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1.
J Toxicol Sci ; 45(9): 549-558, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32879254

RESUMO

Trimethyltin chloride (TMT) is a stabilizer by-product in the process of manufacturing plastic, which is a kind of very strong toxic substance, and has acute, cumulative and chronic toxicity. TMT may cause bradycardia in patients with occupational poisoning, the mechanism of which has not been reported. This study explored the mechanism of TMT resulting in bradycardia of C57BL/6 mice. TMT was administered to mice to measure heart rate, serum succinate dehydrogenase (SDH) level, and myocardial Na+/K+-ATPase activity and expression. The effects of TMT on myocardial apoptosis were observed by changing the expressions of caspase-3, Bax and Bcl-2 in myocardium. It was found that the heart rate and SDH activity in serum of mice gradually decreased with the increase of TMT dose compared with the control group. The activity and the expression of Na+/K+-ATPase in the heart tissue of mice exposed to TMT was measured and gradually decreased with the increase of dose and time. We measured the expression of Bcl-2, Bax, caspase-3 and cleaved caspase-3 in the heart tissues of TMT exposed mice and found that the expressions of Bax, caspase-3 and cleaved caspase-3 increased and the expressions of Bcl-2 decreased in the heart tissues of the TMT-exposed mice at different doses. With the extension of TMT exposure time, the expression of Bax and caspase-3 increased and the expression of Bcl-2 decreased in the heart tissues of TMT exposed mice. Our findings suggest the mechanisms of TMT resulting in bradycardia may be associated with the inhibited activity and decreased content of Na+/K+-ATPase, thus further leading to the changes of Bcl-2, Bax, caspase-3 and cleaved caspase-3 in the mice's ventricular tissues.


Assuntos
Apoptose/efeitos dos fármacos , Bradicardia/etiologia , Miocárdio/metabolismo , Miocárdio/patologia , ATPase Trocadora de Sódio-Potássio/genética , ATPase Trocadora de Sódio-Potássio/metabolismo , Compostos de Trimetilestanho/toxicidade , Animais , Apoptose/genética , Bradicardia/genética , Caspase 3/genética , Caspase 3/metabolismo , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Camundongos Endogâmicos C57BL , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
2.
Anticancer Res ; 40(10): 5379-5391, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988857

RESUMO

BACKGROUND/AIM: Hypoxia-inducible factor 1 (HIF1) inhibitors have been proposed as therapeutic agents for several tumor types. HIF1α is induced by hypoxia and by pathogens in normoxia through toll-like receptors (TLRs). The TLR3 activator polyinosinic:polycytidylic acid [poly(I:C)] induces apoptosis in various types of cancer but not in the most aggressive breast cancer cell lines. We hypothesized that the failure of TLR3 stimulation to induce apoptosis in these cells might be due to an elevated HIF1α level and this link might be exploited. MATERIALS AND METHODS: Poly(I:C)-induced signaling pathway and expression of HIF1α and HIF1α targets were studied in MDA MB-231 and MCF-7 breast cancer cell lines by western blot. Flow cytometry was used for apoptotic responses and vasculogenic mimicry as bioassay. RESULTS: Poly(I:C) increased expression of HIF1α and its targets BCL2 apoptosis regulator and c-MYC. Moreover, using pharmacological or genetic HIF1 inhibition, reduction of poly(I:C)-induced expression of HIF1α was paralleled by lowering of c-MYC and increased sensitivity to poly(I:C)-induced apoptosis, demonstrating the crucial role of this factor. We provide the first evidence in breast cancer cells that TLR3 stimulation induces HIF1α-dependent vasculogenic mimicry. By using specific inhibitors, we identified a signaling cascade upstream of HIF1α induction. CONCLUSION: Combined treatment with poly(I:C) and HIF1 inhibitors deserves consideration as an effective strategy in breast cancer therapy.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Poli I-C/farmacologia , Receptor 3 Toll-Like/genética , Apoptose/efeitos dos fármacos , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Feminino , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-myc/genética , Transdução de Sinais/efeitos dos fármacos , Receptor 3 Toll-Like/agonistas
3.
Anticancer Res ; 40(10): 5417-5421, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988862

RESUMO

BACKGROUND: Type II diabetes agents have anticancer effects on head and neck squamous cell carcinoma (HNSCC). The mechanistic target of rapamycin (MTOR) pathway represents a putative target. MATERIALS AND METHODS: We interrogated an Affymetrix HNSCC dataset for MTOR-related gene expression. RESULTS: MTOR expression itself was unchanged, but various related genes demonstrated differential expression. Pathway promoters ras homolog (RHEB), MTOR-associated protein (MLST8), and ribosomal protein S6 kinase B1 (RPS6KB1) were up-regulated. Expression of growth suppressors tuberous sclerosis complex 2 (TSC2), programmed cell death 4 (PDCD4), and BCL2 apoptosis regulator-associated agonist of cell death (BAD) were reduced in HNSCC. Upstream, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), AKT serine/threonine kinase 1 (AKT1), and phosphatase and tensin homolog (PTEN) were up-regulated in cancer. CONCLUSION: Several MTOR pathway promoters and tumor suppressors were found to be differentially expressed, favoring MTOR pathway up-regulation in HNSCC. Genomic databases can be interrogated to identify intervention targets and endpoints in HNSCC trials.


Assuntos
Bases de Dados Genéticas , Neoplasias de Cabeça e Pescoço/genética , Proteínas de Neoplasias/genética , Serina-Treonina Quinases TOR/genética , Proteínas Reguladoras de Apoptose/genética , Classe I de Fosfatidilinositol 3-Quinases/genética , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias de Cabeça e Pescoço/classificação , Neoplasias de Cabeça e Pescoço/patologia , Humanos , PTEN Fosfo-Hidrolase/genética , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas de Ligação a RNA/genética , Proteína Enriquecida em Homólogo de Ras do Encéfalo/genética , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Transdução de Sinais/genética , Proteína 2 do Complexo Esclerose Tuberosa/genética , Proteína de Morte Celular Associada a bcl/genética , Homólogo LST8 da Proteína Associada a mTOR/genética
4.
PLoS One ; 15(8): e0236338, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785215

RESUMO

Dysregulation of BCL2 is a pathophysiology observed in haematological malignancies. For implementation of available treatment-options it is preferred to know the relative quantification of BCL2 mRNA with appropriate reference genes. For the choice of reference genes-(i) Reference Genes were selected by assessing variation of >60,000 genes from 4 RNA-seq datasets of haematological malignancies followed by filtering based on their GO biological process annotations and proximity of their chromosomal locations to known disease translocations. Selected genes were experimentally validated across various haematological malignancy samples followed by stability comparison using geNorm, NormFinder, BestKeeper and RefFinder. (ii) 43 commonly used Reference Genes were obtained from literature through extensive systematic review. Levels of BCL2 mRNA was assessed by qPCR normalized either by novel reference genes from this study or GAPDH, the most cited reference gene in literature and compared. The analysis showed PTCD2, PPP1R3B and FBXW9 to be the most unregulated genes across lymph-nodes, bone marrow and PBMC samples unlike the Reference Genes used in literature. BCL2 mRNA level shows a consistent higher expression in haematological malignancy patients when normalized by these novel Reference Genes as opposed to GAPDH, the most cited Reference Gene. These reference genes should also be applicable in qPCR platforms using Taqman probes and other model systems including cell lines and rodent models. Absence of sample from healthy-normal individual in diagnostic cases call for careful selection of Reference Genes for relative quantification of a biomarker by qPCR.BCL2 can be used as molecular diagnostics only if normalized with a set of reference genes with stable yet low levels of expression across different types of haematological malignancies.


Assuntos
Biomarcadores Tumorais/isolamento & purificação , Neoplasias Hematológicas/diagnóstico , Proteínas Proto-Oncogênicas c-bcl-2/isolamento & purificação , RNA Mensageiro/isolamento & purificação , RNA-Seq/normas , Animais , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Medula Óssea/patologia , Linhagem Celular Tumoral , Conjuntos de Dados como Assunto , Modelos Animais de Doenças , Estudos de Viabilidade , Regulação Neoplásica da Expressão Gênica , Genes Essenciais , Neoplasias Hematológicas/sangue , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/patologia , Humanos , Leucócitos Mononucleares , Proteínas Proto-Oncogênicas c-bcl-2/sangue , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Mensageiro/sangue , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real/normas , Padrões de Referência
5.
Ann Hematol ; 99(9): 2125-2132, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32613279

RESUMO

High-grade B cell lymphomas with rearrangements on C-MYC and BCL2 and/or BCL6 (HGBL with MYC and BCL2 and/or Bcl6 rearrangement) are associated with worse clinical outcomes and thus were introduced as a separate new category in the recently updated WHO classification. From 2012 to 2016, we analyzed a consecutive cohort of large B cell lymphomas (LBCLs) for C-MYC, BCL2, and BCL6 rearrangements and correlated our results with clinical-pathological parameters. Ten of 78 (13%) cases had a C-MYC and BCL2 and/or BCL6 rearrangement, so-called double or triple hit (DH), while double/triple copy number gains (CNGs) were found in eight (10%) patients. Patients with a high-grade lymphoma with DH or CNG progressed significantly more often after first-line chemotherapy (p = 0.005). When treated with standard chemotherapy, patients with a DH or CNG had a significantly worse overall (OS) and recurrence free survival (RFS) compared with all other patients (p = 0.033 and p < 0.001, respectively). Thus, patients with a diffuse large B cell lymphoma, harboring a double/triple CNG, seem to have a similar poor prognosis than those with a DH. Though our data can only be regarded as preliminary, our results warrant further investigations to fully elucidate the role of CNGs as well as underlying molecular mechanisms resulting in aggressive behavior in LBCL.


Assuntos
Variações do Número de Cópias de DNA/genética , Proteínas de Ligação a DNA/genética , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-6/genética , Fatores de Transcrição/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Estudos de Coortes , Feminino , Humanos , Linfoma Difuso de Grandes Células B/mortalidade , Masculino , Pessoa de Meia-Idade , Gradação de Tumores/mortalidade , Prognóstico , Estudos Retrospectivos
7.
Proc Natl Acad Sci U S A ; 117(28): 16409-16417, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32601185

RESUMO

The polar trophoblast overlays the epiblast in eutherian mammals and, depending on the species, has one of two different fates. It either remains a single-layered, thinning epithelium called "Rauber's layer," which soon disintegrates, or, alternatively, it keeps proliferating, contributing heavily to the population of differentiating, invasive trophoblast cells and, at least in mice, to the induction of gastrulation. While loss of the persistent polar trophoblast in mice leads to reduced induction of gastrulation, we show here that prevention of the loss of the polar trophoblast in cattle results in ectopic domains of the gastrulation marker, BRACHYURY This phenotype, and increased epiblast proliferation, arose when Rauber's layer was maintained for a day longer by countering apoptosis through BCL2 overexpression. This suggests that the disappearance of Rauber's layer is a necessity, presumably to avoid excessive signaling interactions between this layer and the subjacent epiblast. We note that, in all species in which the polar trophoblast persists, including humans and mice, ectopic polar trophoblast signaling is prevented via epiblast cavitation which leads to the (pro)amniotic cavity, whose function is to distance the central epiblast from such signaling interactions.


Assuntos
Trofoblastos/citologia , Animais , Apoptose , Bovinos , Diferenciação Celular , Proliferação de Células , Feminino , Proteínas Fetais/genética , Proteínas Fetais/metabolismo , Gastrulação , Camadas Germinativas/embriologia , Camadas Germinativas/metabolismo , Camadas Germinativas/fisiopatologia , Camundongos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Trofoblastos/metabolismo
8.
Nat Commun ; 11(1): 3301, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620849

RESUMO

Many cellular stresses are transduced into apoptotic signals through modification or up-regulation of the BH3-only subfamily of BCL2 proteins. Through direct or indirect mechanisms, these proteins activate BAK and BAX to permeabilize the mitochondrial outer membrane. While the BH3-only proteins BIM, PUMA, and tBID have been confirmed to directly activate BAK through its canonical BH3 binding groove, whether the BH3-only proteins BMF, HRK or BIK can directly activate BAK is less clear. Here we show that BMF and HRK bind and directly activate BAK. Through NMR studies, site-directed mutagenesis, and advanced molecular dynamics simulations, we also find that BAK activation by BMF and possibly HRK involves a previously unrecognized binding groove formed by BAK α4, α6, and α7 helices. Alterations in this groove decrease the ability of BMF and HRK to bind BAK, permeabilize membranes and induce apoptosis, suggesting a potential role for this BH3-binding site in BAK activation.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Adaptadoras de Transdução de Sinal/genética , Sequência de Aminoácidos , Animais , Proteínas Reguladoras de Apoptose/química , Proteínas Reguladoras de Apoptose/genética , Sítios de Ligação/genética , Células Cultivadas , Humanos , Células Jurkat , Espectroscopia de Ressonância Magnética , Camundongos Knockout , Membranas Mitocondriais/metabolismo , Simulação de Dinâmica Molecular , Mutação , Ligação Proteica , Domínios Proteicos , Proteínas Proto-Oncogênicas c-bcl-2/química , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Homologia de Sequência de Aminoácidos , Proteína Killer-Antagonista Homóloga a bcl-2/química , Proteína Killer-Antagonista Homóloga a bcl-2/genética
9.
J Stroke Cerebrovasc Dis ; 29(8): 104977, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32689608

RESUMO

BACKGROUND: Ischemic stroke is a severe neurological disorder that affected millions of people worldwide. Neuro-inflammation and apoptosis play an essential role in the pathogenesis of neuronal death during ischemic stroke. Alpha-pinene is a bicyclic terpenoid with anti-inflammatory and anti-apoptotic activities. Accordingly, the main purpose of this study was to assess the protective effect of α-pinene in ischemic stroke. MATERIALS AND METHODS: To induce ischemic stroke in male Wistar rats, the middle cerebral artery was occluded for 60 min followed by 24 h reperfusion. Alpha-pinene was injected intraperitoneally at the beginning of reperfusion. A day after reperfusion, the neurological deficits, volume of infarct area, and blood-brain barrier (BBB) permeability were evaluated. The mRNA expression of inflammatory cytokines as well as pro- and anti-apoptotic genes was assessed by using reverse transcription-polymerase chain reaction. The protein levels of inflammatory cytokines were also measured by ELISA method. RESULTS: The results showed that α-pinene (50 and 100 mg/kg) significantly improved sensorimotor function and decreased the volume of infarct area in the brain. The high permeability of BBB was also alleviated by α-pinene (50 and 100 mg/kg) in ischemic areas. Besides, α-pinene (100 mg/kg) attenuated neuro-inflammation through decreasing both the gene and protein expression of TNF-α and IL-1ß in the hippocampus, cortex, and striatum. Besides, α-pinene (100 mg/kg) suppressed apoptosis via downregulation of the pro-apoptotic Bax mRNA expression with a concomitant upregulation of anti-apoptotic Bcl-2 gene expression. CONCLUSIONS: Overall, it was concluded that α-pinene exerts neuroprotective effect during ischemic stroke through attenuating neuroinflammation and inhibition of apoptosis.


Assuntos
Anti-Inflamatórios/farmacologia , Apoptose/efeitos dos fármacos , Monoterpenos Bicíclicos/farmacologia , Encéfalo/efeitos dos fármacos , Citocinas/metabolismo , Infarto da Artéria Cerebral Média/tratamento farmacológico , Mediadores da Inflamação/metabolismo , Fármacos Neuroprotetores/farmacologia , Traumatismo por Reperfusão/prevenção & controle , Animais , Comportamento Animal/efeitos dos fármacos , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/fisiopatologia , Permeabilidade Capilar/efeitos dos fármacos , Citocinas/genética , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/patologia , Infarto da Artéria Cerebral Média/fisiopatologia , Masculino , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos Wistar , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologia , Transdução de Sinais , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
10.
Lasers Med Sci ; 35(8): 1841-1848, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32483748

RESUMO

Photobiomodulation (PBM) has been used to modulate the inflammatory and immune responses, pain relief, and to promote wound healing. PBM is widely used in dental practice and its cellular effects should be investigated. The aim was to evaluate if PBM changes proteins cell death-related, such as caspase-6 and Bcl-2, in periodontal ligament cells. Eighteen mice were divided in three groups (n = 6), i.e., (I) control, (II) 3 J cm-2, and (III) 30 J cm-2. Low power infrared laser (830 nm) parameters were power at 10 mW, energy densities at 3 and 30 J cm-2 in continuous emission mode, exposure time of 15 and 150 s, respectively for 4 days in a row. Twenty-four hours after last irradiation, the animals were euthanized, and their jaws were fixed and decalcified. Caspase-6 and Bcl-2 were analyzed by real-time polymerase chain reaction and immunocytochemical techniques, and DNA fragmentation was evaluated by TUNEL. Statistical differences were not significant to caspase-6 mRNA relative levels in tissues from jaws at both energy densities, but a significant increase of Bcl-2 mRNA relative levels was obtained at 30 J cm-2 group. Also, 30 J cm-2 group showed caspase-6 positive-labeled cells decreased and Bcl-2 positive-labeled cells significantly increased. TUNEL-labeled cells demonstrated DNA fragmentation decreased at 30 J cm-2. PBM can alter Bcl-2 mRNA relative level and both caspase-6 and Bcl-2 protein, modulating cell survival, as well as to reduce DNA fragmentation. More studies must be performed in order to obtain conclusive results about photobiostimulation effects using infrared low-level laser in apoptosis process as to achieve the optimum dosage.


Assuntos
Apoptose/efeitos da radiação , Terapia com Luz de Baixa Intensidade , Ligamento Periodontal/citologia , Animais , Sobrevivência Celular/efeitos da radiação , Fragmentação do DNA/efeitos da radiação , Regulação da Expressão Gênica/efeitos da radiação , Camundongos , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Mensageiro/genética , Cicatrização/efeitos da radiação
11.
Biol Res ; 53(1): 19, 2020 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-32366289

RESUMO

BACKGROUND: Breast cancer is the most common cancer types among women. Recent researches have focused on determining the efficiency of alternative molecules and miRNAs in breast cancer treatment. The aim of this study was to determine the effect of usnic acid response-miR-185-5p on proliferation in the breast cancer cell and to determine its relationship with apoptosis pathway. METHODS: The cell proliferation and cell apoptosis rate were significantly increased following the ectopic expression of miR-185-5p in BT-474 cells. Furthermore, the results of cell cycle assay performed by flow cytometry revealed that the transfection with miR-185-5p induced G1/S phase arrest. The apoptosis-related genes expression analysis was performed by qRT-PCR and the direct target of miR-185-5p in BT-474 cells was identified by western blot and luciferase reporter assay. RESULTS: Our data showed that miR-185-5p can cause significant changes in apoptosis-related genes expression levels, suggesting that cell proliferation was suppressed by miR-185-5p via inducing apoptosis in breast cancer cells. According to western blot results, miR-185-5p lead to decrease BCL2 protein level in BT-474 cells and direct target of miR-185-5p was identified as BCL by luciferase reporter assay. CONCLUSION: This study revealed that miR-185-5p may be an effective agent in the treatment of breast cancer.


Assuntos
Benzofuranos/metabolismo , Neoplasias da Mama/genética , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Apoptose , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Regulação para Baixo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Transfecção
12.
Gene ; 750: 144723, 2020 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-32387119

RESUMO

The BCL2L12, one of the latest discovered members of the BCL2 family, has both pro- and anti-apoptotic roles that are cell-type-dependent. Its role in tumorigenesis is highly implicated. Sixty-three splice variants of this gene have been identified so far, with significant differences in expression patterns between various cancer cell lines. Presently, little is known regarding the regulation of expression of the BCL2L12 gene. For the vast majority of BCL2L12 gene splice variants, the 5'- and 3'-untranslated regions as well as their transcriptional regulation have not been determined yet. The aim of this study was to get insight into the regulation of the BCL2L12 gene transcription in human chronic myelogenous leukemia (K562) cell line. Our results point to the activity of novel transcription start site of the BCL2L12 gene and indicate that Sp1 and GATA-1 transcription factors could be involved in the regulation of BCL2L12 gene expression in K562 cells. The previously reported active promoter of BCL2L12 gene differs from the one we described in our study. If this novel BCL2L12 promoter is confirmed to be active in other malignancies, transcripts generated from this region could be considered as new cancer-specific biomarkers. The results of our study contribute to the better understanding of the transcriptional regulation of the BCL2L12 gene.


Assuntos
Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Apoptose/fisiologia , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Expressão Gênica , Humanos , Células K562 , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sítio de Iniciação de Transcrição , Transcrição Genética
13.
Cell Prolif ; 53(6): e12826, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32419250

RESUMO

OBJECTIVES: BCL2 family proteins have been widely studied over the past decade due to their essential roles in apoptosis, oncogenesis and anti-cancer therapy. However, the similarities and differences in the spatial pattern of the BCL2 gene family within the context of chromatin have not been well characterized. We sought to fill this knowledge gap by assessing correlations between gene alteration, gene expression, chromatin accessibility, and clinical outcomes in gynaecologic and breast cancer. MATERIALS AND METHODS: In this study, the molecular characteristics of the BCL2 gene family in gynaecologic cancer were systematically analysed by integrating multi-omics datasets, including transcriptomics, chromatin accessibility, copy number variation, methylomics and clinical outcome. RESULTS: We evaluated spatiotemporal associations between long-range regulation peaks and tumour heterogeneity. Differential expression of the BCL2 family was coupled with widespread chromatin accessibility changes in gynaecologic cancer, accompanied by highly heterogeneous distal non-coding accessibility surrounding the BCL2L1 gene loci. A relationship was also identified between gene expression, gene amplification, enhancer signatures, DNA methylation and overall patient survival. Prognostic analysis implied clinical correlations with BAD, BIK and BAK1. A shared protein regulatory network was established in which the co-mutation signature of TP53 and PIK3CA was linked to the BCL2L1 gene. CONCLUSIONS: Our results provide the first systematic identification of the molecular features of the BCL2 family under the spatial pattern of chromatin in gynaecologic and breast cancer. These findings broaden the therapeutic scope of the BCL2 family to the non-coding region by including a significantly conserved distal region overlaying an enhancer.


Assuntos
Neoplasias da Mama/genética , Neoplasias dos Genitais Femininos/genética , Família Multigênica , Proteínas Proto-Oncogênicas c-bcl-2/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Cromatina/metabolismo , Metilação de DNA , Elementos Facilitadores Genéticos , Feminino , Regulação Neoplásica da Expressão Gênica , Neoplasias dos Genitais Femininos/metabolismo , Neoplasias dos Genitais Femininos/mortalidade , Humanos , Estimativa de Kaplan-Meier , Prognóstico , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Mensageiro/metabolismo
14.
J Cancer Res Ther ; 16(1): 183-185, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32362635

RESUMO

Diffuse large B-cell lymphomas (DLBCL) with MYC translocations combined with translocations involving BCL-2 or BCL-6 are referred to as double-hit lymphomas. These lymphomas are generally refractory to currently available therapies and have a poor prognosis. Primary mediastinal B-cell lymphoma (PMBL) is a rare subtype of DLBCL, which shares clinical, pathologic, and genetic similarities with classical Hodgkin's lymphoma. Unlike DLBCL, rearrangements involving MYC, BCL-2, and BCL-6 are typically absent in PMBL. We present a patient with PMBL who had increased gene copy numbers of MYC and BCL-2 along with increased protein expression of BCL-2 (c-Myc expression was about 15%-20% by immunostain). The disease was refractory to standard and salvage chemotherapies. The lymphoma, however, responded to brentuximab vedotin, a CD30-directed chemoimmunoconjugate.


Assuntos
Brentuximab Vedotin/uso terapêutico , Antígeno Ki-1/metabolismo , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Neoplasias do Mediastino/tratamento farmacológico , Mutação , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Adulto , Antineoplásicos Imunológicos/uso terapêutico , Feminino , Humanos , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/patologia , Neoplasias do Mediastino/genética , Neoplasias do Mediastino/metabolismo , Neoplasias do Mediastino/patologia , Prognóstico , Proteínas Proto-Oncogênicas c-bcl-2/genética
15.
Nat Commun ; 11(1): 2598, 2020 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-32451402

RESUMO

DNA double-strand breaks (DSBs) are toxic to mammalian cells. However, during meiosis, more than 200 DSBs are generated deliberately, to ensure reciprocal recombination and orderly segregation of homologous chromosomes. If left unrepaired, meiotic DSBs can cause aneuploidy in gametes and compromise viability in offspring. Oocytes in which DSBs persist are therefore eliminated by the DNA-damage checkpoint. Here we show that the DNA-damage checkpoint eliminates oocytes via the pro-apoptotic BCL-2 pathway members Puma, Noxa and Bax. Deletion of these factors prevents oocyte elimination in recombination-repair mutants, even when the abundance of unresolved DSBs is high. Remarkably, surviving oocytes can extrude a polar body and be fertilised, despite chaotic chromosome segregation at the first meiotic division. Our findings raise the possibility that allelic variants of the BCL-2 pathway could influence the risk of embryonic aneuploidy.


Assuntos
Mutação , Oócitos/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Reparo de DNA por Recombinação/genética , Aneuploidia , Animais , Apoptose , Proteínas Reguladoras de Apoptose/deficiência , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas de Ciclo Celular/deficiência , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Segregação de Cromossomos , Quebras de DNA de Cadeia Dupla , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Endodesoxirribonucleases/deficiência , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/metabolismo , Feminino , Fertilização , Genes bcl-2 , Meiose/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oócitos/citologia , Proteínas de Ligação a Fosfato/deficiência , Proteínas de Ligação a Fosfato/genética , Proteínas de Ligação a Fosfato/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/deficiência , Proteínas Proto-Oncogênicas c-bcl-2/genética , Transdução de Sinais , Proteínas Supressoras de Tumor/deficiência , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Proteína X Associada a bcl-2/deficiência , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
16.
Ann Hematol ; 99(9): 2149-2157, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32390113

RESUMO

Although MYC and BCL2 co-expression in diffuse large B cell lymphoma (DLBCL) is associated with inferior prognosis, it remains uncertain whether upfront autologous hematopoietic stem cell transplantation (ASCT) is beneficial in this lymphoma. This study aimed to investigate whether ASCT consolidation could have a positive role for patients with MYC and BCL2 co-expression (double-expressor lymphoma, DEL). We retrospectively evaluated 67 DLBCL patients who underwent upfront ASCT following rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy. The 5-year overall survival (OS) and progression-free survival (PFS) were 82.3% and 79.2%, respectively. There were 23 (34.3%) patients with DEL and 51 (76.1%) patients with non-germinal center B cell (GCB) subtype. The 5-year OS and PFS of patients with DEL were not different from those with non-DEL (P = 0.429 and P = 0.614, respectively). No survival difference for OS and PFS was also observed between GCB and non-GCB subtypes (P = 0.950 and P = 0.901, respectively). The OS and PFS were comparable for patients with DEL and non-DEL and both GCB and non-GCB subtypes. In conclusion, MYC and BCL2 co-expression did not have a poor prognostic impact among high-risk patients with DLBCL treated with upfront ASCT regardless of molecular classification. This preliminary study suggested that the role of consolidative ASCT is needed to be evaluated in a prospective randomized clinical trial.


Assuntos
Regulação Neoplásica da Expressão Gênica , Transplante de Células-Tronco Hematopoéticas/métodos , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/terapia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-myc/genética , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ciclofosfamida/uso terapêutico , Doxorrubicina/uso terapêutico , Feminino , Humanos , Linfoma Difuso de Grandes Células B/diagnóstico , Masculino , Pessoa de Meia-Idade , Prednisona/uso terapêutico , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteínas Proto-Oncogênicas c-myc/biossíntese , Estudos Retrospectivos , Fatores de Risco , Transplante Autólogo/métodos , Vincristina/uso terapêutico , Adulto Jovem
17.
Mutat Res ; 852: 503165, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32265046

RESUMO

Human risk assessment of genotoxic chemicals is an important area of research. However, the specificity of in vitro mammalian genotoxicity assays is sometime low, as they yield to misleading positive results that are not observe in in vivo studies. Apoptosis can be a confounding factor in the interpretation of the results. Recently, a new strategy for genotoxicity screening, based on the combined analysis of phosphorylated histones H2AX (γH2AX) and H3 (pH3), was proposed to discriminate efficiently aneugenic from clastogenic compounds. However, γH2AX biomarker could also be induce by apoptosis. The aim of the present study was to investigate the specificity of this genotoxic biomarker. For this purpose, we analyzed 26 compounds inducing apoptosis by different mechanism of action, with the γH2AX assay in three human cell lines after 24 h treatment. Most of the tested chemicals were negative in the assay, whatever the cell line tested. The few compounds that generated positive data have also been report positive in other genotoxicity assays. The data presented here demonstrate that the γH2AX assay is not vulnerable to the generation of misleading positive results by apoptosis inducers. Currently, no formal guidelines have been approve for the γH2AX assay for regular genotoxicity studies, but we suggest that this biomarker could be used as a new standard genotoxicity assay.


Assuntos
Apoptose/efeitos dos fármacos , Biomarcadores Tumorais/genética , Western Blotting/métodos , Histonas/genética , Micronúcleos com Defeito Cromossômico/efeitos dos fármacos , Mutagênicos/toxicidade , Apoptose/genética , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Expressão Gênica , Células Hep G2 , Histonas/metabolismo , Humanos , Testes para Micronúcleos , Testes de Mutagenicidade , Mutagênicos/classificação , Fosforilação , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo
18.
Proc Natl Acad Sci U S A ; 117(18): 9912-9921, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32321829

RESUMO

Triple-negative breast cancer (TNBC) accounts for 10 to 20% of breast cancer, with chemotherapy as its mainstay of treatment due to lack of well-defined targets, and recent genomic sequencing studies have revealed a paucity of TNBC-specific mutations. Recurrent gene fusions comprise a class of viable genetic targets in solid tumors; however, their role in breast cancer remains underappreciated due to the complexity of genomic rearrangements in this cancer. Our interrogation of the whole-genome sequencing data for 215 breast tumors catalogued 99 recurrent gene fusions, 57% of which are cryptic adjacent gene rearrangements (AGRs). The most frequent AGRs, BCL2L14-ETV6, TTC6-MIPOL1, ESR1-CCDC170, and AKAP8-BRD4, were preferentially found in the more aggressive forms of breast cancers that lack well-defined genetic targets. Among these, BCL2L14-ETV6 was exclusively detected in TNBC, and interrogation of four independent patient cohorts detected BCL2L14-ETV6 in 4.4 to 12.2% of TNBC tumors. Interestingly, these fusion-positive tumors exhibit more aggressive histopathological features, such as gross necrosis and high tumor grade. Amid TNBC subtypes, BCL2L14-ETV6 is most frequently detected in the mesenchymal entity, accounting for ∼19% of these tumors. Ectopic expression of BCL2L14-ETV6 fusions induce distinct expression changes from wild-type ETV6 and enhance cell motility and invasiveness of TNBC and benign breast epithelial cells. Furthermore, BCL2L14-ETV6 fusions prime partial epithelial-mesenchymal transition and endow resistance to paclitaxel treatment. Together, these data reveal AGRs as a class of underexplored genetic aberrations that could be pathological in breast cancer, and identify BCL2L14-ETV6 as a recurrent gene fusion in more aggressive form of TNBC tumors.


Assuntos
Rearranjo Gênico/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-ets/genética , Proteínas Repressoras/genética , Neoplasias de Mama Triplo Negativas/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Transição Epitelial-Mesenquimal/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Fusão Gênica/genética , Genômica/métodos , Humanos , Mutação , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Proteínas de Fusão Oncogênica/genética , Paclitaxel/administração & dosagem , Paclitaxel/efeitos adversos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Sequenciamento Completo do Genoma
20.
Hum Cell ; 33(3): 610-618, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32342278

RESUMO

Chronic myeloid leukemia (CML) is a hematopoietic stem cell disease caused by abnormal DNA replication of bone marrow stem cells and chemotherapy resistance is a major obstacle to the effective treatment of patients with CML. Imatinib (IM), a tyrosine kinase inhibitor (TKI), is a first-line drug clinically used for CML. Mounting evidence has indicated that the dysregulation of microRNAs (miRNAs) is associated with the chemoresistance of CML. In this study, miR-153-3p, which had been implicated with numerous types of tumors, was identified to be downregulated in IM-resistant CML cells. Upregulation of miR-153-3p significantly increased IM sensitivity and decreased the survival rate of IM-resistant CML cells, whereas downregulation of miR-153-3p attenuated these effects in IM-resistant CML cells. Upregulated miR-153-3p could decrease the autophagy caused by IM in IM-resistant CML cells. Dual-luciferase reporter assays confirmed that Bcl-2 is a direct target of miR-153-3p. Bcl-2 restoration reversed the increased sensitivity to IM induced by miR-153-3p-mimic transfection in IM-resistant CML cells. The results of the present study showed that dysregulated miR-153-3p may target Bcl-2 to promote the development of IM resistance and attenuate IM-induced apoptosis in CML. Therefore, miR-153-3p upregulation combined with IM treatment may serve as a promising therapeutic strategy for patients with low sensitivity.


Assuntos
Autofagia/genética , Mesilato de Imatinib/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , MicroRNAs/fisiologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Apoptose/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Mesilato de Imatinib/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , MicroRNAs/metabolismo , Terapia de Alvo Molecular , Regulação para Cima
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