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1.
Cell Mol Life Sci ; 81(1): 276, 2024 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-38909325

RESUMO

N6-methyladenosine (m6A) is one of the most prevalent and conserved RNA modifications. It controls several biological processes, including the biogenesis and function of circular RNAs (circRNAs), which are a class of covalently closed-single stranded RNAs. Several studies have revealed that proteotoxic stress response induction could be a relevant anticancer therapy in Acute Myeloid Leukemia (AML). Furthermore, a strong molecular interaction between the m6A mRNA modification factors and the suppression of the proteotoxic stress response has emerged. Since the proteasome inhibition leading to the imbalance in protein homeostasis is strictly linked to the stress response induction, we investigated the role of Bortezomib (Btz) on m6A regulation and in particular its impact on the modulation of m6A-modified circRNAs expression. Here, we show that treating AML cells with Btz downregulated the expression of the m6A regulator WTAP at translational level, mainly because of increased oxidative stress. Indeed, Btz treatment promoted oxidative stress, with ROS generation and HMOX-1 activation and administration of the reducing agent N-acetylcysteine restored WTAP expression. Additionally, we identified m6A-modified circRNAs modulated by Btz treatment, including circHIPK3, which is implicated in protein folding and oxidative stress regulation. These results highlight the intricate molecular networks involved in oxidative and ER stress induction in AML cells following proteotoxic stress response, laying the groundwork for future therapeutic strategies targeting these pathways.


Assuntos
Adenosina , Leucemia Mieloide Aguda , Estresse Oxidativo , RNA Circular , Humanos , RNA Circular/genética , RNA Circular/metabolismo , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/tratamento farmacológico , Adenosina/análogos & derivados , Adenosina/metabolismo , Adenosina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Bortezomib/farmacologia , Linhagem Celular Tumoral , Espécies Reativas de Oxigênio/metabolismo , Fatores de Processamento de RNA/metabolismo , Fatores de Processamento de RNA/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Heme Oxigenase-1/metabolismo , Heme Oxigenase-1/genética , Proteínas Serina-Treonina Quinases , Peptídeos e Proteínas de Sinalização Intracelular
2.
Semin Cancer Biol ; 97: 50-67, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37956937

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is an extremely deadly form of cancer, with limited progress in 5-year survival rates despite significant research efforts. The main challenges in treating PDAC include difficulties in early detection, and resistance to current therapeutic approaches due to aggressive molecular and microenvironment features. These challenges emphasize the importance of identifying clinically validated biomarkers for early detection and clinical management. Extracellular vesicles (EVs), particularly exosomes, have emerged as crucial mediators of intercellular communication by transporting molecular cargo. Recent research has unveiled their role in initiation, metastasis, and chemoresistance of PDAC. Consequently, utilizing EVs in liquid biopsies holds promise for the identification of biomarkers for early detection, prognosis, and monitoring of drug efficacy. However, numerous limitations, including challenges in isolation and characterization of homogeneous EVs populations, as well as the absence of standardized protocols, can affect the reliability of studies involving EVs as biomarkers, underscoring the necessity for a prudent approach. EVs have also garnered considerable attention as a promising drug delivery system and novel therapy for tumors. The loading of biomolecules or chemical drugs into exosomes and their subsequent delivery to target cells can effectively impede tumor progression. Nevertheless, there are obstacles that must be overcome to ensure the accuracy and efficacy of therapies relying on EVs for the treatment of tumors. In this review, we examine both recent advancements and remaining obstacles, exploring the potential of utilizing EVs in biomarker discovery as well as for the development of drug delivery vehicles.


Assuntos
Carcinoma Ductal Pancreático , Exossomos , Vesículas Extracelulares , Neoplasias Pancreáticas , Humanos , Reprodutibilidade dos Testes , Vesículas Extracelulares/patologia , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/tratamento farmacológico , Biomarcadores , Carcinoma Ductal Pancreático/diagnóstico , Carcinoma Ductal Pancreático/tratamento farmacológico , Microambiente Tumoral
3.
J Transl Med ; 22(1): 213, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38424512

RESUMO

BACKGROUND: First identified in Drosophila melanogaster, the Hippo pathway is considered a major regulatory cascade controlling tissue homeostasis and organ development. Hippo signaling components include kinases whose activity regulates YAP and TAZ final effectors. In response to upstream stimuli, YAP and TAZ control transcriptional programs involved in cell proliferation, cytoskeletal reorganization and stemness. MAIN TEXT: While fine tuning of Hippo cascade components is essential for maintaining the balance between proliferative and non-proliferative signals, pathway signaling is frequently dysregulated in gastrointestinal cancers. Also, YAP/TAZ aberrant activation has been described in conditions characterized by chronic inflammation that precede cancer development, suggesting a role of Hippo effectors in triggering carcinogenesis. In this review, we summarize the architecture of the Hippo pathway and discuss the involvement of signaling cascade unbalances in premalignant lesions of the gastrointestinal tract, providing a focus on the underlying molecular mechanisms. CONCLUSIONS: The biology of premalignant Hippo signaling dysregulation needs further investigation in order to elucidate the evolutionary trajectories triggering cancer inititation and develop effective early therapeutic strategies targeting the Hippo/YAP pathway.


Assuntos
Via de Sinalização Hippo , Neoplasias , Animais , Drosophila melanogaster , Neoplasias/tratamento farmacológico , Transdução de Sinais , Trato Gastrointestinal
4.
Clin Sci (Lond) ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38884602

RESUMO

The high-grade serous ovarian cancer (HG-SOC) tumor microenvironment (TME) is constellated by cellular elements and a network of soluble constituents that contribute to tumor progression. In the multitude of the secreted molecules, the endothelin-1 (ET-1) has emerged to be implicated in the tumor/TME interplay, however the molecular mechanisms induced by the ET-1-driven feed-forward loops (FFL) and associated with the HG-SOC metastatic potential need to be further investigated. The tracking of the patient-derived (PD) HG-SOC cell transcriptome by RNA-seq identified the vascular endothelial growth factor (VEGF) gene and its associated signature among those mostly upregulated by ET-1 and down-modulated by the dual ET-1R antagonist macitentan. Within the ligand-receptor pairs concurrently expressed in PD-HG-SOC cells, endothelial cells and activated fibroblasts, we discovered two intertwined FFL, the ET-1/ET-1R and VEGF/VEGF receptors, concurrently activated by ET-1 and shutting-down by macitentan, or by the anti-VEGF antibody bevacizumab. In parallel, we observed that ET-1 fine-tuned the tumoral and stromal secretome towards a pro-invasive pattern. Into the fray of the HG-SOC/TME double and triple co-cultures, the secretion of ET-1 and VEGF, that share a common co-regulation, was inhibited upon the administration of macitentan. Functionally, macitentan, mimicking the effect of bevacizumab, interfered with the HG-SOC/TME FFL-driven communication that fuel the HG-SOC invasive behaviour. The identification of ET-1 and VEGF FFL as tumor and TME actionable vulnerabilities, reveal how ET-1R blockade, targeting the HG-SOC cells and the TME simultaneously, may represent an effective therapeutic option for HG-SOC patients.

5.
Mol Cancer ; 22(1): 192, 2023 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-38031025

RESUMO

BACKGROUND: Immune checkpoint inhibitors (ICIs) are a therapeutic strategy for various cancers although only a subset of patients respond to the therapy. Identifying patients more prone to respond to ICIs may increase the therapeutic benefit and allow studying new approaches for resistant patients. METHODS: We analyzed the TCGA cohort of HNSCC patients in relation to their activation of 26 immune gene expression signatures, as well as their cell type composition, in order to define signaling pathways associated with resistance to ICIs. Results were validated on two cohorts of 102 HNSCC patients and 139 HNSCC patients under treatment with PD-L1 inhibitors, respectively, and a cohort of 108 HNSCC HPV negative patients and by in vitro experiments in HNSCC cell lines. RESULTS: We observed a significant association between the gene set and TP53 gene status and OS and PFS of HNSCC patients. Surprisingly, the presence of a TP53 mutation together with another co-driver mutation was associated with significantly higher levels of the immune gene expression, in comparison to tumors in which the TP53 gene was mutated alone. In addition, the higher level of TP53 mutated-dependent MYC signature was associated with lower levels of the immune gene expression signature. In vitro and three different patient cohorts validation analyses corroborated these findings. CONCLUSIONS: Immune gene signature sets associated with TP53 status and co-mutations classify with more accuracy HNSCC patients. These biomarkers may be easily implemented in clinical setting.


Assuntos
Neoplasias de Cabeça e Pescoço , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/genética , Estudos de Coortes , Transdução de Sinais , Mutação , Prognóstico , Proteína Supressora de Tumor p53/genética
6.
Semin Cell Dev Biol ; 98: 105-117, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31112799

RESUMO

Deregulated cell metabolism is one of the cancer hallmarks. Mitochondrial DNA mutations and enzyme defects, aberrant tumor suppressor or oncogenic activities cause mitochondrial dysfunction leading to deregulated cellular energetics. The tumor suppressor protein, p53 is a tetrameric transcription factor that in response to diverse genotoxic and non-genotoxic insults activates a plethora of target genes to preserve genome integrity. In the last two decades the discovery of cytoplasmic p53 localization focused intense research on its extra-nuclear functions. The ability of p53 to induce apoptosis acting directly at mitochondria and the related mechanisms of p53 localization and translocation in the cytoplasm have been investigated. A role of cytoplasmic p53 in autophagy, pentose phosphate pathway, fatty acid synthesis and oxidation, and drug response has been proposed. TP53 gene is mutated in more than half of human cancers. In parallel to loss of tumor suppressive functions, mutant p53 proteins often gain new tumorigenic activities (GOF, gain of function). It has been recently shown that mutant p53 proteins mediate metabolic changes thereby promoting cancer development and metastases. Here we review the contribution of either wild-type p53 or mutant p53 proteins to the fine-tuning of mitochondrial metabolism of both normal and cancer cells. Greater knowledge at the mechanistic level might provide insights to develop new cancer therapeutic approaches.


Assuntos
Mitocôndrias/patologia , Neoplasias/genética , Neoplasias/patologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Animais , Humanos
7.
Mol Cancer ; 21(1): 33, 2022 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-35090471

RESUMO

The role of circular RNAs in oncogenesis has begun to be widely studied in recent years, due to the significant impact that these molecules have in disease pathogenesis, as well as their potential for the future of innovative therapies. Moreover, due to their characteristically circular shape, circular RNAs are very resistant molecules to RNA degradation whose levels are easily assessed in body fluids. Accordingly, they represent an opportunity for the discovery of new diagnostic and prognostic markers in a wide range of diseases. Among circular RNAs, circPVT1 is a rather peculiar one that originates from the circularization of the exon 2 of the PVT1 gene that encodes a pro-tumorigenic long non-coding RNA named lncPVT1. There are a few examples of circular RNAs that derive from a locus producing another non-coding RNA. Despite their apparent transcriptional independence, which occurs using two different promoters, a possible synergistic effect in tumorigenesis cannot be excluded considering that both have been reported to correlate with the oncogenic phenotype. This complex mechanism of regulation appears to also be controlled by c-MYC. Indeed, the PVT1 locus is located only 53 Kb downstream c-MYC gene, a well-known oncogene that regulates the expression levels of about 15% of all genes. Here, we review circPVT1 origin and biogenesis highlighting the most important mechanisms through which it plays a fundamental role in oncogenesis, such as the well-known sponge activity on microRNAs, as well as its paradigmatic interactome link with lncPVT1 and c-MYC expression.


Assuntos
MicroRNAs , RNA Longo não Codificante , Carcinogênese/genética , Genes myc , Humanos , MicroRNAs/genética , Oncogenes , RNA Circular/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo
8.
Eur Respir J ; 60(2)2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35086840

RESUMO

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection of the respiratory system can progress to a multisystemic disease with aberrant inflammatory response. Cellular senescence promotes chronic inflammation, named senescence-associated secretory phenotype (SASP). We investigated whether coronavirus disease 2019 (COVID-19) is associated with cellular senescence and SASP. METHODS: Autopsy lung tissue samples from 11 COVID-19 patients and 43 age-matched non-COVID-19 controls with similar comorbidities were analysed by immunohistochemistry for SARS-CoV-2, markers of senescence and key SASP cytokines. Virally induced senescence was functionally recapitulated in vitro, by infecting epithelial Vero-E6 cells and a three-dimensional alveosphere system of alveolar type 2 (AT2) cells with SARS-CoV-2 strains isolated from COVID-19 patients. RESULTS: SARS-CoV-2 was detected by immunocytochemistry and electron microscopy predominantly in AT2 cells. Infected AT2 cells expressed angiotensin-converting enzyme 2 and exhibited increased senescence (p16INK4A and SenTraGor positivity) and interleukin (IL)-1ß and IL-6 expression. In vitro, infection of Vero-E6 cells with SARS-CoV-2 induced senescence (SenTraGor), DNA damage (γ-H2AX) and increased cytokine (IL-1ß, IL-6, CXCL8) and apolipoprotein B mRNA-editing (APOBEC) enzyme expression. Next-generation sequencing analysis of progenies obtained from infected/senescent Vero-E6 cells demonstrated APOBEC-mediated SARS-CoV-2 mutations. Dissemination of the SARS-CoV-2-infection and senescence was confirmed in extrapulmonary sites (kidney and liver) of a COVID-19 patient. CONCLUSIONS: We demonstrate that in severe COVID-19, AT2 cells infected by SARS-CoV-2 exhibit senescence and a proinflammatory phenotype. In vitro, SARS-CoV-2 infection induces senescence and inflammation. Importantly, infected senescent cells may act as a source of SARS-CoV-2 mutagenesis mediated by APOBEC enzymes. Therefore, SARS-CoV-2-induced senescence may be an important molecular mechanism of severe COVID-19, disease persistence and mutagenesis.


Assuntos
COVID-19 , SARS-CoV-2 , Senescência Celular , Citocinas/metabolismo , Humanos , Inflamação , Interleucina-6 , Pulmão/metabolismo , Mutagênese , Fenótipo
9.
Int J Mol Sci ; 23(23)2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36498861

RESUMO

New evidence on the impact of dysregulation of the CDK4/6 pathway on breast cancer (BC) cell proliferation has led to the development of selective CDK4/6 inhibitors, which have radically changed the management of advanced BC. Despite the improved outcomes obtained by CDK4/6 inhibitors, approximately 10% of tumors show primary resistance, whereas acquired resistance appears to be an almost ubiquitous occurrence, leading to treatment failure. The identification of differentially expressed genes or genomic mutational signatures able to predict sensitivity or resistance to CDK4/6 inhibitors is critical for medical decision making and for avoiding or counteracting primary or acquired resistance against CDK4/6 inhibitors. In this review, we summarize the main mechanisms of resistance to CDK4/6 inhibitors, focusing on those associated with potentially relevant biomarkers that could predict patients' response/resistance to treatment. Recent advances in biomarker identification are discussed, including the potential use of liquid biopsy for BC management and the role of multiple microRNAs as molecular predictors of cancer cell sensitivity and resistance to CDK4/6 inhibitors.


Assuntos
Neoplasias da Mama , MicroRNAs , Inibidores de Proteínas Quinases , Feminino , Humanos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Biópsia Líquida , MicroRNAs/genética , MicroRNAs/uso terapêutico , Terapia de Alvo Molecular , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Purinas/farmacologia
10.
Nucleic Acids Res ; 47(7): 3365-3382, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-30698737

RESUMO

The telomeric protein TRF2 is overexpressed in several human malignancies and contributes to tumorigenesis even though the molecular mechanism is not completely understood. By using a high-throughput approach based on the multiplexed Luminex X-MAP technology, we demonstrated that TRF2 dramatically affects VEGF-A level in the secretome of cancer cells, promoting endothelial cell-differentiation and angiogenesis. The pro-angiogenic effect of TRF2 is independent from its role in telomere capping. Instead, TRF2 binding to a distal regulatory element promotes the expression of SULF2, an endoglucosamine-6-sulfatase that impairs the VEGF-A association to the plasma membrane by inducing post-synthetic modification of heparan sulfate proteoglycans (HSPGs). Finally, we addressed the clinical relevance of our findings showing that TRF2/SULF2 expression is a worse prognostic biomarker in colorectal cancer (CRC) patients.


Assuntos
Neoplasias do Colo/metabolismo , Sulfotransferases/genética , Proteína 2 de Ligação a Repetições Teloméricas/metabolismo , Microambiente Tumoral , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Linhagem Celular Tumoral , Neoplasias do Colo/irrigação sanguínea , Neoplasias do Colo/patologia , Proteoglicanas de Heparan Sulfato/química , Proteoglicanas de Heparan Sulfato/metabolismo , Heparina/metabolismo , Humanos , Masculino , Camundongos , Camundongos Nus , Metástase Neoplásica , Neovascularização Patológica , Sulfatases , Sulfotransferases/biossíntese , Proteína 2 de Ligação a Repetições Teloméricas/deficiência , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Proc Natl Acad Sci U S A ; 115(12): 3132-3137, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29439204

RESUMO

Aberrant activation of endothelin-1 receptors (ET-1R) elicits pleiotropic effects relevant for tumor progression. The network activated by this receptor might be finely, spatially, and temporarily orchestrated by ß-arrestin1 (ß-arr1)-driven interactome. Here, we identify hMENA, a member of the actin-regulatory protein ENA/VASP family, as an interacting partner of ß-arr1, necessary for invadopodial function downstream of ET-1R in serous ovarian cancer (SOC) progression. ET-1R activation by ET-1 up-regulates expression of hMENA/hMENAΔv6 isoforms through ß-arr1, restricted to mesenchymal-like invasive SOC cells. The interaction of ß-arr1 with hMENA/hMENAΔv6 triggered by ET-1 leads to activation of RhoC and cortactin, recruitment of membrane type 1-matrix metalloprotease, and invadopodia maturation, thereby enhancing cell plasticity, transendothelial migration, and the resulting spread of invasive cells. The treatment with the ET-1R antagonist macitentan impairs the interaction of ß-arr1 with hMENA and inhibits invadopodial maturation and tumor dissemination in SOC orthotopic xenografts. Finally, high ETAR/hMENA/ß-arr1 gene expression signature is associated with a poor prognosis in SOC patients. These data define a pivotal function of hMENA/hMENAΔv6 for ET-1/ß-arr1-induced invadopodial activity and ovarian cancer progression.


Assuntos
Cistadenocarcinoma Seroso/patologia , Endotelina-1/metabolismo , Proteínas dos Microfilamentos/metabolismo , Neoplasias Ovarianas/patologia , beta-Arrestina 1/metabolismo , Animais , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/mortalidade , Citoesqueleto/metabolismo , Antagonistas do Receptor de Endotelina A/farmacologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos Nus , Proteínas dos Microfilamentos/genética , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/mortalidade , Podossomos/efeitos dos fármacos , Podossomos/metabolismo , Pirimidinas/farmacologia , Receptor de Endotelina A/metabolismo , Sulfonamidas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína de Ligação a GTP rhoC/metabolismo
12.
Int J Mol Sci ; 22(21)2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34769499

RESUMO

Chemoresistance is a hallmark of malignant pleural mesothelioma (MPM) management and the expression of ALDH1A3 is responsible for the survival and activity of MPM chemoresistant cell subpopulations (ALDHbright cells). We enriched mesothelioma ALDHbright cells to near homogeneity by FACS sorting and an Aldefluor assay and performed unbiased Affymetrix gene expression profiling. Viability and ELISA assays were used to rule out significant apoptosis in the sorted cell subpopulations and to assess target engagement by butein. Statistical analysis of the results, pathway enrichment and promoter enrichment were employed for the generation of the data. Q-RTPCR was used to validate a subset of the identified, modulated mRNAs In this work, we started from the observation that the mRNA levels of the ALDH1A3 isoform could prognostically stratify MPM patients. Thus, we purified MPM ALDHbright cells from NCI-H2595 cells and interrogated their gene expression (GES) profile. We analyzed the GES of the purified cells at both a steady state and upon treatment with butein (a multifunctional tetrahydroxy-chalcone), which abates the ALDHbright cell number, thereby exerting chemo-sensitizing effects in vitro and in vivo. We identified 924 genes modulated in a statistically significant manner as a function of ALDH status and of the response to the inhibitor. Pathway and promoter enrichment identified the molecular determinant of high ALDH status and how butein treatment altered the molecular portrait of those chemoresistant cell subpopulations. Further, we unraveled an eighteen-gene signature with high prognostic significance for MPM patients, and showed that most of the identified prognostic contributors escaped the analysis of unfractionated samples. This work proves that digging into the unexplored field of intra-tumor heterogeneity (ITH) by working at the cell subpopulation level may provide findings of prognostic relevance, in addition to mechanistic insights into tumor resistance to therapy.


Assuntos
Aldeído Oxirredutases/metabolismo , Reparo do DNA , Mesotelioma Maligno/patologia , NF-kappa B/metabolismo , Linhagem Celular Tumoral , Evolução Clonal , Resistencia a Medicamentos Antineoplásicos , Citometria de Fluxo/métodos , Humanos , Mesotelioma Maligno/tratamento farmacológico , Mesotelioma Maligno/genética , Mesotelioma Maligno/metabolismo , Prognóstico , Taxa de Sobrevida
13.
EMBO Rep ; 19(3)2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29367285

RESUMO

Despite progress in treating B-cell precursor acute lymphoblastic leukemia (BCP-ALL), disease recurrence remains the main cause of treatment failure. New strategies to improve therapeutic outcomes are needed, particularly in high-risk relapsed patients. Che-1/AATF (Che-1) is an RNA polymerase II-binding protein involved in proliferation and tumor survival, but its role in hematological malignancies has not been clarified. Here, we show that Che-1 is overexpressed in pediatric BCP-ALL during disease onset and at relapse, and that its depletion inhibits the proliferation of BCP-ALL cells. Furthermore, we report that c-Myc regulates Che-1 expression by direct binding to its promoter and describe a strict correlation between Che-1 expression and c-Myc expression. RNA-seq analyses upon Che-1 or c-Myc depletion reveal a strong overlap of the respective controlled pathways. Genomewide ChIP-seq experiments suggest that Che-1 acts as a downstream effector of c-Myc. These results identify the pivotal role of Che-1 in the control of BCP-ALL proliferation and present the protein as a possible therapeutic target in children with relapsed BCP-ALL.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Repressoras/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Proteínas de Ligação a DNA/genética , Regulação Leucêmica da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Regiões Promotoras Genéticas/genética
14.
EMBO J ; 34(9): 1214-30, 2015 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-25770584

RESUMO

Mammalian target of rapamycin (mTOR) is a key protein kinase that regulates cell growth, metabolism, and autophagy to maintain cellular homeostasis. Its activity is inhibited by adverse conditions, including nutrient limitation, hypoxia, and DNA damage. In this study, we demonstrate that Che-1, a RNA polymerase II-binding protein activated by the DNA damage response, inhibits mTOR activity in response to stress conditions. We found that, under stress, Che-1 induces the expression of two important mTOR inhibitors, Redd1 and Deptor, and that this activity is required for sustaining stress-induced autophagy. Strikingly, Che-1 expression correlates with the progression of multiple myeloma and is required for cell growth and survival, a malignancy characterized by high autophagy response.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Autofagia/fisiologia , Mieloma Múltiplo/patologia , Proteínas Repressoras/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Proteínas Reguladoras de Apoptose/genética , Linhagem Celular Tumoral , Sobrevivência Celular , Feminino , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina , Alvo Mecanístico do Complexo 2 de Rapamicina , Camundongos Nus , Mieloma Múltiplo/metabolismo , Complexos Multiproteicos/metabolismo , Fosforilação , Proteínas Repressoras/genética , Estresse Fisiológico , Serina-Treonina Quinases TOR/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
16.
Haematologica ; 104(1): 82-92, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30076175

RESUMO

MicroRNAs, non-coding regulators of gene expression, are likely to function as important downstream effectors of many transcription factors including MYB. Optimal levels of MYB are required for transformation/maintenance of BCR-ABL-expressing cells. We investigated whether MYB silencing modulates microRNA expression in Philadelphia-positive (Ph+) leukemia cells and if MYB-regulated microRNAs are important for the "MYB addiction" of these cells. Thirty-five microRNAs were modulated by MYB silencing in lymphoid and erythromyeloid chronic myeloid leukemia-blast crisis BV173 and K562 cells; 15 of these were concordantly modulated in both lines. We focused on the miR-17-92 cluster because of its oncogenic role in tumors and found that: i) it is a direct MYB target; ii) it partially rescued the impaired proliferation and enhanced apoptosis of MYB-silenced BV173 cells. Moreover, we identified FRZB, a Wnt/ß-catenin pathway inhibitor, as a novel target of the miR-17-92 cluster. High expression of MYB in blast cells from 2 Ph+leukemia patients correlated positively with the miR-17-92 cluster and inversely with FRZB. This expression pattern was also observed in a microarray dataset of 122 Ph+acute lymphoblastic leukemias. In vivo experiments in NOD scid gamma mice injected with BV173 cells confirmed that FRZB functions as a Wnt/ß-catenin inhibitor even as they failed to demonstrate that this pathway is important for BV173-dependent leukemogenesis. These studies illustrate the global effects of MYB expression on the microRNAs profile of Ph+cells and supports the concept that the "MYB addiction" of these cells is, in part, caused by modulation of microRNA-regulated pathways affecting cell proliferation and survival.


Assuntos
Crise Blástica/metabolismo , Regulação Leucêmica da Expressão Gênica , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , MicroRNAs/biossíntese , Família Multigênica , Proteínas Proto-Oncogênicas c-myb/biossíntese , RNA Neoplásico/biossíntese , Ativação Transcricional , Animais , Crise Blástica/tratamento farmacológico , Crise Blástica/genética , Crise Blástica/patologia , Humanos , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-myb/genética , RNA Neoplásico/genética , Ensaios Antitumorais Modelo de Xenoenxerto
17.
EMBO Rep ; 18(8): 1331-1351, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28652379

RESUMO

The abundant, nuclear-retained, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been associated with a poorly differentiated and aggressive phenotype of mammary carcinomas. This long non-coding RNA (lncRNA) localizes to nuclear speckles, where it interacts with a subset of splicing factors and modulates their activity. In this study, we demonstrate that oncogenic splicing factor SRSF1 bridges MALAT1 to mutant p53 and ID4 proteins in breast cancer cells. Mutant p53 and ID4 delocalize MALAT1 from nuclear speckles and favor its association with chromatin. This enables aberrant recruitment of MALAT1 on VEGFA pre-mRNA and modulation of VEGFA isoforms expression. Interestingly, VEGFA-dependent expression signatures associate with ID4 expression specifically in basal-like breast cancers carrying TP53 mutations. Our results highlight a key role for MALAT1 in control of VEGFA isoforms expression in breast cancer cells expressing gain-of-function mutant p53 and ID4 proteins.


Assuntos
Neoplasias da Mama/fisiopatologia , Proteínas Inibidoras de Diferenciação/metabolismo , RNA Longo não Codificante/genética , Proteína Supressora de Tumor p53/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Neoplasias da Mama/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Inibidoras de Diferenciação/genética , Mutação , Neovascularização Patológica , Isoformas de Proteínas/metabolismo , Splicing de RNA , Fatores de Processamento de Serina-Arginina/genética , Proteína Supressora de Tumor p53/genética , Fator A de Crescimento do Endotélio Vascular/biossíntese
18.
Mol Cell ; 44(4): 515-6, 2011 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-22099301

RESUMO

In this issue of Molecular Cell, Sen et al. (2011) report the involvement of PGC1α in modulating the transcriptional activity of p53 in metabolically challenged cells. They provide important insights into the mechanisms linking length and strength of the metabolic stress stimuli to the specific activation of p53 target genes.

19.
Semin Cell Dev Biol ; 50: 133-42, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26773212

RESUMO

Emerging evidence point to a crucial role for non-coding RNAs in modulating homeostatic signaling under physiological and pathological conditions. MicroRNAs, the best-characterized non-coding RNAs to date, can exquisitely integrate spatial and temporal signals in complex networks, thereby confer specificity and sensitivity to tissue response to changes in the microenvironment. MicroRNAs appear as preferential partners for Receptor Tyrosine Kinases (RTKs) in mediating signaling under stress conditions. Stress signaling can be especially relevant to disease. Here we focus on the ability of microRNAs to mediate RTK signaling in cancer, by acting as both tumor suppressors and oncogenes. We will provide a few general examples of microRNAs modulating specific tumorigenic functions downstream of RTK signaling and integrate oncogenic signals from multiple RTKs. A special focus will be devoted to epidermal growth factor receptor (EGFR) signaling, a system offering relatively rich information. We will explore the role of selected microRNAs as bidirectional modulators of EGFR functions in cancer cells. In addition, we will present the emerging evidence for microRNAs being specifically modulated by oncogenic EGFR mutants and we will discuss how this impinges on EGFRmut driven chemoresistance, which fits into the tumor heterogeneity-driven cancer progression. Finally, we discuss how other non-coding RNA species are emerging as important modulators of cancer progression and why the scenario depicted herein is destined to become increasingly complex in the future.


Assuntos
MicroRNAs/metabolismo , Neoplasias/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Transdução de Sinais , Animais , Receptores ErbB/metabolismo , Humanos , MicroRNAs/genética , Neoplasias/genética , Estresse Fisiológico
20.
Carcinogenesis ; 39(2): 293-304, 2018 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-29236960

RESUMO

Alteration in microRNAs (miRNAs) expression is a frequent finding in human cancers. In particular, widespread miRNAs down-regulation is a hallmark of malignant transformation. In the present report, we showed that the miR-128-3p, which is up-regulated in lung cancer tissues, has Drosha and Dicer, two key enzymes of miRNAs processing, as the main modulation targets leading to the widespread down-regulation of miRNA expression. We observed that the miRNAs downregulation induced by miR-128-3p contributed to the tumorigenic properties of lung cancer cells. In particular, miR-128-3p-mediated miRNAs down-regulation contributed to aberrant SNAIL and ZEB1 expression thereby promoting the epithelial-to-mesenchymal transition (EMT) program. Drosha also resulted to be implicated in the control of migratory phenotype as its expression counteracted miR-128-3p functional effects. Our study provides mechanistic insights into the function of miR-128-3p as a key regulator of the malignant phenotype of lung cancer cells. This also enforces the remarkable impact of Drosha and Dicer alteration in cancer, and in particular it highlights a role for Drosha in non-small-cell lung cancer cells migration.


Assuntos
Adenocarcinoma/genética , Adenocarcinoma/patologia , Movimento Celular/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , MicroRNAs/genética , Ribonuclease III/biossíntese , Adenocarcinoma/mortalidade , Adenocarcinoma de Pulmão , Linhagem Celular Tumoral , Intervalo Livre de Doença , Regulação Neoplásica da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/mortalidade , Ribonuclease III/genética
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