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Melanomas display increased cytoprotection to hypericin‐mediated cytotoxicity through the induction of autophagy
Author(s) -
Davids Lester M.,
Kleemann Britta,
Cooper Susan,
Kidson Susan H.
Publication year - 2009
Publication title -
cell biology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 77
eISSN - 1095-8355
pISSN - 1065-6995
DOI - 10.1016/j.cellbi.2009.06.026
Subject(s) - hypericin , autophagy , photosensitizer , cytoprotection , photodynamic therapy , melanoma , programmed cell death , viability assay , cell culture , phototoxicity , cancer research , cell , cell damage , chemistry , microbiology and biotechnology , biology , apoptosis , pharmacology , in vitro , biochemistry , genetics , organic chemistry
Abstract Photodynamic therapy (PDT) as a regime for melanoma is of limited success due to factors such as the efficacy of the photosensitizer used, penetration depth and the presence of pigment. We characterised a pigmented and an unpigmented melanoma cell line with respect to their phenotypes. Cell viability was assessed after exposure to hypericin, a UVA‐activated photosensitizer. Exposure to 3 μM activated hypericin induced a cytoprotective (autophagic) response from both cell lines. However, the pigmented cells accumulated a large amount of glycogen in their cytoplasm. We hypothesise that the treatment induces an initial cytoprotective response through autophagy, but with increased stress results in a different mode of cell death in pigmented melanoma cells from unpigmented cells. These results indicate that hypericin‐PDT could be an adjuvant therapy for melanoma.