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1.
Nutrients ; 15(14)2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37513513

RESUMO

Combining exercise with fasting is known to boost fat mass-loss, but detailed analysis on the consequential mobilization of visceral and subcutaneous WAT-derived fatty acids has not been performed. In this study, a subset of fasted male rats (66 h) was submitted to daily bouts of mild exercise. Subsequently, by using gas chromatography-flame ionization detection, the content of 22 fatty acids (FA) in visceral (v) versus subcutaneous (sc) white adipose tissue (WAT) depots was compared to those found in response to the separate events. Findings were related to those obtained in serum and liver samples, the latter taking up FA to increase gluconeogenesis and ketogenesis. Each separate intervention reduced scWAT FA content, associated with increased levels of adipose triglyceride lipase (ATGL) protein despite unaltered AMP-activated protein kinase (AMPK) Thr172 phosphorylation, known to induce ATGL expression. The mobility of FAs from vWAT during fasting was absent with the exception of the MUFA 16:1 n-7 and only induced by combining fasting with exercise which was accompanied with reduced hormone sensitive lipase (HSL) Ser563 and increased Ser565 phosphorylation, whereas ATGL protein levels were elevated during fasting in association with the persistently increased phosphorylation of AMPK at Thr172 both during fasting and in response to the combined intervention. As expected, liver FA content increased during fasting, and was not further affected by exercise, despite additional FA release from vWAT in this condition, underlining increased hepatic FA metabolism. Both fasting and its combination with exercise showed preferential hepatic metabolism of the prominent saturated FAs C:16 and C:18 compared to the unsaturated FAs 18:1 n-9 and 18:2 n-6:1. In conclusion, depot-specific differences in WAT fatty acid molecule release during fasting, irrelevant to their degree of saturation or chain length, are mitigated when combined with exercise, to provide fuel to surrounding organs such as the liver which is correlated with increased ATGL/ HSL ratios, involving AMPK only in vWAT.


Assuntos
Ácidos Graxos , Esterol Esterase , Ratos , Masculino , Animais , Esterol Esterase/metabolismo , Ácidos Graxos/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Lipase/metabolismo , Lipólise/fisiologia , Obesidade/metabolismo , Jejum/metabolismo , Tecido Adiposo/metabolismo
2.
Bioinformatics ; 39(7)2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37432499

RESUMO

MOTIVATION: The process of drug development is inherently complex, marked by extended intervals from the inception of a pharmaceutical agent to its eventual launch in the market. Additionally, each phase in this process is associated with a significant failure rate, amplifying the inherent challenges of this task. Computational virtual screening powered by machine learning algorithms has emerged as a promising approach for predicting therapeutic efficacy. However, the complex relationships between the features learned by these algorithms can be challenging to decipher. RESULTS: We have engineered an artificial neural network model designed specifically for predicting drug sensitivity. This model utilizes a biologically informed visible neural network, thereby enhancing its interpretability. The trained model allows for an in-depth exploration of the biological pathways integral to prediction and the chemical attributes of drugs that impact sensitivity. Our model harnesses multiomics data derived from a different tumor tissue sources, as well as molecular descriptors that encapsulate the properties of drugs. We extended the model to predict drug synergy, resulting in favorable outcomes while retaining interpretability. Given the imbalanced nature of publicly available drug screening datasets, our model demonstrated superior performance to state-of-the-art visible machine learning algorithms. AVAILABILITY AND IMPLEMENTATION: MOViDA is implemented in Python using PyTorch library and freely available for download at https://github.com/Luigi-Ferraro/MOViDA. Training data, RIS score and drug features are archived on Zenodo https://doi.org/10.5281/zenodo.8180380.


Assuntos
Multiômica , Redes Neurais de Computação , Algoritmos , Aprendizado de Máquina , Desenvolvimento de Medicamentos
3.
Genes (Basel) ; 14(5)2023 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-37239344

RESUMO

A rhabdoid colorectal tumor (RCT) is a rare cancer with aggressive clinical behavior. Recently, it has been recognized as a distinct disease entity, characterized by genetic alterations in the SMARCB1 and Ciliary Rootlet Coiled-Coil (CROCC). We here investigate the genetic and immunophenotypic profiling of 21 RCTs using immunohistochemistry and next-generation sequencing. Mismatch repair-deficient phenotypes were identified in 60% of RCTs. Similarly, a large proportion of cancers exhibited the combined marker phenotype (CK7-/CK20-/CDX2-) not common to classical adenocarcinoma variants. More than 70% of cases displayed aberrant activation of the mitogen-activated protein kinase (MAPK) pathway with mutations prevalently in BRAF V600E. SMARCB1/INI1 expression was normal in a large majority of lesions. In contrast, ciliogenic markers including CROCC and γ-tubulin were globally altered in tumors. Notably, CROCC and γ-tubulin were observed to colocalize in large cilia found on cancer tissues but not in normal controls. Taken together, our findings indicate that primary ciliogenesis and MAPK pathway activation contribute to the aggressiveness of RCTs and, therefore, may constitute a novel therapeutic target.


Assuntos
Cílios , Neoplasias Colorretais , Humanos , Cílios/genética , Cílios/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Tubulina (Proteína) , Neoplasias Colorretais/patologia , Proteínas do Citoesqueleto
4.
iScience ; 26(5): 106602, 2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-37250316

RESUMO

Ribonucleoprotein (RNP) condensates are crucial for controlling RNA metabolism and splicing events in animal cells. We used spatial proteomics and transcriptomic to elucidate RNP interaction networks at the centrosome, the main microtubule-organizing center in animal cells. We found a number of cell-type specific centrosome-associated spliceosome interactions localized in subcellular structures involved in nuclear division and ciliogenesis. A component of the nuclear spliceosome BUD31 was validated as an interactor of the centriolar satellite protein OFD1. Analysis of normal and disease cohorts identified the cholangiocarcinoma as target of centrosome-associated spliceosome alterations. Multiplexed single-cell fluorescent microscopy for the centriole linker CEP250 and spliceosome components including BCAS2, BUD31, SRSF2 and DHX35 recapitulated bioinformatic predictions on the centrosome-associated spliceosome components tissue-type specific composition. Collectively, centrosomes and cilia act as anchor for cell-type specific spliceosome components, and provide a helpful reference for explore cytoplasmic condensates functions in defining cell identity and in the origin of rare diseases.

5.
Cancer Cell Int ; 22(1): 253, 2022 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-35953834

RESUMO

In addition to being novel biomarkers for poor cancer prognosis, members of Lymphocyte antigen-6 (Ly6) gene family also play a crucial role in avoiding immune responses to tumors. However, it has not been possible to identify the underlying mechanism of how Ly6 gene regulation operates in human cancers. Transcriptome, epigenome and proteomic data from independent cancer databases were analyzed in silico and validated independently in 334 colorectal cancer tissues (CRC). RNA mediated gene silencing of regulatory genes, and treatment with MEK and p38 MAPK inhibitors were also tested in vitro. We report here that the Lymphocyte antigen 6G6D is universally downregulated in mucinous CRC, while its activation progresses through the classical adenoma-carcinoma sequence. The DNA methylation changes in LY6G6D promoter are intimately related to its transcript regulation, epigenomic and histological subtypes. Depletion of DNA methyltransferase 1 (DNMT1), which maintains DNA methylation, results in the derepression of LY6G6D expression. RNA-mediated gene silencing of p38α MAPK or its selective chemical inhibition, however, reduces LY6G6D expression, reducing trametinib's anti-inflammatory effects. Patients treated with FOLFOX-based first-line therapy experienced decreased survival due to hypermethylation of the LY6G6D promoter and decreased p38α MAPK signaling. We found that cancer-specific immunodominant epitopes are controlled by p38α MAPKs signaling and suppressed by DNA methylation in histological variants with Mucinous differentiation. This work provides a promising prospective for clinical application in diagnosis and personalized therapeutic strategies of colorectal cancer.

6.
Entropy (Basel) ; 24(5)2022 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-35626622

RESUMO

Gene-set enrichment analysis is the key methodology for obtaining biological information from transcriptomic space's statistical result. Since its introduction, Gene-set Enrichment analysis methods have obtained more reliable results and a wider range of application. Great attention has been devoted to global tests, in contrast to competitive methods that have been largely ignored, although they appear more flexible because they are independent from the source of gene-profiles. We analyzed the properties of the Mann-Whitney-Wilcoxon test, a competitive method, and adapted its interpretation in the context of enrichment analysis by introducing a Normalized Enrichment Score that summarize two interpretations: a probability estimate and a location index. Two implementations are presented and compared with relevant literature methods: an R package and an online web tool. Both allow for obtaining tabular and graphical results with attention to reproducible research.

7.
iScience ; 25(4): 104054, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35345456

RESUMO

Brain-derived neurotrophic factor (BDNF) plays a pivotal role in neuronal growth and differentiation, neuronal plasticity, learning, and memory. Using CRISPR/Cas9 technology, we generated a vital Bdnf null mutant line in zebrafish and carried out its molecular and behavioral characterization. Although no defects are evident on a morphological inspection, 66% of coding genes and 37% of microRNAs turned out to be differentially expressed in bdnf -/- compared with wild type sibling embryos. We deeply investigated the circadian clock pathway and confirmed changes in the rhythmic expression of clock (arntl1a, clock1a and clock2) and clock-controlled (aanat2) genes. The modulatory role of Bdnf on the zebrafish circadian clock was then validated by behavioral tests highlighting the absence of circadian activity rhythms in bdnf -/- larvae. The circadian behavior was partially rescued by pharmacological treatment. The bdnf -/- zebrafish line presented here is the first valuable and stable vertebrate model for the study of BDNF-related neurodevelopmental diseases.

8.
Nucleic Acids Res ; 50(4): 2019-2035, 2022 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-35137158

RESUMO

It is currently unknown how many RNA transcripts are able to induce degradation of microRNAs (miRNA) via the mechanism known as target-directed miRNA degradation (TDMD). We developed TDMDfinder, a computational pipeline that identifies 'high confidence' TDMD interactions in the Human and Mouse transcriptomes by combining sequence alignment and feature selection approaches. Our predictions suggested that TDMD is widespread, with potentially every miRNA controlled by endogenous targets. We experimentally tested 37 TDMDfinder predictions, of which 17 showed TDMD effects as measured by RT-qPCR and small RNA sequencing, linking the miR-17, miR-19, miR-30, miR-221, miR-26 and miR-23 families to novel endogenous TDMDs. In some cases, TDMD was found to affect different members of the same miRNA family selectively. Features like complementarity to the miRNA 3' region, bulge size and hybridization energy appeared to be the main factors determining sensitivity. Computational analyses performed using the multiomic TCGA platform substantiated the involvement of many TDMD transcripts in human cancer and highlighted 36 highly significant interactions, suggesting TDMD as a new potential oncogenic mechanism. In conclusion, TDMDfinder provides the first inventory of bona fide human and mouse TDMDs. Available as a free webtool, TDMDfinder allows users to search for any TDMD interaction of interest by customizing its selection criteria.


Assuntos
MicroRNAs , Neoplasias , Animais , Humanos , Mamíferos/genética , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias/genética , Oncogenes , Estabilidade de RNA/genética , Análise de Sequência de RNA
9.
Biomolecules ; 11(5)2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33922633

RESUMO

Metastasis is a process by which cancer cells escape from the location of the primary tumor invading normal tissues at distant organs. Chromosomal instability (CIN) is a hallmark of human cancer, associated with metastasis and therapeutic resistance. The centrosome plays a major role in organizing the microtubule cytoskeleton in animal cells regulating cellular architecture and cell division. Loss of centrosome integrity activates the p38-p53-p21 pathway, which results in cell-cycle arrest or senescence and acts as a cell-cycle checkpoint pathway. Structural and numerical centrosome abnormalities can lead to aneuploidy and CIN. New findings derived from studies on cancer and rare genetic disorders suggest that centrosome dysfunction alters the cellular microenvironment through Rho GTPases, p38, and JNK (c-Jun N-terminal Kinase)-dependent signaling in a way that is favorable for pro-invasive secretory phenotypes and aneuploidy tolerance. We here review recent data on how centrosomes act as complex molecular platforms for Rho GTPases and p38 MAPK (Mitogen activated kinase) signaling at the crossroads of CIN, cytoskeleton remodeling, and immune evasion via both cell-autonomous and non-autonomous mechanisms.


Assuntos
Centrossomo/metabolismo , Inflamação/patologia , Metástase Neoplásica/patologia , Aneuploidia , Animais , Ciclo Celular/fisiologia , Pontos de Checagem do Ciclo Celular/fisiologia , Centrossomo/fisiologia , Instabilidade Cromossômica/fisiologia , Citoesqueleto/fisiologia , Humanos , Inflamação/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Sistema de Sinalização das MAP Quinases/fisiologia , Microtúbulos/metabolismo , Metástase Neoplásica/genética , Neoplasias/metabolismo , Transdução de Sinais , Microambiente Tumoral , Proteína Supressora de Tumor p53/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologia , Proteínas rho de Ligação ao GTP/metabolismo
10.
Brief Bioinform ; 22(2): 701-713, 2021 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-33279954

RESUMO

The stratification of patients at risk of progression of COVID-19 and their molecular characterization is of extreme importance to optimize treatment and to identify therapeutic options. The bioinformatics community has responded to the outbreak emergency with a set of tools and resource to identify biomarkers and drug targets that we review here. Starting from a consolidated corpus of 27 570 papers, we adopt latent Dirichlet analysis to extract relevant topics and select those associated with computational methods for biomarker identification and drug repurposing. The selected topics span from machine learning and artificial intelligence for disease characterization to vaccine development and to therapeutic target identification. Although the way to go for the ultimate defeat of the pandemic is still long, the amount of knowledge, data and tools generated so far constitutes an unprecedented example of global cooperation to this threat.


Assuntos
Biomarcadores/sangue , Tratamento Farmacológico da COVID-19 , Sistemas de Liberação de Medicamentos , Antivirais/uso terapêutico , COVID-19/sangue , COVID-19/virologia , Reposicionamento de Medicamentos/métodos , Humanos , Aprendizado de Máquina , SARS-CoV-2/isolamento & purificação
11.
Bioinformatics ; 37(10): 1420-1427, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-33165571

RESUMO

MOTIVATION: The cost of drug development has dramatically increased in the last decades, with the number new drugs approved per billion US dollars spent on R&D halving every year or less. The selection and prioritization of targets is one the most influential decisions in drug discovery. Here we present a Gaussian Process model for the prioritization of drug targets cast as a problem of learning with only positive and unlabeled examples. RESULTS: Since the absence of negative samples does not allow standard methods for automatic selection of hyperparameters, we propose a novel approach for hyperparameter selection of the kernel in One Class Gaussian Processes. We compare our methods with state-of-the-art approaches on benchmark datasets and then show its application to druggability prediction of oncology drugs. Our score reaches an AUC 0.90 on a set of clinical trial targets starting from a small training set of 102 validated oncology targets. Our score recovers the majority of known drug targets and can be used to identify novel set of proteins as drug target candidates. AVAILABILITY AND IMPLEMENTATION: The matrix of features for each protein is available at: https://bit.ly/3iLgZTa. Source code implemented in Python is freely available for download at https://github.com/AntonioDeFalco/Adaptive-OCGP. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Preparações Farmacêuticas , Software , Desenvolvimento de Medicamentos , Descoberta de Drogas , Proteínas
12.
PLoS Comput Biol ; 16(11): e1008415, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33175836

RESUMO

Small non-coding RNAs (ncRNAs) are short non-coding sequences involved in gene regulation in many biological processes and diseases. The lack of a complete comprehension of their biological functionality, especially in a genome-wide scenario, has demanded new computational approaches to annotate their roles. It is widely known that secondary structure is determinant to know RNA function and machine learning based approaches have been successfully proven to predict RNA function from secondary structure information. Here we show that RNA function can be predicted with good accuracy from a lightweight representation of sequence information without the necessity of computing secondary structure features which is computationally expensive. This finding appears to go against the dogma of secondary structure being a key determinant of function in RNA. Compared to recent secondary structure based methods, the proposed solution is more robust to sequence boundary noise and reduces drastically the computational cost allowing for large data volume annotations. Scripts and datasets to reproduce the results of experiments proposed in this study are available at: https://github.com/bioinformatics-sannio/ncrna-deep.


Assuntos
Aprendizado Profundo , RNA não Traduzido/genética , RNA não Traduzido/fisiologia , Biologia Computacional , Bases de Dados de Ácidos Nucleicos/estatística & dados numéricos , Sequenciamento de Nucleotídeos em Larga Escala/estatística & dados numéricos , Humanos , Método de Monte Carlo , Redes Neurais de Computação , Conformação de Ácido Nucleico , RNA não Traduzido/química , Análise de Sequência de RNA/estatística & dados numéricos , Sequenciamento do Exoma/estatística & dados numéricos
13.
Gigascience ; 9(10)2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33155039

RESUMO

BACKGROUND: Single-cell RNA sequencing is the reference technique for characterizing the heterogeneity of the tumor microenvironment. The composition of the various cell types making up the microenvironment can significantly affect the way in which the immune system activates cancer rejection mechanisms. Understanding the cross-talk signals between immune cells and cancer cells is of fundamental importance for the identification of immuno-oncology therapeutic targets. RESULTS: We present a novel method, single-cell Tumor-Host Interaction tool (scTHI), to identify significantly activated ligand-receptor interactions across clusters of cells from single-cell RNA sequencing data. We apply our approach to uncover the ligand-receptor interactions in glioma using 6 publicly available human glioma datasets encompassing 57,060 gene expression profiles from 71 patients. By leveraging this large-scale collection we show that unexpected cross-talk partners are highly conserved across different datasets in the majority of the tumor samples. This suggests that shared cross-talk mechanisms exist in glioma. CONCLUSIONS: Our results provide a complete map of the active tumor-host interaction pairs in glioma that can be therapeutically exploited to reduce the immunosuppressive action of the microenvironment in brain tumor.


Assuntos
Neoplasias Encefálicas , Glioma , Neoplasias Encefálicas/genética , Comunicação Celular , Glioma/genética , Humanos , Análise de Sequência de RNA , Microambiente Tumoral
14.
Genome Biol ; 21(1): 216, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32847614

RESUMO

BACKGROUND: Glioblastoma (GBM) is a complex disease with extensive molecular and transcriptional heterogeneity. GBM can be subcategorized into four distinct subtypes; tumors that shift towards the mesenchymal phenotype upon recurrence are generally associated with treatment resistance, unfavorable prognosis, and the infiltration of pro-tumorigenic macrophages. RESULTS: We explore the transcriptional regulatory networks of mesenchymal-associated tumor-associated macrophages (MA-TAMs), which drive the malignant phenotypic state of GBM, and identify macrophage receptor with collagenous structure (MARCO) as the most highly differentially expressed gene. MARCOhigh TAMs induce a phenotypic shift towards mesenchymal cellular state of glioma stem cells, promoting both invasive and proliferative activities, as well as therapeutic resistance to irradiation. MARCOhigh TAMs also significantly accelerate tumor engraftment and growth in vivo. Moreover, both MA-TAM master regulators and their target genes are significantly correlated with poor clinical outcomes and are often associated with genomic aberrations in neurofibromin 1 (NF1) and phosphoinositide 3-kinases/mammalian target of rapamycin/Akt pathway (PI3K-mTOR-AKT)-related genes. We further demonstrate the origination of MA-TAMs from peripheral blood, as well as their potential association with tumor-induced polarization states and immunosuppressive environments. CONCLUSIONS: Collectively, our study characterizes the global transcriptional profile of TAMs driving mesenchymal GBM pathogenesis, providing potential therapeutic targets for improving the effectiveness of GBM immunotherapy.


Assuntos
Redes Reguladoras de Genes , Glioblastoma/genética , Macrófagos Associados a Tumor , Animais , Carcinogênese , Linhagem Celular Tumoral , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica , Glioblastoma/metabolismo , Glioblastoma/patologia , Glioma/genética , Humanos , Imunoterapia , Macrófagos/metabolismo , Camundongos , Neurofibromina 1/genética , Fenótipo , Prognóstico , Células-Tronco , Transcriptoma , Microambiente Tumoral
15.
J Exp Clin Cancer Res ; 38(1): 28, 2019 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-30670049

RESUMO

BACKGROUND: Human microsatellite-stable (MSS) colorectal cancers (CRCs) are immunologically "cold" tumour subtypes characterized by reduced immune cytotoxicity. The molecular linkages between immune-resistance and human MSS CRC is not clear. METHODS: We used transcriptome profiling, in silico analysis, immunohistochemistry, western blot, RT-qPCR and immunofluorescence staining to characterize novel CRC immune biomarkers. The effects of selective antagonists were tested by in vitro assays of long term viability and analysis of kinase active forms using anti-phospho antibodies. RESULTS: We identified the lymphocyte antigen 6 complex, locus G6D (LY6G6D) as significantly overexpressed (around 15-fold) in CRC when compared with its relatively low expression in other human solid tumours. LY6G6D up-regulation was predominant in MSS CRCs characterized by an enrichment of immune suppressive regulatory T-cells and a limited repertoire of PD-1/PD-L1 immune checkpoint receptors. Coexpression of LY6G6D and CD15 increases the risk of metastatic relapse in response to therapy. Both JAK-STAT5 and RAS-MEK-ERK cascades act in concert as key regulators of LY6G6D and Fucosyltransferase 4 (FUT4), which direct CD15-mediated immune-resistance. Momelotinib, an inhibitor of JAK1/JAK2, consistently abrogated the STAT5/LY6G6D axis in vitro, sensitizing MSS cancer cells with an intact JAK-STAT signaling, to efficiently respond to trametinib, a MEK inhibitor used in clinical setting. Notably, colon cancer cells can evade JAK2/JAK1-targeted therapy by a reversible shift of the RAS-MEK-ERK pathway activity, which explains the treatment failure of JAK1/2 inhibitors in refractory CRC. CONCLUSIONS: Combined targeting of STAT5 and MAPK pathways has superior therapeutic effects on immune resistance. In addition, the new identified LY6G6D antigen is a promising molecular target for human MSS CRC.


Assuntos
Neoplasias Colorretais/genética , Reparo de Erro de Pareamento de DNA/genética , Imunoglobulinas/genética , Fator de Transcrição STAT5/genética , Antígeno B7-H1/genética , Antígeno B7-H1/imunologia , Benzamidas/farmacologia , Linhagem Celular Tumoral , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/patologia , Feminino , Fucosiltransferases/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Janus Quinase 1/antagonistas & inibidores , Janus Quinase 1/genética , Janus Quinase 2/antagonistas & inibidores , Janus Quinase 2/genética , Antígenos CD15/genética , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Instabilidade de Microssatélites , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/imunologia , Pirimidinas/farmacologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia
16.
Front Cell Dev Biol ; 7: 385, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32010697

RESUMO

Embryonic stem cells (ESCs) are derived from inner cell mass (ICM) of the blastocyst. In serum/LIF culture condition, they show variable expression of pluripotency genes that mark cell fluctuation between pluripotency and differentiation metastate. The ESCs subpopulation marked by zygotic genome activation gene (ZGA) signature, including Zscan4, retains a wider differentiation potency than epiblast-derived ESCs. We have recently shown that retinoic acid (RA) significantly enhances Zscan4 cell population. However, it remains unexplored how RA initiates the ESCs to 2-cell like reprogramming. Here we found that RA is decisive for ESCs to 2C-like cell transition, and reconstructed the gene network surrounding Zscan4. We revealed that RA regulates 2C-like population co-activating Dux and Duxbl1. We provided novel evidence that RA dependent ESCs to 2C-like cell transition is regulated by Dux, and antagonized by Duxbl1. Our suggested mechanism could shed light on the role of RA on ESC reprogramming.

17.
Leuk Lymphoma ; 60(3): 805-811, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30188232

RESUMO

Chronic myeloid leukemia (CML) is a stem cell derived malignant disorder result of translocation t(9;22)(q34;q11) called Philadelphia chromosome (Ph+). microRNAS (miRNAs) are involved in several biological processes, altering the progression of various pathologies, including CML. This study evaluated whether circulating miRNAs display differential expression profiles in peripheral blood of CML-Chronic Phase (CML-CP) patients newly diagnosed in comparison with CML-CP treated with imatinib. We obtained peripheral blood samples from CML-CP Ph+ patients divided among group 1 (untreated newly diagnosed) and group 2 (treated with imatinib). A pool of total leukocytes from healthy donors was considered as control group. Expression analyses were performed for 768 miRNAs by RT-qPCR array. Bioinformatic tools were used to identify significant pathways and interaction networks. We found 80 deregulated miRNAs between the groups and, according to bioinformatic analysis, they are involved in different pathways, including molecular mechanisms of cancer. The study allows better understanding of disease molecular behavior, and it is useful for possible monitoring CML treatment and prognostic biomarkers identification.


Assuntos
Biomarcadores Tumorais , MicroRNA Circulante , Mesilato de Imatinib/uso terapêutico , Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Leucemia Mieloide de Fase Crônica/genética , Inibidores de Proteínas Quinases/uso terapêutico , Transcriptoma , Biologia Computacional/métodos , Perfilação da Expressão Gênica , Regulação Leucêmica da Expressão Gênica , Humanos , Mesilato de Imatinib/administração & dosagem , Mesilato de Imatinib/efeitos adversos , Leucemia Mieloide de Fase Crônica/sangue , Leucemia Mieloide de Fase Crônica/diagnóstico , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/efeitos adversos
18.
BMC Bioinformatics ; 19(1): 407, 2018 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-30400819

RESUMO

BACKGROUND: Long non-coding RNAs (lncRNAs) represent a novel class of non-coding RNAs having a crucial role in many biological processes. The identification of long non-coding homologs among different species is essential to investigate such roles in model organisms as homologous genes tend to retain similar molecular and biological functions. Alignment-based metrics are able to effectively capture the conservation of transcribed coding sequences and then the homology of protein coding genes. However, unlike protein coding genes the poor sequence conservation of long non-coding genes makes the identification of their homologs a challenging task. RESULTS: In this study we compare alignment-based and alignment-free string similarity metrics and look at promoter regions as a possible source of conserved information. We show that promoter regions encode relevant information for the conservation of long non-coding genes across species and that such information is better captured by alignment-free metrics. We perform a genome wide test of this hypothesis in human, mouse, and zebrafish. CONCLUSIONS: The obtained results persuaded us to postulate the new hypothesis that, unlike protein coding genes, long non-coding genes tend to preserve their regulatory machinery rather than their transcribed sequence. All datasets, scripts, and the prediction tools adopted in this study are available at https://github.com/bioinformatics-sannio/lncrna-homologs .


Assuntos
Sequência Conservada , Regulação da Expressão Gênica , Genoma , RNA Longo não Codificante/genética , Alinhamento de Sequência/métodos , Animais , Humanos , Camundongos , Peixe-Zebra/genética
19.
Nucleic Acids Res ; 46(7): e39, 2018 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-29361062

RESUMO

We propose a generic framework for gene regulatory network (GRN) inference approached as a feature selection problem. GRNs obtained using Machine Learning techniques are often dense, whereas real GRNs are rather sparse. We use a Tikonov regularization inspired optimal L-curve criterion that utilizes the edge weight distribution for a given target gene to determine the optimal set of TFs associated with it. Our proposed framework allows to incorporate a mechanistic active biding network based on cis-regulatory motif analysis. We evaluate our regularization framework in conjunction with two non-linear ML techniques, namely gradient boosting machines (GBM) and random-forests (GENIE), resulting in a regularized feature selection based method specifically called RGBM and RGENIE respectively. RGBM has been used to identify the main transcription factors that are causally involved as master regulators of the gene expression signature activated in the FGFR3-TACC3-positive glioblastoma. Here, we illustrate that RGBM identifies the main regulators of the molecular subtypes of brain tumors. Our analysis reveals the identity and corresponding biological activities of the master regulators characterizing the difference between G-CIMP-high and G-CIMP-low subtypes and between PA-like and LGm6-GBM, thus providing a clue to the yet undetermined nature of the transcriptional events among these subtypes.


Assuntos
Redes Reguladoras de Genes/genética , Glioma/genética , Motivos de Nucleotídeos/genética , Fatores de Transcrição/genética , Algoritmos , Regulação Neoplásica da Expressão Gênica/genética , Glioma/classificação , Glioma/patologia , Humanos , Aprendizado de Máquina , Proteínas Associadas aos Microtúbulos/genética , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/genética
20.
Nature ; 553(7687): 222-227, 2018 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-29323298

RESUMO

Chromosomal translocations that generate in-frame oncogenic gene fusions are notable examples of the success of targeted cancer therapies. We have previously described gene fusions of FGFR3-TACC3 (F3-T3) in 3% of human glioblastoma cases. Subsequent studies have reported similar frequencies of F3-T3 in many other cancers, indicating that F3-T3 is a commonly occuring fusion across all tumour types. F3-T3 fusions are potent oncogenes that confer sensitivity to FGFR inhibitors, but the downstream oncogenic signalling pathways remain unknown. Here we show that human tumours with F3-T3 fusions cluster within transcriptional subgroups that are characterized by the activation of mitochondrial functions. F3-T3 activates oxidative phosphorylation and mitochondrial biogenesis and induces sensitivity to inhibitors of oxidative metabolism. Phosphorylation of the phosphopeptide PIN4 is an intermediate step in the signalling pathway of the activation of mitochondrial metabolism. The F3-T3-PIN4 axis triggers the biogenesis of peroxisomes and the synthesis of new proteins. The anabolic response converges on the PGC1α coactivator through the production of intracellular reactive oxygen species, which enables mitochondrial respiration and tumour growth. These data illustrate the oncogenic circuit engaged by F3-T3 and show that F3-T3-positive tumours rely on mitochondrial respiration, highlighting this pathway as a therapeutic opportunity for the treatment of tumours with F3-T3 fusions. We also provide insights into the genetic alterations that initiate the chain of metabolic responses that drive mitochondrial metabolism in cancer.


Assuntos
Respiração Celular , Proteínas Associadas aos Microtúbulos/genética , Mitocôndrias/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Proteínas de Fusão Oncogênica/genética , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/genética , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Linhagem Celular Tumoral , Respiração Celular/efeitos dos fármacos , Transformação Celular Neoplásica/efeitos dos fármacos , Feminino , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Masculino , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Peptidilprolil Isomerase de Interação com NIMA/química , Peptidilprolil Isomerase de Interação com NIMA/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Biogênese de Organelas , Fosforilação Oxidativa/efeitos dos fármacos , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Peroxissomos/efeitos dos fármacos , Peroxissomos/metabolismo , Fosforilação , Biossíntese de Proteínas , Espécies Reativas de Oxigênio/metabolismo , Receptores de Estrogênio/metabolismo , Transcrição Gênica , Ensaios Antitumorais Modelo de Xenoenxerto
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