PHYTOESTROGENS DERIVED FROM BELAMCANDA CHINENSIS HAVE AN ANTIPROLIFERATIVE EFFECT ON PROSTATE CANCER CELLS IN VITRO
ABSTRACT
Purpose
Phytoestrogens are nonsteroidal plant derived compounds with estrogenic activity that have been implicated in protecting against prostate cancer progression. We hypothesized that these compounds would alter cell number and increase the ability of antiandrogens to induce cell death in prostate cancer cells.
Materials and Methods
RWPE-1, LNCaP and PC-3 cells were treated with or without an extract of Belamcanda chinensis, 2 purified phytoestrogens derived from this extract (irigenin and tectorigenin) and the antiandrogen bicalutamide. We assessed the effect on cell number, proliferation and apoptosis.
Results
Phytoestrogens (50 to 100 μM) and bicalutamide (10 to 50 μM) alone decreased the cell number in all 3 cell lines. Phytoestrogens (50 μM) combined with bicalutamide (10 μM) further decreased the number of RWPE-1 and PC-3 cells compared to these agents alone. Tectorigenin and irigenin inhibited the proliferation of RWPE-1, LNCaP and PC-3 cells, causing G1 arrest and the induction of p21 (WAF1) or p27kip1 protein expression, whereas bicalutamide induced apoptosis in a dose dependent manner in all 3 cell lines. Phytoestrogens did not have antiandrogenic activity.
Conclusions
These in vitro studies demonstrate a role for tectorigenin and irigenin in regulating prostate cancer cell number by inhibiting proliferation through cell cycle regulation.
From the Department of Surgery, Mater Misericordiae University Hospital, Conway Institute of Biomolecular and Biomedical Research, Dublin Molecular Medicine Centre, University College Dublin (CM, DG, JMF, RWGW), Dublin, Ireland, Bionorica AG (BS, VC), Neumarkt, Germany, and Department of Urology, University Hospital Innsbruck (JB, HK), Innsbruck, Austria
Correspondence: Department of Surgery, F057, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland (telephone: 353-1-7166749; FAX: 353-1-7166887;)
Accepted for publication June 4, 2004.
Supported by Euroestrogenes Grant Contract QLK6-CT-2000-00565.
1 Financial interest and/or other relationship with Bionorica AG
ABSTRACT