PMID: 8609454Feb 1, 1996Paper

Radiosensitization of HL-60 human leukaemia cells by bryostatin-1 in the absence of increased DNA fragmentation or apoptotic cell death

International Journal of Radiation Biology
N C WatsonD A Gewirtz

Abstract

Ionizing radiation produced a dose-dependent reduction in the proliferative capacity of HL-60 human promyelocytic leukaemia cells. A small percentage of the cell population demonstrated morphological evidence of apoptosis at 24h following radiation doses of > or = 5 Gy (i.e. 8% at 5 Gy and 16% at 10 Gy respectively) and produced a laddered oligonucleosomal pattern of DNA fragments by static-field gel electrophoresis. The antiproliferative effects of 1 and 2.5 Gy ionizing radiation were significantly enhanced by preincubating cells with bryostatin-1 at a concentration (10 nM) and time frame (24h) associated with down-regulation of total cellular protein kinase C (PKC) activity. Potentiation by bryostatin-1 of the radiation effect on proliferation was not associated with a concomitant increase in internucleosomal DNA fragmentation, in the fraction of cells exhibiting apoptotic morphology, or in the extent of radiation-induced single- or double-strand breaks in bulk DNA. Staurosporine, a potent but nonspecific inhibitor of PKC, was ineffective in altering the radiosensitivity of HL-60 cells or the degree of DNA fragmentation induced by ionizing radiation. These findings indicate that bryostatin 1 increases the sensitivity of human...Continue Reading

References

Dec 1, 1987·Proceedings of the National Academy of Sciences of the United States of America·W S MayL L Sensenbrenner
Aug 30, 1988·Biochemical and Biophysical Research Communications·L D TomeiC E Wenner
Mar 1, 1994·International Journal of Radiation Biology·I R Radford
May 1, 1994·International Journal of Radiation Biology·R E LangleyE A Bump
Jan 4, 1994·Proceedings of the National Academy of Sciences of the United States of America·W D JarvisS Grant
Oct 1, 1994·Trends in Cell Biology·D J McConkey, S Orrenius

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