Genetic Inhibition of the Ubiquitin Ligase Rnf5 Attenuates Phenotypes Associated to F508del Cystic Fibrosis Mutation

Cystic fibrosis (CF) is caused by mutations in the CFTR chloride channel. Deletion of phenylalanine 508 (F508del), the most frequent CF mutation, impairs CFTR trafficking and gating. F508del-CFTR mistrafficking may be corrected by acting directly on mutant CFTR itself or by modulating expression/activity of CFTR-interacting proteins, that may thus represent potential drug targets. To evaluate possible candidates for F508del-CFTR rescue, we screened a siRNA library targeting known CFTR interactors. Our analysis identified RNF5 as a protein whose inhibition promoted significant F508del-CFTR rescue and displayed an additive effect with the investigational drug VX-809. Significantly, RNF5 loss in F508del-CFTR transgenic animals ameliorated intestinal malabsorption and concomitantly led to an increase in CFTR activity in intestinal epithelial cells. In addition, we found that RNF5 is differentially expressed in human bronchial epithelia from CF vs. control patients. Our results identify RNF5 as a target for therapeutic modalities to antagonize mutant CFTR proteins

Molecular mechanisms involved in the pathogenesis of gastric carcinoma: interactions between genetic alterations, cellular phenotype and cancer histotype

Gastric cancer develops through the accumulation of multiple genetic lesions that involve oncogenes, tumor suppressor genes and DNA mismatch repair genes. Lauren's classification of gastric carcinoma does not correlate with cellular phenotypes expressed by neoplastic cells and gastric and intestinal cell differentiation markers are widely expressed in both types (intestinal and diffuse) of gastric carcinoma. In contrast, the study of the correlation between morphologic events and genetic alterations, which come about in the cancerogenetic process, seems to indicate the existence of distinct cancerogenetic pathways for the intestinal (or glandular) and diffuse type carcinoma, both originating from a HP-positive gastritis. In particular there seem to be three different profiles of cancerogenesis: 1) p53 mutations which accompany the onset of dysplasia and intestinal-type carcinoma; 2) DNA repair mechanism alterations conditioning microsatellite instability, seem mutually exclusive with regards to p53 mutations. Microsatellite instability correlates with antrally located intestinal-type carcinoma, with little metastatic tendency and a better prognosis; microsatellite instability frequently involves the TGF beta RII, IGF II R genes or the BAX proapoptotic gene, in as much as these contain microsatellite sequences; 3) alterations of E-cadherin, both with regards to mutations and abnormal expression. These lead to junctional and cell polarity loss and are primarily associated with diffuse type carcinoma, which is characterized by poorly cohesive neoplastic cells. Some tumors, initially arising as intestinal-type (glandular structure), acquire a mixed histotype during neoplastic progression, in which both the typical alterations of the intestinal cancerogenesis (p53, microsatellite instability) and those of the diffuse carcinoma (E-cadherin) coexist. The identification of a mixed histotype could have importance both in epidemiologic, pathogenetic and prognostic terms

Achalasia with Dense Eosinophilic Infiltrate Responding To Steroidal Treatment.

A patient presented with chronic substernal discomfort and intermittent dysphagia for solids. High-resolution impedance manometry (HRIM) of the esophagus showed that there was no peristalsis in the esophageal body but incomplete relaxation of the lower esophageal sphincter and incomplete bolus transit, so the patient was diagnosed with achalasia. Moreover, probably because of esophageal stasis, eosinophilic infiltration that mimicked a pattern of eosinophilic esophagitis was observed, on the basis of multiple biopsies of the esophagus. The patient was given 50 mg prednisolone once daily; the symptoms improved dramatically, and HRIM showed complete recovery of esophageal peristalsis, deeper relaxation of the lower esophageal sphincter, and complete bolus transit profile. HRIM can therefore be used to assess dysmotility abnormalities in patients with achalasia and eosinophilic-like esophagitis, and steroids relieve these symptoms. Treatment with a high dose of prednisolone resulted in a complete disappearance of dysphagia because of improved esophageal motility and reduced eosinophilic infiltrate. It is therefore important to control the inflammatory process in patients with idiopathic achalasia, which is likely to result from an autoimmune reaction

Development of consensus guidelines for the histologic recognition of microscopic esophagitis in patients with gastroesophageal reflux disease: the Esohisto project.

No gold standard test exists for gastroesophageal reflux disease (GERD). Diagnostic difficulties are greatest when reflux symptoms occur without visible esophageal mucosal damage at conventional endoscopy. However, two thirds of such patients do have microscopic esophageal lesions. This study aimed to develop and standardize criteria for recognizing these microscopic esophageal lesions in GERD. Draft histologic criteria were developed and tested by an international group of 5 independent gastrointestinal pathologists using 167 biopsy specimens from GERD patients and healthy controls (phase I). Draft criteria were refined and reassessed using 250 photographs of biopsy specimens (phase II). Histologic lesions evaluated were basal cell hyperplasia, papillary elongation, intraepithelial eosinophil, neutrophil and mononuclear cell number, necrosis/erosion, healed erosion, and dilated intercellular spaces. Interobserver agreement and \u3ba values increased significantly from phase I to II. When tested in annotated photographs (phase II), mean pairwise agreements were 74%, 89%, 93%, 97%, 81%, 97%, 94%, and 74%, respectively. Mean pairwise \u3ba estimates (\ub1SD) were 0.49 (0.16), 0.81 (0.05), 0.87 (0.05), 0.84 (0.09), 0.60 (0.09), 0.90 (0.04), 0.73 (0.14), and 0.61 (0.08), respectively. Estimated intraclass correlation coefficients for basal cell layer thickness and papillary length increased from 0.38 and 0.56 to 0.69 and 0.95, respectively, when revised criteria were used. The draft criteria achieved promising levels of agreement when assessed independently by 5 pathologists. Further steps include evaluation of lesions without indicating the area to be assessed and exploring the correlation of microscopic esophagitis with symptoms and esophageal acid exposure

Long-term outcome of microscopic esophagitis in chronic GERD patients treated with esomeprazole or laparoscopic anti-reflux surgery, in the LOTUS trial.

OBJECTIVES: Gastroesophageal refl ux disease (GERD)-associated changes in esophageal histology have been reported mainly after short-term medical antirefl ux therapy, and few individual lesions have been examined. We report detailed histological fi ndings from the LOTUS study, at baseline and at 1 and 3 years after laparoscopic antirefl ux surgery (LARS) or esomeprazole treatment in patients with chronic GERD. METHODS: LOTUS is a long-term, open, parallel-group, multicenter, randomized, controlled trial conducted in 11 European countries that compared LARS ( n = 248) with esomeprazole 20 \u2013 40 mg daily ( n = 266). Biopsies from the distal esophagus 2 cm above the Z-line and at the Z-line were taken at baseline, and 1 and 3 years. The following lesions were assessed: basal cell hyperplasia (BCH), papillary elongation (PE), intercellular space dilatations (ISDs), intraepithelial eosinophils (EOSs), neutrophils, and necrosis / erosion. A severity score (SS, range 0 \u2013 2) was calculated by taking the average score of all assessable lesions. RESULTS: All lesions were more severe on Z-line biopsies than at 2 cm, and almost all improved signifi cantly from baseline to 1 and 3 years. The average SS (from 2 cm to Z-line) changed from 0.95 to 0.57 (1 year) and to 0.49 (3 years) on esomeprazole, and from 0.91 to 0.56 (1 year) and to 0.52 (3 years) after LARS ( P < 0.001 for both treatments at 1 and 3 years, with no signifi cant difference between treatments). The proportions of patients with severe histological changes decreased from approximately 50 % at baseline to 11 % at 3 years. CONCLUSIONS: Both continuous esomeprazole treatment and laparoscopic fundoplication are associated with signifi cant and similar overall improvement in microscopic esophagitis after 1 year that is maintained at 3 years

Interobserver agreement of a gastric adenocarcinoma tumor regression grading system that incorporates assessment of lymph nodes

Perioperative chemotherapy is increasingly used in combination with surgery for the treatment of patients with locally advanced, resectable gastric cancer. Histologic tumor regression grade (TRG) has emerged as an important prognostic factor; however, a common standard for its evaluation is lacking. Moreover, the clinical significance of regressive changes in metastatic lymph nodes (LNs) remains unclear. We conducted an international study to examine the interobserver agreement of a TRG system that is based on the Becker system for the primary tumors and additionally incorporates regression grading in LNs. Twenty observers at different levels of experience evaluated the TRG in 60 histologic slides (30 primary tumors and 30 LNs) based on the following criteria: for primary tumors, grade 1 represented complete response (no residual tumor), grade 2 represented 50% residual tumor, as described by Becker et al. For LNs, grade "a" represented complete, grade "b" represented partial, and grade "c" represented no regression. The interobserver agreement was estimated using the Kendall's coefficient of concordance (W). Regarding primary tumors, agreement was good irrespective of the level of experience, reaching a W-value of 0.70 overall, 0.71 among subspecialized, and 0.71 among nonsubspecialized observers. Regarding LNs, interobserver agreement was moderate to good, with W-values of 0.52 overall, 0.64 among subspecialized, and 0.45 among nonsubspecialized observers. These findings indicate that the combination of the Becker TRG system with a three-tiered grading of regression in LNs generates a system that is reproducible. Future studies should investigate whether the additional information of TRG in LNs adds to the prognostic value of histologic regression grading in gastric cancer specimens

Interobserver agreement of a gastric adenocarcinoma tumor regression grading system that incorporates assessment of lymph nodes

none14: Perioperative chemotherapy is increasingly used in combination with surgery for the treatment of patients with locally advanced, resectable gastric cancer. Histologic tumor regression grade (TRG) has emerged as an important prognostic factor; however, a common standard for its evaluation is lacking. Moreover, the clinical significance of regressive changes in metastatic lymph nodes (LNs) remains unclear. We conducted an international study to examine the interobserver agreement of a TRG system that is based on the Becker system for the primary tumors and additionally incorporates regression grading in LNs. Twenty observers at different levels of experience evaluated the TRG in 60 histologic slides (30 primary tumors and 30 LNs) based on the following criteria: for primary tumors, grade 1 represented complete response (no residual tumor), grade 2 represented <10%, grade 3 represented 10-50%, and grade 4 represented >50% residual tumor, as described by Becker et al. For LNs, grade "a" represented complete, grade "b" represented partial, and grade "c" represented no regression. The interobserver agreement was estimated using the Kendall's coefficient of concordance (W). Regarding primary tumors, agreement was good irrespective of the level of experience, reaching a W-value of 0.70 overall, 0.71 among subspecialized, and 0.71 among nonsubspecialized observers. Regarding LNs, interobserver agreement was moderate to good, with W-values of 0.52 overall, 0.64 among subspecialized, and 0.45 among nonsubspecialized observers. These findings indicate that the combination of the Becker TRG system with a three-tiered grading of regression in LNs generates a system that is reproducible. Future studies should investigate whether the additional information of TRG in LNs adds to the prognostic value of histologic regression grading in gastric cancer specimens.openTsekrekos, Andrianos; Vieth, Michael; Ndegwa, Nelson; Bateman, Adrian; Flejou, Jean-François; Grabsch, Heike I; Mastracci, Luca; Meijer, Sybren L; Saragoni, Luca; Sheahan, Kieran; Shetye, Jayant; Yantiss, Rhonda; Lundell, Lars; Detlefsen, SönkeTsekrekos, Andrianos; Vieth, Michael; Ndegwa, Nelson; Bateman, Adrian; Flejou, Jean-François; Grabsch, Heike I; Mastracci, Luca; Meijer, Sybren L; Saragoni, Luca; Sheahan, Kieran; Shetye, Jayant; Yantiss, Rhonda; Lundell, Lars; Detlefsen, Sönk