RESUMO
Progesterone receptor (PR) expression is used as a biomarker of oestrogen receptor-α (ERα) function and breast cancer prognosis. Here we show that PR is not merely an ERα-induced gene target, but is also an ERα-associated protein that modulates its behaviour. In the presence of agonist ligands, PR associates with ERα to direct ERα chromatin binding events within breast cancer cells, resulting in a unique gene expression programme that is associated with good clinical outcome. Progesterone inhibited oestrogen-mediated growth of ERα(+) cell line xenografts and primary ERα(+) breast tumour explants, and had increased anti-proliferative effects when coupled with an ERα antagonist. Copy number loss of PGR, the gene coding for PR, is a common feature in ERα(+) breast cancers, explaining lower PR levels in a subset of cases. Our findings indicate that PR functions as a molecular rheostat to control ERα chromatin binding and transcriptional activity, which has important implications for prognosis and therapeutic interventions.
Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Receptor alfa de Estrogênio/metabolismo , Regulação Neoplásica da Expressão Gênica , Receptores de Progesterona/metabolismo , Animais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromatina/efeitos dos fármacos , Cromatina/genética , Cromatina/metabolismo , Variações do Número de Cópias de DNA/genética , Progressão da Doença , Receptor alfa de Estrogênio/antagonistas & inibidores , Estrogênios/metabolismo , Estrogênios/farmacologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Ligantes , Camundongos , Progesterona/metabolismo , Progesterona/farmacologia , Ligação Proteica/efeitos dos fármacos , Receptores de Progesterona/genética , Transcrição Gênica/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
At least half of the human genome is derived from repetitive elements, which are often lineage specific and silenced by a variety of genetic and epigenetic mechanisms. Using a transchromosomic mouse strain that transmits an almost complete single copy of human chromosome 21 via the female germline, we show that a heterologous regulatory environment can transcriptionally activate transposon-derived human regulatory regions. In the mouse nucleus, hundreds of locations on human chromosome 21 newly associate with activating histone modifications in both somatic and germline tissues, and influence the gene expression of nearby transcripts. These regions are enriched with primate and human lineage-specific transposable elements, and their activation corresponds to changes in DNA methylation at CpG dinucleotides. This study reveals the latent regulatory potential of the repetitive human genome and illustrates the species specificity of mechanisms that control it.
Assuntos
Cromossomos Humanos Par 21/genética , Elementos de DNA Transponíveis , Inativação Gênica , Ativação Transcricional , Animais , Cromossomos Humanos Par 21/metabolismo , Metilação de DNA , Feminino , Histonas/metabolismo , Humanos , Rim/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Especificidade de Órgãos , Ligação Proteica , Especificidade da Espécie , Testículo/metabolismo , Fatores de Transcrição/metabolismo , Iniciação da Transcrição GenéticaRESUMO
BACKGROUND: Activating transcription factor-2 (ATF2), a member of the leucine zipper family of DNA binding proteins, has been implicated as a tumour suppressor in breast cancer. However, its exact role in breast cancer endocrine resistance is still unclear. We have previously shown that silencing of ATF2 leads to a loss in the growth-inhibitory effects of tamoxifen in the oestrogen receptor (ER)-positive, tamoxifen-sensitive MCF7 cell line and highlighted that this multi-faceted transcription factor is key to the effects of tamoxifen in an endocrine sensitive model. In this work, we explored further the in vitro role of ATF2 in defining the resistance to endocrine treatment. MATERIALS AND METHODS: We knocked down ATF2 in TAMR, LCC2 and LCC9 tamoxifen-resistant breast cancer cell lines as well as the parental tamoxifen sensitive MCF7 cell line and investigated the effects on growth, colony formation and cell migration. We also performed a microarray gene expression profiling (Illumina Human HT12_v4) to explore alterations in gene expression between MCF7 and TAMRs after ATF2 silencing and confirmed gene expression changes by quantitative RT-PCR. RESULTS: By silencing ATF2, we observed a significant growth reduction of TAMR, LCC2 and LCC9 with no such effect observed with the parental MCF7 cells. ATF2 silencing was also associated with a significant inhibition of TAMR, LCC2 and LCC9 cell migration and colony formation. Interestingly, knockdown of ATF2 enhanced the levels of ER and ER-regulated genes, TFF1, GREB1, NCOA3 and PGR, in TAMR cells both at RNA and protein levels. Microarray gene expression identified a number of genes known to mediate tamoxifen resistance, to be differentially regulated by ATF2 in TAMR in relation to the parental MCF7 cells. Moreover, differential pathway analysis confirmed enhanced ER activity after ATF2 knockdown in TAMR cells. CONCLUSION: These data demonstrate that ATF2 silencing may overcome endocrine resistance and highlights further the dual role of this transcription factor that can mediate endocrine sensitivity and resistance by modulating ER expression and activity.
Assuntos
Fator 2 Ativador da Transcrição/metabolismo , Antineoplásicos Hormonais/farmacologia , Neoplasias da Mama/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica/genética , Fator 2 Ativador da Transcrição/genética , Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Movimento Celular/genética , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Células MCF-7 , Análise de Sequência com Séries de Oligonucleotídeos , Receptores de Estrogênio/análise , Receptores de Estrogênio/antagonistas & inibidores , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Tamoxifeno/farmacologia , Tamoxifeno/uso terapêuticoRESUMO
Cancers occurring at the gastroesophageal junction (GEJ) are classified as predominantly esophageal or gastric, which is often difficult to decipher. We hypothesized that the transcriptomic profile might reveal molecular subgroups which could help to define the tumor origin and behavior beyond anatomical location. The gene expression profiles of 107 treatment-naïve, intestinal type, gastroesophageal adenocarcinomas were assessed by the Illumina-HTv4.0 beadchip. Differential gene expression (limma), unsupervised subgroup assignment (mclust) and pathway analysis (gage) were undertaken in R statistical computing and results were related to demographic and clinical parameters. Unsupervised assignment of the gene expression profiles revealed three distinct molecular subgroups, which were not associated with anatomical location, tumor stage or grade (p > 0.05). Group 1 was enriched for pathways involved in cell turnover, Group 2 was enriched for metabolic processes and Group 3 for immune-response pathways. Patients in group 1 showed the worst overall survival (p = 0.019). Key genes for the three subtypes were confirmed by immunohistochemistry. The newly defined intrinsic subtypes were analyzed in four independent datasets of gastric and esophageal adenocarcinomas with transcriptomic data available (RNAseq data: OCCAMS cohort, n = 158; gene expression arrays: Belfast, n = 63; Singapore, n = 191; Asian Cancer Research Group, n = 300). The subgroups were represented in the independent cohorts and pooled analysis confirmed the prognostic effect of the new subtypes. In conclusion, adenocarcinomas at the GEJ comprise three distinct molecular phenotypes which do not reflect anatomical location but rather inform our understanding of the key pathways expressed.
Assuntos
Adenocarcinoma/genética , Adenocarcinoma/patologia , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Junção Esofagogástrica/patologia , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Transcriptoma/genética , Perfilação da Expressão Gênica/métodos , Humanos , Imuno-Histoquímica/métodos , Fenótipo , Prognóstico , Estudos ProspectivosRESUMO
BACKGROUND: Cancers result from the accumulation of somatic mutations, and their properties are thought to reflect the sum of these mutations. However, little is known about the effect of the order in which mutations are acquired. METHODS: We determined mutation order in patients with myeloproliferative neoplasms by genotyping hematopoietic colonies or by means of next-generation sequencing. Stem cells and progenitor cells were isolated to study the effect of mutation order on mature and immature hematopoietic cells. RESULTS: The age at which a patient presented with a myeloproliferative neoplasm, acquisition of JAK2 V617F homozygosity, and the balance of immature progenitors were all influenced by mutation order. As compared with patients in whom the TET2 mutation was acquired first (hereafter referred to as "TET2-first patients"), patients in whom the Janus kinase 2 (JAK2) mutation was acquired first ("JAK2-first patients") had a greater likelihood of presenting with polycythemia vera than with essential thrombocythemia, an increased risk of thrombosis, and an increased sensitivity of JAK2-mutant progenitors to ruxolitinib in vitro. Mutation order influenced the proliferative response to JAK2 V617F and the capacity of double-mutant hematopoietic cells and progenitor cells to generate colony-forming cells. Moreover, the hematopoietic stem-and-progenitor-cell compartment was dominated by TET2 single-mutant cells in TET2-first patients but by JAK2-TET2 double-mutant cells in JAK2-first patients. Prior mutation of TET2 altered the transcriptional consequences of JAK2 V617F in a cell-intrinsic manner and prevented JAK2 V617F from up-regulating genes associated with proliferation. CONCLUSIONS: The order in which JAK2 and TET2 mutations were acquired influenced clinical features, the response to targeted therapy, the biology of stem and progenitor cells, and clonal evolution in patients with myeloproliferative neoplasms. (Funded by Leukemia and Lymphoma Research and others.).
Assuntos
Proteínas de Ligação a DNA/genética , Células-Tronco Hematopoéticas/fisiologia , Janus Quinase 2/genética , Mutação , Transtornos Mieloproliferativos/genética , Proteínas Proto-Oncogênicas/genética , Idade de Início , Proliferação de Células/genética , Análise Mutacional de DNA , Dioxigenases , Expressão Gênica , Homozigoto , Humanos , Policitemia Vera/genética , Trombocitemia Essencial/genética , Trombose/genética , Transcrição Gênica , Regulação para CimaRESUMO
The downstream functions of the DNA binding tumor suppressor p53 vary depending on the cellular context, and persistent p53 activation has recently been implicated in tumor suppression and senescence. However, genome-wide information about p53-target gene regulation has been derived mostly from acute genotoxic conditions. Using ChIP-seq and expression data, we have found distinct p53 binding profiles between acutely activated (through DNA damage) and chronically activated (in senescent or pro-apoptotic conditions) p53. Compared to the classical 'acute' p53 binding profile, 'chronic' p53 peaks were closely associated with CpG-islands. Furthermore, the chronic CpG-island binding of p53 conferred distinct expression patterns between senescent and pro-apoptotic conditions. Using the p53 targets seen in the chronic conditions together with external high-throughput datasets, we have built p53 networks that revealed extensive self-regulatory 'p53 hubs' where p53 and many p53 targets can physically interact with each other. Integrating these results with public clinical datasets identified the cancer-associated lipogenic enzyme, SCD, which we found to be directly repressed by p53 through the CpG-island promoter, providing a mechanistic link between p53 and the 'lipogenic phenotype', a hallmark of cancer. Our data reveal distinct phenotype associations of chronic p53 targets that underlie specific gene regulatory mechanisms.
Assuntos
Metilação de DNA/genética , Proteínas de Ligação a DNA/genética , Mapas de Interação de Proteínas/genética , Proteína Supressora de Tumor p53/genética , Envelhecimento/genética , Apoptose/genética , Linhagem Celular , Ilhas de CpG/genética , Dano ao DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Genes Supressores de Tumor , Humanos , Fenótipo , Estearoil-CoA Dessaturase/genética , Estearoil-CoA Dessaturase/metabolismo , Proteína Supressora de Tumor p53/metabolismoRESUMO
Multipronged approach was used to synthesize a library of diverse C-8 cyclopentyl hypoxanthine analogs from a common intermediate III. Several potent and selective compounds were identified and evaluated for pharmacokinetic (PK) properties in Wistar rats. One of the compounds 14 with acceptable PK parameters was selected for testing in in vivo primary acute diuresis model. The compound demonstrated significant diuretic activity in this model.
Assuntos
Antagonistas do Receptor A1 de Adenosina/química , Antagonistas do Receptor A1 de Adenosina/farmacologia , Hipoxantinas/química , Hipoxantinas/farmacologia , Antagonistas do Receptor A1 de Adenosina/síntese química , Antagonistas do Receptor A1 de Adenosina/farmacocinética , Animais , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Cromatografia Líquida , Desenho de Fármacos , Células HEK293 , Humanos , Hipoxantinas/síntese química , Hipoxantinas/farmacocinética , Masculino , Espectrometria de Massas , Espectroscopia de Prótons por Ressonância Magnética , Ensaio Radioligante , Ratos , Ratos WistarRESUMO
Estrogen receptor (ESR1) drives growth in the majority of human breast cancers by binding to regulatory elements and inducing transcription events that promote tumor growth. Differences in enhancer occupancy by ESR1 contribute to the diverse expression profiles and clinical outcome observed in breast cancer patients. GATA3 is an ESR1-cooperating transcription factor mutated in breast tumors; however, its genomic properties are not fully defined. In order to investigate the composition of enhancers involved in estrogen-induced transcription and the potential role of GATA3, we performed extensive ChIP-sequencing in unstimulated breast cancer cells and following estrogen treatment. We find that GATA3 is pivotal in mediating enhancer accessibility at regulatory regions involved in ESR1-mediated transcription. GATA3 silencing resulted in a global redistribution of cofactors and active histone marks prior to estrogen stimulation. These global genomic changes altered the ESR1-binding profile that subsequently occurred following estrogen, with events exhibiting both loss and gain in binding affinity, implying a GATA3-mediated redistribution of ESR1 binding. The GATA3-mediated redistributed ESR1 profile correlated with changes in gene expression, suggestive of its functionality. Chromatin loops at the TFF locus involving ESR1-bound enhancers occurred independently of ESR1 when GATA3 was silenced, indicating that GATA3, when present on the chromatin, may serve as a licensing factor for estrogen-ESR1-mediated interactions between cis-regulatory elements. Together, these experiments suggest that GATA3 directly impacts ESR1 enhancer accessibility, and may potentially explain the contribution of mutant-GATA3 in the heterogeneity of ESR1+ breast cancer.
Assuntos
Elementos Facilitadores Genéticos , Receptor alfa de Estrogênio/metabolismo , Fator de Transcrição GATA3/metabolismo , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Transcrição Gênica , Linhagem Celular Tumoral , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina , Estrogênios/metabolismo , Fator de Transcrição GATA3/genética , Histonas/metabolismo , Humanos , Ligação Proteica , RNA Interferente Pequeno , Fator Trefoil-1 , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismoRESUMO
In prostate cancer (PC), the androgen receptor (AR) is a key transcription factor at all disease stages, including the advanced stage of castrate-resistant prostate cancer (CRPC). In the present study, we show that GABPα, an ETS factor that is up-regulated in PC, is an AR-interacting transcription factor. Expression of GABPα enables PC cell lines to acquire some of the molecular and cellular characteristics of CRPC tissues as well as more aggressive growth phenotypes. GABPα has a transcriptional role that dissects the overlapping cistromes of the two most common ETS gene fusions in PC: overlapping significantly with ETV1 but not with ERG target genes. GABPα bound predominantly to gene promoters, regulated the expression of one-third of AR target genes and modulated sensitivity to AR antagonists in hormone responsive and castrate resistant PC models. This study supports a critical role for GABPα in CRPC and reveals potential targets for therapeutic intervention.
Assuntos
Fator de Transcrição de Proteínas de Ligação GA/metabolismo , Neoplasias da Próstata/genética , Receptores Androgênicos/metabolismo , Antagonistas de Receptores de Andrógenos/farmacologia , Animais , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Fenótipo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Transdução de Sinais , Transcrição GênicaRESUMO
The complexity and incompleteness of metabolic-regulatory networks make it challenging to predict metabolomes from other omics. Using machine learning, we predicted metabolomic variation across ~1000 different cancer cell lines from matched oct-omics data: genomics, epigenomics (histone post-translational modifications (PTMs) and DNA-methylation), transcriptomics, RNA splicing, miRNA-omics, proteomics, and phosphoproteomics. Overall, the metabolome is tightly associated with the transcriptome, while miRNAs, phosphoproteins and histone PTMs have the highest metabolic information per feature. Metabolites in peripheral metabolism are predictable via levels of corresponding enzymes, while those in central metabolism require combinatorial predictors in signaling and redox pathways, and may not reflect corresponding pathway expression. We reconstruct multiomic interaction subnetworks for highly predictable metabolites, and YAP1 signaling emerged as a top global predictor across 4 omic layers. We prioritize predictive multiomic features for single-cell and spatial metabolomics assays. Top predictors were enriched for synthetic-lethal interactions and synergistic combination therapies that target compensatory metabolic modulators.
RESUMO
Islet transplantation for treatment of diabetes is limited by availability of donor islets and requirements for immunosuppression. Stem cell-derived islets might circumvent these issues. SC-islets effectively control glucose metabolism post transplantation, but do not yet achieve full function in vitro with current published differentiation protocols. We aimed to identify markers of mature subpopulations of SC-ß cells by studying transcriptional changes associated with in vivo maturation of SC-ß cells using RNA-seq and co-expression network analysis. The ß cell-specific hormone islet amyloid polypeptide (IAPP) emerged as the top candidate to be such a marker. IAPP+ cells had more mature ß cell gene expression and higher cellular insulin content than IAPP- cells in vitro. IAPP+ INS+ cells were more stable in long-term culture than IAPP- INS+ cells and retained insulin expression after transplantation into mice. Finally, we conducted a small molecule screen to identify compounds that enhance IAPP expression. Aconitine up-regulated IAPP and could help to optimize differentiation protocols.
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A series of novel heterocyclic carboxylic acid based protein tyrosine phosphatase 1B (PTP1B) inhibitors with hydrophobic tail have been synthesized and characterized. Structure-activity relationship (SAR) optimization resulted in identification of several potent, selective (over the highly homologous T-cell protein tyrosine phosphatase, TCPTP) and metabolically stable PTP1B inhibitors. Compounds 7a, 19a and 19c showed favorable cell permeability and pharmacokinetic properties in mouse with moderate to very good oral (% F=13-70) bio-availability.
Assuntos
Ácidos Carboxílicos/síntese química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Compostos Heterocíclicos/síntese química , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Administração Oral , Animais , Ácidos Carboxílicos/química , Ácidos Carboxílicos/farmacologia , Ativação Enzimática/efeitos dos fármacos , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Interações Hidrofóbicas e Hidrofílicas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Relação Estrutura-AtividadeRESUMO
Cytosine hydroxymethylation (5hmC) in mammalian DNA is the product of oxidation of methylated cytosines (5mC) by Ten-Eleven-Translocation (TET) enzymes. While it has been shown that the TETs influence 5mC metabolism, pluripotency and differentiation during early embryonic development, the functional relationship between gene expression and 5hmC in adult (somatic) stem cell differentiation is still unknown. Here we report that 5hmC levels undergo highly dynamic changes during adult stem cell differentiation from intestinal progenitors to differentiated intestinal epithelium. We profiled 5hmC and gene activity in purified mouse intestinal progenitors and differentiated progeny to identify 43425 differentially hydroxymethylated regions and 5325 differentially expressed genes. These differentially marked regions showed both losses and gains of 5hmC after differentiation, despite lower global levels of 5hmC in progenitor cells. In progenitors, 5hmC did not correlate with gene transcript levels, however, upon differentiation the global increase in 5hmC content showed an overall positive correlation with gene expression level as well as prominent associations with histone modifications that typify active genes and enhancer elements. Our data support a gene regulatory role for 5hmC that is predominant over its role in controlling DNA methylation states.
Assuntos
5-Metilcitosina/análogos & derivados , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Intestinos/citologia , 5-Metilcitosina/farmacologia , Células-Tronco Adultas/citologia , Células-Tronco Adultas/efeitos dos fármacos , Animais , CamundongosRESUMO
Elucidation of mechanisms underlying the increased androgen receptor (AR) activity and subsequent development of aggressive prostate cancer (PrCa) is pivotal in developing new therapies. Using a systems biology approach, we interrogated the AR-regulated proteome and identified PDZ binding kinase (PBK) as a novel AR-regulated protein that regulates full-length AR and AR variants (ARVs) activity in PrCa. PBK overexpression in aggressive PrCa is associated with early biochemical relapse and poor clinical outcome. In addition to its carboxy terminus ligand-binding domain, PBK directly interacts with the amino terminus transactivation domain of the AR to stabilise it thereby leading to increased AR protein expression observed in PrCa. Transcriptome sequencing revealed that PBK is a mediator of global AR signalling with key roles in regulating tumour invasion and metastasis. PBK inhibition decreased growth of PrCa cell lines and clinical specimen cultured ex vivo. We uncovered a novel interplay between AR and PBK that results in increased AR and ARVs expression that executes AR-mediated growth and progression of PrCa, with implications for the development of PBK inhibitors for the treatment of aggressive PrCa.
Assuntos
Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/metabolismo , Transdução de Sinais , Linhagem Celular Tumoral , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Humanos , Masculino , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Invasividade Neoplásica , Metástase Neoplásica , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Inibidores de Proteínas Quinases/farmacologia , Receptores Androgênicos/genéticaRESUMO
Mucopolysaccharidoses (MPS) type III also termed as Sanfillipo syndrome, involves defect in enzymes required for degradation of heparan sulphate. We report a clinical case of MPS-III later followed by genetic investigation for MPS-III genes SGSH, NAGLU, HGSNAT and GNS. It allowed us to identify a novel and likely pathogenic variant p. G205R in SGSH. Protein based Inslico prediction and protein modelling suggests aberration of helical structure of SGSH protein and reduced binding affinity for its substrate.
RESUMO
OBJECTIVE: Dedifferentiation could explain reduced functional pancreatic ß-cell mass in type 2 diabetes (T2D). METHODS: Here we model human ß-cell dedifferentiation using growth factor stimulation in the human ß-cell line, EndoC-ßH1, and human pancreatic islets. RESULTS: Fibroblast growth factor 2 (FGF2) treatment reduced expression of ß-cell markers, (INS, MAFB, SLC2A2, SLC30A8, and GCK) and activated ectopic expression of MYC, HES1, SOX9, and NEUROG3. FGF2-induced dedifferentiation was time- and dose-dependent and reversible upon wash-out. Furthermore, FGF2 treatment induced expression of TNFRSF11B, a decoy receptor for RANKL and protected ß-cells against RANKL signaling. Finally, analyses of transcriptomic data revealed increased FGF2 expression in ductal, endothelial, and stellate cells in pancreas from T2D patients, whereas FGFR1, SOX,9 and HES1 expression increased in islets from T2D patients. CONCLUSIONS: We thus developed an FGF2-induced model of human ß-cell dedifferentiation, identified new markers of dedifferentiation, and found evidence for increased pancreatic FGF2, FGFR1, and ß-cell dedifferentiation in T2D.
Assuntos
Desdiferenciação Celular , Diabetes Mellitus Tipo 2/metabolismo , Células Secretoras de Insulina/citologia , Células Cultivadas , Diabetes Mellitus Tipo 2/patologia , Fator 2 de Crescimento de Fibroblastos/farmacologia , Humanos , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Osteoprotegerina/genética , Osteoprotegerina/metabolismo , Ligante RANK/metabolismo , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Fatores de Transcrição HES-1/genética , Fatores de Transcrição HES-1/metabolismoRESUMO
BACKGROUND: Trypanosomes are coated with a variant surface glycoprotein (VSG) that is so densely packed that it physically protects underlying proteins from effectors of the host immune system. Periodically cells expressing a distinct VSG arise in a population and thereby evade immunity. The main structural feature of VSGs are two long alpha-helices that form a coiled coil, and sets of relatively unstructured loops that are distal to the plasma membrane and contain most or all of the protective epitopes. The primary structure of different VSGs is highly variable, typically displaying only ~20% identity with each other. The genome has nearly 2000 VSG genes, which are located in subtelomeres. Only one VSG gene is expressed at a time, and switching between VSGs primarily involves gene conversion events. The archive of silent VSGs undergoes diversifying evolution rapidly, also involving gene conversion. The VSG family is a paradigm for alpha helical coiled coil structures, epitope variation and GPI-anchor signals. At the DNA level, the genes are a paradigm for diversifying evolutionary processes and for the role of subtelomeres and recombination mechanisms in generation of diversity in multigene families. To enable ready availability of VSG sequences for addressing these general questions, and trypanosome-specific questions, we have created VSGdb, a database of all known sequences. DESCRIPTION: VSGdb contains fully annotated VSG sequences from the genome sequencing project, with which it shares all identifiers and annotation, and other available sequences. The database can be queried in various ways. Sequence retrieval, in FASTA format, can deliver protein or nucleotide sequence filtered by chromosomes or contigs, gene type (functional, pseudogene, etc.), domain and domain sequence family. Retrieved sequences can be stored as a temporary database for BLAST querying, reports from which include hyperlinks to the genome project database (GeneDB) CDS Info and to individual VSGdb pages for each VSG, containing annotation and sequence data. Queries (text search) with specific annotation terms yield a list of relevant VSGs, displayed as identifiers leading again to individual VSG web pages. CONCLUSION: VSGdb http://www.vsgdb.org/ is a freely available, web-based platform enabling easy retrieval, via various filters, of sets of VSGs that will enable detailed analysis of a number of general and trypanosome-specific questions, regarding protein structure potential, epitope variability, sequence evolution and recombination events.
Assuntos
Bases de Dados Factuais , Glicoproteínas Variantes de Superfície de Trypanosoma/genética , Sequência de Bases/genética , Dados de Sequência Molecular , Estrutura Terciária de Proteína/genética , Análise de Sequência de DNA/métodosRESUMO
Our initial structure-activity relationship studies on 7-methoxy-4-morpholino-benzothiazole derivatives featured by aryloxy-2-methylpropanamide moieties at the 2-position led to identification of compound 25 as a potent and selective A2A adenosine receptor (A2AAdoR) antagonist with reasonable ADME and pharmacokinetic properties. However, poor intrinsic solubility and low to moderate oral bioavailability made this series unsuitable for further development. Further optimization using structure-based drug design approach resulted in discovery of potent and selective adenosine A2A receptor antagonists bearing substituted 1-methylcyclohexyl-carboxamide groups at position 2 of the benzothiazole scaffold and endowed with better solubility and oral bioavailability. Compounds 41 and 49 demonstrated a number of positive attributes with respect to in vitro ADME properties. Both compounds displayed good pharmacokinetic properties with 63% and 61% oral bioavailability, respectively, in rat. Further, compound 49 displayed oral efficacy in 6-OHDA lesioned rat model of Parkinson diseases.
Assuntos
Antagonistas do Receptor A2 de Adenosina/farmacologia , Benzotiazóis/farmacologia , Cicloexanóis/farmacologia , Receptor A2A de Adenosina/metabolismo , Antagonistas do Receptor A2 de Adenosina/síntese química , Antagonistas do Receptor A2 de Adenosina/farmacocinética , Administração Oral , Animais , Antiparkinsonianos/síntese química , Antiparkinsonianos/farmacocinética , Antiparkinsonianos/farmacologia , Benzotiazóis/síntese química , Benzotiazóis/farmacocinética , Cicloexanóis/síntese química , Cicloexanóis/farmacocinética , Desenho de Fármacos , Células HEK293 , Humanos , Levodopa/farmacologia , Masculino , Microssomos Hepáticos/metabolismo , Simulação de Acoplamento Molecular , Ratos Wistar , Relação Estrutura-AtividadeRESUMO
Adenosine induces bronchial hyperresponsiveness and inflammation in asthmatics through activation of A2B adenosine receptor (A2BAdoR). Selective antagonists have been shown to attenuate airway reactivity and improve inflammatory conditions in pre-clinical studies. Hence, the identification of novel, potent and selective A2BAdoR antagonist may be beneficial for the potential treatment of asthma and Chronic Obstructive Pulmonary Disease (COPD). Towards this effort, we explored several prop-2-ynylated C8-aryl or heteroaryl substitutions on xanthine chemotype and found that 1-prop-2-ynyl-1H-pyrazol-4-yl moiety was better tolerated at the C8 position. Compound 59, exhibited binding affinity (Ki) of 62 nM but was non-selective for A2BAdoR over other AdoRs. Incorporation of substituted phenyl on the terminal acetylene increased the binding affinity (Ki) significantly to <10 nM. Various substitutions on terminal phenyl group and different alkyl substitutions on N-1 and N-3 were explored to improve the potency, selectivity for A2BAdoR and the solubility. In general, compounds with meta-substituted phenyl provided better selectivity for A2BAdoR compared to that of para-substituted analogs. Substitutions such as basic amines like pyrrolidine, piperidine, piperazine or cycloalkyls with polar group were tried on terminal acetylene, keeping in mind the poor solubility of xanthine analogs in general. However, these substitutions led to a decrease in affinity compared to compound 59. Subsequent SAR optimization resulted in identification of compound 46 with high human A2BAdoR affinity (Ki = 13 nM), selectivity against other AdoR subtypes and with good pharmacokinetic properties. It was found to be a potent functional A2BAdoR antagonist with a Ki of 8 nM in cAMP assay in hA2B-HEK293 cells and an IC50 of 107 nM in IL6 assay in NIH-3T3 cells. Docking study was performed to rationalize the observed affinity data. Structure-activity relationship (SAR) studies also led to identification of compound 36 as a potent A2BAdoR antagonist with Ki of 1.8 nM in cAMP assay and good aqueous solubility of 529 µM at neutral pH. Compound 46 was further tested for in vivo efficacy and found to be efficacious in ovalbumin-induced allergic asthma model in mice.