Enhancement of cell killing of HL-60 cells by ultrasound in the presence of the photosensitizing drug Photofrin II.
Enhancement of acute cell killing of HL-60 cells by low-level ultrasound in the presence of the photosensitizing drug Photofrin II was examined. HL-60 cells were exposed to ultrasound (270 kHz) at intensities of 150, 300 and 450 mW/cm2 for 60 s in the presence of Photofrin II (200 micrograms/ml). Cell survival after treatment was 49.6 +/- 5.1%, 34.5 +/- 3.1% and 27.4 +/- 3.9%, respectively. Ultrasound exposure alone at 150, 300 and 450 mW/cm2 resulted in a decrease in cell survival to 92.9 +/- 1.5%, 82.3 +/- 2.2% and 77.9 +/- 7.2%, respectively. The cell survival rate after the addition of Photofrin II alone showed no significant cell killing. These results indicate that Photofrin II was sensitized by low-level, non-thermal ultrasound to enhance the cell killing of HL-60 cells.
Tachibana
K
K
First Department of Internal Medicine, Fukuoka University School of Medicine, Japan.
Kimura
N
N
Okumura
M
M
Eguchi
H
H
Tachibana
S
S
D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D017323:Dihematoporphyrin Ether / Q000633:toxicity*; D006801:Humans; D007700:Kinetics; D015473:Leukemia, Promyelocytic, Acute; D013997:Time Factors; D014407:Tumor Cells, Cultured; D014465:Ultrasonics
D017323:Dihematoporphyrin Ether