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. 1998;77(2):216–220. doi: 10.1038/bjc.1998.36

Bryostatin 1-tamoxifen combinations show synergistic effects on the inhibition of growth of P388 cells in vitro.

A T McGown 1, G Jayson 1, G R Pettit 1, M S Haran 1, T H Ward 1, D Crowther 1
PMCID: PMC2151232  PMID: 9460991

Abstract

This study shows that combinations of bryostatin 1, a novel modulator of protein kinase C currently under clinical evaluation, with the anti-oestrogenic agent tamoxifen caused a large synergistic enhancement of growth inhibition in P388 cells in vitro. The growth-inhibitory effects of bryostatin 1 in the presence of non-inhibitory concentrations of tamoxifen were increased by approximately 200-fold, whereas growth inhibition by tamoxifen in the presence of non-inhibitory concentrations of bryostatin 1 were increased over 30-fold. These data have been confirmed by isobologram analysis. The precise mechanism underlying this effect is unknown, although preliminary data implicating protein kinase C is presented. The magnitude of this synergistic effect, together with evidence of clinical responses seen when these agents were given sequentially in ovarian cancer, merits further study.

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Selected References

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