9-Hydroxypheophorbide α-mediated photodynamic therapy induces matrix metalloproteinase-2 (MMP-2) and MMP-9 down-regulation in Hep-2 cells via ROS-mediated suppression of the ERK pathway.
BACKGROUND
Photodynamic therapy (PDT) is a promising treatment modality for malignant diseases through the generation of reactive oxygen species (ROS). In this study, we assessed the change of migration and invasion of HEp-2 cells after sublethal doses of 9-hydroxypheophorbide α (9-HPbD)-mediated PDT in vitro, and explored the role of ROS in 9-HPbD-PDT-induced anti-metastatic effects in HEp-2 cells.


METHODS
Following PDT, ROS were measured by a fluorescence microscope in both the presence and absence of glutathione (GSH) pretreatment. Wound healing assay, cell migration assay, and matrigel invasion assay were used to evaluate the cellular migration and invasion. Western blot was performed to investigate the signaling pathways that may have been involved.


RESULTS
ROS were rapidly generated in 9-HPbD-loaded HEp-2 laryngeal cancer cells by the activation of a diode laser and were significantly inhibited by a 6-h GSH pretreatment. Wound healing assay, cell migration assay, and matrigel invasion assay showed that sublethal PDT significantly suppressed the migration and invasion of HEp-2 cells. GSH decreased the ability of PDT to inhibit the invasion of HEp-2 cells. Western blot analysis showed that PDT significantly inhibited the phosphorylation of MEK1/2 and ERK1/2, and significantly suppressed the expression of MMP-2 and MMP-9 after 24h following the implementation of sublethal PDT, and these efficacies of PDT could be abrogated by GSH pretreatment.


CONCLUSIONS
9-HPbD-PDT attenuated the migration and invasion of HEp-2 cells in vitro, which may be related to the down-regulated expression of MMP-2 and MMP-9 via ROS-mediated-inhibition of phosphorylation in the ERK/MEK signaling pathway.
Department of Otorhinolaryngology-Head and Neck Surgery, Affiliated Eye, Ear, Nose and Throat Hospital, Fudan University, Shanghai, China.
Huankang
H
Zhang
Institute of Radiation Medicine, Fudan University, Shanghai, China.
Bo
B
Shen
Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, United States.
Joanna T
JT
Swinarska
Research Center, Affiliated Eye, Ear, Nose and Throat Hospital, Fudan University, Shanghai, China.
Wen
W
Li
Department of Otorhinolaryngology-Head and Neck Surgery, Affiliated Eye, Ear, Nose and Throat Hospital, Fudan University, Shanghai, China. Electronic address: xiaokuanlin@hotmail.com.
Kuanlin
K
Xiao
Department of Otorhinolaryngology-Head and Neck Surgery, Affiliated Eye, Ear, Nose and Throat Hospital, Fudan University, Shanghai, China. Electronic address: hepj2002@sina.com.
Peijie
P
He
D045744:Cell Line, Tumor; D002465:Cell Movement; D002734:Chlorophyll / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D005978:Glutathione / Q000494:pharmacology; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D010778:Photochemotherapy / Q000379:methods*; D017382:Reactive Oxygen Species; D015398:Signal Transduction
C491791:9-hydroxypheophorbide alpha; D017382:Reactive Oxygen Species; D002734:Chlorophyll; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D005978:Glutathione
9-Hydroxypheophorbide α; Invasion; Laryngeal cancer; Migration; Photodynamic therapy; Reactive oxygen species