Photosensitization with protoporphyrin IX inhibits attachment of cancer cells to a substratum.
Effects of photodynamic therapy (PDT) on adhesion of human adenocarcinoma cells of the line WiDr to a plastic substratum were investigated. Protoporphyrin IX induced by 5-aminolevulinic acid (ALA) was used as a photosensitizer. Light exposure inhibited attachment of suspended cells to a substratum. The adhesion was most strongly pronounced for light exposures around 200 mJ/cm(2) causing cell death. However, sub-lethal exposures (42 mJ/cm(2), 97% survival) inhibited cell adhesion as well. Sub-lethal ALA-PDT increased the intracellular space in dense colonies of WiDr cells. This was attributed to formation of lamellipodia between the cells and to increased numbers of focal contacts containing alpha(V)beta(3) integrin in some of the cells. The E-cadherin distribution was not changed by the treatment. Complex processes, including changes in cellular shape and reorganization of the cytoskeleton, are suggested to participate in the observed ALA-PDT effect on the cell adhesion.
Institute for Cancer Research, 0310 Montebello, Oslo, Norway. uzd@krinc.ru
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Uzdensky
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A
Juzeniene
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E
Kolpakova
G-O
GO
Hjortland
P
P
Juzenas
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J
Moan
D015820:Cadherins / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects; D005455:Fluorescent Antibody Technique; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000378:metabolism; D008027:Light; D009369:Neoplasms / Q000188:drug therapy*; D017319:Photosensitizing Agents / Q000494:pharmacology*; D011524:Protoporphyrins / Q000494:pharmacology*; D013997:Time Factors; D014407:Tumor Cells, Cultured
D015820:Cadherins; D039302:Integrin alphaVbeta3; D017319:Photosensitizing Agents; D011524:Protoporphyrins; C028025:protoporphyrin IX