The effects of two metallophthalocyanines on the viability and proliferation of an esophageal cancer cell line.
OBJECTIVE
The objective of this study was to establish the influence of two metallophthalocyanine photosensitizers, in their inactive and activated forms, on the cellular reactions of esophageal cancer cells.


BACKGROUND
Photodynamic therapy (PDT) is an alternative used in the treatment of cancer. During PDT, the activated compound produces cytotoxic singlet molecular oxygen ((1)O(2)), which ultimately leads to cell death. Esophageal cancer has become one of the most common cancers to occur in the world, and the incidence in South Africa is high, especially within the black male population.


METHODS
Optimal photosensitizer concentration was determined by following the viability of esophageal cancer (SNO) cells treated with a range of concentrations of two metallophthalocyanine photosensitizers, GePcSmix and AlPcSmix, activated by irradiation at a fluence of 20 J/cm(2). Changes in cell morphology were observed after treatment with optimal photosensitizer concentrations, and the effect of the treatment on cell proliferation and cytotoxicity were studied.


RESULTS
Cell viability decreased in a dose-dependent manner after PDT, while the photosensitizers in their inactive forms did not have an effect on the cells. The altered morphology of cells after PDT was indicative of a necrotic mode of cell death. The optimal photosensitizer concentrations reduced cell proliferation by more than 50% and a significant reduction in cytotoxicity, as detected by lactate dehydrogenase release, was observed following PDT.


CONCLUSIONS
Under the studied parameters PDT using GePcSmix and AlPcSmix in vitro could be a useful therapy for esophageal cancer since the photosensitizers alone caused no damage, but cell death is imminent post-PDT.
Kresfelder
Tina L
TL
Department of Biochemistry, Faculty of Science, University of Johannesburg, Doornfontein, South Africa.
Cronjé
Marianne J
MJ
Abrahamse
Heidi
H
D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects*; D004938:Esophageal Neoplasms; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D054833:Isoindoles; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology*
D007211:Indoles; D054833:Isoindoles; D017319:Photosensitizing Agents; C013647:phthalocyanine