Apoptosis and migration suppression of HN-3 human laryngeal squamous cancer cells induced by photo-activation of 9-hydroxypheophorbide-α / 临床耳鼻咽喉头颈外科杂志

ABSTRACT

OBJECTIVE@#To investigate the effect and potential mechanisms about apoptosis induction and migration suppression of photodynamic therapy with a new photosensitizer, 9-hydroxypheophorbide-α (9-HPbD), and diode laser on HN-3 human laryngeal squamous cancer cells.@*METHOD@#The attached HN-3 cancer cells were photosesitized with 0.29 μg/ml and 0.59 μg/ml 9-HPbD for 6 h and irradiated by 664 nm diode laser for 15 min at an energy density of 2.0 J/cm for activating 9-HPbD. Wound healing assay and photographing was respectively performed immediately after laser irradiation. Photographing focusing on the same location was repeated 12 h, 24 h and 36 h after PDT and cells migration distance counted respectively. H2DCFDA staining was used to assess accumulation of reactive oxygen series (ROS) 1 h after PDT. MTT assay, Hoechst33342/PI double staining, western blotting were respectively performed to assess cellular viability, apoptosis and the expression of Enos, p-c-Jun, EGFR.@*RESULT@#Phototoxicity and apoptosis on HN-3 cells induced by 9-HPbD-PDT was exhibited in a dose-related manner. Neither 9-HPbD alone nor laser alone was cytotoxic to HN-3 cells. Generation of ROS was initiated immediately after PDT. The apoptotic cells, marked with condensed/fragmented blue or pink nuclei, and up-regulated expression of eNOS, p-c-Jun were subsequently induced 24 h after PDT. Coupled with a down-regulated expression of EGFR, a photosensitizer dose-ralated cell migration suppression was initiated by PDT. After pretreatment of GSH or ascorbic acid, a kind of antioxidant, the efficacy of PDT-induced apoptosis and migration suppression was partially inhibited.@*CONCLUSION@#Activation of p-c-Jun, eNOS and down-regulated expression of EGFR may respectively involve in the apoptosis induction and cell migration suppression after 9-HPbD-PDT. Generation of ROS may play an important role in the course of apoptosis induction and migration suppression of HN-3 cells initiated by 9-HPbD-PDT.