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2.
Oncogene ; 35(6): 691-701, 2016 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-25639871

RESUMO

The myc oncogene is overexpressed in almost half of all breast and ovarian cancers, but attempts at therapeutic interventions against myc have proven to be challenging. Myc regulates multiple biological processes, including the cell cycle, and as such is associated with cell proliferation and tumor progression. We identified a protein signature of high myc, low p27 and high phospho-Rb significantly correlated with poor patient survival in breast and ovarian cancers. Screening of a miRNA library by functional proteomics in multiple cell lines and integration of data from patient tumors revealed a panel of five microRNAs (miRNAs) (miR-124, miR-365, miR-34b*, miR-18a and miR-506) as potential tumor suppressors capable of reversing the p27/myc/phospho-Rb protein signature. Mechanistic studies revealed an RNA-activation function of miR-124 resulting in direct induction of p27 protein levels by binding to and inducing transcription on the p27 promoter region leading to a subsequent G1 arrest. Additionally, in vivo studies utilizing a xenograft model demonstrated that nanoparticle-mediated delivery of miR-124 could reduce tumor growth and sensitize cells to etoposide, suggesting a clinical application of miRNAs as therapeutics to target the functional effect of myc on tumor growth.


Assuntos
Neoplasias da Mama/genética , Inibidor de Quinase Dependente de Ciclina p27/genética , Regulação Neoplásica da Expressão Gênica , Genes myc , MicroRNAs/fisiologia , Neoplasias Ovarianas/genética , Proteína do Retinoblastoma/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Feminino , Humanos , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/patologia , Fosfoproteínas/metabolismo , Proteômica/métodos , Proteína do Retinoblastoma/metabolismo , Transcriptoma , Células Tumorais Cultivadas
3.
Eur J Clin Nutr ; 68(6): 730-5, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24619108

RESUMO

BACKGROUND/OBJECTIVE: The aim of the study was to compare the prevalence of undernutrition in children on presentation to hospital and on discharge. METHODS: On a screening week, 141 children aged from birth to 17 years who were hospitalised for ⩾72 h were reviewed on presentation and discharge or after 3 months (if still in hospital) by auditing hospital records. Weight for age standard deviation (s.d.<-2) was used to define undernutrition on admission and discharge. The number of children referred for dietetic advice was recorded. RESULTS: The prevalence of undernutrition on admission was 27% (14% moderate (s.d.: -2 to -3) and 13% severe (s.d.: ⩾-3)) according to weight s.d. and increased to 32% by discharge (11% moderate; 21% severe). The most nutritionally vulnerable children, with a prevalence of undernutrition from 33 to 53% on admission, were aged less than 2 years, inpatients for >1 month and those with multiple medical problems. In all, 74% (n=104) of cases were referred to Dietetics, including 73% (n=79) of those without evidence of undernutrition. CONCLUSIONS: Undernutrition is a major problem in children during hospitalisation. The risk of nutritional depletion needs to be identified at the time of admission, especially for children under 2 years and those with multiple medical problems, in order to initiate appropriate nutritional intervention.


Assuntos
Hospitais Pediátricos , Desnutrição/epidemiologia , Estado Nutricional , Admissão do Paciente , Adolescente , Fatores Etários , Peso Corporal , Criança , Pré-Escolar , Dietética , Hospitalização , Humanos , Lactente , Recém-Nascido , Masculino , Desnutrição/diagnóstico , Avaliação Nutricional , Prevalência
4.
Breast Cancer (Auckl) ; 6: 137-50, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23012497

RESUMO

This study investigates differences in expression of clock and clock-controlled genes (CCGs) between human breast epithelial and breast cancer cells and breast tumor xenografts in circadian intact rats and examines if the pineal hormone melatonin influences clock gene and CCG expression. Oscillation of clock gene expression was not observed under standard growth conditions in vitro, however, serum shock (50% horse serum for 2 h) induced oscillation of clock gene and CCG expression in MCF-10A cells, which was repressed or disrupted in MCF-7 cells. Melatonin administration following serum shock differentially suppressed or induced clock gene (Bmal1 and Per2) and CCG expression in MCF10A and MCF-7 cells. These studies demonstrate the lack of rhythmic expression of clock genes and CCGs of cells in vitro and that transplantation of breast cancer cells as xenografts into circadian competent hosts re-establishes a circadian rhythm in the peripheral clock genes of tumor cells.

5.
Endocrinology ; 153(9): 4144-59, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22733972

RESUMO

Elevated phosphorylation of estrogen receptor α (ERα) at serines 118 (S118) and 167 (S167) is associated with favorable outcome for tamoxifen adjuvant therapy and may serve as surrogate markers for a functional ERα signaling pathway in breast cancer. It is possible that loss of phosphorylation at S118 and/or S167 could disrupt ERα signaling, resulting in aggressive ERα-independent breast cancer cells. To this end, MCF-7 breast cancer cells were stably transfected with an ERα-specific short hairpin RNA that reduced endogenous ERα. The resulting cell line was stably transfected with wild-type ERα (ER-AB cells), or ERα containing serine to alanine mutation at S118 or S167 (S118A cells and S167A cells, respectively). These stable cell lines expressed approximately equivalent ERα compared with parental MCF-7 cells and were evaluated for growth, morphology, migration/invasion, and ERα-regulated gene expression. S118A cells and S167A cells exhibited increased growth and migration/invasion in vitro. Forward- and side-scatter flow cytometry revealed that S167A cells were smaller in size, and both S118A and S167A cells exhibited less cellular complexity. S118A and S167A cells expressed pancytokeratin and membrane localization of ß-catenin and did not express vimentin, indicating retention of epithelial lineage markers. Expression of ERα-target genes and other genes regulated by ERα signaling or involved in breast cancer were markedly altered in both S118A and S167A cells. In summary, attenuated phosphorylation of ERα at S118 and S167 significantly affected cellular physiology and behavior in MCF-7 breast cancer cells, resulting in increased growth, migration/invasion, compromised expression of ERα target genes, and markedly altered gene expression patterns.


Assuntos
Neoplasias da Mama/metabolismo , Receptor alfa de Estrogênio/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Movimento Celular/fisiologia , Proliferação de Células , Receptor alfa de Estrogênio/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Fosforilação , RNA Interferente Pequeno , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
6.
J Steroid Biochem Mol Biol ; 119(1-2): 14-25, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20045459

RESUMO

The majority of cancers derived from ovarian surface epithelial (OSE) cells are lethal. Estrogens promote proliferation of OSE cells, whereas progesterone inhibits proliferation and promotes apoptosis of OSE cells. Human steroidogenic factor-1 (hSF-1) induction of the steroidogenic acute regulatory protein (StAR) gene, and the steroidogenic enzymes CYP11A1 and HSD3B2 is central to progesterone biosynthesis. Whereas hSF-1 and StAR are expressed in human ovarian surface epithelial (HOSE) cells, hSF-1 and StAR protein were not expressed in a panel of malignant ovarian cancer cell lines (SKOV-3, BG-1, and Caov-3), and in human OSE cells immortalized by SV40 large T antigen (IOSE-121). Transient expression of hSF-1 in SKOV-3 cells activated the expression of StAR, p450scc and 3betaHSD-II mRNAs, and induced progesterone biosynthesis. Additionally, hSF-1 suppressed proliferation and promoted apoptosis of SKOV-3 cells and suppressed SKOV-3 cell growth induced by ERalpha and estradiol. These findings suggest that hSF-1 is central to progesterone biosynthesis in OSE cells. Human SF-1 may decrease OSE cancer cell numbers directly by apoptosis, and indirectly by opposing estradiol-induced proliferation. These findings are consistent with the hypothesis, that down-regulation of hSF-1 contributes to progression of ovarian epithelial cancers.


Assuntos
Proliferação de Células , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Ovarianas/patologia , Progesterona/biossíntese , Fator Esteroidogênico 1/fisiologia , Apoptose/genética , Apoptose/fisiologia , Células Cultivadas , Enzima de Clivagem da Cadeia Lateral do Colesterol/genética , Enzima de Clivagem da Cadeia Lateral do Colesterol/metabolismo , Progressão da Doença , Feminino , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Modelos Biológicos , Neoplasias Epiteliais e Glandulares/genética , Neoplasias Epiteliais e Glandulares/metabolismo , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Ovário/metabolismo , Ovário/patologia , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Progesterona Redutase/genética , Progesterona Redutase/metabolismo
7.
Acute Med ; 9(3): 118-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21597592

RESUMO

In life-threatening cases of Acute Asthma the administration of epinephrine may be given as part of the initial management by paramedics. Concurrent infection is a frequent precipitant of an asthma exacerbation and consequently a leucocytosis is often found in such a situation. This case illustrates that marked leucocytosis can occur without an underlying infective process following epinphrine use.

8.
Oncol Rep ; 17(4): 947-53, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17342341

RESUMO

A major mechanism through which melatonin reduces the development of breast cancer is based on its anti-estrogenic actions by interfering at different levels with the estrogen-signalling pathways. Melatonin inhibits both aromatase activity and expression in vitro (MCF-7 cells) as well as in vivo, thus behaving as a selective estrogen enzyme modulator. The objective of this study was to study the effect of MT1 melatonin receptor overexpression in MCF-7 breast cancer cells on the aromatase-suppressive effects of melatonin. Transfection of the MT1 melatonin receptor in MCF-7 cells significantly decreased aromatase activity of the cells and MT1-transfected cells showed a level of aromatase activity that was 50% of vector-transfected MCF-7 cells. The proliferation of estrogen-sensitive MCF-7 cells in an estradiol-free media but in the presence of testosterone (an indirect measure of aromatase activity) was strongly inhibited by melatonin in those cells overexpressing the MT1 receptor. This inhibitory effect of melatonin on cell growth was higher on MT1 transfected cells than in vector transfected ones. In MT1-transfected cells, aromatase activity (measured by the tritiated water release assay) was inhibited by melatonin (20% at 1 nM; 40% at 10 microM concentrations). The same concentrations of melatonin did not significantly influence the aromatase activity of vector-transfected cells. MT1 melatonin receptor transfection also induced a significant 55% inhibition of aromatase steady-state mRNA expression in comparison to vector-transfected MCF-7 cells (p<0.001). In addition, in MT1-transfected cells melatonin treatment inhibited aromatase mRNA expression and 1 nM melatonin induced a higher and significant down-regulation of aromatase mRNA expression (p<0.05) than in vector-transfected cells. The findings presented herein point to the importance of MT1 melatonin receptor in mediating the oncostatic action of melatonin in MCF-7 human breast cancer cells and confirm MT1 melatonin receptor as a major mediator in the melatonin signalling pathway in breast cancer.


Assuntos
Antineoplásicos Hormonais/farmacologia , Aromatase , Neoplasias da Mama/enzimologia , Melatonina/farmacologia , Receptor MT1 de Melatonina/metabolismo , Aromatase/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo , Humanos , RNA Mensageiro/metabolismo , Receptor MT1 de Melatonina/genética
9.
Gene Ther ; 13(18): 1342-50, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16642030

RESUMO

Gene delivery of angiogenic growth factors is a promising approach for the treatment of ischemic cardiovascular diseases. However, success of this new therapeutic principle is hindered by the lack of critical understanding as to how disease pathology affects the efficiency of gene delivery and/or the downstream signaling pathways of angiogenesis. Critical limb ischemia occurs in patients with advanced atherosclerosis often exhibiting deficiency in endothelial nitric oxide production. Similar to these patients, segmental femoral artery resection progresses into severe ischemic necrosis in mice deficient in endothelial nitric oxide synthase (ecNOS-KO) as well as in balb/c mice. We used these models to evaluate the influence of severe ischemia on transfection efficiency and duration of transgene expression in the skeletal muscle following plasmid injection in combination with electroporation. Subsequently, we also explored the potential therapeutic effect of the phosphomimetic mutant of ecNOS gene (NOS1177D) using optimized delivery parameters, and found significant benefit both in ecNOS-KO and balb/c mice. Our results indicate that NOS1177D gene delivery to the ischemic skeletal muscle can be efficient to reverse critical limb ischemia in pathological settings, which are refractory to treatments with a single growth factor, such as vascular endothelial growth factor.


Assuntos
Terapia Genética/métodos , Isquemia/terapia , Músculo Esquelético/metabolismo , Óxido Nítrico Sintase Tipo III/genética , Transfecção/métodos , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Eletroporação , Endotélio Vascular/metabolismo , Expressão Gênica , Vetores Genéticos , Membro Posterior , Humanos , Isquemia/metabolismo , Isquemia/patologia , Fluxometria por Laser-Doppler , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Esquelético/patologia , Neovascularização Fisiológica , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/análise , Óxido Nítrico Sintase Tipo III/metabolismo , Fluxo Sanguíneo Regional , Transgenes , Vasodilatação
10.
J Pediatr Gastroenterol Nutr ; 42(2): 245-8, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16456427

RESUMO

Fulminating acute ulcerative colitis (UC) is a potentially life threatening medical emergency. Up to 30% of individuals respond poorly to corticosteroids alone and second line medical or surgical therapies are indicated. We describe the successful use of chimeric anti-CD25 therapy in 4 such children poorly responsive to combined therapy with intravenous steroids and calcineurin inhibitors with a pretreatment predictive risk of colectomy of 85-100%. Clinical disease activity scores normalized within 72 hours of anti-CD25 administration and colonic histology provided evidence of mucosal healing within 10-14 days. None required emergency colectomy. Anti-CD25 is efficacious in fulminating UC and randomized placebo controlled trials appear indicated.


Assuntos
Anticorpos Anti-Idiotípicos/uso terapêutico , Colite Ulcerativa/tratamento farmacológico , Receptores de Interleucina-2/imunologia , Doença Aguda , Adolescente , Corticosteroides/uso terapêutico , Inibidores de Calcineurina , Criança , Colectomia , Humanos , Fatores de Risco , Índice de Gravidade de Doença , Resultado do Tratamento
11.
Gut ; 55(3): 356-61, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16162683

RESUMO

BACKGROUND AND AIMS: Total enteral nutrition (TEN) with a liquid formula can suppress gut inflammation and induce remission in active Crohn's disease. The mechanism is obscure. Studies have suggested that long term nutritional supplementation with a liquid formula (partial enteral nutrition (PEN)) may also suppress inflammation and prevent relapse. The aim of this study was to compare PEN with conventional TEN in active Crohn's disease. PATIENTS AND METHODS: Fifty children with a paediatric Crohn's disease activity index (PCDAI)>20 were randomly assigned to receive 50% (PEN) or 100% (TEN) of their energy requirement as elemental formula for six weeks. The PEN group was encouraged to eat an unrestricted diet while those receiving TEN were not allowed to eat. The primary outcome was achievement of remission (PCDAI<10). Secondary analyses of changes in erythrocyte sedimentation rate (ESR), C reactive protein, albumin, and platelets were performed to look for evidence of anti-inflammatory effects. RESULTS: Remission rate with PEN was lower than with TEN (15% v 42%; p=0.035). Although PCDAI fell in both groups (p=0.001 for both), the reduction was greater with TEN (p=0.005). Moreover, the fall in PCDAI with PEN was due to symptomatic and nutritional benefits. With both treatments there were significant improvements in relation to abdominal pain, "sense of wellbeing", and nutritional status. However, only TEN led to a reduction in diarrhoea (p=0.02), an increase in haemoglobin and albumin, and a fall in platelets and ESR. CONCLUSIONS: TEN suppresses inflammation in active Crohn's disease but PEN does not. This suggests that long term nutritional supplementation, although beneficial to some patients, is unlikely to suppress inflammation and so prevent disease relapse.


Assuntos
Doença de Crohn/terapia , Nutrição Enteral/métodos , Adolescente , Fenômenos Fisiológicos da Nutrição do Adolescente , Sedimentação Sanguínea , Proteína C-Reativa/metabolismo , Criança , Fenômenos Fisiológicos da Nutrição Infantil , Doença de Crohn/sangue , Ingestão de Energia , Feminino , Alimentos Formulados/análise , Humanos , Masculino , Indução de Remissão , Índice de Gravidade de Doença , Resultado do Tratamento
12.
J Hepatobiliary Pancreat Surg ; 12(4): 332-5, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16133704

RESUMO

Unlike in Japan, autoimmune pancreatitis is uncommon in the Western world, particularly in Europe. We report the first case of a Caucasian male with typical features of autoimmune pancreatitis in the UK. Recognizing autoimmune pancreatitis as a new clinical entity in Europe will change the management of many patients who have been labelled as having acute or chronic pancreatitis.


Assuntos
Doenças Autoimunes/diagnóstico , Pancreatite/diagnóstico , Idoso , Humanos , Masculino , População Branca
13.
Cancer Lett ; 227(1): 39-48, 2005 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-16051031

RESUMO

A significant increase in tumor regression was induced in N-nitroso-N-methylurea-induced mammary tumors in rats treated with the combination of melatonin and 9-cis-retinoic acid (9cRA). Treatment groups included: control (ethanolic saline), 9cRA (30 mg/kg chow/day), melatonin 500 microg/day, melatonin 1000 microg/day, melatonin 500 microg/day+9cRA and melatonin 1000 microg/day+9cRA. Rats treated with the lower dose of melatonin 500 microg+9cRA show the greatest degree of tumor regression (78%), with 54% undergoing complete regression and a significant increase in apoptotic cells observed by TUNEL Assay. Furthermore, tumor multiplicity and burden were significantly decreased by the combination of melatonin and 9cRA.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Mamárias Experimentais/tratamento farmacológico , Melatonina/administração & dosagem , Tretinoína/administração & dosagem , Alitretinoína , Animais , Apoptose/efeitos dos fármacos , Receptor alfa de Estrogênio/genética , Feminino , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/patologia , Metilnitrosoureia , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley
14.
Forensic Sci Int ; 139(2-3): 255-9, 2004 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-15040926

RESUMO

The Forensic Science Service carries out human identification and familial investigations using the AMPFlSTR SGM Plus kit (PE Biosystems, Warrington, England). We have studied approximately 42,000 parent/child allelic transfers (meioses) for deviations from expected Mendelian Inheritance patterns. Of 55 apparent mutations detected, 20 had patterns suggestive of the presence of a primer binding site mutation producing a silent/null allele. The presence of a silent allele was unequivocally demonstrated in 13 of the 20 suspected cases by using alternative primer sets. Of the 13 confirmed cases, 9 involved the D18S51 locus. As the individuals in these cases all originated from the same geographic region of the Middle East, this cluster suggests the presence of a relatively common variant D18S51 allele in that particular group. These data taken together with our previously published work, confirm that the primer binding sites utilised for amplification of the loci contained in the AMPFlSTR SGM Plus kit have highly conserved nucleotide sequences.


Assuntos
Alelos , Mutação , Sequências de Repetição em Tandem , Sítios de Ligação , Criança , Impressões Digitais de DNA/métodos , Primers do DNA , Etnicidade/genética , Humanos , Pais , Reação em Cadeia da Polimerase/métodos , Análise de Sequência de DNA
15.
Cancer Lett ; 189(1): 49-57, 2003 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-12445677

RESUMO

Overexpression of the MT1 melatonin receptor in MCF-7 human breast cancer cells significantly enhances the response of these cells to the growth-inhibitory actions of melatonin. Athymic nude mice implanted with MT1-overexpressing MCF-7 cells developed significantly fewer palpable tumors (60% reduction) compared to mice receiving vector-transfected MCF-7 cells (vt-MCF-7). In response to exogenous melatonin, tumor incidence in the mice receiving the MT1-overexpressing MCF-7 cells was decreased by 80% compared to mice receiving vt-MCF-7 cells. Interestingly, daily melatonin administration did not decrease tumor incidence in mice receiving vt-MCF-7 cells, but rather stimulated overall tumor formation.


Assuntos
Neoplasias da Mama/prevenção & controle , Receptores de Superfície Celular/fisiologia , Receptores Citoplasmáticos e Nucleares/fisiologia , Animais , Feminino , Humanos , Melatonina/farmacologia , Camundongos , Camundongos Nus , Transplante de Neoplasias , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores de Melatonina , Transfecção , Transplante Heterólogo , Células Tumorais Cultivadas
16.
Breast Cancer Res Treat ; 72(1): 33-43, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12004806

RESUMO

Our laboratory has demonstrated that treatment of MCF-7 breast cancer cells with melatonin (Mlt) followed 24h later with physiological concentrations of all-trans retinoic acid (atRA) results in apoptosis. These studies were extended into trials using the N-nitroso-N-methylurea (NMU)-induced rat mammary tumor model. Initial studies conducted by feeding the animals 9-cis-retinoic acid (9cRA in the chow) and administering melatonin by subcutaneous injection in the late afternoon demonstrated that the combination of Mlt and 9cRA was able to significantly prevent tumor development, and that the combination was more efficacious that either Mlt or 9cRA alone. In this report, we conducted studies to determine if lower doses of 9cRA could be used in combination with Mlt while still maintaining anti-tumor activity and if the route of administration of 9cRA (bolus (gavage) v.s. chronic (chow) routes) affected its interaction with Mlt. The studies presented here demonstrate that significantly reduced doses of 9cRA can be used in combination with Mlt while maintaining anti-tumor efficacy. Furthermore, our studies demonstrate that 9cRA is equally effective when it is administered chronically (chow) or as a bolus (gavage). These data demonstrate that the combined use of Mlt and 9cRA produces additive or synergistic effects, which are more efficacious than 9cRA alone. This combination of Mlt and 9cRA could be a potentially useful clinical treatment regimen for breast cancer since it allows the use of lower doses of retinoic acid, thus, avoiding the toxic side effects associated with the use of high dose retinoids.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias Mamárias Experimentais/prevenção & controle , Melatonina/farmacologia , Tretinoína/farmacologia , Administração Oral , Alitretinoína , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Feminino , Injeções Subcutâneas , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/patologia , Melatonina/administração & dosagem , Melatonina/uso terapêutico , Metilnitrosoureia , Ratos , Ratos Sprague-Dawley , Tretinoína/administração & dosagem , Tretinoína/uso terapêutico
17.
Cancer Lett ; 179(2): 141-50, 2002 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-11888668

RESUMO

Two putative melatonin receptors have been described including the cell surface G-protein-linked receptors, mt1 and MT2, and the nuclear retinoic orphan receptor alpha (RORalpha). The mt1 receptor, but not the MT2 receptor, is expressed in human breast tumor cell lines, and melatonin-induced growth suppression can be mimicked by the mt1 and MT2 agonist, AMMTC, and blocked by the antagonist, CBPT. RORalpha receptors are also expressed in MCF-7 breast cancer cells and the putative RORalpha agonist CPG-52608 inhibits MCF-7 cell growth but with a very different dose-response than melatonin. Finally, melatonin and AMMTC, but not CPG-52608, can repress RORalpha transcriptional activity in MCF-7 cells.


Assuntos
Neoplasias da Mama/patologia , Receptores de Superfície Celular/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Carbazóis/farmacologia , Divisão Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Immunoblotting , Luciferases/efeitos dos fármacos , Luciferases/genética , Luciferases/metabolismo , Melatonina/farmacologia , Membro 1 do Grupo F da Subfamília 1 de Receptores Nucleares , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Superfície Celular/efeitos dos fármacos , Receptores de Superfície Celular/genética , Receptores Citoplasmáticos e Nucleares/efeitos dos fármacos , Receptores Citoplasmáticos e Nucleares/genética , Receptores de Melatonina , Proteínas Recombinantes de Fusão/efeitos dos fármacos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tiazóis/farmacologia , Tiossemicarbazonas/farmacologia , Transativadores/genética , Transativadores/metabolismo , Células Tumorais Cultivadas
18.
Breast Cancer Res Treat ; 71(1): 37-45, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11859872

RESUMO

We have previously demonstrated that the pineal hormone, melatonin, can inhibit the growth of estrogen receptor-alpha (ERalpha)-positive breast cancer cells and suppress ERalpha gene transcription. To investigate the relationship between the estrogen response pathway and melatonin's growth inhibition, ERalpha-positive MCF-7 human breast cancer cells were transiently transfected with an estrogen response element (ERE) luciferase reporter construct and then treated with melatonin (10(-9)-10(-6) M) for 30 min followed by 10(-9) M 17-beta-estradiol (E2) or treated with each compound alone. Melatonin pre-treatment significantly reduced E2-induced ERalpha transactivation and ERalpha-ERE binding activity. We also conducted experiments to determine if melatonin modulates cAMP levels in MCF-7 cells. Melatonin inhibited the forskolin-induced and E2-induced elevation of cAMP levels by 57 and 45%, respectively. These data indicate that melatonin can act as a biological modifier to affect ERalpha transcriptional activity by regulating signal transduction pathways which impinge on the ERalpha and by altering E2-mediated ERalpha transactivation and ERalpha DNA binding activity.


Assuntos
Adjuvantes Imunológicos/farmacologia , Neoplasias da Mama/patologia , AMP Cíclico/biossíntese , Regulação Neoplásica da Expressão Gênica , Melatonina/farmacologia , Receptores de Estrogênio/biossíntese , Estradiol/farmacologia , Receptor alfa de Estrogênio , Feminino , Humanos , Transdução de Sinais , Transfecção , Células Tumorais Cultivadas
19.
Cancer Lett ; 168(2): 155-63, 2001 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-11403920

RESUMO

In experimental trials using the N-nitroso-N-methylurea (NMU)-induced rat mammary tumor model, a significant decrease in tumor incidence (to 5%) was observed in rats treated with melatonin and 9-cis-retinoic acid (9 cRA) compared to controls (55%). Although 9cRA alone decreased tumor incidence to 26%, this response did not reach statistical significance. Tumor incidence was significantly inhibited to 20% in the animals that received melatonin and 9cRA on alternating days. Latency to tumor onset was prolonged in animals receiving either of the combination treatments compared with controls, and tumor multiplicity was also significantly decreased.


Assuntos
Adenocarcinoma/prevenção & controle , Anticarcinógenos/farmacologia , Neoplasias Mamárias Experimentais/prevenção & controle , Melatonina/farmacologia , Tretinoína/farmacologia , Adenocarcinoma/induzido quimicamente , Adenocarcinoma/patologia , Alitretinoína , Animais , Antioxidantes/farmacologia , Peso Corporal/efeitos dos fármacos , Carcinógenos/antagonistas & inibidores , Sinergismo Farmacológico , Quimioterapia Combinada , Estradiol/sangue , Receptor alfa de Estrogênio , Feminino , Sequestradores de Radicais Livres/farmacologia , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/patologia , Metilnitrosoureia , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Receptores de Estrogênio/biossíntese , Receptores do Ácido Retinoico/biossíntese , Receptor alfa de Ácido Retinoico , Útero/anatomia & histologia , Útero/efeitos dos fármacos
20.
Mol Cell Endocrinol ; 176(1-2): 111-20, 2001 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-11369450

RESUMO

Melatonin has repeatedly been shown to inhibit the proliferation of MCF-7 human breast cancer cells. Previous reports suggest that the actions of melatonin can be mediated either through G-protein coupled membrane receptors or via retinoid orphan receptors (RORalphas). In this study, we demonstrated the expression of RORalpha2, 3, and 4 transcripts in MCF-7 cells. These cells exhibited a high basal level of RORalpha transcriptional activity, which was further stimulated by serum. In the presence of serum, RORalpha transactivation and DNA-binding activity was repressed by melatonin even though melatonin had no effect on RORalpha protein levels. We found that RORalpha transcriptional activity in MCF-7 cells was regulated by modulators of the Ca2+/CaM signaling pathway. Given that melatonin has been reported to modulate the Ca2+/CaM signaling pathway in other tissues, our data indicate that melatonin may affect RORalpha transcriptional activity, expression of RORalpha regulated genes, and even breast cancer cell proliferation via modulation of the Ca2+/CaM signaling pathway.


Assuntos
Neoplasias da Mama/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Melatonina/farmacologia , Receptores Citoplasmáticos e Nucleares/genética , Transativadores/genética , Transcrição Gênica/efeitos dos fármacos , Antioxidantes/farmacologia , Western Blotting , Neoplasias da Mama/enzimologia , Sinalização do Cálcio/efeitos dos fármacos , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Calmodulina/antagonistas & inibidores , Calmodulina/metabolismo , DNA/genética , DNA/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Humanos , Membro 1 do Grupo F da Subfamília 1 de Receptores Nucleares , Ligação Proteica/efeitos dos fármacos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transativadores/metabolismo , Ativação Transcricional/efeitos dos fármacos , Transfecção , Células Tumorais Cultivadas
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