RESUMO
Vascular endothelial growth factor A (VEGFA) has different biological activities and plays a central role in tumor proliferation, angiogenesis and metastasis. Different VEGFA isoforms are generated by alternative splice site selection of exons 6, 7 and 8. In this paper, we analyzed the physical and chemical properties of the VEGFA exon 6 sequence, and modeled the three-dimensional structures of the regions corresponding to exons 6, 7 and 8 of six different pro-angiogenic isoforms of VEGFA in comparison to the experimental structure of VEGFA_165 by a combined approach of fold recognition and comparative modeling strategies and molecular dynamics simulations. Our results showed that i) exon 6 is a very flexible polycation with high disordered propensity, features well conserved in all mammals, ii) the structures of all the isoforms are stabilized by H-bond sub-networks organized around HUB residues and, iii) the charge content of exon 6 modulates the intrinsic structural preference of its flexible backbone, which can be described as an ensemble of conformations. Moreover, complexes between NRP-1 and VEGFA isoforms were modeled by molecular docking to study what isoforms are able to bind NRP-1. The analysis of complexes evidenced that VEGFA_121, VEGFA_145, VEGFA_183, VEGFA_189 and VEGFA_206, containing exons 7 and 8a, are able to interact with NRP-1 because they have the key regions of exons 7b and/or 8a. An overview of the isoforms shows how the fluctuations are the main guidance of their biological function. MD simulations also provide insights into factors that stabilize the binding regions of isoforms.
Assuntos
Carcinogênese , Fator A de Crescimento do Endotélio Vascular/química , Fator A de Crescimento do Endotélio Vascular/fisiologia , Sequência de Aminoácidos , Indutores da Angiogênese/química , Carcinogênese/genética , Carcinogênese/metabolismo , Humanos , Modelos Moleculares , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Neuropilina-1/química , Neuropilina-1/metabolismo , Domínios e Motivos de Interação entre Proteínas , Isoformas de Proteínas/química , Isoformas de Proteínas/fisiologia , Estrutura Quaternária de Proteína , Alinhamento de Sequência , Relação Estrutura-AtividadeRESUMO
In recent years, many researchers are focusing their attention on the link between inflammation and cancer. The inflammation is involved in the tumor development and suppression, by stimulating the immune response. In particular, the transition from chronic inflammation to cancer produces angiogenic and growth factors able to repair the tissue and to promote cancer cell survival, implantation, and growth. In this contest, the cytokines contribute to the development of these processes becoming active before and during the inflammatory process and playing an important function at the various disease levels. Thus, these proteins can represent specific markers of tumor development and progression. Therefore the "cytokinome" term is used to indicate the evaluation of cytokine pattern by using an "omics" approach. Newly, specific protein chips of considerable and improved sensitivity are being developed to determine simultaneously several and different cytokines. This can be achieved by a multiplex technology that, through the use of small amounts of serum or other fluids, is used to determine the presence and the levels of underrepresented cytokines. Since this method is an accurate, sensitive, and reproducible cytokine assay, it is already used in many different studies. Thus, this review focuses on the more latest aspects related to cytokinome profile evaluation in different cancers.
Assuntos
Citocinas/sangue , Imunoensaio/métodos , Neoplasias/sangue , Biomarcadores/sangue , Regulação Neoplásica da Expressão Gênica , Humanos , Inflamação/sangue , Metástase Neoplásica , PrognósticoRESUMO
Many studies have evidenced that the phenolic components from flaxseed (FS) oil have potential health benefits. The effect of the phenolic extract from FS oil has been evaluated on two human breast cancer cell lines, MCF7 and MDA-MB231, and on the human non-cancerous breast cell line, MCF10A, by SRB assay, cellular death, cell cycle, cell signaling, lipid peroxidation and expression of some key genes. We have evidenced that the extract shows anti-proliferative activity on MCF7 cells by inducing cellular apoptosis, increase of the percentage of cells in G0/G1 phase and of lipid peroxidation, activation of the H2AX signaling pathway, and upregulation of a six gene signature. On the other hand, on the MDA-MB2131 cells we verified only an anti-proliferative activity, a weak lipid peroxidation, the activation of the PI3K signaling pathway and an up-regulation of four genes. Overall these data suggest that the extract has both cytotoxic and pro-oxidant effects only on MCF7 cells, and can act as a metabolic probe, inducing differences in the gene expression. For this purpose, we have performed an interactomic analysis, highlighting the existing associations. From this approach, we show that the phenotypic difference between the two cell lines can be explained through their differential response to the phenolic extract.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Óleo de Semente do Linho/administração & dosagem , Apoptose/efeitos dos fármacos , Neoplasias da Mama/patologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Histonas/biossíntese , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Células MCF-7 , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
In humans we know 25 selenoproteins that play important roles in redox regulation, detoxification, immune-system protection and viral suppression. In particular, selenoprotein M (SelM) may function as thiol disulfide oxidoreductase that participates in the formation of disulfide bonds, and can be implicated in calcium responses. However, it presents a redox motif (CXXU), where U is a selenocysteine, and may also function as redox regulator because its decreased or increased expression regulated by dietary selenium alters redox homeostasis. No data are reported in literature about its involvement in cancer but only in neurodegenerative diseases. In this paper we evaluated the SelM expression in two hepatoma cell lines, HepG2 and Huh7, compared to normal hepatocytes. The results suggested its involvement in hepatocellular carcinoma (HCC) as well as its possible use to follow the progression of this cancer as putative marker. The aim of this study has been to analyze the structure-function relationships of SelM. Hence, firstly we studied the evolutionary history of this protein by phylogenetic analysis and GC content of genes from various species. So, we modeled the three-dimensional structure of the human SelM evaluating its energetic stability by molecular dynamics simulations. Moreover, we modeled some of its mutants to obtain structural information helpful for structure-based drug design.
Assuntos
Carcinoma Hepatocelular/enzimologia , Evolução Molecular , Neoplasias Hepáticas/enzimologia , Selenoproteínas/química , Sequência de Aminoácidos , Células Hep G2 , Humanos , Modelos Moleculares , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Filogenia , Selenoproteínas/genética , Homologia de Sequência de Aminoácidos , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
Many research groups are working to find new possible anti-inflammatory molecules, and marine sponges represent a rich source of biologically active compounds with pharmacological applications. In the present study, we tested different concentrations of the methanol extract from the marine sponge, Geodia cydonium, on normal human breast epithelial cells (MCF-10A) and human breast cancer cells (MCF-7). Our results show that this extract has no cytotoxic effects on both cell lines whereas it induces a decrease in levels of VEGF and five proinflammatory cytokines (CCL2, CXCL8, CXCL10, IFN-γ, and TNF-α) only in MCF-7 cells in a dose-dependent manner, thereby indicating an anti-inflammatory effect. Moreover, interactomic analysis suggests that all six cytokines are involved in a network and are connected with some HUB nodes such as NF-kB subunits and ESR1 (estrogen receptor 1). We also report a decrease in the expression of two NFKB1 and c-Rel subunits by RT-qPCR experiments only in MCF-7 cells after extract treatment, confirming NF-kB inactivation. These data highlight the potential of G. cydonium for future drug discovery against major diseases, such as breast cancer.
Assuntos
Geodia/química , Metanol/química , Animais , Neoplasias da Mama/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Células MCF-7RESUMO
It has been suggested that imprinted genes are important in the regulation of sleep. However, the fundamental question of whether genomic imprinting has a role in sleep has remained elusive up to now. In this work we show that REM and NREM sleep states are differentially modulated by the maternally expressed imprinted gene Gnas. In particular, in mice with loss of imprinting of Gnas, NREM and complex cognitive processes are enhanced while REM and REM-linked behaviors are inhibited. This is the first demonstration that a specific overexpression of an imprinted gene affects sleep states and related complex behavioral traits. Furthermore, in parallel to the Gnas overexpression, we have observed an overexpression of Ucp1 in interscapular brown adipose tissue (BAT) and a significant increase in thermoregulation that may account for the REM/NREM sleep phenotypes. We conclude that there must be significant evolutionary advantages in the monoallelic expression of Gnas for REM sleep and for the consolidation of REM-dependent memories. Conversely, biallelic expression of Gnas reinforces slow wave activity in NREM sleep, and this results in a reduction of uncertainty in temporal decision-making processes.
Assuntos
Cognição/fisiologia , Subunidades alfa Gs de Proteínas de Ligação ao GTP/genética , Impressão Genômica , Sono REM/genética , Sono REM/fisiologia , Tecido Adiposo Marrom , Alelos , Animais , Temperatura Corporal , Regulação da Temperatura Corporal/genética , Regulação da Temperatura Corporal/fisiologia , Cromograninas , Metilação de DNA , Eletroencefalografia , Éxons , Subunidades alfa Gs de Proteínas de Ligação ao GTP/fisiologia , Regulação da Expressão Gênica , Canais Iônicos , Camundongos , Proteínas Mitocondriais , Deleção de Sequência , Proteína Desacopladora 1 , VigíliaRESUMO
This work reports on the design and the synthesis of two short linear peptides both containing a few amino acids with disorder propensity and an allylic ester group at the C-terminal end. Their structural properties were firstly analyzed by means of experimental techniques in solution such as CD and NMR methods that highlighted peptide flexibility. These results were further confirmed by MD simulations that demonstrated the ability of the peptides to assume conformational ensembles. They revealed a network of transient and dynamic H-bonds and interactions with water molecules. Binding assays with a well-known drug-target, i.e., the CXCR4 receptor, were also carried out in an attempt to verify their biological function and the possibility to use the assays to develop new specific targets for CXCR4. Moreover, our data indicate that these peptides represent useful tools for molecular recognition processes in which a flexible conformation is required in order to obtain an interaction with a specific target.
Assuntos
Proteínas Intrinsicamente Desordenadas/química , Peptídeos/síntese química , Peptídeos/metabolismo , Receptores CXCR4/metabolismo , Dicroísmo Circular , Humanos , Ligação de Hidrogênio , Simulação de Dinâmica Molecular , Peptídeos/química , Ligação Proteica , Conformação Proteica , Dobramento de Proteína , Espectroscopia de Prótons por Ressonância MagnéticaRESUMO
Protein-protein interaction networks are useful for studying human diseases and to look for possible health care through a holistic approach. Networks are playing an increasing and important role in the understanding of physiological processes such as homeostasis, signaling, spatial and temporal organizations, and pathological conditions. In this article we show the complex system of interactions determined by human Sirtuins (Sirt) largely involved in many metabolic processes as well as in different diseases. The Sirtuin family consists of seven homologous Sirt-s having structurally similar cores but different terminal segments, being rather variable in length and/or intrinsically disordered. Many studies have determined their cellular location as well as biological functions although molecular mechanisms through which they act are actually little known therefore, the aim of this work was to define, explore and understand the Sirtuin-related human interactome. As a first step, we have integrated the experimentally determined protein-protein interactions of the Sirtuin-family as well as their first and second neighbors to a Sirtuin-related sub-interactome. Our data showed that the second-neighbor network of Sirtuins encompasses 25% of the entire human interactome, and exhibits a scale-free degree distribution and interconnectedness among top degree nodes. Moreover, the Sirtuin sub interactome showed a modular structure around the core comprising mixed functions. Finally, we extracted from the Sirtuin sub-interactome subnets related to cancer, aging and post-translational modifications for information on key nodes and topological space of the subnets in the Sirt family network.
Assuntos
Envelhecimento/metabolismo , Biologia Computacional , Neoplasias/metabolismo , Mapas de Interação de Proteínas , Processamento de Proteína Pós-Traducional , Sirtuínas/metabolismo , Acetilação , Envelhecimento/genética , Bases de Dados de Proteínas , Humanos , Metilação , Neoplasias/genética , Fosforilação , Mapeamento de Interação de Proteínas , Sirtuínas/genéticaRESUMO
Chemokine receptors play a crucial role in the cellular signaling enrolling extracellular ligands chemotactic proteins which recruit immune cells. They possess seven trans-membrane helices, an extracellular N-terminal region with three extracellular hydrophilic loops being important for search and recognition of specific ligand(s), and an intracellular C-terminal region with three intracellular loops that couple G-proteins. Although the functional aspects of the terminal segments of the extra-and intra-cellular G proteins are universally identified, the molecular basis on which they rest are still unclear because they are not definable by means of X-rays due to their high mobility and are not easy to study in the membrane. The purpose of this work is to define which physical-chemical properties of the terminal segments of the human chemokine receptors are at the basis of their functional mechanisms. Therefore, we have evaluated their physical-chemical properties in terms of amino acid composition, local flexibility, disorder propensity, net charge distribution and putative sites of post-translational modifications. Our results support the conclusion that all 19 C-terminal and N-terminal segments of human chemokine receptors are very flexible due to the systematic presence of intrinsic disorder. Although, the purpose of this plasticity clearly appears that of controlling and modulating the binding of ligands, we provide evidence that the overlap of linearly charged stretches, intrinsic disorder and post-translational modification sites, consistently found in these motives, is a necessary feature to exert the function. The role of the intrinsic disorder has been discussed considering the structural information coming from intrinsically disordered model compounds which support the view that the chemokine terminals have to be considered as strong polyampholytes or polyelectrolytes where conformational ensembles and structural transitions between them are modulated by charge fraction variations. Also the role of post-translational modifications has been found coherent with this view because, changing the charge fraction, they guide structural transitions between ensembles. Moreover, we have also considered our results from an evolutionary point of view in order to understand if the features found in humans were also present in other species. Our data evidenced that the structural features of the human terminals of the chemokine receptors were shared and evolutionarily conserved particularly among mammals. This means that the various organisms not only tolerate but select intrinsic disorder for the terminal regions of their receptors, reflecting constraints that point to molecular recognition. In conclusion the terminal segments of chemokine receptors must be considered as strong polyampholytes where the charge fraction variations induced by post-translational modifications are the driving physico-chemical feature able to adapt the conformations of the terminal segments to their functions.
Assuntos
Receptores de Quimiocinas/química , Análise de Sequência de Proteína , Sequência de Aminoácidos , Animais , Humanos , Interações Hidrofóbicas e Hidrofílicas , Proteínas Intrinsicamente Desordenadas/química , Filogenia , Proteínas Quinases/metabolismo , Processamento de Proteína Pós-TraducionalRESUMO
The limited effectiveness of chemotherapy and the high recurrence rate of cancers highlight the urgent need to identify new molecular targets and to develop new treatments. Numerous epidemiological studies have recently highlighted the existence of an inverse association between fruit and vegetable consumption, natural antioxidants, and cancer risk; in fact, antioxidant intake through diet or supplements of plant origin is strongly recommended for cancer prevention and cure. In general, antioxidants are substances of vegetable, mineral, or animal origin that neutralize free radicals and protect the body from their negative actions on the plasma membrane, proteins, and DNA. Hence, cancer can be prevented by the stimulation of the immune system to destroy cancer cells or to block their proliferation. Since living organisms may be studied as a whole complex system by the "omics sciences" which tend toward understanding and describing the global information of genes, mRNA, proteins, and metabolites, our aim is to use bioinformatics and systems biology to study cytokinome, which plays an important role in the evolution of inflammatory processes and is also a key component in the evolution of cancer, a disease recognized as depending on chronic inflammation and also with the concomitant presence of type 2 diabetes and obesity. On the whole, we define cytokinome as the totality of these proteins and their interactions in and around biological cells. Understanding the complex interaction network of cytokines in patients affected by cancers should be very useful both to follow the evolution of cancer from its early stages and to define innovative therapeutic strategies by using systems biology approaches. In this paper, we review some results of our group in the light of the "omics" logic, and in particular (1) the need for a global approach to study complex systems such as multifactorial cancer and, in particular, hepatocellular carcinoma, (2) the correlation between natural antioxidants, inflammation, and liver cancer, (3) the challenge and significance of the cytokinome profile, (4) the evaluation of the cytokinome profile of patients with type 2 diabetes and/or chronic hepatitis C infection, and (5) adipokine interactome.
Assuntos
Antioxidantes/uso terapêutico , Produtos Biológicos/uso terapêutico , Inflamação/prevenção & controle , Neoplasias Hepáticas/prevenção & controle , Animais , HumanosRESUMO
CXCR4 is a G-protein-coupled receptor involved in a number of physiological processes in the hematopoietic and immune systems. CXCL12/CXCR4 axis plays a central role in diseases, such as HIV, cancer, WHIM syndrome, rheumatoid arthritis, pulmonary fibrosis, and lupus and, hence, indicated as putative therapeutic target. Although multiple CXCR4 antagonists have been developed, there is only one marketed drug, plerixafor, indicated for stem cell mobilization in poor mobilizer patients. In this work, we have designed and synthesized two peptides, six and seven residues long, using as template the N-terminal region of CXCL12; analyzed their conformations by CD, NMR, and molecular dynamics simulations; simulated their complexes with CXCR4 by docking methods; and validated these data by in vitro studies. The results showed that the two peptides are rather flexible in aqueous solution lacking ordered secondary structure elements and present a promising affinity for CXCR4. This affinity is not revealed for CXCR7, indicating a specificity for CXCR4.
Assuntos
Peptídeos/química , Receptores CXCR4/química , Sequência de Aminoácidos , Humanos , Dados de Sequência Molecular , Homologia de Sequência de AminoácidosRESUMO
Hepatocellular carcinoma is the fifth most common cancer worldwide and shows a complex clinical course, poor response to pharmacological treatment, and a severe prognosis. Thus, the aim of this study was to investigate whether tacrolimus (FK506) has synergistic antitumor effects with doxorubicin on two human hepatocellular carcinoma cell lines, Huh7 and HepG2. Cell viability was analyzed by Sulforhodamine B assay and synergic effect was evaluated by the software CalcuSyn. Cell apoptosis was evaluated using Annexin V and Dead Cell assay. Apoptosis-related protein PARP-1 cleaved and autophagy-related protein expressions (Beclin-1 and LC3B) were measured by western blotting analysis. Cytokines concentration in cellular supernatants after treatments was studied by Bio-Plex assay. Interestingly the formulation with doxorubicin and tacrolimus induced higher cytotoxicity level on tumor cells than single treatment. Moreover, our results showed that the mechanisms involved were (i) a strong cell apoptosis induction, (ii) contemporaneous decrease of autophagy activation, understood as prosurvival process, and (iii) downregulation of proinflammatory cytokines. In conclusion, future studies could relate to the doxorubicin/tacrolimus combination effects in mice models bearing HCC in order to see if this formulation could be useful in HCC treatment.
Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Carcinoma Hepatocelular/tratamento farmacológico , Doxorrubicina/administração & dosagem , Imunossupressores/administração & dosagem , Neoplasias Hepáticas/tratamento farmacológico , Tacrolimo/administração & dosagem , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Células Hep G2 , Humanos , Neoplasias Hepáticas/patologiaRESUMO
This study presents the interaction with the human host metabolism of SARS-CoV-2 ORF7b protein (43 aa), using a protein-protein interaction network analysis. After pruning, we selected from BioGRID the 51 most significant proteins among 2753 proven interactions and 1708 interactors specific to ORF7b. We used these proteins as functional seeds, and we obtained a significant network of 551 nodes via STRING. We performed topological analysis and calculated topological distributions by Cytoscape. By following a hub-and-spoke network architectural model, we were able to identify seven proteins that ranked high as hubs and an additional seven as bottlenecks. Through this interaction model, we identified significant GO-processes (5057 terms in 15 categories) induced in human metabolism by ORF7b. We discovered high statistical significance processes of dysregulated molecular cell mechanisms caused by acting ORF7b. We detected disease-related human proteins and their involvement in metabolic roles, how they relate in a distorted way to signaling and/or functional systems, in particular intra- and inter-cellular signaling systems, and the molecular mechanisms that supervise programmed cell death, with mechanisms similar to that of cancer metastasis diffusion. A cluster analysis showed 10 compact and significant functional clusters, where two of them overlap in a Giant Connected Component core of 206 total nodes. These two clusters contain most of the high-rank nodes. ORF7b acts through these two clusters, inducing most of the metabolic dysregulation. We conducted a co-regulation and transcriptional analysis by hub and bottleneck proteins. This analysis allowed us to define the transcription factors and miRNAs that control the high-ranking proteins and the dysregulated processes within the limits of the poor knowledge that these sectors still impose.
Assuntos
COVID-19 , Mapas de Interação de Proteínas , SARS-CoV-2 , Proteínas Virais , Humanos , SARS-CoV-2/metabolismo , SARS-CoV-2/genética , Mapas de Interação de Proteínas/genética , COVID-19/virologia , COVID-19/metabolismo , COVID-19/genética , Proteínas Virais/metabolismo , Proteínas Virais/genéticaRESUMO
BACKGROUND: Sirtuins genes are widely distributed by evolution and have been found in eubacteria, archaea and eukaryotes. While prokaryotic and archeal species usually have one or two sirtuin homologs, in humans as well as in eukaryotes we found multiple versions and in mammals this family is comprised of seven different homologous proteins being all NAD-dependent de-acylases. 3D structures of human SIRT2, SIRT3, and SIRT5 revealed the overall conformation of the conserved core domain but they were unable to give a structural information about the presence of very flexible and dynamically disordered regions, the role of which is still structurally and functionally unclear. Recently, we modeled the 3D-structure of human SIRT1, the most studied member of this family, that unexpectedly emerged as a member of the intrinsically disordered proteins with its long disordered terminal arms. Despite clear similarities in catalytic cores between the human sirtuins little is known of the general structural characteristics of these proteins. The presence of disorder in human SIRT1 and the propensity of these proteins in promoting molecular interactions make it important to understand the underlying mechanisms of molecular recognition that reasonably should involve terminal segments. The mechanism of recognition, in turn, is a prerequisite for the understanding of any functional activity. Aim of this work is to understand what structural properties are shared among members of this family in humans as well as in other organisms. RESULTS: We have studied the distribution of the structural features of N- and C-terminal segments of sirtuins in all known organisms to draw their evolutionary histories by taking into account average length of terminal segments, amino acid composition, intrinsic disorder, presence of charged stretches, presence of putative phosphorylation sites, flexibility, and GC content of genes. Finally, we have carried out a comprehensive analysis of the putative phosphorylation sites in human sirtuins confirming those sites already known experimentally for human SIRT1 and 2 as well as extending their topology to all the family to get feedback of their physiological functions and cellular localization. CONCLUSIONS: Our results highlight that the terminal segments of the majority of sirtuins possess a number of structural features and chemical and physical properties that strongly support their involvement in activities of recognition and interaction with other protein molecules. We also suggest how a multisite phosphorylation provides a possible mechanism by which flexible and intrinsically disordered segments of a sirtuin supported by the presence of positively or negatively charged stretches might enhance the strength and specificity of interaction with a particular molecular partner.
Assuntos
Evolução Molecular , Família Multigênica , Sirtuínas/genética , Sequência de Aminoácidos , Animais , Composição de Bases , Humanos , Sinais de Exportação Nuclear , Sinais de Localização Nuclear , Fosforilação , Filogenia , Plantas , Estrutura Secundária de Proteína , Alinhamento de Sequência , Sirtuína 1/genéticaRESUMO
Chemokine receptor trio composed by CXCR3, CXCR4 and CXCR7 represents a hard and interesting challenge for cancer biology because these three receptors are found to be over-expressed in different cancers as well as to bind the same chemokines. In fact, CXCR4 interacts with CXCL12, CXCR7 not only with CXCL12 but also with CXCL11, that is a natural ligand for CXCR3. For these reasons, it seems necessary to define and to identify the structural determinants of CXCR3, CXCR4 and CXCR7 and their related physic-chemical properties that permit them to bind CXCL11 and CXCL12. Hence in this paper we show the modeling of CXCR7 and its complex with CXCL11 and CXCL12 compared to CXCR3/CXCL11 and CXCR4/CXCL12. Our results show that (i) CXCR3, CXCR4 and CXCR7 present similar trans-membrane helices and different conformations of N-terminal and C-terminal regions as well as of three extracellular loops, and (ii) the predominant interaction between the three receptors and the two chemokines are on hydrophobic and electrostatic basis. Moreover, our data confirm that CXCL12 binds to CXCR7 with higher affinity than to CXCR4. Methodologically, we can also conclude that our computational strategy is adequate to model correctly the interactions between these chemokines and their receptors; therefore, our models represent a good structural basis to design and develop peptides able to block contemporaneously CXCR3, CXCR4 and CXCR7 receptor trio.
Assuntos
Quimiocina CXCL11/metabolismo , Quimiocina CXCL12/metabolismo , Receptores CXCR3/metabolismo , Receptores CXCR4/metabolismo , Receptores CXCR/metabolismo , Sequência de Aminoácidos , Animais , Bovinos , Linhagem Celular Tumoral , Humanos , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Dados de Sequência Molecular , Neoplasias/metabolismo , Ligação Proteica , Rodopsina/genética , Rodopsina/metabolismo , Alinhamento de Sequência , Análise de Sequência de Proteína , Eletricidade EstáticaRESUMO
An accurate and simultaneous estimate of cellular levels of a large cytokine number is very useful to obtain information about an organ dysfunction leading to cancer because through the understanding of the evolution of cytokine patterns we can recognize and predict the disease progression. Cancer cell lines are commonly used to study the cancer microenvironment, to analyze their chemosensitivity and carcinogenesis as well as to test in vitro the effect of molecules, such as drugs or anti-oxidants, on the inflammation status and its progression. We noted that various cell lines commonly used as a model for studies on liver and colon cancer possess different patterns of cytokines. This aspect may generate data not comparable in laboratories using different cell lines; thus, to investigate the origin of these abnormalities we compared the cell lines HepG2 and Huh7, and HT-29 and HCT-116, for liver and colon cancer, respectively. In this context we have evaluated and compared the levels of cytokines, chemokines and growth factors in the supernatants of these cellular lines. Our aim was to identify what cytokines were significantly different correlating similarities and differences to the specific inflammation status of each cellular model of cancer.
Assuntos
Neoplasias do Colo/metabolismo , Citocinas/metabolismo , Neoplasias Hepáticas/metabolismo , Linhagem Celular Tumoral , Análise por Conglomerados , Fluorescência , Humanos , Proteínas de Neoplasias/metabolismoRESUMO
The need to explore new alternative therapeutic strategies and chemoprevention methods for hepatocellular carcinoma is growing significantly. Selenium is a trace element that plays a critical role in physiological processes, and is used in cancer chemoprevention. The aim of this work was to test in vitro the effect of sodium selenite on the human hepatoma cell lines, HepG2 and Huh7, to assess its effect on the expression of GPX1, SELK and SELENBP1 and also to evaluate its action on inflammation determinants such as cytokines. Our results show that: (i) the increase observed for the GPX1 and SELK expression is correlated with an increase in the sodium selenite concentration, also evidencing an inverse association between the levels of these two proteins and SELENBP1; (ii) the selenium concentrations evaluated in protein extracts increase in proportional way with the selenite concentrations used in the treatment, suggesting that other selenoproteins can also be modulated and should be evaluated in further studies, and (iii) some cytokines, VEGF and three pro-inflammatory cytokines, i.e., IL-6, IL-8, and IL-17, decreased with an increasing selenite concentration. Finally, interactomic studies show that GPX1 and SELK, and the four pro-inflammatory cytokines are functionally correlated evidencing a putative anti-inflammatory role for the selenite.
Assuntos
Carcinoma Hepatocelular/metabolismo , Citocinas/metabolismo , Neoplasias Hepáticas/metabolismo , Selenoproteínas/metabolismo , Selenito de Sódio/farmacologia , Linhagem Celular Tumoral , Glutationa Peroxidase/metabolismo , Células Hep G2 , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Ligação Proteica , Mapeamento de Interação de Proteínas , Mapas de Interação de Proteínas , Proteínas de Ligação a Selênio/metabolismo , Glutationa Peroxidase GPX1RESUMO
The reduced expression of human selenium binding protein-1 (SELENBP1) has been reported for some human cancers. In this work we have estimated a reduced SELENBP1 expression by immunohistochemistry for the first time also in liver tissues of patients with hepatocarcinoma (HCC). Since the structure-function relationships of SELENBP1 are unknown, we have performed computational and experimental studies to have insight on the structural features of this protein focusing our attention on the properties of cysteines to assess their ability to interact with selenium. We have performed CD studies on the purified protein, modeled its three-dimensional structure, studied the energetic stability of the protein by molecular dynamics simulations, and titrated the cysteines by DTNB (5,5'-dithiobis (2-nitrobenzoic acid). The secondary structure content evaluated by CD has been found similar to that of 3D model. Our studies demonstrate that (i) SELENBP1 is an alpha-beta protein with some loop regions characterized by the presence of intrinsically unordered segments, (ii) only one cysteine (Cys57) is enough exposed to solvent, located on a loop and surrounded by charged and hydrophobic residues, and can be the cysteine able to bind the selenium. Furthermore, during the molecular dynamics simulation at neutral pH the loop containing Cys57 opens and exposes this residue to solvent, confirming that it is the best candidate to bind the selenium. Experimentally we found that only one cysteine is titratable by DTNB. This supports the hypothesis that Cys57 is a residue functionally important and this may open new pharmacological perspectives.
Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas de Ligação a Selênio/química , Proteínas de Ligação a Selênio/metabolismo , Idoso , Sequência de Aminoácidos , Carcinoma Hepatocelular/patologia , Dicroísmo Circular , Feminino , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Alinhamento de Sequência , Sulfetos/metabolismo , TitulometriaRESUMO
Biomedical institutions rely on data evaluation and are turning into data factories. Big-data storage centers, supercomputing systems, and increased algorithmic efficiency allow us to analyze the ever-increasing amount of data generated every day in biomedical research centers. In network science, the principal intrinsic problem is how to integrate the data and information from different experiments on genes or proteins. Data curation is an essential process in annotating new functional data to known genes or proteins, undertaken by a biobank curator, which is then reflected in the calculated networks. We provide an example of how protein-protein networks today have space-time limits. The next step is the integration of data and information from different biobanks. Omics data and networks are essential parts of this step but also have flawed protocols and errors. Consider data from patients with cancer: from biopsy procedures to experimental tests, to archiving methods and computational algorithms, these are continuously handled so require critical and continuous "updates" to obtain reproducible, reliable, and correct results. We show, as a second example, how all this distorts studies in cellular hepatocellular carcinoma. It is not unlikely that these flawed data have been polluting biobanks for some time before stringent conditions for the veracity of data were implemented in Big data. Therefore, all this could contribute to errors in future medical decisions.
Assuntos
Biomarcadores Tumorais/genética , Carcinoma Hepatocelular/genética , Biologia Computacional/métodos , Neoplasias Hepáticas/genética , Algoritmos , Big Data , Curadoria de Dados , Predisposição Genética para Doença , HumanosRESUMO
AIM: To assess feasibility, complications and efficacy of induction chemotherapy followed by standard chemoradiotherapy in patients with bulky anal canal cancer. PATIENTS AND METHODS: Patients with squamous cell carcinoma of the anal canal, staged bulky tumor with or without nodal involvement were prospectively enrolled. Before standard chemoradiotherapy, patients received induction chemotherapy with 3 cycles of 75 mg/m2 cisplatin and 750 mg/m2 5-fluorouracil. Patients were followed-up routinely until recurrence or death. RESULTS: Seven patients with bulky anal canal cancer were evaluable for this pilot phase of the study. All patients had human papillomavirus-negative disease. Five completed the scheduled induction chemotherapy and all patients completed the programmed concomitant chemoradiotherapy. None had severe hematological toxicity. The majority of patients (6/7) had tumor downsizing after induction treatment. Six months after chemoradiotherapy, complete response was documented in three patients and salvage surgery was performed in two cases. With a median follow-up of 38 months (range=28-48 months), two patients are disease-free survivors. CONCLUSION: Induction chemotherapy has the potential to become a standard approach in patients with bulky human papillomavirus-negative anal canal cancer.