Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 54
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Cell Biochem Funct ; 40(7): 784-796, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36128730

RESUMO

Biosynthetic procedure is one of the best alternatives, inexpensive and ecologically sound for the synthesis of titanium dioxide (TiO2 ) nanoparticles using a methanolic extract of medicinal plant. The main prospect of this study was to investigate the antiglycation activity of the TiO2 nanoparticles (TNP) prepared by ethanolic leaf extract of the Coleus scutellarioides. In this study, biosynthesized TNP characterized with UV-Visible spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscope. These TNP were further investigated with respect to their antiglycation property and it was checked in the mixture of d-ribose glycated bovine serum albumin (BSA) by measuring ketoamine, carbonyl content, Advanced glycation end products (AGEs) and aggregation of protein instigated by glycation process. The inhibitory effect of TNP to restore the structure of BSA in presence of d-ribose were also characterize by biophysical techniques mentioned above. Therefore, the findings of this study suggest repurposing of TNP for its antiglycation property that could be helpful in prevention of glycation instigated AGEs formation and structural loss of proteins.


Assuntos
Nanopartículas , Soroalbumina Bovina , Produtos Finais de Glicação Avançada/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ribose/química , Ribose/metabolismo , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismo , Titânio
2.
Int J Cancer ; 146(6): 1686-1699, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31381135

RESUMO

Currently, no effective targeted therapeutics exists for treatment of metastatic prostate cancer (PCa). Given that matrix metalloproteinases 9 (MMP9) and its associated vascular endothelial growth factor (VEGF) are critical for tumor vascularization and invasion under castration-resistant condition, it is therefore of great importance to define the functional association and interplay between androgen receptor (AR) and MMP9 and their associated key survival and invasion pathways in PCa cells. Here, we found that there was a significant correlation between MMP9 and AR protein expression in primary and metastatic PCa tissues, and a trend that high level of MMP9 expression was associated with poor prognosis. We demonstrated that constitutive activation of AR increased expression of MMP9 and VEGF/VEGF receptors. We further showed that AR exerts its effect on MMP9/VEGF signaling axis through PIP5K1α/AKT. We showed that MMP9 physically interacted with PIP5K1α via formation of protein-protein complexes. Furthermore, elevated expression of MMP9 enhanced ability of AR to activate its target gene cyclin A1. The elevated sequential activation of AR/PIP5K1α/AKT/MMP9/VEGF signaling axis contributed to increased invasiveness and growth of metastatic tumors. Conversely, treatment with PIP5K1α inhibitor significantly suppressed invasiveness of PCa cells expressing constitutively activated AR, this was coincident with its inhibitory effect of this inhibitor on AR/MMP9/VEGF pathways. Our results suggest that AR and MMP9-associated network proteins may be effectively targeted by blocking PIP5K1α/AKT pathways using PIP5K1α inhibitor in metastatic PCa.


Assuntos
Metaloproteinase 9 da Matriz/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Androgênicos/metabolismo , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Neoplasias Ósseas/secundário , Linhagem Celular Tumoral , Modelos Animais de Doenças , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Metaloproteinase 9 da Matriz/genética , Camundongos , Modelos Biológicos , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Ligação Proteica , Receptores Androgênicos/genética , Ensaios Antitumorais Modelo de Xenoenxerto
3.
Analyst ; 144(22): 6736-6750, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31612875

RESUMO

Over a third of brain tumour patients visit their general practitioner more than five times prior to diagnosis in the UK, leading to 62% of patients being diagnosed as emergency presentations. Unfortunately, symptoms are non-specific to brain tumours, and the majority of these patients complain of headaches on multiple occasions before being referred to a neurologist. As there are currently no methods in place for the early detection of brain cancer, the affected patients' average life expectancy is reduced by 20 years. These statistics indicate that the current pathway is ineffective, and there is a vast need for a rapid diagnostic test. Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy is sensitive to the hallmarks of cancer, as it analyses the full range of macromolecular classes. The combination of serum spectroscopy and advanced data analysis has previously been shown to rapidly and objectively distinguish brain tumour severity. Recently, a novel high-throughput ATR accessory has been developed, which could be cost-effective to the National Health Service in the UK, and valuable for clinical translation. In this study, 765 blood serum samples have been collected from healthy controls and patients diagnosed with various types of brain cancer, contributing to one of the largest spectroscopic studies to date. Three robust machine learning techniques - random forest, partial least squares-discriminant analysis and support vector machine - have all provided promising results. The novel high-throughput technology has been validated by separating brain cancer and non-cancer with balanced accuracies of 90% which is comparable to the traditional fixed diamond crystal methodology. Furthermore, the differentiation of brain tumour type could be useful for neurologists, as some are difficult to distinguish through medical imaging alone. For example, the highly aggressive glioblastoma multiforme and primary cerebral lymphoma can appear similar on magnetic resonance imaging (MRI) scans, thus are often misdiagnosed. Here, we report the ability of infrared spectroscopy to distinguish between glioblastoma and lymphoma patients, at a sensitivity and specificity of 90.1% and 86.3%, respectively. A reliable serum diagnostic test could avoid the need for surgery and speed up time to definitive chemotherapy and radiotherapy.


Assuntos
Análise Química do Sangue/estatística & dados numéricos , Neoplasias Encefálicas/diagnóstico , Glioblastoma/diagnóstico , Linfoma/diagnóstico , Espectroscopia de Infravermelho com Transformada de Fourier/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Conjuntos de Dados como Assunto , Diagnóstico Diferencial , Análise Discriminante , Feminino , Humanos , Análise dos Mínimos Quadrados , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos , Sensibilidade e Especificidade , Máquina de Vetores de Suporte , Adulto Jovem
4.
Mol Cancer ; 17(1): 76, 2018 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-29580241

RESUMO

DNA damage-specific histone chaperone Aprataxin PNK-like factor (APLF) regulates mesenchymal-to-epithelial transition (MET) during cellular reprogramming. We investigated the role of APLF in epithelial-to-mesenchymal transition (EMT) linked to breast cancer invasiveness and metastasis. Here, we show that a significant manifestation of APLF is present in tumor sections of patients with invasive ductal carcinoma when compared to their normal adjacent tissues. APLF was significantly induced in triple negative breast cancer (TNBC) cells, MDAMB-231, in comparison to invasive MCF7 or normal MCF10A breast cells and supported by studies on invasive breast carcinoma in The Cancer Genome Atlas (TCGA). Functionally, APLF downregulation inhibited proliferative capacity, altered cell cycle behavior, induced apoptosis and impaired DNA repair ability of MDAMB-231 cells. Reduction in APLF level impeded invasive, migratory, tumorigenic and metastatic potential of TNBC cells with loss in expression of genes associated with EMT while upregulation of MET-specific gene E-cadherin (CDH1). So, here we provided novel evidence for enrichment of APLF in breast tumors, which could regulate metastasis-associated EMT in invasive breast cancer. We anticipate that APLF could be exploited as a biomarker for breast tumors and additionally could be targeted in sensitizing cancer cells towards DNA damaging agents.


Assuntos
Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Regulação para Cima , Animais , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Carcinoma Ductal de Mama/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Transição Epitelial-Mesenquimal , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Transplante de Neoplasias , Análise Serial de Tecidos , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia
5.
Int J Cancer ; 142(8): 1620-1626, 2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29194603

RESUMO

Many traits of cancer progression (e.g., development of metastases or resistance to therapy) are facilitated by tumour evolution: Darwinian selection of subclones with distinct genotypes or phenotypes that enable such progression. Characterising these subclones provide an opportunity to develop drugs to better target their specific properties but requires the accurate identification of somatic mutations shared across multiple spatiotemporal tumours from the same patient. Current best practices for calling somatic mutations are optimised for single samples, and risk being too conservative to identify shared mutations with low prevalence in some samples. We reasoned that datasets from multiple matched tumours can be used for mutual validation and thus propose an adapted two-stage approach: (1) low-stringency mutation calling to identify mutations shared across samples irrespective of the weight of evidence in a single sample; (2) high-stringency mutation calling to further characterise mutations present in a single sample. We applied our approach to three-independent cohorts of paired primary and recurrent glioblastoma tumours, two of which have previously been analysed using existing approaches, and found that it significantly increased the amount of biologically relevant shared somatic mutations identified. We also found that duplicate removal was detrimental when identifying shared somatic mutations. Our approach is also applicable when multiple datasets e.g. DNA and RNA are available for the same tumour.


Assuntos
Glioblastoma/genética , Genótipo , Humanos , Mutação/genética , Recidiva Local de Neoplasia/genética , Fenótipo
6.
Mol Med ; 24(1): 34, 2018 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-30134822

RESUMO

BACKGROUND: Metastatic Prostate cancer (PCa) cells have gained survival and invasive advantages. Epidermal growth factor (EGF) receptor is a receptor tyrosine kinase, which may mediate signalling to promote progression and invasion of various cancers. In this study, we uncovered the molecular mechanisms underlying the interconnection among the androgen receptor (AR), matrix metalloproteinase-9 (MMP9) and EGFR in promoting PCa progression. METHODS: Immunohistochemical analysis of the tissue microarrays consisting of primary and metastatic PCa tissues was performed. The clinical importance of EGFR and its association with survivals were analyzed using three cohorts from MSKCC Prostate Oncogenome Project dataset (For primary tumors, n = 181; for metastatic tumors n = 37) and The Cancer Genome Atlas Prostate Adenocarcinoma Provisional dataset (n = 495). Targeted overexpression or inhibition of the proteins of interests was introduced into PCa cell lines. Treatment of PCa cell lines with the compounds was conducted. Immunoblot analysis was performed. RESULTS: We showed that AR, MMP-9 and EGFR are interconnect factors, which may cooperatively promote PCa progression. Altered EGFR expression was associated with poor disease-free survival in PCa patients. Induced overexpression of AR led to an increase in the expression of EGFR, p-GSK-3ß and decrease in p27 expression in PCa cell lines in the presence of androgen stimulation. Overexpression of MMP9 significantly induced EGFR expression in PCa cells. Inhibition of PIP5K1α, a lipid kinase that acts upstream of PI3K/AKT greatly reduced expressions of AR, MMP-9 and EGFR. CONCLUSIONS: Our findings also suggest that PCa cells may utilize AR, EGFR and MMP-9 pathways in androgen-dependent as well as in castration-resistant conditions. Our data suggest a new therapeutic potential to block cancer metastasis by targeting AR, EGFR and MMP-9 pathways in subsets of PCa patients.


Assuntos
Metaloproteinase 9 da Matriz/metabolismo , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/metabolismo , Linhagem Celular Tumoral , Receptores ErbB/metabolismo , Humanos , Masculino , Transdução de Sinais
7.
J Cell Sci ; 129(24): 4576-4591, 2016 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-27875275

RESUMO

Induction of pluripotency in differentiated cells through the exogenous expression of the transcription factors Oct4, Sox2, Klf4 and cellular Myc involves reprogramming at the epigenetic level. Histones and their metabolism governed by histone chaperones constitute an important regulator of epigenetic control. We hypothesized that histone chaperones facilitate or inhibit the course of reprogramming. For the first time, we report here that the downregulation of histone chaperone Aprataxin PNK-like factor (APLF) promotes reprogramming by augmenting the expression of E-cadherin (Cdh1), which is implicated in the mesenchymal-to-epithelial transition (MET) involved in the generation of induced pluripotent stem cells (iPSCs) from mouse embryonic fibroblasts (MEFs). Downregulation of APLF in MEFs expedites the loss of the repressive MacroH2A.1 (encoded by H2afy) histone variant from the Cdh1 promoter and enhances the incorporation of active histone H3me2K4 marks at the promoters of the pluripotency genes Nanog and Klf4, thereby accelerating the process of cellular reprogramming and increasing the efficiency of iPSC generation. We demonstrate a new histone chaperone (APLF)-MET-histone modification cohort that functions in the induction of pluripotency in fibroblasts. This regulatory axis might provide new mechanistic insights into perspectives of epigenetic regulation involved in cancer metastasis.


Assuntos
Proteínas de Transporte/metabolismo , Fibroblastos/metabolismo , Chaperonas de Histonas/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Animais , Caderinas/genética , Caderinas/metabolismo , Pontos de Checagem do Ciclo Celular/genética , Diferenciação Celular/genética , Reprogramação Celular/genética , Ensaio de Unidades Formadoras de Colônias , Reparo do DNA/genética , DNA Liase (Sítios Apurínicos ou Apirimidínicos) , Regulação para Baixo/genética , Embrião de Mamíferos/citologia , Células Epiteliais/citologia , Feminino , Fibroblastos/citologia , Técnicas de Silenciamento de Genes , Células HEK293 , Histonas/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Fator 4 Semelhante a Kruppel , Lisina/metabolismo , Masculino , Mesoderma/citologia , Metilação , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Ligação a Poli-ADP-Ribose , Regiões Promotoras Genéticas/genética , Regulação para Cima/genética
8.
Clin Exp Immunol ; 191(2): 189-197, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28963773

RESUMO

Programmed death-1 (PD-1) and interactions with PD-ligand 1 (PD-L1) play critical roles in the tumour evasion of immune responses through different mechanisms, including inhibition of effector T cell proliferation, reducing cytotoxic activity, induction of apoptosis in tumour-infiltrating T cells and regulatory T cell (Treg ) expansion. Effective blockade of immune checkpoints can therefore potentially eliminate these detrimental effects. The aim of this study was to investigate the effect of anti-PD-1 antibody, pembrolizumab, on various Treg subpopulations. Peripheral blood mononuclear cells (PBMC) from healthy donors (HD) and primary breast cancer patients (PBC) were treated in vitro with pembrolizumab, which effectively reduced PD-1 expression in both cohorts. We found that PD-1 was expressed mainly on CD4+ CD25+ T cells and pembrolizumab had a greater effect on PD-1 expression in CD4+ CD25- T cells, compared to CD4+ CD25+ cells. In addition, pembrolizumab did not affect the expression levels of Treg -related markers, including cytotoxic T lymphocyte antigen-4 (CTLA-4), CD15s, latency-associated peptide (LAP) and Ki-67. Moreover, we report that CD15s is expressed mainly on forkhead box P3 (FoxP3)- Helios+ Treg in HD, but it is expressed on FoxP3+ Helios- Treg subset in addition to FoxP3- Helios+ Treg in PBC. Pembrolizumab did not affect the levels of FoxP3+/- Helios+/- Treg subsets in both cohorts. Taken together, our study suggests that pembrolizumab does not affect Treg or change their phenotype or function but rather blocks signalling via the PD-1/PD-L1 axis in activated T cells.


Assuntos
Anticorpos Monoclonais Humanizados/farmacologia , Antineoplásicos Imunológicos/farmacologia , Neoplasias da Mama/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Subpopulações de Linfócitos T/efeitos dos fármacos , Linfócitos T Reguladores/efeitos dos fármacos , Antígeno B7-H1/metabolismo , Células Cultivadas , Feminino , Fatores de Transcrição Forkhead/metabolismo , Voluntários Saudáveis , Humanos , Leucócitos Mononucleares/patologia , Receptor de Morte Celular Programada 1/genética , Subpopulações de Linfócitos T/fisiologia , Linfócitos T Reguladores/fisiologia , Evasão Tumoral
9.
Blood ; 128(3): 384-94, 2016 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-27222480

RESUMO

Daratumumab targets CD38-expressing myeloma cells through a variety of immune-mediated mechanisms (complement-dependent cytotoxicity, antibody-dependent cell-mediated cytotoxicity, and antibody-dependent cellular phagocytosis) and direct apoptosis with crosslinking. These mechanisms may also target nonplasma cells that express CD38, which prompted evaluation of daratumumab's effects on CD38-positive immune subpopulations. Peripheral blood (PB) and bone marrow (BM) from patients with relapsed/refractory myeloma from 2 daratumumab monotherapy studies were analyzed before and during therapy and at relapse. Regulatory B cells and myeloid-derived suppressor cells, previously shown to express CD38, were evaluated for immunosuppressive activity and daratumumab sensitivity in the myeloma setting. A novel subpopulation of regulatory T cells (Tregs) expressing CD38 was identified. These Tregs were more immunosuppressive in vitro than CD38-negative Tregs and were reduced in daratumumab-treated patients. In parallel, daratumumab induced robust increases in helper and cytotoxic T-cell absolute counts. In PB and BM, daratumumab induced significant increases in CD8(+):CD4(+) and CD8(+):Treg ratios, and increased memory T cells while decreasing naïve T cells. The majority of patients demonstrated these broad T-cell changes, although patients with a partial response or better showed greater maximum effector and helper T-cell increases, elevated antiviral and alloreactive functional responses, and significantly greater increases in T-cell clonality as measured by T-cell receptor (TCR) sequencing. Increased TCR clonality positively correlated with increased CD8(+) PB T-cell counts. Depletion of CD38(+) immunosuppressive cells, which is associated with an increase in T-helper cells, cytotoxic T cells, T-cell functional response, and TCR clonality, represents possible additional mechanisms of action for daratumumab and deserves further exploration.


Assuntos
ADP-Ribosil Ciclase 1 , Anticorpos Monoclonais/administração & dosagem , Linfócitos T CD8-Positivos , Glicoproteínas de Membrana , Mieloma Múltiplo , Proteínas de Neoplasias , Linfócitos T Reguladores , ADP-Ribosil Ciclase 1/sangue , ADP-Ribosil Ciclase 1/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Relação CD4-CD8 , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Glicoproteínas de Membrana/sangue , Glicoproteínas de Membrana/imunologia , Pessoa de Meia-Idade , Mieloma Múltiplo/sangue , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/imunologia , Proteínas de Neoplasias/sangue , Proteínas de Neoplasias/imunologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo
10.
Blood ; 128(7): 959-70, 2016 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-27307294

RESUMO

The anti-CD38 monoclonal antibody daratumumab is well tolerated and has high single agent activity in heavily pretreated relapsed and refractory multiple myeloma (MM). However, not all patients respond, and many patients eventually develop progressive disease to daratumumab monotherapy. We therefore examined whether pretreatment expression levels of CD38 and complement-inhibitory proteins (CIPs) are associated with response and whether changes in expression of these proteins contribute to development of resistance. In a cohort of 102 patients treated with daratumumab monotherapy (16 mg/kg), we found that pretreatment levels of CD38 expression on MM cells were significantly higher in patients who achieved at least partial response (PR) compared with patients who achieved less than PR. However, cell surface expression of the CIPs, CD46, CD55, and CD59, was not associated with clinical response. In addition, CD38 expression was reduced in both bone marrow-localized and circulating MM cells, following the first daratumumab infusion. CD38 expression levels on MM cells increased again following daratumumab discontinuation. In contrast, CD55 and CD59 levels were significantly increased on MM cells only at the time of progression. All-trans retinoic acid increased CD38 levels and decreased CD55 and CD59 expression on MM cells from patients who developed daratumumab resistance, to approximately pretreatment values. This resulted in significant enhancement of daratumumab-mediated complement-dependent cytotoxicity. Together, these data demonstrate an important role for CD38 and CIP expression levels in daratumumab sensitivity and suggest that therapeutic combinations that alter CD38 and CIP expression levels should be investigated in the treatment of MM. These trials were registered at www.clinicaltrials.gov as #NCT00574288 (GEN501) and #NCT01985126 (SIRIUS).


Assuntos
ADP-Ribosil Ciclase 1/metabolismo , Anticorpos Monoclonais/uso terapêutico , Inativadores do Complemento/metabolismo , Resistencia a Medicamentos Antineoplásicos , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/metabolismo , Anticorpos Monoclonais/farmacologia , Antígenos CD55 , Antígenos CD59 , Células Clonais , Citotoxicidade Imunológica/imunologia , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Tretinoína/farmacologia
11.
Cancer Immunol Immunother ; 66(6): 753-764, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28283696

RESUMO

Pathological conditions including cancers lead to accumulation of a morphological mixture of highly immunosuppressive cells termed as myeloid-derived suppressor cells (MDSC). The lack of conclusive markers to identify human MDSC, due to their heterogeneous nature and close phenotypical and functional proximity with other cell subsets, made it challenging to identify these cells. Nevertheless, expansion of MDSC has been reported in periphery and tumor microenvironment of various cancers. The majority of studies on breast cancers were performed on murine models and hence limited literature is available on the relation of MDSC accumulation with clinical settings in breast cancer patients. The aim of this study was to investigate levels and phenotypes of myeloid cells in peripheral blood (n = 23) and tumor microenvironment of primary breast cancer patients (n = 7), compared with blood from healthy donors (n = 21) and paired non-tumor normal breast tissues from the same patients (n = 7). Using multicolor flow cytometric assays, we found that breast cancer patients had significantly higher levels of tumor-infiltrating myeloid cells, which comprised of granulocytes (P = 0.022) and immature cells that lack the expression of markers for fully differentiated monocytes or granulocytes (P = 0.016). Importantly, this expansion was not reflected in the peripheral blood. The immunosuppressive potential of these cells was confirmed by expression of Arginase 1 (ARG1), which is pivotal for T-cell suppression. These findings are important for developing therapeutic modalities to target mechanisms employed by immunosuppressive cells that generate an immune-permissive environment for the progression of cancer.


Assuntos
Neoplasias da Mama/patologia , Mama/patologia , Células Mieloides/patologia , Evasão Tumoral , Microambiente Tumoral/imunologia , Adulto , Idoso , Arginase/metabolismo , Mama/imunologia , Mama/metabolismo , Neoplasias da Mama/sangue , Neoplasias da Mama/imunologia , Estudos de Casos e Controles , Feminino , Humanos , Pessoa de Meia-Idade , Células Mieloides/imunologia , Células Mieloides/metabolismo , Gradação de Tumores , Invasividade Neoplásica , Estadiamento de Neoplasias , Prognóstico , Adulto Jovem
12.
J Biol Chem ; 290(21): 13053-63, 2015 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-25847244

RESUMO

RUNX1 (Runt-related transcription factor 1) is indispensable for the generation of hemogenic endothelium. However, the regulation of RUNX1 during this developmental process is poorly understood. We investigated the role of the histone chaperone HIRA (histone cell cycle regulation-defective homolog A) from this perspective and report that HIRA significantly contributes toward the regulation of RUNX1 in the transition of differentiating mouse embryonic stem cells from hemogenic to hematopoietic stage. Direct interaction of HIRA and RUNX1 activates the downstream targets of RUNX1 implicated in generation of hematopoietic stem cells. At the molecular level, HIRA-mediated incorporation of histone H3.3 variant within the Runx1 +24 mouse conserved noncoding element is essential for the expression of Runx1 during endothelial to hematopoietic transition. An inactive chromatin at the intronic enhancer of Runx1 in absence of HIRA significantly repressed the transition of cells from hemogenic to hematopoietic fate. We expect that the HIRA-RUNX1 axis might open up a novel approach in understanding leukemogenesis in future.


Assuntos
Proteínas de Ciclo Celular/fisiologia , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Endotélio Vascular/citologia , Regulação da Expressão Gênica , Hematopoese/fisiologia , Células-Tronco Hematopoéticas/citologia , Chaperonas de Histonas/fisiologia , Fatores de Transcrição/fisiologia , Animais , Western Blotting , Proteínas de Ciclo Celular/antagonistas & inibidores , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Imunoprecipitação da Cromatina , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Endotélio Vascular/metabolismo , Citometria de Fluxo , Imunofluorescência , Células-Tronco Hematopoéticas/metabolismo , Chaperonas de Histonas/antagonistas & inibidores , Humanos , Imunoprecipitação , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/antagonistas & inibidores , Saco Vitelino/citologia , Saco Vitelino/metabolismo
14.
Eur J Immunol ; 44(10): 2968-78, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25042153

RESUMO

Treg-cell function is compromised in rheumatoid arthritis (RA). As the master regulator of Treg cells, FOXP3 controls development and suppressive function. Stable Treg-cell FOXP3 expression is epigenetically regulated; constitutive expression requires a demethylated Treg-specific demethylated region. Here, we hypothesised that methylation of the FOXP3 locus is altered in Treg cells of established RA patients. Methylation analysis of key regulatory regions in the FOXP3 locus was performed on Treg cells from RA patients and healthy controls. The FOXP3 Treg-specific demethylated region and proximal promoter displayed comparable methylation profiles in RA and healthy-donor Treg cells. We identified a novel differentially methylated region (DMR) upstream of the FOXP3 promoter, with enhancer activity sensitive to methylation-induced silencing. In RA Treg cells we observed significantly reduced DMR methylation and lower DNA methyltransferase (DNMT1/3A) expression compared with healthy Treg cells. Furthermore, DMR methylation negatively correlated with FOXP3 mRNA expression, and Treg cells isolated from rheumatoid factor negative RA patients were found to express significantly higher levels of FOXP3 than Treg cells from RhF-positive patients, with an associated decrease in DMR methylation. In conclusion, the novel DMR is involved in the regulation of Treg-cell FOXP3 expression, but this regulation is lost post-transcriptionally in RA Treg cells.


Assuntos
Artrite Reumatoide/imunologia , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/imunologia , Regulação da Expressão Gênica/imunologia , Linfócitos T Reguladores/imunologia , Adulto , Idoso , Artrite Reumatoide/genética , Metilação de DNA/genética , Metilação de DNA/imunologia , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real
15.
Eur J Cell Biol ; 103(3): 151439, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38968704

RESUMO

Our recent studies revealed the role of mouse Aprataxin PNK-like Factor (APLF) in development. Nevertheless, the comprehensive characterization of mouse APLF remains entirely unexplored. Based on domain deletion studies, here we report that mouse APLF's Acidic Domain and Fork Head Associated (FHA) domain can chaperone histones and repair DNA like the respective human orthologs. Immunofluorescence studies in mouse embryonic stem cells showed APLF co-localized with γ-tubulin within and around the centrosomes and govern the number and integrity of centrosomes via PLK4 phosphorylation. Enzymatic analysis established mouse APLF as a kinase. Docking studies identified three putative ATP binding sites within the FHA domain. Site-directed mutagenesis showed that R37 residue within the FHA domain is indispensable for the kinase activity of APLF thereby regulating the centrosome number. These findings might assist us comprehend APLF in different pathological and developmental conditions and reveal non-canonical kinase activity of proteins harbouring FHA domains that might impact multiple cellular processes.

16.
Cureus ; 16(6): e61663, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38966466

RESUMO

Background High-risk pregnancies, encompassing pregnancy-induced hypertension (PIH), gestational diabetes mellitus (GDM), preeclampsia toxemia (PET), and intrauterine growth restriction (IUGR), represent intricate medical challenges with potential repercussions for maternal and fetal health. This research undertakes a comprehensive comparative investigation into the variations of Doppler indices and placental parameters within the context of these high-risk conditions when juxtaposed against pregnancies characterized as normal. Methodology Employing a rigorous cross-sectional study design, a diverse cohort of pregnant individuals with gestational diabetes, IUGR, PIH, and preeclampsia was meticulously assembled. Additionally, a group of normal pregnant women served as the comparative reference. Doppler ultrasound assessments, viz, pulsatility index (PI), were carefully performed to estimate blood flow velocities within critical maternal and fetal vessels, while placental parameters were meticulously quantified, encompassing dimensions, vascular architecture, and morphological features. Results Except in the GDM group, all high-risk groups had reduced estimated placental weight and actual birth weight than normal pregnant women. All high-risk groups showed a highly significant elevation of the PI of the umbilical artery and PI of the middle cerebral artery (MCA) than normal but the PI of MCA was significantly reduced in the PET group than in normal individuals. The cerebro-placental ratio in the GDM and IUGR groups revealed markedly greater values, whereas PET showed lower values. IUGR and PIH groups showed a substantial reduction in the fetal birth weight. All high-risk groups (GDM, IUGR, PIH, and PET) showed a highly significant reduction in luminal area umbilical artery 1 than the normal pregnant women. In IUGR, marginal placental insertion was very high, followed by GDM and PET groups. Conclusions This study reveals that Doppler indices, placental parameters, newborn weight, and their related ratios may be utilized to anticipate gestation difficulties and gain insight into the pathophysiology of problematic conceptions.

17.
Artigo em Inglês | MEDLINE | ID: mdl-38639898

RESUMO

Diabetes's effects on wound healing present a major treatment challenge and increase the risk of amputation. When traditional therapies fail, new approaches must be investigated. With their submicron size and improved cellular internalisation, nanoparticles present a viable way to improve diabetic wound healing. They are attractive options because of their innate antibacterial qualities, biocompatibility, and biodegradability. Nanoparticles loaded with organic or inorganic compounds, or embedded in biomimetic matrices such as hydrogels, chitosan, and hyaluronic acid, exhibit excellent anti-inflammatory, antibacterial, and antioxidant properties. Drug delivery systems (DDSs)-more precisely, nanodrug delivery systems (NDDSs)-use the advantages of nanotechnology to get around some of the drawbacks of traditional DDSs. Recent developments show how expertly designed nanocarriers can carry a variety of chemicals, transforming the treatment of diabetic wounds. Biomaterials that deliver customised medications to the wound microenvironment demonstrate potential. Delivery techniques for nanomedicines become more potent than ever, overcoming conventional constraints. Therapeutics for diabetes-induced non-healing wounds are entering a revolutionary era thanks to precisely calibrated nanocarriers that effectively distribute chemicals. This review highlights the therapeutic potential of nanoparticles and outlines the multifunctional nanoparticles of the future that will be used for complete wound healing in diabetics. The investigation of novel nanodrug delivery systems has the potential to revolutionise diabetic wound therapy and provide hope for more efficient and focused therapeutic approaches.

18.
bioRxiv ; 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38405931

RESUMO

Parkinson's disease (PD) is a neurodegenerative disorder caused by complex genetic and environmental factors. Genome-edited human pluripotent stem cells (hPSCs) offer the uniique potential to advance our understanding of PD etiology by providing disease-relevant cell-types carrying patient mutations along with isogenic control cells. To facilitate this experimental approach, we generated a collection of 55 cell lines genetically engineered to harbor mutations in genes associated with monogenic PD (SNCA A53T, SNCA A30P, PRKN Ex3del, PINK1 Q129X, DJ1/PARK7 Ex1-5del, LRRK2 G2019S, ATP13A2 FS, FBXO7 R498X/FS, DNAJC6 c.801 A>G+FS, SYNJ1 R258Q/FS, VPS13C A444P, VPS13C W395C, GBA1 IVS2+1). All mutations were generated in a fully characterized and sequenced female human embryonic stem cell (hESC) line (WIBR3; NIH approval number NIHhESC-10-0079) using CRISPR/Cas9 or prime editing-based approaches. We implemented rigorous quality controls, including high density genotyping to detect structural variants and confirm the genomic integrity of each cell line. This systematic approach ensures the high quality of our stem cell collection, highlights differences between conventional CRISPR/Cas9 and prime editing and provides a roadmap for how to generate gene-edited hPSCs collections at scale in an academic setting. We expect that our isogenic stem cell collection will become an accessible platform for the study of PD, which can be used by investigators to understand the molecular pathophysiology of PD in a human cellular setting.

19.
Chem Biol Interact ; 398: 111114, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38897341

RESUMO

Withaferin A, a steroid lactone from Withania somnifera, exhibits anti-inflammatory, immunomodulatory, and antioxidant properties. This study investigated the effects of withaferin A on collagen-induced arthritis (CIA) rats, focusing on NF-κB p65 regulation and cytokine release. Withaferin A (50 mg/kg b.wt., orally) or methotrexate (0.25 mg/kg b.wt., i.p., as a reference drug) was given to CIA rats daily for 20 days postarthritis induction. Joints were removed from nonarthritic and arthritic rats to assess the levels of NO, MPO, interleukin (IL)-1ß, IL-6, IL-10, TNF-α, COX-2, and NF-κB via ELISA. Furthermore, the mRNA expression of IL-1ß, IL-10, TNF-α, COX-2, iNOS, and NF-κB was also assessed through qPCR. Treatment with withaferin A significantly inhibited the levels of inflammatory cytokines and the transcription factor NF-κB; suppressed the expression of IL-1ß, IL-10, TNF-α, COX-2, iNOS, and NF-κB in the joint tissue of CIA rats; and reduced cartilage and bone destruction, as shown by H&E staining. To confirm the results obtained from biochemical and molecular studies and to determine the molecular target of withaferin A, we performed a molecular simulation of the potential targets of withaferin A, which identified the NF-κB pathway as its target. These results suggested that withaferin A effectively attenuated rheumatoid arthritis progression by inhibiting the activation of the NF-κB pathway and the downstream secretion of inflammatory cytokines.


Assuntos
Artrite Experimental , Citocinas , NF-kappa B , Transdução de Sinais , Vitanolídeos , Animais , Vitanolídeos/farmacologia , Vitanolídeos/uso terapêutico , Ratos , Citocinas/metabolismo , Artrite Experimental/tratamento farmacológico , Artrite Experimental/metabolismo , Artrite Experimental/patologia , NF-kappa B/metabolismo , Masculino , Transdução de Sinais/efeitos dos fármacos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Ciclo-Oxigenase 2/metabolismo , Ciclo-Oxigenase 2/genética , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Ratos Wistar , Modelos Animais de Doenças , Withania/química
20.
Genome Biol ; 25(1): 45, 2024 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-38326875

RESUMO

BACKGROUND: Glioblastoma (GBM) brain tumors lacking IDH1 mutations (IDHwt) have the worst prognosis of all brain neoplasms. Patients receive surgery and chemoradiotherapy but tumors almost always fatally recur. RESULTS: Using RNA sequencing data from 107 pairs of pre- and post-standard treatment locally recurrent IDHwt GBM tumors, we identify two responder subtypes based on longitudinal changes in gene expression. In two thirds of patients, a specific subset of genes is upregulated from primary to recurrence (Up responders), and in one third, the same genes are downregulated (Down responders), specifically in neoplastic cells. Characterization of the responder subtypes indicates subtype-specific adaptive treatment resistance mechanisms that are associated with distinct changes in the tumor microenvironment. In Up responders, recurrent tumors are enriched in quiescent proneural GBM stem cells and differentiated neoplastic cells, with increased interaction with the surrounding normal brain and neurotransmitter signaling, whereas Down responders commonly undergo mesenchymal transition. ChIP-sequencing data from longitudinal GBM tumors suggests that the observed transcriptional reprogramming could be driven by Polycomb-based chromatin remodeling rather than DNA methylation. CONCLUSIONS: We show that the responder subtype is cancer-cell intrinsic, recapitulated in in vitro GBM cell models, and influenced by the presence of the tumor microenvironment. Stratifying GBM tumors by responder subtype may lead to more effective treatment.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Humanos , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Glioblastoma/patologia , Recidiva Local de Neoplasia/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Encéfalo/patologia , Metilação de DNA , Regulação Neoplásica da Expressão Gênica , Microambiente Tumoral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA