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1.
Breast Cancer Res ; 25(1): 119, 2023 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-37803350

RESUMO

BACKGROUND: Triple negative breast cancer (TNBC) is a particularly aggressive and difficult-to-treat subtype of breast cancer that requires the development of novel therapeutic strategies. To pave the way for such developments it is essential to characterize new molecular players in TNBC. MicroRNAs (miRNAs) constitute interesting candidates in this regard as they are frequently deregulated in cancer and contribute to numerous aspects of carcinogenesis. METHODS AND RESULTS: Here, we discovered that miR-4649-5p, a miRNA yet uncharacterized in breast cancer, is associated with better overall survival of TNBC patients. Ectopic upregulation of the otherwise very low endogenous expression levels of miR-4646-5p significantly decreased the growth, proliferation, and migration of TNBC cells. By performing whole transcriptome analysis and physical interaction assays, we were able to identify the phosphatidylinositol phosphate kinase PIP5K1C as a direct target of miR-4649-5p. Downregulation or pharmacologic inhibition of PIP5K1C phenocopied the growth-reducing effects of miR-4649-5p. PIP5K1C is known to play an important role in migration and cell adhesion, and we could furthermore confirm its impact on downstream PI3K/AKT signaling. Combinations of miR-4649-5p upregulation and PIP5K1C or AKT inhibition, using the pharmacologic inhibitors UNC3230 and capivasertib, respectively, showed additive growth-reducing effects in TNBC cells. CONCLUSION: In summary, miR-4649-5p exerts broad tumor-suppressive effects in TNBC and shows potential for combined therapeutic approaches targeting the PIP5K1C/PI3K/AKT signaling axis.


Assuntos
MicroRNAs , Neoplasias de Mama Triplo Negativas , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica
2.
Front Endocrinol (Lausanne) ; 13: 977331, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36111296

RESUMO

Androgen receptor (AR) is expressed in 60-70% of breast cancers (BCs) and the availability of anti-AR compounds, currently used for treating prostate cancer, paves the way to tackle specifically AR-positive BC patients. The prognostic and predictive role of AR in BC is a matter of debate, since the results from clinical trials are not striking, probably due to both technical and biological reasons. In this review, we aimed to highlight WHAT is AR, describing its structure and functions, WHAT to test and HOW to detect AR, WHERE AR should be tested (on primary tumor or metastasis) and WHY studying this fascinating hormone receptor, exploring and debating on its prognostic and predictive role. We considered AR and its ratio with other hormone receptors, analyzing also studies including patients with ductal carcinoma in situ and with early and advanced BC, as well. We also emphasized the effects that both other hormone receptors and the newly emerging androgen-inducible non coding RNAs may have on AR function in BC pathology and the putative implementation in the clinical setting. Moreover, we pointed out the latest results by clinical trials and we speculated about the use of anti-AR therapies in BC clinical practice.


Assuntos
Neoplasias da Mama , Receptores Androgênicos , Androgênios , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Feminino , Humanos , Prognóstico , Receptores Androgênicos/genética
3.
Cell Mol Life Sci ; 79(7): 391, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35776213

RESUMO

The RNA-binding protein ALYREF (THOC4) is involved in transcriptional regulation and nuclear mRNA export, though its role and molecular mode of action in breast carcinogenesis are completely unknown. Here, we identified high ALYREF expression as a factor for poor survival in breast cancer patients. ALYREF significantly influenced cellular growth, apoptosis and mitochondrial energy metabolism in breast cancer cells as well as breast tumorigenesis in orthotopic mouse models. Transcriptional profiling, phenocopy and rescue experiments identified the short isoform of the lncRNA NEAT1 as a molecular trigger for ALYREF effects in breast cancer. Mechanistically, we found that ALYREF binds to the NEAT1 promoter region to enhance the global NEAT1 transcriptional activity. Importantly, by stabilizing CPSF6, a protein that selectively activates the post-transcriptional generation of the short isoform of NEAT1, as well as by direct binding and stabilization of the short isoform of NEAT1, ALYREF selectively fine-tunes the expression of the short NEAT1 isoform. Overall, our study describes ALYREF as a novel factor contributing to breast carcinogenesis and identifies novel molecular mechanisms of regulation the two isoforms of NEAT1.


Assuntos
Neoplasias da Mama , Proteínas Nucleares , RNA Longo não Codificante , Proteínas de Ligação a RNA , Fatores de Transcrição , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Transformação Celular Neoplásica , Feminino , Humanos , Camundongos , Proteínas Nucleares/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Transporte de RNA , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proteínas de Ligação a RNA/metabolismo , Fatores de Transcrição/metabolismo
4.
Sci Rep ; 11(1): 2980, 2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33536459

RESUMO

While the molecular functions of miR-200 family have been deeply investigated, a role for these miRNAs as breast cancer biomarkers remains largely unexplored. In the attempt to clarify this, we profiled the miR-200 family members expression in a large cohort of breast cancer cases with a long follow-up (H-CSS cohort) and in TCGA-BRCA cohort. Overall, miR-200 family was found upregulated in breast tumors with respect to normal breast tissues while downregulated in more aggressive breast cancer molecular subtypes (i.e. Luminal B, HER2 and triple negative), consistently with their function as repressors of the epithelial-to-mesenchymal transition (EMT). In particular miR-141-3p was found differentially expressed in breast cancer molecular subtypes in both H-CSS and TCGA-BRCA cohorts, and the combined analysis of all miR-200 family members demonstrated a slight predictive accuracy on H-CSS cancer specific survival at 12 years (survival c-statistic: 0.646; 95%CI 0.538-0.754).


Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/mortalidade , MicroRNAs/análise , MicroRNAs/genética , Recidiva Local de Neoplasia/epidemiologia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Mama/patologia , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Neoplasias da Mama/terapia , Linhagem Celular Tumoral , Estudos de Coortes , Intervalo Livre de Doença , Transição Epitelial-Mesenquimal/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Família Multigênica/genética , Recidiva Local de Neoplasia/genética , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Medição de Risco/métodos , Regulação para Cima
5.
Front Oncol ; 10: 1415, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32903519

RESUMO

miR-155-5p is a well-known oncogenic microRNA, showing frequent overexpression in human malignancies, including breast cancer. Here, we show that high miR-155-5p levels are associated with unfavorable prognostic factors in two independent breast cancer cohorts (CSS cohort, n = 283; and TCGA-BRCA dataset, n = 1,095). Consistently, miR-155-5p results as differentially expressed in the breast cancer subgroups identified by the surrogate molecular classification in the CSS cohort and the PAM50 classifier in TCGA-BRCA dataset, with the TNBC and HER2-amplified tumors carrying the highest levels. Since the analysis of TCGA-BC dataset also demonstrated a significant association between miR-155-5p levels and the presence of mutations in homologous recombination (HR) genes, we hypothesized that miR-155-5p might affect cell response to the PARP-1 inhibitor Olaparib. As expected, miR-155-5p ectopic overexpression followed by Olaparib administration resulted in a greater reduction of cell viability as compared to Olaparib administration alone, suggesting that miR-155-5p might induce a synthetic lethal effect in cancer cells when coupled with PARP-1-inhibition. Overall, our data point to a role of miR-155-5p in homologous recombination deficiency and suggest miR-155-5p might be useful in predicting response to PARP1 inhibitors in the clinical setting.

6.
Int J Mol Sci ; 21(3)2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31979064

RESUMO

Members of the carbonic anhydrase family are functionally involved in the regulation of intracellular and extracellular pH in physiological and pathological conditions. Their expression is finely regulated to maintain a strict control on cellular homeostasis, and it is dependent on the activation of extracellular and intracellular signaling pathways. Combining RNA sequencing (RNA-seq), NanoString, and bioinformatics data, we demonstrated that the expression of carbonic anhydrase 12 (CAXII) is significantly different in luminal and triple negative breast cancer (BC) models and patients, and is associated with the activation of an epithelial mesenchymal transition (EMT) program. In BC models, the phorbol ester 12-myristate 13-acetate (PMA)-mediated activation of protein kinase C (PKC) induced a down-regulation of CAXII with a concomitant modulation of other members of the transport metabolon, including CAIX and the sodium bicarbonate cotransporter 3 (NBCn1). This is associated with a remodeling of tumor glycolytic metabolism induced after PKC activation. Overall, this analysis highlights the dynamic nature of transport metabolom and identifies signaling pathways finely regulating this plasticity.


Assuntos
Anidrases Carbônicas/genética , Transição Epitelial-Mesenquimal/genética , Proteína Quinase C/genética , Adulto , Idoso , Antígenos de Neoplasias/genética , Linhagem Celular Tumoral , Regulação para Baixo/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Células MCF-7 , Pessoa de Meia-Idade , Transdução de Sinais/genética , Simportadores de Sódio-Bicarbonato/genética , Neoplasias de Mama Triplo Negativas/genética
7.
Sci Rep ; 9(1): 14913, 2019 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-31624308

RESUMO

MicroRNA-210-3p is the most prominent hypoxia regulated microRNA, and it has been found significantly overexpressed in different human cancers. We performed the expression analysis of miR-210-3p in a retrospective cohort of breast cancer patients with a median follow-up of 76 months (n = 283). An association between higher levels of miR-210-3p and risk of disease progression (HR: 2.13, 95%CI: 1.33-3.39, P = 0.002) was found in the subgroup of patients treated with Epirubicin and Cyclophosphamide followed by Docetaxel. Moreover, a cut off value of 20.966 established by ROC curve analyses allowed to discriminate patients who developed distant metastases with an accuracy of 85% at 3- (AUC: 0.870, 95%CI: 0.690-1.000) and 83% at 5-years follow up (AUC: 0.832, 95%CI: 0.656-1.000). Whereas the accuracy in discriminating patients who died for the disease was of 79.6% at both 5- (AUC: 0.804, 95%CI: 0.517-1.000) and 10-years (AUC: 0.804. 95%CI: 0.517-1.000) follow-up. In silico analysis of miR-210-3p and Docetaxel targets provided evidence for a putative molecular cross-talk involving microtubule regulation, drug efflux metabolism and oxidative stress response. Overall, our data point to the miR-210-3p involvement in the response to therapeutic regimens including Docetaxel in sequential therapy with anthracyclines, suggesting it may represent a predictive biomarker in breast cancer patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/terapia , Docetaxel/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , MicroRNAs/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais/análise , Mama/patologia , Mama/cirurgia , Neoplasias da Mama/genética , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Quimioterapia Adjuvante/métodos , Biologia Computacional , Ciclofosfamida/farmacologia , Ciclofosfamida/uso terapêutico , Progressão da Doença , Docetaxel/uso terapêutico , Epirubicina/farmacologia , Epirubicina/uso terapêutico , Feminino , Seguimentos , Regulação Neoplásica da Expressão Gênica , Humanos , Mastectomia , MicroRNAs/análise , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos
8.
Int J Mol Sci ; 20(12)2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31212911

RESUMO

In both developing and industrialized Countries, the growing prevalence of Type 2 Diabetes Mellitus (T2DM) and the severity of its related complications make T2DM one of the most challenging metabolic diseases worldwide. The close relationship between genetic and environmental factors suggests that eating habits and unhealthy lifestyles may significantly affect metabolic pathways, resulting in dynamic modifications of chromatin-associated proteins and homeostatic transcriptional responses involved in the progression of T2DM. Epigenetic mechanisms may be implicated in the complex processes linking environmental factors to genetic predisposition to metabolic disturbances, leading to obesity and type 2 diabetes mellitus (T2DM). Endothelial dysfunction represents an earlier marker and an important player in the development of this disease. Dysregulation of the endothelial ability to produce and release vasoactive mediators is recognized as the initial feature of impaired vascular activity under obesity and other insulin resistance conditions and undoubtedly concurs to the accelerated progression of atherosclerotic lesions and overall cardiovascular risk in T2DM patients. This review aims to summarize the most current knowledge regarding the involvement of epigenetic changes associated with endothelial dysfunction in T2DM, in order to identify potential targets that might contribute to pursuing "precision medicine" in the context of diabetic illness.


Assuntos
Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/metabolismo , Endotélio Vascular/metabolismo , Epigênese Genética , Medicina de Precisão , Animais , Doenças Cardiovasculares/etiologia , Metilação de DNA , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/terapia , Endotélio Vascular/efeitos dos fármacos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Histonas/metabolismo , Humanos , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Medicina de Precisão/métodos
9.
Breast Cancer Res ; 21(1): 20, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30709367

RESUMO

BACKGROUND: Non-coding RNAs and especially microRNAs have been discovered to act as master regulators of cancer initiation and progression. The aim of our study was to discover and characterize the function of yet functionally uncharacterized microRNAs in human breast carcinogenesis. METHODS: In an unbiased approach, we utilized an established model system for breast cancer (BC) stem cell formation ("mammosphere assay") to identify whole miRNome alterations in breast carcinogenesis. Clinical samples of BC patients were used to evaluate the human relevance of the newly identified miRNA candidates. One promising candidate, miR-1287-5p, was further explored on its impact on several hallmarks of cancer. The molecular mode of action was characterized by whole transcriptome analysis, in silico prediction tools, miRNA-interaction assays, pheno-copy assays, and drug sensitivity assays. RESULTS: Among several other microRNAs, miR-1287-5p was significantly downregulated in mammospheres and human BC tissue compared to normal breast tissue (p < 0.0001). Low expression levels were significantly associated with poor prognosis in BC patients. MiR-1287-5p significantly decreased cellular growth, cells in S phase of cell cycle, anchorage-independent growth, and tumor formation in vivo. In addition, we identified PIK3CB as a direct molecular interactor of miR-1287-5p and a novel prognostic factor in BC. Finally, PI3Kinase pathway chemical inhibitors combined with miR-1287-5p mimic increased the pharmacological growth inhibitory potential in triple negative BC cells. CONCLUSION: Our data identified for the first time the involvement of miR-1287-5p in human BC and suggest a potential for therapeutic interventions in difficult to treat triple negative BC.


Assuntos
Carcinogênese/genética , Classe I de Fosfatidilinositol 3-Quinases/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/metabolismo , Neoplasias de Mama Triplo Negativas/genética , Animais , Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Classe I de Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Regulação para Baixo , Feminino , Perfilação da Expressão Gênica , Células HEK293 , Humanos , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Prognóstico , Análise de Sobrevida , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/mortalidade , Neoplasias de Mama Triplo Negativas/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Semin Cancer Biol ; 51: 22-35, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29339244

RESUMO

In the last years, mortality from breast cancer has declined in western countries as a consequence of a more widespread screening resulting in earlier detection, as well as an improved molecular classification and advances in adjuvant treatment. Nevertheless, approximately one third of breast cancer patients will develop distant metastases and eventually die for the disease. There is now a compelling body of evidence suggesting that epigenetic modifications comprising DNA methylation and chromatin remodeling play a pivotal role since the early stages of breast cancerogenesis. In addition, recently, increasing emphasis is being placed on the property of ncRNAs to finely control gene expression at multiple levels by interacting with a wide array of molecules such that they might be designated as epigenetic modifiers. In this review, we summarize the current knowledge about the involvement of epigenetic modifications in breast cancer, and provide an overview of the significant association of epigenetic traits with the breast cancer clinicopathological features, emphasizing the potentiality of epigenetic marks to become biomarkers in the context of precision medicine.


Assuntos
Neoplasias da Mama/genética , Metilação de DNA , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Medicina de Precisão , Neoplasias da Mama/patologia , Feminino , Humanos
11.
Genome Biol ; 18(1): 98, 2017 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-28535802

RESUMO

BACKGROUND: Non-coding RNAs have been drawing increasing attention in recent years as functional data suggest that they play important roles in key cellular processes. N-BLR is a primate-specific long non-coding RNA that modulates the epithelial-to-mesenchymal transition, facilitates cell migration, and increases colorectal cancer invasion. RESULTS: We performed multivariate analyses of data from two independent cohorts of colorectal cancer patients and show that the abundance of N-BLR is associated with tumor stage, invasion potential, and overall patient survival. Through in vitro and in vivo experiments we found that N-BLR facilitates migration primarily via crosstalk with E-cadherin and ZEB1. We showed that this crosstalk is mediated by a pyknon, a short ~20 nucleotide-long DNA motif contained in the N-BLR transcript and is targeted by members of the miR-200 family. In light of these findings, we used a microarray to investigate the expression patterns of other pyknon-containing genomic loci. We found multiple such loci that are differentially transcribed between healthy and diseased tissues in colorectal cancer and chronic lymphocytic leukemia. Moreover, we identified several new loci whose expression correlates with the colorectal cancer patients' overall survival. CONCLUSIONS: The primate-specific N-BLR is a novel molecular contributor to the complex mechanisms that underlie metastasis in colorectal cancer and a potential novel biomarker for this disease. The presence of a functional pyknon within N-BLR and the related finding that many more pyknon-containing genomic loci in the human genome exhibit tissue-specific and disease-specific expression suggests the possibility of an alternative class of biomarkers and therapeutic targets that are primate-specific.


Assuntos
Neoplasias Colorretais/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Leucemia Linfocítica Crônica de Células B/genética , RNA Longo não Codificante/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Caderinas/genética , Caderinas/metabolismo , Movimento Celular , Proliferação de Células , Estudos de Coortes , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Feminino , Loci Gênicos , Células HCT116 , Humanos , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/mortalidade , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , MicroRNAs/genética , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Motivos de Nucleotídeos , RNA Longo não Codificante/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Análise de Sobrevida , Transcrição Gênica , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo
12.
Sci Rep ; 7: 45283, 2017 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-28345661

RESUMO

miR-9 was initially identified as an epigenetically regulated miRNA in tumours, but inconsistent findings have been reported so far. We analysed the expression of miR-9-5p, miR-9-3p, pri-miRs and MIR9 promoters methylation status in 131 breast cancer cases and 12 normal breast tissues (NBTs). The expression of both mature miRs was increased in tumours as compared to NBTs (P < 0.001) and negatively correlated with ER protein expression (P = 0.005 and P = 0.003, for miR-9-3p and miR-9-5p respectively). In addition, miR-9-5p showed a significant negative correlation with PgR (P = 0.002). Consistently, miR-9-5p and miR-9 3p were differentially expressed in the breast cancer subgroups identified by ER and PgR expression and HER2 amplification. No significant correlation between promoter methylation and pri-miRNAs expressions was found either in tumours or in NBTs. In the Luminal breast cancer subtype the expression of miR-9-5p was associated with a worse prognosis in both univariable and multivariable analyses. Ingenuity Pathway Analysis exploring the putative interactions among miR-9-5p/miR-9-3p, ER and PgR upstream and downstream regulators suggested a regulatory loop by which miR-9-5p but not miR-9-3p is induced by steroid hormone receptor and acts within hormone-receptor regulated pathways.


Assuntos
Neoplasias da Mama/genética , Estrogênios/genética , Loci Gênicos/genética , MicroRNAs/genética , Transdução de Sinais/genética , Idoso , Biomarcadores Tumorais/genética , Feminino , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Pessoa de Meia-Idade , Regiões Promotoras Genéticas/genética , Estudos Prospectivos
13.
Mol Cell ; 61(4): 520-534, 2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26853146

RESUMO

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.


Assuntos
Glutaminase/genética , Neoplasias/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Fatores de Poliadenilação e Clivagem de mRNA/metabolismo , Alelos , Processamento Alternativo , Metabolismo Energético , Células HCT116 , Humanos , Neoplasias/genética , Precursores de RNA/química , Precursores de RNA/metabolismo , RNA Mensageiro/metabolismo
15.
Sci Rep ; 5: 18592, 2015 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-26690267

RESUMO

BRAF codon 600 mutation testing of melanoma patients is mandatory for the choice of the most appropriate therapy in the clinical setting. Competitive allele specific TaqMan PCR (Cast-PCR) technology allows not only the selective amplification of minor alleles, but it also blocks the amplification of non-mutant allele. We genotyped codon 600 of the BRAF gene in 54 patients' samples by Cast-PCR and bidirectional direct sequence analysis. All the mutations detected by sequencing were also identified by Cast-PCR. In addition, Cast-PCR assay detected four samples carrying mutations and was able to clearly identify two mutations of uncertain interpretation by Sanger sequencing. The limit of detection of Cast-PCR was evaluated by constructing dilution curves of BRAF(V600E) and BRAF(V600K) mutated clinical samples mixed with a not-mutated specimens. Both mutations could be detected until a 1:100 mutated/not mutated ratio. Cloning and sequencing of the clones was used to confirm mutations on representative discrepant cases. Cast PCR performances were not affected by intratumour heterogeneity, and less affected by melanin content. Our results indicate that Cast-PCR is a reliable diagnostic tool for the identification of melanoma patients as eligible to be treated with TKIs and might be implemented in the clinical setting as elective screening method.


Assuntos
Alelos , Melanoma/genética , Mutação/genética , Reação em Cadeia da Polimerase/métodos , Proteínas Proto-Oncogênicas B-raf/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Bases , Clonagem Molecular , Códon/genética , Análise Mutacional de DNA , Feminino , Heterogeneidade Genética , Humanos , Limite de Detecção , Masculino , Melaninas/metabolismo , Melanoma/tratamento farmacológico , Pessoa de Meia-Idade , Dados de Sequência Molecular , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Sensibilidade e Especificidade , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/genética
16.
PLoS One ; 9(10): e108950, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25279461

RESUMO

Gliomas represent a disparate group of tumours for which there are to date no cure. Thus, there is a recognized need for new diagnostic and therapeutic approaches based on increased understanding of their molecular nature. We performed the comparison of the microRNA (miRNA) profile of 8 WHO grade II gliomas and 24 higher grade tumours (2 WHO grade III and 22 glioblastomas) by using the Affymetrix GeneChip miRNA Array v. 1.0. A relative quantification method (RT-qPCR) with standard curve was used to confirm the 22 miRNA signature resulted by array analysis. The prognostic performances of the confirmed miRNAs were estimated on the Tumor Cancer Genome Atlas (TCGA) datasets. We identified 22 miRNAs distinguishing grade II gliomas from higher grade tumours. RT-qPCR confirmed the differential expression in the two patients' groups for 13 out of the 22 miRNAs. The analysis of the Glioblastoma Multiforme (GBM) and Lower Grade Glioma (LGG) datasets from TCGA demonstrated the association with prognosis for 6 of those miRNAs. Moreover, in the GBM dataset miR-21 and miR-210 were predictors of worse prognosis in both univariable and multivariable Cox regression analyses (HR 1.19, p = 0.04, and HR 1.18, p = 0.029 respectively). Our results support a direct contribution of miRNAs to glioma cancerogenesis and suggest that miR-21 and miR-210 may play a role in the aggressive clinical behaviour of glioblastomas.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Glioma/genética , MicroRNAs/genética , Invasividade Neoplásica/genética , Adulto , Idoso , Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Glioma/metabolismo , Glioma/patologia , Humanos , Masculino , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Invasividade Neoplásica/patologia , Fenótipo , Prognóstico
17.
Expert Opin Biol Ther ; 14(11): 1667-83, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25190496

RESUMO

INTRODUCTION: Maintenance of genome stability requires the integrity of the DNA repair machinery. DNA damage response (DDR) determines cell fate and regulates the expression of microRNAs (miRNAs), which in turn may also regulate important components of the DNA repair machinery. AREAS COVERED: In this review, we describe the bidirectional connection between miRNAs and DDR and their link with important biological functions such as, DNA repair, cell cycle and apoptosis in cancer. Furthermore, we highlight the potential implications of recent findings on miRNA/DDR in determining chemotherapy response in cancer patients, and the use of these biomarkers for novel potential therapeutic approaches. EXPERT OPINION: Defects in the DDR and deregulation of miRNAs are important hallmarks of human cancer. A full understanding of the mechanisms underlying the connection between miRNAs and DDR/DNA repair pathways will positively impact our knowledge on human tumor biology and on different responses to distinct drugs. Specific miRNAs interact with distinct DDR components and are promising targets for enhancing the effects of, and/or to overcome the resistance to, conventional chemotherapeutic agents. Finally, the development of innovative tools to deliver miRNA-targeting oligonucleotides may represents novel types of cancer interventions in clinic.


Assuntos
Dano ao DNA/fisiologia , Reparo do DNA/fisiologia , Sistemas de Liberação de Medicamentos/tendências , Marcação de Genes/tendências , MicroRNAs/fisiologia , Neoplasias/genética , Neoplasias/terapia , Animais , Antineoplásicos/administração & dosagem , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Instabilidade Genômica/fisiologia , Humanos , MicroRNAs/antagonistas & inibidores
18.
CA Cancer J Clin ; 64(5): 311-36, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25104502

RESUMO

The interplay between abnormalities in genes coding for proteins and noncoding microRNAs (miRNAs) has been among the most exciting yet unexpected discoveries in oncology over the last decade. The complexity of this network has redefined cancer research as miRNAs, produced from what was once considered "genomic trash," have shown to be crucial for cancer initiation, progression, and dissemination. Naturally occurring miRNAs are very short transcripts that never produce a protein or amino acid chain, but act by regulating protein expression during cellular processes such as growth, development, and differentiation at the transcriptional, posttranscriptional, and/or translational level. In this review article, miRNAs are presented as ubiquitous players involved in all cancer hallmarks. The authors also describe the most used methods to detect their expression, which have revealed the identity of hundreds of miRNAs dysregulated in cancer cells or tumor microenvironment cells. Furthermore, the role of miRNAs as hormones and as reliable cancer biomarkers and predictors of treatment response is discussed. Along with this, the authors explore current strategies in designing miRNA-targeting therapeutics, as well as the associated challenges that research envisions to overcome. Finally, a new wave in molecular oncology translational research is introduced: the study of long noncoding RNAs.


Assuntos
MicroRNAs/fisiologia , Neoplasias/diagnóstico , Neoplasias/terapia , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/genética , Regulação Neoplásica da Expressão Gênica , Genoma , Humanos , MicroRNAs/análise , MicroRNAs/uso terapêutico , Mutação , Neoplasias/genética
19.
Mol Cancer ; 13: 142, 2014 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-24897960

RESUMO

BACKGROUND: MicroRNA-10b (miR-10b) has a prominent role in regulating tumor invasion and metastasis by targeting the HOXD10 transcriptional repressor and has been found up-regulated in several tumor types. METHODS: We evaluated the expression of miR-10b in paired tumor and normal specimens obtained from a prospective cohort of breast cancer patients with at least 36 months follow-up enrolled according to the REMARK guidelines (n = 150). RNA quality was measured and only samples with RNA Integrity Number (RIN) ≥7.0 were analyzed. RESULTS: The relative expression of miR-10b in tumor as compared to its normal counterpart (RER) was determined by RT-qPCR. miR-10b RERs were higher in the subgroup of patients with synchronous metastases (n = 11, Median 0.25; IQR 0.11-1.02) as compared with patients without metastases (n = 90, Median 0.09; IQR 0.04-0.29) (p = 0.028). In the subgroup of patients without synchronous metastases (n = 90), higher miR-10b RERs were associated with increased risk of disease progression and death in both univariable (HR 1.16, p = 0.021 and HR 1.20, p = 0.015 respectively for 0.10 unitary increase of miR-10b RERs levels) and multivariable (HR1.30, p < 0.001, and HR 1.31, p = 0.003 respectively for 0.10 unitary increase of miR-10b RERs levels) Cox regression models. The addition of miR-10b RERs to the Nottingham Prognostic Index (NPI) provided an improvement in discrimination power and risk reclassification abilities for the clinical outcomes at 36 months. Survival C-indices significantly increased from 0.849 to 0.889 (p = 0.009) for OS and from 0.735 to 0.767 (p = 0.050) for DFS. CONCLUSIONS: Our results provide evidences that the addition of miR-10b RERs to the prognostic factors used in clinical routine could improve the prediction abilities for both overall mortality and disease progression in breast cancer patients.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/genética , MicroRNAs/genética , Fatores de Transcrição/genética , Adulto , Idoso , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Feminino , Proteínas de Homeodomínio/metabolismo , Humanos , Metástase Linfática , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Prognóstico , Modelos de Riscos Proporcionais , Estudos Prospectivos , Transdução de Sinais , Análise de Sobrevida , Fatores de Transcrição/metabolismo
20.
Epigenetics ; 8(1): 105-12, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23249627

RESUMO

Keap1 (Kelch-like ECH-associated protein 1) is an adaptor protein that mediates the ubiquitination/degradation of genes regulating cell survival and apoptosis under oxidative stress conditions. We determined methylation status of the KEAP1 promoter in 102 primary breast cancers, 14 pre-invasive lesions, 38 paired normal breast tissues and 6 normal breast from reductive mammoplasty by quantitative methylation specific PCR (QMSP). Aberrant promoter methylation was detected in 52 out of the 102 primary breast cancer cases (51%) and 10 out of 14 pre-invasive lesions (71%). No mutations of the KEAP1 gene were identified in the 20 breast cancer cases analyzed by fluorescence based direct sequencing. Methylation was more frequent in the subgroup of patients identified as ER positive-HER2 negative tumors (66.7%) as compared with triple-negative breast cancers (35%) (p = 0.05, Chi-square test). The impact of the interactions between Er, PgR, Her2 expression and KEAP1 methylation on mortality was investigated by RECPAM multivariable statistical analysis, identifying four prognostic classes at different mortality risks. Triple-negative breast cancer patients with KEAP1 methylation had higher mortality risk than patients without triple-negative breast cancer (HR = 14.73, 95%CI: 3.65-59.37). Both univariable and multivariable COX regressions analyses showed that KEAP1 methylation was associated with a better progression free survival in patients treated with epirubicin/cyclophosfamide and docetaxel as sequential chemotherapy (HR = 0.082; 95%CI: 0.007-0.934). These results indicate that aberrant promoter methylation of the KEAP1 gene is involved in breast cancerogenesis. In addition, identifying patients with KEAP1 epigenetic abnormalities may contribute to disease progression prediction in breast cancer patients.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Metilação de DNA/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Mama/metabolismo , Mama/patologia , Neoplasias da Mama/tratamento farmacológico , Ciclofosfamida/uso terapêutico , Intervalo Livre de Doença , Docetaxel , Epirubicina/uso terapêutico , Feminino , Humanos , Estimativa de Kaplan-Meier , Proteína 1 Associada a ECH Semelhante a Kelch , Pessoa de Meia-Idade , Regiões Promotoras Genéticas/genética , Fatores de Risco , Taxoides/uso terapêutico
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