RESUMO
BACKGROUND AND OBJECTIVE: There is a growing need to comprehend the potential outcomes of nanoparticles (NPs) on human well-being, including their potential for detecting and treating leukemia. This study examined the role of iron folate core-shell and iron oxide nanoparticles in inducing apoptosis and altering the expression of the B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X-protein (Bax), and Caspase-3 genes in leukemia cells. METHODS: The obtained iron oxide and iron folate core-shell nanoparticles were analyzed using a variety of analytical techniques, including ultraviolet-visible (UV-Vis) absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS), zeta potential, and transmission electron microscopy (TEM). Additionally, FTIR and UV-Vis were used to characterize doxorubicin. The MTT test was utilized to investigate the cytotoxicity of iron oxide and iron folate core-shell nanoparticles. The expression of the apoptotic signaling proteins Bcl-2, Bax, and Caspase-3 was evaluated using the real-time reverse transcription polymerase chain reaction (RT-qPCR) method. Additionally, flow cytometry was performed to gauge the degrees of necrosis and apoptosis. RESULTS: UV-Visible spectroscopy analysis showed that the generated iron oxide and iron folate core-shell NPs had a distinctive absorption curve in the 250-300 nm wavelength range. The XRD peaks were also discovered to index the spherical form with a size of less than 50 nm, which validated the crystal structure. The FTIR analysis determined the bonds and functional groups at wavenumbers between 400 and 4000 cm-1. A viable leukemia treatment approach is a nanocomposite consisting of iron and an iron folate core-shell necessary for inhibiting and activating cancer cell death. The nearly resistant apoptosis in the CCRF-CEM cells may have resulted from upregulating Bax and Casepase-3 while downregulating Bcl-2 expression. CONCLUSIONS: Our study documents the successful synthetization and characterization of iron oxide, which has excellent anticancer activities. A metal oxide conjugation with the nanoparticles' core-shell enhanced the effect against acute leukemia.
Assuntos
Apoptose , Ácido Fólico , Humanos , Ácido Fólico/química , Ácido Fólico/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Caspase 3/metabolismo , Nanopartículas Magnéticas de Óxido de Ferro/química , Leucemia/tratamento farmacológico , Leucemia/metabolismo , Proteína X Associada a bcl-2/metabolismo , Proteína X Associada a bcl-2/genética , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Doxorrubicina/química , Compostos Férricos/químicaRESUMO
BACKGROUND: Graphene oxide nanosheets (GONS) are recognized for their role in enhancing drug delivery and effectiveness in cancer treatment. With colon cancer being a prevalent global issue and the significant side effects associated with chemotherapy, the primary treatment for colon cancer alongside surgery, there is a critical need for novel therapeutic strategies to support patients in combating this disease. Hesperetin (HSP), a natural compound found in specific fruits, exhibits anti-cancer properties. The aim of this study is to investigate the effect of GONS on the LS174t colon cancer cell line. METHODS: In this study, an anti-cancer nano-drug was synthesized by creating a hesperetin-graphene oxide nanocomposite (Hsp-GO), which was subsequently evaluated for its efficacy through in vitro cell toxicity assays. Three systems were investigated: HSP, GONS, and HSP-loaded GONS, to determine their cytotoxic and pro-apoptotic impacts on the LS174t colon cancer cell line, along with assessing the expression of BAX and BCL2. The morphology and properties of both GO and Hsp-GO were examined using scanning electron microscopy (SEM), X-ray diffraction, and Fourier transform infrared spectroscopy (FTIR). RESULTS: The Hsp-GO nanocomposite displayed potent cytotoxic and pro-apoptotic effects on LS174t colon cancer cells, outperforming individual treatments with HSP or GONS. Cell viability assays showed a significant decrease in cell viability with Hsp-GO treatment. Analysis of BAX and BCL2 expression revealed elevated BAX and reduced BCL2 levels in Hsp-GO treated cells, indicating enhanced apoptotic activity. Morphological analysis confirmed successful Hsp-GO synthesis, while structural integrity was supported by X-ray diffraction and FTIR analyses. CONCLUSIONS: These study highlight the potential of Hsp-GO as a promising anti-cancer nano-drug for colon cancer therapy.
Assuntos
Neoplasias do Colo , Sistemas de Liberação de Medicamentos , Grafite , Hesperidina , Grafite/química , Grafite/farmacologia , Humanos , Hesperidina/farmacologia , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Neoplasias do Colo/metabolismo , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos/métodos , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Nanocompostos/química , Proteína X Associada a bcl-2/metabolismo , Proteína X Associada a bcl-2/genéticaRESUMO
Although remarkable progress has been made, colorectal cancer remains a significant global health issue. One of the most challenging aspects of cancer treatment is the resistance of tumor cells to classical chemotherapy. Conventional therapy for colorectal cancer often involves the use of 5-fluorouracil as a chemotherapeutic agent. Aspirin, a drug used primarily to prevent cardiovascular complications, became a focus of attention due to its potential use as an antitumor agent. The purpose of the study was to evaluate the potential synergistic cytotoxic effects of aspirin and 5-fluorouracil on colorectal adenocarcinoma cells. The viability of cells, the impact on the morphology and nuclei of cells, the potential antimigratory effect, and the impact on the expression of the major genes associated with cell apoptosis (Bcl-2, Bax, Bad), as well as caspases 3 and 8, were evaluated. The results indicated that the two compounds exerted a synergistic effect, causing a reduction in cell viability accompanied by changes characteristic of the apoptosis process-the condensation of nuclei and the reorganization of actin filaments in cells, the reduction in the expression of the Bcl-2 gene, and the increase in the expression of Bax and Bad genes, along with caspases 3 and 8. Considering all these findings, it appears that aspirin may be investigated in depth in order to be used in conjunction with 5-fluorouracil to increase antitumor activity.
Assuntos
Adenocarcinoma , Antineoplásicos , Neoplasias Colorretais , Humanos , Fluoruracila/farmacologia , Fluoruracila/uso terapêutico , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo , Proteína X Associada a bcl-2/uso terapêutico , Aspirina/farmacologia , Aspirina/uso terapêutico , Antineoplásicos/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Adenocarcinoma/tratamento farmacológico , Caspases/metabolismo , Caspases/uso terapêuticoRESUMO
AIM: This study aimed to assess the effect of photodynamic therapy (PDT) on apoptosis of head and neck squamous cell carcinoma (HNSCC) cells by flow cytometry and evaluating BAX and BCL2 genes expression.
Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Fotoquimioterapia , Apoptose , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Linhagem Celular , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/genética , Humanos , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêutico , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Mensageiro/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Proteína X Associada a bcl-2/genéticaRESUMO
BACKGROUND: Gentamicin (GM) is a low-cost, low-resistance antibiotic commonly used to treat gram-negative bacterial diseases. Cisplatin (Csp) is a platinum-derived anti-neoplastic agent. This experiment aimed to identify the early signs of gentamicin and cisplatin-induced nephrotoxicity in rats. Thirty Wistar rats were divided into three groups of 10: a control group, which received no treatment; a gentamicin group administered by a dose of (100 mg/kg, IP) for 7 consecutive days, and a cisplatin group was administered intraperitoneal in a dose of (1.5 mg/kg body weight) repeated twice a week for 3 weeks. RESULTS: Both experimental groups exhibited increased levels of creatinine, urea, and uric acid, with the cisplatin-treated group showing higher levels than the gentamicin group. Experimental groups also exhibited significantly increased Malondialdehyde (MDA), reduced glutathione (GSH), and glutathione peroxidase (GSH-Px) with more pronounced effects in the cisplatin-treated group. Further, both experimental groups exhibited significant up-regulation of Tumor Necrosis Factor α (TNF-α), caspase-3, and Bax and down regulation of Bcl-2. CONCLUSION: These findings confirm the use of necrotic, apoptotic genes as early biomarkers in the detection of tubular kidney damage. Further, cisplatin was shown to have a greater nephrotoxic effect than gentamicin; therefore, its use should be constrained accordingly when co-administered with gentamicin.
Assuntos
Cisplatino/toxicidade , Gentamicinas/toxicidade , Nefropatias/induzido quimicamente , Animais , Antibacterianos/toxicidade , Antineoplásicos/toxicidade , Apoptose/genética , Biomarcadores , Caspase 3/genética , Genes bcl-2/genética , Nefropatias/patologia , Masculino , Necrose/genética , Ratos Wistar , Fator de Necrose Tumoral alfa/genética , Proteína X Associada a bcl-2/genéticaRESUMO
The edible parts of the plants Camellia sinensis, Vitis vinifera and Withania somnifera were extensively used in ancient practices such as Ayurveda, owing to their potent biomedical significance. They are very rich in secondary metabolites such as polyphenols, which are very good antioxidants and exhibit anti-carcinogenic properties. This study aims to evaluate the anti-cancerous properties of these plant crude extracts on human liver cancer HepG2 cells. The leaves of Camellia sinensis, Withania somnifera and the seeds of Vitis vinifera were collected and methanolic extracts were prepared. Then, these extracts were subjected to DPPH, α- amylase assays to determine the antioxidant properties. A MTT assay was performed to investigate the viability of the extracts of HepG2 cells, and the mode of cell death was detected by Ao/EtBr staining and flow cytometry with PI Annexin- V FITC dual staining. Then, the protein expression of BAX and BCl2 was studied using fluorescent dye to determine the regulation of the BAX and BCl2 genes. We observed that all the three extracts showed the presence of bioactive compounds such as polyphenols or phytochemicals. The W. somnifera bioactive compounds were found to have the highest anti-proliferative activity on human liver cancer cells.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Camellia sinensis/química , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Vitis/química , Withania/química , Alcaloides/química , Alcaloides/isolamento & purificação , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antioxidantes/química , Antioxidantes/isolamento & purificação , Compostos de Bifenilo/antagonistas & inibidores , Compostos de Bifenilo/química , Morte Celular/efeitos dos fármacos , Flavonoides/química , Flavonoides/isolamento & purificação , Células Hep G2 , Humanos , Picratos/antagonistas & inibidores , Picratos/química , Extratos Vegetais/química , Folhas de Planta/química , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Sementes/química , Transdução de Sinais , Taninos/química , Taninos/isolamento & purificação , Terpenos/química , Terpenos/isolamento & purificação , alfa-Amilases/genética , alfa-Amilases/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismoRESUMO
Melanoma represents one of the most aggressive and drug resistant skin cancers with poor prognosis in its advanced stages. Despite the increasing number of targeted therapies, novel approaches are needed to counteract both therapeutic resistance and the side effects of classic therapy. Betulinic acid (BA) is a bioactive phytocompound that has been reported to induce apoptosis in several types of cancers including melanomas; however, its effects on mitochondrial bioenergetics are less investigated. The present study performed in A375 human melanoma cells was aimed to characterize the effects of BA on mitochondrial bioenergetics and cellular behavior. BA demonstrated a dose-dependent inhibitory effect in both mitochondrial respiration and glycolysis in A375 melanoma cells and at sub-toxic concentrations (10 µM) induced mitochondrial dysfunction by eliciting a decrease in the mitochondrial membrane potential and changes in mitochondria morphology and localization. In addition, BA triggered a dose-dependent cytotoxic effect characterized by apoptotic features: morphological alterations (nuclear fragmentation, apoptotic bodies) and the upregulation of pro-apoptotic markers mRNA expression (Bax, Bad and Bak). BA represents a viable therapeutic option via a complex modulatory effect on mitochondrial metabolism that might be useful in advanced melanoma or as reliable strategy to counteract resistance to standard therapy.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Melanócitos/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Triterpenos Pentacíclicos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Apoptose/genética , Linhagem Celular Tumoral , Regulação da Expressão Gênica , Glicólise/efeitos dos fármacos , Glicólise/genética , Humanos , Concentração Inibidora 50 , Melanócitos/metabolismo , Melanócitos/patologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Fosforilação Oxidativa/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/agonistas , Transdução de Sinais , Proteína Killer-Antagonista Homóloga a bcl-2/genética , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo , Proteína de Morte Celular Associada a bcl/genética , Proteína de Morte Celular Associada a bcl/metabolismo , Ácido BetulínicoRESUMO
Gazpacho is a traditional cold soup of the Mediterranean diet consisting of a main base of fresh pureed tomato and other vegetables. Tomato and tomato products have demonstrated chemopreventive activity against several types of cancer through in vitro studies, and in animal and clinical research. Here we have applied a whole-food approach for the preclinical assessment of the antitumor potential of gazpacho. Colon cancer cells (HT-29) were exposed to growing concentrations of gazpacho previously digested in vitro to simulate the delivery of bioactive molecules to colon cells after food consumption. The cytotoxicity of gazpacho ingredients was also tested in independent experiments. Programmed cell death by apoptosis was detected by using a multiparametric analysis that combines image-based bright-field and fluorescence cytometry, intracellular ATP level determination and enzymatic activity of caspase-3/7. Modulation of gene expression of key regulatory genes (p53, Bcl-2, BAX, and cyclin D1) was also investigated. Our cytotoxicity data showed that in vitro digestion of samples allowed the delivery of bioactive levels of antitumor phytochemicals to cultured cells. Controlled experiments showed significant repetitive dose and time-response cytotoxicity of gazpacho. Gazpacho digestates caused net cell death of cultures suggesting synergic activity among phytochemicals from its vegetable ingredients. Multiparametric and genetic analyses showed that gazpacho digestates can trigger colon cancer cells death by apoptosis through the activation of caspase cascade. Our results show that coupled in vitro methodology employed can be applied to investigate the antitumor potential of complex food matrixes or combinations of foods in the diet.
Assuntos
Anticarcinógenos/farmacologia , Solanum lycopersicum/química , Apoptose/efeitos dos fármacos , Caspase 3/genética , Caspase 3/metabolismo , Caspase 7/genética , Caspase 7/metabolismo , Proliferação de Células , Sobrevivência Celular , Ciclina D1/genética , Ciclina D1/metabolismo , Regulação da Expressão Gênica , Células HT29 , Humanos , Compostos Fitoquímicos/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Verduras/química , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismoRESUMO
Opioids bind to specific receptors that are located in the central nervous system (CNS) and many other organs such as cardiovascular tissue. Morphine binds to opioid receptors and can induce oxidative stress under some certain conditions. Thymoquinone (TQ) has shown many therapeutic effects such as anti-inflammatory, antioxidant and immunomodulatory ones. Considering the oxidative effects of morphine, antioxidant effects of TQ and effects of oxidative damage in various types of biomolecules, the present study was conducted to determine the effect of morphine plus TQ on the expression of apoptotic genes in the heart of male mice. Hence we used real-time PCR to identify alterations in mRNA expression of genes involved in apoptotic pathway, including p53, Bax and Bcl-2 between the morphine-treated and TQ plus morphine-treated mice. Serum nitric oxide (NO) (Griess assay) and total antioxidant capacity (TAC) were analyzed and compared. In the morphine group, compared to control group, a significant increase in P53 and Bax mRNA expression and a significant decrease in Bcl-2 mRNA expression were observed (p < 0.01). In TQ plus morphine groups, NO was decreased (P <0 .001) and TAC levels were increased significantly (P < .001). Interestingly, TQ (9 and 18 mg/kg) plus morphine caused a significant decrease in p53 and Bax and a significant increase in Bcl2 mRNA expression, compared to morphine-treated group (p < 0.01). Collectively, the results of this study indicated that TQ, as an antioxidant, can improve the apoptotic effects induced by morphine in the heart tissue of mice.
Assuntos
Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Benzoquinonas/farmacologia , Coração/efeitos dos fármacos , Morfina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Miocárdio/metabolismo , Óxido Nítrico/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismoRESUMO
PURPOSE: The plant-derived natural product 4-O-methylhonokiol (MH) has been reported to possess tremendous pharmacological potential ranging from neuroprotection to anticancer activity. However, the anticancer activity of MH in oral squamous cell carcinoma (OSCC) cells has not been evaluated. In the present study, MH was evaluated for its anticancer activity against OSSC PE/CA-PJ41 cells and the possible underlying mechanism was determined. METHODS: Cell cytotoxicity was evaluated by colorimetrybased MTT assay while the effects on cell cycle phase distribution were assessed by flow cytometry. Effects of MH on reactive oxygen species (ROS) production and mitochondrial membrane potential (MMP) were evaluated by flow cytometry. Western blot assay was finally utilized to study the effects of MH on key cancer and apoptosis-linked proteins including Bax and Bcl-2. RESULTS: MH induced cytotoxicity in OSCC PE/CA-PJ41 cells with an observed IC50 of 1.25 µM. It also caused significant increase in the production of ROS and disrupted the MMP in a dose-dependent manner. The reduction in MMP favored mitochondrial apoptotic pathway which was further confirmed by determining the expression of Bax and Bcl-2. It was observed that MH downregulated the expression of Bax and upregulated the expression of MMP, ultimately leading to apoptosis of OSSC PE/CA-PJ41 cells. Additionally, MH also caused G2/M cell cycle arrest in a dose-dependent manner. CONCLUSION: Taken together, our results indicate that 4-Omethylhonokiol may prove a potential natural anticancer molecule against human oral carcinoma cells.
Assuntos
Compostos de Bifenilo/farmacologia , Carcinoma de Células Escamosas/tratamento farmacológico , Lignanas/farmacologia , Neoplasias Bucais/tratamento farmacológico , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteína X Associada a bcl-2/genética , Apoptose/efeitos dos fármacos , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Neoplasias Bucais/genética , Neoplasias Bucais/patologia , Espécies Reativas de Oxigênio/metabolismoRESUMO
Conjugates of anthracyclines are a new possibility for anticancer agent delivery, which seems to be a very promising alternative to the currently used cancer treatment strategies. In our study, we investigated the ability of a doxorubicin-transferrin (DOX-TRF) conjugate to induce cell death in two solid tumor cell lines: non-small cell lung cancer (A549) and hepatocellular liver carcinoma (HepG2). The observed effects of the DOX-TRF conjugate on these cell cultures were compared with those of free doxorubicin (DOX), a widely used antineoplastic therapeutic agent. Our results provided direct evidence that the investigated conjugate is considerably more cytotoxic to the examined human cancer cell lines than is DOX alone. Moreover, we confirmed that the antitumor efficacy of DOX-TRF conjugate is related to its apoptosis-inducing ability, which was shown during measurements of typical features of programmed cell death. In solid tumor cell lines, the DOX-TRF conjugate induced changes in cellular morphology, mitochondrial membrane potential and caspases-3 and -9 activities. Furthermore, all of the analyzed hallmarks of apoptosis were confirmed by the oligonucleosomal DNA fragmentation assay and by a real-time PCR quantitative study, which displayed the superiority of the conjugate-induced programmed cell death over free drug-triggered cell death.
Assuntos
Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , Células Epiteliais/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Transferrina/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Fator de Indução de Apoptose/genética , Fator de Indução de Apoptose/metabolismo , Calpaína/genética , Calpaína/metabolismo , Caspase 3/genética , Caspase 3/metabolismo , Caspase 9/genética , Caspase 9/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Células Hep G2 , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismoRESUMO
OBJECTIVE: Quantitative assessment of BAX transcripts and protein in acute myeloid leukemia (AML). METHODS: We quantitatively evaluated BAX gene transcripts by real-time polymerase chain reaction (TaqMan probe chemistry) and protein expression by flow cytometry. RESULTS: Consecutive 112 AML patients with a median age of 16 (1-59) years were recruited in the study. By flow cytometry, the percentage expression was in linear correlation with relative median fluorescent intensity (RMFI; R = 0.4425; P < 0.001). However, there was no linear relationship between the transcript copies of the BAX with its RMFI (R = -0.0559; P = 0.586). The expression of the BAX at both protein and transcript level was significantly higher in AML patients as compared with normal control. RMFI of the BAX were higher in the cohort with lower white blood cell count (P = 0.029). None of the other baseline characteristics correlated with either the BAX transcript or the RMFI. BAX expression did not correlate with complete remission rate, event free, disease free, and overall survival. CONCLUSION: BAX gene expression in AML was evaluated first time with two different methods but did not correlate with the survival outcome.
Assuntos
Leucemia Mieloide/genética , Leucemia Mieloide/metabolismo , Proteína X Associada a bcl-2/biossíntese , Proteína X Associada a bcl-2/genética , Doença Aguda , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Criança , Pré-Escolar , Feminino , Citometria de Fluxo , Regulação Leucêmica da Expressão Gênica , Humanos , Quimioterapia de Indução , Lactente , Leucemia Mieloide/tratamento farmacológico , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sobrevida , Transcrição Gênica , Resultado do Tratamento , Adulto JovemRESUMO
The mitochondrial pathway of apoptosis proceeds when molecules, such as cytochrome c, sequestered between the outer and inner mitochondrial membranes are released to the cytosol by mitochondrial outer membrane (MOM) permeabilization. Bax, a member of the Bcl-2 protein family, plays a pivotal role in mitochondrion-mediated apoptosis. In response to apoptotic stimuli, Bax integrates into the MOM, where it mediates the release of cytochrome c from the intermembrane space into the cytosol, leading to caspase activation and cell death. The pro-death action of Bax is regulated by interactions with both other prosurvival proteins, such as tBid, and the MOM, but the exact mechanisms remain largely unclear. Here, the mechanisms of integration of Bax into a model membrane mimicking the MOM were studied by Monte Carlo simulations preceded by a computer prediction of the docking of tBid with Bax. A novel model of Bax activation by tBid was predicted by the simulations. In this model, tBid binds to Bax at an interaction site formed by Bax helices alpha1, alpha2, alpha3 and alpha5 leading, due to interaction of the positively charged N-terminal fragment of tBid with anionic lipid headgroups, to Bax reorientation such that a hydrogen-bonded pair of residues, Asp98 and Ser184, is brought into close proximity with negatively charged lipid headgroups. The interaction with these headgroups destabilizes the hydrogen bond which results in the release of helix alpha9 from the Bax-binding groove, its insertion into the membrane, followed by insertion into the membrane of the alpha5-alpha6 helical hairpin.