Send to

Choose Destination
Cancer Lett. 1998 Jan 16;123(1):99-105.

ZR-75-1 human breast cancer cells: expression of inducible nitric oxide synthase and effect of tamoxifen and phorbol ester on nitric oxide production.

Author information

Division of Biomedical Sciences, School of Health Sciences, University of Wolverhampton, UK.


The existence of the L-arginine-nitric oxide pathway was investigated in ZR-75-1 human breast cancer cells. The presence of inducible nitric oxide synthase in these cells was confirmed by staining with an anti-iNOS antibody. ZR-75-1 cells spontaneously produced nitric oxide (NO) and this production could be significantly (P < 0.001) enhanced by L-arginine (0.01-10 mM) and was inhibited by L-NAME (2 mM). Stimulating the cells with phorbol 12-myristate 13-acetate (PMA) (200-1000 nM) resulted in a significant (P < 0.001) increase in NO2- secreted into the medium. Although treatment of the same cells with tamoxifen (10(-10)-10(-6) M) had no effect on NO production, tamoxifen was able to significantly (P < 0.001) downregulate PMA-enhanced nitrite production. Our results suggest that tamoxifen could play a role in the biology of nitric oxide in breast tumours.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center