RESUMO
In the United States the prevalence of end-stage renal disease (ESRD) reached epidemic proportions in 2012 with over 600,000 patients being treated. The rates of ESRD among the elderly are disproportionally high. Consequently, as life expectancy increases and the baby-boom generation reaches retirement age, the already heavy burden imposed by ESRD on the US health care system is set to increase dramatically. ESRD represents the terminal stage of chronic kidney disease (CKD). A large body of evidence indicating that CKD is driven by renal tissue hypoxia has led to the development of therapeutic strategies that increase kidney oxygenation and the contention that chronic hypoxia is the final common pathway to end-stage renal failure. Numerous studies have demonstrated that one of the most potent means by which hypoxic conditions within the kidney produce CKD is by inducing a sustained inflammatory attack by infiltrating leukocytes. Indispensable to this attack is the acquisition by leukocytes of an adhesive phenotype. It was thought that this process resulted exclusively from leukocytes responding to cytokines released from ischemic renal endothelium. However, recently it has been demonstrated that leukocytes also become activated independent of the hypoxic response of endothelial cells. It was found that this endothelium-independent mechanism involves leukocytes directly sensing hypoxia and responding by transcriptional induction of the genes that encode the ß2-integrin family of adhesion molecules. This induction likely maintains the long-term inflammation by which hypoxia drives the pathogenesis of CKD. Consequently, targeting these transcriptional mechanisms would appear to represent a promising new therapeutic strategy.
Assuntos
Hipóxia , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/patologia , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/patologia , Adulto , Idoso , Anemia/complicações , Animais , Aterosclerose/complicações , Adesão Celular , Humanos , Hipercolesterolemia/complicações , Hiperglicemia/complicações , Hipertensão/complicações , Inflamação , Cadeias beta de Integrinas/metabolismo , Antígenos Comuns de Leucócito/metabolismo , Leucócitos/citologia , Leucossialina/metabolismo , Pessoa de Meia-Idade , Fenótipo , Síndromes da Apneia do Sono/complicações , Fumar , Transcrição Gênica , Ativação TranscricionalRESUMO
RhoH is a member of the Rho family of small GTP-binding proteins that lacks GTPase activity. Since RhoH is constantly bound by GTP, it is thought to be constitutively active and controlled predominantly by changes in quantitative expression. RhoH is produced specifically in haematopoietic cells and aberrant expression has been linked to various forms of leukaemia. Transcription of the RHOH gene is the first level at which the quantitative levels of the RhoH protein are regulated. Previous studies have demonstrated that RHOH gene transcription is initiated by three distinct promoter regions designated P1, P2 and P3 that define the 5' end of exons 1, 2 and 4 respectively. In the present study we report that the P3 promoter is largely responsible for RHOH gene transcription in the B-lymphocytic cell line Raji. The P3 promoter contains a minimal promoter region and a repressor region extending from -236 to +67 and +68 to +245 respectively, relative to the 5' end of exon 4. Chromatin immunoprecipitation demonstrated that two AP1 (activator protein 1) sites in the minimal promoter region bind JunD. When JUND is overexpressed, the endogenous RHOH gene is repressed; however, when JUND is inhibited, expression of endogenous RHOH is induced both in the Raji cell line and AML (acute myeloid leukaemia) cells. In the HCL (hairy cell leukaemia) cell line JOK-1, induction of RHOH increases expression of the α isoform of protein kinase C. This downstream target of RHOH is also induced in AML cells by JUND inhibition. Collectively, these data indicate that JunD is an inhibitor of RHOH gene expression.
Assuntos
Proteínas Proto-Oncogênicas c-jun/metabolismo , Fatores de Transcrição/genética , Proteínas rho de Ligação ao GTP/genética , Linfócitos B/metabolismo , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Regulação da Expressão Gênica , Células HeLa , Humanos , Leucemia Mieloide Aguda/genética , Regiões Promotoras Genéticas , RNA Interferente Pequeno/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Transfecção , Proteínas rho de Ligação ao GTP/antagonistas & inibidoresRESUMO
We analyzed molecular data on 2,579 tumors from The Cancer Genome Atlas (TCGA) of four gynecological types plus breast. Our aims were to identify shared and unique molecular features, clinically significant subtypes, and potential therapeutic targets. We found 61 somatic copy-number alterations (SCNAs) and 46 significantly mutated genes (SMGs). Eleven SCNAs and 11 SMGs had not been identified in previous TCGA studies of the individual tumor types. We found functionally significant estrogen receptor-regulated long non-coding RNAs (lncRNAs) and gene/lncRNA interaction networks. Pathway analysis identified subtypes with high leukocyte infiltration, raising potential implications for immunotherapy. Using 16 key molecular features, we identified five prognostic subtypes and developed a decision tree that classified patients into the subtypes based on just six features that are assessable in clinical laboratories.
Assuntos
Neoplasias da Mama/genética , Variações do Número de Cópias de DNA , Redes Reguladoras de Genes , Neoplasias dos Genitais Femininos/genética , Mutação , Bases de Dados Genéticas , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Humanos , Especificidade de Órgãos , Prognóstico , RNA Longo não Codificante/genética , Receptores de Estrogênio/genéticaRESUMO
Molecular alterations involving the PI3K/AKT/mTOR pathway (including mutation, copy number, protein, or RNA) were examined across 11,219 human cancers representing 32 major types. Within specific mutated genes, frequency, mutation hotspot residues, in silico predictions, and functional assays were all informative in distinguishing the subset of genetic variants more likely to have functional relevance. Multiple oncogenic pathways including PI3K/AKT/mTOR converged on similar sets of downstream transcriptional targets. In addition to mutation, structural variations and partial copy losses involving PTEN and STK11 showed evidence for having functional relevance. A substantial fraction of cancers showed high mTOR pathway activity without an associated canonical genetic or genomic alteration, including cancers harboring IDH1 or VHL mutations, suggesting multiple mechanisms for pathway activation.
Assuntos
Neoplasias/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteogenômica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Bases de Dados Genéticas , Perfilação da Expressão Gênica , Humanos , Mutação , Neoplasias/metabolismo , Transdução de Sinais , Análise de SobrevidaRESUMO
On the basis of multidimensional and comprehensive molecular characterization (including DNA methalylation and copy number, RNA, and protein expression), we classified 894 renal cell carcinomas (RCCs) of various histologic types into nine major genomic subtypes. Site of origin within the nephron was one major determinant in the classification, reflecting differences among clear cell, chromophobe, and papillary RCC. Widespread molecular changes associated with TFE3 gene fusion or chromatin modifier genes were present within a specific subtype and spanned multiple subtypes. Differences in patient survival and in alteration of specific pathways (including hypoxia, metabolism, MAP kinase, NRF2-ARE, Hippo, immune checkpoint, and PI3K/AKT/mTOR) could further distinguish the subtypes. Immune checkpoint markers and molecular signatures of T cell infiltrates were both highest in the subtype associated with aggressive clear cell RCC. Differences between the genomic subtypes suggest that therapeutic strategies could be tailored to each RCC disease subset.
Assuntos
Carcinoma de Células Renais/patologia , Genômica , Neoplasias Renais/patologia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/mortalidade , Cromatina/metabolismo , Perfilação da Expressão Gênica , Humanos , Neoplasias Renais/genética , Neoplasias Renais/mortalidade , MicroRNAs/metabolismo , Mutação , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/metabolismo , Transdução de Sinais/genética , Taxa de Sobrevida , Serina-Treonina Quinases TOR/metabolismoRESUMO
Hairy cell leukemia (HCL) is characterized by underexpression of the intracellular signaling molecule RhoH. Reconstitution of RhoH expression limits HCL pathogenesis in a mouse model, indicating this could represent a new therapeutic strategy. However, while RhoH reconstitution is theoretically possible as a therapy, it is technically immensely challenging as an appropriately functional RhoH protein needs to be specifically targeted. Because of this problem, we sought to identify druggable proteins on the HCL surface that were dependent upon RhoH underexpression. One such protein was identified as CD38. Analysis of 51 HCL patients demonstrated that 18 were CD38-positive. Interrogation of the clinical record of 23 relapsed HCL patients demonstrated those that were CD38-positive had a mean time to salvage therapy 71 months shorter than patients who were CD38-negative. Knockout of the CD38 gene in HCL cells increased apoptosis, inhibited adherence to endothelial monolayers, and compromised ability to produce tumors in vivo. Furthermore, an anti-CD38 antibody proved effective against pre-existing HCL tumors. Taken together, our data indicate that CD38 expression in HCL drives poor prognosis by promoting survival and heterotypic adhesion. Our data also indicate that CD38-positive HCL patients might benefit from treatments based on CD38 targeting.
Assuntos
ADP-Ribosil Ciclase 1/fisiologia , Anticorpos Monoclonais Humanizados/uso terapêutico , Antígenos de Neoplasias/fisiologia , Imunoglobulina G/uso terapêutico , Leucemia de Células Pilosas/imunologia , Glicoproteínas de Membrana/fisiologia , Terapia de Alvo Molecular , ADP-Ribosil Ciclase 1/análise , ADP-Ribosil Ciclase 1/imunologia , Animais , Antígenos de Neoplasias/análise , Antígenos de Neoplasias/imunologia , Apoptose , Adesão Celular , Células Endoteliais/citologia , Feminino , Técnicas de Inativação de Genes , Humanos , Leucemia de Células Pilosas/mortalidade , Leucemia de Células Pilosas/terapia , Masculino , Glicoproteínas de Membrana/análise , Glicoproteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos Nus , Proteínas de Neoplasias/fisiologia , Transplante de Neoplasias , Prognóstico , Terapia de Salvação , Fatores de Transcrição/fisiologia , Transfecção , Proteínas rho de Ligação ao GTP/fisiologiaRESUMO
The cause of hairy cell leukemia (HCL) is unknown. Current treatments seem effective only for a limited period of time. In addition, a significant proportion of patients remain refractive to all treatment options. These considerations indicate the need to develop alternative therapeutic strategies for HCL. Here, we report that HCL is characterized by underexpression of RhoH. In vitro reconstitution of RhoH expression inhibits the aberrant adhesion and transendothelial migration that drives disease pathogenesis. In an in vivo model of HCL, RhoH reconstitution limits malignant progression and protects against mortality. These findings provide the proof of principle that RhoH reconstitution represents a potential new approach to the treatment of HCL.