficacy of hemoporfin PDT for PWS treatment.
Keywords: Hemoporfin; Photodynamic therapy; Port-wine stain; Vascular endothelial growth factor.