RESUMEN
Altered energy metabolism is a cancer hallmark as malignant cells tailor their metabolic pathways to meet their energy requirements. Glucose and glutamine are the major nutrients that fuel cellular metabolism, and the pathways utilizing these nutrients are often altered in cancer. Here, we show that the long ncRNA CCAT2, located at the 8q24 amplicon on cancer risk-associated rs6983267 SNP, regulates cancer metabolism in vitro and in vivo in an allele-specific manner by binding the Cleavage Factor I (CFIm) complex with distinct affinities for the two subunits (CFIm25 and CFIm68). The CCAT2 interaction with the CFIm complex fine-tunes the alternative splicing of Glutaminase (GLS) by selecting the poly(A) site in intron 14 of the precursor mRNA. These findings uncover a complex, allele-specific regulatory mechanism of cancer metabolism orchestrated by the two alleles of a long ncRNA.
Asunto(s)
Glutaminasa/genética , Neoplasias/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Factores de Escisión y Poliadenilación de ARNm/metabolismo , Alelos , Empalme Alternativo , Metabolismo Energético , Células HCT116 , Humanos , Neoplasias/genética , Precursores del ARN/química , Precursores del ARN/metabolismo , ARN Mensajero/metabolismoRESUMEN
Endometrial cancer is the most frequent malignant tumor of the female reproductive tract but lacks effective therapy. EphA2, a receptor tyrosine kinase, is overexpressed by various cancers including endometrial cancer and is associated with poor clinical outcomes. In preclinical models, EphA2-targeted drugs had modest efficacy. To discover potential synergistic partners for EphA2-targeted drugs, we performed a high-throughput drug screen and identified panobinostat, a histone deacetylase inhibitor, as a candidate. We hypothesized that combination therapy with an EphA2 inhibitor and panobinostat leads to synergistic cell death. Indeed, we found that the combination enhanced DNA damage, increased apoptosis, and decreased clonogenic survival in Ishikawa and Hec1A endometrial cancer cells and significantly reduced tumor burden in mouse models of endometrial carcinoma. Upon RNA sequencing, the combination was associated with downregulation of cell survival pathways, including senescence, cyclins, and cell cycle regulators. The Axl-PI3K-Akt-mTOR pathway was also decreased by combination therapy. Together, our results highlight EphA2 and histone deacetylase as promising therapeutic targets for endometrial cancer.
Asunto(s)
Neoplasias Endometriales , Inhibidores de Histona Desacetilasas , Receptor EphA2 , Animales , Femenino , Humanos , Ratones , Apoptosis , Línea Celular Tumoral , Neoplasias Endometriales/tratamiento farmacológico , Neoplasias Endometriales/genética , Neoplasias Endometriales/patología , Inhibidores de Histona Desacetilasas/uso terapéutico , Panobinostat/farmacología , Panobinostat/uso terapéutico , Fosfatidilinositol 3-Quinasas , Terapia Molecular Dirigida , Receptor EphA2/antagonistas & inhibidoresRESUMEN
EphA2 tyrosine kinase is upregulated in many cancers and correlated with poor survival of patients, including those with endometrial cancer. EphA2-targeted drugs have shown modest clinical benefit. To improve the therapeutic response to such drugs, we performed a high-throughput chemical screen to discover novel synergistic partners for EphA2-targeted therapeutics. Our screen identified the Wee1 kinase inhibitor, MK1775, as a synergistic partner to EphA2, and this finding was confirmed using both in vitro and in vivo experiments. We hypothesized that Wee1 inhibition would sensitize cells to EphA2-targeted therapy. Combination treatment decreased cell viability, induced apoptosis, and reduced clonogenic potential in endometrial cancer cell lines. In vivo Hec1A and Ishikawa-Luc orthotopic mouse models of endometrial cancer showed greater anti-tumor responses to combination treatment than to either monotherapy. RNASeq analysis highlighted reduced cell proliferation and defective DNA damage response pathways as potential mediators of the combination's effects. In conclusion, our preclinical findings indicate that Wee1 inhibition can enhance the response to EphA2-targeted therapeutics in endometrial cancer; this strategy thus warrants further development.
Asunto(s)
Antineoplásicos , Neoplasias Endometriales , Terapia Molecular Dirigida , Inhibidores de Proteínas Quinasas , Proteínas Tirosina Quinasas , Receptor EphA2 , Animales , Femenino , Humanos , Ratones , Antineoplásicos/uso terapéutico , Apoptosis , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Proliferación Celular , Neoplasias Endometriales/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Receptor EphA2/antagonistas & inhibidoresRESUMEN
Aptamers, synthetic single-strand oligonucleotides that are similar in function to antibodies, are promising as therapeutics because of their minimal side effects. However, the stability and bioavailability of the aptamers pose a challenge. We developed aptamers converted from RNA aptamer to modified DNA aptamers that target phospho-AXL with improved stability and bioavailability. On the basis of the comparative analysis of a library of 17 converted modified DNA aptamers, we selected aptamer candidates, GLB-G25 and GLB-A04, that exhibited the highest bioavailability, stability, and robust antitumor effect in in vitro experiments. Backbone modifications such as thiophosphate or dithiophosphate and a covalent modification of the 5'-end of the aptamer with polyethylene glycol optimized the pharmacokinetic properties, improved the stability of the aptamers in vivo by reducing nuclease hydrolysis and renal clearance, and achieved high and sustained inhibition of AXL at a very low dose. Treatment with these modified aptamers in ovarian cancer orthotopic mouse models significantly reduced tumor growth and the number of metastases. This effective silencing of the phospho-AXL target thus demonstrated that aptamer specificity and bioavailability can be improved by the chemical modification of existing aptamers for phospho-AXL. These results lay the foundation for the translation of these aptamer candidates and companion biomarkers to the clinic.
Asunto(s)
Anticuerpos/inmunología , Aptámeros de Nucleótidos/inmunología , Neoplasias/inmunología , Anticuerpos/química , Aptámeros de Nucleótidos/química , Humanos , Neoplasias/terapiaRESUMEN
The cancer-risk-associated rs6983267 single nucleotide polymorphism (SNP) and the accompanying long noncoding RNA CCAT2 in the highly amplified 8q24.21 region have been implicated in cancer predisposition, although causality has not been established. Here, using allele-specific CCAT2 transgenic mice, we demonstrate that CCAT2 overexpression leads to spontaneous myeloid malignancies. We further identified that CCAT2 is overexpressed in bone marrow and peripheral blood of myelodysplastic/myeloproliferative neoplasms (MDS/MPN) patients. CCAT2 induces global deregulation of gene expression by down-regulating EZH2 in vitro and in vivo in an allele-specific manner. We also identified a novel non-APOBEC, non-ADAR, RNA editing at the SNP locus in MDS/MPN patients and CCAT2-transgenic mice. The RNA transcribed from the SNP locus in malignant hematopoietic cells have different allelic composition from the corresponding genomic DNA, a phenomenon rarely observed in normal cells. Our findings provide fundamental insights into the functional role of rs6983267 SNP and CCAT2 in myeloid malignancies.
Asunto(s)
Proliferación Celular/genética , Enfermedades Mielodisplásicas-Mieloproliferativas/genética , ARN Largo no Codificante/genética , Adulto , Anciano , Anciano de 80 o más Años , Animales , Línea Celular Tumoral , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Masculino , Ratones , Ratones Transgénicos , Persona de Mediana Edad , Enfermedades Mielodisplásicas-Mieloproliferativas/patología , Polimorfismo de Nucleótido Simple/genética , Edición de ARN/genéticaRESUMEN
TP53, a well-known tumour suppressor gene that encodes p53, is frequently inactivated by mutation or deletion in most human tumours. A tremendous effort has been made to restore p53 activity in cancer therapies. However, no effective p53-based therapy has been successfully translated into clinical cancer treatment owing to the complexity of p53 signalling. Here we demonstrate that genomic deletion of TP53 frequently encompasses essential neighbouring genes, rendering cancer cells with hemizygous TP53 deletion vulnerable to further suppression of such genes. POLR2A is identified as such a gene that is almost always co-deleted with TP53 in human cancers. It encodes the largest and catalytic subunit of the RNA polymerase II complex, which is specifically inhibited by α-amanitin. Our analysis of The Cancer Genome Atlas (TCGA) and Cancer Cell Line Encyclopedia (CCLE) databases reveals that POLR2A expression levels are tightly correlated with its gene copy numbers in human colorectal cancer. Suppression of POLR2A with α-amanitin or small interfering RNAs selectively inhibits the proliferation, survival and tumorigenic potential of colorectal cancer cells with hemizygous TP53 loss in a p53-independent manner. Previous clinical applications of α-amanitin have been limited owing to its liver toxicity. However, we found that α-amanitin-based antibody-drug conjugates are highly effective therapeutic agents with reduced toxicity. Here we show that low doses of α-amanitin-conjugated anti-epithelial cell adhesion molecule (EpCAM) antibody lead to complete tumour regression in mouse models of human colorectal cancer with hemizygous deletion of POLR2A. We anticipate that inhibiting POLR2A will be a new therapeutic approach for human cancers containing such common genomic alterations.
Asunto(s)
Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Genes p53/genética , Proteína p53 Supresora de Tumor/deficiencia , Alfa-Amanitina/efectos adversos , Alfa-Amanitina/química , Alfa-Amanitina/farmacología , Alfa-Amanitina/uso terapéutico , Animales , Anticuerpos/química , Anticuerpos/inmunología , Antígenos de Neoplasias/inmunología , Dominio Catalítico , Moléculas de Adhesión Celular/inmunología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Neoplasias Colorrectales/enzimología , Neoplasias Colorrectales/patología , Bases de Datos Genéticas , Modelos Animales de Enfermedad , Molécula de Adhesión Celular Epitelial , Femenino , Eliminación de Gen , Dosificación de Gen/genética , Humanos , Inmunoconjugados/efectos adversos , Inmunoconjugados/química , Inmunoconjugados/inmunología , Inmunoconjugados/uso terapéutico , Ratones , Subunidades de Proteína/química , Subunidades de Proteína/deficiencia , Subunidades de Proteína/genética , ARN Polimerasa II/antagonistas & inhibidores , ARN Polimerasa II/química , ARN Polimerasa II/deficiencia , ARN Polimerasa II/genética , Proteína p53 Supresora de Tumor/biosíntesis , Proteína p53 Supresora de Tumor/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Many long noncoding RNAs have been implicated in tumorigenesis and chemoresistance; however, the underlying mechanisms are not well understood. We investigated the role of PRKAR1B-AS2 long noncoding RNA in ovarian cancer (OC) and chemoresistance and identified potential downstream molecular circuitry underlying its action. Analysis of The Cancer Genome Atlas OC dataset, in vitro experiments, proteomic analysis, and a xenograft OC mouse model were implemented. Our findings indicated that overexpression of PRKAR1B-AS2 is negatively correlated with overall survival in OC patients. Furthermore, PRKAR1B-AS2 knockdown-attenuated proliferation, migration, and invasion of OC cells and ameliorated cisplatin and alpelisib resistance in vitro. In proteomic analysis, silencing PRKAR1B-AS2 markedly inhibited protein expression of PI3K-110α and abrogated the phosphorylation of PDK1, AKT, and mTOR, with no significant effect on PTEN. The RNA immunoprecipitation detected a physical interaction between PRKAR1B-AS2 and PI3K-110α. Moreover, PRKAR1B-AS2 knockdown by systemic administration of 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine nanoparticles loaded with PRKAR1B-AS2-specific small interfering RNA enhanced cisplatin sensitivity in a xenograft OC mouse model. In conclusion, PRKAR1B-AS2 promotes tumor growth and confers chemoresistance by modulating the PI3K/AKT/mTOR pathway. Thus, targeting PRKAR1B-AS2 may represent a novel therapeutic approach for the treatment of OC patients.
Asunto(s)
Carcinogénesis/metabolismo , Resistencia a Antineoplásicos , Neoplasias Ováricas/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Largo no Codificante/metabolismo , ARN Neoplásico/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo , Línea Celular Tumoral , Supervivencia Celular , Femenino , Humanos , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Fosfatidilinositol 3-Quinasas/genética , Proteínas Proto-Oncogénicas c-akt/genética , ARN Largo no Codificante/genética , ARN Neoplásico/genética , Serina-Treonina Quinasas TOR/genéticaRESUMEN
OBJECTIVE: To investigate the function of a novel primate-specific long non-coding RNA (lncRNA), named FLANC, based on its genomic location (co-localised with a pyknon motif), and to characterise its potential as a biomarker and therapeutic target. DESIGN: FLANC expression was analysed in 349 tumours from four cohorts and correlated to clinical data. In a series of multiple in vitro and in vivo models and molecular analyses, we characterised the fundamental biological roles of this lncRNA. We further explored the therapeutic potential of targeting FLANC in a mouse model of colorectal cancer (CRC) metastases. RESULTS: FLANC, a primate-specific lncRNA feebly expressed in normal colon cells, was significantly upregulated in cancer cells compared with normal colon samples in two independent cohorts. High levels of FLANC were associated with poor survival in two additional independent CRC patient cohorts. Both in vitro and in vivo experiments demonstrated that the modulation of FLANC expression influenced cellular growth, apoptosis, migration, angiogenesis and metastases formation ability of CRC cells. In vivo pharmacological targeting of FLANC by administration of 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine nanoparticles loaded with a specific small interfering RNA, induced significant decrease in metastases, without evident tissue toxicity or pro-inflammatory effects. Mechanistically, FLANC upregulated and prolonged the half-life of phosphorylated STAT3, inducing the overexpression of VEGFA, a key regulator of angiogenesis. CONCLUSIONS: Based on our findings, we discovered, FLANC as a novel primate-specific lncRNA that is highly upregulated in CRC cells and regulates metastases formation. Targeting primate-specific transcripts such as FLANC may represent a novel and low toxic therapeutic strategy for the treatment of patients.
Asunto(s)
Carcinogénesis , Proliferación Celular , Neoplasias Colorrectales , Neovascularización Patológica , ARN Largo no Codificante , Factor de Transcripción STAT3/metabolismo , Animales , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Carcinogénesis/efectos de los fármacos , Carcinogénesis/genética , Proliferación Celular/efectos de los fármacos , Proliferación Celular/genética , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/terapia , Descubrimiento de Drogas , Regulación Neoplásica de la Expresión Génica , Marcadores Genéticos , Terapia Genética , Humanos , Ratones , Neovascularización Patológica/genética , Neovascularización Patológica/metabolismo , Pruebas de Farmacogenómica , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Long non-coding RNAs (lncRNAs), initially recognized as byproducts of the transcription process, have been proven to play crucial modulatory roles in preserving overall homoeostasis of cells and tissues. Furthermore, aberrant levels of these transcripts have been shown to contribute many diseases, including cancer. Among these, many aspects of ovarian cancer biology have been found to be regulated by lncRNAs, including cancer initiation, progression and dissemination. In this review, we summarize recent studies to highlight the various roles of lncRNAs in ovary in normal and pathological conditions, immune system, diagnosis, prognosis, and therapy. We address lncRNAs that have been extensively studied in ovarian cancer and their contribution to cellular dynamics.
Asunto(s)
Biomarcadores de Tumor , Regulación Neoplásica de la Expresión Génica , Neoplasias Ováricas/genética , ARN Largo no Codificante/genética , Animales , Manejo de la Enfermedad , Progresión de la Enfermedad , Susceptibilidad a Enfermedades , Femenino , Perfilación de la Expresión Génica/métodos , Humanos , Inmunomodulación/genética , Neovascularización Patológica/genética , Neovascularización Patológica/metabolismo , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/patología , Pronóstico , Interferencia de ARN , Transcripción Genética , TranscriptomaRESUMEN
Cyclin-dependent kinase (CDK)-7 inhibitors are emerging as promising drugs for the treatment of different types of cancer that show chemotherapy resistance. Evaluation of the effects of CDK7 inhibitor, THZ1, alone and combined with tamoxifen is of paramount importance. Thus, in the current work, we assessed the effects of THZ1 and/or tamoxifen in two estrogen receptor-positive (ER+) breast cancer cell lines (MCF7) and its tamoxifen resistant counterpart (LCC2) in vitro and in xenograft mouse models of breast cancer. Furthermore, we evaluated the expression of CDK7 in clinical samples from breast cancer patients. Cell viability, apoptosis, and genes involved in cell cycle regulation and tamoxifen resistance were determined. Tumor volume and weight, proliferation marker (Ki67), angiogenic marker (CD31), and apoptotic markers were assayed. Bioinformatic data indicated CDK7 expression was associated with negative prognosis, enhanced pro-oncogenic pathways, and decreased response to tamoxifen. Treatment with THZ1 enhanced tamoxifen-induced cytotoxicity, while it inhibited genes involved in tumor progression in MCF-7 and LCC2 cells. In vivo, THZ1 boosted the effect of tamoxifen on tumor weight and tumor volume, reduced Ki67 and CD31 expression, and increased apoptotic cell death. Our findings identify CDK7 as a possible therapeutic target for breast cancer whether it is sensitive or resistant to tamoxifen therapy.
Asunto(s)
Neoplasias de la Mama/metabolismo , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Resistencia a Antineoplásicos/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Animales , Antineoplásicos Hormonales/farmacología , Antineoplásicos Hormonales/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Apoptosis/efectos de los fármacos , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Femenino , Humanos , Ratones , Ensayos Antitumor por Modelo de Xenoinjerto , Quinasa Activadora de Quinasas Ciclina-DependientesRESUMEN
RNA interference (RNAi) is considered a highly specific approach for gene silencing and holds tremendous potential for treatment of various pathologic conditions such as cardiovascular diseases, viral infections, and cancer. Although gene silencing approaches such as RNAi are widely used in preclinical models, the clinical application of RNAi is challenging primarily because of the difficulty in achieving successful systemic delivery. Effective delivery systems are essential to enable the full therapeutic potential of RNAi. An ideal nanocarrier not only addresses the challenges of delivering naked siRNA/miRNA, including its chemically unstable features, extracellular and intracellular barriers, and innate immune stimulation, but also offers "smart" targeted delivery. Over the past decade, great efforts have been undertaken to develop RNAi delivery systems that overcome these obstacles. This review presents an update on current progress in the therapeutic application of RNAi with a focus on cancer therapy and strategies for optimizing delivery systems, such as lipid-based nanoparticles.
Asunto(s)
Técnicas de Transferencia de Gen , Terapia Genética , Neoplasias/genética , Neoplasias/terapia , Interferencia de ARN , ARN Interferente Pequeño/genética , Animales , Tratamiento Basado en Trasplante de Células y Tejidos , Resistencia a Antineoplásicos/genética , Genes MDR , Humanos , Terapia Molecular Dirigida , Nanopartículas , Neoplasias/inmunología , Células Madre/metabolismoRESUMEN
UNLABELLED: The death rate from hepatocellular carcinoma (HCC) is increasing, and liver cancer is the second leading cause of cancer-related mortality worldwide. Most patients with HCC have underlying liver cirrhosis and compromised liver function, limiting treatment options. Cirrhosis is associated with cell dedifferentiation and expansion of hepatocholangiolar progenitor cells. We identified a microRNA signature associated with HCC and hepatocytic differentiation of progenitor cells. We further identified miR-148a as an inducer of hepatocytic differentiation that is down-regulated in HCC. MiR-148a-mimetic treatment in vivo suppressed tumor growth, reduced tumor malignancy and liver fibrosis, and prevented tumor development. These effects were associated with an increased differentiated phenotype and mediated by IκB kinase alpha/NUMB/NOTCH signaling. CONCLUSION: miR-148a is an inhibitor of the IκB kinase alpha/NUMB/NOTCH pathway and an inducer of hepatocytic differentiation that when deregulated promotes HCC initiation and progression. Differentiation-targeted therapy may be a promising strategy to treat and prevent HCC.
Asunto(s)
Carcinoma Hepatocelular/terapia , Diferenciación Celular , Neoplasias Hepáticas/terapia , MicroARNs/metabolismo , Animales , Benzazepinas , Biomarcadores/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Fibrosis , Hepatocitos/citología , Hepatocitos/metabolismo , Humanos , Quinasa I-kappa B/metabolismo , Hígado/patología , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Fenotipo , Receptores Notch/antagonistas & inhibidores , Receptores Notch/metabolismoRESUMEN
UNLABELLED: Metabolic activation is a common feature of many cancer cells and is frequently associated with the clinical outcomes of various cancers, including hepatocellular carcinoma. Thus, aberrantly activated metabolic pathways in cancer cells are attractive targets for cancer therapy. Yes-associated protein 1 (YAP1) and transcriptional coactivator with PDZ-binding motif (TAZ) are oncogenic downstream effectors of the Hippo tumor suppressor pathway, which is frequently inactivated in many cancers. Our study revealed that YAP1/TAZ regulates amino acid metabolism by up-regulating expression of the amino acid transporters solute carrier family 38 member 1 (SLC38A1) and solute carrier family 7 member 5 (SLC7A5). Subsequently, increased uptake of amino acids by the transporters (SLC38A1 and SLC7A5) activates mammalian target of rapamycin complex 1 (mTORC1), a master regulator of cell growth, and stimulates cell proliferation. We also show that high expression of SLC38A1 and SLC7A5 is significantly associated with shorter survival in hepatocellular carcinoma patients. Furthermore, inhibition of the transporters and mTORC1 significantly blocks YAP1/TAZ-mediated tumorigenesis in the liver. These findings elucidate regulatory networks connecting the Hippo pathway to mTORC1 through amino acid metabolism and the mechanism's potential clinical implications for treating hepatocellular carcinoma. CONCLUSION: YAP1 and TAZ regulate cancer metabolism and mTORC1 through regulation of amino acid transportation, and two amino acid transporters, SLC38A1 and SLC7A5, might be important therapeutic targets.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/fisiología , Sistemas de Transporte de Aminoácidos/fisiología , Carcinoma Hepatocelular/metabolismo , Péptidos y Proteínas de Señalización Intracelular/fisiología , Neoplasias Hepáticas/metabolismo , Complejos Multiproteicos/fisiología , Fosfoproteínas/fisiología , Serina-Treonina Quinasas TOR/fisiología , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Carcinoma Hepatocelular/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Hepáticas/genética , Diana Mecanicista del Complejo 1 de la Rapamicina , Ratones , Fosfoproteínas/genética , Estructura Terciaria de Proteína , Transducción de Señal , Transactivadores , Factores de Transcripción , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ , Proteínas Señalizadoras YAPRESUMEN
Intercellular communication via cell-released vesicles is a very important process for both normal and tumor cells. Cell communication may involve exosomes, small vesicles of endocytic origin that are released by all types of cells and are found in abundance in body fluids, including blood, saliva, urine, and breast milk. Exosomes have been shown to carry lipids, proteins, mRNAs, non-coding RNAs, and even DNA out of cells. They are more than simply molecular garbage bins, however, in that the molecules they carry can be taken up by other cells. Thus, exosomes transfer biological information to neighboring cells and through this cell-to-cell communication are involved not only in physiological functions such as cell-to-cell communication, but also in the pathogenesis of some diseases, including tumors and neurodegenerative conditions. Our increasing understanding of why cells release exosomes and their role in intercellular communication has revealed the very complex and sophisticated contribution of exosomes to health and disease. The aim of this review is to reveal the emerging roles of exosomes in normal and pathological conditions and describe the controversial biological role of exosomes, as it is now understood, in carcinogenesis. We also summarize what is known about exosome biogenesis, composition, functions, and pathways and discuss the potential clinical applications of exosomes, especially as biomarkers and novel therapeutic agents.
Asunto(s)
Exosomas/fisiología , Neoplasias/patología , Enfermedades Neurodegenerativas/patología , Transporte Biológico , Comunicación Celular , Sistemas de Liberación de Medicamentos , Humanos , Neoplasias/metabolismo , Neoplasias/terapia , Enfermedades Neurodegenerativas/metabolismo , Enfermedades Neurodegenerativas/terapiaRESUMEN
Large-scale molecular annotation of epithelial ovarian cancer (EOC) indicates remarkable heterogeneity in the etiology of that disease. This diversity presents a significant obstacle against intervention target discovery. However, inactivation of miRNA biogenesis is commonly associated with advanced disease. Thus, restoration of miRNA activity may represent a common vulnerability among diverse EOC oncogenotypes. To test this, we employed genome-scale, gain-of-function, miRNA mimic toxicity screens in a large, diverse spectrum of EOC cell lines. We found that all cell lines responded to at least some miRNA mimics, but that the nature of the miRNA mimics provoking a response was highly selective within the panel. These selective toxicity profiles were leveraged to define modes of action and molecular response indicators for miRNA mimics with tumor-suppressive characteristics in vivo. A mechanistic principle emerging from this analysis was sensitivity of EOC to miRNA-mediated release of cell fate specification programs, loss of which may be a prerequisite for development of this disease.
Asunto(s)
Materiales Biomiméticos/administración & dosificación , MicroARNs/genética , Neoplasias Glandulares y Epiteliales/tratamiento farmacológico , Neoplasias Glandulares y Epiteliales/genética , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/genética , Animales , Materiales Biomiméticos/farmacología , Carcinoma Epitelial de Ovario , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Regulación hacia Abajo , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Estudio de Asociación del Genoma Completo , Humanos , Ratones , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Extensive investigations have shown that miRNAs are important regulators of epithelial-to-mesenchymal transition (EMT), mainly targeting the transcriptional repressors of E-cadherin (E-cad). Less is known about the post-transcriptional regulation of vimentin or N-cadherin (N-cad) in EMT. Our previous study identified miR-506 as a key EMT inhibitor through directly targeting the E-cad transcriptional repressor SNAI2. In this study, we provide evidence that miR-506 simultaneously suppresses vimentin and N-cad. The knockdown of vimentin using siRNA reversed EMT, suppressed cell migration and invasion, and increased E-cad expression on the cell membrane in epithelial ovarian cancer (EOC) cells. In a set of tissue microarrays that included 204 EOCs of all major subtypes (eg serous, endometrioid, clear cell, and mucinous), miR-506 was positively correlated with E-cad and negatively correlated with vimentin and N-cad in all subtypes of EOC. A high level of miR-506 was positively associated with early FIGO stage and longer survival in EOC. Introduction of miR-506, mediated by nanoparticle delivery, in EOC orthotopic mouse models resulted in decreased vimentin, N-cad, and SNAI2 expression and increased E-cad expression; it also suppressed the dissemination of EOC cells. Thus, miR-506 represents a new class of miRNA that regulates both E-cad and vimentin/N-cad in the suppression of EMT and metastasis.
Asunto(s)
Transición Epitelial-Mesenquimal/genética , Regulación Neoplásica de la Expresión Génica/genética , MicroARNs/genética , Neoplasias Glandulares y Epiteliales/genética , Neoplasias Ováricas/genética , Adulto , Anciano , Anciano de 80 o más Años , Cadherinas/metabolismo , Carcinoma Epitelial de Ovario , Línea Celular Tumoral , Movimiento Celular/genética , Femenino , Regulación de la Expresión Génica/genética , Humanos , Persona de Mediana Edad , Neoplasias Glandulares y Epiteliales/diagnóstico , Neoplasias Ováricas/diagnóstico , Pronóstico , Factores de Transcripción/metabolismo , Vimentina/metabolismoRESUMEN
Glutamine can play a critical role in cellular growth in multiple cancers. Glutamine-addicted cancer cells are dependent on glutamine for viability, and their metabolism is reprogrammed for glutamine utilization through the tricarboxylic acid (TCA) cycle. Here, we have uncovered a missing link between cancer invasiveness and glutamine dependence. Using isotope tracer and bioenergetic analysis, we found that low-invasive ovarian cancer (OVCA) cells are glutamine independent, whereas high-invasive OVCA cells are markedly glutamine dependent. Consistent with our findings, OVCA patients' microarray data suggest that glutaminolysis correlates with poor survival. Notably, the ratio of gene expression associated with glutamine anabolism versus catabolism has emerged as a novel biomarker for patient prognosis. Significantly, we found that glutamine regulates the activation of STAT3, a mediator of signaling pathways which regulates cancer hallmarks in invasive OVCA cells. Our findings suggest that a combined approach of targeting high-invasive OVCA cells by blocking glutamine's entry into the TCA cycle, along with targeting low-invasive OVCA cells by inhibiting glutamine synthesis and STAT3 may lead to potential therapeutic approaches for treating OVCAs.
Asunto(s)
Proliferación Celular , Metabolismo Energético/genética , Glutamina/metabolismo , Neoplasias Ováricas/metabolismo , Ciclo Celular/genética , Línea Celular Tumoral , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Pronóstico , Transducción de Señal/genéticaRESUMEN
The E3 ubiquitin ligase EDD is overexpressed in recurrent, platinum-resistant ovarian cancers, suggesting a role in tumor survival and/or platinum resistance. EDD knockdown by small interfering RNA (siRNA) induced apoptosis in A2780ip2, OVCAR5 and ES-2 ovarian cancer cells, correlating with loss of the prosurvival protein myeloid cell leukemia sequence 1 (Mcl-1) through a glycogen synthase kinase 3 beta-independent mechanism. SiRNA to EDD or Mcl-1 induced comparable levels of apoptosis in A2780ip2 and ES-2 cells. Stable overexpression of Mcl-1 protected cells from apoptosis following EDD knockdown, accompanied by a loss of endogenous, but not exogenous, Mcl-1 protein, suggesting that EDD regulated Mcl-1 synthesis. Indeed, EDD knockdown induced a 1.87-fold decrease in Mcl-1 messenger RNA and EDD transfection enhanced murine Mcl-1 promoter-driven luciferase expression 5-fold. To separate EDD survival and potential cisplatin resistance functions, we generated EDD shRNA stable cell lines that could survive initial EDD knockdown and showed that these cells were 4- to 21-fold more sensitive to cisplatin. Moreover, transient EDD overexpression in COS-7 cells was sufficient to promote cisplatin resistance 2.4-fold, dependent upon its E3 ligase activity. In vivo, mouse intraperitoneal ES-2 and A2780ip2 xenograft experiments showed that mice treated with EDD siRNA by nanoliposomal delivery [1,2-dioleoyl-sn-glycero-3-phophatidylcholine (DOPC)] and cisplatin had significantly less tumor burden than those treated with control siRNA/DOPC alone (ES-2, 77.9% reduction, P = 0.004; A2780ip2, 75.9% reduction, P = 0.042) or control siRNA/DOPC with cisplatin in ES-2 (64.4% reduction, P = 0.035), with a trend in A2780ip2 (60.3% reduction, P = 0.168). These results identify EDD as a dual regulator of cell survival and cisplatin resistance and suggest that EDD is a therapeutic target for ovarian cancer.