Tamoxifen is a synthetic non steroidal anti-estrogen used to treat patients with breast cancer and healthy subjects with high risk of breast cancer. It was aimed to study the short term effects of tamoxifen on the plasma total antioxidant capacity (TAC), nitric oxide (NO) and the adenosine deaminase activity (ADA) in healthy rabbits. Sixteen healthy New Zealand rabbits were allocated to 2 group...

ERBB2 overexpression in estrogen receptor (ER)-positive breast cancer cells such as BT474 (BT) cells has been found to confer resistance to tamoxifen, and suppression of ERBB2 improves the antiproliferative effects of tamoxifen. In this study, the responsiveness to tamoxifen in the BT/HerR, Herceptin-resistant BT cell lines established through constant Herceptin exposure, was evaluated. Compare...

Tamoxifen has been reported to inhibit acidification of cytoplasmic organelles in mammalian cells. Here, the mechanism of this inhibition is investigated using in vitro assays on isolated organelles and liposomes. Tamoxifen inhibited ATP-dependent acidification in organelles from a variety of sources, including isolated microsomes from mammalian cells, vacuoles from Saccharomyces cerevisiae, an...

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...

Tamoxifen was administered orally to neonatal rats on days 2-5 after birth and the subsequent effects on the uterus were characterized, morphometrically, over the following 12 months. Tamoxifen inhibited development of the uterus and glands in the endometrium, indicating a classical oestrogen antagonist action. Between 24 and 35 months after tamoxifen treatment there was a significant increase ...

BACKGROUND Estrogen receptor (ER) α is a successful therapeutic target in breast cancer, but patients eventually develop resistance to antiestrogens such as tamoxifen. METHODS To identify genes whose expression was associated with the development of tamoxifen resistance and metastasis, we used microarrays to compare gene expression in four primary tumors from tamoxifen-treated patients whose ...

We believe that hypercalcaemia after tamoxifen may signify tumour response and be a reason for continuing with tamoxifen and treating the hypercalcaemia. This is supported by a report of tamoxifen "flare" in metastatic breast cancer and the observation that acute exacerbation of bone pain in patients with breast cancer after tamoxifen may be associated with tumour response.'5 The mechanism of t...

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...

Cases of drug-induced lung injury caused by tamoxifen are rare. A 74-year-old man underwent surgery for the treatment of right breast cancer; tamoxifen was administered as an adjuvant therapy after surgery. The patient developed cough and dyspnea and chest computed tomography showed ground glass opacification in the lower lobe of the right lung. He was diagnosed with tamoxifen-induced lung inju...

The International Tamoxifen Pharmacogenomics Consortium was established to address the controversy regarding cytochrome P450 2D6 (CYP2D6) status and clinical outcomes in tamoxifen therapy. We performed a meta-analysis on data from 4,973 tamoxifen-treated patients (12 globally distributed sites). Using strict eligibility requirements (postmenopausal women with estrogen receptor-positive breast c...