The Wnt signalling pathway is upregulated in an in vitro model of acquired tamoxifen resistant breast cancer

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Loh, Yan Ni; Hedditch, Ellen L; Baker, Laura A; Jary, Eve; Ward, Robyn L; Ford, Caroline E

2013-01-01

Acquired resistance to Tamoxifen remains a critical problem in breast cancer patient treatment, yet the underlying causes of resistance have not been fully elucidated. Abberations in the Wnt signalling pathway have been linked to many human cancers, including breast cancer, and appear to be associated with more metastatic and aggressive types of cancer. Here, our aim was to investigate if this key pathway was involved in acquired Tamoxifen resistance, and could be targeted therapeutically. An in vitro model of acquired Tamoxifen resistance (named TamR) was generated by growing the estrogen receptor alpha (ER) positive MCF7 breast cancer cell line in increasing concentrations of Tamoxifen (up to 5 uM). Alterations in the Wnt signalling pathway and epithelial to mesenchymal transition (EMT) in response to Tamoxifen and treatment with the Wnt inhibitor, IWP-2 were measured via quantitative RT-PCR (qPCR) and TOP/FOP Wnt reporter assays. Resistance to Tamoxifen, and effects of IWP-2 treatment were determined by MTT proliferation assays. TamR cells exhibited increased Wnt signalling as measured via the TOP/FOP Wnt luciferase reporter assays. Genes associated with both the β-catenin dependent (AXIN2, MYC, CSNK1A1) and independent arms (ROR2, JUN), as well as general Wnt secretion (PORCN) of the Wnt signalling pathway were upregulated in the TamR cells compared to the parental MCF7 cell line. Treatment of the TamR cell line with human recombinant Wnt3a (rWnt3a) further increased the resistance of both MCF7 and TamR cells to the anti-proliferative effects of Tamoxifen treatment. TamR cells demonstrated increased expression of EMT markers (VIM, TWIST1, SNAI2) and decreased CDH1, which may contribute to their resistance to Tamoxifen. Treatment with the Wnt inhibitor, IWP-2 inhibited cell proliferation and markers of EMT. These data support the role of the Wnt signalling pathway in acquired resistance to Tamoxifen. Further research into the mechanism by which activated Wnt

Steroid receptor coactivators, HER-2 and HER-3 expression is stimulated by tamoxifen treatment in DMBA-induced breast cancer

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Moi, Line L Haugan; Flågeng, Marianne Hauglid; Gjerde, Jennifer; Madsen, Andre; Røst, Therese Halvorsen; Gudbrandsen, Oddrun Anita; Lien, Ernst A; Mellgren, Gunnar

2012-01-01

Steroid receptor coactivators (SRCs) may modulate estrogen receptor (ER) activity and the response to endocrine treatment in breast cancer, in part through interaction with growth factor receptor signaling pathways. In the present study the effects of tamoxifen treatment on the expression of SRCs and human epidermal growth factor receptors (HERs) were examined in an animal model of ER positive breast cancer. Sprague-Dawley rats with DMBA-induced breast cancer were randomized to 14 days of oral tamoxifen 40 mg/kg bodyweight/day or vehicle only (controls). Tumors were measured throughout the study period. Blood samples and tumor tissue were collected at sacrifice and tamoxifen and its main metabolites were quantified using LC-MS/MS. The gene expression in tumor of SRC-1, SRC-2/transcription intermediary factor-2 (TIF-2), SRC-3/amplified in breast cancer 1 (AIB1), ER, HER-1, -2, -3 and HER-4, as well as the transcription factor Ets-2, was measured by real-time RT-PCR. Protein levels were further assessed by Western blotting. Tamoxifen and its main metabolites were detected at high concentrations in serum and accumulated in tumor tissue in up to tenfolds the concentration in serum. Mean tumor volume/rat decreased in the tamoxifen treated group, but continued to increase in controls. The mRNA expression levels of SRC-1 (P = 0.035), SRC-2/TIF-2 (P = 0.002), HER-2 (P = 0.035) and HER-3 (P = 0.006) were significantly higher in tamoxifen treated tumors compared to controls, and the results were confirmed at the protein level using Western blotting. SRC-3/AIB1 protein was also higher in tamoxifen treated tumors. SRC-1 and SRC-2/TIF-2 mRNA levels were positively correlated with each other and with HER-2 (P ≤ 0.001), and the HER-2 mRNA expression correlated with the levels of the other three HER family members (P < 0.05). Furthermore, SRC-3/AIB1 and HER-4 were positively correlated with each other and Ets-2 (P < 0.001). The expression of SRCs and HER-2 and -3 is stimulated

“Iron-saturated” bovine lactoferrin improves the chemotherapeutic effects of tamoxifen in the treatment of basal-like breast cancer in mice

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Sun, Xueying; Jiang, Ruohan; Przepiorski, Aneta; Reddy, Shiva; Palmano, Kate P; Krissansen, Geoffrey W

2012-01-01

Tamoxifen is used in hormone therapy for estrogen-receptor (ER)-positive breast cancer, but also has chemopreventative effects against ER-negative breast cancers. This study sought to investigate whether oral iron-saturated bovine lactoferrin (Fe-Lf), a natural product which enhances chemotherapy, could improve the chemotherapeutic effects of tamoxifen in the treatment of ER-negative breast cancers. In a model of breast cancer prevention, female Balb/c mice treated with tamoxifen (5 mg/Kg) were fed an Fe-Lf supplemented diet (5 g/Kg diet) or the base diet. At week 2, 4T1 mammary carcinoma cells were injected into an inguinal mammary fat pad. In a model of breast cancer treatment, tamoxifen treatment was not started until two weeks following tumor cell injection. Tumor growth, metastasis, body weight, and levels of interleukin 18 (IL-18) and interferon γ (IFN-γ) were analyzed. Tamoxifen weakly (IC 50 ~ 8 μM) inhibited the proliferation of 4T1 cells at pharmacological concentrations in vitro. In the tumor prevention study, a Fe-Lf diet in combination with tamoxifen caused a 4 day delay in tumor formation, and significantly inhibited tumor growth and metastasis to the liver and lung by 48, 58, and 66% (all P < 0.001), respectively, compared to untreated controls. The combination therapy was significantly (all P < 0.05) more effective than the respective monotherapies. Oral Fe-Lf attenuated the loss of body weight caused by tamoxifen and cancer cachexia. It prevented tamoxifen-induced reductions in serum levels of IL-18 and IFN-γ, and intestinal cells expressing IL-18 and IFN-γ. It increased the levels of Lf in leukocytes residing in gut-associated lymphoid tissues. B, T and Natural killer (NK) cells containing high levels of Lf were identified in 4T1 tumors, suggesting they had migrated from the intestine. Similar effects of Fe-Lf and tamoxifen on tumor cell viability were seen in the treatment of established tumors. The results indicate that Fe-Lf is a potent

“Iron-saturated” bovine lactoferrin improves the chemotherapeutic effects of tamoxifen in the treatment of basal-like breast cancer in mice

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Sun, Xueying [Department of Molecular Medicine & Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, 1005 (New Zealand); Department of General Surgery, The Hepatosplenic Surgery Center, The First Affiliated Hospital of Harbin Medical University, Harbin, 150001 (China); Jiang, Ruohan; Przepiorski, Aneta; Reddy, Shiva [Department of Molecular Medicine & Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, 1005 (New Zealand); Palmano, Kate P [Fonterra Research Centre, Palmerston North, 4442 (New Zealand); Krissansen, Geoffrey W [Department of Molecular Medicine & Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, 1005 (New Zealand)

2012-12-11

Tamoxifen is used in hormone therapy for estrogen-receptor (ER)-positive breast cancer, but also has chemopreventative effects against ER-negative breast cancers. This study sought to investigate whether oral iron-saturated bovine lactoferrin (Fe-Lf), a natural product which enhances chemotherapy, could improve the chemotherapeutic effects of tamoxifen in the treatment of ER-negative breast cancers. In a model of breast cancer prevention, female Balb/c mice treated with tamoxifen (5 mg/Kg) were fed an Fe-Lf supplemented diet (5 g/Kg diet) or the base diet. At week 2, 4T1 mammary carcinoma cells were injected into an inguinal mammary fat pad. In a model of breast cancer treatment, tamoxifen treatment was not started until two weeks following tumor cell injection. Tumor growth, metastasis, body weight, and levels of interleukin 18 (IL-18) and interferon γ (IFN-γ) were analyzed. Tamoxifen weakly (IC{sub 50} ~ 8 μM) inhibited the proliferation of 4T1 cells at pharmacological concentrations in vitro. In the tumor prevention study, a Fe-Lf diet in combination with tamoxifen caused a 4 day delay in tumor formation, and significantly inhibited tumor growth and metastasis to the liver and lung by 48, 58, and 66% (all P < 0.001), respectively, compared to untreated controls. The combination therapy was significantly (all P < 0.05) more effective than the respective monotherapies. Oral Fe-Lf attenuated the loss of body weight caused by tamoxifen and cancer cachexia. It prevented tamoxifen-induced reductions in serum levels of IL-18 and IFN-γ, and intestinal cells expressing IL-18 and IFN-γ. It increased the levels of Lf in leukocytes residing in gut-associated lymphoid tissues. B, T and Natural killer (NK) cells containing high levels of Lf were identified in 4T1 tumors, suggesting they had migrated from the intestine. Similar effects of Fe-Lf and tamoxifen on tumor cell viability were seen in the treatment of established tumors. The results indicate that Fe-Lf is a

Tumorigenic Effects of Tamoxifen on the Female Genital Tract

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Kaei Nasu M.D., Ph.D.

2008-01-01

Full Text Available Tamoxifen is widely used for endocrine treatment and breast cancer prevention. It acts as both an estrogen antagonist in breast tissue and an estrogen agonist in the female lower genital tract. Tamoxifen causes severe gynecologic side effects, such as endometrial cancer. This review focuses on the effects of prolonged tamoxifen treatment on the human female genital tract and considers its tumorigenicity in the gynecologic organs through clinical data analysis. Tamoxifen is associated with an increased incidence of benign endometrial lesions such as polyps and hyperplasia and a two- to four-fold increased risk of endometrial cancer in postmenopausal patients. Moreover, the incidence of functional ovarian cysts is significantly high in premenopausal tamoxifen users. To prevent tamoxifen from having severe side effects in gynecologic organs, frequent gynecological examination should be performed for both premenopausal and postmenopausal patients with breast cancer who are treated with this drug.

Therapeutic Effects of a Traditional Chinese Medicine Formula Plus Tamoxifen vs. Tamoxifen for the Treatment of Mammary Gland Hyperplasia: A Meta-Analysis of Randomized Trials

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Li, Hao-Tian; Liu, Hong-Hong; Yang, Yu-Xue; Wang, Tao; Zhou, Xue-Lin; Yu, Yang; Li, Su-Na; Zheng, Yi; Zhang, Ping; Wang, Rui-Lin; Li, Jian-Yu; Wei, Shi-Zhang; Li, Kun; Li, Peng-Yan; Qian, Li-Qi

2018-01-01

As a common disorder that accounts for over 70% of all breast disease cases, mammary gland hyperplasia (MGH) causes a severe problem for the quality of patients' life, and confers an increased risk of breast carcinoma. However, the etiology and pathogenesis of MGH remain unclear, and the safety and efficacy of current western drug therapy for MGH still need to be improved. Therefore, a meta-analysis was conducted by our team to determine whether a TCM formula named Ru-Pi-Xiao in combination with tamoxifen or Ru-Pi-Xiao treated alone can show more prominent therapeutic effects against MGH with fewer adverse reactions than that of tamoxifen. Studies published before June 2017 were searched based on standardized searching rules in several mainstream medical databases. A total of 27 articles with 4,368 patients were enrolled in this meta-analysis. The results showed that the combination of Ru-Pi-Xiao and tamoxifen could exhibit better therapeutic effects against MGH than that of tamoxifen (OR: 3.79; 95% CI: 3.09–4.65; P < 0.00001) with a lower incidence of adverse reactions (OR: 0.35; 95% CI: 0.28–0.43; P < 0.00001). The results also suggested that this combination could improve the level of progesterone (MD: 2.22; 95% CI: 1.72–2.71; P < 0.00001) and decrease the size of breast lump (MD: −0.67; 95% CI: −0.86 to −0.49; P < 0.00001) to a greater extent, which might provide a possible explanation for the pharmacodynamic mechanism of Ru-Pi-Xiao plus tamoxifen. In conclusion, Ru-Pi-Xiao and related preparations could be recommended as auxiliary therapy combined tamoxifen for the treatment of MGH. PMID:29456506

Tamoxifen treatment in hamsters induces protection during taeniosis by Taenia solium.

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Escobedo, Galileo; Palacios-Arreola, M Isabel; Olivos, Alfonso; López-Griego, Lorena; Morales-Montor, Jorge

2013-01-01

Human neurocysticercosis by Taenia solium is considered an emergent severe brain disorder in developing and developed countries. Discovery of new antiparasitic drugs has been recently aimed to restrain differentiation and establishment of the T. solium adult tapeworm, for being considered a central node in the disease propagation to both pigs and humans. Tamoxifen is an antiestrogenic drug with cysticidal action on Taenia crassiceps, a close relative of T. solium. Thus, we evaluated the effect of tamoxifen on the in vitro evagination and the in vivo establishment of T. solium. In vitro, tamoxifen inhibited evagination of T. solium cysticerci in a dose-time dependent manner. In vivo, administration of tamoxifen to hamsters decreased the intestinal establishment of the parasite by 70%, while recovered tapeworms showed an 80% reduction in length, appearing as scolices without strobilar development. Since tamoxifen did not show any significant effect on the proliferation of antigen-specific immune cells, intestinal inflammation, and expression of Th1/Th2 cytokines in spleen and duodenum, this drug could exert its antiparasite actions by having direct detrimental effects upon the adult tapeworm. These results demonstrate that tamoxifen exhibits a strong cysticidal and antitaeniasic effect on T. solium that should be further explored in humans and livestock.

Cre recombinase expression or topical tamoxifen treatment do not affect retinal structure and function, neuronal vulnerability or glial reactivity in the mouse eye.

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Boneva, S K; Groß, T R; Schlecht, A; Schmitt, S I; Sippl, C; Jägle, H; Volz, C; Neueder, A; Tamm, E R; Braunger, B M

2016-06-14

Mice with a constitutive or tamoxifen-induced Cre recombinase (Cre) expression are frequently used research tools to allow the conditional deletion of target genes via the Cre-loxP system. Here we analyzed for the first time in a comprehensive and comparative way, whether retinal Cre expression or topical tamoxifen treatment itself would cause structural or functional changes, including changes in the expression profiles of molecular markers, glial reactivity and photoreceptor vulnerability. To this end, we characterized the transgenic α-Cre, Lmop-Cre and the tamoxifen-inducible CAGG-CreER™ mouse lines, all having robust Cre expression in the neuronal retina. In addition, we characterized the effects of topical tamoxifen treatment itself in wildtype mice. We performed morphometric analyses, immunohistochemical staining, in vivo ERG and angiography analyses and realtime RT-PCR analyses. Furthermore, the influence of Cre recombinase or topical tamoxifen exposure on neuronal vulnerability was studied by using light damage as a model for photoreceptor degeneration. Taken together, neither the expression of Cre, nor topical tamoxifen treatment caused detectable changes in retinal structure and function, the expression profiles of investigated molecular markers, glial reactivity and photoreceptor vulnerability. We conclude that the Cre-loxP system and its induction through tamoxifen is a safe and reliable method to delete desired target genes in the neural retina. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Mammographic density changes following discontinuation of tamoxifen in premenopausal women with oestrogen receptor-positive breast cancer.

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Kim, Won Hwa; Cho, Nariya; Kim, Young-Seon; Yi, Ann

2018-04-06

To evaluate the changes in mammographic density after tamoxifen discontinuation in premenopausal women with oestrogen receptor-positive breast cancers and the underlying factors METHODS: A total of 213 consecutive premenopausal women with breast cancer who received tamoxifen treatment after curative surgery and underwent three mammograms (baseline, after tamoxifen treatment, after tamoxifen discontinuation) were included. Changes in mammographic density after tamoxifen discontinuation were assessed qualitatively (decrease, no change, or increase) by two readers and measured quantitatively by semi-automated software. The association between % density change and clinicopathological factors was evaluated using univariate and multivariate regression analyses. After tamoxifen discontinuation, a mammographic density increase was observed in 31.9% (68/213, reader 1) to 22.1% (47/213, reader 2) by qualitative assessment, with a mean density increase of 1.8% by quantitative assessment compared to density before tamoxifen discontinuation. In multivariate analysis, younger age (≤ 39 years) and greater % density decline after tamoxifen treatment (≥ 17.0%) were independent factors associated with density change after tamoxifen discontinuation (p density change with a mean density increase of 1.8%, which was associated with younger age and greater density change after tamoxifen treatment. • Increased mammographic density after tamoxifen discontinuation can occur in premenopausal women. • Mean density increase after tamoxifen discontinuation was 1.8%. • Density increase is associated with age and density decrease after tamoxifen.

A Role for Estrogen Receptor Phosphorylation in the Resistance to Tamoxifen

International Nuclear Information System (INIS)

De Leeuw, R.; Neefjes, J.; Michalides, R.

2011-01-01

About two thirds of all human breast cancer cases are estrogen receptor positive. The drug of first choice for these patients is tamoxifen. However, about half of the recurrences after removal of the primary tumor are or become resistant to this drug. While many mechanisms have been identified for tamoxifen resistance in the lab, at present only a few have been translated to the clinic. This paper highlights the role in tamoxifen resistance of phosphorylation by different kinases on different sites of the estrogen receptor. We will discuss the molecular pathways and kinases that are involved in phosphorylation of ERa and how these affect tamoxifen resistance. Finally, we will elaborate on the clinical translation of these observations and the possibility to predict tamoxifen responses in patient tumor samples before treatment onset. The findings made originally on the bench may translate into a better and personalized treatment of breast cancer patients using an old and safe anticancer drug: tamoxifen

[Effect of the estrogen antagonist tamoxifen in the treatment of advanced mastocarcinoma (author's transl)].

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Szepesi, T; Kärcher, K H

1977-12-01

Today the endocrin therapy of the advanced mastocarcinoma is in common use. Besides the already known therapy by estrogens, androgens, gestagens, and steroids, Tamoxifen, and estrogen antagonist, is a very promising therapeutic drug. In the presented study, Tamoxifen was submitted to a critical clinical control during a period of one year from 1st October 1975 until 1st October 1976. After a three months' treatment, a rate of 41% of objective remissions could be obtained. The criteria of success were estimated according to the scheme of Karnofsky. The average remission time is 5,5 months. By a determination of the estrogen receptors it would be possible to realize a therapeutic selection and to achieve a higher remission rate. The authors made an interesting observation, i.e. a probably immuno-stimulating effect which, however, still has to be submitted to further examinations. The side effects are described in detail and the indications are established. Its is astonishing that the subjective ameliorations, i.e. cessation of pains in case of generalized formation of metastases in the bones are much more frequent than the objective remissions. We came to the conclusion that the treatment by Tamoxifen is a valuable alternative in the therapy of the mastocarcinoma, above all in the postmenopausal period if the disease is advanced and incurable.

Phase I Clinical Trial Assessing Temozolomide and Tamoxifen With Concomitant Radiotherapy for Treatment of High-Grade Glioma

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Patel, Shilpen; DiBiase, Steven; Meisenberg, Barry; Flannery, Todd; Patel, Ashish; Dhople, Anil; Cheston, Sally; Amin, Pradip

2012-01-01

Purpose: The new standard treatment of glioblastoma multiforme is concurrent radiotherapy (RT) and temozolomide. The proliferation of high-grade gliomas might be partly dependent on protein kinase C-mediated pathways. Tamoxifen has been shown in vitro to inhibit protein kinase C through estrogen receptor-independent antineoplastic effects. This Phase I trial was designed to determine the maximal tolerated dose (MTD) of tamoxifen when given with temozolomide and concurrent RT to patients with high-grade gliomas. Methods and Materials: A total of 17 consecutive patients in four cohorts with World Health Organization Grade 3 (n = 2) and 4 (n = 15) gliomas were given tamoxifen twice daily during 6 weeks of concurrent RT and temozolomide. Eligibility included histologic diagnosis, age >18 years old, Karnofsky performance status ≥60, and no previous brain RT or chemotherapy. The starting dose was 50 mg/m 2 divided twice daily. If no dose-limiting toxicities (DLTs) occurred in 3 patients, the dose was escalated in 25-mg/m 2 increments until the MTD was reached. When ≥2 patients within a cohort experienced a DLT, the MTD had been exceeded. Temozolomide was given with RT at 75 mg/m 2 . A dose of 60 Gy in 2 Gy/d fractions to a partial brain field was delivered. Results: A total of 6 patients in Cohort 4 had received tamoxifen at 125 mg/m 2 . One patient was excluded, and the fourth patient developed Grade 4 thrombocytopenia (DLT). Thus, 3 more patients needed to be enrolled. A deep venous thrombosis (DLT) occurred in the sixth patient. Thus, the MTD was 100 mg/m 2 . Conclusions: The MTD of tamoxifen was 100 mg/m 2 when given concurrently with temozolomide 75 mg/m 2 and RT. Tamoxifen might have a role in the initial treatment of high-grade gliomas and should be studied in future Phase II trials building on the newly established platform of concurrent chemoradiotherapy.

Spectral domain optical coherence tomography findings in tamoxifen retinopathy--a case report.

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Nair, Sandhya Narayanan; Anantharaman, Giridhar; Gopalakrishnan, Mahesh; Vyas, Jyothiprakash

2013-01-01

To report spectral domain optical coherence tomography findings in a case of typical tamoxifen retinopathy. In this observational case report, a patient with tamoxifen retinopathy was imaged with spectral domain optical coherence tomography and fundus auto fluorescence. Spectral domain optical coherence tomography showed numerous hyperreflective spots within the retina, mainly in the inner retinal layers in both the eyes. The external limiting membrane, the Inner Segment-Outer Segment junction, and the photoreceptors were not discernable at the fovea in the right eye. In the left eye, there was foveal atrophy with total loss of photoreceptors. The autofluorescent images showed macular hypofluorescence with foveal hyperfluorescence. Spectral domain optical coherence tomography demonstrated abnormalities in the outer retinal layers in tamoxifen retinopathy. There were also characteristic alterations in the autofluorescence pattern at the macula in tamoxifen retinopathy.

Gene expression profiling reveals underlying molecular mechanisms of the early stages of tamoxifen-induced rat hepatocarcinogenesis

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Pogribny, Igor P.; Bagnyukova, Tetyana V.; Tryndyak, Volodymyr P.; Muskhelishvili, Levan; Rodriguez-Juarez, Rocio; Kovalchuk, Olga; Han Tao; Fuscoe, James C.; Ross, Sharon A.; Beland, Frederick A.

2007-01-01

Tamoxifen is a widely used anti-estrogenic drug for chemotherapy and, more recently, for the chemoprevention of breast cancer. Despite the indisputable benefits of tamoxifen in preventing the occurrence and re-occurrence of breast cancer, the use of tamoxifen has been shown to induce non-alcoholic steatohepatitis, which is a life-threatening fatty liver disease with a risk of progression to cirrhosis and hepatocellular carcinoma. In recent years, the high-throughput microarray technology for large-scale analysis of gene expression has become a powerful tool for increasing the understanding of the molecular mechanisms of carcinogenesis and for identifying new biomarkers with diagnostic and predictive values. In the present study, we used the high-throughput microarray technology to determine the gene expression profiles in the liver during early stages of tamoxifen-induced rat hepatocarcinogenesis. Female Fisher 344 rats were fed a 420 ppm tamoxifen containing diet for 12 or 24 weeks, and gene expression profiles were determined in liver of control and tamoxifen-exposed rats. The results indicate that early stages of tamoxifen-induced liver carcinogenesis are characterized by alterations in several major cellular pathways, specifically those involved in the tamoxifen metabolism, lipid metabolism, cell cycle signaling, and apoptosis/cell proliferation control. One of the most prominent changes during early stages of tamoxifen-induced hepatocarcinogenesis is dysregulation of signaling pathways in cell cycle progression from the G 1 to S phase, evidenced by the progressive and sustained increase in expression of the Pdgfc, Calb3, Ets1, and Ccnd1 genes accompanied by the elevated level of the PI3K, p-PI3K, Akt1/2, Akt3, and cyclin B, D1, and D3 proteins. The early appearance of these alterations suggests their importance in the mechanism of neoplastic cell transformation induced by tamoxifen

Clinical evidence on the magnitude of change in growth pathway activity in relation to Tamoxifen resistance is required.

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Mansouri, Sepideh; Farahmand, Leila; Teymourzadeh, Azin; Majidzadeh-A, Keivan

2017-08-08

Despite prolonged disease-free survival and overall survival rates in estrogen receptor (ER)-positive patients undergoing adjuvant treatment, Tamoxifen therapy tends to fail due to eventual acquisition of resistance. Although numerous studies have emphasized the role of receptor tyrosine kinases (RTKs) in the development of Tamoxifen resistance, inadequate clinical evidence is available regarding the alteration of biomarker expression during acquired resistance, thus undermining the validity of the findings. Results of two meta-analyses investigating the effect of HER2 status on the prognosis of Tamoxifen-receiving patients have demonstrated that despite HER2-negative patients having longer disease-free survival; there is no difference in overhaul survival between the two groups. Furthermore, due to the intricate molecular interactions among estrogen receptors including ERα36, ERα66, and also RTKs, it is not surprising that RTK suppression does not restore Tamoxifen sensitivity. In considering such a complex network, we speculate that by the time HER2/EGFR is suppressed via targeted therapies, activation of ERα66 and ERα36 initiate molecular signaling pathways downstream of RTKs, thereby enhancing cell proliferation even in the presence of both Tamoxifen and RTK inhibitors. Although clinical findings regarding the molecular pathways downstream of RTKs have been thoroughly discussed in this review, further clinical studies are required in determining a consistency between preclinical and clinical findings. Discovering the best targets in preventing tumor progression requires thorough comprehension of estrogen-dependent and estrogen-independent pathways during Tamoxifen resistance development. Indeed, exploring additional clinically-proven targets would allow for better characterized treatments being available for breast cancer patients. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Tamoxifen and ovarian function.

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Martine Berliere

Full Text Available BACKGROUND: Some studies suggest that the clinical parameter "amenorrhea" is insufficient to define the menopausal status of women treated with chemotherapy or tamoxifen. In this study, we investigated and compared the ovarian function defined either by clinical or biological parameters in pre-menopausal breast cancer patients treated with tamoxifen administered as adjuvant therapy. MATERIALS AND METHODS: Between 1999 and 2003, 138 premenopausal patients consecutively treated for early breast cancer were included. Sixty-eight received tamoxifen in monotherapy as the only adjuvant systemic treatment (Group I and 70 were treated with tamoxifen after adjuvant chemotherapy (Group II. All patients had a confirmed premenopausal status based on clinical parameters and hormonal values at study entry. They were followed prospectively every 3 months for 3 years: menses data, physical examination and blood tests (LH, FSH, 17-beta-estradiol. Vaginal ultrasonography was carried out every 6 months. After 3 years, prospective evaluation was completed and monitoring of ovarian function was performed as usual in our institution (1x/year. All data were retrospectively evaluated in 2011. RESULTS: Three patients were excluded from the study in group I and 2 were excluded in group II. Patients were divided into 4 subgroups according to clinical data, i.e. menses patterns. These patterns were assessed by questionnaires. a: Regular menses (>10 cycles/year b: Oligomenorrhea (5 to 9 cycles/year c: Severe oligomenorrhea (1 to 4 cycles/year d: Complete amenorrhea Estrogen levels did not appear to have any impact on disease-free survival rates after 3 or 8 years. FSH values were also documented and analyzed. They exhibited the same profile as estradiol values. CONCLUSIONS: Amenorrhea is an insufficient parameter to define menopausal status in patients receiving tamoxifen. Low estradiol levels must be coupled with other biological parameters to characterize endocrine status

Physiologically-based pharmacokinetic modeling of tamoxifen and its metabolites in women of different CYP2D6 phenotypes provides new insight into the tamoxifen mass balance

Directory of Open Access Journals (Sweden)

Kristin eDickschen

2012-05-01

Full Text Available Tamoxifen is a first-line endocrine agent in the mechanism-based treatment of estrogen receptor positive (ER+ mammary carcinoma and applied to breast cancer patients all over the world. Endoxifen is a secondary and highly active metabolite of tamoxifen that is formed among others by the polymorphic cytochrome P450 2D6 (CYP2D6. It is widely accepted that CYP2D6 poor metabolizers (PM exert a pronounced decrease in endoxifen steady-state plasma concentrations compared to CYP2D6 extensive metabolizers (EM. Nevertheless, an in-depth understanding of the chain of cause and effect between CYP2D6 genotype, endoxifen steady-state plasma concentration, and subsequent tamoxifen treatment benefit still remains to be evolved.In this context, physiologically-based pharmacokinetic (PBPK-modeling provides a useful tool to mechanistically investigate the impact of CYP2D6 phenotype on endoxifen formation in female breast cancer patients undergoing tamoxifen therapy.It has long been thought that only a minor percentage of endoxifen is formed via 4-hydroxytamoxifen. However, the current investigation supports very recently published data that postulates a contribution of 4-hydroxytamoxifen above 20 % to total endoxifen formation. The developed PBPK-model describes tamoxifen PK in rats and humans. Moreover, tamoxifen metabolism in dependence of CYP2D6 phenotype in populations of European female individuals is well described, thus providing a good basis to further investigate the linkage of PK, mode of action, and treatment outcome in dependence of factors such as phenotype, ethnicity or co-treatment with CYP2D6 inhibitors.

Estrogen receptor (ESR1) mRNA expression and benefit from tamoxifen in the treatment and prevention of estrogen receptor-positive breast cancer.

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Kim, Chungyeul; Tang, Gong; Pogue-Geile, Katherine L; Costantino, Joseph P; Baehner, Frederick L; Baker, Joffre; Cronin, Maureen T; Watson, Drew; Shak, Steven; Bohn, Olga L; Fumagalli, Debora; Taniyama, Yusuke; Lee, Ahwon; Reilly, Megan L; Vogel, Victor G; McCaskill-Stevens, Worta; Ford, Leslie G; Geyer, Charles E; Wickerham, D Lawrence; Wolmark, Norman; Paik, Soonmyung

2011-11-01

Several mechanisms have been proposed to explain tamoxifen resistance of estrogen receptor (ER) -positive tumors, but a clinically useful explanation for such resistance has not been described. Because the ER is the treatment target for tamoxifen, a linear association between ER expression levels and the degree of benefit from tamoxifen might be expected. However, such an association has never been demonstrated with conventional clinical ER assays, and the ER is currently used clinically as a dichotomous marker. We used gene expression profiling and ER protein assays to help elucidate molecular mechanism(s) responsible for tamoxifen resistance in breast tumors. We performed gene expression profiling of paraffin-embedded tumors from National Surgical Adjuvant Breast and Bowel Project (NSABP) trials that tested the worth of tamoxifen as an adjuvant systemic therapy (B-14) and as a preventive agent (P-1). This was a retrospective subset analysis based on available materials. In B-14, ESR1 was the strongest linear predictor of tamoxifen benefit among 16 genes examined, including PGR and ERBB2. On the basis of these data, we hypothesized that, in the P-1 trial, a lower level of ESR1 mRNA in the tamoxifen arm was the main difference between the two study arms. Only ESR1 was downregulated by more than two-fold in ER-positive cancer events in the tamoxifen arm (P < .001). Tamoxifen did not prevent ER-positive tumors with low levels of ESR1 expression. These data suggest that low-level expression of ESR1 is a determinant of tamoxifen resistance in ER-positive breast cancer. Strategies should be developed to identify, treat, and prevent such tumors.

Adjuvant tamoxifen influences the lipid profile in breast cancer patients.

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Lin, Che; Chen, Li-Sheng; Kuo, Shou-Jen; Chen, Dar-Ren

2014-02-01

Currently there is a debate regarding whether tamoxifen used in breast cancer has an impact on lipid profiles. The aim of this study was to determine whether tamoxifen has an impact on the serum lipid profile in Taiwanese women. Data of 109 patients were collected from the routine clinical follow-up for women with hormone receptor-positive breast cancer who were treated between July 2005 and March 2008. These patients were divided into 2 subgroups, based on their tumor grade and lymph node status. Subgroup 1 patients had tumor grade I/II and a negative lymph node status. Those patients with tumor grade III or a positive lymph node status were defined as subgroup 2. In the 109 patients, the mean serum total cholesterol (TC) levels after tamoxifen treatment, as well as the serum low-density lipoprotein cholesterol (LDL-C) levels, were lower than the baseline levels, with statistically significant differences. Treatment with tamoxifen lowered the serum TC and LDL-C levels in both subgroups. The results indicate that tamoxifen has an impact on the serum lipid profile of breast cancer patients in Taiwan. Physicians should follow up the lipid profile in these patients.

Tamoxifen treatment and gynecologic side effects : A review

NARCIS (Netherlands)

Mourits, MJE; De Vries, EGE; Willemse, PHB; Ten Hoor, KA; Hollema, H; Van der Zee, AGJ

Objective: To review the literature on tamoxifen side effects on the female genital tract and psychosexual function in premenopausal and postmenopausal women. Data Sources: We used the English-language literature in MEDLINE and reference lists from selected articles. Search terms included:

Estrogen Receptor (ESR1) mRNA Expression and Benefit From Tamoxifen in the Treatment and Prevention of Estrogen Receptor–Positive Breast Cancer

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Kim, Chungyeul; Tang, Gong; Pogue-Geile, Katherine L.; Costantino, Joseph P.; Baehner, Frederick L.; Baker, Joffre; Cronin, Maureen T.; Watson, Drew; Shak, Steven; Bohn, Olga L.; Fumagalli, Debora; Taniyama, Yusuke; Lee, Ahwon; Reilly, Megan L.; Vogel, Victor G.; McCaskill-Stevens, Worta; Ford, Leslie G.; Geyer, Charles E.; Wickerham, D. Lawrence; Wolmark, Norman; Paik, Soonmyung

2011-01-01

Purpose Several mechanisms have been proposed to explain tamoxifen resistance of estrogen receptor (ER) –positive tumors, but a clinically useful explanation for such resistance has not been described. Because the ER is the treatment target for tamoxifen, a linear association between ER expression levels and the degree of benefit from tamoxifen might be expected. However, such an association has never been demonstrated with conventional clinical ER assays, and the ER is currently used clinically as a dichotomous marker. We used gene expression profiling and ER protein assays to help elucidate molecular mechanism(s) responsible for tamoxifen resistance in breast tumors. Patients and Methods We performed gene expression profiling of paraffin-embedded tumors from National Surgical Adjuvant Breast and Bowel Project (NSABP) trials that tested the worth of tamoxifen as an adjuvant systemic therapy (B-14) and as a preventive agent (P-1). This was a retrospective subset analysis based on available materials. Results In B-14, ESR1 was the strongest linear predictor of tamoxifen benefit among 16 genes examined, including PGR and ERBB2. On the basis of these data, we hypothesized that, in the P-1 trial, a lower level of ESR1 mRNA in the tamoxifen arm was the main difference between the two study arms. Only ESR1 was downregulated by more than two-fold in ER-positive cancer events in the tamoxifen arm (P < .001). Tamoxifen did not prevent ER-positive tumors with low levels of ESR1 expression. Conclusion These data suggest that low-level expression of ESR1 is a determinant of tamoxifen resistance in ER-positive breast cancer. Strategies should be developed to identify, treat, and prevent such tumors. PMID:21947828

Gene expression profiling identifies FYN as an important molecule in tamoxifen resistance and a predictor of early recurrence in patients treated with endocrine therapy

DEFF Research Database (Denmark)

Elias, D; (Hansen) Vever, Henriette; Lænkholm, A-V

2015-01-01

To elucidate the molecular mechanisms of tamoxifen resistance in breast cancer, we performed gene array analyses and identified 366 genes with altered expression in four unique tamoxifen-resistant (TamR) cell lines vs the parental tamoxifen-sensitive MCF-7/S0.5 cell line. Most of these genes were...

Paradoxical action of fulvestrant in estradiol-induced regression of tamoxifen-stimulated breast cancer.

Science.gov (United States)

Osipo, Clodia; Gajdos, Csaba; Liu, Hong; Chen, Bin; Jordan, V Craig

2003-11-05

Long-term tamoxifen treatment of breast cancer can result in tamoxifen-stimulated breast cancer, in which estrogen inhibits tumor growth after tamoxifen withdrawal. We investigated the molecular mechanism(s) of estradiol-induced tumor regression by using an in vivo model of tamoxifen-stimulated human breast cancer. Growth of parental estradiol-stimulated MCF-7E2 and long-term tamoxifen-stimulated MCF-7TAMLT xenografts in athymic mice was measured during treatment with vehicle, estradiol, estradiol plus tamoxifen, tamoxifen alone, estradiol plus fulvestrant, or fulvestrant alone. Apoptosis was detected by the terminal deoxynucleotidyltransferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. Protein expression was assessed by western blot analysis. mRNA expression was assessed by real-time reverse transcription-polymerase chain reaction. All statistical tests were two-sided. MCF-7E2 tumor growth was stimulated by estradiol (cross-sectional area at week 13 = 1.06 cm2, 95% confidence interval [CI] = 0.82 to 1.30 cm2; Pestradiol-induced regression to 0.18 cm2 (95% CI = 0.15 to 0.21 cm2; P<.001), and tamoxifen or estradiol plus fulvestrant enhanced tumor growth to 1.00 cm2 (95% CI = 0.88 to 1.22 cm2). Estradiol increased the number of apoptotic cells in tumors by 23% (95% CI = 20% to 26%; P<.001) compared with all other treatments, decreased estrogen receptor alpha(ERalpha) protein expression, increased the expression of Fas mRNA and protein, decreased the expression of HER2/neu mRNA and protein and nuclear factor kappaB (NF-kappaB) protein but did not affect Fas ligand protein expression compared with control. Paradoxically, fulvestrant reversed this effect and stimulated MCF-7TAMLT tumor growth apparently through ERalpha-mediated regulation of Fas, HER2/neu, and NF-kappaB. Physiologic levels of estradiol induced regression of tamoxifen-stimulated breast cancer tumors, apparently by inducing the death receptor Fas and suppressing the antiapoptotic

The effect of tamoxifen on pubertal bone development in adolescents with pubertal gynecomastia.

Science.gov (United States)

Akgül, Sinem; Derman, Orhan; Kanbur, Nuray

2016-01-01

During puberty, estrogen has a biphasic effect on epiphyses; at low levels, it leads to an increase in height and bone mass, whereas at high levels, it leads to closure of the epiphysis. Tamoxifen is a selective estrogen receptor modulator that has been used in the treatment of pubertal gynecomastia. Although it has not been approved for this indication, studies have shown it to be both successful and safe. In males, the peak of pubertal bone development occurs during Tanner stage 3-4, which is also when pubertal gynecomastia reaches its highest prevalence. Thus tamoxifen treatment could potentially effect pubertal bone development. The aim of this study was to assess the effects of tamoxifen on bone mineral density (BMD) and skeletal maturation when used for pubertal gynecomastia. We evaluated 20 boys with pubertal gynecomastia receiving tamoxifen for at least 4 months. BMD was measured with dual-energy X-ray absorptiometry. Z-score and absolute BMD (g/cm(2)) was determined at baseline and 2 months after completing tamoxifen treatment. Bone age and height was evaluated before treatment and again one year later. Using absolute BMD (g/cm(2)), the mean difference from baseline was significant between the two groups both at spine (p=0.002) and femur (p=0.001), but not with the Z-score. This result was attributed to the expected increase during puberty according to sex and age. No significant effect on skeletal maturation was found (p=1.112). We conclude that when pubertal bone development is concerned, tamoxifen is safe for the treatment of pubertal gynecomastia as neither bone mineralization nor growth potential was affected.

Functional screen for genes responsible for tamoxifen resistance in human breast cancer cells

NARCIS (Netherlands)

Meijer, Danielle; van Agthoven, Ton; Bosma, Peter T.; Nooter, Kees; Dorssers, Lambert C. J.

2006-01-01

Antiestrogens, such as tamoxifen, are widely used for endocrine treatment of estrogen receptor-positive breast cancer. However, as breast cancer progresses, development of tamoxifen resistance is inevitable. The mechanisms underlying this resistance are not well understood. To identify genes

The anticancer drug tamoxifen counteracts the pathology in a mouse model of duchenne muscular dystrophy.

Science.gov (United States)

Dorchies, Olivier M; Reutenauer-Patte, Julie; Dahmane, Elyes; Ismail, Heham M; Petermann, Olivier; Patthey- Vuadens, Ophélie; Comyn, Sophie A; Gayi, Elinam; Piacenza, Tony; Handa, Robert J; Décosterd, Laurent A; Ruegg, Urs T

2013-02-01

Duchenne muscular dystrophy (DMD) is a severe disorder characterized by progressive muscle wasting,respiratory and cardiac impairments, and premature death. No treatment exists so far, and the identification of active substances to fight DMD is urgently needed. We found that tamoxifen, a drug used to treat estrogen-dependent breast cancer, caused remarkable improvements of muscle force and of diaphragm and cardiac structure in the mdx(5Cv) mouse model of DMD. Oral tamoxifen treatment from 3 weeks of age for 15 months at a dose of 10 mg/kg/day stabilized myofiber membranes, normalized whole body force, and increased force production and resistance to repeated contractions of the triceps muscle above normal values. Tamoxifen improved the structure of leg muscles and diminished cardiac fibrosis by~ 50%. Tamoxifen also reduced fibrosis in the diaphragm, while increasing its thickness,myofiber count, and myofiber diameter, thereby augmenting by 72% the amount of contractile tissue available for respiratory function. Tamoxifen conferred a markedly slower phenotype to the muscles.Tamoxifen and its metabolites were present in nanomolar concentrations in plasma and muscles,suggesting signaling through high-affinity targets. Interestingly, the estrogen receptors ERa and ERb were several times more abundant in dystrophic than in normal muscles, and tamoxifen normalized the relative abundance of ERb isoforms. Our findings suggest that tamoxifen might be a useful therapy for DMD.

Metformin enhances tamoxifen-mediated tumor growth inhibition in ER-positive breast carcinoma

International Nuclear Information System (INIS)

Ma, Ji; Zhang, Jian; Liu, Wenchao; Guo, Yan; Chen, Suning; Zhong, Cuiping; Xue, Yan; Zhang, Yuan; Lai, Xiaofeng; Wei, Yifang; Yu, Shentong

2014-01-01

Tamoxifen, an endocrine therapy drug used to treat breast cancer, is designed to interrupt estrogen signaling by blocking the estrogen receptor (ER). However, many ER-positive patients are low reactive or resistant to tamoxifen. Metformin is a widely used anti-diabetic drug with noteworthy anti-cancer effects. We investigated whether metformin has the additive effects with tamoxifen in ER-positive breast cancer therapy. The efficacy of metformin alone and in combination with tamoxifen against ER-positive breast cancer was analyzed by cell survival, DNA replication activity, plate colony formation, soft-agar, flow cytometry, immunohistochemistry, and nude mice model assays. The involved signaling pathways were detected by western blot assay. When metformin was combined with tamoxifen, the concentration of tamoxifen required for growth inhibition was substantially reduced. Moreover, metformin enhanced tamoxifen-mediated inhibition of proliferation, DNA replication activity, colony formation, soft-agar colony formation, and induction of apoptosis in ER-positive breast cancer cells. In addition, these tamoxifen-induced effects that were enhanced by metformin may be involved in the bax/bcl-2 apoptotic pathway and the AMPK/mTOR/p70S6 growth pathway. Finally, two-drug combination therapy significantly inhibited tumor growth in vivo. The present work shows that metformin and tamoxifen additively inhibited the growth and augmented the apoptosis of ER-positive breast cancer cells. It provides leads for future research on this drug combination for the treatment of ER-positive breast cancer

Tamoxifen for women at high risk of breast cancer

OpenAIRE

Nazarali, Safia A; Narod, Steven A

2014-01-01

Safia A Nazarali, Steven A Narod Women's College Research Institute, Women's College Hospital, and The University of Toronto, Toronto, Ontario, Canada Abstract: Tamoxifen has been used as a treatment for women who have been diagnosed with breast cancer for roughly four decades and has been approved as chemoprevention for over ten years. Although tamoxifen has been proven to be beneficial in preventing breast cancer in high-risk women, its use has not been widely embraced. To ...

The anticancer drug tamoxifen is active against Trypanosoma cruzi in vitro but ineffective in the treatment of the acute phase of Chagas disease in mice

Directory of Open Access Journals (Sweden)

Danilo Ciccone Miguel

2010-11-01

Full Text Available The activity of the antineoplastic drug tamoxifen was evaluated against Trypanosoma cruzi. In vitro activity was determined against epimastigote, trypomastigote and amastigote forms of CL14, Y and Y benznidazole resistant T. cruzi strains. Regardless of the strain used, the drug was active against all life-cycle stages of the parasite with a half maximal effective concentration ranging from 0.7-17.9 µM. Two experimental models of acute Chagas disease were used to evaluate the in vivo efficacy of treatment with tamoxifen. No differences in parasitemia and mortality were observed between control mock-treated and tamoxifen-treated mice.

Radiolytic oxidation of tamoxifen using the free radicals .OH and (or) HO2

International Nuclear Information System (INIS)

Leguene, C.; Clavere, P.; Jore, D.; Gardes-Albert, M.

2001-01-01

Tamoxifen is the most widely used antiestrogen in the treatment of breast cancer. In this work, we have studied its antioxidant properties. We have investigated the ability of tamoxifen to scavenge, in vitro, . OH and (or) HO 2 . free radicals that are produced by water radiolysis. Aqueous solutions of tamoxifen of concentrations ranging between 10 -5 and 2.5 x 10 -5 M have been irradiated (γ 137 Cs) in aerated acidic medium (H 3 PO 4 10 -3 M or HCOOH 10 -1 M). The results show that tamoxifen reacts quantitatively with . OH free radicals but does not react with HO 2 . free radicals under our experimental conditions. (author)

Antiarrhythmic effect of tamoxifen on the vulnerability induced by hyperthyroidism to heart ischemia/reperfusion damage.

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Pavón, Natalia; Hernández-Esquivel, Luz; Buelna-Chontal, Mabel; Chávez, Edmundo

2014-09-01

Hyperthyroidism, known to have deleterious effects on heart function, and is associated with an enhanced metabolic state, implying an increased production of reactive oxygen species. Tamoxifen is a selective antagonist of estrogen receptors. These receptors make the hyperthyroid heart more susceptible to ischemia/reperfusion. Tamoxifen is also well-known as an antioxidant. The aim of the present study was to explore the possible protective effect of tamoxifen on heart function in hyperthyroid rats. Rats were injected daily with 3,5,3'-triiodothyronine at 2mg/kg body weight during 5 days to induce hyperthyroidism. One group was treated with 10mg/kg tamoxifen and another was not. The protective effect of the drug on heart rhythm was analyzed after 5 min of coronary occlusion followed by 5 min reperfusion. In hyperthyroid rats not treated with tamoxifen, ECG tracings showed post-reperfusion arrhythmias, and heart mitochondria isolated from the ventricular free wall lost the ability to accumulate and retain matrix Ca(2+) and to form a high electric gradient. Both of these adverse effects were avoided with tamoxifen treatment. Hyperthyroidism-induced oxidative stress caused inhibition of cis-aconitase and disruption of mitochondrial DNA, effects which were also avoided by tamoxifen treatment. The current results support the idea that tamoxifen inhibits the hypersensitivity of hyperthyroid rat myocardium to reperfusion damage, probably because its antioxidant activity inhibits the mitochondrial permeability transition. Copyright © 2014 Elsevier Ltd. All rights reserved.

Tamoxifen enhances erlotinib-induced cytotoxicity through down-regulating AKT-mediated thymidine phosphorylase expression in human non-small-cell lung cancer cells.

Science.gov (United States)

Ko, Jen-Chung; Chiu, Hsien-Chun; Syu, Jhan-Jhang; Jian, Yi-Jun; Chen, Chien-Yu; Jian, Yun-Ting; Huang, Yi-Jhen; Wo, Ting-Yu; Lin, Yun-Wei

2014-03-01

Tamoxifen is a triphenylethylene nonsteroidal estrogen receptor (ER) antagonist used worldwide as an adjuvant hormone therapeutic agent in the treatment of breast cancer. However, the molecular mechanism of tamoxifen-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. Thymidine phosphorylase (TP) is an enzyme of the pyrimidine salvage pathway which is upregulated in cancers. In this study, tamoxifen treatment inhibited cell survival in two NSCLC cells, H520 and H1975. Treatment with tamoxifen decreased TP mRNA and protein levels through AKT inactivation. Furthermore, expression of constitutively active AKT (AKT-CA) vectors significantly rescued the decreased TP protein and mRNA levels in tamoxifen-treated NSCLC cells. In contrast, combination treatment with PI3K inhibitors (LY294002 or wortmannin) and tamoxifen further decreased the TP expression and cell viability of NSCLC cells. Knocking down TP expression by transfection with small interfering RNA of TP enhanced the cytotoxicity and cell growth inhibition of tamoxifen. Erlotinib (Tarceva, OSI-774), an orally available small molecular inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase, is approved for clinical treatment of NSCLC. Compared to a single agent alone, tamoxifen combined with erlotinib resulted in cytotoxicity and cell growth inhibition synergistically in NSCLC cells, accompanied with reduced activation of phospho-AKT and phospho-ERK1/2, and reduced TP protein levels. These findings may have implications for the rational design of future drug regimens incorporating tamoxifen and erlotinib for the treatment of NSCLC. Copyright © 2014 Elsevier Inc. All rights reserved.

Tamoxifen attenuates development of lithium-induced nephrogenic diabetes insipidus in rats

DEFF Research Database (Denmark)

Tingskov, Stine Julie; Hu, Shan; Frøkiær, Jorgen

2018-01-01

of aquaporin-2 (AQP2), which are essential for water reabsorption of tubular fluid in the collecting duct. Sex hormones have previously been shown to affect the regulation of AQP2, so we tested whether tamoxifen (TAM), a selective estrogen receptor modulator, would attenuate lithium-induced alterations...... on renal water homeostasis. Rats were treated for 14 days with lithium and TAM treatment was initiated one week after onset of lithium administration. Lithium treatment resulted in severe polyuria and reduced AQP2 expression, which was ameliorated by TAM. Consistent with this, TAM attenuated downregulation...... of AQP2 and increased phosphorylation of the cAMP responsive element binding protein (CREB), which induced AQP2 expression, in freshly isolated inner medullary collecting duct suspension prepared from lithium-treated rats. In conclusion, TAM attenuated dose-dependently polyuria, impaired urine...

The anticancer estrogen receptor antagonist tamoxifen impairs consolidation of inhibitory avoidance memory through estrogen receptor alpha.

Science.gov (United States)

Lichtenfels, Martina; Dornelles, Arethuza da Silva; Petry, Fernanda Dos Santos; Blank, Martina; de Farias, Caroline Brunetto; Roesler, Rafael; Schwartsmann, Gilberto

2017-11-01

Over two-thirds of women with breast cancer have positive tumors for hormone receptors, and these patients undergo treatment with endocrine therapy, tamoxifen being the most widely used agent. Despite being very effective in breast cancer treatment, tamoxifen is associated with side effects that include cognitive impairments. However, the specific aspects and mechanisms underlying these impairments remain to be characterized. Here, we have investigated the effects of tamoxifen and interaction with estrogen receptors on formation of memory for inhibitory avoidance conditioning in female rats. In the first experiment, Wistar female rats received a single oral dose of tamoxifen (1, 3, or 10 mg/kg) or saline by gavage immediately after training and were tested for memory consolidation 24 h after training. In the second experiment, rats received a single dose of 1 mg/kg tamoxifen or saline by gavage 3 h after training and were tested 24 h after training for memory consolidation. In the third experiment, rats received a subcutaneous injection with estrogen receptor α agonist or estrogen receptor beta agonist 30 min before the training. After training, rats received a single oral dose of tamoxifen 1 mg/kg or saline and were tested 24 h after training. In the fourth experiment, rats were trained and tested 24 h later. Immediately after test, rats received a single dose of tamoxifen (1 mg/kg) or saline by gavage and were given four additional daily test trials followed by a re-instatement. Tamoxifen at 1 mg/kg impaired memory consolidation when given immediately after training and the estrogen receptor alpha agonist improved the tamoxifen-related memory impairment. Moreover, tamoxifen impairs memory consolidation of the test. These findings indicate that estrogen receptors regulate the early phase of memory consolidation and the effects of tamoxifen on memory consolidation.

Differential effect of EGFR inhibitors on tamoxifen-resistant breast cancer cells.

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Kim, Sangmin; Lee, Jeongmin; Oh, Soo Jin; Nam, Seok Jin; Lee, Jeong Eon

2015-09-01

Although tamoxifen is the most common and effective therapy for treatment of estrogen receptor-α (ER-α) breast cancer patients, resistance of endocrine therapy occurs, either de novo or acquired during therapy. Here, we investigated the clinical value of epidermal growth factor receptor (EGFR) in tamoxifen-resistant (TamR) patients and the differential effect of EGFR inhibitors, neratinib and gefitinib, on TamR breast cancer cell model. The morphology of TamR MCF7 cells showed mesenchymal phenotypes and did not induce cell death by tamoxifen treatment compared with tamoxifen‑sensitive (TamS) MCF7 cells. In addition, mesenchymal marker proteins, including N-cadherin (N-cad), fibronectin (FN), and Slug, significantly increased in TamR cells. In contrast, ER-α and E-cadherin (E-cad) were greatly decreased. We also found that the levels of EGFR and HER2 expression were increased in TamR cells. Furthermore, we observed that EGFR expression was directly involved with poor prognosis of tamoxifen-treated breast cancer patients using the GSE1378 date set. Thus, we treated TamR and TamS cells with EGFR inhibitors, neratinib and gefitinib, respectively. Interestingly, neratinib induced apoptotic cell death of TamR but not gefitinib. Cleaved PARP-1 expression was also increased by neratinib treatment in TamR cells. Therefore, we suggest that neratinib may be a potential therapeutic drug for treating TamR breast cancer.

Tumor specific HMG-CoA reductase expression in primary pre-menopausal breast cancer predicts response to tamoxifen

LENUS (Irish Health Repository)

Brennan, Donal J

2011-01-31

Abstract Introduction We previously reported an association between tumor-specific 3-hydroxy-3-methylglutharyl-coenzyme A reductase (HMG-CoAR) expression and a good prognosis in breast cancer. Here, the predictive value of HMG-CoAR expression in relation to tamoxifen response was examined. Methods HMG-CoAR protein and RNA expression was analyzed in a cell line model of tamoxifen resistance using western blotting and PCR. HMG-CoAR mRNA expression was examined in 155 tamoxifen-treated breast tumors obtained from a previously published gene expression study (Cohort I). HMG-CoAR protein expression was examined in 422 stage II premenopausal breast cancer patients, who had previously participated in a randomized control trial comparing 2 years of tamoxifen with no systemic adjuvant treatment (Cohort II). Kaplan-Meier analysis and Cox proportional hazards modeling were used to estimate the risk of recurrence-free survival (RFS) and the effect of HMG-CoAR expression on tamoxifen response. Results HMG-CoAR protein and RNA expression were decreased in tamoxifen-resistant MCF7-LCC9 cells compared with their tamoxifen-sensitive parental cell line. HMG-CoAR mRNA expression was decreased in tumors that recurred following tamoxifen treatment (P < 0.001) and was an independent predictor of RFS in Cohort I (hazard ratio = 0.63, P = 0.009). In Cohort II, adjuvant tamoxifen increased RFS in HMG-CoAR-positive tumors (P = 0.008). Multivariate Cox regression analysis demonstrated that HMG-CoAR was an independent predictor of improved RFS in Cohort II (hazard ratio = 0.67, P = 0.010), and subset analysis revealed that this was maintained in estrogen receptor (ER)-positive patients (hazard ratio = 0.65, P = 0.029). Multivariate interaction analysis demonstrated a difference in tamoxifen efficacy relative to HMG-CoAR expression (P = 0.05). Analysis of tamoxifen response revealed that patients with ER-positive\\/HMG-CoAR tumors had a significant response to tamoxifen (P = 0.010) as well as

Inhibition of herpes simplex virus type 1 entry by chloride channel inhibitors tamoxifen and NPPB

Energy Technology Data Exchange (ETDEWEB)

Zheng, Kai [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); College of Life Science and Technology, Jinan University, Guangzhou (China); Chen, Maoyun [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); College of pharmacy, Jinan University, Guangzhou (China); Xiang, Yangfei; Ma, Kaiqi [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); Jin, Fujun [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); College of pharmacy, Jinan University, Guangzhou (China); Wang, Xiao [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China); Wang, Xiaoyan; Wang, Shaoxiang [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China); Wang, Yifei, E-mail: twang-yf@163.com [Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou (China)

2014-04-18

Highlights: • We analyze the anti-HSV potential of chloride channel inhibitors. • Tamoxifen and NPPB show anti-HSV-1 and anti-ACV-resistant HSV-1 activities. • HSV-1 infection induces intracellular chloride concentration increasing. • Tamoxifen and NPPB inhibit HSV-1 early infection. • Tamoxifen and NPPB prevent the fusion process of HSV-1. - Abstract: Herpes simplex virus type 1 (HSV-1) infection is very common worldwide and can cause significant health problems from periodic skin and corneal lesions to encephalitis. Appearance of drug-resistant viruses in clinical therapy has made exploring novel antiviral agents emergent. Here we show that chloride channel inhibitors, including tamoxifen and 5-nitro-2-(3-phenyl-propylamino) benzoic acid (NPPB), exhibited extensive antiviral activities toward HSV-1 and ACV-resistant HSV viruses. HSV-1 infection induced chloride ion influx while treatment with inhibitors reduced the increase of intracellular chloride ion concentration. Pretreatment or treatment of inhibitors at different time points during HSV-1 infection all suppressed viral RNA synthesis, protein expression and virus production. More detailed studies demonstrated that tamoxifen and NPPB acted as potent inhibitors of HSV-1 early entry step by preventing viral binding, penetration and nuclear translocation. Specifically the compounds appeared to affect viral fusion process by inhibiting virus binding to lipid rafts and interrupting calcium homeostasis. Taken together, the observation that tamoxifen and NPPB can block viral entry suggests a stronger potential for these compounds as well as other ion channel inhibitors in antiviral therapy against HSV-1, especially the compound tamoxifen is an immediately actionable drug that can be reused for treatment of HSV-1 infections.

Inhibition of herpes simplex virus type 1 entry by chloride channel inhibitors tamoxifen and NPPB

International Nuclear Information System (INIS)

Zheng, Kai; Chen, Maoyun; Xiang, Yangfei; Ma, Kaiqi; Jin, Fujun; Wang, Xiao; Wang, Xiaoyan; Wang, Shaoxiang; Wang, Yifei

2014-01-01

Highlights: • We analyze the anti-HSV potential of chloride channel inhibitors. • Tamoxifen and NPPB show anti-HSV-1 and anti-ACV-resistant HSV-1 activities. • HSV-1 infection induces intracellular chloride concentration increasing. • Tamoxifen and NPPB inhibit HSV-1 early infection. • Tamoxifen and NPPB prevent the fusion process of HSV-1. - Abstract: Herpes simplex virus type 1 (HSV-1) infection is very common worldwide and can cause significant health problems from periodic skin and corneal lesions to encephalitis. Appearance of drug-resistant viruses in clinical therapy has made exploring novel antiviral agents emergent. Here we show that chloride channel inhibitors, including tamoxifen and 5-nitro-2-(3-phenyl-propylamino) benzoic acid (NPPB), exhibited extensive antiviral activities toward HSV-1 and ACV-resistant HSV viruses. HSV-1 infection induced chloride ion influx while treatment with inhibitors reduced the increase of intracellular chloride ion concentration. Pretreatment or treatment of inhibitors at different time points during HSV-1 infection all suppressed viral RNA synthesis, protein expression and virus production. More detailed studies demonstrated that tamoxifen and NPPB acted as potent inhibitors of HSV-1 early entry step by preventing viral binding, penetration and nuclear translocation. Specifically the compounds appeared to affect viral fusion process by inhibiting virus binding to lipid rafts and interrupting calcium homeostasis. Taken together, the observation that tamoxifen and NPPB can block viral entry suggests a stronger potential for these compounds as well as other ion channel inhibitors in antiviral therapy against HSV-1, especially the compound tamoxifen is an immediately actionable drug that can be reused for treatment of HSV-1 infections

CYP2D6 polymorphisms may predict occurrence of adverse effects to tamoxifen: a preliminary retrospective study

Directory of Open Access Journals (Sweden)

Wickramage I

2017-03-01

Full Text Available Ishani Wickramage,1 Kamani Hemamala Tennekoon,1 Merenchi Arachchige Yasantha Ariyaratne,2 Asanka Sudeshini Hewage,1 Tharmini Sundralingam,1 1Institute of Biochemistry, Molecular Biology and Biotechnology (IBMBB, University of Colombo, Colombo, Sri Lanka; 2National Cancer Institute, Maharagama, Sri Lanka Introduction and aims: Tamoxifen is an adjuvant drug effective in treating hormone ­receptor – positive breast cancer. However, 30%–50% of patients relapse and many develop adverse effects, such as hot flashes and fatty liver. Allelic variations altering the activity of cytochrome P450-2D6 enzyme affect response to tamoxifen by modulating metabolism of tamoxifen into its pharmacologically active metabolite endoxifen. Although association between CYP2D6 polymorphisms and recurrence of breast cancer in patients on tamoxifen had been reported, little evidence exists on association between these polymorphisms and adverse effects to tamoxifen. This study explored the association between CYP2D6 polymorphisms and tamoxifen effects, hitherto not studied in Sri Lanka. Methods: A retrospective preliminary study was carried out on 24 breast cancer patients on tamoxifen for minimally 3 months attending National Cancer Institute, Maharagama, Sri Lanka. They were not on CYP2D6-inhibiting drugs, chemotherapy or other endocrine therapy, and had no conditions that could occur as adverse effects to tamoxifen before starting the therapy. Their blood samples were collected, DNA was extracted and genotyped using SNaPshot Multiplex sequencing based single-nucleotide polymorphism (SNP assay. Results: SNP/allele frequencies detected: 1846G>A (confirmatory of *4 null allele=8.3%; 2549delA (confirmatory of *3 null allele=50%; 100C>T (suggestive of *10 reduced functional allele, in addition to other alleles=0%; combination of 2988G>A, -1584C and 2850C>T (strongly suggestive of *41 or other reduced functional allele=4.8%. Occurrence of heterozygous 2988G>A SNP with

Radiolytic oxidation of tamoxifen using the free radicals {sup .}OH and (or) HO{sub 2}{sup .}; Oxydation radiolytique du tamoxifene par les radicaux libres {sup .}OH et (ou) HO{sub 2}{sup .}

Energy Technology Data Exchange (ETDEWEB)

Leguene, C. [Lab. de Chimie-Physique, Centre national de la recherche scientifique, CNRS, Univ. Rene Descartes, Paris (France); Clavere, P. [Service de Radiotherapie et d' Oncologie, Centre hospitalier universitaire, CHU, Dupuytren, Limoges (France); Jore, D.; Gardes-Albert, M. [Lab. de Chimie-Physique, Centre national de la recherche scientifique, CNRS, Univ. Rene Descartes, Paris (France)

2001-02-01

Tamoxifen is the most widely used antiestrogen in the treatment of breast cancer. In this work, we have studied its antioxidant properties. We have investigated the ability of tamoxifen to scavenge, in vitro, {sup .}OH and (or) HO{sub 2}{sup .} free radicals that are produced by water radiolysis. Aqueous solutions of tamoxifen of concentrations ranging between 10{sup -5} and 2.5 x 10{sup -5} M have been irradiated ({gamma} {sup 137}Cs) in aerated acidic medium (H{sub 3}PO{sub 4} 10{sup -3} M or HCOOH 10{sup -1} M). The results show that tamoxifen reacts quantitatively with {sup .}OH free radicals but does not react with HO{sub 2}{sup .} free radicals under our experimental conditions. (author)

Bioanalytical methods for determination of tamoxifen and its phase I metabolites: A review

International Nuclear Information System (INIS)

Teunissen, S.F.; Rosing, H.; Schinkel, A.H.; Schellens, J.H.M.; Beijnen, J.H.

2010-01-01

The selective estrogen receptor modulator tamoxifen is used in the treatment of early and advanced breast cancer and in selected cases for breast cancer prevention in high-risk subjects. The cytochrome P450 enzyme system and flavin-containing monooxygenase are responsible for the extensive metabolism of tamoxifen into several phase I metabolites that vary in toxicity and potencies towards estrogen receptor (ER) alpha and ER beta. An extensive overview of publications on the determination of tamoxifen and its phase I metabolites in biological samples is presented. In these publications techniques were used such as capillary electrophoresis, liquid, gas and thin layer chromatography coupled with various detection techniques (mass spectrometry, ultraviolet or fluorescence detection, liquid scintillation counting and nuclear magnetic resonance spectroscopy). A trend is seen towards the use of liquid chromatography coupled to mass spectrometry (LC-MS). State-of-the-art LC-MS equipment allowed for identification of unknown metabolites and quantification of known metabolites reaching lower limit of quantification levels in the sub pg mL -1 range. Although tamoxifen is also metabolized into phase II metabolites, the number of publications reporting on phase II metabolism of tamoxifen is scarce. Therefore the focus of this review is on phase I metabolites of tamoxifen. We conclude that in the past decades tamoxifen metabolism has been studied extensively and numerous metabolites have been identified. Assays have been developed for both the identification and quantification of tamoxifen and its metabolites in an array of biological samples. This review can be used as a resource for method transfer and development of analytical methods used to support pharmacokinetic and pharmacodynamic studies of tamoxifen and its phase I metabolites.

Tamoxifen-Containing Eye Drops Successfully Trigger Cre-Mediated Recombination in the Entire Eye.

Science.gov (United States)

Schlecht, Anja; Leimbeck, Sarah V; Tamm, Ernst R; Braunger, Barbara M

2016-01-01

Embryonic lethality in mice with targeted gene deletion is a major issue that can be circumvented by using Cre-loxP-based animal models. Various inducible Cre systems are available, e.g. such that are activated following tamoxifen treatment, and allow deletion of a specific target gene at any desired time point during the life span of the animal. In this study, we describe the efficiency of topical tamoxifen administration by eye drops using a Cre- reporter mouse strain (R26R). We report that tamoxifen-responsive CAGGCre-ER (TM) mice show a robust Cre- mediated recombination throughout the entire eye.

CB1 and CB2 receptors are novel molecular targets for Tamoxifen and 4OH-Tamoxifen

International Nuclear Information System (INIS)

Prather, Paul L.; FrancisDevaraj, FeAna; Dates, Centdrika R.; Greer, Aleksandra K.; Bratton, Stacie M.; Ford, Benjamin M.; Franks, Lirit N.; Radominska-Pandya, Anna

2013-01-01

Highlights: •Tamoxifen produces cytotoxicity via estrogen-receptor (ER) independent mechanisms. •Tamoxifen binds to CB1 and CB2 cannabinoid receptors and acts as an inverse agonist. •CB1 and CB2 receptors are novel molecular targets for Tamoxifen. •ER-independent effects for Tamoxifen may be mediated via CB1 and/or CB2 receptors. -- Abstract: Tamoxifen (Tam) is classified as a selective estrogen receptor modulator (SERM) and is used for treatment of patients with ER-positive breast cancer. However, it has been shown that Tam and its cytochrome P450-generated metabolite 4-hydroxy-Tam (4OH-Tam) also exhibit cytotoxic effects in ER-negative breast cancer cells. These observations suggest that Tam and 4OH-Tam can produce cytotoxicity via estrogen receptor (ER)-independent mechanism(s) of action. The molecular targets responsible for the ER-independent effects of Tam and its derivatives are poorly understood. Interestingly, similar to Tam and 4OH-Tam, cannabinoids have also been shown to exhibit anti-proliferative and apoptotic effects in ER-negative breast cancer cells, and estrogen can regulate expression levels of cannabinoid receptors (CBRs). Therefore, this study investigated whether CBRs might serve as novel molecular targets for Tam and 4OH-Tam. We report that both compounds bind to CB1 and CB2Rs with moderate affinity (0.9–3 μM). Furthermore, Tam and 4OH-Tam exhibit inverse activity at CB1 and CB2Rs in membrane preparations, reducing basal G-protein activity. Tam and 4OH-Tam also act as CB1/CB2R-inverse agonists to regulate the downstream intracellular effector adenylyl cyclase in intact cells, producing concentration-dependent increases in intracellular cAMP. These results suggest that CBRs are molecular targets for Tam and 4OH-Tam and may contribute to the ER-independent cytotoxic effects reported for these drugs. Importantly, these findings also indicate that Tam and 4OH-Tam might be used as structural scaffolds for development of novel

CB1 and CB2 receptors are novel molecular targets for Tamoxifen and 4OH-Tamoxifen

Energy Technology Data Exchange (ETDEWEB)

Prather, Paul L. [Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR 72205 (United States); FrancisDevaraj, FeAna; Dates, Centdrika R.; Greer, Aleksandra K.; Bratton, Stacie M. [Department of Biochemistry and Molecular Biology, College of Medicine, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR 72205 (United States); Ford, Benjamin M.; Franks, Lirit N. [Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR 72205 (United States); Radominska-Pandya, Anna, E-mail: RadominskaAnna@uams.edu [Department of Biochemistry and Molecular Biology, College of Medicine, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR 72205 (United States)

2013-11-15

Highlights: •Tamoxifen produces cytotoxicity via estrogen-receptor (ER) independent mechanisms. •Tamoxifen binds to CB1 and CB2 cannabinoid receptors and acts as an inverse agonist. •CB1 and CB2 receptors are novel molecular targets for Tamoxifen. •ER-independent effects for Tamoxifen may be mediated via CB1 and/or CB2 receptors. -- Abstract: Tamoxifen (Tam) is classified as a selective estrogen receptor modulator (SERM) and is used for treatment of patients with ER-positive breast cancer. However, it has been shown that Tam and its cytochrome P450-generated metabolite 4-hydroxy-Tam (4OH-Tam) also exhibit cytotoxic effects in ER-negative breast cancer cells. These observations suggest that Tam and 4OH-Tam can produce cytotoxicity via estrogen receptor (ER)-independent mechanism(s) of action. The molecular targets responsible for the ER-independent effects of Tam and its derivatives are poorly understood. Interestingly, similar to Tam and 4OH-Tam, cannabinoids have also been shown to exhibit anti-proliferative and apoptotic effects in ER-negative breast cancer cells, and estrogen can regulate expression levels of cannabinoid receptors (CBRs). Therefore, this study investigated whether CBRs might serve as novel molecular targets for Tam and 4OH-Tam. We report that both compounds bind to CB1 and CB2Rs with moderate affinity (0.9–3 μM). Furthermore, Tam and 4OH-Tam exhibit inverse activity at CB1 and CB2Rs in membrane preparations, reducing basal G-protein activity. Tam and 4OH-Tam also act as CB1/CB2R-inverse agonists to regulate the downstream intracellular effector adenylyl cyclase in intact cells, producing concentration-dependent increases in intracellular cAMP. These results suggest that CBRs are molecular targets for Tam and 4OH-Tam and may contribute to the ER-independent cytotoxic effects reported for these drugs. Importantly, these findings also indicate that Tam and 4OH-Tam might be used as structural scaffolds for development of novel

The Working Memory and Dorsolateral Prefrontal-Hippocampal Functional Connectivity Changes in Long-Term Survival Breast Cancer Patients Treated with Tamoxifen

Science.gov (United States)

Chen, Xingui; Tao, Longxiang; Li, Jingjing; Wu, Jiaonan; Zhu, Chunyan; Yu, Fengqiong; Zhang, Lei; Zhang, Jingjie; Qiu, Bensheng; Yu, Yongqiang; He, Xiaoxuan

2017-01-01

Abstract Background: Tamoxifen is the most widely used drug for treating patients with estrogen receptor-sensitive breast cancer. There is evidence that breast cancer patients treated with tamoxifen exhibit cognitive dysfunction. However, the underlying neural mechanism remains unclear. The present study aimed to investigate the neural mechanisms underlying working memory deficits in combination with functional connectivity changes in premenopausal women with breast cancer who received long-term tamoxifen treatment. Methods: A total of 31 premenopausal women with breast cancer who received tamoxifen and 32 matched healthy control participants were included. The participants completed n-back tasks and underwent resting-state functional magnetic resonance imaging, which measure working memory performance and brain functional connectivity, respectively. A seed-based functional connectivity analysis within the whole brain was conducted, for which the dorsolateral prefrontal cortex was chosen as the seed region. Results: Our results indicated that the tamoxifen group had significant deficits in working memory and general executive function performance and significantly lower functional connectivity of the right dorsolateral prefrontal cortex with the right hippocampus compared with the healthy controls. There were no significant changes in functional connectivity in the left dorsolateral prefrontal cortex within the whole brain between the tamoxifen group and healthy controls. Moreover, significant correlations were found in the tamoxifen group between the functional connectivity strength of the dorsolateral prefrontal cortex with the right hippocampus and decreased working memory performance. Conclusion: This study demonstrates that the prefrontal cortex and hippocampus may be affected by tamoxifen treatment, supporting an antagonistic role of tamoxifen in the long-term treatment of breast cancer patients. PMID:28177081

Aspirin regulation of c-myc and cyclinD1 proteins to overcome tamoxifen resistance in estrogen receptor-positive breast cancer cells.

Science.gov (United States)

Cheng, Ran; Liu, Ya-Jing; Cui, Jun-Wei; Yang, Man; Liu, Xiao-Ling; Li, Peng; Wang, Zhan; Zhu, Li-Zhang; Lu, Si-Yi; Zou, Li; Wu, Xiao-Qin; Li, Yu-Xia; Zhou, You; Fang, Zheng-Yu; Wei, Wei

2017-05-02

Tamoxifen is still the most commonly used endocrine therapy drug for estrogen receptor (ER)-positive breast cancer patients and has an excellent outcome, but tamoxifen resistance remains a great impediment to successful treatment. Recent studies have prompted an anti-tumor effect of aspirin. Here, we demonstrated that aspirin not only inhibits the growth of ER-positive breast cancer cell line MCF-7, especially when combined with tamoxifen, but also has a potential function to overcome tamoxifen resistance in MCF-7/TAM. Aspirin combined with tamoxifen can down regulate cyclinD1 and block cell cycle in G0/G1 phase. Besides, tamoxifen alone represses c-myc, progesterone receptor (PR) and cyclinD1 in MCF-7 cell line but not in MCF-7/TAM, while aspirin combined with tamoxifen can inhibit the expression of these proteins in the resistant cell line. When knocking down c-myc in MCF-7/TAM, cells become more sensitive to tamoxifen, cell cycle is blocked as well, indicating that aspirin can regulate c-myc and cyclinD1 proteins to overcome tamoxifen resistance. Our study discovered a novel role of aspirin based on its anti-tumor effect, and put forward some kinds of possible mechanisms of tamoxifen resistance in ER-positive breast cancer cells, providing a new strategy for the treatment of ER-positive breast carcinoma.

Tamoxifen enhances stemness and promotes metastasis of ERα36+ breast cancer by upregulating ALDH1A1 in cancer cells

Science.gov (United States)

Wang, Qiang; Jiang, Jun; Ying, Guoguang; Xie, Xiao-Qing; Zhang, Xia; Xu, Wei; Zhang, Xuemin; Song, Erwei; Bu, Hong; Ping, Yi-Fang; Yao, Xiao-Hong; Wang, Bin; Xu, Shilei; Yan, Ze-Xuan; Tai, Yanhong; Hu, Baoquan; Qi, Xiaowei; Wang, Yan-Xia; He, Zhi-Cheng; Wang, Yan; Wang, Ji Ming; Cui, You-Hong; Chen, Feng; Meng, Kun; Wang, Zhaoyi; Bian, Xiu-Wu

2018-01-01

The 66 kDa estrogen receptor alpha (ERα66) is the main molecular target for endocrine therapy such as tamoxifen treatment. However, many patients develop resistance with unclear mechanisms. In a large cohort study of breast cancer patients who underwent surgery followed by tamoxifen treatment, we demonstrate that ERα36, a variant of ERα66, correlates with poor prognosis. Mechanistically, tamoxifen directly binds and activates ERα36 to enhance the stemness and metastasis of breast cancer cells via transcriptional stimulation of aldehyde dehydrogenase 1A1 (ALDH1A1). Consistently, the tamoxifen-induced stemness and metastasis can be attenuated by either ALDH1 inhibitors or a specific ERα36 antibody. Thus, tamoxifen acts as an agonist on ERα36 in breast cancer cells, which accounts for hormone therapy resistance and metastasis of breast cancer. Our study not only reveals ERα36 as a stratifying marker for endocrine therapy but also provides a promising therapeutic avenue for tamoxifen-resistant breast cancer. PMID:29393296

Fibroblast growth factor receptor 4 predicts failure on tamoxifen therapy in patients with recurrent breast cancer

NARCIS (Netherlands)

Meijer, Danielle; Sieuwerts, Anieta M.; Look, Maxime P.; van Agthoven, Ton; Foekens, John A.; Dorssers, Lambert C. J.

2008-01-01

Tamoxifen treatment of estrogen-dependent breast cancer ultimately loses its effectiveness due to the development of resistance. From a functional screen for identifying genes responsible for tamoxifen resistance in human ZR-75-1 breast cancer cells, fibroblast growth factor (FGF) 17 was recovered.

Genotype of metabolic enzymes and the benefit of tamoxifen in postmenopausal breast cancer patients

International Nuclear Information System (INIS)

Wegman, Pia; Vainikka, Linda; Stål, Olle; Nordenskjöld, Bo; Skoog, Lambert; Rutqvist, Lars-Erik; Wingren, Sten

2005-01-01

Tamoxifen is widely used as endocrine therapy for oestrogen-receptor-positive breast cancer. However, many of these patients experience recurrence despite tamoxifen therapy by incompletely understood mechanisms. In the present report we propose that tamoxifen resistance may be due to differences in activity of metabolic enzymes as a result of genetic polymorphism. Cytochrome P450 2D6 (CYP2D6) and sulfotransferase 1A1 (SULT1A1) are polymorphic and are involved in the metabolism of tamoxifen. The CYP2D6*4 and SULT1A1*2 genotypes result in decreased enzyme activity. We therefore investigated the genotypes of CYP2D6 and SULT1A1 in 226 breast cancer patients participating in a trial of adjuvant tamoxifen treatment in order to validate the benefit from the therapy. The patients were genotyped using PCR followed by cleavage with restriction enzymes. Carriers of the CYP2D6*4 allele demonstrated a decreased risk of recurrence when treated with tamoxifen (relative risk = 0.28, 95% confidence interval = 0.11–0.74, P = 0.0089). A similar pattern was seen among the SULT1A1*1 homozygotes (relative risk = 0.48, 95% confidence interval = 0.21–1.12, P = 0.074). The combination of CYP2D6*4 and/or SULT1A1*1/*1 genotypes comprised 60% of the patients and showed a 62% decreased risk of distant recurrence with tamoxifen (relative risk = 0.38, 95% confidence interval = 0.19–0.74, P = 0.0041). The present study suggests that genotype of metabolic enzymes might be useful as a guide for adjuvant endocrine treatment of postmenopausal breast cancer patients. However, results are in contradiction to prior hypotheses and the present sample size is relatively small. Findings therefore need to be confirmed in a larger cohort

Tamoxifen: an FDA approved drug with neuroprotective effects for spinal cord injury recovery

Directory of Open Access Journals (Sweden)

Jennifer M Colón

2016-01-01

Full Text Available Spinal cord injury (SCI is a condition without a cure, affecting sensory and/or motor functions. The physical trauma to the spinal cord initiates a cascade of molecular and cellular events that generates a non-permissive environment for cell survival and axonal regeneration. Among these complex set of events are damage of the blood-brain barrier, edema formation, inflammation, oxidative stress, demyelination, reactive gliosis and apoptosis. The multiple events activated after SCI require a multi-active drug that could target most of these events and produce a permissive environment for cell survival, regeneration, vascular reorganization and synaptic formation. Tamoxifen, a selective estrogen receptor modulator, is an FDA approved drug with several neuroprotective properties that should be considered for the treatment of this devastating condition. Various investigators using different animal models and injury parameters have demonstrated the beneficial effects of this drug to improve functional locomotor recovery after SCI. Results suggest that the mechanism of action of Tamoxifen administration is to modulate anti-oxidant, anti-inflammatory and anti-gliotic responses. A gap of knowledge exists regarding the sex differences in response to Tamoxifen and the therapeutic window available to administer this treatment. In addition, the effects of Tamoxifen in axonal outgrowth or synapse formation needs to be investigated. This review will address some of the mechanisms activated by Tamoxifen after SCI and the results recently published by investigators in the field.

Circadian and Melatonin Disruption by Exposure to Light at Night Drives Intrinsic Resistance to Tamoxifen Therapy in Breast Cancer

Science.gov (United States)

Dauchy, Robert T.; Xiang, Shulin; Mao, Lulu; Brimer, Samantha; Wren, Melissa A.; Yuan, Lin; Anbalagan, Muralidharan; Hauch, Adam; Frasch, Tripp; Rowan, Brian G.; Blask, David E.; Hill, Steven M.

2014-01-01

Resistance to endocrine therapy is a major impediment to successful treatment of breast cancer. Preclinical and clinical evidence links resistance to anti-estrogen drugs in breast cancer cells with the overexpression and/or activation of various pro-oncogenic tyrosine kinases. Disruption of circadian rhythms by night shift work or disturbed sleep-wake cycles may lead to an increased risk of breast cancer and other diseases. Moreover, light exposure at night (LEN) suppresses the nocturnal production of melatonin that inhibits breast cancer growth. In this study, we used a rat model of ERα+ MCF-7 tumor xenografts to demonstrate how altering light/dark cycles with dim LEN (dLEN) speeds the development of breast tumors, increasing their metabolism and growth and conferring an intrinsic resistance to tamoxifen therapy. These characters were not produced in animals where circadian rhythms were not disrupted, or in animals subjected to dLEN if they received nocturnal melatonin replacement. Strikingly, our results also showed that melatonin acted both as a tumor metabolic inhibitor and a circadian-regulated kinase inhibitor to re-establish the sensitivity of breast tumors to tamoxifen and tumor regression. Together, our findings show how dLEN-mediated disturbances in nocturnal melatonin production can render tumors insensitive to tamoxifen. PMID:25062775

Tamoxifen affects glucose and lipid metabolism parameters, causes browning of subcutaneous adipose tissue and transient body composition changes in C57BL/6NTac mice

International Nuclear Information System (INIS)

Hesselbarth, Nico; Pettinelli, Chiara; Gericke, Martin; Berger, Claudia; Kunath, Anne; Stumvoll, Michael; Blüher, Matthias; Klöting, Nora

2015-01-01

Tamoxifen is a selective estrogen receptor (ER) modulator which is widely used to generate inducible conditional transgenic mouse models. Activation of ER signaling plays an important role in the regulation of adipose tissue (AT) metabolism. We therefore tested the hypothesis that tamoxifen administration causes changes in AT biology in vivo. 12 weeks old male C57BL/6NTac mice were treated with either tamoxifen (n = 18) or vehicle (n = 18) for 5 consecutive days. Tamoxifen treatment effects on body composition, energy homeostasis, parameters of AT biology, glucose and lipid metabolism were investigated up to an age of 18 weeks. We found that tamoxifen treatment causes: I) significantly increased HbA 1c , triglyceride and free fatty acid serum concentrations (p < 0.01), II) browning of subcutaneous AT and increased UCP-1 expression, III) increased AT proliferation marker Ki67 mRNA expression, IV) changes in adipocyte size distribution, and V) transient body composition changes. Tamoxifen may induce changes in body composition, whole body glucose and lipid metabolism and has significant effects on AT biology, which need to be considered when using Tamoxifen as a tool to induce conditional transgenic mouse models. Our data further suggest that tamoxifen-treated wildtype mice should be characterized in parallel to experimental transgenic models to control for tamoxifen administration effects. - Highlights: • Tamoxifen treatment causes significantly increased HbA 1c , triglyceride and free fatty acid serum concentrations. • Tamoxifen induces browning of subcutaneous AT and increased UCP-1 expression. • Tamoxifen changes adipocyte size distribution, and transient body composition

Tamoxifen affects glucose and lipid metabolism parameters, causes browning of subcutaneous adipose tissue and transient body composition changes in C57BL/6NTac mice

Energy Technology Data Exchange (ETDEWEB)

Hesselbarth, Nico; Pettinelli, Chiara [Department of Medicine, University of Leipzig, D-04103 Leipzig (Germany); Gericke, Martin [Institute of Anatomy, University of Leipzig, D-04103 Leipzig (Germany); Berger, Claudia [IFB Adiposity Disease, Core Unit Animal Models, University of Leipzig, D-04103 Leipzig (Germany); Kunath, Anne [German Center for Diabetes Research (DZD), Leipzig (Germany); Stumvoll, Michael; Blüher, Matthias [Department of Medicine, University of Leipzig, D-04103 Leipzig (Germany); Klöting, Nora, E-mail: nora.kloeting@medizin.uni-leipzig.de [IFB Adiposity Disease, Core Unit Animal Models, University of Leipzig, D-04103 Leipzig (Germany)

2015-08-28

Tamoxifen is a selective estrogen receptor (ER) modulator which is widely used to generate inducible conditional transgenic mouse models. Activation of ER signaling plays an important role in the regulation of adipose tissue (AT) metabolism. We therefore tested the hypothesis that tamoxifen administration causes changes in AT biology in vivo. 12 weeks old male C57BL/6NTac mice were treated with either tamoxifen (n = 18) or vehicle (n = 18) for 5 consecutive days. Tamoxifen treatment effects on body composition, energy homeostasis, parameters of AT biology, glucose and lipid metabolism were investigated up to an age of 18 weeks. We found that tamoxifen treatment causes: I) significantly increased HbA{sub 1c}, triglyceride and free fatty acid serum concentrations (p < 0.01), II) browning of subcutaneous AT and increased UCP-1 expression, III) increased AT proliferation marker Ki67 mRNA expression, IV) changes in adipocyte size distribution, and V) transient body composition changes. Tamoxifen may induce changes in body composition, whole body glucose and lipid metabolism and has significant effects on AT biology, which need to be considered when using Tamoxifen as a tool to induce conditional transgenic mouse models. Our data further suggest that tamoxifen-treated wildtype mice should be characterized in parallel to experimental transgenic models to control for tamoxifen administration effects. - Highlights: • Tamoxifen treatment causes significantly increased HbA{sub 1c}, triglyceride and free fatty acid serum concentrations. • Tamoxifen induces browning of subcutaneous AT and increased UCP-1 expression. • Tamoxifen changes adipocyte size distribution, and transient body composition.

One year of adjuvant tamoxifen compared with chemotherapy and tamoxifen in postmenopausal patients with stage II breast cancer

DEFF Research Database (Denmark)

Ejlertsen, Bent; Jensen, Maj-Britt; Elversang, Johanna

2013-01-01

We report the long-term results of a randomised trial comparing tamoxifen with tamoxifen plus cyclophosphamide, methotrexate and fluorouracil (CMF) in postmenopausal high-risk breast cancer patients. In addition, we analyse the prognostic and predictive value of centrally assessed subtypes....

Role of RBP2-Induced ER and IGF1R-ErbB Signaling in Tamoxifen Resistance in Breast Cancer.

Science.gov (United States)

Choi, Hee-Joo; Joo, Hyeong-Seok; Won, Hee-Young; Min, Kyueng-Whan; Kim, Hyung-Yong; Son, Taekwon; Oh, Young-Ha; Lee, Jeong-Yeon; Kong, Gu

2018-04-01

Despite the benefit of endocrine therapy, acquired resistance during or after treatment still remains a major challenge in estrogen receptor (ER)-positive breast cancer. We investigated the potential role of histone demethylase retinoblastoma-binding protein 2 (RBP2) in endocrine therapy resistance of breast cancer. Survival of breast cancer patients according to RBP2 expression was analyzed in three different breast cancer cohorts including METABRIC (n = 1980) and KM plotter (n = 1764). RBP2-mediated tamoxifen resistance was confirmed by invitro sulforhodamine B (SRB) colorimetric, colony-forming assays, and invivo xenograft models (n = 8 per group). RNA-seq analysis and receptor tyrosine kinase assay were performed to identify the tamoxifen resistance mechanism by RBP2. All statistical tests were two-sided. RBP2 was associated with poor prognosis to tamoxifen therapy in ER-positive breast cancer (P = .04 in HYU cohort, P = .02 in KM plotter, P = .007 in METABRIC, log-rank test). Furthermore, RBP2 expression was elevated in patients with tamoxifen-resistant breast cancer (P = .04, chi-square test). Knockdown of RBP2 conferred tamoxifen sensitivity, whereas overexpression of RBP2 induced tamoxifen resistance invitro and invivo (MCF7 xenograft: tamoxifen-treated control, mean [SD] tumor volume = 70.8 [27.9] mm3, vs tamoxifen-treated RBP2, mean [SD] tumor volume = 387.9 [85.1] mm3, P < .001). Mechanistically, RBP2 cooperated with ER co-activators and corepressors and regulated several tamoxifen resistance-associated genes, including NRIP1, CCND1, and IGFBP4 and IGFBP5. Furthermore, epigenetic silencing of IGFBP4/5 by RBP2-ER-NRIP1-HDAC1 complex led to insulin-like growth factor-1 receptor (IGF1R) activation. RBP2 also increased IGF1R-ErbB crosstalk and subsequent PI3K-AKT activation via demethylase activity-independent ErbB protein stabilization. Combinational treatment with tamoxifen and PI3K inhibitor could overcome RBP2-mediated tamoxifen

The selective estrogen receptor modulators (SERMs) raloxifene and tamoxifen improve ANP levels and decrease nuclear translocation of NF-kB in estrogen-deficient rats.

Science.gov (United States)

Lamas, Aline Z; Nascimento, Andrews M; Medeiros, Ana Raquel S; Caliman, Izabela F; Dalpiaz, Polyana L M; Firmes, Luciana B; Sousa, Glauciene J; Oliveira, Phablo Wendell C; Andrade, Tadeu U; Reis, Adelina M; Gouvea, Sônia A; Bissoli, Nazaré S

2017-08-01

The selective estrogen receptor modulators (SERMs) raloxifene and tamoxifen are used for the treatment of osteoporosis and cancer, respectively, in women. The impairment of both the Atrial Natriuretic Peptide (ANP) cell signaling system and the translocation of nuclear factor-kappa B (NF-kB) to the cell nucleus are associated with detrimental cardiovascular effects and inflammation. The effects of SERMs on these parameters in the cardiac tissue of estrogen-deficient rats has not been reported. We investigated the effects of raloxifene and tamoxifen on ANP signaling, p65 NF-kB nuclear translocation, cardiac histology and contractility. Female rats were divided into five groups: control (SHAM), ovariectomized (OVX), OVX-treated 17-β-estradiol (E), OVX-treated raloxifene (RLX) and OVX-treated tamoxifen (TAM). The treatments started 21days after ovariectomy and continued for 14days. Ovariectomy reduced ANP mRNA in the left atrium (LA), decreased the content of ANP protein in the LA and in plasma, and increased the level of p65 NF-kB nuclear translocation in the left ventricle. Both 17-β-estradiol and SERMs were able to reverse these alterations, which were induced by the estrogen deficient state. The hemodynamic and cardiac structural parameters analyzed in the present work were not modified by the interventions. Our study demonstrates, for the first time, the additional benefits of raloxifene and tamoxifen in an estrogen-deficient state. These include the normalization of plasmatic and cardiac ANP levels and cardiac p65 NF-kB translocation. Therefore, these treatments promote cardiovascular protection and may contribute to the prevention of cardiac dysfunction observed long-term in postmenopausal women. Copyright © 2017. Published by Elsevier Urban & Partner Sp. z o.o.

Effect of tamoxifen on the coronary vascular reactivity of spontaneously hypertensive female rats

Directory of Open Access Journals (Sweden)

M.V. Borgo

2011-08-01

Full Text Available Tamoxifen has been associated with a reduction in the incidence of myocardial infarction. However, the effects of tamoxifen on coronary reactivity have not been fully elucidated. The objective of this study was to determine the effects of chronic treatment with tamoxifen on coronary vascular reactivity in spontaneously hypertensive rats (SHR. Female SHR were divided into four groups (N = 7 each: sham-operated (SHAM, sham-operated and treated with tamoxifen (10 mg/kg by gavage for 90 days (TAMOX, ovariectomized (OVX, and ovariectomized and treated with tamoxifen (OVX+TAMOX. Mean arterial pressure (MAP, heart rate (HR, coronary perfusion pressure (CPP, and coronary vascular reactivity were measured. MAP and HR were reduced (9.42 and 11.67%, respectively in the OVX+TAMOX group compared to the OVX group (P < 0.01. The coronary vascular reactivity of the OVX+TAMOX group presented smaller vasoconstrictor responses to acetylcholine (2-64 µg when compared to the OVX group (P < 0.01 and this response was similar to that of the SHAM group. The adenosine-induced vasodilator response was greater in the TAMOX group compared to the SHAM and OVX groups (P < 0.05. Baseline CPP was higher in OVX+TAMOX and TAMOX groups (136 ± 3.6 and 130 ± 1.5 mmHg than in OVX and SHAM groups (96 ± 2 and 119 ± 2.3 mmHg; P < 0.01. Tamoxifen, when combined with OVX, attenuated the vasoconstriction induced by acetylcholine and increased the adenosine-induced vasodilatory response, as well as reducing the MAP, suggesting beneficial effects of tamoxifen therapy on coronary vascular reactivity after menopause.

Tamoxifen with and without radiation after partial mastectomy in patients with involved nodes

Energy Technology Data Exchange (ETDEWEB)

Cooke, Andrew L; Perera, Francisco; Fisher, Barbara; Opeitum, Abiola; Yu, Norman

1995-02-15

Purpose: To determine the effect of tamoxifen on local control after partial mastectomy with and without adjuvant breast irradiation. Methods and Materials: A retrospective study of 97 node positive patients identified from the records of the London Regional Cancer Center included 44 patients who received tamoxifen and breast irradiation (40 or 50 Gy plus booster dose) after partial mastectomy, and 53 patients who received tamoxifen only after partial mastectomy. Base line characteristics of the two groups were similar. Results: At 39 months actuarial follow-up there was a breast tumor recurrence (BTR) in 5% vs. 21% of patients when radiation was omitted (p = 0.0388), but there was no difference in the cause-specific mortality of the two treatment groups. Cox Regression analysis (on only 10 BTR) showed age and adjuvant radiation as significant predictors of BTR. In patients not receiving radiation, no BTR was seen in 22 patients {>=}70 years of age at diagnosis vs. 8 BTR in 31 patients <70 years (p = 0.0130). All BTR occurred while patients were receiving tamoxifen. Conclusion: Tamoxifen alone with omission of radiation after partial mastectomy provides inferior breast tumor control in node positive patients. This is especially true for patients under 70 years of age. Patients aged 70 years or older at the time of diagnosis of breast cancer who receive tamoxifen have a low rate of breast tumor recurrence when radiation is omitted. These patients represent a group for whom radiation might not be necessary.

The effects of soy and tamoxifen on apoptosis in the hippocampus and dentate gyrus in a pentylenetetrazole-induced seizure model of ovariectomized rats.

Science.gov (United States)

Ebrahimzadeh-Bideskan, Ali Reza; Mansouri, Somaieh; Ataei, Mariam Lale; Jahanshahi, Mehrdad; Hosseini, Mahmoud

2018-03-01

The effects of tamoxifen and soy on apoptosis of the hippocampus and dentate gyrus of ovariectomized rats after repeated seizures were investigated. Female rats were divided into: (1) Control, (2) Sham, (3) Sham-Tamoxifen (Sham-T), (4) Ovariectomized (OVX), (5) OVX-Tamoxifen (OVX-T), (6)OVX-Soy(OVX-S) and (7) OVX-S-T. The animals in the OVX-S, OVX-T and OVX-S-T groups received soy extract (60 mg/kg; i.p.), tamoxifen (10 mg/kg) or both for 2 weeks before induction of seizures. The animals in these groups additionally received the mentioned treatments before each injection of pentylenetetrazole (PTZ; 40 mg/kg) for 6 days. The animals in the Sham and OVX groups received a vehicle of tamoxifen and soy. A significant decrease in the seizure score and TUNEL-positive neurons was seen in the OVX group compared to the Sham (P < 0.001). The animals in both the OVX-T and OVX-S groups had a significantly higher seizure score as well as number of TUNEL-positive neurons compared to the OVX group (P < 0.01-P < 0.001). Co-treatment of the OVX rats by the extract and tamoxifen decreased the seizure score and number of TUNEL-positive neurons compared to OVX-S (P < 0.001). Treatment of the OVX rats by either soy or tamoxifen increased the seizure score as well as the number of TUNEL-positive neurons in the hippocampal formation. Co-administration of tamoxifen and soy extract inhibited the effects of the soy extract and tamoxifen when they were administered alone. It might be suggested that both soy and tamoxifen have agonistic effects on estrogen receptors by changing the seizure severity.

Endocrine effects of adjuvant letrozole compared with tamoxifen in hormone-responsive postmenopausal patients with early breast cancer: the HOBOE trial.

Science.gov (United States)

Rossi, Emanuela; Morabito, Alessandro; Di Rella, Francesca; Esposito, Giuseppe; Gravina, Adriano; Labonia, Vincenzo; Landi, Gabriella; Nuzzo, Francesco; Pacilio, Carmen; De Maio, Ermelinda; Di Maio, Massimo; Piccirillo, Maria Carmela; De Feo, Gianfranco; D'Aiuto, Giuseppe; Botti, Gerardo; Chiodini, Paolo; Gallo, Ciro; Perrone, Francesco; de Matteis, Andrea

2009-07-01

PURPOSE We compared the endocrine effects of 6 and 12 months of adjuvant letrozole versus tamoxifen in postmenopausal patients with hormone-responsive early breast cancer within an ongoing phase III trial. PATIENTS AND METHODS Patients were randomly assigned to receive tamoxifen, letrozole, or letrozole plus zoledronic acid. Serum values of estradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, dehydroepiandrosterone-sulphate (DHEA-S), progesterone, and cortisol were measured at baseline and after 6 and 12 months of treatment. For each hormone, changes from baseline at 6 and 12 months were compared between treatment groups, and differences over time for each group were analyzed. Results Hormonal data were available for 139 postmenopausal patients with a median age of 62 years, with 43 patients assigned to tamoxifen and 96 patients assigned to letrozole alone or combined with zoledronic acid. Baseline values were similar between the two groups for all hormones. Many significant changes were observed between drugs and for each drug over time. Namely, three hormones seemed significantly affected by one drug only: estradiol that decreased and progesterone that increased with letrozole and cortisol that increased with tamoxifen. Both drugs affected FSH (decreasing with tamoxifen and slightly increasing with letrozole), LH (decreasing more with tamoxifen than with letrozole), testosterone (slightly increasing with letrozole but not enough to differ from tamoxifen), and DHEA-S (increasing with both drugs but not differently between them). Zoledronic acid did not have significant impact on hormonal levels. CONCLUSION Adjuvant letrozole and tamoxifen result in significantly distinct endocrine effects. Such differences can explain the higher efficacy of letrozole as compared with tamoxifen.

Analysis of the Ki-67 index in the vaginal epithelium of castrated rats treated with tamoxifen

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Afif Rieth Nery-Aguiar

2016-02-01

Full Text Available OBJECTIVES: Vaginal atrophy and breast cancer are common conditions in postmenopausal women and tamoxifen is the standard endocrine treatment for hormone-sensitive tumors. The present study aimed to assess the effect of tamoxifen on Ki-67 protein expression in the vaginal epithelium of castrated rats. MATERIAL AND METHODS: Forty Wistar-Hannover adult, virgin, castrated rats were randomly divided into two groups, group I (control, n=20 and group II (tamoxifen, n=20, receiving 0.5 ml of propylene glycol and 250 µg of tamoxifen diluted in 0.5 ml of propylene glycol, respectively, daily by gavage for 30 days. On the 31st day, the rats were euthanized and their vaginas were removed and fixed in 10% buffered formalin for the immunohistochemical study of Ki-67 protein expression. Data were analyzed by the Levene and Student’s t tests (p<0.05. RESULTS: The mean index of Ki-67 expression in the rat vagina of groups I and II was 4.04±0.96 and 26.86±2.19, respectively (p<0.001. CONCLUSIONS: According to the results of the present study, tamoxifen, at the dose and treatment length used, induced a significant increase in the cell proliferation of the vaginal mucosa in castrated rats, as evaluated by Ki-67 protein expression.

Incidence of new primary cancers after adjuvant tamoxifen therapy and radiotherapy for early breast cancer

International Nuclear Information System (INIS)

Andersson, M.; Storm, H.H.; Mouridsen, H.T.

1991-01-01

The incidence of new primary cancers was evaluated in 3538 postmenopausal patients who had received surgical treatment for primary breast cancer. Of these patients, 1828 with a low risk of recurrence received no further treatment. High-risk patients were randomly assigned to one of two groups. The first group (n = 846) received postoperative radiotherapy, while the second group (n = 864) received radiotherapy plus tamoxifen at a dose of 30 mg given daily for 48 weeks. The median observation time was 7.9 years. In comparison with the number of new cancers in the general population, the number of new cancers in the three groups was elevated mostly due to a high number of cancers of the contralateral breast and of colorectal cancers in the high-risk groups. The cumulative risk of nonlymphatic leukemia was increased among patients who received postoperative radiotherapy (P = .04). Cancer incidence in the high-risk tamoxifen-treated group relative to that in the high-risk group not treated with tamoxifen was not significant (1.3). No protective effect of tamoxifen on the opposite breast was seen (rate ratio for breast cancer = 1.1), but a tendency to an elevated risk of endometrial cancer was observed (rate ratio = 3.3; 95% confidence interval = 0.6-32.4). Continued and careful follow-up of women treated with tamoxifen is necessary to clarify the potential cancer-suppressive or cancer-promoting effects of this drug

CB1 and CB2 Receptors are Novel Molecular Targets for Tamoxifen and 4OH-Tamoxifen

OpenAIRE

Prather, Paul L.; FrancisDevaraj, FeAna; Dates, Centdrika R.; Greer, Aleksandra K.; Bratton, Stacie M.; Ford, Benjamin M.; Franks, Lirit N.; Radominska-Pandya, Anna

2013-01-01

Tamoxifen (Tam) is classified as a selective estrogen receptor modulator (SERM) and is used for treatment of patients with ER-positive breast cancer. However, it has been shown that Tam and its cytochrome P450-generated metabolite 4-hydroxy-Tam (4OH-Tam) also exhibit cytotoxic effects in ER-negative breast cancer cells. These observations suggest that Tam and 4OH-Tam can produce cytotoxicity via estrogen receptor (ER)-independent mechanism(s) of action. The molecular targets responsible for t...

ATLAS: Adjuvant Tamoxifen Longer Against Shorter

Science.gov (United States)

1998-09-01

largely tunaffected by other these 30 000 women during about 10 years of follow-up patient characteristics or treatments. were 21% (SD 3), 29% (SD 2...for both types of mosted to stop part of the eduon y epatient . most of them did stop, part of the reduction in the The right side of figure 4...patient characteristics (e.g. high/ low-risk, ER+/ER-, pre/post-menopausal) recorded at entry. Other trials of tamoxifen duration The Atlas collaboration

Nuclear respiratory factor-1 and bioenergetics in tamoxifen-resistant breast cancer cells

International Nuclear Information System (INIS)

Radde, Brandie N.; Ivanova, Margarita M.; Mai, Huy Xuan; Alizadeh-Rad, Negin; Piell, Kellianne; Van Hoose, Patrick; Cole, Marsha P.; Muluhngwi, Penn; Kalbfleisch, Ted S.; Rouchka, Eric C.; Hill, Bradford G.; Klinge, Carolyn M.

2016-01-01

Acquired tamoxifen (TAM) resistance is a significant clinical problem in treating patients with estrogen receptor α (ERα)+ breast cancer. We reported that ERα increases nuclear respiratory factor-1 (NRF-1), which regulates nuclear-encoded mitochondrial gene transcription, in MCF-7 breast cancer cells and NRF-1 knockdown stimulates apoptosis. Whether NRF-1 and target gene expression is altered in endocrine resistant breast cancer cells is unknown. We measured NRF-1and metabolic features in a cell model of progressive TAM-resistance. NRF-1 and its target mitochondrial transcription factor A (TFAM) were higher in TAM-resistant LCC2 and LCC9 cells than TAM-sensitive MCF-7 cells. Using extracellular flux assays we observed that LCC1, LCC2, and LCC9 cells showed similar oxygen consumption rate (OCR), but lower mitochondrial reserve capacity which was correlated with lower Succinate Dehydrogenase Complex, Subunit B in LCC1 and LCC2 cells. Complex III activity was lower in LCC9 than MCF-7 cells. LCC1, LCC2, and LCC9 cells had higher basal extracellular acidification (ECAR), indicating higher aerobic glycolysis, relative to MCF-7 cells. Mitochondrial bioenergetic responses to estradiol and 4-hydroxytamoxifen were reduced in the endocrine-resistant cells compared to MCF-7 cells. These results suggest the acquisition of altered metabolic phenotypes in response to long term antiestrogen treatment may increase vulnerability to metabolic stress. - Highlights: • NRF-1 and TFAM expression are higher in endocrine-resistant breast cancer cells. • Oxygen consumption rate is similar in endocrine-sensitive and resistant cells. • Mitochondrial reserve capacity is lower in endocrine-resistant cells. • Endocrine-resistant breast cancer cells have increased glycolysis. • Bioenergetic responses to E2 and tamoxifen are lower in endocrine-resistant cells.

Nuclear respiratory factor-1 and bioenergetics in tamoxifen-resistant breast cancer cells

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Radde, Brandie N.; Ivanova, Margarita M.; Mai, Huy Xuan; Alizadeh-Rad, Negin; Piell, Kellianne; Van Hoose, Patrick; Cole, Marsha P.; Muluhngwi, Penn; Kalbfleisch, Ted S. [Department of Biochemistry & Molecular Genetics, Center for Genetics and Molecular Medicine, University of Louisville School of Medicine, Louisville, KY 40292 (United States); Rouchka, Eric C. [Bioinformatics and Biomedical Computing Laboratory, Department of Computer Engineering and Computer Science, University of Louisville, Louisville, KY 40292 (United States); Hill, Bradford G. [Department of Medicine, University of Louisville School of Medicine, Louisville, KY 40292 (United States); Klinge, Carolyn M., E-mail: carolyn.klinge@louisville.edu [Department of Biochemistry & Molecular Genetics, Center for Genetics and Molecular Medicine, University of Louisville School of Medicine, Louisville, KY 40292 (United States)

2016-09-10

Acquired tamoxifen (TAM) resistance is a significant clinical problem in treating patients with estrogen receptor α (ERα)+ breast cancer. We reported that ERα increases nuclear respiratory factor-1 (NRF-1), which regulates nuclear-encoded mitochondrial gene transcription, in MCF-7 breast cancer cells and NRF-1 knockdown stimulates apoptosis. Whether NRF-1 and target gene expression is altered in endocrine resistant breast cancer cells is unknown. We measured NRF-1and metabolic features in a cell model of progressive TAM-resistance. NRF-1 and its target mitochondrial transcription factor A (TFAM) were higher in TAM-resistant LCC2 and LCC9 cells than TAM-sensitive MCF-7 cells. Using extracellular flux assays we observed that LCC1, LCC2, and LCC9 cells showed similar oxygen consumption rate (OCR), but lower mitochondrial reserve capacity which was correlated with lower Succinate Dehydrogenase Complex, Subunit B in LCC1 and LCC2 cells. Complex III activity was lower in LCC9 than MCF-7 cells. LCC1, LCC2, and LCC9 cells had higher basal extracellular acidification (ECAR), indicating higher aerobic glycolysis, relative to MCF-7 cells. Mitochondrial bioenergetic responses to estradiol and 4-hydroxytamoxifen were reduced in the endocrine-resistant cells compared to MCF-7 cells. These results suggest the acquisition of altered metabolic phenotypes in response to long term antiestrogen treatment may increase vulnerability to metabolic stress. - Highlights: • NRF-1 and TFAM expression are higher in endocrine-resistant breast cancer cells. • Oxygen consumption rate is similar in endocrine-sensitive and resistant cells. • Mitochondrial reserve capacity is lower in endocrine-resistant cells. • Endocrine-resistant breast cancer cells have increased glycolysis. • Bioenergetic responses to E2 and tamoxifen are lower in endocrine-resistant cells.

Detection of tamoxifen metabolites by GC-MSD.

Science.gov (United States)

Báez, H; Camargo, C; Osorio, H; Umpiérrez, F

2004-01-01

Tamoxifen is an antiestrogen used in the adjuvant endocrine therapy of early breast cancer and malignant breast disorders. It is also used in women with anovulatory infertility caused by its stimulating effect on the secretion of the pituitary gonadotrophic hormones. In males it could increase the endogenous production of androgens. Because of these properties tamoxifen may be misused in some sports to treat the androgens suppression caused by the extensive abuse of anabolic androgenic steroids. A method for identification and confirmation of tamoxifen metabolites is described. Hydroxymetoxytamoxifen is detected in urine by gas chromatography and mass spectrometry in a selective ion monitoring method followed by the routine postrun in the screening of anabolic steroids. Once the hydroxymetoxytamoxifen is detected, confirmation of reported metabolites could be performed with a 5973 mass selective detector in the scan mode after solid-phase extraction by cationic exchange. This study also reports an excretion profile for a single dose of tamoxifen equivalent to 40 mg administrated orally to two males volunteers.

Tamoxifen added to radiotherapy and surgery for the treatment of ductal carcinoma in situ of the breast: A meta-analysis of 2 randomized trials

International Nuclear Information System (INIS)

Petrelli, Fausto; Barni, Sandro

2011-01-01

Background: Surgical excision with adequate margins is the treatment of choice for ductal, in situ carcinoma of the breast (DCIS). The addition of radiotherapy (RT) halved local in situ and invasive recurrence. The purpose of our meta-analysis is to evaluate the reduction in recurrence (in situ or invasive) with the addition of tamoxifen (T), in particular in patients with DCIS treated with surgery + RT. Patients and methods: The eligible studies (NSABP-B24 and UK ANZ DCIS trials) included prospective, randomized, controlled trials in which the addition of T had been compared with surgery + RT without T in women with DCIS of the breast. Relative risks (RRs) with 95% confidence intervals (CIs) were calculated for both in situ and invasive recurrence (local and controlateral). Results: Tamoxifen does not reduce breast cancer-specific or overall mortality when added to loco-regional therapy for DCIS of the breast (surgery plus or minus RT). Tamoxifen reduces overall breast cancer recurrence by 29% in all patients and by 33% in those treated with both surgery and RT. Only ipsilateral invasive (RR 0.61 [95% CI 0.41, 0.92]; p = 0.02) and controlateral in situ relapses (RR 0.40 [95% CI 0.16, 0.96]; p = 0.04) are significantly lowered when T is added to RT. Tamoxifen seems to exert a local synergistic effect with RT. Both young and older women ( 50 years) achieve some benefit from the addition of T (RR 0.6 and 0.74, respectively). Conclusion: The addition of T to surgery and RT for DCIS of the breast reduces the risk of local invasive and controlateral in situ relapses, but not the survival. The benefit is independent of age. In conclusion, surgery associated with RT and T is the treatment of choice for patients with (estrogen-receptor positive) DCIS of the breast.

Endocrine effects of adjuvant letrozole + triptorelin compared with tamoxifen + triptorelin in premenopausal patients with early breast cancer.

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Rossi, Emanuela; Morabito, Alessandro; De Maio, Ermelinda; Di Rella, Francesca; Esposito, Giuseppe; Gravina, Adriano; Labonia, Vincenzo; Landi, Gabriella; Nuzzo, Francesco; Pacilio, Carmen; Piccirillo, Maria Carmela; D'Aiuto, Giuseppe; D'Aiuto, Massimiliano; Rinaldo, Massimo; Botti, Gerardo; Gallo, Ciro; Perrone, Francesco; de Matteis, Andrea

2008-01-10

To compare the endocrine effects of 6 months of adjuvant treatment with letrozole + triptorelin or tamoxifen + triptorelin in premenopausal patients with early breast cancer within an ongoing phase 3 trial (Hormonal Adjuvant Treatment Bone Effects study). Prospectively collected hormonal data were available for 81 premenopausal women, of whom 30 were assigned to receive tamoxifen + triptorelin and 51 were assigned letrozole + triptorelin +/- zoledronate. Serum 17-beta-estradiol (E2), follicle-stimulating hormone (FSH), luteinizing hormone (LH), Delta4-androstenedione, testosterone, dehydroepiandrosterone-sulfate, progesterone, adrenocorticotropic hormone (ACTH), and cortisol were measured at baseline and after 6 months of treatment. For each hormone, 6-month values were compared between treatment groups by the Wilcoxon-Mann-Whitney exact test. Median age was 44 years for both groups of patients. Letrozole + triptorelin (+/- zoledronate) induced a stronger suppression of median E2 serum levels (P = .0008), LH levels (P = .0005), and cortisol serum levels (P < .0001) compared with tamoxifen + triptorelin. Median FSH serum levels were suppressed in both groups, but such suppression was lower among patients receiving letrozole, who showed significantly higher median FSH serum levels (P < .0001). No significant differences were observed for testosterone, progesterone, ACTH, androstenedione, and dehydroepiandrosterone between the two groups of patients. Letrozole in combination with triptorelin induces a more intense estrogen suppression than tamoxifen + triptorelin in premenopausal patients with early breast cancer.

Tamoxifen- Induced Dermatomyositis

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Bandyopadhyay Debabrata

1997-01-01

Full Text Available A 38 year old woman developed dermatomyositis after radical mastectomy and tamoxifen therapy for metastatic breast carcinoma. The possibility of the drug as the underlying cause of the connective tissue disease is discussed.

Metabolism and transport of tamoxifen in relation to its effectiveness

DEFF Research Database (Denmark)

Cronin-Fenton, Deirdre P; Damkier, Per; Lash, Timothy L

2014-01-01

Tamoxifen reduces the rate of breast cancer recurrence by approximately a half. Tamoxifen is metabolized to more active metabolites by enzymes encoded by polymorphic genes, including cytochrome P450 2D6 (CYP2D6). Tamoxifen is a substrate for ATP-binding cassette transporter proteins. We review ta...

Hormone therapy with tamoxifen reduces plasma levels of NT-B-type natriuretic peptide but does not change ventricular ejection fraction after chemotherapy in women with breast cancer

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F.B. Silva

2015-02-01

Full Text Available The objective of this study was to evaluate the effect of tamoxifen on the plasma concentration of NT-pro-B-type natriuretic peptide (NT-proBNP in women undergoing chemotherapy for breast cancer and to correlate changes in NT-proBNP with the left ventricular ejection fraction (LVEF. Over a period of 12 months, we followed 60 women with a diagnosis of breast cancer. The patients were separated into a group that received only chemotherapy (n=23, a group that received chemotherapy + tamoxifen (n=21, and a group that received only tamoxifen (n=16. Plasma levels of NT-proBNP were assessed at 0 (T0, 6 (T6, and 12 (T12 months of treatment, and echocardiography data were assessed at T0 and T12. Plasma NT-proBNP levels were increased in the chemotherapy-only group at T6 and T12, whereas elevated NT-proBNP levels were only found at T6 in the chemotherapy + tamoxifen group. At T12, the chemotherapy + tamoxifen group exhibited a significant reduction in the peptide to levels similar to the group that received tamoxifen alone. The chemotherapy-only group exhibited a significant decrease in LVEF at T12, whereas the chemotherapy + tamoxifen and tamoxifen-only groups maintained levels similar to those at the beginning of treatment. Treatment with tamoxifen for 6 months after chemotherapy significantly reduced the plasma levels of NT-proBNP and did not change LVEF in women with breast cancer.

Reprogramming of the ERRα and ERα target gene landscape triggers tamoxifen resistance in breast cancer.

Science.gov (United States)

Thewes, Verena; Simon, Ronald; Schroeter, Petra; Schlotter, Magdalena; Anzeneder, Tobias; Büttner, Reinhard; Benes, Vladimir; Sauter, Guido; Burwinkel, Barbara; Nicholson, Robert I; Sinn, Hans-Peter; Schneeweiss, Andreas; Deuschle, Ulrich; Zapatka, Marc; Heck, Stefanie; Lichter, Peter

2015-02-15

Endocrine treatment regimens for breast cancer that target the estrogen receptor-α (ERα) are effective, but acquired resistance remains a limiting drawback. One mechanism of acquired resistance that has been hypothesized is functional substitution of the orphan receptor estrogen-related receptor-α (ERRα) for ERα. To examine this hypothesis, we analyzed ERRα and ERα in recurrent tamoxifen-resistant breast tumors and conducted a genome-wide target gene profiling analysis of MCF-7 breast cancer cell populations that were sensitive or resistant to tamoxifen treatment. This analysis uncovered a global redirection in the target genes controlled by ERα, ERRα, and their coactivator AIB1, defining a novel set of target genes in tamoxifen-resistant cells. Beyond differences in the ERα and ERRα target gene repertoires, both factors were engaged in similar pathobiologic processes relevant to acquired resistance. Functional analyses confirmed a requirement for ERRα in tamoxifen- and fulvestrant-resistant MCF-7 cells, with pharmacologic inhibition of ERRα sufficient to partly restore sensitivity to antiestrogens. In clinical specimens (n = 1041), increased expression of ERRα was associated with enhanced proliferation and aggressive disease parameters, including increased levels of p53 in ERα-positive cases. In addition, increased ERRα expression was linked to reduced overall survival in independent tamoxifen-treated patient cohorts. Taken together, our results suggest that ERα and ERRα cooperate to promote endocrine resistance, and they provide a rationale for the exploration of ERRα as a candidate drug target to treat endocrine-resistant breast cancer. ©2015 American Association for Cancer Research.

Compound list: tamoxifen [Open TG-GATEs

Lifescience Database Archive (English)

Full Text Available tamoxifen TMX 00054 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/in_vitro/tam...oxifen.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vitro/tam...oxifen.Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Single/tam...open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/tamoxifen.Rat.in_vivo.Liver.Repeat.zip ...

FGFR2-Driven Signaling Counteracts Tamoxifen Effect on ERα-Positive Breast Cancer Cells

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Lukasz Turczyk

2017-10-01

Full Text Available Signaling mediated by growth factors receptors has long been suggested as one of the key factors responsible for failure of endocrine treatment in breast cancer (BCa. Herein we present that in the presence of tamoxifen, FGFs (Fibroblast Growth Factors promote BCa cell growth with the strongest effect being produced by FGF7. FGFR2 was identified as a mediator of FGF7 action and the FGFR2-induced signaling was found to underlie cancer-associated fibroblasts-dependent resistance to tamoxifen. FGF7/FGFR2-triggered pathway was shown to induce ER phosphorylation, ubiquitination and subsequent ER proteasomal degradation which counteracted tamoxifen-promoted ER stabilization. We also identified activation of PI3K/AKT signaling targeting ER-Ser167 and regulation of Bcl-2 expression as a mediator of FGFR2-promoted resistance to tamoxifen. Analysis of tissue samples from patients with invasive ductal carcinoma revealed an inversed correlation between expression of FGFR2 and ER, thus supporting our in vitro data. These results unveil the complexity of ER regulation by FGFR2-mediated signaling likely to be associated with BCa resistance to endocrine therapy.

131I labeling of tamoxifen and biodistribution studies in rats

International Nuclear Information System (INIS)

Biber Muftuler, F.Z.; Unak, P.; Teksoz, S.; Acar, C.; Yolcular, S.; Yuerekli, Y.

2008-01-01

Tamoxifen [TAM ([Z]-2-[4-(1,2-diphenyl-1-di-butenyl)-phenoxy]-N,N-dimethylethanamine)] has been used as an antiestrogen drug for treatment and prevention of human breast cancer. Tamoxifen was labeled with 131 I using iodogen as an oxidizing agent. Mass spectroscopy of the cold standard showed that the labeling occurs in ortho position to the phenyl ether position of TAM as expected. Quality control, radiochemical yield and stability were established using the radioelectrophoresis method. The radiolabeled compound maintained its stability throughout working period of 24 h. Scintigraphic imaging was performed and tissue distribution was determined in Albino Wistar rats. According to biodistribution and imaging experiments the radiolabeled compound presented estrogen receptor (ER) specificity and it was uptaken by endometrium as well as breast tissue

Gene expression changes induced by estrogen and selective estrogen receptor modulators in primary-cultured human endometrial cells: signals that distinguish the human carcinogen tamoxifen

International Nuclear Information System (INIS)

Pole, Jessica C.M.; Gold, Leslie I.; Orton, Terry; Huby, Russell; Carmichael, Paul L.

2005-01-01

Tamoxifen has long been the endocrine treatment of choice for women with breast cancer and is now employed for prophylactic use in women at high risk from breast cancer. Other selective estrogen receptor modulators (SERMs), such as raloxifene, mimic some of tamoxifen's beneficial effects and, like tamoxifen, exhibit a complex mixture of organ-specific estrogen agonist and antagonistic properties. However, accompanying the positive effects of tamoxifen has been the emergence of evidence for an increased risk of endometrial cancer associated with its use. A more complete understanding of the mechanism(s) of SERM carcinogenicity and endometrial effects is therefore required. We have sought to compare and characterise the transcript profile of tamoxifen, raloxifene and the agonist estradiol in human endometrial cells. Using primary cultures of human endometria, to best emulate the in vivo responses in a manageable in vitro system, we have shown 230 significant changes in gene expression for epithelial cultures and 83 in stromal cultures, either specific to 17β-estradiol, tamoxifen or raloxifene, or changed across more than one of the treatments. Considering the transcriptome as a whole, the endometrial responses to raloxifene or tamoxifen were more similar than either drug was to 17β-estradiol. Treatment of endometrial cultures with tamoxifen resulted in the largest number of gene changes relative to control cultures and a high proportion of genes associated with regulation of gene transcription, cell-cycle control and signal transduction. Tamoxifen-specific changes that might point towards mechanisms for its proliferative response in the endometrium included changes in retinoblastoma and c-myc binding proteins, the APCL, dihydrofolate reductase (DHFR) and E2F1 genes and other transcription factors. Tamoxifen was also found to give rise to the highest number of gene expression changes common to those that characterise malignant endometria. It is anticipated that this

AIB1 is required for the acquisition of epithelial growth factor receptor-mediated tamoxifen resistance in breast cancer cells

International Nuclear Information System (INIS)

Zhao Wenhui; Zhang Qingyuan; Kang Xinmei; Jin Shi; Lou Changjie

2009-01-01

Acquired resistance to tamoxifen has become a serious obstacle in breast cancer treatment. The underlying mechanism responsible for this condition has not been completely elucidated. In this study, a tamoxifen-resistant (Tam-R) MCF-7 breast cancer cell line was developed to mimic the occurrence of acquired tamoxifen resistance as seen in clinical practice. Increased expression levels of HER1, HER2 and the estrogen receptor (ER)-AIB1 complex were found in tamoxifen-resistant cells. EGF stimulation and gefitinib inhibition experiments further demonstrated that HER1/HER2 signaling and AIB1 were involved in the proliferation of cells that had acquired Tam resistance. However, when AIB1 was silenced with AIB1-siRNA in Tam-R cells, the cell growth stimulated by the HER1/HER2 signaling pathway was significantly reduced, and the cells were again found to be inhibited by tamoxifen. These results suggest that the AIB1 protein could be a limiting factor in the HER1/HER2-mediated hormone-independent growth of Tam-R cells. Thus, AIB1 may be a new therapeutic target, and the removal of AIB1 may decrease the crosstalk between ER and the HER1/HER2 pathway, resulting in the restoration of tamoxifen sensitivity in tamoxifen-resistant cells.

Augmentation of Endoxifen Exposure in Tamoxifen-Treated Women Following SSRI Switch

NARCIS (Netherlands)

L. Binkhorst (Lisette); M. Bannink (Marjolein); P. de Bruijn (Peter); J.B. Ruit (Jos); J. Droogendijk (Jolanda); R.J. van Alphen (Robbert); T.D. den Boer (Tilly D.); M.H. Lam (Mei); A. Jager (Agnes); T. van Gelder (Teun); A.H.J. Mathijssen (Ron)

2016-01-01

textabstractBackground and Objective: The anti-oestrogen tamoxifen requires metabolic activation to endoxifen by cytochrome P450 (CYP) enzymes, predominantly CYP2D6. Potent CYP2D6-inhibiting antidepressants can seriously disrupt tamoxifen metabolism, probably influencing the efficacy of tamoxifen.

Tamoxifen Forms DNA Adducts In Human Colon After Administration Of A Single [14C]-Labeled Therapeutic Dose.

Energy Technology Data Exchange (ETDEWEB)

Brown, K; Tompkins, E M; Boocock, D J; Martin, E A; Farmer, P B; Turteltaub, K W; Ubick, E; Hemingway, D; Horner-Glister, E; White, I H

2007-05-23

Tamoxifen is widely prescribed for the treatment of breast cancer and is also licensed in the U.S. for the prevention of this disease. However, tamoxifen therapy is associated with an increased occurrence of endometrial cancer in women and there is also evidence that it may elevate the risk of colorectal cancer. The underlying mechanisms responsible for tamoxifen-induced carcinogenesis in women have not yet been elucidated but much interest has focussed on the role of DNA adduct formation. We investigated the propensity of tamoxifen to bind irreversibly to colorectal DNA when given to ten women as a single [{sup 14}C]-labeled therapeutic (20 mg) dose, {approx}18 h prior to undergoing colon resections. Using the sensitive technique of accelerator mass spectrometry, coupled with HPLC separation of enzymatically digested DNA, a peak corresponding to authentic dG-N{sup 2}-tamoxifen adduct was detected in samples from three patients, at levels ranging from 1-7 adducts/10{sup 9} nucleotides. No [{sup 14}C]-radiolabel associated with tamoxifen or its major metabolites was detected. The presence of detectable CYP3A4 protein in all colon samples suggests this tissue has the potential to activate tamoxifen to {alpha}-hydroxytamoxifen, in addition to that occurring in the systemic circulation, and direct interaction of this metabolite with DNA could account for the binding observed. Although the level of tamoxifeninduced damage displayed a degree of inter-individual variability, when present it was {approx}10-100 times higher than that reported for other suspect human colon carcinogens such as PhIP. These findings provide a mechanistic basis through which tamoxifen could increase the incidence of colon cancers in women.

The impact of tamoxifen on breast recurrence, cosmesis, complications, and survival in estrogen receptor-positive early-stage breast cancer

International Nuclear Information System (INIS)

Fowble, Barbara; Fein, Douglas A.; Hanlon, Alexandra L.; Eisenberg, Burton L.; Hoffman, John P.; Sigurdson, Elin R.; Daly, Mary B.; Goldstein, Lori J.

1996-01-01

Purpose: To evaluate the impact of tamoxifen on breast recurrence, cosmesis, complications, overall and cause-specific survival in women with Stage I-II breast cancer and estrogen receptor positive tumors undergoing conservative surgery and radiation. Methods and Materials: From 1982 to 1991, 491 women with estrogen receptor positive Stage I-II breast cancer underwent excisional biopsy, axillary dissection, and radiation. The median age of the patient population was 60 years with 21% < 50 years of age. The median follow-up was 5.3 years (range 0.1 to 12.8). Sixty-nine percent had T1 tumors and 83% had histologically negative axillary nodes. Reexcision was performed in 49% and the final margin of resection was negative in 64%. One hundred fifty-four patients received tamoxifen and 337 patients received no adjuvant therapy. None of the patients received adjuvant chemotherapy. Results: There were no significant differences between the two groups for age, race, clinical tumor size, histology, the use of reexcision, or median total dose to the primary. Patients who received tamoxifen were more often axillary node positive (44% tamoxifen vs. 5% no tamoxifen), and, therefore, a greater percentage received treatment to the breast and regional nodes. The tamoxifen patients less often had unknown margins of resection (9% tamoxifen vs. 22% no tamoxifen). The 5-year actuarial breast recurrence rate was 4% for the tamoxifen patients compared to 7% for patients not receiving tamoxifen (p 0.21). Tamoxifen resulted in a modest decrease in the 5-year actuarial risk of a breast recurrence in axillary node-negative patients, in those with unknown or close margins of resection, and in those who underwent a single excision. Axillary node-positive patients had a clinically significant decrease in the 5-year actuarial breast recurrence rate (21 vs. 4%; p 0.08). The 5-year actuarial rate of distant metastasis was not significantly decreased by the addition of adjuvant tamoxifen in all

Letrozole compared with tamoxifen for elderly patients with endocrine-responsive early breast cancer: the BIG 1-98 trial

DEFF Research Database (Denmark)

Crivellari, D.; Sun, Z.; Coates, A.S.

2008-01-01

PURPOSE: To explore potential differences in efficacy, treatment completion, and adverse events (AEs) in elderly women receiving adjuvant tamoxifen or letrozole for five years in the Breast International Group (BIG) 1-98 trial. METHODS: This report includes the 4,922 patients allocated to 5 years...... of letrozole or tamoxifen in the BIG 1-98 trial. The median follow-up was 40.4 months. Subpopulation Treatment Effect Pattern Plot (STEPP) analysis was used to examine the patterns of differences in disease-free survival and incidences of AEs according to age. In addition, three categoric age groups were...... had superior efficacy (DFS) compared with tamoxifen in all age groups. On the basis of a small number of patients older than 75 years (6%), age per se should not unduly affect the choice of adjuvant endocrine therapy Udgivelsesdato: 2008/4/20...

Tamoxifen induces apoptotic neutrophil efferocytosis in horses.

Science.gov (United States)

Olave, C; Morales, N; Uberti, B; Henriquez, C; Sarmiento, J; Ortloff, A; Folch, H; Moran, G

2018-03-01

Macrophages and neutrophils are important cellular components in the process of acute inflammation and its subsequent resolution, and evidence increasingly suggests that they play important functions during the resolution of chronic, adaptive inflammatory processes. Exacerbated neutrophil activity can be harmful to surrounding tissues; this is important in a range of diseases, including allergic asthma and chronic obstructive pulmonary disease in humans, and equine asthma (also known as recurrent airway obstruction (RAO). Tamoxifen (TX) is a non-steroidal estrogen receptor modulator with effects on cell growth and survival. Previous studies showed that TX treatment in horses with induced acute pulmonary inflammation promoted early apoptosis of blood and BALF neutrophils, reduction of BALF neutrophils, and improvement in animals' clinical status. The aim of this study was to describe if TX induces in vitro efferocytosis of neutrophils by alveolar macrophages. Efferocytosis assay, myeloperoxidase (MPO) detection and translocation phosphatidylserine (PS) were performed on neutrophils isolated from peripheral blood samples from five healthy horses. In in vitro samples from heathy horses, TX treatment increases the phenomenon of efferocytosis of peripheral neutrophils by alveolar macrophages. Similar increases in supernatant MPO concentration and PS translocation were observed in TX-treated neutrophils, compared to control cells. In conclusion, these results confirm that tamoxifen has a direct effect on equine peripheral blood neutrophils, through stimulation of the engulfment of apoptotic neutrophils by alveolar macrophages.

An open, randomised, multicentre, phase 3 trial comparing the efficacy of two tamoxifen schedules in preventing gynaecomastia induced by bicalutamide monotherapy in prostate cancer patients.

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Bedognetti, Davide; Rubagotti, Alessandra; Conti, Giario; Francesca, Francesco; De Cobelli, Ottavio; Canclini, Luca; Gallucci, Michele; Aragona, Francesco; Di Tonno, Pasquale; Cortellini, Pietro; Martorana, Giuseppe; Lapini, Alberto; Boccardo, Francesco

2010-02-01

Bicalutamide monotherapy is a valuable option for prostate cancer (PCa) patients who wish to avoid the consequences of androgen deprivation; however, this treatment induces gynaecomastia and mastalgia in most patients. Tamoxifen is safe and effective in preventing breast events induced by bicalutamide monotherapy without affecting antitumor activity, but possible interference between bicalutamide and tamoxifen remains a matter of concern. To reduce the exposure to tamoxifen, we considered the putative advantages of weekly administration. To compare the efficacy of two different schedules of tamoxifen in preventing breast events. Toxicity, prostate-specific antigen behaviour, and sexual-functioning scores were also evaluated. This was a noninferiority trial. From December 2003 to February 2006, 80 patients with localised/locally advanced or biochemically recurrent PCa who were also candidates for bicalutamide single therapy were randomised to receive two different schedules of tamoxifen: daily (n=41) and weekly (n=39). Median follow-up was 24.2 mo. Daily bicalutamide (150 mg) plus daily tamoxifen 20mg continuously (daily group) or the same but with tamoxifen at 20mg weekly after the first 8 wk of daily treatment (weekly group). Three patients in the weekly group and one in the daily group were discontinued for adverse events. For gynaecomastia, we used ultrasonography. For mastalgia and sexual functioning, we used questionnaires. Gynaecomastia developed in 31.7% of patients in the daily group and in 74.4% of patients in the weekly group (p<0.0001), and it was more severe in patients who switched to weekly tamoxifen (p=0.001). Mastalgia occurred in 12.2% and 46.1% of patients, respectively (p=0.001). There were no major differences among treatment schedules relative to sexual functioning scores and incidence and severity of adverse events. No differences between groups in PSA behaviour and disease progression have been detected so far. This study demonstrated that

Minimal impact of adjuvant exemestane or tamoxifen treatment on mammographic breast density in postmenopausal breast cancer patients: A Dutch TEAM trial analysis

NARCIS (Netherlands)

J.G.H. van Nes; L.V. Beex (Louk); C.M. Seynaeve (Caroline); H. Putter (Hein); A. Sramek (Alexandr); S. Lardenoije (Susanne); M.D.-D.E. Carpentier (Marjolijn Duijm-D.E.); I. Van Rongen (Inge); J.W.R. Nortier (Johan W. R.); H.M. Zonderland (Harmine); C.J.H. van de Velde (Cornelis)

2015-01-01

textabstractBackground. Mammographic breast density is one of the strongest independent risk factors for developing breast cancer. We examined the effect of exemestane and tamoxifen on breast density in Dutch postmenopausal early breast cancer patients participating in the Tamoxifen Exemestane

Tamoxifen dosing for Cre-mediated recombination in experimental bronchopulmonary dysplasia.

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Ruiz-Camp, Jordi; Rodríguez-Castillo, José Alberto; Herold, Susanne; Mayer, Konstantin; Vadász, István; Tallquist, Michelle D; Seeger, Werner; Ahlbrecht, Katrin; Morty, Rory E

2017-02-01

Bronchopulmonary dysplasia (BPD) is the most common complication of preterm birth characterized by blunted post-natal lung development. BPD can be modelled in mice by exposure of newborn mouse pups to elevated oxygen levels. Little is known about the mechanisms of perturbed lung development associated with BPD. The advent of transgenic mice, where genetic rearrangements can be induced in particular cell-types at particular time-points during organogenesis, have great potential to explore the pathogenic mechanisms at play during arrested lung development. Many inducible, conditional transgenic technologies available rely on the application of the estrogen-receptor modulator, tamoxifen. While tamoxifen is well-tolerated and has been widely employed in adult mice, or in healthy developing mice; tamoxifen is not well-tolerated in combination with hyperoxia, in the most widely-used mouse model of BPD. To address this, we set out to establish a safe and effective tamoxifen dosing regimen that can be used in newborn mouse pups subjected to injurious stimuli, such as exposure to elevated levels of environmental oxygen. Our data reveal that a single intraperitoneal dose of tamoxifen of 0.2 mg applied to newborn mouse pups in 10 μl Miglyol vehicle was adequate to successfully drive Cre recombinase-mediated genome rearrangements by the fifth day of life, in a murine model of BPD. The number of recombined cells was comparable to that observed in regular tamoxifen administration protocols. These findings will be useful to investigators where tamoxifen dosing is problematic in the background of injurious stimuli and mouse models of human and veterinary disease.

Bazedoxifene exhibits antiestrogenic activity in animal models of tamoxifen-resistant breast cancer: implications for treatment of advanced disease.

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Wardell, Suzanne E; Nelson, Erik R; Chao, Christina A; McDonnell, Donald P

2013-05-01

There is compelling evidence to suggest that drugs that function as pure estrogen receptor (ER-α) antagonists, or that downregulate the expression of ER-α, would have clinical use in the treatment of advanced tamoxifen- and aromatase-resistant breast cancer. Although such compounds are currently in development, we reasoned, based on our understanding of ER-α pharmacology, that there may already exist among the most recently developed selective estrogen receptor modulators (SERM) compounds that would have usage as breast cancer therapeutics. Thus, our objective was to identify among available SERMs those with unique pharmacologic activities and to evaluate their potential clinical use with predictive models of advanced breast cancer. A validated molecular profiling technology was used to classify clinically relevant SERMs based on their impact on ER-α conformation. The functional consequences of these observed mechanistic differences on (i) gene expression, (ii) receptor stability, and (iii) activity in cellular and animal models of advanced endocrine-resistant breast cancer were assessed. The high-affinity SERM bazedoxifene was shown to function as a pure ER-α antagonist in cellular models of breast cancer and effectively inhibited the growth of both tamoxifen-sensitive and -resistant breast tumor xenografts. Interestingly, bazedoxifene induced a unique conformational change in ER-α that resulted in its proteasomal degradation, although the latter activity was dispensable for its antagonist efficacy. Bazedoxifene was recently approved for use in the European Union for the treatment of osteoporosis and thus may represent a near-term therapeutic option for patients with advanced breast cancer. ©2013 AACR.

Black cohosh (Cimicifuga racemosa) in tamoxifen-treated breast cancer patients with climacteric complaints - a prospective observational study.

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Rostock, Matthias; Fischer, Julia; Mumm, Andreas; Stammwitz, Ute; Saller, Reinhard; Bartsch, Hans Helge

2011-10-01

The antihormonal therapy of breast cancer patients with the antiestrogen tamoxifen often induces or aggravates menopausal complaints. As estrogen substitution is contraindicated, herbal alternatives, e.g. extracts of black cohosh are often used. A prospective observational study was carried out in 50 breast cancer patients with tamoxifen treatment. All patients had had surgery, most of them had undergone radiation therapy (87%) and approximately 50% had received chemotherapy. Every patient was treated with an isopropanolic extract of black cohosh (1-4 tablets, 2.5 mg) for 6 months. Patients recorded their complaints before therapy and after 1, 3, and 6 months of therapy using the menopause rating scale (MRS II). The reduction of the total MRS II score under black cohosh treatment from 17.6 to 13.6 was statistically significant. Hot flashes, sweating, sleep problems, and anxiety improved, whereas urogenital and musculoskeletal complaints did not change. In all, 22 patients reported adverse events, none of which were linked with the study medication; 90% reported the tolerability of the black cohosh extract as very good or good. Black cohosh extract seems to be a reasonable treatment approach in tamoxifen treated breast cancer patients with predominantly psychovegetative symptoms.

17 beta-estradiol and tamoxifen upregulate estrogen receptor beta expression and control podocyte signaling pathways in a model of type 2 diabetes.

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Catanuto, Paola; Doublier, Sophie; Lupia, Enrico; Fornoni, Alessia; Berho, Mariana; Karl, Michael; Striker, Gary E; Xia, Xiaomei; Elliot, Sharon

2009-06-01

Diabetic nephropathy remains one of the most important causes of end-stage renal disease. This is particularly true for women from racial/ethnic minorities. Although administration of 17beta-estradiol to diabetic animals has been shown to reduce extracellular matrix deposition in glomeruli and mesangial cells, effects on podocytes are lacking. Given that podocyte injury has been implicated as a factor leading to the progression of proteinuria and diabetic nephropathy, we treated db/db mice, a model of type 2 diabetic glomerulosclerosis, with 17beta-estradiol or tamoxifen to determine whether these treatments reduce podocyte injury and decrease glomerulosclerosis. We found that albumin excretion, glomerular volume, and extracellular matrix accumulation were decreased in these mice compared to placebo treatment. Podocytes isolated from all treatment groups were immortalized and these cell lines were found to express the podocyte markers WT-1, nephrin, and the TRPC6 cation channel. Tamoxifen and 17beta-estradiol treatment decreased podocyte transforming growth factor-beta mRNA expression but increased that of the estrogen receptor subtype beta protein. 17beta-estradiol, but not tamoxifen, treatment decreased extracellular-regulated kinase phosphorylation. These data, combined with improved albumin excretion, reduced glomerular size, and decreased matrix accumulation, suggest that both 17beta-estradiol and tamoxifen may protect podocytes against injury and therefore ameliorate diabetic nephropathy.

Tamoxifen for the management of breast events induced by non-steroidal antiandrogens in patients with prostate cancer: a systematic review

Directory of Open Access Journals (Sweden)

Kunath Frank

2012-08-01

Full Text Available Abstract Background Tamoxifen has emerged as a potential management option for gynecomastia and breast pain due to non-steroidal antiandrogens, and it is considered an alternative to surgery or radiotherapy. The objective of this systematic review was to assess the benefits and harms of tamoxifen, in comparison to other treatment options, for either the prophylaxis or treatment of breast events induced by non-steroidal antiandrogens in prostate cancer patients. Methods We searched CENTRAL, MEDLINE, EMBASE, reference lists, the abstracts of three major conferences and three trial registers to identify ongoing randomized controlled trials (RCTs. Two authors independently screened the articles identified, assessed the trial quality and extracted data. The protocol was prospectively registered (CRD42011001320; http://www.crd.york.ac.uk/PROSPERO. Results Four studies were identified. Tamoxifen significantly reduced the risk of suffering from gynecomastia (risk ratio 9RR0 0.10, 95% CI 0.05 to 0.22 or breast pain (RR 0.06, 95% CI 0.02 to 0.17 at six months compared to untreated controls. Tamoxifen also showed a significant benefit for the prevention of gynecomastia (RR 0.22, 95% CI 0.08 to 0.58 and breast pain (RR 0.25, 95% CI 0.10 to 0.64 when compared to anastrozole after a median of 12 months. One study showed a significant benefit of tamoxifen for the prevention of gynecomastia (RR 0.24, 95% CI 0.09 to 0.65 and breast pain (RR 0.20, 95% CI 0.06 to 0.65 when compared with radiotherapy at six months. Radiotherapy increased the risk of suffering from nipple erythema and skin irritation, but there were no significant differences for any other adverse events (all P > 0.05. Conclusions The currently available evidence suggests good efficacy of tamoxifen for the prevention and treatment of breast events induced by non-steroidal antiandrogens. The impact of tamoxifen therapy on long-term adverse events, disease progression and survival remains unclear

C-Cbl reverses HER2-mediated tamoxifen resistance in human breast cancer cells.

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Li, Wei; Xu, Ling; Che, Xiaofang; Li, Haizhou; Zhang, Ye; Song, Na; Wen, Ti; Hou, Kezuo; Yang, Yi; Zhou, Lu; Xin, Xing; Xu, Lu; Zeng, Xue; Shi, Sha; Liu, Yunpeng; Qu, Xiujuan; Teng, Yuee

2018-05-02

Tamoxifen is a frontline therapy for estrogen receptor (ER)-positive breast cancer in premenopausal women. However, many patients develop resistance to tamoxifen, and the mechanism underlying tamoxifen resistance is not well understood. Here we examined whether ER-c-Src-HER2 complex formation is involved in tamoxifen resistance. MTT and colony formation assays were used to measure cell viability and proliferation. Western blot was used to detect protein expression and protein complex formations were detected by immunoprecipitation and immunofluorescence. SiRNA was used to examine the function of HER2 in of BT474 cells. An in vivo xenograft animal model was established to examine the role of c-Cbl in tumor growth. MTT and colony formation assay showed that BT474 cells are resistant to tamoxifen and T47D cells are sensitive to tamoxifen. Immunoprecipitation experiments revealed ER-c-Src-HER2 complex formation in BT474 cells but not in T47D cells. However, ER-c-Src-HER2 complex formation was detected after overexpressing HER2 in T47D cells and these cells were more resistant to tamoxifen. HER2 knockdown by siRNA in BT474 cells reduced ER-c-Src-HER2 complex formation and reversed tamoxifen resistance. ER-c-Src-HER2 complex formation was also disrupted and tamoxifen resistance was reversed in BT474 cells by the c-Src inhibitor PP2 and HER2 antibody trastuzumab. Nystatin, a lipid raft inhibitor, reduced ER-c-Src-HER2 complex formation and partially reversed tamoxifen resistance. ER-c-Src-HER2 complex formation was disrupted by overexpression of c-Cbl but not by the c-Cbl ubiquitin ligase mutant. In addition, c-Cbl could reverse tamoxifen resistance in BT474 cells, but the ubiquitin ligase mutant had no effect. The effect of c-Cbl was validated in BT474 tumor-bearing nude mice in vivo. Immunofluorescence also revealed ER-c-Src-HER2 complex formation was reduced in tumor tissues of nude mice with c-Cbl overexpression. Our results suggested that c-Cbl can reverse tamoxifen

Effects of repeated administration of chemotherapeutic agents tamoxifen, methotrexate, and 5-fluorouracil on the acquisition and retention of a learned response in mice

Science.gov (United States)

Foley, John J.; Clark-Vetri, Rachel; Raffa, Robert B.

2011-01-01

Rationale A number of cancer chemotherapeutic agents have been associated with a loss of memory in breast cancer patients although little is known of the causality of this effect. Objectives To assess the potential cognitive effects of repeated exposure to chemotherapeutic agents, we administered the selective estrogen receptor modulator tamoxifen or the antimetabolite chemotherapy, methotrexate, and 5-fluorouracil, alone and in combination to mice and tested them in a learning and memory assay. Methods Swiss-Webster male mice were injected with saline, 32 mg/kg tamoxifen, 3.2 or 32 mg/kg methotrexate, 75 mg/kg 5-fluorouracil, 3.2 or 32 mg/kg methotrexate in combination with 75 mg/kg 5-fluorouracil once per week for 3 weeks. On days 23 and 24, mice were tested for acquisition and retention of a nose-poke response in a learning procedure called autoshaping. In addition, the acute effects of tamoxifen were assessed in additional mice in a similar procedure. Results The chemotherapeutic agents alone and in combination reduced body weight relative to saline treatment over the course of 4 weeks. Repeated treatment with tamoxifen produced both acquisition and retention effects relative to the saline-treated group although acute tamoxifen was without effect except at a behaviorally toxic dose. Repeated treatment with methotrexate in combination with 5-fluorouracil produced effects on retention, but the magnitude of these changes depended on the methotrexate dose. Conclusions These data demonstrate that repeated administration of tamoxifen or certain combination of methotrexate and 5-fluorouracil may produce deficits in the acquisition or retention of learned responses which suggest potential strategies for prevention or remediation might be considered in vulnerable patient populations. PMID:21537942

Tamoxifen from Failed Contraceptive Pill to Best-Selling Breast Cancer Medicine: A Case-Study in Pharmaceutical Innovation

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Viviane M. Quirke

2017-09-01

Full Text Available Today, tamoxifen is one of the world's best-selling hormonal breast cancer drugs. However, it was not always so. Compound ICI 46,474 (as it was first known was synthesized in 1962 within a project to develop a contraceptive pill in the pharmaceutical laboratories of ICI (now part of AstraZeneca. Although designed to act as an anti-estrogen, the compound stimulated, rather than suppressed ovulation in women. This, and the fact that it could not be patented in the USA, its largest potential market, meant that ICI nearly stopped the project. It was saved partly because the team's leader, Arthur Walpole, threatened to resign, and pressed on with another project: to develop tamoxifen as a treatment for breast cancer. Even then, its market appeared small, because at first it was mainly used as a palliative treatment for advanced breast cancer. An important turning point in tamoxifen's journey from orphan drug to best-selling medicine occurred in the 1980s, when clinical trials showed that it was also useful as an adjuvant to surgery and chemotherapy in the early stages of the disease. Later, trials demonstrated that it could prevent its occurrence or re-occurrence in women at high risk of breast cancer. Thus, it became the first preventive for any cancer, helping to establish the broader principles of chemoprevention, and extending the market for tamoxifen and similar drugs further still. Using tamoxifen as a case study, this paper discusses the limits of the rational approach to drug design, the role of human actors, and the series of feedback loops between bench and bedside that underpins pharmaceutical innovation. The paper also highlights the complex evaluation and management of risk that are involved in all therapies, but more especially perhaps in life-threatening and emotion-laden diseases like cancer.

National Prociency Testing Result of CYP2D6*10 Genotyping for Adjuvant Tamoxifen Therapy in China.

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Guigao Lin

Full Text Available Tamoxifen has been successfully used for treating breast cancer and preventing cancer recurrence. Cytochrome P450 2D6 (CYP2D6 plays a key role in the process of metabolizing tamoxifen to its active moiety, endoxifen. Patients with variants of the CYP2D6 gene may not receive the full benefit of tamoxifen treatment. The CYP2D6*10 variant (the most common variant in Asians was analyzed to optimize the prescription of tamoxifen in China. To ensure referring clinicians have accurate information for genotype-guided tamoxifen treatment, the Chinese National Center for Clinical Laboratories (NCCL organized a national proficiency testing (PT to evaluate the performance of laboratories providing CYP2D6*10 genotyping. Ten genomic DNA samples with CYP2D6 wild-type or CYP2D6*10 variants were validated by PCR-sequencing and sent to 28 participant laboratories. The genotyping results and pharmacogenomic test reports were submitted and evaluated by NCCL experts. Additional information regarding the number of samples tested, the accreditation/certification status, and detecting technology was also requested. Thirty-one data sets were received, with a corresponding analytical sensitivity of 98.2% (548/558 challenges; 95% confidence interval: 96.7-99.1% and an analytic specificity of 96.5% (675/682; 95% confidence interval: 97.9-99.5%. Overall, 25/28 participants correctly identified CYP2D6*10 status in 10 samples; however, two laboratories made serious genotyping errors. Most of the essential information was included in the 20 submitted CYP2D6*10 test reports. The majority of Chinese laboratories are reliable for detecting the CYP2D6*10 variant; however, several issues revealed in this study underline the importance of PT schemes in continued external assessment and provision of guidelines.

The distribution pattern of ERα expression, ESR1 genetic variation and expression of growth factor receptors: association with breast cancer prognosis in Russian patients treated with adjuvant tamoxifen.

Science.gov (United States)

Babyshkina, Nataliya; Vtorushin, Sergey; Zavyalova, Marina; Patalyak, Stanislav; Dronova, Tatyana; Litviakov, Nikolay; Slonimskaya, Elena; Kzhyshkowska, Julia; Cherdyntseva, Nadejda; Choynzonov, Evgeny

2017-08-01

Identification of additional biomarkers associated with ER genomic and nongenomic pathways could be very useful to distinguish patients who will benefit from tamoxifen treatment. The aim of this study was to analyze the prognostic significance of the distribution pattern of ERα expression, ESR1 gene single-nucleotide polymorphisms and expression levels of growth factor receptors in Russian hormone receptor-positive breast cancer patients treated with adjuvant tamoxifen. Formalin-fixed paraffin-embedded tumor tissue samples from 97 patients were examined for the distribution pattern of ERα expression, as well as for EGFR and TGF-βR1 expression by immunohistochemistry. Genotypes for ESR1 +30T>C (rs2077647) and ESR1 2014G>A (rs2228480) were analyzed using a TaqMan assay. Progression-free survival (PFS) was used as an endpoint for the survival analyses. We found that patients with the heterogeneous distribution of ERα expression had poor prognosis on tamoxifen treatment (P = 0.021). We identified a high EGFR expression in patients who developed distant metastasis or recurrence during tamoxifen treatment (a tamoxifen-resistant group-TR) in contrast to the distant metastasis-free patients (a tamoxifen-sensitive group-TS) (80.0 vs. 41.9 %, respectively, P = 0.009). Carriers of the ESR12014A mutant allele were more prevalent among the TR patients compared to the TS patients (26.3 vs. 8.0 %, respectively, P = 0.009). EGFR expression and the distribution pattern of ERα expression were associated with the response to tamoxifen by both univariate and multivariate logistic regression analyses. The presence of these markers either alone or in combination was correlated with the worse PFS for all patients. Analysis of the distribution pattern of ERα expression and the EGFR status in tumor tissue may be valuable for patient selection for tamoxifen adjuvant therapy.

Adjuvant letrozole versus tamoxifen according to centrally-assessed ERBB2 status for postmenopausal women with endocrine-responsive early breast cancer: supplementary results from the BIG 1-98 randomised trial

DEFF Research Database (Denmark)

Regan, M.M.; Lykkesfeldt, A.E.; Dell'Orto, P.

2008-01-01

Background The Breast International Group (BIG) 1-98 trial (a randomised double-blind phase III trial) has shown that letrozole significantly improves disease-free survival (DFS) compared with tamoxifen in postmenopausal women with endocrine-responsive early breast cancer. Our aim was to establish...... whether the benefit of letrozole versus tamoxifen differs according to the ERBB2 status of tumours. Methods The BIG 1-98 trial consists of four treatment groups that compare 5 years of monotherapy with letrozole or tamoxifen, and sequential administration of one drug for 2 years followed by the other drug...... for 3 years. Our study includes data from the 4922 patients randomly assigned to the two monotherapy treatment groups (letrozole or tamoxifen for 5 years; 51 months median follow-up [range

Implication of protein tyrosine phosphatase 1B in MCF-7 cell proliferation and resistance to 4-OH tamoxifen

International Nuclear Information System (INIS)

Blanquart, Christophe; Karouri, Salah-Eddine; Issad, Tarik

2009-01-01

The protein tyrosine phosphatase 1B (PTP1B) and the T-cell protein tyrosine phosphatase (TC-PTP) were initially thought to be mainly anti-oncogenic. However, overexpression of PTP1B and TC-PTP has been observed in human tumors, and recent studies have demonstrated that PTP1B contributes to the appearance of breast tumors by modulating ERK pathway. In the present work, we observed that decreasing the expression of TC-PTP or PTP1B in MCF-7 cells using siRNA reduced cell proliferation without affecting cell death. This reduction in proliferation was associated with decreased ERK phosphorylation. Moreover, selection of tamoxifen-resistant MCF-7 cells, by long-term culture in presence of 4-OH tamoxifen, resulted in cells that display overexpression of PTP1B and TC-PTP, and concomitant increase in ERK and STAT3 phosphorylation. siRNA experiments showed that PTP1B, but not TC-PTP, is necessary for resistance to 4-OH tamoxifen. Therefore, our work indicates that PTP1B could be a relevant therapeutic target for treatment of tamoxifen-resistant breast cancers.

Effects of liarozole fumarate (R85246) in combination with tamoxifen on N-methyl-N-nitrosourea (MNU)-induced mammary carcinoma and uterus in the rat model

International Nuclear Information System (INIS)

Goss, Paul E; Strasser-Weippl, Kathrin; Qi, Shangle; Hu, Haiqing

2007-01-01

Liarozole fumarate (liarozole – R85246) is a novel compound with characteristics of both aromatase inhibitor (AI) and a retinoic acid metabolism blocking agent (RAMBA). Our objective was to determine the effects of liarozole alone or in combination with tamoxifen on the N-methyl-N-nitrosourea (MNU)-induced rat mammary carcinoma model, as well as on the uterus in ovariectomized immature rats. (1) Tumor burden experiments: Animals bearing one or more tumors greater than 10 mm in diameter were treated for 56 consecutive days with 20 mg/kg or 80 mg/kg of liarozole by oral gavage, tamoxifen 100 μg/kg by subcutaneous injection, or a combination of liarozole and tamoxifen. At the end of the treatment period, total cumulative tumor volume as well as retinoic acid levels were measured. (2) Uterotrophic assay and proliferation experiments: 21-day-old ovariectomized (OVX) Sprague-Dawley rats were treated with 20 mg/kg or 80 mg/kg of liarozole by oral gavage, tamoxifen 1 mg/kg by subcutaneous injection, and combination of both for 4 consecutive days. At the end of the treatment period, uterine weight, epithelial lining cell height and indices of proliferation cell nuclear antigen (PCNA) were measured. The tumor burden experiments in rats bearing estrogen receptor (ER) positive mammary tumours showed that liarozole has a marked anti-tumour effect. In combination with tamoxifen, liarozole had neither an additive nor an antagonistic effect. However, liarozole markedly reduced the uterotrophic effects induced by tamoxifen. Liarozole's antitumor effects on ER positive mammary tumors and its protective effect on the uterus merit further studies to confirm its clinical value in combination with tamoxifen in ER positive postmenopausal breast cancer. Liarozole and other retinomimetics might also be suitable chemoprevention drugs in combination with tamoxifen because of their favorable toxicity profile

Smart coumarin-tagged imprinted polymers for the rapid detection of tamoxifen.

Science.gov (United States)

Ray, Judith V; Mirata, Fosca; Pérollier, Celine; Arotcarena, Michel; Bayoudh, Sami; Resmini, Marina

2016-03-01

A signalling molecularly imprinted polymer was synthesised for easy detection of tamoxifen and its metabolites. 6-Vinylcoumarin-4-carboxylic acid (VCC) was synthesised from 4-bromophenol to give a fluorescent monomer, designed to switch off upon binding of tamoxifen. Clomiphene, a chlorinated analogue, was used as the template for the imprinting, and its ability to quench the coumarin fluorescence when used in a 1:1 ratio was demonstrated. Tamoxifen and 4-hydroxytamoxifen were also shown to quench coumarin fluorescence. Imprinted and non-imprinted polymers were synthesised using VCC, methacrylic acid as a backbone monomer and ethylene glycol dimethacrylate as cross-linker, and were ground and sieved to particle sizes ranging between 45 and 25 μm. Rebinding experiments demonstrate that the imprinted polymer shows very strong affinity for both clomiphene and tamoxifen, while the non-imprinted polymer shows negligible rebinding. The fluorescence of the imprinted polymer is quenched by clomiphene, tamoxifen and 4-hydroxytamoxifen. The switch off in fluorescence of the imprinted polymer under these conditions could also be detected under a UV lamp with the naked eye, making this matrix suitable for applications when coupled with a sample preparation system.

CYP2C19*2 and CYP2C19*17 variants and effect of tamoxifen on breast cancer recurrence

DEFF Research Database (Denmark)

Damkier, Per; Kjaersgaard, Anders; Barker, Kimberly A.

2017-01-01

*17 allele were 1.02 (CI 0.71-1.46) and 0.57 (CI 0.26-1.24), respectively. Accounting for CYP2D6 genotype status did not change these estimates. We found no evidence to support a clinically meaningful role of CYP2C19 polymorphisms and response to tamoxifen in breast cancer patients and, consequently, CYP2C19...... genotype status should not be included in clinical decisions on tamoxifen treatment....

Uptake of tamoxifen in consecutive premenopausal women under surveillance in a high-risk breast cancer clinic.

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Donnelly, L S; Evans, D G; Wiseman, J; Fox, J; Greenhalgh, R; Affen, J; Juraskova, I; Stavrinos, P; Dawe, S; Cuzick, J; Howell, A

2014-04-02

Randomised trials of tamoxifen versus placebo indicate that tamoxifen reduces breast cancer risk by approximately 33%, yet uptake is low. Approximately 10% of women in our clinic entered the IBIS-I prevention trial. We assess the uptake of tamoxifen in a consecutive series of premenopausal women not in a trial and explore the reasons for uptake through interviews. All eligible women between 33 and 46 years at ≥17% lifetime risk of breast cancer and undergoing annual mammography in our service were invited to take a 5-year course of tamoxifen. Reasons for accepting (n=15) or declining (n=15) were explored using semi-structured interviews. Of 1279 eligible women, 136 (10.6%) decided to take tamoxifen. Women >40 years (74 out of 553 (13.4%)) and those at higher non-BRCA-associated risk were more likely to accept tamoxifen (129 out of 1109 (11.6%)). Interviews highlighted four themes surrounding decision making: perceived impact of side effects, the impact of others' experience on beliefs about tamoxifen, tamoxifen as a 'cancer drug', and daily reminder of cancer risk. Tamoxifen uptake was similar to previously ascertained uptake in a randomised controlled trial (IBIS-I). Concerns were similar in women who did or did not accept tamoxifen. Decision making appeared to be embedded in the experience of significant others.

Bone fractures among postmenopausal patients with endocrine-responsive early breast cancer treated with 5 years of letrozole or tamoxifen in the BIG 1-98 trial

DEFF Research Database (Denmark)

Rabaglio, M; Sun, Z; Price, K N

2009-01-01

of letrozole or tamoxifen in the BIG 1-98 trial who received at least some study medication (median follow-up 60.3 months). Bone fracture information (grade, cause, site) was collected every 6 months during trial treatment. RESULTS: The incidence of bone fractures was higher among patients treated......BACKGROUND: To compare the incidence and timing of bone fractures in postmenopausal women treated with 5 years of adjuvant tamoxifen or letrozole for endocrine-responsive early breast cancer in the Breast International Group (BIG) 1-98 trial. METHODS: We evaluated 4895 patients allocated to 5 years...... with letrozole [228 of 2448 women (9.3%)] versus tamoxifen [160 of 2447 women (6.5%)]. The wrist was the most common site of fracture in both treatment groups. Statistically significant risk factors for bone fractures during treatment included age, smoking history, osteoporosis at baseline, previous bone...

Motivators and barriers of tamoxifen use as risk-reducing medication amongst women at increased breast cancer risk: a systematic literature review.

Science.gov (United States)

Meiser, B; Wong, W K T; Peate, M; Julian-Reynier, C; Kirk, J; Mitchell, G

2017-01-01

Selective estrogen receptor modulators, such as tamoxifen, reduce breast cancer risk by up to 50% in women at increased risk for breast cancer. Despite tamoxifen's well-established efficacy, many studies show that most women are not taking up tamoxifen. This systematic literature review aimed to identify the motivators and barriers to tamoxifen use 's amongst high-risk women. Using MEDLINE, PsycINFO, and Embase plus reviewing reference lists of relevant articles published between 1995 and 2016, 31 studies (published in 35 articles) were identified, which addressed high-risk women's decisions about risk-reducing medication to prevent breast cancer and were peer-reviewed primary clinical studies. A range of factors were identified as motivators of, and barriers to, tamoxifen uptake including: perceived risk, breast-cancer-related anxiety, health professional recommendation, perceived drug effectiveness, concerns about side-effects, knowledge and access to information about side-effects, beliefs about the role of risk-reducing medication, provision of a biomarker, preference for other forms of breast cancer risk reduction, previous treatment experience, concerns about randomization in clinical trial protocols and finally altruism. Results indicate that the decision for high-risk women regarding tamoxifen use or non-use as a risk-reducing medication is not straightforward. Support of women making this decision is essential and needs to encompass the full range of factors, both informational and psychological.

THE PROFILE OF TAMOXIFEN USER DUE TO GYNECOMASTIA INDUCED BY ANABOLIC STEROIDS FOR BODYBUILDERS OR BODYBUILDING

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E. Santos

2016-09-01

Full Text Available Due to valorization of body appearance, the seek for a good physic body gets a central importance in externalization of subjectivity and in the construction the identities of the people. Because of this, them invest time to look for devices to streamline results to get a perfect body, between mechanisms used there is the use of anabolic steroids (AS. With the rapid response this kind of treatment, there are aware concerns their side effects such as gynecomastia which is characterized by breast enlargement of man. In an attempt to prevent this effect aesthetically uncomfortable, the users seek take medicines such as tamoxifen to reverse or prevent this situation without proper prescription or monitoring of a pharmacist professional, as well as almost all treatments with EA which are made clandestinely. This work aimed to describe profile among consumers seeking the tamoxifen therapy to prevent or treat gynecomastia induced using EA. The target audience was composed of bodybuilders men that were making anabolic cycles, aiming fast muscular hypertrophy. Two questionnaires were applied, one to the drugstores that sell these drugs and one for bodybuilders who buy these drugs. Tamoxifen user profile found in this study shows that they are young people aged 18 to 35 years old, seeking muscle hypertrophy strength. As the natural results are slow, influenced by training friends, start using EA, even declaring know about the risks to health. Use along with these steroids, tamoxifen, in an attempt to prevent or treat gynecomastia, get the medication in drugstores without a prescription and without the pharmacist questioning, demonstrating that pharmaceutical care is still not fully deployed and functioning

Tamoxifen therapy for the management of pubertal gynecomastia: a systematic review

NARCIS (Netherlands)

Lapid, Oren; van Wingerden, Jan J.; Perlemuter, Leon

2013-01-01

Objective: A systematic review to assess the efficacy of tamoxifen in the management of idiopathic pubertal gynecomastia. Data sources: Searches were conducted using the databases of Medline (search engine PubMed) and Web of Science (R). Study selection: Studies reporting the use of Tamoxifen for

Poly(amidoamine-Cholesterol Conjugate Nanoparticles Obtained by Electrospraying as Novel Tamoxifen Delivery System

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R. Cavalli

2011-01-01

Full Text Available A new poly(amidoamine-cholesterol (PAA-cholesterol conjugate was synthesized, characterized and used to produce nanoparticles by the electrospraying technique. The electrospraying is a method of liquid atomization that consists in the dispersion of a solution into small charged droplets by an electric field. Tuning the electrospraying process parameters spherical PAA-chol nanoparticles formed. The PAA-cholesterol nanoparticles showed sizes lower than 500 nm and spherical shape. The drug incorporation capacity was investigated using tamoxifen, a lipophilic anticancer drug, as model drug. The incorporation of the tamoxifen did not affect the shape and sizes of nanoparticles showing a drug loading of 40%. Tamoxifen-loaded nanoparticles exhibited a higher dose-dependent cytotoxicity than free tamoxifen, while blank nanoparticles did not show any cytotoxic effect at the same concentrations. The electrospray technique might be proposed to produce tamoxifen-loaded PAA-chol nanoparticle in powder form without any excipient in a single step.

Tamoxifen-loaded polymeric micelles: preparation, physico-chemical characterization and in vitro evaluation studies.

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Cavallaro, Gennara; Maniscalco, Laura; Licciardi, Mariano; Giammona, Gaetano

2004-11-20

Several samples of polymeric micelles, formed by amphiphilic derivatives of PHEA, obtained by grafting into polymeric backbone of PEGs and/or hexadecylamine groups (PHEA-PEG-C(16) and PHEA-C(16)) and containing different amount of Tamoxifen, were prepared. All Tamoxifen-loaded polymeric micelles showed to increase drug water solubility. TEM studies provided evidence of the formation of supramolecular core/shell architectures containing drug, in the nanoscopic range and with spherical shape. Samples with different amount of encapsulated Tamoxifen were subjected to in vitro cytotoxic studies in order to evaluate the effect of Tamoxifen micellization on cell growth inhibition. All samples of Tamoxifen-loaded polymeric micelles showed a significantly higher antiproliferative activity in comparison with free drug, probably attributable to fluidification of cellular membranes, caused by amphiphilic copolymers, that allows a higher penetration of the drug into tumoral cells. To gain preliminary information about the potential use of prepared micelles as Tamoxifen drug delivery systems, studies evaluating drug release ability of micelle systems in media mimicking biological fluids (buffer solutions at pH 7.4 and 5.5) and in human plasma were carried out. These studies, performed evaluating the amount of Tamoxifen that remains in solution as a function of time, showed that at pH 7.4, as well as in plasma, PHEA-C(16) polymeric micelles were able to release lower drug amounts than PHEA-PEG(5000)-C(16) ones, while at pH 5.5, the behavior difference between two kind of micelles was less pronounced.

Integrative analyses of gene expression and DNA methylation profiles in breast cancer cell line models of tamoxifen-resistance indicate a potential role of cells with stem-like properties

DEFF Research Database (Denmark)

Lin, Xue; Li, Jian; Yin, Guangliang

2013-01-01

Development of resistance to tamoxifen is an important clinical issue in the treatment of breast cancer. Tamoxifen resistance may be the result of acquisition of epigenetic regulation within breast cancer cells, such as DNA methylation, resulting in changed mRNA expression of genes pivotal for es...

Estrogen receptor alpha/beta ratio and estrogen receptor beta as predictors of endocrine therapy responsiveness–a randomized neoadjuvant trial comparison between anastrozole and tamoxifen for the treatment of postmenopausal breast cancer

International Nuclear Information System (INIS)

Madeira, Marcelo; Mattar, André; Logullo, Ângela Flávia; Soares, Fernando Augusto; Gebrim, Luiz Henrique

2013-01-01

The role of estrogen receptor beta (ER-β) in breast cancer (BC) remains unclear. Some studies have suggested that ER-β may oppose the actions of estrogen receptor alpha (ER-α), and clinical evidence has indicated that the loss of ER-β expression is associated with a poor prognosis and resistance to endocrine therapy. The objective of the present study was to determine the role of ER-β and the ER-α/ER-β ratio in predicting the response to endocrine therapy and whether different regimens have any effect on ER-β expression levels. Ninety postmenopausal patients with primary BC were recruited for a short-term double-blinded randomized prospective controlled study. To determine tumor cell proliferation, we measured the expression of Ki67 in tumor biopsy samples taken before and after 26 days of treatment with anastrozole 1 mg/day (N = 25), tamoxifen 20 mg/day (N = 24) or placebo (N = 29) of 78 participants. The pre- and post-samples were placed in tissue microarray blocks and submitted for immunohistochemical assay. Biomarker statuses (ER-β, ER-α and Ki67) were obtained by comparing each immunohistochemical evaluation of the pre- and post-surgery samples using the semi-quantitative Allred’s method. Statistical analyses were performed using an ANOVA and Spearman’s correlation coefficient tests, with significance at p ≤ 0.05. The frequency of ER-β expression did not change after treatment (p = 0.33). There were no significant changes in Ki67 levels in ER-β-negative cases (p = 0.45), but in the ER-β-positive cases, the anastrozole (p = 0.01) and tamoxifen groups (p = 0.04) presented a significant reduction in post-treatment Ki67 scores. There was a weak but positive correlation between the ER-α and ER-β expression levels. Only patients with an ER-α/ER-β expression ratio between 1 and 1.5 demonstrated significant differences in Ki67 levels after treatment with anastrozole (p = 0.005) and tamoxifen (p = 0.026). Our results provide additional data that

Glucose impairs tamoxifen responsiveness modulating connective tissue growth factor in breast cancer cells.

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Ambrosio, Maria Rosaria; D'Esposito, Vittoria; Costa, Valerio; Liguoro, Domenico; Collina, Francesca; Cantile, Monica; Prevete, Nella; Passaro, Carmela; Mosca, Giusy; De Laurentiis, Michelino; Di Bonito, Maurizio; Botti, Gerardo; Franco, Renato; Beguinot, Francesco; Ciccodicola, Alfredo; Formisano, Pietro

2017-12-12

Type 2 diabetes and obesity are negative prognostic factors in patients with breast cancer (BC). We found that sensitivity to tamoxifen was reduced by 2-fold by 25 mM glucose (High Glucose; HG) compared to 5.5 mM glucose (Low Glucose; LG) in MCF7 BC cells. Shifting from HG to LG ameliorated MCF7 cell responsiveness to tamoxifen. RNA-Sequencing of MCF7 BC cells revealed that cell cycle-related genes were mainly affected by glucose. Connective Tissue Growth Factor (CTGF) was identified as a glucose-induced modulator of cell sensitivity to tamoxifen. Co-culturing MCF7 cells with human adipocytes exposed to HG, enhanced CTGF mRNA levels and reduced tamoxifen responsiveness of BC cells. Inhibition of adipocyte-released IL8 reverted these effects. Interestingly, CTGF immuno-detection in bioptic specimens from women with estrogen receptor positive (ER + ) BC correlated with hormone therapy resistance, distant metastases, reduced overall and disease-free survival. Thus, glucose affects tamoxifen responsiveness directly modulating CTGF in BC cells, and indirectly promoting IL8 release by adipocytes.

Development of biodegradable polymer based tamoxifen citrate loaded nanoparticles and effect of some manufacturing process parameters on them: a physicochemical and in-vitro evaluation

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Basudev Sahana

2010-08-01

Full Text Available Basudev Sahana, Kousik Santra, Sumit Basu, Biswajit MukherjeeDepartment of Pharmaceutical Technology, Jadavpur University, Kolkata, IndiaAbstract: The aim of the present study was to develop nanoparticles of tamoxifen citrate, a non-steroidal antiestrogenic drug used for the treatment of breast cancer. Biodegradable poly (D, L- lactide-co-glycolide-85:15 (PLGA was used to develop nanoparticles of tamoxifen citrate by multiple emulsification (w/o/w and solvent evaporation technique. Drug-polymer ratio, polyvinyl alcohol concentrations, and homogenizing speeds were varied at different stages of preparation to optimize the desired size and release profile of drug. The characterization of particle morphology and shape was performed by field emission scanning electron microscope (FE-SEM and particle size distribution patterns were studied by direct light scattering method using zeta sizer. In vitro drug release study showed that release profile of tamoxifen from biodegradable nanoparticles varied due to the change in speed of centrifugation for separation. Drug loading efficiency varied from 18.60% to 71.98%. The FE-SEM study showed that biodegradable nanoparticles were smooth and spherical in shape. The stability studies of tamoxifen citrate in the experimental nanoparticles showed the structural integrity of tamoxifen citrate in PLGA nanoparticles up to 60°C in the tested temperatures. Nanoparticles containing tamoxifen citrate could be useful for the controlled delivery of the drug for a prolonged period.Keywords: biodegradable, nanoparticles, PLGA, stability, tamoxifen citrate

Tamoxifen for prevention of breast cancer: extended long-term follow-up of the IBIS-I breast cancer prevention trial.

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Cuzick, Jack; Sestak, Ivana; Cawthorn, Simon; Hamed, Hisham; Holli, Kaija; Howell, Anthony; Forbes, John F

2015-01-01

Four previously published randomised clinical trials have shown that tamoxifen can reduce the risk of breast cancer in healthy women at increased risk of breast cancer in the first 10 years of follow-up. We report the long-term follow-up of the IBIS-I trial, in which the participants and investigators remain largely masked to treatment allocation. In the IBIS-I randomised controlled trial, premenopausal and postmenopausal women 35-70 years of age deemed to be at an increased risk of developing breast cancer were randomly assigned (1:1) to receive oral tamoxifen 20 mg daily or matching placebo for 5 years. Patients were randomly assigned to the two treatment groups by telephone or fax according to a block randomisation schedule (permuted block sizes of six or ten). Patients and investigators were masked to treatment assignment by use of central randomisation and coded drug supply. The primary endpoint was the occurrence of breast cancer (invasive breast cancer and ductal carcinoma in situ), analysed by intention to treat. Cox proportional hazard models were used to assess breast cancer occurrence and mortality. The trial is closed to recruitment and active treatment is completed, but long-term follow-up is ongoing. This trial is registered with controlledtrials.com, number ISRCTN91879928. Between April 14, 1992, and March 30, 2001, 7154 eligible women recruited from genetics clinics and breast care clinics in eight countries were enrolled into the IBIS-I trial and were randomly allocated to the two treatment groups: 3579 to tamoxifen and 3575 to placebo. After a median follow up of 16.0 years (IQR 14.1-17.6), 601 breast cancers have been reported (251 [7.0%] in 3579 patients in the tamoxifen group vs 350 [9.8%] in 3575 women in the placebo group; hazard ratio [HR] 0.71 [95% CI 0.60-0.83], pbreast cancer was similar between years 0-10 (226 [6.3%] in 3575 women in the placebo group vs 163 [4.6%] in 3579 women in the tamoxifen group; hazard ratio [HR] 0.72 [95% CI 0

Production and Investigation of Controlled Drug Release Properties of Tamoxifen Loaded Alginate-Gum Arabic Microbeads

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Rukiye Yavaşer

2016-08-01

Full Text Available The entrapment of tamoxifen onto alginate-gum arabic beads and the production of controlled drug release was investigated in this study. The polymeric system that would provide the controlled release of tamoxifen was formed using alginate and gum arabic. In the first phase of the study, the optimization of the alginate-gum arabic beads production was conducted; then the study continued with drug entrapment experiments. Tamoxifen entrapment yield was found to be approximately 90% of initial tamoxifen concentration. In vitro drug release experiments were performed in simulated gastric juice and intestinal fluid where the tamoxifen release was 20% and 53% of the initial drug present, respectively. As a result of this study, it is expected that a valuable contribution to the field of controlled drug release system production is realized.

Tamoxifen-independent recombination in the RIP-CreER mouse.

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Yanmei Liu

Full Text Available BACKGROUND: The inducible Cre-lox system is a valuable tool to study gene function in a spatial and time restricted fashion in mouse models. This strategy relies on the limited background activity of the modified Cre recombinase (CreER in the absence of its inducer, the competitive estrogen receptor ligand, tamoxifen. The RIP-CreER mouse (Tg (Ins2-cre/Esr1 1Dam is among the few available β-cell specific CreER mouse lines and thus it has been often used to manipulate gene expression in the insulin-producing cells of the endocrine pancreas. PRINCIPAL FINDINGS: Here, we report the detection of tamoxifen-independent Cre activity as early as 2 months of age in RIP-CreER mice crossed with three distinct reporter strains. SIGNIFICANCE: Evidence of Cre-mediated recombination of floxed alleles even in the absence of tamoxifen administration should warrant cautious use of this mouse for the study of pancreatic β-cells.

Thrombosis of digital arteries associated with tamoxifen use: case report.

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Hutchison, Richard L; Rayan, Ghazi M

2012-02-01

Arterial thrombosis in the upper extremity occurs often at the wrist. We report a unique case of thrombosis that involved multiple digital arteries, without radial or ulnar artery involvement, which developed only after using tamoxifen despite chronic occupational blunt percussive hand use. Revascularization was achieved after thrombectomy. Multiple digital arterial thromboses may complicate the use of tamoxifen. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

A tamoxifen inducible knock-in allele for investigation of E2A function

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Kondo Motonari

2009-10-01

Full Text Available Abstract Background E-proteins are transcription factors important for the development of a variety of cell types, including neural, muscle and lymphocytes of the immune system. E2A, the best characterized E-protein family member in mammals, has been shown to have stage specific roles in cell differentiation, lineage commitment, proliferation, and survival. However, due to the complexity of E2A function, it is often difficult to separate these roles using conventional genetic approaches. Here, we have developed a new genetic model for reversible control of E2A protein activity at physiological levels. This system was created by inserting a tamoxifen-responsive region of the estrogen receptor (ER at the carboxyl end of the tcfe2a gene to generate E2AER fusion proteins. We have characterized and analyzed the efficiency and kinetics of this inducible E2AER system in the context of B cell development. Results B cell development has been shown previously to be blocked at an early stage in E2A deficient animals. Our E2AER/ER mice demonstrated this predicted block in B cell development, and E2AER DNA binding activity was not detected in the absence of ligand. In vitro studies verified rapid induction of E2AER DNA binding activity upon tamoxifen treatment. While tamoxifen treatment of E2AER/ER mice showed inefficient rescue of B cell development in live animals, direct exposure of bone marrow cells to tamoxifen in an ex vivo culture was sufficient to rescue and support early B cell development from the pre-proB cell stage. Conclusion The E2AER system provides inducible and reversible regulation of E2A function at the protein level. Many previous studies have utilized over-expression systems to induce E2A function, which are complicated by the toxicity often resulting from high levels of E2A. The E2AER model instead restores E2A activity at an endogenous level and in addition, allows for tight regulation of the timing of induction. These features make

Tamoxifen Promotes Axonal Preservation and Gait Locomotion Recovery after Spinal Cord Injury in Cats

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Braniff de la Torre Valdovinos

2016-01-01

Full Text Available We performed experiments in cats with a spinal cord penetrating hemisection at T13-L1 level, with and without tamoxifen treatment. The results showed that the numbers of the ipsilateral and contralateral ventral horn neurons were reduced to less than half in the nontreated animals compared with the treated ones. Also, axons myelin sheet was preserved to almost normal values in treated cats. On the contrary, in the untreated animals, their myelin sheet was reduced to 28% at 30 days after injury (DAI, in both the ipsilateral and contralateral regions of the spinal cord. Additionally, we made hindlimb kinematics experiments to study the effects of tamoxifen on cat locomotion after the injury: at 4, 16, and 30 DAI. We observed that the ipsilateral hindlimb angular displacement (AD of the pendulum-like movements (PLM during gait locomotion was recovered to almost normal values in treated cats. Contralateral PLM acquired similar values to those obtained in intact cats. At 4 DAI, untreated animals showed a compensatory increment of PLM occurring in the contralateral hindlimb, which was partially recovered at 30 DAI. Our findings indicate that tamoxifen exerts a neuroprotective effect and preserves or produces myelinated axons, which could benefit the locomotion recovery in injured cats.

Toxicidade ocular causada pelo tamoxifeno: relato de caso Ocular toxicity caused by tamoxifen: case report

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Eliane Terumi Inada

2005-08-01

Full Text Available O objetivo desse trabalho é relatar um caso de toxicidade ocular pelo tamoxifeno. Para isso, aferiu-se a melhor acuidade visual corrigida de ambos os olhos em tabela de Snellen. Foram realizados biomicroscopia do segmento anterior, refração, oftalmoscopia, angiofluoresceinografia e retinografia numa paciente de 63 anos, sexo feminino, cor branca, em uso de tamoxifeno 20 mg/dia há 4 anos, com acuidade visual corrigida de 20/70 e 20/40. A biomicroscopia do segmento anterior apresentava ceratopatia verticilata e catarata nuclear e cortical posterior de 1+/4 em ambos os olhos. À oftalmoscopia, foi verificado alteração do brilho macular de ambos os olhos. E a angiofluoresceinografia mostrou hiperfluorescência na área macular em fase precoce (defeito em janela. Relata-se um caso de ceratopatia e maculopatia causadas pelo tamoxifeno.To report tamoxifen ocular toxicity. The best visual acuity was measured in both eyes with Snellen chart, slit-lamp examination of anterior segment, refraction, dilated fundus examination, fluorescein angiography and retinography in a 63-year-old patient, female, white, using tamoxifen 20 mg/day for 4 years, with 20/70 and 20/40 corrected visual acuity. The anterior segment examination showed corneal linear subepithelial opacity inferior to the visual axis and nuclear and posterior cortical cataract (1+/4 in both eyes. Fundus examination showed alteration of macular color in both eyes. Fluorescein angiography presented hyperfluorescence in the macular area at an early phase (window defect. Report of keratopathy and maculopathy caused by tamoxifen.

Targeting glycolysis by 3-bromopyruvate improves tamoxifen cytotoxicity of breast cancer cell lines.

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Attia, Yasmin M; El-Abhar, Hanan S; Al Marzabani, Mahmoud M; Shouman, Samia A

2015-11-03

Tamoxifen is the standard endocrine therapy for ER+ breast cancer; however, many women still relapse after long-term therapy. 3-Bromopyruvate, a glycolytic inhibitor, has shown high selective anti-tumor activity in vitro, and in vivo. The aim of this study was to evaluate the possible augmentation of the effect of tamoxifen via reprograming cancer cell metabolism using 3-bromopyruvate. An in vitro screening of antitumor activity as well as the apoptotic, anti-metastatic, and anti-angiogenic potentials of the combination therapy were carried out using different techniques on breast cancer cell lines MCF7and T47D. In addition the antitumor effect of the combined therapy was done on mice bearing tumor. Our results showed modulation in apoptosis, angiogenesis and metastatic potential by either drug alone; however, their combination has surpassed that of the individual one. Combination regimen enhanced activated caspases-3, 7 and 9, as well as oxidative stress, signified by increased malondialdehyde and decreased glutathione level. Additionally, the angiogenesis and metastasis markers, including hypoxia inducing factor-1α, vascular endothelia growth factor, and metaloproteinases-2 and 9 were decreased after using the combination regimen. These results were further confirmed by the in vivo study, which depicted a decrease in the tumor volume and angiogenesis and an increase in oxidative stress as well. 3-bromopyruvate could be a valuable compound when added with tamoxifen in breast cancer treatment.

Targeting glycolysis by 3-bromopyruvate improves tamoxifen cytotoxicity of breast cancer cell lines

International Nuclear Information System (INIS)

Attia, Yasmin M.; EL-Abhar, Hanan S.; Al Marzabani, Mahmoud M.; Shouman, Samia A.

2015-01-01

Tamoxifen is the standard endocrine therapy for ER+ breast cancer; however, many women still relapse after long-term therapy. 3-Bromopyruvate, a glycolytic inhibitor, has shown high selective anti-tumor activity in vitro, and in vivo. The aim of this study was to evaluate the possible augmentation of the effect of tamoxifen via reprograming cancer cell metabolism using 3-bromopyruvate. An in vitro screening of antitumor activity as well as the apoptotic, anti-metastatic, and anti-angiogenic potentials of the combination therapy were carried out using different techniques on breast cancer cell lines MCF7and T47D. In addition the antitumor effect of the combined therapy was done on mice bearing tumor. Our results showed modulation in apoptosis, angiogenesis and metastatic potential by either drug alone; however, their combination has surpassed that of the individual one. Combination regimen enhanced activated caspases-3, 7 and 9, as well as oxidative stress, signified by increased malondialdehyde and decreased glutathione level. Additionally, the angiogenesis and metastasis markers, including hypoxia inducing factor-1α, vascular endothelia growth factor, and metaloproteinases-2 and 9 were decreased after using the combination regimen. These results were further confirmed by the in vivo study, which depicted a decrease in the tumor volume and angiogenesis and an increase in oxidative stress as well. 3-bromopyruvate could be a valuable compound when added with tamoxifen in breast cancer treatment

CYP2D6 genotype and tamoxifen response in postmenopausal women with endocrine-responsive breast cancer

DEFF Research Database (Denmark)

Regan, Meredith M; Leyland-Jones, Brian; Bouzyk, Mark

2012-01-01

Adjuvant tamoxifen therapy is effective for postmenopausal women with endocrine-responsive breast cancer. Cytochrome P450 2D6 (CYP2D6) enzyme metabolizes tamoxifen to clinically active metabolites, and CYP2D6 polymorphisms may adversely affect tamoxifen efficacy. In this study, we investigated...

Direct and Systemic Administration of a CNS-Permeant Tamoxifen Analog Reduces Amphetamine-Induced Dopamine Release and Reinforcing Effects.

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Carpenter, Colleen; Zestos, Alexander G; Altshuler, Rachel; Sorenson, Roderick J; Guptaroy, Bipasha; Showalter, Hollis D; Kennedy, Robert T; Jutkiewicz, Emily; Gnegy, Margaret E

2017-09-01

Amphetamines (AMPHs) are globally abused. With no effective treatment for AMPH addiction to date, there is urgent need for the identification of druggable targets that mediate the reinforcing action of this stimulant class. AMPH-stimulated dopamine efflux is modulated by protein kinase C (PKC) activation. Inhibition of PKC reduces AMPH-stimulated dopamine efflux and locomotor activity. The only known CNS-permeant PKC inhibitor is the selective estrogen receptor modulator tamoxifen. In this study, we demonstrate that a tamoxifen analog, 6c, which more potently inhibits PKC than tamoxifen but lacks affinity for the estrogen receptor, reduces AMPH-stimulated increases in extracellular dopamine and reinforcement-related behavior. In rat striatal synaptosomes, 6c was almost fivefold more potent at inhibiting AMPH-stimulated dopamine efflux than [ 3 H]dopamine uptake through the dopamine transporter (DAT). The compound did not compete with [ 3 H]WIN 35,428 binding or affect surface DAT levels. Using microdialysis, direct accumbal administration of 1 μM 6c reduced dopamine overflow in freely moving rats. Using LC-MS, we demonstrate that 6c is CNS-permeant. Systemic treatment of rats with 6 mg/kg 6c either simultaneously or 18 h prior to systemic AMPH administration reduced both AMPH-stimulated dopamine overflow and AMPH-induced locomotor effects. Finally, 18 h pretreatment of rats with 6 mg/kg 6c s.c. reduces AMPH-self administration but not food self-administration. These results demonstrate the utility of tamoxifen analogs in reducing AMPH effects on dopamine and reinforcement-related behaviors and suggest a new avenue of development for therapeutics to reduce AMPH abuse.

The formation of estrogen-like tamoxifen metabolites and their influence on enzyme activity and gene expression of ADME genes.

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Johänning, Janina; Kröner, Patrick; Thomas, Maria; Zanger, Ulrich M; Nörenberg, Astrid; Eichelbaum, Michel; Schwab, Matthias; Brauch, Hiltrud; Schroth, Werner; Mürdter, Thomas E

2018-03-01

Tamoxifen, a standard therapy for breast cancer, is metabolized to compounds with anti-estrogenic as well as estrogen-like action at the estrogen receptor. Little is known about the formation of estrogen-like metabolites and their biological impact. Thus, we characterized the estrogen-like metabolites tamoxifen bisphenol and metabolite E for their metabolic pathway and their influence on cytochrome P450 activity and ADME gene expression. The formation of tamoxifen bisphenol and metabolite E was studied in human liver microsomes and Supersomes™. Cellular metabolism and impact on CYP enzymes was analyzed in upcyte® hepatocytes. The influence of 5 µM of tamoxifen, anti-estrogenic and estrogen-like metabolites on CYP activity was measured by HPLC MS/MS and on ADME gene expression using RT-PCR analyses. Metabolite E was formed from tamoxifen by CYP2C19, 3A and 1A2 and from desmethyltamoxifen by CYP2D6, 1A2 and 3A. Tamoxifen bisphenol was mainly formed from (E)- and (Z)-metabolite E by CYP2B6 and CYP2C19, respectively. Regarding phase II metabolism, UGT2B7, 1A8 and 1A3 showed highest activity in glucuronidation of tamoxifen bisphenol and metabolite E. Anti-estrogenic metabolites (Z)-4-hydroxytamoxifen, (Z)-endoxifen and (Z)-norendoxifen inhibited the activity of CYP2C enzymes while tamoxifen bisphenol consistently induced CYPs similar to rifampicin and phenobarbital. On the transcript level, highest induction up to 5.6-fold was observed for CYP3A4 by tamoxifen, (Z)-4-hydroxytamoxifen, tamoxifen bisphenol and (E)-metabolite E. Estrogen-like tamoxifen metabolites are formed in CYP-dependent reactions and are further metabolized by glucuronidation. The induction of CYP activity by tamoxifen bisphenol and the inhibition of CYP2C enzymes by anti-estrogenic metabolites may lead to drug-drug-interactions.

Levonorgestrel intrauterine system for endometrial protection in women with breast cancer on adjuvant tamoxifen.

Science.gov (United States)

Dominick, Sally; Hickey, Martha; Chin, Jason; Su, H Irene

2015-12-09

endometrial biopsy. Secondary outcome measures included fibroids, abnormal vaginal bleeding or spotting, breast cancer recurrence, and breast cancer-related deaths. The overall quality of evidence was rated using GRADE methods. Four randomised controlled trials involving 543 women were identified and are included in this review. In the included studies, the active treatment arm was the 20 μg/day levonorgestrel-releasing intrauterine system (LNG-IUS) plus endometrial surveillance; the control arm was endometrial surveillance alone. In tamoxifen users, the LNG-IUS led to a reduction in the incidence of endometrial polyps over both a 12-month period (Peto OR 0.22, 95% CI 0.08 to 0.64, 2 studies, n = 212, I² = 0%) and over a long-term follow-up period (24 to 60 months) (Peto OR 0.22, 95% CI 0.13 to 0.39, 4 studies, n = 417, I² = 0%, moderate quality evidence). Also the LNG-IUS led to a reduction in the incidence of endometrial hyperplasia over a long-term follow-up period (24 to 60 months) (Peto OR 0.13, 95% CI 0.03 to 0.67, four studies, n = 417, I² = 0%, moderate quality evidence). However, it should be noted that the number of events of endometrial hyperplasia was low (n = 6). None of the trials were sufficiently powered to detect whether LNG-IUS leads to significant changes in the incidence of endometrial cancer in tamoxifen users. At 12 months of follow-up abnormal vaginal bleeding or spotting was more common in the LNG-IUS treatment group (Peto OR 7.26, 95% CI 3.37 to 15.66, 3 studies, n = 376, I² = 0%, moderate quality evidence). By 24 months of follow-up, abnormal vaginal bleeding or spotting occurred less frequently compared to 12 months of follow-up in the LNG-IUS treatment group but was still more common than the control group (Peto OR 2.72, 95% CI 1.04 to 7.10, 2 studies, n = 233, I² = 0%, moderate quality evidence). By 60 months of follow-up, no cases of abnormal vaginal bleeding or spotting were reported in either group. The numbers of events for the following

Two years of tamoxifen or no adjuvant systemic therapy for patients with high-risk breast cancer

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Jensen, Maj-Britt; Krarup, Jens Fabricius; Palshof, Torben

2018-01-01

randomly assigned to two years of daily placebo or tamoxifen. Survival statistics was collected from the Danish Civil Registration System. RESULTS: The five-year invasive breast cancer recurrence (BCR) rate was 43.2% in the placebo arm and 31.9% in the tamoxifen arm. Compared with the placebo arm...... the hazard ratio for a BCR event was 0.73 in the tamoxifen arm (p = .07). With an estimated median follow-up on overall survival of 40.9 years, 154 and 145 patients had died in the placebo and tamoxifen arm, respectively. After adjustment for baseline characteristics a significant reduction in mortality...

Effect of Tamoxifen on Seminiferous Tubules Structure during Pregnancy in Adult Mice

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J Soleimani Rad

2016-03-01

Full Text Available Introduction: Tamoxifen is a nonsteroidal drug which mainly treats breast cancer. It is also applied for stimulation of ovulation and remedy of infertility. Regarding the tamoxifen binding to estrogen receptors and the possible role of estrogens in spermatogenesis, the present study aimed to histologically evaluate spermatogenesis in the seminiferous ducts of mice, whose mothers had received tamoxifen during pregnancy. Methods: In the present study, 30 female and 15 male mice of NMRI race were selected for mating. Since 13th day of pregnancy, the experimental group received tamoxifen with the dosage of 5 mg/kg intra-peritoneally for 7 days, wherease the control group received normal saline. After childbirth of the mated mice, male infants were selected and monitored in the standard laboratory conditions. After reaching the age of puberty (6-8Weeks, adult mice were sacrificed by the cervical dislocation, and the testes were removed for histological evaluation of spermatogenesis. After routine histological processing, the samples were studied by the light microscope. Results: Histological studies showed that spermatogenic and Sertoli cells in the seminiferous tubules in control and experimental groups were significantly different, though no difference was observed in the number of Leydig cells in the both groups. Conclusion: The findings of the present study showed that tamoxifen exposure during development can cause histological changes in the seminiferous tubules, which can lead to infertility in the male rat.

Lack of evidence from HPLC 32P-post-labelling for tamoxifen-DNA adducts in the human endometrium.

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Carmichael, P L; Sardar, S; Crooks, N; Neven, P; Van Hoof, I; Ugwumadu, A; Bourne, T; Tomas, E; Hellberg, P; Hewer, A J; Phillips, D H

1999-02-01

Tamoxifen is associated with an increased incidence of endometrial cancer in women. It is also a potent carcinogen in rat liver and forms covalent DNA adducts in this tissue. A previous study exploring DNA adducts in human endometria, utilizing thin layer chromatography 32P-postlabelling, found no evidence for adducts in tamoxifen-treated women [Carmichael,P.L., Ugwumadu,A.H.N., Neven,P., Hewer,A.J., Poon,G.K. and Phillips,D.H. (1996) Cancer Res., 56, 1475-1479]. However, subsequent work utilizing HPLC 32P-post-labelling [Hemminki,K., Ranjaniemi,H., Lindahl,B. and Moberger,B. (1996) Cancer Res., 56, 4374-4377] suggested that very low levels could be detected. We have sought to investigate this question further by reproducing the HPLC methodology at two centres, and analysing endometrial DNA from 20 patients treated with 20 mg/day tamoxifen for between 22 and 65 months. Liver DNA isolated from tamoxifen-treated rats was used as a positive control. We found no convincing evidence for tamoxifen-derived DNA adducts in human endometrium. HPLC elution profiles of post-labelled DNA from tamoxifen-treated women were indistinguishable from those obtained with DNA from 14 untreated women and from six women taking toremifene, an analogue of tamoxifen.

The role of the expression of bcl-2, p53 gene in tamoxifen-induced apoptosis of breast cancer cells and its relationship with hormone receptor status

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Noh, Woo Chul; Ham, Yong Ho [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

1998-01-01

To investigate the relationship of bcl-2, p53, ER and tamoxifen-induced apoptosis of breast cancer cells, MCF-7 (ER+/bcl-2+/p53-) and MB MDA 468 (ER-/bcl-2-/p53+) cell line were cultured in estrogen-free condition. E2(10`-`9M) and tamoxifen (10`-`5M) were added to the media. The changes of bcl-2 and mutant p53 protein were checked by Western blot and apoptosis were measured by flowcytometry. In MCF-7 cells, we found that treatment with tamoxifen resulted in a decrease in bcl-2 protein level, but produced no change in mutant p53. In MB MDA 468 cell however, there were no changes of bcl-2 and mutant p53 protein level when E2 or tamoxifen were added. Apoptotic cells increased with time-dependent pattern when tamoxifen was added to MCF-7 cells. According to these result, ER+/blc-2+/mutant p53- cells, when treated with tamoxifen, were converted into bcl-2/mutant p53- cells which were more prone to apoptosis than bcl-2-/mutant p53+ cells. The paradoxical correlation of bcl-2 and ER which had been observed in clinical studies might be explained with this results and bcl-2 protein seems to be one of important factors that can predict the effect of hormone therapy. (author). 26 refs., 5 figs

The role of the expression of bcl-2, p53 gene in tamoxifen-induced apoptosis of breast cancer cells and its relationship with hormone receptor status

International Nuclear Information System (INIS)

Noh, Woo Chul; Ham, Yong Ho

1998-01-01

To investigate the relationship of bcl-2, p53, ER and tamoxifen-induced apoptosis of breast cancer cells, MCF-7 (ER+/bcl-2+/p53-) and MB MDA 468 (ER-/bcl-2-/p53+) cell line were cultured in estrogen-free condition. E2(10'-'9M) and tamoxifen (10'-'5M) were added to the media. The changes of bcl-2 and mutant p53 protein were checked by Western blot and apoptosis were measured by flowcytometry. In MCF-7 cells, we found that treatment with tamoxifen resulted in a decrease in bcl-2 protein level, but produced no change in mutant p53. In MB MDA 468 cell however, there were no changes of bcl-2 and mutant p53 protein level when E2 or tamoxifen were added. Apoptotic cells increased with time-dependent pattern when tamoxifen was added to MCF-7 cells. According to these result, ER+/blc-2+/mutant p53- cells, when treated with tamoxifen, were converted into bcl-2/mutant p53- cells which were more prone to apoptosis than bcl-2-/mutant p53+ cells. The paradoxical correlation of bcl-2 and ER which had been observed in clinical studies might be explained with this results and bcl-2 protein seems to be one of important factors that can predict the effect of hormone therapy. (author). 26 refs., 5 figs

Anastrozole versus tamoxifen for the prevention of locoregional and contralateral breast cancer in postmenopausal women with locally excised ductal carcinoma in situ (IBIS-II DCIS): a double-blind, randomised controlled trial.

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Forbes, John F; Sestak, Ivana; Howell, Anthony; Bonanni, Bernardo; Bundred, Nigel; Levy, Christelle; von Minckwitz, Gunter; Eiermann, Wolfgang; Neven, Patrick; Stierer, Michael; Holcombe, Chris; Coleman, Robert E; Jones, Louise; Ellis, Ian; Cuzick, Jack

2016-02-27

Third-generation aromatase inhibitors are more effective than tamoxifen for preventing recurrence in postmenopausal women with hormone-receptor-positive invasive breast cancer. However, it is not known whether anastrozole is more effective than tamoxifen for women with hormone-receptor-positive ductal carcinoma in situ (DCIS). Here, we compare the efficacy of anastrozole with that of tamoxifen in postmenopausal women with hormone-receptor-positive DCIS. In a double-blind, multicentre, randomised placebo-controlled trial, we recruited women who had been diagnosed with locally excised, hormone-receptor-positive DCIS. Eligible women were randomly assigned in a 1:1 ratio by central computer allocation to receive 1 mg oral anastrozole or 20 mg oral tamoxifen every day for 5 years. Randomisation was stratified by major centre or hub and was done in blocks (six, eight, or ten). All trial personnel, participants, and clinicians were masked to treatment allocation and only the trial statistician had access to treatment allocation. The primary endpoint was all recurrence, including recurrent DCIS and new contralateral tumours. All analyses were done on a modified intention-to-treat basis (in all women who were randomised and did not revoke consent for their data to be included) and proportional hazard models were used to compute hazard ratios and corresponding confidence intervals. This trial is registered at the ISRCTN registry, number ISRCTN37546358. Between March 3, 2003, and Feb 8, 2012, we enrolled 2980 postmenopausal women from 236 centres in 14 countries and randomly assigned them to receive anastrozole (1449 analysed) or tamoxifen (1489 analysed). Median follow-up was 7·2 years (IQR 5·6-8·9), and 144 breast cancer recurrences were recorded. We noted no statistically significant difference in overall recurrence (67 recurrences for anastrozole vs 77 for tamoxifen; HR 0·89 [95% CI 0·64-1·23]). The non-inferiority of anastrozole was established (upper 95% CI

Tamoxifen and CYP2D6

DEFF Research Database (Denmark)

Cronin-Fenton, Deirdre P.; Damkier, Per

2018-01-01

Tamoxifen reduces the rate of breast cancer recurrence by about one-half. It is converted to more active metabolites by enzymes encoded by polymorphic genes, including cytochrome P450 2D6 (CYP2D6) and transported by ATP-binding cassette transporters. Genetic polymorphisms that confer reduced CYP2...

Identification of a putative protein-profile associating with tamoxifen therapy-resistance in breast cancer

NARCIS (Netherlands)

A. Umar (Arzu); J.W.M. Martens (John); J.A. Foekens (John); L. Paša-Tolić (Ljiljana); H. Kang; A.M. Timmermans (Mieke); M.P. Look (Maxime); M.E. Meijer van Gelder (Marion); N. Jaitly (Navdeep); M.A. den Bakker (Michael)

2009-01-01

textabstractTamoxifen-resistance is a major cause of death in patients with recurrent breast cancer. Current clinical parameters can correctly predict therapy response in only half of the treated patients. Identification of proteins that associate with tamoxifen-resistance is a first step towards

Approaches for predicting effects of unintended environmental exposure to an endocrine active pharmaceutical, tamoxifen

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Tamoxifen is an endocrine-active pharmaceutical (EAP) that is used world-wide. Because tamoxifen is a ubiquitous pharmaceutical and interacts with estrogen receptors, a case study was conducted with this compound to (1) determine effects on reproductive endpoints in a nontarget s...

Ribavirin restores ESR1 gene expression and tamoxifen sensitivity in ESR1 negative breast cancer cell lines

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Sappok Anne

2011-12-01

Full Text Available Abstract Tumor growth is estrogen independent in approximately one-third of all breast cancers, which makes these patients unresponsive to hormonal treatment. This unresponsiveness to hormonal treatment may be explained through the absence of the estrogen receptor alpha (ESR1. The ESR1 gene re-expression through epigenetic modulators such as DNA methyltransferase inhibitors and/or histone deacetylase inhibitors restores tamoxifen sensitivity in ESR1 negative breast cancer cell lines and opens new treatment horizons in patients who were previously associated with a poor prognosis. In the study presented herein, we tested the ability of ribavirin, which shares some structural similarities with the DNA-methyltransferase inhibitor 5-azacytidine and which is widely known as an anti-viral agent in the treatment of hepatitis C, to restore ESR1 gene re-expression in ESR1 negative breast cancer cell lines. In our study we identified ribavirin to restore ESR1 gene re-expression alone and even more in combination with suberoylanilide hydroxamic acid (SAHA - up to 276 fold induction. Ribavirin and analogs could pave the way to novel translational research projects that aim to restore ESR1 gene re-expression and thus the susceptibility to tamoxifen-based endocrine treatment strategies.

Integrated molecular analysis of Tamoxifen-resistant invasive lobular breast cancer cells identifies MAPK and GRM/mGluR signaling as therapeutic vulnerabilities.

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Stires, Hillary; Heckler, Mary M; Fu, Xiaoyong; Li, Zhao; Grasso, Catherine S; Quist, Michael J; Lewis, Joseph A; Klimach, Uwe; Zwart, Alan; Mahajan, Akanksha; Győrffy, Balázs; Cavalli, Luciane R; Riggins, Rebecca B

2018-08-15

Invasive lobular breast cancer (ILC) is an understudied malignancy with distinct clinical, pathological, and molecular features that distinguish it from the more common invasive ductal carcinoma (IDC). Mounting evidence suggests that estrogen receptor-alpha positive (ER+) ILC has a poor response to Tamoxifen (TAM), but the mechanistic drivers of this are undefined. In the current work, we comprehensively characterize the SUM44/LCCTam ILC cell model system through integrated analysis of gene expression, copy number, and mutation, with the goal of identifying actionable alterations relevant to clinical ILC that can be co-targeted along with ER to improve treatment outcomes. We show that TAM has several distinct effects on the transcriptome of LCCTam cells, that this resistant cell model has acquired copy number alterations and mutations that impinge on MAPK and metabotropic glutamate receptor (GRM/mGluR) signaling networks, and that pharmacological inhibition of either improves or restores the growth-inhibitory actions of endocrine therapy. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Effects of 13- cis-retinoic acid on the tamoxifen induced uterine histological changes in the rabbit

International Nuclear Information System (INIS)

Hamid, S.; Minhas, L.A.; Khan, M.Y.

2013-01-01

Objective: To study the effects of 13-cis-retinoic acid on the tamoxifen induced uterine histological changes in the rabbit. Study Design: Experimental - randomized controlled trial. Place and Duration of study: The study was conducted for 4 months at the department of Anatomy, Army Medical College and National Institute of Health in 2007. Material and Methods: The animals were randomly divided into three groups, a control group A, and two experimental groups B and C, consisting of thirty rabbits each. The experimental groups were treated with tamoxifen only and tamoxifen plus retinoic acid, respectively. The animals were sacrificed after three months. The uteri were then processed for paraffin embedding. Sections were then assessed for the luminal epithelial height, endometrial area and percentage of mitotic figures. Results: The results obtained were suggestive of uterine proliferation by tamoxifen. The adjuvant administration of 13-cis-retinoic acid produced a statistically significant (p = 0.002) inhibitory effect on the tamoxifen induced increase in the area of endometrium, whereas no significant suppressive effect of this drug has been observed on the other parameters when compared with Group B. Conclusion: 13-cis Retinoic acid has not shown a significant role in the reversal of tamoxifen induced changes in the uterine tissue after a short term administration of three months. (author)

Is tamoxifen associated with an increased risk for thromboembolic complications in patients undergoing microvascular breast reconstruction? [Ist die Einnahme von Tamoxifen zum Zeitpunkt der mikrovaskulären Brustrekonstruktion mit einer erhöhten Rate an thrombembolischen Komplikationen assoziiert?

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Krämer, Robert

2013-02-01

Full Text Available [english] Introduction: Tamoxifen is associated with a twofold increased risk of thromboembolic events. Third generation aromatase inhibitors (AIs, such as letrozole, anastrozole, and exemestane have therefore replaced tamoxifen in the adjuvant therapy of hormone receptor-positive breast cancer. A retrospective review was performed in patients who underwent delayed microvascular breast reconstruction and received tamoxifen at the time of surgery in order to assess the risk of both minor and major flap complications including thromboembolic events.Patients and methods: Twenty-nine patients who underwent delayed microsurgical breast reconstruction with autologous tissue between 2006 and 2012 were included in the study. The overall complication rates were compared between patients who did versus those who did not receive tamoxifen at the time of microsurgical breast reconstruction. Results: Breast reconstruction was performed with a DIEP flap in and with a TRAM flap in 4 patients. Overall, the complication rate was 37.9% (n=11 consisting of 5 major (including one total flap loss and 6 minor complications. In patients receiving tamoxifen (n=5, we observed one minor complication and one major complication with a total flap loss due to thrombus formation at the anastomosis site. In one patient pulmonary embolism occurred without association to tamoxifen. The number of thromboembolic events was equivalent in both groups (p=0.642. No increase of major (p=0.858 or minor (p=0.967 complications in the tamoxifen group could be observed. Taking the overall complication rate into account there was no statistically difference between the two groups (p=0.917.Conclusion: In our study we could not observe an increased risk for thromobembolic events in patients receiving tamoxifen while undergoing autologous microvascular breast reconstruction.[german] Aromatasehemmer der dritten Generation haben mittlerweile Tamoxifen in der neoadjuvanten und adjuvanten Therapie

Tamoxifen and estradiol improved locomotor function and increased spared tissue in rats after spinal cord injury: their antioxidant effect and role of estrogen receptor alpha.

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Mosquera, Laurivette; Colón, Jennifer M; Santiago, José M; Torrado, Aranza I; Meléndez, Margarita; Segarra, Annabell C; Rodríguez-Orengo, José F; Miranda, Jorge D

2014-05-02

17β-Estradiol is a multi-active steroid that imparts neuroprotection via diverse mechanisms of action. However, its role as a neuroprotective agent after spinal cord injury (SCI), or the involvement of the estrogen receptor-alpha (ER-α) in locomotor recovery, is still a subject of much debate. In this study, we evaluated the effects of estradiol and of Tamoxifen (an estrogen receptor mixed agonist/antagonist) on locomotor recovery following SCI. To control estradiol cyclical variability, ovariectomized female rats received empty or estradiol filled implants, prior to a moderate contusion to the spinal cord. Estradiol improved locomotor function at 7, 14, 21, and 28 days post injury (DPI), when compared to control groups (measured with the BBB open field test). This effect was ER-α mediated, because functional recovery was blocked with an ER-α antagonist. We also observed that ER-α was up-regulated after SCI. Long-term treatment (28 DPI) with estradiol and Tamoxifen reduced the extent of the lesion cavity, an effect also mediated by ER-α. The antioxidant effects of estradiol were seen acutely at 2 DPI but not at 28 DPI, and this acute effect was not receptor mediated. Rats treated with Tamoxifen recovered some locomotor activity at 21 and 28 DPI, which could be related to the antioxidant protection seen at these time points. These results show that estradiol improves functional outcome, and these protective effects are mediated by the ER-α dependent and independent-mechanisms. Tamoxifen׳s effects during late stages of SCI support the use of this drug as a long-term alternative treatment for this condition. Copyright © 2014 Elsevier B.V. All rights reserved.

A comparison of survival outcomes and side effects of toremifene or tamoxifen therapy in premenopausal estrogen and progesterone receptor positive breast cancer patients: a retrospective cohort study

International Nuclear Information System (INIS)

Gu, Ran; Long, Meijun; Chen, Kai; Chen, Lili; Xiao, Qiaozhen; Wu, Mei; Song, Erwei; Su, Fengxi; Jia, Weijuan; Zeng, Yunjie; Rao, Nanyan; Hu, Yue; Li, Shunrong; Wu, Jiannan; Jin, Liang; Chen, Lijuan

2012-01-01

In premenopausal women, endocrine adjuvant therapy for breast cancer primarily consists of tamoxifen alone or with ovarian suppressive strategies. Toremifene is a chlorinated derivative of tamoxifen, but with a superior risk-benefit profile. In this retrospective study, we sought to establish the role of toremifene as an endocrine therapy for premenopausal patients with estrogen and/or progesterone receptor positive breast cancer besides tamoxifen. Patients with early invasive breast cancer were selected from the breast tumor registries at the Sun Yat-Sen Memorial Hospital (China). Premenopausal patients with endocrine responsive breast cancer who underwent standard therapy and adjuvant therapy with toremifene or tamoxifen were considered eligible. Patients with breast sarcoma, carcinosarcoma, concurrent contralateral primary breast cancer, or with distant metastases at diagnosis, or those who had not undergone surgery and endocrine therapy were ineligible. Overall survival and recurrence-free survival were the primary outcomes measured. Toxicity data was also collected and compared between the two groups. Of the 810 patients reviewed, 452 patients were analyzed in the study: 240 received tamoxifen and 212 received toremifene. The median and mean follow up times were 50.8 and 57.3 months, respectively. Toremifene and tamoxifen yielded similar overall survival values, with 5-year overall survival rates of 100% and 98.4%, respectively (p = 0.087). However, recurrence-free survival was significantly better in the toremifene group than in the tamoxifen group (p = 0.022). Multivariate analysis showed that recurrence-free survival improved independently with toremifene (HR = 0.385, 95% CI = 0.154-0.961; p = 0.041). Toxicity was similar in the two treatment groups with no women experiencing severe complications, other than hot flashes, which was more frequent in the toremifene patients (p = 0.049). No patients developed endometrial cancer. Toremifene may be a valid and

Assessment of letrozole and tamoxifen alone and in sequence for postmenopausal women with steroid hormone receptor-positive breast cancer: the BIG 1-98 randomised clinical trial at 8·1 years median follow-up.

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Regan, Meredith M; Neven, Patrick; Giobbie-Hurder, Anita; Goldhirsch, Aron; Ejlertsen, Bent; Mauriac, Louis; Forbes, John F; Smith, Ian; Láng, István; Wardley, Andrew; Rabaglio, Manuela; Price, Karen N; Gelber, Richard D; Coates, Alan S; Thürlimann, Beat

2011-11-01

Postmenopausal women with hormone receptor-positive early breast cancer have persistent, long-term risk of breast-cancer recurrence and death. Therefore, trials assessing endocrine therapies for this patient population need extended follow-up. We present an update of efficacy outcomes in the Breast International Group (BIG) 1-98 study at 8·1 years median follow-up. BIG 1-98 is a randomised, phase 3, double-blind trial of postmenopausal women with hormone receptor-positive early breast cancer that compares 5 years of tamoxifen or letrozole monotherapy, or sequential treatment with 2 years of one of these drugs followed by 3 years of the other. Randomisation was done with permuted blocks, and stratified according to the two-arm or four-arm randomisation option, participating institution, and chemotherapy use. Patients, investigators, data managers, and medical reviewers were masked. The primary efficacy endpoint was disease-free survival (events were invasive breast cancer relapse, second primaries [contralateral breast and non-breast], or death without previous cancer event). Secondary endpoints were overall survival, distant recurrence-free interval (DRFI), and breast cancer-free interval (BCFI). The monotherapy comparison included patients randomly assigned to tamoxifen or letrozole for 5 years. In 2005, after a significant disease-free survival benefit was reported for letrozole as compared with tamoxifen, a protocol amendment facilitated the crossover to letrozole of patients who were still receiving tamoxifen alone; Cox models and Kaplan-Meier estimates with inverse probability of censoring weighting (IPCW) are used to account for selective crossover to letrozole of patients (n=619) in the tamoxifen arm. Comparison of sequential treatments to letrozole monotherapy included patients enrolled and randomly assigned to letrozole for 5 years, letrozole for 2 years followed by tamoxifen for 3 years, or tamoxifen for 2 years followed by letrozole for 3 years

Mitotically Active Leiomyoma of the Uterus in a Postmenopausal Breast Cancer Patient Receiving Tamoxifen

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I-Feng Liu

2006-06-01

Conclusion: Endometrial cancer is rarely noted in breast cancer patients taking tamoxifen. Further, none have reported mitotically active leiomyoma of the uterus. From this case, endometrial proliferation and mitotically active leiomyoma of the uterus may be related to tamoxifen therapy, and should not be neglected in breast cancer patients.

Treatment Adherence and Its Impact on Disease-Free Survival in the Breast International Group 1-98 Trial of Tamoxifen and Letrozole, Alone and in Sequence

DEFF Research Database (Denmark)

Chirgwin, Jacquie H; Giobbie-Hurder, Anita; Coates, Alan S

2016-01-01

PURPOSE: To investigate adherence to endocrine treatment and its relationship with disease-free survival (DFS) in the Breast International Group (BIG) 1-98 clinical trial. METHODS: The BIG 1-98 trial is a double-blind trial that randomly assigned 6,193 postmenopausal women with hormone receptor......-positive early breast cancer in the four-arm option to 5 years of tamoxifen (Tam), letrozole (Let), or the agents in sequence (Let-Tam, Tam-Let). This analysis included 6,144 women who received at least one dose of study treatment. Conditional landmark analyses and marginal structural Cox proportional hazards......). Sequential treatments were associated with higher rates of nonpersistence (Tam-Let, 20.8%; Let-Tam, 20.3%; Tam 16.9%; Let 17.6%). Adverse events were the reason for most trial treatment early discontinuations (82.7%). Apart from sequential treatment assignment, reduced adherence was associated with older age...

Tamoxifen in combination with temozolomide induce a synergistic inhibition of PKC-pan in GBM cell lines.

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Balça-Silva, Joana; Matias, Diana; do Carmo, Anália; Girão, Henrique; Moura-Neto, Vivaldo; Sarmento-Ribeiro, Ana Bela; Lopes, Maria Celeste

2015-04-01

Glioblastoma (GBM) is a highly proliferative, angiogenic grade IV astrocytoma that develops resistance to the alkylating agents used in chemotherapy, such as temozolomide (TMZ), which is considered the gold standard. The mean survival time for GBM patients is approximately 12 months, increasing to 14.6 months after TMZ treatment. The resistance of GBM to chemotherapy seems to be associated to genetic alterations and to the constitutive activation of several signaling pathways. Therefore, the combination of different drugs with different mechanisms of action may contribute to circumvent the chemoresistance of glioma cells. Here we describe the potential synergistic behavior of the therapeutic combination of tamoxifen (TMX), a known inhibitor of PKC, and TMZ in GBM. We used two GBM cell lines incubated in absence and presence of TMX and/or TMZ and measured cell viability, proliferation, apoptosis, cell cycle, migration ability, cytoskeletal organization and the phosphorylated amount of the p-PKC-pan. The combination of low doses of TMX with increasing doses of TMZ shows an increased antiproliferative and apoptotic effect compared to the effect with TMX alone. The combination of TMX and TMZ seems to potentiate the effect of each other. These alterations seem to be associated to a decrease in the phosphorylation status of PKC. We emphasize that TMX is an inhibitor of the p-PKC-pan and that these combination is more effective in the reduction of proliferation and in the increase of apoptosis than each drug alone, which presents a new therapeutic strategy in GBM treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

The role of the addition of ovarian suppression to tamoxifen in young women with hormone-sensitive breast cancer who remain premenopausal or regain menstruation after chemotherapy (ASTRRA): study protocol for a randomized controlled trial and progress

International Nuclear Information System (INIS)

Kim, Hyun-Ah; Ahn, Sei Hyun; Nam, Seok Jin; Park, Seho; Ro, Jungsil

2016-01-01

Ovarian function suppression (OFS) has been shown to be effective as adjuvant endocrine therapy in premenopausal women with hormone receptor-positive breast cancer. However, it is currently unclear if addition of OFS to standard tamoxifen therapy after completion of adjuvant chemotherapy results in a survival benefit. In 2008, the Korean Breast Cancer Society Study Group initiated the ASTRRA randomized phase III trial to evaluate the efficacy of OFS in addition to standard tamoxifen treatment in hormone receptor-positive breast cancer patients who remain or regain premenopausal status after chemotherapy. Premenopausal women with estrogen receptor-positive breast cancer treated with definitive surgery were enrolled after completion of neoadjuvant or adjuvant chemotherapy. Ovarian function was assessed at the time of enrollment and every 6 months for 2 years by follicular-stimulating hormone levels and bleeding history. If ovarian function was confirmed as premenopausal status, the patient was randomized to receive 2 years of goserelin plus 5 years of tamoxifen treatment or 5 years of tamoxifen alone. The primary end point will be the comparison of the 5-year disease-free survival rates between the OFS and tamoxifen alone groups. Patient recruitment was finished on March 2014 with the inclusion of a total of 1483 patients. The interim analysis will be performed at the time of the observation of the 187th event. This study will provide evidence of the benefit of OFS plus tamoxifen compared with tamoxifen only in premenopausal patients with estrogen receptor-positive breast cancer treated with chemotherapy

Mitochondrial markers predict recurrence, metastasis and tamoxifen-resistance in breast cancer patients: Early detection of treatment failure with companion diagnostics.

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Sotgia, Federica; Fiorillo, Marco; Lisanti, Michael P

2017-09-15

Here, we used a data-mining and informatics approach to discover new biomarkers of resistance to hormonal therapy in breast cancer. More specifically, we investigated whether nuclear-encoded genes associated with mitochondrial biogenesis can be used to predict tumor recurrence, distant metastasis and treatment failure in high-risk breast cancer patients. Overall, this strategy allowed us to directly provide in silico validation of the prognostic value of these mitochondrial components in large and clinically relevant patient populations, with >15 years of follow-up data. For this purpose, we employed a group of 145 ER(+) luminal A breast cancer patients, with lymph-node (LN) metastasis at diagnosis, that were treated with tamoxifen, but not any chemotherapy agents. Using this approach, we identified >60 new individual mitochondrial biomarkers that predicted treatment failure and tumor recurrence, with hazard-ratios (HR) of up to 4.17 ( p =2.2e-07). These include mitochondrial chaperones (HSPD1, HSPA9), membrane proteins (VDAC2, TOMM70A) and anti-oxidants (SOD2), as well as 18 different mitochondrial ribosomal proteins (MRPs) and >20 distinct components of the OXPHOS complexes. In addition, we combined 4 mitochondrial proteins (HSPD1, UQCRB, MRPL15, COX17), to generate a compact mitochondrial gene signature, associated with a HR of 5.34 ( p =1e-09). This signature also successfully predicted distant metastasis and was effective in larger groups of ER(+) ( N =2,447), basal ( N =540) and HER2(+) ( N =193) breast cancers. It was also effective in all breast cancers ( N =3,180), if considered together as a single group. Based on this analysis, we conclude that mitochondrial biogenesis should be considered as a new therapeutic target for overcoming tumor recurrence, distant metastasis and treatment failure in patients with breast cancer. In summary, we identified individual mitochondrial biomarkers and 2 compact mitochondrial gene signatures that can be used to predict

The Prescription Pattern of Chinese Herbal Products That Contain Dang-Qui and Risk of Endometrial Cancer among Tamoxifen-Treated Female Breast Cancer Survivors in Taiwan: A Population-Based Study

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Wu, Chien-Tung; Lai, Jung-Nien; Tsai, Yueh-Ting

2014-01-01

Purpose The increased practice of traditional Chinese medicine worldwide has raised concerns regarding herb-drug interactions. We analyzed the usage of Chinese herbal products containing dang-qui and investigated whether dang-qui therapy increases endometrial cancer risk among tamoxifen-treated breast cancer survivors in Taiwan. Methods All patients newly diagnosed with invasive breast cancer who received tamoxifen treatment from January 1, 1998, to December 31, 2008 were selected from the National Health Insurance Research Database. The usage, frequency of service and type of Chinese herbal products containing dang-qui prescribed across the 31,970 survivors were evaluated. Logistic regression method was employed to estimate the odds ratios for utilization of Chinese herbal products containing dang-qui. Cox proportional hazard regression was performed to calculate the hazard ratio of endometrial cancer associated with dang-qui use within the cohort. Results Almost one in two study subjects had used dang-qui. Among 31,938 tamoxifen-treated breast cancer survivors, 157 cases of subsequent endometrial cancer were identified. The hazard ratio for development of endometrial cancer among breast cancer survivors aged 20–79 years who had taken dang-qui after tamoxifen treatment was decreased compared to survivors who had never used dang-qui (HR: 0.61, 95%CI: 0.44–0.84). To minimise potential confounding factors, women with breast cancer in the reproductive age were excluded from further analysis, and the negative relationship between dang-qui consumption and subsequent endometrial cancer among breast cancer survivors aged 55–79 years was still observed, although not significantly (HR: 0.74, 95%CI: 0.46–1.17). Conclusions Dang-qui consumption is common among breast cancer survivors aged 20–79 years and seems decrease the risk of subsequent endometrial cancer after less than a cumulative dose of 7,500 mg of tamoxifen treatment. PMID:25485843

Discrepancy between ultrasonography and hysteroscopy and histology of endometrium in postmenopausal breast cancer patients using tamoxifen

NARCIS (Netherlands)

Mourits, MJE; Van der Zee, AGJ; Willemse, PHB; Ten Hoor, KA; Hollema, H; De Vries, EGE

Background. The increased risk of endometrial carcinoma following the use of tamoxifen has stimulated studies on endometrial diagnostic screening methods. In tamoxifen users the endometrial thickening observed with transvaginal ultrasonography (TVU) frequently cannot be confirmed by hysteroscopy or

A pooled analysis of CYP2D6 genotype in breast cancer prevention trials of low-dose tamoxifen.

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Johansson, Harriet; Gandini, Sara; Serrano, Davide; Gjerde, Jennifer; Lattanzi, Monia; Macis, Debora; Guerrieri-Gonzaga, Aliana; Aristarco, Valentina; Mellgren, Gunnar; Lien, Ernst; DeCensi, Andrea; Bonanni, Bernardo

2016-08-01

Decreased CYP2D6 activity is associated with lower levels of active tamoxifen metabolites. We examined the impact of CYP2D6 genotype on tamoxifen pharmacokinetics, biomarker activity, and efficacy in a pooled analysis of low-dose tamoxifen. Four randomized breast cancer prevention trials of very-low-dose (1 mg/day, n = 52 or 10 mg/week, n = 152) or low-dose tamoxifen (5 mg/day, n = 171) were pooled. DNA from 367 subjects was genotyped for CYP2D6 alleles associated with absent (PM allele: *3, *4, *5, *6, *7, *8, *12, and *14), reduced (IM allele: *9, *10, *17, *29, *41), normal (EM allele), or increased (UM: *XN) enzyme activity. Associations of tamoxifen, metabolites, activity biomarkers, and event-free survival with rapid (UM/EM, UM/IM, EM/EM, EM/IM, or EM/PM alleles) versus slow metabolizers (PM/IM or PM/PM) were investigated through random effects models, with 'study' as the random factor, and Cox regression models, adjusting for confounders. Rapid metabolizers had higher endoxifen levels than slow metabolizers: 15.3 versus 12.2 ng/mL (P = 0.018) with 5 mg/day, and 3.8 versus 2.8 ng/mL (P = 0.004) with 1 mg/day or 10 mg/week tamoxifen. The IGF-I decrease correlated with endoxifen (P = 0.002) and 4-hydroxytamoxifen levels, demonstrating steeper decreases at higher metabolite levels (P = 0.001). After a median follow-up of 12 years, rapid metabolizers with prior history of breast neoplasms allocated to tamoxifen 5 mg/day had a 60 % reduction of risk of recurrences (HR = 0.40, 95 % CI: 0.16-0.99) compared to slow metabolizers. CYP2D6 genotype may have an impact on tamoxifen efficacy at low doses. Trials investigating tamoxifen dose adjustments based on the woman's hormonal context and CYP2D6 genotype are warranted.

Detection of a negative correlation between prescription of Chinese herbal products containing coumestrol, genistein or daidzein and risk of subsequent endometrial cancer among tamoxifen-treated female breast cancer survivors in Taiwan between 1998 and 2008: A population-based study.

Science.gov (United States)

Hu, Yi-Cheng; Wu, Chien-Tung; Lai, Jung-Nien; Tsai, Yueh-Ting

2015-07-01

Tamoxifen users sometimes seek complementary and alternative medicine advice for treatment of a variety of illness and co-administer with phytoestrogen-containing herbs, resulting in an increasing concern of its influence in subsequent endometrial cancer risk. Our study aims to determine the prevalence of Chinese herbal products containing coumestrol, genistein, or daidzein and their association with subsequent endometrial cancer risk among tamoxifen-treated breast cancer survivors in Taiwan. We selected all patients who were newly diagnosed with invasive breast cancer and received tamoxifen treatment between January 1, 1998, and December 31, 2008, from the National Health Insurance Research Database. Among the 26,656 tamoxifen-treated breast cancer survivors, we evaluated the usage, frequency of service, and prescription of Chinese herbal products containing coumestrol, genistein, or daidzein. The logistic regression method was employed to calculate the odds ratios for utilization of those herbal products. Cox proportional hazard regression was set to calculate the hazard ratios of endometrial cancer associated with such usage. Of the patients surveyed, 36.2% (n=9652) of the tamoxifen-treated breast cancer survivors examined in the study had consumed Chinese herbal products containing coumestrol, genistein, or daidzein during the study period. Exposure to Ge Gen(Puerariae Radix) specifically was the most extensive. For it, the population consumed an average cumulative dose of above 180g. Compared to those who had never used Chinese herbal products, breast cancer survivors who had taken Chinese herbal products containing coumestrol, genistein, or daidzein concurrently with tamoxifen treatment did not have a higher hazard ratio for subsequent development of endometrial cancer. Among those tamoxifen-treated female breast cancer survivors in Taiwan, consumption of Chinese herbal products containing coumestrol, genistein, or daidzein is negatively correlated with

Tamoxifen in the Mouse Brain: Implications for Fate-Mapping Studies Using the Tamoxifen-Inducible Cre-loxP System

Czech Academy of Sciences Publication Activity Database

Valný, Martin; Honsa, Pavel; Kirdajová, Denisa; Kameník, Zdeněk; Anděrová, Miroslava

2016-01-01

Roč. 10, ost (2016), s. 243 ISSN 1662-5102 R&D Projects: GA ČR(CZ) GA16-10214S; GA ČR(CZ) GA15-02760S Institutional support: RVO:68378041 ; RVO:61388971 Keywords : tamoxifen * brain metabolism * fate-mapping Subject RIV: FH - Neurology; EE - Microbiology, Virology (MBU-M) Impact factor: 4.555, year: 2016

The Possible Therapeutic Role of Polyphenyl Constituents in Turmeric and Tamoxifen on Hepatocellular Carcinoma Chemically Induced in Rats

International Nuclear Information System (INIS)

Abdelgawad, M.R.

2017-01-01

Tamoxifen is a drug wildly used for the adjuvant therapy in the treatment of women with estrogen receptor-positive breast tumors and has a low incidence of serious side-effects. Feeding turmeric ( Curcuma longa L .) to rats has no apparent side effects; reduced the types of inflammation that can cause liver cell damage, blockage and scarring. Turmeric delay the damage caused by progressive inflammatory liver disease. This study was carried out to study the possible therapeutic effect of polyphenyl constituents in turmeric and tamoxifen on hepatocarcinogenesis in rats chemically induced by diethylnitrosamine (DEN). Thirty five male rats were injected with DEN in a single dose i.p. (200mg/kg), 7 rats were sacrificed after ~6 months for histopathological examination for HCC nodules in different lobes and lobules, many nodules were observed by naked eye with a diameter of about ~2-3mm. The remaining 28 hepatoma (HCC) bearing rats chemically induced were randomized divided into 4 groups (each of 7rats): hepatoma bearing rats receiving the control diet; hepatoma bearing rats (supplemented with 4g/kg (wt/wt) turmeric (~200 μg curcumin /rat/day/4weeks; hepatoma bearing rats treated with 50mg/kg (wt/wt) tamoxifen dissolved in 0.1 ml dimethylsulfoxide and diluted with normal saline and drinking water; hepatoma bearing rats treated with 50mg/kg (wt/wt) tamoxifen in 0.1 ml dimethylsulfoxide and diluted with normal saline and drinking water and supplemented with 4g/ kg (wt/wt) turmeric(~200 μg curcumin /rat/day/4weeks; besides, 7 male rats serves as control group. By the end of the experiment at 4 weeks, rats in each group were sacrificed for examination.

Phenotype anchoring in zebrafish reveals a potential role for matrix metalloproteinases (MMPs) in tamoxifen's effects on skin epithelium

Energy Technology Data Exchange (ETDEWEB)

Bugel, Sean M., E-mail: Sean.Bugel@oregonstate.edu; Wehmas, Leah C., E-mail: wehmasl@onid.oregonstate.edu; La Du, Jane K., E-mail: Jane.LaDu@oregonstate.edu; Tanguay, Robert L., E-mail: Robert.Tanguay@oregonstate.edu

2016-04-01

The zebrafish is a powerful alternative model used to link phenotypes with molecular effects to discover drug mode of action. Using a zebrafish embryo-larval toxicity bioassay, we evaluated the effects of tamoxifen — a widely used anti-estrogen chemotherapeutic. Zebrafish exposed to ≥ 10 μM tamoxifen exhibited a unique necrotic caudal fin phenotype that was rapidly induced regardless of developmental life-stage when treatment was applied. To define tamoxifen's bioactivity resulting in this phenotype, targeted gene expression was used to evaluate 100 transcripts involved in tissue remodeling, calcium signaling, cell cycle and cell death, growth factors, angiogenesis and hypoxia. The most robustly misregulated transcripts in the tail were matrix metalloproteinases mmp9 and mmp13a, induced 127 and 1145 fold, respectively. Expression of c-fos, c-jun, and ap1s1 were also moderately elevated (3–7 fold), consistent with AP-1 activity — a transcription factor that regulates MMP expression. Immunohistochemistry confirmed high levels of induction for MMP13a in affected caudal fin skin epithelial tissue. The necrotic caudal fin phenotype was significantly attenuated or prevented by three functionally unique MMP inhibitors: EDTA (metal chelator), GM 6001 (broad MMP inhibitor), and SR 11302 (AP-1 transcription factor inhibitor), suggesting MMP-dependence. SR 11302 also inhibited induction of mmp9, mmp13a, and a putative MMP target, igfbp1a. Overall, our studies suggest that tamoxifen's effect is the result of perturbation of the MMP system in the skin leading to ectopic expression, cytotoxicity, and the necrotic caudal fin phenotype. These studies help advance our understanding of tamoxifen's non-classical mode of action and implicate a possible role for MMPs in tissues such as skin. - Highlights: • Tamoxifen rapidly induced a unique necrotic caudal fin phenotype in zebrafish. • Apoptosis co-localized temporally and spatially in the necrotic tail. �

Tamoxifen up-regulates catalase production, inhibits vessel wall neutrophil infiltration, and attenuates development of experimental abdominal aortic aneurysms.

Science.gov (United States)

Grigoryants, Vladimir; Hannawa, Kevin K; Pearce, Charles G; Sinha, Indranil; Roelofs, Karen J; Ailawadi, Gorav; Deatrick, Kristopher B; Woodrum, Derek T; Cho, Brenda S; Henke, Peter K; Stanley, James C; Eagleton, Matthew J; Upchurch, Gilbert R

2005-01-01

Selective estrogen receptor modulators (SERMs), similar to estrogens, possess vasoprotective effects by reducing release of reactive oxygen species. Little is known about the potential effects of SERMs on the pathogenesis of abdominal aortic aneurysms (AAAs). This study's objective was to investigate the growth of experimental AAAs in the setting of the SERM tamoxifen. In the first set of experiments, adult male rats underwent subcutaneous tamoxifen pellet (delivering 10 mg/kg/day) implantation (n = 14) or sham operation (n = 16). Seven days later, all animals underwent pancreatic elastase perfusion of the abdominal aorta. Aortic diameters were determined at that time, and aortas were harvested 7 and 14 days after elastase perfusion for immunohistochemistry, real-time polymerase chain reaction, Western blot analysis, and zymography. In the second set of experiments, a direct irreversible catalase inhibitor, 3-amino-1,2,4-triazole (AT), was administered intraperitoneally (1 mg/kg) daily to tamoxifen-treated (n = 6) and control rats (n = 6), starting on day 7 after elastase perfusion. Aortic diameters were measured on day 14. In a third set of experiments, rats were perfused with catalase (150 mg/kg) after the elastase (n = 5), followed by daily intravenous injections of catalase (150 mg/kg/day) administered for 10 days. A control group of rats (n = 7) received 0.9% NaCl instead of catalase. Mean AAA diameters were approximately 50% smaller in tamoxifen-treated rats compared with sham rats 14 days after elastase perfusion (P = .002). The tamoxifen-treated group's aortas had a five-fold increase in catalase mRNA expression (P = .02) on day 7 and an eight-fold increase in catalase protein on day 14 (P = .04). Matrix metalloprotroteinase-9 activity was 2.4-fold higher (P = .01) on day 7 in the aortas of the controls compared to the tamoxifen-treated group's aortas. Tamoxifen-treated rats had approximately 40% fewer aortic polymorphonuclear neutrophils compared to

Tamoxifen for one year versus two years versus 6 months of Tamoxifen and 6 months of megestrol acetate: A randomized comparison in postmenopausal patients with high-risk breast cancer (DBCG 89C)

DEFF Research Database (Denmark)

Andersen, Jørn; Kamby, C.; Ejlertsen, B.

2008-01-01

From January 1, 1990 to December 31, 1994, DBCG conducted a randomised trial in 1 615 postmenopausal women with operable, high-risk, receptor-positive or -unknown breast cancer. The patients were after surgery randomised to Tamoxifen for 1 year (TAM1), Tamoxifen for 2 years (TAM 2) or Tamoxifen...... for 6 months followed by megestrol acetate for 6 months (TAM/MA). When the preplanned sample size of 1 500 patients was reached it was decided to continue randomisation to TAM1 or TAM2 and the study was finally closed December 31, 1996. With a median follow-up of more than 10 years...... in hazard ratios for DFS or OS among the three arms. Sideeffects were rare but more common in the TAM2 and TAM/MA arms Udgivelsesdato: 2008...

Dried blood spots voor het bepalen van de serumconcentratie van tamoxifen en zijn actieve metaboliet endoxifen

NARCIS (Netherlands)

Jager, Nynke G L; Rosing, Hilde; Schellens, Jan H M; Beijnen, Jos H.; Linn, Sabine C.

2016-01-01

OBJECTIVE To establish the relationship between dried blood spot (DBS) and serum concentrations of tamoxifen and endoxifen in order to allow the use of DBS sampling, a simple and patient-friendly alternative to venous sampling, in clinical practice. The antiestrogenic effect of tamoxifen is

Menstruation recovery after chemotherapy and luteinizing hormone-releasing hormone agonist plus tamoxifen therapy for premenopausal patients with breast cancer.

Science.gov (United States)

Sakurai, Kenichi; Matsuo, Sadanori; Enomoto, Katsuhisa; Amano, Sadao; Shiono, Motomi

2011-01-01

Little is known about the period required for menstruation recovery after long-term luteinizing hormone-releasing hormone (LH-RH) agonist plus tamoxifen therapy following chemotherapy. In this study we investigated the period required for menstruation recovery after the therapy. The subjects comprised 105 premenopausal breast cancer patients who had undergone surgery. All patients were administered an LH-RH agonist for 24 months and tamoxifen for 5 years following the postoperative adjuvant chemotherapy, and the status of menstruation recovery was examined. Menstruation resumed in 16 cases (15.2%) after the last LH-RH agonist treatment session. The mean period from the last LH-RH agonist treatment to the recovery of menstruation was 6.9 months. The rate of menstruation recovery was 35.5% in patients aged 40 years or younger and 8.0% in those aged 41 years or older, and it was significantly higher in those aged 40 years or younger. The period until menstruation recovery tended to be longer in older patients at the end of treatment. This study showed that menstruation resumed after treatment at higher rates in younger patients. However, because it is highly likely that ovarian function will be destroyed by the treatment even in young patients, it is considered necessary to explain the risk to patients and obtain informed consent before introducing this treatment modality.

Prescribing tamoxifen in primary care for the prevention of breast cancer: a national online survey of GPs' attitudes.

Science.gov (United States)

Smith, Samuel G; Foy, Robbie; McGowan, Jennifer A; Kobayashi, Lindsay C; DeCensi, Andrea; Brown, Karen; Side, Lucy; Cuzick, Jack

2017-06-01

The cancer strategy for England (2015-2020) recommends GPs prescribe tamoxifen for breast cancer primary prevention among women at increased risk. To investigate GPs' attitudes towards prescribing tamoxifen. In an online survey, GPs in England, Northern Ireland, and Wales ( n = 928) were randomised using a 2 × 2 between-subjects design to read one of four vignettes describing a healthy patient seeking a tamoxifen prescription. In the vignette, the hypothetical patient's breast cancer risk (moderate versus high) and the clinician initiating the prescription (GP prescriber versus secondary care clinician [SCC] prescriber) were manipulated in a 1:1:1:1 ratio. Outcomes were willingness to prescribe, comfort discussing harms and benefits, comfort managing the patient, factors affecting the prescribing decision, and awareness of tamoxifen and the National Institute for Health and Care Excellence (NICE) guideline CG164. Half (51.7%) of the GPs knew tamoxifen can reduce breast cancer risk, and one-quarter (24.1%) were aware of NICE guideline CG164. Responders asked to initiate prescribing (GP prescriber) were less willing to prescribe tamoxifen than those continuing a prescription initiated in secondary care (SCC prescriber) (68.9% versus 84.6%, P preventive therapy in secondary care before asking GPs to continue the patient's care may overcome some prescribing barriers. © British Journal of General Practice 2017.

Construction of a Nanodiamond–Tamoxifen Complex as a Breast Cancer Drug Delivery Vehicle

Directory of Open Access Journals (Sweden)

Linda-Lucila Landeros-Martínez

2016-01-01

Full Text Available According to the World Health Organization, breast cancer represents 16% of all cancer cases in women and is the second most common cancer. In the past decades, the mortality among patients with metastasis breast cancer has been reduced significantly via drug delivery by means of nanodiamond therapies, which are both biocompatible and scalable. In this study, we determined a theoretical pathway for the construction of a nanodiamond–tamoxifen complex that will act as a drug delivery vehicle for targeting tumor tissues of breast cancer. The tamoxifen pharmacophore was defined and the binding zone was identified for the electrostatic interaction between tamoxifen and a functionalized site of a nanodiamond particle allowing for attachment of the payload (this drug to the surface of the nanodiamond particle. In addition, an analysis of the intermolecular interaction between the nanodiamond and tamoxifen was conducted, showing three hydrogen bonds complying fully with Lipinski’s rule of five, which states that a compound should have five or fewer hydrogen bonds to be permeating and easily absorbed by the body (qualitative prediction. All calculations were performed using the conceptual Density Functional Theory with the M06 functional and the basis set 6-31G(d. The solvent effect has been taken into account by an implicit model, the conductor like polarizable continuum model.

MCAM/CD146 promotes tamoxifen resistance in breast cancer cells through induction of epithelial-mesenchymal transition, decreased ER alpha expression and AKT activation

NARCIS (Netherlands)

Liang, Yuan-Ke; Zeng, De; Xiao, Ying-Sheng; Wu, Yang; Ouyang, Yan-Xiu; Chen, Min; Li, Yao-Chen; Lin, Hao-Yu; Wei, Xiao-Long; Zhang, Yong-Qu; Kruyt, Frank A. E.; Zhang, Guo-Jun

2017-01-01

Tamoxifen resistance presents a prominent clinical challenge in endocrine therapy for hormone sensitive breast cancer. However, the underlying mechanisms that contribute to tamoxifen resistance are not fully understood. In this study, we established a tamoxifen resistant MCF-7 cell line

Relationship of ZNF423 and CTSO with breast cancer risk in two randomised tamoxifen prevention trials.

Science.gov (United States)

Brentnall, Adam R; Cuzick, Jack; Byers, Helen; Segal, Corrinne; Reuter, Caroline; Detre, Simone; Sestak, Ivana; Howell, Anthony; Powles, Trevor J; Newman, William G; Dowsett, Mitchell

2016-08-01

A case-control study from two randomised breast cancer prevention trials of tamoxifen and raloxifene (P-1 and P-2) identified single-nucleotide polymorphisms (SNPs) in or near genes ZNF423 and CTSO as factors which predict which women will derive most anti-cancer benefit from selective oestrogen receptor modulator (SERM) therapy. In this article, we further examine this question using blood samples from two randomised tamoxifen prevention trials: the International Breast Cancer Intervention Study I (IBIS-I) and the Royal Marsden trial (Marsden). A nested case-control study was designed with 2:1 matching in IBIS-I and 1:1 matching in Marsden. The OncoArray was used for genotyping and included two SNPs previously identified (rs8060157 in ZNF423 and rs10030044 near CTSO), and 102 further SNPs within the same regions. Overall, there were 369 cases and 662 controls, with 148 cases and 268 controls from the tamoxifen arms. Odds ratios were estimated by conditional logistic regression, with Wald 95 % confidence intervals. In the tamoxifen arms, the per-allele odds ratio for rs8060157 was 0.99 (95 %CI 0.73-1.34) and 1.00 (95 %CI 0.76-1.33) for rs10030044. In the placebo arm, the odds ratio was 1.10 (95 %CI 0.87-1.40) for rs8060157 and 1.01 (95 %CI 0.79-1.29) for rs10030044. There was no evidence to suggest that other SNPs in the surrounding regions of these SNPs might predict response to tamoxifen. Results from these two prevention trials do not support the earlier findings. rs8060157 in ZNF423 and rs10030044 near CTSO do not appear to predict response to tamoxifen.

Monitoring mammary tumor progression and effect of tamoxifen treatment in MMTV-PymT using MRI and magnetic resonance spectroscopy with hyperpolarized [1-¹³C]pyruvate

DEFF Research Database (Denmark)

Asghar Butt, Sadia; Søgaard, Lise V.; Ardenkjær-Larsen, Jan Henrik

2015-01-01

Purpose: To use dynamic magnetic resonance spectroscopy (MRS) of hyperpolarized 13C-pyruvate to follow the progress over time in vivo of breast cancer metabolism in the MMTV-PymT model, and to follow the response to the anti-estrogen drug tamoxifen. Methods: Tumor growth was monitored by anatomical...... significantly in the treated group. Conclusion: These hyperpolarized 13C MRS findings indicate that tumor metabolic changes affects kP. The measured kp did not relate to treatment response to the same extent as did tumor growth, histological evaluation, and in vitro determination of LDH activity. © 2014 Wiley...

Induction of microRNAome deregulation in rat liver by long-term tamoxifen exposure

International Nuclear Information System (INIS)

Pogribny, Igor P.; Tryndyak, Volodymyr P.; Boyko, Alex; Rodriguez-Juarez, Rocio; Beland, Frederick A.; Kovalchuk, Olga

2007-01-01

Micro RNAs (miRNAs) are small non-coding RNA molecules that function as negative regulators of gene expression. They play a crucial role in the regulation of genes involved in the control of development, cell proliferation, apoptosis, and stress response. Although miRNA levels are substantially altered in tumors, their role in carcinogenesis, specifically at the early pre-cancerous stages, has not been established. Here we report that exposure of Fisher 344 rats to tamoxifen, a potent hepatocarcinogen in rats, for 24 weeks leads to substantial changes in the expression of miRNA genes in the liver. We noted a significant up-regulation of known oncogenic miRNAs, such as the 17-92 cluster, miR-106a, and miR-34. Furthermore, we confirmed the corresponding changes in the expression of proteins targeted by these miRNAs, which include important cell cycle regulators, chromatin modifiers, and expression regulators implicated in carcinogenesis. All these miRNA changes correspond to previously reported alterations in full-fledged tumors, including hepatocellular carcinomas. Thus, our findings indicate that miRNA changes occur prior to tumor formation and are not merely a consequence of a transformed state

Memory enhancement by Tamoxifen on amyloidosis mouse model.

Science.gov (United States)

Pandey, Deepika; Banerjee, Sugato; Basu, Mahua; Mishra, Nibha

2016-03-01

Tamoxifen (TMX) is a selective estrogen receptor modulator (SERM) used in the treatment of breast cancer. Earlier studies show its neuroprotection via regulating apoptosis, microglial functions, and synaptic plasticity. TMX also showed memory enhancement in ovariectomized mice, and protection from amyloid induced damage in hippocampal cell line. These reports encouraged us to explore the role of TMX in relevance to Alzheimer's disease (AD). We report here, the effect of TMX treatment a) on memory, and b) levels of neurotransmitters (acetylcholine (ACh) and dopamine (DA)) in breeding-retired-female mice injected with beta amyloid1-42 (Aβ1-42). Mice were treated with TMX (10mg/kg, i.p.) for 15 days. In Morris water maze test, the TMX treated mice escape latency decreased during training trials. They also spent longer time in the platform quadrant on probe trial, compared to controls. In Passive avoidance test, TMX treated mice avoided stepping on the shock chamber. This suggests that TMX protects memory from Aβ induced toxicity. In frontal cortex, ACh was moderately increased, with TMX treatment. In striatum, dopamine was significantly increased, 3,4-dihydroxyphenylacetic acid (DOPAC) level and DOPAC/DA ratio was decreased post TMX treatment. Therefore, TMX enhances spatial and contextual memory by reducing dopamine metabolism and increasing ACh level in Aβ1-42 injected-breeding-retired-female mice. Copyright © 2015. Published by Elsevier Inc.

Optimizing tamoxifen-inducible Cre/loxp system to reduce tamoxifen effect on bone turnover in long bones of young mice.

Science.gov (United States)

Zhong, Zhendong A; Sun, Weihua; Chen, Haiyan; Zhang, Hongliang; Lay, Yu-An E; Lane, Nancy E; Yao, Wei

2015-12-01

For tamoxifen-dependent Cre recombinase, also known as CreER recombinase, tamoxifen (TAM) is used to activate the Cre to generate time- and tissue-specific mouse mutants. TAM is a potent CreER system inducer; however, TAM is also an active selective estrogen receptor modulator (SERM) that can influence bone homeostasis. The purpose of this study was to optimize the TAM dose for Cre recombinase activation while minimizing the effects of TAM on bone turnover in young growing mice. To evaluate the effects of TAM on bone turnover and bone mass, 1-month-old wild-type male and female mice were intraperitoneally injected with TAM at 0, 1, 10 or 100mg/kg/day for four consecutive days, or 100, 300 mg/kg/day for one day. The distal femurs were analyzed one month after the last TAM injection by microCT, mechanical test, and surface-based bone histomorphometry. Similar doses of TAM were used in Col1 (2.3 kb)-CreERT2; mT/mG reporter male mice to evaluate the dose-dependent efficacy of Cre-ER activation in bone tissue. A TAM dose of 100 mg/kg × 4 days significantly increased trabecular bone volume/total volume (BV/TV) of the distal femur, femur length, bone strength, and serum bone turnover markers compared to the 0mg control group. In contrast, TAM doses ≤ 10 mg/kg did not significantly change any of these parameters compared to the 0mg group, although a higher bone strength was observed in the 10mg group. Surface-based histomorphometry revealed that the 100mg/kg dose of TAM dose significantly increased trabecular bone formation and decreased periosteal bone formation at 1-week post-TAM treatment. Using the reporter mouse model Col1-CreERT2; mT/mG, we found that 10mg/kg TAM induced Col1-CreERT2 activity in bone at a comparable level to the 100mg/kg dose. TAM treatment at 100mg/kg/day × 4 days significantly affects bone homeostasis, resulting in an anabolic bone effect on trabecular bone in 1-month-old male mice. However, a lower dose of TAM at 10 mg/kg/day × 4 days can

Tamoxifen therapy improves overall survival in luminal A subtype of ductal carcinoma in situ: a study based on nationwide Korean Breast Cancer Registry database.

Science.gov (United States)

Hwang, Ki-Tae; Kim, Eun-Kyu; Jung, Sung Hoo; Lee, Eun Sook; Kim, Seung Il; Lee, Seokwon; Park, Heung Kyu; Kim, Jongjin; Oh, Sohee; Kim, Young A

2018-06-01

To determine the prognostic role of tamoxifen therapy for patients with ductal carcinoma in situ (DCIS) according to molecular subtypes. Data of 14,944 patients with DCIS were analyzed. Molecular subtypes were classified into four categories based on expression of estrogen receptor (ER)/progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). Kaplan-Meier estimator was used for overall survival analysis while Cox proportional hazards model was used for univariate and multivariate analyses. Luminal A subtype (ER/PR+, HER2-) showed higher (P = .009) survival rate than triple-negative (TN) subtype. Tamoxifen therapy group showed superior (P < .001) survival than no-tamoxifen therapy group. It had survival benefit only for luminal A subtype (P = .001). Tamoxifen therapy resulted in higher survival rate in subgroups with positive ER (P = .006), positive PR (P = .009), and negative HER2 (P < .001). In luminal A subtype, tamoxifen therapy showed lower hazard ratio (HR) compared to no-tamoxifen therapy (HR, 0.420; 95% CI 0.250-0.705; P = .001). Tamoxifen therapy was a significant independent factor by multivariate analysis (HR, 0.538; 95% CI 0.306-0.946; P = .031) as well as univariate analysis. Tamoxifen therapy group showed superior prognosis than the no-tamoxifen therapy group. Its prognostic influence was only effective for luminal A subtype. Patients with luminal A subtype showed higher survival rate than those with TN subtype. Active tamoxifen therapy is recommended for DCIS patients with luminal A subtype, and routine tests for ER, PR, and HER2 should be considered for DCIS.

Principles of management of recurrence of breast cancer after tamoxifen therapy (abstract)

International Nuclear Information System (INIS)

Rasool, I.

1999-01-01

The management of recurrence of breast cancer after Tamoxifen therapy needs special attention. The recurrence can be local or distant. The patient, should be thoroughly investigated to find out exact sites of recurrences. Local recurrence is managed by excision, skin grafting or various types of flaps. If extensive radiation is administrated or if not given previously. The distant recurrence in patients who have had adjuvant menopausal status, sites of recurrence while life threatening or not and previous response. The patients who are post menopausal have responded to previous Tamoxifen therapy, long DFI and soft tissues and bony metastasis are best managed by Aromatase inhibitors i.e. Letrozole. (author)

Effect of tamoxifen pre-treatment on the retention of tritiated oestradiol and 5. cap alpha. -dihydrotestosterone and on glucose metabolism in human breast carcinomas

Energy Technology Data Exchange (ETDEWEB)

Deshpande, N; Mitchell, I [Imperial Cancer Research Fund, London (UK). Labs.; Hughes, D

1978-05-01

The effect of pre-treatment with tamoxifen on glucose metabolism and retention of injected oestradiol-17B and 5..cap alpha..-dihydrotestosterone by human breast carcinomas were studied in patients undergoing mastectomy. The following effects were observed: the pretreatment reduced retention of oestradiol-17B whereas a small but statistically significant rise in 5..cap alpha..-dihydrotestosterone accumulation was observed. There was an increase in both phosphofructokinase (PFK) and glucose-6-phosphate dehydrogenase (G6PDH) activities in tumours from treated patients whereas ..cap alpha..-glycerolphosphate dehydrogenase (..cap alpha..-GPDH) activity was significantly reduced in the same tumours. The significance of these findings is discussed and it is argued that these changes in carbohydrate metabolism may not be due to the blocking of hormone receptors.

Serum-dependent effects of tamoxifen and cannabinoids upon C6 glioma cell viability.

Science.gov (United States)

Jacobsson, S O; Rongård, E; Stridh, M; Tiger, G; Fowler, C J

2000-12-15

In the present study, the effects of the combination of tamoxifen ((Z)-2[p-(1,2-diphenyl-1-butenyl)phenoxy]-N,N-dimethylamine citrate) and three cannabinoids (Delta(9)-tetrahydrocannabinol [Delta(9)-THC], cannabidiol, and anandamide [AEA]) upon the viability of C6 rat glioma cells was assessed at different incubation times and using different culturing concentrations of foetal bovine serum (FBS). Consistent with previous data for human glioblastoma cells, the tamoxifen sensitivity of the cells was increased as the FBS content of the culture medium was reduced from 10 to 0.4 and 0%. The cells expressed protein kinase C alpha and calmodulin (the concentration of which did not change significantly as the FBS concentration was reduced), but did not express estrogen receptors. Delta(9)-THC and cannabidiol, but not AEA, produced a modest reduction in cell viability after 6 days of incubation in serum-free medium, whereas no effects were seen in 10% FBS-containing medium. There was no observed synergy between the effects of tamoxifen and the cannabinoids upon cell viability.

Apoptotic efficiency of aqueous extracts of turmeric, garlic and their active compounds in combination with Tamoxifen in lung and oral cancers: A comparative study

Directory of Open Access Journals (Sweden)

Satish Kumar Vemuri

2018-06-01

Full Text Available Anticancer treatment against oral and lung cancers has caught the eye of oncologist and researchers worldwide as most common cause deaths in India and worldwide is due to these cancers and most of the treatment strategies employed are not showing any effectiveness against neoplastic ability of the cancers. One of the reasons for cancer deaths could be because of poor prognosis and associated therapies. The existing cancer agents are being re-evaluated and development of new mechanisms of treatment being explored continuously, but it’s inadequate in offering treatment. Therefore, endeavors for new anticancer agents with high efficacy and considerable side effects still going on. The literature reviews shows numerous medicinal plants exhibiting anti-proliferative, pro-apoptotic, anti-metastatic and anti-angiogenic properties and these effects were reported by conducting both in vitro experiments and animal studies. Use of natural phytochemical compounds in cancer chemoprevention is an emerging strategy to forestall the cancer progression or cure cancer.In the present study we have attempted to evaluate the efficacy of Curcumin longa and Allium sativum aqueous extracts individually and in combination with its active compounds (Curcumin and Quercetin and also with Tamoxifen hydrochloride. Our results suggest that aqueous extracts of Curcumin longa and Allium sativum were effective in inducing apoptosis and cell death in two immortal cell lines i.e. A549 and SCC-9 (Adeno carcinoma of lung, squamous cell carcinoma of tongue, but there was no apoptosis or cell senescence in normal cell line (HEK 293. There was significant increase in apoptosis and cell senescence in combination therapy. Hence a combination of natural extracts along with Tamoxifen can be considered an alternate in cancer treatments but this requires more research. Keywords: Curcumin longa, Allium sativum, Tamoxifen hydrochloride, A549, SCC-9, HEK 293 cell lines

Alteration of diaspore by thermal treatment

Institute of Scientific and Technical Information of China (English)

杨华明; 胡岳华; 杨武国; 敖伟琴; 邱冠周

2004-01-01

Diaspore (α-AlOOH) was heated at various temperatures from 300 to 1000 ℃ for 2 h. The alteration of diaspore by thermal treatment was investigated by differential thermal analysis, thermogravimetric analysis and X-ray diffraction. The mechanism of thermal decomposition of diaspore was discussed according to the Coats-Redfern equation. It is found that after thermal treatment at 500 ℃, diaspore is transformed entirely to corundum (α-Al2O3). Combined with the mass loss ratio obtained from the thermogravimetric analysis data, the activation energies for the thermal treatment of diaspore are calculated as Ea=10.4 kJ/mol below 400 ℃ and Eb=47.5 kJ/mol above 400 ℃, respectively, which is directly related to the structural alteration of diaspore during the thermal treatment. The results indicate that the thermal decomposition of diaspore is conducted primarily by means of an interfacial reaction.

Relationship between intratumoral expression of genes coding for xenobiotic-metabolizing enzymes and benefit from adjuvant tamoxifen in estrogen receptor alpha-positive postmenopausal breast carcinoma

International Nuclear Information System (INIS)

Bièche, Ivan; Girault, Igor; Urbain, Estelle; Tozlu, Sengül; Lidereau, Rosette

2004-01-01

Little is known of the function and clinical significance of intratumoral dysregulation of xenobiotic-metabolizing enzyme expression in breast cancer. One molecular mechanism proposed to explain tamoxifen resistance is altered tamoxifen metabolism and bioavailability. To test this hypothesis, we used real-time quantitative RT-PCR to quantify the mRNA expression of a large panel of genes coding for the major xenobiotic-metabolizing enzymes (12 phase I enzymes, 12 phase II enzymes and three members of the ABC transporter family) in a small series of normal breast (and liver) tissues, and in estrogen receptor alpha (ERα)-negative and ERα-positive breast tumors. Relevant genes were further investigated in a well-defined cohort of 97 ERα-positive postmenopausal breast cancer patients treated with primary surgery followed by adjuvant tamoxifen alone. Seven of the 27 genes showed very weak or undetectable expression in both normal and tumoral breast tissues. Among the 20 remaining genes, seven genes (CYP2A6, CYP2B6, FMO5, NAT1, SULT2B1, GSTM3 and ABCC11) showed significantly higher mRNA levels in ERα-positive breast tumors than in normal breast tissue, or showed higher mRNA levels in ERα-positive breast tumors than in ERα-negative breast tumors. In the 97 ERα-positive breast tumor series, most alterations of these seven genes corresponded to upregulations as compared with normal breast tissue, with an incidence ranging from 25% (CYP2A6) to 79% (NAT1). Downregulation was rare. CYP2A6, CYP2B6, FMO5 and NAT1 emerged as new putative ERα-responsive genes in human breast cancer. Relapse-free survival was longer among patients with FMO5-overexpressing tumors or NAT1-overexpressing tumors (P = 0.0066 and P = 0.000052, respectively), but only NAT1 status retained prognostic significance in Cox multivariate regression analysis (P = 0.0013). Taken together, these data point to a role of genes coding for xenobiotic-metabolizing enzymes in breast tumorigenesis, NAT1 being an

Effect of adjuvant systemic treatment on cosmetic outcome and late normal-tissue reactions after breast conservation

International Nuclear Information System (INIS)

Johansen, Joergen; Overgaard, Jens; Overgaard, Marie

2007-01-01

To investigate whether adjuvant treatment with CMF or tamoxifen predisposes to an unfavorable cosmetic outcome or increased breast morbidity after radiotherapy in breast conservation. Data from 266 patients who entered a randomized breast conservation trial (DBCG-82TM protocol) was analyzed. The patients were treated with lumpectomy and axillary dissection followed by external beam radiotherapy to the residual breast. High-risk patients (n 94), as well as 31 low-risk patients, received additional radiation to the regional lymph nodes. Adjuvant systemic treatment was given to all high-risk patients: premenopausal patients (n = 67) received eight cycles of CMF intravenously (600/40/600 mg/m 2 ) every fourth week; postmenopausal patients (n = 27) received 30 mg of tamoxifen daily for one year. Clinical assessments included cosmetic outcome, breast fibrosis, skin telangiectasia, and dyspigmentation which were scored on a 4-point categorical scale after median 6.6 years. The observations were analyzed in multivariate logistic regression analysis which included potential risk factors on outcome related to systemic treatment, surgery, radiation technique, tumor, and patient characteristics. In premenopausal patients, systemic treatment with CMF independently predicted a fair/poor cosmetic outcome, RR = 2.2 (95% CI 1.2-4.2), as well as increased skin telangiectasia, RR = 3.3 (1.4-8.2). There was no impact of tamoxifen treatment on cosmetic outcome in postmenopausal patients (p 0.32). However, univariate analysis showed that tamoxifen was significantly associated with breast fibrosis (p <0.004), as was radiation to the regional lymph nodes (p <0.0001). A strong interaction between axillary irradiation and tamoxifen treatment occurred since 26 of 27 high-risk postmenopausal patients had received both tamoxifen and axillary irradiation. In multivariate regression analysis, axillary irradiation independently predicted moderate/severe breast fibrosis with a relative risk of 5

Tamoxifen induces regression of estradiol-induced mammary cancer in ACI.COP-Ept2 rat model

OpenAIRE

Ruhlen, Rachel L.; Willbrand, Dana M.; Besch-Williford, Cynthia L.; Ma, Lixin; Shull, James D.; Sauter, Edward R.

2008-01-01

The ACI rat is a unique model of human breast cancer in that mammary cancers are induced by estrogen without carcinogens, irradiation, xenografts or transgenic manipulations. We sought to characterize mammary cancers in a congenic variant of the ACI rat, the ACI.COP-Ept2. All rats with estradiol implants developed mammary cancers in 5–7 months. Rats bearing estradiol-induced mammary cancers were treated with tamoxifen for three weeks. Tamoxifen reduced tumor mass, measured by magnetic resonan...

Limited predictive value of achieving beneficial plasma (Z)-endoxifen threshold level by CYP2D6 genotyping in tamoxifen-treated Polish women with breast cancer

International Nuclear Information System (INIS)

Hennig, Ewa E.; Piatkowska, Magdalena; Karczmarski, Jakub; Goryca, Krzysztof; Brewczynska, Elzbieta; Jazwiec, Radoslaw; Kluska, Anna; Omiotek, Robert; Paziewska, Agnieszka; Dadlez, Michal; Ostrowski, Jerzy

2015-01-01

dose of tamoxifen. This finding emphasizes the limited value of CYP2D6 genotyping in routine clinical practice for identifying patients who might not benefit from the therapy. In its place, direct monitoring of plasma steady-state (Z)-endoxifen concentration should be performed to personalize and optimize the treatment. The online version of this article (doi:10.1186/s12885-015-1575-4) contains supplementary material, which is available to authorized users

Side effects associated with ultrarapid cytochrome P450 2D6 genotype among women with early stage breast cancer treated with tamoxifen.

Science.gov (United States)

Rolla, R; Vidali, M; Meola, S; Pollarolo, P; Fanello, M R; Nicolotti, C; Saggia, C; Forti, L; Agostino, F D; Rossi, V; Borra, G; Stratica, F; Alabiso, O; Bellomo, G

2012-01-01

The side effects of tamoxifen, a drug widely used for the treatment and the prevention of recurrence in patients with estrogen receptor positive breast cancers (ER+), have been reported in clinical trials, but to date no information is available on their possible association with an increased enzymatic activity of CYP2D6 (ultra-metabolizers, UMs). The aim of this study was therefore to evaluate the association between the presence of multiple functional CYP2D6 alleles and the occurrence of side effects. 61 women with ER+ breast cancer receiving tamoxifen monotherapy were investigated in order to assess the relationships between CYP2D6 UM phenotype and side effects. Genotyping of 16 CYP2D6 polymorphisms was performed using a new DNA microarray technology. A highly significant difference was detected (41.2% of difference, 95% CI 6 - 61%, Fisher's exact test, p = 0.030) between the numbers of Ultrarapid Metabolizer patients (UM; high activity) with two or more adverse drug reactions to tamoxifen (7/9; 77.8%), compared to the number of Extensive Metabolizers (EM; normal activity), Intermediate Metabolizers (IM; reduced activity), and Poor Metabolizers (PM; no activity) with at least two side effects (19/52, 36.5%). A similar difference was also observed comparing the two groups (UM vs EM-IM-PM) for the number of side effects (median and inter quartile range, IQR: AM/EM/IM 1, IQR 0-2 vs. ULTRA 2, IQR 2-4; Mann-Whitney p = 0.005). Our results suggest a new association between CYP2D6 gene duplication and side effects to tamoxifen, indicating a possible role of CYP2D6 in their occurrence.

A systematic review and methodological evaluation of published cost-effectiveness analyses of aromatase inhibitors versus tamoxifen in early stage breast cancer.

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Ava A John-Baptiste

Full Text Available BACKGROUND: A key priority in developing policies for providing affordable cancer care is measuring the value for money of new therapies using cost-effectiveness analyses (CEAs. For CEA to be useful it should focus on relevant outcomes and include thorough investigation of uncertainty. Randomized controlled trials (RCTs of five years of aromatase inhibitors (AI versus five years of tamoxifen in the treatment of post-menopausal women with early stage breast cancer, show benefit of AI in terms of disease free survival (DFS but not overall survival (OS and indicate higher risk of fracture with AI. Policy-relevant CEA of AI versus tamoxifen should focus on OS and include analysis of uncertainty over key assumptions. METHODS: We conducted a systematic review of published CEAs comparing an AI to tamoxifen. We searched Ovid MEDLINE, EMBASE, PsychINFO, and the Cochrane Database of Systematic Reviews without language restrictions. We selected CEAs with outcomes expressed as cost per life year or cost per quality adjusted life year (QALY. We assessed quality using the Neumann checklist. Using structured forms two abstractors collected descriptive information, sources of data, baseline assumptions on effectiveness and adverse events, and recorded approaches to assessing parameter uncertainty, methodological uncertainty, and structural uncertainty. RESULTS: We identified 1,622 citations and 18 studies met inclusion criteria. All CE estimates assumed a survival benefit for aromatase inhibitors. Twelve studies performed sensitivity analysis on the risk of adverse events and 7 assumed no additional mortality risk with any adverse event. Sub-group analysis was limited; 6 studies examined older women, 2 examined women with low recurrence risk, and 1 examined women with multiple comorbidities. CONCLUSION: Published CEAs comparing AIs to tamoxifen assumed an OS benefit though none has been shown in RCTs, leading to an overestimate of the cost-effectiveness of AIs

Novel Carbonyl Analogs of Tamoxifen: Design, Synthesis, and Biological Evaluation

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Konstantinos M. Kasiotis

2017-09-01

Full Text Available Aim of this work was to provide tamoxifen analogs with enhanced estrogen receptor (ER binding affinity. Hence, several derivatives were prepared using an efficient triarylethylenes synthetic protocol. The novel compounds bioactivity was evaluated through the determination of their receptor binding affinity and their agonist/antagonist activity against breast cancer tissue using a MCF-7 cell-based assay. Phenyl esters 6a,b and 8a,b exhibited binding affinity to both ERα and ERβ higher than 4-hydroxytamoxifen while compounds 13 and 14 have shown cellular antiestrogenic activity similar to 4-hydroxytamoxifen and the known ER inhibitor ICI182,780. Theoretical calculations and molecular modeling were applied to investigate, support and explain the biological profile of the new compounds. The relevant data indicated an agreement between calculations and demonstrated biological activity allowing to extract useful structure-activity relationships. Results herein underline that modifications of tamoxifen structure still provide molecules with substantial activity, as portrayed in the inhibition of MCF-7 cells proliferation.

A misdiagnosed Riedel's thyroiditis successfully treated by thyroidectomy and tamoxifen.

Science.gov (United States)

Wang, Chih-Jung; Wu, Ta-Jen; Lee, Chung-Ta; Huang, Shih-Ming

2012-12-01

Riedel's thyroiditis, known as invasive fibrous thyroiditis, is a very rare form of chronic thyroiditis. It is hard to make the diagnosis without surgical biopsy. We present a case of Riedel's thyroiditis in a 52-year-old female with past history of Hashimoto's thyroiditis. She suffered from bilateral neck pain, which radiated to both lower jaws. The erythrocyte sedimentation rate was 125 mm/hour. Subacute thyroiditis superimposed on Hashimoto's thyroiditis was diagnosed and treated with steroid. However the response was poor and she had a history of severe peptic ulcer. To avoid inducing the peptic ulcer by steroid, she received bilateral subtotal thyroidectomy. During surgery, the thyroid had severe adhesion to surrounding soft tissue and the pathology showed Riedel's thyroiditis. The neck pain improved after thyroidectomy. Tamoxifen has been given for 8 months and the size of remnant thyroid decreased to 8 mm. We concluded that combined thyroidectomy and tamoxifen successfully cured a patient with Riedel's thyroiditis. Copyright © 2012. Published by Elsevier B.V.

Novel Carbonyl Analogues of Tamoxifen: Design, Synthesis, and Biological Evaluation

Science.gov (United States)

Kasiotis, Konstantinos M.; Lambrinidis, George; Fokialakis, Nikolas; Tzanetou, Evangelia N.; Mikros, Emmanuel; Haroutounian, Serkos A.

2017-09-01

Aim of this work was to provide tamoxifen analogues with enhanced estrogen receptor binding affinity. Hence, several derivatives were prepared using an efficient triarylethylenes synthetic protocol. The novel compounds bioactivity was evaluated through the determination of their receptor binding affinity and their agonist/antagonist activity against breast cancer tissue using a MCF-7 cell-based assay. Phenyl esters 6a,b and 8a,b exhibited binding affinity to both ERα and ERβ higher than 4-hydroxytamoxifen while compounds 13 and 14 have shown cellular antiestrogenic activity similar to 4-hydroxytamoxifen and the known estrogen receptor inhibitor ICI182,780. Theoretical calculations and molecular modelling were applied to investigate, support and explain the biological profile of the new compounds. The relevant data indicated an agreement between calculations and demonstrated biological activity allowing to extract useful structure-activity relationships. Results herein underline that modifications of tamoxifen structure still provide molecules with substantial activity, as portrayed in the inhibition of MCF-7 cells proliferation.

Safety and efficacy of high-dose tamoxifen and sulindac for desmoid tumor in children: results of a Children's Oncology Group (COG) phase II study.

Science.gov (United States)

Skapek, Stephen X; Anderson, James R; Hill, D Ashley; Henry, David; Spunt, Sheri L; Meyer, William; Kao, Simon; Hoffer, Fredric A; Grier, Holcombe E; Hawkins, Douglas S; Raney, R Beverly

2013-07-01

Desmoid fibromatosis (desmoid tumor, DT) is a soft tissue neoplasm prone to recurrence despite complete surgical resection. Numerous small retrospective reports suggest that non-cytotoxic chemotherapy using tamoxifen and sulindac may be effective for DT. We evaluated the safety and efficacy of tamoxifen and sulindac in a prospective phase II study within the Children's Oncology Group. Eligible patients were <19 years of age who had measurable DT that was recurrent or not amenable to surgery or radiation. The primary objective was to estimate progression-free survival (PFS). Patients received tamoxifen and sulindac daily for 12 months or until disease progression or intolerable toxicity occurred. Response was assessed by magnetic resonance imaging. Fifty-nine eligible patients were enrolled from 2004 to 2009; 78% were 10-18 years old. Twenty-two (38%) were previously untreated; 15 (41%) of the remaining 37 enrolling with recurrent DT had prior systemic chemotherapy and six (16%) had prior radiation. No life-threatening toxicity was reported. Twelve (40%) of 30 females developed ovarian cysts, which were asymptomatic in 11 cases. Ten patients completed therapy without disease progression or discontinuing treatment. Responses included four partial and one complete (5/59, 8%). The estimated 2-year PFS and survival rates were 36% (95% confidence interval: 0.23-0.48) and 96%, respectively. All three deaths were due to progressive DT. Tamoxifen and sulindac caused few serious side effects in children with DT, although ovarian cysts were common. However, the combination showed relatively little activity as measured by response and PFS rates. Copyright © 2012 Wiley Periodicals, Inc.

Establishment of a tamoxifen-inducible Cre-driver mouse strain for widespread and temporal genetic modification in adult mice.

Science.gov (United States)

Ichise, Hirotake; Hori, Akiko; Shiozawa, Seiji; Kondo, Saki; Kanegae, Yumi; Saito, Izumu; Ichise, Taeko; Yoshida, Nobuaki

2016-07-29

Temporal genetic modification of mice using the ligand-inducible Cre/loxP system is an important technique that allows the bypass of embryonic lethal phenotypes and access to adult phenotypes. In this study, we generated a tamoxifen-inducible Cre-driver mouse strain for the purpose of widespread and temporal Cre recombination. The new line, named CM32, expresses the GFPneo-fusion gene in a wide variety of tissues before FLP recombination and tamoxifen-inducible Cre after FLP recombination. Using FLP-recombined CM32 mice (CM32Δ mice) and Cre reporter mouse lines, we evaluated the efficiency of Cre recombination with and without tamoxifen administration to adult mice, and found tamoxifen-dependent induction of Cre recombination in a variety of adult tissues. In addition, we demonstrated that conditional activation of an oncogene could be achieved in adults using CM32Δ mice. CM32Δ;T26 mice, which harbored a Cre recombination-driven, SV40 large T antigen-expressing transgene, were viable and fertile. No overt phenotype was found in the mice up to 3 months after birth. Although they displayed pineoblastomas (pinealoblastomas) and/or thymic enlargement due to background Cre recombination by 6 months after birth, they developed epidermal hyperplasia when administered tamoxifen. Collectively, our results suggest that the CM32Δ transgenic mouse line can be applied to the assessment of adult phenotypes in mice with loxP-flanked transgenes.

Tool Weighs Benefits, Risks of Raloxifene or Tamoxifen to Prevent Breast Cancer

Science.gov (United States)

Researchers have developed a benefit-risk index to help guide decisions on whether postmenopausal women at increased risk of developing breast cancer should take raloxifene or tamoxifen to reduce that risk.

Tamoxifen and the Rafoxifene analog LY117018: their effects on arachidonic acid release from cells in culture and on prostaglandin I2 production by rat liver cells

International Nuclear Information System (INIS)

Levine, Lawrence

2004-01-01

Tamoxifen is being used successfully to treat breast cancer. However, tamoxifen also increases the risk of developing endometrial cancer in postmenopausal women. Raloxifene also decreases breast cancer in women at high risk and may have a lower risk at developing cancer of the uterus. Tamoxifen has been shown to stimulate arachidonic acid release from rat liver cells. I have postulated that arachidonic acid release from cells may be associated with cancer chemoprevention. Rat liver, rat glial, human colon carcinoma and human breast carcinoma cells were labelled with [ 3 H] arachidonic acid. The release of the radiolabel from these cells during incubation with tamoxifen and the raloxifene analog LY117018 was measured. The prostaglandin I 2 produced during incubation of the rat liver cells with μM concentrations of tamoxifen and the raloxifene analog was quantitatively estimated. Tamoxifen is about 5 times more effective than LY117018 at releasing arachidonic acid from all the cells tested. In rat liver cells only tamoxifen stimulates basal prostaglandin I 2 production and that induced by lactacystin and 12-O-tetradecanoyl-phorbol-13-acetate. LY117018, however, blocks the tamoxifen stimulated prostaglandin production. The stimulated prostaglandin I 2 production is rapid and not affected either by preincubation of the cells with actinomycin or by incubation with the estrogen antagonist ICI-182,780. Tamoxifen and the raloxifene analog, LY117018, may prevent estrogen-independent as well as estrogen-dependent breast cancer by stimulating phospholipase activity and initiating arachidonic acid release. The release of arachidonic acid and/or molecular reactions that accompany that release may initiate pathways that prevent tumor growth. Oxygenation of the intracellularly released arachidonic acid and its metabolic products may mediate some of the pharmacological actions of tamoxifen and raloxifene

Tamoxifen-resistant breast cancer cells are resistant to DNA-damaging chemotherapy because of upregulated BARD1 and BRCA1.

Science.gov (United States)

Zhu, Yinghua; Liu, Yujie; Zhang, Chao; Chu, Junjun; Wu, Yanqing; Li, Yudong; Liu, Jieqiong; Li, Qian; Li, Shunying; Shi, Qianfeng; Jin, Liang; Zhao, Jianli; Yin, Dong; Efroni, Sol; Su, Fengxi; Yao, Herui; Song, Erwei; Liu, Qiang

2018-04-23

Tamoxifen resistance is accountable for relapse in many ER-positive breast cancer patients. Most of these recurrent patients receive chemotherapy, but their chemosensitivity is unknown. Here, we report that tamoxifen-resistant breast cancer cells express significantly more BARD1 and BRCA1, leading to resistance to DNA-damaging chemotherapy including cisplatin and adriamycin, but not to paclitaxel. Silencing BARD1 or BRCA1 expression or inhibition of BRCA1 phosphorylation by Dinaciclib restores the sensitivity to cisplatin in tamoxifen-resistant cells. Furthermore, we show that activated PI3K/AKT pathway is responsible for the upregulation of BARD1 and BRCA1. PI3K inhibitors decrease the expression of BARD1 and BRCA1 in tamoxifen-resistant cells and re-sensitize them to cisplatin both in vitro and in vivo. Higher BARD1 and BRCA1 expression is associated with worse prognosis of early breast cancer patients, especially the ones that received radiotherapy, indicating the potential use of PI3K inhibitors to reverse chemoresistance and radioresistance in ER-positive breast cancer patients.

Bilateral macular edema in a patient treated with tamoxifen: a case report and review of the literature.

Science.gov (United States)

Zafeiropoulos, Paraskevas; Nanos, Panagiotis; Tsigkoulis, Evangelos; Stefaniotou, Maria

2014-01-01

We present a case of a 41-year-old female patient with progressive bilateral visual loss. On examination, her best corrected visual acuity (BCVA) in her right eye was 3/10 and her BCVA in her left eye was 2/10. Fundus and optical coherence tomography examination revealed severe bilateral macular edema. She had been diagnosed with breast cancer 6 years ago and was receiving tamoxifen at a dosage of 20 mg/day ever since. Tamoxifen therapy was discontinued, and the patient received 250 mg of acetazolamide three times a day for a period of 1 month. Both foveae regained their normal contour within 2 months, and her vision was restored to 10/10 BCVA 3 months later. To our knowledge, this is the first case reported where bilateral intraretinal macular edema is the only retinal manifestation in a patient on oral tamoxifen.

Polypoid endometriosis mimicking invasive cancer in an obese, postmenopausal tamoxifen user

Directory of Open Access Journals (Sweden)

William T. Jaegle

2017-11-01

Précis: Endometriosis is a benign estrogen dependent condition rarely problematic in a postmenopausal patient. Tamoxifen use in the setting of an obese patient may contribute to a proliferation of pre-existing endometriosis which resembles an aggressive late-stage gynecological malignancy.

Safety and Efficacy of High-Dose Tamoxifen and Sulindac for Desmoid Tumor in Children: Results of a Children’s Oncology Group (COG) Phase II Study

Science.gov (United States)

Skapek, Stephen X.; Anderson, James R.; Hill, D. Ashley; Henry, David; Spunt, Sheri L.; Meyer, William; Kao, Simon; Hoffer, Fredric A.; Grier, Holcombe E.; Hawkins, Douglas S.; Raney, R. Beverly

2015-01-01

Background Desmoid fibromatosis (desmoid tumor, DT) is a soft tissue neoplasm prone to recurrence despite complete surgical resection. Numerous small retrospective reports suggest that non-cytotoxic chemotherapy using tamoxifen and sulindac may be effective for DT. We evaluated the safety and efficacy of tamoxifen and sulindac in a prospective phase II study within the Children’s Oncology Group. Procedures Eligible patients were <19 years of age who had measurable DT that was recurrent or not amenable to surgery or radiation. The primary objective was to estimate progression-free survival (PFS). Patients received tamoxifen and sulindac daily for 12 months or until disease progression or intolerable toxicity occurred. Response was assessed by magnetic resonance imaging. Results Fifty-nine eligible patients were enrolled from 2004 to 2009; 78% were 10–18 years old. Twenty-two (38%) were previously untreated; 15 (41%) of the remaining 37 enrolling with recurrent DT had prior systemic chemotherapy and six (16%) had prior radiation. No life-threatening toxicity was reported. Twelve (40%) of 30 females developed ovarian cysts, which were asymptomatic in 11 cases. Ten patients completed therapy without disease progression or discontinuing treatment. Responses included four partial and one complete (5/59, 8%). The estimated 2-year PFS and survival rates were 36% (95% confidence interval: 0.23–0.48) and 96%, respectively. All three deaths were due to progressive DT. Conclusions Tamoxifen and sulindac caused few serious side effects in children with DT, although ovarian cysts were common. However, the combination showed relatively little activity as measured by response and PFS rates. PMID:23281268

GPER1-mediated IGFBP-1 induction modulates IGF-1-dependent signaling in tamoxifen-treated breast cancer cells.

Science.gov (United States)

Vaziri-Gohar, Ali; Houston, Kevin D

2016-02-15

Tamoxifen, a selective estrogen receptor modulator, is a commonly prescribed adjuvant therapy for estrogen receptor-α (ERα)-positive breast cancer patients. To determine if extracellular factors contribute to the modulation of IGF-1 signaling after tamoxifen treatment, MCF-7 cells were treated with IGF-1 in conditioned medium (CM) obtained from 4-OHT-treated MCF-7 cells and the accumulation of phospho-Akt (S473) was measured. CM inhibited IGF-1-dependent cell signaling and suggesting the involvement of extracellular factors (ie. IGFBPs). A significant increase in IGFBP-1 mRNA and extracellular IGFBP-1 protein was observed in 4-OHT-treated MCF-7 cells. Knockdown experiments demonstrated that both GPER1 and CREB mediate IGFBP-1 induction. Furthermore, experiments showed that 4-OHT-dependent IGFBP-1 transcription is downstream of GPER1-activation in breast cancer cells. Additionally, neutralization and knockdown experiments demonstrated a role for IGFBP-1 in the observed inhibition of IGF-1 signaling. These results suggested that 4-OHT inhibits IGF-1 signaling via GPER1 and CREB mediated extracellular IGFBP-1 accumulation in breast cancer cells. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Effect of long-term treatment with steroid hormones or tamoxifen on the progesterone receptor and androgen receptor in the endometrium of ovariectomized cynomolgus macaques

Directory of Open Access Journals (Sweden)

Cline J Mark

2003-02-01

Full Text Available Abstract The progesterone receptor (PR and androgen receptor (AR belong to the nuclear receptor superfamily. Two isoforms of PR (A and B have been identified with different functions. The expression of AR, each isoform of PR and their involvement in long-term effects on the endometrium after hormonal replacement therapy (HRT or tamoxifen (TAM treatment is not known. The aims of this study were to determine PR(A+B, PRB and AR distribution by immunohistochemistry in the macaque (Macaca fascicularis endometrium. Ovariectomized (OVX animals were orally treated continuously for 35 months with either conjugated equine estrogens (CEE; medroxyprogesterone acetate (MPA; the combination of CEE/MPA; or TAM. Treatment with CEE/MPA tended to down-regulate PR in the superficial glands, but increased it in the stroma. TAM treatment increased both the PR and PRB levels in the stroma. Overall, less than 20% of the cells were positive for the PRB isoform and less variation was observed after steroid treatment. AR was found in the stroma, mainly distributed in the basal layer of the endometrium in the OVX and steroid treated groups, but was absent in the TAM treated group. No AR was found in the glandular epithelium. The present data show that long-term hormone treatment affects the PR level, and also the ratio between PRA and PRB in the endometrium.

Antiproliferation and apoptosis induced by tamoxifen in human bile duct carcinoma QBC939 cells via upregulated p53 expression

International Nuclear Information System (INIS)

Han, Peng; Kang, Jin-He; Li, Hua-Liang; Hu, Su-Xian; Lian, Hui-Hui; Qiu, Ping-Ping; Zhang, Jian; Li, Wen-Gang; Chen, Qing-Xi

2009-01-01

Tamoxifen (TAM) is a nonsteroidal antiestrogen that has been used in the treatment of breast cancer for over 30 years. Recently, it was shown that TAM also has efficacy on gastrointestinal neoplasms such as hepatocarcinoma and pancreatic carcinoma, and that the chemopreventive activities of TAM might be due to its abilities to inhibit cell growth and induce apoptosis. In the present study, we investigated the effects of tamoxifen on growth and apoptosis in the human bile duct carcinoma (BDC) cell line QBC939 using MTT assay, inverted microscopy, fluorescence microscopy, transmission electron microscopy, classic DNA fragmentation agarose gel electrophoresis assay, PI single- and FITC/PI double-staining flow cytometry, and Western blotting. Our data revealed that TAM could significantly inhibit growth and induce apoptosis in QBC939 cells. Increased expression of p53 was observed in TAM-treated cells, indicating that p53 might play an important role in TAM-induced apoptosis in QBC939 cells. These results provide significant insight into the anticarcinogenic action of TAM on BDC.

Antiproliferation and apoptosis induced by tamoxifen in human bile duct carcinoma QBC939 cells via upregulated p53 expression

Energy Technology Data Exchange (ETDEWEB)

Han, Peng; Kang, Jin-He; Li, Hua-Liang [Key Laboratory of Ministry of Education for Cell Biology and Tumor Cell Engineering, School of Life Sciences, Xiamen University, Xiamen 361005 (China); Hu, Su-Xian [First Hospital Attached to Fujian Medical University, Xiamen 361004 (China); Lian, Hui-Hui; Qiu, Ping-Ping; Zhang, Jian [Key Laboratory of Ministry of Education for Cell Biology and Tumor Cell Engineering, School of Life Sciences, Xiamen University, Xiamen 361005 (China); Li, Wen-Gang [First Hospital Attached to Fujian Medical University, Xiamen 361004 (China); Chen, Qing-Xi [Key Laboratory of Ministry of Education for Cell Biology and Tumor Cell Engineering, School of Life Sciences, Xiamen University, Xiamen 361005 (China); Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiamen 361005 (China)

2009-07-24

Tamoxifen (TAM) is a nonsteroidal antiestrogen that has been used in the treatment of breast cancer for over 30 years. Recently, it was shown that TAM also has efficacy on gastrointestinal neoplasms such as hepatocarcinoma and pancreatic carcinoma, and that the chemopreventive activities of TAM might be due to its abilities to inhibit cell growth and induce apoptosis. In the present study, we investigated the effects of tamoxifen on growth and apoptosis in the human bile duct carcinoma (BDC) cell line QBC939 using MTT assay, inverted microscopy, fluorescence microscopy, transmission electron microscopy, classic DNA fragmentation agarose gel electrophoresis assay, PI single- and FITC/PI double-staining flow cytometry, and Western blotting. Our data revealed that TAM could significantly inhibit growth and induce apoptosis in QBC939 cells. Increased expression of p53 was observed in TAM-treated cells, indicating that p53 might play an important role in TAM-induced apoptosis in QBC939 cells. These results provide significant insight into the anticarcinogenic action of TAM on BDC.

Tamoxifen effects on subjective and psychosexual well-being, in a randomised breast cancer study comparing high-dose and standard-dose chemotherapy

NARCIS (Netherlands)

Mourits, MJ; Bockermann, [No Value; de Vries, EG; van der Zee, AG; ten Hoor, KA; van der Graaf, WT; Sluiter, WJ; Willemse, PH

2002-01-01

To evaluate the impact of tamoxifen on subjective and psychosexual well-being in breast cancer patients in relation to type of prior chemotherapy and menopausal status. Longitudinal interview study in breast cancer patients during and after adjuvant tamoxifen use. Menopausal status was defined by

Bilateral Macular Edema in a Patient Treated with Tamoxifen: A Case Report and Review of the Literature

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Paraskevas Zafeiropoulos

2014-12-01

Full Text Available We present a case of a 41-year-old female patient with progressive bilateral visual loss. On examination, her best corrected visual acuity (BCVA in her right eye was 3/10 and her BCVA in her left eye was 2/10. Fundus and optical coherence tomography examination revealed severe bilateral macular edema. She had been diagnosed with breast cancer 6 years ago and was receiving tamoxifen at a dosage of 20 mg/day ever since. Tamoxifen therapy was discontinued, and the patient received 250 mg of acetazolamide three times a day for a period of 1 month. Both foveae regained their normal contour within 2 months, and her vision was restored to 10/10 BCVA 3 months later. To our knowledge, this is the first case reported where bilateral intraretinal macular edema is the only retinal manifestation in a patient on oral tamoxifen.

Global characterization of signalling networks associated with tamoxifen resistance in breast cancer

DEFF Research Database (Denmark)

Browne, Brigid C.; Hochgräfe, Falko; Wu, Jianmin

2013-01-01

R cells. Phosphorylation of the tyrosine kinase Yes and expression of the actin‐binding protein myristoylated alanine‐rich C‐kinase substrate (MARCKS) were increased two‐ and eightfold in TamR cells respectively, and these proteins were selected for further analysis. Knockdown of either protein in Tam......Acquired resistance to the anti‐estrogen tamoxifen remains a significant challenge in breast cancer management. In this study, we used an integrative approach to characterize global protein expression and tyrosine phosphorylation events in tamoxifen‐resistant MCF7 breast cancer cells (Tam...... was perturbed in TamR cells, together with pathways enriched for proteins associated with growth factor, cell–cell and cell matrix‐initiated signalling. Consistent with known roles for Ras/MAPK and PI3‐kinase signalling in tamoxifen resistance, tyrosine‐phosphorylated MAPK1, SHC1 and PIK3R2 were elevated in Tam...

The curability of breast cancer and the treatment of advanced disease

International Nuclear Information System (INIS)

Guarneri, Valentina; Conte, Pier Franco

2004-01-01

Breast cancer represents a major health problem, with more than 1,000,000 new cases and 370,000 deaths yearly worldwide. In the last decade, in spite of an increasing incidence, breast cancer mortality has been declining in the majority of developed countries. This is the combined result of better education, widespread screening programmes and more efficacious adjuvant treatments. Better knowledge of breast cancer biology now allows the cosmetic, physical and psychological consequences of radical mastectomy to be spared in the majority of breast cancer patients. Use of the sentinel node technique is rapidly expanding and this will further reduce the extent and the consequences of surgery. Several clinico-pathological factors are used to discriminate between patients at low (<10%), average (10-40%) and high risk of relapse. Nodal status, tumour size, tumour grade and age are accepted universally as important factors to define risk categories. Newer factors such as uPA/PAI-1, HERer2-neu, proliferative indices and gene expression profile are promising and will allow better discrimination between patients at different risk. Endocrine manipulation with tamoxifen, ovarian ablation or both is the preferred option in the case of endocrine-responsive tumours. Tamoxifen administered for 5 years is the standard treatment for postmenopausal patients; tamoxifen plus ovarian ablation is more effective than tamoxifen alone for premenopausal women. Recent data demonstrate that, for postmenopausal patients, the aromatase inhibitors are superior to tamoxifen, with a different safety profile. At present, anastrozole can be used in the adjuvant setting in cases of tamoxifen intolerance or toxicity. Chemotherapy is the treatment of choice for steroid receptor-negative tumours. Polychemotherapy is superior to single agents and anthracycline-containing regimens are superior to CMF. Six courses of FEC or FAC or the sequential administration of four doses of anthracycline followed by four

The curability of breast cancer and the treatment of advanced disease

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Guarneri, Valentina; Conte, Pier Franco [Department of Oncology and Hematology, University of Modena and Reggio Emilia, Modena (Italy)

2004-06-01

Breast cancer represents a major health problem, with more than 1,000,000 new cases and 370,000 deaths yearly worldwide. In the last decade, in spite of an increasing incidence, breast cancer mortality has been declining in the majority of developed countries. This is the combined result of better education, widespread screening programmes and more efficacious adjuvant treatments. Better knowledge of breast cancer biology now allows the cosmetic, physical and psychological consequences of radical mastectomy to be spared in the majority of breast cancer patients. Use of the sentinel node technique is rapidly expanding and this will further reduce the extent and the consequences of surgery. Several clinico-pathological factors are used to discriminate between patients at low (<10%), average (10-40%) and high risk of relapse. Nodal status, tumour size, tumour grade and age are accepted universally as important factors to define risk categories. Newer factors such as uPA/PAI-1, HERer2-neu, proliferative indices and gene expression profile are promising and will allow better discrimination between patients at different risk. Endocrine manipulation with tamoxifen, ovarian ablation or both is the preferred option in the case of endocrine-responsive tumours. Tamoxifen administered for 5 years is the standard treatment for postmenopausal patients; tamoxifen plus ovarian ablation is more effective than tamoxifen alone for premenopausal women. Recent data demonstrate that, for postmenopausal patients, the aromatase inhibitors are superior to tamoxifen, with a different safety profile. At present, anastrozole can be used in the adjuvant setting in cases of tamoxifen intolerance or toxicity. Chemotherapy is the treatment of choice for steroid receptor-negative tumours. Polychemotherapy is superior to single agents and anthracycline-containing regimens are superior to CMF. Six courses of FEC or FAC or the sequential administration of four doses of anthracycline followed by four

The advantage of letrozole over tamoxifen in the BIG 1-98 trial is consistent in younger postmenopausal women and in those with chemotherapy-induced menopause

DEFF Research Database (Denmark)

Chirgwin, Jacquie; Sun, Zhuoxin; Smith, Ian

2012-01-01

subclinical ovarian estrogen production), and those with chemotherapy-induced menopause who may experience return of ovarian function. In these situations tamoxifen may be preferable to an aromatase inhibitor. Among 4,922 patients allocated to the monotherapy arms (5 years of letrozole or tamoxifen......) in the BIG 1-98 trial we identified two relevant subpopulations: patients with potential residual ovarian function, defined as having natural menopause, treated without adjuvant or neoadjuvant chemotherapy and age ≤ 55 years (n = 641); and those with chemotherapy-induced menopause (n = 105). Neither...... of the subpopulations examined showed treatment effects differing from the trial population as a whole (interaction P values are 0.23 and 0.62, respectively). Indeed, both among the 641 patients aged ≤ 55 years with natural menopause and no chemotherapy (HR 0.77 [0.51, 1.16]) and among the 105 patients...

Effect of paclitaxel, epirubicin and tamoxifen on labelling index in cultured ehrlich ascites tumor cells

International Nuclear Information System (INIS)

Arican, G. Oe.; Oezalpan, A.

2001-01-01

The effect of Paclitaxel (PAC), Epirubicin (EPR) and Tamoxifen (TAM) on ''3H-thymidine labelling index (''3H-TdR LI) of Ehrlich ascites tumor cells (EAT) was investigated in cultured. In the present study, an estrogen receptor positive ER(+) hyper diploid cell lines were studied. We used optimum doses of PAC, EPR and TAM (12 mg/ml, 12 mg/ml and 2 mg/ml, respectively). Cells were treated with these doses for 0, 4, 8, 16 and 32 hours. At the end of these periods, both control and treated cells were labelled for 5 mCi/ml 3H-thymidine for 30 minutes. The results showed that inhibition of DNA synthesis in cultured EAT cells were increased in the combined treatment of two drugs when compared to the treatment of a single drug (p<0.01). In the treatment of three drugs, however, this effect reached a maximum (p<0.001). As a result, PAC+EPR+TAM treatment's had a maximum synergistic effect at 4 hours treatment

Microarray Analysis on Gene Regulation by Estrogen, Progesterone and Tamoxifen in Human Endometrial Stromal Cells

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Chun-E Ren

2015-03-01

Full Text Available Epithelial stromal cells represent a major cellular component of human uterine endometrium that is subject to tight hormonal regulation. Through cell-cell contacts and/or paracrine mechanisms, stromal cells play a significant role in the malignant transformation of epithelial cells. We isolated stromal cells from normal human endometrium and investigated the morphological and transcriptional changes induced by estrogen, progesterone and tamoxifen. We demonstrated that stromal cells express appreciable levels of estrogen and progesterone receptors and undergo different morphological changes upon hormonal stimulation. Microarray analysis indicated that both estrogen and progesterone induced dramatic alterations in a variety of genes associated with cell structure, transcription, cell cycle, and signaling. However, divergent patterns of changes, and in some genes opposite effects, were observed for the two hormones. A large number of genes are identified as novel targets for hormonal regulation. These hormone-responsive genes may be involved in normal uterine function and the development of endometrial malignancies.

Radiation recall dermatitis induced by Amol during tamoxifen therapy - case report

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Obtulowicz, A.; Pirowska, M.; Kosiniak-Kamysz, A.

2011-01-01

In the course of radiation therapy different types of adverse reactions of the skin are observed in approximately 95% of patients. Among the various complications encountered after radiotherapy, radiation recall dermatitis (RRD) deserves special attention. Radiation dermatitis is a form of delayed hypersensitivity of irradiated skin, and the direct trigger factors are medicines - most chemotherapeutics. The reaction is an inflammatory dermatosis. It is limited to previously irradiated skin and appears a number of months after radiotherapy. The aetiology of RRD is still unclear. Its clinical presentation may vary from mild erythema to necrosis and ulceration. The article presents the case of a 50-year-old patient, who after radiotherapy for breast cancer, during the hormonal therapy (tamoxifen), developed RRD type skin reactions after skin application of Amol. The article presents a detailed differential diagnosis of skin changes of RRD type, and discusses the principles of treatment and prevention. (authors)

Bone effect of adjuvant tamoxifen, letrozole or letrozole plus zoledronic acid in early-stage breast cancer: the randomized phase 3 HOBOE study.

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Nuzzo, F; Gallo, C; Lastoria, S; Di Maio, M; Piccirillo, M C; Gravina, A; Landi, G; Rossi, E; Pacilio, C; Labonia, V; Di Rella, F; Bartiromo, A; Buonfanti, G; De Feo, G; Esposito, G; D'Aniello, R; Maiolino, P; Signoriello, S; De Maio, E; Tinessa, V; Colantuoni, G; De Laurentiis, M; D'Aiuto, M; Di Bonito, M; Botti, G; Giordano, P; Daniele, G; Morabito, A; Normanno, N; de Matteis, A; Perrone, F

2012-08-01

To measure bone mineral density (BMD) reduction produced by letrozole as compared with tamoxifen and the benefit of the addition of zoledronic acid. A phase 3 trial comparing tamoxifen, letrozole or letrozole+zoledronic acid in patients with hormone receptor-positive early breast cancer was conducted; triptorelin was given to premenopausal patients. Two comparisons were planned: letrozole versus tamoxifen and letrozole+zoledronic acid versus letrozole. Primary end point was the difference in 1-year change of T-score at lumbar spine (LTS) measured by dual energy X-ray absorptiometry scan. Out of 483 patients enrolled, 459 were available for primary analyses. Median age was 50 (range 28-80). The estimated mean difference (95% confidence interval [CI]) in 1-year change of LTS was equal to -0.30 (95% CI -0.44 to -0.17) in the letrozole versus tamoxifen comparison (P<0.0001) and to +0.60 (95% CI +0.46 to +0.77) in the letrozole+zoledronic acid versus letrozole comparison (P<0.0001). Bone damage by letrozole decreased with increasing baseline body mass index in premenopausal, but not postmenopausal, patients (interaction test P=0.004 and 0.47, respectively). In the HOBOE (HOrmonal BOne Effects) trial, the positive effect of zoledronic acid on BMD largely counteracts damage produced by letrozole as compared with tamoxifen. Letrozole effect is lower among overweight/obese premenopausal patients.

The biochemical effects of nano tamoxifen and some bioactive components in experimental breast cancer.

Science.gov (United States)

Ezzat, Afaf; Abdelhamid, Abdou Osman; El Awady, Mostafa K; Abd El Azeem, Amal S; Mohammed, Dina Mostafa

2017-11-01

The effect of nano tamoxifen and some bioactive components such as yeast, isoflavone, and silymarin on the level of resistance and prevention of breast cancer progression in experimental animals is the target of this study. Thirty female Sprague-Dawley rats received a single medication dosage of 7,12-dimethylbenz[a]anthracene (DMBA) intragastrically. After fourteen days of DMBA admission, the procedure protocol started out. Finally, all the experimental results evaluated, tabulated and statistically analyzed. The results demonstrated a highly significant elevation in the 8-OHdG level in group 1 (nano yeast) and 3 (nano silymarin) while the results demonstrated a highly significant reduction in group 2 (nano tamoxifen). The apoptosis results demonstrated a significant elevation in group 3 (nano silymarin) where appeared significant reduction in group 4 (nano isoflavone). ErbB-2 results demonstrated a significant elevation in group 2 (nano tamoxifen) and a significant reduction in each of group 3 (nano silymarin) and 4 (nano isoflavone). The lipid peroxide level demonstrated an extremely significant reduction in group 4 (nano isoflavone). And a significant reduction of total antioxidant was observed in group 3 (nano silymarin) in comparison to injected animals control. This may be considered a new vision and strategy to resist breast cancer disease or prevent progression. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Study of Sperm Parameters and Sperm Fertility in Mice were Exposed to Tamoxifen during Embryonic Development

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J Soleimanirad

2017-05-01

Full Text Available Introduction: Tamoxifen is steroidal drug, which mainly treats breast cancer and also used to stimulate ovulation. The purpose of the present study was the evaluation of sperm parameters and fertility of mice whose mothers had received tamoxifen during pregnancy. Methods: In this study, 30 female and 15 male mice of NMRI were selected for mating. After mating female mice were randomly divided into two groups, the first group (control and second group (experimental. All of which contained 15 mice. From the day 13th day of pregnancy, experimental group has received tamoxifen with the dosage of 5 mg/kg for 7 days. After childbirth of the mated mice, male infants were selected. After reaching the age of puberty (6-8Weeks, adult mice were sacrificed by the cervical dislocation. After take sperm, sperm parameters (count, normality and motility, and sperm fertility was performed. In this study SPSS software and statistical t-test was used (p <0.001. Results: Studies showed that sperm parameters and sperm fertilization were significantly different. The number of sperm in the control group was 83.50±28.20 million, and in the experimental group was 60±14.14 million. There was a decrease in average sperm count in the experimental group compared with the control group (p <0.001. Our findings from in vitro fertilization culture media showed that embryos formation and oocyte disruption between control and experimental groups significantly different (p <0.001. Conclusion: The results showed that tamoxifen exposure during development can cause histological changes in the seminiferous tubules, which can lead to infertility.

Generation of NSE-MerCreMer transgenic mice with tamoxifen inducible Cre activity in neurons.

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Mandy Ka Man Kam

Full Text Available To establish a genetic tool for conditional deletion or expression of gene in neurons in a temporally controlled manner, we generated a transgenic mouse (NSE-MerCreMer, which expressed a tamoxifen inducible type of Cre recombinase specifically in neurons. The tamoxifen inducible Cre recombinase (MerCreMer is a fusion protein containing Cre recombinase with two modified estrogen receptor ligand binding domains at both ends, and is driven by the neural-specific rat neural specific enolase (NSE promoter. A total of two transgenic lines were established, and expression of MerCreMer in neurons of the central and enteric nervous systems was confirmed. Transcript of MerCreMer was detected in several non-neural tissues such as heart, liver, and kidney in these lines. In the background of the Cre reporter mouse strain Rosa26R, Cre recombinase activity was inducible in neurons of adult NSE-MerCreMer mice treated with tamoxifen by intragastric gavage, but not in those fed with corn oil only. We conclude that NSE-MerCreMer lines will be useful for studying gene functions in neurons for the conditions that Cre-mediated recombination resulting in embryonic lethality, which precludes investigation of gene functions in neurons through later stages of development and in adult.

Generation of brain tumours in mice by Cre-mediated recombination of neural progenitors in situ with the tamoxifen metabolite endoxifen

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Anna Benedykcinska

2016-02-01

Full Text Available Targeted cell- or region-specific gene recombination is widely used in the functional analysis of genes implicated in development and disease. In the brain, targeted gene recombination has become a mainstream approach to study neurodegeneration or tumorigenesis. The use of the Cre-loxP system to study tumorigenesis in the adult central nervous system (CNS can be limited, when the promoter (such as GFAP is also transiently expressed during development, which can result in the recombination of progenies of different lineages. Engineering of transgenic mice expressing Cre recombinase fused to a mutant of the human oestrogen receptor (ER allows the circumvention of transient developmental Cre expression by inducing recombination in the adult organism. The recombination of loxP sequences occurs only in the presence of tamoxifen. Systemic administration of tamoxifen can, however, exhibit toxicity and might also recombine unwanted cell populations if the promoter driving Cre expression is active at the time of tamoxifen administration. Here, we report that a single site-specific injection of an active derivative of tamoxifen successfully activates Cre recombinase and selectively recombines tumour suppressor genes in neural progenitor cells of the subventricular zone in mice, and we demonstrate its application in a model for the generation of intrinsic brain tumours.

Generation of brain tumours in mice by Cre-mediated recombination of neural progenitors in situ with the tamoxifen metabolite endoxifen.

Science.gov (United States)

Benedykcinska, Anna; Ferreira, Andreia; Lau, Joanne; Broni, Jessica; Richard-Loendt, Angela; Henriquez, Nico V; Brandner, Sebastian

2016-02-01

Targeted cell- or region-specific gene recombination is widely used in the functional analysis of genes implicated in development and disease. In the brain, targeted gene recombination has become a mainstream approach to study neurodegeneration or tumorigenesis. The use of the Cre-loxP system to study tumorigenesis in the adult central nervous system (CNS) can be limited, when the promoter (such as GFAP) is also transiently expressed during development, which can result in the recombination of progenies of different lineages. Engineering of transgenic mice expressing Cre recombinase fused to a mutant of the human oestrogen receptor (ER) allows the circumvention of transient developmental Cre expression by inducing recombination in the adult organism. The recombination of loxP sequences occurs only in the presence of tamoxifen. Systemic administration of tamoxifen can, however, exhibit toxicity and might also recombine unwanted cell populations if the promoter driving Cre expression is active at the time of tamoxifen administration. Here, we report that a single site-specific injection of an active derivative of tamoxifen successfully activates Cre recombinase and selectively recombines tumour suppressor genes in neural progenitor cells of the subventricular zone in mice, and we demonstrate its application in a model for the generation of intrinsic brain tumours. © 2016. Published by The Company of Biologists Ltd.

Overexpression of CD44 accompanies acquired tamoxifen resistance in MCF7 cells and augments their sensitivity to the stromal factors, heregulin and hyaluronan

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Hiscox Stephen

2012-10-01

Full Text Available Abstract Background Acquired resistance to endocrine therapy in breast cancer is a significant problem with relapse being associated with local and/or regional recurrence and frequent distant metastases. Breast cancer cell models reveal that endocrine resistance is accompanied by a gain in aggressive behaviour driven in part through altered growth factor receptor signalling, particularly involving erbB family receptors. Recently we identified that CD44, a transmembrane cell adhesion receptor known to interact with growth factor receptors, is upregulated in tamoxifen-resistant (TamR MCF7 breast cancer cells. The purpose of this study was to explore the consequences of CD44 upregulation in an MCF7 cell model of acquired tamoxifen resistance, specifically with respect to the hypothesis that CD44 may influence erbB activity to promote an adverse phenotype. Methods CD44 expression in MCF7 and TamR cells was assessed by RT-PCR, Western blotting and immunocytochemistry. Immunofluorescence and immunoprecipitation studies revealed CD44-erbB associations. TamR cells (± siRNA-mediated CD44 suppression or MCF7 cells (± transfection with the CD44 gene were treated with the CD44 ligand, hyaluronon (HA, or heregulin and their in vitro growth (MTT, migration (Boyden chamber and wound healing and invasion (Matrigel transwell migration determined. erbB signalling was assessed using Western blotting. The effect of HA on erbB family dimerisation in TamR cells was determined by immunoprecipitation in the presence or absence of CD44 siRNA. Results TamR cells overexpressed CD44 where it was seen to associate with erbB2 at the cell surface. siRNA-mediated suppression of CD44 in TamR cells significantly attenuated their response to heregulin, inhibiting heregulin-induced cell migration and invasion. Furthermore, TamR cells exhibited enhanced sensitivity to HA, with HA treatment resulting in modulation of erbB dimerisation, ligand-independent activation of erbB2

Overexpression of CD44 accompanies acquired tamoxifen resistance in MCF7 cells and augments their sensitivity to the stromal factors, heregulin and hyaluronan

International Nuclear Information System (INIS)

Hiscox, Stephen; Gee, Julia; Baruha, Bedanta; Smith, Chris; Bellerby, Rebecca; Goddard, Lindy; Jordan, Nicola; Poghosyan, Zaruhi; Nicholson, Robert I; Barrett-Lee, Peter

2012-01-01

Acquired resistance to endocrine therapy in breast cancer is a significant problem with relapse being associated with local and/or regional recurrence and frequent distant metastases. Breast cancer cell models reveal that endocrine resistance is accompanied by a gain in aggressive behaviour driven in part through altered growth factor receptor signalling, particularly involving erbB family receptors. Recently we identified that CD44, a transmembrane cell adhesion receptor known to interact with growth factor receptors, is upregulated in tamoxifen-resistant (TamR) MCF7 breast cancer cells. The purpose of this study was to explore the consequences of CD44 upregulation in an MCF7 cell model of acquired tamoxifen resistance, specifically with respect to the hypothesis that CD44 may influence erbB activity to promote an adverse phenotype. CD44 expression in MCF7 and TamR cells was assessed by RT-PCR, Western blotting and immunocytochemistry. Immunofluorescence and immunoprecipitation studies revealed CD44-erbB associations. TamR cells (± siRNA-mediated CD44 suppression) or MCF7 cells (± transfection with the CD44 gene) were treated with the CD44 ligand, hyaluronon (HA), or heregulin and their in vitro growth (MTT), migration (Boyden chamber and wound healing) and invasion (Matrigel transwell migration) determined. erbB signalling was assessed using Western blotting. The effect of HA on erbB family dimerisation in TamR cells was determined by immunoprecipitation in the presence or absence of CD44 siRNA. TamR cells overexpressed CD44 where it was seen to associate with erbB2 at the cell surface. siRNA-mediated suppression of CD44 in TamR cells significantly attenuated their response to heregulin, inhibiting heregulin-induced cell migration and invasion. Furthermore, TamR cells exhibited enhanced sensitivity to HA, with HA treatment resulting in modulation of erbB dimerisation, ligand-independent activation of erbB2 and EGFR and induction of cell migration

Effect of adjuvant systemic treatment on cosmetic outcome and late normal-tissue reactions after breast conservation

DEFF Research Database (Denmark)

Johansen, Jørgen; Overgaard, Jens; Overgaard, Marie

2007-01-01

To investigate whether adjuvant treatment with CMF or tamoxifen predisposes to an unfavorable cosmetic outcome or increased breast morbidity after radiotherapy in breast conservation. Data from 266 patients who entered a randomized breast conservation trial (DBCG-82TM protocol) was analyzed......-risk patients: premenopausal patients (n = 67) received eight cycles of CMF intravenously (600/40/600 mg per m(2)) every fourth week; postmenopausal patients (n = 27) received 30 mg of tamoxifen daily for one year. Clinical assessments included cosmetic outcome, breast fibrosis, skin telangiectasia....... In premenopausal patients, systemic treatment with CMF independently predicted a fair/poor cosmetic outcome, RR = 2.2 (95% CI 1.2-4.2), as well as increased skin telangiectasia, RR = 3.3 (1.4-8.2). There was no impact of tamoxifen treatment on cosmetic outcome in postmenopausal patients (p = 0.32). However...

Transgenic mice for a tamoxifen-induced, conditional expression of the Cre recombinase in osteoclasts.

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Maria Arantzazu Sanchez-Fernandez

Full Text Available BACKGROUND: Studies on osteoclasts, the bone resorbing cells, have remained limited due to the lack of transgenic mice allowing the conditional knockout of genes in osteoclasts at any time during development or adulthood. METHODOLOGY/PRINCIPAL FINDING: We report here on the generation of transgenic mice which specifically express a tamoxifen-inducible Cre recombinase in osteoclasts. These mice, generated on C57BL/6 and FVB background, express a fusion Cre recombinase-ERT2 protein whose expression is driven by the promoter of cathepsin K (CtsK, a gene highly expressed in osteoclasts. We tested the cellular specificity of Cre activity in CtsKCreERT2 strains by breeding with Rosa26LacZ reporter mice. PCR and histological analyses of the CtsKCreERT2LacZ positive adult mice and E17.5 embryos show that Cre activity is restricted largely to bone tissue. In vitro, primary osteoclasts derived from the bone marrow of CtsKCreERT2+/-LacZ+/- adult mice show a Cre-dependent β-galactosidase activity after tamoxifen stimulation. CONCLUSIONS/SIGNIFICANCE: We have generated transgenic lines that enable the tamoxifen-induced, conditional deletion of loxP-flanked genes in osteoclasts, thus circumventing embryonic and postnatal gene lethality and avoiding gene deletion in other cell types. Such CtsKCreERT2 mice provide a convenient tool to study in vivo the different facets of osteoclast function in bone physiology during different developmental stages and adulthood of mice.

Tamoxifen induces regression of estradiol-induced mammary cancer in the ACI.COP-Ept2 rat model.

Science.gov (United States)

Ruhlen, Rachel L; Willbrand, Dana M; Besch-Williford, Cynthia L; Ma, Lixin; Shull, James D; Sauter, Edward R

2009-10-01

The ACI rat is a unique model of human breast cancer in that mammary cancers are induced by estrogen without carcinogens, irradiation, xenografts or transgenic manipulations. We sought to characterize mammary cancers in a congenic variant of the ACI rat, the ACI.COP-Ept2. All rats with estradiol implants developed mammary cancers in 5-7 months. Rats bearing estradiol-induced mammary cancers were treated with tamoxifen for three weeks. Tamoxifen reduced tumor mass, measured by magnetic resonance imaging, by 89%. Tumors expressed estrogen receptors (ER), progesterone receptor (PR), and Erbb2. ERalpha and PR were overexpressed in tumor compared to adjacent non-tumor mammary gland. Thus, this model is highly relevant to hormone responsive human breast cancers.

Cost-effectiveness of anastrozole, in comparison with tamoxifen, in the adjuvant treatment of early breast cancer in Brazil Custo-efetividade do anastrozol em comparação com tamoxifeno no tratamento adjuvante do câncer de mama precoce no Brasil

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Marcelo Fonseca

2009-01-01

Full Text Available OBJECTIVE: Breast cancer, a leading type of cancer in many developing countries, is the most frequent non-cutaneous tumor in Brazil. Hormone therapy is the standard of care in the adjuvant treatment of early-stage, hormone-receptor-positive disease, and both tamoxifen and third-generation aromatase inhibitors are options in postmenopausal women. The comparative cost-effectiveness of different treatment strategies is of considerable interest in societies facing limited resources. METHODS: In an attempt to compare cost-effectiveness of upfront treatment with tamoxifen or anastrozole, the medical and economic results in a hypothetical cohort of 64-year-old postmenopausal women, was analyzed considering the Brazilian healthcare system in 2005, the primary perspective of the private sector, and a lifetime horizon. Data from the ATAC Trial, Markov modeling, a modified Delphi panel, and microcosting (in Brazilian R$ were used to estimate costs and effectiveness of the two upfront strategies. RESULTS: The model estimated a gain of 0.55 discounted life-years for patients receiving anastrozole, relative to those treated with tamoxifen. With an incremental cost of R$ 15,141.15, the model estimated that the cost-effectiveness of anastrozole, in relation to tamoxifen, was R$ 27,326.80. Monte Carlo simulations showed that approximately 50% of the cases fell below the threshold of R$ 29,229.00 per life-year gained, which is recommended by the World Health Organization for Brazil. CONCLUSION: It was concluded that upfront anastrozole is a cost-effective option compared with tamoxifen in the adjuvant treatment of postmenopausal women with hormone-receptor-positive early breast cancer.RESUMO OBJETIVO: O câncer de mama, o mais comum em vários países desenvolvidos, é o tumor não cutâneo mais frequente no Brasil. A terapia hormonal é o tratamento adjuvante padrão para os estágios precoces, em doença com receptor hormonal positivo, e o tamoxifeno e os

Effect of tamoxifen on fatty degeneration and atrophy of rotator cuff muscles in chronic rotator cuff tear: An animal model study.

Science.gov (United States)

Cho, Edward; Zhang, Yue; Pruznak, Anne; Kim, H Mike

2015-12-01

Fatty degeneration of the rotator cuff muscles is an irreversible change resulting from chronic rotator cuff tear and is associated with poor clinical outcomes following rotator cuff repair. We evaluated the effect of Tamoxifen, a competitive estrogen receptor inhibitor, on fatty degeneration using a mouse model for chronic rotator cuff tear. Sixteen adult mice were divided into two diet groups (Tamoxifen vs. Regular) and subjected to surgical creation of a large rotator cuff tear and suprascapular nerve transection in their left shoulder with the right shoulder serving as a control. The rotator cuff muscles were harvested at 16 weeks and subjected to histology and RT-PCR for adipogenic and myogenic markers. Histology showed substantially decreased atrophy and endomysial inflammation in Tamoxifen group, but no significant differences in the amount of intramuscular adipocytes and lipid droplets compared to the Regular group. With RT-PCR, the operated shoulders showed significant upregulation of myogenin and PPAR-γ, and downregulation of myostatin compared to the nonsurgical shoulder. No significant differences of gene expression were found between the two diet groups. Our study demonstrated that tamoxifen diet leads to decreased muscle atrophy and inflammatory changes following chronic rotator cuff tear, but has no apparent effect on adipogenesis. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

An ER activity profile including ER, PR, Bcl-2 and IGF-IR may have potential as selection criterion for letrozole or tamoxifen treatment of patients with advanced breast cancer

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Henriksen, Katrine L; Rasmussen, Birgitte B; Lykkesfeldt, Anne E

2009-01-01

microarrays from formalin fixed paraffin embedded primary tumor material from a subgroup of patients (9.4%), who have participated in the international, randomized, phase III clinical trial PO25 comparing letrozole with tamoxifen in 907 patients with advanced breast cancer. The expression levels of ER...

Epidermal growth factor receptor signalling in human breast cancer cells operates parallel to estrogen receptor α signalling and results in tamoxifen insensitive proliferation

International Nuclear Information System (INIS)

Moerkens, Marja; Zhang, Yinghui; Wester, Lynn; Water, Bob van de; Meerman, John HN

2014-01-01

Tamoxifen resistance is a major problem in the treatment of estrogen receptor (ER) α -positive breast cancer patients. Although the mechanisms behind tamoxifen resistance are still not completely understood, clinical data suggests that increased expression of receptor tyrosine kinases is involved. Here, we studied the estrogen and anti-estrogen sensitivity of human breast cancer MCF7 cells that have a moderate, retroviral-mediated, ectopic expression of epidermal growth factor receptor (MCF7-EGFR). Proliferation of MCF7-EGFR and parental cells was induced by 17β-estradiol (E2), epidermal growth factor (EGF) or a combination of these. Inhibition of proliferation under these conditions was investigated with 4-hydroxy-tamoxifen (TAM) or fulvestrant at 10 -12 to 10 -6 M. Cells were lysed at different time points to determine the phosphorylation status of EGFR, MAPK 1/3 , AKT and the expression of ERα. Knockdown of target genes was established using smartpool siRNAs. Transcriptomics analysis was done 6 hr after stimulation with growth factors using Affymetrix HG-U133 PM array plates. While proliferation of parental MCF7 cells could only be induced by E2, proliferation of MCF7-EGFR cells could be induced by either E2 or EGF. Treatment with TAM or fulvestrant did significantly inhibit proliferation of MCF7-EGFR cells stimulated with E2 alone. EGF treatment of E2/TAM treated cells led to a marked cell proliferation thereby overruling the anti-estrogen-mediated inhibition of cell proliferation. Under these conditions, TAM however did still inhibit ERα- mediated transcription. While siRNA-mediated knock-down of EGFR inhibited the EGF- driven proliferation under TAM/E2/EGF condition, knock down of ERα did not. The TAM resistant cell proliferation mediated by the conditional EGFR-signaling may be dependent on the PI3K/Akt pathway but not the MEK/MAPK pathway, since a MEK inhibitor (U0126), did not block the proliferation. Transcriptomic analysis under the various E2/TAM

Orthodontic treatment-induced temporal alteration of jaw-opening reflex excitability.

Science.gov (United States)

Sasaki, Au; Hasegawa, Naoya; Adachi, Kazunori; Sakagami, Hiroshi; Suda, Naoto

2017-10-01

The impairment of orofacial motor function during orthodontic treatment needs to be addressed, because most orthodontic patients experience pain and motor excitability would be affected by pain. In the present study, the temporal alteration of the jaw-opening reflex excitability was investigated to determine if orthodontic treatment affects orofacial motor function. The excitability of jaw-opening reflex evoked by electrical stimulation on the gingiva and recorded bilaterally in the anterior digastric muscles was evaluated at 1 (D1), 3 (D3), and 7 days (D7) after orthodontic force application to the teeth of right side; morphological features (e.g., osteoclast genesis and tooth movement) were also evaluated. To clarify the underlying mechanism of orthodontic treatment-induced alteration of orofacial motor excitability, analgesics were administrated for 1 day. At D1 and D3, orthodontic treatment significantly decreased the threshold for inducing the jaw-opening reflex but significantly increased the threshold at D7. Other parameters of the jaw-opening reflex were also evaluated (e.g., latency, duration and area under the curve of anterior digastric muscles activity), and only the latency of the D1 group was significantly different from that of the other groups. Temporal alteration of the jaw-opening reflex excitability was significantly correlated with changes in morphological features. Aspirin (300 mg·kg -1 ·day -1 ) significantly increased the threshold for inducing the jaw-opening reflex, whereas a lower dose (75-150 mg·kg -1 ·day -1 ) of aspirin or acetaminophen (300 mg·kg -1 ·day -1 ) failed to alter the jaw-opening reflex excitability. These results suggest that an increase of the jaw-opening reflex excitability can be induced acutely by orthodontic treatment, possibly through the cyclooxygenase activation. NEW & NOTEWORTHY It is well known that motor function is affected by pain, but the effect of orthodontic treatment-related pain on the trigeminal

The different effects of lithium and tamoxifen on memory formation and the levels of neurotrophic factors in the brain of male and female rats.

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Valvassori, Samira S; Borges, Cenita P; Varela, Roger B; Bavaresco, Daniela V; Bianchini, Guilherme; Mariot, Edemilson; Arent, Camila O; Resende, Wilson R; Budni, Josiane; Quevedo, João

2017-09-01

Lithium (Li) is a mood-stabilizing drug used in the treatment of bipolar disorder (BD). Recently, preclinical studies have demonstrated the potential of tamoxifen (TMX) in the treatment of acute episodes of BD. However, the prolonged use of TMX for mood disorders treatment is controversial. In this study, we evaluated the effects of TMX or Li on cognitive behavior, as well as the levels of neurotrophic factors in the brain of male and female rats. Male and female Wistar rats received administrations of water (control group), TMX or Li via gavage for a period of 28days; the rats were then subjected to the open-field test (to evaluate spontaneous locomotion), and the novel object recognition and step-down inhibitory avoidance tests (to evaluate cognition). The levels of NGF, BDNF and GDNF were evaluated in the hippocampus and frontal cortex of the subject rats. No significant differences were observed in the open-field and inhibitory avoidance tests after drug administration in either the male or female rats. The administration of TMX, but not Li, decreased the recognition index of both the male and female rats in the object recognition test. The chronic administration of TMX decreased, whereas Li increased the levels of BDNF in the hippocampus of both the male and female rats. Tamoxifen decreased the levels of NGF in the hippocampus of female rats. In conclusion, it can be suggested that long-term treatments with TMX can lead to significant cognitive impairments by reducing the levels of neurotrophic factors in the brain of rats. Copyright © 2017. Published by Elsevier Inc.

Prediction of risk of distant recurrence using the 21-gene recurrence score in node-negative and node-positive postmenopausal patients with breast cancer treated with anastrozole or tamoxifen: a TransATAC study.

Science.gov (United States)

Dowsett, Mitch; Cuzick, Jack; Wale, Christopher; Forbes, John; Mallon, Elizabeth A; Salter, Janine; Quinn, Emma; Dunbier, Anita; Baum, Michael; Buzdar, Aman; Howell, Anthony; Bugarini, Roberto; Baehner, Frederick L; Shak, Steven

2010-04-10

PURPOSE To determine whether the Recurrence Score (RS) provided independent information on risk of distant recurrence (DR) in the tamoxifen and anastrozole arms of the Arimidex, Tamoxifen, Alone or in Combination (ATAC) Trial. PATIENTS AND METHODS RNA was extracted from 1,372 tumor blocks from postmenopausal patients with hormone receptor-positive primary breast cancer in the monotherapy arms of ATAC. Twenty-one genes were assessed by quantitative reverse transcriptase polymerase chain reaction, and the RS was calculated. Cox proportional hazards models assessed the value of adding RS to a model with clinical variables (age, tumor size, grade, and treatment) in node-negative (N0) and node-positive (N+) women. RESULTS Reportable scores were available from 1,231 evaluable patients (N0, n = 872; N+, n = 306; and node status unknown, n = 53); 72, 74, and six DRs occurred in N0, N+, and node status unknown patients, respectively. For both N0 and N+ patients, RS was significantly associated with time to DR in multivariate analyses (P or = 31) groups were 4%, 12%, and 25%, respectively, in N0 patients and 17%, 28%, and 49%, respectively, in N+ patients. The prognostic value of RS was similar in anastrozole- and tamoxifen-treated patients. CONCLUSION This study confirmed the performance of RS in postmenopausal HR+ patients treated with tamoxifen in a large contemporary population and demonstrated that RS is an independent predictor of DR in N0 and N+ hormone receptor-positive patients treated with anastrozole, adding value to estimates with standard clinicopathologic features.

Mechanisms of Resistance to Endocrine Therapy in Breast Cancer: Focus on Signaling Pathways, miRNAs and Genetically Based Resistance

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García-Becerra, Rocío; Santos, Nancy; Díaz, Lorenza; Camacho, Javier

2013-01-01

Breast cancer is the most frequent malignancy diagnosed in women. Approximately 70% of breast tumors express the estrogen receptor (ER). Tamoxifen and aromatase inhibitors (AIs) are the most common and effective therapies for patients with ERα-positive breast cancer. Alone or combined with chemotherapy, tamoxifen significantly reduces disease progression and is associated with more favorable impact on survival in patients. Unfortunately, endocrine resistance occurs, either de novo or acquired during the course of the treatment. The mechanisms that contribute to hormonal resistance include loss or modification in the ERα expression, regulation of signal transduction pathways, altered expression of specific microRNAs, balance of co-regulatory proteins, and genetic polymorphisms involved in tamoxifen metabolic activity. Because of the clinical consequences of endocrine resistance, new treatment strategies are arising to make the cells sensitive to tamoxifen. Here, we will review the current knowledge on mechanisms of endocrine resistance in breast cancer cells. In addition, we will discuss novel therapeutic strategies to overcome such resistance. Undoubtedly, circumventing endocrine resistance should help to improve therapy for the benefit of breast cancer patients. PMID:23344024

Biopolymer mediated nanoparticles synthesized from Adenia hondala for enhanced tamoxifen drug delivery in breast cancer cell line

Science.gov (United States)

Varadharajaperumal, Pradeepa; Subramanian, Balakumar; Santhanam, Amutha

2017-09-01

Silver nanoparticles (AgNPs) are an important class of nanomaterials, which have used as antimicrobial and disinfectant agents due to their detrimental effect on target cells. In the present study it was explored to deliver a novel tamoxifen drug system that can be used in breast cancer treatment, based on chitosan coated silver nanoparticles on MCF-7 human breast cancer cells. AgNPs synthesized from Adenia hondala tuber extract were used to make the chitosan coated AgNPs (Ch-AgNPs), in which the drug tamoxifen was loaded on chitosan coated silver nanoparticles (Tam-Ch-AgNPs) to construct drug loaded nanoparticles as drug delivery system. The morphology and characteristics of the Ch-AgNPs were investigated by UV, FTIR, zeta potential and FESEM. Furthermore, the toxicity of AgNPs, Ch-AgNPs, Tam-Ch-AgNPs was evaluated through cell viability, lactate dehydrogenase leakage, reactive oxygen species generation, caspase-3, DNA laddering, and TUNEL assay in human breast cancer cells (MCF-7) and HBL-100 continuous cell line as a control. Treatment of cancer cells with various concentrations of AgNPs, Ch-AgNPs, Tam-Ch-AgNPs for 24 h revealed that Tam-Ch-AgNPs could inhibit cell viability and induce significant membrane leakage in a dose-dependent manner. Cells exposed to Tam-Ch-AgNPs showed increased reactive oxygen species and hydroxyl radical production when compared to AgNPs, Ch-AgNPs. Furthermore, the apoptotic effects of AgNPs, Ch-AgNPs, Tam-Ch-AgNPs were confirmed by activation of caspase-3 and DNA nuclear fragmentation. The present findings suggest that Tam-Ch-AgNPs could contribute to the development of a suitable anticancer drug delivery.

Development and validation of a liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of tamoxifen, anastrozole, and letrozole in human plasma and its application to a clinical study.

Science.gov (United States)

Beer, Beate; Schubert, Birthe; Oberguggenberger, Anne; Meraner, Verena; Hubalek, Michael; Oberacher, Herbert

2010-10-01

There is substantial evidence that circulating estrogens promote the proliferation of breast cancer. Consequently, adjuvant hormonal treatment strategies targeting estrogen action have been established. Such hormonal therapies include selective estrogen receptor modulators, such as tamoxifen, which interfere at the estrogen receptors directly, or non-steroidal aromatase inhibitors, such as anastrozole and letrozole, which inhibit estrogen synthesis through blocking the aromatase, a key enzyme of estrogen production. Despite considerable therapeutic success, in several cases, the use of these drugs is limited by side effects that have been described to significantly impair the adherence of patients to endocrine treatment. However, objective data concerning patient adherence and its clinical relevance are limited. One promising approach to check patient-reported adherence is drug monitoring in human plasma. Therefore, a liquid chromatography-tandem mass spectrometry method to determine the plasma concentrations of tamoxifen, anastrozole, and letrozole has been developed and fully validated according to guidelines for clinical and forensic toxicology. The validation criteria evaluated were selectivity, linearity, accuracy and precision, limit of quantification, recovery and matrix effects, sample stability, and carryover. The six-point calibration curves showed linearity over the range of concentrations from 25 to 500 ng/ml for tamoxifen, 5 to 200 ng/ml for anastrozole, and 10 to 300 ng/ml for letrozole. The intra- and inter-day precision and accuracies were always better than 15%. The validated procedure was successfully applied to a clinical study (Patient-Reported Outcomes in Breast Cancer Patients undergoing Endocrine Therapy, PRO-BETh). A major aim of PRO-BETh study is the comprehensive evaluation of adherence to treatment in pre- and post-menopausal women with breast cancer. Plasma samples of 310 breast cancer patients undergoing anti-estrogen therapy were

The Efficacy of Medical Treatment of Peyronie’s Disease: Potassium Para-Aminobenzoate Monotherapy vs. Combination Therapy with Tamoxifen, L-Carnitine, and Phosphodiesterase Type 5 Inhibitor

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Tae Yong Park

2016-04-01

Full Text Available Purpose: This study was designed to evaluate the efficacy of medical treatment of Peyronie’s disease. Materials and Methods: A total of 109 patients with Peyronie’s disease who had been treated from January 2011 to December 2014 were retrospectively reviewed in this study. Forty-four patients (Group 1 were treated with 12 mg of potassium para-aminobenzoate daily. Sixty-five patients (Group 2 were treated with combination therapy: tamoxifen (20 mg and acetyl-L-carnitine (300 mg twice daily in addition to a phosphodiesterase type 5 inhibitor. Ability to perform sexual intercourse, pain during erection, size of plaque, and penile curvature angle were assessed. Results: In Group 1, 30 of 44 patients (68.2% discontinued treatment within 12 weeks, while 5 patients (7.7% in Group 2 discontinued treatment. Pain during erection and plaque size were improved in both groups but showed no statistical difference due to the high dropout rate in Group 1. In both groups, penile curvature was improved, but demonstrated no statistical difference between the treatment groups. However, combination therapy demonstrated a better response rate in patients whose penile curvature angle was less than 30o (44.4% vs. 79.1%, p=0.048. The rate of successful sexual intercourse was significantly higher in Group 2 (42.8% vs. 78.3%, p=0.034. The number of patients who underwent surgical correction despite medical treatment was significantly higher in Group 1 (35.7% vs. 13.3%, p=0.048. Conclusions: Early medical combination therapy in Peyronie’s disease may present better results in patients whose curvature angle is less than 30o.

Brain Function, Structure, and Neurochemistry After Tamoxifen/Chemotherapy Assessed by Neuropsychologic Testing and H Magnetic Resonance Spectroscopy

National Research Council Canada - National Science Library

Ernst, Thomas

2000-01-01

...). On magnetic resonance spectroscopy (1H MRS), women who received tamoxifen (average 4.4 years) had no statistically significant differences in brain metabolite ratios compared to the negative control group...

Oral health-related concerns, behavior, and communication with health care providers of patients with breast cancer: impact of different treatments.

Science.gov (United States)

Taichman, L Susan; Van Poznak, Catherine H; Inglehart, Marita R

2018-01-01

The objectives are to compare responses of breast cancer (BCa) treatment groups (chemotherapy, tamoxifen, and aromatase inhibitors (AIs) to each other and a control regarding (a) subjective oral health, (b) oral health-related behaviors, (c) oral health-related concerns, and (d) communication with health care providers. Survey data were collected from 140 postmenopausal BCa patients and 41 healthy postmenopausal control respondents. BCa patients reported on average more frequent mouth sores/mucositis (5-point scale with 1 = never: 1.63 vs. 1.14; p oral health than patients on tamoxifen/AI (93% vs. 55%/56%; p oral health-related effects of cancer treatment than by dentists. Oncologists/nurses were more likely to communicate about oral health-related treatment effects with patients undergoing chemotherapy than patients on tamoxifen or AIs. Few BCa patients perceived dentists as knowledgeable about cancer treatment-related oral concerns and trusted them less than oncologists. BCa treatments impact oral health. Low percentages of BCa patients had received specific information about impacts of BCa treatments on oral health from their dentists. © 2018 Special Care Dentistry Association and Wiley Periodicals, Inc.

[Effect of Evn-50 on cell growth and apoptosis in tamoxifen-resistance human breast cancer cell line MCF-7/TAM-R].

Science.gov (United States)

Hu, Hui-yong; Zhou, Jun; Wan, Fang; Dong, Li-feng; Zhang, Feng; Wang, Yi-ke; Chen, Fang-fang; Chen, Yi-ding

2012-09-01

To investigate the effect of Evn-50 extracted from Vitex negundo on human breast cancer cell line MCF-7 and MCF-7/TAM-R cells in vitro. MCF-7 and tamoxifen-resistant MCF-7/TAM-R cells were treated with Evn-50,tamoxifen or combination of Evn-50 and tamoxifen. Cell proliferation inhibition rates were determined by MTT assay. The apoptosis rate and the change of cell cycle were detected by PI staining flow cytometry. Protein expression of phospho-MAPK 44/42 (Thr202/Tyr204),MAPK P44/42, phospho-AKT (Ser473) and AKT were detected with Western blotting. The viability of MCF-7 cells was decreased in combination group [(28.65 ±11.43)%] and Evn-50 group [(53.02 ±15.14)%] compared with TAM group (PTAM-R in combination group [(42.11 ±14.30)%] was significantly lower than that in TAM group [(92.18 ±13.16)%] (PTAM-R cells,the expression of phosphorylation of AKT and MAPK44/42 protein was not changed in Evn-50 or TAM alone group,but significantly inhibited in the combination group at 72 h. Evn-50 can inhibit cell growth and induce apoptosis in MCF-7 and MCF-7/TAM-R cells,it can reverse tamoxifen-resistance of MCF-7/TAM-R cells.The mechanisms may be related to the down-regulation of phosphorylated ERK1/2 in MAPK signal pathway and phosphorylated AKT in AKT signal pathway.

Inducible arginase 1 deficiency in mice leads to hyperargininemia and altered amino acid metabolism.

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Yuan Yan Sin

Full Text Available Arginase deficiency is a rare autosomal recessive disorder resulting from a loss of the liver arginase isoform, arginase 1 (ARG1, which is the final step in the urea cycle for detoxifying ammonia. ARG1 deficiency leads to hyperargininemia, characterized by progressive neurological impairment, persistent growth retardation and infrequent episodes of hyperammonemia. Using the Cre/loxP-directed conditional gene knockout system, we generated an inducible Arg1-deficient mouse model by crossing "floxed" Arg1 mice with CreER(T2 mice. The resulting mice (Arg-Cre die about two weeks after tamoxifen administration regardless of the starting age of inducing the knockout. These treated mice were nearly devoid of Arg1 mRNA, protein and liver arginase activity, and exhibited symptoms of hyperammonemia. Plasma amino acid analysis revealed pronounced hyperargininemia and significant alterations in amino acid and guanidino compound metabolism, including increased citrulline and guanidinoacetic acid. Despite no alteration in ornithine levels, concentrations of other amino acids such as proline and the branched-chain amino acids were reduced. In summary, we have generated and characterized an inducible Arg1-deficient mouse model exhibiting several pathologic manifestations of hyperargininemia. This model should prove useful for exploring potential treatment options of ARG1 deficiency.

Use of dried blood spots for the determination of serum concentrations of tamoxifen and endoxifen

NARCIS (Netherlands)

Jager, N G L; Rosing, H; Schellens, J H M; Beijnen, J H; Linn, S C

The anti-estrogenic effect of tamoxifen is suggested to be mainly attributable to its metabolite (Z)-endoxifen, and a minimum therapeutic threshold for (Z)-endoxifen in serum has been proposed. The objective of this research was to establish the relationship between dried blood spot (DBS) and serum

Tamoxifen is a potent antioxidant modulator for sperm quality in patients with idiopathic oligoasthenospermia.

Science.gov (United States)

Guo, Li; Jing, Jun; Feng, Yu-Ming; Yao, Bing

2015-09-01

To explore the new mechanisms of tamoxifen (TAM) in the treatment for patients with idiopathic oligoasthenospermia-antioxidation. In a prospective, randomized, controlled clinical trial, 120 cases of idiopathic oligoasthenospermia were enrolled and randomly assigned to the indomethacin group (n = 60) treated with indomethacin (25 mg, bid) and TAM group (n = 60) treated with TAM (10 mg, bid) for 3 months. Before and after treatment, we evaluated semen parameters, serum malondialdehyde (MDA) and total antioxidant capacity (TAC), seminal plasma MDA and TAC, spermatozoa intracellular reactive oxygen species (ROS), sperm succinate dehydrogenase (SDH) activity, sperm mitochondrial membrane potential (MMP), and sperm adenosine triphosphate (ATP) content. The independent t test and one-way repeated measures analysis of variance were used to compare the variables between and within two groups. In the indomethacin group, the percentage of progressive motile sperms, total motility, sperm MMP, and ATP content were increased significantly after 3-month treatment (P sperm count, sperm concentration, the percentage of progressive motile sperms, total motility, serum and seminal plasma TAC, sperm MMP, and ATP content were significantly improved or increased (P sperm count, sperm concentration, serum TAC, seminal plasma TAC, spermatozoa intracellular ROS, and sperm SDH activity. TAM treatment can significantly improve sperm quality, which is achieved through alleviating oxidative stress, improving sperm mitochondrial functionality, and subsequently increasing sperm motility.

Inhibition of MAP kinase promotes the recruitment of corepressor SMRT by tamoxifen-bound estrogen receptor alpha and potentiates tamoxifen action in MCF-7 cells

International Nuclear Information System (INIS)

Hong, Wei; Chen, Linfeng; Li, Juan; Yao, Zhi

2010-01-01

Estrogen receptor alpha (ERα), a ligand controlled transcription factor, plays an important role in breast cancer growth and endocrine therapy. Tamoxifen (TAM) antagonizes ERα activity and has been applied in breast cancer treatment. TAM-bound ERα associates with nuclear receptor-corepressors. Mitogen-activated protein kinase (MAPK) has been elucidated to result in cross-talk between growth factor and ERα mediated signaling. We show that activated MAPK represses interaction of TAM-bound ERα with silencing mediator for retinoid and thyroid hormone receptors (SMRT) and inhibits the recruitment of SMRT by ERα to certain estrogen target genes. Blockade of MAPK signaling cascade with MEK inhibitor U0126 promotes the interaction and subsequently inhibits ERα activity via enhanced recruitment of SMRT, leading to reduced expression of ERα target genes. The growth rate of MCF-7 cells was decelerated when treated with both TAM and U0126. Moreover, the growth of MCF-7 cells stably expressing SMRT showed a robust repression in the presence of TAM and U0126. These results suggest that activated MAPK signaling cascade attenuates antagonist-induced recruitment of SMRT to ERα, suggesting corepressor mediates inhibition of ERα transactivation and breast cancer cell growth by antagonist. Taken together, our finding indicates combination of antagonist and MAPK inhibitor could be a helpful approach for breast cancer therapy.

Effect of tamoxifen in RAFT miniemulsion polymerization during the synthesis of polymer nanoparticles

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Tailane Sant'Anna Moreira

2014-01-01

Full Text Available Tamoxifen (TXF is currently the only hormonal agent used for treatment of breast cancer. Although very effective, TXF presents low solubility in water, which affects its absorption and bioavailability. A common strategy to overcome this barrier is the formulation of a drug delivery system (DDS in order to increase the drug stability and improve the treatment effectiveness. Reversible addition-fragmentation chain transfer (RAFT polymerization is the most versatile method of controlled/living radical polymerization (CLRP, allowing for synthesis of well-defined polymers and being adapted to a wide range of polymerization systems. Miniemulsion polymerization is a dispersed system that is commonly used to prepare nanoparticles (NP with 50 to 500 nm of diameter. The aim of this work was to evaluate the effect of the in situ incorporation of TXF during miniemulsion conventional and RAFT polymerizations, using methyl methacrylate (MMA as monomer. Although the in situ addition of TXF promoted a slight reduction of the reaction rate, it did not affect the final particle size distribution of the latex or the molecular weight control exerted by the RAFT agent. The obtained results suggest that in situ incorporation of TXF during the synthesis of polymer NP via RAFT polymerization allows for production of a polymer DDS for different uses, such as the breast cancer treatment.

In Vitro and In Vivo Effects of Tamoxifen against Larval Stage Echinococcus granulosus

Science.gov (United States)

Nicolao, María Celeste; Elissondo, María Celina; Denegri, Guillermo M.; Goya, Alejandra B.

2014-01-01

Cystic echinococcosis is a zoonotic infection caused by the larval stage of the cestode Echinococcus granulosus. Chemotherapy currently employs benzimidazoles; however, 40% of cases do not respond favorably. With regard to these difficulties, novel therapeutic tools are needed to optimize treatment in humans. The aim of this work was to explore the in vitro and in vivo effects of tamoxifen (TAM) against E. granulosus. In addition, possible mechanisms for the susceptibility of TAM are discussed in relation to calcium homeostasis, P-glycoprotein inhibition, and antagonist effects on a putative steroid receptor. After 24 h of treatment, TAM, at a low micromolar concentration range (10 to 50 μM), inhibited the survival of E. granulosus protoscoleces and metacestodes. Moreover, we demonstrated the chemotherapeutic and chemopreventive pharmacological effects of the drug. At a dose rate of 20 mg/kg of body weight, TAM induced protection against the infection in mice. In the clinical efficacy studies, a reduction in cyst weight was observed after the administration of 20 mg/kg in mice with cysts developed during 3 or 6 months, compared to that of those collected from control mice. Since the collateral effects of high TAM doses have been largely documented in clinical trials, the use of low doses of this drug as a short-term therapy may be a novel alternative approach for human cystic echinococcosis treatment. PMID:24936598

Effect of tamoxifen, methoxyprogesterone acetate and combined treatment on cellular proliferation and apoptosis in SKOV3/DDP cells via the regulation of vascular endothelial growth factor.

Science.gov (United States)

Wen, Lv; Hong, Ding; Yanyin, Wu; Mingyue, Zhang; Baohua, Li

2013-05-01

The aim of this study was to investigate the effect of tamoxifen (TAM), methoxyprogesterone acetate (MPA) and their combined treatment on cisplatin-resistant ovarian cancer SKOV3/DDP cells, as well as the potential mechanisms. MTT assay was used to investigate the effect of different concentrations (0.01, 0.1, 1, 10 and 100 μM) of TAM, MPA and their combined treatment on the proliferation of cisplatin-resistant ovarian cancer SKOV3/DDP cells. Flow cytometry was employed to analyze the cell cycle and apoptosis rate of SKOV3/DDP cells treated with medium concentration (10 μM) of TAM, MPA and their combined treatment. Change in the protein level of vascular endothelial growth factor (VEGF) in response to drug treatments was measured using Western-blot. The proliferation of SKOV3/DDP cells was inhibited by 1, 10 and 100 μM of TAM or MPA in a dose-dependent manner. Compared to the control group, 10 μM TAM could significantly arrest SKOV3/DDP cells in the G0/G1 stage and induce apoptosis (p < 0.01). However, 10 μM MPA only promoted cell apoptosis, while exhibited little effect on the cell cycle. We further found that 10 μM TAM could remarkably reduce the protein expression of VEGF, while 10 μM MPA only induce a slight reduction. Strikingly, the combined treatment of TAM and MPA exhibited additive effect on the proliferation, cell cycle, apoptosis rate and VEGF expression of SKOV3/DDP cells. We found that TAM, MPA and their combined treatment exhibited significant inhibitory effect on the cisplatin-resistant ovarian cancer SKOV3/DDP cells. Hence, TAM and MPA could be potential cytotoxic drugs to treat cisplatin-resistant patients with advanced ovarian cancer.

Pak1, adjuvant tamoxifen therapy, and breast cancer recurrence risk in a Danish population-based study

DEFF Research Database (Denmark)

Ahern, Thomas P; Cronin-Fenton, Deirdre P; Lash, Timothy L

2016-01-01

-/TAM - group. Pak1 cytoplasmic intensity was not associated with breast cancer recurrence in either group (ER+/TAM + ORadj for strong vs. no cytoplasmic staining = 0.91, 95% CI 0.57, 1.5; ER-/TAM - ORadj for strong vs. no cytoplasmic staining = 0.74, 95% CI 0.39, 1.4). Associations between Pak1 nuclear......Background Adjuvant tamoxifen therapy approximately halves the risk of estrogen receptor-positive (ER+) breast cancer recurrence, but many women do not respond to therapy. Observational studies nested in clinical trial populations suggest that overexpression or nuclear localization of p21-activated...... by immunohistochemical staining of primary breast tumors from recurrence cases and matched controls from two breast cancer populations; women diagnosed with ER-positive tumors who received at least one year of tamoxifen therapy (ER+/TAM+), and women diagnosed with ER-negative tumors who survived for at least one year...

ABCB1 and ABCC2 and the risk of distant metastasis in Thai breast cancer patients treated with tamoxifen

Directory of Open Access Journals (Sweden)

Sensorn I

2016-04-01

Full Text Available Insee Sensorn,1,* Chonlaphat Sukasem,2,* Ekaphop Sirachainan,3 Montri Chamnanphon,2 Ekawat Pasomsub,4 Narumol Trachu,5 Porntip Supavilai,1 Darawan Pinthong,1 Sansanee Wongwaisayawan6 1Department of Pharmacology, Faculty of Science, Mahidol University, 2Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, 3Division of Medical Oncology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, 4Division of Virology, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, 5Research Center, Faculty of Medicine, Ramathibodi Hospital, 6Division of Anatomical Pathology, Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand *These authors contributed equally to this work Background: Genetic polymorphisms of drug-metabolizing enzymes and transporters have been extensively studied with regard to tamoxifen treatment outcomes. However, the results are inconclusive. Analysis of organ-specific metastasis may reveal the association of these pharmacogenetic factors. The aim of this study is to investigate the impact of CYP3A5, CYP2D6, ABCB1, and ABCC2 polymorphisms on the risk of all distant and organ-specific metastases in Thai patients who received tamoxifen adjuvant therapy. Methods: Genomic DNA was extracted from blood samples of 73 patients with breast cancer who received tamoxifen adjuvant therapy. CYP3A5 (6986A>G, CYP2D6 (100C>T, ABCB1 (3435C>T, and ABCC2 (-24C>T were genotyped using allelic discrimination real-time polymerase chain reaction assays. The impacts of prognostic clinical factors and genetic variants on disease-free survival were analyzed using the Kaplan–Meier method and Cox regression analysis. Results: In the univariate analysis, primary tumor size >5 cm was significantly associated with increased risk of distant metastasis (P=0

Tamoxifen counteracts estradiol induced effects on striatal and hypophyseal dopamine receptors

International Nuclear Information System (INIS)

Ferretti, C.; Blengio, M.; Ghi, P.; Racca, S.; Genazzani, E.; Portaleone, P.

1988-01-01

We investigated the ability of Tamoxifen (TAM), an antiestrogen drug, to counteract the modification induced by estrogens on dopamine (DA) receptors on striatum and on adenohypophysis of ovex female rats. Subacute treatment with 17β-estradiol (E 2 ) at both low (0.1 μg/kg) and high (20 μg/kg) doses confirmed its ability to increase the number of striatal 3 H-Spiperone ( 3 H-SPI) binding sites in a dose dependent manner. By contrast in the pituitary, only high doses of estrogen were effective in reducing the number of DA receptors. We treated ovex female rats for 15 days with TAM alone or associated with E 2 , to see if these estrogenic effects could be suppressed by an antiestrogenic drug. TAM did not affect the number of striatal DA receptors, but significantly increased the adenohypophy-seal DA binding sites, without varying their affinity. No changes were observed in pituitary and striatal DA receptor density, even when TAM was injected in association with estradiol. In conclusions: TAM is able to counteract the effects estrogens have on DA receptors. However there is some evidence that it could influence the pituitary DA systems independently of it antiestrogenic activity

Medico-legal aspects of altered sensation following endodontic treatment: a retrospective case series

DEFF Research Database (Denmark)

Givol, Navot; Rosen, Eyal; Bjørndal, Lars

2011-01-01

The objective of this study was to analyze cases of liability claims related to persistent altered sensation following endodontic treatments so as to characterize the medico-legal aspects of this complication.......The objective of this study was to analyze cases of liability claims related to persistent altered sensation following endodontic treatments so as to characterize the medico-legal aspects of this complication....

Morphologic alterations in normal and neoplastic tissues following hyperthermia treatment

International Nuclear Information System (INIS)

Badylak, S.F.; Babbs, C.F.

1984-01-01

The sequential morphologic alterations in normal skeletal muscle in rats, Walker 256 tumors in rats, and transmissible venereal tumors (TVT) in dogs following microwave-induced hyperthermia (43 0 C and 45 0 for 20 minutes) were studied by light and electron microscopy. Normal muscle and Walker 256 tumors showed vascular damage at 5 minutes post-heating (PH), followed by suppuration and thrombosis at 6 and 48 hours PH, and by regeneration and repair at 7 days PH. Endothelial damage and parenchymal degeneration were present 5 minutes PH. Progressive ischemic injury occurred for at least 48 hours PH. Two hyperthermia treatments, separated by a 30 or 60 minute cooling interval, were applied to rats implanted with Walker 256 tumors. Increased selective heating of tumor tissue versus surrounding normal tissue, and increased intratumoral temperatures were found during the second hyperthermia treatment. Canine TVTs were resistant to hyperthermia damage. These results characterized the sequential morphologic alterations following hyperthermia treatment and showed that: 1) vascular damage contributed to the immediate and latent cytotoxic effects of hyperthermia, 2) selective heating occurred in the neoplastic tissue disrupted by prior heat treatment, and 3) not all neoplasms are responsive to hyperthermia treatment

Gene expression alterations associated with outcome in aromatase inhibitor-treated ER+ early-stage breast cancer patients

DEFF Research Database (Denmark)

Gravgaard Thomsen, Karina Hedelund; Lyng, Maria Bibi; Elias, Daniel

2015-01-01

predictive of outcome of ER+ breast cancer patients treated with AIs are needed. Global gene expression analysis was performed on ER+ primary breast cancers from patients treated with adjuvant AI monotherapy; half experienced recurrence (median follow-up 6.7 years). Gene expression alterations were validated...... by qRT-PCR, and functional studies evaluating the effect of siRNA-mediated gene knockdown on cell growth were performed. Twenty-six genes, including TFF3, DACH1, RGS5, and GHR, were shown to exhibit altered expression in tumors from patients with recurrence versus non-recurrent (fold change ≥1.5, p ....05), and the gene expression alterations were confirmed using qRT-PCR. Ten of these 26 genes could be linked in a network associated with cellular proliferation, growth, and development. TFF3, which encodes for trefoil factor 3 and is an estrogen-responsive oncogene shown to play a functional role in tamoxifen...

Periconceptional growth hormone treatment alters fetal growth and development in lambs.

Science.gov (United States)

Koch, J M; Wilmoth, T A; Wilson, M E

2010-05-01

Research in the area of fetal programming has focused on intrauterine growth restriction. Few studies have attempted to examine programming mechanisms that ultimately lead to lambs with a greater potential for postnatal growth. We previously demonstrated that treatment of ewes with GH at the time of breeding led to an increase in birth weight. Therefore, the objective of this study was to determine the effects of a single injection of sustained-release GH given during the periconceptional period on fetal growth and development and to determine if the GH axis would be altered in these offspring. Estrus was synchronized using 2 injections of PGF(2alpha); at the time of the second injection, ewes assigned to treatment were also given an injection of sustained-release GH. A maternal jugular vein sample was taken weekly to analyze IGF-I as a proxy for GH to estimate the duration of the treatment effect. In ewes treated with GH, IGF-I increased (P brain weights were obtained, as well as left and right ventricular wall thicknesses. On postnatal d 100, a subset of ewe lambs were weighed and challenged with an intravenous injection of GHRH. Lambs from treated ewes had increased (P left ventricular wall was thinner (P development. Lambs born to ewes treated with GH were larger at birth and had altered organ development, which may indicate that early maternal GH treatment may lead to permanent changes in the developing fetus. The ewe lambs maintained their growth performance to at least 100 d of postnatal life and appeared to have an altered GH axis, as demonstrated by the altered response to GHRH.

Valor da ultra-sonografia na avaliação das alterações endometriais em pacientes tratadas com tamoxifeno Value of sonographic endometrial findings in patients under tamoxifen therapy

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Arildo Corrêa Teixeira

2007-12-01

Full Text Available OBJETIVO: Avaliar as alterações endometriais por meio da ultra-sonografia transvaginal e correlacioná-las com os achados da histeroscopia e histologia, em pacientes submetidas a tratamento com tamoxifeno. MATERIAIS E MÉTODOS: No período de janeiro de 2003 a dezembro de 2005, foram incluídas pacientes com câncer de mama usuárias de tamoxifeno que apresentaram espessamento endometrial acima de 5 mm. Os achados foram correlacionados com os dados de histeroscopia e anatomopatologia. RESULTADOS: Foram selecionadas 25 pacientes com idade média de 62,6 anos. O tempo médio do diagnóstico do câncer foi de 4,3 anos e do uso de tamoxifeno, três anos. Vinte pacientes eram assintomáticas (80% e as demais apresentaram sangramento (20%. À ultra-sonografia, 16% apresentaram espessamento endometrial entre 5 mm e 8 mm, 40% entre 9 mm e 15 mm, e 44% acima de 15 mm. Ao estudo com a histeroscopia, 40% apresentaram atrofia, 16% atrofia cística, 28% pólipos, e 16% lesão hiperplásica. O estudo anatomopatológico apresentou-se normal em 35,2% dos casos e mostrou atrofia em 5,8%, pólipo em 29,4% e hiperplasia em 11,7%. Foi observado um caso de adenocarcinoma (5,8%. CONCLUSÃO: A ultra-sonografia associada à histeroscopia apresentam-se como importantes aliados na avaliação de pacientes usuárias de tamoxifeno. A detecção de espessamento endometrial à ultra-sonografia apresenta baixa especificidade, enquanto a histeroscopia é mais acurada na detecção de pólipos, hiperplasia e alterações neoplásicas.OBJECTIVE: To evaluate endometrial alterations by means of transvaginal ultrasound and to correlate them with hysteroscopic and histological findings in patients under tamoxifen therapy. MATERIALS AND METHODS: The present study was developed in the period between January 2003 and December 2005, including patients under tamoxifen therapy for breast cancer, and presenting with endometrial thickening > 5 mm. The sonographic findings were correlated

Alteration of split renal function during Captopril treatment

International Nuclear Information System (INIS)

Aburano, Tamio; Takayama, Teruhiko; Nakajima, Kenichi; Tonami, Norihisa; Hisada, Kinichi; Yasuhara, Shuichirou; Miyamori, Isamu; Takeda, Ryoyu

1987-01-01

Two different methods to evaluate the alteration of split renal function following continued Captopril treatment were studied in a total of 21 patients with hypertension. Eight patients with renovascular hypertension (five with unilateral renal artery stenosis and three with bilateral renal artery stenoses), three patients with diabetic nephropathy, one patient with primary aldosteronism, and nine patients with essential hypertension were included. The studies were performed the day prior to receiving Captopril (baseline), and 6th or 7th day following continued Captopril treatment (37.5 mg or 75 mg/day). Split effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) after injections of I-131 hippuran and Tc-99m DTPA were measured using kidney counting corrected for depth and dose, described by Schlegel and Gates. In the patients with renovascular hypertension, split GFR in the stenotic kidney was significantly decreased 6th or 7th day following continued Captopril treatment compared to a baseline value. And split ERPF in the stenotic kidney was slightly increased although significant increase of split ERPF was not shown. In the patients with diabetic nephropathy, primary aldosteronism or essential hypertension, on the other hand, split GFR was not changed and split ERPF was slightly increased. These findings suggest that the Captopril induced alterations of split renal function may be of importance for the diagnosis of renovascular hypertension. For this purpose, split GFR determination is more useful than split ERPF determination. (author)

Tamoxifen counteracts estradiol induced effects on striatal and hypophyseal dopamine receptors

Energy Technology Data Exchange (ETDEWEB)

Ferretti, C.; Blengio, M.; Ghi, P.; Racca, S.; Genazzani, E.; Portaleone, P.

1988-01-01

We investigated the ability of Tamoxifen (TAM), an antiestrogen drug, to counteract the modification induced by estrogens on dopamine (DA) receptors on striatum and on adenohypophysis of ovex female rats. Subacute treatment with 17..beta..-estradiol (E/sub 2/) at both low (0.1 ..mu..g/kg) and high (20 ..mu..g/kg) doses confirmed its ability to increase the number of striatal /sup 3/H-Spiperone (/sup 3/H-SPI) binding sites in a dose dependent manner. By contrast in the pituitary, only high doses of estrogen were effective in reducing the number of DA receptors. We treated ovex female rats for 15 days with TAM alone or associated with E/sub 2/, to see if these estrogenic effects could be suppressed by an antiestrogenic drug. TAM did not affect the number of striatal DA receptors, but significantly increased the adenohypophy-seal DA binding sites, without varying their affinity. No changes were observed in pituitary and striatal DA receptor density, even when TAM was injected in association with estradiol. In conclusions: TAM is able to counteract the effects estrogens have on DA receptors. However there is some evidence that it could influence the pituitary DA systems independently of it antiestrogenic activity.

Effects of tamoxifen on neuronal morphology, connectivity and biochemistry of hypothalamic ventromedial neurons: Impact on the modulators of sexual behavior.

Science.gov (United States)

Sá, Susana I; Teixeira, Natércia; Fonseca, Bruno M

2018-01-01

Tamoxifen (TAM) is a selective estrogen receptor modulator, widely used in the treatment and prevention of estrogen-dependent breast cancer. Although with great clinical results, women on TAM therapy still report several side effects, such as sexual dysfunction, which impairs quality of life. The anatomo-functional substrates of the human sexual behavior are still unknown; however, these same substrates are very well characterized in the rodent female sexual behavior, which has advantage of being a very simple reflexive response, dependent on the activation of estrogen receptors (ERs) in the ventrolateral division of the hypothalamic ventromedial nucleus (VMNvl). In fact, in the female rodent, the sexual behavior is triggered by increasing circulation levels of estradiol that changes the nucleus neurochemistry and modulates its intricate neuronal network. Therefore, we considered of notice the examination of the possible neurochemical alterations and the synaptic plasticity impairment in VMNvl neurons of estradiol-primed female rats treated with TAM that may be in the basis of this neurological disorder. Accordingly, we used stereological and biochemical methods to study the action of TAM in axospinous and axodendritic synaptic plasticity and on ER expression. The administration of TAM changed the VMNvl neurochemistry by reducing ERα mRNA and increasing ERβ mRNA expression. Furthermore, present results show that TAM induced neuronal atrophy and reduced synaptic connectivity, favoring electrical inactivity. These data suggest that these cellular and molecular changes may be a possible neuronal mechanism of TAM action in the disruption of the VMNvl network, leading to the development of behavioral disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

New treatment option for women with hormone-sensitive breast cancer

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A drug used for treating breast cancer, known as exemestane, is more effective than a common breast cancer prevention drug, tamoxifen, in preventing breast cancer recurrence in young women who also receive post-surgical treatment to suppress ovarian funct

Review of hormonal treatment of breast cancer

African Journals Online (AJOL)

2011-07-28

Jul 28, 2011 ... Although tamoxifen is the established drug for hormonal treatment of breast cancer, cases of .... This is a growth factor protein which is over‑expressed in different types of .... These groups of drugs act as receptor binding competitors of estrogens and ... Mechanism of Action of Selective Estrogen. Receptor ...

A randomized trial of tamoxifen with or without breast radiation in women over 50 years of age with T1/2 N0 disease

International Nuclear Information System (INIS)

Fyles, A.; Manchul, L.; McCready, D.; Merante, P.; Pintilie, M.; Trudeuau, M.; Olivotto, I.; Weir, L.

2003-01-01

To determine the effect of breast radiation (RT) on disease-free survival (DFS) and ipsilateral breast relapse (IBR) in women over 50 with T1 and T2 node negative breast cancer. Between December 1992 and June 2000, 769 women were randomized to RT and Tamoxifen (Tam) 20 mg daily for 5 years or Tam alone. Median age was 68 years, 639 patients had pT1 lesions and ER/PR were positive in 700 patients. Six hundred and thirty-four patients had pathologically negative nodes and 135 over age 65 were clinically node negative. Median follow-up was 5.6 years and patient and tumour characteristics were well balanced between the two arms. Overall, there were 54 relapses from breast cancer in the Tam arm and 27 in the Tam + RT arm. IBR at 5 years was 7.7% in the Tam arm compared to 0.6% in the Tam + RT group (p<0.0001). Significant factors for breast relapse and DFS at 5 years included tumour size (p=0.02 and 0.0001 respectively), hormone-receptor status (p=0.0008 and 0.0001), grade (p=0.001 and 0.003) and treatment arm (p=0.0001 and 0.004). Four-hundred and nineteen patients with low-risk features (T1, receptor-positive and grade 1/2) treated with Tam alone had a 5% risk of IBR at 5 years, increasing to 10% at 8 years. There was no difference in relapse at regional or distant sites, or in the contralateral breast. No difference was seen in the number of deaths due to breast cancer (13 and 11 for Tam + RT and Tam, respectively), nor in OS (93% at 5 years in both arms). Tamoxifen and breast RT results in a significantly lower rate of breast relapse than Tam alone in women over 50 with node-negative breast cancer. There does not appear to be a low-risk group who can be treated with Tamoxifen without breast radiation

Bioactive dietary supplements reactivate ER expression in ER-negative breast cancer cells by active chromatin modifications.

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Syed M Meeran

Full Text Available Breast cancer is the most common cancer and the leading cause of cancer death in women. Although tamoxifen therapy is successful for some patients, it does not provide adequate benefit for those who have estrogen receptor (ER-negative cancers. Therefore, we approached novel treatment strategies by combining two potential bioactive dietary supplements for the reactivation of ERα expression for effective treatment of ERα-negative breast cancer with tamoxifen. Bioactive dietary supplements such as green tea polyphenols (GTPs and sulforaphane (SFN inhibit DNA methyltransferases (DNMTs and histone deacetylases (HDACs, respectively, which are of central importance to cancer prevention. In the present study, we have observed that treatment of ERα-negative breast cancer cells with GTPs and SFN alone or in combination leads to the reactivation of ERα expression. The combination of 20 µg/mL GTPs and 5 µM SFN was found to be the optimal dose of ERα-reactivation at 3 days in MDA-MB-231 cells. The reactivation of ERα expression was consistently correlated with ERα promoter hypomethylation and hyperacetylation. Chromatin immunoprecipitation (ChIP analysis of the ERα promoter revealed that GTPs and SFN altered the binding of ERα-transcriptional co-repressor complex thereby contributing to ERα-reactivation. In addition, treatment with tamoxifen in combination with GTPs and SFN significantly increased both cell death and inhibition of cellular proliferation in MDA-MB-231 cells in comparison to treatment with tamoxifen alone. Collectively, our findings suggest that a novel combination of bioactive-HDAC inhibitors with bioactive-demethylating agents is a promising strategy for the effective treatment of hormonal refractory breast cancer with available anti-estrogens.

Anterior Cingulate Volumetric Alterations in Treatment-Naive Adults with ADHD: A Pilot Study

Science.gov (United States)

Makris, Nikos; Seidman, Larry J.; Valera, Eve M.; Biederman, Joseph; Monuteaux, Michael C.; Kennedy, David N.; Caviness, Verne S., Jr.; Bush, George; Crum, Katherine; Brown, Ariel B.; Faraone, Stephen V.

2010-01-01

Objective: We sought to examine preliminary results of brain alterations in anterior cingulate cortex (ACC) in treatment-naive adults with ADHD. The ACC is a central brain node for the integration of cognitive control and allocation of attention, affect and drive. Thus its anatomical alteration may give rise to impulsivity, hyperactivity and…

25-Hydroxy vitamin-D, obesity, and associated variables as predictors of breast cancer risk and tamoxifen benefit in NSABP-P1.

Science.gov (United States)

Amir, Eitan; Cecchini, Reena S; Ganz, Patricia A; Costantino, Joseph P; Beddows, Samantha; Hood, Nicola; Goodwin, Pamela J

2012-06-01

Observational studies suggest that host factors are associated with breast cancer risk. The influence of obesity, vitamin-D status, insulin resistance, inflammation, and elevated adipocytokines in women at high risk of breast cancer is unknown. The NSABP-P1 trial population was used for a nested case-control study. Cases were drawn from those who developed invasive breast cancer and controls selected from unaffected participants (≤4 per case) matched for age, race, 5 year Gail score, and geographic location of clinical center as a surrogate for latitude. Fasting serum banked at trial enrolment was assayed for 25-hydroxy vitamin-D (25OHD), insulin, leptin (adipocytokine), and C-reactive protein (CRP, marker of inflammation). Logistic regression was used to test for associations between study variables and the risk of invasive breast cancer. Two hundred and thirty-one cases were matched with 856 controls. Mean age was 54, and 49% were premenopausal. There were negative correlations for 25OHD with body mass index (BMI), insulin, CRP, and leptin. BMI ≥ 25 kg/m(2) was associated with higher breast cancer risk (odds ratio [OR] 1.45, p = 0.02) and tamoxifen treatment was associated with lower risk (OR = 0.44, p continuous variables, 25OHD, insulin, CRP, and leptin levels were not associated with breast cancer risk (all p > 0.34). In this high risk population, higher BMI was associated with a greater breast cancer risk. Serum levels of 25OHD, insulin, CRP, and leptin were not independent predictors of either breast cancer risk or tamoxifen benefit.

Estrogen receptor, Progesterone receptor, HER2 status and Ki67 index and responsiveness to adjuvant tamoxifen in postmenopausal high-risk breast cancer patients enrolled in the DBCG 77C trial

DEFF Research Database (Denmark)

Knoop, Ann; Lænkholm, Anne Vibeke; Jensen, M. B.

2014-01-01

BCRR and BCM in postmenopausal patients with ER positive breast cancers. The relative benefit from tamoxifen was not significantly different in luminal A and B subtypes. Funding: The Danish Breast Cancer Cooperative Group (DBCG) prepared the original protocol (DBCG 77C) and was the sponsor of the study......Background: The DBCG 77C trial compared one year of tamoxifen in postmenopausal, steroid-receptor unknown, high-risk breast cancer patients to no adjuvant systemic therapy. After a potential follow-up of 30 years we report overall efficacy of the study and results according to subtypes subsequently...... assessed by immunohistochemistry and fluorescent in situ hybridisation (FISH). Methods: Between 1977 and 1982, 1716 postmenopausal patients with tumours larger than 5 cm or positive axillary nodes were randomly assigned to no systemic therapy or tamoxifen 30 mg daily for one year. Archival tumour tissue...

Modulation of Tamoxifen Cytotoxicity by Caffeic Acid Phenethyl Ester in MCF-7 Breast Cancer Cells

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Tarek K. Motawi

2016-01-01

Full Text Available Although Tamoxifen (TAM is one of the most widely used drugs in managing breast cancer, many women still relapse after long-term therapy. Caffeic acid phenethyl ester (CAPE is a polyphenolic compound present in many medicinal plants and in propolis. The present study examined the effect of CAPE on TAM cytotoxicity in MCF-7 cells. MCF-7 cells were treated with different concentrations of TAM and/or CAPE for 48 h. This novel combination exerted synergistic cytotoxic effects against MCF-7 cells via induction of apoptotic machinery with activation of caspases and DNA fragmentation, along with downregulation of Bcl-2 and Beclin 1 expression levels. However, the mammalian microtubule-associated protein light chain LC 3-II level was unchanged. Vascular endothelial growth factor level was also decreased, whereas levels of glutathione and nitric oxide were increased. In conclusion, CAPE augmented TAM cytotoxicity via multiple mechanisms, providing a novel therapeutic approach for breast cancer treatment that can overcome resistance and lower toxicity. This effect provides a rationale for further investigation of this combination.

Mechanisms of the hepatoprotective effects of tamoxifen against drug-induced and chemical-induced acute liver injuries

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Yoshikawa, Yukitaka; Miyashita, Taishi; Higuchi, Satonori [Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920‐1192 (Japan); Tsuneyama, Koichi [Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Science for Research, University of Toyama, Sugitani, Toyama 930‐0194 (Japan); Endo, Shinya [Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920‐1192 (Japan); Tsukui, Tohru [Research Center for Genomic Medicine, Saitama Medical University, Yamane, Hidaka 350‐1241 (Japan); Toyoda, Yasuyuki; Fukami, Tatsuki; Nakajima, Miki [Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920‐1192 (Japan); Yokoi, Tsuyoshi, E-mail: tyokoi@p.kanazawa-u.ac.jp [Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920‐1192 (Japan)

2012-10-01

Although estrogen receptor (ER)α agonists, such as estradiol and ethinylestradiol (EE2), cause cholestasis in mice, they also reduce the degree of liver injury caused by hepatotoxicants as well as ischemia–reperfusion. The functional mechanisms of ERα have yet to be elucidated in drug-induced or chemical-induced liver injury. The present study investigated the effects of an ERα agonist, selective ER modulators (SERMs) and an ER antagonist on drug-induced and chemical-induced liver injuries caused by acetaminophen, bromobenzene, diclofenac, and thioacetamide (TA). We observed hepatoprotective effects of EE2, tamoxifen (TAM) and raloxifene pretreatment in female mice that were exposed to a variety of hepatotoxic compounds. In contrast, the ER antagonist did not show any hepatoprotective effects. DNA microarray analyses suggested that monocyte to macrophage differentiation-associated 2 (Mmd2) protein, which has an unknown function, is commonly increased by TAM and RAL pretreatment, but not by pretreatment with the ER antagonist. In ERα-knockout mice, the hepatoprotective effects of TAM and the increased expression of Mmd2 mRNA were not observed in TA-induced liver injury. To investigate the function of Mmd2, the expression level of Mmd2 mRNA was significantly knocked down to approximately 30% in mice by injection of siRNA for Mmd2 (siMmd2). Mmd2 knockdown resulted in a reduction of the protective effects of TAM on TA-induced liver injury in mice. This is the first report of the involvement of ERα in drug-induced or chemical-induced liver injury. Upregulation of Mmd2 protein in the liver was suggested as the mechanism of the hepatoprotective effects of EE2 and SERMs. -- Highlights: ► Liver injury induced by drugs or chemicals was investigated in mice. ► Liver injury was suppressed by pretreatment with tamoxifen in female mice. ► Mmd2, whose function was unknown, could be a candidate gene for liver protection. ► Tamoxifen up-regulated Mmd2 mRNA expression

Mechanisms of the hepatoprotective effects of tamoxifen against drug-induced and chemical-induced acute liver injuries

International Nuclear Information System (INIS)

Yoshikawa, Yukitaka; Miyashita, Taishi; Higuchi, Satonori; Tsuneyama, Koichi; Endo, Shinya; Tsukui, Tohru; Toyoda, Yasuyuki; Fukami, Tatsuki; Nakajima, Miki; Yokoi, Tsuyoshi

2012-01-01

Although estrogen receptor (ER)α agonists, such as estradiol and ethinylestradiol (EE2), cause cholestasis in mice, they also reduce the degree of liver injury caused by hepatotoxicants as well as ischemia–reperfusion. The functional mechanisms of ERα have yet to be elucidated in drug-induced or chemical-induced liver injury. The present study investigated the effects of an ERα agonist, selective ER modulators (SERMs) and an ER antagonist on drug-induced and chemical-induced liver injuries caused by acetaminophen, bromobenzene, diclofenac, and thioacetamide (TA). We observed hepatoprotective effects of EE2, tamoxifen (TAM) and raloxifene pretreatment in female mice that were exposed to a variety of hepatotoxic compounds. In contrast, the ER antagonist did not show any hepatoprotective effects. DNA microarray analyses suggested that monocyte to macrophage differentiation-associated 2 (Mmd2) protein, which has an unknown function, is commonly increased by TAM and RAL pretreatment, but not by pretreatment with the ER antagonist. In ERα-knockout mice, the hepatoprotective effects of TAM and the increased expression of Mmd2 mRNA were not observed in TA-induced liver injury. To investigate the function of Mmd2, the expression level of Mmd2 mRNA was significantly knocked down to approximately 30% in mice by injection of siRNA for Mmd2 (siMmd2). Mmd2 knockdown resulted in a reduction of the protective effects of TAM on TA-induced liver injury in mice. This is the first report of the involvement of ERα in drug-induced or chemical-induced liver injury. Upregulation of Mmd2 protein in the liver was suggested as the mechanism of the hepatoprotective effects of EE2 and SERMs. -- Highlights: ► Liver injury induced by drugs or chemicals was investigated in mice. ► Liver injury was suppressed by pretreatment with tamoxifen in female mice. ► Mmd2, whose function was unknown, could be a candidate gene for liver protection. ► Tamoxifen up-regulated Mmd2 mRNA expression

Advantages of concurrent biochemotherapy modified by decrescendo interleukin-2, granulocyte colony-stimulating factor, and tamoxifen for patients with metastatic melanoma.

Science.gov (United States)

O'Day, S J; Gammon, G; Boasberg, P D; Martin, M A; Kristedja, T S; Guo, M; Stern, S; Edwards, S; Fournier, P; Weisberg, M; Cannon, M; Fawzy, N W; Johnson, T D; Essner, R; Foshag, L J; Morton, D L

1999-09-01

Concurrent biochemotherapy results in high response rates but also significant toxicity in patients with metastatic melanoma. We attempted to improve its efficacy and decrease its toxicity by using decrescendo dosing of interleukin-2 (IL-2), posttreatment granulocyte colony-stimulating factor (G-CSF), and low-dose tamoxifen. Forty-five patients with poor prognosis metastatic melanoma were treated at a community hospital inpatient oncology unit affiliated with the John Wayne Cancer Institute (Santa Monica, CA) between July 1995 and September 1997. A 5-day modified concurrent biochemotherapy regimen of dacarbazine, vinblastine, cisplatin, decrescendo IL-2, interferon alfa-2b, and tamoxifen was repeated at 21-day intervals. G-CSF was administered beginning on day 6 for 7 to 10 days. The overall response rate was 57% (95% confidence interval, 42% to 72%), the complete response rate was 23%, and the partial response rate was 34%. Complete remissions were achieved in an additional 11% of patients by surgical resection of residual disease after biochemotherapy. The median time to progression was 6.3 months and the median duration of survival was 11.4 months. At a maximum follow-up of 36 months (range, 10 to 36 months), 32% of patients are alive and 14% remain free of disease. Decrescendo IL-2 dosing and administration of G-CSF seemed to reduce toxicity, length of hospital stay, and readmission rates. No patient required intensive care unit monitoring, and there were no treatment-related deaths. The data from this study indicate that the modified concurrent biochemotherapy regimen reduces the toxicity of concurrent biochemotherapy with no apparent decrease in response rate in patients with poor prognosis metastatic melanoma.

Gynecomastia during imatinib mesylate treatment for gastrointestinal stromal tumor: a rare adverse event

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Yan ZhongShu

2011-11-01

Full Text Available Abstract Background Imatinib mesylate has been the standard therapeutic treatment for chronic myeloid leukemia, advanced and metastatic gastrointestinal stromal tumor (GIST. It is well tolerated with mild adverse effects. Gynecomastia development during the course of treatment has been rarely reported. Methods Ninety-eight patients with advanced or recurrent GIST were treated with imatinib mesylate. Among the fifty-seven male patients six developed gynecomastia during the treatment. The lesions were confirmed by sonography. Sex hormone levels were determined in six patients with and without the presence of gynecomastia respectively. The patients with gynecomatia were treated with tamoxifene and the sex hormones were assayed before and after tamoxifene treatment. Results In patients with gynecomastia the lump underneath the bilateral nipples was 2.5 to 5 centimeters in diameter. Their serum free testosterone levels ranged between 356.61 and 574.60 ng/dl with a mean ± SD of 408.64 ± 82.06 ng/dl (95% CI 343.03~474.25 ng/dl, which is within the normal range. The level of serum estradiol was 42.89 ± 16.54 pg/ml (95% CI 29.66~56.12 pg/ml. Three patients had higher levels (43.79~71.21 pg/ml and the others' were within normal range of 27.00~34.91 pg/ml. Six patients without the development of gynecomastia had normal free testosterone. One patient died because of large tumor burden. The sex hormones had no significant changes before and after tamoxifene treatment.(P > 0.05 Conclusions Testosterone levels were not decreased in the six GIST patients with gynecomastia. Three patients had increased serum estradiol level which suggests that imbalance of sex hormones may be the cause of gynecomastia during treatment with imatinib mesylate.

Analyses adjusting for selective crossover show improved overall survival with adjuvant letrozole compared with tamoxifen in the BIG 1-98 study

DEFF Research Database (Denmark)

Colleoni, Marco; Giobbie-Hurder, Anita; Regan, Meredith M

2011-01-01

Among postmenopausal women with endocrine-responsive breast cancer, the aromatase inhibitor letrozole, when compared with tamoxifen, has been shown to significantly improve disease-free survival (DFS) and time to distant recurrence (TDR). We investigated whether letrozole monotherapy prolonged ov...

Impact of DNA mismatch repair system alterations on human fertility and related treatments.

Science.gov (United States)

Hu, Min-hao; Liu, Shu-yuan; Wang, Ning; Wu, Yan; Jin, Fan

2016-01-01

DNA mismatch repair (MMR) is one of the biological pathways, which plays a critical role in DNA homeostasis, primarily by repairing base-pair mismatches and insertion/deletion loops that occur during DNA replication. MMR also takes part in other metabolic pathways and regulates cell cycle arrest. Defects in MMR are associated with genomic instability, predisposition to certain types of cancers and resistance to certain therapeutic drugs. Moreover, genetic and epigenetic alterations in the MMR system demonstrate a significant relationship with human fertility and related treatments, which helps us to understand the etiology and susceptibility of human infertility. Alterations in the MMR system may also influence the health of offspring conceived by assisted reproductive technology in humans. However, further studies are needed to explore the specific mechanisms by which the MMR system may affect human infertility. This review addresses the physiological mechanisms of the MMR system and associations between alterations of the MMR system and human fertility and related treatments, and potential effects on the next generation.

Effect of chronic administration of Tamoxifen on fertility in male bonnet monkeys (Macaca radiata).

Science.gov (United States)

Rao, A J; Ramachandra, S G; Ramesh, V; Krishnamurthy, H N; Jayaraman, S; Gopalakrishnan, K; Juneja, H S

1998-01-01

Administration of Tamoxifen via the Alzet pump at a rate of 50 micrograms hr-1 for 90 days in the adult male bonnet monkeys Macaca radiata had no effect on the serum testosterone concentration determined at 10 AM and 10 PM as well as total sperm count determined at 15-day intervals over a period of 260 days. However, a significant reduction in sperm motility was observed beyond 90 days up until the 225th day. Breeding studies conducted from day 90 to 260 revealed that these males were infertile.

Association of CYP2D6 and CYP2C19 polymorphisms and disease-free survival of Thai post-menopausal breast cancer patients who received adjuvant tamoxifen

Directory of Open Access Journals (Sweden)

Chamnanphon M

2013-05-01

.90%, and *36 (1 of 114, 0.90%; the CYP2C19 variant alleles were *2 (27 of 114, 23.70% and *3 (6 of 114, 5.30%. Kaplan–Meier estimates showed significantly shorter disease-free survival in patients with homozygous TT when compared to those with heterozygous CT or homozygous CC at nucleotides 100C>T and 1039C>T (CYP2D6*10 post-menopausal (log-rank test; P = 0.046. They also had increased risk of recurrence, but no statistically significant association was observed (hazard ratio 3.48; 95% confidence interval 0.86–14.07; P = 0.080.Conclusion: The CYP2D6 and CYP2C19 polymorphisms were not involved in tamoxifen efficacy. However, in the subgroup of post-menopausal women, the polymorphisms in CYP2D6 and CYP2C19 might be useful in predicting tamoxifen efficacy and clinical outcomes in breast cancer patients receiving adjuvant tamoxifen treatment. As the number of breast cancer patients was relatively small in this study, results should be confirmed in a larger group of prospective patients.Keywords: CYP2D6, CYP2C19, disease-free survival, tamoxifen, pharmacogenetics, breast cancer

Cancer Care Coordinators to Improve Tamoxifen Persistence in Breast Cancer: How Heterogeneity in Baseline Prognosis Impacts on Cost-Effectiveness.

Science.gov (United States)

Nair, Nisha; Kvizhinadze, Giorgi; Blakely, Tony

2016-12-01

To assess the cost-effectiveness of a cancer care coordinator (CCC) in helping women with estrogen receptor positive (ER+) early breast cancer persist with tamoxifen for 5 years. We investigated the cost-effectiveness of a CCC across eight breast cancer subtypes, defined by progesterone receptor (PR) status, human epidermal growth factor receptor 2 (HER2) status, and local/regional spread. These subtypes range from excellent to poorer prognoses. The CCC helped in improving tamoxifen persistence by providing information, checking-in by phone, and "troubleshooting" concerns. We constructed a Markov macrosimulation model to estimate health gain (in quality-adjusted life-years or QALYs) and health system costs in New Zealand, compared with no CCC. Participants were modeled until death or till the age of 110 years. Some input parameters (e.g., the impact of a CCC on tamoxifen persistence) had sparse evidence. Therefore, we used estimates with generous uncertainty and conducted sensitivity analyses. The cost-effectiveness of a CCC for regional ER+/PR-/HER2+ breast cancer (worst prognosis) was NZ $23,400 (US $15,800) per QALY gained, compared with NZ $368,500 (US $248,800) for local ER+/PR+/HER2- breast cancer (best prognosis). Using a cost-effectiveness threshold of NZ $45,000 (US $30,400) per QALY, a CCC would be cost-effective only in the four subtypes with the worst prognoses. There is value in investigating cost-effectiveness by different subtypes within a disease. In this example of breast cancer, the poorer the prognosis, the greater the health gains from a CCC and the better the cost-effectiveness. Incorporating heterogeneity in a cost-utility analysis is important and can inform resource allocation decisions. It is also feasible to undertake in practice. Copyright © 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Tamoxifen-elicited uterotrophy: cross-species and cross-ligand analysis of the gene expression program

Directory of Open Access Journals (Sweden)

Forgacs Agnes L

2009-04-01

Full Text Available Abstract Background Tamoxifen (TAM is a well characterized breast cancer drug and selective estrogen receptor modulator (SERM which also has been associated with a small increase in risk for uterine cancers. TAM's partial agonist activation of estrogen receptor has been characterized for specific gene promoters but not at the genomic level in vivo.Furthermore, reducing uncertainties associated with cross-species extrapolations of pharmaco- and toxicogenomic data remains a formidable challenge. Results A comparative ligand and species analysis approach was conducted to systematically assess the physiological, morphological and uterine gene expression alterations elicited across time by TAM and ethynylestradiol (EE in immature ovariectomized Sprague-Dawley rats and C57BL/6 mice. Differential gene expression was evaluated using custom cDNA microarrays, and the data was compared to identify conserved and divergent responses. 902 genes were differentially regulated in all four studies, 398 of which exhibit identical temporal expression patterns. Conclusion Comparative analysis of EE and TAM differentially expressed gene lists suggest TAM regulates no unique uterine genes that are conserved in the rat and mouse. This demonstrates that the partial agonist activities of TAM extend to molecular targets in regulating only a subset of EE-responsive genes. Ligand-conserved, species-divergent expression of carbonic anhydrase 2 was observed in the microarray data and confirmed by real time PCR. The identification of comparable temporal phenotypic responses linked to related gene expression profiles demonstrates that systematic comparative genomic assessments can elucidate important conserved and divergent mechanisms in rodent estrogen signalling during uterine proliferation.

17a-Ethynyl-5a-androstane-3a, 17 β-diol Treatment of MNU-Induced Mammary Cancer in Rats

International Nuclear Information System (INIS)

Ahlem, C.N.; Frincke, J.M.; White, S.K.; Reading, Ch.L.; Trauger, R.J.; Lakshmanaswamy, R.

2011-01-01

N-methyl-N-nitrosourea (MNU) induces estrogen-dependent mammary tumors in female Lewis rats. We explored the antineoplastic activity of a synthetic androstane derivative, 17 a-ethynyl-5a-androstane-3a, 17β-diol (HE3235), as a single agent or in combination with docetaxel compared to tamoxifen, anastrazole, and docetaxel mono therapies against MNU-induced mammary tumors in female Lewis rats. Treatment with HE3235 alone rapidly reduced tumor burden, similar in effect to tamoxifen and anastrozole. The combination of HE3235 with docetaxel was more effective than any single agent, although without apparent toxicity. Only HE3235 or HE3235 plus docetaxel continued to suppress tumor growth after cessation of treatment. HE3235 treatment increased immunohistochemical markers of apoptosis and expression of pro apoptotic genes and estrogen receptor beta and decreased expression of anti apoptotic genes, androgen receptor, and estrogen receptor alpha. These data warrant clinical investigation of HE3235 for breast cancer treatment.

My Lived Experiences Are More Important Than Your Probabilities: The Role of Individualized Risk Estimates for Decision Making about Participation in the Study of Tamoxifen and Raloxifene (STAR).

Science.gov (United States)

Holmberg, Christine; Waters, Erika A; Whitehouse, Katie; Daly, Mary; McCaskill-Stevens, Worta

2015-11-01

Decision-making experts emphasize that understanding and using probabilistic information are important for making informed decisions about medical treatments involving complex risk-benefit tradeoffs. Yet empirical research demonstrates that individuals may not use probabilities when making decisions. To explore decision making and the use of probabilities for decision making from the perspective of women who were risk-eligible to enroll in the Study of Tamoxifen and Raloxifene (STAR). We conducted narrative interviews with 20 women who agreed to participate in STAR and 20 women who declined. The project was based on a narrative approach. Analysis included the development of summaries of each narrative, and thematic analysis with developing a coding scheme inductively to code all transcripts to identify emerging themes. Interviewees explained and embedded their STAR decisions within experiences encountered throughout their lives. Such lived experiences included but were not limited to breast cancer family history, a personal history of breast biopsies, and experiences or assumptions about taking tamoxifen or medicines more generally. Women's explanations of their decisions about participating in a breast cancer chemoprevention trial were more complex than decision strategies that rely solely on a quantitative risk-benefit analysis of probabilities derived from populations In addition to precise risk information, clinicians and risk communicators should recognize the importance and legitimacy of lived experience in individual decision making. © The Author(s) 2015.

Effects of Pharmaceuticals Used for Breast Cancer Treatment on Reproduction and Aromatase Activity in a Marine Fish

Science.gov (United States)

Laboratory experiments were conducted with the marine fish cunner (Tautogolabrus adspersus) to evaluate whether four pharmaceuticals used in breast cancer treatment have an impact on reproduction or aromatase activity. Tamoxifen binds to estrogen receptors, while anastrozole, let...

Cardiac risks in multimodal breast cancer treatment

Energy Technology Data Exchange (ETDEWEB)

Budach, W. [Dept. of Radiation Oncology, Univ. of Duesseldorf (Germany)

2007-12-15

Almost all breast cancer patients receive one or more adjuvant treatments consisting of tamoxifen, aromatase inhibitors, LHRH-antogonists, chemotherapy, trastuzumab, and radiotherapy. These treatments have been shown to considerably improve overall survival. As a result, long term survival for 15 and more years is achieved in more than two thirds of newly diagnosed breast cancer patients. Therefore, more interest in short and long term risks of adjuvant treatments has been arisen. The focus of this article is the long term cardiac risks of adjuvant radiotherapy in breast cancer patients and possible interactions with chemotherapy and trastuzumab. (orig.)

Late tamoxifen in patients previously operated for breast cancer without postoperative tamoxifen: 5-year results of a single institution randomised study

International Nuclear Information System (INIS)

Veronesi, Andrea; Miolo, GianMaria; Magri, Maria D; Crivellari, Diana; Scalone, Simona; Bidoli, Ettore; Lombardi, Davide

2010-01-01

A population of breast cancer patients exists who, for various reasons, never received adjuvant post-operative tamoxifen (TAM). This study was aimed to evaluate the role of late TAM in these patients. From 1997 to 2003, patients aged 35 to 75 years, operated more than 2 years previously for monolateral breast cancer without adjuvant TAM, with no signs of metastases and no contraindication to TAM were randomized to TAM 20 mg/day orally for 2 years or follow-up alone. Events were categorized as locoregional relapse, distant metastases, metachronous breast cancer, tumours other than breast cancer and death from any causes, whichever occurred first. The sample size (197 patients per arm, plus 10% allowance) was based on the assumption of a 30% decrease in the number of events occurring at a rate of 5% annually in the 10 years following randomization. Four hundred and thirty-three patients were randomized in the study (TAM 217, follow-up 216). Patients characteristics (TAM/follow-up) included: median age 55/55 years, median time from surgery 25/25 months (range, 25-288/25-294), in situ carcinoma 18/24, oestrogen receptor (ER) positive in 75/68, negative in 70/57, unknown in 72/91 patients. Previous adjuvant treatment included chemotherapy in 131/120 and an LHRH analogue in 11/13 patients. Thirty-six patients prematurely discontinued TAM after a median of 1 month, mostly because of subjective intolerance. Eighty-three events (TAM 39, follow-up 44) occurred: locoregional relapse in 10/8, distant metastases in 14/16, metachronous breast cancer in 4/10, other tumours in 11/10 patients. Less ER-positive secondary breast cancers occurred in the TAM treated patients than in follow-up patients (1 vs 10, p = 0.005). Event-free survival was similar in both groups of patients. This 5-year analysis revealed significantly less metachronous ER-positive breast cancers in the TAM treated patients. No other statistically significant differences have emerged thus far

27 CFR 4.22 - Blends, cellar treatment, alteration of class or type.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Blends, cellar treatment, alteration of class or type. 4.22 Section 4.22 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS LABELING AND ADVERTISING OF WINE Standards of...

Alterations in Gene Expression in Depression: Prospects for Personalize Patient Treatment.

Science.gov (United States)

Donev, Rossen; Alawam, Khaled

2015-01-01

The number of people around the world suffering from depression has dramatically increased in last few decades. It has been predicted that by 2020 depression will become the second most common cause of disability. Furthermore, depression is often misdiagnosed and confused with other psychiatric disorders showing similar symptoms, i.e., anxiety and bipolar disorder, due to the fact that diagnosing is often carried out by medical workers who are not psychiatrically trained. These facts prompt us to prepare this review which focuses on alterations in gene expression in depression. We believe that an in-depth knowledge of molecular bases of behavior in depression and other mood disorders would be of a great benefit for the correct diagnosing of these disorders, as well as for prescribing a treatment that best suits each individual depending on expression alterations in depression-related genes. Therefore, the main aim of this review is to promote further translational research on the biochemistry of mood disorders and take the results further for the design of new targeted therapeutics that can be used for personalized treatment with minimal adverse effects. © 2015 Elsevier Inc. All rights reserved.

Tank waste remediation system optimized processing strategy with an altered treatment scheme

International Nuclear Information System (INIS)

Slaathaug, E.J.

1996-03-01

This report provides an alternative strategy evolved from the current Hanford Site Tank Waste Remediation System (TWRS) programmatic baseline for accomplishing the treatment and disposal of the Hanford Site tank wastes. This optimized processing strategy with an altered treatment scheme performs the major elements of the TWRS Program, but modifies the deployment of selected treatment technologies to reduce the program cost. The present program for development of waste retrieval, pretreatment, and vitrification technologies continues, but the optimized processing strategy reuses a single facility to accomplish the separations/low-activity waste (LAW) vitrification and the high-level waste (HLW) vitrification processes sequentially, thereby eliminating the need for a separate HLW vitrification facility

Efficacy and safety of endocrine monotherapy as first-line treatment for hormone-sensitive advanced breast cancer: A network meta-analysis.

Science.gov (United States)

Zhang, Jingwen; Huang, Yanhong; Wang, Changyi; He, Yuanfang; Zheng, Shukai; Wu, Kusheng

2017-08-01

Endocrine therapy was recommended as the preferred first-line treatment for hormone receptor-positive (HR+, i.e., ER+ and/or PgR+), human epidermal growth factor receptor-2-negative (HER2-) postmenopausal advanced breast cancer (ABC), but which endocrine monotherapy is optimal lacks consensus. We aimed to identify the optimal endocrine monotherapy with a network meta-analysis. We performed a network meta-analysis for a comprehensive analysis of 6 first-line endocrine monotherapies (letrozole, anastrozole, exemestane, tamoxifen, fulvestrant 250 mg and 500 mg) for HR+ HER2- metastatic or locally advanced breast cancer in postmenopausal patients. The main outcomes were objective response rate (ORR), time to progression (TTP), and progression-free survival (PFS). Secondary outcomes were adverse events. We identified 27 articles of 8 randomized controlled trials including 3492 patients in the network meta-analysis. For ORR, the treatments ranked in descending order of effectiveness were letrozole > exemestane > anastrozole > fulvestrant 500 mg > tamoxifen > fulvestrant 250 mg. For TTP/PFS, the order was fulvestrant 500 mg > letrozole > anastrozole > exemestane > tamoxifen > fulvestrant 250 mg. We directly compared adverse events and found that tamoxifen produced more hot flash events than fulvestrant 250 mg. Fulvestrant 500 mg and letrozole might be optimal first-line endocrine monotherapy choices for HR+ HER2- ABC because of efficacious ORR and TTP/PFS, with a favorable tolerability profile. However, direct comparisons among endocrine monotherapies in the first-line therapy setting are still required to robustly demonstrate any differences among these endocrine agents. Clinical choices should also depend on the specific disease situation and duration of endocrine therapy.

Long-term efficacy and safety of anastrozole for adjuvant treatment of early breast cancer in postmenopausal women

Directory of Open Access Journals (Sweden)

Sharath Gangadhara

2009-04-01

Full Text Available Sharath Gangadhara, Gianfilippo BertelliSouth West Wales Cancer Institute, Singleton Hospital, Swansea, UKAbstract: For more than 20 years, tamoxifen has been the gold standard for the adjuvant treatment of postmenopausal women with hormone-responsive early breast cancer. However, recent randomized trials have shown efficacy and tolerability benefits with the third-generation aromatase inhibitor anastrozole, resulting in an increased use of this agent in the adjuvant setting. Data on anastrozole’s long-term efficacy and tolerability are therefore of interest in clinical practice and will be reviewed here, especially in the light of the 100-month analysis of the ATAC (Anastrozole, Tamoxifen Alone or in Combination trial.Keywords: anastrozole, aromatase inhibitors, breast cancer, adjuvant therapy 

Global DNA methylation is altered by neoadjuvant chemoradiotherapy in rectal cancer and may predict response to treatment - A pilot study.

LENUS (Irish Health Repository)

Tsang, J S

2014-07-28

In rectal cancer, not all tumours display a response to neoadjuvant treatment. An accurate predictor of response does not exist to guide patient-specific treatment. DNA methylation is a distinctive molecular pathway in colorectal carcinogenesis. Whether DNA methylation is altered by neoadjuvant treatment and a potential response predictor is unknown. We aimed to determine whether DNA methylation is altered by neoadjuvant chemoradiotherapy (CRT) and to determine its role in predicting response to treatment.

Efeito do tamoxifeno no perfil das proteínas plasmáticas em condição de diabetes mellitus tipo 1 Effect of tamoxifen on plasma proteins in diabetes mellitus type 1

Directory of Open Access Journals (Sweden)

Teresa Cristina P. Silva

2005-01-01

Full Text Available OBJETIVO: Considerando-se que importantes avanços científicos têm sido obtidos através de estudos com Diabetes mellitus experimental, e que a ação do tamoxifeno em humanos permanece obscura, o presente trabalho objetiva acompanhar as modificações promovidas pelo diabetes e tamoxifeno no perfil eletroforético das proteínas plasmáticas. MÉTODOS: Foram utilizados 27 ratos fêmeas Wistar (180-220g peso corporal, divididos randomicamente em 5 grupos: C1 (n=3, receberam veículo, C2 (n=3, sem tratamento, T (n=5, tratados com tamoxifeno, 0,3mg/kg/dia, D (n=8, diabéticos experimentais por estreptozotocina, 45mg/Kg e DT (n=8, diabéticos tratados com tamoxifeno. A eletroforese foi realizada em acetato de celulose, pH 8,6-8,8, cuba TECNOW, e as fitas foram coradas em Ponceau S. As proteínas totais foram determinadas pelo método do Biureto (Kit Labtest. Os proteinogramas foram obtidos em densitômetro BioSystems BTS-235. RESULTADOS: Albumina diminuiu progressivamente nos grupos T, D e DT; a fração a1 aumentou nos grupos T e DT; a fração a2 aumentou nos grupos T e D, havendo efeito aditivo no grupo DT; a fração b aumentou nos grupos T e D; a fração g aumentou nos grupos T, D e DT. CONCLUSÃO: Os resultados indicam uma resposta de fase aguda, com efeito aditivo do tamoxifeno e diabetes, sugerindo uma provável lesão hepática.PURPOSE: Considering that important scientific advances have been obtained through studies based on experimental Diabetes mellitus, and that tamoxifen action in humans remains unknown, the aim of the present work is to follow the modifications promoted by diabetes and tamoxifen in the electrophoretic profile of plasmatic proteins. METHODS: It was used 27 Wistar female rats (180-250 body weight, randomicaly divided into five groups: C1 (n=3, received vehicle, C2 (n=3, no treatment, T (n=5, treated with tamoxifen, 0.3mg/Kg/day, D (n=8, experimental diabetes by estreptozotocin, 45mg/Kg and DT (n=8, diabetic treated

Obesity and risk of recurrence or death after adjuvant endocrine therapy with letrozole or tamoxifen in the breast international group 1-98 trial

DEFF Research Database (Denmark)

Ewertz, Marianne; Gray, Kathryn P; Regan, Meredith M

2012-01-01

To examine the association of baseline body mass index (BMI) with the risk of recurrence or death in postmenopausal women with early-stage breast cancer receiving adjuvant tamoxifen or letrozole in the Breast International Group (BIG) 1-98 trial at 8.7 years of median follow-up....

Genetic pharmacotherapy as an early CNS drug development strategy: testing glutaminase inhibition for schizophrenia treatment in adult mice

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Susana eMingote

2016-01-01

Full Text Available Genetic pharmacotherapy is an early drug development strategy for the identification of novel CNS targets in mouse models prior to the development of specific ligands. Here for the first time, we have implemented this strategy to address the potential therapeutic value of a glutamate-based pharmacotherapy for schizophrenia involving inhibition of the glutamate recycling enzyme phosphate-activated glutaminase. Mice constitutively heterozygous for GLS1, the gene encoding glutaminase, manifest a schizophrenia resilience phenotype, a key dimension of which is an attenuated locomotor response to propsychotic amphetamine challenge. If resilience is due to glutaminase deficiency in adulthood, then glutaminase inhibitors should have therapeutic potential. However, this has been difficult to test given the dearth of neuroactive glutaminase inhibitors. So, we used genetic pharmacotherapy to test the therapeutic potential of glutaminase inhibition. We specifically asked whether adult induction of GLS1 heterozygosity would attenuate amphetamine responsiveness. We generated conditional floxGLS1 mice and crossed them with global CAG ERT2 cre/+ mice to produce GLS1 iHET mice, susceptible to tamoxifen induction of GLS1 heterozygosity. One month after tamoxifen treatment of adult GLS1 iHET mice, we found a 50% reduction in GLS1 allelic abundance and glutaminase mRNA levels in the brain. While GLS1 iHET mice showed some recombination prior to tamoxifen, there was no impact on mRNA levels. We then asked whether induction of GLS heterozygosity would attenuate the locomotor response to propsychotic amphetamine challenge. Before tamoxifen, control and GLS1 iHET mice did not differ in their response to amphetamine. One month after tamoxifen treatment, amphetamine-induced hyperlocomotion was blocked in GLS1 iHET mice. The block was largely maintained after 5 months. Thus, a genetically induced glutaminase reduction — mimicking pharmacological inhibition — strongly

5-year follow-up of a randomized controlled trial of immediate versus delayed zoledronic acid for the prevention of bone loss in postmenopausal women with breast cancer starting letrozole after tamoxifen: N03CC (Alliance) trial.

Science.gov (United States)

Wagner-Johnston, Nina D; Sloan, Jeff A; Liu, Heshan; Kearns, Ann E; Hines, Stephanie L; Puttabasavaiah, Suneetha; Dakhil, Shaker R; Lafky, Jacqueline M; Perez, Edith A; Loprinzi, Charles L

2015-08-01

Postmenopausal women with breast cancer receiving aromatase inhibitors are at an increased risk of bone loss. The current study was undertaken to determine whether upfront versus delayed treatment with zoledronic acid (ZA) impacted bone loss. This report described the 5-year follow-up results. A total of 551 postmenopausal women with breast cancer who completed tamoxifen treatment and were undergoing daily letrozole treatment were randomized to either upfront (274 patients) or delayed (277 patients) ZA at a dose of 4 mg intravenously every 6 months. In the patients on the delayed treatment arm, ZA was initiated for a postbaseline bone mineral density T-score of prevented bone loss compared with delayed treatment in postmenopausal women receiving letrozole and these differences were maintained at 5 years. The incidence of osteoporosis or fractures was not found to be significantly different between treatment arms. © 2015 American Cancer Society.

Drug: D04672 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available r ... DG01619 ... Clomifene and tamoxifen derivative ... DG01620 ... Tamoxifene-type antineoplastic ... DG01621 ... Cloimife...ne-type osteoporosis agent ATC code: G03XC03 ... Clomifene, tamoxifen derivative Treatment and prevention of o

Prognostic and predictive importance of the estrogen receptor coactivator AIB1 in a randomized trial comparing adjuvant letrozole and tamoxifen therapy in postmenopausal breast cancer

DEFF Research Database (Denmark)

Alkner, S; Jensen, Maj-Britt Raaby; Rasmussen, B B

2017-01-01

PURPOSE: To evaluate the estrogen receptor coactivator amplified in breast cancer 1 (AIB1) as a prognostic marker, as well as a predictive marker for response to adjuvant tamoxifen and/or aromatase inhibitors, in early estrogen receptor-positive breast cancer. METHOD: AIB1 was analyzed...... with immunohistochemistry in tissue microarrays of the Danish subcohort (N = 1396) of the International Breast Cancer Study Group's trial BIG 1-98 (randomization between adjuvant tamoxifen versus letrozole versus the sequence of the two drugs). RESULTS: Forty-six percent of the tumors had a high AIB1 expression. In line...... with previous studies, AIB1 correlated to a more aggressive tumor-phenotype (HER2 amplification and a high malignancy grade). High AIB1 also correlated to higher estrogen receptor expression (80-100 vs. 1-79%), and ductal histological type. High AIB1 expression was associated with a poor disease-free survival...

The evaluation of in vitro effect of daunorubicin and tamoxifen in ehrlich ascites tumour (EAT) cells

International Nuclear Information System (INIS)

Topcul, M.; Topcul, F.; Oezalpan, A.

2001-01-01

In the most countries, breast cancer is still the most important cancer among women. It is known that Ehrlich Ascites Tumour is experimental breast cancer model in animal. The cells used in the study are hyper diploid line of Ehrlich Ascites Tumour (EAT) cells, initially provided to us from Institute of Pathology, Koln University. In the present study, an hyper diploid line which is estrogen receptor positive was used. An anthracycline-derived antibiotic, Daunorubicin (DNR, Cerubidine) is one of the clinically used anticancer drugs. DNR has been used alone or in combination with other cytotoxic agents against a variety of animal and human tumours. In vitro cell culture studies show that DNR enters the cell nuclei, inhibits nucleic acid synthesis, and arrest cell division. Tamoxifen (TAM, Nolvadex) is a semi-synthetical estrogen antagonist, used in the management of pre and post menopausal breast cancer. This drug bind to intracellular estrogen receptors, and prevents endogenous estrogens from binding to their own receptors. It is known that Ehrlich Ascites Tumour is experimental breast cancer model in animal. The cells used in the study are hyper diploid line of EAT cells initially provided to us from Institute of Pathology, Koln University. In the present study, an hyper diploid line which is Estrogen Receptor (+) was used. Estrogen Receptor levels were studied by the methods of Lippman and Huff and Raynaud et al. with minor modifications. Estrogen Receptor activity as demonstrated by dextran-coated charcoal technique is closely correlated with the clinical ability of Tamoxifen to inhibit tumour growth

The impact of tamoxifen on breast recurrence, cosmesis, complications, and survival in estrogen receptor positive early stage breast cancer

International Nuclear Information System (INIS)

Fowble, B.; Fein, D.A.; Hanlon, A.L.; Eisenberg, B.L.; Hoffman, J.P.; Sigurdson, E.R.; Daly, M.B.; Goldstein, L.J.

1995-01-01

) and positive axillary nodes (4% tam vs 21% no tam, p=.08). For patients with negative axillary nodes the 5 yr act breast recurrence rates were 6% tam vs 7% no tam (p=.29). Tamoxifen did not result in a decreased 5 year act. breast recurrence rate in patients who had a reexcision (5% tam vs 3% no tam, p=.91), or women ≤50 years of age (17% tam vs 13% no tam, p=.59). The 5 year act. cause-specific survival was 89% with tam and 94% without tam for the axillary node negative patients (p=.29). For the axillary node positive patients, the 5 year act. cause-specific survival was 90% with tam compared to 70% without tam. Cosmesis (physician assessment) was good-excellent in 85% of the tam patients compared to 88% of the no tam patients. For patients receiving radiation to the breast only, cosmesis was good-excellent in 84% of the tam patients and 87% of the no tam patients. For patients receiving treatment to the breast and regional nodes, 86% of the tam patients had a good to excellent cosmetic result compared to 92% of the no tam patients. Breast edema was more common in the patients receiving tam (49% tam vs 31% no tam). There was a slight increase in the incidence of breast cellulitis in the patients receiving tam (3% tam vs 1% no tam). Tamoxifen did not increase the incidence of arm edema, rib fracture, or symptomatic pneumonitis. Conclusion: Overall, tamoxifen results in a decreased risk of breast recurrence at 5 and 8 years, however, the benefit was no longer observed at 9 years. This finding suggests that tam may delay rather than prevent a breast recurrence in patients undergoing conservative surgery and radiation. Patients who appeared to benefit most in terms of a diminished risk of breast recurrence at 5 yrs from the addition of tam were those with no reexcision, unknown or close margins and positive axillary nodes. There was no decrease in breast recurrence with tam for patients ≤50 years of age or those who had a reexcision. There was an improvement in cause

The impact of tamoxifen on breast recurrence, cosmesis, complications, and survival in estrogen receptor positive early stage breast cancer

Energy Technology Data Exchange (ETDEWEB)

Fowble, B; Fein, D A; Hanlon, A L; Eisenberg, B L; Hoffman, J P; Sigurdson, E R; Daly, M B; Goldstein, L J

1995-07-01

) and positive axillary nodes (4% tam vs 21% no tam, p=.08). For patients with negative axillary nodes the 5 yr act breast recurrence rates were 6% tam vs 7% no tam (p=.29). Tamoxifen did not result in a decreased 5 year act. breast recurrence rate in patients who had a reexcision (5% tam vs 3% no tam, p=.91), or women {<=}50 years of age (17% tam vs 13% no tam, p=.59). The 5 year act. cause-specific survival was 89% with tam and 94% without tam for the axillary node negative patients (p=.29). For the axillary node positive patients, the 5 year act. cause-specific survival was 90% with tam compared to 70% without tam. Cosmesis (physician assessment) was good-excellent in 85% of the tam patients compared to 88% of the no tam patients. For patients receiving radiation to the breast only, cosmesis was good-excellent in 84% of the tam patients and 87% of the no tam patients. For patients receiving treatment to the breast and regional nodes, 86% of the tam patients had a good to excellent cosmetic result compared to 92% of the no tam patients. Breast edema was more common in the patients receiving tam (49% tam vs 31% no tam). There was a slight increase in the incidence of breast cellulitis in the patients receiving tam (3% tam vs 1% no tam). Tamoxifen did not increase the incidence of arm edema, rib fracture, or symptomatic pneumonitis. Conclusion: Overall, tamoxifen results in a decreased risk of breast recurrence at 5 and 8 years, however, the benefit was no longer observed at 9 years. This finding suggests that tam may delay rather than prevent a breast recurrence in patients undergoing conservative surgery and radiation. Patients who appeared to benefit most in terms of a diminished risk of breast recurrence at 5 yrs from the addition of tam were those with no reexcision, unknown or close margins and positive axillary nodes. There was no decrease in breast recurrence with tam for patients {<=}50 years of age or those who had a reexcision. There was an improvement in

A multigene assay to predict recurrence of tamoxifen-treated, node-negative breast cancer.

Science.gov (United States)

Paik, Soonmyung; Shak, Steven; Tang, Gong; Kim, Chungyeul; Baker, Joffre; Cronin, Maureen; Baehner, Frederick L; Walker, Michael G; Watson, Drew; Park, Taesung; Hiller, William; Fisher, Edwin R; Wickerham, D Lawrence; Bryant, John; Wolmark, Norman

2004-12-30

The likelihood of distant recurrence in patients with breast cancer who have no involved lymph nodes and estrogen-receptor-positive tumors is poorly defined by clinical and histopathological measures. We tested whether the results of a reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay of 21 prospectively selected genes in paraffin-embedded tumor tissue would correlate with the likelihood of distant recurrence in patients with node-negative, tamoxifen-treated breast cancer who were enrolled in the National Surgical Adjuvant Breast and Bowel Project clinical trial B-14. The levels of expression of 16 cancer-related genes and 5 reference genes were used in a prospectively defined algorithm to calculate a recurrence score and to determine a risk group (low, intermediate, or high) for each patient. Adequate RT-PCR profiles were obtained in 668 of 675 tumor blocks. The proportions of patients categorized as having a low, intermediate, or high risk by the RT-PCR assay were 51, 22, and 27 percent, respectively. The Kaplan-Meier estimates of the rates of distant recurrence at 10 years in the low-risk, intermediate-risk, and high-risk groups were 6.8 percent (95 percent confidence interval, 4.0 to 9.6), 14.3 percent (95 percent confidence interval, 8.3 to 20.3), and 30.5 percent (95 percent confidence interval, 23.6 to 37.4). The rate in the low-risk group was significantly lower than that in the high-risk group (P<0.001). In a multivariate Cox model, the recurrence score provided significant predictive power that was independent of age and tumor size (P<0.001). The recurrence score was also predictive of overall survival (P<0.001) and could be used as a continuous function to predict distant recurrence in individual patients. The recurrence score has been validated as quantifying the likelihood of distant recurrence in tamoxifen-treated patients with node-negative, estrogen-receptor-positive breast cancer. Copyright 2004 Massachusetts Medical Society.

[Rare cause for severe hypertriglyceridemia - case 9/2013].

Science.gov (United States)

Kahl, Sabine; Roden, Michael; Mörike, Klaus; Müssig, Karsten

2013-11-01

We report on a 48-year-old female patient with recently developed severe hypertriglyceridemia. Medical history was remarkable for breast cancer with breast-preserving surgery and chemoradiotherapy. The patient has been treated with 20 mg tamoxifen per day for three months. Laboratory results showed hypertriglyeridemia, hypercholesterolemia and lowered HDL-cholesterol. Findings were consistent with a drug-induced hypertriglyceridemia caused by anti-estrogenic therapy with tamoxifen. After consulting the patient's gynaecologist, we discontinued tamoxifen treatment. Thereupon, triglyceride levels fell consistently. There were no signs of pancreatitis, serum amylase and lipase were in the normal range. Patients with pre-diagnosed metabolic disorders, especially dyslipidemia and type 2 diabetes, should undergo regular controls of serum triglycerides during tamoxifen treatment. Also, one should keep in mind that a subacute, severe rise in serum triglyceride levels may be caused, in rare cases, by tamoxifen treatment. © Georg Thieme Verlag KG Stuttgart · New York.

Celecoxib alleviates tamoxifen-instigated angiogenic effects by ROS-dependent VEGF/VEGFR2 autocrine signaling

International Nuclear Information System (INIS)

Kumar, B N Prashanth; Rajput, Shashi; Dey, Kaushik Kumar; Parekh, Aditya; Das, Subhasis; Mazumdar, Abhijit; Mandal, Mahitosh

2013-01-01

Tamoxifen (TAM) is widely used in the chemotherapy of breast cancer and as a preventive agent against recurrence after surgery. However, extended TAM administration for breast cancer induces increased VEGF levels in patients, promoting new blood vessel formation and thereby limiting its efficacy. Celecoxib (CXB), a selective COX-2 inhibitor, suppresses VEGF gene expression by targeting the VEGF promoter responsible for its inhibitory effect. For this study, we had selected CXB as non-steroidal anti-inflammatory drug in combination with TAM for suppressing VEGF expression and simultaneously reducing doses of both the drugs. The effects of CXB combined with TAM were examined in two human breast cancer cell lines in culture, MCF7 and MDA-MB-231. Assays of proliferation, apoptosis, angiogenesis, metastasis, cell cycle distribution, and receptor signaling were performed. Here, we elucidated how the combination of TAM and CXB at nontoxic doses exerts anti-angiogenic effects by specifically targeting VEGF/VEGFR2 autocrine signaling through ROS generation. At the molecular level, TAM-CXB suppresses VHL-mediated HIF-1α activation, responsible for expression of COX-2, MMP-2 and VEGF. Besides low VEGF levels, TAM-CXB also suppresses VEGFR2 expression, confirmed through quantifying secreted VEGF levels, luciferase and RT-PCR studies. Interestingly, we observed that TAM-CXB was effective in blocking VEGFR2 promoter induced expression and further 2 fold decrease in VEGF levels was observed in combination than TAM alone in both cell lines. Secondly, TAM-CXB regulated VEGFR2 inhibits Src expression, responsible for tumor progression and metastasis. FACS and in vivo enzymatic studies showed significant increase in the reactive oxygen species upon TAM-CXB treatment. Taken together, our experimental results indicate that this additive combination shows promising outcome in anti-metastatic and apoptotic studies. In a line, our preclinical studies evidenced that this additive

Phytoestrogens in menopausal supplements induce ER-dependent cell proliferation and overcome breast cancer treatment in an in vitro breast cancer model

International Nuclear Information System (INIS)

Duursen, Majorie B.M. van; Smeets, Evelien E.J.W.; Rijk, Jeroen C.W.; Nijmeijer, Sandra M.; Berg, Martin van den

2013-01-01

Breast cancer treatment by the aromatase inhibitor Letrozole (LET) or Selective Estrogen Receptor Modulator Tamoxifen (TAM) can result in the onset of menopausal symptoms. Women often try to relieve these symptoms by taking menopausal supplements containing high levels of phytoestrogens. However, little is known about the potential interaction between these supplements and breast cancer treatment, especially aromatase inhibitors. In this study, interaction of phytoestrogens with the estrogen receptor alpha and TAM action was determined in an ER-reporter gene assay (BG1Luc4E2 cells) and human breast epithelial tumor cells (MCF-7). Potential interactions with aromatase activity and LET were determined in human adrenocorticocarcinoma H295R cells. We also used the previously described H295R/MCF-7 co-culture model to study interactions with steroidogenesis and tumor cell proliferation. In this model, genistein (GEN), 8-prenylnaringenin (8PN) and four commercially available menopausal supplements all induced ER-dependent tumor cell proliferation, which could not be prevented by physiologically relevant LET and 4OH-TAM concentrations. Differences in relative effect potencies between the H295R/MCF-7 co-culture model and ER-activation in BG1Luc4E2 cells, were due to the effects of the phytoestrogens on steroidogenesis. All tested supplements and GEN induced aromatase activity, while 8PN was a strong aromatase inhibitor. Steroidogenic profiles upon GEN and 8PN exposure indicated a strong inhibitory effect on steroidogenesis in H295R cells and H295R/MCF-7 co-cultures. Based on our in vitro data we suggest that menopausal supplement intake during breast cancer treatment should better be avoided, at least until more certainty regarding the safety of supplemental use in breast cancer patients can be provided. - Highlights: • Supplements containing phytoestrogens are commonly used by women with breast cancer. • Phytoestrogens alter steroidogenesis in a co-culture breast

Phytoestrogens in menopausal supplements induce ER-dependent cell proliferation and overcome breast cancer treatment in an in vitro breast cancer model

Energy Technology Data Exchange (ETDEWEB)

Duursen, Majorie B.M. van, E-mail: M.vanDuursen@uu.nl [Endocrine Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, PO Box 80177, 3508 TD, Utrecht (Netherlands); Smeets, Evelien E.J.W. [Endocrine Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, PO Box 80177, 3508 TD, Utrecht (Netherlands); Rijk, Jeroen C.W. [RIKILT - Institute for Food Safety, Wageningen UR, P.O. Box 230, 6700 AE, Wageningen (Netherlands); Nijmeijer, Sandra M.; Berg, Martin van den [Endocrine Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, PO Box 80177, 3508 TD, Utrecht (Netherlands)

2013-06-01

Breast cancer treatment by the aromatase inhibitor Letrozole (LET) or Selective Estrogen Receptor Modulator Tamoxifen (TAM) can result in the onset of menopausal symptoms. Women often try to relieve these symptoms by taking menopausal supplements containing high levels of phytoestrogens. However, little is known about the potential interaction between these supplements and breast cancer treatment, especially aromatase inhibitors. In this study, interaction of phytoestrogens with the estrogen receptor alpha and TAM action was determined in an ER-reporter gene assay (BG1Luc4E2 cells) and human breast epithelial tumor cells (MCF-7). Potential interactions with aromatase activity and LET were determined in human adrenocorticocarcinoma H295R cells. We also used the previously described H295R/MCF-7 co-culture model to study interactions with steroidogenesis and tumor cell proliferation. In this model, genistein (GEN), 8-prenylnaringenin (8PN) and four commercially available menopausal supplements all induced ER-dependent tumor cell proliferation, which could not be prevented by physiologically relevant LET and 4OH-TAM concentrations. Differences in relative effect potencies between the H295R/MCF-7 co-culture model and ER-activation in BG1Luc4E2 cells, were due to the effects of the phytoestrogens on steroidogenesis. All tested supplements and GEN induced aromatase activity, while 8PN was a strong aromatase inhibitor. Steroidogenic profiles upon GEN and 8PN exposure indicated a strong inhibitory effect on steroidogenesis in H295R cells and H295R/MCF-7 co-cultures. Based on our in vitro data we suggest that menopausal supplement intake during breast cancer treatment should better be avoided, at least until more certainty regarding the safety of supplemental use in breast cancer patients can be provided. - Highlights: • Supplements containing phytoestrogens are commonly used by women with breast cancer. • Phytoestrogens alter steroidogenesis in a co-culture breast

Breast conservation treatment of early stage breast cancer: patterns of failure

Energy Technology Data Exchange (ETDEWEB)

Leborgne, Felix; Leborgne, Jose H; Ortega, Bettys; Doldan, Raquel; Zubizarreta, Eduardo

1995-02-15

Purpose: This study retrospectively assesses the patterns of failure in conservatively treated early stage breast cancer patients by correlating various clinical, pathologic, and treatment-related factors with local, axillary, and distant relapse. Methods and Materials: Between 1973 and 1990, 796 patients (817 breasts) received breast conservation surgery followed by radiotherapy. Local recurrences were counted as events even if they occurred simultaneously or after the appearance of axillary or distant metastases. Results: The 10-year actuarial relative disease-free survival (DFS) rate for T1N0, T2N0, and T1-2N1 was 82%, 71%, and 54%, respectively. Stage N0 patients had a significant DFS advantage over N1 patients (p = 0.02). The 15-year actuarial local recurrence-free rate for T1 and T2 tumors was 82% and 87%, respectively (p = nonsignificant). Univariate analysis identified three significant risk factors for local relapse: (a) 48 breasts with tumors showing an extensive intraductal component had a crude local recurrence rate of 23% compared to 8% for 769 breasts without intraductal component (p 0.0016); (b) the actuarial 10-year local recurrence-free rate for patients under age 40 years was 64% compared to 88% for patients over 40 years (p < 0.0001); (c) the 10-year actuarial local recurrence-free rate for 416 postmenopausal women without adjuvant tamoxifen was 83% compared to 97% for 107 postmenopausal women with tamoxifen (p = 0.0479). Salvage therapy for operable local recurrent patients resulted in a 8-year actuarial DFS rate of 47%, significantly lower than that obtained with primary treatment. The incidence of axillary relapse as the first sign of recurrence was 2%, and could be correlated with the lack of axillary dissection (p < 0.0000005) and primary tumor size (p = 0.03). Radiotherapy to the axilla did not influence axillary relapse. Actuarial 5-year DFS rate after treatment of isolated axillary recurrence was 27%. Axillary failure was a marker for

Breast conservation treatment of early stage breast cancer: patterns of failure

International Nuclear Information System (INIS)

Leborgne, Felix; Leborgne, Jose H.; Ortega, Bettys; Doldan, Raquel; Zubizarreta, Eduardo

1995-01-01

Purpose: This study retrospectively assesses the patterns of failure in conservatively treated early stage breast cancer patients by correlating various clinical, pathologic, and treatment-related factors with local, axillary, and distant relapse. Methods and Materials: Between 1973 and 1990, 796 patients (817 breasts) received breast conservation surgery followed by radiotherapy. Local recurrences were counted as events even if they occurred simultaneously or after the appearance of axillary or distant metastases. Results: The 10-year actuarial relative disease-free survival (DFS) rate for T1N0, T2N0, and T1-2N1 was 82%, 71%, and 54%, respectively. Stage N0 patients had a significant DFS advantage over N1 patients (p = 0.02). The 15-year actuarial local recurrence-free rate for T1 and T2 tumors was 82% and 87%, respectively (p = nonsignificant). Univariate analysis identified three significant risk factors for local relapse: (a) 48 breasts with tumors showing an extensive intraductal component had a crude local recurrence rate of 23% compared to 8% for 769 breasts without intraductal component (p 0.0016); (b) the actuarial 10-year local recurrence-free rate for patients under age 40 years was 64% compared to 88% for patients over 40 years (p < 0.0001); (c) the 10-year actuarial local recurrence-free rate for 416 postmenopausal women without adjuvant tamoxifen was 83% compared to 97% for 107 postmenopausal women with tamoxifen (p = 0.0479). Salvage therapy for operable local recurrent patients resulted in a 8-year actuarial DFS rate of 47%, significantly lower than that obtained with primary treatment. The incidence of axillary relapse as the first sign of recurrence was 2%, and could be correlated with the lack of axillary dissection (p < 0.0000005) and primary tumor size (p = 0.03). Radiotherapy to the axilla did not influence axillary relapse. Actuarial 5-year DFS rate after treatment of isolated axillary recurrence was 27%. Axillary failure was a marker for

Update of the BIG 1-98 Trial: where do we stand?

Science.gov (United States)

Joerger, Markus; Thürlimann, Beat

2009-10-01

There is accumulating data on the clinical benefit of aromatase inhibitors in the adjuvant treatment of early-stage breast cancer in postmenopausal women. The Breast International Group (BIG) 1-98 study is a randomized, phase 3, double-blind trial comparing four adjuvant endocrine treatments of 5 years duration in postmenopausal women with hormone-receptor-positive breast cancer: letrozole or tamoxifen monotherapy, sequential treatment with tamoxifen followed by letrozole, or vice versa. This article summarizes data presented at the 2009 St. Gallen early breast cancer conference: an update on the monotherapy arms of the BIG 1-98 study, and results from the sequential treatment arms. Implications for daily practice from BIG 1-98 and from other adjuvant trials will be discussed. Despite cross-over from tamoxifen to letrozole by 25% of the patients after unblinding of the tamoxifen monotherapy arm, the improvement of disease-free survival (HR 0.88, 0.78-0.99, p = 0.03) and time to distant recurrence (HR 0.85, 0.72-1.00, p = 0.05) for letrozole monotherapy as compared to tamoxifen monotherapy remained significant in the intention-to-treat (ITT) analysis. A trend for an overall survival advantage for letrozole was seen in the ITT analysis (HR 0.87, 0.75-1.02, p = 0.08). No statistically significant differences were found for the sequential treatment arms versus letrozole monotherapy, with respect to disease-free survival, time to distant recurrence or overall survival. Cumulative incidence analysis of breast cancer recurrence favors the initiation of adjuvant endocrine treatment with letrozole instead of tamoxifen, especially in patients at higher risk for early recurrence. Similarly, data suggest that patients commenced on letrozole can be switched to tamoxifen after 2 years, if required. The BIG 1-98 study update with median follow up of 76 months confirms a significant reduction in the risk of breast cancer recurrence and a trend towards improved overall survival

Population pharmacokinetic modelling to assess the impact of CYP2D6 and CYP3A metabolic phenotypes on the pharmacokinetics of tamoxifen and endoxifen

NARCIS (Netherlands)

ter Heine, Rob; Binkhorst, Lisette; de Graan, Anne Joy M; de Bruijn, Peter; Beijnen, Jos H; Mathijssen, Ron H J; Huitema, Alwin D R

AIMS: Tamoxifen is considered a pro-drug of its active metabolite endoxifen. The major metabolic enzymes involved in endoxifen formation are CYP2D6 and CYP3A. There is considerable evidence that variability in activity of these enzymes influences endoxifen exposure and thereby may influence the

Relative Effectiveness of Letrozole Compared With Tamoxifen for Patients With Lobular Carcinoma in the BIG 1-98 Trial

DEFF Research Database (Denmark)

Metzger Filho, Otto; Giobbie-Hurder, Anita; Mallon, Elizabeth

2015-01-01

assigned onto the Breast International Group (BIG) 1-98 trial and who had centrally reviewed pathology data were included (N = 2,923). HER2-negative IDC and ILC were additionally classified as hormone receptor-positive with high (luminal B [LB] -like) or low (luminal A [LA] -like) proliferative activity......PURPOSE: To evaluate the relative effectiveness of letrozole compared with tamoxifen for patients with invasive ductal or lobular carcinoma. PATIENTS AND METHODS: Patients diagnosed with early-stage invasive ductal carcinoma (IDC) or classic invasive lobular carcinoma (ILC) who were randomly...

Avaliação da Atividade Proliferativa no Epitélio Mamário Adjacente a Fibroadenoma em Mulheres Tratadas com Tamoxifeno Evaluation of Proliferative Activity in the Mammary Epithelium Adjacent to Fibroadenoma in Women Treated with Tamoxifen

Directory of Open Access Journals (Sweden)

Juarez Antônio de Sousa

2000-08-01

Full Text Available Objetivo: estudar a atividade proliferativa do epitélio mamário normal adjacente a fibroadenoma em mulheres na fase lútea do ciclo menstrual, tratadas com tamoxifeno. Pacientes e Métodos: estudou-se por técnica imuno-histoquímica, com o uso do anticorpo monoclonal MIB-1, a atividade proliferativa no epitélio mamário adjacente a fibroadenoma. O estudo foi randomizado e duplo-cego. As 44 mulheres com fibroadenoma foram divididas em 3 grupos: A (n = 16; placebo, B (n = 15; tamoxifeno, 10 mg e C (n = 13; tamoxifeno, 20 mg. O tamoxifeno foi utilizado por 22 dias, a partir do 2º dia do ciclo menstrual, e a biópsia realizada no 23º dia. Resultados: a porcentagem média de núcleos corados por 1000 células no grupo A foi 9,2, no grupo B, 4,5, e no grupo C, 3,2. O teste de Fisher revelou que o tamoxifeno reduziu de forma significante a imunoexpressão do MIB-1 nas doses de 10 e 20 mg em comparação com o grupo placebo (pPurpose: to study the monoclonal antibody MIB-1 in the normal breast epithelium adjacent to a fibroadenoma in women in the luteal phase of the menstrual cycle treated with tamoxifen. Patients and methods: the proliferative activity of the mammary epithelium adjacent to the fibroadenoma was studied by immunohistochemistry based on immunoexpression of the monoclonal antibody MIB-1. The study was randomized and double blind and was conducted on 44 women with fibroadenomas, divided into 3 groups: A (n = 16; placebo, B (n = 15; tamoxifen, 10 mg, and C (n = 13; tamoxifen, 20 mg. Tamoxifen was administered for 22 days starting on the 2nd day of the menstrual cycle and a biopsy was taken on the 23rd day. Results: the mean percentage of stained nuclei per 1000 cells was 9.2 in group A, 4.5 in group B, and 3.2 in group C. Fisher's test revealed that tamoxifen significantly reduced the immunoexpression of MIB-1 at the doses of 10 and 20 mg compared to the placebo group (p<0.0001, with no significant differences between doses in terms of

Treatment of gynecomastia in patients with prostate cancer and androgen deprivation.

Science.gov (United States)

Bautista-Vidal, C; Barnoiu, O; García-Galisteo, E; Gómez-Lechuga, P; Baena-González, V

2014-01-01

Gynecomastia, defined as benign proliferation of glandular breast tissue has a prevalence of 32% to 72% in the male. In the urology setting, it is associated to patients with prostate cancer and hormone treatment with a prevalence of 15% in the case of complete hormone blockage and 75% in monotherapy. The different options of treatment in prostate cancer have changed in recent decades. Thus, we have focused on this subject to evaluate the different therapy options of hormone manipulation induced gynecomastia in prostate cancer patients. To synthesize the available evidence on the different therapeutic options in prostate cancer patients who develop gynecomastia due to the use of nonsteroidal antiandrogens and to generate a diagnostic algorithm and treatment. Using the PICO type structured search strategy (Patient or problem, Intervention, Comparison, Outcome or result) in the data bases of PubMed-Medline and Cochrane, identification was made of the relevant studies related to the treatment of gynecomastia in Prostate Cancer patients treated with nonsteroidal antiandrogens. We have found 3 possible therapeutic options for the treatment of gynecomastia and mastodynia in patients with hormone deprivation therapy for prostate cancer. The 10Gy radiotherapy would be an option for the treatment of gynecomastia, although not all the patients need prophylactic treatment since only 50% report moderate-severe discomfort. Another option is the use of drugs such as tamoxifen 20mg/day that lead to a significant decrease in the mammary effects. Gynecomastia and mastodynia, given their high incidence, make the physical examination a fundamental tool for all patients before initiating treatment with antiandrogens. The use of tamoxifen 20mg/day is the best treatment and prevention option against gynecomastia and mastodynia, while in the case of long-course established gynecomastia, surgery is the gold standard. Copyright © 2012 AEU. Published by Elsevier Espana. All rights reserved.

HER2 status predicts for upfront AI benefit: A TRANS-AIOG meta-analysis of 12,129 patients from ATAC, BIG 1-98 and TEAM with centrally determined HER2.

Science.gov (United States)

Bartlett, John M S; Ahmed, Ikhlaaq; Regan, Meredith M; Sestak, Ivana; Mallon, Elizabeth A; Dell'Orto, Patrizia; Thürlimann, Beat; Seynaeve, Caroline; Putter, Hein; Van de Velde, Cornelis J H; Brookes, Cassandra L; Forbes, John F; Viale, Giuseppe; Cuzick, Jack; Dowsett, Mitchell; Rea, Daniel W

2017-07-01

A meta-analysis of the effects of HER2 status, specifically within the first 2-3 years of adjuvant endocrine therapy, has the potential to inform patient selection for upfront aromatase inhibitor (AI) therapy or switching strategy tamoxifen followed by AI. The pre-existing standardisation of methodology for HER2 (immunohistochemistry/fluorescence in situ hybridization) facilitates analysis of existing data for this key marker. Following a prospectively designed statistical analysis plan, patient data from 3 phase III trials Arimidex, Tamoxifen, Alone or in Combination Trial (ATAC), Breast International Group (BIG) 1-98 and Tamoxifen Exemestane Adjuvant Multicentre Trial (TEAM)] comparing an AI to tamoxifen during the first 2-3 years of adjuvant endocrine treatment were collected and a treatment-by-marker analysis of distant recurrence-free interval-censored at 2-3 years treatment - for HER2 status × AI versus tamoxifen treatment was performed to address the clinical question relating to efficacy of 'upfront' versus 'switch' strategies for AIs. A prospectively planned, patient-level data meta-analysis across 3 trials demonstrated a significant treatment (AI versus tamoxifen) by marker (HER2) interaction in a multivariate analysis; (interaction hazard ratio [HR] = 1.61, 95% CI 1.01-2.57; p data meta-analysis demonstrated a significant interaction between HER2 status and treatment with AI versus tamoxifen in the first 2-3 years of adjuvant endocrine therapy. Patients with HER2-ve cancers experienced improved outcomes (distant relapse) when treated with upfront AI rather than tamoxifen, whilst patients with HER2+ve cancers fared no better or slightly worse in the first 2-3 years. However, the small number of HER2+ve cancers/events may explain a large degree of heterogeneity in the HER2+ve groups across all 3 trials. Other causes, perhaps related to subtle differences between AIs, cannot be excluded and warrant further exploration. Copyright © 2017 Elsevier Ltd

Optimized axolotl (Ambystoma mexicanum) husbandry, breeding, metamorphosis, transgenesis and tamoxifen-mediated recombination.

Science.gov (United States)

Khattak, Shahryar; Murawala, Prayag; Andreas, Heino; Kappert, Verena; Schuez, Maritta; Sandoval-Guzmán, Tatiana; Crawford, Karen; Tanaka, Elly M

2014-03-01

The axolotl (Mexican salamander, Ambystoma mexicanum) has become a very useful model organism for studying limb and spinal cord regeneration because of its high regenerative capacity. Here we present a protocol for successfully mating and breeding axolotls in the laboratory throughout the year, for metamorphosing axolotls by a single i.p. injection and for axolotl transgenesis using I-SceI meganuclease and the mini Tol2 transposon system. Tol2-mediated transgenesis provides different features and advantages compared with I-SceI-mediated transgenesis, and it can result in more than 30% of animals expressing the transgene throughout their bodies so that they can be directly used for experimentation. By using Tol2-mediated transgenesis, experiments can be performed within weeks (e.g., 5-6 weeks for obtaining 2-3-cm-long larvae) without the need to establish germline transgenic lines (which take 12-18 months). In addition, we describe here tamoxifen-induced Cre-mediated recombination in transgenic axolotls.

Carboplatin treatment of antiestrogen-resistant breast cancer cells

DEFF Research Database (Denmark)

Larsen, Mathilde S; Yde, Christina Westmose; Christensen, Ib J

2012-01-01

Antiestrogen resistance is a major clinical problem in current breast cancer treatment. Therefore, biomarkers and new treatment options for antiestrogen-resistant breast cancer are needed. In this study, we investigated whether antiestrogen‑resistant breast cancer cell lines have increased...... sensitivity to carboplatin, as it was previously shown with cisplatin, and whether low Bcl-2 expression levels have a potential value as marker for increased carboplatin sensitivity. Breast cancer cells resistant to the pure antiestrogen fulvestrant, and two out of four cell lines resistant...... to the antiestrogen tamoxifen, were more sensitive to carboplatin treatment compared to the parental MCF-7 cell line. This indicates that carboplatin may be an advantageous treatment in antiestrogen‑resistant breast cancer; however, a marker for increased sensitivity would be needed. Low Bcl-2 expression...

A nanomedicine based combination therapy based on QLPVM peptide functionalized liposomal tamoxifen and doxorubicin against Luminal A breast cancer.

Science.gov (United States)

Wang, Xiaoyou; Chen, Xianhui; Yang, Xiucong; Gao, Wei; He, Bing; Dai, Wenbing; Zhang, Hua; Wang, Xueqing; Wang, Jiancheng; Zhang, Xuan; Dai, Zhifei; Zhang, Qiang

2016-02-01

Though combination chemotherapy or antitumor nanomedicine is extensively investigated, their combining remains in infancy. Additionally, enhanced delivery of estrogen or its analogs to tumor with highly-expressed estrogen-receptor (ER) is seldom considered, despite its necessity for ER-positive breast cancer treatment. Here, nanomedicine based combination therapy using QLPVM conjugated liposomal tamoxifen (TAM) and doxorubicin (DOX) was designed and testified, where the penta-peptide was derived from Ku70 Bax-binding domain. Quantitative, semi-quantitative and qualitative approaches demonstrated the enhanced endocytosis and cytotoxicity of QLPVM conjugated sterically stabilized liposomes (QLPVM-SSLs) in vitro and in vivo. Mechanism studies of QLPVM excluded the possible electrostatic, hydrophobic or receptor-ligand interactions. However, as a weak cell-penetrating peptide, QLPVM significantly induced drug release from QLPVM-SSLs during their interaction with cells, which was favorable for drug internalization. These findings suggested that the nanomedicine based combination therapy using QLPVM-SSL-TAM and QLPVM-SSL-DOX might provide a rational strategy for Luminal A breast cancer. Breast cancer remains a leading cause of mortality in women worldwide. Although combined therapy using hormonal antagonist and chemotherapy is the norm nowadays, the use of these agents together in a single delivery system has not been tested. Here, the authors investigated this approach using QLPVM conjugated liposomes in in-vitro and in-vivo models. The positive findings may provide a novel direction for breast cancer treatment in the near future. Copyright © 2015 Elsevier Inc. All rights reserved.

CYP2D6 gene polymorphisms in Brazilian patients with breast cancer treated with adjuvant tamoxifen and its association with disease recurrence

Science.gov (United States)

De Ameida Melo, Mariella; De Vasconcelos-Valença, Rodrigo José; Neto, Fidelis Manes; Borges, Rafael Soares; Costa-Silva, Danylo Rafhael; Da Conceição Barros-Oliveira, Maria; Borges, Umbelina Soares; Alencar, Airlane Pereira; Silva, Vladimir Costa; Da Silva, Benedito Borges

2016-01-01

At present, there is controversy regarding the efficacy of tamoxifen in breast cancer patients who are carriers of cytochrome P450 2D6 (CYP2D6) gene polymorphisms, in terms of recurrence and overall survival. Thus, the aim of the present study was to investigate the association of the CYP2D6 *4, *10 and *17 gene polymorphisms with breast cancer recurrence in a Brazilian population. The cohort comprised 40 receptor-positive breast cancer patients without recurrence and 40 with distant recurrence. A 3-ml sample of peripheral blood was collected from each patient to determine the presence of the *4, *10 and *17 single nucleotide polymorphisms of the CYP2D6 gene by quantitative polymerase chain reaction analysis. There was no statistically significant difference between the two groups regarding the polymorphism frequency (P=0.246). The results revealed that intermediate metabolizers occurred in 5% of patients without recurrence and in 15% of those with distant recurrence. Poor metabolizers occurred in only 1 patient (2.5%) per group, and there was no significant difference between the groups (P=0.789). The present study concluded that the CYP2D6 gene polymorphism in women with hormone-sensitive breast cancer treated with tamoxifen was not associated with disease recurrence. PMID:27882219

Survival benefit of tamoxifen and aromatase inhibitor in male and female breast cancer.

Science.gov (United States)

Eggemann, Holm; Altmann, Udo; Costa, Serban-Dan; Ignatov, Atanas

2018-02-01

Our goal was to compare the survival advantage of tamoxifen (TAM) and aromatase inhibitor (AI) in female (FBC) and male breast cancer (MBC). We performed a retrospective study of 2785 FBC and 257 MBC patients treated with hormonal therapy. The median follow-up was 106 months (range 3-151 months) and 42 months (range 2-115 months) for FBC and MBC, respectively. The patients were divided into two groups according to the hormonal therapy used: TAM-treated and AI-treated. MBC was characterized by older age, advanced tumor stage, and higher rate of lymph node metastases, in comparison with FBC. Matching analysis was performed using six prognostic criteria: patient age, tumor stage, tumor grade, lymph node status, human epidermal growth factor receptor (HER2) status, and administration of chemotherapy. The female and male patients were matched 2:1. In this analysis, 316 women and 158 men treated with TAM, and 60 women and 30 men treated with AI, were included. The overall survival (OS) was estimated by the Kaplan-Meier method and was compared between FBC and MBC. TAM-treated FBC and MBC patients had similar 5-year OS, 85.1 and 89.2%, respectively (p = 0.972). Notably, FBC patients treated with AI had significantly greater 5-year OS (85.0%) in comparison with AI-treated MBC patients (5-year OS of 73.3%; p = 0.028). The OS of TAM-treated patients with MBC was similar to the OS of TAM-treated FBC patients, whereas AI treatment is associated with poorer survival of MBC patients.

The alterations of serum FGF-21 levels, metabolic and body composition in early breast cancer patients receiving adjuvant endocrine therapy.

Science.gov (United States)

Akyol, Murat; Alacacioglu, Ahmet; Demir, Leyla; Kucukzeybek, Yuksel; Yildiz, Yasar; Gumus, Zehra; Kara, Mete; Salman, Tarik; Varol, Umut; Taskaynatan, Halil; Oflazoglu, Utku; Bayoglu, Vedat; Tarhan, Mustafa Oktay

2017-01-01

In early breast cancer patients, the effects of hormonal therapy (tamoxifen and aromatase inhibitors) on plasma fibroblast growth factor 21 (FGF-21), lipid levels and body composition have not yet been investigated. Therefore, we aimed to analyze the relationship between FGF-21 and body composition as well as the effects of tamoxifen and aromatase inhibitors on plasma lipid levels, FGF-21, and body composition. A total of 72 patients were treated with either tamoxifen or aromatase inhibitors due to their menopausal status after adjuvant radiotherapy. Each patient was followed-up over a period of 1 year. Changes in body composition and serum lipid profile, glucose and FGF-21 levels were evaluated. We recorded the type of hormonal therapy, body mass index, waist-to-hip ratio, lipid profile, and FGF-21 levels both at the beginning and after 12 months. There was a statistically significant decrease in serum FGF-21 levels after 12 months of adjuvant endocrine therapy (46 ± 19.21 pg/ml vs. 30.99 ± 13.81 pg/ml, pbody water (pbody composition, glucose, lipid profile and FGF-21 were similar in tamoxifen and aromatase inhibitor groups. A positive correlation was found between basal weight, fat mass, fat-free mass and serum FGF-21 levels; however, the correlation was maintained only for the fat-free mass at the 12th month. As part of the present study, we suggest that both tamoxifen and aromatase inhibitors can reduce FGF-21 levels independently of body compositions, and these drugs can provide antihyperlipidemic, antidiabetic and cardio-protective effects. We also recommend that serum FGF-21 level can be utilized as a tumor biomarker in early-stage breast cancer and for monitoring purposes. FGF-21 levels may help physicians estimate prognosis, too. Further studies with larger populations may shed light on the role of FGF-21 in breast cancer.

Anti-cancer potential of a mix of natural extracts of turmeric, ginger and garlic: A cell-based study

Directory of Open Access Journals (Sweden)

Satish Kumar Vemuri

2017-12-01

Full Text Available Cancer related morbidity and mortality is a major health care concern. Developing potent anti-cancer therapies which are non-toxic, sustainable and affordable is of alternative medicine. This study was designed to investigate the aqueous natural extracts mixture (NE mix prepared from common spices turmeric, ginger and garlic for its free radical scavenging potential and anti-cancer property against human breast cancer cell lines (MCF-7, ZR-75 and MDA-MB 231. Qualitative analysis of their bioactive constituents from turmeric, ginger and garlic were done using liquid chromatography-ESI- mass spectrometry (LC-ESI-MS/MS. To the best of our knowledge, NE mix with and without Tamoxifen has not been tested for its anti-cancer potential. We observed that the NE mix induced apoptosis in all the breast cancer cell lines, but it was more prominent in MCF-7 and ZR-75 cell lines in comparison to MDA-MB 231 cell line. The extent of apoptosis due to combined treatment with NE mix-Tamoxifen was higher than Tamoxifen alone, indicating a potential role of the NE mix in sensitizing the ER-positive breast cancer cells towards Tamoxifen. In support to MTT assay, cell cycle analysis, our RT-PCR results also prove that the NE mix 10 μg, Tam 20 μg and combination of NE mix 10 μg-Tam 20 μg altered the expression of apoptotic markers (p53 and Caspase 9 leading to apoptosis in all three cell lines. Our data strongly indicate that our NE mixture is a potential alternative therapeutic approach in certain types of cancer. Keywords: Breast cancer, Antagonists, Natural extracts, Tamoxifen, Turmeric, Ginger, Garlic, LC-ESI-MS/MS

Chronic clenbuterol treatment compromises force production without directly altering skeletal muscle contractile machinery

Science.gov (United States)

Py, G; Ramonatxo, C; Sirvent, P; Sanchez, A M J; Philippe, A G; Douillard, A; Galbès, O; Lionne, C; Bonnieu, A; Chopard, A; Cazorla, O; Lacampagne, A; Candau, R B

2015-01-01

Clenbuterol is a β2-adrenergic receptor agonist known to induce skeletal muscle hypertrophy and a slow-to-fast phenotypic shift. The aim of the present study was to test the effects of chronic clenbuterol treatment on contractile efficiency and explore the underlying mechanisms, i.e. the muscle contractile machinery and calcium-handling ability. Forty-three 6-week-old male Wistar rats were randomly allocated to one of six groups that were treated with either subcutaneous equimolar doses of clenbuterol (4 mg kg−1 day−1) or saline solution for 9, 14 or 21 days. In addition to the muscle hypertrophy, although an 89% increase in absolute maximal tetanic force (Po) was noted, specific maximal tetanic force (sPo) was unchanged or even depressed in the slow twitch muscle of the clenbuterol-treated rats (P muscle contraction and relaxation force kinetics indicated that clenbuterol treatment significantly reduced the rate constant of force development and the slow and fast rate constants of relaxation in extensor digitorum longus muscle (P fast rate constant of relaxation in soleus muscle (P fibres (fast twitch fibres) from clenbuterol-treated animals demonstrated decreased amplitude after 14 days (−19%, P < 0.01) and 21 days (−25%, P < 0.01). In conclusion, we showed that chronic clenbuterol treatment reduces contractile efficiency, with altered contraction and relaxation kinetics, but without directly altering the contractile machinery. Lower Ca2+ release during contraction could partially explain these deleterious effects. PMID:25656230

Apolipoprotein D expression does not predict breast cancer recurrence among tamoxifen-treated patients

DEFF Research Database (Denmark)

Klebaner, Daniella; Hamilton-Dutoit, Stephen; Ahern, Thomas P

2017-01-01

confounding using logistic regression. RESULTS: Cytoplasmic ApoD expression was seen in 68% of ER+ tumors, in 66% of ER- tumors, and in 66% of controls across both groups. In women with ER+ tumors, the associations of cytoplasmic ApoD expression with recurrence (OR = 1.0; 95% CI = 0.7 to 1.4) and increasing...... cytoplasmic expression with recurrence (OR = 1.0; 95% CI = 0.996 to 1.003) were null, as were those for women with ER- tumors. Associations for nuclear ApoD expression and combined nuclear and cytoplasmic expression were similarly near-null. CONCLUSION: ApoD expression is likely not a predictor of recurrence......BACKGROUND: Apolipoprotein D (ApoD) has been proposed as a predictor of breast cancer recurrence among estrogen receptor-positive (ER+), tamoxifen-treated patients. METHODS: We conducted a population-based case-control study nested in a population of 11,251 women aged 35-69 years at diagnosis...

Lumpectomy Plus Tamoxifen or Anastrozole With or Without Whole Breast Irradiation in Women With Favorable Early Breast Cancer

International Nuclear Information System (INIS)

Poetter, Richard; Gnant, Michael; Kwasny, Werner; Tausch, Christoph; Handl-Zeller, Leonore; Pakisch, Brigitte; Taucher, Susanne; Hammer, Josef; Luschin-Ebengreuth, Gero; Schmid, Marianne; Sedlmayer, Felix; Stierer, Michael; Reiner, Georg; Kapp, Karin; Hofbauer, Friedrich; Rottenfusser, Andrea; Poestlberger, Sabine; Haider, Karin; Draxler, Wolfgang; Jakesz, Raimund

2007-01-01

Purpose: In women with favorable early breast cancer treated by lumpectomy plus tamoxifen or anastrazole, it remains unclear whether whole breast radiotherapy is beneficial. Methods and Material: Between January 1996 and June 2004, the Austrian Breast and Colorectal Cancer Study Group (ABCSG) randomly assigned 869 women to receive breast radiotherapy ± boost (n 414) or not (n = 417) after breast-conserving surgery (ABCSG Study 8A). Favorable early breast cancer was specified as tumor size <3 cm, Grading 1 or 2, negative lymph nodes, positive estrogen and/or progesterone receptor status, and manageable by breast-conserving surgery. Breast radiotherapy was performed after lumpectomy with 2 tangential opposed breast fields with mean 50 Gy, plus boost in 71% of patients with mean 10 Gy, in a median of 6 weeks. The primary endpoint was local relapse-free survival; further endpoints were contralateral breast cancer, distant metastases, and disease-free and overall survival. The median follow-up was 53.8 months. Results: The mean age was 66 years. Overall, there were 21 local relapses, with 2 relapses in the radiotherapy group (5-y rate 0.4%) vs. 19 in the no-radiotherapy group (5.1%), respectively (p = 0.0001, hazard ratio 10.2). Overall relapses occurred in 30 patients, with 7 events in the radiotherapy group (5-y rate 2.1%) vs. 23 events in the no-radiotherapy group (6.1%) (p = 0.002, hazard ratio 3.5). No significant differences were found for distant metastases and overall survival. Conclusion: Breast radiotherapy ± boost in women with favorable early breast cancer after lumpectomy combined with tamoxifen/anastrazole leads to a significant reduction in local and overall relapse

Anti-inflammatory salicylate treatment alters the metabolic adaptations to lactation in dairy cattle

Science.gov (United States)

Farney, Jaymelynn K.; Mamedova, Laman K.; Coetzee, Johann F.; KuKanich, Butch; Sordillo, Lorraine M.; Stoakes, Sara K.; Minton, J. Ernest; Hollis, Larry C.

2013-01-01

Adapting to the lactating state requires metabolic adjustments in multiple tissues, especially in the dairy cow, which must meet glucose demands that can exceed 5 kg/day in the face of negligible gastrointestinal glucose absorption. These challenges are met through the process of homeorhesis, the alteration of metabolic setpoints to adapt to a shift in physiological state. To investigate the role of inflammation-associated pathways in these homeorhetic adaptations, we treated cows with the nonsteroidal anti-inflammatory drug sodium salicylate (SS) for the first 7 days of lactation. Administration of SS decreased liver TNF-α mRNA and marginally decreased plasma TNF-α concentration, but plasma eicosanoids and liver NF-κB activity were unaltered during treatment. Despite the mild impact on these inflammatory markers, SS clearly altered metabolic function. Plasma glucose concentration was decreased by SS, but this was not explained by a shift in hepatic gluconeogenic gene expression or by altered milk lactose secretion. Insulin concentrations decreased in SS-treated cows on day 7 compared with controls, which was consistent with the decline in plasma glucose concentration. The revised quantitative insulin sensitivity check index (RQUICKI) was then used to assess whether altered insulin sensitivity may have influenced glucose utilization rate with SS. The RQUICKI estimate of insulin sensitivity was significantly elevated by SS on day 7, coincident with the decline in plasma glucose concentration. Salicylate prevented postpartum insulin resistance, likely causing excessive glucose utilization in peripheral tissues and hypoglycemia. These results represent the first evidence that inflammation-associated pathways are involved in homeorhetic adaptations to lactation. PMID:23678026

Measuring persistence to hormonal therapy in patients with breast cancer: accounting for temporary treatment discontinuation.

Science.gov (United States)

Huiart, Laetitia; Ferdynus, Cyril; Dell'Aniello, Sophie; Bakiri, Naciba; Giorgi, Roch; Suissa, Samy

2014-08-01

Several studies have been conducted to estimate persistence to hormonal therapy among women with breast cancer (BC). Most studies focus on first treatment discontinuation. Patients, however, can have numerous periods of treatment discontinuation or treatment exposure. Our objective is to estimate persistence to tamoxifen in patients with BC while accounting for temporary treatment discontinuations and this by using multi-state (MS) models. A cohort of 10,806 women with BC having received at least one prescription of tamoxifen between 1998 and 2008 was constituted from the UK General Practice Research Database. We fitted a semi-Markov model with three states to estimate the probability of being off treatment over a 5-year period while accounting for temporary treatment discontinuations (transition between on treatment and off treatment) and competing risks (recurrence of BC or death). Non-persistence, as estimated from the MS model, ranged from 12.1% (95% confidence interval [95%CI]: 9.2-15.1) at 1 year to 14.9% (95%CI: 11.7-18.1) at 5 years. Estimations of non-persistence based on the Kaplan-Meier model were higher, i.e., 29.3% (95%CI: 28.1-30.6) at 5 years, as well as those obtained from a competing risk model, i.e., 24.0% (95%CI: 22.9-25.1). Most temporary discontinuations (94.7%) lasted less than 6 months. Temporary treatment discontinuations are frequent and should be accounted for when measuring adherence to treatment. MS models can provide a useful framework for this sort of analysis insofar as they help describe patients' complex behavior. This may help tailor interventions that improve persistence to hormonal therapy among women with BC. Copyright © 2014 John Wiley & Sons, Ltd.

Cocaine abstinence following chronic treatment alters cerebral metabolism in dopaminergic reward regions. Bromocriptine enhances recovery

International Nuclear Information System (INIS)

Clow, D.W.; Hammer, R.P. Jr.

1991-01-01

2-[14C]deoxyglucose autoradiography was used to determine local cerebral glucose utilization (lCGU) in rats following chronic cocaine treatment and subsequent abstinence. lCGU was examined in 43 discrete brain regions in animals which had received daily injections of cocaine for 14 days (10 mg/kg) followed by 3 days of saline or bromocriptine (10 mg/kg) treatment. Cocaine abstinence following chronic treatment significantly reduced lCGU in several regions including mesocorticolimbic structures such as ventral tegmental area, medial prefrontal cortex, and nucleus accumbens (NAc). Within the NAc, however, only the rostral pole showed significant reduction. In contrast, when bromocriptine treatment accompanied abstinence, lCGU was no longer reduced in mesocorticolimbic and most other regions, implying that metabolic recovery was enhanced by bromocriptine treatment during early abstinence following chronic cocaine treatment. These data suggest that cerebral metabolism is decreased during cocaine abstinence following chronic treatment in critical brain regions, and that this alteration can be prevented by treatment with direct-acting dopamine agonists such as bromocriptine

Cocaine abstinence following chronic treatment alters cerebral metabolism in dopaminergic reward regions. Bromocriptine enhances recovery

Energy Technology Data Exchange (ETDEWEB)

Clow, D.W.; Hammer, R.P. Jr. (Univ. of Hawaii School of Medicine, Honolulu (USA))

1991-01-01

2-(14C)deoxyglucose autoradiography was used to determine local cerebral glucose utilization (lCGU) in rats following chronic cocaine treatment and subsequent abstinence. lCGU was examined in 43 discrete brain regions in animals which had received daily injections of cocaine for 14 days (10 mg/kg) followed by 3 days of saline or bromocriptine (10 mg/kg) treatment. Cocaine abstinence following chronic treatment significantly reduced lCGU in several regions including mesocorticolimbic structures such as ventral tegmental area, medial prefrontal cortex, and nucleus accumbens (NAc). Within the NAc, however, only the rostral pole showed significant reduction. In contrast, when bromocriptine treatment accompanied abstinence, lCGU was no longer reduced in mesocorticolimbic and most other regions, implying that metabolic recovery was enhanced by bromocriptine treatment during early abstinence following chronic cocaine treatment. These data suggest that cerebral metabolism is decreased during cocaine abstinence following chronic treatment in critical brain regions, and that this alteration can be prevented by treatment with direct-acting dopamine agonists such as bromocriptine.

Large-scale downy brome treatments alter plant-soil relationships and promote perennial grasses in salt desert shrublands

Science.gov (United States)

The interrelationship between invasive annual grass abundance and soil resource availability varies spatially and temporally within ecosystems and may be altered by land treatments. We evaluated these relationships in two salt desert landscapes where the local abundance of Bromus tectorum L. (downy...

Agonistic activity of tamoxifen, a selective estrogen-receptor modulator (SERM), on arthritic ovariectomized mice

Science.gov (United States)

Silva, L.A.S.; Felix, F.B.; Araujo, J.M.D.; Souza, E.V.; Camargo, E.A.; Grespan, R.

2017-01-01

Arthritis is positively associated with the decline of sex hormones, especially estrogen. Tamoxifen (TMX) is a selective estrogen receptor modulator, possessing agonist or antagonistic activity in different tissues. Thus, the objective of this study was to investigate the effect of TMX on the zymosan-induced arthritis model. Female Swiss normal and ovariectomized (OVX) mice were divided into groups and treated for five days with TMX (0.3, 0.9 or 2.7 mg/kg) or 17-β-estradiol (E2, 50 µg/kg). On the fifth day, arthritis was induced and 4 h later, leukocyte migration into joint cavities was evaluated. The neutrophil migration in OVX animals, but not in normal mice, treated with TMX (all tested doses) was significantly decreased compared with mice that received the vehicle (P≤0.05). Similarly, this effect was also demonstrated in the E2-treated group. Therefore, the present study demonstrates that TMX presented agonist effects in inhibiting neutrophil migration and preventing arthritis progression in OVX mice. PMID:29160416

Cytochrome P450 Bioconjugate as a Nanovehicle for Improved Chemotherapy Treatment.

Science.gov (United States)

Quester, Katrin; Juarez-Moreno, Karla; Secundino, Isamel; Roseinstein, Yvonne; Alejo, Karla P; Huerta-Saquero, Alejandro; Vazquez-Duhalt, Rafael

2017-05-01

Cancer is still a growing public health problem, especially breast cancer that is one of the most important cancers in women. Chemotherapy, even though a successful treatment, is accompanied by severe side effects. Moreover, most of the drugs used for chemotherapy are administered as prodrugs and need to be transformed to the active form by cytochromes P450 (CYPs). In addition, increasing numbers of cancer tissues show lower CYP activity than the surrounding healthy tissues in which prodrugs are preferentially activated causing cytotoxicity. Here, the design of a functionalized cytochrome P450 bioconjugate is reported as nanovehicle for the enzyme direct delivery to the tumor tissue in order to improve the local drug activation. MCF-7 breast cancer cells are treated with CYP-polyethylene glycol bioconjugate functionalized folic acid, where it activates the prodrug tamoxifen and significantly reduces the dose of tamoxifen needed to kill the tumor cells. The CYP bioconjugate covered with polyethylene glycol shows no immunogenic activity. The advantages of increasing the site-specific CYP activity in tumor tissues are discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Clinical utility of exemestane in the treatment of breast cancer 

Directory of Open Access Journals (Sweden)

Zucchini G

2015-05-01

Full Text Available Giorgia Zucchini,1 Elena Geuna,1 Andrea Milani,1 Caterina Aversa,2 Rossella Martinello,2 Filippo Montemurro1 1Investigative Clinical Oncology, Fondazione del Piemonte per l’Oncologia-Candiolo Cancer Institute (IRCCs, Candiolo, 2University of Turin Medical School, Turin, Italy Abstract: Breast cancer is the most prevalent cancer in women, causing a significant mortality worldwide. Different endocrine strategies are available for the treatment of hormone-sensitive breast cancer, including antiestrogen tamoxifen and fulvestrant, as well as third-generation aromatase inhibitors (AIs, such as letrozole, anastrozole, and exemestane. In this review, we will focus on exemestane, its clinical use, and its side effects. Exemestane is a steroidal third-generation AI now used in all treatment settings for breast cancer. In the metastatic disease, it has been extensively investigated as the first-, second-, and further-line treatment and it is now registered for the treatment of postmenopausal women with advanced estrogen-receptor-positive breast cancer whose disease has progressed following antiestrogen therapy. A potential lack of cross-resistance with nonsteroidal AIs has been described, giving additional therapeutic opportunities in sequences of endocrine agents. Exemestane is also approved for the adjuvant treatment of postmenopausal early breast cancer, either as upfront monotherapy for 5 years, as a switch following 2–3 years of tamoxifen, or as extended therapy beyond 5 years of adjuvant treatment. New promising data also showed a beneficial effect in young premenopausal early breast cancer patients, when administered together with ovarian suppression. Interesting results have also emerged when exemestane has been investigated as neodjuvant treatment as well as preventive agent in healthy women at high risk for breast cancer. Exemestane is generally well tolerated, with a side effect profile similar to that of other AIs, including menopausal

A new day dawns: women without oestrogen or is a balance best?

International Nuclear Information System (INIS)

Jordan, V Craig

2002-01-01

Building on the 30-year success story with tamoxifen, the question now is whether one agent can be used for treatment and prevention or should new medicines be targeted to specific applications? The early results with anastrozole suggest it could replace tamoxifen for treatment and should be tested as a preventive. Unfortunately, long-term testing of aromatase inhibitors will be required to avoid concerns about osteoporosis, Alzheimer's disease and coronary heart disease. Most importantly, the knowledge gained with tamoxifen has resulted in a new generation of selective oestrogen receptor modulators that can be used to prevent osteoporosis, breast cancer and uterine cancer. It is now clear that strategies utilising aromatase inhibitors and selective oestrogen receptor modulators will provide much needed options for individualised treatments

Potent inhibition of rhabdoid tumor cells by combination of flavopiridol and 4OH-tamoxifen

International Nuclear Information System (INIS)

Cimica, Velasco; Smith, Melissa E; Zhang, Zhikai; Mathur, Deepti; Mani, Sridhar; Kalpana, Ganjam V

2010-01-01

Rhabdoid Tumors (RTs) are highly aggressive pediatric malignancies with poor prognosis. There are currently no standard or effective treatments for RTs in part because treatments are not designed to specifically target these tumors. Our previous studies indicated that targeting the cyclin/cdk pathway is a novel therapeutic strategy for RTs and that a pan-cdk inhibitor, flavopiridol, inhibits RT growth. Since the toxicities and narrow window of activity associated with flavopiridol may limit its clinical use, we tested the effect of combining flavopiridol with 4-hydroxy-Tamoxifen (4OH-Tam) in order to reduce the concentration of flavopiridol needed for inhibition of RTs. The effects of flavopiridol, 4OH-Tam, and their combination on RT cell cycle regulation and apoptosis were assessed by: i) cell survival assays, ii) FACS analysis, iii) caspase activity assays, and iv) immunoblot analysis. Furthermore, the role of p53 in flavopiridol- and 4OH-Tam-mediated induction of cell cycle arrest and apoptosis was characterized using RNA interference (siRNA) analysis. The effect of p53 on flavopiridol-mediated induction of caspases 2, 3, 8 and 9 was also determined. We found that the combination of flavopiridol and 4OH-Tam potently inhibited the growth of RT cells. Low nanomolar concentrations of flavopiridol induced G 2 arrest, which was correlated to down-modulation of cyclin B1 and up-regulation of p53. Addition of 4OH-Tam did not affect flavopiridol-mediated G 2 arrest, but enhanced caspase 3,7-mediated apoptosis induced by the drug. Abrogation of p53 by siRNA abolished flavopiridol-induced G 2 arrest, but enhanced flavopiridol- (but not 4OH-Tam-) mediated apoptosis, by enhancing caspase 2 and 3 activities. Combining flavopiridol with 4OH-Tam potently inhibited the growth of RT cells by increasing the ability of either drug alone to induce caspases 2 and 3 thereby causing apoptosis. The potency of flavopiridol was enhanced by abrogation of p53. Our results warrant further

Potent inhibition of rhabdoid tumor cells by combination of flavopiridol and 4OH-tamoxifen

Energy Technology Data Exchange (ETDEWEB)

Cimica, Velasco; Smith, Melissa E; Zhang, Zhikai; Mathur, Deepti [Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461 (United States); Mani, Sridhar [Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461 (United States); Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461 (United States); Albert Einstein Cancer Center, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461 (United States); Kalpana, Ganjam V [Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461 (United States); Albert Einstein Cancer Center, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461 (United States)

2010-11-19

Rhabdoid Tumors (RTs) are highly aggressive pediatric malignancies with poor prognosis. There are currently no standard or effective treatments for RTs in part because treatments are not designed to specifically target these tumors. Our previous studies indicated that targeting the cyclin/cdk pathway is a novel therapeutic strategy for RTs and that a pan-cdk inhibitor, flavopiridol, inhibits RT growth. Since the toxicities and narrow window of activity associated with flavopiridol may limit its clinical use, we tested the effect of combining flavopiridol with 4-hydroxy-Tamoxifen (4OH-Tam) in order to reduce the concentration of flavopiridol needed for inhibition of RTs. The effects of flavopiridol, 4OH-Tam, and their combination on RT cell cycle regulation and apoptosis were assessed by: i) cell survival assays, ii) FACS analysis, iii) caspase activity assays, and iv) immunoblot analysis. Furthermore, the role of p53 in flavopiridol- and 4OH-Tam-mediated induction of cell cycle arrest and apoptosis was characterized using RNA interference (siRNA) analysis. The effect of p53 on flavopiridol-mediated induction of caspases 2, 3, 8 and 9 was also determined. We found that the combination of flavopiridol and 4OH-Tam potently inhibited the growth of RT cells. Low nanomolar concentrations of flavopiridol induced G{sub 2} arrest, which was correlated to down-modulation of cyclin B1 and up-regulation of p53. Addition of 4OH-Tam did not affect flavopiridol-mediated G{sub 2} arrest, but enhanced caspase 3,7-mediated apoptosis induced by the drug. Abrogation of p53 by siRNA abolished flavopiridol-induced G{sub 2} arrest, but enhanced flavopiridol- (but not 4OH-Tam-) mediated apoptosis, by enhancing caspase 2 and 3 activities. Combining flavopiridol with 4OH-Tam potently inhibited the growth of RT cells by increasing the ability of either drug alone to induce caspases 2 and 3 thereby causing apoptosis. The potency of flavopiridol was enhanced by abrogation of p53. Our results

Potent inhibition of rhabdoid tumor cells by combination of flavopiridol and 4OH-tamoxifen

Directory of Open Access Journals (Sweden)

Mani Sridhar

2010-11-01

Full Text Available Abstract Background Rhabdoid Tumors (RTs are highly aggressive pediatric malignancies with poor prognosis. There are currently no standard or effective treatments for RTs in part because treatments are not designed to specifically target these tumors. Our previous studies indicated that targeting the cyclin/cdk pathway is a novel therapeutic strategy for RTs and that a pan-cdk inhibitor, flavopiridol, inhibits RT growth. Since the toxicities and narrow window of activity associated with flavopiridol may limit its clinical use, we tested the effect of combining flavopiridol with 4-hydroxy-Tamoxifen (4OH-Tam in order to reduce the concentration of flavopiridol needed for inhibition of RTs. Methods The effects of flavopiridol, 4OH-Tam, and their combination on RT cell cycle regulation and apoptosis were assessed by: i cell survival assays, ii FACS analysis, iii caspase activity assays, and iv immunoblot analysis. Furthermore, the role of p53 in flavopiridol- and 4OH-Tam-mediated induction of cell cycle arrest and apoptosis was characterized using RNA interference (siRNA analysis. The effect of p53 on flavopiridol-mediated induction of caspases 2, 3, 8 and 9 was also determined. Results We found that the combination of flavopiridol and 4OH-Tam potently inhibited the growth of RT cells. Low nanomolar concentrations of flavopiridol induced G2 arrest, which was correlated to down-modulation of cyclin B1 and up-regulation of p53. Addition of 4OH-Tam did not affect flavopiridol-mediated G2 arrest, but enhanced caspase 3,7-mediated apoptosis induced by the drug. Abrogation of p53 by siRNA abolished flavopiridol-induced G2 arrest, but enhanced flavopiridol- (but not 4OH-Tam- mediated apoptosis, by enhancing caspase 2 and 3 activities. Conclusions Combining flavopiridol with 4OH-Tam potently inhibited the growth of RT cells by increasing the ability of either drug alone to induce caspases 2 and 3 thereby causing apoptosis. The potency of flavopiridol was

Quadrantectomy and radiotherapy (QUART) in the treatment of early breast cancer

Energy Technology Data Exchange (ETDEWEB)

Latini, P; Checcaglini, F; Maranzano, E; Panizza, B M; Aristei, C; Caprino, G

1986-01-01

One hundred twenty nine patients with T1 N0 M0 breast cancer were selectively treated with QUART. Mean age was 50 years. Ninety-eight patients (76%) were N- and 31 (24%) were N+. N+ cases received chemotherapy or Tamoxifen if R+. Patients evaluated are 95/129 in a 3 years average follow-up (range 2-7 years). Overall actuariall survival rate at 5 years is 88.9%. Three patients died; local relapses were 3/95 and metastases 3/95. Overall treatment tolerance was satisfactory and esthetic results were good. 27 refs.

Quadrantectomy and radiotherapy (QUART) in the treatment of early breast cancer

International Nuclear Information System (INIS)

Latini, P.; Checcaglini, F.; Maranzano, E.; Panizza, B.M.; Aristei, C.; Caprino, G.

1986-01-01

One hundred twenty nine patients with T1 N0 M0 breast cancer were selectively treated with QUART. Mean age was 50 years. Ninety-eight patients (76%) were N- and 31 (24%) were N+. N+ cases received chemotherapy or Tamoxifen if R+. Patients evaluated are 95/129 in a 3 years average follow-up (range 2-7 years). Overall actuariall survival rate at 5 years is 88.9%. Three patients died; local relapses were 3/95 and metastases 3/95. Overall treatment tolerance was satisfactory and esthetic results were good

Prognostic and predictive value of the 21-gene recurrence score assay in postmenopausal women with node-positive, oestrogen-receptor-positive breast cancer on chemotherapy: a retrospective analysis of a randomised trial.

Science.gov (United States)

Albain, Kathy S; Barlow, William E; Shak, Steven; Hortobagyi, Gabriel N; Livingston, Robert B; Yeh, I-Tien; Ravdin, Peter; Bugarini, Roberto; Baehner, Frederick L; Davidson, Nancy E; Sledge, George W; Winer, Eric P; Hudis, Clifford; Ingle, James N; Perez, Edith A; Pritchard, Kathleen I; Shepherd, Lois; Gralow, Julie R; Yoshizawa, Carl; Allred, D Craig; Osborne, C Kent; Hayes, Daniel F

2010-01-01

The 21-gene recurrence score assay is prognostic for women with node-negative, oestrogen-receptor-positive breast cancer treated with tamoxifen. A low recurrence score predicts little benefit of chemotherapy. For node-positive breast cancer, we investigated whether the recurrence score was prognostic in women treated with tamoxifen alone and whether it identified those who might not benefit from anthracycline-based chemotherapy, despite higher risks of recurrence. The phase 3 trial SWOG-8814 for postmenopausal women with node-positive, oestrogen-receptor-positive breast cancer showed that chemotherapy with cyclophosphamide, doxorubicin, and fluorouracil (CAF) before tamoxifen (CAF-T) added survival benefit to treatment with tamoxifen alone. Optional tumour banking yielded specimens for determination of recurrence score by RT-PCR. In this retrospective analysis, we assessed the effect of recurrence score on disease-free survival by treatment group (tamoxifen vs CAF-T) using Cox regression, adjusting for number of positive nodes. There were 367 specimens (40% of the 927 patients in the tamoxifen and CAF-T groups) with sufficient RNA for analysis (tamoxifen, n=148; CAF-T, n=219). The recurrence score was prognostic in the tamoxifen-alone group (p=0.006; hazard ratio [HR] 2.64, 95% CI 1.33-5.27, for a 50-point difference in recurrence score). There was no benefit of CAF in patients with a low recurrence score (score or =31; log-rank p=0.033; HR 0.59, 0.35-1.01), after adjustment for number of positive nodes. The recurrence score by treatment interaction was significant in the first 5 years (p=0.029), with no additional prediction beyond 5 years (p=0.58), although the cumulative benefit remained at 10 years. Results were similar for overall survival and breast-cancer-specific survival. The recurrence score is prognostic for tamoxifen-treated patients with positive nodes and predicts significant benefit of CAF in tumours with a high recurrence score. A low recurrence

Generation of knock-in mice that express nuclear enhanced green fluorescent protein and tamoxifen-inducible Cre recombinase in the notochord from Foxa2 and T loci.

Science.gov (United States)

Imuta, Yu; Kiyonari, Hiroshi; Jang, Chuan-Wei; Behringer, Richard R; Sasaki, Hiroshi

2013-03-01

The node and the notochord are important embryonic signaling centers that control embryonic pattern formation. Notochord progenitor cells present in the node and later in the posterior end of the notochord move anteriorly to generate the notochord. To understand the dynamics of cell movement during notochord development and the molecular mechanisms controlling this event, analyses of cell movements using time-lapse imaging and conditional manipulation of gene activities are required. To achieve this goal, we generated two knock-in mouse lines that simultaneously express nuclear enhanced green fluorescent protein (EGFP) and tamoxifen-inducible Cre, CreER(T2) , from two notochord gene loci, Foxa2 and T (Brachury). In Foxa2(nEGFP-CreERT2/+) and T(nEGFP-CreERT2/+) embryos, nuclei of the Foxa2 or T-expressing cells, which include the node, notochord, and endoderm (Foxa2) or wide range of posterior mesoderm (T), were labeled with EGFP at intensities that can be used for live imaging. Cre activity was also induced in cells expressing Foxa2 and T 1 day after tamoxifen administration. These mice are expected to be useful tools for analyzing the mechanisms of notochord development. Copyright © 2013 Wiley Periodicals, Inc.

Estrogen receptor testing and 10-year mortality from breast cancer: A model for determining testing strategy

Directory of Open Access Journals (Sweden)

Christopher Naugler

2012-01-01

Full Text Available Background: The use of adjuvant tamoxifen therapy in the treatment of estrogen receptor (ER expressing breast carcinomas represents a major advance in personalized cancer treatment. Because there is no benefit (and indeed there is increased morbidity and mortality associated with the use of tamoxifen therapy in ER-negative breast cancer, its use is restricted to women with ER expressing cancers. However, correctly classifying cancers as ER positive or negative has been challenging given the high reported false negative test rates for ER expression in surgical specimens. In this paper I model practice recommendations using published information from clinical trials to address the question of whether there is a false negative test rate above which it is more efficacious to forgo ER testing and instead treat all patients with tamoxifen regardless of ER test results. Methods: I used data from randomized clinical trials to model two different hypothetical treatment strategies: (1 the current strategy of treating only ER positive women with tamoxifen and (2 an alternative strategy where all women are treated with tamoxifen regardless of ER test results. The variables used in the model are literature-derived survival rates of the different combinations of ER positivity and treatment with tamoxifen, varying true ER positivity rates and varying false negative ER testing rates. The outcome variable was hypothetical 10-year survival. Results: The model predicted that there will be a range of true ER rates and false negative test rates above which it would be more efficacious to treat all women with breast cancer with tamoxifen and forgo ER testing. This situation occurred with high true positive ER rates and false negative ER test rates in the range of 20-30%. Conclusions: It is hoped that this model will provide an example of the potential importance of diagnostic error on clinical outcomes and furthermore will give an example of how the effect of that

Alteration of brain viscoelasticity after shunt treatment in normal pressure hydrocephalus

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Freimann, Florian Baptist; Sprung, Christian [Charite - University Medicine Berlin, Campus Virchow-Klinikum, Neurosurgical Department, Berlin (Germany); Streitberger, Kaspar-Josche; Klatt, Dieter; Sack, Ingolf [Charite - University Medicine Berlin, Campus Charite Mitte, Department of Radiology, Berlin (Germany); Lin, Kui; McLaughlin, Joyce [Rensselaer Polytechnic Institute, Mathematics Department, Troy, NY (United States); Braun, Juergen [Charite - University Medicine Campus Benjamin Franklin, Institute of Medical Informatics, Berlin (Germany)

2012-03-15

Normal pressure hydrocephalus (NPH) represents a chronic neurological disorder with increasing incidence. The symptoms of NPH may be relieved by surgically implanting a ventriculoperitoneal shunt to drain excess cerebrospinal fluid. However, the pathogenesis of NPH is not yet fully elucidated, and the clinical response of shunt treatment is hard to predict. According to current theories of NPH, altered mechanical properties of brain tissue seem to play an important role. Magnetic resonance elastography (MRE) is a unique method for measuring in vivo brain mechanics. In this study cerebral MRE was applied to test the viscoelastic properties of the brain in 20 patients with primary (N = 14) and secondary (N = 6) NPH prior and after (91 {+-} 16 days) shunt placement. Viscoelastic parameters were derived from the complex modulus according to the rheological springpot model. This model provided two independent parameters {mu} and {alpha}, related to the inherent rigidity and topology of the mechanical network of brain tissue. The viscoelastic parameters {mu} and {alpha} were found to be decreased with -25% and -10%, respectively, compared to age-matched controls (P < 0.001). Interestingly, {alpha} increased after shunt placement (P < 0.001) to almost normal values whereas {mu} remained symptomatically low. The results indicate the fundamental role of altered viscoelastic properties of brain tissue during disease progression and tissue repair in NPH. Clinical improvement in NPH is associated with an increasing complexity of the mechanical network whose inherent strength, however, remains degraded. (orig.)

Alteration of brain viscoelasticity after shunt treatment in normal pressure hydrocephalus

International Nuclear Information System (INIS)

Freimann, Florian Baptist; Sprung, Christian; Streitberger, Kaspar-Josche; Klatt, Dieter; Sack, Ingolf; Lin, Kui; McLaughlin, Joyce; Braun, Juergen

2012-01-01

Normal pressure hydrocephalus (NPH) represents a chronic neurological disorder with increasing incidence. The symptoms of NPH may be relieved by surgically implanting a ventriculoperitoneal shunt to drain excess cerebrospinal fluid. However, the pathogenesis of NPH is not yet fully elucidated, and the clinical response of shunt treatment is hard to predict. According to current theories of NPH, altered mechanical properties of brain tissue seem to play an important role. Magnetic resonance elastography (MRE) is a unique method for measuring in vivo brain mechanics. In this study cerebral MRE was applied to test the viscoelastic properties of the brain in 20 patients with primary (N = 14) and secondary (N = 6) NPH prior and after (91 ± 16 days) shunt placement. Viscoelastic parameters were derived from the complex modulus according to the rheological springpot model. This model provided two independent parameters μ and α, related to the inherent rigidity and topology of the mechanical network of brain tissue. The viscoelastic parameters μ and α were found to be decreased with -25% and -10%, respectively, compared to age-matched controls (P < 0.001). Interestingly, α increased after shunt placement (P < 0.001) to almost normal values whereas μ remained symptomatically low. The results indicate the fundamental role of altered viscoelastic properties of brain tissue during disease progression and tissue repair in NPH. Clinical improvement in NPH is associated with an increasing complexity of the mechanical network whose inherent strength, however, remains degraded. (orig.)

[Alterations in tears aqueous layer during cytostatics treatment].

Science.gov (United States)

Wojciechowska, Katarzyna; Wieckowska-Szakiel, Marzena; Rózalska, Barbara; Jurowski, Piotr

2013-01-01

The aim of the study was to evaluate tears secretion, pH and lysozyme activity in tears aqueous layer during chemotherapy in lung, breast and bowel cancer. 36 patients were enrolled to the study. Depending on the type of cancer and type of chemotherapy patients were divided into three groups. Group I (12 patients) diagnosed with non-small-cell lung cancer treated with PE schema (cisplatin, etoposide), Group II (12 patients) with breast cancer treated with FAC schema (fluorouracil, doxorubicin, cyclophosphamide), Group III (12 patients) with bowel cancer treated with FU/LV schema (fluorouracil, leucovorin). In all the patients: Schirmer's I test, pH measurements and lysozyme test were performed. Patients were examined before chemotherapy, after 2nd, 4th, 6th cycle. In group I and II lowering of tears secretion (p tears secretion (p tears film in all groups (p tears aqueous layer causing alterations of tears secretions. PH alterations depending on type of chemotherapy was observed. Lowering of lysozyme activity in tears was observed. All the deteriorations aggravate with duration of chemotherapy. Alterations of tears film parameters during chemotherapy may influence upon eye surface homeostasis and infectious complication. tears aqueous layer, Schirmer's test, lysozyme activity, tears pH.

Iodine-125-labelled tamoxifen is differentially cytoxic to cells containing oestrogen receptors

International Nuclear Information System (INIS)

Bloomer, W.D.; McLaughlin, W.H.; Weichselbaum, R.R.

1980-01-01

Tamoxifen, a non-steroidal anti-oestrogen competes with 17 - oestradiol for oestrogen receptor protein and is translocated to the nucleus. Carrier-free 125 I-TAM was tested for cytotoxicity in oestrogen receptor rich (human breast cancer MCF-7) and poor (V-79 Chinese hamster) cells. 125 I-TAM was differentially cytotoxic to MCF-7 cells. The D 37 values for MCF-7 and V-79 cells were 0.5 and 1.5 pCi/cell respectively. No radiotoxicity was observed with Na 125 I at doses equal to 125 I-TAM; iodide was effectively excluded from both cell lines and remained in the extracellular space. Also, nonradioactive 127 I-TAM and TAM were both non-toxic when tested at levels comparable to 125 I-TAM. It is suggested that the marked cytotoxicity in MCF-7 cells results from close approximation of 125 I with the genetic apparatus as a result of direct charging of specific nuclear receptors and/or translocation of 125 I-TAM receptor complexes from the cytoplasm to the nucleus, and that the minimal toxicity in V-79 cells reflects transmitted cytoplasmic radiation effects, limited direct nuclear charging and/or limited nuclear translocation resulting from the relative paucity of oestrogen in the cells. (U.K.)

Prognostic and Predictive Value of the 21-Gene Recurrence Score Assay in a Randomized Trial of Chemotherapy for Postmenopausal, Node-Positive, Estrogen Receptor-Positive Breast Cancer

Science.gov (United States)

Albain, Kathy S.; Barlow, William E.; Shak, Steven; Hortobagyi, Gabriel N.; Livingston, Robert B.; Yeh, I-Tien; Ravdin, Peter; Bugarini, Roberto; Baehner, Frederick L.; Davidson, Nancy E.; Sledge, George W.; Winer, Eric P.; Hudis, Clifford; Ingle, James N.; Perez, Edith A.; Pritchard, Kathleen I.; Shepherd, Lois; Gralow, Julie R.; Yoshizawa, Carl; Allred, D. Craig; Osborne, C. Kent; Hayes, Daniel F.

2010-01-01

SUMMARY Background The 21-gene Recurrence Score assay (RS) is prognostic for women with node-negative, estrogen receptor (ER)-positive breast cancer (BC) treated with tamoxifen. A low RS predicts little benefit of chemotherapy. For node-positive BC, we investigated whether RS was prognostic in women treated with tamoxifen alone and whether it identified those who might not benefit from anthracycline-based chemotherapy, despite higher recurrence risks. Methods The phase III trial S8814 for postmenopausal women with node-positive, ER-positive BC showed that CAF chemotherapy prior to tamoxifen (CAF-T) added survival benefit to tamoxifen alone. Optional tumor banking yielded specimens for RS determination by RT-PCR. We evaluated the effect of RS on disease-free survival (DFS) by treatment group (tamoxifen versus CAF-T) using Cox regression adjusting for number of positive nodes. Findings There were 367 specimens (40% of parent trial) with sufficient RNA (tamoxifen, 148; CAF-T, 219). The RS was prognostic in the tamoxifen arm (p=0.006). There was no CAF benefit in the low RS group (logrank p=0.97; HR=1.02, 95% CI (0.54,1.93)), but major DFS improvement for the high RS subset (logrank p=.03; HR=0.59, 95% CI (0.35, 1.01)), adjusting for number of positive nodes. The RS-by-treatment interaction was significant in the first 5 years (p=0.029), with no additional prediction beyond 5 years (p=0.58), though the cumulative benefit remained at 10 years. Results were similar for overall survival and BC-specific survival. Interpretation In this retrospective analysis, the RS is prognostic for tamoxifen-treated patients with positive nodes and predicts significant CAF benefit in tumors with a high RS. A low RS identifies women who may not benefit from anthracycline-based chemotherapy despite positive nodes. PMID:20005174

The effect of reimbursement on medical decision making: do physicians alter treatment in response to a managed care incentive?

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Melichar, Lori

2009-07-01

The empirical literature that explores whether physicians respond to financial incentives has not definitively answered the question of whether physicians alter their treatment behavior at the margin. Previous research has not been able to distinguish that part of a physician response that uniformly alters treatment of all patients under a physician's care from that which affects some, but not all of a physician's patients. To explore physicians' marginal responses to financial incentives while accounting for the selection of physicians into different financial arrangements where others could not, I use data from a survey of physician visits to isolate the effect that capitation, a form of reimbursement wherein physicians receive zero marginal revenue for a range of physician provided services, has on the care provided by a physician. Fixed effects regression results reveal that physicians spend less time with their capitated patients than with their non-capitated patients.

Alteration of dentin-enamel mechanical properties due to dental whitening treatments.

Science.gov (United States)

Zimmerman, B; Datko, L; Cupelli, M; Alapati, S; Dean, D; Kennedy, M

2010-05-01

The mechanical properties of dentin and enamel affect the reliability and wear properties of a tooth. This study investigated the influence of clinical dental treatments and procedures, such as whitening treatments or etching prior to restorative procedures. Both autoclaved and non-autoclaved teeth were studied in order to allow for both comparison with published values and improved clinical relevance. Nanoindentation analysis with the Oliver-Pharr model provided elastic modulus and hardness across the dentin-enamel junction (DEJ). Large increases were observed in the elastic modulus of enamel in teeth that had been autoclaved (52.0 GPa versus 113.4 GPa), while smaller increases were observed in the dentin (17.9 GPa versus 27.9 GPa). Likewise, there was an increase in the hardness of enamel (2.0 GPa versus 4.3 GPa) and dentin (0.5 GPa versus 0.7 GPa) with autoclaving. These changes suggested that the range of elastic modulus and hardness values previously reported in the literature may be partially due to the sterilization procedures. Treatment of the exterior of non-autoclaved teeth with Crest Whitestrips, Opalescence or UltraEtch caused changes in the mechanical properties of both the enamel and dentin. Those treated with Crest Whitestrips showed a reduction in the elastic modulus of enamel (55.3 GPa to 32.7 GPa) and increase in the elastic modulus of dentin (17.2 GPa to 24.3 GPa). Opalescence treatments did not significantly affect the enamel properties, but did result in a decrease in the modulus of dentin (18.5 GPa to 15.1 GPa). Additionally, as expected, UltraEtch treatment decreased the modulus and hardness of enamel (48.7 GPa to 38.0 GPa and 1.9 GPa to 1.5 GPa, respectively) and dentin (21.4 GPa to 15.0 GPa and 1.9 GPa to 1.5 GPa, respectively). Changes in the mechanical properties were linked to altered protein concentration within the tooth, as evidenced by fluorescence microscopy and Fourier transform infrared spectroscopy. Published by Elsevier Ltd.

ISSN 2073 East Cent. Afr. j. surg.

African Journals Online (AJOL)

DELL

Background: Tamoxifen has been in use worldwide in the care of breast cancer over decades. It has been ... treatment, thus adequate counseling and education on benefit and side effects of tamoxifen is strongly advised. .... Research till date has suggested that the young, elderly, non-white women, previous emotional ...

Neuropathic pain due to fibromatosis: Does anticancer treatment help?

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David Mathew

2011-01-01

Full Text Available Desmoid fibromatosis, although histologically benign, infiltrates local structures. The involvement of neural structures can lead to difficult neuropathic pain and the escalating use of analgesics. We report a patient with desmoid fibromatosis of the chest wall causing brachial plexus infiltration. As the tumor was locally invasive and unresectable, he was treated with radiation therapy and oral tamoxifen. On follow-up, there was significant pain relief, sustained reduction in the tumor size, and reduced analgesic requirement. Antineoplastic treatments like local radiation therapy and targeted systemic therapy with hormones or other agents can be considered in the management of selected unresectable desmoid fibromatosis to improve symptom control and reduce polypharmacy.

Alteration of consciousness in focal epilepsy: the global workspace alteration theory.

Science.gov (United States)

Bartolomei, Fabrice; McGonigal, Aileen; Naccache, Lionel

2014-01-01

Alteration of consciousness (AOC) is an important clinical manifestation of partial seizures that greatly impacts the quality of life of patients with epilepsy. Several theories have been proposed in the last fifty years. An emerging concept in neurology is the global workspace (GW) theory that postulates that access to consciousness (from several sensorial modalities) requires transient coordinated activity from associative cortices, in particular the prefrontal cortex and the posterior parietal associative cortex. Several lines of evidence support the view that partial seizures alter consciousness through disturbance of the GW. In particular, a nonlinear relation has been shown between excess of synchronization in the GW regions and the degree of AOC. Changes in thalamocortical synchrony occurring during the spreading of the ictal activity seem particularly involved in the mechanism of altered consciousness. This link between abnormal synchrony and AOC offers new perspectives in the treatment of the AOC since means of decreasing consciousness alteration in seizures could improve patients' quality of life. © 2013.

The role of miRNA regulation in cancer progression and drug resistance

DEFF Research Database (Denmark)

Joshi, Tejal

RNAs in the context of cancer biology, drug resistance and disease progression. The first project described in Chapter 6 addresses the problem of tamoxifen resistance, an anti-estrogen drug that is generally highly effective in the treatment of ER-positive breast cancers. The underlying molecular mechanisms...... to the disease transformation. In summary, this thesis focuses on regulatory role of miRNAs in drug resistance and disease progression. The findings provide hints toward various biologically and perhaps therapeutically relevant gene regulatory events. This thesis demonstrates the right choice of data analysis...... for the acquired resistance to tamoxifen are not very well understood. Therefore, with the aid of miRNA and gene expression profiles for MCF7/S0.5 (tamoxifen sensitive) and three MCF7/S0.5 derived tamoxifen resistant cell lines, we obtained several miRNA-mediated regulatory events in the tamoxifen resistant cell...

Genital tuberculosis in a tamoxifen-treated postmenopausal woman with breast cancer and bloody vaginal discharge

Directory of Open Access Journals (Sweden)

Maraki Sofia

2006-09-01

Full Text Available Abstract Background Female genital tuberculosis is an uncommon disease that is rarely diagnosed in developed countries. Case presentation A 61-year-old postmenopausal woman who had undergone surgery and treated with adjuvant chemotherapy for infiltrating ductal carcinoma of the breast five years ago, presented with bloody vaginal discharge, fatigue, weight loss, and low grade fevers at night for two months. Histological examination of the endometrium, done based on the suspicion of a second primary cancer due to the tamoxifen therapy, revealed a granulomatous reaction. Liquid and solid mycobacterial cultures of the tissues were performed. Although the acid fast staining was negative, the liquid culture was positive for Mycobacterium tuberculosis. Involvement of other systems was not detected. The patient was treated with a three-drug antituberculosis regimen for 9 months and recovered fully. Conclusion Female genital tuberculosis is a rare but curable disease that should be included in the differential diagnosis of women with menstrual problems. Early diagnosis is important and may prevent unnecessary invasive procedures for the patient.

Does Scoliosis-Specific Exercise Treatment in Adolescence Alter Adult Quality of Life?

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Płaszewski, Maciej; Cieśliński, Igor; Kowalski, Paweł; Truszczyńska, Aleksandra; Nowobilski, Roman

2014-01-01

Objective. Health-related quality of life in adults, who in adolescence participated in a scoliosis-specific exercise program, was not previously studied. Design. Cross-sectional study, with retrospective data collection. Material and Methods. Homogenous groups of 68 persons (43 women) aged 30.10 (25–39) years, with mild or moderate scoliosis, and 76 (38 women) able-bodied persons, aged 30.11 (24–38) years, who 16.5 (12–26) years earlier had completed scoliosis-specific exercise or observation regimes, participated. Their respiratory characteristics did not differ from predicted values. The WHOQOL-BREF questionnaire, Oswestry Disability Questionnaire, and pain scale (VAS) were applied. Results. The transformed WHOQOL-BREF scores ranged from 54.6 ± 11.19 in the physical domain in the mild scoliotic subgroup to 77.1 ± 16.05 in the social domain in the able-bodied subgroup. The ODQ values did not generally exceed 5.3 ± 7.53. Inter- and intragroup differences were nonsignificant. Age, marital status, education, and gender were significantly associated with the ODQ scores. Significant association between the ODQ and WHOQOL-BREF social relationships domain scores with the participation in exercise treatment was found. Conclusions. Participants with the history of exercise treatment generally did not differ significantly from their peers who were only under observation. This study cannot conclude that scoliosis-specific exercise treatment in adolescence alters quality of life in adulthood. PMID:25436225

Does Scoliosis-Specific Exercise Treatment in Adolescence Alter Adult Quality of Life?

Directory of Open Access Journals (Sweden)

Maciej Płaszewski

2014-01-01

Full Text Available Objective. Health-related quality of life in adults, who in adolescence participated in a scoliosis-specific exercise program, was not previously studied. Design. Cross-sectional study, with retrospective data collection. Material and Methods. Homogenous groups of 68 persons (43 women aged 30.10 (25–39 years, with mild or moderate scoliosis, and 76 (38 women able-bodied persons, aged 30.11 (24–38 years, who 16.5 (12–26 years earlier had completed scoliosis-specific exercise or observation regimes, participated. Their respiratory characteristics did not differ from predicted values. The WHOQOL-BREF questionnaire, Oswestry Disability Questionnaire, and pain scale (VAS were applied. Results. The transformed WHOQOL-BREF scores ranged from 54.6 ± 11.19 in the physical domain in the mild scoliotic subgroup to 77.1 ± 16.05 in the social domain in the able-bodied subgroup. The ODQ values did not generally exceed 5.3 ± 7.53. Inter- and intragroup differences were nonsignificant. Age, marital status, education, and gender were significantly associated with the ODQ scores. Significant association between the ODQ and WHOQOL-BREF social relationships domain scores with the participation in exercise treatment was found. Conclusions. Participants with the history of exercise treatment generally did not differ significantly from their peers who were only under observation. This study cannot conclude that scoliosis-specific exercise treatment in adolescence alters quality of life in adulthood.

Osteopontin splice variants are differential predictors of breast cancer treatment responses.

Science.gov (United States)

Zduniak, Krzysztof; Agrawal, Anil; Agrawal, Siddarth; Hossain, Md Monir; Ziolkowski, Piotr; Weber, Georg F

2016-07-11

Osteopontin is a marker for breast cancer progression, which in previous studies has also been associated with resistance to certain anti-cancer therapies. It is not known which splice variants may mediate treatment resistance. Here we analyze the association of osteopontin variant expression before treatment, differentiated according to immunohistochemistry with antibodies to exon 4 and to the osteopontin-c splice junction respectively, with the ensuing therapy responses in 119 Polish breast cancer patients who presented between 1995 and 2008. We found from Cox hazard models, logrank test and Wilcoxon test that osteopontin exon 4 was associated with a favorable response to tamoxifen, but a poor response to chemotherapy with CMF (cyclophosphamide, methotrexate, fluorouracil). Osteopontin-c is prognostic, but falls short of being a significant predictor for sensitivity to treatment. The addition of osteopontin splice variant immunohistochemistry to standard pathology work-ups has the potential to aid decision making in breast cancer treatment.

Osteopontin splice variants are differential predictors of breast cancer treatment responses

International Nuclear Information System (INIS)

Zduniak, Krzysztof; Agrawal, Anil; Agrawal, Siddarth; Hossain, Md Monir; Ziolkowski, Piotr; Weber, Georg F.

2016-01-01

Osteopontin is a marker for breast cancer progression, which in previous studies has also been associated with resistance to certain anti-cancer therapies. It is not known which splice variants may mediate treatment resistance. Here we analyze the association of osteopontin variant expression before treatment, differentiated according to immunohistochemistry with antibodies to exon 4 and to the osteopontin-c splice junction respectively, with the ensuing therapy responses in 119 Polish breast cancer patients who presented between 1995 and 2008. We found from Cox hazard models, logrank test and Wilcoxon test that osteopontin exon 4 was associated with a favorable response to tamoxifen, but a poor response to chemotherapy with CMF (cyclophosphamide, methotrexate, fluorouracil). Osteopontin-c is prognostic, but falls short of being a significant predictor for sensitivity to treatment. The addition of osteopontin splice variant immunohistochemistry to standard pathology work-ups has the potential to aid decision making in breast cancer treatment

Cognitive function after adjuvant treatment for early breast cancer

DEFF Research Database (Denmark)

Debess, Jeanne; Riis, Jens Østergaard; Engebjerg, Malene Cramer

2010-01-01

The purpose of this study was to examine cognitive function in patients with early breast cancer before and after adjuvant chemotherapy or 6 months of tamoxifen. We performed a population-based study in the county of North Jutland, Denmark, including 120 women aged ... chemotherapy with seven cycles of cyclophosphamide, epirubicin and fluoruracil or adjuvant tamoxifen for 6 months for early breast cancer from 2004 to 2006. They were compared with an aged-matched group of 208 women without previous cancer selected randomly from the same population. Data were collected before...... themselves as impaired at 6 months. Our results do not support that adjuvant chemotherapy is associated with cognitive side effects in breast cancer patients....

General toxicity and peripheral nerve alterations induced by chronic vincristine treatment in the rabbit.

Science.gov (United States)

Norido, F; Finesso, M; Fiorito, C; Marini, P; Favaro, G; Fusco, M; Tessari, F; Prosdocimi, M

1988-05-01

The effects of five 0.3 mg/kg intravenous administrations of vincristine (VCR) at weekly intervals were studied in the rabbit. Body weight gain was impaired starting from the first injection, while gross signs of motor paralysis and hair loss initiated from the third week. At the end of the observation period blood analysis revealed normocytic normochromic anemia, elevated serum creatine kinase, and low serum alkaline phosphatase, whereas all the tested parameters related to liver and kidney functions where within normal limits. The decreased number of red blood cells was the consequence of a complete, although reversible, blockade of staminal hematopoietic activity. Two important indexes of peripheral nerve function were clearly altered at the end of the treatment: (i) the sciatic nerve conduction velocity in vitro was 27% reduced and (ii) the latency between sciatic nerve stimulation and extensor digitorum longus (EDL) twitch in vivo was 34% prolonged. The usefulness of the rabbit as an animal model to study side-effects of VCR treatment is discussed.

Gynecomastia: physiopathology, evaluation and treatment

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Alfredo Carlos Simões Dornellas de Barros

Full Text Available Gynecomastia (GM is characterized by enlargement of the male breast, caused by glandular proliferation and fat deposition. GM is common and occurs in adolescents, adults and in old age. The aim of this review is to discuss the pathophysiology, etiology, evaluation and therapy of GM. A hormonal imbalance between estrogens and androgens is the key hallmark of GM generation. The etiology of GM is attributable to physiological factors, endocrine tumors or dysfunctions, non-endocrine diseases, drug use or idiopathic causes. Clinical evaluation must address diagnostic confirmation, search for an etiological factor and classify GM into severity grades to guide the treatment. A proposal for tailored therapy is presented. Weight loss, reassurance, pharmacotherapy with tamoxifen and surgical correction are the therapeutic options. For long-standing GM, the best results are generally achieved through surgery, combining liposuction and mammary adenectomy.

[(Modic) signal alterations of vertebral endplates and their correlation to a minimally invasive treatment of lumbar disc herniation using epidural injections].

Science.gov (United States)

Liphofer, J P; Theodoridis, T; Becker, G T; Koester, O; Schmid, G

2006-11-01

To study the influence of (Modic) signal alterations (SA) of the cartilage endplate (CEP) of vertebrae L3-S1 on the outcome of an in-patient minimally invasive treatment (MIT) using epidural injections on patients with lumbar disc herniation (LDH). The MR images of 59 consecutive patients with LDH within segments L3/L4 - L5/S1 undergoing in-patient minimally invasive treatment with epidural injections were evaluated in a clinical study. The (Modic) signal alterations of the CEP were recorded using T1- and T2-weighted sagittal images. On the basis of the T2-weighted sagittal images, the extension and distribution of the SA were measured by dividing each CEP into 9 areas. The outcome of the MIT was recorded using the Oswestry Disability Index (ODI) before and after therapy and in a 3-month follow-up. Within a subgroup of patients (n = 35), the distribution and extension of the signal alterations were correlated with the development of the ODI. Segments with LDH showed significantly more (p < 0.001) SA of the CEP than segments without LDH. Although the extension of the SA was not dependent on sex, it did increase significantly with age (p = 0.017). The outcome after MIT did not depend on the sex and age of the patients nor on the type of LDH. The SA extension tended to have a negative correlation with the outcome after MIT after 3 months (p = 0.071). A significant negative correlation could be established between the SA extension in the central section of the upper endplate and the outcome after 3 months (p = 0.019). 1. Lumbar disc herniation is clearly associated with the prevalence of (Modic) signal alterations. 2. Extensive signal alterations tend to correlate with a negative outcome of an MIT using epidural injections. 3. Such SA in the central portion of the upper CEP correlate significantly with a negative treatment result. 4. The central portion of the upper CEP being extensively affected by (Modic) SA is a negative predictor for the success of a minimally

Lipid remodeling and an altered membrane-associated proteome may drive the differential effects of EPA and DHA treatment on skeletal muscle glucose uptake and protein accretion.

Science.gov (United States)

Jeromson, Stewart; Mackenzie, Ivor; Doherty, Mary K; Whitfield, Phillip D; Bell, Gordon; Dick, James; Shaw, Andy; Rao, Francesco V; Ashcroft, Stephen P; Philp, Andrew; Galloway, Stuart D R; Gallagher, Iain; Hamilton, D Lee

2018-06-01

In striated muscle, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have differential effects on the metabolism of glucose and differential effects on the metabolism of protein. We have shown that, despite similar incorporation, treatment of C 2 C 12 myotubes (CM) with EPA but not DHA improves glucose uptake and protein accretion. We hypothesized that these differential effects of EPA and DHA may be due to divergent shifts in lipidomic profiles leading to altered proteomic profiles. We therefore carried out an assessment of the impact of treating CM with EPA and DHA on lipidomic and proteomic profiles. Fatty acid methyl esters (FAME) analysis revealed that both EPA and DHA led to similar but substantials changes in fatty acid profiles with the exception of arachidonic acid, which was decreased only by DHA, and docosapentanoic acid (DPA), which was increased only by EPA treatment. Global lipidomic analysis showed that EPA and DHA induced large alterations in the cellular lipid profiles and in particular, the phospholipid classes. Subsequent targeted analysis confirmed that the most differentially regulated species were phosphatidylcholines and phosphatidylethanolamines containing long-chain fatty acids with five (EPA treatment) or six (DHA treatment) double bonds. As these are typically membrane-associated lipid species we hypothesized that these treatments differentially altered the membrane-associated proteome. Stable isotope labeling by amino acids in cell culture (SILAC)-based proteomics of the membrane fraction revealed significant divergence in the effects of EPA and DHA on the membrane-associated proteome. We conclude that the EPA-specific increase in polyunsaturated long-chain fatty acids in the phospholipid fraction is associated with an altered membrane-associated proteome and these may be critical events in the metabolic remodeling induced by EPA treatment.

Enhanced urinary bladder and liver carcinogenesis in male CD1 mice exposed to transplacental inorganic arsenic and postnatal diethylstilbestrol or tamoxifen

International Nuclear Information System (INIS)

Waalkes, Michael P.; Liu Jie; Ward, Jerrold M.; Diwan, Bhalchandra A.

2006-01-01

Pregnant CD1 mice received 85 ppm arsenite in the drinking water from gestation day 8 to 18, groups (n = 35) of male offspring were subsequently injected on postpartum days 1 through 5 with diethylstilbestrol (DES; 2 μg/pup/day) or tamoxifen (TAM; 10 μg/pup/day), and tumor formation was assessed over 90 weeks. Arsenic alone increased hepatocellular carcinoma (14%), adenoma (23%) and total tumors (31%) compared to control (0, 2 and 2%, respectively). Arsenic alone also increased lung adenocarcinoma, adrenal cortical adenoma and renal cystic tubular hyperplasia compared to control. Compared to arsenic alone, arsenic plus DES increased liver tumor incidence in mice at risk 2.2-fold and increased liver tumor multiplicity (tumors/liver) 1.8-fold. The treatments alone did not impact urinary bladder carcinogenesis, but arsenic plus TAM significantly increased formation of urinary bladder transitional cell tumors (papilloma and carcinoma; 13%) compared to control (0%). Urinary bladder proliferative lesions (combined tumors and hyperplasia) were also increased by arsenic plus TAM (40%) or arsenic plus DES (43%) compared to control (0%) or the treatments alone. Urinary bladder proliferative lesions occurred in the absence of any evidence of uroepithelial cytotoxic lesions. Urinary bladder lesions and hepatocellular carcinoma induced by arsenic plus TAM and/or DES overexpressed estrogen receptor-α, indicating that aberrant estrogen signaling may have been a factor in the enhanced carcinogenic response. Thus, in male CD1 mice, gestational arsenic exposure alone induced liver adenoma and carcinoma, lung adenocarcinoma, adrenal adenoma and renal cystic hyperplasia. Furthermore, DES enhanced transplacental arsenic-induced hepatocarcinogenesis. In utero arsenic also initiated urinary bladder tumor formation when followed by postnatal TAM and uroepithelial proliferative lesions when followed by TAM or DES

Gene expression and benefit of chemotherapy in women with node-negative, estrogen receptor-positive breast cancer.

Science.gov (United States)

Paik, Soonmyung; Tang, Gong; Shak, Steven; Kim, Chungyeul; Baker, Joffre; Kim, Wanseop; Cronin, Maureen; Baehner, Frederick L; Watson, Drew; Bryant, John; Costantino, Joseph P; Geyer, Charles E; Wickerham, D Lawrence; Wolmark, Norman

2006-08-10

The 21-gene recurrence score (RS) assay quantifies the likelihood of distant recurrence in women with estrogen receptor-positive, lymph node-negative breast cancer treated with adjuvant tamoxifen. The relationship between the RS and chemotherapy benefit is not known. The RS was measured in tumors from the tamoxifen-treated and tamoxifen plus chemotherapy-treated patients in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B20 trial. Cox proportional hazards models were utilized to test for interaction between chemotherapy treatment and the RS. A total of 651 patients were assessable (227 randomly assigned to tamoxifen and 424 randomly assigned to tamoxifen plus chemotherapy). The test for interaction between chemotherapy treatment and RS was statistically significant (P = .038). Patients with high-RS (> or = 31) tumors (ie, high risk of recurrence) had a large benefit from chemotherapy (relative risk, 0.26; 95% CI, 0.13 to 0.53; absolute decrease in 10-year distant recurrence rate: mean, 27.6%; SE, 8.0%). Patients with low-RS (< 18) tumors derived minimal, if any, benefit from chemotherapy treatment (relative risk, 1.31; 95% CI, 0.46 to 3.78; absolute decrease in distant recurrence rate at 10 years: mean, -1.1%; SE, 2.2%). Patients with intermediate-RS tumors did not appear to have a large benefit, but the uncertainty in the estimate can not exclude a clinically important benefit. The RS assay not only quantifies the likelihood of breast cancer recurrence in women with node-negative, estrogen receptor-positive breast cancer, but also predicts the magnitude of chemotherapy benefit.

Sustained Treatment with Insulin Detemir in Mice Alters Brain Activity and Locomotion.

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Tina Sartorius

Full Text Available Recent studies have identified unique brain effects of insulin detemir (Levemir®. Due to its pharmacologic properties, insulin detemir may reach higher concentrations in the brain than regular insulin. This might explain the observed increased brain stimulation after acute insulin detemir application but it remained unclear whether chronic insulin detemir treatment causes alterations in brain activity as a consequence of overstimulation.In mice, we examined insulin detemir's prolonged brain exposure by continuous subcutaneous (s.c. application using either micro-osmotic pumps or daily s.c. injections and performed continuous radiotelemetric electrocorticography and locomotion recordings.Acute intracerebroventricular injection of insulin detemir activated cortical and locomotor activity significantly more than regular insulin in equimolar doses (0.94 and 5.63 mU in total, suggesting an enhanced acute impact on brain networks. However, given continuously s.c., insulin detemir significantly reduced cortical activity (theta: 21.3±6.1% vs. 73.0±8.1%, P<0.001 and failed to maintain locomotion, while regular insulin resulted in an increase of both parameters.The data suggest that permanently-increased insulin detemir levels in the brain convert its hyperstimulatory effects and finally mediate impairments in brain activity and locomotion. This observation might be considered when human studies with insulin detemir are designed to target the brain in order to optimize treatment regimens.

Diagnosis and treatment of breast cancer

International Nuclear Information System (INIS)

Doihara, Hiroyoshi; Taira, Naruhito

2008-01-01

This paper explains the outline of the present diagnosis and treatment of breast cancer essentially based on its therapeutic guideline by the Japan Breast Cancer Society (2005) and on authors' experiences. The diagnosis item contains the medical interview of patients, observatory and palpating examinations, mammography (for this, Japan-Breast Imaging Recording and Data System), ultrasonography (guideline for sonographic diagnosis of mammary gland, 2004), fine needle aspiration (FNA) or aspiration biopsy cytology, bases of triple test (palpation, mammography and FNA) for the cancer diagnosis, core needle biopsy, and mammotome biopsy of non-palpable calcified lesion. The treatment item contains the surgery involving conservation, sentinel lymph node biopsy (for this, lymphoscintigraphy with Tc-phytate is illustrated), radiofrequency ablation, adjuvant chemotherapy essentially using anthracycline and taxane, endocrinological therapy using tamoxifen, LH-RH analogues and aromatase inhibitors, and molecular target therapy with HER2 monoclonal antibody like trastuzumab. Recent progress of systemic therapy with medicals is remarkable, and the educational promotion of experts and medicare circumstances are concluded to be important. (R.T.)

8-prenylnaringenin and tamoxifen inhibit the shedding of irradiated epithelial cells and increase the latency period of radiation-induced oral mucositis. Cell culture and murine model

Energy Technology Data Exchange (ETDEWEB)

Ryck, Tine de; Impe, Annouchka van; Bracke, Marc E. [Ghent University, Laboratory of Experimental Cancer Research, Department Radiation Oncology and Experimental Cancer Research, Ghent (Belgium); Vanhoecke, Barbara W. [Ghent University, Laboratory of Experimental Cancer Research, Department Radiation Oncology and Experimental Cancer Research, Ghent (Belgium); Ghent University, Laboratory of Microbial Ecology and Technology (LabMET), Ghent (Belgium); Heyerick, Arne [Ghent University, Laboratory of Pharmacognosy and Phytochemistry, Ghent (Belgium); Vakaet, Luc; Neve, Wilfried de [Ghent University Hospital, Department of Radiation Oncology, Ghent (Belgium); Mueller, Doreen [Medical Faculty and University Hospital Carl Gustav Carus, Technische Universitaet Dresden, Department of Radiotherapy and Radiation Oncology, OncoRay-National Center for Radiation Research in Oncology, Dresden (Germany); Schmidt, Margret [Medical Faculty and University Hospital Carl Gustav Carus, Technische Universitaet Dresden, Department of Radiotherapy and Radiation Oncology, OncoRay-National Center for Radiation Research in Oncology, Dresden (Germany); German Cancer Consortium (DKTK) partner site Dresden and German Cancer Center (DKFZ), Heidelberg (Germany); Doerr, Wolfgang [Medical Faculty and University Hospital Carl Gustav Carus, Technische Universitaet Dresden, Department of Radiotherapy and Radiation Oncology, OncoRay-National Center for Radiation Research in Oncology, Dresden (Germany); Medical University, Department of Radiation Oncology, CCC, and CD-Laboratory RadOnc, Vienna (Austria)

2015-05-01

The major component in the pathogenesis of oral radiation-induced mucositis is progressive epithelial hypoplasia and eventual ulceration. Irradiation inhibits cell proliferation, while cell loss at the surface continues. We conceived to slow down this desquamation by increasing intercellular adhesion, regulated by the E-cadherin/catenin complex. We investigated if 8-prenylnaringenin (8-PN) or tamoxifen (TAM) decrease the shedding of irradiated human buccal epithelial cells in vitro and thus delay the ulcerative phase of radiation-induced mucositis in vivo. In vitro, aggregates of buccal epithelial cells were irradiated and cultured in suspension for 11 days. 8-PN or TAM were investigated regarding their effect on cell shedding. In vivo, the lower tongue surface of mice was irradiated with graded single doses of 25 kV X-rays. The incidence, latency, and duration of the resulting mucosal ulcerations were analyzed after topical treatment with 8-PN, TAM or solvent. 8-PN or TAM prevented the volume reduction of the irradiated cell aggregates during the incubation period. This was the result of a higher residual cell number in the treated versus the untreated irradiated aggregates. In vivo, topical treatment with 8-PN or TAM significantly increased the latency of mucositis from 10.9 to 12.1 and 12.4 days respectively, while the ulcer incidence was unchanged. 8-PN and TAM prevent volume reduction of irradiated cell aggregates in suspension culture. In the tongues of mice, these compounds increase the latency period. This suggests a role for these compounds for the amelioration of radiation-induced mucositis in the treatment of head and neck tumors. (orig.) [German] Die wesentliche Komponente in der Pathogenese der radiogenen Mukositis ist eine progressive epitheliale Hypoplasie und letztendlich Ulzeration. Die Bestrahlung hemmt die Zellproliferation, waehrend der Zellverlust an der Oberflaeche fortbesteht. Wir versuchten, diese Desquamation durch eine Stimulation der

Changes in the transcriptome of the human endometrial Ishikawa cancer cell line induced by estrogen, progesterone, tamoxifen, and mifepristone (RU486 as detected by RNA-sequencing.

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Karin Tamm-Rosenstein

Full Text Available BACKGROUND: Estrogen (E2 and progesterone (P4 are key players in the maturation of the human endometrium. The corresponding steroid hormone modulators, tamoxifen (TAM and mifepristone (RU486 are widely used in breast cancer therapy and for contraception purposes, respectively. METHODOLOGY/PRINCIPAL FINDINGS: Gene expression profiling of the human endometrial Ishikawa cancer cell line treated with E2 and P4 for 3 h and 12 h, and TAM and RU486 for 12 h, was performed using RNA-sequencing. High levels of mRNA were detected for genes, including PSAP, ATP5G2, ATP5H, and GNB2L1 following E2 or P4 treatment. A total of 82 biomarkers for endometrial biology were identified among E2 induced genes, and 93 among P4 responsive genes. Identified biomarkers included: EZH2, MDK, MUC1, SLIT2, and IL6ST, which are genes previously associated with endometrial receptivity. Moreover, 98.8% and 98.6% of E2 and P4 responsive genes in Ishikawa cells, respectively, were also detected in two human mid-secretory endometrial biopsy samples. TAM treatment exhibited both antagonistic and agonistic effects of E2, and also regulated a subset of genes independently. The cell cycle regulator cyclin D1 (CCND1 showed significant up-regulation following treatment with TAM. RU486 did not appear to act as a pure antagonist of P4 and a functional analysis of RU486 response identified genes related to adhesion and apoptosis, including down-regulated genes associated with cell-cell contacts and adhesion as CTNND1, JUP, CDH2, IQGAP1, and COL2A1. CONCLUSIONS: Significant changes in gene expression by the Ishikawa cell line were detected after treatments with E2, P4, TAM, and RU486. These transcriptome data provide valuable insight into potential biomarkers related to endometrial receptivity, and also facilitate an understanding of the molecular changes that take place in the endometrium in the early stages of breast cancer treatment and contraception usage.

How to combine hormonotherapy and radiation treatment in adjuvant breast cancer?

International Nuclear Information System (INIS)

Azria, D.; Llacer Moscardo, C.; Lemanski, C.; Ozsahin, M.; Gligorov, J.; Zaman, K.; Jacot, W.; Belkacemi, Y.

2008-01-01

Combined radiation and hormone therapies have become common clinical practice in recent years for locally-advanced prostate cancers. The use of such concomitant therapy in the treatment of breast disease has been infrequently reported in the literature, but seems justified given the common hormonal dependence of breast cancer and the potential synergistic effect of these two treatment modalities. As adjuvant therapy, two strategies are used in daily clinical practice: up front aromatase inhibitors or sequentially after a variable delay of tamoxifen. These molecules may, thus, interact with radiotherapy. Retrospective studies recently published did not show any differences in terms of locoregional recurrences between concurrent or sequential radio hormonotherapy. Lung and skin fibroses due to concurrent treatment are still under debate. Nevertheless, late side effects appeared to be increased by such a treatment, particularly in hypersensitive patients identified at risk by the lymphocyte predictive test. Concurrent radio hormonotherapy should, thus, be delivered cautiously at least for these patients. This article details the potent advantages and risks of concurrent use of adjuvant hormonotherapy and radiotherapy in localized breast cancers. (authors)

Insights on Genomic and Molecular Alterations in Multiple Myeloma and Their Incorporation towards Risk-Adapted Treatment Strategy: Concise Clinical Review

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Taiga Nishihori

2017-01-01

Full Text Available Although recent advances in novel treatment approaches and therapeutics have shifted the treatment landscape of multiple myeloma, it remains an incurable plasma cell malignancy. Growing knowledge of the genome and expressed genomic information characterizing the biologic behavior of multiple myeloma continues to accumulate. However, translation and incorporation of vast molecular understanding of complex tumor biology to deliver personalized and precision treatment to cure multiple myeloma have not been successful to date. Our review focuses on current evidence and understanding of myeloma biology with characterization in the context of genomic and molecular alterations. We also discuss future clinical application of the genomic and molecular knowledge, and more translational research is needed to benefit our myeloma patients.

Risperidone reverses the spatial object recognition impairment and hippocampal BDNF-TrkB signalling system alterations induced by acute MK-801 treatment

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Chen, Guangdong; Lin, Xiaodong; Li, Gongying; Jiang, Diego; Lib, Zhiruo; Jiang, Ronghuan; Zhuo, Chuanjun

2017-01-01

The aim of the present study was to investigate the effects of a commonly-used atypical antipsychotic, risperidone, on alterations in spatial learning and in the hippocampal brain-derived neurotrophic factor (BDNF)-tyrosine receptor kinase B (TrkB) signalling system caused by acute dizocilpine maleate (MK-801) treatment. In experiment 1, adult male Sprague-Dawley rats subjected to acute treatment of either low-dose MK801 (0.1 mg/kg) or normal saline (vehicle) were tested for spatial object recognition and hippocampal expression levels of BDNF, TrkB and the phophorylation of TrkB (p-TrkB). We found that compared to the vehicle, MK-801 treatment impaired spatial object recognition of animals and downregulated the expression levels of p-TrkB. In experiment 2, MK-801- or vehicle-treated animals were further injected with risperidone (0.1 mg/kg) or vehicle before behavioural testing and sacrifice. Of note, we found that risperidone successfully reversed the deleterious effects of MK-801 on spatial object recognition and upregulated the hippocampal BDNF-TrkB signalling system. Collectively, the findings suggest that cognitive deficits from acute N-methyl-D-aspartate receptor blockade may be associated with the hypofunction of hippocampal BDNF-TrkB signalling system and that risperidone was able to reverse these alterations. PMID:28451387

Cancer treatment: dealing with hot flashes and night sweats

Science.gov (United States)

... women with certain types of breast cancer. Opioids. Strong pain relievers given to some people with cancer. Tamoxifen. A drug used to treat breast cancer in both women and men. It is also used to prevent cancer in ...

Breast cancer with Her-22 hormone receptor-positive neu: primary systemic treatment, sentinel node biopsy and hormone

International Nuclear Information System (INIS)

Lopez C, Nayara; Sanchez M, Jose Ignacio; De Santiago G, Javier

2013-01-01

Neoadjuvant chemotherapy is an interesting option in the therapy of some breast cancer cases. Cases in which the timing for sentinel lymph node biopsy is controversial. Co-expression of estrogen receptors and Her2/neu (cc-erbB-2) in breast cancer may imply hormone resistance, especially to tamoxifen. We present a clinic case with co-expression of estrogen receptors and Her2/neu that was treated with neoadjuvant chemotherapy and previous sentinel lymph node biopsy followed by breast tumorectomy with axillar lympha- denectomy, radiotherapy and hormonotherapy with letrozol, geserelina and trastuzumab. A good treatment response as found

Comprehensive analysis of temporal alterations in cellular proteome of Bacillus subtilis under curcumin treatment.

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Panga Jaipal Reddy

Full Text Available Curcumin is a natural dietary compound with antimicrobial activity against various gram positive and negative bacteria. This study aims to investigate the proteome level alterations in Bacillus subtilis due to curcumin treatment and identification of its molecular/cellular targets to understand the mechanism of action. We have performed a comprehensive proteomic analysis of B. subtilis AH75 strain at different time intervals of curcumin treatment (20, 60 and 120 min after the drug exposure, three replicates to compare the protein expression profiles using two complementary quantitative proteomic techniques, 2D-DIGE and iTRAQ. To the best of our knowledge, this is the first comprehensive longitudinal investigation describing the effect of curcumin treatment on B. subtilis proteome. The proteomics analysis revealed several interesting targets such UDP-N-acetylglucosamine 1-carboxyvinyltransferase 1, putative septation protein SpoVG and ATP-dependent Clp protease proteolytic subunit. Further, in silico pathway analysis using DAVID and KOBAS has revealed modulation of pathways related to the fatty acid metabolism and cell wall synthesis, which are crucial for cell viability. Our findings revealed that curcumin treatment lead to inhibition of the cell wall and fatty acid synthesis in addition to differential expression of many crucial proteins involved in modulation of bacterial metabolism. Findings obtained from proteomics analysis were further validated using 5-cyano-2,3-ditolyl tetrazolium chloride (CTC assay for respiratory activity, resazurin assay for metabolic activity and membrane integrity assay by potassium and inorganic phosphate leakage measurement. The gene expression analysis of selected cell wall biosynthesis enzymes has strengthened the proteomics findings and indicated the major effect of curcumin on cell division.

Effective treatment with icotinib in lung adenocarcinoma with EGFR and ALK co-alterations and brain metastasis

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Ye CY

2016-10-01

Full Text Available Chenyang Ye,1,* Ji Wang,2,* Shu Zheng,1 Ying Chai3 1Cancer Institute, Key Laboratory of Cancer Prevention and Intervention, National Ministry of Education, Provincial Key Laboratory of Molecular Biology in Medical Sciences, The Second Affiliated Hospital, Zhejiang University School of Medicine, 2Department of Surgical Oncology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, 3Department of Thoracic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People’s Republic of China *These authors contributed equally to this work Abstract: We report a rare case of advanced lung cancer with epidermal growth factor receptor and anaplastic lymphoma kinase co-alterations and brain metastasis, in which icotinib treatment was effective for both the primary lung tumor and the brain metastasis. The patient achieved important clinical remission with a progression-free survival for two years. Our treatment strategy appears to be a promising therapeutic approach for this subgroup of patients. Keywords: lung cancer, brain metastasis, EGFR, ALK, icotinib

Mesolimbic dopamine function is not altered during continuous chronic treatment of rats with typical or atypical neuroleptic drugs

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Rupniak, N M.J.; Hall, M D; Kelly, E; Fleminger, S; Kilpatrick, G; Jenner, P; Marsden, C D

1985-01-01

Rats were treated continuously for up to 20 months with either haloperidol (1.4-1.6 mg/kg/day), sulpiride (102-109 mg/kg/day) or clozapine (24-27 mg/kg/day). Bsub(max) for specific mesolimbic binding of TH-spiperone, TH-N, n-propylnorapomorphine or TH-piflutixol did not differ in tissue taken from animals treated for up to 12 months with haloperidol, sulpiride or clozapine by comparison to age-matched control rats. Mesolimbic dopamine (50 M)-stimulated adenylate cyclase activity was not altered in any drug treatment group. Spontaneous locomotor activity was transiently decreased during treatment with haloperidol for 1 or 3 months, but not by chronic sulpiride or clozapine treatment. Locomotor activity was not consistently increased in any drug treatment group. After 20 months of continuous drug treatment, focal bilateral application of dopamine (12.5 or 25 g) into the nucleus accumbens caused equivalent increases in locomotor activity in control rats and in animals receiving haloperidol, sulpiride of clozapine. These findings suggest that dopamine receptor blockade is not maintained in the mesolimbic area following chronic treatment with haloperidol, sulpiride or clozapine, and indicate that, under these conditions, clozapine and sulpiride may not act selectively on mesolimbic dopamine receptors. (Author).

Mesolimbic dopamine function is not altered during continuous chronic treatment of rats with typical or atypical neuroleptic drugs

International Nuclear Information System (INIS)

Rupniak, N.M.J.; Hall, M.D.; Kelly, E.; Fleminger, S.; Kilpatrick, G.; Jenner, P.; Marsden, C.D.

1985-01-01

Rats were treated continuously for up to 20 months with either haloperidol (1.4-1.6 mg/kg/day), sulpiride (102-109 mg/kg/day) or clozapine (24-27 mg/kg/day). Bsub(max) for specific mesolimbic binding of 3 H-spiperone, 3 H-N, n-propylnorapomorphine or 3 H-piflutixol did not differ in tissue taken from animals treated for up to 12 months with haloperidol, sulpiride or clozapine by comparison to age-matched control rats. Mesolimbic dopamine (50 μM)-stimulated adenylate cyclase activity was not altered in any drug treatment group. Spontaneous locomotor activity was transiently decreased during treatment with haloperidol for 1 or 3 months, but not by chronic sulpiride or clozapine treatment. Locomotor activity was not consistently increased in any drug treatment group. After 20 months of continuous drug treatment, focal bilateral application of dopamine (12.5 or 25 μg) into the nucleus accumbens caused equivalent increases in locomotor activity in control rats and in animals receiving haloperidol, sulpiride of clozapine. These findings suggest that dopamine receptor blockade is not maintained in the mesolimbic area following chronic treatment with haloperidol, sulpiride or clozapine, and indicate that, under these conditions, clozapine and sulpiride may not act selectively on mesolimbic dopamine receptors. (Author)

Tamoxifen induces the expression of maspin through estrogen receptor-alpha.

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Liu, Zesheng; Shi, Heidi Y; Nawaz, Zafar; Zhang, Ming

2004-06-08

Maspin (mammary serine protease inhibitor) is a tumor suppressor gene that plays an important role in inhibiting tumor growth, invasion and metastasis. Maspin expression is down regulated at transcription level in primary and metastatic breast tumor cells. Previous studies on hormonal regulation of maspin prompt us to test whether an estrogen antagonist tamoxifen (TAM) can exert its anti-tumor function by up regulating maspin gene expression. For this purpose, we first tested whether maspin promoter could be activated in normal and several breast tumor cells. We then carried out a series of promoter analysis in which estrogen receptors and TAM were reconstituted in an in vitro cell culture system. Here we report our new finding that tumor suppresser gene maspin is one of the TAM target genes. TAM induces a maspin/luciferase reporter in cell culture and this induction requires the presence of (estrogen receptor alpha) ERalpha but not estrogen receptor-beta (ERbeta). Maspin promoter deletion and mutation analysis showed that the cis element(s) within a region between -90and+87 bp but not the HRE site (-272 bp) was involved in TAM induction of maspin expression. TAM bound ERalpha may directly control maspin gene expression through the interaction with cofactor (s). Analysis using several ERalpha mutants showed that the N-terminal A/B motif (AF-1) was critical for maspin basal level transcription activation. An ERalpha mutant with point mutations at DNA binding domain abolished estrogen induction of an ERE-luciferase reporter but was still active in activating maspin promoter by TAM. LBD-AF2 domain was required for ERalpha-dependent TAM induction. Deletion of LBD-AF2 or a point mutation in the ERalpha LBD-AF2 region (LBDmtL539A) completely abolished the activation of maspin promoter, suggesting that TAM induction of maspin involves the recruitment of cofactor(s) by ERalpha to the maspin promoter region. This finding indicates that one of the pathways for cancer

Phosphorus availability from the solid fraction of pig slurry is altered by composting or thermal treatment

DEFF Research Database (Denmark)

Christel, Wibke; Bruun, Sander; Magid, Jakob

2014-01-01

The alteration of easily available phosphorus (P) from the separated solid fraction of pig slurry by composting and thermal processing (pyrolysis or combustion at 300-1000. °C) was investigated by water and acidic extractions and the diffusive gradients in thin films (DGT) technique. Temporal...... changes in P availability were monitored by repeated DGT application in three amended temperate soils over 16. weeks. P availability was found to decrease in the order: drying. >. composting. >. pyrolysis. >. combustion with increasing degree of processing. Water extractions suggested that no P would....... Composting and thermal treatment produced a slow-release P fertilizer, with P availability being governed by abiotic and biotic mechanisms....

Chronic desipramine treatment alters tyrosine hydroxylase but not norepinephrine transporter immunoreactivity in norepinephrine axons in the rat prefrontal cortex

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Erickson, Susan L.; Gandhi, Anjalika R.; Asafu-Adjei, Josephine K.; Sampson, Allan R.; Miner, LeeAnn; Blakely, Randy D.; Sesack, Susan R.

2011-01-01

Pharmacological blockade of norepinephrine (NE) reuptake is clinically effective in treating several mental disorders. Drugs that bind to the NE transporter (NET) alter both protein levels and activity of NET and also the catecholamine synthetic enzyme tyrosine hydroxylase (TH). We examined the rat prefrontal cortex (PFC) by electron microscopy to determine whether the density and subcellular distribution of immunolabeling for NET and colocalization of NET with TH within individual NE axons were altered by chronic treatment with the selective NE uptake inhibitor desipramine (DMI). Following DMI treatment (21 days, 15 mg/kg/day), NET-immunoreactive (-ir) axons were significantly less likely to colocalize TH. This finding is consistent with reports of reduced TH levels and activity in the locus coeruleus after chronic DMI and indicates a reduction of NE synthetic capacity in the PFC. Measures of NET expression and membrane localization, including the number of NET-ir profiles per tissue area sampled, the number of gold particles per NET-ir profile area, and the proportion of gold particles associated with the plasma membrane, were similar in DMI and vehicle treated rats. These findings were verified using two different antibodies directed against distinct epitopes of the NET protein. The results suggest that chronic DMI treatment does not reduce NET expression within individual NE axons in vivo or induce an overall translocation of NET protein away from the plasma membrane in the PFC as measured by ultrastructural immunogold labeling. Our findings encourage consideration of possible postranslational mechanisms for regulating NET activity in antidepressant-induced modulation of NE clearance. PMID:21208501

Molecular alterations and biomarkers in colorectal cancer

Science.gov (United States)

Grady, William M.; Pritchard, Colin C.

2013-01-01

The promise of precision medicine is now a clinical reality. Advances in our understanding of the molecular genetics of colorectal cancer genetics is leading to the development of a variety of biomarkers that are being used as early detection markers, prognostic markers, and markers for predicting treatment responses. This is no more evident than in the recent advances in testing colorectal cancers for specific molecular alterations in order to guide treatment with the monoclonal antibody therapies cetuximab and panitumumab, which target the epidermal growth factor receptor (EGFR). In this review, we update a prior review published in 2010 and describe our current understanding of the molecular pathogenesis of colorectal cancer and how these alterations relate to emerging biomarkers for early detection and risk stratification (diagnostic markers), prognosis (prognostic markers), and the prediction of treatment responses (predictive markers). PMID:24178577

Developmental programming: gestational bisphenol-A treatment alters trajectory of fetal ovarian gene expression.

Science.gov (United States)

Veiga-Lopez, Almudena; Luense, Lacey J; Christenson, Lane K; Padmanabhan, Vasantha

2013-05-01

Bisphenol-A (BPA), a ubiquitous environmental endocrine disrupting chemical, is a component of polycarbonate plastic and epoxy resins. Because of its estrogenic properties, there is increasing concern relative to risks from exposures during critical periods of early organ differentiation. Prenatal BPA treatment in sheep results in low birth weight, hypergonadotropism, and ovarian cycle disruptions. This study tested the hypothesis that gestational exposure to bisphenol A, at an environmentally relevant dose, induces early perturbations in the ovarian transcriptome (mRNA and microRNA). Pregnant Suffolk ewes were treated with bisphenol A (0.5 mg/kg, sc, daily, produced ∼2.6 ng/mL of unconjugated BPA in umbilical arterial samples of BPA treated fetuses approaching median levels of BPA measured in maternal circulation) from days 30 to 90 of gestation. Expression of steroidogenic enzymes, steroid/gonadotropin receptors, key ovarian regulators, and microRNA biogenesis components were measured by RT-PCR using RNA derived from fetal ovaries collected on gestational days 65 and 90. An age-dependent effect was evident in most steroidogenic enzymes, steroid receptors, and key ovarian regulators. Prenatal BPA increased Cyp19 and 5α-reductase expression in day 65, but not day 90, ovaries. Fetal ovarian microRNA expression was altered by prenatal BPA with 45 down-regulated (>1.5-fold) at day 65 and 11 down-regulated at day 90 of gestation. These included microRNAs targeting Sry-related high-mobility-group box (SOX) family genes, kit ligand, and insulin-related genes. The results of this study demonstrate that exposure to BPA at an environmentally relevant dose alters fetal ovarian steroidogenic gene and microRNA expression of relevance to gonadal differentiation, folliculogenesis, and insulin homeostasis.

Adjuvant endocrine therapy for premenopausal women with hormone-responsive breast cancer.

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Mathew, Aju; Davidson, Nancy E

2015-11-01

Multiple strategies for endocrine treatment of premenopausal women with hormone-responsive breast cancer have been assessed and results have been presented over the last two years. These include tamoxifen for 5-10 years (ATLAS and aTTom), tamoxifen for 5 years followed by aromatase inhibitor (AI) for 5 years for women who have become postmenopausal (MA-17); ovarian ablation (OA) by surgery (EBCTCG overview); ovarian function suppression (OFS) by LHRH agonist (LHRH agonist meta-analysis); or combinations of approaches including OFS plus tamoxifen or AI (SOFT, TEXT, ABCSG 12 and E3193). Many of these trials have taken place in the backdrop of (neo)adjuvant chemotherapy which can confound interpretation because such therapy can suppress ovarian function either transiently or permanently. Nonetheless these trials suggest in aggregate that 10 years of tamoxifen are better than 5 years and that a program of extended adjuvant therapy of tamoxifen for 5 years followed by aromatase inhibitor for 5 years is effective for suitable candidates. The SOFT and E3193 trials do not show a major advantage for use of OFS + tamoxifen compared to tamoxifen alone. The joint SOFT/TEXT analysis and ABCGS12 trials both suggest that outcomes can be excellent with the use of combined endocrine therapy alone in properly selected patients but give conflicting results with regard to potential benefits for OFS + AI compared with OFS + tamoxifen. Further work will be needed to ascertain long-term outcomes, identify factors that predict who will benefit from extended adjuvant endocrine therapy, and assess role of OFS by medical or surgical means. It is clear, however, that endocrine therapy is a critical part of the adjuvant regimen for most premenopausal women with hormone-responsive breast cancer, and a subset of these women with luminal A-type tumors can be safely treated with endocrine therapy alone. Copyright © 2015 Elsevier Ltd. All rights reserved.

Anti-estrogen Resistance in Human Breast Tumors Is Driven by JAG1-NOTCH4-Dependent Cancer Stem Cell Activity

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Bruno M. Simões

2015-09-01

Full Text Available Breast cancers (BCs typically express estrogen receptors (ERs but frequently exhibit de novo or acquired resistance to hormonal therapies. Here, we show that short-term treatment with the anti-estrogens tamoxifen or fulvestrant decrease cell proliferation but increase BC stem cell (BCSC activity through JAG1-NOTCH4 receptor activation both in patient-derived samples and xenograft (PDX tumors. In support of this mechanism, we demonstrate that high ALDH1 predicts resistance in women treated with tamoxifen and that a NOTCH4/HES/HEY gene signature predicts for a poor response/prognosis in 2 ER+ patient cohorts. Targeting of NOTCH4 reverses the increase in Notch and BCSC activity induced by anti-estrogens. Importantly, in PDX tumors with acquired tamoxifen resistance, NOTCH4 inhibition reduced BCSC activity. Thus, we establish that BCSC and NOTCH4 activities predict both de novo and acquired tamoxifen resistance and that combining endocrine therapy with targeting JAG1-NOTCH4 overcomes resistance in human breast cancers.

17β-estradiol and tamoxifen protect mice from manganese-induced dopaminergic neurotoxicity.

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Pajarillo, Edward; Johnson, James; Kim, Judong; Karki, Pratap; Son, Deok-Soo; Aschner, Michael; Lee, Eunsook

2018-03-01

Chronic exposure to manganese (Mn) causes neurotoxicity, referred to as manganism, with common clinical features of parkinsonism. 17β-estradiol (E2) and tamoxifen (TX), a selective estrogen receptor modulator (SERM), afford neuroprotection in several neurological disorders, including Parkinson's disease (PD). In the present study, we tested if E2 and TX attenuate Mn-induced neurotoxicity in mice, assessing motor deficit and dopaminergic neurodegeneration. We implanted E2 and TX pellets in the back of the neck of ovariectomized C57BL/6 mice two weeks prior to a single injection of Mn into the striatum. One week later, we assessed locomotor activity and molecular mechanisms by immunohistochemistry, real-time quantitative PCR, western blot and enzymatic biochemical analyses. The results showed that both E2 and TX attenuated Mn-induced motor deficits and reversed the Mn-induced loss of dopaminergic neurons in the substantia nigra. At the molecular level, E2 and TX reversed the Mn-induced decrease of (1) glutamate aspartate transporter (GLAST) and glutamate transporter 1 (GLT-1) mRNA and protein levels; (2) transforming growth factor-α (TGF-α) and estrogen receptor-α (ER-α) protein levels; and (3) catalase (CAT) activity and glutathione (GSH) levels, and Mn-increased (1) malondialdehyde (MDA) levels and (2) the Bax/Bcl-2 ratio. These results indicate that E2 and TX afford protection against Mn-induced neurotoxicity by reversing Mn-reduced GLT1/GLAST as well as Mn-induced oxidative stress. Our findings may offer estrogenic agents as potential candidates for the development of therapeutics to treat Mn-induced neurotoxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

A naringenin–tamoxifen combination impairs cell proliferation and survival of MCF-7 breast cancer cells

Energy Technology Data Exchange (ETDEWEB)

Hatkevich, Talia; Ramos, Joseph; Santos-Sanchez, Idalys; Patel, Yashomati M., E-mail: ympatel@uncg.edu

2014-10-01

Since over 60% of breast cancers are estrogen receptor positive (ER+), many therapies have targeted the ER. The ER is activated by both estrogen binding and phosphorylation. While anti-estrogen therapies, such as tamoxifen (Tam) have been successful they do not target the growth factor promoting phosphorylation of the ER. Other proliferation pathways such as the phosphatidylinositol-3 kinase, (PI3K) and the mitogen-activated protein kinase (MAPK) pathways are activated in breast cancer cells and are associated with poor prognosis. Thus targeting multiple cellular proliferation and survival pathways at the onset of treatment is critical for the development of more effective therapies. The grapefruit flavanone naringenin (Nar) is an inhibitor of both the PI3K and MAPK pathways. Previous studies examining either Nar or Tam used charcoal-stripped serum which removed estrogen as well as other factors. We wanted to use serum containing medium in order to retain all the potential inducers of cell proliferation so as not to exclude any targets of Nar. Here we show that a Nar–Tam combination is more effective than either Tam alone or Nar alone in MCF-7 breast cancer cells. We demonstrate that a Nar–Tam combination impaired cellular proliferation and viability to a greater extent than either component alone in MCF-7 cells. Furthermore, the use of a Nar–Tam combination requires lower concentrations of both compounds to achieve the same effects on proliferation and viability. Nar may function by inhibiting both PI3K and MAPK pathways as well as localizing ERα to the cytoplasm in MCF-7 cells. Our results demonstrate that a Nar–Tam combination induces apoptosis and impairs proliferation signaling to a greater extent than either compound alone. These studies provide critical information for understanding the molecular mechanisms involved in cell proliferation and apoptosis in breast cancer cells. - Highlights: • Nar–Tam impairs cell viability more effectively than

A naringenin–tamoxifen combination impairs cell proliferation and survival of MCF-7 breast cancer cells

International Nuclear Information System (INIS)

Hatkevich, Talia; Ramos, Joseph; Santos-Sanchez, Idalys; Patel, Yashomati M.

2014-01-01

Since over 60% of breast cancers are estrogen receptor positive (ER+), many therapies have targeted the ER. The ER is activated by both estrogen binding and phosphorylation. While anti-estrogen therapies, such as tamoxifen (Tam) have been successful they do not target the growth factor promoting phosphorylation of the ER. Other proliferation pathways such as the phosphatidylinositol-3 kinase, (PI3K) and the mitogen-activated protein kinase (MAPK) pathways are activated in breast cancer cells and are associated with poor prognosis. Thus targeting multiple cellular proliferation and survival pathways at the onset of treatment is critical for the development of more effective therapies. The grapefruit flavanone naringenin (Nar) is an inhibitor of both the PI3K and MAPK pathways. Previous studies examining either Nar or Tam used charcoal-stripped serum which removed estrogen as well as other factors. We wanted to use serum containing medium in order to retain all the potential inducers of cell proliferation so as not to exclude any targets of Nar. Here we show that a Nar–Tam combination is more effective than either Tam alone or Nar alone in MCF-7 breast cancer cells. We demonstrate that a Nar–Tam combination impaired cellular proliferation and viability to a greater extent than either component alone in MCF-7 cells. Furthermore, the use of a Nar–Tam combination requires lower concentrations of both compounds to achieve the same effects on proliferation and viability. Nar may function by inhibiting both PI3K and MAPK pathways as well as localizing ERα to the cytoplasm in MCF-7 cells. Our results demonstrate that a Nar–Tam combination induces apoptosis and impairs proliferation signaling to a greater extent than either compound alone. These studies provide critical information for understanding the molecular mechanisms involved in cell proliferation and apoptosis in breast cancer cells. - Highlights: • Nar–Tam impairs cell viability more effectively than

A human beta cell line with drug inducible excision of immortalizing transgenes

Science.gov (United States)

Benazra, Marion; Lecomte, Marie-José; Colace, Claire; Müller, Andreas; Machado, Cécile; Pechberty, Severine; Bricout-Neveu, Emilie; Grenier-Godard, Maud; Solimena, Michele; Scharfmann, Raphaël; Czernichow, Paul; Ravassard, Philippe

2015-01-01

Objectives Access to immortalized human pancreatic beta cell lines that are phenotypically close to genuine adult beta cells, represent a major tool to better understand human beta cell physiology and develop new therapeutics for Diabetes. Here we derived a new conditionally immortalized human beta cell line, EndoC-βH3 in which immortalizing transgene can be efficiently removed by simple addition of tamoxifen. Methods We used lentiviral mediated gene transfer to stably integrate a tamoxifen inducible form of CRE (CRE-ERT2) into the recently developed conditionally immortalized EndoC βH2 line. The resulting EndoC-βH3 line was characterized before and after tamoxifen treatment for cell proliferation, insulin content and insulin secretion. Results We showed that EndoC-βH3 expressing CRE-ERT2 can be massively amplified in culture. We established an optimized tamoxifen treatment to efficiently excise the immortalizing transgenes resulting in proliferation arrest. In addition, insulin expression raised by 12 fold and insulin content increased by 23 fold reaching 2 μg of insulin per million cells. Such massive increase was accompanied by enhanced insulin secretion upon glucose stimulation. We further observed that tamoxifen treated cells maintained a stable function for 5 weeks in culture. Conclusions EndoC βH3 cell line represents a powerful tool that allows, using a simple and efficient procedure, the massive production of functional non-proliferative human beta cells. Such cells are close to genuine human beta cells and maintain a stable phenotype for 5 weeks in culture. PMID:26909308

Aromatase inhibitors, efficacy and metabolic risk in the treatment of postmenopausal women with early breast cancer

Directory of Open Access Journals (Sweden)

Stefano Gonnelli

2008-12-01

Full Text Available Stefano Gonnelli1, Roberto Petrioli21Department of Internal Medicine, Endocrine-Metabolic Science and Biochemistry, University of Siena, Italy (Dir. R. Nuti.; 2Department of Human Pathology and Oncology, Medical Oncology Section, University of Siena, Italy (Dir. G. FranciniAbstract: The third-generation aromatase inhibitors (AIs, letrozole, anastrozole and exemestane, are becoming the first choice endocrine drugs for post-menopausal women with breast cancer, since they present greater efficacy when compared with tamoxifen in both adjuvant and metastatic setting. In particular, several large and well designed trials have suggested an important role for AIs in the adjuvant treatment of postmenopausal women with estrogen-receptor positive breast cancer either in the upfront, sequential or extended adjuvant mode. Overall, AIs are associated with a small but significant improvement in disease free survival. The expanding use of AIs in the treatment of early breast cancer means that individual patients will be exposed to the agents for longer durations, making it increasingly important to establish their long-term safety. This review focused on the effects of AIs on bone metabolism, serum lipids and cardiovascular risk. AIs have adverse effects on bone turnover with a reduction of bone mineral density and an increase in the rate of fragility fractures. With respect to tamoxifen AIs present lower thrombotic risk and a less favorable impact on lipid profile, whereas the true effects on cardiovascular risk still remain to be clarified. An adequate monitoring of bone mineral density (BMD and lipid profile could be recommended for post-menopausal women candidate to AIs.Keywords: breast cancer, aromatase inhibitors, bone loss, lipids, cardiovascular risk

Endoxifen, 4-Hydroxytamoxifen and an Estrogenic Derivative Modulate Estrogen Receptor Complex Mediated Apoptosis in Breast Cancer.

Science.gov (United States)

Maximov, Philipp Y; Abderrahman, Balkees; Fanning, Sean W; Sengupta, Surojeet; Fan, Ping; Curpan, Ramona F; Quintana Rincon, Daniela Maria; Greenland, Jeffery A; Rajan, Shyamala S; Greene, Geoffrey L; Jordan, V Craig

2018-05-08

Estrogen therapy was used to treat advanced breast cancer in postmenopausal women for decades until the introduction of tamoxifen. Resistance to long-term estrogen deprivation (LTED) with tamoxifen and aromatase inhibitors used as a treatment for breast cancer inevitably occurs, but unexpectedly low dose estrogen can cause regression of breast cancer and increase disease free survival in some patients. This therapeutic effect is attributed to estrogen-induced apoptosis in LTED breast cancer. Here we describe modulation of the estrogen receptor liganded with antiestrogens (endoxifen, 4-hydroxytamoxifen) and an estrogenic triphenylethylene (TPE) EthoxyTPE (EtOXTPE) on estrogen-induced apoptosis in LTED breast cancer cells. Our results show that the angular TPE estrogen (EtOXTPE) is able to induce the ER-mediated apoptosis only at a later time compared to planar estradiol in these cells. Using RT-PCR, ChIP, Western blotting, molecular modelling and X-ray crystallography techniques we report novel conformations of the ER complex with an angular estrogen EtOXTPE and endoxifen. We propose that alteration of the conformation of the ER complexes, with changes in coactivator binding, governs estrogen-induced apoptosis through the PERK sensor system to trigger an Unfolded Protein Response (UPR). The American Society for Pharmacology and Experimental Therapeutics.

Improved solar light stimulated charge separation of g-C3N4 through self-altering acidic treatment

Science.gov (United States)

Leong, Kah Hon; Lim, Ping Feng; Sim, Lan Ching; Punia, Varun; Pichiah, Saravanan

2018-02-01

Herein, we report the use of acid treatment to treat g-C3N4 nanostructured by a direct and facile synthesis route. The adopted treatment enhanced photoactivity of g-C3N4 and reflected in the removal of recalcitrant organic pollutant, Bisphenol A under direct sunlight. A complete removal of Bisphenol A was attained in a short duration (225 min) as compared to pure g-C3N4. The analysis clearly substantiated the robustness of acid exfoliation that promoted a blue shift, extended the conjugated length of its respective conduction and valance band. It also drastically prolonged the recombination rate of charge carriers, by producing excess of unpaired electrons in the conduction band for active radicals' generation. Thus, this new findings could offer a new sight of self-alteration in improving the photoactivity of complex organic pollutants for sustainable environmental remediation.

Ultrastructural alterations in adult Schistosoma mansoni caused by artemether

Directory of Open Access Journals (Sweden)

Shuhua Xiao

2002-07-01

Full Text Available Progress has been made over the last decade with the development and clinical use of artemether as an agent against major human schistosome parasites. The tegument has been identified as a key target of artemether, implying detailed studies on ultrastructural damage induced by this compound. We performed a temporal examination, employing a transmission electron microscope to assess the pattern and extent of ultrastructural alterations in adult Schistosoma mansoni harboured in mice treated with a single dose of 400 mg/kg artemether. Eight hours post-treatment, damage to the tegument and subtegumental structures was seen. Tegumental alterations reached a peak 3 days after treatment and were characterized by swelling, fusion of distal cytoplasma, focal lysis of the tegumental matrix and vacuolisation. Tubercles and sensory organelles frequently degenerated or collapsed. Typical features of subtegumental alterations, including muscle fibres, syncytium and parenchyma tissues, were focal or extensive lysis, vacuolisation and degeneration of mitochondria. Severe alterations were also observed in gut epithelial cells and vitelline cells of female worms. Our findings of artemether-induced ultrastructural alterations in adult S. mansoni confirm previous results obtained with juvenile S. mansoni and S. japonicum of different ages.

Prevention of Gynecomastia and Breast Pain Caused by Androgen Deprivation Therapy in Prostate Cancer: Tamoxifen or Radiotherapy?

Energy Technology Data Exchange (ETDEWEB)

Arruda Viani, Gustavo, E-mail: gusviani@gmail.com [Department of Radiation Oncology, Marilia Medical School, Marilia, Sao Paulo (Brazil); Bernardes da Silva, Lucas Godoi; Stefano, Eduardo Jose [Department of Radiation Oncology, Marilia Medical School, Marilia, Sao Paulo (Brazil)

2012-07-15

Purpose: To determine, in a meta-analysis, whether gynecomastia and breast pain rates in men with prostate cancer treated with androgen deprivation therapy (ADT) are reduced if treated with prophylactic radiotherapy (RT) or tamoxifen (TMX). Methods and Materials: The MEDLINE, EMBASE, CANCERLIT, and Cochrane Library databases, as well as proceedings of annual meetings, were systematically searched to identify randomized, controlled studies comparing RT or TMX with observation for men with prostate cancer using ADT. Results: Six RCTs (three RT trials and three TMX trials, N = 777 patients total) were identified that met the study criteria. Pooled results from these RCTs comparing RT vs. observation showed a significant reduction in the incidence of gynecomastia and breast pain rates in patients treated with RT (odds ratio [OR] = 0.21, 95% confidence interval [CI] = 0.12-0.37, p < 0.0001, and OR = 0.34, 95% CI 0.20-0.57, p < 0.0001, respectively). Use of RT resulted in an absolute risk reduction (ARR) of 29.4% and 19.9%, with a number needed to treat (NNT) of 3.4 and 5 to avoid one case of gynecomastia and breast pain, respectively. Pooled results from trials comparing TMX vs. observation showed a statistical benefit for breast pain and gynecomastia in favor of TMX arms (OR = 0.04, 95% CI = 0.02-0.08, p < 0.0001 and OR = 0.07, 95% CI = 0.0-0.14, p < 0.00001). TMX resulted in an ARR = 64.1% and 47.6%, with an NNT of 1.56 and 2.1 to avoid one case of gynecomastia and breast pain, respectively. Considering adverse effects, TMX was 6 times more adverse effects than RT. Conclusions: Our data have shown that both TMX and RT prevented gynecomastia and breast pain in patients with prostate cancer receiving ADT for prostate cancer. Although TMX was two times more effective in preventing gynecomastia, RT should represent an effective and safe treatment option, to take into account mainly in patients with cardiovascular risk factors or thrombotic diathesis.

Prevention of Gynecomastia and Breast Pain Caused by Androgen Deprivation Therapy in Prostate Cancer: Tamoxifen or Radiotherapy?

International Nuclear Information System (INIS)

Arruda Viani, Gustavo; Bernardes da Silva, Lucas Godói; Stefano, Eduardo Jose

2012-01-01

Purpose: To determine, in a meta-analysis, whether gynecomastia and breast pain rates in men with prostate cancer treated with androgen deprivation therapy (ADT) are reduced if treated with prophylactic radiotherapy (RT) or tamoxifen (TMX). Methods and Materials: The MEDLINE, EMBASE, CANCERLIT, and Cochrane Library databases, as well as proceedings of annual meetings, were systematically searched to identify randomized, controlled studies comparing RT or TMX with observation for men with prostate cancer using ADT. Results: Six RCTs (three RT trials and three TMX trials, N = 777 patients total) were identified that met the study criteria. Pooled results from these RCTs comparing RT vs. observation showed a significant reduction in the incidence of gynecomastia and breast pain rates in patients treated with RT (odds ratio [OR] = 0.21, 95% confidence interval [CI] = 0.12–0.37, p < 0.0001, and OR = 0.34, 95% CI 0.20–0.57, p < 0.0001, respectively). Use of RT resulted in an absolute risk reduction (ARR) of 29.4% and 19.9%, with a number needed to treat (NNT) of 3.4 and 5 to avoid one case of gynecomastia and breast pain, respectively. Pooled results from trials comparing TMX vs. observation showed a statistical benefit for breast pain and gynecomastia in favor of TMX arms (OR = 0.04, 95% CI = 0.02–0.08, p < 0.0001 and OR = 0.07, 95% CI = 0.0–0.14, p < 0.00001). TMX resulted in an ARR = 64.1% and 47.6%, with an NNT of 1.56 and 2.1 to avoid one case of gynecomastia and breast pain, respectively. Considering adverse effects, TMX was 6 times more adverse effects than RT. Conclusions: Our data have shown that both TMX and RT prevented gynecomastia and breast pain in patients with prostate cancer receiving ADT for prostate cancer. Although TMX was two times more effective in preventing gynecomastia, RT should represent an effective and safe treatment option, to take into account mainly in patients with cardiovascular risk factors or thrombotic diathesis.

Alterations of papilla dimensions after orthodontic closure of the maxillary midline diastema: a retrospective longitudinal study.

Science.gov (United States)

Jeong, Jin-Seok; Lee, Seung-Youp; Chang, Moontaek

2016-06-01

The aim of this study was to evaluate alterations of papilla dimensions after orthodontic closure of the diastema between maxillary central incisors. Sixty patients who had a visible diastema between maxillary central incisors that had been closed by orthodontic approximation were selected for this study. Various papilla dimensions were assessed on clinical photographs and study models before the orthodontic treatment and at the follow-up examination after closure of the diastema. Influences of the variables assessed before orthodontic treatment on the alterations of papilla height (PH) and papilla base thickness (PBT) were evaluated by univariate regression analysis. To analyze potential influences of the 3-dimensional papilla dimensions before orthodontic treatment on the alterations of PH and PBT, a multiple regression model was formulated including the 3-dimensional papilla dimensions as predictor variables. On average, PH decreased by 0.80 mm and PBT increased after orthodontic closure of the diastema (Porthodontic treatment influenced the alteration of PH. With respect to the alteration of PBT, the diastema width (P=0.045) and PBT (P=0.000) were found to be influential factors. PBT before the orthodontic treatment significantly influenced the alteration of PBT in the multiple regression model. PH decreased but PBT increased after orthodontic closure of the diastema. The papilla dimensions before orthodontic treatment influenced the alterations of PH and PBT after closure of the diastema. The PBT increased more when the diastema width before the orthodontic treatment was larger.

Chemical Probes of Rapid Estrogen Signaling in Breast Cancer Treatment and Chemoprevention

National Research Council Canada - National Science Library

Weatherman, Rose V

2007-01-01

The goal of this project was to design new chemical tools to selectively probe the molecular mechanisms of action of rapid estrogen receptor action and their relevance to breast cancer drugs like tamoxifen...

Compliance to the prescribed dose and overall treatment time in five randomized clinical trials of altered fractionation in radiotherapy for head-and-neck carcinomas

International Nuclear Information System (INIS)

Khalil, Azza A.; Bentzen, Soeren M.; Bernier, Jacques; Saunders, Michele I.; Horiot, Jean-Claude; Bogaert, Walter van den; Cummings, Bernard J.; Dische, Stanley

2003-01-01

Purpose: To investigate compliance to the prescribed dose-fractionation schedule in five randomized controlled trials of altered fractionation in radiotherapy for head-and-neck carcinoma. Methods and Materials: Individual patient data from 2566 patients participating in the European Organization for Research and Treatment of Cancer (EORTC) 22791, EORTC 22811, EORTC 22851, Princess Margaret Hospital (PMH), and continuous hyperfractionated accelerated radiotherapy (CHART) head-and-neck trials were merged in the fractionation IMPACT (Intergroup Merger of Patient data from Altered or Conventional Treatment schedules) study database. The ideal treatment time was defined as the minimum time required to deliver a prescribed schedule. Compliance to the prescribed overall treatment time was quantified as the difference between the actual and the ideal overall time. An overall measure of compliance in an individual patient, the total dose lost (TDL), was calculated as the dose lost due to prolongation of therapy (assuming a D prolif of 0.64 Gy/day) plus the difference between the prescribed and the actual dose given. Results: The time in excess of the ideal ranged up to 97 days (average 3.9 days), and 25% of the patients had delays of 6 days or more. World Health Organization (WHO) performance status and nodal stage had a significant effect on TDL. TDL was significantly higher in the conventional than in the altered arm of the EORTC 22851 and CHART trials. In the PMH trial, TDL was significantly higher in the hyperfractionation than in the conventional arm. Centers participating in the three EORTC trials varied significantly in their compliance. There was a significant improvement in compliance in patients treated more recently. Conclusions: Even in randomized controlled trials, compliance to the prescribed radiation therapy schedule may be relatively poor, especially after conventional fractionation. This affects the interpretation of the outcome of these trials

Physico-chemical characterisation, cytotoxic activity, and biocompatibility studies of tamoxifen-loaded solid lipid nanoparticles prepared via a temperature-modulated solidification method.

Science.gov (United States)

Lakkadwala, Sushant; Nguyen, Sanko; Lawrence, Joseph; Nauli, Surya M; Nesamony, Jerry

2014-01-01

Solid lipid nanoparticles (SLNs) can efficiently and efficaciously incorporate anti-cancer agents. To prepare and characterise tamoxifen (TAM)-loaded SLNs. Glyceryl monostearate, Tween-80, and trehalose were used in SLNs. SLNs were tested via dynamic light scattering (DLS), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Characterisation studies revealed SLNs of about 540 nm with a negative surface charge and confirmed the entrapment of TAM in the SLNs. The entrapment efficiency was estimated to be 60%. The in vitro drug release profile demonstrated a gradual increase followed by a release plateau for several days. A drug concentration-dependent increase in cytotoxic activity was observed when the SLNs were evaluated in cell cultures. Biocompatible and stable lyophilised SLNs were successfully prepared and found to possess properties that may be utilised in an anti-cancer drug delivery system.

The combination of glutamate receptor antagonist MK-801 with tamoxifen and its active metabolites potentiates their antiproliferative activity in mouse melanoma K1735-M2 cells

International Nuclear Information System (INIS)

Ribeiro, Mariana P.C.; Nunes-Correia, Isabel; Santos, Armanda E.; Custódio, José B.A.

2014-01-01

Recent reports suggest that N-methyl-D-aspartate receptor (NMDAR) blockade by MK-801 decreases tumor growth. Thus, we investigated whether other ionotropic glutamate receptor (iGluR) antagonists were also able to modulate the proliferation of melanoma cells. On the other hand, the antiestrogen tamoxifen (TAM) decreases the proliferation of melanoma cells, and is included in combined therapies for melanoma. As the efficacy of TAM is limited by its metabolism, we investigated the effects of the NMDAR antagonist MK-801 in combination with TAM and its active metabolites, 4-hydroxytamoxifen (OHTAM) and endoxifen (EDX). The NMDAR blockers MK-801 and memantine decreased mouse melanoma K1735-M2 cell proliferation. In contrast, the NMDAR competitive antagonist APV and the AMPA and kainate receptor antagonist NBQX did not affect cell proliferation, suggesting that among the iGluR antagonists only the NMDAR channel blockers inhibit melanoma cell proliferation. The combination of antiestrogens with MK-801 potentiated their individual effects on cell biomass due to diminished cell proliferation, since it decreased the cell number and DNA synthesis without increasing cell death. Importantly, TAM metabolites combined with MK-801 promoted cell cycle arrest in G1. Therefore, the data obtained suggest that the activity of MK-801 and antiestrogens in K1735-M2 cells is greatly enhanced when used in combination. - Highlights: • MK-801 and memantine decrease melanoma cell proliferation. • The combination of MK-801 with antiestrogens inhibits melanoma cell proliferation. • These combinations greatly enhance the effects of the compounds individually. • MK-801 combined with tamoxifen active metabolites induces cell cycle arrest in G1. • The combination of MK-801 and antiestrogens is an innovative strategy for melanoma

Novel use of rituximab in a case of Riedel's thyroiditis refractory to glucocorticoids and tamoxifen.

Science.gov (United States)

Soh, Shui-Boon; Pham, Alan; O'Hehir, Robyn E; Cherk, Martin; Topliss, Duncan J

2013-09-01

A 42-year-old woman presented with a rapidly enlarging right-sided thyroid mass and underwent hemithyroidectomy. Riedel's thyroiditis was only diagnosed upon surgical decompression of the right carotid artery 2 years later. She became more symptomatic as Riedel's thyroiditis progressed, and mediastinal fibrosclerosis developed over the next 12 months. Oral prednisolone failed to improve her condition, and she was commenced on tamoxifen. Despite initial improvement, her symptoms recurred 2 years later, mainly arising from compression of the trachea and esophagus at the thoracic inlet. Fluorodeoxyglucose positron emission tomographic scan showed locally advanced active invasive fibrosclerosis in the neck and mediastinum. An elevated activin-A level of 218 pg/mL was consistent with active inflammation. IgG subtypes (including IgG4) were normal. Two courses of iv methylprednisolone were given but only produced transient improvement. Subsequently, the patient received 3 doses of i.v. rituximab at monthly intervals and had prompt sustained symptomatic improvement. Activin-A level decreased to 122 pg/mL 10 months after rituximab therapy. Fluorodeoxyglucose positron emission tomographic scan 6 weeks after therapy showed reduction in inflammation. A further scan at 10 months demonstrated ongoing response to rituximab. This is a case of refractory Riedel's thyroiditis with symptomatic, biochemical, and radiological improvement that has persisted 14 months after rituximab. The likelihood and duration of response to rituximab in Riedel's thyroiditis requires further study.

Altered network communication following a neuroprotective drug treatment.

Directory of Open Access Journals (Sweden)

Kathleen Vincent

Full Text Available Preconditioning is defined as a range of stimuli that allow cells to withstand subsequent anaerobic and other deleterious conditions. While cell protection under preconditioning is well established, this paper investigates the influence of neuroprotective preconditioning drugs, 4-aminopyridine and bicuculline (4-AP/bic, on synaptic communication across a broad network of in vitro rat cortical neurons. Using a permutation test, we evaluated cross-correlations of extracellular spiking activity across all pairs of recording electrodes on a 64-channel multielectrode array. The resulting functional connectivity maps were analyzed in terms of their graph-theoretic properties. A small-world effect was found, characterized by a functional network with high clustering coefficient and short average path length. Twenty-four hours after exposure to 4-AP/bic, small-world properties were comparable to control cultures that were not treated with the drug. Four hours following drug washout, however, the density of functional connections increased, while path length decreased and clustering coefficient increased. These alterations in functional connectivity were maintained at four days post-washout, suggesting that 4-AP/bic preconditioning leads to long-term effects on functional networks of cortical neurons. Because of their influence on communication efficiency in neuronal networks, alterations in small-world properties hold implications for information processing in brain systems. The observed relationship between density, path length, and clustering coefficient is captured by a phenomenological model where connections are added randomly within a spatially-embedded network. Taken together, results provide information regarding functional consequences of drug therapies that are overlooked in traditional viability studies and present the first investigation of functional networks under neuroprotective preconditioning.

The effect of postoperative radiotherapy on leukocyte zinc, serum trace elements and nutritional status of breast cancer patients

International Nuclear Information System (INIS)

Antila, H.M.J.; Salo, M.S.; Kirvelae, O.; Nikkanen, V.

1992-01-01

Mononuclear (MNC) and polymorphonuclear cell (PMNC) zinc content was determined together with serum zinc, copper, selenium and iron concentrations in 24 operable breast cancer patients during and after postoperative radiotherapy. Anthropometric and biochemical indices of nutritional status were measured as background data. The measurements were carried out in the years 1987-1988. Nine patients used unconventional multivitamin or trace element preparations. A steady but statistically insignificant decrease in PMNC zinc was seen during treatment. No changes occurred in MNC zinc. Serum copper levels increased in five patients possibly due to tamoxifen treatment, but no other alterations occurred in serum trace element levels. Appetite was well maintained and nutritional status remained unaltered. Postoperative radiotherapy for breast carcinoma had thus no effect on either trace element or nutritional status. Patient-initiated alternative treatments did not significantly affect their trace element levels. This was probably due to small supplementation doses or irregular use of the preparations. (orig.)

Systematic drug screening reveals specific vulnerabilities and co-resistance patterns in endocrine-resistant breast cancer.

Science.gov (United States)

Kangaspeska, Sara; Hultsch, Susanne; Jaiswal, Alok; Edgren, Henrik; Mpindi, John-Patrick; Eldfors, Samuli; Brück, Oscar; Aittokallio, Tero; Kallioniemi, Olli

2016-07-04

The estrogen receptor (ER) inhibitor tamoxifen reduces breast cancer mortality by 31 % and has served as the standard treatment for ER-positive breast cancers for decades. However, 50 % of advanced ER-positive cancers display de novo resistance to tamoxifen, and acquired resistance evolves in 40 % of patients who initially respond. Mechanisms underlying resistance development remain poorly understood and new therapeutic opportunities are urgently needed. Here, we report the generation and characterization of seven tamoxifen-resistant breast cancer cell lines from four parental strains. Using high throughput drug sensitivity and resistance testing (DSRT) with 279 approved and investigational oncology drugs, exome-sequencing and network analysis, we for the first time, systematically determine the drug response profiles specific to tamoxifen resistance. We discovered emerging vulnerabilities towards specific drugs, such as ERK1/2-, proteasome- and BCL-family inhibitors as the cells became tamoxifen-resistant. Co-resistance to other drugs such as the survivin inhibitor YM155 and the chemotherapeutic agent paclitaxel also occurred. This study indicates that multiple molecular mechanisms dictate endocrine resistance, resulting in unexpected vulnerabilities to initially ineffective drugs, as well as in emerging co-resistances. Thus, combatting drug-resistant tumors will require patient-tailored strategies in order to identify new drug vulnerabilities, and to understand the associated co-resistance patterns.

The 4Ps of Breast Cancer Chemoprevention: Putting Proven Principles into Practice.

Science.gov (United States)

Jordan, V Craig

2017-04-01

The pioneering Royal Marsden Tamoxifen Prevention Trial recruited 2,471 eligible high-risk women to be randomized to either placebo or tamoxifen (20 mg daily) for 8 years. Breast cancer incidence was evaluated at a median of 18.4 years from the start of the study. There was a 32% reduction in estrogen/progesterone receptor (ER/PR)-positive breast cancers after tamoxifen treatment finished. Translational research, to study "the good, the bad, and the ugly of tamoxifen" in the 1980s, subsequently ensured women's safety from possible increases in osteoperosis, coronary heart disease, and endometrial cancer. Other tamoxifen chemoprevention trials followed. The result of laboratory research was the unanticipated discovery of raloxifene to prevent osteoporosis and breast cancer at the same time. A new group of medicines, now known as selective ER modulators, was established. Indeed, the ability to prevent or delay multiple diseases with a single cheap medicine has the potential to alleviate pressure on health care systems that are overwhelmed. It is a priority to educate physicians appropriately to apply recommended proven medicines as preventives. Cancer Prev Res; 10(4); 219-22. ©2017 AACR See related article by Detre, et al., Cancer Prev Res 2017;10(3):171-6 . ©2017 American Association for Cancer Research.

Long-term hippocampal glutamate synapse and astrocyte dysfunctions underlying the altered phenotype induced by adolescent THC treatment in male rats.

Science.gov (United States)

Zamberletti, Erica; Gabaglio, Marina; Grilli, Massimo; Prini, Pamela; Catanese, Alberto; Pittaluga, Anna; Marchi, Mario; Rubino, Tiziana; Parolaro, Daniela

2016-09-01

Cannabis use has been frequently associated with sex-dependent effects on brain and behavior. We previously demonstrated that adult female rats exposed to delta-9-tetrahydrocannabinol (THC) during adolescence develop long-term alterations in cognitive performances and emotional reactivity, whereas preliminary evidence suggests the presence of a different phenotype in male rats. To thoroughly depict the behavioral phenotype induced by adolescent THC exposure in male rats, we treated adolescent animals with increasing doses of THC twice a day (PND 35-45) and, at adulthood, we performed a battery of behavioral tests to measure affective- and psychotic-like symptoms as well as cognition. Poorer memory performance and psychotic-like behaviors were present after adolescent THC treatment in male rats, without alterations in the emotional component. At cellular level, the expression of the NMDA receptor subunit, GluN2B, as well as the levels of the AMPA subunits, GluA1 and GluA2, were significantly increased in hippocampal post-synaptic fractions from THC-exposed rats compared to controls. Furthermore, increases in the levels of the pre-synaptic marker, synaptophysin, and the post-synaptic marker, PSD95, were also present. Interestingly, KCl-induced [(3)H]D-ASP release from hippocampal synaptosomes, but not gliosomes, was significantly enhanced in THC-treated rats compared to controls. Moreover, in the same brain region, adolescent THC treatment also resulted in a persistent neuroinflammatory state, characterized by increased expression of the astrocyte marker, GFAP, increased levels of the pro-inflammatory markers, TNF-α, iNOS and COX-2, as well as a concomitant reduction of the anti-inflammatory cytokine, IL-10. Notably, none of these alterations was observed in the prefrontal cortex (PFC). Together with our previous findings in females, these data suggest that the sex-dependent detrimental effects induced by adolescent THC exposure on adult behavior may rely on its

Krüppel-like factor 5 is essential for proliferation and survival of mouse intestinal epithelial stem cells

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Mandayam O. Nandan

2015-01-01

Full Text Available Krüppel-like factor 5 (KLF5 is a pro-proliferative transcription factor that is expressed in dividing epithelial cells of the intestinal crypt. Leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5 has been identified as a stem cell marker in both small intestinal and colonic epithelial cells. To determine whether KLF5 regulates proliferation of intestinal stem cells, we investigated the effects of Klf5 deletion specifically from the intestinal stem cells in adult mice. Mice with inducible intestinal stem cell-specific deletion of Klf5 (Lgr5-Klf5fl/fl were injected with tamoxifen for 5 consecutive days to induce Lgr5-driven Cre expression. Intestinal and colonic tissues were examined by immunohistochemistry at various time points up to 112 days following start of tamoxifen treatment. Klf5 is co-localized in the crypt-based columnar (CBC cells that express Lgr5. By 11 days following the start of tamoxifen treatment, Lgr5-positive crypts from which Klf5 was deleted exhibited a loss of proliferation that was accompanied by an increase in apoptosis. Beginning at 14 days following the start of tamoxifen treatment, both Klf5 expression and proliferation were re-established in the transit-amplifying epithelial cells but not in the Lgr5-positive CBC cells. By 112 days post-treatment, up to 90% of the Lgr5-positive cells from which Klf5 was deleted were lost from the intestinal crypts. These results indicate a critical role for KLF5 in the survival and maintenance of intestinal stem cells.

Metagenomic analyses of alcohol induced pathogenic alterations in the intestinal microbiome and the effect of Lactobacillus rhamnosus GG treatment.

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Lara Bull-Otterson

Full Text Available Enteric dysbiosis plays an essential role in the pathogenesis of alcoholic liver disease (ALD. Detailed characterization of the alterations in the gut microbiome is needed for understanding their pathogenic role in ALD and developing effective therapeutic approaches using probiotic supplementation. Mice were fed liquid Lieber-DeCarli diet without or with alcohol (5% v/v for 6 weeks. A subset of mice were administered the probiotic Lactobacillus rhamnosus GG (LGG from 6 to 8 weeks. Indicators of intestinal permeability, hepatic steatosis, inflammation and injury were evaluated. Metagenomic analysis of the gut microbiome was performed by analyzing the fecal DNA by amplification of the V3-V5 regions of the 16S rRNA gene and large-scale parallel pyrosequencing on the 454 FLX Titanium platform. Chronic ethanol feeding caused a decline in the abundance of both Bacteriodetes and Firmicutes phyla, with a proportional increase in the gram negative Proteobacteria and gram positive Actinobacteria phyla; the bacterial genera that showed the biggest expansion were the gram negative alkaline tolerant Alcaligenes and gram positive Corynebacterium. Commensurate with the qualitative and quantitative alterations in the microbiome, ethanol caused an increase in plasma endotoxin, fecal pH, hepatic inflammation and injury. Notably, the ethanol-induced pathogenic changes in the microbiome and the liver were prevented by LGG supplementation. Overall, significant alterations in the gut microbiome over time occur in response to chronic alcohol exposure and correspond to increases in intestinal barrier dysfunction and development of ALD. Moreover, the altered bacterial communities of the gut may serve as significant therapeutic target for the prevention/treatment of chronic alcohol intake induced intestinal barrier dysfunction and liver disease.

(Modic) signal alterations of vertebral endplates and their correlation to a minimally invasive treatment of lumbar disc herniation using epidural injections

International Nuclear Information System (INIS)

Liphofer, J.P.; Becker, G.T.; Koester, O.; Theodoridis, T.; Schmid, G.

2006-01-01

Purpose: To study the influence of (Modic) signal alterations (SA) of the cartilage endplate (CEP) of vertebrae L3-S1 on the outcome of an in-patient minimally invasive treatment (MIT), using epidural injections on patients with lumbar disc herniation (LDH). Materials and Methods: The MR images of 59 consecutive patients with LDH within segments L3/L4-L5/S1 undergoing in-patient minimally invasive treatment with epidural injections were evaluated in a clinical study. The (Modic) signal alterations of the CEP were recorded using T1- and T2-weighted sagittal images. On the basis of the T2-weighted sagittal images, the extension and distribution of the SA were measured by dividing each CEP into 9 areas. The outcome of the MIT was recorded using the Oswestry Disability Index (ODI) before and after therapy and in a 3-month follow-up. Within a subgroup of patients (n=35), the distribution and extension of the signal alterations were correlated with the development of the ODI. Results: Segments with LDH showed significantly more (p<0.001) SA of the CEP than segments without LDH. Although the extension of the SA was not dependent on sex, it did increase significantly with age (p=0.017). The outcome after MIT did not depend on the sex and age of the patients or on the type od LDH. The SA extension tended to have a negative correlation with the outcome after MIT after 3 months (p=0.071). A significant negative correlation could be established between the SA extension in the central section of the upper endplate and the outcome after 3 months (p=0.019). (orig.)

Effects of OK-432 (picibanil) on the estrogen receptors of MCF-7 cells and potentiation of antiproliferative effects of tamoxifen in combination with OK-432.

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Aoyagi, H; Iino, Y; Takeo, T; Horii, Y; Morishita, Y; Horiuchi, R

1997-01-01

OK-432 (picibanil), a streptococcal preparation, has a strong biological response modifier (BRM) function and is expected to produce clinical improvement and prolongation of survival in treated cancer patients in Japan. We were interested in whether OK-432 augments estrogen receptor (ER) levels in breast cancer. To investigate the effect of the BRMs on cellular growth and the characteristics of ER and progesterone receptors (PgR) in the human breast cancer cell line MCF-7, we used OK-432, Krestin (PSK), a protein-bound polysaccharide extracted from Coriolus versicolor, and lentinan, a fungal branched (1...3)-beta-D-glycan. OK432 and PSK dose dependently inhibited DNA synthesis of MCF-7 cells, and the 50% inhibitory concentrations of OK-432 and PSK were 1.2 KE (klinische Einheit, clinical unit)/ml and 200 micrograms/ml, respectively. Lentinan showed no direct anticancer effect in vitro. We found that OK-432 induced a 2-fold increase in ER levels in MCF-7 cells at 0.005 KE/ml, but not in PgR. Lentinan and low-dose PSK did not change ER or PgR levels, but high-dose PSK decreased ER and PgR. We also studied the combined effect of OK-432 and antiestrogens, tamoxifen (TAM) and DP-TAT-59. The combined treatment with OK-432 and TAM showed an additive inhibitory effect on MCF-7 cells. These results suggest that OK-432 may augment the therapeutic effect of TAM in breast cancer.

Alterations in cardiomyocyte function after pulmonary treatment with stainless steel welding fume in rats.

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Popstojanov, Risto; Antonini, James M; Salmen, Rebecca; Ye, Morgan; Zheng, Wen; Castranova, Vincent; Fekedulegn, Desta B; Kan, Hong

2014-01-01

Welding fume is composed of a complex of different metal particulates. Pulmonary exposure to different welding fumes may exert a negative impact on cardiac function, although the underlying mechanisms remain unclear. To explore the effect of welding fumes on cardiac function, Sprague-Dawley rats were exposed by intratracheal instillation to 2 mg/rat of manual metal arc hard surfacing welding fume (MMA-HS) once per week for 7 wk. Control rats received saline. Cardiomyocytes were isolated enzymatically at d 1 and 7 postexposure. Intracellular calcium ([Ca(2+)]i) transients (fluorescence ratio) were measured on the stage of an inverted phase-contrast microscope using a myocyte calcium imaging/cell length system. Phosphorylation levels of cardiac troponin I (cTnI) were determined by Western blot. The levels of nonspecific inflammatory marker C-reactive protein (CRP) and proinflammatory cytokine interleukin-6 (IL-6) in serum were measured by enzyme-linked immunosorbent assay (ELISA). Contraction of isolated cardiomyocytes was significantly reduced at d 1 and d 7 postexposure. Intracellular calcium levels were decreased in response to extracellular calcium stimulation at d 7 postexposure. Changes of intracellular calcium levels after isoprenaline hydrochloride (ISO) stimulation were not markedly different between groups at either time point. Phosphorylation levels of cTnI in the left ventricle were significantly lower at d 1 postexposure. The serum levels of CRP were not markedly different between groups at either time point. Serum levels of IL-6 were not detectable in both groups. Cardiomyocyte alterations observed after welding fume treatment were mainly due to alterations in intracellular calcium handling and phosphorylation levels of cTnI.

Prevention of Memory Impairment and Neurotrophic Factors Increased by Lithium in Wistar Rats Submitted to Pneumococcal Meningitis Model

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Lutiana R. Simões

2017-01-01

Full Text Available The aim of this study was to investigate the effects of lithium on brain-derived neurotrophic factor (BDNF, nerve growth factor (NGF, and glial cell line-derived neurotrophic factor (GDNF expression in the hippocampus and on memory in experimental pneumococcal meningitis. The mood-stabilizer lithium is known as a neuroprotective agent with many effects on the brain. In this study, animals received either artificial cerebrospinal fluid or Streptococcus pneumoniae suspension at a concentration of 5 × 109 CFU/mL. Eighteen hours after induction, all animals received ceftriaxone. The animals received saline or lithium (47.5 mg/kg or tamoxifen (1 mg/kg as adjuvant treatment, and they were separated into six groups: control/saline, control/lithium, control/tamoxifen, meningitis/saline, meningitis/lithium, and meningitis/tamoxifen. Ten days after meningitis induction, animals were subjected to open-field habituation and the step-down inhibitory avoidance tasks. Immediately after these tasks, the animals were killed and their hippocampus was removed to evaluate the expression of BDNF, NGF, and GDNF. In the meningitis group, treatment with lithium and tamoxifen resulted in improvement in memory. Meningitis group showed decreased expression of BDNF and GDNF in the hippocampus while lithium reestablished the neurotrophin expression. Lithium was able to prevent memory impairment and reestablishes hippocampal neurotrophin expression in experimental pneumococcal meningitis.

Mammographic Density Reduction as a Prognostic Marker for Postmenopausal Breast Cancer: Results Using a Joint Longitudinal-Survival Modeling Approach.

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Andersson, Therese M-L; Crowther, Michael J; Czene, Kamila; Hall, Per; Humphreys, Keith

2017-11-01

Previous studies have linked reductions in mammographic density after a breast cancer diagnosis to an improved prognosis. These studies focused on short-term change, using a 2-stage process, treating estimated change as a fixed covariate in a survival model. We propose the use of a joint longitudinal-survival model. This enables us to model long-term trends in density while accounting for dropout as well as for measurement error. We studied the change in mammographic density after a breast cancer diagnosis and its association with prognosis (measured by cause-specific mortality), overall and with respect to hormone replacement therapy and tamoxifen treatment. We included 1,740 women aged 50-74 years, diagnosed with breast cancer in Sweden during 1993-1995, with follow-up until 2008. They had a total of 6,317 mammographic density measures available from the first 5 years of follow-up, including baseline measures. We found that the impact of the withdrawal of hormone replacement therapy on density reduction was larger than that of tamoxifen treatment. Unlike previous studies, we found that there was an association between density reduction and survival, both for tamoxifen-treated women and women who were not treated with tamoxifen. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.

Epidermal growth factor treatment of A431 cells alters the binding capacity and electrophoretic mobility of the cytoskeletally associated epidermal growth factor receptor

International Nuclear Information System (INIS)

Roy, L.M.; Gittinger, C.K.; Landreth, G.E.

1991-01-01

Epidermal growth factor receptor interacts with structural elements of A431 cells and remains associated with the cytoskeleton following extraction with nonionic detergents. Extraction of cells with 0.15% Triton X-100 resulted in detection of only approximately 40% of the EGF binding sites on the cytoskeleton. If the cells were exposed to EGF prior to extraction, approximately twofold higher levels of low-affinity EGF binding sites were detected. The difference in number of EGF binding sites was not a consequence of differences in numbers of EGF receptors associated with the cytoskeleton; equal amounts of 35S-labeled receptor were immunoprecipitated from the cytoskeletons of both control and EGF-treated cells. The effect of EGF pretreatment on binding activity was coincident with a change in the mobility of the receptor from a doublet of Mr approximately 160-180 kDa to a single sharp band at 180 kDa. The alteration in receptor mobility was not a simple consequence of receptor phosphorylation in that the alteration was not reversed by alkaline phosphatase treatment, nor was the shift produced by treatment of the cells with phorbol ester. The two EGF receptor species demonstrated differential susceptibility to V8 proteinase digestion. The EGF-induced 180 kDa species was preferentially digested by the proteinase relative to the 160 kDa species, indicating that EGF binding results in a conformational change in the receptor. The EGF-mediated preservation of binding activity and altered conformation may be related to receptor oligomerization

[Plastic surgery for the treatment of gynaecomastia following hormone therapy in prostate carcinoma].

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Ryssel, H; Germann, G; Köllensperger, E; Riedel, K

2008-04-01

Gynecomastia is a potential side effect of hormone therapy for prostate cancer. In large, randomized, placebo controlled studies approximately 50% or more of patients with prostate cancer experienced gynecomastia attributable to various mechanisms. Although it is mostly reported as mild to moderate, gynecomastia is one of the reasons most frequently cited for premature discontinuation of such treatment. Prophylactic radiotherapy and prophylactic tamoxifen have been shown to decrease the incidence of hormone-induced gynecomastia; nevertheless, there are still cases of refractory gynecomastia, and in these plastic surgery is needed for correction. Gynecomastia is a benign enlargement of the male breast, requiring no treatment unless it is a source of embarrassment and/or distress for the adolescent or man affected. The indications for surgical treatment of gynecomastia are founded on two main objectives: restoration of the male chest shape and diagnostic evaluation of suspected breast lesions. The authors believe that the complete circumareolar technique with no further scarring creates the best aesthetic results with fewer complications. When this is used in combination with liposuction very pleasing aesthetic results can be achieved.

Drug Repurposing Screening Identifies Novel Compounds That Effectively Inhibit Toxoplasma gondii Growth

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Dittmar, Ashley J.; Drozda, Allison A.

2016-01-01

ABSTRACT The urgent need to develop new antimicrobial therapies has spawned the development of repurposing screens in which well-studied drugs and other types of compounds are tested for potential off-label uses. As a proof-of-principle screen to identify compounds effective against Toxoplasma gondii, we screened a collection of 1,120 compounds for the ability to significantly reduce Toxoplasma replication. A total of 94 compounds blocked parasite replication with 50% inhibitory concentrations of parasite invasion and replication but did so independently of inhibition of dopamine or other neurotransmitter receptor signaling. Tamoxifen, which is an established inhibitor of the estrogen receptor, also reduced parasite invasion and replication. Even though Toxoplasma can activate the estrogen receptor, tamoxifen inhibits parasite growth independently of this transcription factor. Tamoxifen is also a potent inducer of autophagy, and we find that the drug stimulates recruitment of the autophagy marker light chain 3-green fluorescent protein onto the membrane of the vacuolar compartment in which the parasite resides and replicates. In contrast to other antiparasitic drugs, including pimozide, tamoxifen treatment of infected cells leads to a time-dependent elimination of intracellular parasites. Taken together, these data suggest that tamoxifen restricts Toxoplasma growth by inducing xenophagy or autophagic destruction of this obligate intracellular parasite. IMPORTANCE There is an urgent need to develop new therapies to treat microbial infections, and the repurposing of well-characterized compounds is emerging as one approach to achieving this goal. Using the protozoan parasite Toxoplasma gondii, we screened a library of 1,120 compounds and identified several compounds with significant antiparasitic activities. Among these were pimozide and tamoxifen, which are well-characterized drugs prescribed to treat patients with psychiatric disorders and breast cancer

Postmastectomy irradiation in high-risk breast cancer patients

International Nuclear Information System (INIS)

Overgaard, M.; Juul Christensen, J.; Johansen, H.; Nybo-Rasmussen, A.; Brincker, H.; Kooy, P. van der; Frederiksen, P.L.; Laursen, F.; Panduro, J.; Soerensen, N.E.; Gadeberg, C.C.; Hjelm-Hansen, M.; Overgaard, J.; West Andersen, K.; Zedeler, K.

1988-01-01

All pre- and postmenopausal high-risk breast cancer patients in the protocols DBCG 77 of the Danish Breast Cancer Cooperative Group received postmastectomy irradiation before randomization to either adjuvant systemic therapy or no such treatment. The actuarial loco-regional recurrence rate at 9 years was 6-17%, with the lowest rate in patients who also received additional adjuvant chemotherapy or tamoxifen. In a subsequent study (DBCG 82) the role of postmastectomy irradiation together with systemic treatment was evaluated in high-risk patients. Pre- and menopausal patients were randomized to postmastectomy irradiation+CMF (cyclophosphamide, methotrexate, 5-fluorouracil), CMF alone or CMF+TAM (tamoxifen). Postmenopausal patients were randomized to postmastectomy irradiation+TAM, TAM or CMF+TAM. At 4 years the loco-regional recurrence rate was significantly lower in the irradiated patients (5-7% vs. 23-33%). Further, disease-free survival was significantly improved in both pre- and postmenopausal irradiated patients compared with those who had only systemic treatment. At present, there are no significant differences between survival in the treatment groups. Thus, adjuvant systemic treatment alone (chemotherapy and/or tamoxifen) did not prevent loco-regional recurrences in high-risk patients after mastectomy and axillary lymph node sampling. However, a longer observation time is necessary to evaluate the consequence of primary optimal loco-regional tumour control in high-risk breast cancer patients with respect to survival. (orig.)

The Impact of Endocrine Therapy on Cognitive Functions of Breast Cancer Patients: A Systematic Review.

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Bakoyiannis, Ioannis; Tsigka, Eleousa-Alexandra; Perrea, Despina; Pergialiotis, Vasilios

2016-02-01

The purpose of the present review was to study the impact of endocrine therapy (ET) on the cognitive outcomes of breast cancer patients. We systematically searched the literature using the MEDLINE (1966-2015), Scopus (2004-2015), ClinicalTrials.gov (2008-2015) and Cochrane Central Register (CENTRAL) databases, as well as the references of the electronically retrieved articles. Twelve studies were included in the present systematic review, which assessed the cognitive function of 2756 patients. Among these patients, 2381 received ET, whereas the remaining 375 served as controls (placebo or no therapy). The majority of patients were postmenopausal, and the minimum follow-up period was 3 months and the maximum 2 years. Treatment with ET seems to be accompanied by altered cognitive abilities, including verbal memory, verbal fluency, motor speed, attention and working memory. Tamoxifen seems to be related to decreased cognitive performances compared with treatment with an aromatase inhibitor. ET among breast cancer patients seems to negatively alter the cognitive outcomes of breast cancer patients. However, the methodological heterogeneity of the included studies, as well as the relatively small follow-up period, render imperative the conduct of further studies in the field.

Up-regulation of HOXB cluster genes are epigenetically regulated in tamoxifen-resistant MCF7 breast cancer cells.

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Yang, Seoyeon; Lee, Ji-Yeon; Hur, Ho; Oh, Ji Hoon; Kim, Myoung Hee

2018-05-28

Tamoxifen (TAM) is commonly used to treat estrogen receptor (ER)-positive breast cancer. Despite the remarkable benefits, resistance to TAM presents a serious therapeutic challenge. Since several HOX transcription factors have been proposed as strong candidates in the development of resistance to TAM therapy in breast cancer, we generated an in vitro model of acquired TAM resistance using ER-positive MCF7 breast cancer cells (MCF7-TAMR), and analyzed the expression pattern and epigenetic states of HOX genes. HOXB cluster genes were uniquely up-regulated in MCF7-TAMR cells. Survival analysis of in slico data showed the correlation of high expression of HOXB genes with poor response to TAM in ER-positive breast cancer patients treated with TAM. Gain- and loss-of-function experiments showed that the overexpression of multi HOXB genes in MCF7 renders cancer cells more resistant to TAM, whereas the knockdown restores TAM sensitivity. Furthermore, activation of HOXB genes in MCF7-TAMR was associated with histone modifications, particularly the gain of H3K9ac. These findings imply that the activation of HOXB genes mediate the development of TAM resistance, and represent a target for development of new strategies to prevent or reverse TAM resistance.

Epilepsy in patients with GRIN2A alterations

DEFF Research Database (Denmark)

von Stülpnagel, Celina; Ensslen, M; Møller, R S

2017-01-01

indicate that children with epilepsy due to pathogenic GRIN2A mutations present with different clinical phenotypes and a spectrum of seizure types in the context of a pharmacoresistant epilepsy providing information for clinicians treating children with this form of genetically determined epileptic......OBJECTIVE: To delineate the genetic, neurodevelopmental and epileptic spectrum associated with GRIN2A alterations with emphasis on epilepsy treatment. METHODS: Retrospective study of 19 patients (7 females; age: 1-38 years; mean 10.1 years) with epilepsy and GRIN2A alteration. Genetic variants were...... classified according to the guidelines and recommendations of the American College of Medical Genetics (ACMG). Clinical findings including epilepsy classification, treatment, EEG findings, early childhood development and neurodevelopmental outcome were collected with an electronic questionnaire. RESULTS: 7...

Arctigenin inhibits the activation of the mTOR pathway, resulting in autophagic cell death and decreased ER expression in ER-positive human breast cancer cells.

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Maxwell, Thressi; Lee, Kyu Shik; Kim, Soyoung; Nam, Kyung-Soo

2018-04-01

Arctigenin, a member of the Asteraceae family, is a biologically active lignan that is consumed worldwide due to its several health benefits. However, its use may pose a problem for patients with estrogen receptor (ER)α-positive breast cancer, since studies have shown that arctigenin is a phytoestrogen that exerts a proliferative effect by binding to the ER. Thus, in this study, we examined the effect of arctigenin on ERα-positive MCF-7 human breast cancer cells to determine whether the consumption of arctigenin is safe for patients with breast cancer. First, we found that arctigenin inhibited the viability of the MCF-7 cells, and colony formation assay confirmed that this effect was cytotoxic rather than cytostatic. The cytotoxic effects were not mediated by cell cycle arrest, apoptosis, or necroptosis, despite DNA damage, as indicated by poly(ADP-ribose) polymerase (PARP) cleavage and phosphorylated H2A.X. An increase in lipidated LC3, a marker of autophagosome formation, was observed, indicating that autophagy was induced by arctigenin, which was found to be triggered by the inhibition of the mechanistic target of rapamycin (mTOR) pathway. We then examined the effects of arctigenin on ERα expression and determined whether it affects the sensitivity of the cells to tamoxifen, as tamoxifen is commonly used against hormone-responsive cancers and is known to act via the ERα. We found that treatment with arctigenin effectively downregulated ERα expression, which was found to be a consequence of the inhibition of the mTOR pathway. However, treatment with arctigenin in combination with tamoxifen did not affect the sensitivity of the cells to tamoxifen, but instead, exerted a synergistic effect. On the whole, our data indicate that the phytoestrogen, arctigenin, mainly targeted the mTOR pathway in ERα-positive MCF-7 human breast cancer cells, leading to autophagy-induced cell death and the downregulation of ERα expression. Furthermore, the synergistic effects

Caffeine exposure alters cardiac gene expression in embryonic cardiomyocytes

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Fang, Xiefan; Mei, Wenbin; Barbazuk, William B.; Rivkees, Scott A.

2014-01-01

Previous studies demonstrated that in utero caffeine treatment at embryonic day (E) 8.5 alters DNA methylation patterns, gene expression, and cardiac function in adult mice. To provide insight into the mechanisms, we examined cardiac gene and microRNA (miRNA) expression in cardiomyocytes shortly after exposure to physiologically relevant doses of caffeine. In HL-1 and primary embryonic cardiomyocytes, caffeine treatment for 48 h significantly altered the expression of cardiac structural genes (Myh6, Myh7, Myh7b, Tnni3), hormonal genes (Anp and BnP), cardiac transcription factors (Gata4, Mef2c, Mef2d, Nfatc1), and microRNAs (miRNAs; miR208a, miR208b, miR499). In addition, expressions of these genes were significantly altered in embryonic hearts exposed to in utero caffeine. For in utero experiments, pregnant CD-1 dams were treated with 20–60 mg/kg of caffeine, which resulted in maternal circulation levels of 37.3–65.3 μM 2 h after treatment. RNA sequencing was performed on embryonic ventricles treated with vehicle or 20 mg/kg of caffeine daily from E6.5-9.5. Differential expression (DE) analysis revealed that 124 genes and 849 transcripts were significantly altered, and differential exon usage (DEU) analysis identified 597 exons that were changed in response to prenatal caffeine exposure. Among the DE genes identified by RNA sequencing were several cardiac structural genes and genes that control DNA methylation and histone modification. Pathway analysis revealed that pathways related to cardiovascular development and diseases were significantly affected by caffeine. In addition, global cardiac DNA methylation was reduced in caffeine-treated cardiomyocytes. Collectively, these data demonstrate that caffeine exposure alters gene expression and DNA methylation in embryonic cardiomyocytes. PMID:25354728

Synthesis and Biological Activity of Diastereomeric and Geometric Analogs of Calcipotriol, PRI-2202 and PRI-2205, Against Human HL-60 Leukemia and MCF-7 Breast Cancer Cells.

Science.gov (United States)

Milczarek, Magdalena; Chodyński, Michał; Filip-Psurska, Beata; Martowicz, Agnieszka; Krupa, Małgorzata; Krajewski, Krzysztof; Kutner, Andrzej; Wietrzyk, Joanna

2013-10-31

Diastereomeric and geometric analogs of calcipotriol, PRI-2202 and PRI-2205, were synthesized as advanced intermediates from vitamin D C-22 benzothiazoyl sulfones and side-chain aldehydes using our convergent strategy. Calcitriol, calcipotriol (PRI-2201) and tacalcitol (PRI-2191) were used as the reference compounds. Among a series of tested analogs the diastereomeric analog PRI-2202 showed the strongest antiproliferative activity on the human breast cancer cell line MCF-7, whereas the geometric analog PRI-2205 was the weakest. Both analogs were less potent in antiproliferative activity against HL-60 cells compared to the reference compounds. The ability to potentiate antiproliferative effect of cisplatin or doxorubicin against HL-60 cells or that of tamoxifen against the MCF-7 cell line was observed at higher doses of PRI-2202 or PRI-2205 than those of the reference compounds. The proapoptotic activity of tamoxifen, expressed as the diminished mitochondrial membrane potential, as well as the increased phosphatidylserine expression, was partially attenuated by calcitriol, PRI-2191, PRI-2201 and PRI-2205. The treatment of the MCF-7 cells with tamoxifen alone resulted in an increase in VDR expression. Moreover, a further increase in VDR expression was observed when the analogs PRI-2201 or PRI-2205, but not PRI-2191, were used in combination with tamoxifen. This observation could partially explain the potentiation of the antiproliferative effect of tamoxifen by vitamin D analogs.

Association between the 21-gene recurrence score assay and risk of locoregional recurrence in node-negative, estrogen receptor-positive breast cancer: results from NSABP B-14 and NSABP B-20.

Science.gov (United States)

Mamounas, Eleftherios P; Tang, Gong; Fisher, Bernard; Paik, Soonmyung; Shak, Steven; Costantino, Joseph P; Watson, Drew; Geyer, Charles E; Wickerham, D Lawrence; Wolmark, Norman

2010-04-01

The 21-gene OncotypeDX recurrence score (RS) assay quantifies the risk of distant recurrence in tamoxifen-treated patients with node-negative, estrogen receptor (ER)-positive breast cancer. We investigated the association between RS and risk for locoregional recurrence (LRR) in patients with node-negative, ER-positive breast cancer from two National Surgical Adjuvant Breast and Bowel Project (NSABP) trials (NSABP B-14 and B-20). RS was available for 895 tamoxifen-treated patients (from both trials), 355 placebo-treated patients (from B-14), and 424 chemotherapy plus tamoxifen-treated patients (from B-20). The primary end point was time to first LRR. Distant metastases, second primary cancers, and deaths before LRR were censored. In tamoxifen-treated patients, LRR was significantly associated with RS risk groups (P 30). There were also significant associations between RS and LRR in placebo-treated patients from B-14 (P = .022) and in chemotherapy plus tamoxifen-treated patients from B-20 (P = .028). In multivariate analysis, RS was an independent significant predictor of LRR along with age and type of initial treatment. Similar to the association between RS and risk for distant recurrence, a significant association exists between RS and risk for LRR. This information has biologic consequences and potential clinical implications relative to locoregional therapy decisions for patients with node-negative and ER-positive breast cancer.

Characterizing genomic alterations in cancer by complementary functional associations.

Science.gov (United States)

Kim, Jong Wook; Botvinnik, Olga B; Abudayyeh, Omar; Birger, Chet; Rosenbluh, Joseph; Shrestha, Yashaswi; Abazeed, Mohamed E; Hammerman, Peter S; DiCara, Daniel; Konieczkowski, David J; Johannessen, Cory M; Liberzon, Arthur; Alizad-Rahvar, Amir Reza; Alexe, Gabriela; Aguirre, Andrew; Ghandi, Mahmoud; Greulich, Heidi; Vazquez, Francisca; Weir, Barbara A; Van Allen, Eliezer M; Tsherniak, Aviad; Shao, Diane D; Zack, Travis I; Noble, Michael; Getz, Gad; Beroukhim, Rameen; Garraway, Levi A; Ardakani, Masoud; Romualdi, Chiara; Sales, Gabriele; Barbie, David A; Boehm, Jesse S; Hahn, William C; Mesirov, Jill P; Tamayo, Pablo

2016-05-01

Systematic efforts to sequence the cancer genome have identified large numbers of mutations and copy number alterations in human cancers. However, elucidating the functional consequences of these variants, and their interactions to drive or maintain oncogenic states, remains a challenge in cancer research. We developed REVEALER, a computational method that identifies combinations of mutually exclusive genomic alterations correlated with functional phenotypes, such as the activation or gene dependency of oncogenic pathways or sensitivity to a drug treatment. We used REVEALER to uncover complementary genomic alterations associated with the transcriptional activation of β-catenin and NRF2, MEK-inhibitor sensitivity, and KRAS dependency. REVEALER successfully identified both known and new associations, demonstrating the power of combining functional profiles with extensive characterization of genomic alterations in cancer genomes.

Medicinsk efterbehandling af brystkraeft. Endokrin behandling

DEFF Research Database (Denmark)

Mouridsen, Henning T; Andersen, Jørn

2007-01-01

For women with steroid receptor-positive breast cancers, endocrine therapy has proven to be a major component of adjuvant therapy reducing the risk of recurrence and death. The selective estrogen-receptor modulator (SERM) tamoxifen has been well established as safe and effective in the adjuvant...... care of both pre- and postmenopausal women. For premenopausal women, ovarian suppression is an important option to be considered. Additionally, aromatase inhibitors have recently demonstrated further benefits in postmenopausal women. The ideal sequencing of treatment with tamoxifen and/or an aromatase...

Metformin alters the gut microbiome of individuals with treatment-naive type 2 diabetes, contributing to the therapeutic effects of the drug

DEFF Research Database (Denmark)

Wu, Hao; Esteve, Eduardo; Tremaroli, Valentina

2017-01-01

months and showed that metformin had strong effects on the gut microbiome. These results were verified in a subset of the placebo group that switched to metformin 6 months after the start of the trial. Transfer of fecal samples (obtained before and 4 months after treatment) from metformin-treated donors......Metformin is widely used in the treatment of type 2 diabetes (T2D), but its mechanism of action is poorly defined. Recent evidence implicates the gut microbiota as a site of metformin action. In a double-blind study, we randomized individuals with treatment-naive T2D to placebo or metformin for 4...... to germ-free mice showed that glucose tolerance was improved in mice that received metformin-altered microbiota. By directly investigating metformin-microbiota interactions in a gut simulator, we showed that metformin affected pathways with common biological functions in species from two different phyla...

Conditional reduction of adult born doublecortin-positive neurons reversibly impairs selective behaviours

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Lillian eGarrett

2015-11-01

Full Text Available Adult neurogenesis occurs in the adult mammalian subventricular zone (SVZ along the walls of the lateral ventricles and the subgranular zone (SGZ of the hippocampal dentate gyrus. While a burgeoning body of research implicates adult neurogenesis in olfactory bulb (OB - and hippocampal-related behaviors, the precise function continues to elude. To further assess the behavioral importance of adult neurogenesis, we herein generated a novel inducible transgenic mouse model of adult neurogenesis reduction where mice with CreERT2 under doublecortin (DCX promoter control were crossed with mice where diphtheria toxin A (DTA was driven by the Rosa26 promoter. Activation of DTA, through the administration of tamoxifen (TAM, results in a specific reduction of DCX+ immature neurons in both the hippocampal dentate gyrus and OB. We show that the decrease of DCX+ cells causes impaired social discrimination ability in both young adult (from 3 months and middle (from 10 months aged mice. Furthermore, these animals showed an age-independent altered coping behavior in the Forced Swim Test without clear changes in anxiety-related behavior. Notably, these behavior changes were reversible on repopulating the neurogenic zones with DCX+ cells on cessation of the tamoxifen treatment, demonstrating the specificity of this effect. Overall, these results support the notion that adult neurogenesis plays a role in social memory and in stress coping but not necessarily in anxiety-related behavior.

Dgroup: DG00734 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available DG00734 Chemical ... DGroup Tamoxifen ... D08559 ... Tamoxifen (INN) D00966 ... Tamoxifen cit...rate (JP17/USP) ... Antineoplastic ... DG01585 ... Estrogen receptor antagonist Other ... DG01619 ... Clomifene and tamox...ifen derivative ... DG01620 ... Tamoxifene-type antineoplastic Cyp substrate ... DG01892 ... CYP1A2 substrate ... DG01642

Exemestane in early breast cancer: a review

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Michael Untch

2008-12-01

Full Text Available Michael Untch1, Christian Jackisch21Interdisciplinary Breast Centre, Helios Klinikum Berlin-Buch, University Charité, Berlin, Germany; 2Department of Gynecology/Obstetrics, Klinikum Offenbach GmbH, Offenbach, GermanyAbstract: The adjuvant treatment of women with endocrine-sensitive early breast cancer has been dominated for the last 40 years by tamoxifen. However, the side-effects associated with this therapy have prompted a search for safer and biochemically more selective endocrine agents and led to the development of the third-generation aromatase inhibitors (AIs anastrozole, letrozole and exemestane. Promising results in advanced disease have paved the way for treating early breast cancer, and AIs are increasingly replacing tamoxifen in the adjuvant setting. Several large, randomized trials with AIs have been completed or are ongoing in women with early-stage breast cancer, documenting the significant impact that these drugs are making on the risk for recurrence of breast cancer. As a result, there is increasing and widespread use of AI therapy for the treatment of early-stage endocrine-responsive breast cancer. This review summarizes the data for exemestane in the adjuvant setting, showing that a switch to exemestane after 2 to 3 years of tamoxifen therapy is associated with a statistically significant survival benefit and is regarded as being sensitive by international and national experts.Keywords: early breast cancer, adjuvant setting, endocrine-sensitive, tamoxifen, aromatase inhibitor, exemestane, switch, IES 31, NSABP B-33, TEAM

Connective tissue alteration in abdominal wall hernia

DEFF Research Database (Denmark)

Henriksen, N A; Yadete, D H; Sørensen, Lars Tue

2011-01-01

The aetiology and pathogenesis of abdominal wall hernia formation is complex. Optimal treatment of hernias depends on a full understanding of the pathophysiological mechanisms involved in their formation. The aim of this study was to review the literature on specific collagen alterations in abdom...

Dgroup: DG01620 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available DG01620 DGroup Tamoxifene-type antineoplastic -ifen(e) ... DG00734 ... Tamoxifen ... D08559 ... Tam...oxifen (INN) ... D00966 ... Tamoxifen citrate (JP17/USP) ... DG00735 ... Toremifene ... D08620 ... Toremifene (INN) ... D0...USAN/INN) D09380 ... Sivifene (USAN/INN) Other ... DG01619 ... Clomifene and tamoxifen derivative ... Antiestrogens or e

Uptake of breast cancer preventive therapy in the UK: results from a multicentre prospective survey and qualitative interviews.

Science.gov (United States)

Hackett, Julia; Thorneloe, Rachael; Side, Lucy; Wolf, Michael; Horne, Rob; Cuzick, Jack; Smith, Samuel G

2018-04-24

Uptake of preventive therapy for women at increased breast cancer risk in England is unknown following the introduction of UK clinical guidelines in 2013. Preventive therapy could create socioeconomic inequalities in cancer incidence if it is more readily accepted by particular socio-demographic groups. In this multicentre study, we investigated uptake of tamoxifen and evaluated socio-demographic and clinical factors associated with initiation. We explored women's experiences of treatment decision-making using qualitative interview data. Between September 2015 and December 2016, women (n = 732) attending an appointment at one of 20 centres in England to discuss breast cancer risk were approached to complete a survey containing socio-demographic details and nulliparity. Of the baseline survey respondents (n = 408/732, 55.7% response rate), self-reported uptake of tamoxifen at 3-month follow-up was reported in 258 (63.2%). Sixteen women participated in semi-structured interviews. One in seven (38/258 = 14.7%) women initiated tamoxifen. Women who had children were more likely to report use of tamoxifen than those without children (OR = 5.26; 95%CI: 1.13-24.49, p = 0.035). Interview data suggested that women weigh up risks and benefits of tamoxifen within the context of familial commitments, with exposure to significant other's beliefs and experiences of cancer and medication a basis for their decision. Uptake of tamoxifen is low in clinical practice. There were no socio-demographic differences in uptake, suggesting that the introduction of breast cancer preventive therapy is unlikely to create socioeconomic inequalities in cancer incidence. Women's decision-making was influenced by familial priorities, particularly having children.

When "altering brain function" becomes "mind control".

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Koivuniemi, Andrew; Otto, Kevin

2014-01-01

Functional neurosurgery has seen a resurgence of interest in surgical treatments for psychiatric illness. Deep brain stimulation (DBS) technology is the preferred tool in the current wave of clinical experiments because it allows clinicians to directly alter the functions of targeted brain regions, in a reversible manner, with the intent of correcting diseases of the mind, such as depression, addiction, anorexia nervosa, dementia, and obsessive compulsive disorder. These promising treatments raise a critical philosophical and humanitarian question. "Under what conditions does 'altering brain function' qualify as 'mind control'?" In order to answer this question one needs a definition of mind control. To this end, we reviewed the relevant philosophical, ethical, and neurosurgical literature in order to create a set of criteria for what constitutes mind control in the context of DBS. We also outline clinical implications of these criteria. Finally, we demonstrate the relevance of the proposed criteria by focusing especially on serendipitous treatments involving DBS, i.e., cases in which an unintended therapeutic benefit occurred. These cases highlight the importance of gaining the consent of the subject for the new therapy in order to avoid committing an act of mind control.

Prognostic Impact of the Combination of Recurrence Score and Quantitative Estrogen Receptor Expression (ESR1) on Predicting Late Distant Recurrence Risk in Estrogen Receptor-Positive Breast Cancer After 5 Years of Tamoxifen: Results From NRG Oncology/National Surgical Adjuvant Breast and Bowel Project B-28 and B-14.

Science.gov (United States)

Wolmark, Norman; Mamounas, Eleftherios P; Baehner, Frederick L; Butler, Steven M; Tang, Gong; Jamshidian, Farid; Sing, Amy P; Shak, Steven; Paik, Soonmyung

2016-07-10

We determined the utility of the 21-Gene Recurrence Score (RS) in predicting late (> 5 years) distant recurrence (LDR) in stage I and II breast cancer within high and low-ESR1-expressing groups. RS was assessed in chemotherapy/tamoxifen-treated, estrogen receptor (ER) -positive, node-positive National Surgical Adjuvant Breast and Bowel Project B-28 patients and tamoxifen-treated, ER-positive, node-negative B-14 patients. The association of the RS with risk of distant recurrence (DR) 0 to 5 years and those at risk > 5 years was assessed. An ESR1 expression cut point was optimized in B-28 and tested in B-14. Median follow-up was 11.2 years for B-28 and 13.9 years for B-14. Of 1,065 B-28 patients, 36% had low ( 5 to 10 years (log-rank P = .02) regardless of ESR1 expression. An ESR1 expression cut point of 9.1 CT was identified in B-28. It was validated in B-14 patients for whom the RS was associated with DR in years 5 to 15: 6.8% (95% CI, 4.4% to 10.6%) versus 11.2% (95% CI, 6.2% to 19.9%) versus 16.4% (95% CI, 10.2% to 25.7%) for RS < 18, RS 18 to 30, and RS ≥ 31, respectively (log-rank P = .01). For LDR, RS is strongly prognostic in patients with higher quantitative ESR1. Risk of LDR is relatively low for patients with low RS. These results suggest the value of extended tamoxifen therapy merits evaluation in patients with intermediate and high RS with higher ESR1 expression at initial diagnosis. © 2016 by American Society of Clinical Oncology.

Prognostic Impact of the Combination of Recurrence Score and Quantitative Estrogen Receptor Expression (ESR1) on Predicting Late Distant Recurrence Risk in Estrogen Receptor–Positive Breast Cancer After 5 Years of Tamoxifen: Results From NRG Oncology/National Surgical Adjuvant Breast and Bowel Project B-28 and B-14

Science.gov (United States)

Wolmark, Norman; Baehner, Frederick L.; Butler, Steven M.; Tang, Gong; Jamshidian, Farid; Sing, Amy P.; Shak, Steven; Paik, Soonmyung

2016-01-01

Purpose We determined the utility of the 21-Gene Recurrence Score (RS) in predicting late (> 5 years) distant recurrence (LDR) in stage I and II breast cancer within high and low-ESR1–expressing groups. Patients and Methods RS was assessed in chemotherapy/tamoxifen-treated, estrogen receptor (ER) –positive, node-positive National Surgical Adjuvant Breast and Bowel Project B-28 patients and tamoxifen-treated, ER-positive, node-negative B-14 patients. The association of the RS with risk of distant recurrence (DR) 0 to 5 years and those at risk > 5 years was assessed. An ESR1 expression cut point was optimized in B-28 and tested in B-14. Results Median follow-up was 11.2 years for B-28 and 13.9 years for B-14. Of 1,065 B-28 patients, 36% had low ( 5 to 10 years (log-rank P = .02) regardless of ESR1 expression. An ESR1 expression cut point of 9.1 CT was identified in B-28. It was validated in B-14 patients for whom the RS was associated with DR in years 5 to 15: 6.8% (95% CI, 4.4% to 10.6%) versus 11.2% (95% CI, 6.2% to 19.9%) versus 16.4% (95% CI, 10.2% to 25.7%) for RS < 18, RS 18 to 30, and RS ≥ 31, respectively (log-rank P = .01). Conclusion For LDR, RS is strongly prognostic in patients with higher quantitative ESR1. Risk of LDR is relatively low for patients with low RS. These results suggest the value of extended tamoxifen therapy merits evaluation in patients with intermediate and high RS with higher ESR1 expression at initial diagnosis. PMID:27217450

Tamoxifen-loaded nanoparticles based on a novel mixture of biodegradable polyesters: characterization and in vitro evaluation as sustained release systems.

Science.gov (United States)

Pérez, Elena; Benito, Marta; Teijón, César; Olmo, Rosa; Teijón, José M; Blanco, M Dolores

2012-01-01

Nanoparticles (NP) from mixtures of two poly(D,L-lactide-co-caprolactone) (PLC) copolymers, PLC 40/60 and PLC 86/14, with poly(D,L-lactide) (PDLLA) and PCL were prepared: PLC 40/60-PCL (25:75), PLC 86/14-PCL (75:25) and PLC 86/14-PLA (75:25). Tamoxifen was loaded with encapsulation efficiency between 65% and 75% (29.9-36.3 µg TMX/ mg NP). All selected systems showed spherical shape and nano-scale size. TMX-loaded NPs were in the range of 293-352 nm. TMX release from NP took place with different profiles depending on polymeric composition of the particles. After 60 days, 59.81% and 82.65% of the loaded drug was released. The cytotoxicity of unloaded NP in MCF7 and HeLa cells was very low. Cell uptake of NP took place in both cell types by unspecific internalization in a time dependent process. The administration of 6 and 10 µm TMX by TMX-loaded NP was effective on both cellular types, mainly in MCF7 cells.

Errantum: Treatment of human astrocytoma U87 cells with silicon dioxide nanoparticles lowers their survival and alters their expression of mitochondrial and cell signaling proteins

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Lai JCK

2010-12-01

Full Text Available Lai JCK, Ananthakrishnan G, Jandhyam S, et al. Treatment of human astrocytoma U87 cells with silicon dioxide nanoparticles lowers their survival and alters their expression of mitochondrial and cell signaling proteins. Int J Nanomedicine. 2010;5:715–723.The wrong image was used in Figure 5 on page 719.

Prospective comparison of breast pain in patients participating in a randomized trial of breast-conserving surgery and tamoxifen with or without radiotherapy

International Nuclear Information System (INIS)

Rayan, Gamal; Dawson, Laura A.; Bezjak, Andrea; Lau, Anthea; Fyles, Anthony W.; Yi, Q.-L.; Merante, Pat; Vallis, Katherine A.

2003-01-01

Purpose: To determine whether breast pain affects quality of life (QOL) after breast-conserving surgery and tamoxifen (TAM) with or without adjuvant breast radiotherapy (RT). Methods and Materials: A randomized clinical trial was carried out at the Princess Margaret Hospital between 1992 and 2000 to evaluate the need for breast RT in addition to TAM in women ≥50 years treated with breast-conserving surgery for T1-T2N0 breast cancer. A companion study to assess breast pain was carried out during the last 2 years of the randomized clinical trial. The short-form McGill Pain Questionnaire (SF-MPQ), the European Organization for Research and Treatment of Cancer (EORTC) QOL (QLQ-C30) and EORTC breast cancer module (QLQ-BR23) questionnaires were completed by patients within 1 week of randomization in the randomized clinical trial (baseline) and at 3, 6, and 12 months. Results: Eighty-six patients participated in the breast pain study; 41 received RT plus TAM and 45 received TAM alone. The median age was 70 years (range 51-80). The baseline pain and QOL scores were similar for the two groups. No significant difference was found between the two groups for each scale of the QLQ-C30 and QLQ-BR23 questionnaires at 3, 6, or 12 months (p>0.100), except that at 12 months, the score for role function (QLQ-C30) was higher in the RT plus TAM group than in the RT-only group (p=0.02). At 3 months, the difference between the mean scores for the SF-MPQ was 0.553 (p=0.47). At 12 months, the pain scores had decreased in both groups; the difference was 0.199 (p=0.71). The number of breast operations or surgical complications did not correlate with breast pain in either group. Acute RT toxicity scores did not correlate with breast pain or QOL scores at 12 months. Conclusion: These results suggest that breast RT does not significantly contribute to breast pain or adversely impact the QOL up to 12 months after treatment in postmenopausal patients with node-negative breast cancer who take

Theophylline, a methylxanthine drug induces osteopenia and alters calciotropic hormones, and prophylactic vitamin D treatment protects against these changes in rats

International Nuclear Information System (INIS)

Pal, Subhashis; Khan, Kainat; China, Shyamsundar Pal; Mittal, Monika; Porwal, Konica; Shrivastava, Richa; Taneja, Isha; Hossain, Zakir; Mandalapu, Dhanaraju; Gayen, Jiaur R.; Wahajuddin, Muhammad; Sharma, Vishnu Lal; Trivedi, Arun K.; Sanyal, Sabyasachi; Bhadauria, Smrati; Godbole, Madan M.; Gupta, Sushil K.; Chattopadhyay, Naibedya

2016-01-01

The drug, theophylline is frequently used as an additive to medications for people suffering from chronic obstructive pulmonary diseases (COPD). We studied the effect of theophylline in bone cells, skeleton and parameters related to systemic calcium homeostasis. Theophylline induced osteoblast apoptosis by increasing reactive oxygen species production that was caused by increased cAMP production. Bone marrow levels of theophylline were higher than its serum levels, indicating skeletal accumulation of this drug. When adult Sprague-Dawley rats were treated with theophylline, bone regeneration at fracture site was diminished compared with control. Theophylline treatment resulted in a time-dependent (at 4- and 8 weeks) bone loss. At 8 weeks, a significant loss of bone mass and deterioration of microarchitecture occurred and the severity was comparable to methylprednisone. Theophylline caused formation of hypomineralized osteoid and increased osteoclast number and surface. Serum bone resorption and formation marker were respectively higher and lower in the theophylline group compared with control. Bone strength was reduced by theophylline treatment. After 8 weeks, serum 25-D3 and liver 25-hydroxylases were decreased in theophylline group than control. Further, theophylline treatment reduced serum 1, 25-(OH) 2 vitamin D 3 (1,25-D3), and increased parathyroid hormone and fibroblast growth factor-23. Theophylline treated rats had normal serum calcium and phosphate but displayed calciuria and phosphaturia. Co-administration of 25-D3 with theophylline completely abrogated theophylline-induced osteopenia and alterations in calcium homeostasis. In addition, 1,25-D3 protected osteoblasts from theophylline-induced apoptosis and the attendant oxidative stress. We conclude that theophylline has detrimental effects in bone and prophylactic vitamin D supplementation to subjects taking theophylline could be osteoprotective. - Highlights: • Theophylline induced osteoblast apoptosis

Theophylline, a methylxanthine drug induces osteopenia and alters calciotropic hormones, and prophylactic vitamin D treatment protects against these changes in rats

Energy Technology Data Exchange (ETDEWEB)

Pal, Subhashis; Khan, Kainat; China, Shyamsundar Pal; Mittal, Monika; Porwal, Konica [Division of Endocrinology and Center for Research in Anabolic Skeletal Target in Health and Illness (ASTHI), Central Drug Research Institute - CDRI, Council of Scientific and Industrial Research (CSIR), Lucknow 226021 (India); Shrivastava, Richa [Division of Toxicology, CDRI-CSIR, Lucknow 226021 (India); Taneja, Isha; Hossain, Zakir [Pharmacokinetics and Metabolism Division, CDRI-CSIR, Lucknow 226021 (India); Mandalapu, Dhanaraju [Division of Medicinal and Process Chemistry, CDRI-CSIR, Lucknow 226021 (India); Gayen, Jiaur R.; Wahajuddin, Muhammad [Pharmacokinetics and Metabolism Division, CDRI-CSIR, Lucknow 226021 (India); Sharma, Vishnu Lal [Division of Medicinal and Process Chemistry, CDRI-CSIR, Lucknow 226021 (India); Trivedi, Arun K.; Sanyal, Sabyasachi [Division of Biochemistry, CDRI-CSIR, Lucknow 226021 (India); Bhadauria, Smrati [Division of Toxicology, CDRI-CSIR, Lucknow 226021 (India); Godbole, Madan M.; Gupta, Sushil K. [Department of Medical Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014 (India); Chattopadhyay, Naibedya, E-mail: n_chattopadhyay@cdri.res.in [Division of Endocrinology and Center for Research in Anabolic Skeletal Target in Health and Illness (ASTHI), Central Drug Research Institute (CDRI), Council of Scientific and Industrial Research - CSIR, Lucknow 226021 (India)

2016-03-15

The drug, theophylline is frequently used as an additive to medications for people suffering from chronic obstructive pulmonary diseases (COPD). We studied the effect of theophylline in bone cells, skeleton and parameters related to systemic calcium homeostasis. Theophylline induced osteoblast apoptosis by increasing reactive oxygen species production that was caused by increased cAMP production. Bone marrow levels of theophylline were higher than its serum levels, indicating skeletal accumulation of this drug. When adult Sprague-Dawley rats were treated with theophylline, bone regeneration at fracture site was diminished compared with control. Theophylline treatment resulted in a time-dependent (at 4- and 8 weeks) bone loss. At 8 weeks, a significant loss of bone mass and deterioration of microarchitecture occurred and the severity was comparable to methylprednisone. Theophylline caused formation of hypomineralized osteoid and increased osteoclast number and surface. Serum bone resorption and formation marker were respectively higher and lower in the theophylline group compared with control. Bone strength was reduced by theophylline treatment. After 8 weeks, serum 25-D3 and liver 25-hydroxylases were decreased in theophylline group than control. Further, theophylline treatment reduced serum 1, 25-(OH){sub 2} vitamin D{sub 3} (1,25-D3), and increased parathyroid hormone and fibroblast growth factor-23. Theophylline treated rats had normal serum calcium and phosphate but displayed calciuria and phosphaturia. Co-administration of 25-D3 with theophylline completely abrogated theophylline-induced osteopenia and alterations in calcium homeostasis. In addition, 1,25-D3 protected osteoblasts from theophylline-induced apoptosis and the attendant oxidative stress. We conclude that theophylline has detrimental effects in bone and prophylactic vitamin D supplementation to subjects taking theophylline could be osteoprotective. - Highlights: • Theophylline induced osteoblast

Getting the right balance in treatment of ductal carcinoma in situ (DCIS

Directory of Open Access Journals (Sweden)

Ian Stuart Fentiman

2013-12-01

Full Text Available As a result of mammographic detection, ductal carcinoma in situ (DCIS is an increasing problem in breast clinics. Both histopathology and molecular profiling can identify subtypes likely to progress to invasive disease, but there is no subgroup with a zero likelihood of subsequent invasion. In patients with low/intermediate grade DCIS, if breast irradiation is not being carried out after free margins have been achieved the patient should be aware of the risks of withholding and the benefits and morbidity of adjuvant radiotherapy. Either tamoxifen or an aromatase inhibitor may be of value in those with low/intermediate ER+ve disease if radiotherapy is being withheld. For those patients with extensive or multicentric DCIS, mastectomy is the appropriate treatment. This is best combined with sentinel node biopsy and all such cases should be offered immediate reconstruction.----------------------------Cite this article as:Fentiman IS. Getting the right balance in treatment of ductal carcinoma in situ (DCIS. Int J Cancer Ther Oncol 2013; 1(2:01029.DOI: http://dx.doi.org/10.14319/ijcto.0102.9 

Comparing guidelines for adjuvant endocrine therapy in postmenopausal women with breast cancer: a coming of age.

Science.gov (United States)

Verma, Sunil; Jackisch, Christian

2011-02-01

Following surgery for early breast cancer, the standard of care for postmenopausal women is adjuvant therapy with any combination of radiation therapy, endocrine therapy, chemotherapy and/or targeted therapy. Clinicians rely on many tools, including guidelines, to make these treatment decisions. Such guidelines include the St Gallen consensus statement, the American Society of Clinical Oncology guidelines and the National Comprehensive Cancer Network guidelines, as well as various regional and national guidelines. Recommendations may vary, because different methods and criteria were used to assess the strength of supporting data. This article provides an overview of global guidelines for the adjuvant treatment of breast cancer and points out the major differences. Ongoing changes are highlighted, particularly those regarding the adjuvant endocrine treatment of postmenopausal women with breast cancer. While previous guidelines recommended tamoxifen alone, all major guidelines now recommend using third-generation aromatase inhibitors either in sequence with tamoxifen or as upfront treatment.

Orthognathic surgery during breast cancer treatment—A case report

Directory of Open Access Journals (Sweden)

Tsuyoshi Shimo

2017-01-01

Conclusion: We experienced a case in which breast cancer was found just before the orthognathic surgery; we performed a bimaxillary osteotomy, including follow-up tamoxifen administration, during breast cancer treatment.

Combinatorial Therapies for Neurofibroma and MPNST Treatment and Prevention

Science.gov (United States)

2017-08-01

response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and...experiments utilizing genetically engineered mouse models. Consequently, we were not allowed to start actual experimental work towards the goals of this...different genetic backgrounds. Consequently, before beginning the full study, it was necessary that we will first determine the MTD for tamoxifen and

Systematic drug screening reveals specific vulnerabilities and co-resistance patterns in endocrine-resistant breast cancer

International Nuclear Information System (INIS)

Kangaspeska, Sara; Hultsch, Susanne; Jaiswal, Alok; Edgren, Henrik; Mpindi, John-Patrick; Eldfors, Samuli; Brück, Oscar; Aittokallio, Tero; Kallioniemi, Olli

2016-01-01

The estrogen receptor (ER) inhibitor tamoxifen reduces breast cancer mortality by 31 % and has served as the standard treatment for ER-positive breast cancers for decades. However, 50 % of advanced ER-positive cancers display de novo resistance to tamoxifen, and acquired resistance evolves in 40 % of patients who initially respond. Mechanisms underlying resistance development remain poorly understood and new therapeutic opportunities are urgently needed. Here, we report the generation and characterization of seven tamoxifen-resistant breast cancer cell lines from four parental strains. Using high throughput drug sensitivity and resistance testing (DSRT) with 279 approved and investigational oncology drugs, exome-sequencing and network analysis, we for the first time, systematically determine the drug response profiles specific to tamoxifen resistance. We discovered emerging vulnerabilities towards specific drugs, such as ERK1/2-, proteasome- and BCL-family inhibitors as the cells became tamoxifen-resistant. Co-resistance to other drugs such as the survivin inhibitor YM155 and the chemotherapeutic agent paclitaxel also occurred. This study indicates that multiple molecular mechanisms dictate endocrine resistance, resulting in unexpected vulnerabilities to initially ineffective drugs, as well as in emerging co-resistances. Thus, combatting drug-resistant tumors will require patient-tailored strategies in order to identify new drug vulnerabilities, and to understand the associated co-resistance patterns. The online version of this article (doi:10.1186/s12885-016-2452-5) contains supplementary material, which is available to authorized users

Synthesis and Biological Activity of Diastereomeric and Geometric Analogs of Calcipotriol, PRI-2202 and PRI-2205, Against Human HL-60 Leukemia and MCF-7 Breast Cancer Cells

Directory of Open Access Journals (Sweden)

Andrzej Kutner

2013-10-01

Full Text Available Diastereomeric and geometric analogs of calcipotriol, PRI-2202 and PRI-2205, were synthesized as advanced intermediates from vitamin D C-22 benzothiazoyl sulfones and side-chain aldehydes using our convergent strategy. Calcitriol, calcipotriol (PRI-2201 and tacalcitol (PRI-2191 were used as the reference compounds. Among a series of tested analogs the diastereomeric analog PRI-2202 showed the strongest antiproliferative activity on the human breast cancer cell line MCF-7, whereas the geometric analog PRI-2205 was the weakest. Both analogs were less potent in antiproliferative activity against HL-60 cells compared to the reference compounds. The ability to potentiate antiproliferative effect of cisplatin or doxorubicin against HL-60 cells or that of tamoxifen against the MCF-7 cell line was observed at higher doses of PRI-2202 or PRI-2205 than those of the reference compounds. The proapoptotic activity of tamoxifen, expressed as the diminished mitochondrial membrane potential, as well as the increased phosphatidylserine expression, was partially attenuated by calcitriol, PRI-2191, PRI-2201 and PRI-2205. The treatment of the MCF-7 cells with tamoxifen alone resulted in an increase in VDR expression. Moreover, a further increase in VDR expression was observed when the analogs PRI-2201 or PRI-2205, but not PRI-2191, were used in combination with tamoxifen. This observation could partially explain the potentiation of the antiproliferative effect of tamoxifen by vitamin D analogs.

Gynecomastia in Patients with Prostate Cancer: A Systematic Review.

Science.gov (United States)

Fagerlund, Anders; Cormio, Luigi; Palangi, Lina; Lewin, Richard; Santanelli di Pompeo, Fabio; Elander, Anna; Selvaggi, Gennaro

2015-01-01

Gynecomastia and/or mastodynia is a common medical problem in patients receiving antiandrogen (bicalutamide or flutamide) treatment for prostate cancer; up to 70% of these patients result to be affected; furthermore, this can jeopardise patients' quality of life. To systematically review the quality of evidence of the current literature regarding treatment options for bicalutamide-induced gynecomastia, including efficacy, safety and patients' quality of life. The PubMed, Medline, Scopus, The Cochrane Library and SveMed+ databases were systematically searched between January 1, 2000 and December 31, 2014. All searches were undertaken between January and February 2015. The search phrase used was:"gynecomastia AND treatment AND prostate cancer". Two reviewers assessed 762 titles and abstracts identified. The search and review process was done in accordance with the PRISMA statement. The PICOS (patients, intervention, comparator, outcomes and study design) process was used to specify inclusion criteria. Quality of evidence was rated according to GRADE. Primary outcomes were: treatment effects, number of complications and side effects. Secondary outcome was: Quality of Life. Eleven studies met the inclusion criteria and are analysed in this review. Five studies reported pharmacological intervention with tamoxifen and/or anastrozole, either as prophylactic or therapeutic treatment. Four studies reported radiotherapy as prophylactic and/or therapeutic treatment. Two studies compared pharmacological treatment to radiotherapy. Most of the studies were randomized with varying risk of bias. According to GRADE, quality of evidence was moderate to high. Bicalutamide-induced gynecomastia and/or mastodynia can effectively be managed by oral tamoxifen (10-20 mg daily) or radiotherapy without relevant side effects. Prophylaxis or therapeutic treatment with tamoxifen results to be more effective than radiotherapy.

Comparative study on individual aromatase inhibitors on cardiovascular safety profile: a network meta-analysis

Science.gov (United States)

Zhao, Xihe; Liu, Lei; Li, Kai; Li, Wusheng; Zhao, Li; Zou, Huawei

2015-01-01

The third-generation aromatase inhibitors (AIs: anastrozole, letrozole, and exemestane) have now become standard adjuvant endocrine treatment for postmenopausal estrogen receptor-positive breast cancer complementing chemotherapy and surgery. Because of the absence of direct head-to-head comparisons of these AIs, an indirect comparison is needed for individual treatment choice. In this network systemic assessment, the cardiovascular (CV) side effects in using anastrozole, letrozole, and exemestane based on original studies on AIs vs placebo or tamoxifen were compared. We integrated all available direct and indirect evidences. The odds ratio (OR) of severe CV events for indirect comparisons between exemestane and anastrozole was 1.41 (95% confidence interval [CI] =0.49–2.78), letrozole and anastrozole was 1.80 (95% CI =0.40–3.92), and letrozole and exemestane was 1.46 (95% CI =0.34–3.4). OR of subgroup risk for AIs and tamoxifen were all >1 except for thrombolism risk subgroup. The results showed that the total and severe CV risk ranking is letrozole, exemestane, and anastrozole in descending order. None of the AIs showed advantages in CV events than tamoxifen except for thromboembolism event incidence. PMID:26491345

Gestational treatment with methylazoxymethanol (MAM) that disrupts hippocampal-dependent memory does not alter behavioural response to cocaine.

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Featherstone, Robert E; Burton, Christie L; Coppa-Hopman, Romina; Rizos, Zoë; Sinyard, Judy; Kapur, Shitij; Fletcher, Paul J

2009-10-01

Schizophrenia is associated with increased rates of substance abuse that are thought to be the result of changes in cortical and mesolimbic dopamine activity. Previous work has shown that gestational methylazoxymethanol acetate (MAM) treatment induces increased mesolimbic dopamine activity when given around the time of embryonic day 17 (ED17), suggesting that MAM treatment may model some aspects of schizophrenia. Given that increased dopaminergic activity facilitates aspects of drug self-administration and reinstatement of drug seeking, the current experiments sought to assess cocaine self-administration in MAM treated animals. Experiment 1 examined the acquisition of cocaine self-administration in ED17 MAM and saline treated rats using a sub-threshold dose of cocaine. In experiment 2 ED17 MAM and saline treated animals were trained to self-administer cocaine and were then assessed under varying doses of cocaine (dose-response), followed by extinction and drug-induced reinstatement of responding. A subset of these animals was trained on a win-shift radial maze task, designed to detect impairments in hippocampal-dependent memory. In experiment 3, MAM and saline treated animals were assessed on a progressive ratio schedule of cocaine delivery. Finally, in experiment 4 MAM and saline treated animals were assessed on cocaine-induced locomotor activity across a range of doses of cocaine. MAM treatment disrupted performance of the win-shift task but did not alter cocaine self-administration or cocaine-induced locomotion. Implications of these results for the MAM model of schizophrenia are discussed.

Diazinon alters sperm chromatin structure in mice by phosphorylating nuclear protamines

International Nuclear Information System (INIS)

Pina-Guzman, B.; Solis-Heredia, M.J.; Quintanilla-Vega, B.

2005-01-01

Organophosphorus (OP) pesticides, widely used in agriculture and pest control, are associated with male reproductive effects, including sperm chromatin alterations, but the mechanisms underlying these effects are unknown. The main toxic action of OP is related to phosphorylation of proteins. Chemical alterations in sperm nuclear proteins (protamines), which pack DNA during the last steps of spermatogenesis, contribute to male reproductive toxicity. Therefore, in the present study, we tested the ability of diazinon (DZN), an OP compound, to alter sperm chromatin by phosphorylating nuclear protamines. Mice were injected with a single dose of DZN (8.12 mg/kg, i.p.), and killed 8 and 15 days after treatment. Quality of sperm from epididymis and vas deferens was evaluated through standard methods and chromatin condensation by flow cytometry (DNA Fragmented Index parameters: DFI and DFI%) and fluorescence microscopy using chromomycin-A 3 (CMA 3 ). Increases in DFI (15%), DFI% (4.5-fold), and CMA 3 (2-fold) were observed only at 8 days post-treatment, indicating an alteration in sperm chromatin condensation and DNA damage during late spermatid differentiation. In addition, an increase of phosphorous content (approximately 50%) in protamines, especially in the phosphoserine content (approximately 73%), was found at 8 days post-treatment. Sperm viability, motility, and morphology showed significant alterations at this time. These data strongly suggest that spermatozoa exposed during the late steps of maturation were the targets of DZN exposure. The correlation observed between the phosphorous content in nuclear protamines with DFI%, DFI, and CMA 3 provides evidence that phosphorylation of nuclear protamines is involved in the OP effects on sperm chromatin

Biallelic ATM alterations detected at diagnosis identify a subset of treatment-naïve chronic lymphocytic leukemia patients with reduced overall survival similar to patients with p53 deletion.

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Lozano-Santos, Carol; García-Vela, José A; Pérez-Sanz, Nuria; Nova-Gurumeta, Sara; Fernandez-Cuevas, Belen; Gomez-Lozano, Natalia; Sánchez-Beato, Margarita; Sanchez-Godoy, Pedro; Bueno, José Luis; Garcia-Marco, José A

2017-04-01

The prognostic impact of biallelic ATM abnormalities (ATM mutation and concurrent 11q deletion) remains unknown. We studied ATM, BIRC3, SF3B1, and NOTCH1 genes in 118 treatment-naïve CLL patients at diagnosis. Patients with biallelic ATM alteration had a similar time to first treatment (TTFT) and shorter overall survival (OS) compared with patients with isolated 11q deletion and shorter TTFT and OS when compared to patients with wild-type ATM. Furthermore, biallelic ATM alteration (HR: 6.4; p ≤ 0.007) was significantly associated with an increased risk of death similar to p53 deletion (HR: 6.1; p ≤ 0.004), superior to 11q deletion alone (HR: 2.8; p ≤ 0.022) and independent of other significant parameters such as age, advanced clinical stage, and complex karyotype. Our results suggest the identification of ATM mutations in CLL patients with 11q deletion at diagnosis is clinically relevant and predicts disease progression, poor response to the treatment, and reduced OS independent of other molecular prognostic factors.

Equol enhances tamoxifen’s anti-tumor activity by induction of caspase-mediated apoptosis in MCF-7 breast cancer cells

International Nuclear Information System (INIS)

Charalambous, Christiana; Pitta, Chara A; Constantinou, Andreas I

2013-01-01

Soy phytoestrogens, such as daidzein and its metabolite equol, have been proposed to be responsible for the low breast cancer rate in Asian women. Since the majority of estrogen receptor positive breast cancer patients are treated with tamoxifen, the basic objective of this study is to determine whether equol enhances tamoxifen’s anti-tumor effect, and to identify the molecular mechanisms involved. For this purpose, we examined the individual and combined effects of equol and tamoxifen on the estrogen-dependent MCF-7 breast cancer cells using viability assays, annexin-V/PI staining, cell cycle and western blot analysis. We found that equol (>50 μM) and 4-hydroxy-tamoxifen (4-OHT; >100 nM) significantly reduced the MCF-7 cell viability. Furthermore, the combination of equol (100 μM) and 4-OHT (10 μM) induced apoptosis more effectively than each compound alone. Subsequent treatment of MCF-7 cells with the pan-caspase inhibitor Z-VAD-FMK inhibited equol- and 4-OHT-mediated apoptosis, which was accompanied by PARP and α-fodrin cleavage, indicating that apoptosis is mainly caspase-mediated. These compounds also induced a marked reduction in the bcl-2:bax ratio, which was accompanied by caspase-9 and caspase-7 activation and cytochrome-c release to the cytosol. Taken together, these data support the notion that the combination of equol and tamoxifen activates the intrinsic apoptotic pathway more efficiently than each compound alone. Consequently, equol may be used therapeutically in combination treatments and clinical studies to enhance tamoxifen’s effect by providing additional protection against estrogen-responsive breast cancers

3-Bromopyruvate treatment induces alterations of metabolic and stress-related pathways in glioblastoma cells.

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Chiasserini, Davide; Davidescu, Magdalena; Orvietani, Pier Luigi; Susta, Federica; Macchioni, Lara; Petricciuolo, Maya; Castigli, Emilia; Roberti, Rita; Binaglia, Luciano; Corazzi, Lanfranco

2017-01-30

Glioblastoma (GBM) is the most common and aggressive brain tumour of adults. The metabolic phenotype of GBM cells is highly dependent on glycolysis; therefore, therapeutic strategies aimed at interfering with glycolytic pathways are under consideration. 3-Bromopyruvate (3BP) is a potent antiglycolytic agent, with a variety of targets and possible effects on global cell metabolism. Here we analyzed the changes in protein expression on a GBM cell line (GL15 cells) caused by 3BP treatment using a global proteomic approach. Validation of differential protein expression was performed with immunoblotting and enzyme activity assays in GL15 and U251 cell lines. The results show that treatment of GL15 cells with 3BP leads to extensive changes in the expression of glycolytic enzymes and stress related proteins. Importantly, other metabolisms were also affected, including pentose phosphate pathway, aminoacid synthesis, and glucose derivatives production. 3BP elicited the activation of stress response proteins, as shown by the phosphorylation of HSPB1 at serine 82, caused by the concomitant activation of the p38 pathway. Our results show that inhibition of glycolysis in GL15 cells by 3BP influences different but interconnected pathways. Proteome analysis may help in the molecular characterization of the glioblastoma response induced by pharmacological treatment with antiglycolytic agents. Alteration of the glycolytic pathway characterizes glioblastoma (GBM), one of the most common brain tumours. Metabolic reprogramming with agents able to inhibit carbohydrate metabolism might be a viable strategy to complement the treatment of these tumours. The antiglycolytic agent 3-bromopyruvate (3BP) is able to strongly inhibit glycolysis but it may affect also other cellular pathways and its precise cellular targets are currently unknown. To understand the protein expression changes induced by 3BP, we performed a global proteomic analysis of a GBM cell line (GL15) treated with 3BP. We

Climate change alters seedling emergence and establishment in an old-field ecosystem.

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Aimée T Classen

2010-10-01

Full Text Available Ecological succession drives large-scale changes in ecosystem composition over time, but the mechanisms whereby climatic change might alter succession remain unresolved. Here, we asked if the effects of atmospheric and climatic change would alter tree seedling emergence and establishment in an old-field ecosystem, recognizing that small shifts in rates of seedling emergence and establishment of different species may have long-term repercussions on the transition of fields to forests in the future.We introduced seeds from three early successional tree species into constructed old-field plant communities that had been subjected for 4 years to altered temperature, precipitation, and atmospheric CO(2 regimes in an experimental facility. Our experiment revealed that different combinations of atmospheric CO(2 concentration, air temperature, and soil moisture altered seedling emergence and establishment. Treatments directly and indirectly affected soil moisture, which was the best predictor of seedling establishment, though treatment effects differed among species.The observed impacts, coupled with variations in the timing of seed arrival, are demonstrated as predictors of seedling emergence and establishment in ecosystems under global change.

Cardiomyocyte specific deletion of Crif1 causes mitochondrial cardiomyopathy in mice.

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Juhee Shin

Full Text Available Mitochondria are key organelles dedicated to energy production. Crif1, which interacts with the large subunit of the mitochondrial ribosome, is indispensable for the mitochondrial translation and membrane insertion of respiratory subunits. To explore the physiological function of Crif1 in the heart, Crif1(f/f mice were crossed with Myh6-cre/Esr1 transgenic mice, which harbor cardiomyocyte-specific Cre activity in a tamoxifen-dependent manner. The tamoxifen injections were given at six weeks postnatal, and the mutant mice survived only five months due to hypertrophic heart failure. In the mutant cardiac muscles, mitochondrial mass dramatically increased, while the inner structure was altered with lack of cristae. Mutant cardiac muscles showed decreased rates of oxygen consumption and ATP production, suggesting that Crif1 plays a critical role in the maintenance of both mitochondrial structure and respiration in cardiac muscles.

Treatment options for polycystic ovary syndrome