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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Vascular alterations after photodynamic therapy mediated by 5-aminolevulinic acid in oral leukoplakia

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Author(s):
Perillo Rosin, Flavia Cristina ; Barcessat, Ana Rita Ribeiro ; Giovanni Borges, Giuliana Gadoni ; Valente Ferreira, Luciana Goncalves ; Correa, Luciana
Total Authors: 5
Document type: Journal article
Source: Lasers in Medical Science; v. 32, n. 2, p. 379-387, FEB 2017.
Web of Science Citations: 2
Abstract

Impairment of vascular functions after photodynamic therapy (PDT) is frequently associated with tumor remission and is considered one of the main antineoplastic PDT effects. Vascular alterations in oral leukoplakia (OL) treated with PDT have not yet been described. The aim of this study was to evaluate the effect of topical 5-ALA-mediated PDT on the vascular network of 4NQO-induced OL in rats. After applying 4NQO topically on the tongue during 16 weeks, there was induction of dysplastic lesions, which were treated with two PDT sessions (with an interval of 72 h between them), using topical application of 5-ALA and posterior irradiation with a laser (90 J/cm(2) fluency). Histological sections of the tongues were obtained and analyzed concerning plasmatic exudation and microvessel density after immunolabeling with CD31 and CD34 vessel markers. There was intense plasmatic exudation after 6 h of the first PDT session; at 6 h of the second PDT session, there was a significant reduction in the density of CD31- and CD34-positive microvessels in comparison to controls (p < 0.05). In the PDT intervals, there was an increase in the density of CD31 and CD34 microvessels, suggesting angiogenesis. Topical application of 5-ALA-mediated PDT caused an immediate deleterious effect on the vascular network, increasing vessel permeability and reducing vessel density, mainly after two sessions of the treatment. However, secondary angiogenesis emerged in these lesions during intervals of the PDT session. This fact may be considered during the adoption of a PDT protocol, to avoid OL resistance and recurrence after the treatment. (AU)

FAPESP's process: 11/07437-0 - Expression of cellular death markers in premalignant lesions induced in rat tongue and treated with photodynamic therapy
Grantee:Luciana Corrêa
Support Opportunities: Regular Research Grants