Mammalian lignans enterolactone and enterodiol, alone and in combination with the isoflavone genistein, do not promote the growth of MCF‐7 xenografts in ovariectomized athymic nude mice
Open Access
- 20 December 2005
- journal article
- research article
- Published by Wiley in International Journal of Cancer
- Vol. 118 (5), 1316-1320
- https://doi.org/10.1002/ijc.21464
Abstract
This study determined the effect of the mammalian lignans enterolactone (ENL) and enterodiol (END) alone and in combination with the isoflavone genistein (GEN) on the growth of MCF-7 tumors in ovariectomized nude mice. Ovariectomized athymic nude mice with established MCF-7 tumors were fed a basal diet (AIN-93G) and divided into 5 groups that received daily subcutaneous injections (10 mg/kg body weight (BW)) of ENL, END, GEN, a mixture of these compounds (MIX), or vehicle as a negative control for 22 weeks. A positive control group was implanted with an estradiol pellet in order to establish an estrogenic tumor growth response. In the ENL- and END-treated mice, palpable tumors regressed significantly by 91 and 83%, respectively, resulting in final tumors that were similar to the negative control tumors. However, tumor cell apoptosis was significantly enhanced by the lignans. In the GEN-treated mice, tumors initially regressed significantly by 64% but regression ceased following prolonged treatment, resulting in final tumors that were significantly larger compared to negative control, ENL-, and END-treated mice, in part by increasing tumor cell proliferation. The MIX treatment significantly regressed palpable tumors by 87% similar to negative control group, with no effects on tumor cell apoptosis or proliferation. The isoflavone GEN alone promoted the growth of established MCF-7 human breast cancer xenografts after prolonged treatment while the mammalian lignans ENL and END did not. When these phytoestrogens were given in combination, no tumor growth-promoting effects were observed.Keywords
This publication has 40 references indexed in Scilit:
- Dietary Flaxseed Alters Tumor Biological Markers in Postmenopausal Breast CancerClinical Cancer Research, 2005
- Dietary Flaxseed Enhances the Inhibitory Effect of Tamoxifen on the Growth of Estrogen-Dependent Human Breast Cancer (MCF-7) in Nude MiceClinical Cancer Research, 2004
- The use of complementary and alternative medications by menopausal women in South East QueenslandWomen's Health Issues, 2004
- Soy processing influences growth of estrogen-dependent breast cancer tumorsCarcinogenesis: Integrative Cancer Research, 2004
- Global cancer statistics in the year 2000The Lancet Oncology, 2001
- Effects of phytoestrogens on DNA synthesis in MCF‐7 cells in the presence of estradiol or growth factorsNutrition and Cancer, 1998
- Short-term Effects of Phytoestrogen-rich Diet on Postmenopausal WomenMenopause, 1997
- Phytoestrogen concentration determines effects on DNA synthesis in human breast cancer cellsNutrition and Cancer, 1997
- Enterolactone and estradiol inhibit each other's proliferative effect on MCF-7 breast cancer cells in cultureThe Journal of Steroid Biochemistry and Molecular Biology, 1992
- Stimulation of breast cancer cellsin vitro by the environmental estrogen enterolactone and the phytoestrogen equolBreast Cancer Research and Treatment, 1987