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1.
Prz Gastroenterol ; 18(3): 225-248, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37937106

RESUMEN

Helicobacter pylori remains a major health problem worldwide, causing considerable morbidity and mortality due to peptic ulcer disease and gastric cancer. These guidelines constitute an update of the previous "Recommendations on the diagnosis and management of Helicobacter pylori infection" issued in 2014. They have been developed by a Task Force organized by the Governing Board of the Polish Society of Gastroenterology. They discuss, with particular emphasis on new scientific data covering papers published since 2014: the epidemiology, clinical presentation, diagnostic principles and criteria for the diagnosis, and recommendations for the treatment of H. pylori infection. The guidelines in particular determine which patients need to be tested and treated for infection. The Task Force also discussed recommended treatment algorithms. Accordingly, a combination of available evidence and consensus-based expert opinion were used to develop these best practice advice statements. It is worth noting that guidelines are not mandatory to implement but they offer advice for pragmatic, relevant and achievable diagnostic and treatment pathways based on established key treatment principles and using local knowledge and available resources to guide regional practice.

2.
J Clin Med ; 12(17)2023 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-37685710

RESUMEN

Pancreatic ductal adenocarcinoma (PDAC) is one of humans' most common and fatal neoplasms. Nowadays, a number of PDAC studies are being conducted in two different fields: non-coding RNA (especially microRNA and long non-coding RNA) and microbiota. It has been recently discovered that not only does miRNA affect particular bacteria in the gut microbiome that can promote carcinogenesis in the pancreas, but the microbiome also has a visible impact on the miRNA. This suggests that it is possible to use the combined impact of the microbiome and noncoding RNA to suppress the development of PDAC. Nevertheless, insufficient research has focused on bounding both approaches to the diagnosis, treatment, and prevention of pancreatic ductal adenocarcinoma. In this article, we summarize the recent literature on the molecular basis of carcinogenesis in the pancreas, the two-sided impact of particular types of non-coding RNA and the pancreatic cancer microbiome, and possible medical implications of the discovered phenomenon.

3.
Int J Mol Sci ; 23(21)2022 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-36362164

RESUMEN

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.


Asunto(s)
Colelitiasis , Humanos , Niño , Adolescente , Colelitiasis/epidemiología , Colelitiasis/etiología , Colelitiasis/diagnóstico , Causalidad , Comorbilidad , Predisposición Genética a la Enfermedad
4.
Ann Agric Environ Med ; 29(2): 246-251, 2022 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-35767758

RESUMEN

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.


Asunto(s)
Fumar Cigarrillos , FN-kappa B , Pancreatitis Crónica , Proteínas Proto-Oncogénicas p21(ras) , Enfermedad Aguda , Animales , Ceruletida/toxicidad , Fumar Cigarrillos/efectos adversos , Fumar Cigarrillos/genética , Fumar Cigarrillos/metabolismo , Modelos Animales de Enfermedad , Ratones , Ratones Endogámicos C57BL , FN-kappa B/biosíntesis , FN-kappa B/genética , FN-kappa B/metabolismo , Pancreatitis Crónica/genética , Pancreatitis Crónica/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/biosíntesis , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Proto-Oncogénicas p21(ras)/metabolismo
5.
Artículo en Inglés | MEDLINE | ID: mdl-35564692

RESUMEN

BACKGROUND: Gastroesophageal reflux disease (GERD) may present as nonerosive reflux disease (NERD), erosive esophagitis (EE), or be complicated by Barrett's esophagus (BE). The explanation as to what determines the phenotype of GERD is awaited. Therefore, we assessed the correlation between the growth factors expression and endoscopic as histologic findings in GERD patients. METHODS: The squamous esophageal epithelium of 50 patients (20-NERD, 7-EE, 15-BE, 8 controls) was examined by: (1) magnification endoscopy with evaluation of minimal GERD changes such as: microerosions, white spots, palisade blood vessels visibility, and intrapapillary capillary loops (IPCLs) appearance, (2) histology, (3) immunohistochemistry with evaluation of the expression of vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and their receptors (VEGFR and EGFR). RESULTS: The expression of VEGF, but not VEGFR, EGF, and EGFR, was significantly increased in EE patients compared to NERD patients and controls. VEGF levels correlated significantly with the presence of white spots, but not with other minimal endoscopic and histologic features. The EGFR expression correlated positively with basal cell hyperplasia and enlarged IPCLs. CONCLUSIONS: Our findings suggest a correlation between growth factors expression and findings in conventional endoscopy, formation of endoscopic minimal changes, and histologic lesions.


Asunto(s)
Esófago de Barrett , Carcinoma de Células Escamosas , Reflujo Gastroesofágico , Esófago de Barrett/patología , Endoscopía Gastrointestinal , Factor de Crecimiento Epidérmico , Receptores ErbB , Mucosa Esofágica/metabolismo , Mucosa Esofágica/patología , Humanos , Fenotipo , Factor A de Crecimiento Endotelial Vascular
6.
J Clin Med ; 10(23)2021 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-34884327

RESUMEN

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.

7.
Surg Endosc ; 35(3): 1067-1087, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-32107632

RESUMEN

BACKGROUND: Endoscopic techniques have become the first-line therapy in bariatric surgery-related complications such as leaks and fistulas. We performed a systematic review and meta-analysis on the effectiveness of self-expandable stents, clipping, and tissue sealants in closing of post-bariatric surgery leak/fistula. METHODS: A systematic literature search of the Medline/Scopus databases was performed to identify full-text articles published up to February 2019 on the use of self-expandable stents, clipping, or tissue sealants as primary endoscopic strategies used for leak/fistula closure. Meta-analysis of studies reporting stents was performed with the PRISMA guidelines. RESULTS: Data concerning the efficacy of self-expanding stents in the treatment of leaks/fistulas after bariatric surgery were extracted from 40 studies (493 patients). The overall proportion of successful leak/fistula closure was 92% (95% CI, 90-95%). The overall proportion of stent migration was 23% (95% CI, 19-28%). Seventeen papers (98 patients) reported the use of clipping: the over-the-scope clips (OTSC) system was used in 85 patients with a successful closure rate of 67.1% and a few complications (migration, stenosis, tear). The successful fistula/leak closure using other than OTSC types was achieved in 69.2% of patients. In 10 case series (63 patients), fibrin glue alone was used with a 92.8-100% success rate of fistula closure that usually required repeated sessions at scheduled intervals. The complications of fibrin glue applications were reported in only one study and included pain and fever in 12.5% of patients. CONCLUSIONS: Endoscopic techniques are effective for management of post-bariatric leaks and fistulas in properly selected patients.


Asunto(s)
Fuga Anastomótica/etiología , Endoscopía , Fístula/etiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Cirugía Bariátrica/efectos adversos , Femenino , Derivación Gástrica , Humanos , Masculino , Persona de Mediana Edad , Stents Metálicos Autoexpandibles , Adhesivos Tisulares/farmacología , Resultado del Tratamiento , Adulto Joven
8.
J Paediatr Child Health ; 56(8): 1233-1241, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32364307

RESUMEN

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.


Asunto(s)
Enfermedad de Crohn , Inhibidor Tisular de Metaloproteinasa-1 , Biomarcadores , Niño , Enfermedad de Crohn/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Metaloproteinasa 9 de la Matriz , Metaloproteasas
10.
Inflamm Bowel Dis ; 25(7): 1120-1128, 2019 06 18.
Artículo en Inglés | MEDLINE | ID: mdl-30772902

RESUMEN

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.


Asunto(s)
Biomarcadores/análisis , Colitis Ulcerosa/diagnóstico , Enfermedad de Crohn/diagnóstico , Heces/química , Mediadores de Inflamación/metabolismo , Metaboloma , Adolescente , Estudios de Casos y Controles , Colitis Ulcerosa/metabolismo , Enfermedad de Crohn/metabolismo , Femenino , Estudios de Seguimiento , Humanos , Masculino
11.
Adv Med Sci ; 64(1): 9-14, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30237086

RESUMEN

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.


Asunto(s)
Enfermedad de Crohn/sangre , Enfermedad de Crohn/diagnóstico , Heces/química , Complejo de Antígeno L1 de Leucocito/metabolismo , Albúmina Sérica/metabolismo , Adolescente , Área Bajo la Curva , Biomarcadores/metabolismo , Sedimentación Sanguínea , Proteína C-Reactiva/metabolismo , Niño , Preescolar , Femenino , Humanos , Lactante , Inflamación/patología , Masculino , Análisis Multivariante , Sensibilidad y Especificidad
12.
Int J Colorectal Dis ; 32(11): 1551-1559, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28812128

RESUMEN

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.


Asunto(s)
Fumar Cigarrillos/fisiología , Colitis Ulcerosa , Sulfato de Dextran/farmacología , Animales , Relación CD4-CD8/métodos , Colitis Ulcerosa/inmunología , Colitis Ulcerosa/patología , Colitis Ulcerosa/prevención & control , Colon/efectos de los fármacos , Colon/inmunología , Colon/patología , Modelos Animales de Enfermedad , Factores Inmunológicos/farmacología , Subgrupos Linfocitarios/efectos de los fármacos , Subgrupos Linfocitarios/inmunología , Subgrupos Linfocitarios/patología , Ratones , Factores Protectores , Índice de Severidad de la Enfermedad
13.
Gastroenterology ; 145(6): 1449-58, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23958541

RESUMEN

BACKGROUND & AIMS: Obesity is a risk factor for pancreatic ductal adenocarcinoma (PDAC), but it is not clear how obesity contributes to pancreatic carcinogenesis. The oncogenic form of KRAS is expressed during early stages of PDAC development and is detected in almost all of these tumors. However, there is evidence that mutant KRAS requires an additional stimulus to activate its full oncogenic activity and that this stimulus involves the inflammatory response. We investigated whether the inflammation induced by a high-fat diet, and the accompanying up-regulation of cyclooxygenase-2 (COX2), increases Kras activity during pancreatic carcinogenesis in mice. METHODS: We studied mice with acinar cell-specific expression of KrasG12D (LSL-Kras/Ela-CreERT mice) alone or crossed with COX2 conditional knockout mice (COXKO/LSL-Kras/Ela-CreERT). We also studied LSL-Kras/PDX1-Cre mice. All mice were fed isocaloric diets with different amounts of fat, and a COX2 inhibitor was administered to some LSL-Kras/Ela-CreERT mice. Pancreata were collected from mice and analyzed for Kras activity, levels of phosphorylated extracellular-regulated kinase, inflammation, fibrosis, pancreatic intraepithelial neoplasia (PanIN), and PDACs. RESULTS: Pancreatic tissues from LSL-Kras/Ela-CreERT mice fed high-fat diets (HFDs) had increased Kras activity, fibrotic stroma, and numbers of PanINs and PDACs than LSL-Kras/Ela-CreERT mice fed control diets; the mice fed the HFDs also had shorter survival times than mice fed control diets. Administration of a COX2 inhibitor to LSL-Kras/Ela-CreERT mice prevented these effects of HFDs. We also observed a significant reduction in survival times of mice fed HFDs. COXKO/LSL-Kras/Ela-CreERT mice fed HFDs had no evidence for increased numbers of PanIN lesions, inflammation, or fibrosis, as opposed to the increases observed in LSL-Kras/Ela-CreERT mice fed HFDs. CONCLUSIONS: In mice, an HFD can activate oncogenic Kras via COX2, leading to pancreatic inflammation and fibrosis and development of PanINs and PDAC. This mechanism might be involved in the association between risk for PDAC and HFDs.


Asunto(s)
Adenocarcinoma/fisiopatología , Carcinoma Ductal Pancreático/fisiopatología , Ciclooxigenasa 2/fisiología , Dieta Alta en Grasa/efectos adversos , Neoplasias Pancreáticas/fisiopatología , Proteínas Proto-Oncogénicas p21(ras)/fisiología , Adenocarcinoma/patología , Adiposidad/fisiología , Animales , Carcinoma Ductal Pancreático/patología , Ciclooxigenasa 2/deficiencia , Ciclooxigenasa 2/genética , Modelos Animales de Enfermedad , Fibrosis , Regulación Neoplásica de la Expresión Génica/fisiología , Ratones , Ratones Noqueados , Ratones Transgénicos , Páncreas/patología , Neoplasias Pancreáticas/patología
14.
Gastroenterology ; 144(1): 202-10, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23041324

RESUMEN

BACKGROUND & AIMS: Nuclear factor-κB (NF-κB) is activated during early stages of pancreatitis. This transcription factor regulates genes that control many cell activities, including inflammation and survival. There is evidence that activation of NF-κB protects against pancreatitis, and, in other cases, that it promotes this disease. We compared the effects of NF-κB in different mouse models of pancreatitis to understand these complications. METHODS: To model constitutive activation of NF-κB, we expressed a transgene that encodes its p65 subunit or the inhibitor of κB kinase (IKK)2 in pancreatic acinar cells of mice. We analyzed effects on pancreatic tissues and levels of NF-κB target genes in these mice and compared them with mice that did not express transgenic p65 or IKK2 (controls). RESULTS: Transgenic expression of p65 led to compensatory expression of the inhibitory subunit IKB-α and, therefore, no clear phenotype. However, p65 transgenic mice given injections of cerulein, to induce acute pancreatitis, had higher levels of NF-κB activity in acinar cells, greater levels of inflammation, and more severe outcomes than control mice. In contrast, constitutive expression of IKK2 directly increased the activity of NF-κB in acinar cells and induced pancreatitis. Prolonged activity of IKK2 (3 months) resulted in activation of stellate cells, loss of acinar cells, and fibrosis, which are characteristics of chronic pancreatitis. Co-expression of IKK2 and p65 greatly increased the expression of inflammatory mediators and the severity of pancreatitis, compared with control mice. CONCLUSIONS: The level of NF-κB activation correlates with the severity of acute pancreatitis in mice. Longer periods of activation (3 months) lead to chronic pancreatitis. These findings indicate that strategies to inactivate NF-κB might be used to treat patients with acute or chronic pancreatitis.


Asunto(s)
Células Acinares/metabolismo , Quinasa I-kappa B/metabolismo , FN-kappa B/metabolismo , Pancreatitis/metabolismo , Pancreatitis/patología , Factor de Transcripción ReIA/metabolismo , Animales , Ceruletida , Modelos Animales de Enfermedad , Fibrosis/genética , Fibrosis/metabolismo , Regulación de la Expresión Génica , Quinasa I-kappa B/genética , Proteínas I-kappa B/genética , Proteínas I-kappa B/metabolismo , Ratones , Ratones Transgénicos , Inhibidor NF-kappaB alfa , FN-kappa B/genética , Células Estrelladas Pancreáticas/metabolismo , Pancreatitis/inducido químicamente , Índice de Severidad de la Enfermedad , Factores de Tiempo , Factor de Transcripción ReIA/genética
15.
J Clin Invest ; 122(4): 1519-28, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22406536

RESUMEN

Genetic mutations that give rise to active mutant forms of Ras are oncogenic and found in several types of tumor. However, such mutations are not clear biomarkers for disease, since they are frequently detected in healthy individuals. Instead, it has become clear that elevated levels of Ras activity are critical for Ras-induced tumorigenesis. However, the mechanisms underlying the production of pathological levels of Ras activity are unclear. Here, we show that in the presence of oncogenic Ras, inflammatory stimuli initiate a positive feedback loop involving NF-κB that further amplifies Ras activity to pathological levels. Stimulation of Ras signaling by typical inflammatory stimuli was transient and had no long-term sequelae in wild-type mice. In contrast, these stimuli generated prolonged Ras signaling and led to chronic inflammation and precancerous pancreatic lesions (PanINs) in mice expressing physiological levels of oncogenic K-Ras. These effects of inflammatory stimuli were disrupted by deletion of inhibitor of NF-κB kinase 2 (IKK2) or inhibition of Cox-2. Likewise, expression of active IKK2 or Cox-2 or treatment with LPS generated chronic inflammation and PanINs only in mice expressing oncogenic K-Ras. The data support the hypothesis that in the presence of oncogenic Ras, inflammatory stimuli trigger an NF-κB-mediated positive feedback mechanism involving Cox-2 that amplifies Ras activity to pathological levels. Because a large proportion of the adult human population possesses Ras mutations in tissues including colon, pancreas, and lung, disruption of this positive feedback loop may be an important strategy for cancer prevention.


Asunto(s)
Carcinoma Ductal Pancreático/etiología , Retroalimentación Fisiológica/fisiología , Regulación Neoplásica de la Expresión Génica/fisiología , Genes ras , Inflamación/metabolismo , FN-kappa B/fisiología , Neoplasias Pancreáticas/etiología , Proteínas Proto-Oncogénicas p21(ras)/fisiología , Animales , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patología , Transformación Celular Neoplásica/genética , Ceruletida/toxicidad , Ciclooxigenasa 2/biosíntesis , Ciclooxigenasa 2/fisiología , Inhibidores de la Ciclooxigenasa 2/farmacología , Inducción Enzimática , Ésteres , Gabexato/análogos & derivados , Gabexato/toxicidad , Técnicas de Sustitución del Gen , Guanidinas , Humanos , Quinasa I-kappa B/deficiencia , Quinasa I-kappa B/genética , Quinasa I-kappa B/fisiología , Inflamación/inducido químicamente , Inflamación/complicaciones , Inflamación/genética , Mediadores de Inflamación/metabolismo , Lipopolisacáridos/toxicidad , Ratones , Ratones Transgénicos , Proteínas de Neoplasias/biosíntesis , Páncreas/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Pancreatitis Crónica/inducido químicamente , Pancreatitis Crónica/genética , Pancreatitis Crónica/metabolismo , Lesiones Precancerosas/inducido químicamente , Lesiones Precancerosas/genética , Proteínas Proto-Oncogénicas p21(ras)/biosíntesis , Sincalida/toxicidad
16.
Gastroenterology ; 137(3): 1072-82, 1082.e1-6, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19501586

RESUMEN

BACKGROUND & AIMS: Differentiated pancreatic acinar cells expressing endogenous levels of mutant K-Ras do not spontaneously develop pancreatic ductal adenocarcinoma (PDAC). However, we hypothesized that acinar cells would develop PDAC in the presence of Ras activity levels mimicking those of human tumor cells. METHODS: We measured Ras activity in PDAC cells from mice and humans using a Raf pull-down assay. We compared the effects of acinar cell expression of mutant K-Ras at endogenous and elevated levels on Ras activity and on the development of PDAC. RESULTS: Ras activity was greatly elevated in PDAC cells compared with nontransformed cells expressing endogenous levels of mutant K-Ras. Expression of endogenous levels of mutant K-Ras in differentiated acinar cells resulted in moderately elevated Ras activity and in sparse murine pancreatic intraepithelial neoplasias (mPanINs) that did not spontaneously advance to PDAC unless the tumor suppressor p53 was simultaneously deleted. In contrast, expression of mutant K-Ras at higher levels generated Ras activity equal to that in PDAC. High Ras activity mimicking levels in PDAC led to acinar cell senescence and generated inflammation and fibrosis resembling the histologic features of chronic pancreatitis. With higher Ras activity in acinar cells, abundant mPanINs formed and spontaneously progressed to both cystic papillary carcinoma and metastatic PDAC. CONCLUSIONS: There is an important relationship between Ras activity levels and the progression of PDAC. Sufficient Ras activity in pancreatic acinar induces several important pancreatic disease manifestations not previously reported and supports a potential direct linkage between chronic pancreatitis, cystic papillary carcinoma, and PDAC.


Asunto(s)
Carcinoma Ductal Pancreático/metabolismo , Genes ras/fisiología , Neoplasias Pancreáticas/metabolismo , Pancreatitis Crónica/metabolismo , Animales , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patología , Línea Celular Tumoral , Genes ras/genética , Humanos , Ratones , Ratones Transgénicos , Mutación , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patología , Pancreatitis Crónica/genética , Pancreatitis Crónica/patología
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