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1.
J Am Pharm Assoc (2003) ; 63(4): 1175-1179, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37116796

RESUMO

BACKGROUND: Few studies have examined the effect of pharmacist-led telemanagement on diabetes outcomes during the COVID-19 pandemic. OBJECTIVES: Assess for noninferiority for the absolute change in mean A1C between telehealth and hybrid groups versus the in-office group during the COVID-19 pandemic. Secondary objectives were to compare the percentage of patients achieving population health A1C goals and patient no-show rates between study groups. METHODS: A retrospective, noninferiority analysis was conducted for patients seen by a primary care pharmacist from November 1, 2020 to May 31, 2021 across 17 primary care clinics in the Northeast Ohio region of Cleveland Clinic. The noninferiority margin was prespecified at > 0.3% A1C reduction. Patients with a baseline A1C of 8% or greater were included. Patients were separated into 3 study groups (telehealth, in-office, and hybrid) based on the visit types that were conducted by the pharmacist during the study period. RESULTS: Hybrid care delivery (N = 366) was noninferior to in-office care delivery (N = 180), with regards to absolute change in mean A1C reduction (0.24% [95% CI: -0.13, 0.61], P = 0.002). Similar results were shown when comparing the telehealth group (N = 691) to the in-office group (0.04 [95% CI: -0.28, 0.36], P = 0.02). The mean A1C reduction in the in-office (1.36 ± 1.9), hybrid (1.60 ± 2.2), and telehealth (1.40 ± 2.0) groups were not significantly different (P = 0.23). Subgroup analyses showed that newly consulted patients had a larger reduction in A1C compared to the overall population, in all groups. No-show rates and percentage of patients achieving population health A1C goals were not significantly different based on visit type. CONCLUSION: Telehealth and hybrid visit types were noninferior to in-office visits with regards to mean change in A1C reduction. Results demonstrate the importance of primary care pharmacists continuing to offer diverse visit types based on patient preference.


Assuntos
COVID-19 , Diabetes Mellitus Tipo 2 , Telemedicina , Humanos , Farmacêuticos , Estudos Retrospectivos , Hemoglobinas Glicadas , Pandemias
2.
J Am Pharm Assoc (2003) ; 63(3): 778-784, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36774236

RESUMO

OBJECTIVES: The primary objective was to identify the proportion of patients who successfully completed PGx testing. Secondary objectives included determining the proportion of patients with actionable PGx results, determining the proportion of patients with a baseline medication intervention within 6 months of successfully completing PGx testing, and identifying barriers for not completing testing. DESIGN: This was a single center, non-interventional, retrospective cohort study, approved by the institutional review board. SETTING AND PARTICIPANTS: Patients included were 65 years of age or older and referred for PGx testing from geriatric outpatient clinics between May 1, 2019 and July 31, 2020. OUTCOME MEASURES: This study aimed to assess the implementation of pharmacist-led pharmacogenomics (PGx) in the care of community-dwelling older adults in an outpatient clinic. Little is known about the acceptance and impact of this type of service within this population. RESULTS: Of the 67 patients included, majority were female (78%), white (76%), and an average age of 78 years ± 5.98 SD. Majority were insured by Original Medicare or Medicaid (61%), had a history of cognitive impairment (84%), had a referring diagnosis of anxiety (40%) or depression (67%), and were prescribed a selective serotonin reuptake inhibitor (69%) at baseline. Majority successfully completed PGx testing (72%), with 72% having actionable PGx findings and 83% having a pharmacological intervention made thereafter. Nineteen patients did not complete testing (28%), with the primary barrier being not having an appointment scheduled (63%). CONCLUSION: This study demonstrated majority of older adults were accepting of PGx testing and majority of findings were relevant to clinical care of anxiety, depression, or cognitive impairment.


Assuntos
Farmacêuticos , Farmacogenética , Humanos , Masculino , Feminino , Idoso , Estados Unidos , Farmacogenética/métodos , Estudos Retrospectivos , Medicare , Instituições de Assistência Ambulatorial
3.
Hum Mol Genet ; 29(R2): R177-R185, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-32601683

RESUMO

An individual's inherited genetic makeup and acquired genomic variants may account for a significant portion of observable variability in therapy efficacy and toxicity. Pharmacogenomics (PGx) is the concept that treatments can be modified to account for these differences to increase chances of therapeutic efficacy while minimizing risk of adverse effects. This is particularly applicable to oncology in which treatment may be multimodal. Each tumor type has a unique genomic signature that lends to inclusion of targeted therapy but may be associated with cumulative toxicity, such as cardiotoxicity, and can impact quality of life. A greater understanding of therapeutic agents impacted by PGx and subsequent implementation has the potential to improve outcomes and reduce risk of drug-induced adverse effects.


Assuntos
Antineoplásicos/efeitos adversos , Cardiotoxicidade/patologia , Doenças Cardiovasculares/patologia , Terapia de Alvo Molecular/efeitos adversos , Neoplasias/tratamento farmacológico , Farmacogenética , Variantes Farmacogenômicos , Cardiotoxicidade/etiologia , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/genética , Humanos , Neoplasias/genética , Neoplasias/patologia , Medicina de Precisão , Medição de Risco
4.
PLoS Comput Biol ; 16(2): e1007701, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32101536

RESUMO

Tumor-specific genomic alterations allow systematic identification of genetic interactions that promote tumorigenesis and tumor vulnerabilities, offering novel strategies for development of targeted therapies for individual patients. We develop an Individualized Network-based Co-Mutation (INCM) methodology by inspecting over 2.5 million nonsynonymous somatic mutations derived from 6,789 tumor exomes across 14 cancer types from The Cancer Genome Atlas. Our INCM analysis reveals a higher genetic interaction burden on the significantly mutated genes, experimentally validated cancer genes, chromosome regulatory factors, and DNA damage repair genes, as compared to human pan-cancer essential genes identified by CRISPR-Cas9 screenings on 324 cancer cell lines. We find that genes involved in the cancer type-specific genetic subnetworks identified by INCM are significantly enriched in established cancer pathways, and the INCM-inferred putative genetic interactions are correlated with patient survival. By analyzing drug pharmacogenomics profiles from the Genomics of Drug Sensitivity in Cancer database, we show that the network-predicted putative genetic interactions (e.g., BRCA2-TP53) are significantly correlated with sensitivity/resistance of multiple therapeutic agents. We experimentally validated that afatinib has the strongest cytotoxic activity on BT474 (IC50 = 55.5 nM, BRCA2 and TP53 co-mutant) compared to MCF7 (IC50 = 7.7 µM, both BRCA2 and TP53 wild type) and MDA-MB-231 (IC50 = 7.9 µM, BRCA2 wild type but TP53 mutant). Finally, drug-target network analysis reveals several potential druggable genetic interactions by targeting tumor vulnerabilities. This study offers a powerful network-based methodology for identification of candidate therapeutic pathways that target tumor vulnerabilities and prioritization of potential pharmacogenomics biomarkers for development of personalized cancer medicine.


Assuntos
Biologia Computacional/métodos , Redes Reguladoras de Genes , Neoplasias/genética , Antineoplásicos/uso terapêutico , Proteína BRCA2/genética , Biomarcadores Tumorais , Sistemas CRISPR-Cas , Carcinogênese , Linhagem Celular Tumoral , Exoma , Testes Genéticos , Genômica , Humanos , Concentração Inibidora 50 , Modelos Teóricos , Mutação , Neoplasias/tratamento farmacológico , Farmacogenética , Medicina de Precisão , Mapeamento de Interação de Proteínas , Taxa de Sobrevida , Proteína Supressora de Tumor p53/genética
5.
Biochim Biophys Acta ; 1859(2): 235-45, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26597160

RESUMO

kRAS is one of the most prevalent oncogenic aberrations. It is either upregulated or mutationally activated in a multitude of cancers, including pancreatic, lung, and colon cancers. While a significant effort has been made to develop drugs that target kRAS, their clinical activity has been disappointing due to a variety of mechanistic hurdles. The presented works describe a novel mechanism and molecular target to downregulate kRAS expression--a previously undescribed G-quadruplex (G4) secondary structure within the proximal promoter acting as a transcriptional silencer. There are three distinct guanine-rich regions within the core kRAS promoter, including a previously examined region (G4near). Of these regions, the most distal region does not form an inducible and stable structure, whereas the two more proximal regions (termed near and mid) do form strong G4s. G4near is predominantly a tri-stacked structure with a discontinuous guanine run incorporated; G4mid consists of seven distinct runs of continuous guanines and forms numerous competing isoforms, including a stable three-tetrad stacked mixed parallel and antiparallel loop structures with longer loops of up to 10 nucleotides. Comprehensive analysis of the regulation of transcription by higher order structures has revealed that the guanine-rich region in the middle of the core promoter, termed G4mid, is a stronger repressor of promoter activity than G4near. Using the extensive guanine-rich region of the kRAS core promoter, and particularly the G4mid structure, as the primary target, future drug discovery programs will have potential to develop a potent, specifically targeted small molecule to be used in the treatment of pancreatic, ovarian, lung, and colon cancers.


Assuntos
Quadruplex G , Neoplasias/genética , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas p21(ras)/genética , Dicroísmo Circular , Regulação Neoplásica da Expressão Gênica , Humanos , Modelos Moleculares , Mutação , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Conformação de Ácido Nucleico , Proteínas Proto-Oncogênicas p21(ras)/química
6.
Support Care Cancer ; 25(6): 1853-1858, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28120115

RESUMO

PURPOSE: Febrile neutropenia (FN) is a major risk factor for infection-related morbidity and mortality. The National Comprehensive Cancer Network recommends the prophylactic use of granulocyte-colony stimulating factors (G-CSF), dosed at 5 mcg/kg and rounded to the nearest vial size. A previous medication use evaluation conducted within a multi-hospital healthcare system demonstrated that only 67% of patients were started on appropriate weight-based dosing. The purpose of this study was to evaluate the effect of appropriate weight-based G-CSF dosing in patients on clinical outcomes. METHODS: A retrospective chart review of patients with acute leukemia or stem cell transplant recipients who received G-CSF from May 2009 to September 2015 was conducted. Patient admissions were reviewed in regards to neutropenia length, incidence of FN, length of stay, and final disposition (alive or deceased). Admissions were divided into one of three weight-based dosing groups of under 5 mcg/kg, recommended 5 mcg/kg within a 10% range, and over 5 mcg/kg which were named under, recommended, and over, respectively. RESULTS: Ninety-four admissions were included. Average age of this patient population was 58 years old, and the majority of patients were male (53%) and Caucasian (55%). Majority of patients had been diagnosed with acute myeloid leukemia (91%). Data showed average duration of neutropenia was around 10 days regardless if the patient received under 5 mcg/kg, the recommended 5 mcg/kg or over 5 mcg/kg G-CSF (10.1 ± 6.7 days, 8.9 ± 9.2 days, 10.1 ± 9.1 days, respectively). Length of stay was similar for patients regardless of initial G-CSF dose (29.6 ± 16.0 days, 29.1 ± 18.4 days, and 24.5 ± 17.0, respectively). However, the incidence of FN was significantly greater for those who received under 5 mcg/kg of G-CSF (87% for under, 68% for recommended, and 54% for over). CONCLUSIONS: In this retrospective analysis, variations from the recommended 5 mcg/kg G-CSF dose did not significantly impact length of neutropenia, length of stay, nor mortality. However, patients who received under the 5 mcg/kg of G-CSF dose may be at a greater risk of FN.


Assuntos
Febre/prevenção & controle , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Neutropenia/prevenção & controle , Transplante de Células-Tronco/métodos , Peso Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
7.
Front Pain Res (Lausanne) ; 4: 1139883, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37251592

RESUMO

Taxanes, particularly paclitaxel and docetaxel, are chemotherapeutic agents commonly used to treat breast cancers. A frequent side effect is chemotherapy-induced peripheral neuropathy (CIPN) that occurs in up to 70% of all treated patients and impacts the quality of life during and after treatment. CIPN presents as glove and stocking sensory deficits and diminished motor and autonomic function. Nerves with longer axons are at higher risk of developing CIPN. The causes of CIPN are multifactorial and poorly understood, limiting treatment options. Pathophysiologic mechanisms can include: (i) disruptions of mitochondrial and intracellular microtubule functions, (ii) disruption of axon morphology, and (iii) activation of microglial and other immune cell responses, among others. Recent work has explored the contribution of genetic variation and selected epigenetic changes in response to taxanes for any insights into their relation to pathophysiologic mechanisms of CIPN20, with the hope of identifying predictive and targetable biomarkers. Although promising, many genetic studies of CIPN are inconsistent making it difficult to develop reliable biomarkers of CIPN. The aims of this narrative review are to benchmark available evidence and identify gaps in the understanding of the role genetic variation has in influencing paclitaxel's pharmacokinetics and cellular membrane transport potentially related to the development of CIPN.

8.
Front Neurol ; 13: 942643, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36188379

RESUMO

Objective: Seizure outcomes after brain surgery for drug-resistant epilepsy (DRE) are very heterogeneous and difficult to predict with models utilizing the current clinical, imaging, and electrophysiological variables. In this pilot study, we investigated whether genetic and molecular biomarkers (e.g., genomic, transcriptomic) can provide additional insight into differential response to surgery. Methods: Post-operative seizure-outcomes were collected at last follow-up (>6 months) for 201 adult patients with DRE who underwent surgery between 2004 and 2020. Resected tissue was sent for miRNA sequencing (n = 132) and mRNA sequencing (n = 135). Following the selection of 10 genes (SCN1A, NBEA, PTEN, GABRA1, LGL1, DEPDC5, IL1A, ABCB1, C3, CALHM1), we investigated SNPs in those 10 genes from previously acquired exome sequencing data (n = 106). Logistic regression was performed to test for associations between individual features (mRNAs, miRNAs, and SNPs) and post-operative seizure-outcome with an exploratory FDR P < 0.25 as the threshold for significance. Post-operative time-to-seizure analyses were performed for each SNP using a Cox proportional hazards model. Results: The majority of patients (83%) had temporal lobe epilepsy. Mean age at surgery was 38.3 years, and 56% were female. Three SNPs (rs10276036, rs11975994, rs1128503) in multi-drug resistance gene, ABCB1, were associated with post-operative seizure outcomes. Patients with alternate alleles in ABCB1 were more likely to be seizure-free at last follow-up (52-56% reduction in seizure recurrence; FDR P = 0.24). All three SNPs were in linkage disequilibrium and highly correlated with each other. Median post-operative time-to-seizure was 63 months for patients with 2 alternate alleles, 24-33 months with 1 alternate allele, and 10-11 months with 0 alternate alleles. These SNPs improved outcome prediction beyond MRI and sex alone. No independent miRNAs or mRNAs were significantly associated with seizure-outcome (P > 0.05). However, pathway analysis identified "cancer drug resistance by drug efflux" (mir-154 and mir-379) as enriched (P = 0.02), supporting the role of drug response genes in post-operative seizure recurrence. Significance: ABCB1 may have a role in epileptogenesis and surgery outcomes independent of its drug efflux activity necessitating further investigation. SNPs in ABCB1 may serve as independent predictors of post-operative outcome.

9.
Technol Cancer Res Treat ; 21: 15330338221127169, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36172750

RESUMO

Introduction: Taxanes are a class of chemotherapeutics commonly used to treat various solid tumors, including breast and ovarian cancers. Taxane-induced peripheral neuropathy (TIPN) occurs in up to 70% of patients, impacting quality of life both during and after treatment. TIPN typically manifests as tingling and numbness in the hands and feet and can cause irreversible loss of function of peripheral nerves. TIPN can be dose-limiting, potentially impacting clinical outcomes. The mechanisms underlying TIPN are poorly understood. As such, there are limited treatment options and no tools to provide early detection of those who will develop TIPN. Although some patients may have a genetic predisposition, genetic biomarkers have been inconsistent in predicting chemotherapy-induced peripheral neuropathy (CIPN). Moreover, other molecular markers (eg, metabolites, mRNA, miRNA, proteins) may be informative for predicting CIPN, but remain largely unexplored. We anticipate that combinations of multiple biomarkers will be required to consistently predict those who will develop TIPN. Methods: To address this clinical gap of identifying patients at risk of TIPN, we initiated the Genetics and Inflammatory Markers for CIPN (GENIE) study. This longitudinal multicenter observational study uses a novel, multimodal approach to evaluate genomic variation, metabolites, DNA methylation, gene expression, and circulating cytokines/chemokines prior to, during, and after taxane treatment in 400 patients with breast cancer. Molecular and patient reported data will be collected prior to, during, and after taxane therapy. Multi-modal data will be used to develop a set of comprehensive predictive biomarker signatures of TIPN. Conclusion: The goal of this study is to enable early detection of patients at risk of developing TIPN, provide a tool to modify taxane treatment to minimize morbidity from TIPN, and improved patient quality of life. Here we provide a brief review of the current state of research into CIPN and TIPN and introduce the GENIE study design.


Assuntos
Antineoplásicos , Neoplasias da Mama , Doenças do Sistema Nervoso Periférico , Taxoides , Antineoplásicos/efeitos adversos , Biomarcadores , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Hidrocarbonetos Aromáticos com Pontes , Citocinas , Feminino , Humanos , MicroRNAs , Estudos Multicêntricos como Assunto , Estudos Observacionais como Assunto , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/diagnóstico , Doenças do Sistema Nervoso Periférico/genética , Qualidade de Vida , RNA Mensageiro , Taxoides/efeitos adversos
10.
Cleve Clin J Med ; 87(2): 91-99, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32015062

RESUMO

Pharmacogenomics, ie, the study of how an individual's genomic profile influences his or her response to drugs, has emerged as a clinical tool to optimize drug therapy. Certain variants in some genes increase the risk of severe, life-threatening adverse effects from certain drugs. Integrating pharmacogenomics into clinical practice to assist in drug selection and dosing has the potential to improve the outcomes of treatment, reduce the risk of drug-induced morbidity and death, and be cost-effective.


Assuntos
Codeína/metabolismo , Citocromo P-450 CYP2D6/genética , Farmacogenética , Variantes Farmacogenômicos , Medicina de Precisão , Antidepressivos Tricíclicos/efeitos adversos , Antidepressivos Tricíclicos/metabolismo , Clopidogrel/metabolismo , Codeína/efeitos adversos , Citocromo P-450 CYP2C19/genética , Triagem e Testes Direto ao Consumidor , Testes Genéticos/economia , Genótipo , Humanos , Farmacogenética/economia , Farmacogenética/educação , Farmacogenética/organização & administração , Inibidores Seletivos de Recaptação de Serotonina/efeitos adversos , Inibidores Seletivos de Recaptação de Serotonina/metabolismo
11.
Clin Pharmacol Ther ; 106(4): 726-733, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31006110

RESUMO

The HIV type-1 nonnucleoside reverse transcriptase inhibitor, efavirenz, is widely used to treat HIV type-1 infection. Efavirenz is predominantly metabolized into inactive metabolites by cytochrome P450 (CYP)2B6, and patients with certain CYP2B6 genetic variants may be at increased risk for adverse effects, particularly central nervous system toxicity and treatment discontinuation. We summarize the evidence from the literature and provide therapeutic recommendations for efavirenz prescribing based on CYP2B6 genotypes.


Assuntos
Benzoxazinas/farmacologia , Citocromo P-450 CYP2B6/genética , Infecções por HIV , HIV-1 , Testes Farmacogenômicos/métodos , Alcinos , Fármacos Anti-HIV/farmacologia , Ciclopropanos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/genética , Humanos , Farmacogenética , Guias de Prática Clínica como Assunto
12.
Breast Cancer Res ; 10(2): R29, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18377656

RESUMO

INTRODUCTION: Increased estrogen level has been regarded to be a risk factor for breast cancer. However, estrogen has also been shown to induce the expression of the tumor suppressor gene, BRCA1. Upregulation of BRCA1 is thought to be a feedback mechanism for controlling DNA repair in proliferating cells. Estrogens enhance transcription of target genes by stimulating the association of the estrogen receptor (ER) and related coactivators to estrogen response elements or to transcription complexes formed at activator protein (AP)-1 or specificity protein (Sp)-binding sites. Interestingly, the BRCA1 gene lacks a consensus estrogen response element. We previously reported that estrogen stimulated BRCA1 transcription through the recruitment of a p300/ER-alpha complex to an AP-1 site harbored in the proximal BRCA1 promoter. The purpose of the study was to analyze the contribution of cis-acting sites flanking the AP-1 element to basal and estrogen-dependent regulation of BRCA1 transcription. METHODS: Using transfection studies with wild-type and mutated BRCA1 promoter constructs, electromobility binding and shift assays, and DNA-protein interaction and chromatin immunoprecipitation assays, we investigated the role of Sp-binding sites and cAMP response element (CRE)-binding sites harbored in the proximal BRCA1 promoter. RESULTS: We report that in the BRCA1 promoter the AP-1 site is flanked upstream by an element (5'-GGGGCGGAA-3') that recruits Sp1, Sp3, and Sp4 factors, and downstream by a half CRE-binding motif (5'-CGTAA-3') that binds CRE-binding protein. In ER-alpha-positive MCF-7 cells and ER-alpha-negative Hela cells expressing exogenous ER-alpha, mutation of the Sp-binding site interfered with basal and estrogen-induced BRCA1 transcription. Conversely, mutation of the CRE-binding element reduced basal BRCA1 promoter activity but did not prevent estrogen activation. In combination with the AP-1/CRE sites, the Sp-binding domain enhanced the recruitment of nuclear proteins to the BRCA1 promoter. Finally, we report that the MEK1 (mitogen-activated protein kinase kinase-1) inhibitor PD98059 attenuated the recruitment of Sp1 and phosphorylated ER-alpha, respectively, to the Sp and AP-1 binding element. CONCLUSION: These cumulative findings suggest that the proximal BRCA1 promoter segment comprises cis-acting elements that are targeted by Sp-binding and CRE-binding proteins that contribute to regulation of BRCA1 transcription.


Assuntos
Fator 2 Ativador da Transcrição/metabolismo , Neoplasias da Mama/genética , Estrogênios/metabolismo , Genes BRCA1 , Proteínas Quinases/metabolismo , Receptores de Estrogênio/metabolismo , Fator de Transcrição AP-1/metabolismo , Transcrição Gênica , Proteína BRCA1/genética , Imunoprecipitação da Cromatina , Ensaio de Desvio de Mobilidade Eletroforética , Feminino , Flavonoides/farmacologia , Regulação Neoplásica da Expressão Gênica , Humanos , MAP Quinase Quinase 1/antagonistas & inibidores , Mutação , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas , Regulação para Cima
13.
Cancer Res ; 66(4): 2224-32, 2006 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-16489025

RESUMO

In sporadic breast cancers, BRCA-1 expression is down-regulated in the absence of mutations in the BRCA-1 gene. This suggests that disruption of BRCA-1 expression may contribute to the onset of mammary tumors. Environmental contaminants found in industrial pollution, tobacco smoke, and cooked foods include benzo(a)pyrene [B(a)P] and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), which have been shown to act as endocrine disruptors and tumor promoters. In previous studies, we documented that estrogen (E2) induced BRCA-1 transcription through the recruitment of an activator protein-1/estrogen receptor-alpha (ER alpha) complex to the proximal BRCA-1 promoter. Here, we report that activation of BRCA-1 transcription by E2 requires occupancy of the BRCA-1 promoter by the unliganded aromatic hydrocarbon receptor (AhR). The stimulatory effects of E2 on BRCA-1 transcription are counteracted by (a) cotreatment with the AhR antagonist 3'-methoxy-4'-nitroflavone; (b) transient expression in ER alpha-negative HeLa cells of ER alpha lacking the protein-binding domain for the AhR; and (c) mutation of two consensus xenobiotic-responsive elements (XRE, 5'-GCGTG-3') located upstream of the ER alpha-binding region. These results suggest that the physical interaction between the unliganded AhR and the liganded ER alpha plays a positive role in E2-dependent activation of BRCA-1 transcription. Conversely, we show that the AhR ligands B(a)P and TCDD abrogate E2-induced BRCA-1 promoter activity. The repressive effects of TCDD are paralleled by increased recruitment of the liganded AhR and HDAC1, reduced occupancy by p300, SRC-1, and diminished acetylation of H4 at the BRCA-1 promoter region flanking the XREs. We propose that the ligand status of the AhR modulates activation of the BRCA-1 promoter by estrogen.


Assuntos
Estradiol/farmacologia , Receptor alfa de Estrogênio/metabolismo , Genes BRCA1/fisiologia , Receptores de Hidrocarboneto Arílico/metabolismo , Proteína BRCA1/biossíntese , Proteína BRCA1/genética , Benzo(a)pireno/metabolismo , Benzo(a)pireno/farmacologia , Neoplasias da Mama/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/fisiologia , Genes BRCA1/efeitos dos fármacos , Células HeLa , Humanos , Ligantes , Dibenzodioxinas Policloradas/metabolismo , Dibenzodioxinas Policloradas/farmacologia , Regiões Promotoras Genéticas/efeitos dos fármacos , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptor Cross-Talk/efeitos dos fármacos , Receptor Cross-Talk/fisiologia , Receptores de Hidrocarboneto Arílico/antagonistas & inibidores , Fator de Transcrição AP-1/metabolismo , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/fisiologia , Transfecção
15.
Neoplasia ; 7(9): 873-82, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16229810

RESUMO

One of the puzzles in cancer predisposition is that women carrying BRCA-1 mutations preferentially develop tumors in epithelial tissues of the breast and ovary. Moreover, sporadic breast tumors contain lower levels of BRCA-1 in the absence of mutations in the BRCA-1 gene. The problem of tissue specificity requires analysis of factors that are unique to tissues of the breast. For example, the expression of estrogen receptor-alpha (ER alpha) is inversely correlated with breast cancer risk, and 90% of BRCA-1 tumors are negative for ER alpha. Here, we show that estrogen stimulates BRCA-1 promoter activity in transfected cells and the recruitment of ER alpha and its cofactor p300 to an AP-1 site that binds Jun/Fos transcription factors. The recruitment of ER alpha/p300 coincides with accumulation in the S-phase of the cell cycle and is antagonized by the antiestrogen tamoxifen. Conversely, we document that overexpression of wild-type p53 prevents the recruitment of ER alpha to the AP-1 site and represses BRCA-1 promoter activity. Taken together, our findings support a model in which an ER alpha/AP-1 complex modulates BRCA-1 transcription under conditions of estrogen stimulation. Conversely, the formation of this transcription complex is abrogated in cells overexpressing p53.


Assuntos
Proteína BRCA1/metabolismo , Proteína p300 Associada a E1A/metabolismo , Receptor alfa de Estrogênio/metabolismo , Fator de Transcrição AP-1/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteína BRCA1/genética , Linhagem Celular Tumoral , DNA de Neoplasias/metabolismo , Estrogênios/farmacologia , Células HCT116 , Células HeLa , Humanos , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-fos/metabolismo , Proteínas Proto-Oncogênicas c-jun/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica , Proteína Supressora de Tumor p53/genética
16.
Nutr Cancer ; 59(2): 248-57, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18001219

RESUMO

The role of the aromatic hydrocarbon receptor (AhR) in transcriptional regulation of the human cyclooxygenase-2 (COX-2) gene remains elusive. We report that the AhR-ligands benzo[a]pyrene and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced transcription activity of COX-2 in breast cancer MCF-7 cells. The TCDD-dependent activation of the COX-2 promoter was abrogated by mutation of 2 xenobiotic response elements (XREs) = CGTG). We found that TCDD stimulated the binding of the AhR to COX-2 and cytochrome P4501A1 (CYP1A1) oligonucleotides containing consensus XREs. Conversely, the cotreatment with TCDD plus a mixture of conjugated linoleic acid (CLA) or selected CLA isomers prevented (CLAmix = t10,c12-CLA > c9,t11-CLA) the induction of transcription from the COX-2 promoter. The TCDD-induced binding of the AhR to COX-2 and CYP1A1 oligonucleotides was repressed by cotreatment with CLA (t10,c12-CLA > c9,t11-CLA), and the AhR antagonists, 3-methoxy-4-naphthoflavone, and resveratrol. We conclude that the AhR may be a suitable target for prophylactic strategies that target COX-2 expression.


Assuntos
Neoplasias da Mama/enzimologia , Ciclo-Oxigenase 2/metabolismo , Ativação Enzimática/efeitos dos fármacos , Ácidos Linoleicos Conjugados/farmacologia , Receptores de Hidrocarboneto Arílico/antagonistas & inibidores , Receptores de Hidrocarboneto Arílico/metabolismo , Linhagem Celular Tumoral , Ciclo-Oxigenase 2/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Ligantes , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/toxicidade , Transdução de Sinais , Transcrição Gênica
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