Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0278488 (metastatic breast cancer)
 7,812 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Estrogens occurring naturally in the body are metabolized to catecholestrogens (2- and 4-hydroxyestradiol) by the cytochrome P450 enzymes. 2-Hydroxy catecholestrogens are further metabolized by catechol-O-methyltransferase to 2-methoxyestradiol, which is known to be protective against tumor formation. 2-Methoxyestradiol exhibits potent apoptotic activity against rapidly growing tumor cells. It also possesses antiangiogenic activity through a direct apoptotic effect on endothelial cells. Other molecular mechanisms, including microtubule stabilization by inhibition of the colchicine-binding site, have been reported. The exact mechanism of action of 2-methoxyestradiol is still unclear, but it has been shown to be effective in preventing tumor growth in a variety of cell lines. 2-Methoxyestradiol also possesses cardioprotective activity by inhibiting vascular smooth muscle cell growth in arteries. It has a lower binding affinity for estrogen receptor alpha compared with that of estradiol, and its affinity for estrogen receptor beta is even lower than that of estrogen receptor alpha, thus it has minimal estrogenic activity. 2-Methoxyestradiol is distinct because of its inability to engage estrogen receptors as an agonist, and its unique antiproliferative and apoptotic activities are mediated independently of estrogen receptors alpha and beta. A phase I clinical trial of 2-methoxyestradiol 200, 400, 600, 800, and 1,000 mg/day in 15 patients with breast cancer showed significant reduction in bone pain and analgesic intake in some patients, with no significant adverse effects. Another phase I study of 2-methoxyestradiol 200-1,000 mg/day in combination with docetaxel 35 mg/m2/week for 4-6 weeks performed in 15 patients with advanced refractory metastatic breast cancer showed no serious drug-related adverse effects. A phase II randomized, double-blind trial of 2-methoxyestradiol 400 and 1,200 mg/day in 33 patients with hormone-refractory prostate cancer showed that it was well tolerated and showed prostate specific antigen stabilizations and declines. We have started a phase I clinical trial to explore dosages greater than 1,000 mg/day.
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PMID:2-Methoxyestradiol, a promising anticancer agent. 1258 5

2-Methoxyestradiol (2ME) is an endogenous estradiol metabolite, which acts antiproliferative in various tumor cell lines independent of the hormone receptor status. We investigated whether combinations of 2ME with various chemotherapeutic or endocrine compounds may result in an additive effect on the proliferation of human breast cancer cells. The breast cancer cell lines MCF-7 (receptor-positive), BM (receptor-negative) and a MCF-7 line transfected with the aromatase gene were used. All cell lines were incubated in the concentration range of 0.8 microM to 25 microM with 2ME alone and in equimolar combinations with the following compounds: epirubicine, daunorubicine, paclitaxel, docetaxel, carboplatin, vinorelbine, 5-fluorouracil, mafosfamide and 4-OH tamoxifen. The effect of letrozole and 2ME alone and in equimolar combinations was tested in the concentration range of 0.6 to 1 microM. Proliferation was measured after 4 days using the ATP-chemosensitivity test. In MCF-7 cells 2ME in combination with 4OH-tamoxifen, epirubicine, docetaxel, 5-fluoprouracil, mafosfamide and carboplatin led to an additive effect. In BM cells only 2ME combined with 4OH-tamoxifen, daunorubicine and mafosfamide showed an additive action. Both letrozole and 2ME were nearly similar effective in inhibition of the aromatase gene. Here no additive effect was found. 2ME displayed antiproliferative actions in various human breast cancer cells. In addition 2ME was able to increase the antiproliferative property of certain antihormones and cytostatic substances. Furthermore 2ME exhibits a similar property as compared to letrozole in inhibiting the aromatase activity. Since 2ME was well tolerated in a recently conducted phase II trial in patients with refractory metastatic breast cancer, the combination of 2ME with chemotherapeutics or antihormones may offer a new clinically relevant treatment regimen.
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PMID:Chemotherapy of breast cancer-additive anticancerogenic effects by 2-methoxyestradiol? 1521 8

2-Methoxyestradiol (2ME(2)), a physiologic metabolite of 17beta-estradiol (estrogen), has emerged as a promising cancer therapy because of its potent growth-inhibitory and proapoptotic effects on both endothelial and tumor cells. 2ME(2) also suppresses osteoclast differentiation and induces apoptosis of mature osteoclasts, and has been shown to effectively repress bone loss in an animal model of postmenopausal osteoporosis. Given these observations, we have examined whether 2ME(2) could effectively target metastasis to bone, osteolytic tumors, and soft tissue tumors. A 4T1 murine metastatic breast cancer cell line was generated that stably expressed Far Red fluorescence protein (4T1/Red) to visualize tumor development and metastasis to bone. In an intervention study, 4T1/Red cells were injected into bone marrow of the left femur and the mammary pad. In the latter study, 2ME(2) (10, 25, and 50 mg/kg/d) treatment began on the same day as surgery and was continued for the 16-day duration of study. Tumor cell growth and metastasis to bone were monitored and bone volume was determined by micro-computed tomography. 2ME(2) inhibited tumor growth in soft tissue, metastasis to bone, osteolysis, and tumor growth in bone, with maximum effects at 50 mg/kg/d. Furthermore, tumor-induced osteolysis was significantly reduced in mice receiving 2ME(2). In vitro, 2ME(2) repressed osteoclast number by inducing apoptosis of osteoclast precursors as well as mature osteoclasts. Our data support the conclusion that 2ME(2) could be an important new therapy in the arsenal to fight metastatic breast cancer.
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PMID:2-Methoxyestradiol suppresses osteolytic breast cancer tumor progression in vivo. 1797 50