RESUMO

Obesity is a pandemic and a serious health problem in developed and undeveloped countries. Activation of estrogen receptor beta (ERß) has been shown to promote weight loss without modifying caloric intake, making it an attractive target for developing new drugs against obesity. This work aimed to predict new small molecules as potential ERß activators. A ligand-based virtual screening of the ZINC15, PubChem, and Molport databases by substructure and similarity was carried out using the three-dimensional organization of known ligands as a reference. A molecular docking screening of FDA-approved drugs was also conducted as a repositioning strategy. Finally, selected compounds were evaluated by molecular dynamic simulations. Compounds 1 (-24.27 ± 0.34 kcal/mol), 2 (-23.33 ± 0.3 kcal/mol), and 6 (-29.55 ± 0.51 kcal/mol) showed the best stability on the active site in complex with ERß with an RMSD < 3.3 Å. RMSF analysis showed that these compounds do not affect the fluctuation of the Cα of ERß nor the compactness according to the radius of gyration. Finally, an in silico evaluation of ADMET showed they are safe molecules. These results suggest that new ERß ligands could be promising molecules for obesity control.

Assuntos

Assuntos

RESUMO

Protein-protein interactions (PPI) play a key role in predicting the function of a target protein and drug ability to affect an entire biological system. Prediction of PPI networks greatly contributes to determine a target protein and signal pathways related to its function. Polyadenylation of mRNA 3'-end is essential for gene expression regulation and several polyadenylation factors have been shown as valuable targets for controlling protozoan parasites that affect human health. Here, by using a computational strategy based on sequence-based prediction approaches, phylogenetic analyses, and computational prediction of PPI networks, we compared interactomes of polyadenylation factors in relevant protozoan parasites and the human host, to identify key proteins and define potential targets for pathogen control. Then, we used Entamoeba histolytica as a working model to validate our computational results. RT-qPCR assays confirmed the coordinated modulation of connected proteins in the PPI network and evidenced that silencing of the bottleneck protein EhCFIm25 affects the expression of interacting proteins. In addition, molecular dynamics simulations and docking approaches allowed to characterize the relationships between EhCFIm25 and Ehnopp34, two connected bottleneck proteins. Interestingly, the experimental identification of EhCFIm25 interactome confirmed the close relationships among proteins involved in gene expression regulation and evidenced new links with moonlight proteins in E. histolytica, suggesting a connection between RNA biology and metabolism as described in other organisms. Altogether, our results strengthened the relevance of comparative genomics and interactomics of polyadenylation factors for the prediction of new targets for the control of these human pathogens.

Assuntos

RESUMO

Organotypic three-dimensional (3D) cell cultures more accurately mimic the characteristics of solid tumors in vivo in comparison with traditional two-dimensional (2D) monolayer cell models. Currently, studies on the regulation of long non-coding RNAs (lncRNAs) have not been explored in breast cancer cells cultured in 3D microenvironments. In the present research, we studied the expression and potential roles of lncRNAs in estrogen receptor-positive luminal B subtype BT-474 breast cancer cells grown over extracellular matrix proteins-enriched 3D cultures. Global expression profiling using DNA microarrays identifies 290 upregulated and 183 downregulated lncRNAs in 3D cultures relative to 2D condition. Using a co-expression analysis approach of lncRNAs and mRNAs pairs expressed in the same experimental conditions, we identify hundreds of regulatory axes modulating genes involved in cancer hallmarks, such as responses to estrogens, cell proliferation, hypoxia, apical junctions, and resistance to endocrine therapy. In addition, we identified 102 lncRNAs/mRNA correlations in 3D cultures, which were similar to those reported in TCGA datasets obtained from luminal B breast cancer patients. Interestingly, we also found a set of mRNAs transcripts co-expressed with LINC00847 and CTD-2566J3.1 lncRNAs, which were predictors of pathologic complete response and overall survival. Finally, both LINC00847 and CTD -2566J3.1 were co-expressed with essential genes for cancer genetic dependencies, such as FOXA1 y GINS2. Our experimental and predictive findings show that co-expressed lncRNAs/mRNAs pairs exhibit a high degree of similarity with those found in luminal B breast cancer patients, suggesting that they could be adequate pre-clinical tools to identify not only biomarkers related to endocrine therapy response and PCR, but to understand the biological behavior of cancer cells in 3D microenvironments.

Assuntos

RESUMO

Quinoxalines are heterocyclic compounds that contain a benzene ring and a pyrazine ring. The oxidation of both nitrogen of the pyrazine ring results in quinoxaline derivatives (QdNO), which exhibit a variety of biological properties, including antiparasitic activity. However, its activity against Entamoeba histolytica, the protozoan that causes human amebiasis, is poorly understood. Recently, our group reported that various QdNOs produce morphological changes in E. histolytica trophozoites, increase reactive oxygen species, and inhibit thioredoxin reductase activity. Notably, T-001 and T-017 derivatives were among the QdNOs with the best activity. In order to contribute to the characterization of the antiamebic effect of QdNOs, in this work we analyzed the proteomic profile of E. histolytica trophozoites treated with the QdNOs T-001 and T-017, and the results were correlated with functional assays. A total number of 163 deregulated proteins were found in trophozoites treated with T-001, and 131 in those treated with T-017. A set of 21 overexpressed and 24 under-expressed proteins was identified, which were mainly related to cytoskeleton and intracellular traffic, nucleic acid transcription, translation and binding, and redox homeostasis. Furthermore, T-001 and T-017 modified the virulence of trophozoites, since they altered their erythrophagocytosis, migration, adhesion and cytolytic capacity. Our results show that in addition to alter reactive oxygen species, and thioredoxin reductase activity, T-001 and T-017 affect essential functions related to the actin cytoskeleton, which eventually affects E. histolytica virulence and survival.

Assuntos

RESUMO

Traditional two-dimensional (2D) monolayer cell cultures have long been the gold standard for cancer biology research. However, their ability to accurately reflect the molecular mechanisms of tumors occurring in vivo is limited. Recent development of three-dimensional (3D) cell culture models facilitate the possibility to better recapitulate several of the biological and molecular characteristics of tumors in vivo, such as cancer cells heterogeneity, cell-extracellular matrix interactions, development of a hypoxic microenvironment, signaling pathway activities depending on contacts with extracellular matrix, differential growth kinetics, more accurate drugs response, and specific gene expression and epigenetic patterns. In this review, we discuss the utilization of different types of 3D culture models including spheroids, organotypic models and patient-derived organoids in gynecologic cancers research, as well as its potential applications in oncological research mainly for screening drugs with major physiological and clinical relevance. Moreover, microRNAs regulation of cancer hallmarks in 3D cell cultures from different types of cancers is discussed.

RESUMO

Vasculogenic mimicry is a cellular mechanism in which tumor cells grow and align forming complex three-dimensional (3D) channel-like structures in a hypoxic microenvironment. This phenomenon represents a novel oxygen, nutrient, and blood supply, in a similar way as occurs in classic angiogenesis. Vasculogenic mimicry has been described in numerous clinical tumors including breast, prostate, lung, and ovarian cancers where it is associated with poor prognosis; thus, it is considered as a hallmark of highly aggressive and metastatic tumors. Here, we describe a simple method to model the in vitro formation of three-dimensional cellular networks over Matrigel in SKOV3 ovarian cancer cells representing the early stages of vasculogenic mimicry.

Assuntos

RESUMO

The 3D organotypic cultures, which depend on the growth of cells over the extracellular matrix (ECM) used as a scaffold, can better mimic several characteristics of solid cancers that influence tumor biology and the response to drug therapies. Most of our current knowledge on cancer is derived from studies in 2D cultures, which lack the ECM-mediated microenvironment. Moreover, the role of miRNAs that is critical for fine-tuning of gene expression is poorly understood in 3D cultures. The aim of this study was to compare the miRNA expression profiles of breast cancer cells grown in 2D and 3D conditions. On an on-top 3D cell culture model using a basement membrane matrix enriched with laminin, collagen IV, entactin, and heparin-sulfate proteoglycans, the basal B (Hs578T) and luminal (T47D) breast cancer cells formed 3D spheroid-like stellate and rounded mass structures, respectively. Morphological changes in 3D cultures were observed as cell stretching, cell-cell, and cell-ECM interactions associated with a loss of polarity and reorganization on bulk structures. Interestingly, we found prolongations of the cytoplasmic membrane of Hs578T cells similar to tunneled nanotubes contacting between neighboring cells, suggesting the existence of cellular intercommunication processes and the possibility of fusion between spheroids. Expression profiling data revealed that 354 miRNAs were differentially expressed in 3D relative to 2D cultures in Hs578T cells. Downregulated miRNAs may contribute to a positive regulation of genes involved in hypoxia, catabolic processes, and focal adhesion, whereas overexpressed miRNAs modulate genes involved in negative regulation of the cell cycle. Target genes of the top ten modulated miRNAs were selected to construct miRNA/mRNA coregulation networks. Around 502 interactions were identified for downregulated miRNAs, including miR-935/HIF1A and miR-5189-3p/AKT that could contribute to cell migration and the response to hypoxia. Furthermore, the expression levels of miR-935 and its target HIF1A correlated with the expression found in clinical tumors and predicted poor outcomes. On the other hand, 416 interactions were identified for overexpressed miRNAs, including miR-6780b-5p/ANKRD45 and miR-7641/CDK4 that may result in cell proliferation inhibition and cell cycle arrest in quiescent layers of 3D cultures. In conclusion, 3D cultures could represent a suitable model that better resembles the miRNA transcriptional programs operating in tumors, with implications not only in the understanding of basic cancer biology in 3D microenvironments, but also in the identification of novel biomarkers of disease and potential targets for personalized therapies in cancer.

RESUMO

Preeclampsia (PE) is a leading cause of maternal-fetal mortality worldwide, and obesity is an important risk factor. Genes associated with pathophysiological events common to preeclampsia and obesity, such as PLAC8, remain to be studied; therefore, the aim of the present study was to evaluate this gene in the placentas of women affected with preeclampsia and healthy pregnant women. This case-controlled study included 71 healthy and 64 preeclampsia pregnancies. Gene expression was evaluated in primary human cytotrophoblasts (PHCT) from six normal and six preeclampsia pregnancies, and protein expression was verified in placentas from five healthy and six preeclampsia pregnancies. The whole coding and 5' regions of the PLAC8 gene were sequenced from healthy (n = 10) and preeclamptic (n = 10) pregnancies. The presence of the observed nucleotide variations was analyzed by RT-PCR in the total population. Statistical analyses were performed accordingly. Obesity was associated with severe preeclampsia (SPE) (OR = 3.34; CI 95% 1.3-8.2, p < 0.01). Significantly higher mRNA and protein expression was observed in preeclamptic vs. healthy placentas (p < 0.05). After sequencing, a single nucleotide variation was identified in 10 cases and one control (p < 0.01), which was then evaluated in the total population showing no association with preeclampsia. This preliminary study confirms the association of SPE with obesity and suggests higher expression of PLAC8 mRNA and protein in placentas from preeclampsia. No differences in nucleotide variations between cases and controls of the whole population were observed. Further research is required to evaluate the implications of higher gene/protein expression in preeclampsia and the causes of such variation.

RESUMO

A higher Th17-immune response characterises obesity and obesity-related asthma phenotype. Nevertheless, obesity-related asthma has a more significant Th17-immune response than obesity alone. Retinoid-related orphan receptor C (RORC) is the essential transcription factor for Th17 polarisation. Previous studies have found that adolescents with obesity-related asthma presented upregulation of RORC, IL17A, and TNFA. However, the mechanisms that cause these higher mRNA expression levels in this asthmatic phenotype are poorly understood. Methylation directly regulates gene expression by adding a methyl group to carbon 5 of dinucleotide CpG cytosine. Thus, we evaluated the relationship between RORC, IL17A, and TNFA methylation status and mRNA expression levels to investigate a possible epigenetic regulation. A total of 102 adolescents (11-18 years) were studied in the following four groups: 1) healthy participants (HP), 2) allergic asthmatic participants (AAP), 3) obese participants without asthma (OP), and 4) non-allergic obesity-related asthma participants (OAP). Real-time qPCR assessed the methylation status and gene expression levels in peripheral blood leukocytes. Remarkably, the OAP and AAP groups have lower promoter methylation patterns of RORC, IL17A, and TNFA than the HP group. Notably, the OAP group presents lower RORC promoter methylation status than the OP group. Interestingly, RORC promoter methylation status was moderately negatively associated with gene expression of RORC (r s = -0.39, p < 0.001) and IL17A (r s = -0.37, p < 0.01), respectively. Similarly, the promoter methylation pattern of IL17A was moderately negatively correlated with IL17A gene expression (r s = -0.3, p < 0.01). There is also a moderate inverse relationship between TNFA promoter methylation status and TNFA gene expression (r s = -0.3, p < 0.01). The present study suggests an association between lower RORC, IL17A, and TNFA gene promoter methylation status with obesity-related asthma and allergic asthma. RORC, IL17A, and TNFA gene promoter methylation patterns are moderately inversely correlated with their respective mRNA expression levels. Therefore, DNA methylation may regulate RORC, IL17A, and TNF gene expression in both asthmatic phenotypes.