Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 98
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Nat Commun ; 12(1): 5044, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34413298

RESUMO

Indirect somatic genetic rescue (SGR) of a germline mutation is thought to be rare in inherited Mendelian disorders. Here, we establish that acquired mutations in the EIF6 gene are a frequent mechanism of SGR in Shwachman-Diamond syndrome (SDS), a leukemia predisposition disorder caused by a germline defect in ribosome assembly. Biallelic mutations in the SBDS or EFL1 genes in SDS impair release of the anti-association factor eIF6 from the 60S ribosomal subunit, a key step in the translational activation of ribosomes. Here, we identify diverse mosaic somatic genetic events (point mutations, interstitial deletion, reciprocal chromosomal translocation) in SDS hematopoietic cells that reduce eIF6 expression or disrupt its interaction with the 60S subunit, thereby conferring a selective advantage over non-modified cells. SDS-related somatic EIF6 missense mutations that reduce eIF6 dosage or eIF6 binding to the 60S subunit suppress the defects in ribosome assembly and protein synthesis across multiple SBDS-deficient species including yeast, Dictyostelium and Drosophila. Our data suggest that SGR is a universal phenomenon that may influence the clinical evolution of diverse Mendelian disorders and support eIF6 suppressor mimics as a therapeutic strategy in SDS.


Assuntos
Mutação , Subunidades Ribossômicas Maiores de Eucariotos/metabolismo , Ribossomos/genética , Ribossomos/patologia , Síndrome de Shwachman-Diamond/genética , Síndrome de Shwachman-Diamond/patologia , Adolescente , Adulto , Animais , Fenômenos Biológicos , Células Cultivadas , Criança , Pré-Escolar , Dictyostelium , Drosophila , Fatores de Iniciação em Eucariotos/genética , Fatores de Iniciação em Eucariotos/metabolismo , Células Germinativas , Humanos , Lactente , Simulação de Dinâmica Molecular , Fatores de Alongamento de Peptídeos/genética , Fatores de Alongamento de Peptídeos/metabolismo , Ligação Proteica , Biossíntese de Proteínas , Proteínas/genética , Proteínas/metabolismo , Ribonucleoproteína Nuclear Pequena U5/genética , Ribonucleoproteína Nuclear Pequena U5/metabolismo , Ribossomos/metabolismo , Saccharomyces cerevisiae , Homologia de Sequência de Aminoácidos , Síndrome de Shwachman-Diamond/metabolismo , Adulto Jovem
2.
Int J Mol Sci ; 22(11)2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-34070742

RESUMO

Nephrogenesis is driven by complex signaling pathways that control cell growth and differentiation. The endoplasmic reticulum chaperone calreticulin (Calr) is well known for its function in calcium storage and in the folding of glycoproteins. Its role in kidney development is still not understood. We provide evidence for a pivotal role of Calr in nephrogenesis in this investigation. We show that Calr deficiency results in the disrupted formation of an intact nephrogenic zone and in retardation of nephrogenesis, as evidenced by the disturbance in the formation of comma-shaped and s-shaped bodies. Using proteomics and transcriptomics approaches, we demonstrated that in addition to an alteration in Wnt-signaling key proteins, embryonic kidneys from Calr-/- showed an overall impairment in expression of ribosomal proteins which reveals disturbances in protein synthesis and nephrogenesis. CRISPR/cas9 mediated knockout confirmed that Calr deficiency is associated with a deficiency of several ribosomal proteins and key proteins in ribosome biogenesis. Our data highlights a direct link between Calr expression and the ribosome biogenesis.


Assuntos
Cálcio/metabolismo , Calreticulina/genética , Rim/metabolismo , Biogênese de Organelas , Proteínas Ribossômicas/genética , Ribossomos/genética , Animais , Sinalização do Cálcio , Calreticulina/deficiência , Embrião de Mamíferos , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/patologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Glicoproteínas/classificação , Glicoproteínas/genética , Glicoproteínas/metabolismo , Rim/crescimento & desenvolvimento , Rim/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Organogênese/genética , Dobramento de Proteína , Proteômica/métodos , Proteínas Ribossômicas/deficiência , Ribossomos/metabolismo , Ribossomos/patologia , Via de Sinalização Wnt
3.
Commun Biol ; 4(1): 543, 2021 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-33972671

RESUMO

The majorities of colorectal cancer (CRC) cases are sporadic in origin and a large proportion of etiologies are associated with environmental stress responses. In response to external and internal stress, the ribosome stands sentinel and stress-driven ribosomal dysfunction triggers the cellular decision pathways via transcriptional reprogramming. In the present study, PR domain zinc finger protein (PRDM) 1, a master transcriptional regulator, was found to be closely associated with ribosomal actions in patients with CRC and the murine models. Stress-driven ribosomal dysfunction enhanced PRDM1 levels in intestinal cancer cells, which contributed to their survival and enhanced cancer cell stemness against cancer treatment. Mechanistically, PRDM1 facilitated clustering modulation of insulin-like growth factor (IGF) receptor-associated genes, which supported cancer cell growth and stemness-linked features. Ribosomal dysfunction-responsive PRDM1 facilitated signaling remodeling for the survival of tumor progenitors, providing compelling evidence for the progression of sporadic CRC.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Colorretais/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos , Células-Tronco Neoplásicas/patologia , Fator 1 de Ligação ao Domínio I Regulador Positivo/metabolismo , Ribossomos/patologia , Estresse Fisiológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Apoptose , Biomarcadores Tumorais/genética , Proliferação de Células , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Mucosa Intestinal/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Nus , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Fator 1 de Ligação ao Domínio I Regulador Positivo/genética , Prognóstico , Transdução de Sinais , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Nat Cell Biol ; 23(2): 127-135, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33495632

RESUMO

Ribosomes are multicomponent molecular machines that synthesize all of the proteins of living cells. Most of the genes that encode the protein components of ribosomes are therefore essential. A reduction in gene dosage is often viable albeit deleterious and is associated with human syndromes, which are collectively known as ribosomopathies1-3. The cell biological basis of these pathologies has remained unclear. Here, we model human ribosomopathies in Drosophila and find widespread apoptosis and cellular stress in the resulting animals. This is not caused by insufficient protein synthesis, as reasonably expected. Instead, ribosomal protein deficiency elicits proteotoxic stress, which we suggest is caused by the accumulation of misfolded proteins that overwhelm the protein degradation machinery. We find that dampening the integrated stress response4 or autophagy increases the harm inflicted by ribosomal protein deficiency, suggesting that these activities could be cytoprotective. Inhibition of TOR activity-which decreases ribosomal protein production, slows down protein synthesis and stimulates autophagy5-reduces proteotoxic stress in our ribosomopathy model. Interventions that stimulate autophagy, combined with means of boosting protein quality control, could form the basis of a therapeutic strategy for this class of diseases.


Assuntos
Mutação/genética , Proteínas/toxicidade , Ribossomos/genética , Ribossomos/patologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Alelos , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/metabolismo , Células HEK293 , Heterozigoto , Humanos , Discos Imaginais/efeitos dos fármacos , Discos Imaginais/metabolismo , Agregados Proteicos/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , Proteômica , Proteínas Ribossômicas/biossíntese , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Asas de Animais/efeitos dos fármacos , Asas de Animais/metabolismo
5.
Biomed Res Int ; 2020: 5171242, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33134380

RESUMO

Lung cancer is the leading cause of cancer-related death worldwide, and the most common histologic subtype is lung adenocarcinoma (LUAD). Due to the significant mortality and morbidity rates among patients with LUAD, the identification of novel biomarkers to guide diagnosis, prognosis, and therapy is urgent. Guanosine triphosphate-binding protein 4 (GTPBP4) has been found to be associated with tumorigenesis in recent years, but the underlying molecular mechanism remains to be elucidated. In the present study, we demonstrate that GTPBP4 is significantly overexpressed in LUAD primary tumors. A total of 55 genes were identified as potential targets of GTPBP4. GO enrichment analysis identified the top 25 pathways among these target genes, among which, ribosome biogenesis was shown to be the most central. Each target gene demonstrated strong and complex interactions with other genes. Of the potential target genes, 12 abnormally expressed candidates were associated with survival probability and correlated with GTPBP4 expression. These findings suggest that GTPBP4 is associated with LUAD progression. Finally, we highlight the importance of the role of GTPBP4 in LUAD in vitro. GTPBP4 knockdown in LUAD cells inhibited proliferation and metastasis, promoted apoptosis, and enhanced sensitivity to TP. Overall, we conclude that GTPBP4 may be considered as a potential biomarker of LUAD.


Assuntos
Adenocarcinoma de Pulmão/genética , Proteínas de Ligação ao GTP/genética , Genoma/genética , Neoplasias Pulmonares/genética , Proteínas Nucleares/genética , Células A549 , Adenocarcinoma de Pulmão/patologia , Apoptose/genética , Biomarcadores Tumorais/genética , Carcinogênese/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Biologia Computacional , Procedimentos Clínicos , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Neoplasias Pulmonares/patologia , Masculino , Metástase Neoplásica/genética , Metástase Neoplásica/patologia , Prognóstico , Ribossomos/genética , Ribossomos/patologia
6.
Cells ; 9(10)2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33076379

RESUMO

A number of different defects in the process of ribosome production can lead to a diversified spectrum of disorders that are collectively identified as ribosomopathies. The specific factors involved may either play a role only in ribosome biogenesis or have additional extra-ribosomal functions, making it difficult to ascribe the pathogenesis of the disease specifically to an altered ribosome biogenesis, even if the latter is clearly affected. We reviewed the available literature in the field from this point of view with the aim of distinguishing, among ribosomopathies, the ones due to specific alterations in the process of ribosome production from those characterized by a multifactorial pathogenesis.


Assuntos
RNA Ribossômico/fisiologia , Doenças Raras/etiologia , Proteínas Ribossômicas/fisiologia , Ribossomos/genética , Ribossomos/patologia , Anemia de Diamond-Blackfan , Anemia Macrocítica , Deleção Cromossômica , Cromossomos Humanos Par 5 , Disceratose Congênita , Retardo do Crescimento Fetal , Predisposição Genética para Doença , Cabelo/anormalidades , Doença de Hirschsprung , Humanos , Disostose Mandibulofacial , Osteocondrodisplasias/congênito , Doenças da Imunodeficiência Primária , Transtornos Psicomotores , Síndrome de Shwachman-Diamond
7.
PLoS Genet ; 16(8): e1008967, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32813698

RESUMO

Dysregulation of ribosome production can lead to a number of developmental disorders called ribosomopathies. Despite the ubiquitous requirement for these cellular machines used in protein synthesis, ribosomopathies manifest in a tissue-specific manner, with many affecting the development of the face. Here we reveal yet another connection between craniofacial development and making ribosomes through the protein Paired Box 9 (PAX9). PAX9 functions as an RNA Polymerase II transcription factor to regulate the expression of proteins required for craniofacial and tooth development in humans. We now expand this function of PAX9 by demonstrating that PAX9 acts outside of the cell nucleolus to regulate the levels of proteins critical for building the small subunit of the ribosome. This function of PAX9 is conserved to the organism Xenopus tropicalis, an established model for human ribosomopathies. Depletion of pax9 leads to craniofacial defects due to abnormalities in neural crest development, a result consistent with that found for depletion of other ribosome biogenesis factors. This work highlights an unexpected layer of how the making of ribosomes is regulated in human cells and during embryonic development.


Assuntos
Deficiências do Desenvolvimento/genética , Desenvolvimento Embrionário/genética , Fator de Transcrição PAX9/genética , Ribossomos/genética , Animais , Nucléolo Celular/genética , Deficiências do Desenvolvimento/patologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Humanos , Crista Neural/crescimento & desenvolvimento , Crista Neural/metabolismo , Crista Neural/patologia , Biossíntese de Proteínas/genética , RNA Polimerase II/genética , Ribossomos/patologia , Xenopus/genética , Xenopus/crescimento & desenvolvimento
8.
Am J Med Genet A ; 179(9): 1709-1717, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31250547

RESUMO

Cartilage hair hypoplasia (CHH), anauxetic dysplasia 1, and anauxetic dysplasia 2 are rare metaphyseal dysplasias caused by biallelic pathogenic variants in RMRP and POP1, which encode the components of RNAse-MRP endoribonuclease complex (RMRP) in ribosomal biogenesis pathway. Nucleolus and neural progenitor protein (NEPRO), encoded by NEPRO (C3orf17), is known to interact with multiple protein subunits of RMRP. We ascertained a 6-year-old girl with skeletal dysplasia and some features of CHH. RMRP and POP1 did not harbor any causative variant in the proband. Parents-child trio exomes revealed a candidate biallelic variant, c.435G>C, p.(Leu145Phe) in NEPRO. Two families with four affected individuals with skeletal dysplasia and a homozygous missense variant, c.280C>T, p.(Arg94Cys) in NEPRO, were identified from literature and their published phenotype was compared in detail to the phenotype of the child we described. All the five affected individuals have severe short stature, brachydactyly, skin laxity, joint hypermobility, and joint dislocations. They also have short metacarpals, broad middle phalanges, and metaphyseal irregularities. Protein modeling and stability prediction showed that the mutant protein has decreased stability. Both the reported variants are in the same domain of the protein. Our report delineates the clinical and radiological characteristics of an emerging ribosomopathy caused by biallelic variants in NEPRO.


Assuntos
Nanismo/genética , Glicosídeo Hidrolases/genética , Proteínas do Tecido Nervoso/genética , Osteocondrodisplasias/genética , Proteínas Repressoras/genética , Ribossomos/imunologia , Alelos , Proteínas Reguladoras de Apoptose/genética , Criança , Nanismo/patologia , Feminino , Cabelo/anormalidades , Cabelo/patologia , Doença de Hirschsprung/genética , Doença de Hirschsprung/patologia , Humanos , Complexos Multiproteicos/genética , Mutação , Osteocondrodisplasias/congênito , Osteocondrodisplasias/patologia , Linhagem , Fenótipo , Doenças da Imunodeficiência Primária/genética , Doenças da Imunodeficiência Primária/patologia , RNA Longo não Codificante/genética , Ribonucleoproteínas/genética , Ribossomos/genética , Ribossomos/patologia , Esqueleto/metabolismo , Esqueleto/patologia
9.
Nat Rev Cancer ; 19(4): 228-238, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30670820

RESUMO

Long thought to be too big and too ubiquitous to fail, we now know that human cells can fail to make sufficient amounts of ribosomes, causing a number of diseases collectively known as ribosomopathies. The best characterized ribosomopathies, with the exception of Treacher Collins syndrome, are inherited bone marrow failure syndromes, each of which has a marked increase in cancer predisposition relative to the general population. Although rare, emerging data reveal that the inherited bone marrow failure syndromes may be underdiagnosed on the basis of classical symptomology, leaving undiagnosed patients with these syndromes at an elevated risk of cancer without adequate counselling and surveillance. The link between the inherited ribosomopathies and cancer has led to greater awareness that somatic mutations in factors involved in ribosome biogenesis may also be drivers in sporadic cancers. Our goal here is to compare and contrast the pathophysiological mechanisms underpinning ribosomopathies to gain a better understanding of the mechanisms that predispose these disorders to cancer.


Assuntos
Neoplasias/genética , Neoplasias/patologia , Ribossomos/genética , Ribossomos/patologia , Animais , Predisposição Genética para Doença/genética , Humanos , Mutação/genética , Proteínas Ribossômicas/genética
10.
Cancer Res ; 79(2): 320-327, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30482776

RESUMO

Ribosomopathies are congenital disorders caused by mutations in ribosomal proteins (RP) or assembly factors and are characterized by cellular hypoproliferation at an early stage. Paradoxically, many of these disorders have an elevated risk to progress to hyperproliferative cancer at a later stage. In addition, somatic RP mutations have recently been identified in various cancer types, for example, the recurrent RPL10-R98S mutation in T-cell acute lymphoblastic leukemia (T-ALL) and RPS15 mutations in chronic lymphocytic leukemia (CLL). We previously showed that RPL10-R98S promotes expression of oncogenes, but also induces a proliferative defect due to elevated oxidative stress. In this study, we demonstrate that this proliferation defect is eventually rescued by RPL10-R98S mouse lymphoid cells that acquire 5-fold more secondary mutations than RPL10-WT cells. The presence of RPL10-R98S and other RP mutations also correlated with a higher mutational load in patients with T-ALL, with an enrichment in NOTCH1-activating lesions. RPL10-R98S-associated cellular oxidative stress promoted DNA damage and impaired cell growth. Expression of NOTCH1 eliminated these phenotypes in RPL10-R98S cells, in part via downregulation of PKC-θ, with no effect on RPL10-WT cells. Patients with RP-mutant CLL also demonstrated a higher mutational burden, enriched for mutations that may diminish oxidative stress. We propose that oxidative stress due to ribosome dysfunction causes hypoproliferation and cellular insufficiency in ribosomopathies and RP-mutant cancer. This drives surviving cells, potentiated by genomic instability, to acquire rescuing mutations, which ultimately promote transition to hyperproliferation. SIGNIFICANCE: Ribosomal lesions cause oxidative stress and increase mutagenesis, promoting acquisition of rescuing mutations that stimulate proliferation.


Assuntos
Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Ribossomos/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células/genética , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Mutagênese , Mutação , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Receptor Notch1/genética , Receptor Notch1/metabolismo , Proteína Ribossômica L10 , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Ribossomos/metabolismo , Ribossomos/patologia
11.
J Neurochem ; 148(3): 325-347, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30144322

RESUMO

Development of the nervous system is carried out by complex gene expression programs that are regulated at both transcriptional and translational level. In addition, quality control mechanisms such as the TP53-mediated apoptosis or neuronal activity-stimulated survival ensure successful neurogenesis and formation of functional circuitries. In the nucleolus, production of ribosomes is essential for protein synthesis. In addition, it participates in chromatin organization and regulates the TP53 pathway via the ribosomal stress response. Its tight regulation is required for maintenance of genomic integrity. Mutations in several ribosomal components and trans-acting ribosomal biogenesis factors result in neurodevelopmental syndromes that present with microcephaly, autism, intellectual deficits and/or progressive neurodegeneration. Furthermore, ribosomal biogenesis is perturbed by exogenous factors that disrupt neurodevelopment including alcohol or Zika virus. In this review, we present recent literature that argues for a role of dysregulated ribosomal biogenesis in pathogenesis of various neurodevelopmental syndromes. We also discuss potential mechanisms through which such dysregulation may lead to cellular pathologies of the developing nervous system including insufficient proliferation and/or loss of neuroprogenitors cells, apoptosis of immature neurons, altered neuronal morphogenesis, and neurodegeneration.


Assuntos
Transtornos do Neurodesenvolvimento/fisiopatologia , Neurogênese/fisiologia , Biogênese de Organelas , Ribossomos/patologia , Animais , Humanos
12.
Small GTPases ; 10(5): 388-394, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-28657426

RESUMO

The Rho GTPase family members Rac1, Cdc42 and RhoA play key contributory roles in the transformed phenotype of human cancers. Epithelial Cell Transforming Sequence 2 (Ect2), a guanine nucleotide exchange factor (GEF) for these Rho GTPases, has also been implicated in a variety of human cancers. We have shown that Ect2 is frequently overexpressed in both major forms of non-small cell lung cancer (NSCLC), lung adenocarcinoma (LADC) and lung squamous cell carcinoma (LSCC), which together make up approximately 70% of all lung cancer diagnoses. Furthermore, we have found that Ect2 is required for multiple aspects of the transformed phenotype of NSCLC cells including transformed growth and invasion in vitro and tumorigenesis in vivo. More recently, we showed that a major mechanism by which Ect2 drives KRAS-mediated LADC transformation is by regulating rRNA (rRNA) synthesis. However, it remains unclear whether Ect2 plays a similar role in ribosome biogenesis in LSCC. Here we demonstrate that Ect2 expression correlates positively with expression of ribosome biogenesis genes and with pre-ribosomal 45S RNA abundance in primary LSCC tumors. Furthermore, we demonstrate that Ect2 functionally regulates rRNA synthesis in LSCC cells. Based on these data, we propose that inhibition of Ect2-mediated nucleolar signaling holds promise as a potential therapeutic strategy for improved treatment of both LADC and LSCC.


Assuntos
Carcinogênese/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , RNA Neoplásico/biossíntese , RNA Ribossômico/biossíntese , Transdução de Sinais , Animais , Carcinogênese/patologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Humanos , Neoplasias Pulmonares/patologia , Invasividade Neoplásica , Ribossomos/metabolismo , Ribossomos/patologia
13.
J Clin Invest ; 128(12): 5620-5633, 2018 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-30300142

RESUMO

Activating mutations in the Wnt pathway drive a variety of cancers, but the specific targets and pathways activated by Wnt ligands are not fully understood. To bridge this knowledge gap, we performed a comprehensive time-course analysis of Wnt-dependent signaling pathways in an orthotopic model of Wnt-addicted pancreatic cancer, using a porcupine (PORCN) inhibitor currently in clinical trials, and validated key results in additional Wnt-addicted models. The temporal analysis of the drug-perturbed transcriptome demonstrated direct and indirect regulation of more than 3,500 Wnt-activated genes (23% of the transcriptome). Regulation was both via Wnt/ß-catenin and through the modulation of protein abundance of important transcription factors, including MYC, via Wnt-dependent stabilization of proteins (Wnt/STOP). Our study identifies a central role of Wnt/ß-catenin and Wnt/STOP signaling in controlling ribosome biogenesis, a key driver of cancer proliferation.


Assuntos
Neoplasias Experimentais/metabolismo , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Ribossomos/metabolismo , Transcriptoma , Via de Sinalização Wnt , Aciltransferases/antagonistas & inibidores , Aciltransferases/genética , Aciltransferases/metabolismo , Animais , Linhagem Celular Tumoral , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/genética , Neoplasias Experimentais/patologia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Estabilidade Proteica , Proteínas Proto-Oncogênicas c-myc/genética , Ribossomos/genética , Ribossomos/patologia
14.
Blood ; 132(22): 2375-2388, 2018 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-30181176

RESUMO

Genomic studies have recently identified RPS15 as a new driver gene in aggressive and chemorefractory cases of chronic lymphocytic leukemia (CLL). RPS15 encodes a ribosomal protein whose conserved C-terminal domain extends into the decoding center of the ribosome. We demonstrate that mutations in highly conserved residues of this domain affect protein stability, by increasing its ubiquitin-mediated degradation, and cell-proliferation rates. On the other hand, we show that mutated RPS15 can be loaded into the ribosomes, directly impacting on global protein synthesis and/or translational fidelity in a mutation-specific manner. Quantitative mass spectrometry analyses suggest that RPS15 variants may induce additional alterations in the translational machinery, as well as a metabolic shift at the proteome level in HEK293T and MEC-1 cells. These results indicate that CLL-related RPS15 mutations might act following patterns known for other ribosomal diseases, likely switching from a hypo- to a hyperproliferative phenotype driven by mutated ribosomes. In this scenario, loss of translational fidelity causing altered cell proteostasis can be proposed as a new molecular mechanism involved in CLL pathobiology.


Assuntos
Leucemia Linfocítica Crônica de Células B/genética , Mutação , Proteínas Ribossômicas/genética , Ribossomos/genética , Linhagem Celular Tumoral , Estudos de Coortes , Células HEK293 , Humanos , Leucemia Linfocítica Crônica de Células B/patologia , Taxa de Mutação , Mutação Puntual , Biossíntese de Proteínas , Domínios Proteicos , Proteínas Ribossômicas/química , Ribossomos/patologia
15.
Toxicol Lett ; 295: 424-437, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29990561

RESUMO

The sulfated forms of the Fusarium toxin deoxynivalenol (DON), deoxynivalenol-3-sulfate (DON-3-Sulf) and deoxynivalenol-15-sulfate (DON-15-Sulf) were recently described, however little is known about their mechanism of action in mammalian cells. DON-3-Sulf and DON-15-Sulf were taken up by HT-29 colon carcinoma cells, although to a lesser extent compared to DON. All three compounds were found to enhance the intracellular ROS level in the dichlorofluorescein assay (≥ 1µM), even though substantial differences were observed in their cytotoxic potential. In silico modelling highlighted that DON-sulfates do not share the classical mechanism of action of DON, being unable to fit into the ribosomal pocket and trigger the classical ribotoxic stress response. However, DON-3-Sulf and DON-15-Sulf sustained a distinctive proliferative stimulus in HT-29 and activated autophagy. The mechanisms of action of DON-3-Sulf and DON-15-Sulf suggest a potential interplay between the onset of ribosomal inhibition and autophagy activation as an alternative and/or complementary mode of action for DON and its sulfated analogues.


Assuntos
Colo/efeitos dos fármacos , Tricotecenos/toxicidade , Autofagia/efeitos dos fármacos , Biotransformação , Proliferação de Células/efeitos dos fármacos , Colo/metabolismo , Colo/patologia , Relação Dose-Resposta a Droga , Células HT29 , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Ribossomos/efeitos dos fármacos , Ribossomos/metabolismo , Ribossomos/patologia , Relação Estrutura-Atividade , Fatores de Tempo , Tricotecenos/química , Tricotecenos/metabolismo
16.
Muscle Nerve ; 58(2): 277-285, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29572878

RESUMO

INTRODUCTION: Children with cerebral palsy (CP) and acquired brain injury (ABI) commonly develop muscle contractures with advancing age. An underlying growth defect contributing to skeletal muscle contracture formation in CP/ABI has been suggested. METHODS: The biceps muscles of children and adolescents with CP/ABI (n = 20) and typically developing controls (n = 10) were investigated. We used immunohistochemistry, quantitative real-time polymerase chain reaction, and Western blotting to assess gene expression relevant to growth and size homeostasis. RESULTS: Classical pro-inflammatory cytokines and genes involved in extracellular matrix (ECM) production were elevated in skeletal muscle of children with CP/ABI. Intramuscular collagen content was increased and satellite cell number decreased and this was associated with reduced levels of RNA polymerase I transcription factors, 45s pre-rRNA and 28S rRNA. DISCUSSION: The present study provides novel data suggesting a role for pro-inflammatory cytokines and reduced ribosomal production in the development/maintenance of muscle contractures, possibly underlying stunted growth and perimysial ECM expansion. Muscle Nerve 58: 277-285, 2018.


Assuntos
Lesões Encefálicas/patologia , Paralisia Cerebral/patologia , Matriz Extracelular/patologia , Músculo Esquelético/patologia , RNA Ribossômico/biossíntese , Adolescente , Contagem de Células , Criança , Colágeno/metabolismo , Citocinas/biossíntese , Citocinas/genética , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Fibras Musculares Esqueléticas/patologia , RNA Ribossômico/genética , Reação em Cadeia da Polimerase em Tempo Real , Ribossomos/genética , Ribossomos/patologia , Células Satélites de Músculo Esquelético/patologia
17.
Hematology Am Soc Hematol Educ Program ; 2017(1): 716-719, 2017 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-29222326

RESUMO

A mutation in the gene encoding the small subunit-associated ribosomal protein RPS19, leading to RPS19 haploinsufficiency, is one of the ribosomal protein gene defects responsible for the rare inherited bone marrow failure syndrome Diamond Blackfan anemia (DBA). Additional inherited and acquired defects in ribosomal proteins (RPs) continue to be identified and are the basis for a new class of diseases called the ribosomopathies. Acquired RPS14 haploinsufficiency has been found to be causative of the bone marrow failure found in 5q- myelodysplastic syndromes. Both under- and overexpression of RPs have also been implicated in several malignancies. This review will describe the somatic ribosomopathies that have been found to be associated with a variety of solid tumors as well as leukemia and will review cancers in which over- or underexpression of these proteins seem to be associated with outcome.


Assuntos
Anemia de Diamond-Blackfan/genética , Haploinsuficiência , Leucemia/genética , Mutação , Síndromes Mielodisplásicas/genética , Ribossomos/genética , Anemia de Diamond-Blackfan/metabolismo , Anemia de Diamond-Blackfan/patologia , Humanos , Leucemia/metabolismo , Leucemia/patologia , Síndromes Mielodisplásicas/metabolismo , Síndromes Mielodisplásicas/patologia , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Ribossomos/metabolismo , Ribossomos/patologia
18.
Adv Exp Med Biol ; 1038: 183-200, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29178077

RESUMO

The mitochondria have the most vital processes in eukaryotic cells to produce ATP composed of polypeptides that are produced via ribosomes, as oxidative phosphorylation. Initially, studies regarding human mitochondrial ribosomes were performed in the model system, bovine mitochondrial ribosome, to investigate how ribosomes are biosynthesized and evolved as well as what their structure and function are. Advances in X-ray crystallography have led to dramatic progresses in structural studies of the ribosome. In recent years, there has been a growing interest in the properties of the mitochondrial ribosome. Although one of its main functions is the production of ATP, it was also linked to multiple diseases. A key area that remains unexplored and requires investigation and exploration is how mitochondrial ribosomal RNA (mt-rRNA) variations can affect the mitochondrial ribosomes in developing disease. This review summarizes the structure, elements, functions, and regulatory roles in associated diseases. With the continuous development of technology, studies on the mechanism of mitochondrial ribosome related diseases are crucial, in order to identify methods of prevention and treatment of these disorders.


Assuntos
Pneumopatias/metabolismo , Mitocôndrias/metabolismo , RNA Ribossômico/metabolismo , RNA/metabolismo , Ribossomos/metabolismo , Animais , Bovinos , Humanos , Pneumopatias/genética , Pneumopatias/patologia , Mitocôndrias/genética , Mitocôndrias/patologia , RNA/genética , RNA Mitocondrial , RNA Ribossômico/genética , Ribossomos/genética , Ribossomos/patologia
19.
PLoS One ; 12(10): e0186047, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29016636

RESUMO

Few quantifiable tissue biomarkers for the diagnosis and prognosis of prostate cancer exist. Using an unbiased, quantitative approach, this study evaluates the potential of three proteins of the 40S ribosomal protein complex as putative biomarkers of malignancy in prostate cancer. Prostate tissue arrays, constructed from 82 patient samples (245 tissue cores, stage pT3a or pT3b), were stained for antibodies against three ribosomal proteins, RPS19, RPS21 and RPS24. Semi-automated Ox-DAB signal quantification using ImageJ software revealed a significant change in expression of RPS19, RPS21 and RPS24 in malignant vs non-malignant tissue (p<0.0001). Receiver operating characteristics curves were calculated to evaluate the potential of each protein as a biomarker of malignancy in prostate cancer. Positive likelihood ratios for RPS19, RPS21 and RPS24 were calculated as 2.99, 4.21, and 2.56 respectively, indicating that the overexpression of the protein is correlated with the presence of disease. Triple-labelled, quantitative, immunofluorescence (with RPS19, RPS21 and RPS24) showed significant changes (p<0.01) in the global intersection coefficient, a measure of how often two fluorophore signals intersect, for RPS19 and RPS24 only. No change was observed in the co-localization of any other permutations of the three proteins. Our results show that RPS19, RPS21 or RPS24 are upregulated in malignant tissue and may serve as putative biomarkers for prostate cancer.


Assuntos
Biomarcadores Tumorais/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/diagnóstico , Proteínas Ribossômicas/genética , Idoso , Biomarcadores Tumorais/metabolismo , Imunofluorescência , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Próstata/metabolismo , Próstata/patologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Curva ROC , Estudos Retrospectivos , Proteínas Ribossômicas/metabolismo , Ribossomos/genética , Ribossomos/metabolismo , Ribossomos/patologia , Análise Serial de Tecidos
20.
J Biol Chem ; 292(49): 20208-20217, 2017 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-28978646

RESUMO

Impaired mitochondrial oxidative phosphorylation (OXPHOS) capacity, accompanied by enhanced glycolysis, is a key metabolic feature of cancer cells, but its underlying mechanism remains unclear. Previously, we reported that human hepatoma cells that harbor OXPHOS defects exhibit high tumor cell invasiveness via elevated claudin-1 (CLN1). In the present study, we show that OXPHOS-defective hepatoma cells (SNU354 and SNU423 cell lines) exhibit reduced expression of mitochondrial ribosomal protein L13 (MRPL13), a mitochondrial ribosome (mitoribosome) subunit, suggesting a ribosomal defect. Specific inhibition of mitoribosomal translation by doxycycline, chloramphenicol, or siRNA-mediated MRPL13 knockdown decreased mitochondrial protein expression, reduced oxygen consumption rate, and increased CLN1-mediated tumor cell invasiveness in SNU387 cells, which have active mitochondria. Interestingly, we also found that exogenous lactate treatment suppressed MRPL13 expression and oxygen consumption rate and induced CLN1 expression. A bioinformatic analysis of the open RNA-Seq database from The Cancer Genome Atlas (TCGA) liver hepatocellular carcinoma (LIHC) cohort revealed a significant negative correlation between MRPL13 and CLN1 expression. Moreover, in patients with low MRPL13 expression, two oxidative metabolic indicators, pyruvate dehydrogenase B expression and the ratio of lactate dehydrogenase type B to type A, significantly and negatively correlated with CLN1 expression, indicating that the combination of elevated glycolysis and deficient MRPL13 activity was closely linked to CLN1-mediated tumor activity in LIHC. These results suggest that OXPHOS defects may be initiated and propagated by lactate-mediated mitoribosomal deficiencies and that these deficiencies are critically involved in LIHC development.


Assuntos
Carcinoma Hepatocelular/patologia , Ácido Láctico/farmacologia , Proteínas de Membrana/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas de Neoplasias/metabolismo , Fosforilação Oxidativa , Proteínas Ribossômicas/metabolismo , Tioléster Hidrolases/metabolismo , Carcinoma Hepatocelular/ultraestrutura , Linhagem Celular Tumoral , Humanos , Invasividade Neoplásica , Fosforilação Oxidativa/efeitos dos fármacos , Consumo de Oxigênio , Ribossomos/efeitos dos fármacos , Ribossomos/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...