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A Comparison of the Photodynamic Effects of Temoporfin (mTHPC) and MC540 on Leukemia Cells: Efficacy and Apoptosis
Author(s) -
Chen J. Y.,
Mak N. K.,
Wen J. M.,
Leung W. N.,
Chen S. C.,
Fung M. C.,
Cheung N. H.
Publication year - 1998
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1998.tb02512.x
Subject(s) - photodynamic therapy , apoptosis , leukemia , chemistry , cancer research , biology , biochemistry , immunology , organic chemistry
The photodynamic effects of temoporfin ( meso ‐tetrahy‐droxyphenylchlorin, m THPC) and merocyanine 540 (MC540) in murine myeloid leukemia M1 and WEHI 3B (JCS) cells were compared. The m THPC was found to be more potent and selective. At a lethal dosage of 90% killing (LD90), only 1.3 μ M of m THPC and 4.2 kj/m2 of light irradiation was required, which was a 20‐fold lower drug concentration and 11‐fold smaller light dose than that required when using MC540. Meanwhile, three times less, or 15%, of the coincubated erythrocytes were destroyed by m THPC than by MC540. Confocal micrographs showed that both drugs accumulated diffusely inside the cytoplasm in a very similar fashion, but m THPC induced a more extensive apoptosis in photosensitized JCS cells. For example, at LD90, m THPC practically killed all JCS cells via apoptosis and cleaved the DNA to extremely small 150 base‐pair fragments. In contrast, among the JCS cells killed by MC540, about 88% died via apoptosis and large DNA fragments were abundant. Relative to MC540, the ability of m THPC to trigger large‐scale and thorough apoptosis in leukemia cells may help explain its potency and selectivity.