title: Light fractionated ALA-PDT enhances therapeutic efficacy in vitro; the influence of PpIX concentration and illumination parameters.
abstract: Light fractionation, with a long dark interval, significantly increases the response to ALA-PDT in pre-clinical models and in non-melanoma skin cancer. We investigated if this increase in efficacy can be replicated in PAM 212 cells in vitro. The results show a significant decrease in cell survival after light fractionation which is dependent on the PpIX concentration and light dose of the first light fraction. This study supports the hypothesis that an underlying cellular mechanism is involved in the response to light fractionation in which a first light fraction leads to sub-lethally damaged cells that are sensitised to a second light fraction 2 hours later. The current study reveals the in vitro circumstances under which we can investigate the cellular pathways involved.
authors.affiliation: Center for Optical Diagnostics and Therapy, Department of Radiation Oncology, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
authors.forename: Henriëtte S
authors.initials: HS
authors.lastname: de Bruijn
authors.forename: Adriana G
authors.initials: AG
authors.lastname: Casas
authors.forename: Gabriela
authors.initials: G
authors.lastname: Di Venosa
authors.forename: Lautato
authors.initials: L
authors.lastname: Gandara
authors.forename: Henricus J C M
authors.initials: HJ
authors.lastname: Sterenborg
authors.forename: Alcira
authors.initials: A
authors.lastname: Batlle
authors.forename: Dominic J
authors.initials: DJ
authors.lastname: Robinson
mesh_terms: D000622:Aminolevulinic Acid / Q000494:pharmacology*; D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D008027:Light; D051379:Mice; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D017319:Photosensitizing Agents; D000622:Aminolevulinic Acid