RESUMO
IMPORTANCE: Candida infections are often fatal in immuno-compromised individuals, resulting in many thousands of deaths per year. Caspofungin has proven to be an excellent anti-Candida drug and is now the frontline treatment for infections. However, as expected, the number of resistant cases is increasing; therefore, new treatment modalities are needed. We are determining metabolic pathways leading to decreased drug susceptibility in order to identify mechanisms facilitating evolution of clinical resistance. This study expands the understanding of genes that modulate drug susceptibility and reveals new targets for the development of novel antifungal drugs.
Assuntos
Candida albicans , beta-Glucanas , Humanos , Caspofungina/farmacologia , Candida albicans/genética , Candida albicans/metabolismo , Equinocandinas/farmacologia , beta-Glucanas/metabolismo , Cromossomos Humanos Par 5/metabolismo , Epitopos , Antifúngicos/uso terapêutico , Parede Celular/metabolismoRESUMO
Inflammation is associated with the pathogenesis of myelodysplastic syndromes (MDS) and emerging evidence suggests that MDS hematopoietic stem and progenitor cells (HSPC) exhibit an altered response to inflammation. Deletion of chromosome 5 (del(5q)) is the most common chromosomal abnormality in MDS. Although this MDS subtype contains several haploinsufficient genes that impact innate immune signaling, the effects of inflammation on del(5q) MDS HSPC remains undefined. Utilizing a model of del(5q)-like MDS, inhibiting the IRAK1/4-TRAF6 axis improved cytopenias, suggesting that activation of innate immune pathways contributes to certain clinical features underlying the pathogenesis of low-risk MDS. However, low-grade inflammation in the del(5q)-like MDS model did not contribute to more severe disease but instead impaired the del(5q)-like HSPC as indicated by their diminished numbers, premature attrition and increased p53 expression. Del(5q)-like HSPC exposed to inflammation became less quiescent, but without affecting cell viability. Unexpectedly, the reduced cellular quiescence of del(5q) HSPC exposed to inflammation was restored by p53 deletion. These findings uncovered that inflammation confers a competitive advantage of functionally defective del(5q) HSPC upon loss of p53. Since TP53 mutations are enriched in del(5q) AML following an MDS diagnosis, increased p53 activation in del(5q) MDS HSPC due to inflammation may create a selective pressure for genetic inactivation of p53 or expansion of a pre-existing TP53-mutant clone.
Assuntos
Síndromes Mielodisplásicas , Proteína Supressora de Tumor p53 , Humanos , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Deleção Cromossômica , Síndromes Mielodisplásicas/patologia , Células-Tronco Hematopoéticas/metabolismo , Transdução de Sinais , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 5/metabolismoRESUMO
Previously, we reported a series of families presenting with trichodiscomas, inherited in an autosomal dominant pattern. The phenotype was named familial multiple discoid fibromas (FMDF). The genetic cause of FMDF remained unknown so far. Trichodiscomas are skin lesions previously reported to be part of the same spectrum as the fibrofolliculoma observed in Birt-Hogg-Dubé syndrome (BHD), an inherited disease caused by pathogenic variants in the FLCN gene. Given the clinical and histological differences with BHD and the exclusion of linkage with the FLCN locus, the phenotype was concluded to be distinct from BHD. We performed extensive clinical evaluations and genetic testing in ten families with FMDF. We identified a FNIP1 frameshift variant in nine families and genealogical studies showed common ancestry for eight families. Using whole exome sequencing, we identified six additional rare variants in the haplotype surrounding FNIP1, including a missense variant in the PDGFRB gene that was found to be present in all tested patients with FMDF. Genome-wide linkage analysis showed that the locus on chromosome 5 including FNIP1 was the only region reaching the maximal possible LOD score. We concluded that FMDF is linked to a haplotype on chromosome 5. Additional evaluations in families with FMDF are required to unravel the exact genetic cause underlying the phenotype. When evaluating patients with multiple trichodisomas without a pathogenic variant in the FLCN gene, further genetic testing is warranted and can include analysis of the haplotype on chromosome 5.
Assuntos
Síndrome de Birt-Hogg-Dubé , Fibroma , Neoplasias Renais , Humanos , Neoplasias Renais/genética , Cromossomos Humanos Par 5/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Proto-Oncogênicas/genética , Síndrome de Birt-Hogg-Dubé/genética , Síndrome de Birt-Hogg-Dubé/patologia , Fibroma/genética , Proteínas de Transporte/genéticaRESUMO
Merkel cell carcinoma (MCC) is an uncommon, lethal cancer of the skin caused by either Merkel cell polyomavirus (MCPyV) or UV-linked mutations. MCPyV is found integrated into MCC tumor genomes, accompanied by truncation mutations that render the MCPyV large T antigen replication incompetent. We used the open access HPV Detector/Cancer-virus Detector tool to determine MCPyV integration sites in whole-exome sequencing data from five MCC cases, thereby adding to the limited published MCPyV integration site junction data. We also systematically reviewed published data on integration for MCPyV in the human genome, presenting a collation of 123 MCC cases and their linked chromosomal sites. We confirmed that there were no highly recurrent specific sites of integration. We found that chromosome 5 was most frequently involved in MCPyV integration and that integration sites were significantly enriched for genes with binding sites for oncogenic transcription factors such as LEF1 and ZEB1, suggesting the possibility of increased open chromatin in these gene sets. Additionally, in one case we found, for the first time, integration involving the tumor suppressor gene KMT2D, adding to previous reports of rare MCPyV integration into host tumor suppressor genes in MCC.
Assuntos
Carcinoma de Célula de Merkel/metabolismo , Proteínas de Ligação a DNA/metabolismo , Poliomavírus das Células de Merkel/fisiologia , Proteínas de Neoplasias/metabolismo , Infecções por Polyomavirus/metabolismo , Infecções Tumorais por Vírus/metabolismo , Carcinoma de Célula de Merkel/genética , Carcinoma de Célula de Merkel/virologia , Linhagem Celular Tumoral , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 5/metabolismo , Cromossomos Humanos Par 5/virologia , Proteínas de Ligação a DNA/genética , Genes Supressores de Tumor , Humanos , Poliomavírus das Células de Merkel/genética , Proteínas de Neoplasias/genética , Infecções por Polyomavirus/genética , Infecções por Polyomavirus/virologia , Infecções Tumorais por Vírus/genética , Infecções Tumorais por Vírus/virologia , Integração Viral , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismoRESUMO
The platelet-derived growth factor receptor ß (PDGFRB) gene translocations lead to a spectrum of chronic myeloid neoplasms, frequently associated with eosinophilia. Clinical heterogeneity is associated with a molecular one. Here, we report a novel case of a patient harboring a t(5;8)(q33;p22) translocation, resulting in the PCM1/PDGFRB fusion. Conventional cytogenetics and RNA sequencing were performed to identify the chromosomes and the genes involved in the rearrangement, respectively. This study shows that the combination of different strategies is pivotal to fine-tune the diagnosis and the clinical management of the patient. After 1 year of treatment with imatinib, the patient achieves hematological and molecular remission. We present an attractive strategy to identify novel and/or cryptic fusions, which will be relevant for clinicians dealing with the diagnosis of the patients with myelodysplastic syndrome/myeloproliferative diseases with atypical manifestations.
Assuntos
Autoantígenos , Proteínas de Ciclo Celular , Mesilato de Imatinib/administração & dosagem , Leucemia Mielogênica Crônica BCR-ABL Positiva , Proteínas de Fusão Oncogênica , Receptor beta de Fator de Crescimento Derivado de Plaquetas , Análise de Sequência de RNA , Autoantígenos/genética , Autoantígenos/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 5/metabolismo , Cromossomos Humanos Par 8/genética , Cromossomos Humanos Par 8/metabolismo , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Masculino , Pessoa de Meia-Idade , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Translocação GenéticaRESUMO
RPS14, CSNK1A1, and miR-145 are universally co-deleted in the 5q- syndrome, but mouse models of each gene deficiency recapitulate only a subset of the composite clinical features. We analyzed the combinatorial effect of haploinsufficiency for Rps14, Csnk1a1, and miRNA-145, using mice with genetically engineered, conditional heterozygous inactivation of Rps14 and Csnk1a1 and stable knockdown of miR-145/miR-146a. Combined Rps14/Csnk1a1/miR-145/146a deficiency recapitulated the cardinal features of the 5q- syndrome, including (1) more severe anemia with faster kinetics than Rps14 haploinsufficiency alone and (2) pathognomonic megakaryocyte morphology. Macrophages, regulatory cells of erythropoiesis and the innate immune response, were significantly increased in Rps14/Csnk1a1/miR-145/146a deficient mice as well as in 5q- syndrome patient bone marrows and showed activation of the innate immune response, reflected by increased expression of S100A8, and decreased phagocytic function. We demonstrate that Rps14/Csnk1a1/miR-145 and miR-146a deficient macrophages alter the microenvironment and induce S100A8 expression in the mesenchymal stem cell niche. The increased S100A8 expression in the mesenchymal niche was confirmed in 5q- syndrome patients. These data indicate that intrinsic defects of the 5q- syndrome hematopoietic stem cell directly alter the surrounding microenvironment, which in turn affects hematopoiesis as an extrinsic mechanism.
Assuntos
Anemia Macrocítica/imunologia , Anemia/imunologia , Caseína Quinase Ialfa/fisiologia , Haploinsuficiência , MicroRNAs/fisiologia , Proteínas Ribossômicas/fisiologia , Microambiente Tumoral/imunologia , Anemia/metabolismo , Anemia/patologia , Anemia Macrocítica/metabolismo , Anemia Macrocítica/patologia , Animais , Medula Óssea/imunologia , Medula Óssea/metabolismo , Medula Óssea/patologia , Calgranulina A/genética , Calgranulina A/metabolismo , Deleção Cromossômica , Cromossomos Humanos Par 5/imunologia , Cromossomos Humanos Par 5/metabolismo , Eritropoese , Feminino , Células-Tronco Hematopoéticas/imunologia , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/patologia , Humanos , Megacariócitos/imunologia , Megacariócitos/metabolismo , Megacariócitos/patologia , Camundongos , Camundongos Knockout , Fenótipo , Células Tumorais CultivadasAssuntos
Medula Óssea , Deleção Cromossômica , Cromossomos Humanos Par 5 , Janus Quinase 2 , Megacariócitos , Síndromes Mielodisplásicas , Idoso , Medula Óssea/metabolismo , Medula Óssea/patologia , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 5/metabolismo , Feminino , Humanos , Janus Quinase 2/genética , Janus Quinase 2/metabolismo , Megacariócitos/metabolismo , Megacariócitos/patologia , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/metabolismo , Síndromes Mielodisplásicas/patologiaRESUMO
Therapy-related acute lymphoblastic leukemia remains poorly defined due to a lack of large data sets recognizing the defining characteristics of this entity. We reviewed all consecutive cases of adult acute lymphoblastic leukemia treated at our institution between 2000 and 2017 and identified therapy-related cases - defined as acute lymphoblastic leukemia preceded by prior exposure to cytotoxic chemotherapy and/or radiation. Of 1022 patients with acute lymphoblastic leukemia, 93 (9.1%) were classified as therapy-related. The median latency for therapy-related acute lymphoblastic leukemia onset was 6.8 years from original diagnosis, and this was shorter for patients carrying the MLL gene rearrangement compared to those with other cytogenetics. When compared to de novo acute lymphoblastic leukemia, therapy-related patients were older (P<0.01), more often female (P<0.01), and had more MLL gene rearrangement (P<0.0001) and chromosomes 5/7 aberrations (P=0.02). Although therapy-related acute lymphoblastic leukemia was associated with inferior 2-year overall survival compared to de novo cases (46.0% vs 68.1%, P=0.001), prior exposure to cytotoxic therapy (therapy-related) did not independently impact survival in multivariate analysis (HR=1.32; 95% CI: 0.97-1.80, P=0.08). There was no survival difference (2-year = 53.4% vs 58.9%, P=0.68) between the two groups in patients who received allogenic hematopoietic cell transplantation. In conclusion, therapy-related acute lymphoblastic leukemia represents a significant proportion of adult acute lymphoblastic leukemia diagnoses, and a subset of cases carry clinical and cytogenetic abnormalities similar to therapy-related myeloid neoplasms. Although survival of therapy-related acute lymphoblastic leukemia was inferior to de novo cases, allogeneic hematopoietic cell transplantation outcomes were comparable for the two entities.
Assuntos
Aberrações Cromossômicas , Rearranjo Gênico , Histona-Lisina N-Metiltransferase , Proteína de Leucina Linfoide-Mieloide , Segunda Neoplasia Primária , Leucemia-Linfoma Linfoblástico de Células Precursoras , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 5/metabolismo , Cromossomos Humanos Par 7/genética , Cromossomos Humanos Par 7/metabolismo , Intervalo Livre de Doença , Feminino , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Proteína de Leucina Linfoide-Mieloide/genética , Proteína de Leucina Linfoide-Mieloide/metabolismo , Segunda Neoplasia Primária/genética , Segunda Neoplasia Primária/metabolismo , Segunda Neoplasia Primária/mortalidade , Segunda Neoplasia Primária/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Fatores Sexuais , Taxa de SobrevidaRESUMO
Ribosomal protein (RP) expression in higher eukaryotes is regulated translationally through the 5'TOP sequence. This mechanism evolved to more rapidly produce RPs on demand in different tissues. Here we show that 40S ribosomes, in a complex with the mRNA binding protein LARP1, selectively stabilize 5'TOP mRNAs, with disruption of this complex leading to induction of the impaired ribosome biogenesis checkpoint (IRBC) and p53 stabilization. The importance of this mechanism is underscored in 5q− syndrome, a macrocytic anemia caused by a large monoallelic deletion, which we found to also encompass the LARP1 gene. Critically, depletion of LARP1 alone in human adult CD34+ bone marrow precursor cells leads to a reduction in 5'TOP mRNAs and the induction of p53. These studies identify a 40S ribosome function independent of those in translation that, with LARP1, mediates the autogenous control of 5'TOP mRNA stability, whose disruption is implicated in the pathophysiology of 5q− syndrome.
Assuntos
Autoantígenos/metabolismo , Biossíntese de Proteínas , Sequência de Oligopirimidina na Região 5' Terminal do RNA , Estabilidade de RNA , RNA Mensageiro/metabolismo , Ribonucleoproteínas/metabolismo , Proteínas Ribossômicas/metabolismo , Ribossomos/metabolismo , Anemia Macrocítica/genética , Anemia Macrocítica/metabolismo , Autoantígenos/genética , Células da Medula Óssea/metabolismo , Deleção Cromossômica , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 5/metabolismo , Células HCT116 , Humanos , Complexos Multiproteicos , Ligação Proteica , Interferência de RNA , RNA Mensageiro/genética , Ribonucleoproteínas/genética , Proteínas Ribossômicas/genética , Ribossomos/genética , Fatores de Tempo , Transfecção , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Antígeno SS-BRESUMO
Primary myelofibrosis (PMF) is a clonal hematologic malignancy characterized by BM fibrosis, extramedullary hematopoiesis, circulating CD34+ cells, splenomegaly, and a propensity to evolve to acute myeloid leukemia. Moreover, the spleen and BM of patients harbor atypical, clustered megakaryocytes, which contribute to the disease by secreting profibrotic cytokines. Here, we have revealed that megakaryocytes in PMF show impaired maturation that is associated with reduced GATA1 protein. In investigating the cause of GATA1 downregulation, our gene-expression study revealed the presence of the RPS14-deficient gene signature, which is associated with defective ribosomal protein function and linked to the erythroid lineage in 5q deletion myelodysplastic syndrome. Surprisingly, reduced GATA1 expression and impaired differentiation were limited to megakaryocytes, consistent with a proproliferative effect of a GATA1 deficiency on this lineage. Importantly, expression of GATA1 effectively rescued maturation of PMF megakaryocytes. Together, these results suggest that ribosomal deficiency contributes to impaired megakaryopoiesis in myeloproliferative neoplasms.
Assuntos
Regulação para Baixo , Fator de Transcrição GATA1/biossíntese , Megacariócitos/metabolismo , Mielofibrose Primária/metabolismo , Trombopoese , Animais , Deleção Cromossômica , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 5/metabolismo , Fator de Transcrição GATA1/genética , Humanos , Megacariócitos/patologia , Camundongos , Mielofibrose Primária/genética , Mielofibrose Primária/patologia , Proteínas Ribossômicas/biossíntese , Proteínas Ribossômicas/genéticaRESUMO
Anemia is a key survival prognostic factor in lower-risk myelodysplastic syndromes (MDS). Lenalidomide (LEN) can correct anemia in 25% of MDS patients without deletion 5q (del5q). As this therapy will inevitably fail, understanding the outcome of these patients will facilitate development of subsequent treatment strategies. To answer this question, an international retrospective study focused on LEN-treated lower-risk, non-del5q, MDS patients was performed. We analyzed the overall survival after LEN failure, its prognostic factors and the impact of post LEN treatment options. We included a total of 384 patients. The median overall survival after failure of LEN was 43 months. In multivariate analysis, adverse cytogenetics, excess of blasts at the initiation of LEN, and the type of failure (classified as stable disease, relapse, intolerance, or progression) were the main determinants of outcome. Subsequent therapy with hypomethylating agents was associated with a prolonged survival compared to BSC (median OS= 51m vs. 36m, p=0.01). In conclusion, the survival for non-del5q MDS patients after failure of LEN remains relatively prolonged, though with a wide range. Clinical trial participation remains the recommendation for these patients even if options such as hypomethylating agents may be considered.
Assuntos
Anemia/etiologia , Inibidores da Angiogênese/uso terapêutico , Cromossomos Humanos Par 5/metabolismo , Síndromes Mielodisplásicas/tratamento farmacológico , Talidomida/análogos & derivados , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia/tratamento farmacológico , Inibidores da Angiogênese/farmacologia , Deleção Cromossômica , Progressão da Doença , Feminino , Humanos , Lenalidomida , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/mortalidade , Prognóstico , Análise de Sobrevida , Talidomida/farmacologia , Talidomida/uso terapêutico , Resultado do Tratamento , Adulto JovemRESUMO
PURPOSE OF REVIEW: Myelodysplastic syndromes (MDS) are heterogeneous diseases of the hematopoietic stem cell in the elderly. Anemia is the main symptom that mostly correlates with dysplastic erythropoiesis in the bone marrow. We will review the recent advances in understanding the diverse mechanisms of dyserythropoiesis. RECENT FINDINGS: Dyserythropoiesis defined as 10% dysplastic erythroid cells in the bone marrow is found in more than 80% of early MDS. Immature erythroblasts accumulate at the expense of mature erythroblasts due to differentiation arrest and apoptosis. In early MDS with dyserythropoiesis, caspase-dependent cleavage of the erythroid transcription factor GATA-1 occurring in basophilic erythroblasts accounts for impairment of final maturation. Depending on initiating genetic alteration, specific mechanisms contribute to erythroid defect. In MDS with 5q deletion, the haploinsufficiency of ribosomal protein gene, RPS14, opposes the transition of immature to mature erythroblasts by inducing a p53-dependent ribosome stress, cell cycle arrest and apoptosis. Recent work identifies the activation of a p53-S100A8/9 innate immune pathway that both intrinsically and extrinsically contributes to defective erythropoiesis. In MDS with ring sideroblasts, a paradigm of dyserythropoiesis, a unique mutation in SF3B1 splicing factor gene induces a multiplicity of alterations at RNA level that deeply modifies the patterns of gene expression. SUMMARY: Insights in the pathophysiology of MDS with dyserythropoiesis may guide the choice of the appropriate therapy, for instance lenalidomide in MDS with del(5q). A better understanding of the mechanisms of dyserthropoiesis is required to treat anemia in non-del(5q) MDS, especially in case of resistance to first-line therapy by erythropoiesis-stimulating agents.
Assuntos
Células da Medula Óssea/metabolismo , Medula Óssea/metabolismo , Eritropoese , Síndromes Mielodisplásicas/etiologia , Síndromes Mielodisplásicas/metabolismo , Anemia Macrocítica/genética , Anemia Macrocítica/metabolismo , Anemia Macrocítica/patologia , Anemia Sideroblástica/etiologia , Anemia Sideroblástica/metabolismo , Anemia Sideroblástica/patologia , Animais , Medula Óssea/patologia , Células da Medula Óssea/patologia , Deleção Cromossômica , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 5/metabolismo , Células Eritroides/citologia , Células Eritroides/metabolismo , Células Eritroides/patologia , Eritropoese/genética , Fator de Transcrição GATA1/genética , Fator de Transcrição GATA1/metabolismo , Regulação da Expressão Gênica , Humanos , Imunidade Inata , Mitocôndrias/genética , Mitocôndrias/imunologia , Mitocôndrias/metabolismo , Síndromes Mielodisplásicas/diagnóstico , Splicing de RNA , Transdução de SinaisRESUMO
Cri-du-chat syndrome is a chromosomal disorder caused by a deletion of the short arm of chromosome 5. The disease severity, levels of intellectual and developmental delay, and patient prognosis have been related to the size and position of the deletion. Aiming to establish genotype-phenotype correlations, we applied array-CGH to evaluate six patients carrying cytogenetically detected deletions of the short arm of chromosome 5 who were followed at a genetics community service. The patients' cytogenetic and clinical profiles were reevaluated. A database review was performed to predict additional genes and regulatory elements responsible for the characteristic phenotypic and behavioral traits of this disorder. Array-CGH analysis allowed for delineation of the terminal deletions, which ranged in size from approximately 11.2 Mb to 28.6 Mb, with breakpoints from 5p15.2 to 5p13. An additional dup(8)(p23) (3.5 Mb), considered to be a benign copy number variation, was also observed in one patient. The correlation coefficient value (ρ = 0.13) calculated indicated the presence of a weak relationship between developmental delay and deletion size. Genetic background, family history, epigenetic factors, quantitative trait locus polymorphisms, and environmental factors may also affect patient phenotype and must be taken into account in genotype-phenotype correlations.
Assuntos
Cromossomos Humanos Par 5 , Síndrome de Cri-du-Chat , Deficiências do Desenvolvimento , Análise de Sequência com Séries de Oligonucleotídeos , Adolescente , Criança , Pré-Escolar , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 5/metabolismo , Síndrome de Cri-du-Chat/genética , Síndrome de Cri-du-Chat/metabolismo , Síndrome de Cri-du-Chat/patologia , Síndrome de Cri-du-Chat/fisiopatologia , Deficiências do Desenvolvimento/metabolismo , Deficiências do Desenvolvimento/patologia , Deficiências do Desenvolvimento/fisiopatologia , Feminino , Seguimentos , Humanos , MasculinoRESUMO
Jeune asphyxiating thoracic dystrophy (JATD) is a skeletal dysplasia characterized by a small thoracic cage and a range of skeletal and extra-skeletal anomalies. JATD is genetically heterogeneous with at least nine genes identified, all encoding ciliary proteins, hence the classification of JATD as a skeletal ciliopathy. Consistent with the observation that the heterogeneous molecular basis of JATD has not been fully determined yet, we have identified two consanguineous Saudi families segregating JATD who share a single identical ancestral homozygous haplotype among the affected members. Whole-exome sequencing revealed a single novel variant within the disease haplotype in CEP120, which encodes a core centriolar protein. Subsequent targeted sequencing of CEP120 in Saudi and European JATD cohorts identified two additional families with the same missense mutation. Combining the four families in linkage analysis confirmed a significant genome-wide linkage signal at the CEP120 locus. This missense change alters a highly conserved amino acid within CEP120 (p.Ala199Pro). In addition, we show marked reduction of cilia and abnormal number of centrioles in fibroblasts from one affected individual. Inhibition of the CEP120 ortholog in zebrafish produced pleiotropic phenotypes characteristic of cilia defects including abnormal body curvature, hydrocephalus, otolith defects and abnormal renal, head and craniofacial development. We also demonstrate that in CEP120 morphants, cilia are shortened in the neural tube and disorganized in the pronephros. These results are consistent with aberrant CEP120 being implicated in the pathogenesis of JATD and expand the role of centriolar proteins in skeletal ciliopathies.
Assuntos
Osso e Ossos/anormalidades , Proteínas de Ciclo Celular/genética , Centríolos/genética , Síndrome de Ellis-Van Creveld/genética , Mutação de Sentido Incorreto , Sequência de Aminoácidos , Animais , Osso e Ossos/metabolismo , Proteínas de Ciclo Celular/metabolismo , Centríolos/metabolismo , Mapeamento Cromossômico , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 5/metabolismo , Cílios/patologia , Estudos de Coortes , Modelos Animais de Doenças , Europa (Continente) , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Loci Gênicos , Estudo de Associação Genômica Ampla , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Dados de Sequência Molecular , Linhagem , Fenótipo , Arábia Saudita , Peixe-ZebraRESUMO
OBJECTIVES: Lenalidomide is a potent drug with pleiotropic effects in patients with myelodysplastic syndrome (MDS) with deletion of the long arm of chromosome 5 [del(5q)]. We investigated its effect on regulation of microRNA (miRNA) expression profiles in del(5q) patients with MDS in vivo. METHODS: We used miRNA expression microarrays to study changes in miRNA levels in peripheral blood CD14+ monocytes collected from patients before and during lenalidomide treatment and compared them with those from healthy donors. RESULTS: Before treatment, we observed strong upregulation of pro-apoptotic miR-34a and miR-34a* that diminished during lenalidomide exposure. Upregulation of HOX-related miR-196b and erythroid-specific miR-451 seen in untreated patients remained unchanged after the treatment. At the time of hematologic response, expression of several miRNAs clustering to the 14q32 locus was reduced. Additionally, we focused more deeply on miRNAs from the 5q commonly deleted region and found that levels of miR-378 and miR-378* followed haploinsufficiency trend. CONCLUSIONS: This report describes changes in miRNA expression in del(5q) patients with MDS treated with lenalidomide, likely arising from deregulation of pathways implicated in lenalidomide action.
Assuntos
Anemia Macrocítica/tratamento farmacológico , Regulação Neoplásica da Expressão Gênica , Fatores Imunológicos/uso terapêutico , MicroRNAs/genética , Síndromes Mielodisplásicas/tratamento farmacológico , Talidomida/análogos & derivados , Idoso , Anemia Macrocítica/genética , Anemia Macrocítica/metabolismo , Anemia Macrocítica/patologia , Estudos de Casos e Controles , Deleção Cromossômica , Cromossomos Humanos Par 14 , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 5/metabolismo , Feminino , Perfilação da Expressão Gênica , Loci Gênicos , Estudo de Associação Genômica Ampla , Haploinsuficiência , Humanos , Lenalidomida , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/patologia , Masculino , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/metabolismo , Síndromes Mielodisplásicas/patologia , Cultura Primária de Células , Splicing de RNA , Transdução de Sinais , Talidomida/uso terapêuticoRESUMO
Downregulation of cereblon (CRBN) gene expression is associated with resistance to the immunomodulatory drug lenalidomide and poor survival outcomes in multiple myeloma (MM) patients. However, the importance of CRBN gene expression in patients with myelodysplastic syndrome (MDS) and its impact on lenalidomide therapy are not clear. In this study, we evaluate cereblon expression in mononuclear cells isolated from bone marrow [23 lower risk MDS patients with isolated 5q deletion (5q-), 37 lower risk MDS patients with chromosome 5 without the deletion of long arms (non-5q-), and 24 healthy controls] and from peripheral blood (38 patients with 5q-, 52 non-5q- patients and 25 healthy controls) to gain insight into, firstly, the role of cereblon in lower risk MDS patients with or without 5q deletion and, secondly, into the mechanisms of lenalidomide action. Patients with 5q- lower risk MDS have the highest levels of CRBN mRNA in comparison with both lower risk MDS without the deletion of long arms of chromosome 5 and healthy controls. CRBN gene expression was measured using the quantitative TaqMan real-time PCR. High levels of CRBN mRNA were detected in all lenalidomide responders during the course of therapy. A significant decrease of the CRBN mRNA level during lenalidomide treatment is associated with loss of response to treatment and disease progression. These results suggest that, similar to the treatment of MM, high levels of full-length CRBN mRNA in lower risk 5q- patients are necessary for the efficacy of lenalidomide.
Assuntos
Anemia Macrocítica/tratamento farmacológico , Regulação Neoplásica da Expressão Gênica , Fatores Imunológicos/uso terapêutico , Síndromes Mielodisplásicas/tratamento farmacológico , Peptídeo Hidrolases/genética , RNA Mensageiro/genética , Talidomida/análogos & derivados , Proteínas Adaptadoras de Transdução de Sinal , Anemia Macrocítica/genética , Anemia Macrocítica/metabolismo , Anemia Macrocítica/patologia , Estudos de Casos e Controles , Deleção Cromossômica , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 5/metabolismo , Humanos , Lenalidomida , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/patologia , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/metabolismo , Síndromes Mielodisplásicas/patologia , Peptídeo Hidrolases/metabolismo , Polimorfismo de Nucleotídeo Único , Splicing de RNA , RNA Mensageiro/metabolismo , Transdução de Sinais , Talidomida/uso terapêutico , Resultado do Tratamento , Ubiquitina-Proteína LigasesRESUMO
Several studies have reported associations between multiple cancer types and single-nucleotide polymorphisms (SNPs) on chromosome 5p15, which harbours TERT and CLPTM1L, but no such association has been reported with endometrial cancer. To evaluate the role of genetic variants at the TERT-CLPTM1L region in endometrial cancer risk, we carried out comprehensive fine-mapping analyses of genotyped and imputed SNPs using a custom Illumina iSelect array which includes dense SNP coverage of this region. We examined 396 SNPs (113 genotyped, 283 imputed) in 4,401 endometrial cancer cases and 28,758 controls. Single-SNP and forward/backward logistic regression models suggested evidence for three variants independently associated with endometrial cancer risk (P = 4.9 × 10(-6) to P = 7.7 × 10(-5)). Only one falls into a haplotype previously associated with other cancer types (rs7705526, in TERT intron 1), and this SNP has been shown to alter TERT promoter activity. One of the novel associations (rs13174814) maps to a second region in the TERT promoter and the other (rs62329728) is in the promoter region of CLPTM1L; neither are correlated with previously reported cancer-associated SNPs. Using TCGA RNASeq data, we found significantly increased expression of both TERT and CLPTM1L in endometrial cancer tissue compared with normal tissue (TERT P = 1.5 × 10(-18), CLPTM1L P = 1.5 × 10(-19)). Our study thus reports a novel endometrial cancer risk locus and expands the spectrum of cancer types associated with genetic variation at 5p15, further highlighting the importance of this region for cancer susceptibility.
Assuntos
Cromossomos Humanos Par 5/genética , Loci Gênicos , Proteínas de Membrana/genética , Modelos Genéticos , Proteínas de Neoplasias/genética , Polimorfismo de Nucleotídeo Único , Telomerase/genética , Cromossomos Humanos Par 5/metabolismo , Bases de Dados de Ácidos Nucleicos , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Haplótipos , Humanos , Proteínas de Membrana/biossíntese , Proteínas de Neoplasias/biossíntese , Regiões Promotoras Genéticas , Fatores de Risco , Telomerase/biossínteseRESUMO
Haploinsufficiency of ribosomal proteins (RPs) and upregulation of the tumour suppressor TP53 have been shown to be the common basis for the anaemia observed in Diamond Blackfan anaemia and 5q- myelodysplastic syndrome. We previously demonstrated that treatment with L-Leucine resulted in a marked improvement in anaemia in disease models. To determine if the L-Leucine effect was Tp53-dependent, we used antisense MOs to rps19 and rps14 in zebrafish; expression of tp53 and its downstream target cdkn1a remained elevated following L-leucine treatment. We confirmed this observation in human CD34+ cells. L-Leucine thus alleviates anaemia in RP-deficient cells in a TP53-independent manner.
Assuntos
Anemia de Diamond-Blackfan/tratamento farmacológico , Anemia Macrocítica/tratamento farmacológico , Proteína Supressora de Tumor p53/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Anemia de Diamond-Blackfan/genética , Anemia de Diamond-Blackfan/metabolismo , Anemia de Diamond-Blackfan/patologia , Anemia Macrocítica/genética , Anemia Macrocítica/metabolismo , Anemia Macrocítica/patologia , Animais , Deleção Cromossômica , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 5/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Modelos Animais de Doenças , Humanos , Leucina , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Proteína Supressora de Tumor p53/genética , Proteínas de Peixe-Zebra/genéticaRESUMO
Nonsyndromic Hereditary Hearing Loss is a common disorder accounting for at least 60% of prelingual deafness. GJB2 gene mutations, GJB6 deletion, and the A1555G mitochondrial mutation play a major role worldwide in causing deafness, but there is a high degree of genetic heterogeneity and many genes involved in deafness have not yet been identified. Therefore, there remains a need to search for new causative mutations. In this study, a combined strategy using both linkage analysis and sequencing identified a new mutation causing hearing loss. Linkage analysis identified a region of 40 Mb on chromosome 5q13 (LOD score 3.8) for which exome sequencing data revealed a mutation (c.7873 T>G leading to p.*2625Gluext*11) in the BDP1 gene (B double prime 1, subunit of RNA polymerase III transcription initiation factor IIIB) in patients from a consanguineous Qatari family of second degree, showing bilateral, post-lingual, sensorineural moderate to severe hearing impairment. The mutation disrupts the termination codon of the transcript resulting in an elongation of 11 residues of the BDP1 protein. This elongation does not contain any known motif and is not conserved across species. Immunohistochemistry studies carried out in the mouse inner ear showed Bdp1 expression within the endothelial cells in the stria vascularis, as well as in mesenchyme-derived cells surrounding the cochlear duct. The identification of the BDP1 mutation increases our knowledge of the molecular bases of Nonsyndromic Hereditary Hearing Loss and provides new opportunities for the diagnosis and treatment of this disease in the Qatari population.
Assuntos
Cromossomos Humanos Par 5/genética , Exoma , Doenças Genéticas Inatas/genética , Perda Auditiva Funcional/genética , Mutação , Fator de Transcrição TFIIIB/genética , Animais , Cromossomos Humanos Par 5/metabolismo , Ducto Coclear/metabolismo , Ducto Coclear/patologia , Conexina 26 , Conexinas , Análise Mutacional de DNA , Feminino , Doenças Genéticas Inatas/metabolismo , Doenças Genéticas Inatas/patologia , Ligação Genética , Perda Auditiva Funcional/metabolismo , Humanos , Escore Lod , Masculino , Camundongos , Linhagem , Fator de Transcrição TFIIIB/metabolismoRESUMO
The incidence of lung diseases and cancer caused by cigarette smoke is increasing. The molecular mechanisms of gene regulation induced by cigarette smoke that ultimately lead to cancer remain unclear. This report describes a novel long noncoding RNA (lncRNA) that is induced by cigarette smoke extract (CSE) both in vitro and in vivo and is elevated in numerous lung cancer cell lines. We have termed this lncRNA the smoke and cancer-associated lncRNA-1 (SCAL1). This lncRNA is located in chromosome 5, and initial sequencing analysis reveals a transcript with four exons and three introns. The expression of SCAL1 is regulated transcriptionally by nuclear factor erythroid 2-related factor (NRF2), as determined by the small, interfering RNA (siRNA) knockdown of NRF2 and kelch-like ECH-associated protein 1 (KEAP1). A nuclear factor erythroid-derived 2 (NF-E2) motif was identified in the promoter region that shows binding to NRF2 after its activation. Functionally, the siRNA knockdown of SCAL1 in human bronchial epithelial cells shows a significant potentiation of cytotoxicity induced by CSE in vitro. Altogether, these results identify a novel and intriguing new noncoding RNA that may act downstream of NRF2 to regulate gene expression and mediate oxidative stress protection in airway epithelial cells.