Abstract
Background: Delta(9)-tetrahydrocannabinol (THC) exerts palliative effects in cancer patients, but produces adverse effects on the endocrine and reproductive systems. Experimental evidence concerning such effects is controversial. Whether THC exhibits estrogenic or androgenic activity in vitro was investigated. Materials and Methods: Estrogenic effects of THC were analyzed in vitro by measuring the proliferation of estrogen-sensitive MCF7 cells. Androgenic activity was investigated by the A-Screen assay that measures androgen-dependent inhibition of proliferation of the androgen receptor (AR)-positive human mammary carcinoma cell line, MCF7-AR1. Results: In contrast to 17β-estradiol, included as positive control with an EC50 value (concentration required for 50% of maximal 17β-estradiol-induced proliferation) of 1.00×10-12 M, THC failed to induce cell proliferation in the MCF7 cell line at concentrations between 10-13 and 10-4 M. THC inhibited 17β-estradiol-induced proliferation in wild-type MCF7 and MCF7-AR1 cells, with an IC50 value of 2.6×10-5 M and 9×10-6 M, respectively. Conclusion: THC failed to act as an estrogen, but antagonized 17β-estradiol-induced proliferation. This effect was independent of the AR expression level.
- Received October 3, 2007.
- Revision received November 9, 2007.
- Accepted November 28, 2007.
- Copyright© 2008 International Institute of Anticaner Research (Dr. John G. Delinassios), All rights reserved
