title: Changes in actin and E-cadherin expression induced by 5-aminolevulinic acid photodynamic therapy in normal and Ras-transfected human mammary cell lines.
abstract: Photodynamic therapy (PDT) is an anticancer treatment based on light-induced destruction of photosensitised malignant cells. It has been reported that PDT strongly affects cell-cell and cell-substrate adhesion through the reorganization of some cytoskeletal and adhesion proteins. The aim of the present work was to study the changes induced by PDT employing aminolevulinic acid (ALA), on the cytoskeleton actin network and E-cadherin expression. We employed the normal mammary HB4a cell line and its tumor counterpart transfected with the oncogene H-Ras, which has been shown to be resistant to PDT. Ras insertion induces per se disorganization of both F-actin and E-cadherin distribution. ALA-PDT induces on HB4a cells a dramatic disorganization of actin stress fibers, resembling normal Ras-transfected cells. After 48h some features of disorganization remain present. In HB4a-Ras cells, F-actin exhibits signals of photodamage, but distribution is recovered 24h after treatment. On the other hand, PDT did not impact on E-cadherin distribution, other than a transient disorganization, which was recovered at 24h. Moreover, E-cadherin disorganization did not favoured cell-cell detachment after PDT of HB4a-Ras cells. Actin but not E-cadherin constitutes in this model an important target of PDT. The fact that some features of microfilament disorganization remain present in HB4a surviving cells but not in Ras-transfected cells, suggests that cytoskeletal structures such as F-actin may be involved in the mechanisms of resistance to PDT.
authors.affiliation: Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires, CP 1120AAF, Argentina.
authors.forename: G
authors.initials: G
authors.lastname: Di Venosa
authors.forename: L
authors.initials: L
authors.lastname: Rodriguez
authors.forename: L
authors.initials: L
authors.lastname: Mamone
authors.forename: L
authors.initials: L
authors.lastname: Gándara
authors.forename: M V
authors.initials: MV
authors.lastname: Rossetti
authors.forename: A
authors.initials: A
authors.lastname: Batlle
authors.forename: A
authors.initials: A
authors.lastname: Casas
mesh_terms: D000199:Actins / Q000378:metabolism*; D000622:Aminolevulinic Acid / Q000737:chemistry / Q000494:pharmacology*; D015820:Cadherins / Q000378:metabolism*; D002448:Cell Adhesion / Q000187:drug effects / Q000528:radiation effects; D002460:Cell Line; D003599:Cytoskeleton / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D008027:Light; D042361:Mammary Glands, Human / Q000187:drug effects / Q000528:radiation effects; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology*; D014162:Transfection; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D000199:Actins; D015820:Cadherins; D017319:Photosensitizing Agents; D000622:Aminolevulinic Acid; D018631:ras Proteins