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1.
Int J Nanomedicine ; 19: 5381-5395, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38859950

RESUMO

Background: Current immunotherapies with unexpected severe side effects and treatment resistance have not resulted in the desired outcomes for patients with melanoma, and there is a need to discover more effective medications. Cytotoxin (CTX) from Cobra Venom has been established to have favorable cytolytic activity and antitumor efficacy and is regarded as a promising novel anticancer agent. However, amphiphilic CTX with excellent anionic phosphatidylserine lipid-binding ability may also damage normal cells. Methods: We developed pH-responsive liposomes with a high CTX load (CTX@PSL) for targeted acidic-stimuli release of drugs in the tumor microenvironment. The morphology, size, zeta potential, drug-release kinetics, and preservation stability were characterized. Cell uptake, apoptosis-promoting effects, and cytotoxicity were assessed using MTT assay and flow cytometry. Finally, the tissue distribution and antitumor effects of CTX@PSL were systematically assessed using an in vivo imaging system. Results: CTX@PSL exhibited high drug entrapment efficiency, drug loading, stability, and a rapid release profile under acidic conditions. These nanoparticles, irregularly spherical in shape and small in size, can effectively accumulate at tumor sites (six times higher than free CTX) and are rapidly internalized into cancer cells (2.5-fold higher cell uptake efficiency). CTX@PSL displayed significantly stronger cytotoxicity (IC50 0.25 µg/mL) and increased apoptosis in than the other formulations (apoptosis rate 71.78±1.70%). CTX@PSL showed considerably better tumor inhibition efficacy than free CTX or conventional liposomes (tumor inhibition rate 79.78±5.93%). Conclusion: Our results suggest that CTX@PSL improves tumor-site accumulation and intracellular uptake for sustained and targeted CTX release. By combining the advantages of CTX and stimuli-responsive nanotechnology, the novel CTX@PSL nanoformulation is a promising therapeutic candidate for cancer treatment.


Assuntos
Antineoplásicos , Venenos Elapídicos , Lipossomos , Lipossomos/química , Concentração de Íons de Hidrogênio , Animais , Venenos Elapídicos/química , Venenos Elapídicos/farmacologia , Humanos , Linhagem Celular Tumoral , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/farmacocinética , Camundongos , Apoptose/efeitos dos fármacos , Liberação Controlada de Fármacos , Citotoxinas/química , Citotoxinas/farmacologia , Citotoxinas/farmacocinética , Sistemas de Liberação de Medicamentos/métodos , Distribuição Tecidual , Microambiente Tumoral/efeitos dos fármacos , Nanopartículas/química
2.
Nat Commun ; 15(1): 5028, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38866748

RESUMO

Cholesterol-dependent cytolysins (CDCs) comprise a large family of pore-forming toxins produced by Gram-positive bacteria, which are used to attack eukaryotic cells. Here, we functionally characterize a family of 2-component CDC-like (CDCL) toxins produced by the Gram-negative Bacteroidota that form pores by a mechanism only described for the mammalian complement membrane attack complex (MAC). We further show that the Bacteroides CDCLs are not eukaryotic cell toxins like the CDCs, but instead bind to and are proteolytically activated on the surface of closely related species, resulting in pore formation and cell death. The CDCL-producing Bacteroides is protected from the effects of its own CDCL by the presence of a surface lipoprotein that blocks CDCL pore formation. These studies suggest a prevalent mode of bacterial antagonism by a family of two-component CDCLs that function like mammalian MAC and that are wide-spread in the gut microbiota of diverse human populations.


Assuntos
Complexo de Ataque à Membrana do Sistema Complemento , Humanos , Complexo de Ataque à Membrana do Sistema Complemento/metabolismo , Bacteroides/genética , Bacteroides/metabolismo , Toxinas Bacterianas/metabolismo , Toxinas Bacterianas/genética , Citotoxinas/metabolismo , Microbioma Gastrointestinal , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas do Sistema Complemento/metabolismo , Proteínas do Sistema Complemento/imunologia , Animais , Células Eucarióticas/metabolismo
3.
Vitae (Medellín) ; 31(1): 1-6, 2024-05-03. Ilustraciones
Artigo em Inglês | LILACS, COLNAL | ID: biblio-1538068

RESUMO

Background: Moringa peregrina Forssk is a well-known plant in ethnomedicine due to its widespread uses in various diseases like cough, wound healing, rhinitis, fever, and detoxification. The plant seeds contain compounds that are cytotoxic to many cancer cells. During the therapeutic use of plants via the oral route, some compounds present in the plants may be cytotoxic to normal cell lines and red blood cells. Objective: This study was the first report of investigation of the cytotoxic profile on oral cancer, CAL 27, cell line, and hemolytic activities on human erythrocytes of Moringa peregrina seeds ethanolic extract (MPSE). Methods: MPSE was screened for its cytotoxic effect against oral cancer, CAL 27, cell line using 3-(4, 5-dimethylthiazol-2-yl)-2, 5,-diphenyltetrazolium bromide (MTT) assay. The toxicity of MPSE on human erythrocytes was determined by in vitro hemolytic assay. Results: MPSE showed significant anti-proliferative activity against oral cancer, CAL 27 cell line at lower concentrations with half maximal inhibitory concentration (IC50) value of 21.03 µg/mL. At 1,000 µg/ml of MPSE, the maximum hemolysis was found to be 14.3% which is within safer limit. Conclusions: This study revealed a potential anti-oral cancer of MPSE and provided a baseline for its potential use in oral cancer treatment with minimum hemolytic effect on human RBCs.


La Moringa peregrina Forssk es una planta muy conocida en etnomedicina debido a sus usos generalizados en diversas enfermedades como la tos, la cicatrización de heridas, la rinitis, la fiebre y la desintoxicación. Las semillas de la planta contienen compuestos citotóxicos para muchas células cancerosas. Durante el uso terapéutico de las plantas por vía oral, algunos compuestos presentes en ellas pueden ser citotóxicos para las líneas celulares normales y los glóbulos rojos. Objetivo: Este estudio fue el primer informe de investigación del perfil citotóxico sobre el cáncer oral, CAL 27, línea celular, y las actividades hemolíticas en eritrocitos humanos del extracto etanólico de semillas de Moringa peregrina (MPSE). Métodos: Se examinó el efecto citotóxico del MPSE contra la línea celular de cáncer oral CAL 27 mediante el ensayo con bromuro de 3-(4, 5-dimetiltiazol-2-il)-2, 5,-difeniltetrazolio (MTT). La toxicidad del MPSE sobre los eritrocitos humanos se determinó mediante un ensayo hemolítico in vitro. Resultados: MPSE mostró una actividad antiproliferativa significativa contra el cáncer oral, línea celular CAL 27 a concentraciones más bajas con un valor de concentración inhibitoria media máxima (IC50) de 21,03 µg/mL. A 1.000 µg/ml de MPSE, la hemólisis máxima fue del 14,3%, lo que está dentro del límite de seguridad. Conclusiones: Este estudio reveló un potencial anticancerígeno oral de MPSE y proporcionó una base para su uso potencial en el tratamiento del cáncer oral con un efecto hemolítico mínimo en los glóbulos rojos humanos.


Assuntos
Humanos , Moringa , Neoplasias Bucais , Citotoxinas , Eritrócitos , Medicina Tradicional
4.
Commun Biol ; 7(1): 655, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38806706

RESUMO

The gut microbiota influences human health and the development of chronic diseases. However, our understanding of potentially protective or harmful microbe-host interactions at the molecular level is still in its infancy. To gain further insights into the hidden gut metabolome and its impact, we identified a cryptic non-ribosomal peptide BGC in the genome of Bacillus cereus DSM 28590 from the mouse intestine ( www.dsmz.de/miBC ), which was predicted to encode a thiazol(in)e substructure. Cloning and heterologous expression of this BGC revealed that it produces bacillamide D. In-depth functional evaluation showed potent cytotoxicity and inhibition of cell migration using the human cell lines HCT116 and HEK293, which was validated using primary mouse organoids. This work establishes the bacillamides as selective cytotoxins from a bacterial gut isolate that affect mammalian cells. Our targeted structure-function-predictive approach is demonstrated to be a streamlined method to discover deleterious gut microbial metabolites with potential effects on human health.


Assuntos
Bacillus cereus , Microbioma Gastrointestinal , Bacillus cereus/metabolismo , Bacillus cereus/genética , Animais , Camundongos , Humanos , Células HEK293 , Citotoxinas/metabolismo , Citotoxinas/genética , Células HCT116 , Intestinos/microbiologia , Movimento Celular , Organoides/metabolismo
5.
Int J Nanomedicine ; 19: 4163-4180, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38751660

RESUMO

Purpose: The study aimed to address the non-specific toxicity of cytotoxins (CTX) in liver cancer treatment and explore their combined application with the photosensitizer Ce6, co-loaded into carbonized Zn/Co bimetallic organic frameworks. The goal was to achieve controlled CTX release and synergistic photodynamic therapy, with a focus on evaluating anti-tumor activity against human liver cancer cell lines (Hep G2). Methods: Purified cobra cytotoxin (CTX) and photosensitizer Ce6 were co-loaded into carbonized Zn/Co bimetallic organic frameworks, resulting in RGD-PDA@C-ZIF@(CTX+Ce6). The formulation was designed with surface-functionalization using polydopamine and tumor-penetrating peptide RGD. This approach aimed to facilitate controlled CTX release and enhance the synergistic effect of photodynamic therapy. The accumulation of RGD-PDA@C-ZIF@(CTX+Ce6) at tumor sites was achieved through RGD's active targeting and the enhanced permeability and retention (EPR) effect. In the acidic tumor microenvironment, the porous structure of the metal-organic framework disintegrated, releasing CTX and Ce6 into tumor cells. Results: Experiments demonstrated that RGD-PDA@C-ZIF@(CTX+Ce6) nanoparticles, combined with near-infrared laser irradiation, exhibited optimal anti-tumor effects against human liver cancer cells. The formulation showcased heightened anti-tumor activity without discernible systemic toxicity. Conclusion: The study underscores the potential of utilizing metal-organic frameworks as an efficient nanoplatform for co-loading cytotoxins and photodynamic therapy in liver cancer treatment. The developed formulation, RGD-PDA@C-ZIF@(CTX+Ce6), offers a promising avenue for advancing the clinical application of cytotoxins in oncology, providing a solid theoretical foundation for future research and development.


Assuntos
Indóis , Neoplasias Hepáticas , Estruturas Metalorgânicas , Fotoquimioterapia , Fármacos Fotossensibilizantes , Zinco , Humanos , Fotoquimioterapia/métodos , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Zinco/química , Zinco/farmacologia , Indóis/química , Indóis/farmacologia , Indóis/administração & dosagem , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/administração & dosagem , Animais , Células Hep G2 , Cobalto/química , Cobalto/farmacologia , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Oligopeptídeos/farmacocinética , Polímeros/química , Camundongos , Citotoxinas/química , Citotoxinas/farmacologia , Citotoxinas/farmacocinética , Camundongos Nus , Camundongos Endogâmicos BALB C , Sobrevivência Celular/efeitos dos fármacos
6.
Sci Rep ; 14(1): 10561, 2024 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719884

RESUMO

This study focuses on understanding the structural and molecular changes in lipid membranes under the influence of six halogenated flavonoid derivatives differing in the number and position of substitution of chlorine and bromine atoms (D1-D6). Utilizing various analytical techniques, including fluorometric methods, dynamic light scattering (DLS), attenuated Fourier transform infrared spectroscopy (ATR- FTIR), and FT-Raman spectroscopy, the research aims to elucidate the mechanisms underlying the interaction of flavonoids with cell membranes. Additionally, the study includes in silico analyses to explore the physicochemical properties of these compounds and their potential pharmaceutical applications, along with toxicity studies to assess their effects on cancer, normal, and red blood cells. Our study showed the ability of halogenated derivatives to interact mostly with the outer part of the membrane, especially in the lipid heads region however, some of them were able to penetrate deeper into the membrane and affect the fluidity of hydrocarbon chains. The potential to reduce cancer cell viability, the lack of toxicity towards erythrocytes, and the favourable physicochemical and pharmacokinetic properties suggest these halogenated flavonoids potential candidates for exploring their potential for medical use.


Assuntos
Flavonoides , Lipídeos de Membrana , Flavonoides/química , Flavonoides/farmacologia , Flavonoides/metabolismo , Humanos , Lipídeos de Membrana/metabolismo , Lipídeos de Membrana/química , Membrana Celular/metabolismo , Halogenação , Citotoxinas/química , Citotoxinas/farmacologia , Citotoxinas/metabolismo , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Análise Espectral Raman , Espectroscopia de Infravermelho com Transformada de Fourier , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/metabolismo , Linhagem Celular Tumoral
7.
mSystems ; 9(4): e0020624, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38514462

RESUMO

Helicobacter pylori is a highly successful pathogen that poses a substantial threat to human health. However, the dynamic interaction between H. pylori and the human gastric epithelium has not been fully investigated. In this study, using dual RNA sequencing technology, we characterized a cytotoxin-associated gene A (cagA)-modulated bacterial adaption strategy by enhancing the expression of ATP-binding cassette transporter-related genes, metQ and HP_0888, upon coculturing with human gastric epithelial cells. We observed a general repression of electron transport-associated genes by cagA, leading to the activation of oxidative phosphorylation. Temporal profiling of host mRNA signatures revealed the downregulation of multiple splicing regulators due to bacterial infection, resulting in aberrant pre-mRNA splicing of functional genes involved in the cell cycle process in response to H. pylori infection. Moreover, we demonstrated a protective effect of gastric H. pylori colonization against chronic dextran sulfate sodium (DSS)-induced colitis. Mechanistically, we identified a cluster of propionic and butyric acid-producing bacteria, Muribaculaceae, selectively enriched in the colons of H. pylori-pre-colonized mice, which may contribute to the restoration of intestinal barrier function damaged by DSS treatment. Collectively, this study presents the first dual-transcriptome analysis of H. pylori during its dynamic interaction with gastric epithelial cells and provides new insights into strategies through which H. pylori promotes infection and pathogenesis in the human gastric epithelium. IMPORTANCE: Simultaneous profiling of the dynamic interaction between Helicobacter pylori and the human gastric epithelium represents a novel strategy for identifying regulatory responses that drive pathogenesis. This study presents the first dual-transcriptome analysis of H. pylori when cocultured with gastric epithelial cells, revealing a bacterial adaptation strategy and a general repression of electron transportation-associated genes, both of which were modulated by cytotoxin-associated gene A (cagA). Temporal profiling of host mRNA signatures dissected the aberrant pre-mRNA splicing of functional genes involved in the cell cycle process in response to H. pylori infection. We demonstrated a protective effect of gastric H. pylori colonization against chronic DSS-induced colitis through both in vitro and in vivo experiments. These findings significantly enhance our understanding of how H. pylori promotes infection and pathogenesis in the human gastric epithelium and provide evidence to identify targets for antimicrobial therapies.


Assuntos
Colite , Helicobacter pylori , Animais , Humanos , Camundongos , Proteínas de Bactérias/genética , Antígenos de Bactérias/genética , Helicobacter pylori/genética , Transcriptoma/genética , Precursores de RNA/metabolismo , Interações Hospedeiro-Patógeno/genética , Análise de Sequência de RNA , RNA Mensageiro/metabolismo , Citotoxinas/metabolismo
8.
Genes (Basel) ; 15(3)2024 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-38540398

RESUMO

Helicobacter pylori (H. pylori) is associated with gastric inflammation and mucosal antibodies against its cytotoxin-associated gene A (CagA) are protective. Vaccine-elicited immunity against H. pylori requires MHC class II expression, indicating that CD4+ T cells are protective. We hypothesized that the HLA-DR genotypes in human populations include protective alleles that more effectively bind immunogenic CagA peptide fragments and susceptible alleles with an impaired capacity to present CagA peptides. We recruited patients (n = 170) admitted for gastroendoscopy procedures and performed high-resolution HLA-DRB1 typing. Serum anti-CagA IgA levels were analyzed by ELISA (23.2% positive) and H. pylori classified as positive or negative in gastric mucosal tissue slides (72.9% positive). Pearson Chi-square analysis revealed that H. pylori infection was significantly increased in DRB1*11:04-positive individuals (p = 0.027). Anti-CagA IgA was significantly decreased in DRB1*11:04 positive individuals (p = 0.041). In contrast, anti-CagA IgA was significantly increased in DRB1*03:01 positive individuals (p = 0.030). For these HLA-DRB1 alleles of interest, we utilized two in silico prediction methods to compare their capacity to present CagA peptides. Both methods predicted increased numbers of peptides for DRB1*03:01 than DRB1*11:04. In addition, both alleles preferred distinctively different CagA 15mer peptide sequences for high affinity binding. These observations suggest that DRB1*11:04 is a susceptible genotype with impaired CagA immunity, whereas DRB1*03:01 is a protective genotype that promotes enhanced CagA immunity.


Assuntos
Gastrite , Helicobacter pylori , Humanos , Helicobacter pylori/genética , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Cadeias HLA-DRB1/genética , Citotoxinas , Gastrite/genética , Genótipo , Peptídeos/genética , Imunoglobulina A/genética
9.
Curr Opin Infect Dis ; 37(3): 164-169, 2024 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-38527455

RESUMO

PURPOSE OF REVIEW: Many cholesterol-dependent cytolysin (CDC)-producing pathogens pose a significant threat to human health. Herein, we review the pore-dependent and -independent properties CDCs possess to assist pathogens in evading the host immune response. RECENT FINDINGS: Within the last 5 years, exciting new research suggests CDCs can act to inhibit important immune functions, disrupt critical cell signaling pathways, and have tissue-specific effects. Additionally, recent studies have identified a key region of CDCs that generates robust immunity, providing resources for the development of CDC-based vaccines. SUMMARY: This review provides new information on how CDCs alter host immune responses to aid bacteria in pathogenesis. These studies can assist in the design of more efficient vaccines and therapeutics against CDCs that will enhance the immune response to CDC-producing pathogens while mitigating the dampening effects CDCs have on the host immune response.


Assuntos
Colesterol , Citotoxinas , Humanos , Colesterol/metabolismo , Citotoxinas/imunologia , Interações Hospedeiro-Patógeno/imunologia , Bactérias/imunologia , Evasão da Resposta Imune/imunologia
10.
PLoS One ; 19(2): e0298816, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38394060

RESUMO

BACKGROUND: Bacterial pneumonia and sepsis are both common causes of end-organ dysfunction, especially in immunocompromised and critically ill patients. Pre-clinical data demonstrate that bacterial pneumonia and sepsis elicit the production of cytotoxic tau and amyloids from pulmonary endothelial cells, which cause lung and brain injury in naïve animal subjects, independent of the primary infection. The contribution of infection-elicited cytotoxic tau and amyloids to end-organ dysfunction has not been examined in the clinical setting. We hypothesized that cytotoxic tau and amyloids are present in the bronchoalveolar lavage fluid of critically ill patients with bacterial pneumonia and that these tau/amyloids are associated with end-organ dysfunction. METHODS: Bacterial culture-positive and culture-negative mechanically ventilated patients were recruited into a prospective, exploratory observational study. Levels of tau and Aß42 in, and cytotoxicity of, the bronchoalveolar lavage fluid were measured. Cytotoxic tau and amyloid concentrations were examined in comparison with patient clinical characteristics, including measures of end-organ dysfunction. RESULTS: Tau and Aß42 were increased in culture-positive patients (n = 49) compared to culture-negative patients (n = 50), independent of the causative bacterial organism. The mean age of patients was 52.1 ± 16.72 years old in the culture-positive group and 52.78 ± 18.18 years old in the culture-negative group. Males comprised 65.3% of the culture-positive group and 56% of the culture-negative group. Caucasian culture-positive patients had increased tau, boiled tau, and Aß42 compared to both Caucasian and minority culture-negative patients. The increase in cytotoxins was most evident in males of all ages, and their presence was associated with end-organ dysfunction. CONCLUSIONS: Bacterial infection promotes the generation of cytotoxic tau and Aß42 within the lung, and these cytotoxins contribute to end-organ dysfunction among critically ill patients. This work illuminates an unappreciated mechanism of injury in critical illness.


Assuntos
Pneumonia Bacteriana , Sepse , Masculino , Animais , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Feminino , Estudos Prospectivos , Estado Terminal , Células Endoteliais , Insuficiência de Múltiplos Órgãos , Irrigação Terapêutica , Líquido da Lavagem Broncoalveolar/microbiologia , Pneumonia Bacteriana/microbiologia , Amiloide , Citotoxinas , Peptídeos beta-Amiloides , Proteínas tau
11.
Eur J Med Chem ; 268: 116233, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38408390

RESUMO

Antibody-drug conjugates (ADCs) have arisen as a promising class of biotherapeutics for targeted cancer treatment, combining the specificity of monoclonal antibodies with the cytotoxicity of small-molecule drugs. The choice of an appropriate payload is crucial for the success development of ADCs, as it determines the therapeutic efficacy and safety profile. This review focuses on payloads derived from natural products, including cytotoxic agents, DNA-damaging agents, and immunomodulators. These offer several advantages such as diverse chemical structures, unique mechanism of actions, and potential for improved therapeutic index. Challenges and opportunities associated with their development were highlighted. This review underscores the significance of natural product payloads in the elaboration of ADCs, which serves as a valuable resource for researchers involved in developing and optimizing next-generation ADCs for cancer treatment.


Assuntos
Antineoplásicos , Produtos Biológicos , Imunoconjugados , Neoplasias , Humanos , Imunoconjugados/farmacologia , Imunoconjugados/uso terapêutico , Imunoconjugados/química , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Antineoplásicos/química , Produtos Biológicos/química , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais/química , Citotoxinas/uso terapêutico , Neoplasias/tratamento farmacológico
12.
J Cell Biochem ; 125(3): e30527, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38332574

RESUMO

The presence of Helicobacter pylori (H. pylori) infection poses a substantial risk for the development of gastric adenocarcinoma. The primary mechanism through which H. pylori exerts its bacterial virulence is the cytotoxin CagA. This cytotoxin has the potential to induce inter-epithelial mesenchymal transition, proliferation, metastasis, and the acquisition of stem cell-like properties in gastric cancer (GC) cells infected with CagA-positive H. pylori. Cancer stem cells (CSCs) represent a distinct population of cells capable of self-renewal and generating heterogeneous tumor cells. Despite evidence showing that CagA can induce CSCs-like characteristics in GC cells, the precise mechanism through which CagA triggers the development of GC stem cells (GCSCs) remains uncertain. This study reveals that CagA-positive GC cells infected with H. pylori exhibit CSCs-like properties, such as heightened expression of CD44, a specific surface marker for CSCs, and increased ability to form tumor spheroids. Furthermore, we have observed that H. pylori activates the PI3K/Akt signaling pathway in a CagA-dependent manner, and our findings suggest that this activation is associated with the CSCs-like characteristics induced by H. pylori. The cytotoxin CagA, which is released during H. pylori infection, triggers the activation of the PI3K/Akt signaling pathway in a CagA-dependent manner. Additionally, CagA inhibits the transcription of FOXO3a and relocates it from the nucleus to the cytoplasm by activating the PI3K/Akt pathway. Furthermore, the regulatory function of the Akt/FOXO3a axis in the transformation of GC cells into a stemness state was successfully demonstrated.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Humanos , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Citotoxinas/metabolismo , Mucosa Gástrica/metabolismo , Infecções por Helicobacter/patologia , Células-Tronco Neoplásicas/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Neoplasias Gástricas/metabolismo
13.
Biochem Pharmacol ; 222: 116059, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38364984

RESUMO

Isatin derivatives have attracted a lot of interest for their potential in the development of new anticancer drugs. A library of 38 isatin derivatives, created through an Ugi four-component reaction, underwent an initial screening in a panel of six human solid tumor cell lines. The four most active derivatives were then selected for further testing. These compounds showed selectivity towards the non-small cell lung cancer (NSCLC) cell line SW1573, whilst NSCLC A549 cells were barely affected. The combination of phenotypic assays, including wound healing, clonogenic and continuous live cell imaging provided a deeper understanding of the compounds' mode of action. In particular, the latter demonstrated that isatin derivatives were able to induce necroptosis in SW1573 cells. The kinetics of cell death showed that necroptosis appeared after 2.5 h of exposure, which could be delayed to 7 h when co-treated with necrostatin-1. Interaction between the isatin derivatives and the KRAS G12C protein variant was discarded after in silico studies. Further studies are warranted to identify the cellular target responsible for the observed selectivity among cell lines.


Assuntos
Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Isatina , Neoplasias Pulmonares , Humanos , Citotoxinas , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Isatina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Relação Estrutura-Atividade , Proliferação de Células , Estrutura Molecular
14.
Exp Mol Med ; 56(2): 441-452, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38383581

RESUMO

Helicobacter pylori, particularly cytotoxin-associated gene A (CagA)-positive strains, plays a key role in the progression of gastric cancer (GC). Ferroptosis, associated with lethal lipid peroxidation, has emerged to play an important role in malignant and infectious diseases, but the role of CagA in ferroptosis in cancer cells has not been determined. Here, we report that CagA confers GC cells sensitivity to ferroptosis both in vitro and in vivo. Mechanistically, CagA promotes the synthesis of polyunsaturated ether phospholipids (PUFA-ePLs), which is mediated by increased expression of alkylglycerone phosphate synthase (AGPS) and 1-acylglycerol-3-phosphate O-acyltransferase 3 (AGPAT3), leading to susceptibility to ferroptosis. This susceptibility is mediated by activation of the MEK/ERK/SRF pathway. SRF is a crucial transcription factor that increases AGPS transcription by binding to the AGPS promoter region. Moreover, the results demonstrated that CagA-positive cells are more sensitive to apatinib than are CagA-negative cells, suggesting that detecting the H. pylori CagA status may aid patient stratification for treatment with apatinib.


Assuntos
Ferroptose , Helicobacter pylori , Neoplasias Gástricas , Humanos , Citotoxinas , Éteres Fosfolipídicos
15.
Food Chem ; 442: 138423, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38241994

RESUMO

The aim of this study was to determine the chemical structure and biological activity of melanoidin fractions derived from cocoa beans, carob kibbles, and acorns roasted at different temperature-time conditions. The results showed that plant origin and roasting conditions had significant effects on the chemical composition, structural features, and morphology of melanoidins. All tested melanoidins exhibited significant antioxidant properties in three in vitro assays. In addition, they show significant in vitro anti-inflammatory activity by reducing lipoxygenase. The results from MTT assay showed that the all studied melanoidins had a cytotoxic effect against SW-480 cells in a dose- and time-dependent manner. Furthermore, the most pronounced activity was observed for acorn melanoidins. This is a unique finding, as the specific cytotoxic effect has not been reported for cocoa, carob and acorn melanoidins, and opens up a great opportunity to develop a potential novel cytotoxic agent against deadly colon cancer in the future.


Assuntos
Citotoxinas , Galactanos , Temperatura Alta , Mananas , Gomas Vegetais , Polímeros
16.
PLoS Biol ; 22(1): e3002451, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38180978

RESUMO

Lipoproteins of the opportunistic pathogen Staphylococcus aureus play a crucial role in various cellular processes and host interactions. Consisting of a protein and a lipid moiety, they support nutrient acquisition and anchor the protein to the bacterial membrane. Recently, we identified several processed and secreted small linear peptides that derive from the secretion signal sequence of S. aureus lipoproteins. Here, we show, for the first time, that the protein moiety of the S. aureus lipoprotein CamS has a biological role that is distinct from its associated linear peptide staph-cAM373. The small peptide was shown to be involved in interspecies horizontal gene transfer, the primary mechanism for the dissemination of antibiotic resistance among bacteria. We provide evidence that the CamS protein moiety is a potent repressor of cytotoxins, such as α-toxin and leukocidins. The CamS-mediated suppression of toxin transcription was reflected by altered disease severity in in vivo infection models involving skin and soft tissue, as well as bloodstream infections. Collectively, we have uncovered the role of the protein moiety of the staphylococcal lipoprotein CamS as a previously uncharacterized repressor of S. aureus toxin production, which consequently regulates virulence and disease outcomes. Notably, the camS gene is conserved in S. aureus, and we also demonstrated the muted transcriptional response of cytotoxins in 2 different S. aureus lineages. Our findings provide the first evidence of distinct biological functions of the protein moiety and its associated linear peptide for a specific lipoprotein. Therefore, lipoproteins in S. aureus consist of 3 functional components: a lipid moiety, a protein moiety, and a small linear peptide, with putative different biological roles that might not only determine the outcome of host-pathogen interactions but also drive the acquisition of antibiotic resistance determinants.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Humanos , Staphylococcus aureus/genética , Lipoproteínas/genética , Interações Hospedeiro-Patógeno , Moléculas de Adesão Celular , Citotoxinas , Peptídeos
17.
J Pharm Biomed Anal ; 240: 115964, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38219442

RESUMO

Approximately 25% of breast cancer patients with HER2 overexpression tend to have a high risk of disease progression and death. Various HER2-targeting therapies have been approved for treatment. Recently, a novel antibody-drug conjugate, SHR-A1201, is being researched and developed. For the pharmacokinetic study of SHR-A1201, suitable bioanalytical methods are needed for quantifying unconjugated cytotoxin, cytotoxin-conjugated antibodies and total antibodies. In this research, bioanalytical methods involving a highly sensitive LC-MS/MS assay for unconjugated cytotoxic payload DM1 in human plasma, ELISA strategies for DM1-conjugated trastuzumab and total trastuzumab in human serum were developed, validated and successfully applied to a phase I dose-escalation pharmacokinetic study of SHR-A1201. The pharmacokinetic properties and exposure-to-dose proportionality was evaluated for SHR-A1201. According to the bioanalytical method validation guidance, the bioanalytical methods were fully validated and the validation results met the acceptance criteria. The nonspecific binding of DM1 and dimer was avoided for the LC-MS/MS assay. In the dose-escalation pharmacokinetic study of SHR-A1201, a potential dose-proportional pharmacokinetics was observed over the dose from 1.2 mg/kg to 4.8 mg/kg. The validated bioanalytical strategies are robust and reproducible and these bioanalytical methods will contribute to better understanding of the pharmacokinetic properties of SHR-A1201.


Assuntos
Neoplasias da Mama , Imunoconjugados , Maitansina , Humanos , Feminino , Ado-Trastuzumab Emtansina , Imunoconjugados/uso terapêutico , Cromatografia Líquida , Anticorpos Monoclonais Humanizados/farmacocinética , Receptor ErbB-2/metabolismo , Espectrometria de Massas em Tandem , Trastuzumab/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Citotoxinas
18.
Int J Mol Sci ; 25(2)2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38256019

RESUMO

Chloroquine (CQ) and its derivate hydroxychloroquine (HCQ), the compounds with recognized ability to suppress autophagy, have been tested in experimental works and in clinical trials as adjuvant therapy for the treatment of tumors of different origin to increase the efficacy of cytotoxic agents. Such a strategy can be effective in overcoming the resistance of cancer cells to standard chemotherapy or anti-angiogenic therapy. This review presents the results of the combined application of CQ/HCQ with conventional chemotherapy drugs (doxorubicin, paclitaxel, platinum-based compounds, gemcitabine, tyrosine kinases and PI3K/Akt/mTOR inhibitors, and other agents) for the treatment of different malignancies obtained in experiments on cultured cancer cells, animal xenografts models, and in a few clinical trials. The effects of such an approach on the viability of cancer cells or tumor growth, as well as autophagy-dependent and -independent molecular mechanisms underlying cellular responses of cancer cells to CQ/HCQ, are summarized. Although the majority of experimental in vitro and in vivo studies have shown that CQ/HCQ can effectively sensitize cancer cells to cytotoxic agents and increase the potential of chemotherapy, the results of clinical trials are often inconsistent. Nevertheless, the pharmacological suppression of autophagy remains a promising tool for increasing the efficacy of standard chemotherapy, and the development of more specific inhibitors is required.


Assuntos
Cloroquina , Neoplasias , Animais , Humanos , Cloroquina/farmacologia , Cloroquina/uso terapêutico , Fosfatidilinositol 3-Quinases , Terapias em Estudo , Hidroxicloroquina/farmacologia , Hidroxicloroquina/uso terapêutico , Antineoplásicos Alquilantes , Citotoxinas , Neoplasias/tratamento farmacológico
19.
World J Gastroenterol ; 30(1): 91-107, 2024 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-38293320

RESUMO

BACKGROUND: The pathogenicity of Helicobacter pylori is dependent on factors including the environment and the host. Although selenium is closely related to pathogenicity as an environmental factor, the specific correlation between them remains unclear. AIM: To investigate how selenium acts on virulence factors and reduces their toxicity. METHODS: H. pylori strains were induced by sodium selenite. The expression of cytotoxin-associated protein A (CagA) and vacuolating cytotoxin gene A (VacA) was determined by quantitative PCR and Western blotting. Transcriptomics was used to analyze CagA, CagM, CagE, Cag1, Cag3, and CagT. C57BL/6A mice were infected with the attenuated strains subjected to sodium selenite induction, and H. pylori colonization, inflammatory reactions, and the cell adhesion ability of H. pylori were assessed. RESULTS: CagA and VacA expression was upregulated at first and then downregulated in the H. pylori strains after sodium selenite treatment. Their expression was significantly and steadily downregulated after the 5th cycle (10 d). Transcriptome analysis revealed that sodium selenite altered the levels affect H. pylori virulence factors such as CagA, CagM, CagE, Cag1, Cag3, and CagT. Of these factors, CagM and CagE expression was continuously downregulated and further downregulated after 2 h of induction with sodium selenite. Moreover, CagT expression was upregulated before the 3rd cycle (6 d) and significantly downregulated after the 5th cycle. Cag1 and Cag3 expression was upregulated and downregulated, respectively, but no significant change was observed by the 5th cycle. C57BL/6A mice were infected with the attenuated strains subjected to sodium selenite induction. The extent of H. pylori colonization in the stomach increased; however, sodium selenite also induced a mild inflammatory reaction in the gastric mucosa of H. pylori-infected mice, and the cell adhesion ability of H. pylori was significantly weakened. CONCLUSION: These results demonstrate that H. pylori displayed virulence attenuation after the 10th d of sodium selenite treatment. Sodium selenite is a low toxicity compound with strong stability that can reduce the cell adhesion ability of H. pylori, thus mitigating the inflammatory damage to the gastric mucosa.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Selênio , Animais , Camundongos , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Selenito de Sódio/farmacologia , Camundongos Endogâmicos C57BL , Citotoxinas , Infecções por Helicobacter/metabolismo
20.
Mol Biol Rep ; 51(1): 95, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38194007

RESUMO

BACKGROUND: Helicobacter pylori is a fastidious pathogen that is required a complicated medium for growth. Invading epithelial cells of the stomach. H. pylori virulence factors are classified by function, acidic resistivity, adhesion, chemotaxis and motility, molecular mimicry, immunological invasion and modulation, and toxins formation such as cytotoxin-associated genes A (cagA) and vacuolating cytotoxin A (vacA). This study aims to determine a simple and innovative technique to isolate H. pylori from gastric biopsies and assess pathogenicity by virulence factor gene detection. METHODS: A total of 200 patients who were suspected of having H. pylori infection had two antral gastric biopsies undertaken. A rapid urease test (RUT) was used for one, and Brain Heart Infusion broth (BHI) was used to cultivate the other. The molecular study included diagnostics utilizing the 16sRNA housekeeping gene along with the identification of the virulence factors genes (cagA, cagT, and vacA) and sequencing, RESULT: Of the 200 antral gastric biopsies collected, 135 were positive rapid urease tests, and 17 H. pylori isolates were successfully obtained from 135 biopsies. The 16SrRNA as a housekeeping gene is confirmed, and about 53%, 70.5%, and 82.3% of the 17 isolates show carrying cagA, cagT, and vacA genes, respectively. All peptic ulcer isolates have the cagA gene, while Gastroesophageal Reflux Disease (GERD) and non-peptic ulcer disease (NPUD) isolates show the lack of the cagA gene. All bacteria, which were isolated from peptic ulcer, nodular gastritis, and gastritis patients, have a vacA gene. CONCLUSION: The effective method for isolating H. pylori is centrifuging the transport broth after 24 h of incubation. The cagA toxin causes peptic ulcer while vacA toxin induces several histopathological changes in the stomach. Three virulence genes were present in all peptic ulcer-causing bacteria, while only one or none were present in the GERD and NPUD biopsy isolates.


Assuntos
Gastrite , Refluxo Gastroesofágico , Helicobacter pylori , Úlcera Péptica , Humanos , Virulência/genética , Helicobacter pylori/genética , Urease/genética , Fatores de Virulência/genética , Citotoxinas
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