Anticancer Res. 2008 Jan-Feb;28(1A):85-9. [In-Process]
Delta(9)-tetrahydrocannabinol inhibits 17beta-estradiol-induced proliferation and fails to activate androgen and estrogen receptors in MCF7 human breast cancer cells.
von Bueren AO, Schlumpf M, Lichtensteiger W.
Institute of Pharmacology and Toxicology, University of Zurich, Switzerland. Andre.vonBueren@kispi.uzh.ch
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 17beta-estradiol, included as positive control with an EC50 value (concentration required for 50% of maximal 17beta-estradiol-induced proliferation) of 1.00 x 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 17beta-estradiol-induced proliferation in wild-type MCF7 and MCF7-AR1 cells, with an IC50 value of 2.6 x 10(-5) M and 9 x 10(-6) M, respectively. CONCLUSION: THC failed to act as an estrogen, but antagonized 17beta-estradiol-induced proliferation. This effect was independent of the AR expression level.
PMID: 18383828Journal of Pharmacology And Experimental Therapeutics Fast Forward
First published on May 25, 2006; DOI: 10.1124/jpet.106.105247
0022-3565/06/3183-1375-1387$20.00
JPET 318:1375-1387, 2006
CHEMOTHERAPY, ANTIBIOTICS, AND GENE THERAPY
Antitumor Activity of Plant Cannabinoids with Emphasis on the Effect of Cannabidiol on Human Breast Carcinoma
Endocannabinoid Research Group, Istituto di Chimica Biomolecolare (A.L., A.S.M., K.S., I.M., V.D.M.), and Istituto di Cibernetica (A.S.M., L.D.P.), Consiglio Nazionale delle Ricerche Pozzuoli, Italy; Dipartimento di Biologia e Patologia Cellulare e Molecolare "L. Califano", Università di Napoli "Federico II", Napoli, Italy (S.P., C.L., G.P., M.B.); and Dipartimento di Scienze Farmaceutiche, Università degli Studi di Salerno, Fisciano, Italy (S.P., M.B.)
9-Tetrahydrocannabinol (THC) exhibits antitumor effects on various cancer cell types, but its use in chemotherapy is limited by its psychotropic activity. We investigated the antitumor activities of other plant cannabinoids, i.e., cannabidiol, cannabigerol,cannabichromene, cannabidiol acid and THC acid, and assessed whether there is any advantage in using Cannabis extracts (enriched in either cannabidiol or THC) over pure cannabinoids. Results obtained in a panel of tumor cell lines clearly indicate that, of the five natural compounds tested, cannabidiol is the most potent inhibitor of cancer cell growth (IC50 between 6.0 and 10.6 µM), with significantly lower potency in noncancer cells. The cannabidiol-rich extract was equipotent to cannabidiol, whereas cannabigerol and cannabichromene followed in the rank of potency. Both cannabidiol and the cannabidiol-rich extract inhibited the growth of xenograft tumors obtained by s.c. injection into athymic mice of human MDA-MB-231 breast carcinoma or rat v-K-ras-transformed thyroid epithelial cells and reduced lungmetastases deriving from intrapaw injection of MDA-MB-231 cells. Judging from several experiments on its possible cellular and molecular mechanisms of action, we propose that cannabidiol lacks a unique mode of action in the cell lines investigated. At least for MDA-MB-231 cells, however, our experiments indicate that cannabidiol effect is due to its capability of inducing apoptosis via: direct or indirect activation of cannabinoid CB2 and vanilloid transient receptor potential vanilloid type-1 receptors and cannabinoid/vanilloid receptor-independent elevation of intracellular Ca2+ and reactive oxygen species. Our data support the further testing of cannabidiol and cannabidiol-rich extracts for the potential treatment of cancer.
Received March 25, 2006; accepted May 23, 2006.
Address correspondence to: Dr. Vincenzo Di Marzo, Istituto di Chimica Biomolecolare, Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078 Pozzuoli, Napoli, Italy. E-mail: vdimarzo@icmib.na.cnr.it