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1.
Br J Haematol ; 188(6): 924-929, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31736067

RESUMO

The nucleoside analogue decitabine can deplete the epigenetic regulator DNA methyltransferase 1 (DNMT1), an effect that occurs, and is saturated at, low concentrations/doses. A reason to pursue this molecular-targeted effect instead of the DNA damage/cytotoxicity produced with high concentrations/doses, is that non-cytotoxic DNMT1-depletion can cytoreduce even p53-null myeloid malignancies while sparing normal haematopoiesis. We thus identified minimum doses of decitabine (0·1-0·2 mg/kg) that deplete DNMT1 without off-target anti-metabolite effects/cytotoxicity, and then administered these well-tolerated doses frequently 1-2X/week to increase S-phase dependent DNMT1-depletion, and used a Myeloid Malignancy Registry to evaluate long-term outcomes in 69 patients treated this way. Consistent with the scientific rationale, treatment was well-tolerated and durable responses were produced (~40%) in genetically heterogeneous disease and the very elderly.


Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Decitabina/uso terapêutico , Transtornos Mieloproliferativos/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/farmacologia , Decitabina/farmacologia , Feminino , Humanos , Masculino
2.
Br J Haematol ; 189(2): 318-322, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31958160

RESUMO

T-cell large granular lymphocytic leukaemia (T-LGLL) is a chronic clonal lymphoproliferative disorder of cytotoxic T lymphocytes which commonly occurs in older patients and is often associated with autoimmune diseases. Among 246 patients with T-LGLL seen at our institution over the last 10 years, we encountered 15 cases following solid organ or haematopoietic stem cell transplantation. Here, we studied the clinical characterization of these cases and compared them to de novo T-LGLL. This experience represented a clear picture of the intricate nature of the disease manifestation and the complexities of several immune mechanisms triggering the clonal expansion.


Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Leucemia Linfocítica Granular Grande/etiologia , Condicionamento Pré-Transplante/efeitos adversos , Adolescente , Adulto , Feminino , Humanos , Leucemia Linfocítica Granular Grande/patologia , Masculino , Pessoa de Meia-Idade
3.
Br J Haematol ; 185(5): 935-939, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30891747

RESUMO

Compound heterozygous germline mutations in CTC1 gene have been found in patients with atypical dyskeratosis congenita (DC), whereas heterozygous carriers are unaffected. Through screening of a large cohort of adult patients with acquired bone marrow failure syndromes, in addition to a DC case, we have also found extremely rare or novel heterozygous deleterious germline variants of CTC1 in patients with aplastic anaemia (AA; n = 5), paroxysmal nocturnal haemoglobinuria (PNH; n = 3) and myelodysplastic syndrome (MDS; n = 2). A compound heterozygous case of AA showed clonal evolution. Our results suggest that some of the inherited CTC1 variants may represent predisposition factors for acquired bone marrow failure.


Assuntos
Transtornos da Insuficiência da Medula Óssea/genética , Mutação em Linhagem Germinativa , Proteínas de Ligação a Telômeros/genética , Telômero/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Transtornos da Insuficiência da Medula Óssea/metabolismo , Transtornos da Insuficiência da Medula Óssea/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Telômero/metabolismo , Telômero/patologia , Proteínas de Ligação a Telômeros/metabolismo
4.
Mycoses ; 61(5): 321-325, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29314351

RESUMO

Most superficial mycotic infections of human skin are due to dermatophytes. Children are frequently affected due to different predisposing factors, particularly overcrowding in classrooms. This study aimed to estimate the prevalence of dermatophytes infections and their related risk factors among school children in Menoufia Governorate, Egypt. Six public primary and preparatory schools were randomly selected and their pupils (n = 3464) were asked to complete a predesigned questionnaire covering both personal data and suspected risk factors for superficial dermatophyte infections. The children were also examined for dermatological diseases. Any suspected lesions were biopsied for mycological examination. The prevalence of clinically suspected dermatophytes infections was 1.41%, whereas the prevalence of culture confirmed cases was 0.98%. The most common clinical type was tinea capitis with a prevalence of 1.01%. Microsporum canis was the only isolated organism from the suspicious lesions with a 69.4% positivity rate. A higher prevalence was observed among boys, low socio-economic pupils and those with a family history of dermatophyte infections. Pet contact and sharing towels and caps among pupils were significant risk factors. Dermatophyte infection is still prevalent among basic school pupils. Fortunately, it is related to preventable risk factors. We recommend regular screening and use of educational health programmes for kids to control it.


Assuntos
Arthrodermataceae/isolamento & purificação , Dermatomicoses/epidemiologia , Estudantes , Tinha do Couro Cabeludo/epidemiologia , Adolescente , Animais , Arthrodermataceae/classificação , Biópsia , Criança , Estudos de Coortes , Aglomeração , Dermatomicoses/microbiologia , Dermatomicoses/prevenção & controle , Egito/epidemiologia , Feminino , Humanos , Masculino , Microsporum/isolamento & purificação , Animais de Estimação , Prevalência , Fatores de Risco , Instituições Acadêmicas , Pele/patologia , Inquéritos e Questionários , Tinha do Couro Cabeludo/microbiologia , Trichophyton/isolamento & purificação
5.
J Biol Chem ; 289(21): 14881-95, 2014 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-24695740

RESUMO

Gene activation requires cooperative assembly of multiprotein transcription factor-coregulator complexes. Disruption to cooperative assemblage could underlie repression of tumor suppressor genes in leukemia cells. Mechanisms of cooperation and its disruption were therefore examined for PU.1 and RUNX1, transcription factors that cooperate to activate hematopoietic differentiation genes. PU.1 is highly expressed in leukemia cells, whereas RUNX1 is frequently inactivated by mutation or translocation. Thus, coregulator interactions of Pu.1 were examined by immunoprecipitation coupled with tandem mass spectrometry/Western blot in wild-type and Runx1-deficient hematopoietic cells. In wild-type cells, the NuAT and Baf families of coactivators coimmunoprecipitated with Pu.1. Runx1 deficiency produced a striking switch to Pu.1 interaction with the Dnmt1, Sin3A, Nurd, CoRest, and B-Wich corepressor families. Corepressors of the Polycomb family, which are frequently inactivated by mutation or deletion in myeloid leukemia, did not interact with Pu.1. The most significant gene ontology association of Runx1-Pu.1 co-bound genes was with macrophages, therefore, functional consequences of altered corepressor/coactivator exchange were examined at Mcsfr, a key macrophage differentiation gene. In chromatin immunoprecipitation analyses, high level Pu.1 binding to the Mcsfr promoter was not decreased by Runx1 deficiency. However, the Pu.1-driven shift from histone repression to activation marks at this locus, and terminal macrophage differentiation, were substantially diminished. DNMT1 inhibition, but not Polycomb inhibition, in RUNX1-translocated leukemia cells induced terminal differentiation. Thus, RUNX1 and PU.1 cooperate to exchange corepressors for coactivators, and the specific corepressors recruited to PU.1 as a consequence of RUNX1 deficiency could be rational targets for leukemia differentiation therapy.


Assuntos
Diferenciação Celular/genética , Proteínas Correpressoras/genética , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Proteínas Proto-Oncogênicas/genética , Transativadores/genética , Animais , Western Blotting , Células Cultivadas , Imunoprecipitação da Cromatina , Proteínas Correpressoras/metabolismo , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Perfilação da Expressão Gênica , Células HEK293 , Humanos , Leucemia/genética , Leucemia/metabolismo , Leucemia/patologia , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , Mutação , Análise de Sequência com Séries de Oligonucleotídeos , Ligação Proteica , Proteínas Proto-Oncogênicas/metabolismo , Espectrometria de Massas em Tandem , Transativadores/metabolismo , Células Tumorais Cultivadas
7.
Cytometry B Clin Cytom ; 106(1): 11-24, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38345160

RESUMO

The 5-azacytidine (AZA) and decitabine (DEC) are noncytotoxic, differentiation-inducing therapies approved for treatment of myelodysplastic syndrome, acute myeloid leukemias (AML), and under evaluation as maintenance therapy for AML postallogeneic hematopoietic stem cell transplant and to treat hemoglobinapathies. Malignant cell cytoreduction is thought to occur by S-phase specific depletion of the key epigenetic regulator, DNA methyltransferase 1 (DNMT1) that, in the case of cancers, thereby releases terminal-differentiation programs. DNMT1-targeting can also elevate expression of immune function genes (HLA-DR, MICA, MICB) to stimulate graft versus leukemia effects. In vivo, there is a large inter-individual variability in DEC and 5-AZA activity because of pharmacogenetic factors, and an assay to quantify the molecular pharmacodynamic effect of DNMT1-depletion is a logical step toward individualized or personalized therapy. We developed and analytically validated a flow cytometric assay for DNMT1 epitope levels in blood and bone marrow cell subpopulations defined by immunophenotype and cell cycle state. Wild type (WT) and DNMT1 knock out (DKO) HC116 cells were used to select and optimize a highly specific DNMT1 monoclonal antibody. Methodologic validation of the assay consisted of cytometry and matching immunoblots of HC116-WT and -DKO cells and peripheral blood mononuclear cells; flow cytometry of H116-WT treated with DEC, and patient samples before and after treatment with 5-AZA. Analysis of patient samples demonstrated assay reproducibility, variation in patient DNMT1 levels prior to treatment, and DNMT1 depletion posttherapy. A flow-cytometry assay has been developed that in the research setting of clinical trials can inform studies of DEC or 5-AZA treatment to achieve targeted molecular pharmacodynamic effects and better understand treatment-resistance/failure.


Assuntos
Leucemia Mieloide Aguda , Leucócitos Mononucleares , Humanos , Decitabina/farmacologia , Decitabina/uso terapêutico , Citometria de Fluxo , Reprodutibilidade dos Testes , Azacitidina/farmacologia , Azacitidina/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Biomarcadores
8.
Semin Hematol ; 58(1): 45-55, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33509443

RESUMO

The DNA methyltransferase inhibitor azacytidine (aza) may reactivate pathways associated with plasma cell differentiation, cell cycle control, apoptosis, and immune recognition and thereby restore sensitivity to lenalidomide (len) and dexamethasone (dex) in relapsed and/or refractory multiple myeloma (RRMM). We aimed to develop an aza regimen that reaches epigenetically active levels 8 times in 28 days with less bone marrow toxicity than the myeloid malignancy standard of 7 consecutive doses to enable safe combination with len. Aza was escalated from 30 mg/m2 once a week up to a predefined maximum of 50 mg/m2 twice a week in combination with GFR-adjusted len (≥ 60 mL/min: 25 mg, 3059 mL/min: 10 mg) day 1 to 21 every 28 days and dex 40 mg once a week followed by a limited expansion study to a total N of 23 at the highest tolerated dose. Fifty-one patients (pts) with RRMM were screened, 42 were treated and 41 were evaluable for response based on at least 1 response assessment or progression after treatment start. The median number of prior lines of therapy was 5 (1-11) and 81% (34) were refractory to len and/or pomalidomide (pom). Two DLTs occurred in different cohorts, 1 neutropenic fever in 1/6 pts on the aza 40 mg/m2 twice a week GFR ≥ 60 mL/min cohort and 1 GGT elevation in 1/6 pts on the aza 50 mg/m2 GFR 30-59 mL/min cohort. An MTD was not reached and aza 50 mg/m2 SC twice a week was chosen for the expansion study. At least possibly related Grade 3/4 AEs occurred in 28 pts (67%) with the following in > 1 pt: neutropenia (N = 16, 38%), anemia (N = 6, 14%), lymphopenia (N = 5, 12%), thrombocytopenia (N = 4, 10%), leukopenia (N = 4, 10%), febrile neutropenia (N = 4, 10%), fatigue (N = 3, 7%), fever (N = 2, 5%), and infection (N = 2, 5%). At a median follow up time for alive pts of 60.2 months (range: 36.1-82.5 months), the overall response rate (≥ partial response) and clinical benefit response rate (≥ minor response) was 22 and 32%, respectively, with 4 very good partial responses (10%), 5 partial responses (12%), and 4 minor responses (10%). The median PFS was 3.1 months (95% confidence interval [CI]: 2.1-5.1 months), median TTP 2.7 months (95% CI: 2.1-7.5 months), and median OS 18.6 months (95% CI: 12.9-33.0 months). Achieving at least minor response and reaching TTP > 6 months was associated with approximately 35% lower median plasma levels of the enzyme that inactivates aza, plasma cytidine deaminase (CDA, P< .0001). Two of the len refractory pts achieved longer disease control than with any prior regimen and 1 responded immediately after progression on len, bortezomib, and prednisone. Analyses of the methylation state of over 480,000 CpG sites in purified myeloma cells at screening were possible in 11 pts and on day 28 in 8 of them. As in other studies, the majority of differentially methylated CpGs compared to normal plasma cells were hypomethylated in myeloma. Treatment decreased the number of CpGs that were differentially methylated in normal plasma cells by > 0.5% in 6 and by > 5% in 3 of the 8 pts, most pronounced in 2 pts with clinically convincing aza contribution who achieved a reduction in overall differentially methylated CpGs by 23 and 68%, respectively, associated with increased expression of immunoglobulin genes. The study demonstrated tolerability of twice a week SC aza at 50 mg/m2 with len and dex in RRMM and suggested aza may help overcome the len/pom refractory state, possibly by activating differentiation pathways. Relatively low response rates and association of clinical benefit with low plasma levels of the aza inactivating enzyme CDA suggest the aza regimen will need to be optimized further and pt selection may be required to maximize benefit.


Assuntos
Mieloma Múltiplo , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Azacitidina/efeitos adversos , Metilação de DNA , Dexametasona/efeitos adversos , Humanos , Lenalidomida/farmacologia , Lenalidomida/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Resultado do Tratamento
9.
Reprod Biol Endocrinol ; 7: 143, 2009 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-19961617

RESUMO

Maintaining the integrity of sperm DNA is vital to reproduction and male fertility. Sperm contain a number of molecules and pathways for the repair of base excision, base mismatches and DNA strand breaks. The presence of Poly (ADP-ribose) polymerase (PARP), a DNA repair enzyme, and its homologues has recently been shown in male germ cells, specifically during stage VII of spermatogenesis. High PARP expression has been reported in mature spermatozoa and in proven fertile men. Whenever there are strand breaks in sperm DNA due to oxidative stress, chromatin remodeling or cell death, PARP is activated. However, the cleavage of PARP by caspase-3 inactivates it and inhibits PARP's DNA-repairing abilities. Therefore, cleaved PARP (cPARP) may be considered a marker of apoptosis. The presence of higher levels of cPARP in sperm of infertile men adds a new proof for the correlation between apoptosis and male infertility. This review describes the possible biological significance of PARP in mammalian cells with the focus on male reproduction. The review elaborates on the role played by PARP during spermatogenesis, sperm maturation in ejaculated spermatozoa and the potential role of PARP as new marker of sperm damage. PARP could provide new strategies to preserve fertility in cancer patients subjected to genotoxic stresses and may be a key to better male reproductive health.


Assuntos
Poli(ADP-Ribose) Polimerases/fisiologia , Espermatozoides/enzimologia , Adulto , Animais , Ciclo Celular/fisiologia , Morte Celular/fisiologia , Cromatina/genética , Cromatina/fisiologia , DNA/biossíntese , Dano ao DNA , Fertilidade/fisiologia , Marcadores Genéticos , Humanos , Masculino , Transdução de Sinais/fisiologia , Espermatogênese/fisiologia , Espermatozoides/fisiologia , Transcrição Gênica/fisiologia
10.
J Clin Invest ; 128(10): 4260-4279, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30015632

RESUMO

Nucleophosmin (NPM1) is among the most frequently mutated genes in acute myeloid leukemia (AML). It is not known, however, how the resulting oncoprotein mutant NPM1 is leukemogenic. To reveal the cellular machinery in which NPM1 participates in myeloid cells, we analyzed the endogenous NPM1 protein interactome by mass spectrometry and discovered abundant amounts of the master transcription factor driver of monocyte lineage differentiation PU.1 (also known as SPI1). Mutant NPM1, which aberrantly accumulates in cytoplasm, dislocated PU.1 into cytoplasm with it. CEBPA and RUNX1, the master transcription factors that collaborate with PU.1 to activate granulomonocytic lineage fates, remained nuclear; but without PU.1, their coregulator interactions were toggled from coactivators to corepressors, repressing instead of activating more than 500 granulocyte and monocyte terminal differentiation genes. An inhibitor of nuclear export, selinexor, by locking mutant NPM1/PU.1 in the nucleus, activated terminal monocytic fates. Direct depletion of the corepressor DNA methyltransferase 1 (DNMT1) from the CEBPA/RUNX1 protein interactome using the clinical drug decitabine activated terminal granulocytic fates. Together, these noncytotoxic treatments extended survival by more than 160 days versus vehicle in a patient-derived xenotransplant model of NPM1/FLT3-mutated AML. In sum, mutant NPM1 represses monocyte and granulocyte terminal differentiation by disrupting PU.1/CEBPA/RUNX1 collaboration, a transforming action that can be reversed by pharmacodynamically directed dosing of clinical small molecules.


Assuntos
Granulócitos/metabolismo , Leucemia Mieloide Aguda/metabolismo , Monócitos/metabolismo , Mutação , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Animais , Granulócitos/patologia , Xenoenxertos , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Camundongos , Monócitos/patologia , Proteínas de Neoplasias/genética , Transplante de Neoplasias , Proteínas Nucleares/genética , Nucleofosmina , Células THP-1 , Fatores de Transcrição/genética
11.
Korean J Pain ; 30(2): 134-141, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28416997

RESUMO

BACKGROUND: Postoperative pain is a common, distressing symptom following arthroscopic knee surgery. The aim of this study was to compare the potential analgesic effect of dexmedetomidine after intrathecal versus intra-articular administration following arthroscopic knee surgery. METHODS: Ninety patients undergoing unilateral elective arthroscopic knee surgery were randomly assigned into three groups in a double-blind placebo controlled study. The intrathecal dexmedetomidine group (IT) received an intrathecal block with intrathecal dexmedetomidine, the intra-articular group (IA) received an intrathecal block and intra-articular dexmedetomidine, and the control group received an intrathecal block and intra-articular saline. The primary outcome of our study was postoperative pain as assessed by the visual analogue scale of pain (VAS). Secondary outcomes included the effect of dexmedetomidine on total postoperative analgesic use and time to the first analgesic request, hemodynamics, sedation, postoperative nausea and vomiting, patient satisfaction, and postoperative C-reactive protein (CRP) levels. RESULTS: Dexmedetomidine administration decreased pain scores for 4 h in both the intrathecal and intra-articular groups, compared to only 2 h in the control patient group. Furthermore, there was a significant reduction in pain scores for 6 h in the intra-articular group. The time to the first postoperative analgesia request was longer in the intra-articular group compared to the intrathecal and control groups. The total meperidine requirement was significantly lower in the intra-articular and intrathecal groups than in the control group. CONCLUSIONS: Both intrathecal and intra-articular dexmedetomidine enhanced postoperative analgesia after arthroscopic knee surgery. Less total meperidine was required with intra-articular administration to extend postoperative analgesia to 6 h with hemodynamic stability.

12.
Exp Biol Med (Maywood) ; 239(7): 853-861, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24879424

RESUMO

Cancer chemotherapy is typically toxic. This problem could be addressed by using differences between cancer and normal cells for controlled delivery of drugs to cancer cells. One such difference is the ubiquitously elevated glutathione expression in cancer cells. We report a simple and versatile synthesis of water-soluble gold nanoparticles passivated with amine-containing molecules, which allow for controlled drug release via ligand exchange with bio-available glutathione. Taking methotrexate-passivated gold nanoparticles (Au:MTX) as an example, drug delivery and controlled release via glutathione-mediated ligand exchange was evaluated. Furthermore, the possibility of using Au:MTX to improve therapeutic index in acute myeloid leukemia (AML) models was examined in vitro and in vivo. Au:MTX exhibited cancer selectivity in vitro. Au:MTX had an elevated potency toward an AML cell line THP-1 in a dosage range of 1-5 nM, and therefore an enhanced delivery of drug, whereas normal hematopoietic stem/progenitor cell (HSPC) growth was minimally affected by Au:MTX and MTX treatments within the same range of dosage. In vivo efficacy and safety of Au:MTX was evaluated in a murine xenotransplant model of primary human AML. Au:MTX treatment, compared to control groups including MTX-only and Au nanoparticle-only treatments, produced better leukemia suppression without added toxicity, indicating an enhanced therapeutic index.

13.
Clin Lymphoma Myeloma Leuk ; 14(2): 172-177.e1, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24332215

RESUMO

BACKGROUND: Myelodysplastic syndrome (MDS) continues to cause major morbidity and mortality; thus, novel treatments are needed. The mammalian target of rapamycin (mTOR) inhibitor RAD001 (everolimus) inhibits cellular pathways important to MYC protein stability and cell growth. Pharmacodynamic biomarkers could be useful in distinguishing between (1) disease resistance that occurs even though mTOR is successfully inhibited (suggesting a need for a different treatment strategy) and (2) resistance that might respond to changes in drug dosage or schedule. PATIENTS AND METHODS: This was a small phase II trial of RAD001 in patients with low- and intermediate-1-risk MDS (n = 7). Protein S6K1 (S6) is downstream of mTOR, whereas protein kinase B (AKT) is upstream of mTOR. Therefore, to evaluate the pharmacodynamic effects of RAD001, S6 and AKT phosphorylation (pS6, pAKT) were measured by peripheral blood flow cytometry. RESULTS: Sequential weeks of RAD001 produced a decrease in pS6, whereas pAKT was maintained or increased. There were no clinical responses despite the biomarker evidence of intended pharmacodynamic effect. CONCLUSION: The pS6:pAKT ratio could be useful as a biomarker of target inhibition by RAD001 (clinicaltrials.gov identifier: NCT00809185).


Assuntos
Biomarcadores/metabolismo , Síndromes Mielodisplásicas/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Quinases S6 Ribossômicas/metabolismo , Sirolimo/análogos & derivados , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Esquema de Medicação , Dispneia/induzido quimicamente , Everolimo , Fadiga/induzido quimicamente , Feminino , Febre/induzido quimicamente , Citometria de Fluxo , Humanos , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/metabolismo , Neutropenia/induzido quimicamente , Fosforilação/efeitos dos fármacos , Sirolimo/efeitos adversos , Sirolimo/farmacologia , Sirolimo/uso terapêutico , Serina-Treonina Quinases TOR/metabolismo , Resultado do Tratamento
14.
Clin Cancer Res ; 19(4): 938-48, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23287564

RESUMO

PURPOSE: The cytidine analogs 5-azacytidine and decitabine, used to treat myelodysplastic syndromes (MDS), produce a molecular epigenetic effect, depletion of DNA-methyltransferase 1 (DNMT1). This action is S-phase dependent. Hence, genetic factors that decrease the half-lives of these drugs could impact efficacy. Documentation of such impact, and elucidation of underlying mechanisms, could lead to improved clinical application. EXPERIMENTAL DESIGN: Cytidine deaminase (CDA) rapidly inactivates 5-azacytidine/decitabine. The effect of CDA SNP A79C and gender on CDA expression, enzyme activity, and drug pharmacokinetics/pharmacodynamics was examined in mice and humans, and the impact on overall survival (OS) was evaluated in 5-azacytidine/decitabine-treated patients with MDS (n = 90) and cytarabine-treated patients with acute myeloid leukemia (AML) (n = 76). RESULTS: By high-performance liquid chromatography (HPLC), plasma CDA activity was decreased as expected in individuals with the SNP A79C. Interestingly and significantly, there was an even larger decrease in females than in males. Explaining this decrease, liver CDA expression was significantly lower in female versus male mice. As expected, decitabine plasma levels, measured by mass spectrometry, were significantly higher in females. In mathematical modeling, the detrimental impact of shorter drug half-life (e.g., in males) was greater in low compared with high S-phase fraction disease (e.g., MDS vs. AML), because in high S-phase fraction disease, even a short exposure treats a major portion of cells. Accordingly, in multivariate analysis, OS was significantly worse in male versus female patients with MDS treated with 5-azacytidine/decitabine. CONCLUSIONS: Increased CDA expression/activity in males contributes to decreased cytidine analog half-life and likely contributes to worse outcomes with 5-azacytidine or decitabine therapy.


Assuntos
Citidina Desaminase/genética , DNA (Citosina-5-)-Metiltransferases/genética , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicas/tratamento farmacológico , Animais , Azacitidina/análogos & derivados , Citarabina/administração & dosagem , Citidina/administração & dosagem , Citidina/análogos & derivados , Citidina Desaminase/metabolismo , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/metabolismo , Decitabina , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Leucemia Mieloide Aguda/patologia , Masculino , Camundongos , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/patologia , Polimorfismo de Nucleotídeo Único , Análise de Sobrevida , Resultado do Tratamento
15.
Oncotarget ; 3(10): 1137-45, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23087155

RESUMO

We document for the first time that sanctuary in an organ which expresses high levels of the enzyme cytidine deaminase (CDA) is a mechanism of cancer cell resistance to cytidine analogues. This mechanism could explain why historically, cytidine analogues have not been successful chemotherapeutics against hepatotropic cancers, despite efficacy in vitro. Importantly, this mechanism of resistance can be readily reversed, without increasing toxicity to sensitive organs, by combining a cytidine analogue with an inhibitor of cytidine deaminase (tetrahydrouridine). Specifically, CDA rapidly metabolizes cytidine analogues into inactive uridine counterparts. Hence, to determine if sheltering/protection of cancer cells in organs which express high levels of CDA (e.g., liver) is a mechanism of resistance, we utilized a murine xenotransplant model of myeloid cancer that is sensitive to epigenetic therapeutic effects of the cytidine analogue decitabine in vitro and hepato-tropic in vivo. Treatment of tumor-bearing mice with decitabine (subcutaneous 0.2mg/kg 2X/week) doubled median survival and significantly decreased extra-hepatic tumor burden, but hepatic tumor burden remained substantial, to which the animals eventually succumbed. Combining a clinically-relevant inhibitor of CDA (tetrahydrouridine) with a lower dose of decitabine (subcutaneous 0.1mg/kg 2X/week) markedly decreased liver tumor burden without blood count or bone marrow evidence of myelotoxicity, and with further improvement in survival. In conclusion, sanctuary in a CDA-rich organ is a mechanism by which otherwise susceptible cancer cells can resist the effects of decitabine epigenetic therapy. This protection can be reversed without increasing myelotoxicity by combining tetrahydrouridine with a lower dose of decitabine.


Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Azacitidina/análogos & derivados , Citidina Desaminase/metabolismo , Leucemia Mieloide/enzimologia , Neoplasias Hepáticas/enzimologia , Fígado/enzimologia , Animais , Antimetabólitos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica , Azacitidina/uso terapêutico , Decitabina , Humanos , Leucemia Mieloide/tratamento farmacológico , Leucemia Mieloide/patologia , Fígado/efeitos dos fármacos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Knockout , Tetra-Hidrouridina/uso terapêutico , Transplante Heterólogo , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/fisiologia
16.
Syst Biol Reprod Med ; 58(5): 236-44, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22632096

RESUMO

We explored the relationship between sperm chromatin integrity, hormone levels, seminal plasma total antioxidant capacity (TAC), and routine sperm parameters in men with male factor (MF, n = 81) and non-male factor (NMF, n = 52) infertility. Semen and blood were collected and examined from men undergoing evaluation for infertility in the Avicenna Infertility Clinic. We have examined each patient for serum hormones (LH, FSH, E2, DHEA), sperm chromatin damage, level of protamination and seminal plasma TAC. Levels of FSH, LH, sperm chromatin damage, and abnormal protamination were significantly higher in MF vs. NMF groups (p < 0.001). Sperm chromatin damage was correlated with percentage of CMA(3)- positive sperm (r = 0.64, p < 0.001) and with sperm concentration (r = -0.36, p < 0.001), motility (r = -0.21, p < 0.05), and morphologically normal spermatozoa (r = -0.29, p < 0.001). Linear regression showed sperm chromatin damage was related to percentage of CMA(3)- positive sperm (p < 0.001) in ungrouped patients. It was related to both percentage of CMA(3)- positive sperm and serum DHEA in the MF group (p < 0.001 and p < 0.05, respectively). Sperm chromatin maturity assessed by CMA(3) test was inversely related to sperm chromatin damage assessed by the toludine blue assay. Male factor infertility associated with sperm chromatin damage may be related to sperm protamination and to serum DHEA.


Assuntos
Antioxidantes/análise , Montagem e Desmontagem da Cromatina , Hormônios/sangue , Infertilidade Masculina/diagnóstico , Sêmen/química , Espermatozoides/metabolismo , Adolescente , Adulto , Biomarcadores/sangue , Desidroepiandrosterona/sangue , Estradiol/sangue , Hormônio Foliculoestimulante Humano/sangue , Humanos , Infertilidade Masculina/sangue , Infertilidade Masculina/genética , Infertilidade Masculina/patologia , Irã (Geográfico) , Modelos Lineares , Hormônio Luteinizante/sangue , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise do Sêmen , Espermatozoides/patologia , Testosterona/sangue , Adulto Jovem
17.
Fertil Steril ; 94(6): 2482-5, 2485.e1-2, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20416871

RESUMO

In azoospermic infertile men with varicocele, testicular biopsy revealed histopathologic patterns that varied from disorganized spermatogenesis with low or moderate sperm scores to early (primary spermatocytes stage) or late (spermatid stage) arrested spermatogenesis or germ cell aplasia and Sertoli cells only. Diagnostic testicular biopsy can be helpful for accurate management of azoospermic infertile men with varicoceles before surgical repair.


Assuntos
Azoospermia/patologia , Testículo/patologia , Varicocele/patologia , Adulto , Azoospermia/sangue , Azoospermia/complicações , Biópsia , Hormônio Foliculoestimulante/sangue , Humanos , Infertilidade Masculina/sangue , Infertilidade Masculina/etiologia , Infertilidade Masculina/patologia , Masculino , Tamanho do Órgão , Células de Sertoli/patologia , Motilidade dos Espermatozoides , Espermatogênese/fisiologia , Espermatozoides/patologia , Varicocele/sangue , Varicocele/complicações
18.
J Androl ; 31(5): 482-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20467051

RESUMO

The objective of this study was to elucidate the missense Glu298Asp polymorphism within exon 7 of the endothelial nitric oxide synthase (eNOS) gene in infertile men with asthenozoospermia and its potential role in sperm motility. In this prospective controlled study conducted in our andrology unit, we investigated the frequency of the 894G>T polymorphism (Glu298Asp variant) within exon 7 of the eNOS gene in 70 infertile men and 60 healthy men. Sperm motion kinetics were assessed with computer-assisted semen analysis. The presence of G>T, a single nucleotide polymorphism (SNP) in exon 7 of the eNOS gene (NCBI SNP cluster rs1799983; GenBank accession number NG_011992; protein accession number NP_000594) was determined by allelespecific polymerase chain reaction followed by restriction fragment length polymorphism analysis. Sequencing analysis was used to confirm the specific genotype. The 894G>T eNOS allele (T) was found at a higher frequency in the patients with asthenozoospermia (60% vs 22.5% in the control group; P = .02). The percentage of progressive motile sperm (grade a + b) was lower in the asthenozoospermic infertile men with the homozygous eNOS (TT) genotype than in the wild-type eNOS (GG) (P = .02) and heterozygous eNOS (GT) genotypes (P = .01). However, the percentage of progressive motile sperm (grade a + b) was higher in the wild-type vs mutant eNOS (TT) (P = .03) and heterozygous eNOS (GT) genotypes (P = .04). Our findings suggest that the T allele encoding for aspartic acid of the eNOS (Glu298Asp) gene may contribute to poor sperm motility.


Assuntos
Astenozoospermia/genética , Óxido Nítrico Sintase Tipo III/genética , Polimorfismo de Nucleotídeo Único , Astenozoospermia/enzimologia , Humanos , Masculino , Estudos Prospectivos , Motilidade dos Espermatozoides/genética
19.
Fertil Steril ; 94(6): 2037-42, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20138266

RESUMO

OBJECTIVE: To examine the relationship of early human embryonic development parameters to day 3 reactive oxygen species (D-3 ROS) levels in culture media. DESIGN: Prospective study. SETTING: Tertiary care hospital. PATIENT(S): Patients were undergoing IVF (n=92; 36 with intracytoplasmic sperm injection [ICSI]). INTERVENTION(S): The D-3 ROS levels in sample and control of each embryo culture dish were measured by the chemiluminescence method using a luminol probe. MAIN OUTCOME MEASURE(S): Embryo quality (days 3 and 5) and pregnancy rates (PR). RESULT(S): The D-3 ROS level was significantly lower in pregnant cycles 26.8±13.9×10(6) cpm (counted photon per minute) versus nonpregnant cycles 66.4±39.4×10(6) cpm. This relationship was maintained when the cycles were stratified to conventional IVF (27.1±14.95 vs. 67.0±39.9×10(6) cpm) or ICSI (25.6±12.75 vs. 65.5±39.7×10(6) cpm). After controlling for all variables, D-3 ROS levels were negatively correlated with blastocyst development rate as well as PR. Odds ratio (OR) (95% confidence interval [CI]) of clinical pregnancy corresponding to a 10×10(6) cpm increase in D-3 ROS was 0.47 (0.30-0.74) for ICSI and 0.56 (0.37-0.85) for IVF. CONCLUSION(S): During extended in vitro culture, ROS generated in culture media by day 3 may be an important biochemical marker for blastulation. An increase of 10 units in D-3 ROS may decrease the clinical pregnancy by 41%.


Assuntos
Meios de Cultura/química , Fertilização in vitro , Espécies Reativas de Oxigênio/análise , Injeções de Esperma Intracitoplásmicas , Adulto , Blastocisto/citologia , Blastocisto/metabolismo , Células Cultivadas , Meios de Cultura/metabolismo , Técnicas de Cultura Embrionária , Feminino , Fertilização in vitro/estatística & dados numéricos , Humanos , Masculino , Gravidez , Taxa de Gravidez , Espécies Reativas de Oxigênio/metabolismo , Injeções de Esperma Intracitoplásmicas/estatística & dados numéricos , Fatores de Tempo , Resultado do Tratamento
20.
Fertil Steril ; 93(3): 814-21, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19100530

RESUMO

OBJECTIVE: To investigate sperm viability, incidence of apoptosis, and intracellular basal and induced reactive oxygen species (ROS) in sperm fractions. DESIGN: Prospective controlled study. SETTING: Center for Reproductive Medicine at a tertiary care hospital. METHOD(S): Liquefied seminal ejaculates (n = 12) prepared by density gradient centrifugation were reconstituted to 2 mL with phosphate-buffered saline. Oxidative stress was induced by hydrogen peroxide (H(2)O(2), 100 muM). Sperm viability, intracellular ROS, and incidence of apoptosis/necrosis in neat, immature, and mature sperm fractions were assessed. RESULT(S): Before H(2)O(2) exposure, mature spermatozoa fractions showed a significantly lower incidence of apoptotic sperm and intracellular O(2)(-*) levels but higher amounts of intracellular H(2)O(2) compared with neat semen. Higher levels of intracellular H(2)O(2) were demonstrated in immature sperm fractions compared with neat or mature fractions. In all sperm fractions, intracellular H(2)O(2) levels correlated with the intracellular concentration of O(2)(-*). After H(2)O(2) exposure, neat semen showed a significantly higher percentage of apoptosis compared with the prepared mature spermatozoa. However, no differences were observed in the incidence of apoptosis between immature and mature sperm fractions. CONCLUSION(S): There is a differential shift of both intracellular H(2)O(2) and O(2)(-*) in each sperm fraction that may affect sperm quality. Sperm apoptosis is related to intracellular H(2)O(2) levels, which in turn are affected by intracellular O(-*) levels. Oxidative stress was not associated with an increased incidence of apoptosis in immature or mature sperm fractions.


Assuntos
Apoptose/fisiologia , Estresse Oxidativo/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Espermatozoides/metabolismo , Espermatozoides/patologia , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Citometria de Fluxo , Humanos , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/farmacologia , Masculino , Necrose , Oxidantes/metabolismo , Oxidantes/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos
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