title: The effects of Photofrin-mediated photodynamic therapy on the modulation of EGFR in esophageal squamous cell carcinoma cells.
abstract: Photodynamic therapy (PDT) has been demonstrated to be an effective minimally invasive treatment modality for early esophageal cancer. However, the molecular action in esophageal cancer during PDT is hardly known. EGFR has been known to downregulate in various cancer cells during PDT. In this study, we investigated the effects of Photofrin-mediated PDT on cell death and expression of EGFR in CE48T/VGH (CE48T) esophageal squamous cell carcinoma cells. We found that the photosensitizer Photofrin in the absence of light exposure can downregulate the expression of EGFR at both transcription and translation levels. Higher concentrations of Photofrin results in cytotoxicity whereas lower doses of Photofrin inhibit EGFR expression under dark control without inducing significant cell death. This Photofrin-associated inhibition of EGFR was repeated in lung cancer, cervical cancer, and glioblastoma cells. Another esophageal squamous cell carcinoma cell line CE81T/VGH (CE81T) was found to be resistant to Photofrin-induced inhibition of EGFR as well as to Photofrin-mediated dark toxicity compared with CE48T. The resistance to the cytotoxicity in CE81T cells became insignificant when the Photofrin-treated cells were further irradiated by red light (Photofrin-PDT). We suggest Photofrin modulates the expression of EGFR in cancer cells. However, efficient cell death still requires the combination of Photofrin and light irradiation in esophageal squamous cell carcinoma cells.
authors.affiliation: Department of Surgery, National Taiwan University Hospital, Taipei, 100, Taiwan.
authors.forename: Pei-Wen
authors.initials: PW
authors.lastname: Yang
authors.forename: Mien-Chie
authors.initials: MC
authors.lastname: Hung
authors.forename: Ching-Yueh
authors.initials: CY
authors.lastname: Hsieh
authors.forename: En-Chi
authors.initials: EC
authors.lastname: Tung
authors.forename: Ying-Hao
authors.initials: YH
authors.lastname: Wang
authors.forename: Jui-Chang
authors.initials: JC
authors.lastname: Tsai
authors.forename: Jang-Ming
authors.initials: JM
authors.lastname: Lee
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D016923:Cell Death / Q000187:drug effects; D017323:Dihematoporphyrin Ether / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D004938:Esophageal Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D000077277:Esophageal Squamous Cell Carcinoma; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D002583:Uterine Cervical Neoplasms / Q000188:drug therapy / Q000378:metabolism
chemical_list: D017319:Photosensitizing Agents; D017323:Dihematoporphyrin Ether; C512478:EGFR protein, human; D066246:ErbB Receptors