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1.
PLoS Pathog ; 18(6): e1010417, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35731824

RESUMO

Intracellular pathogens secrete effectors to manipulate their host cells. Histoplasma capsulatum (Hc) is a fungal intracellular pathogen of humans that grows in a yeast form in the host. Hc yeasts are phagocytosed by macrophages, where fungal intracellular replication precedes macrophage lysis. The most abundant virulence factor secreted by Hc yeast cells is Calcium Binding Protein 1 (Cbp1), which is absolutely required for macrophage lysis. Here we take an evolutionary, structural, and cell biological approach to understand Cbp1 function. We find that Cbp1 is present only in the genomes of closely related dimorphic fungal species of the Ajellomycetaceae family that lead primarily intracellular lifestyles in their mammalian hosts (Histoplasma, Paracoccidioides, and Emergomyces), but not conserved in the extracellular fungal pathogen Blastomyces dermatitidis. We observe a high rate of fixation of non-synonymous substitutions in the Cbp1 coding sequences, indicating that Cbp1 is under positive selection. We determine the de novo structures of Hc H88 Cbp1 and the Paracoccidioides americana (Pb03) Cbp1, revealing a novel "binocular" fold consisting of a helical dimer arrangement wherein two helices from each monomer contribute to a four-helix bundle. In contrast to Pb03 Cbp1, we show that Emergomyces Cbp1 orthologs are unable to stimulate macrophage lysis when expressed in the Hc cbp1 mutant. Consistent with this result, we find that wild-type Emergomyces africanus yeast are able to grow within primary macrophages but are incapable of lysing them. Finally, we use subcellular fractionation of infected macrophages and indirect immunofluorescence to show that Cbp1 localizes to the macrophage cytosol during Hc infection, making this the first instance of a phagosomal human fungal pathogen directing an effector into the cytosol of the host cell. We additionally show that Cbp1 forms a complex with Yps-3, another known Hc virulence factor that accesses the cytosol. Taken together, these data imply that Cbp1 is a fungal virulence factor under positive selection that localizes to the cytosol to trigger host cell lysis.


Assuntos
Proteínas de Ligação ao Cálcio , Histoplasmose , Macrófagos , Fatores de Virulência , Animais , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Histoplasma/metabolismo , Histoplasmose/microbiologia , Humanos , Macrófagos/microbiologia , Mamíferos , Saccharomyces cerevisiae , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
2.
Curr Issues Mol Biol ; 45(12): 9549-9565, 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38132443

RESUMO

Colorectal cancer (CRC) represents the second deadliest malignancy worldwide. Around 75% of CRC patients exhibit high levels of chromosome instability that result in the accumulation of somatic copy number alterations. These alterations are associated with the amplification of oncogenes and deletion of tumor-ppressor genes and contribute to the tumoral phenotype in different malignancies. Even though this relationship is well known, much remains to be investigated regarding the effect of said alterations in long non-coding RNAs (lncRNAs) and, in turn, the impact these alterations have on the tumor phenotype. The present study aimed to evaluate the role of differentially expressed lncRNAs coded in regions with copy number alterations in colorectal cancer patient samples. We downloaded RNA-seq files of the Colorectal Adenocarcinoma Project from the The Cancer Genome Atlas (TCGA) repository (285 sequenced tumor tissues and 41 non-tumor tissues), evaluated differential expression, and mapped them over genome sequencing data with regions presenting copy number alterations. We obtained 78 differentially expressed (LFC > 1|< -1, padj < 0.05) lncRNAs, 410 miRNAs, and 5028 mRNAs and constructed a competing endogenous RNA (ceRNA) network, predicting significant lncRNA-miRNA-mRNA interactions. Said network consisted of 30 lncRNAs, 19 miRNAs, and 77 mRNAs. To understand the role that our ceRNA network played, we performed KEGG and GO analysis and found several oncogenic and anti-oncogenic processes enriched by the molecular players in our network. Finally, to evaluate the clinical relevance of the lncRNA expression, we performed survival analysis and found that C5orf64, HOTAIR, and RRN3P3 correlated with overall patient survival. Our results showed that lncRNAs coded in regions affected by SCNAs form a complex gene regulatory network in CCR.

3.
Chem Biodivers ; 20(10): e202300893, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37695827

RESUMO

The cytotoxic activity of combinations of masticadienonic (AMD) or 3αOH-hydroxy-masticadienonic (3αOH-AMD) acids with cisplatin (CDDP) was evaluated against PC3 prostate and HCT116 colon cancer cell lines. Combinations A (half the IC50 value), B (IC50 value), and C (twice the IC50 value) were tested at a 1 : 1 ratio. All AMD plus CDDP combinations demonstrated increased cytotoxic effect, as determined by the sulforhodamine B test, in both cell types. The best combination was B, which showed 93 % and 91 % inhibition of the proliferation of PC3 and HCT116 cells, respectively. It also increased apoptosis in the PC3 cell lines, as evaluated by flow cytometry. However, in vivo tests showed no additional activity from the AMD plus CDDP combinations. These results showed that the increased cytotoxic activity of the combinations in vitro did not reflect in vivo tests. All combinations of 3αOH-AMD plus CDDP exerted antagonistic effects in both cell types.

4.
Mol Microbiol ; 112(3): 896-905, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31177589

RESUMO

The bacterial MscL channel normally functions as an emergency release valve discharging cytoplasmic solutes upon osmotic stress. The channel opens and passes molecules up to 30 Å and its pore is the largest of any gated channel. Opening the MscL pore inappropriately is detrimental to the bacterial cell, suggesting MscL as a potential novel drug target. A small-molecule compound, 011A, has been shown to increase sensitivity of the Escherichia coli MscL channel, slow growth, and even decrease viability of quiescent cultures. The mscL gene is highly conserved and found in the vast majority of bacterial species, including pathogens. Here, we test the hypothesis that 011A can influence the growth and viability of other bacterial species, specifically Staphylococcus aureus and Mycobacterium smegmatis, in a MscL-dependent manner. Furthermore, we demonstrate that the 011A compound can increase potency of other antibiotics, presumably by permeabilizing the membrane and allowing easier access of the antibiotic into the cytoplasm. Thus, MscL activators have potential as novel broad-spectrum antibiotics or adjuvants that work with antibiotics to selectively allow passage across bacterial membranes.


Assuntos
Antibacterianos/farmacologia , Proteínas de Escherichia coli/agonistas , Escherichia coli/efeitos dos fármacos , Canais Iônicos/agonistas , Mycobacterium smegmatis/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Canais Iônicos/genética , Canais Iônicos/metabolismo , Mycobacterium smegmatis/genética , Mycobacterium smegmatis/crescimento & desenvolvimento , Mycobacterium smegmatis/metabolismo , Staphylococcus aureus/genética , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/metabolismo
5.
Molecules ; 25(8)2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32295227

RESUMO

Parthenium argentatum (Gray), commonly known as guayule, has been used to obtain natural rubber since the beginning of the 20th century. Additionally, the so called "resin" is a waste product derived from the industrial process. The cycloartane-type triterpene Argentatin A (AA) is one of the main constituents of the industrial waste resin. In this study we evaluated the AA anticancer activity both in vitro and in vivo in the HCT116 colon cancer cells. The apoptosis promotion of AA was assessed by the annexin V/propidium iodide (PI) assay. The senescence was evaluated for SA-ß-galactosidase, and PCNA was used as a marker of proliferation. Its antitumor activity was evaluated using a xenograft mouse model. The results indicated that AA-induced apoptosis in HCT-116 cells and was positively stained for SA-ß-galactosidase. In the xenografted mice test, the administration of AA at the dose of 250 mg/kg three times a week for 21 days reduced tumor growth by 78.1%. A comparable tumor reduction was achieved with cisplatin at the dose of 2 mg/kg administered three times a week for 21 days. However, nude mice treated with AA did not lose weight, as they did remarkably when treated with cisplatin. Furthermore, the animals treated with AA showed similar blood profiles as the healthy control group. These data indicate the low toxicity of AA compared to that shown by cisplatin.


Assuntos
Antineoplásicos/administração & dosagem , Triterpenos/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Biomarcadores , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Humanos , Imuno-Histoquímica , Camundongos , Estrutura Molecular , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , beta-Galactosidase/metabolismo
6.
J Bacteriol ; 201(22)2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31481541

RESUMO

Conditionally essential (CE) genes are required by pathogenic bacteria to establish and maintain infections. CE genes encode virulence factors, such as secretion systems and effector proteins, as well as biosynthetic enzymes that produce metabolites not found in the host environment. Due to their outsized importance in pathogenesis, CE gene products are attractive targets for the next generation of antimicrobials. However, the precise manipulation of CE gene expression in the context of infection is technically challenging, limiting our ability to understand the roles of CE genes in pathogenesis and accordingly design effective inhibitors. We previously developed a suite of CRISPR interference-based gene knockdown tools that are transferred by conjugation and stably integrate into bacterial genomes that we call Mobile-CRISPRi. Here, we show the efficacy of Mobile-CRISPRi in controlling CE gene expression in an animal infection model. We optimize Mobile-CRISPRi in Pseudomonas aeruginosa for use in a murine model of pneumonia by tuning the expression of CRISPRi components to avoid nonspecific toxicity. As a proof of principle, we demonstrate that knock down of a CE gene encoding the type III secretion system (T3SS) activator ExsA blocks effector protein secretion in culture and attenuates virulence in mice. We anticipate that Mobile-CRISPRi will be a valuable tool to probe the function of CE genes across many bacterial species and pathogenesis models.IMPORTANCE Antibiotic resistance is a growing threat to global health. To optimize the use of our existing antibiotics and identify new targets for future inhibitors, understanding the fundamental drivers of bacterial growth in the context of the host immune response is paramount. Historically, these genetic drivers have been difficult to manipulate precisely, as they are requisite for pathogen survival. Here, we provide the first application of Mobile-CRISPRi to study conditionally essential virulence genes in mouse models of lung infection through partial gene perturbation. We envision the use of Mobile-CRISPRi in future pathogenesis models and antibiotic target discovery efforts.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes/métodos , Pneumonia Bacteriana/microbiologia , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/patogenicidade , Animais , Proteína 9 Associada à CRISPR , Técnicas de Silenciamento de Genes , Genes Bacterianos , Immunoblotting , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pneumonia Bacteriana/metabolismo , Infecções por Pseudomonas/metabolismo , Pseudomonas aeruginosa/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sistemas de Secreção Tipo III/genética
7.
Cancer Cell Int ; 19: 80, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30983885

RESUMO

BACKGROUND: Invasion and metastasis are determinant events in the prognosis of Colorectal cancer (CRC), a common neoplasm worldwide. An important factor for metastasis is the acquired capacity of the cell to proliferate and invade adjacent tissues. In this paper, we explored the role of micro-RNA-26a in the regulation of proliferation and migration in CRC-derived cells through the negative regulation of PTEN, a key negative regulator of the AKT pathway. METHODS: Expression levels of PTEN and mir-26a were surveyed in normal and CRC-derived cell lines; paraffin embedded human tissues, TCGA CRC expression data and a Balb/c mice orthotopic induced CRC model. CRC was induced by an initial intraperitoneal dose of the colonic carcinogen Azoxymethane followed by inflammatory promoter Dextran Sulfate Sodium Salt. Luciferase assays provide information about miR-26a-PTEN 3'UTR interaction. Proliferation and migration by real time cell analysis and wound-healing functional analyses were performed to assess the participation of mir-26a on important hallmarks of CRC and its regulation on the PTEN gene. RESULTS: We observed a negative correlation between PTEN and mir-26a expression in cell lines, human tissues, TCGA data, and tissues derived from the CRC mouse model. Moreover, we showed that negative regulation of PTEN exerted by miR-26a affected AKT phosphorylation levels directly. Functional assays showed that mir-26a directly down-regulates PTEN, and that mir-26a over-expressing cells had higher proliferation and migration rates. CONCLUSIONS: All this data proposes an important role of mir-26a as an oncomir in the progression and invasion of CRC. Our data suggested that mir-26a could be used as a biomarker of tumor development in CRC patients, however more studies must be conducted to establish its clinical role.

8.
Blood ; 137(7): 994-999, 2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-32915956
9.
Tumour Biol ; 39(4): 1010428317695945, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28443472

RESUMO

MicroRNAs are non-coding short RNAs that target the 3' untranslated region of messenger RNAs (mRNAs) and lead to their degradation or to translational repression. Several microRNAs have been designated as oncomirs, owing to their regulating tumor suppressor genes. Interestingly, a few of them have been found to target multiple genes whose simultaneous suppression contributes to the development of a tumoral phenotype. Here, we have showed that miR-26a is overexpressed in colorectal cancer data obtained from TCGA Research Network and in human colon cancer pathological specimens; moreover, an orthotopic in vivo model of colon cancer showed overexpression of miR-26a, while Rb1 expression inversely correlated to miR-26a in TCGA Research Network data, pathological samples, and the in vivo model. Then, by means of luciferase assay, we demonstrated that miR-26a targets the 3' untranslated region of Rb1 mRNA directly. This is, to our knowledge, the first report of miR-26a targeting Rb1 in colon cancer. The results of this study suggested that miR-26a could serve as a progression biomarker in colorectal cancer. Further validation studies are still needed to confirm our findings.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias Colorretais/genética , MicroRNAs/genética , Proteínas de Ligação a Retinoblastoma/biossíntese , Ubiquitina-Proteína Ligases/biossíntese , Regiões 3' não Traduzidas , Animais , Sítios de Ligação , Biomarcadores Tumorais/biossíntese , Linhagem Celular Tumoral , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Humanos , Camundongos , MicroRNAs/biossíntese , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Proteínas de Ligação a Retinoblastoma/genética , Ubiquitina-Proteína Ligases/genética , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Tumour Biol ; 39(6): 1010428317711895, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28639897

RESUMO

Cervical cancer is one of the leading causes of death in women worldwide, which mainly affects developing countries. The patients who suffer a recurrence and/or progression disease have a higher risk of developing distal metastases. Proteases comprising the degradome given its ability to promote cell growth, migration, and invasion of tissues play an important role during tumor development and progression. In this study, we used high-density microarrays and quantitative reverse transcriptase polymerase chain reaction to evaluate the degradome profile and their inhibitors in 112 samples of patients diagnosed with locally advanced cervical cancer. Clinical follow-up was done during a period of 3 years. Using a correlation analysis between the response to treatment and the development of metastasis, we established a molecular signature comprising eight degradome-related genes (FAM111B, FAM111A, CFB, PSMB8, PSMB9, CASP7, PRSS16, and CD74) with the ability to discriminate patients at risk of distal metastases. In conclusion, present results show that molecular signature obtained from degradome genes can predict the possibility of metastasis in patients with locally advanced cervical cancer.


Assuntos
Invasividade Neoplásica/genética , Recidiva Local de Neoplasia/genética , Proteólise , Neoplasias do Colo do Útero/genética , Adulto , Idoso , Movimento Celular/genética , Proliferação de Células/genética , Intervalo Livre de Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Recidiva Local de Neoplasia/patologia , Neoplasias do Colo do Útero/patologia
11.
Molecules ; 22(9)2017 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-28878179

RESUMO

The triterpenes have been constituted as a group of interesting molecules as possible antitumor agents. Despite several of them not presenting a potent cytotoxic activity in vitro against cancer cells, in vivo in xenotransplant tumors studies, they show promising results. Based on the above considerations, we investigated the antitumor activity of both masticadienonic (MDA) and 3α-OH masticadienoic (3α-OH MDA) acids in a mouse prostate cancer xenograft model. Immunohistochemical assays were used to evaluate the decrease in the expression of the Proliferating Cell Nuclear Antigen (PCNA) and the Ki-67 induced by MDA and 3α-OH MDA. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to demonstrate the fragmentation of DNA. Our results showed that the two triterpenes inhibited tumor growth, had anti-proliferative effect in vivo and induced cell death by apoptosis. Collectively, our data suggested that the antitumor mechanism of MDA and 3α-OH MDA involves several molecular targets related to cell proliferation and apoptosis.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Próstata/tratamento farmacológico , Triterpenos/farmacologia , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Xenoenxertos , Humanos , Masculino , Camundongos , Camundongos Nus , Transplante de Neoplasias , Neoplasias da Próstata/patologia , Triterpenos/química
12.
Int J Cancer ; 139(2): 334-46, 2016 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-26954527

RESUMO

Ingested nitrate leads to the endogenous synthesis of N-nitroso compounds (NOCs), animal carcinogens with limited human evidence. We aimed to evaluate the risk of colorectal cancer (CRC) associated with nitrate exposure in drinking water and diet. A case-control study in Spain and Italy during 2008-2013 was conducted. Hospital-based incident cases and population-based (Spain) or hospital-based (Italy) controls were interviewed on residential history, water consumption since age 18, and dietary information. Long-term waterborne ingested nitrate was derived from routine monitoring records, linked to subjects' residential histories and water consumption habits. Dietary nitrate intake was estimated from food frequency questionnaires and published food composition databases. Odd ratios (OR) were calculated using mixed models with area as random effect, adjusted for CRC risk factors and other covariables. Generalized additive models (GAMs) were used to analyze exposure-response relationships. Interaction with endogenous nitrosation factors and other covariables was also evaluated. In total 1,869 cases and 3,530 controls were analyzed. Average waterborne ingested nitrate ranged from 3.4 to 19.7 mg/day, among areas. OR (95% CIs) of CRC was 1.49 (1.24, 1.78) for >10 versus ≤5 mg/day, overall. Associations were larger among men versus women, and among subjects with high red meat intake. GAMs showed increasing exposure-response relationship among men. Animal-derived dietary nitrate was associated with rectal, but not with colon cancer risk. In conclusion, a positive association between CRC risk and waterborne ingested nitrate is suggested, mainly among subgroups with other risk factors. Heterogeneous effects of nitrate from different sources (water, animal and vegetables) warrant further research.


Assuntos
Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/etiologia , Dieta , Água Potável , Nitratos/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Dieta/efeitos adversos , Água Potável/efeitos adversos , Exposição Ambiental/efeitos adversos , Feminino , Humanos , Incidência , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Vigilância da População , Risco , Espanha/epidemiologia , Adulto Jovem
13.
Gynecol Oncol ; 142(3): 557-65, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27423381

RESUMO

OBJECTIVE: Nearly 50% of patients who are diagnosed with locally advanced cervical cancer have an unfavorable pathological response to conventional treatment. MicroRNAs (miRNAs) are potential biomarkers in cervical cancer; however, their role in identifying patients who do not respond to conventional treatment remains poorly investigated. Here, we identify a set of miRNAs that can be used as molecular markers to predict the pathological response in locally advanced cervical cancer patients receiving radiation and chemotherapy treatment. METHODS: Forty-one patients diagnosed with locally advanced cervical cancer were invited to participate in this study and enrolled after they signed an informed consent. Two patient cohorts were randomized for miRNA expression profiling, a discovery cohort (n=10) and a validation cohort (n=31); profiling was performed by means of a miScript miRNA PCR Array. After a median clinical follow-up of 45months, statistical analysis was performed to identify miRNAs that could discriminate non-responders from complete pathological responders to conventional treatment. RESULTS: miRNA expression profiling identified 101 miRNAs that showed significant differences between non-responders and complete pathological responders (p<0.05). Seven differentially expressed miRNAs were selected, and their expression patterns were confirmed in the validation phase; thus, miR-31-3p, -3676, -125a-5p, -100-5p, -125b-5p, and -200a-5p and miR-342 were significantly associated with clinical response. Expression of this miRNA signature above the median level was a significant predictor of non-response to standard treatment (p<0.001). CONCLUSIONS: These seven validated miRNA signatures could be used as molecular biomarkers of chemo- and radio-resistance in locally advanced cervical cancer patients.


Assuntos
Biomarcadores Tumorais/genética , MicroRNAs/biossíntese , Neoplasias do Colo do Útero/genética , Adulto , Idoso , Biomarcadores Tumorais/biossíntese , Braquiterapia , Cisplatino/administração & dosagem , Intervalo Livre de Doença , Resistencia a Medicamentos Antineoplásicos , Feminino , Perfilação da Expressão Gênica , Humanos , MicroRNAs/genética , Pessoa de Meia-Idade , Distribuição Aleatória , Transdução de Sinais , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/radioterapia
14.
Pflugers Arch ; 467(1): 15-25, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24859800

RESUMO

Mechanosensitive channels are integral components for the response of bacteria to osmotic shock. The mechanosensitive channel of large conductance (MscL) responds to extreme turgor pressure increase that would otherwise lyse the cellular membrane. MscL has been studied as a model mechanosensitive channel using both structural and functional approaches. We will summarize the structural data and discuss outstanding questions surrounding the gating mechanism of this homo-oligomeric channel that has ~3 nS conductance. Specifically, we will explore the following: (1) the variability in oligomeric state that has been observed, (2) the open pore size measurements, and (3) the role of the C-terminal coiled coil domain for channel function. The oligomeric state of MscL has been characterized using various techniques, with a pentamer being the predominant form; however, the presence of mixtures of oligomers in the membrane is still uncertain. In the absence of structural data for the open state of MscL, the diameter of the open state pore has been estimated by several different approaches, leading to a current estimate between 25 and 30 Å. While the C-terminal domain is highly conserved among MscL homologues, it is not required for activity in vivo or in vitro. This domain is likely to remain intact during the gating transition and perform a filtering function that retains valuable osmolytes in the cytosol. Overall, studies of MscL have provided significant insight to the field, and serve as a paradigm for the analysis of non-homologous, eukaryotic mechanosensitive channel proteins.


Assuntos
Membrana Celular/química , Membrana Celular/fisiologia , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/fisiologia , Canais Iônicos/química , Canais Iônicos/fisiologia , Mecanotransdução Celular/fisiologia , Osmorregulação/fisiologia , Membrana Celular/ultraestrutura , Simulação por Computador , Proteínas de Escherichia coli/ultraestrutura , Ativação do Canal Iônico/fisiologia , Canais Iônicos/ultraestrutura , Fluidez de Membrana/fisiologia , Modelos Químicos , Modelos Moleculares , Porosidade , Relação Estrutura-Atividade
15.
Environ Res ; 137: 299-307, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25601732

RESUMO

BACKGROUND: Nitrate is a widespread contaminant in drinking water and ingested nitrate under conditions resulting in endogenous nitrosation is suspected to be carcinogenic. However, the suggested association between nitrate in drinking water and bladder cancer remains inconsistent. We evaluated the long-term exposure to drinking water nitrate as a risk factor for bladder cancer, considering endogenous nitrosation modifiers and other covariables. METHODS: We conducted a hospital-based case-control study of bladder cancer in Spain (1998-2001). Residential histories and water consumption information were ascertained through personal interviews. Historical nitrate levels (1940-2000) were estimated in study municipalities based on monitoring records and water source. Residential histories of study subjects were linked with nitrate estimates by year and municipality to calculate individual exposure from age 18 to recruitment. We calculated odds ratios (OR) and 95% confidence intervals (CI) for bladder cancer among 531 cases and 556 controls with reliable interviews and nitrate exposure information covering at least 70% of years from age 18 to interview. RESULTS: Average residential levels ranged from 2.1mg/L to 12.0mg/L among regions. Adjusted OR (95%CI) for average residential levels relative to ≤ 5 mg/L were 1.2 (0.7-2.0) for >5-10mg/L and 1.1 (0.6-1.9) for >10mg/L. The OR for subjects with longest exposure duration (>20 years) to highest levels (>9.5mg/L) was 1.4 (0.9-2.3). Stratification by intake of vitamin C, vitamin E, meat, and gastric ulcer diagnosis did not modify these results. A non-significant negative association was found with waterborne ingested nitrate with an OR of 0.7 (0.4-1.0) for >8 vs. ≤ 4 mg/day. Adjustment for several covariables showed similar results to crude analyses. CONCLUSION: Bladder cancer risk was inconsistently associated with chronic exposure to drinking water nitrate at levels below the current regulatory limit. Elevated risk is suggested only among subjects with longest exposure duration to the highest levels. No evidence of interaction with endogenous nitrosation modifiers was observed.


Assuntos
Carcinógenos/toxicidade , Água Potável/análise , Exposição Ambiental , Nitratos/toxicidade , Neoplasias da Bexiga Urinária/epidemiologia , Poluentes Químicos da Água/toxicidade , Adulto , Idoso , Animais , Estudos de Casos e Controles , Gatos , Monitoramento Ambiental , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Espanha/epidemiologia , Neoplasias da Bexiga Urinária/induzido quimicamente
16.
Molecules ; 19(5): 6263-81, 2014 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-24840898

RESUMO

Cervical carcinoma (CC) is one of the most common cancers and a leading cause of mortality in women worldwide. Epidemiologic and experimental data have clearly demonstrated a causal role of high-risk Human Papillomavirus (HR-HPV) types in CC initiation and progression, affecting the cellular processes by targeting and inactivating p53 and pRB host proteins. HR-HPV E5, E6 and E7 oncoproteins have the ability to deregulate several cellular processes, mostly apoptosis, cell cycle control, migration, immune evasion, and induction of genetic instability, which promote the accumulation of mutations and aneuploidy. In this scenario, genomic profiles have shown that aberrant expression of cellular oncogenic and tumor suppressive miRNAs have an important role in CC carcinogenesis. It has been stated that HPV infection and E6/E7 expression are essential but not sufficient to lead to CC development; hence other genetic and epigenetic factors have to be involved in this complex disease. Recent evidence suggests an important level of interaction among E6/E7 viral proteins and cellular miRNA, and other noncoding RNAs. The aim of the current review is to analyze recent data that mainly describe the interaction between HR-HPV established infections and specific cellular miRNAs; moreover, to understand how those interactions could affect radio-therapeutic response in tumor cells.


Assuntos
MicroRNAs/genética , Proteínas Oncogênicas Virais/genética , Papillomaviridae/metabolismo , Neoplasias do Colo do Útero/genética , Apoptose , Feminino , Humanos , Papillomaviridae/patogenicidade , Tolerância a Radiação/genética , Neoplasias do Colo do Útero/virologia
17.
Cancers (Basel) ; 16(3)2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38339324

RESUMO

Colorectal cancer (CRC) is the third most common neoplasia in the world. Its mortality rate is high due to the lack of specific and effective treatments, metastasis, and resistance to chemotherapy, among other factors. The natural products in cancer are a primary source of bioactive molecules. In this research, we evaluated the antitumor activity of an acetogenin (ACG), laherradurin (LH), isolated from the Mexican medicinal plant Annona macroprophyllata Donn.Sm. in a CRC murine model. The CRC was induced by azoxymethane-dextran sulfate sodium (AOM/DSS) in Balb/c mice and treated for 21 days with LH or cisplatin. This study shows for the first time the antitumor activity of LH in an AOM/DSS CRC model. The acetogenin diminished the number and size of tumors compared with cisplatin; the histologic studies revealed a recovery of the colon tissue, and the blood toxicity data pointed to less damage in animals treated with LH. The TUNEL assay indicated cell death by apoptosis, and the in vitro studies exhibited that LH inhibited cell migration in HCT116 cells. Our study provides strong evidence of a possible anticancer agent for CRC.

18.
Curr Oncol ; 31(4): 2145-2157, 2024 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-38668062

RESUMO

Non-small-cell lung cancer (NSCLC) has experienced several diagnostic and therapeutic changes over the past two decades. However, there are few studies conducted with real-world data regarding the evolution of the cost of these new drugs and the corresponding changes in the survival of these patients. We collected data on patients diagnosed with NSCLC from the tumor registry of the University Hospital of Vic from 2002 to 2021. We analyzed the epidemiological and pathological characteristics of these patients, the diverse oncological treatments administered, and the survival outcomes extending at least 18 months post-diagnosis. We also collected data on pharmacological costs, aligning them with the treatments received by each patient to determine the cost associated with individualized treatments. Our study included 905 patients diagnosed with NSCLC. We observed a dynamic shift in histopathological subtypes from squamous carcinoma in the initial years to adenocarcinoma. Regarding the treatment approach, the use of chemotherapy declined over time, replaced by immunotherapy, while molecular therapy showed relative stability. An increase in survival at 18 months after diagnosis was observed in patients with advanced stages over the most recent years of this study, along with the advent of immunotherapy. Mean treatment costs per patient ranged from EUR 1413.16 to EUR 22,029.87 and reached a peak of EUR 48,283.80 in 2017 after the advent of immunotherapy. This retrospective study, based on real-world data, documents the evolution of pathological characteristics, survival rates, and medical treatment costs for NSCLC over the last two decades. After the introduction of immunotherapy, patients in advanced stages showed an improvement in survival at 18 months, coupled with an increase in treatment costs.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Espanha , Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Estadiamento de Neoplasias , Custos de Cuidados de Saúde
19.
Cells ; 13(11)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38891028

RESUMO

Cervical cancer (CC) remains among the most frequent cancers worldwide despite advances in screening and the development of vaccines against human papillomavirus (HPV), involved in virtually all cases of CC. In mid-income countries, a substantial proportion of the cases are diagnosed in advanced stages, and around 40% of them are diagnosed in women under 49 years, just below the global median age. This suggests that members of this age group share common risk factors, such as chronic inflammation. In this work, we studied samples from 46 patients below 45 years old, searching for a miRNA profile regulating cancer pathways. We found 615 differentially expressed miRNAs between tumor samples and healthy tissues. Through bioinformatic analysis, we found that several of them targeted elements of the JAK/STAT pathway and other inflammation-related pathways. We validated the interactions of miR-30a and miR-34c with JAK1 and STAT3, respectively, through dual-luciferase and expression assays in cervical carcinoma-derived cell lines. Finally, through knockdown experiments, we observed that these miRNAs decreased viability and promoted proliferation in HeLa cells. This work contributes to understanding the mechanisms through which HPV regulates inflammation, in addition to its canonical oncogenic function, and brings attention to the JAK/STAT signaling pathway as a possible diagnostic marker for CC patients younger than 45 years. To our knowledge to date, there has been no previous description of a panel of miRNAs or even ncRNAs in young women with locally advanced cervical cancer.


Assuntos
Regulação Neoplásica da Expressão Gênica , Inflamação , MicroRNAs , Fator de Transcrição STAT3 , Transdução de Sinais , Neoplasias do Colo do Útero , Humanos , Feminino , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , MicroRNAs/genética , MicroRNAs/metabolismo , Transdução de Sinais/genética , Adulto , Inflamação/genética , Inflamação/patologia , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT3/genética , Células HeLa , Janus Quinase 1/metabolismo , Janus Quinase 1/genética , Proliferação de Células/genética , Linhagem Celular Tumoral , Pessoa de Meia-Idade
20.
J Am Chem Soc ; 135(30): 11151-8, 2013 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-23859602

RESUMO

We have designed ruthenium-modified Pseudomonas aeruginosa azurins that incorporate 3-nitrotyrosine (NO2YOH) between Ru(2,2'-bipyridine)2(imidazole)(histidine) and Cu redox centers in electron transfer (ET) pathways. We investigated the structures and reactivities of three different systems: RuH107NO2YOH109, RuH124NO2YOH122, and RuH126NO2YOH122. RuH107NO2YOH109, unlabeled H124NO2YOH122, and unlabeled H126NO2YOH122 were structurally characterized. The pKa's of NO2YOH at positions 122 and 109 are 7.2 and 6.0, respectively. Reduction potentials of 3-nitrotyrosinate (NO2YO(-))-modified azurins were estimated from cyclic and differential pulse voltammetry data: oxidation of NO2YO(-)122 occurs near 1.1 versus NHE; oxidation of NO2YO(-)109 is near 1.2 V. Our analysis of transient optical spectroscopic experiments indicates that hopping via NO2YO(-) enhances Cu(I) oxidation rates over single-step ET by factors of 32 (RuH107NO2YO(-)109), 46 (RuH126NO2YO(-)122), and 13 (RuH124NO2YO(-)122).


Assuntos
Azurina/química , Pseudomonas aeruginosa , Tirosina/análogos & derivados , Azurina/metabolismo , Cobre/química , Transporte de Elétrons , Modelos Moleculares , Compostos Organometálicos/química , Conformação Proteica , Tirosina/química , Tirosina/metabolismo
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