In VitroAnalysis of Photosensitizer Accumulation for Assessment of Applicability of Fluorescence Diagnosis of Squamous Cell Carcinoma of Epidermolysis Bullosa Patients

Patrick Larisch,Thomas Verwanger,Barbara Krammer,Kamil Onder

doi:10.1155/2013/521281

Patrick Larisch, Thomas Verwanger + Show 2 more

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https://doi.org/10.1155/2013/521281

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Abstract

Epidermolysis bullosa (EB) is a group of inherited skin disorders characterized by blistering following mechanical trauma. Chronic wounds of EB patients often lead to tumors such as squamous cell carcinoma (SCC). Early diagnosis may prevent its invasive growth—frequently the reason of premature mortality of EB-patients. Early detection of tumors is achieved by fluorescence diagnosis (FD), where photosensitizers localize selectively in tumors and fluoresce upon illumination. Excessive accumulation of photosensitizers in inflamed areas, as occasionally found at chronic wounds and tumors due to inflammatory processes, leads to false-positive results in FD. This study analyzed accumulation kinetics of the photosensitizers hypericin and endogenous protoporphyrin IX (PpIX) in different skin cell lines including the three EB subtypes under normal and proinflammatory conditions (stimulated with TNF-alpha). The aim was to assess the applicability of FD of SCC in EB. All cell lines accumulate hypericin or PpIX mostly increasing with incubation time, but with different kinetics. SCC cells of recessive dystrophic EB (RDEB) accumulate less hypericin or PpIX than nonmalignant RDEB cells. Nevertheless, tumor selectivity in vivo might be existent. Non-EB cell lines are more active concerning photosensitizer enrichment. Proinflammatory conditions of skin cell lines seem to have no major influence on photosensitizer accumulation.

Highlights

Epidermolysis bullosa (EB) is a group of skin disorders which are genetically determined. ey are characterized by blistering of the skin and mucosa following mechanical trauma [1,2,3]
Fibroblast and keratinocyte cell lines were incubated with lipopolysaccharide (LPS) or TNF-alpha in preliminary tests to induce in ammation
(1) All cell lines take up hypericin or generate protoporphyrin IX (PpIX) mostly increasing with the incubation time, but with different kinetics

Summary

Introduction

Epidermolysis bullosa (EB) is a group of skin disorders which are genetically determined. ey are characterized by blistering of the skin and mucosa following mechanical trauma [1,2,3]. Mutations are occurring in COL7A1, the gene encoding for collagen, type VII, alpha 1 [8] All these forms of EB are resulting in the pain of blistering, in ammation, and in some cases scarring and cancer because of loss of the skin’s barrier function [9]. BioMed Research International e chronic wounds of EB patients are accompanied by in ammatory processes, which may promote induction and growth of skin tumors such as squamous cell carcinoma (SCC), especially when the in ammation lasts for a long period or is derailed [10]. To prove the hypothesis that in ammation of tissues causes excessive accumulation of photosensitizers o en leading to false-positive results in FD, the effect of proin ammatory conditions on uptake or accumulation of hypericin or PpIX, respectively, in normal and malignant EB-cell lines and their respective reference cell lines should be analysed. For establishment of a proin ammatory milieu, we stimulated the cells with TNF-alpha (tumor necrosis factor-alpha) to activate proin ammatory pathways [31]

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