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1.
Pigment Cell Melanoma Res ; 36(1): 19-32, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36112085

RESUMO

Lineage-specific differentiation programs are activated by epigenetic changes in chromatin structure. Melanin-producing melanocytes maintain a gene expression program ensuring appropriate enzymatic conversion of metabolites into the pigment, melanin, and transfer to surrounding cells. During neuroectodermal development, SMARCA4 (BRG1), the catalytic subunit of SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complexes, is essential for lineage specification. SMARCA4 is also required for development of multipotent neural crest precursors into melanoblasts, which differentiate into pigment-producing melanocytes. In addition to the catalytic domain, SMARCA4 and several SWI/SNF subunits contain bromodomains which are amenable to pharmacological inhibition. We investigated the effects of pharmacological inhibitors of SWI/SNF bromodomains on melanocyte differentiation. Strikingly, treatment of murine melanoblasts and human neonatal epidermal melanocytes with selected bromodomain inhibitors abrogated melanin synthesis and visible pigmentation. Using functional genomics, iBRD9, a small molecule selective for the bromodomain of BRD9 was found to repress pigmentation-specific gene expression. Depletion of BRD9 confirmed a requirement for expression of pigmentation genes in the differentiation program from melanoblasts into pigmented melanocytes and in melanoma cells. Chromatin immunoprecipitation assays showed that iBRD9 disrupts the occupancy of BRD9 and the catalytic subunit SMARCA4 at melanocyte-specific loci. These data indicate that BRD9 promotes melanocyte pigmentation whereas pharmacological inhibition of BRD9 is repressive.


Assuntos
Melaninas , Transtornos da Pigmentação , Recém-Nascido , Humanos , Camundongos , Animais , Melaninas/metabolismo , Melanócitos/metabolismo , Diferenciação Celular , Epigênese Genética , Transtornos da Pigmentação/metabolismo , Pigmentação , DNA Helicases/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo
2.
Epigenetics Chromatin ; 13(1): 14, 2020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32151278

RESUMO

BACKGROUND: Pharmacologic inhibition of bromodomain and extra-terminal (BET) proteins is currently being explored as a new therapeutic approach in cancer. Some studies have also implicated BET proteins as regulators of cell identity and differentiation through their interactions with lineage-specific factors. However, the role of BET proteins has not yet been investigated in melanocyte differentiation. Melanocyte inducing transcription factor (MITF) is the master regulator of melanocyte differentiation, essential for pigmentation and melanocyte survival. In this study, we tested the hypothesis that BET proteins regulate melanocyte differentiation through interactions with MITF. RESULTS: Here we show that chemical inhibition of BET proteins prevents differentiation of unpigmented melanoblasts into pigmented melanocytes and results in de-pigmentation of differentiated melanocytes. BET inhibition also slowed cell growth, without causing cell death, increasing the number of cells in G1. Transcriptional profiling revealed that BET inhibition resulted in decreased expression of pigment-specific genes, including many MITF targets. The expression of pigment-specific genes was also down-regulated in melanoma cells, but to a lesser extent. We found that RNAi depletion of the BET family members, bromodomain-containing protein 4 (BRD4) and bromodomain-containing protein 2 (BRD2) inhibited expression of two melanin synthesis enzymes, TYR and TYRP1. Both BRD4 and BRD2 were detected on melanocyte promoters surrounding MITF-binding sites, were associated with open chromatin structure, and promoted MITF binding to these sites. Furthermore, BRD4 and BRD2 physically interacted with MITF. CONCLUSION: These findings indicate a requirement for BET proteins in the regulation of pigmentation and melanocyte differentiation. We identified changes in pigmentation specific gene expression that occur upon BET inhibition in melanoblasts, melanocytes, and melanoma cells.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Diferenciação Celular , Melanócitos/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Ciclo Celular/genética , Células Cultivadas , Células HEK293 , Humanos , Melaninas/biossíntese , Melaninas/genética , Melanócitos/citologia , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Fator de Transcrição Associado à Microftalmia/metabolismo , Monofenol Mono-Oxigenase/genética , Monofenol Mono-Oxigenase/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Fatores de Transcrição/genética
3.
PLoS One ; 14(11): e0225624, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31756235

RESUMO

IL-21 is the most recently discovered common gamma-chain cytokine that promotes persistent T-cell responses in chronic infections, autoimmunity and cancer. However, the therapeutic potential of inhibiting the IL-21-BATF signaling axis, particularly in transplant rejection, remains unclear. We used heart transplant models to examine the effects of IL-21 blockade in prevention of chronic cardiac allograft vasculopathy (CAV) using genetic knock-out and therapeutic approaches. Both wild-type C57BL/6 and IL-21-/- strains acutely rejected Balb/c skin grafts and once immunized with this skin graft, rejected Balb/c heart allografts in an accelerated fashion. However, when transplanted with heart grafts from the class-II major histocompatibility complex mutant, B6bm12 mice; wild-type recipients developed CAV, while IL-21-/- recipients were protected, even at day 100 post-transplant. Similarly, BATF-/- recipients, lacking the transcription factor BATF responsible for IL-21 production, did not develop CAV in B6-bm12 heart allografts. Strikingly, in a transient treatment protocol, the development of CAV in wild-type recipients of B6-bm12 hearts allografts was blocked by the administration of IL-21 receptor fusion protein (R-Fc). Thus, we demonstrate that CAV is regulated at least in part by IL-21 signaling and its blockade by genetic approaches or therapy with IL-21R-Fc prevents CAV in mice.


Assuntos
Rejeição de Enxerto/etiologia , Transplante de Coração/efeitos adversos , Interleucinas/genética , Transplante Homólogo/efeitos adversos , Doenças Vasculares/etiologia , Animais , Fatores de Transcrição de Zíper de Leucina Básica/deficiência , Fatores de Transcrição de Zíper de Leucina Básica/genética , Rejeição de Enxerto/imunologia , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Interferon gama/metabolismo , Interleucinas/deficiência , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Interleucina-21/genética , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/biossíntese , Transplante de Pele/efeitos adversos , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Doenças Vasculares/prevenção & controle
4.
Toxins (Basel) ; 11(6)2019 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-31242640

RESUMO

Inflammatory Bowel Disease (IBD) represents a collection of gastrointestinal disorders resulting from genetic and environmental factors. Microcystin-leucine arginine (MC-LR) is a toxin produced by cyanobacteria during algal blooms and demonstrates bioaccumulation in the intestinal tract following ingestion. Little is known about the impact of MC-LR ingestion in individuals with IBD. In this study, we sought to investigate MC-LR's effects in a dextran sulfate sodium (DSS)-induced colitis model. Mice were separated into four groups: (a) water only (control), (b) DSS followed by water (DSS), (c) water followed by MC-LR (MC-LR), and (d) DSS followed by MC-LR (DSS + MC-LR). DSS resulted in weight loss, splenomegaly, and severe colitis marked by transmural acute inflammation, ulceration, shortened colon length, and bloody stools. DSS + MC-LR mice experienced prolonged weight loss and bloody stools, increased ulceration of colonic mucosa, and shorter colon length as compared with DSS mice. DSS + MC-LR also resulted in greater increases in pro-inflammatory transcripts within colonic tissue (TNF-α, IL-1ß, CD40, MCP-1) and the pro-fibrotic marker, PAI-1, as compared to DSS-only ingestion. These findings demonstrate that MC-LR exposure not only prolongs, but also worsens the severity of pre-existing colitis, strengthening evidence of MC-LR as an under-recognized environmental toxin in vulnerable populations, such as those with IBD.


Assuntos
Colite/induzido quimicamente , Microcistinas/toxicidade , Animais , Antígenos CD40/genética , Colite/genética , Colite/patologia , Colo/efeitos dos fármacos , Colo/metabolismo , Colo/patologia , Citocinas/genética , Sulfato de Dextrana , Expressão Gênica/efeitos dos fármacos , Proliferação Nociva de Algas , Masculino , Toxinas Marinhas , Camundongos Endogâmicos C57BL , Índice de Gravidade de Doença , Baço/efeitos dos fármacos
5.
Transpl Int ; 32(8): 839-853, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30848501

RESUMO

We examined what happened during a 6-year period to 1121 end-stage renal disease patients who registered with their willing/incompatible living donors for kidney exchanges with the Alliance for Paired Donation (APD). Of all patients, 65% were transplanted: 37% in kidney paired donation (APD-KPD, APD-other-KPD); 10% with compatible live donors (APD-LD); and 18% with deceased donors (APD-DD). The remaining patients were withdrawn (sick/died/others; 15%), or were still waiting (20%). For those patients with a cPRA 0-94%, 72% received a transplant. In contrast, only 49% of very highly sensitized (VHS; cPRA 95-100%) were transplanted. Of the VHS patients, 50% were transplanted by KPD/APD-LD while 50% benefited through prioritization of deceased donors in the modified kidney allocation system (KAS introduced in 2014). All APD transplanted groups had similar death-censored 4-year graft survivals as their relevant Organ Procurement and Transplantation Network (OPTN) groups. It is noteworthy that VHS graft and patient survival results were comparable to less sensitized and nonsensitized patients. All patients should be encouraged to search for compatible donors through different options. Expanding the donor pool through KPD and the new KAS of the OPTN increases the likelihood of transplantation for VHS patients.


Assuntos
Falência Renal Crônica/cirurgia , Transplante de Rim/métodos , Obtenção de Tecidos e Órgãos/métodos , Adulto , Algoritmos , Bases de Dados Factuais , Saúde da Família , Feminino , Sobrevivência de Enxerto , Humanos , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Estados Unidos
6.
Diabetologia ; 58(6): 1309-18, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25794782

RESUMO

AIMS/HYPOTHESIS: T cells play a major role in the pathogenesis of type 1 diabetes, and there is great interest in developing curative immunotherapies targeting these cells. In this study, a monoclonal antibody (mAb) targeting the T cell receptor ß-chain (TCRß) was investigated for its ability to prevent and reverse disease in mouse models of diabetes. METHODS: RIP-OVA(hi) (C57BL/6-Tg(Ins2-OVA)59Wehi/WehiJ) mice adoptively transferred with ovalbumin-specific T cells (an induced model of diabetes) and NOD mice (a spontaneous model of diabetes) were used to test anti-TCRß mAb therapy as a means of preventing and reversing type 1 diabetes. RESULTS: A single dose of anti-TCRß completely prevented disease in RIP-OVA(hi) mice without inducing the release of inflammatory cytokines. Transient anti-TCRß therapy prevented diabetes in 90% of NOD mice and reversed the disease after its onset in 73% of NOD mice. Long after the remission of type 1 diabetes, the anti-TCRß treated mice were able to reject BALB/c skin allografts with normal kinetics while maintaining normoglycaemia. Treatment did not cause significant reductions in lymphocyte numbers in the spleen or pancreatic lymph nodes, but did result in a decreased percentage of chemokine receptor 9 (CCR9) positive, CD8(+) T cells. Notably, anti-TCRß therapy increased the expression of programmed death 1 (PD-1) on the surface of the T cells; PD-1 expression is important for maintaining anti-TCRß-induced self-tolerance, as type 1 diabetes recurs in mice following a blockade of PD-1 signalling. CONCLUSIONS/INTERPRETATION: Anti-TCRß mAb is a safe and effective immunotherapy that results in reduced numbers of CCR9(+) T cells, an increased expression of PD-1 on T cells and the restoration of self-tolerance in NOD mice.


Assuntos
Anticorpos Monoclonais/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Receptor de Morte Celular Programada 1/metabolismo , Aloenxertos , Animais , Glicemia/análise , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Citocinas/sangue , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/terapia , Feminino , Teste de Tolerância a Glucose , Inflamação , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Receptores CCR/metabolismo
7.
Hum Immunol ; 75(8): 703-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24755353

RESUMO

Donor-specific alloantibodies (DSA) to HLA-DP may cause antibody-mediated rejection (AMR), especially in re-transplants. We describe the immunization history of a patient who received 3 kidney transplants; the 3rd kidney was completely matched except at DPA1 and DPB1. Prior to the 3rd transplant, single antigen bead analysis (SAB) showed DSA reactivity against DPA1 shared by the 1st and 3rd donors, but B and T flow crossmatch (FXM) results were negative. Within 11 days the 3rd transplant underwent acute C4d+ AMR which coincided with the presence of complement (C1q)-binding IgG1 DSA against donor DPA1 and DPB1. Using HLAMatchmaker and SAB, we provide evidence that eplet (epitope) spreading on DPA1 and eplet sharing on differing DPB1 alleles of the 1st and 3rd transplants was associated with AMR. Since weak DSA to DPA1/DPB1 may induce acute AMR with negative FXM, donor DPA1/DPB1 high resolution typing should be considered in sensitized patients with DP-directed DSA.


Assuntos
Rejeição de Enxerto/imunologia , Antígenos HLA-DP/imunologia , Cadeias alfa de HLA-DP/imunologia , Isoanticorpos/biossíntese , Falência Renal Crônica/imunologia , Transplante de Rim , Complemento C1q/metabolismo , Complemento C4b/metabolismo , Feminino , Rejeição de Enxerto/metabolismo , Rejeição de Enxerto/patologia , Rejeição de Enxerto/cirurgia , Cadeias beta de HLA-DP/imunologia , Cadeias HLA-DRB3/imunologia , Teste de Histocompatibilidade , Humanos , Rim/imunologia , Rim/metabolismo , Rim/patologia , Rim/cirurgia , Falência Renal Crônica/metabolismo , Falência Renal Crônica/patologia , Falência Renal Crônica/cirurgia , Fragmentos de Peptídeos/metabolismo , Doadores não Relacionados , Adulto Jovem
8.
Expert Rev Clin Immunol ; 9(12): 1303-14, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24215417

RESUMO

Apart from clonal deletion of self-reactive T cells in the thymus, Tregs are the major regulators of immune responses in the periphery and maintain a state of self-tolerance free from autoimmune diseases. Due to their inherent suppressive function, Tregs are being explored for their therapeutic potential in preventing autoimmunity and improving survival of allografts. This review provides recent updates on Treg biology and their use in animal as well as clinical models of transplantation. We discuss potential problems that limit the widespread clinical application of Tregs and provide future perspectives on how to optimize their medical use. Special consideration is given to methods by which Tregs should be isolated and expanded in order to facilitate clinical therapies. We also focus on recent discussions of Treg stability and plasticity, with specific insights into preventing the loss of Treg suppression by allotransplant-mediated inflammation.


Assuntos
Rejeição de Enxerto/imunologia , Rejeição de Enxerto/prevenção & controle , Imunoterapia , Linfócitos T Reguladores/imunologia , Transplante , Animais , Humanos , Terapia de Imunossupressão/tendências , Imunoterapia/métodos , Tolerância ao Transplante
9.
Ann Transplant ; 18: 112-24, 2013 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-23792511

RESUMO

Kidney transplantation is the treatment of choice for patients with end-stage renal disease. While living donors provide anywhere from a small to a large fraction of kidneys for transplantation in different countries, at least one-third of these donors are incompatible with their potential recipients. To overcome these challenges, kidney paired donation (KPD) programs have been established that organize donor exchanges to find matches among the pool of incompatible pairs. Each program has developed its own features to accommodate local needs. Reasons for participating in KPD include blood group incompatibility, sensitization of the recipient against the donor, and the potential for improvement in transplant quality (e.g., age difference or graft size), and tissue compatibility. KPD programs use sophisticated algorithms to find matches among the pool of donor-recipient pairs to create simultaneous 2-way, 3-way, or 4-way exchanges or more complex non-simultaneous chains of transplants. These KPD allocation systems should be medically sound and ethically acceptable according to the principles of equity, utility, and justice. The variety of possible exchanges provided by these algorithms allows for maximizing the number of transplants, increasing the quality of transplants, and accommodating patients who are difficult to match. In this review, we describe several examples of successful KPD programs with diverse organizational approaches. By highlighting the strategies used by these programs to meet the needs of their patient populations, we aim to inspire improvements in existing programs and to provide a framework for expanding KPD to better serve international transplant communities.


Assuntos
Doação Dirigida de Tecido , Transplante de Rim , Obtenção de Tecidos e Órgãos/organização & administração , Sistema ABO de Grupos Sanguíneos , Algoritmos , Austrália , Antígenos HLA , Histocompatibilidade , Humanos , Falência Renal Crônica/cirurgia , Doadores Vivos , Países Baixos , República da Coreia , Obtenção de Tecidos e Órgãos/estatística & dados numéricos , Reino Unido , Estados Unidos
10.
J Clin Endocrinol Metab ; 96(2): E368-72, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21106711

RESUMO

CONTEXT: Reactive estrogen species cause genotoxicity and interfere with docetaxel-mediated tubulin polymerization resulting in shortened survival in men with castrate-resistant prostate cancer (CRPC). OBJECTIVE: We hypothesized that polymorphisms in estrogen synthesis and estrogen targets (i.e., CYP19 and ERα) would be linked to interindividual variation in CRPC risk, docetaxel response, and overall survival in men with CRPC. MATERIALS AND METHODS: Patients with CRPC (n=115) treated with docetaxel, single-agent thalidomide (n=42), or healthy controls (n=289) were genotyped for the CYP19 R264C (rs700519) and the ERα PvuII T>C (rs2234693) and XbaI A>G (rs9340799) polymorphisms. RESULTS: Patients carrying two copies of ERα polymorphisms had shorter progression-free survival on docetaxel than other patients (median survival difference ≥ 3.1 months; P ≤ 0.036). When the analysis was limited to nonobese patients, the relationship between the ERα XbaI A>G polymorphism and PFS improved (median survival difference = 3.5 months; P = 0.0078). The CYP19 R264C variant was related to the duration of survival after docetaxel in patients who were >70 years old (median survival difference =10.6 months; P=0.041). Both ERα polymorphisms were also associated with increases in CRPC risk [P ≤ 0.032; double variants vs. wild-type odds ratio ≥ 2.6], and the association with the ERα PvuII T>C also improved in those men who were <70 years old (P = 0.0073; odds ratio = 3.0). CONCLUSIONS: This study demonstrates that estrogen-related genetic variation affects docetaxel clinical response and that this relationship is dependent on age and body-type in men with CRPC. Moreover, this study suggests ERα polymorphisms confer risk of developing prostate cancer, especially in men under 70 years of age.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Aromatase/genética , Receptor alfa de Estrogênio/genética , Orquiectomia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Taxoides/uso terapêutico , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica , Intervalo Livre de Doença , Docetaxel , Genótipo , Humanos , Masculino , Polimorfismo Genético/genética , Prognóstico , Neoplasias da Próstata/cirurgia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Medição de Risco , Análise de Sobrevida , Resultado do Tratamento
11.
Ther Clin Risk Manag ; 6: 579-83, 2010 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-21151627

RESUMO

A single nucleotide polymorphism (SNP) in CYP2C8 (rs1934951), was previously identified in a genome-wide association study as a risk factor for the development of osteonecrosis of the jaw (ONJ) in patients receiving bisphosphonates (BPs) for multiple myeloma. To determine if the same SNP is also associated with the development of ONJ in men receiving BPs for bone metastases from prostate cancer, we genotyped 100 men with castrate-resistant prostate cancer treated with bisphosphonates for bone metastases, 17 of whom developed ONJ. Important clinical characteristics, including type and duration of bisphosphonate therapy, were consistent among those who developed ONJ and those who did not. We found no significant correlation between the variant allele and the development of ONJ (OR = 0.63, 95% CI: 0.165-2.42, P > 0.47). This intronic SNP in CYP2C8 (rs1934951) does not seem to be a risk factor for the development of bisphosphonate-related ONJ in men with prostate cancer. It is important to note that this is only the second study to investigate the genetics associated with BP-related ONJ and the first to do so in men with prostate cancer. More studies are needed to identify genetic risk factors that may predict the development of this important clinical condition.

12.
J Urol ; 184(6): 2297-302, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20952028

RESUMO

PURPOSE: We investigated the association between the length of the polymorphic trinucleotide CAG microsatellite repeats in exon 1 of the AR gene and the risk of prostate cancer. MATERIALS AND METHODS: This is a nested case-control study of 1,159 cases and 1,353 controls from the Prostate Cancer Prevention Trial, a randomized, placebo controlled trial testing whether the 5α-reductase inhibitor finasteride could decrease the 7-year prevalence of prostate cancer. During the course of the trial men underwent annual digital rectal examination and prostate specific antigen measurement. Prostate biopsy was recommended in all men with abnormal digital rectal examination or finasteride adjusted prostate specific antigen greater than 4.0 ng/ml. Cases were drawn from men with biopsy determined prostate cancer identified by for cause or end of study biopsy. Controls were selected from men who completed the end of study biopsy. RESULTS: Mean CAG repeat length did not differ between cases and controls. The frequency distribution of cases and controls for the AR CAG repeat length was similar. There were no significant associations of CAG repeat length with prostate cancer risk when stratified by treatment arm (finasteride or placebo), or when combined. There was also no significant association between CAG repeat length and the risk of low or high grade prostate cancer. CONCLUSIONS: There is no association of AR CAG repeat length with prostate cancer risk. Knowledge of AR CAG repeat length provides no clinically useful information to predict prostate cancer risk.


Assuntos
Neoplasias da Próstata/genética , Receptores Androgênicos/genética , Idoso , Estudos de Casos e Controles , Éxons/genética , Humanos , Masculino , Repetições de Microssatélites/genética , Pessoa de Meia-Idade , Neoplasias da Próstata/prevenção & controle , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco
13.
J Exp Clin Cancer Res ; 29: 95, 2010 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-20630084

RESUMO

BACKGROUND: Hypertension (HT) and hand-foot skin reactions (HFSR) may be related to the activity of bevacizumab and sorafenib. We hypothesized that these toxicities would correspond to favorable outcome in these drugs, that HT and HFSR would coincide, and that VEGFR2 genotypic variation would be related to toxicity and clinical outcomes. METHODS: Toxicities (> or = grade 2 HT or HFSR), progression-free survival (PFS), and overall survival (OS) following treatment initiation were evaluated. Toxicity incidence and VEGFR2 H472Q and V297I status were compared to clinical outcomes. RESULTS: Individuals experiencing HT had longer PFS following bevacizumab therapy than those without this toxicity in trials utilizing bevacizumab in patients with prostate cancer (31.5 vs 14.9 months, n = 60, P = 0.0009), and bevacizumab and sorafenib in patients with solid tumors (11.9 vs. 3.7 months, n = 27, P = 0.052). HT was also linked to a > 5-fold OS benefit after sorafenib and bevacizumab cotherapy (5.7 versus 29.0 months, P = 0.0068). HFSR was a marker for prolonged PFS during sorafenib therapy (6.1 versus 3.7 months respectively, n = 113, P = 0.0003). HT was a risk factor for HFSR in patients treated with bevacizumab and/or sorafenib (OR(95%CI) = 3.2(1.5-6.8), P = 0.0024). Carriers of variant alleles at VEGFR2 H472Q experienced greater risk of developing HT (OR(95%CI) = 2.3(1.2 - 4.6), n = 170, P = 0.0154) and HFSR (OR(95%CI) = 2.7(1.3 - 5.6), n = 170, P = 0.0136). CONCLUSIONS: This study suggests that HT and HFSR may be markers for favorable clinical outcome, HT development may be a marker for HFSR, and VEGFR2 alleles may be related to the development of toxicities during therapy with bevacizumab and/or sorafenib.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Dermatoses do Pé/tratamento farmacológico , Dermatoses da Mão/tratamento farmacológico , Hipertensão/tratamento farmacológico , Neoplasias/complicações , Polimorfismo de Nucleotídeo Único/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais Humanizados , Benzenossulfonatos/administração & dosagem , Bevacizumab , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , DNA de Neoplasias/genética , Feminino , Dermatoses do Pé/etiologia , Dermatoses do Pé/patologia , Genótipo , Dermatoses da Mão/etiologia , Dermatoses da Mão/patologia , Humanos , Hipertensão/etiologia , Hipertensão/patologia , Masculino , Neoplasias/terapia , Niacinamida/análogos & derivados , Compostos de Fenilureia , Reação em Cadeia da Polimerase , Piridinas/administração & dosagem , Sorafenibe , Taxa de Sobrevida , Resultado do Tratamento
15.
Cancer Biol Ther ; 9(5): 383-8, 2010 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-20061791

RESUMO

The androgen receptor gene (AR) plays an important role in molecular signaling and regulation and the subsequent cellular growth of prostate cancer. In addition, it is a highly variable region of the genome. We used direct nucleotide sequencing to genotype the entire exogenous coding region of the androgen receptor in ten commonly used prostate cancer cell lines. Our analysis confirmed the presence or absence of several known SNPs in the cell lines studied. We also assayed the number of CAG-repeat and GGC-repeat sequences for each for the ten cell lines. Our analysis identified three new mutations, one each in the DU145, LnCAP and RWPE-2 cell lines. In DU145, the DNA isolated in our lab was heterozygous at G527G (T>C transition), a polymorphism not previously reported. The LnCAP cells cultured in our lab were found to have a T>C transition (heterozygous), resulting in a S641P change that was not present in the ATCC cell line DNA. Lastly, a homozygous G>T transversion was found in RWPE-2 cells, resulting in the S187I change. This is potentially significant for use in cell culture and future cell model development.


Assuntos
Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Sequência de Bases , Linhagem Celular , Genoma , Humanos , Masculino , Polimorfismo Genético , Próstata/metabolismo , Sequências Repetitivas de Ácido Nucleico
16.
Mol Biotechnol ; 44(2): 152-67, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19950006

RESUMO

This review provides an overview of the pharmacogenetics of membrane transporters including selected ABC transporters (ABCB1, ABCC1, ABCC2, and ABCG2) and OATPs (OATP1B1 and OATP1B3). Membrane transporters are heavily involved in drug clearance and alters drug disposition by actively transporting substrate drugs between organs and tissues. As such, polymorphisms in the genes encoding these proteins may have significant effects on the absorption, distribution, metabolism and excretion of compounds, and may alter pharmacodynamics of many agents. This review discusses the techniques used to identify substrates and inhibitors of these proteins and subsequently to assess the effect of genetic mutation on transport, both in vitro and in vivo. A comprehensive list of substrates for the major drug transporters is included. Finally, studies linking transporter genotype with clinical outcomes are discussed.


Assuntos
Proteínas de Membrana Transportadoras/fisiologia , Farmacogenética/métodos , Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/fisiologia , Animais , Humanos , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Proteína 2 Associada à Farmacorresistência Múltipla , Transportadores de Ânions Orgânicos/antagonistas & inibidores , Transportadores de Ânions Orgânicos/genética , Transportadores de Ânions Orgânicos/metabolismo , Transportadores de Ânions Orgânicos/fisiologia
17.
Clin Cancer Res ; 15(4): 1496-503, 2009 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-19228751

RESUMO

PURPOSE: Romidepsin is a potent histone deacetylase inhibitor under clinical development. The objective of this study was to evaluate the effect of demographic, clinical, and pharmacogenetic covariates on the pharmacokinetics of romidepsin in patients with T-cell lymphoma. EXPERIMENTAL DESIGN: Pharmacokinetic assessment was done in 98 patients enrolled in a phase II study who received 14 or 18 mg/m2 of romidepsin as a 4-hour infusion on day 1 during their first treatment cycle. Population modeling was done using a nonlinear mixed effects modeling approach to explore the effects of polymorphic variations in CYP3A4, CYP3A5, SLCO1B3, and ABCB1, all of which encode genes thought to be involved in romidepsin disposition. RESULTS: A two-compartment model with linear kinetics adequately described the romidepsin disposition. Population clearance was 15.9 L/h with between-patient variability of 37%. ABCB1 2677G>T/A variant alleles tended toward a reduced clearance and lower volume of tissue distribution, but this was not supported by a statistical significance. Genetic variations in CYP3A4/5 and SCLO1B3 had no effect on the systemic exposure. CONCLUSION: The population pharmacokinetic analysis indicates moderate interindividual variability in romidepsin pharmacokinetics and no clinically relevant covariates associated with the unexplained pharmacokinetic variability of romidepsin in this population.


Assuntos
Antibióticos Antineoplásicos/farmacocinética , Depsipeptídeos/farmacocinética , Linfoma Cutâneo de Células T/tratamento farmacológico , Linfoma de Células T Periférico/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Subfamília B de Transportador de Cassetes de Ligação de ATP , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Adulto , Idoso , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos
18.
Clin Cancer Res ; 14(14): 4543-9, 2008 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-18628469

RESUMO

PURPOSE: Polymorphisms that are associated with ABCB1 expression and function may be linked to treatment efficacy and the development of neutropenia and neurotoxicity in patients with androgen-independent prostate cancer receiving docetaxel. EXPERIMENTAL DESIGN: Patients with androgen-independent prostate cancer treated with docetaxel alone (n = 23) or docetaxel and thalidomide (n = 50) were genotyped for the ABCB1 1236C>T, 2677 G>T/A, and 3435 C>T alleles by direct sequencing, and diplotypes were constructed using an EM algorithm. The data were then compared with duration to onset of peripheral neuropathy, neutropenia grade, and survival after docetaxel. RESULTS: For patients receiving docetaxel alone, individuals carrying a diplotype consisting of the 1236C-2677G-3435C linked alleles had improved overall survival after treatment (P = 0.0017). Additionally, patients treated with docetaxel and thalidomide carrying a diplotype consisting of the 2677T-3435T haplotype had a shorter median survival (P = 0.045). After adjusting for a particular set of polymorphisms and diplotype groupings, a hazard ratio of 10.87 was found for patients carrying the 2677GG genotype versus patients carrying other genotypes (P = 0.0048) in the docetaxel and thalidomide cohort. Among both treatment arms together, individuals carrying the 2677GG genotype also had a significantly longer time to neuropathy (P = 0.035). Finally, there was a strong trend toward patients carrying the 2677TT-3435TT diplotype having higher grades of neutropenia (P = 0.053). CONCLUSION: The data suggest that docetaxel-induced neuropathy, neutropenia grade, and overall survival could be linked to ABCB1 allelic variants with ensuing negative implications for docetaxel treatment in patients carrying ABCB1 variant genotypes.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Antineoplásicos/uso terapêutico , Polimorfismo Genético , Neoplasias da Próstata/genética , Taxoides/uso terapêutico , Subfamília B de Transportador de Cassetes de Ligação de ATP , Androgênios/metabolismo , Antineoplásicos/farmacocinética , Docetaxel , Resistencia a Medicamentos Antineoplásicos/genética , Frequência do Gene , Genótipo , Humanos , Estimativa de Kaplan-Meier , Masculino , Reação em Cadeia da Polimerase , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/mortalidade , Taxoides/farmacocinética , Talidomida/uso terapêutico
19.
BJU Int ; 102(5): 617-21, 2008 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-18537956

RESUMO

OBJECTIVE: To determine if patients with advanced prostate cancer carrying a polymorphism that codes for a more active testosterone transporter have less durable responses to androgen-deprivation therapy (ADT) than patients not carrying this polymorphism. PATIENTS AND METHODS: We previously determined that a polymorphism in SLCO1B3 affects testosterone transport and that those men who have at least one wild-type T allele at the 334 T > G polymorphism in this gene have a shorter survival. We hypothesized that the T allele which increases testosterone transport would be associated with a shorter interval from ADT to androgen independence. We examined the association between this SLCO1B3 polymorphism and time from ADT to androgen independence, ADT to prostate-specific antigen (PSA) nadir and PSA nadir to androgen independence in 68 Caucasian patients with advanced prostate cancer who were treated with ADT with metastatic disease (D2) or biochemical failure with no metastatic disease (D0). RESULTS: When examined separately, patients in the individual stages tended to have a shorter time to androgen independence with the T allele in the D0 (P = 0.11) and D2 (P = 0.18) groups. Combining these groups and stratifying by stage yielded a statistically significant shorter time to androgen independence with the T allele (P = 0.048). CONCLUSION: A polymorphism in a transporter that increases testosterone import is associated with a shorter time to androgen independence in patients with prostate cancer who are treated with ADT.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Antineoplásicos Hormonais/uso terapêutico , Neoplasias Hormônio-Dependentes/genética , Polimorfismo Genético/genética , Neoplasias da Próstata/genética , Testosterona/metabolismo , Genótipo , Humanos , Masculino , Proteínas de Membrana Transportadoras/genética , Prognóstico , Antígeno Prostático Específico , Neoplasias da Próstata/tratamento farmacológico
20.
Appl Spectrosc ; 60(12): 1377-85, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17217586

RESUMO

We have developed a novel class of gold multilayer, surface-enhanced Raman scattering (SERS) substrates that are capable of enhancing SERS signals by 15.3-fold over conventional gold film over nanostructure (GFON) SERS substrates, making them comparable in sensitivity to optimized silver film over nanostructure (SFON) substrates, while providing the long-term stability obtained from gold. They are fabricated by depositing 10 A thick silver oxide islands on conventional GFON substrates, followed by deposition of a second continuous gold layer. The silver oxide layer acts as a dielectric spacer between the two continuous gold films and produces significantly enhanced SERS signals, as compared to optimized single layer substrates of the same geometry or comparable substrates prepared by deposition of silver islands that are not oxidized. In addition to the enhanced sensitivity of these multilayer substrates, they also exhibit long SERS active shelf-lives (i.e., months), with no measurable degradation in SERS enhancement, and relative standard deviations in SERS enhancement of less than 5.2% across the substrate's surface.


Assuntos
Ouro/química , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Dióxido de Silício/química , Análise Espectral Raman/métodos , Materiais Revestidos Biocompatíveis/análise , Materiais Revestidos Biocompatíveis/química , Teste de Materiais , Propriedades de Superfície
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