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1.
Med Sci Monit ; 29: e941195, 2023 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-37658600

RESUMO

BACKGROUND In recent years, an increasing prevalence of Helicobacter pylori resistance to antibiotics has been observed. The aim of this study was to assess antibiotic resistance of Helicobacter pylori in previously untreated children from northeast Poland. MATERIAL AND METHODS Inclusion criteria comprised suspicion of Helicobacter pylori infection based on the presence of Helicobacter pylori antigen in the stool and/or characteristic macroscopic lesions seen on esophagogastroduodenoscopy. Samples of the gastric and/or duodenal mucosa were collected from 82 children with a median age of 13 years (range 3-17) during esophagogastroduodenoscopy between February 2019 and May 2022. The material was cultured, and positive Helicobacter pylori strains were tested for drug resistance to amoxicillin, metronidazole, and clarithromycin using the quantitative antibiotic concentration gradient stripe method E-test. RESULTS Based on biopsy culture, Helicobacter pylori infection was confirmed in 50 (61%) children. Helicobacter pylori resistance was most common to clarithromycin (n=19; 38%), followed by metronidazole (n=15; 30%), and the least frequent to amoxicillin (n=13; 26%). The resistance to 1 antibiotic was found in 14 children (28%). Double-drug resistance was noted in 3 children (6%) and triple drug resistance in 9 children (18%). In the whole group, 24 children (48%) were susceptible to all 3 antibiotics. CONCLUSIONS In this study, conducted for the first time in treatment-naïve children in northeast Poland, we found a high proportion of Helicobacter pylori strains resistant to at least 1 antibiotic. Our results may help in the appropriate choice of antibiotics for treatment of Helicobacter pylori in our region.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Criança , Humanos , Pré-Escolar , Adolescente , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Claritromicina/farmacologia , Claritromicina/uso terapêutico , Metronidazol/farmacologia , Metronidazol/uso terapêutico , Infecções por Helicobacter/tratamento farmacológico , Polônia/epidemiologia , Biópsia , Amoxicilina/farmacologia , Amoxicilina/uso terapêutico
2.
Int J Mol Sci ; 23(21)2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36362164

RESUMO

The incidence of gallstone disease has increased in recent years. The pathogenesis of cholelithiasis is not fully understood. The occurrence of the disease is influenced by both genetic and environmental factors. This article reviews the literature on cholelithiasis in children, with the exception of articles on hematological causes of cholelithiasis and cholelithiasis surgery. The aim of this review is to present the latest research on the pathogenesis of gallstone disease in children. The paper discusses the influence of all factors known so far, such as genetic predisposition, age, infections, medications used, parenteral nutrition, and comorbidities, on the development of gallstone disease. The course of cholelithiasis in the pediatric population is complex, ranging from asymptomatic to life-threatening. Understanding the course of the disease and predisposing factors can result in a faster diagnosis of the disease and administration of appropriate treatment.


Assuntos
Colelitíase , Humanos , Criança , Adolescente , Colelitíase/epidemiologia , Colelitíase/etiologia , Colelitíase/diagnóstico , Causalidade , Comorbidade , Predisposição Genética para Doença
3.
Ann Agric Environ Med ; 29(2): 246-251, 2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35767758

RESUMO

INTRODUCTION AND OBJECTIVE: Epidemiological studies have demonstrated a strong association between cigarette smoking (CS) and chronic pancreatitis (CP); however, the exact mechanisms of this phenomenon remains unknown. The authors have previously shown that increased Ras expression activates the NF-κB mediated pathway and promotes development of CP. However, it is unclear whether a similar phenomenon occurs in CS-induced CP. Therefore, the aim of the study was to determine whether CS increases the expression of K-Ras, and promotes the development of CP in mice exposed to repeated episodes of acute pancreatitis (AP). MATERIAL AND METHODS: C57BL6/cmdb mice were exposed to CS or a sham treatment for 12 weeks. After one week of exposure, half of the animals from both groups were additionally subjected to repeated cerulein treatment (once a week, for 10 consecutive weeks) to mimic recurrent episodes of AP. Extension of pancreatic damage was determined histologically by H&E and Trichrome staining. The expression of K-Ras protein and downstream components (NF-κB, Cox-2, TGF-ß) was evaluated by immunohistochemistry. RESULTS: C57BL6/cmdb mice exposed to CS or cerulein alone did not develop any chronic pancreatic damage. However, concomitant treatment with both of these agents caused focal acinar atrophy, with slight intralobular and perivascular areas of fibrosis, and inflammatory cells infiltration resembling mild CP. Moreover, immunohistochemistry examinations revealed increased pancreatic expression of K-Ras and NF-κB only in mice treated both with CS and cerulein. CONCLUSIONS: CS promotes development of CP in mice exposed to repeated episodes of AP. This process may be, at least partially, related to increased expression of K-Ras and NF-κB protein.


Assuntos
Fumar Cigarros , NF-kappa B , Pancreatite Crônica , Proteínas Proto-Oncogênicas p21(ras) , Doença Aguda , Animais , Ceruletídeo/toxicidade , Fumar Cigarros/efeitos adversos , Fumar Cigarros/genética , Fumar Cigarros/metabolismo , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/biossíntese , NF-kappa B/genética , NF-kappa B/metabolismo , Pancreatite Crônica/genética , Pancreatite Crônica/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/biossíntese , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo
4.
J Clin Med ; 10(23)2021 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-34884327

RESUMO

Pancreatic ductal adenocarcinoma is one of the deadliest human neoplasms. Despite the development of new surgical and adjuvant therapies, the prognosis remains very poor, with the overall survival rate not exceeding 9%. There is now increasing evidence that the human microbiome, which is involved in many physiological functions, including the regulation of metabolic processes and the modulation of the immune system, is possibly linked to pancreatic oncogenesis. However, the exact mechanisms of action are poorly understood. Our review summarizes the current understanding of how the microbiome affects pancreatic cancer development and progression. We discuss potential pathways of microbe translocation to the pancreas, as well as the mechanism of their action. We describe the role of the microbiome as a potential marker of pancreatic cancer diagnosis, progression, and survival. Finally, we discuss the possibilities of modifying the microbiome to improve treatment effectiveness for this deadly disease.

5.
Int J Mol Sci ; 22(11)2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070700

RESUMO

BACKGROUND: the molecular mechanism of gastric cancer development related to Helicobacter pylori (H. pylori) infection has not been fully understood, and further studies are still needed. Information regarding nanomechanical aspects of pathophysiological events that occur during H. pylori infection can be crucial in the development of new prevention, treatment, and diagnostic measures against clinical consequences associated with H. pylori infection, including gastric ulcer, duodenal ulcer, and gastric cancer. METHODS: in this study, we assessed mechanical properties of children's healthy and H. pylori positive stomach tissues and the mechanical response of human gastric cells exposed to heat-treated H. pylori cells using atomic force microscopy (AFM NanoWizard 4 BioScience JPK Instruments Bruker). Elastic modulus (i.e., the Young's modulus) was derived from the Hertz-Sneddon model applied to force-indentation curves. Human tissue samples were evaluated using rapid urease tests to identify H. pylori positive samples, and the presence of H. pylori cells in those samples was confirmed using immunohistopathological staining. RESULTS AND CONCLUSION: collected data suggest that nanomechanical properties of infected tissue might be considered as markers indicated H. pylori presence since infected tissues are softer than uninfected ones. At the cellular level, this mechanical response is at least partially mediated by cell cytoskeleton remodeling indicating that gastric cells are able to tune their mechanical properties when subjected to the presence of H. pylori products. Persistent fluctuations of tissue mechanical properties in response to H. pylori infection might, in the long-term, promote induction of cancer development.


Assuntos
Mucosa Gástrica , Infecções por Helicobacter , Helicobacter pylori/metabolismo , Úlcera Gástrica , Adolescente , Feminino , Mucosa Gástrica/metabolismo , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia , Infecções por Helicobacter/metabolismo , Infecções por Helicobacter/patologia , Humanos , Masculino , Úlcera Gástrica/metabolismo , Úlcera Gástrica/microbiologia , Úlcera Gástrica/patologia
6.
Scand J Gastroenterol ; 55(11): 1277-1283, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33032462

RESUMO

BACKGROUND AND AIMS: Eosinophilic esophagitis (EoE) is a chronic, local immune-mediated esophageal disease with eosinophil-dominated inflammation. The incidence of the disease is rapidly increasing in both children and adults. The pathogenesis of the disease is still not well understood. We present a review of the literature devoted to the EoE immunopathology, in particular the markers of inflammation and epithelial integrity, and their usefulness in disease monitoring and therapy. METHODS: We performed a systematic search of the MEDLINE/PubMed databases for studies to examine the use of immunohistochemistry as a diagnostic tool for EoE. RESULTS: The gold standard of EoE diagnosis requires multiple endoscopies with biopsies for histological assessment. The minimum number of eosinophils evaluated in hematoxylin-eosin staining to diagnose EoE is 15 per high-power field in at least one esophageal mucosa biopsy. However, in some cases, the count of eosinophils is not specific and insufficient as the only indicator. Recent works confirm the usefulness of assessment of some biomarkers in establishing the diagnosis and monitoring the treatment effects. CONCLUSIONS: Immunohistochemistry seems to be a promising option not only in clinical recognition, but also in the selection and monitoring of treatment effects. However, these methods have not yet recommended for routine clinical use.


Assuntos
Esofagite Eosinofílica , Adulto , Biomarcadores , Criança , Esofagite Eosinofílica/diagnóstico , Eosinófilos , Mucosa Esofágica , Humanos
7.
Biomolecules ; 10(7)2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32708181

RESUMO

An altered ceramide composition in patients with inflammatory bowel disease (IBD) has been reported recently. The aim of this study was to evaluate the concentrations of sphingolipids in the serum of treatment-naive children with newly diagnosed IBD and to determine the diagnostic value of the tested lipids in pediatric IBD. The concentrations of sphingolipids in serum samples were evaluated using a quantitative method, an ultra-high-performance liquid chromatography-tandem mass spectrometry in children with Crohn's disease (CD) (n=34), ulcerative colitis (UC) (n = 39), and controls (Ctr) (n = 24). Among the study groups, the most significant differences in concentrations were noted for C16:0-LacCer, especially in children with CD compared to Ctr or even to UC. Additionally, the relevant increase in C20:0-Cer and C18:1-Cer concentrations were detected in both IBD groups compared to Ctr. The enhanced C24:0-Cer level was observed only in UC, while C18:0-Cer only in the CD group. The highest area under the curve (AUC), specificity, and sensitivity were determined for C16:0-LacCer in CD diagnosis. Our results suggest that the serum LacC16-Cer may be a potential biomarker that distinguishes children with IBD from healthy controls and differentiates IBD subtypes. In addition, C20:0-Cer and C18:0-Cer levels also seem to be closely connected with IBD.


Assuntos
Doenças Inflamatórias Intestinais/sangue , Lactosilceramidas/sangue , Esfingolipídeos/sangue , Adolescente , Área Sob a Curva , Biomarcadores/sangue , Criança , Pré-Escolar , Colite Ulcerativa/sangue , Colite Ulcerativa/diagnóstico , Doença de Crohn/sangue , Doença de Crohn/diagnóstico , Feminino , Humanos , Doenças Inflamatórias Intestinais/diagnóstico , Masculino
8.
J Paediatr Child Health ; 56(8): 1233-1241, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32364307

RESUMO

AIM: The aim of this study was to determine the relation of non-invasive markers representing gut mucosal damage (metalloproteinase-9 (MMP-9)) and remodelling (tissue inhibitor of metalloproteinase-1 (TIMP-1)) with Crohn's disease (CD) phenotype, disease activity scores (clinical and endoscopic) and radiological evaluation of the ileum in newly diagnosed children. METHODS: Serum and faecal MMP-9 and TIMP-1 concentrations were determined with the sandwich enzyme-linked immunoassay technique. The performance of each marker with reference to the Paris classification, disease activity scores and magnetic resonance enterography results was assessed using non-parametric tests. RESULTS: A total of 32 children with CD demonstrated higher levels of serum and faecal MMP-9 and TIMP-1 compared with a control group including children without gastrointestinal inflammatory disease (all P < 0.05). Only the serum MMP-9 concentration was significantly higher in children with L3 (ileocolonic) compared with children with L1 (distal ileum). The serum TIMP-1 level was significantly higher in patients with an magnetic resonance enterography-detected ileum involvement longer than 51 mm and in children with severe disease activity compared with other patients. The serum MMP-9 level was lower in patients with stenosis combined with prestenotic dilation compared with children without stenosis. CONCLUSION: Increased serum and faecal MMP-9 and TIMP-1 concentrations are some reliable markers of inflammation in newly diagnosed children with CD, but without facilitating clear phenotyping of the disease.


Assuntos
Doença de Crohn , Inibidor Tecidual de Metaloproteinase-1 , Biomarcadores , Criança , Doença de Crohn/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Metaloproteinase 9 da Matriz , Metaloproteases
10.
Int J Dermatol ; 58(9): 1056-1061, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30964204

RESUMO

BACKGROUND: Changing the resources of vitamin D and antioxidant nutrients may affect the course of allergic diseases. The aim of the study was to investigate the association between CoQ10, vitamin D, retinol, and α-tocopherol serum levels and severity of atopic dermatitis (AD) in children. METHODS: Twenty-nine children with AD aged from 1 to 15 years were enrolled into the study. The severity of AD was categorized into mild or moderate (≤50 points in SCORAD - Scoring Atopic Dermatitis index) and severe (>50 SCORAD points). The control group was comprised of 22 children with negative history of allergy aged from 2 to 15. The serum measurements included vitamin D, retinol, α-tocopherol, CoQ10, C-reactive protein (CRP), complete blood count (CBC), and total immunoglobulin E (IgE). RESULTS: Low vitamin D concentration (<20 ng/ml) was observed mainly in patients with severe AD (77.8%), compared to children with mild or moderate AD (25%) or the control group (31.8%). Concentration of retinol was decreased significantly in patients with severe AD (median 1.32 µmol/l), compared to children with mild and moderate AD (median 1.66 µmol/l), but not to the control. Among inflammatory markers, only the group with severe AD demonstrated significantly elevated platelet count (PLT), red blood cell distribution width (RDW), and eosinophil count (EO). Retinol level correlated with PLT (R = -0.7; P = 0.003), white blood count (WBC) (R = -0.54; P = 0.01), total IgE (R = -0.51; P = 0.016), mean platelet volume (MPV) (R = 0.51; P = 0.02), and also with a disease severity index, SCORAD (R = -0.55; P = 0.007), whereas vitamin D level correlated only with MPV (R = 0.61; P = 0.003). No significant changes were found in tocopherol and CoQ10 levels between groups. CONCLUSIONS: Children with AD should be routinely tested for vitamin D deficiency, especially during disease exacerbation. Our results confirmed correlation of serum inflammatory markers with decreased concentration of vitamin A in children with AD. This finding, however, might be an effect of severe stage of disease and not only of inadequate intake of retinol in the diet.


Assuntos
Dermatite Atópica/diagnóstico , Índice de Gravidade de Doença , Vitamina A/sangue , Deficiência de Vitamina D/diagnóstico , Vitamina D/sangue , Adolescente , Biomarcadores/sangue , Estudos de Casos e Controles , Criança , Pré-Escolar , Dermatite Atópica/sangue , Dermatite Atópica/patologia , Progressão da Doença , Comportamento Alimentar , Feminino , Humanos , Lactente , Masculino , Polônia , Estudos Prospectivos , Tocoferóis/sangue , Ubiquinona/análogos & derivados , Ubiquinona/sangue , Deficiência de Vitamina D/sangue
11.
Inflamm Bowel Dis ; 25(7): 1120-1128, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-30772902

RESUMO

BACKGROUND: Metabolic profiling might be used to identify disease biomarkers. The aim of our study was to determine the usefulness of untargeted metabolomics analysis to detect differences in serum metabolites between newly diagnosed and untreated pediatric patients with Crohn's disease (CD) or ulcerative colitis (UC) in comparison with a control group (Ctr). Moreover, we investigated the potential of profiling metabolomics and inflammatory markers to improve the noninvasive diagnosis of CD and UC in children. METHODS: Metabolic fingerprinting of serum samples was estimated with liquid chromatography coupled with mass spectrometry in children with CD (n = 9; median age, 14 years), UC (n = 10; median age, 13.5 years), and controls (n = 10; median age, 12.5 years). RESULTS: The majority of chemically annotated metabolites belonged to phospholipids and were downregulated in CD and UC compared with the Ctr. Only 1 metabolite, lactosylceramide 18:1/16:0 (LacCer 18:1/16:0), significantly discriminated CD from UC patients. Interestingly, combining LacCer 18:1/16:0 with other inflammatory markers resulted in a significant increase in the area under the curve with the highest specificity and sensitivity. CONCLUSIONS: Using serum untargeted metabolomics, we have shown that LacCer 18:1/16:0 is a very unique metabolite for CD patients.


Assuntos
Biomarcadores/análise , Colite Ulcerativa/diagnóstico , Doença de Crohn/diagnóstico , Fezes/química , Mediadores da Inflamação/metabolismo , Metaboloma , Adolescente , Estudos de Casos e Controles , Colite Ulcerativa/metabolismo , Doença de Crohn/metabolismo , Feminino , Seguimentos , Humanos , Masculino
12.
Adv Med Sci ; 64(1): 9-14, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30237086

RESUMO

PURPOSE: Increased fecal calprotectin is a sensitive marker of various types of intestinal inflammation. We investigated correlations between high fecal calprotectin concentration and serum inflammatory markers in children with different intestinal diseases with diarrhea with/without blood and/or abdominal pain, to test whether the combination of these markers can differentiate potential patients with inflammatory bowel disease. MATERIALS/METHODS: The study included 128 children with high fecal calprotectin concentration (>150ug/g) and symptoms suggesting bowel disorders, hospitalized in the years 2013- 2015. Twenty-six (20%) patients were diagnosed with Crohn's disease, 55 (43%) with ulcerative colitis, 32 (25%) with intestinal infection and 15 (12%) with food protein induced proctocolitis. RESULTS: Significantly increased inflammatory markers were detected in children with inflammatory bowel disease, with a correlation between calprotectin and erythrocyte sedimentation rate - ESR (R = 0.53), mean corpuscular volume - MCV (R=-0.64), red blood cell distribution width (R = 0.56), albumin (R = -0.52), hemoglobin (R = -0.53) only in Crohn's disease patients. To discriminate Crohn's disease patients from patients with intestinal infection and patients with food protein induced proctocolitis, AUC analysis was performed. It revealed that considering ESR, CRP and albumin as additional markers to fecal calprotectin significantly improved diagnostic performance (AUC 0.917, p = 0.038). CONCLUSIONS: In children with abdominal pain and/or diarrhea, increased ESR, CRP and decreased albumin combined with a high fecal calprotectin level yields additional diagnostic value in screening potential patients with Crohn's disease. As far as differentiation of ulcerative colitis is concerned, low additional diagnostic value was found when high fecal calprotectin was combined with albumin.


Assuntos
Doença de Crohn/sangue , Doença de Crohn/diagnóstico , Fezes/química , Complexo Antígeno L1 Leucocitário/metabolismo , Albumina Sérica/metabolismo , Adolescente , Área Sob a Curva , Biomarcadores/metabolismo , Sedimentação Sanguínea , Proteína C-Reativa/metabolismo , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Inflamação/patologia , Masculino , Análise Multivariada , Sensibilidade e Especificidade
13.
Int J Colorectal Dis ; 32(11): 1551-1559, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28812128

RESUMO

BACKGROUND: Cigarette smoke (CS) exerts protective effect against ulcerative colitis. The mechanism of this phenomenon remains unknown. One of the possible explanation by which CS exerts its anti-inflammatory action is modulation of immune system. Therefore, the aim of the study was to evaluate the effect of CS on the course of inflammation and subpopulations of lymphocytes in the blood and colon in mice with dextran sulfate sodium (DSS)-induced colitis. METHODS: C57BL6/cmdb mice were exposed to CS for 4 weeks. Colitis was induced with 3.5% DSS given for 10 days. Severity of colitis was determined by disease activity index (DAI), body weight changes, and macro- and microscopic characteristics of inflammation. Peripheral subpopulations of lymphocytes were assessed by flow cytometry (blood) or immunohistochemistry (colonic tissue). RESULTS: Mice treated with 3.5% DSS developed severe colitis with significantly decreased body weight, increased DAI, and macroscopic and histological features of colonic inflammation. These findings were diminished after concomitant exposure to CS. Mice exposed to DSS alone demonstrated significantly decreased percentage of total CD4+ cells (73.1 vs. 52%, p = 0.0007), accompanied by increase of CD8+ cells (18.4 vs. 39.5%, p = 0.0001). Concomitant CS exposure reversed inappropriate CD4+/CD8+ ratio both in the blood and colon and significantly increased B cell presence in the colon. CONCLUSIONS: Our study has demonstrated that CS exposure decreases severity of DSS-induced colitis. This phenomenon was accompanied by changes in CD4/CD8 ratio and B cell level in the peripheral blood and colon. These mechanisms may be responsible for protective effect of smoking in ulcerative colitis.


Assuntos
Fumar Cigarros/fisiologia , Colite Ulcerativa , Sulfato de Dextrana/farmacologia , Animais , Relação CD4-CD8/métodos , Colite Ulcerativa/imunologia , Colite Ulcerativa/patologia , Colite Ulcerativa/prevenção & controle , Colo/efeitos dos fármacos , Colo/imunologia , Colo/patologia , Modelos Animais de Doenças , Fatores Imunológicos/farmacologia , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/patologia , Camundongos , Fatores de Proteção , Índice de Gravidade de Doença
14.
J Exp Clin Cancer Res ; 31: 69, 2012 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-22929310

RESUMO

BACKGROUND: Although significant progress has been made in the treatment of lymphomas, many lymphomas exhibit resistance to cell death, suggesting a defective Fas signaling, which remains poorly understood. We previously reported that cells expressing the K1 protein of human herpesvirus 8 (HHV-8) resist death through the complex formation of the Ig-like domain of K1 with Fas. Recently, we investigated whether peptides derived from the Ig-like domain of the K1 protein may affect cell death. METHODS: K1 positive and negative cell lines were incubated with the K1-derived peptides, and cell death (apoptotic and necrotic) was assessed by flow cytometry and LDH assay. Activation of caspases was assessed by fluorometric assay and flow cytometry. Fas receptor-independent, peptide-mediated cell killing was tested in the Fas-resistant Daudi cell line and Jurkat cell clones deficient in caspase-8 and FADD functionality. Activation of TNF receptors I and II was blocked by pre-incubation with corresponding blocking antibodies. The effect of the K1 peptide in vivo was tested in a mouse xenograft model. RESULTS: We observed that the peptide S20-3 enhanced cell death in K1-positive BJAB cells and HHV-8 positive primary effusion lymphoma (PEL) cell lines. Similar effects of this peptide were observed in B-cell lymphoma and T-lymphoblastic leukemia cells without K1 expression but not in normal human peripheral blood mononuclear cells. A single intratumoral injection of the S20-3 peptide decreased the growth of Jurkat xenografts in SCID mice. The mechanism of tumor cell death induced by the S20-3 peptide was associated with activation of caspases, but this activity was only partially inhibited by the pan-caspase inhibitor z-VAD. Furthermore, the K1 peptide also killed Fas-resistant Daudi cells, and this killing effect was inhibited by pre-incubation of cells with antibodies blocking TNFRI. CONCLUSION: Taken together, these findings indicate that the S20-3 peptide can selectively induce the death of malignant hematological cell lines by Fas- and/or TNFRI-dependent mechanisms, suggesting the K1-derived peptide or peptidomimetic may have promising therapeutic potential for the treatment of hematological cancers.


Assuntos
Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Hematológicas , Peptídeos , Proteínas Virais , Receptor fas , Animais , Apoptose/efeitos dos fármacos , Caspase 8/metabolismo , Proteína de Domínio de Morte Associada a Fas/metabolismo , Neoplasias Hematológicas/tratamento farmacológico , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/metabolismo , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/metabolismo , Humanos , Células Jurkat , Camundongos , Camundongos SCID , Peptídeos/administração & dosagem , Peptídeos/síntese química , Estrutura Terciária de Proteína , Receptores do Fator de Necrose Tumoral/metabolismo , Transdução de Sinais , Proteínas Virais/administração & dosagem , Proteínas Virais/síntese química , Receptor fas/genética , Receptor fas/metabolismo
15.
Blood ; 118(11): 3107-18, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21803845

RESUMO

Defective Fas signaling leads to resistance to various anticancer therapies. Presence of potential inhibitors of Fas which could block Fas signaling can explain cancer cells resistance to apoptosis. We identified promyelocytic leukemia protein (PML) as a Fas-interacting protein using mass spectrometry analysis. The function of PML is blocked by its dominant-negative form PML-retinoic acid receptor α (PMLRARα). We found PMLRARα interaction with Fas in acute promyelocytic leukemia (APL)-derived cells and APL primary cells, and PML-Fas complexes in normal tissues. Binding of PMLRARα to Fas was mapped to the B-box domain of PML moiety and death domain of Fas. PMLRARα blockage of Fas apoptosis was demonstrated in U937/PR9 cells, human APL cells and transgenic mouse APL cells, in which PMLRARα recruited c-FLIP(L/S) and excluded procaspase 8 from Fas death signaling complex. PMLRARα expression in mice protected the mice against a lethal dose of agonistic anti-Fas antibody (P < .001) and the protected tissues contained Fas-PMLRARα-cFLIP complexes. Taken together, PMLRARα binds to Fas and blocks Fas-mediated apoptosis in APL by forming an apoptotic inhibitory complex with c-FLIP. The presence of PML-Fas complexes across different tissues implicates that PML functions in apoptosis regulation and tumor suppression are mediated by direct interaction with Fas.


Assuntos
Apoptose , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Receptor fas/metabolismo , Animais , Apoptose/genética , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/genética , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/fisiologia , Células Cultivadas , Regulação para Baixo , Feminino , Células HL-60 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Biológicos , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/fisiologia , Ligação Proteica/fisiologia , Células U937 , Receptor fas/antagonistas & inibidores , Receptor fas/genética , Receptor fas/fisiologia
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