title: Effect of topical 5-ALA mediated photodynamic therapy on proliferation index of keratinocytes in 4-NQO-induced potentially malignant oral lesions.
abstract: Fractionation can improve photodynamic therapy (PDT) efficacy for potentially malignant oral lesion treatment. The aim of this study was to demonstrate the apoptosis/proliferation index of oral keratinocytes after two sessions of topical 5-ALA-mediated PDT in 4-Nitroquinoline-1-oxide-induced potentially malignant oral lesion, and to suggest the ideal interval between PDT sessions. Immuno-histochemical tests for proliferating cell nuclear antigen and caspase-3, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay were performed at 6h, 24h, 48h, and 72h time intervals after PDT. The number of positive cells showing caspase-3 expression was significantly higher, mainly at 6h after PDT. In the first cycle of PDT, the highest frequency of positive cells for TUNEL was found at 24h. At 72h after PDT, proliferating cell nuclear antigen positive cells increased significantly, indicating that there was an epithelial response in direction towards DNA repair and cell proliferation at this time. Because cell proliferation increases and cell death index decreases at 72h after PDT, it is recommended that the interval between the PDT sessions must not be longer than 2days up to total lesion remission.
authors.affiliation: Oral Pathology Department, School of Dentistry, University of São Paulo, Av. Prof Lineu Prestes, 2227, Cidade Universitária CEP 05508-000, São Paulo, Brazil. ritabarcessat@usp.br
authors.forename: Ana Rita
authors.initials: AR
authors.lastname: Barcessat
authors.forename: Isaac
authors.initials: I
authors.lastname: Huang
authors.forename: Flávia Perillo
authors.initials: FP
authors.lastname: Rosin
authors.forename: Décio
authors.initials: D
authors.lastname: dos Santos Pinto
authors.forename: Denise
authors.initials: D
authors.lastname: Maria Zezell
authors.forename: Luciana
authors.initials: L
authors.lastname: Corrêa
mesh_terms: D015112:4-Nitroquinoline-1-oxide / Q000009:adverse effects; D000287:Administration, Topical; D000622:Aminolevulinic Acid / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D004848:Epithelium / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects; D005260:Female; D015603:Keratinocytes / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects*; D009062:Mouth Neoplasms / Q000139:chemically induced* / Q000188:drug therapy* / Q000473:pathology; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D015363:Quinolones / Q000009:adverse effects*; D017208:Rats, Wistar
chemical_list: C120195:4-nitroquinolone-1-oxide; D017319:Photosensitizing Agents; D015363:Quinolones; D015112:4-Nitroquinoline-1-oxide; D000622:Aminolevulinic Acid
keywords: 5-ALA-mediated photodynamic therapy; Caspase-3 expression; Immunohistochemistry; Potentially malignant oral lesion; Proliferating cell nuclear antigen expression