RESUMO
MicroRNA-423 (miR-423) is highly expressed in breast cancer (BC). Previously, our group showed that the SNP rs6505162:C>A located in the pre-miR-423 was significantly associated with increased familial BC risk in patients with a strong family history of BC. Therefore, in this study, we evaluated the functional role of rs6505162 in mammary tumorigenesis in vitro to corroborate the association of this SNP with BC risk. We found that rs6505162:C>A upregulated expression of both mature miR-423 sequences (3p and 5p). Moreover, pre-miR-423-A enhanced proliferation, and promoted cisplatin resistance in BC cell lines. We also showed that pre-miR-423-A expression decreased cisplatin-induced apoptosis, and increased BC cell migration and invasion. We propose that the rs6505162-A allele promotes miR-423 overexpression, and that the rs6505162-A allele induces BC cell proliferation, viability, chemoresistance, migration, and invasion, and decreases cell apoptosis as a consequence. We suggest that rs6505162:C>A is a functional SNP site with potential utility as a marker for early diagnosis, prognosis, and treatment efficacy monitoring in BRCA1/2-negative BC patients, as well as a possible therapeutic target.
Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Movimento Celular/genética , Resistencia a Medicamentos Antineoplásicos/genética , Variação Genética , MicroRNAs/metabolismo , Apoptose/genética , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , MicroRNAs/genética , Invasividade Neoplásica , Polimorfismo de Nucleotídeo Único/genética , Regulação para Cima/genéticaRESUMO
MicroRNAs (miRNAs) are a highly abundant collection of functional non-coding RNAs involved in cellular regulation and various complex human diseases. Although a large number of miRNAs have been identified, most of their physiological functions remain unknown. Computational methods play a vital role in exploring the potential functions of miRNAs. Here, we present DeepMiR2GO, a tool for integrating miRNAs, proteins and diseases, to predict the gene ontology (GO) functions based on multiple deep neuro-symbolic models. DeepMiR2GO starts by integrating the miRNA co-expression network, protein-protein interaction (PPI) network, disease phenotype similarity network, and interactions or associations among them into a global heterogeneous network. Then, it employs an efficient graph embedding strategy to learn potential network representations of the global heterogeneous network as the topological features. Finally, a deep multi-label classification network based on multiple neuro-symbolic models is built and used to annotate the GO terms of miRNAs. The predicted results demonstrate that DeepMiR2GO performs significantly better than other state-of-the-art approaches in terms of precision, recall, and maximum F-measure.
Assuntos
Doenças Cardiovasculares/genética , MicroRNAs/genética , Neoplasias/genética , Redes Neurais de Computação , Esquizofrenia/genética , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/patologia , Conjuntos de Dados como Assunto , Regulação da Expressão Gênica , Ontologia Genética , Redes Reguladoras de Genes , Humanos , MicroRNAs/classificação , MicroRNAs/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Esquizofrenia/metabolismo , Esquizofrenia/patologiaRESUMO
This chapter describes one of the most reliable quantitative assays to test the silencing of a possible target gene by a specific miRNA using a luciferase reporter gene. The experimental procedure first consists in cloning both the wild-type and mutated forms of the 3'UTR of the miRNA-predicted mRNA target downstream of a firefly luciferase reporter. Next, each construct is co-transfected together with the miRNA into HeLa cells, and the reporter expression is monitored. Changes in luciferase levels will indicate whether or not an miRNA can bind to the UTR and regulate its expression.
Assuntos
Luciferases de Vaga-Lume/genética , MicroRNAs/genética , RNA Mensageiro/genética , Regiões 3' não Traduzidas , Regulação da Expressão Gênica , Genes Reporter , Células HeLa , Humanos , Luciferases de Vaga-Lume/metabolismo , MutaçãoRESUMO
MicroRNA (miRNA) is a class of small non-coding RNAs which mediate post-transcriptional gene silencing (PTGS) by sequence-specific inhibition of target mRNAs translation and/or lowering their half-lives in the cytoplasm. Together with their binding partners, Argonaute (AGO) proteins, miRNAs form cores of RNA-induced silencing complexes (RISC). Despite a substantial progress in understanding RISC structure, until recently little was known about its localization in the cell. This review is aimed to provide an overview of the emerging picture of miRNA and RISC localization and function both in the intracellular space and outside of the cell. In contrast to the common assumption that PTGS occurs in the cytoplasm, it was found to operate mainly on the membranes of the endoplasmic reticulum (ER). Besides ER membranes miRNAs were found in all main cellular compartments including nucleus, nucleolus and mitochondria where they regulate various processes including transcription, translation, alternative splicing and DNA repair. Moreover, a certain pool of miRNAs may not be associated with RISC and carry completely different functions. Finally, the discovery of cell-free miRNAs in all biological fluids suggests that miRNAs might also act as signaling molecules outside the cell, and may be utilized as biomarkers for a variety of diseases. In this review we discuss miRNA secretion mechanisms and possible pathways of cell-cell communication via miRNA-containing exosomes in vivo.
Assuntos
Proteínas Argonautas/genética , Células Eucarióticas/metabolismo , MicroRNAs/genética , Interferência de RNA , RNA Mensageiro/genética , Complexo de Inativação Induzido por RNA/genética , Animais , Proteínas Argonautas/metabolismo , Comunicação Celular , Núcleo Celular/metabolismo , Núcleo Celular/ultraestrutura , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/ultraestrutura , Células Eucarióticas/citologia , Exossomos/metabolismo , Exossomos/ultraestrutura , Humanos , MicroRNAs/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Biossíntese de Proteínas , RNA Mensageiro/metabolismo , Complexo de Inativação Induzido por RNA/química , Complexo de Inativação Induzido por RNA/metabolismo , Transdução de Sinais , Transcrição GênicaRESUMO
Type I interferon (IFN) is one of the first lines of cellular defense against viral pathogens. As a result of IFN signaling, a wide array of IFN-stimulated gene (ISG) products is upregulated to target different stages of the viral life cycle. We review recent findings implicating a subset of ISGs in translational regulation of viral and host mRNAs. Translation inhibition is mediated either by binding to viral RNA or by disrupting physiological interactions or levels of the translation complex components. In addition, many of these ISGs localize to translationally silent cytoplasmic granules, such as stress granules and processing bodies, and intersect with the microRNA (miRNA)-mediated silencing pathway to regulate translation of cellular mRNAs.