RESUMO
Hailey-Hailey disease (HHD) is a rare autosomal dominantly inherited disorder caused by mutations in the ATP2C1 gene that encodes an adenosine triphosphate (ATP)-powered calcium channel pump. HHD is characterized by impaired epidermal cell-to-cell adhesion and defective keratinocyte growth/differentiation. The mechanism by which mutant ATP2C1 causes HHD is unknown and current treatments for affected individuals do not address the underlying defects and are ineffective. Notch signalling is a direct determinant of keratinocyte growth and differentiation. We found that loss of ATP2C1 leads to impaired Notch1 signalling, thus deregulation of the Notch signalling response is therefore likely to contribute to HHD manifestation. NOTCH1 is a transmembrane receptor and upon ligand binding, the intracellular domain (NICD) translocates to the nucleus activating its target genes. In the context of HHD, we found that loss of ATP2C1 function promotes upregulation of the active NOTCH1 protein (NICD-Val1744). Here, deeply exploring this aspect, we observed that NOTCH1 activation is not associated with the transcriptional enhancement of its targets. Moreover, in agreement with these results, we found a cytoplasmic localization of NICD-Val1744. We have also observed that ATP2C1-loss is associated with the degradation of NICD-Val1744 through the lysosomal/proteasome pathway. These results show that ATP2C1-loss could promote a mechanism by which NOTCH1 is endocytosed and degraded by the cell membrane. The deregulation of this phenomenon, finely regulated in physiological conditions, could in HHD lead to the deregulation of NOTCH1 with alteration of skin homeostasis and disease manifestation.
Assuntos
Pênfigo Familiar Benigno , Humanos , Pênfigo Familiar Benigno/genética , Pênfigo Familiar Benigno/metabolismo , Pele/metabolismo , Queratinócitos/metabolismo , Mutação , Epiderme/metabolismo , ATPases Transportadoras de Cálcio/genética , ATPases Transportadoras de Cálcio/metabolismo , Receptor Notch1/genética , Receptor Notch1/metabolismoRESUMO
SPONASTRIME dysplasia is an ultrarare spondyloepimetaphyseal dysplasia featuring short stature and short limbs, platyspondyly, depressed nasal bridge with midface hypoplasia and striated metaphyses. In 2019, an autosomal recessive inheritance was demonstrated by the identification of bi-allelic hypomorphic alleles in TONSL. The encoded protein has a critical role in maintaining genome integrity by promoting the homologous recombination required for repairing spontaneous replication-associated DNA lesions at collapsed replication forks. We report a 9-year-old girl with typical SPONASTRIME dysplasia and resulted in carrier of the novel missense p.(Gln430Arg) and p.(Leu1090Arg) variants in TONSL at whole-exome sequencing. In silico analysis predicted that these variants induced thermodynamic changes with a pathogenic impact on protein function. To support the pathogenicity of the identified variants, cytogenetic analysis and microscopy assays showed that patient-derived fibroblasts exhibited spontaneous chromosomal breaks and flow cytometry demonstrated defects in cell proliferation and enhanced apoptosis. These findings contribute to our understanding of the molecular pathogenesis of SPONASTRIME dysplasia and might open the way to novel therapeutic approaches.
Assuntos
Quebra Cromossômica , Predisposição Genética para Doença , NF-kappa B/genética , Osteocondrodisplasias/genética , Apoptose/genética , Proliferação de Células/genética , Criança , Feminino , Citometria de Fluxo , Humanos , Sequenciamento do ExomaRESUMO
Acute lymphoblastic leukaemia (ALL) is an aggressive haematological tumour driven by the malignant transformation and expansion of B-cell (B-ALL) or T-cell (T-ALL) progenitors. The evolution of T-ALL pathogenesis encompasses different master developmental pathways, including the main role played by Notch in cell fate choices during tissue differentiation. Recently, a growing body of evidence has highlighted epigenetic changes, particularly the altered expression of microRNAs (miRNAs), as a critical molecular mechanism to sustain T-ALL. The immune response is emerging as key factor in the complex multistep process of cancer but the role of miRNAs in anti-leukaemia response remains elusive. In this review we analyse the available literature on miRNAs as tuners of the immune response in T-ALL, focusing on their role in Natural Killer, T, T-regulatory and Myeloid-derived suppressor cells. A better understanding of this molecular crosstalk may provide the basis for the development of potential immunotherapeutic strategies in the leukemia field.
Assuntos
Biomarcadores Tumorais , Regulação Leucêmica da Expressão Gênica , Imunomodulação/genética , MicroRNAs/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/etiologia , Animais , Progressão da Doença , Suscetibilidade a Doenças , Humanos , Células Supressoras Mieloides/imunologia , Células Supressoras Mieloides/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/terapia , Interferência de RNA , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/patologia , Transcrição Gênica , Microambiente Tumoral/genética , Microambiente Tumoral/imunologiaRESUMO
Notch signaling plays a complex role in carcinogenesis, and its signaling pathway has both tumor suppressor and oncogenic components. To identify regulators that might control this dual activity of NOTCH1, we screened a chemical library targeting kinases and identified Polo-like kinase 1 (PLK1) as one of the kinases involved in arsenite-induced NOTCH1 down-modulation. As PLK1 activity drives mitotic entry but also is inhibited after DNA damage, we investigated the PLK1-NOTCH1 interplay in the G2 phase of the cell cycle and in response to DNA damage. Here, we found that PLK1 regulates NOTCH1 expression at G2/M transition. However, when cells in G2 phase are challenged with DNA damage, PLK1 is inhibited to prevent entry into mitosis. Interestingly, we found that the interaction between NOTCH1 and PLK1 is functionally important during the DNA damage response, as we found that whereas PLK1 activity is inhibited, NOTCH1 expression is maintained during DNA damage response. During genotoxic stress, cellular transformation requires that promitotic activity must override DNA damage checkpoint signaling to drive proliferation. Interestingly, we found that arsenite-induced genotoxic stress causes a PLK1-dependent signaling response that antagonizes the involvement of NOTCH1 in the DNA damage checkpoint. Taken together, our data provide evidence that Notch signaling is altered but not abolished in SCC cells. Thus, it is also important to recognize that Notch plasticity might be modulated and could represent a key determinant to switch on/off either the oncogenic or tumor suppressor function of Notch signaling in a single type of tumor.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Dano ao DNA , Mitose , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptor Notch1/metabolismo , Apoptose/efeitos dos fármacos , Arsenitos/toxicidade , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Proteínas de Ciclo Celular/antagonistas & inibidores , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citocinas/metabolismo , Regulação para Baixo/efeitos dos fármacos , Fase G2/efeitos dos fármacos , Humanos , Mediadores da Inflamação/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Mitose/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteólise/efeitos dos fármacos , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Especificidade por Substrato/efeitos dos fármacos , Quinase 1 Polo-LikeRESUMO
DNA is an entity shielded by mechanisms that maintain genomic stability and are essential for living cells; however, DNA is constantly subject to assaults from the environment throughout the cellular life span, making the genome susceptible to mutation and irreparable damage. Cells are prepared to mend such events through cell death as an extrema ratio to solve those threats from a multicellular perspective. However, in cells under various stress conditions, checkpoint mechanisms are activated to allow cells to have enough time to repair the damaged DNA. In yeast, entry into the cell cycle when damage is not completely repaired represents an adaptive mechanism to cope with stressful conditions. In multicellular organisms, entry into cell cycle with damaged DNA is strictly forbidden. However, in cancer development, individual cells undergo checkpoint adaptation, in which most cells die, but some survive acquiring advantageous mutations and selfishly evolve a conflictual behavior. In this review, we focus on how, in cancer development, cells rely on checkpoint adaptation to escape DNA stress and ultimately to cell death.
Assuntos
Dano ao DNA , Pontos de Checagem do Ciclo Celular , Reparo do DNA , Leveduras/genéticaRESUMO
Hailey-Hailey disease (HHD) is a rare, chronic and recurrent blistering disorder, characterized by erosions occurring primarily in intertriginous regions and histologically by suprabasal acantholysis. Mutation of the Golgi Ca2+-ATPase ATP2C1 has been identified as having a causative role in Hailey-Hailey disease. HHD-derived keratinocytes have increased oxidative-stress that is associated with impaired proliferation and differentiation. Additionally, HHD is characterized by skin lesions that do not heal and by recurrent skin infections, indicating that HHD keratinocytes might not respond well to challenges such as wounding or infection. Hypochlorous acid has been demonstrated in vitro and in vivo to possess properties that rescue both oxidative stress and altered wound repair process. Thus, we investigated the potential effects of a stabilized form of hypochlorous acid (APR-TD012) in an in vitro model of HHD. We found that treatment of ATP2C1-defective keratinocytes with APR-TD012 contributed to upregulation of Nrf2 (nuclear factor (erythroid-derived 2)-like 2). Additionally, APR TD012-treatment restored the defective proliferative capability of siATP2C1-treated keratinocytes. We also found that the APR-TD012 treatment might support wound healing process, due to its ability to modulate the expression of wound healing associated cytokines. These observations suggested that the APR-TD012 might be a potential therapeutic agent for HHD-lesions.
Assuntos
Ácidos/química , Ácido Hipocloroso/uso terapêutico , Soluções Hipotônicas/uso terapêutico , Pênfigo Familiar Benigno/tratamento farmacológico , Antioxidantes/metabolismo , ATPases Transportadoras de Cálcio/metabolismo , Linhagem Celular , Citocinas/genética , Citocinas/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Ácido Hipocloroso/farmacologia , Soluções Hipotônicas/farmacologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Queratinócitos/patologia , Fator 2 Relacionado a NF-E2/metabolismo , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Pênfigo Familiar Benigno/genética , Pênfigo Familiar Benigno/patologia , Espécies Reativas de Oxigênio/metabolismo , Soluções , Cicatrização/efeitos dos fármacosRESUMO
The term orthodisease defines human disorders in which the pathogenic gene has orthologs in model organism genomes. Yeasts have been instrumental for gaining insights into the molecular basis of many human disorders, particularly those resulting from impaired cellular metabolism. We and others have used yeasts as a model system to study the molecular basis of Hailey-Hailey disease (HHD), a human blistering skin disorder caused by haploinsufficiency of the gene ATP2C1 the orthologous of the yeast gene PMR1. We observed that K. lactis cells defective for PMR1 gene share several biological similarities with HHD derived keratinocytes. Based on the conservation of ATP2C1/PMR1 function from yeast to human, here we used a yeast-based assay to screen for molecules able to influence the pleiotropy associated with PMR1 deletion. We identified six compounds, Kaempferol, Indirubin, Lappaconite, Cyclocytidine, Azomycin and Nalidixic Acid that induced different major shape phenotypes in K. lactis. These include mitochondrial and the cell-wall morphology-related phenotypes. Interestingly, a secondary assay in mammalian cells confirmed activity for Kaempferol. Indeed, this compound was also active on human keratinocytes depleted of ATP2C1 function by siRNA-treatment used as an in-vitro model of HHD. We found that Kaempferol was a potent NRF2 regulator, strongly inducing its expression and its downstream target NQO1. In addition, Kaempferol could decrease oxidative stress of ATP2C1 defective keratinocytes, characterized by reduced NRF2-expression. Our results indicated that the activation of these pathways might provide protection to the HHD-skin cells. As oxidative stress plays pivotal roles in promoting the skin lesions of Hailey-Hailey, the NRF2 pathway could be a viable therapeutic target for HHD.
Assuntos
Produtos Biológicos/farmacologia , Quempferóis/farmacologia , Kluyveromyces/efeitos dos fármacos , Pênfigo Familiar Benigno/terapia , Produtos Biológicos/uso terapêutico , Cálcio/metabolismo , ATPases Transportadoras de Cálcio/genética , Linhagem Celular , Parede Celular/efeitos dos fármacos , Proteínas Fúngicas/genética , Pleiotropia Genética , Humanos , Quempferóis/uso terapêutico , Queratinócitos/efeitos dos fármacos , Kluyveromyces/genética , Mitocôndrias/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Pênfigo Familiar Benigno/genética , Cultura Primária de CélulasRESUMO
Aberrant upregulation of NOTCH3 gene plays a critical role in cancer pathogenesis. However, the underlying mechanisms are still unknown. We tested here the hypothesis that aberrant epigenetic modifications in the NOTCH3 promoter region might account for its upregulation in cancer cells. We compared DNA and histone methylation status of NOTCH3 promoter region in human normal blood cells and T cell acute lymphoblastic leukemia (T-ALL) cell lines, differentially expressing NOTCH3. We found that histone methylation, rather than DNA hypomethylation, contributes towards establishing an active chromatin status of NOTCH3 promoter in NOTCH3 overexpressing cancer cells. We discovered that the chromatin regulator protein BORIS/CTCFL plays an important role in regulating NOTCH3 gene expression. We observed that BORIS is present in T-ALL cell lines as well as in cell lines derived from several solid tumors overexpressing NOTCH3. Moreover, BORIS targets NOTCH3 promoter in cancer cells and it is able to induce and to maintain a permissive/active chromatin conformation. Importantly, the association between NOTCH3 overexpression and BORIS presence was confirmed in primary T-ALL samples from patients at the onset of the disease. Overall, our results provide novel insights into the determinants of NOTCH3 overexpression in cancer cells, by revealing a key role for BORIS as the main mediator of transcriptional deregulation of NOTCH3.
Assuntos
Proteínas de Ligação a DNA/fisiologia , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Receptores Notch/genética , Células Cultivadas , Metilação de DNA , Humanos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Regiões Promotoras Genéticas , Receptor Notch3RESUMO
BACKGROUND: Rhabdomyosarcoma (RMS) is a highly malignant tumour accounting for nearly half of soft tissue sarcomas in children. MicroRNAs (miRNAs) represent a class of short, non-coding, regulatory RNAs which play a critical role in different cellular processes. Altered miRNA levels have been reported in human cancers, including RMS. METHODS: Using deep sequencing technology, a total of 685 miRNAs were investigated in a group of alveolar RMSs (ARMSs), embryonal RMSs (ERMSs) as well as in normal skeletal muscle (NSM). Q-PCR, MTT, cytofluorimetry, migration assay, western blot and immunofluorescence experiments were carried out to determine the role of miR-378a-3p in cancer cell growth, apoptosis, migration and differentiation. Bioinformatics pipelines were used for miRNA target prediction and clustering analysis. RESULTS: Ninety-seven miRNAs were significantly deregulated in ARMS and ERMS when compared to NSM. MiR-378 family members were dramatically decreased in RMS tumour tissue and cell lines. Interestingly, members of the miR-378 family presented as a possible target the insulin-like growth factor receptor 1 (IGF1R), a key signalling molecule in RMS. MiR-378a-3p over-expression in an RMS-derived cell line suppressed IGF1R expression and affected phosphorylated-Akt protein levels. Ectopic expression of miR-378a-3p caused significant changes in apoptosis, cell migration, cytoskeleton organization as well as a modulation of the muscular markers MyoD1, MyoR, desmin and MyHC. In addition, DNA demethylation by 5-aza-2'-deoxycytidine (5-aza-dC) was able to up-regulate miR-378a-3p levels with a concomitant induction of apoptosis, decrease in cell viability and cell cycle arrest in G2-phase. Cells treated with 5-aza-dC clearly changed their morphology and expressed moderate levels of MyHC. CONCLUSIONS: MiR-378a-3p may function as a tumour suppressor in RMS and the restoration of its expression would be of therapeutic benefit in RMS. Furthermore, the role of epigenetic modifications in RMS deserves further investigations.
Assuntos
MicroRNAs/análise , MicroRNAs/genética , Rabdomiossarcoma/genética , Rabdomiossarcoma/metabolismo , Apoptose , Sequência de Bases , Linhagem Celular Tumoral , Metilação de DNA , Regulação para Baixo , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , MicroRNAs/metabolismo , Dados de Sequência Molecular , Desenvolvimento Muscular , Receptor IGF Tipo 1 , Receptores de Somatomedina/metabolismo , Alinhamento de Sequência , Análise de Sequência de RNARESUMO
Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and accounts for about 5% of all malignant paediatric tumours. ß-Catenin, a multifunctional nuclear transcription factor in the canonical Wnt signaling pathway, is active in myogenesis and embryonal somite patterning. Dysregulation of Wnt signaling facilitates tumour invasion and metastasis. This study characterizes Wnt/ß-catenin signaling and functional activity in paediatric embryonal and alveolar RMS. Immunohistochemical assessment of paraffin-embedded tissues from 44 RMS showed ß-catenin expression in 26 cases with cytoplasmic/membranous expression in 9/14 cases of alveolar RMS, and 15/30 cases of embryonal RMS, whereas nuclear expression was only seen in 2 cases of embryonal RMS. The potential functional significance of ß-catenin expression was tested in four RMS cell lines, two derived from embryonal (RD and RD18) RMS and two from alveolar (Rh4 and Rh30) RMS. Western blot analysis demonstrated the expression of Wnt-associated proteins including ß-catenin, glycogen synthase kinase-3ß, disheveled, axin-1, naked, LRP-6 and cadherins in all cell lines. Cell fractionation and immunofluorescence studies of the cell lines (after stimulation by human recombinant Wnt3a) showed reduced phosphorylation of ß-catenin, stabilization of the active cytosolic form and nuclear translocation of ß-catenin. Reporter gene assay demonstrated a T-cell factor/lymphoid-enhancing factor-mediated transactivation in these cells. In response to human recombinant Wnt3a, the alveolar RMS cells showed a significant decrease in proliferation rate and induction of myogenic differentiation (myogenin, MyoD1 and myf5). These data indicate that the central regulatory components of canonical Wnt/ß-catenin signaling are expressed and that this pathway is functionally active in a significant subset of RMS tumours and might represent a novel therapeutic target.
Assuntos
Rabdomiossarcoma Alveolar/metabolismo , Rabdomiossarcoma Embrionário/metabolismo , Neoplasias de Tecidos Moles/metabolismo , Via de Sinalização Wnt , Proteína Wnt3A/metabolismo , beta Catenina/metabolismo , Adolescente , Adulto , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Núcleo Celular/patologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Fosforilação , Processamento de Proteína Pós-Traducional , Estabilidade Proteica , Transporte Proteico , Proteínas Recombinantes/metabolismo , Rabdomiossarcoma Alveolar/patologia , Rabdomiossarcoma Embrionário/patologia , Neoplasias de Tecidos Moles/patologia , Proteína Wnt3A/genética , Adulto JovemRESUMO
In the yeast Kluyveromyces lactis, glucose 6-phosphate dehydrogenase (G6PDH) is detected as two differently migrating forms on native polyacrylamide gels. The pivotal metabolic role of G6PDH in K. lactis led us to investigate the mechanism controlling the two activities in respiratory and fermentative mutant strains. An extensive analysis of these mutants showed that the NAD(+)(H)/NADP(+)(H)-dependent cytosolic alcohol (ADH) and aldehyde (ALD) dehydrogenase balance affects the expression of the G6PDH activity pattern. Under fermentative/ethanol growth conditions, the concomitant activation of ADH and ALD activities led to cytosolic accumulation of NADPH, triggering an alteration in the oligomeric state of the G6PDH caused by displacement/release of the structural NADP(+) bound to each subunit of the enzyme. The new oligomeric G6PDH form with faster-migrating properties increases as a consequence of intracellular redox unbalance/NADPH accumulation, which inhibits G6PDH activity in vivo. The appearance of a new G6PDH-specific activity band, following incubation of Saccharomyces cerevisiae and human cellular extracts with NADP(+), also suggests that a regulatory mechanism of this activity through NADPH accumulation is highly conserved among eukaryotes.
Assuntos
Glucosefosfato Desidrogenase/metabolismo , Kluyveromyces/enzimologia , NADP/metabolismo , Subunidades Proteicas/metabolismo , Álcool Desidrogenase/genética , Álcool Desidrogenase/metabolismo , Aldeído Desidrogenase/genética , Aldeído Desidrogenase/metabolismo , Sequência de Aminoácidos , Linhagem Celular , Citoplasma/metabolismo , Glucosefosfato Desidrogenase/química , Humanos , Kluyveromyces/genética , Kluyveromyces/metabolismo , Dados de Sequência Molecular , Mutação , Oxirredução , Multimerização Proteica , Saccharomyces cerevisiae/enzimologiaRESUMO
Colorectal cancer (CRC) is characterized by early metastasis, resistance to anti-cancer therapy, and high mortality rate. Despite considerable progress in the development of new treatment options that improved survival benefits in patients with early-stage or advanced CRC, many patients relapse due to the activation of intrinsic or acquired chemoresistance mechanisms. Recently, we reported novel findings about the role of Jagged1 in CRC tumors with Kras signatures. We showed that Jagged1 is a novel proteolytic target of Kras signaling, which induces Jagged1 processing/activation resulting in Jag1-ICD release, which favors tumor development in vivo, through a non-canonical mechanism. Herein, we demonstrate that OXP and 5FU cause a strong accumulation of Jag1-ICD oncogene, through ERK1/2 activation, unveiling a surviving subpopulation with an enforced Jag1-ICD expression, presenting the ability to counteract OXP/5FU-induced apoptosis. Remarkably, we also clarify the clinical ineffectiveness of γ-secretase inhibitors (GSIs) in metastatic CRC (mCRC) patients. Indeed, we show that GSI compounds trigger Jag1-ICD release, which promotes cellular growth and EMT processes, functioning as tumor-promoting agents in CRC cells overexpressing Jagged1. We finally demonstrate that Jagged1 silencing in OXP- or 5FU-resistant subpopulations is enough to restore the sensitivity to chemotherapy, confirming that drug sensitivity/resistance is Jag1-ICD-dependent, suggesting Jagged1 as a molecular predictive marker for the outcome of chemotherapy.
RESUMO
In Saccharomyces cerevisiae, HSL1 (NIK1) encodes a serine-threonine protein kinase involved in cell cycle control and morphogenesis. Deletion of its putative orthologue in Kluyveromyces lactis, KlHSL1, gives rise to sensitivity to the respiratory inhibitor antimycin A (AA). Resistance to AA on glucose (Rag+ phenotype) is associated with genes (RAG) required for glucose metabolism/glycolysis. To understand the relationship between RAG and KlHSL1, rag and Klhsl1Δ mutant strains were investigated. The analysis showed that all the mutants contained a phosphorylated form of Hog1 and displayed an inability to synthesize/accumulate glycerol as a compatible solute. In addition, rag mutants also showed alterations in both cell wall and membrane fatty acids. The pleiotropic defects of these strains indicate that a common pathway regulates glucose utilization and stress response mechanisms, suggesting impaired adaptation of the plasma membrane/cell wall during the respiratory-fermentative transition. KlHsl1 could be the link between these adaptive pathways and the morphogenetic checkpoint.
Assuntos
Proteínas Fúngicas/metabolismo , Glicerol/metabolismo , Kluyveromyces/enzimologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Kluyveromyces/genética , Kluyveromyces/metabolismo , Proteínas Serina-Treonina Quinases/genética , Deleção de SequênciaRESUMO
Hailey-Hailey disease (HHD) is an autosomal dominant disorder characterized by suprabasal cutaneous cell separation (acantholysis) leading to the development of erosive and oozing skin lesion. Micro RNAs (miRNAs) are endogenous post-transcriptional modulators of gene expression with critical functions in health and disease. Here, we evaluated whether the expression of specific miRNAs may play a role in the pathogenesis of HHD. Here, we report that miRNAs are expressed in a non-random manner in Hailey-Hailey patients. miR-125b appeared a promising candidate for playing a role in HHD manifestation. Both Notch1 and p63 are part of a regulatory signalling whose function is essential for the control of keratinocyte proliferation and differentiation and of note, the expression of both Notch1 and p63 is downregulated in HHD-derived keratinocytes. We found that both Notch1 and p63 expression is strongly suppressed by miR-125b expression. Additionally, we found that miR-125b expression is increased by an oxidative stress-dependent mechanism. Our data suggest that oxidative stress-mediated induction of miR-125b plays a specific role in the pathogenesis of HHD by regulating the expression of factors playing an important role in keratinocyte proliferation and differentiation.
Assuntos
MicroRNAs/genética , MicroRNAs/metabolismo , Pênfigo Familiar Benigno/genética , Pênfigo Familiar Benigno/metabolismo , Sequência de Bases , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Primers do DNA/genética , Regulação para Baixo , Humanos , Queratinócitos/metabolismo , Queratinócitos/patologia , Modelos Biológicos , Estresse Oxidativo , Pênfigo Familiar Benigno/patologia , Receptor Notch1/genética , Receptor Notch1/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismoRESUMO
In the physiopathology of cystic fibrosis (CF), oxidative stress implications are recognized and widely accepted. The cystic fibrosis transmembrane conductance regulator (CFTR) defects disrupt the intracellular redox balance causing CF pathological hallmarks. Therefore, oxidative stress together with aberrant expression levels of detoxification genes and microRNAs (miRNAs/miRs) may be associated with clinical outcome. Using total RNA extracted from epithelial nasal cells, the present study analyzed the expression levels of oxidative stress genes and one miRNA using quantitative PCR in a representative number of patients with CF compared with in healthy individuals. The present pilot study revealed the existence of an association among CFTR, genes involved in the oxidative stress response and miR-125b. The observed downregulation of CFTR gene expression was accompanied by increased expression levels of Nuclear factor erythroid derived-2 like2 and its targets NAD(P)H:Quinone Oxidoreductase and glutathione S-transferase 1. Moreover, the expression levels of heme oxygenase-1 (HO-1) and miR-125b were positively correlated with a forced expiratory volume in 1 sec (FEV1) >60% in patients with CF with chronic Pseudomonas aeruginosa lung infection (r=0.74; P<0.001 and r=0.57; P<0.001, respectively). The present study revealed the activation of an inducible, but not fully functional, oxidative stress response to protect airway cells against reactive oxygen species-dependent injury in CF disease. Additionally, the correlations of HO-1 and miR-125b expression with an improved FEV1 value suggested that these factors may synergistically protect the airway cells from oxidative stress damage, inflammation and apoptosis. Furthermore, HO-1 and miR-125b may be used as prognostic markers explaining the wide CF phenotypic variability as an additional control level over the CFTR gene mutations.
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Both CDKN1A (p21 Waf1/Cip1) and Apoptosis signal-regulating kinase 1 (ASK1) play important roles in tumorigenesis. The role of p21 Waf1/Cip1 in attenuating ASK1-induced apoptosis by various stress conditions is well established. However, how ASK1 and p21 Waf1/Cip1 functionally interact during tumorigenesis is still unclear. To address this aspect, we crossed ASK1 knockout (ASK1KO) mice with p21 Waf1/Cip1 knockout (p21KO) mice to compare single and double-mutant mice. We observed that deletion of p21 Waf1/Cip1 leads to increased keratinocyte proliferation but also increased cell death. This is mechanistically linked to the ASK1 axis-induced apoptosis, including p38 and PARP. Indeed, deletion of ASK1 does not alter the proliferation but decreases the apoptosis of p21KO keratinocytes. To analyze as this interaction might affect skin carcinogenesis, we investigated the response of ASK1KO and p21KO mice to DMBA/TPA-induced tumorigenesis. Here we show that while endogenous ASK1 is dispensable for skin homeostasis, ASK1KO mice are resistant to DMBA/TPA-induced tumorigenesis. However, we found that epidermis lacking both p21 and ASK1 reacquires increased sensitivity to DMBA/TPA-induced tumorigenesis. We demonstrate that apoptosis and cell-cycle progression in p21KO keratinocytes are uncoupled in the absence of ASK1. These data support the model that a critical event ensuring the balance between cell death, cell-cycle arrest, and successful divisions in keratinocytes during stress conditions is the p21-dependent ASK1 inactivation.
RESUMO
AIM: Activity and toxiciy of gefitinib in combination with topotecan and cyclophosphamide (CPA) were evaluated in a case-series of relapsed neuroblastoma (NB) patients. The in vitro activity of the combination was also assessed. PROCEDURE: Gefitinib (250 mg/day), topotecan (0.8 mg/m(2)/day), and CPA (50 mg/m(2)/day) (GTC) were administered orally for 14 consecutive days out of 28 days. Antitumor activity of gefitinib as single agent and in combination with either topotecan or CPA was assessed in a panel of NB cell lines. RESULTS: Ninety-two courses were given in 10 patients. Grade 4 neutropenia was observed in 7/92 courses (8%) and grade 4 thrombocytopenia in 8/92 (9%). Two patients had a grade 2 liver toxicity, four a grade 1/2 skin toxicity, and two a grade 1/2 diarrhea. Dose reduction of topotecan and/or CPA was required in eight patients. After four courses, three patients were in partial response (PR) and four with a stable disease (SD), while three experienced a progressive disease (PD). Time to progression (TTP) was 9 months (range, 1-27). After a median follow-up of 16 months (range 5-54), seven patients are died of disease (DOD) and three alive with disease (AWD). All but one patient discontinued oral chemotherapy because of a PD, whilst one patient stopped chemotherapy after 27 months with a SD. In vitro, gefitinib was synergistic with topotecan and additive with CPA. CONCLUSION: The GTC combination was well tolerated and the TTP was encouraging. These promising results, also supported by in vitro evidence, should be further confirmed in a phase II study.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Recidiva Local de Neoplasia/tratamento farmacológico , Neuroblastoma/tratamento farmacológico , Terapia de Salvação , Administração Oral , Idoso , Idoso de 80 Anos ou mais , Ciclofosfamida/administração & dosagem , Resistencia a Medicamentos Antineoplásicos , Receptores ErbB/genética , Receptores ErbB/metabolismo , Feminino , Gefitinibe , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neuroblastoma/genética , Neuroblastoma/metabolismo , Projetos Piloto , Prognóstico , Quinazolinas/administração & dosagem , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de Sobrevida , Topotecan/administração & dosagem , Resultado do TratamentoRESUMO
Neuroblastoma (NB) originates from neural crest-derived precursors and represents the most common childhood extracranial solid tumour. MicroRNAs (miRNAs), a class of small non-coding RNAs that participate in a wide variety of biological processes by regulating gene expression, appear to play an essential role within the NB context. High-throughput next generation sequencing (NGS) was applied to study the miRNA transcriptome in a cohort of NB tumours with and without MYCN-amplification (MNA and MNnA, respectively) and in dorsal root ganglia (DRG), as a control. Out of the 128 miRNAs differentially expressed in the NB vs. DRG comparison, 47 were expressed at higher levels, while 81 were expressed at lower levels in the NB tumours. We also found that 23 miRNAs were differentially expressed in NB with or without MYCN-amplification, with 17 miRNAs being upregulated and 6 being downregulated in the MNA subtypes. Functional annotation analysis of the target genes of these differentially expressed miRNAs demonstrated that many mRNAs were involved in cancer-related pathways, such as DNA-repair and apoptosis as well as FGFR and EGFR signalling. In particular, we found that miR-628-3p negatively affects MYCN gene expression. Furthermore, we identified a novel miRNA candidate with variable expression in MNA vs. MNnA tumours, whose putative target genes are implicated in the mTOR pathway. The present study provides further insight into the molecular mechanisms that correlate miRNA dysregulation to NB development and progression.
Assuntos
Biomarcadores Tumorais/genética , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , MicroRNAs/genética , Proteína Proto-Oncogênica N-Myc/genética , Neuroblastoma/genética , Adolescente , Criança , Pré-Escolar , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lactente , Masculino , Transdução de Sinais , TranscriptomaRESUMO
Mutation of the Golgi Ca(2+)-ATPase ATP2C1 is associated with deregulated calcium homeostasis and altered skin function. ATP2C1 mutations have been identified as having a causative role in Hailey-Hailey disease, an autosomal-dominant skin disorder. Here, we identified ATP2C1 as a crucial regulator of epidermal homeostasis through the regulation of oxidative stress. Upon ATP2C1 inactivation, oxidative stress and Notch1 activation were increased in cultured human keratinocytes. Using RNA-seq experiments, we found that the DNA damage response (DDR) was consistently down-regulated in keratinocytes derived from the lesions of patients with Hailey-Hailey disease. Although oxidative stress activates the DDR, ATP2C1 inactivation down-regulates DDR gene expression. We showed that the DDR response was a major target of oxidative stress-induced Notch1 activation. Here, we show that this activation is functionally important because early Notch1 activation in keratinocytes induces keratinocyte differentiation and represses the DDR. These results indicate that an ATP2C1/NOTCH1 axis might be critical for keratinocyte function and cutaneous homeostasis, suggesting a plausible model for the pathological features of Hailey-Hailey disease.
Assuntos
ATPases Transportadoras de Cálcio/genética , Dano ao DNA , Epiderme/metabolismo , Homeostase , Pênfigo Familiar Benigno/patologia , Receptor Notch1/metabolismo , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Diferenciação Celular , Epiderme/patologia , Expressão Gênica , Humanos , Queratinócitos/citologia , Queratinócitos/metabolismo , Estresse Oxidativo , Pênfigo Familiar Benigno/genéticaRESUMO
Notch signaling plays a complex role in carcinogenesis, and its signaling pathway has both tumor-suppressor and oncogenic components. In this study we investigated the effects of reactive oxygen species (ROS) on Notch1 signaling outcome in keratinocyte biology. We demonstrate that Notch1 function contributes to the arsenic-induced keratinocyte transformation. We found that acute exposure to arsenite increases oxidative stress and inhibits proliferation of keratinocyte cells by upregulation of p21(waf1/Cip1). The necessity of p21(waf1/Cip1) for arsenite-induced cell death was demonstrated by targeted downregulation of p21(waf1/Cip1) by using RNA interference. We further demonstrated that on acute exposure to arsenite, p21(waf1/Cip1) is upregulated and Notch1 downmodulated, whereas on chronic exposure to arsenite, malignant progression of arsenite-treated keratinocytes cells was accompanied by regained expression and activity of Notch1. Notch1 activity in arsenite-transformed keratinocytes inhibits arsenite-induced upregulation of p21(waf1/Cip1) by sustaining c-myc expression. We further demonstrated that c-myc collaborates with Nrf2, a key regulator for the maintenance of redox homeostasis, to promote metabolic activities that support cell proliferation and cytoprotection. Therefore, Notch1-mediated repression of p21(waf1/Cip1) expression results in the inhibition of cell death and keratinocytes transformation. Our results not only demonstrate that sustained Notch1 expression is at least one key event implicated in the arsenite human skin carcinogenic effect, but also may provide mechanistic insights into the molecular aspects that determine whether Notch signaling will be either oncogenic or tumor suppressive.