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The SARS-CoV-2 pandemic, responsible for approximately 7 million deaths worldwide, highlights the urgent need to understand the molecular mechanisms of the virus in order to prevent future outbreaks. The Spike glycoprotein of SARS-CoV-2, which is critical for viral entry through its interaction with ACE2 and other host cell receptors, has been a focus of this study. The present research goes beyond receptor recognition to explore Spike's influence on cellular metabolism. AP-MS interactome analysis revealed an interaction between the Spike S1 domain and lactate dehydrogenase B (LDHB), which was further confirmed by co-immunoprecipitation and immunofluorescence, indicating colocalisation in cells expressing the S1 domain. The study showed that Spike inhibits the catalytic activity of LDHB, leading to increased lactate levels in HEK-293T cells overexpressing the S1 subunit. In the hypothesised mechanism, Spike deprives LDHB of NAD+, facilitating a metabolic switch from aerobic to anaerobic energy production during infection. The Spike-NAD+ interacting region was characterised and mainly involves the W436 within the RDB domain. This novel hypothesis suggests that the Spike protein may play a broader role in altering host cell metabolism, thereby contributing to the pathophysiology of viral infection.
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ATP2B1 is a known regulator of calcium (Ca2+) cellular export and homeostasis. Diminished levels of intracellular Ca2+ content have been suggested to impair SARS-CoV-2 replication. Here, we demonstrate that a nontoxic caloxin-derivative compound (PI-7) reduces intracellular Ca2+ levels and impairs SARS-CoV-2 infection. Furthermore, a rare homozygous intronic variant of ATP2B1 is shown to be associated with the severity of COVID-19. The mechanism of action during SARS-CoV-2 infection involves the PI3K/Akt signaling pathway activation, inactivation of FOXO3 transcription factor function, and subsequent transcriptional inhibition of the membrane and reticulum Ca2+ pumps ATP2B1 and ATP2A1, respectively. The pharmacological action of compound PI-7 on sustaining both ATP2B1 and ATP2A1 expression reduces the intracellular cytoplasmic Ca2+ pool and thus negatively influences SARS-CoV-2 replication and propagation. As compound PI-7 lacks toxicity in vitro, its prophylactic use as a therapeutic agent against COVID-19 is envisioned here.
Assuntos
COVID-19 , Cálcio , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , SARS-CoV-2 , Transdução de Sinais , Replicação Viral , Humanos , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/fisiologia , Replicação Viral/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , COVID-19/virologia , COVID-19/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Cálcio/metabolismo , Animais , Proteína Forkhead Box O3/metabolismo , Proteína Forkhead Box O3/genética , Chlorocebus aethiops , Tratamento Farmacológico da COVID-19 , Células Vero , Feminino , ATPases Transportadoras de Cálcio/metabolismo , ATPases Transportadoras de Cálcio/genética , MasculinoRESUMO
Medulloblastoma (MB) is a highly malignant childhood brain tumor. Group 3 MB (Gr3 MB) is considered to have the most metastatic potential, and tailored therapies for Gr3 MB are currently lacking. Gr3 MB is driven by PRUNE-1 amplification or overexpression. In this paper, we found that PRUNE-1 was transcriptionally regulated by lysine demethylase LSD1/KDM1A. This study aimed to investigate the therapeutic potential of inhibiting both PRUNE-1 and LSD1/KDM1A with the selective inhibitors AA7.1 and SP-2577, respectively. We found that the pharmacological inhibition had a substantial efficacy on targeting the metastatic axis driven by PRUNE-1 (PRUNE-1-OTX2-TGFß-PTEN) in Gr3 MB. Using RNA seq transcriptomic feature data in Gr3 MB primary cells, we provide evidence that the combination of AA7.1 and SP-2577 positively affects neuronal commitment, confirmed by glial fibrillary acidic protein (GFAP)-positive differentiation and the inhibition of the cytotoxic components of the tumor microenvironment and the epithelial-mesenchymal transition (EMT) by the down-regulation of N-Cadherin protein expression. We also identified an impairing action on the mitochondrial metabolism and, consequently, oxidative phosphorylation, thus depriving tumors cells of an important source of energy. Furthermore, by overlapping the genomic mutational signatures through WES sequence analyses with RNA seq transcriptomic feature data, we propose in this paper that the combination of these two small molecules can be used in a second-line treatment in advanced therapeutics against Gr3 MB. Our study demonstrates that the usage of PRUNE-1 and LSD1/KDM1A inhibitors in combination represents a novel therapeutic approach for these highly aggressive metastatic MB tumors.
Assuntos
Neoplasias Encefálicas , Neoplasias Cerebelares , Meduloblastoma , Humanos , Criança , Meduloblastoma/tratamento farmacológico , Meduloblastoma/genética , Histona Desmetilases/genética , Epigênese Genética , Microambiente TumoralRESUMO
Medulloblastoma (MB) is a highly malignant childhood tumor of the cerebellum. Transcriptional and epigenetic signatures have classified MB into four molecular subgroups, further stratified into biologically different subtypes with distinct somatic copy-number aberrations, driver genes, epigenetic alterations, activated pathways, and clinical outcomes. The brain tumor microenvironment (BTME) is of importance to regulate a complex network of cells, including immune cells, involved in cancer progression in brain malignancies. MB was considered with a "cold" immunophenotype due to the low influx of immune cells across the blood brain barrier (BBB). Recently, this assumption has been reconsidered because of the identification of infiltrating immune cells showing immunosuppressive phenotypes in the BTME of MB tumors. Here, we are providing a comprehensive overview of the current status of epigenetics alterations occurring during cancer progression with a description of the genomic landscape of MB by focusing on immune cells within the BTME. We further describe how new immunotherapeutic approaches could influence concurring epigenetic mechanisms of the immunosuppressive cells in BTME. In conclusion, the modulation of these molecular genetic complexes in BTME during cancer progression might enhance the therapeutic benefit, thus firing new weapons to fight MB.
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PURPOSE: Emerging evidence suggest that infection-dependent hyperactivation of complement system (CS) may worsen COVID-19 outcome. We investigated the role of predicted high impact rare variants - referred as qualifying variants (QVs) - of CS genes in predisposing asymptomatic COVID-19 in elderly individuals, known to be more susceptible to severe disease. METHODS: Exploiting exome sequencing data and 56 CS genes, we performed a gene-based collapsing test between 164 asymptomatic subjects (aged ≥60 years) and 56,885 European individuals from the Genome Aggregation Database. We replicated this test comparing the same asymptomatic individuals with 147 hospitalized patients with COVID-19. RESULTS: We found an enrichment of QVs in 3 genes (MASP1, COLEC11, and COLEC10), which belong to the lectin pathway, in the asymptomatic cohort. Analyses of complement activity in serum showed decreased activity of lectin pathway in asymptomatic individuals with QVs. Finally, we found allelic variants associated with asymptomatic COVID-19 phenotype and with a decreased expression of MASP1, COLEC11, and COLEC10 in lung tissue. CONCLUSION: This study suggests that genetic rare variants can protect from severe COVID-19 by mitigating the activity of lectin pathway and prothrombin. The genetic data obtained through ES of 786 asymptomatic and 147 hospitalized individuals are publicly available at http://espocovid.ceinge.unina.it/.
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COVID-19 , Idoso , COVID-19/genética , Colectinas/genética , Colectinas/metabolismo , Células Germinativas , Humanos , Lectinas/genética , SARS-CoV-2 , Sequenciamento do ExomaRESUMO
The development of prophylactic agents against the SARS-CoV-2 virus is a public health priority in the search for new surrogate markers of active virus replication. Early detection markers are needed to follow disease progression and foresee patient negativization. Subgenomic RNA transcripts (with a focus on sgN) were evaluated in oro/nasopharyngeal swabs from COVID-19-affected patients with an analysis of 315 positive samples using qPCR technology. Cut-off Cq values for sgN (Cq < 33.15) and sgE (Cq < 34.06) showed correlations to high viral loads. The specific loss of sgN in home-isolated and hospitalized COVID-19-positive patients indicated negativization of patient condition, 3-7 days from the first swab, respectively. A new detection kit for sgN, gene E, gene ORF1ab, and gene RNAse P was developed recently. In addition, in vitro studies have shown that 2'-O-methyl antisense RNA (related to the sgN sequence) can impair SARS-CoV-2 N protein synthesis, viral replication, and syncytia formation in human cells (i.e., HEK-293T cells overexpressing ACE2) upon infection with VOC Alpha (B.1.1.7)-SARS-CoV-2 variant, defining the use that this procedure might have for future therapeutic actions against SARS-CoV-2.
Assuntos
COVID-19/virologia , Proteínas do Nucleocapsídeo de Coronavírus/genética , SARS-CoV-2/fisiologia , Replicação Viral/fisiologia , Proteínas do Nucleocapsídeo de Coronavírus/análise , Células Gigantes/efeitos dos fármacos , Células Gigantes/virologia , Células HEK293 , Humanos , Limite de Detecção , Nasofaringe/virologia , Fosfoproteínas/análise , Fosfoproteínas/genética , RNA Antissenso/farmacologia , RNA Viral , Ribonuclease P/genética , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/genética , Sensibilidade e Especificidade , Isolamento Social , Carga Viral , Proteínas Viroporinas/genética , Replicação Viral/efeitos dos fármacosRESUMO
Posterior fossa A (PFA) ependymomas are lethal malignancies of the hindbrain in infants and toddlers. Lacking highly recurrent somatic mutations, PFA ependymomas are proposed to be epigenetically driven tumors for which model systems are lacking. Here we demonstrate that PFA ependymomas are maintained under hypoxia, associated with restricted availability of specific metabolites to diminish histone methylation, and increase histone demethylation and acetylation at histone 3 lysine 27 (H3K27). PFA ependymomas initiate from a cell lineage in the first trimester of human development that resides in restricted oxygen. Unlike other ependymomas, transient exposure of PFA cells to ambient oxygen induces irreversible cellular toxicity. PFA tumors exhibit a low basal level of H3K27me3, and, paradoxically, inhibition of H3K27 methylation specifically disrupts PFA tumor growth. Targeting metabolism and/or the epigenome presents a unique opportunity for rational therapy for infants with PFA ependymoma.
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Ependimoma/genética , Ependimoma/metabolismo , Epigenoma/genética , Neoplasias Infratentoriais/genética , Neoplasias Infratentoriais/metabolismo , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Linhagem Celular , Proliferação de Células/genética , Metilação de DNA/genética , Epigenômica/métodos , Histonas/genética , Histonas/metabolismo , Humanos , Lactente , Lisina/genética , Lisina/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Mutação/genéticaRESUMO
Recurrent medulloblastoma and ependymoma are universally lethal, with no approved targeted therapies and few candidates presently under clinical evaluation. Nearly all recurrent medulloblastomas and posterior fossa group A (PFA) ependymomas are located adjacent to and bathed by the cerebrospinal fluid, presenting an opportunity for locoregional therapy, bypassing the blood-brain barrier. We identify three cell-surface targets, EPHA2, HER2 and interleukin 13 receptor α2, expressed on medulloblastomas and ependymomas, but not expressed in the normal developing brain. We validate intrathecal delivery of EPHA2, HER2 and interleukin 13 receptor α2 chimeric antigen receptor T cells as an effective treatment for primary, metastatic and recurrent group 3 medulloblastoma and PFA ependymoma xenografts in mouse models. Finally, we demonstrate that administration of these chimeric antigen receptor T cells into the cerebrospinal fluid, alone or in combination with azacytidine, is a highly effective therapy for multiple metastatic mouse models of group 3 medulloblastoma and PFA ependymoma, thereby providing a rationale for clinical trials of these approaches in humans.
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Neoplasias Encefálicas/terapia , Vacinas Anticâncer/administração & dosagem , Líquido Cefalorraquidiano/efeitos dos fármacos , Ependimoma/terapia , Imunoterapia Adotiva/métodos , Meduloblastoma/terapia , Animais , Neoplasias Encefálicas/líquido cefalorraquidiano , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Neoplasias Cerebelares/líquido cefalorraquidiano , Neoplasias Cerebelares/imunologia , Neoplasias Cerebelares/patologia , Neoplasias Cerebelares/terapia , Líquido Cefalorraquidiano/imunologia , Criança , Pré-Escolar , Sistemas de Liberação de Medicamentos/métodos , Ependimoma/líquido cefalorraquidiano , Ependimoma/imunologia , Ependimoma/patologia , Feminino , Células HEK293 , Humanos , Lactente , Injeções Intraventriculares , Masculino , Meduloblastoma/líquido cefalorraquidiano , Meduloblastoma/imunologia , Meduloblastoma/patologia , Camundongos , Metástase Neoplásica , Receptores de Antígenos Quiméricos/administração & dosagem , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos T/transplante , Resultado do Tratamento , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
In cancer, recurrent somatic single-nucleotide variants-which are rare in most paediatric cancers-are confined largely to protein-coding genes1-3. Here we report highly recurrent hotspot mutations (r.3A>G) of U1 spliceosomal small nuclear RNAs (snRNAs) in about 50% of Sonic hedgehog (SHH) medulloblastomas. These mutations were not present across other subgroups of medulloblastoma, and we identified these hotspot mutations in U1 snRNA in only <0.1% of 2,442 cancers, across 36 other tumour types. The mutations occur in 97% of adults (subtype SHHδ) and 25% of adolescents (subtype SHHα) with SHH medulloblastoma, but are largely absent from SHH medulloblastoma in infants. The U1 snRNA mutations occur in the 5' splice-site binding region, and snRNA-mutant tumours have significantly disrupted RNA splicing and an excess of 5' cryptic splicing events. Alternative splicing mediated by mutant U1 snRNA inactivates tumour-suppressor genes (PTCH1) and activates oncogenes (GLI2 and CCND2), and represents a target for therapy. These U1 snRNA mutations provide an example of highly recurrent and tissue-specific mutations of a non-protein-coding gene in cancer.
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Neoplasias Cerebelares/genética , Proteínas Hedgehog/genética , Meduloblastoma/genética , RNA Nuclear Pequeno/genética , Adolescente , Adulto , Processamento Alternativo , Proteínas Hedgehog/metabolismo , Humanos , Mutação , Sítios de Splice de RNA , Splicing de RNARESUMO
Infant gliomas have paradoxical clinical behavior compared to those in children and adults: low-grade tumors have a higher mortality rate, while high-grade tumors have a better outcome. However, we have little understanding of their biology and therefore cannot explain this behavior nor what constitutes optimal clinical management. Here we report a comprehensive genetic analysis of an international cohort of clinically annotated infant gliomas, revealing 3 clinical subgroups. Group 1 tumors arise in the cerebral hemispheres and harbor alterations in the receptor tyrosine kinases ALK, ROS1, NTRK and MET. These are typically single-events and confer an intermediate outcome. Groups 2 and 3 gliomas harbor RAS/MAPK pathway mutations and arise in the hemispheres and midline, respectively. Group 2 tumors have excellent long-term survival, while group 3 tumors progress rapidly and do not respond well to chemoradiation. We conclude that infant gliomas comprise 3 subgroups, justifying the need for specialized therapeutic strategies.
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Neoplasias Encefálicas/genética , Metilação de DNA , Epigenômica/métodos , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Receptores Proteína Tirosina Quinases/genética , Quinase do Linfoma Anaplásico/genética , Quinase do Linfoma Anaplásico/metabolismo , Neoplasias Encefálicas/classificação , Neoplasias Encefálicas/metabolismo , Feminino , Glioma/classificação , Glioma/metabolismo , Humanos , Lactente , Recém-Nascido , Masculino , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-met/genética , Proteínas Proto-Oncogênicas c-met/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Receptor trkA/genética , Receptor trkA/metabolismo , Análise de Sobrevida , Sequenciamento do Exoma/métodosAssuntos
Carcinoma Hepatocelular/genética , Proteínas de Transporte/genética , Redes Reguladoras de Genes , Neoplasias Hepáticas/genética , Carcinoma Hepatocelular/metabolismo , Proteínas de Transporte/metabolismo , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Regulação Neoplásica da Expressão Gênica , Estudo de Associação Genômica Ampla , Humanos , Neoplasias Hepáticas/metabolismo , Monoéster Fosfórico Hidrolases , Transdução de SinaisRESUMO
Genetic modifications during development of paediatric groups 3 and 4 medulloblastoma are responsible for their highly metastatic properties and poor patient survival rates. PRUNE1 is highly expressed in metastatic medulloblastoma group 3, which is characterized by TGF-ß signalling activation, c-MYC amplification, and OTX2 expression. We describe the process of activation of the PRUNE1 signalling pathway that includes its binding to NME1, TGF-ß activation, OTX2 upregulation, SNAIL (SNAI1) upregulation, and PTEN inhibition. The newly identified small molecule pyrimido-pyrimidine derivative AA7.1 enhances PRUNE1 degradation, inhibits this activation network, and augments PTEN expression. Both AA7.1 and a competitive permeable peptide that impairs PRUNE1/NME1 complex formation, impair tumour growth and metastatic dissemination in orthotopic xenograft models with a metastatic medulloblastoma group 3 cell line (D425-Med cells). Using whole exome sequencing technology in metastatic medulloblastoma primary tumour cells, we also define 23 common 'non-synonymous homozygous' deleterious gene variants as part of the protein molecular network of relevance for metastatic processes. This PRUNE1/TGF-ß/OTX2/PTEN axis, together with the medulloblastoma-driver mutations, is of relevance for future rational and targeted therapies for metastatic medulloblastoma group 3.10.1093/brain/awy039_video1awy039media15742053534001.
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Proteínas de Transporte/metabolismo , Neoplasias Cerebelares/metabolismo , Regulação Neoplásica da Expressão Gênica/fisiologia , Meduloblastoma/metabolismo , Metástase Neoplásica/fisiopatologia , PTEN Fosfo-Hidrolase/metabolismo , Adolescente , Animais , Proteínas de Transporte/genética , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Neoplasias Cerebelares/patologia , Criança , Pré-Escolar , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Redes Reguladoras de Genes , Humanos , Lactente , Masculino , Meduloblastoma/patologia , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Metástase Neoplásica/genética , PTEN Fosfo-Hidrolase/genética , Monoéster Fosfórico Hidrolases , Pirimidinonas/química , Pirimidinonas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Fatores de Transcrição da Família Snail/metabolismo , Fator de Crescimento Transformador beta/metabolismoRESUMO
While the preponderance of morbidity and mortality in medulloblastoma patients are due to metastatic disease, most research focuses on the primary tumor due to a dearth of metastatic tissue samples and model systems. Medulloblastoma metastases are found almost exclusively on the leptomeningeal surface of the brain and spinal cord; dissemination is therefore thought to occur through shedding of primary tumor cells into the cerebrospinal fluid followed by distal re-implantation on the leptomeninges. We present evidence for medulloblastoma circulating tumor cells (CTCs) in therapy-naive patients and demonstrate in vivo, through flank xenografting and parabiosis, that medulloblastoma CTCs can spread through the blood to the leptomeningeal space to form leptomeningeal metastases. Medulloblastoma leptomeningeal metastases express high levels of the chemokine CCL2, and expression of CCL2 in medulloblastoma in vivo is sufficient to drive leptomeningeal dissemination. Hematogenous dissemination of medulloblastoma offers a new opportunity to diagnose and treat lethal disseminated medulloblastoma.
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Meduloblastoma/irrigação sanguínea , Meduloblastoma/patologia , Neoplasias Meníngeas/irrigação sanguínea , Neoplasias Meníngeas/secundário , Aloenxertos , Animais , Linhagem Celular Tumoral , Quimiocina CCL2/metabolismo , Cromossomos Humanos Par 10/genética , Feminino , Humanos , Masculino , Meduloblastoma/genética , Camundongos SCID , Células Neoplásicas Circulantes , ParabioseRESUMO
BACKGROUND: Medulloblastoma is a cerebellar neoplasia of the central nervous system. Four molecular subgrups have been identified (MBWNT, MBSHH, MBgroup3 and MBgroup4) with distinct genetics and clinical outcome. Among these, MBgroup3-4 are highly metastatic with the worst prognosis. The current standard therapy includes surgery, radiation and chemotherapy. Thus, specific treatments adapted to cure those different molecular subgroups are needed. The use of orthotopic xenograft models, together with the non-invasive in vivo biolumiscence imaging (BLI) technology, is emerging during preclinical studies to test novel therapeutics for medulloblastoma treatment. METHODS: Orthotopic MB xenografts were performed by injection of Daoy-luc cells, that had been previously infected with lentiviral particles to stably express luciferase gene, into the fourth right ventricle of the cerebellum of ten nude mice. For the implantation, specific stereotactic coordinates were used. Seven days after the implantation the mice were imaged by acquisitions of bioluminescence imaging (BLI) using IVIS 3D Illumina Imaging System (Xenogen). Tumor growth was evaluated by quantifying the bioluminescence signals using the integrated fluxes of photons within each area of interest using the Living Images Software Package 3.2 (Xenogen-Perkin Elmer). Finally, histological analysis using hematoxylin-eosin staining was performed to confirm the presence of tumorigenic cells into the cerebellum of the mice. RESULTS: We describe a method to use the in vivo bioluminescent imaging (BLI) showing the potential to be used to investigate the potential antitumorigenic effects of a drug for in vivo medulloblastoma treatment. We also discuss other studies in which this technology has been applied to obtain a more comprehensive knowledge of medulloblastoma using orthotopic xenograft mouse models. CONCLUSIONS: There is a need to develop patient's derived-xenograft (PDX) model systems to test novel drugs for medulloblastoma treatment within each molecular sub-groups with a higher predictive value. Here we show how this technology should be applied with hopes on generations of new treatments to be applied then in human.
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Transformação Celular Neoplásica , Meduloblastoma/diagnóstico por imagem , Meduloblastoma/patologia , Imagem Molecular/métodos , Animais , Linhagem Celular Tumoral , Progressão da Doença , Humanos , Medições Luminescentes , Meduloblastoma/tratamento farmacológico , Camundongos , Terapia NeoadjuvanteRESUMO
We recently reported that atypical teratoid rhabdoid tumors (ATRTs) comprise at least two transcriptional subtypes with different clinical outcomes; however, the mechanisms underlying therapeutic heterogeneity remained unclear. In this study, we analyzed 191 primary ATRTs and 10 ATRT cell lines to define the genomic and epigenomic landscape of ATRTs and identify subgroup-specific therapeutic targets. We found ATRTs segregated into three epigenetic subgroups with distinct genomic profiles, SMARCB1 genotypes, and chromatin landscape that correlated with differential cellular responses to a panel of signaling and epigenetic inhibitors. Significantly, we discovered that differential methylation of a PDGFRB-associated enhancer confers specific sensitivity of group 2 ATRT cells to dasatinib and nilotinib, and suggest that these are promising therapies for this highly lethal ATRT subtype.
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Neoplasias do Sistema Nervoso Central/genética , Cromatina/genética , Epigenômica/métodos , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Tumor Rabdoide/genética , Proteína SMARCB1/genética , Teratoma/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Metilação de DNA , Dasatinibe/farmacologia , Dasatinibe/uso terapêutico , Epigênese Genética/efeitos dos fármacos , Humanos , Mutação , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Receptor beta de Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Tumor Rabdoide/tratamento farmacológico , Teratoma/tratamento farmacológicoRESUMO
Nm23-H1 is a metastasis suppressor gene whose overexpression is associated with both reduced cell motility in various cancers and increased metastatic potential in neuroblastomas, osteosarcomas, and hematological malignances. We previously reported that Nm23-H1 exerts tumor suppressor action in prostate cancer cells and that h-Prune, which is overexpressed in various tumor types, binds Nm23-H1. Moreover, blockage of the Nm23-H1/h-Prune interaction with a competitive permeable peptide (CPP) attenuates migration of breast and neuroblastoma cells. This series of events suggests that the Nm23-H1/h-Prune protein complex regulates cancer progression and that its specific impairment could be a new therapeutic strategy in oncology. We found that CPP leads to inhibition of the AKT/mTORv and NF-kBv signaling pathways and also activates apoptosis. To obtain a proof-of-concept of our hypothesis, we used a xenograft model of prostate cancer to evaluate whether impairment of this complex using CPP results in an anti-tumoral effect. Using a mouse orthotopic model with bioluminescent imaging, we show evidences that CPP reduces prostate cancer metastases formation. In conclusion, CPP being able to impair formation of the h-Prune/Nm23-H1 complex holds promise for the treatment of prostate cancer.
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Proteínas de Transporte/metabolismo , Peptídeos Penetradores de Células/uso terapêutico , Nucleosídeo NM23 Difosfato Quinases/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Adenoviridae/genética , Animais , Apoptose , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Peptídeos Penetradores de Células/farmacologia , Humanos , Masculino , Camundongos , Camundongos Nus , Nucleosídeo NM23 Difosfato Quinases/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Previous studies have evaluated the role of miRNAs in cancer initiation and progression. MiR-34a was found to be downregulated in several tumors, including medulloblastomas. Here we employed targeted transgenesis to analyze the function of miR-34a in vivo. We generated mice with a constitutive deletion of the miR-34a gene. These mice were devoid of mir-34a expression in all analyzed tissues, but were viable and fertile. A comprehensive standardized phenotypic analysis including more than 300 single parameters revealed no apparent phenotype. Analysis of miR-34a expression in human medulloblastomas and medulloblastoma cell lines revealed significantly lower levels than in normal human cerebellum. Re-expression of miR-34a in human medulloblastoma cells reduced cell viability and proliferation, induced apoptosis and downregulated the miR-34a target genes, MYCN and SIRT1. Activation of the Shh pathway by targeting SmoA1 transgene overexpression causes medulloblastoma in mice, which is dependent on the presence and upregulation of Mycn. Analysis of miR-34a in medulloblastomas derived from ND2:SmoA1(tg) mice revealed significant suppression of miR-34a compared to normal cerebellum. Tumor incidence was significantly increased and tumor formation was significantly accelerated in mice transgenic for SmoA1 and lacking miR-34a. Interestingly, Mycn and Sirt1 were strongly expressed in medulloblastomas derived from these mice. We here demonstrate that miR-34a is dispensable for normal development, but that its loss accelerates medulloblastomagenesis. Strategies aiming to re-express miR-34a in tumors could, therefore, represent an efficient therapeutic option.