The bisphosphonate, zoledronic acid, induces apoptosis of breast cancer cells: evidence for synergy with paclitaxel

S P Jagdev, R E Coleman, C M Shipman, A Rostami-H, P I Croucher, S P Jagdev, R E Coleman, C M Shipman, A Rostami-H, P I Croucher

Abstract

Bisphosphonates are well established in the management of breast-cancer-induced bone disease. Recent studies have suggested that these compounds are effective in preventing the development of bone metastases. However, it is unclear whether this reflects an indirect effect via an inhibition of bone resorption or a direct anti-tumour effect. The breast cancer cell lines, MCF-7 and MDA-MB-231 cells were treated with increasing concentrations of the bisphosphonate, zoledronic acid, for varying time periods, in the presence or absence of paclitaxel. The effects of zoledronic acid were determined by assessing cell number and rate of apoptosis by evaluating changes in nuclear morphology and using a fluorescence nick translation assay. Zoledronic acid caused a dose- and time-dependent decrease in cell number (P< 0.001) and a concomitant increase in tumour cell apoptosis (P< 0.005). Short-term exposure to zoledronic acid was sufficient to cause a significant reduction in cell number and increase in apoptosis (P< 0.05). These effects could be prevented by incubation with geranyl geraniol, suggesting that zoledronic acid-induced apoptosis is mediated by inhibiting the mevalonate pathway. Treatment with zoledronic acid and clinically achievable concentrations of paclitaxel resulted in a 4-5-fold increase in tumour cell apoptosis (P< 0.02). Isobologram analysis revealed synergistic effects on tumour cell number and apoptosis when zoledronic acid and paclitaxel were combined. Short-term treatment with zoledronic acid, which closely resembles the clinical setting, has a clear anti-tumour effect on breast cancer cells. Importantly, the commonly used anti-neoplastic agent, paclitaxel, potentiates the anti-tumour effects of zoledronic acid. These data suggest that, in addition to inhibiting bone resorption, zoledronic acid has a direct anti-tumour activity on breast cancer cells in vitro.

Copyright 2001 Cancer Research Campaign http://www.bjcancer.com Copyright 2001 Cancer Research Campaign.

References

    1. J Bone Miner Res. 1999 Dec;14(12):2048-56
    1. Cancer Res. 1998 Dec 1;58(23):5294-7
    1. J Bone Miner Res. 2000 Nov;15(11):2211-21
    1. J Clin Oncol. 2001 Jan 1;19(1):10-7
    1. Int Rev Cytol. 1980;68:251-306
    1. Pharmacol Rev. 1989 Jun;41(2):93-141
    1. J Clin Invest. 1991 Dec;88(6):2095-105
    1. J Clin Oncol. 1993 Jan;11(1):59-65
    1. Proc Natl Acad Sci U S A. 1999 Jan 5;96(1):133-8
    1. J Clin Oncol. 1999 Mar;17(3):846-54
    1. Int J Cancer. 1999 Oct 8;83(2):263-9
    1. J Bone Miner Res. 1995 Oct;10(10):1478-87
    1. Toxicol Lett. 1993 Apr;67(1-3):249-58
    1. Cancer Res. 1994 Jan 15;54(2):441-7
    1. J Clin Oncol. 1994 Aug;12(8):1621-9
    1. Pharmacol Rev. 1995 Jun;47(2):331-85
    1. N Engl J Med. 1996 Feb 22;334(8):488-93
    1. J Clin Invest. 1996 Aug 1;98(3):698-705
    1. J Bone Miner Res. 1996 Oct;11(10):1482-91
    1. N Engl J Med. 1996 Dec 12;335(24):1785-91
    1. Bone. 1996 Dec;19(6):663-7
    1. J Bone Miner Res. 1997 Sep;12(9):1358-67
    1. Cancer Res. 1997 Sep 15;57(18):3890-4
    1. Cancer Res. 1997 Oct 1;57(19):4285-300
    1. Br J Haematol. 1997 Sep;98(3):665-72
    1. Br J Haematol. 1998 Feb;100(2):317-25
    1. Leukemia. 1998 Feb;12(2):220-9
    1. J Bone Miner Res. 1998 Apr;13(4):581-9
    1. N Engl J Med. 1998 Aug 6;339(6):357-63
    1. Mol Pharmacol. 1998 Oct;54(4):631-8
    1. Cancer. 2000 Jun 15;88(12 Suppl):2979-88

Source: PubMed

Подписаться