RESUMO
PURPOSE: In artificial intelligence-based modeling, working with a limited number of patient groups is challenging. This retrospective study aimed to evaluate whether applying synthetic data generation methods to the clinical data of small patient groups can enhance the performance of prediction models. MATERIALS AND METHODS: A data set collected by the Cancer Registry Library Project from the Yonsei Cancer Center (YCC), Severance Hospital, between January 2008 and October 2020 was reviewed. Patients with colorectal cancer younger than 50 years who started their initial treatment at YCC were included. A Bayesian network-based synthesizing model was used to generate a synthetic data set, combined with the differential privacy (DP) method. RESULTS: A synthetic population of 5,005 was generated from a data set of 1,253 patients with 93 clinical features. The Hellinger distance and correlation difference metric were below 0.3 and 0.5, respectively, indicating no statistical difference. The overall survival by disease stage did not differ between the synthetic and original populations. Training with the synthetic data and validating with the original data showed the highest performances of 0.850, 0.836, and 0.790 for the Decision Tree, Random Forest, and XGBoost models, respectively. Comparison of synthetic data sets with different epsilon parameters from the original data sets showed improved performance >0.1%. For extremely small data sets, models using synthetic data outperformed those using only original data sets. The reidentification risk measures demonstrated that the epsilons between 0.1 and 100 fell below the baseline, indicating a preserved privacy state. CONCLUSION: The synthetic data generation approach enhances predictive modeling performance by maintaining statistical and clinical integrity, and simultaneously reduces privacy risks through the application of DP techniques.
Assuntos
Inteligência Artificial , Neoplasias Colorretais , Humanos , Teorema de Bayes , Estudos Retrospectivos , Hospitais , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/terapiaRESUMO
BACKGROUND: We investigated the prognostic impact of the neutrophil-to-lymphocyte ratio (NLR) in patients with locally advanced rectal cancer (LARC) and whether modifiable factors in radiotherapy (RT) influenced the NLR. METHODS: Data of 1386 patients who were treated with neoadjuvant RT and concurrent or sequential chemotherapy for LARC between 2006 and 2019 were evaluated. Most patients (97.8%) were treated with long-course RT (LCRT; 50-50.4 Gy in 25-28 fractions) using three-dimensional conformal radiotherapy (3D-CRT) (n = 851) or helical tomotherapy (n = 504), and 30 patients underwent short-course RT (SCRT; 25 Gy in 5 fractions, followed by XELOX administration for 6 weeks). Absolute neutrophil and lymphocyte counts were obtained at initial diagnosis, before and during the preoperative RT course, and after preoperative concurrent chemoradiotherapy. The primary endpoint was distant metastasis-free survival (DMFS). RESULTS: The median follow-up time was 61.3 (4.1-173.7) months; the 5-year DMFS was 80.1% and was significantly associated with the NLR after RT but not before. A post-RT NLR ≥ 4 independently correlated with worse DMFS (hazard ratio, 1.42; 95% confidence interval, 1.12-1.80), along with higher ypT and ypN stages. Post-RT NLR (≥ 4) more frequently increased following LCRT (vs. SCRT, odds ratio [OR] 2.77, p = 0.012) or helical tomotherapy (vs. 3D-CRT, OR 1.29, p < 0.001). CONCLUSIONS: Increased NLR after neoadjuvant RT is associated with increased distant metastasis risk and poor survival outcome in patients with LARC. Moreover, high NLR following RT is directly related to RT fractionation, delivery modality, and tumor characteristics. These results are hypothesis-generating only, and confirmatory studies are required.
Assuntos
Neutrófilos , Neoplasias Retais , Quimiorradioterapia/métodos , Humanos , Linfócitos/patologia , Terapia Neoadjuvante , Estadiamento de Neoplasias , Neutrófilos/patologia , Neoplasias Retais/patologia , Estudos RetrospectivosRESUMO
Most electronic medical records, such as free-text radiological reports, are unstructured; however, the methodological approaches to analyzing these accumulating unstructured records are limited. This article proposes a deep-transfer-learning-based natural language processing model that analyzes serial magnetic resonance imaging reports of rectal cancer patients and predicts their overall survival. To evaluate the model, a retrospective cohort study of 4,338 rectal cancer patients was conducted. The experimental results revealed that the proposed model utilizing pre-trained clinical linguistic knowledge could predict the overall survival of patients without any structured information and was superior to the carcinoembryonic antigen in predicting survival. The deep-transfer-learning model using free-text radiological reports can predict the survival of patients with rectal cancer, thereby increasing the utility of unstructured medical big data.
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Early life maternal separation (MS) increases the vulnerability to depression in rats with chronic mild stress (CMS). N-3 polyunsaturated fatty acids (PUFA) improved depressive behaviors in rats with acute stress; however, their effects on rats with MS+CMS were not apparent. The purpose of the present study was to investigate the hypothesis that lifetime n-3 PUFA supplementation improves post-menopausal depression through the serotonergic and glutamatergic pathways while modulating n-3 PUFA-derived metabolites. Female rats were fed diets of either 0% n-3 PUFA during lifetime or 1% energy n-3 PUFA during pre-weaning, post-weaning, or lifetime periods. Rats were allocated to non-MS or MS groups and underwent CMS after ovariectomy. N-3 PUFA increased brain n-3 PUFA-derived endocannabinoid/oxylipin levels, and reversed depressive behaviors. N-3 PUFA decreased blood levels of adrenocorticotropic hormone and corticosterone, and brain expressions of corticotropin-releasing factor and miRNA-218, which increased the expression of the glucocorticoid receptor. N-3 PUFA decreased the expression of tumor necrosis factor-α, interleukin (IL)-6, IL-1ß, and prostaglandin E2, while increased the expression of miRNA-155. N-3 PUFA also increased brainstem serotonin levels and hippocampal expression of the serotonin-1A receptor, cAMP response element-binding protein (CREB), phospho-CREB, and brain-derived neurotrophic factor. However, n-3 PUFA did not affect brain expression of α-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor subtype 1, N-methyl-D-aspartate receptor subtype 2B, or miRNA-132. Moreover, n-3 PUFA exposure during lifetime caused greater effects than pre- and post-weaning periods. The present study suggested that n-3 PUFA improved depressive behaviors through serotonergic pathway while modulating the metabolites of n-3 PUFA in post-menopausal depressed rats with chronic stress.
Assuntos
Depressão/terapia , Ácidos Graxos Ômega-3/uso terapêutico , Ração Animal/análise , Animais , Depressão/etiologia , Suplementos Nutricionais/análise , Feminino , Masculino , Privação Materna , Pós-Menopausa , Ratos , Ratos Wistar , Estresse Psicológico/complicaçõesRESUMO
Stress and ovarian hormone fluctuation are risk factors for postpartum depression (PPD). Previous studies suggested antidepressant-like effects of n-3 polyunsaturated fatty acids (PUFA), but their effect on dam animal with additional stress were not clear. The purpose of the present study was to investigate the hypothesis that n-3 PUFA improved PPD through the serotonergic and glutamatergic pathways by modulating miRNA. Rats were fed n-3 PUFA or control diet from gestation, with pup separation (PS) on postpartum days 2-14 and non-PS controls. N-3 PUFA reversed PS-induced depressive behaviors, including increased immobility, latencies to contact first pup and retrieve all pups, and decreased sucrose preference. N-3 PUFA also modulated the hypothalamic-pituitary-adrenal (HPA) axis by decreasing circulating levels of adrenocorticotropic hormone and corticosterone and expression of hypothalamic corticotrophin releasing factor and hippocampal miRNA-218 but increasing the hippocampal expression of glucocorticoid receptor. N-3 PUFA inhibited neuroinflammation by decreasing circulating levels of prostaglandin E2 and hippocampal expression of tumor necrosis factor-α, interleukin-6, and miRNA-155. In addition, n-3 PUFA up-regulated the serotonergic pathway by increasing circulating levels of serotonin and hippocampal expression of serotonin-1A receptor, cAMP response element binding protein (CREB), pCREB, brain-derived neurotrophic factor, and miRNA-182 but did not affect the glutamatergic pathway according to the hippocampal expression of N-methyl-D-aspartate receptor-2B. The present study suggested that n-3 PUFA improved PPD through the serotonergic pathway by modifying the HPA axis, neuroinflammation, and related miRNAs.
Assuntos
Depressão Pós-Parto/tratamento farmacológico , Ácidos Graxos Ômega-3/uso terapêutico , MicroRNAs/genética , Serotonina/metabolismo , Transdução de Sinais , Animais , Animais Recém-Nascidos , Depressão Pós-Parto/genética , Depressão Pós-Parto/metabolismo , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Sistema Hipotálamo-Hipofisário/metabolismo , Masculino , Ratos Wistar , Serotonina/genéticaRESUMO
Our previous study showed that n-3 polyunsaturated fatty acid (PUFA) and estrogen (E) had synergistic hypocholesterolemic effects by inhibiting cholesterol synthesis and enhancing bile acid synthesis. The purpose of the present study was to investigate the hypothesis that α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) decrease low-density lipoprotein cholesterol (LDL-C), synergistically with E, via hepatic cholesterol synthesis and clearance. Rats were fed a diet with either 0% n-3 PUFA or 1% ALA, EPA, or DHA, relative to total energy consumption, for the entire 12-week study. After ovariectomy, rats were injected with either corn oil or E every 4â¯days for the last 3â¯weeks of the study. In combination with E, dietary supplementation with EPA or DHA increased the phosphorylated adenosine monophosphate-activated protein kinase/adenosine monophosphate-activated protein kinase ratio and LDL receptor expression, and it decreased the expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase, sterol regulatory element-binding protein-2, and proprotein convertase subtilisin/kexin type 9 in the liver. In addition, dietary supplementation with EPA or DHA increased hepatic expression of cholesterol 7α-hydroxylase, sterol 12α-hydroxylase, and sterol 27-hydroxylase. However, E decreased the expression of cholesterol 7α-hydroxylase and sterol 12α-hydroxylase and increased the expression of estrogen receptor α and ß in the liver. ALA had no significant effects on cholesterol metabolism. In conclusion, the present study suggests that dietary supplementation with EPA and DHA decreased LDL-C synthesis and increased bile acid synthesis and LDL-C clearance by LDL receptor, synergistically with E.
Assuntos
LDL-Colesterol/sangue , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácido Eicosapentaenoico/administração & dosagem , Estrogênios/administração & dosagem , Ácido alfa-Linolênico/administração & dosagem , Animais , Ácidos e Sais Biliares/biossíntese , Colesterol/metabolismo , Dieta , Sinergismo Farmacológico , Ácidos Graxos/sangue , Feminino , Fígado/química , Fígado/efeitos dos fármacos , Fígado/metabolismo , Ovariectomia , Ratos , Ratos Wistar , Receptores de LDL/metabolismo , Triglicerídeos/análiseRESUMO
Conversion of α-linolenic acid (ALA) into the longer chain n-3 PUFA has been suggested to be affected by the dietary intake of linoleic acid (LA), but the mechanism is not well known. Therefore, the purpose of this study was to evaluate the effect of a low-LA diet with and without oestrogen on the fatty acid conversion enzymes and transcription factors. Rats were fed a modified American Institute of Nutrition-93G diet with 0% n-3 PUFA or ALA, containing low or high amounts of LA for 12 weeks. At 8 weeks, the rats were injected with maize oil with or without 17ß-oestradiol-3-benzoate (E) at constant intervals for the remaining 3 weeks. Both the low-LA diet and E significantly increased the hepatic expressions of PPAR-α, fatty acid desaturase (FADS) 2, elongase of very long chain fatty acids 2 (ELOVL2) and ELOVL5 but decreased sterol regulatory element binding protein 1. The low-LA diet, but not E, increased the hepatic expression of FADS1, and E increased the hepatic expression of oestrogen receptor-α and ß. The low-LA diet and E had synergic effects on serum and liver levels of DHA and on the hepatic expression of PPAR-α. In conclusion, the low-LA diet and oestrogen increased the conversion of ALA into DHA by upregulating the elongases and desaturases of fatty acids through regulating the expression of transcription factors. The low-LA diet and E had a synergic effect on serum and liver levels of DHA through increasing the expression of PPAR-α.
Assuntos
Ácidos Docosa-Hexaenoicos/biossíntese , Estrogênios/administração & dosagem , Ácidos Graxos Dessaturases/metabolismo , Elongases de Ácidos Graxos/metabolismo , Ácido Linoleico/administração & dosagem , Ácido alfa-Linolênico/metabolismo , Animais , Dieta , Sinergismo Farmacológico , Ácido Eicosapentaenoico/biossíntese , Ácidos Graxos/análise , Feminino , Expressão Gênica , Fígado/química , Fígado/enzimologia , Fígado/metabolismo , Ovariectomia , PPAR beta/genética , Fosfolipídeos/sangue , Fosfolipídeos/química , Ratos , Ratos WistarRESUMO
Natural killer (NK) cells eliminate cancer cells in a contact-dependent manner. However, how NK cells find cancer cells remain unclear. Here, using time-lapse imaging, we investigated how individual NK cells migrate toward cancer cells. Although naïve B16F10 cancer cells produce low levels of chemokines, IFN-γ-treated B16F10 cells secreted high levels of CXCL10, low levels of CCL5, but did not secrete CCL2, CCL7, or CXCL12. Wild-type NK cells migrated well toward cancer cells and killed them, whereas NK cells deficient in CXCR3 did not. CXCR3-deficient NK cells also showed slower migration speed than did wild-type NK cells. Taken together, our data show that NK cells find cancer cells, at least in part, by sensing CXCL10 produced by cancer cells and suggest that a strategy to increase CXCL10 secretion by cancer cells may improve the efficacy of NK cell-based immunotherapy.
Assuntos
Quimiocina CXCL10/imunologia , Quimiotaxia de Leucócito/imunologia , Células Matadoras Naturais/imunologia , Melanoma Experimental/imunologia , Receptores CXCR3/imunologia , Animais , Linhagem Celular Tumoral , Quimiocina CXCL10/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores CXCR3/genéticaRESUMO
In our search for novel histone deacetylases inhibitors, we have designed and synthesized a series of novel hydroxamic acids and N-hydroxybenzamides incorporating quinazoline heterocycles (4a - 4i, 6a - 6i). Bioevaluation showed that these quinazoline-based hydroxamic acids and N-hydroxybenzamides were potently cytotoxic against three human cancer cell lines (SW620, colon; PC-3, prostate; NCI-H23, lung). In term of cytotoxicity, several compounds, e.g., 4g, 4c, 4g - 4i, 6c, and 6h, displayed from 5- up to 10-fold higher potency than SAHA (suberoylanilidehydroxamic acid, vorinostat). The compounds were also generally comparable to SAHA in inhibiting HDACs with IC50 values in sub-micromolar range. Some compounds, e.g., 4g, 6c, 6e, and 6h, were even more potent HDAC inhibitors compared to SAHA in HeLa extract assay. Docking studies demonstrated that the compounds tightly bound to HDAC2 at the active binding site with binding affinities higher than that of SAHA. Detailed investigation on the estimation of absorption, distribution, metabolism, excretion, and toxicity (ADMET) suggested that compounds 4g, 6c, and 6g, while showing potent HDAC2 inhibitory activity and cytotoxicity, also potentially displayed ADMET characteristics desirable to be expected as promising anticancer drug candidates.
Assuntos
Antineoplásicos/farmacologia , Desenho de Fármacos , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Ácidos Hidroxâmicos/farmacologia , Quinazolinas/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores de Histona Desacetilases/síntese química , Inibidores de Histona Desacetilases/química , Humanos , Ácidos Hidroxâmicos/síntese química , Ácidos Hidroxâmicos/química , Simulação de Acoplamento Molecular , Quinazolinas/química , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
Our previous studies found that n-3 polyunsaturated fatty acids (PUFAs) and estrogen had synergistic antidepressant-like effects. The purpose of the present study was to investigate the hypothesis that three major n-3 PUFAs, α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), individually had antidepressant effects combined with 17ß-estradiol-3-benzoate (E) through a neurobiological pathway in ovariectomized rats. Rats were fed a modified American Institute of Nutrition-93G diet with 0% n-3 PUFAs and 1% ALA, EPA and DHA relative to total energy intake for 12 weeks and were injected with corn oil or E every 4 days during the last 3 weeks. Supplementation of EPA, DHA and E increased serum concentrations of serotonin and climbing behavior, and decreased immobility during a forced swimming test. Supplementation with EPA, DHA and E also decreased hippocampal expressions of interleukin-6 and tumor necrosis factor-α, and increased cAMP response element binding protein, brain-derived neurotrophic factor (BDNF) and estrogen receptor-α. Immunofluorescence staining consistently showed elevated expressions of BDNF. Magnetic resonance spectroscopy showed that E increased glucose and decreased glutamate, glutamine and myo-inositol concentrations regardless of n-3 PUFA supplementation. In addition, supplementation with EPA, DHA and E decreased levels of nitrite and nitrate. However, ALA had no antidepressant effect. The present study suggested that the antidepressant-like effects of EPA and DHA supplementation and E injection could be due to the regulation of serotonergic neurotransmission and inflammatory cytokines rather than due to the antioxidative system. Supplementation with n-3 PUFA and E had the additional function of modulating neurometabolites in the hippocampus.
Assuntos
Antidepressivos/uso terapêutico , Depressão/prevenção & controle , Suplementos Nutricionais , Modelos Animais de Doenças , Ácidos Docosa-Hexaenoicos/uso terapêutico , Ácido Eicosapentaenoico/uso terapêutico , Estradiol/uso terapêutico , Animais , Comportamento Animal/efeitos dos fármacos , Química Encefálica/efeitos dos fármacos , Depressão/imunologia , Depressão/metabolismo , Depressão/patologia , Estradiol/administração & dosagem , Estradiol/análogos & derivados , Feminino , Hipocampo/efeitos dos fármacos , Hipocampo/imunologia , Hipocampo/metabolismo , Hipocampo/patologia , Terapia de Reposição Hormonal , Injeções Subcutâneas , Proteínas do Tecido Nervoso/metabolismo , Ovariectomia/efeitos adversos , Distribuição Aleatória , Ratos Wistar , Neurônios Serotoninérgicos/efeitos dos fármacos , Neurônios Serotoninérgicos/imunologia , Neurônios Serotoninérgicos/metabolismo , Neurônios Serotoninérgicos/patologia , Serotonina/sangue , Ácido alfa-Linolênico/uso terapêuticoRESUMO
CD226 is an activating receptor expressed on natural killer (NK) cells, CD8+ T cells, and other immune cells. Upon binding to its ligands expressed on target cells, CD226 activates intracellular signaling that triggers cytokine production and degranulation in NK cells. However, the role of CD226 in contact dynamics between NK and cancer cells has remained unclear. Our time-lapse images showed that individual wild-type CD226+ NK cells contacted B16F10 melanoma cells for 23.7 min, but Cd226-/- NK cells only for 12.8 min, although both NK cell subsets showed equal contact frequency over 4 h. On the surface of B16F10 cells, CD226+ cells stayed at the same site with oscillating movement (named stable contact), while Cd226-/- NK cells moved around at a velocity of 4 µm/min (named unstable contact). Consequently, Cd226-/- NK cells did not kill B16F10 cells in vitro and did not inhibit their metastasis into the lung in vivo. Taken together, our data demonstrate that CD226 enables prolonged stable interaction between NK and cancer cells, which is needed for efficient killing of cancer cells.
RESUMO
Despite conflicting results, there is evidence to suggest an inverse link between total body cholesterol levels and the risk of certain malignancies. Based on previous reports, this phenomenon appears to vary with cancer site, and, in particular, more consistent data on inverse relations was reported in the risk of gastric cancer. In the current study, the effect of cholesterol on gastric cancer cell viability was examined using an in vitro cell culture system. Addition of cholesterol in culture medium resulted in reduced viability and clonogenicity of SNU601, SNU638 and SNU216 gastric cancer cells by induction of both autophagic and apoptotic death. Transient inactivation of ERK1/2 was linked to reduction of cholesterol-mediated cell viability, and tumor necrosis factorrelated apoptosis-inducing ligand receptor 2 (TRAILR2/DR5) was also involved in cell death signaling. In conclusion, these results imply that cholesterol can act as a signal regulator to modulate cell viability and that proper cellular cholesterol levels may be advantageous to suppress growth of gastric carcinomas.
Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Carcinoma/metabolismo , Colesterol/administração & dosagem , Neoplasias Gástricas/metabolismo , Carcinoma/tratamento farmacológico , Carcinoma/patologia , Sobrevivência Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Células Tumorais CultivadasRESUMO
Ursodeoxycholic acid (UDCA) is known as a suppressor of cholestatic liver diseases and colorectal cancer development. Here, we demonstrate that UDCA induces apoptosis without necrotic features in SNU601, SNU638, SNU1 and SNU216 human gastric cancer cells, implying its possible use as an effective chemotherapeutic agent in treatment of gastric cancer. UDCA-induced apoptosis was dominantly mediated by an extrinsic pathway dependent on caspase-8, -6 and -3. UDCA increased expression of death receptor 5 [(DR5), also known as tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor 2], and this DR appeared to be responsible for UDCA-induced apoptosis, as evidenced by DR5 knockdown. UDCA triggered formation of lipid rafts that played crucial roles in UDCA-induced apoptotic actions. Lipid rafts were required not only for provision of a proper site for DR5 action but also for mediation of DR5 expression. In addition, reactive oxygen species (ROS) and protein kinase C (PKC) δ appeared to be implicated in UDCA-induced raft-dependent DR5 expression. Our results indicate that UDCA-induced apoptosis is mediated by DR5 expression, which is regulated by the raft formation/ROS production/PKCδ activation pathway and DR5 localization into lipid rafts in gastric cancer cells. Tumor-suppressive activity of UDCA was confirmed in an in vivo system: UDCA (120 mg/kg/day) significantly decreased tumor growth in gastric cancer xenograft mice. Taken together, our results demonstrate that UDCA can be used as a potent chemotherapeutic agent for treatment of gastric cancer.
Assuntos
Apoptose/efeitos dos fármacos , Colagogos e Coleréticos/farmacologia , Microdomínios da Membrana , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Ácido Ursodesoxicólico/farmacologia , Animais , Western Blotting , Proliferação de Células , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Necrose , Proteína Quinase C-delta/genética , Proteína Quinase C-delta/metabolismo , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Espécies Reativas de Oxigênio/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/antagonistas & inibidores , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Gástricas/genética , Células Tumorais CultivadasRESUMO
Previously, we showed that mild heat shock modulates patterns of cell death in response to glucose deprivation (GD), a common characteristic of the tumor microenvironment, by switching necrosis to apoptosis through ERK-dependent suppression of reactive oxygen species production in A549 cells. In the present study, we further examined the molecular mechanism underlying mild heat shock-induced necrosis-to-apoptosis switch. We examined the possible implication of p53 and heat shock proteins (HSPs) in the mechanism. Inhibition of p53 by pifithrin-alpha or p53 siRNA markedly suppressed apoptosis induced by heat shock/GD. On the other hand, silencing of HSP27, but not of HSP70, reversed heat shock/GD-induced apoptosis to necrosis, and HSP27 overexpression suppressed GD-induced necrosis. We further demonstrate that mild heat shock activated AKT and ERK1/2 through phosphorylation. Prevention of PI3K by LY294002 blocked heat shock/GD-induced apoptosis without reversing the cell death mode to necrosis, while inhibition of MEK1/2 by U0126 reversed heat shock/GD-induced apoptosis to necrosis, indicating a different role(s) of PI3K and ERK1/2 in heat shock/GD-induced cell death mode determination. We also found that mild heat shock increased HSP27 and p53 protein levels dependent on PI3K and suppressed the GD-induced increase in RIPA-insoluble HSP27 and p53 protein levels dependent on PI3K and ERK1/2. In conclusion, these results indicate that PI3K-dependent HSP27 and p53 induction and PI3K- and ERK1/2-dependent inhibition of the GD-induced increase in RIPA-insoluble HSP27 and p53 protein levels by heat play a key role(s) in heat shock-mediated switch of GD-induced necrosis to apoptosis.
Assuntos
Apoptose/fisiologia , Necrose/metabolismo , Proteínas Serina-Treonina Quinases/biossíntese , Transdução de Sinais/fisiologia , Proteína Supressora de Tumor p53/biossíntese , Linhagem Celular , Glucose/deficiência , Humanos , Immunoblotting , Peptídeos e Proteínas de Sinalização Intracelular , Fosfatidilinositol 3-Quinases/metabolismo , Interferência de RNA , Estresse Fisiológico/fisiologiaRESUMO
Hepatocellular carcinoma (HCC) is resistant to chemotherapy. Recently, however, several oxaliplatin-based combinatorial treatments have shown a promising anti-tumor activity in patients with HCC. Presently, we demonstrate that oxaliplatin triggers necrosis more than apoptosis in HepG2, SK-Hep1, SNU-423 and Hep3B HCC cells, while mainly inducing apoptosis in HCT116 and HT29 colon cancer cells. Interestingly, ursodeoxycholic acid (UDCA), a less hydrophobic bile acid that can suppress carcinogenesis, shifted oxaliplatin-induced necrosis to apoptosis in HepG2 cells. The same effect was produced by hydrophilic bile acids (tauroursodeoxycholic acid and taurohyodeoxycholic acid), but not by highly hydrophobic bile acids (deoxycholic acid and chenodeoxycholic acid). UDCA also triggered the necrosis-to-apoptosis switch when cotreated with other platinum-based chemotherapeutic drugs including cisplatin and carboplatin, suggesting that the cell death mode switching effect of UDCA is a general phenomenon when combined with platinum drugs. Oxaliplatin produced high level of reactive oxygen species (ROS) in HepG2 cells and UDCA significantly reduced oxaliplatin-induced ROS generation. In addition, N-acetyl-L-cysteine and the superoxide scavengers butylated hydroxyanisole and dihydroxybenzene-3,5-disulfonic acid attenuated necrosis, indicating a critical role(s) of ROS in occurrence of necrotic death. Apoptosis induced by combined treatment appeared to be mediated by p53-caspase 8-caspase 3 pathway. In conclusion, UDCA switches oxaliplatin-induced necrosis to apoptosis via inhibition of ROS production and activation of the p53-caspase 8 pathway in HepG2 cells. As necrosis and subsequent inflammation are implicated in tumor progression and malignancy, our results imply a potential improved efficacy of UDCA-combined chemotherapy in HCC by reducing inflammatory responses that may be triggered by oxaliplatin.
Assuntos
Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Caspase 8/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Compostos Organoplatínicos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Ácido Ursodesoxicólico/farmacologia , Antineoplásicos/farmacologia , Western Blotting , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Caspase 8/genética , Colagogos e Coleréticos/farmacologia , Ensaio de Desvio de Mobilidade Eletroforética , Células HT29/efeitos dos fármacos , Células Hep G2/efeitos dos fármacos , Humanos , L-Lactato Desidrogenase/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Necrose , Oxaliplatina , RNA Interferente Pequeno/farmacologia , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/genéticaRESUMO
Sodium salicylate, the active metabolite of aspirin, has been shown to exert anti-inflammatory activities by inhibiting the expression of various pro-inflammatory factors, and has potent anti-cancer effects against a number of human cancers including colon, lung, breast and leukemia. Necrotic cell death is emerging as one of the crucial factors that trigger an inflammatory response since during necrotic death the cell membrane is ruptured and the intracellular constituents including high mobility group box 1 (HMGB1) are released into the extracellular space, thereby activating an inflammatory response. In contrast, autophagic death is regarded as a form of tumour suppressive cell death, as indicated in tumour suppressors such as beclin 1 in autophagic pathways. To better understand the anti-inflammatory properties of sodium salicylate and its effect on necrotic cell death in A549 cells induced by glucose depletion (GD), a common characteristic of the tumour micro-environment, was examined. While GD induced mostly necrotic death in A549 cells, salicylate suppresssed GD-induced necrosis and HMGB1 release. In addition, salicylate shifted the cell death pattern to autophagy by inhibiting GD-induced Cu/Zn superoxide dismutase release and ROS production. These results indicate that the activity of salicylate to prevent necrotic death may contribute to its anti-inflammatory action and suppress tumour development possibly through switching the cell death mode from tumour-promoting necrotic cell death to tumour-suppressive autophagic cell death.
Assuntos
Adenocarcinoma/metabolismo , Autofagia , Inibidores de Ciclo-Oxigenase/farmacologia , Regulação Neoplásica da Expressão Gênica , Glucose/metabolismo , Proteína HMGB1/biossíntese , Neoplasias Pulmonares/embriologia , Necrose , Salicilato de Sódio/farmacologia , Anti-Inflamatórios/farmacologia , Benzimidazóis/farmacologia , Linhagem Celular Tumoral , Proteína HMGB1/metabolismo , Humanos , Superóxido Dismutase/metabolismo , Sais de Tetrazólio/farmacologia , Tiazóis/farmacologiaRESUMO
Both cellular and clinical studies have shown that hyperthermia is one of the most potent sensitizers for the action of ionizing radiation. Although hyperthermic improvement in clinical outcome is suggested to be linked to its ability to induce cell cycle arrest and apoptosis, and to activate the immune system and to cause increases in blood flow and tumor oxygenation, the mechanism behind this is still unclear. Previously, we demonstrated that glucose deprivation (GD), a common characteristic of the tumor microenvironment, induced necrosis, which is implicated in tumor progression and aggressiveness, through the production of reactive oxygen species (ROS) in A549 lung carcinoma cells. We examined the effects of heat shock on ROS production and necrosis in response to GD. Here we show that mild, but not harsh, heat shock prevented GD-induced necrosis and switched the cell death mode to apoptosis in A549 cells through the ERK1/2 pathway that could suppress GD-induced CuZnSOD release and ROS production. These results demonstrate that contrary to severe heat shock, mild heat shock has the ability to decrease oxidative stress in cells, thereby causing the cell death mode switch from tumor promoting necrosis to tumor suppressive apoptosis, which may contribute to its anti-neoplastic activities.
Assuntos
Adenocarcinoma/patologia , Apoptose , Glucose/deficiência , Hipertermia Induzida , Neoplasias Pulmonares/patologia , Linhagem Celular Tumoral , MAP Quinases Reguladas por Sinal Extracelular/fisiologia , Febre de Causa Desconhecida/complicações , Humanos , Necrose , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/fisiologiaRESUMO
Ethyl pyruvate (EP), a stable lipophilic pyruvate derivative, has been shown to exert anti-inflammatory activities through inhibiting the expression of various pro-inflammatory mediators as well as circulating levels of high mobility group box protein 1 (HMGB1) in a variety of in vitro and in vivo model systems. Necrotic cell death triggers an inflammatory response through release of HMGB1 in the extracellular space due to the membrane rupture. In an effort to better understand the pharmacological action mechanism that could explain the anti-inflammatory properties of EP, we examined the effects of EP on necrotic cell death in A549 lung adenocarcinoma cells in response to glucose deprivation (GD), a common characteristic of the tumor microenvironment. Here we show that EP prevented GD-induced necrosis and HMGB1 release and switched the cell death mode to apoptosis through inhibiting GD-induced CuZn superoxide dismutase release and ROS production. These results suggest that the necrosis-to-apoptosis switch activity of EP may contribute to its anti-inflammatory action and that EP may suppress tumor development possibly through its activity to induce the cell death mode switch from tumor promoting necrotic cell death to tumor suppressive apoptotic cell death.
Assuntos
Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Apoptose/efeitos dos fármacos , Proteína HMGB1/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Piruvatos/farmacologia , Glucose/farmacologia , Humanos , Inflamação/prevenção & controle , Necrose/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Células Tumorais CultivadasRESUMO
AIM: To investigate the endothelial differentiation potentiality of umbilical cord blood (UCB), we induced the differentiation of endothelial progenitor cells (EPC) from cryopreserved UCB-derived mononuclear cells (MNC). METHODS: MNC from cryopreserved UCB and peripheral blood (PB) were cultured in M199 medium with endothelial cell growth supplements for 14 d. EPC were characterized by RT-PCR, flow cytometry, and immunocytochemistry analysis. The proliferation of differentiated EPC was studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay, and vascular endothelial growth factor (VEGF) concentration was measured using an ELISA kit. Characteristics of UCB-derived EPC were compared with those of PB-derived EPC. RESULTS: A number of round-shaped cells were loosely attached to the bottom after 24 h culture, and numerous spindleshaped cells began to appear from the round-shaped ones on d 7. Those cells expressed endothelial markers such as, Flt-1/VEGFR-1, ecNOS, VE-cadherin, von Willebrand factor, and secreted VEGF. The patterns of endothelial markers of EPC from PB and UCB did not show striking differences. The results of the proliferation and secretion of VEGF were also similar. CONCLUSION: We successfully cultured UCB cells stored at -196 Celsius degree into cells with the quality of endothelial cells. Those EPC could be used for angiogenic therapeutics by activating adjacent endothelial cells and enhancing angiogenesis.
Assuntos
Diferenciação Celular , Células Endoteliais/fisiologia , Sangue Fetal/fisiologia , Monócitos/fisiologia , Células-Tronco/fisiologia , Biomarcadores , Células Cultivadas , Criopreservação , Células Endoteliais/ultraestrutura , Sangue Fetal/citologia , Humanos , Técnicas In Vitro , Células-Tronco/ultraestrutura , Fator A de Crescimento do Endotélio Vascular/biossíntese , Fator A de Crescimento do Endotélio Vascular/genéticaRESUMO
The protective effects of betulin (BT) against cadmium (Cd)-induced cytotoxicity have been previously reported. However, the mechanisms responsible for these protective effects are unclear. Therefore, this study investigated the mechanisms responsible for the protection of BT against Cd-induced cytotoxicity in human hepatoma cell lines. The protection of BT against Cd cytotoxicity was more effective in the HepG2 than in the Hep3B cells. The protection of BT on Cd-induced cytotoxicity in the HepG2 cells appeared to be related to the inhibition of apoptosis, as determined by PI staining and DNA fragmentation analysis. The anti-apoptosis exerted by BT involved the blocking of Cd-induced reactive oxygen species (ROS) generation, the abrogation of the Cd-induced Fas upregulation, the blocking of caspase-8-dependent Bid activation, and subsequent inhibition of mitochondrial pathway. The BT pretreatment did not affect the p21 and p53 expression levels, when compared with those of the treated cells with Cd alone. BT induced the transient S phase arrest at an early stage and the G0/G1 arrest at a relatively late stage, but it did not observe the sub-G1 apoptotic peak. In the Hep3B cells, Cd did not induce ROS generation. The BT pretreatment partially inhibited the Cd-induced apoptosis, which was related with the incomplete blockage in caspase-9 or -3 activation, as well as in Bax activation. Taken together, it was found that Cd can induce apoptosis via the Fas-dependent and -independent apoptosis pathways. However, the observed protective effects of BT were clearly more sensitive to Fas-expressing HepG2 cells than to Fas-deficient Hep3B cells.