Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
1.
Int J Mol Sci ; 25(15)2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39125649

RESUMO

lncRNAs are noncoding transcripts with tissue and cancer specificity. Particularly, in breast cancer, lncRNAs exhibit subtype-specific expression; they are particularly upregulated in luminal tumors. However, no gene signature-based laboratory tests have been developed for luminal breast cancer identification or the differential diagnosis of luminal tumors, since no luminal A- or B-specific genes have been identified. Particularly, luminal B patients are of clinical interest, since they have the most variable response to neoadjuvant treatment; thus, it is necessary to develop diagnostic and predictive biomarkers for these patients to optimize treatment decision-making and improve treatment quality. In this study, we analyzed the lncRNA expression profiles of breast cancer cell lines and patient tumor samples from RNA-Seq data to identify an lncRNA signature specific for luminal phenotypes. We identified an lncRNA signature consisting of LINC01016, GATA3-AS1, MAPT-IT1, and DSCAM-AS1 that exhibits luminal subtype-specific expression; among these lncRNAs, GATA3-AS1 is associated with the presence of residual disease (Wilcoxon test, p < 0.05), which is related to neoadjuvant chemotherapy resistance in luminal B breast cancer patients. Furthermore, analysis of GATA3-AS1 expression using RNA in situ hybridization (RNA ISH) demonstrated that this lncRNA is detectable in histological slides. Similar to estrogen receptors and Ki67, both commonly detected biomarkers, GATA3-AS1 proves to be a suitable predictive biomarker for clinical application in breast cancer laboratory tests.


Assuntos
Biomarcadores Tumorais , Neoplasias da Mama , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Terapia Neoadjuvante , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , Neoplasias da Mama/genética , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Feminino , Resistencia a Medicamentos Antineoplásicos/genética , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Fator de Transcrição GATA3/genética , Fator de Transcrição GATA3/metabolismo , Transcriptoma
2.
Int J Mol Sci ; 23(20)2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36293551

RESUMO

Central nervous system tumors are the most common solid neoplasia during childhood and represent one of the leading causes of cancer-related mortality. Tumors arising from astrocytic cells (astrocytomas) are the most frequently diagnosed, and according to their histological and pathological characteristics, they are classified into four categories. However, an additional layer of molecular classification considering the DNA sequence of the tumorigenesis-associated genes IDH1/2 and H3F3A has recently been incorporated into the classification guidelines. Although mutations in H3F3A are found exclusively in a subtype of grade IV pediatric astrocytoma, mutations in IDH1/2 genes are very rare in children under 14 years of age. The transcriptomic profiles of astrocytoma in adults and children have been extensively studied. However, there is scarce information on these profiles in pediatric populations considering the status of tumorigenesis-associated genes. Therefore, here we report the transcriptomic landscape of the four grades of pediatric astrocytoma by RNA sequencing. We found several well-documented biological functions associated with the misregulated genes in the four grades of astrocytoma, as well as additional biological pathways. Among the four grades of astrocytoma, we found shared misregulated genes that could have implications in tumorigenesis. Finally, we identified a transcriptional signature for almost all grades of astrocytoma that could be used as a transcription-based identification method.


Assuntos
Astrocitoma , Neoplasias Encefálicas , Adulto , Criança , Humanos , Transcriptoma , Neoplasias Encefálicas/patologia , Astrocitoma/patologia , Mutação , Carcinogênese
3.
Rev Invest Clin ; 70(4): 153-157, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30067721

RESUMO

The significant drop in sequencing costs boosted by chemistries optimization and sample multiplexation has resulted in an immense growth within the field of next-generation sequencing (NGS) in the last decade. This has allowed a diversification of techniques, promoting a rapid advance in knowledge on the molecular basis of human disease. Due to the applicability and importance of this technology in basic research, it has quickly migrated to the clinical setting. NGS enables clinicians to make improved diagnostic and treatment decisions, which ultimately may influence precision medicine.


Assuntos
Tomada de Decisões , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Medicina de Precisão/métodos , Genômica/métodos , Humanos
4.
Front Cell Dev Biol ; 11: 1119514, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37065848

RESUMO

CTCF is an architectonic protein that organizes the genome inside the nucleus in almost all eukaryotic cells. There is evidence that CTCF plays a critical role during spermatogenesis as its depletion produces abnormal sperm and infertility. However, defects produced by its depletion throughout spermatogenesis have not been fully characterized. In this work, we performed single cell RNA sequencing in spermatogenic cells with and without CTCF. We uncovered defects in transcriptional programs that explain the severity of the damage in the produced sperm. In the early stages of spermatogenesis, transcriptional alterations are mild. As germ cells go through the specialization stage or spermiogenesis, transcriptional profiles become more altered. We found morphology defects in spermatids that support the alterations in their transcriptional profiles. Altogether, our study sheds light on the contribution of CTCF to the phenotype of male gametes and provides a fundamental description of its role at different stages of spermiogenesis.

5.
Mol Ther Nucleic Acids ; 20: 409-420, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32244168

RESUMO

MicroRNAs are small noncoding transcripts that posttranscriptionally regulate gene expression via base-pairing complementarity. Their role in cancer can be related to tumor suppression or oncogenic function. Moreover, they have been linked to processes recognized as hallmarks of cancer, such as apoptosis, invasion, metastasis, and proliferation. Particularly, one of the first oncomiRs found upregulated in a variety of cancers, such as gliomas, breast cancer, and colorectal cancer, was microRNA-21 (miR-21). Some of its target genes associated with cancer are PTEN (phosphatase and tensin homolog), PDCD4 (programmed cell death protein 4), RECK (reversion-inducing cysteine-rich protein with Kazal motifs), and STAT3 (signal transducer activator of transcription 3). As a result, miR-21 has been proposed as a plausible diagnostic and prognostic biomarker, as well as a therapeutic target for several types of cancer. Currently, research and clinical trials to inhibit miR-21 through anti-miR-21 oligonucleotides and ADM-21 are being conducted. As all of the evidence suggests, miR-21 is involved in carcinogenic processes; therefore, inhibiting it could have effects on more than one type of cancer. However, whether miR-21 can be used as a tissue-specific biomarker should be analyzed with caution. Consequently, the purpose of this review is to outline the available information and recent advances regarding miR-21 as a potential biomarker in the clinical setting and as a therapeutic target in cancer to highlight its importance in the era of precision medicine.

6.
Front Immunol ; 11: 930, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32508826

RESUMO

The global control of Tuberculosis remains elusive, and Bacillus Calmette-Guérin (BCG) -the most widely used vaccine in history-has proven insufficient for reversing this epidemic. Several authors have suggested that the mass presence of vaccinated hosts might have affected the Mycobacterium tuberculosis (MTB) population structure, and this could in turn be reflected in a prevalence of strains with higher ability to circumvent BCG-induced immunity, such as the recent Beijing genotype. The effect of vaccination on vaccine-escape variants has been well-documented in several bacterial pathogens; however the effect of the interaction between MTB strains and vaccinated hosts has never been previously described. In this study we show for the first time the interaction between MTB Beijing-genotype strains and BCG-vaccinated hosts. Using a well-controlled murine model of progressive pulmonary tuberculosis, we vaccinated BALB/c mice with two different sub-strains of BCG (BCG-Phipps and BCG-Vietnam). Following vaccination, the mice were infected with either one of three selected MTB strains. Strains were selected based on lineage, and included two Beijing-family clinical isolates (strains 46 and 48) and a well-characterized laboratory strain (H37Rv). Two months after infection, mice were euthanized and the bacteria extracted from their lungs. We characterized the genomic composite of the bacteria before and after exposure to vaccinated hosts, and also characterized the local response to the bacteria by sequencing the lung transcriptome in animals during the infection. Results from this study show that the interaction within the lungs of the vaccinated hosts results in the selection of higher-virulence bacteria, specifically for the Beijing genotype strains 46 and 48. After exposure to the BCG-induced immune response, strains 46 and 48 acquire genomic mutations associated with several virulence factors. As a result, the bacteria collected from these vaccinated hosts have an increased ability for immune evasion, as shown in both the host transcriptome and the histopathology studies, and replicates far more efficiently compared to bacteria collected from unvaccinated hosts or to the original-stock strain. Further research is warranted to ascertain the pathways associated with the genomic alterations. However, our results highlight novel host-pathogen interactions induced by exposure of MTB to BCG vaccinated hosts.


Assuntos
Interações Hospedeiro-Patógeno/imunologia , Pulmão/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculose Pulmonar/imunologia , Vacinação , Animais , Vacina BCG/imunologia , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Genoma Bacteriano , Genótipo , Pulmão/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mutação , Mycobacterium tuberculosis/patogenicidade , Virulência
7.
Oncotarget ; 9(29): 20872-20890, 2018 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-29755696

RESUMO

Prostate cancer is the most common cancer in men and the second leading cause of cancer-related deaths. The most used biomarker to detect prostate cancer is Prostate Specific Antigen (PSA), whose levels are measured in serum. However, it has been recently established that molecular markers of cancer should not be based solely on genes and proteins but should also reflect other genomic traits; long non-coding RNAs (lncRNAs) serve this purpose. lncRNAs are transcripts of >200 bases that do not encode proteins and that have been shown to display abnormal expression profiles in different types of cancer. Experimental studies have highlighted lncRNAs as potential biomarkers for prognoses and treatments in patients with different types of cancer, including prostate cancer, where the PCA3 lncRNA is currently used as a diagnostic tool and management strategy. With the development of genomic technologies, particularly next-generation sequencing (NGS), several other lncRNAs have been linked to prostate cancer and are currently under validation for their medical use. In this review, we will discuss different strategies for the discovery of novel lncRNAs that can be evaluated as prognostic biomarkers, the clinical impact of these lncRNAs and how lncRNAs can be used as potential therapeutic targets.

8.
Nat Struct Mol Biol ; 19(10): 1023-30, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22983563

RESUMO

Heterochromatin is important for genome integrity and stabilization of gene-expression programs. We have identified the transcription factors Pax3 and Pax9 as redundant regulators of mouse heterochromatin, as they repress RNA output from major satellite repeats by associating with DNA within pericentric heterochromatin. Simultaneous depletion of Pax3 and Pax9 resulted in dramatic derepression of major satellite transcripts, persistent impairment of heterochromatic marks and defects in chromosome segregation. Genome-wide analyses of methylated histone H3 at Lys9 showed enrichment at intergenic major satellite repeats only when these sequences retained intact binding sites for Pax and other transcription factors. Additionally, bioinformatic interrogation of all histone methyltransferase Suv39h-dependent heterochromatic repeat regions in the mouse genome revealed a high concordance with the presence of transcription factor binding sites. These data define a general model in which reiterated arrangement of transcription factor binding sites within repeat sequences is an intrinsic mechanism of the formation of heterochromatin.


Assuntos
Heterocromatina/metabolismo , Fatores de Transcrição Box Pareados/metabolismo , Animais , Sequência de Bases , Sítios de Ligação , Ciclo Celular/genética , Segregação de Cromossomos , DNA Satélite/metabolismo , Fibroblastos/metabolismo , Genoma , Heterocromatina/genética , Histonas/metabolismo , Lisina/metabolismo , Metilação , Metiltransferases/genética , Metiltransferases/metabolismo , Camundongos , Camundongos Mutantes , Dados de Sequência Molecular , Fator de Transcrição PAX3 , Fator de Transcrição PAX5/genética , Fator de Transcrição PAX5/metabolismo , Fator de Transcrição PAX7/genética , Fator de Transcrição PAX7/metabolismo , Fator de Transcrição PAX9 , Fatores de Transcrição Box Pareados/genética , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA