Low-dose dietary phytoestrogen abrogates tamoxifen-associated mammary tumor prevention.

نویسندگان

  • Bolin Liu
  • Susan Edgerton
  • Xiaohe Yang
  • Aeree Kim
  • Dalia Ordonez-Ercan
  • Terza Mason
  • Kathy Alvarez
  • Christine McKimmey
  • Naxin Liu
  • Ann Thor
چکیده

Wild-type erbB-2/neu transgenic mice were used to study the interactions between tamoxifen and dietary phytoestrogens (or isoflavones) by dose and form in vivo. Mice were randomized to one of four dietary formulas and implanted with an 8-week continuous-release tamoxifen or placebo pellet at 8 weeks of age. In placebo-treated mice, soy meal diet (but not diets supplemented with low-dose or high-dose isoflavones or a casein diet) resulted in prolongation of tumor latency. In tamoxifen-treated mice fed the soy meal, casein, or high-dose isoflavone enriched diets, the majority (>80%) showed no tumor formation by 60 weeks of age. Of the mice that developed tumors, latency was significantly prolonged. In tamoxifen-treated mice fed the low-dose isoflavone enriched diet, a much higher rate of mammary tumor development (>50%; P < 0.002) and a shorter tumor latency were observed. In vitro studies of human and mouse mammary tumor cell lines confirm that low doses of genistein, co-administered with tamoxifen, promote cell proliferation. This is in contrast to tamoxifen alone or tamoxifen with higher doses of genistein that are growth inhibitory. In summary, low-dose dietary isoflavones abrogated tamoxifen-associated mammary tumor prevention in vivo. These interactions are supported by in vitro data from human and mouse mammary tumor cell lines. These dose-associated interactions likely have relevance to the human use of tamoxifen for prevention or treatment of breast cancer.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Tamoxifen-Associated Mammary Tumor Prevention Low-Dose Dietary Phytoestrogen Abrogates

Wild-type erbB-2/neu transgenic mice were used to study the interactions between tamoxifen and dietary phytoestrogens (or isoflavones) by dose and form in vivo . Mice were randomized to one of four dietary formulas and implanted with an 8-week continuous-release tamoxifen or placebo pellet at 8 weeks of age. In placebo-treated mice, soy meal diet (but not diets supplemented with low-dose or hig...

متن کامل

Hormonal and dietary modulation of mammary carcinogenesis in mouse mammary tumor virus-c-erbB-2 transgenic mice.

Exogenous and dietary estrogens have been associated with modification of breast cancer risk. Mammary cancer model systems can be used to explore interactions between specific transgenes, and hormonal and dietary factors. Transgenic mice bearing the rat wild-type erbB-2 gene were used to study the effects of short-term hormonal exposure [17beta-estradiol (E2) or tamoxifen] or a soy meal diet on...

متن کامل

Implications of phytoestrogen intake for breast cancer.

Phytoestrogens are a group of plant-derived substances that are structurally or functionally similar to estradiol. Interest in phytoestrogens has been fueled by epidemiologic data that suggest a decreased risk of breast cancer in women from countries with high phytoestrogen consumption. Women with a history of breast cancer may seek out these "natural" hormones in the belief that they are safe ...

متن کامل

Dietary Phytoestrogen Intake and The Risk of Endometriosis in Iranian Women: A Case-Control Study

Objective The aim of this study is to evaluate the relationship between phytoestrogen intake with endometriosis risk. MaterialsAndMethods A case-control study was conducted on 78 women with a laparoscopically confirmed diagnosis of endometriosis and on 78 normal pelvis women (as the control group). Common dietary intake was collected by a validated 147-item semi-quantitative FFQ. Calculation ty...

متن کامل

Is low-dose tamoxifen useful for the treatment and prevention of breast cancer?

Many studies have demonstrated the utility of tamoxifen for the treatment of estrogen receptor (ER)-positive breast cancer (1) and more recently for the prevention of breast cancer in women at increased risk (2–4). However, the toxicities of tamoxifen such as thromboembolic events and endometrial cancers still pose a clinically significant problem. To reduce the risk of these adverse events, ef...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Cancer research

دوره 65 3  شماره 

صفحات  -

تاریخ انتشار 2005