Relationship Between Immunophenotypes, Genetic Profiles, and Clinicopathologic Characteristics in Small Bowel Adenocarcinoma.

Small bowel adenocarcinoma (SBA) is rare, and scant data exist regarding its molecular and clinicopathologic characteristics. This study aimed to clarify the correlation between immunophenotypes, DNA mismatch repair status, genomic profiling, and clinicopathologic characteristics in patients with SBA. We examined 68 surgical resections from patients with primary SBA for immunohistochemical analyses of CK7, CK20, CD10, CDX2, MUC1, MUC2, MUC4, MUC5AC, and MUC6 expression as well as mismatch repair status. Genomic profiling was performed on 30 cases using targeted next-generation sequencing. Tumor mucin phenotypes were classified as gastric, intestinal, gastrointestinal, or null based on MUC2, MUC5AC, MUC6, and CD10 immunostaining. The expression of these proteins was categorized into 3 classifications according to their relationship to: (1) tumor location: CK7/CK20, MUC4, and MUC6; (2) histologic type: mucinous adenocarcinoma was positive for MUC2 and negative for MUC6; and (3) TNM stage: CD10 was downregulated, whereas MUC1 was upregulated in advanced TNM stages. CDX2 was a specific marker for SBA generally expressed in the small intestine. MUC1 and MUC4 expression was significantly associated with worse prognosis. MUC2 expression correlated with better prognosis, except for mucinous adenocarcinoma. Although the difference was not statistically significant, gastric-type tumors were more frequently located in the duodenum and were absent in the ileum. APC and CTNNB1 mutations were not found in the gastric-type tumors. The SBA immunophenotype correlated with tumor location, biological behavior, and genomic alterations. Our results suggest that the molecular pathway involved in carcinogenesis of gastric-type SBA differs from that of intestinal-type SBA.

Low Expression of Mucin 2, High Expression of Mucin 13, and High Expression of Nuclear Factor Kappa-Light-Enhancer of Activated B Cells were Significant Pathways in Colorectal Cancer Development.

OBJECTIVE: To prove the role of MUC2, MUC13, and NFκB protein expression as significant carcinogenesis pathways in colorectal cancer development. METHODS: This is a nested case-control study conducted at the Udayana University, Sanglah General hospital, from September 2020 to 2021. All eligible subjects who visited the Digestive Surgery outpatient clinic with a colorectal surgery plan 2021 were included. The subjects were classified as case group (cancerous colonic mucosa) and control group (normal colonic mucosa), proved by histopathology examination. The parameters in this study were the expression of MUC2, MUC13, and NFκB by immunohistochemistry analysis. The data in this study will be collected and tabulated in SPSS 25.0 (Chicago, Illinois, USA). RESULTS: A total of 36 subjects with colorectal cancer (case group) and 36 subjects with normal colonic mucosa (control group) were analyzed in this study. The cancerous colonic mucosa significantly had a lower MUC2, higher MUC13, and higher NFκB expression. After multivariate analysis for controlling the age variable, the result showed that only MUC2, MUC13, and NFκB expressions were still significant with p<0.05. The effect from MUC2, MUC13, and NFκB expression totally could assess up to 85.4% of the risk of developing colorectal cancer. CONCLUSION: There was a significantly lower MUC2, higher MUC13, and higher NFκB expression in the carcinogenesis of colorectal cancer, representing the influence of the inflammatory pathway and the abnormality of the protective barrier. Therefore, in the future, this result could remark a future early prediction or scoring system to assess colorectal cancer in clinical application.

Image-based assessment of extracellular mucin-to-tumor area predicts consensus molecular subtypes (CMS) in colorectal cancer.

The backbone of all colorectal cancer classifications including the consensus molecular subtypes (CMS) highlights microsatellite instability (MSI) as a key molecular pathway. Although mucinous histology (generally defined as >50% extracellular mucin-to-tumor area) is a "typical" feature of MSI, it is not limited to this subgroup. Here, we investigate the association of CMS classification and mucin-to-tumor area quantified using a deep learning algorithm, and  the expression of specific mucins in predicting CMS groups and clinical outcome. A weakly supervised segmentation method was developed to quantify extracellular mucin-to-tumor area in H&E images. Performance was compared to two pathologists' scores, then applied to two cohorts: (1) TCGA (n = 871 slides/412 patients) used for mucin-CMS group correlation and (2) Bern (n = 775 slides/517 patients) for histopathological correlations and next-generation Tissue Microarray construction. TCGA and CPTAC (n = 85 patients) were used to further validate mucin detection and CMS classification by gene and protein expression analysis for MUC2, MUC4, MUC5AC and MUC5B. An excellent inter-observer agreement between pathologists' scores and the algorithm was obtained (ICC = 0.92). In TCGA, mucinous tumors were predominantly CMS1 (25.7%), CMS3 (24.6%) and CMS4 (16.2%). Average mucin in CMS2 was 1.8%, indicating negligible amounts. RNA and protein expression of MUC2, MUC4, MUC5AC and MUC5B were low-to-absent in CMS2. MUC5AC protein expression correlated with aggressive tumor features (e.g., distant metastases (p = 0.0334), BRAF mutation (p < 0.0001), mismatch repair-deficiency (p < 0.0001), and unfavorable 5-year overall survival (44% versus 65% for positive/negative staining). MUC2 expression showed the opposite trend, correlating with less lymphatic (p = 0.0096) and venous vessel invasion (p = 0.0023), no impact on survival.The absence of mucin-expressing tumors in CMS2 provides an important phenotype-genotype correlation. Together with MSI, mucinous histology may help predict CMS classification using only histopathology and should be considered in future image classifiers of molecular subtypes.

Molecular Alterations in Gastric Preneoplastic Lesions and Early Gastric Cancer.

Prognosis of gastric cancer is dramatically improved by early diagnosis. Correa's cascade correlates the expression of some molecular markers with the progression of preneoplastic lesions toward carcinoma. This article reviews the diagnostic and prognostic values of molecular markers in complete (MUC2) and incomplete (MUC2, MUC5AC, and MUC6) intestinal metaplasia, gastric dysplasia/intra-epithelial neoplasia, and early gastric cancer. In particular, considering preinvasive neoplasia and early gastric cancer, some studies have demonstrated a correlation between molecular alterations and prognosis, for example, mucins phenotype in gastric dysplasia, and GATA6, TP53 mutation/LOH and MUC6 in early gastric cancer. Moreover, this review considers novelties from the literature regarding the (immuno)histochemical characterization of diffuse-type/signet ring cell gastric cancer, with particular attention to clinical outcomes of patients. The aim of this review is the evaluation of the state of the art regarding suitable biomarkers used in the pre-surgical phase, which can distinguish patients with different prognoses and help decide the best therapeutic strategy.

Modulation of intestinal epithelial permeability and mucin mRNA (MUC2, MUC5AC, and MUC5B) expression and protein secretion in Caco-2/HT29-MTX co-cultures exposed to aflatoxin M1, ochratoxin A, and zearalenone individually or collectively.

Aflatoxin M1 (AFM1), ochratoxin A (OTA), and zearalenone (ZEA) are mycotoxins commonly found in milk. Mycotoxin contamination has caused food safety concerns worldwide since most of the toxic effects in humans are serious. The combined toxic effects of these mycotoxins on intestinal epithelial cells have not been reported. Herein, we investigated the combined effects of AFM1, OTA, and ZEA on intestinal integrity and define the underlying mechanisms(s) of their effects in Caco-2/HT29-MTX co-cultures. Our results showed that the mixtures of AFM1 + OTA, AFM1 + ZEA, and AFM1 + ZEA + OTA significantly increased epithelial permeability. Immunofluorescence analysis and transmission electron microscopy revealed that mycotoxins altered TJ proteins morphology and disrupted their structures. Also, the present study showed that mixtures of mycotoxins significantly modulated MUC5AC and MUC5B mRNA levels and protein secretion. This study demonstrated that the effects of mixtures of mycotoxins on intestinal barrier function were more significant than AFM1 alone. More importantly, the damage of intestinal integrity caused by mycotoxins was correlated to the change of the TJ proteins location and the decrease of mucin secretion. Mixtures of AFM1, OTA, and ZEA in food might pose a health risk to consumers, particularly in children, and toxin risks should be considered.

[Combined application of immunohistochemical markers to identify pathologic subtypes of ampullary carcinoma and its clinical significance].

Objective: To investigate the expression of immunomarkers CK7, CK20, CK17, CDX2, MUC1 and MUC2 in primary adenocarcinoma of the ampulla of Vater, to explore the role of these markers in the histopathologic subclassification of ampullary carcinoma; and to provide biologic basis for precision treatment of patients with different types of ampullary carcinoma. Methods: Forty-two cases of primary ampullary carcinoma were collected at Peking University People's Hospital, from 2012 to 2018 year. There were 22 males and 20 females. Aged range 42 to 88 years old, with mean aged (62±11) years. Among the patients, 6 was high differentiation, 19 median differentiation, and 17 low differentiation. Immunohistochemical studies on the expression of CK7, CK20, CK17, CDX2, MUC1 and MUC2 were performed in 42 cases of primary ampullary carcinoma. The relationship between different ampullary carcinoma subtypes and clinicopathologic survival data was analyzed using SPSS 16.0 statistical software. Results: Three histopathologic subtypes were observed. Among 42 cases, 8(19.0%)were classified as intestinal subtype, which showed a positive expression rate of 8/8 for both CK20 and CDX2, and 5/8 for MUC2. Both CK7 and CK17 were weakly expressed in one case (1/8). No expression was observed for MUC1 in this subtype. Twenty-two (52.4%,22/42) cases were classified as pancreaticobiliary subtype, which showed a positive expression rate of 100.0%(22/22) for both CK7 and MUC1, and 90.9% (20/22) for CK17. No expression was observed for CK20, CDX2 and MUC2.The remaining 12 (28.6%) cases were classified as mixed subtype, which showed variable expression patterns. The expression frequencies of these 6 immunomarkers in different subtypes of ampullary carcinoma did not correlate with various clinicopathologic factors such as patient gender and age, tumor size, histologic differentiation, pancreatic and bile duct invasion, or the depth of duodenal invasion. However, stage Ⅲ+Ⅳ diseases were more commonly seen in pancreaticobiliary type (63.6%,14/22) than intestinal type (2/8) and mixed type (3/9; χ(2)=6.508, P=0.039). Follow-up data showed a trend of better survival rate for patients with intestinal subtype than those with mixed and pancreaticobiliary subtypes. Conclusions: Ampullary carcinoma can be subclassified into three different subtypes using a panel of six immunomarkers, especially for the identification of subtypes of poorly differentiated carcinoma. CK7, CK17 and MUC1 are major markers of pancreaticobiliary subtype, whereas CK20, CDX2 and MUC2 are useful markers for intestinal subtype. The mixed subtype variably expresses these markers. The prognosis of patients with intestinal subtype appears better than that of pancreaticobiliary and mixed subtypes. Accurate subtyping of ampullary carcinoma is clinically important to patient management and prognosis assessment.

Human Milk Oligosaccharides Increase Mucin Expression in Experimental Necrotizing Enterocolitis.

SCOPE: Necrotizing enterocolitis (NEC) is a leading cause of morbidity and death in preterm infants, occurring more often in formula-fed than breastfed infants. Studies in both rats and humans show that human milk oligosaccharides (HMOs) lower the incidence of NEC, but the mechanism underlying such protection is currently unclear. METHODS AND RESULTS: By extracting HMOs from pooled human breastmilk, the impact of HMOs on the intestinal mucin levels in a murine model of NEC are investigated. To confirm the results, the findings are validated by exposing human intestinal epithelial cells and intestinal organoids to HMOs and evaluated for mucin expression. HMO-gavage to pups increases Muc2 levels and decreases intestinal permeability to macromolecular dextran. HMO-treated cells have increased Muc2 expression, decreased bacterial attachment and dextran permeability during challenge by enteric pathogens. To identify the mediators involved in HMO induction of mucins, it is demonstrated that HMOs directly induce the expression of chaperone proteins including protein disulfide isomerase (PDI). Suppression of PDI activity removes the protective effects of HMOs on barrier function in vitro as well as NEC protection in vivo. CONCLUSIONS: Taken together, the results provide insights to the possible mechanisms by which HMOs protect the neonatal intestine through upregulation of mucins.

Differential expression of mucin 1 and mucin 2 in colorectal cancer.

AIM: To determine tissue expression (mRNA, protein) of two types of mucins [mucin 1 (MUC1) and mucin 2 (MUC2)] in patients with colorectal cancer (CRC). METHODS: Expression of membrane-bound mucin (MUC1) and secretory mucin (MUC2) in CRC (mRNA, protein) were analyzed in tissue material including fragments of tumors obtained from CRC patients (n = 34), and fragments of normal colorectal tissue from the same patients (control). The analysis was conducted using real-time quantitative polymerase chain reaction (RT-qPCR) (transcripts), immunohistochemistry (IHC) (apomucins), and the modern approach for morphometric analysis of IHC reaction (HSV filter software). Results on tissue expression of both mucins (mRNA, protein) were compared to histological alterations in colorectal cancer samples and correlated with selected clinical data in the patients. The statistical analysis was conducted using Statistica PL v. 12.0 software. RESULTS: Significantly higher expression of the MUC1 mRNA in the CRC, compared with the control and the borderline correlation of mRNA expression with MUC1 protein levels in colorectal samples was observed. The expression of apomucins concerned cell membranes (MUC1) and cytoplasm (MUC2) and occurred both in control tissues and in most cancerous samples. There were no significant relationships between MUC1 (mRNA, protein) and the clinicopathological data of patients. MUC2 protein expression was significantly lower as compared to the control, while MUC2 mRNA expression was comparable in both groups. The MUC1/MUC2 ratio was significantly higher in CRC tissues than in the control. The higher expression of MUC2 was a feature of mucinous CRC subtypes, and characterized higher histological stage of tumors. Negative correlations have been obtained between MUC2 and the Ki-67 antigen, as well as between MUC2 and p53 protein expressions in CRC. CONCLUSION: A combination of tissue overexpression of MUC1, reduced MUC2 expression, and high ratio of MUC1/MUC2 is a factor of poor prognosis in CRC patients. MUC2 tissue expression allows to differentiate mucinous and nonmucinous CRC subtypes.

Expression of Gastric Markers Is Associated with Malignant Potential of Nonampullary Duodenal Adenocarcinoma.

BACKGROUND: Sporadic nonampullary duodenal epithelial tumors (NADETs) are uncommon, and thus their clinicopathological features have not been fully assessed. AIMS: In this study, we have analyzed a series of early sporadic NADETs, focusing on various immunohistological features. METHODS: We conducted a multicenter retrospective analysis of 68 patients with endoscopically resected sporadic NADETs. Associations between immunohistological features and clinicopathological features were statistically analyzed. RESULTS: The 68 patients consisted of 46 men (68%) and 22 women (32%) with a mean age of 60.7 ± 12.2 years (range 37-85 years). The 68 tumors were composed of 39 adenomas (57%) and 29 early-stage adenocarcinomas (43%). Duodenal adenocarcinomas were larger in size than adenomas and had papillary architecture in their pathological diagnosis with statistical significance. Duodenal adenocarcinomas also demonstrated a significantly higher expression of gastric markers (MUC5AC and MUC6) and a higher MIB-1 index. Duodenal adenomas were contrastively apt to express intestinal markers (MUC2, CDX1 and CDX2). Of the 68 cases analyzed, there were only 3 tumors positive for p53 staining, all of which were adenocarcinoma. When 7 submucosal invasive cancers and 21 intramucosal cancers were compared, submucosal invasion was positively associated with expression of MUC5AC. Also, submucosal invasion showed strong association with double-positivity of MUC5AC and MUC6. CONCLUSIONS: Our results indicate that immunohistochemical evaluation is useful for predicting malignant potential of NADETs, especially focusing on the expression of gastrointestinal markers.

Effects of the Helicobacter pylori Virulence Factor CagA and Ammonium Ion on Mucins in AGS Cells.

PURPOSE: To investigate the effects of Helicobacter pylori (H. pylori)-CagA and the urease metabolite NH4⁺ on mucin expression in AGS cells. MATERIALS AND METHODS: AGS cells were transfected with CagA and/or treated with different concentrations of NH4CL. Mucin gene and protein expression was assessed by qPCR and immunofluorescence assays, respectively. RESULTS: CagA significantly upregulated MUC5AC, MUC2, and MUC5B expression in AGS cells, but did not affect E-cadherin and MUC6 expression. MUC5AC, MUC6, and MUC2 expression in AGS cells increased with increasing NH4⁺ concentrations until reaching a peak level at 15 mM. MUC5B mRNA expression in AGS cells (NH4⁺ concentration of 15 mM) was significantly higher than that at 0, 5, and 10 mM NH4⁺. No changes in E-cadherin expression in AGS cells treated with NH4⁺ were noted, except at 20 mM. The expression of MUC5AC, MUC2, and MUC6 mRNA in CagA-transfected AGS cells at an NH4⁺ concentration of 15 mM was significantly higher than that at 0 mM, and decreased at higher concentrations. The expression of MUC5B mRNA increased with increases in NH4⁺ concentration, and was significantly higher compared to that in untreated cells. No significant change in the expression of E-cadherin mRNA in CagA-transfected AGS cells was observed. Immunofluorescence assays confirmed the observed changes. CONCLUSION: H. pylori may affect the expression of MUC5AC, MUC2, MUC5B, and MUC6 in AGS cells via CagA and/or NH4⁺, but not E-cadherin.

[Effect of ceftriaxone on the intestinal epithelium and microbiota in neonatal mice].

OBJECTIVE: To investigate the effect of ceftriaxone on the intestinal epithelium and microbiota in mice in the early-life stage, as well as the recovery of the intestinal epithelium and reconstruction of intestinal microbiota in adult mice. METHODS: A total of 36 BALB/C neonatal mice were randomly divided into control group and experimental group, with 18 mice in each group. The mice in the experimental group were given ceftriaxone 100 mg/kg every day by gavage within 21 days after birth. Those in the control group were given an equal volume of normal saline by gavage. Immunohistochemistry was used to measure the expression of Ki67, Muc2, and ZO-1 in the intestinal epithelium. qPCR and next-generation sequencing were used to analyze the overall concentration and composition of fecal bacteria. RESULTS: After 21 days of ceftriaxone intervention, the experimental group had a significant reduction in body weight, a significant reduction in the expression of Ki67 and ZO-1 and a significant increase in the expression of Muc2 in intestinal epithelial cells, a significant reduction in the overall concentration of fecal bacteria, and a significant increase in the diversity of fecal bacteria compared with the control group (P<0.05). Firmicutes was the most common type of fecal bacteria in the experimental group, and there were large amounts of Staphylococcus and Enterococcus. The experimental group had a certain degree of recovery of the intestinal epithelium, but there were still significant differences in body weight and the structure of intestinal microbiota between the two groups at 56 days after birth (P<0.05). CONCLUSIONS: Early ceftriaxone intervention significantly affects the development of the intestinal epithelium and the construction of intestinal microbiota in the early-life stage. The injury of the intestinal microbiota in the early-life stage may continue to the adult stage and affect growth and development and physiological metabolism.

Distinct Effects of Growth Hormone and Glutamine on Activation of Intestinal Stem Cells.

BACKGROUND: For patients with short bowel syndrome under parenteral nutrition support, growth hormone (GH) and glutamine (GLN) have been found to help the growth of intestinal mucosa. In this research, we studied the effects of GH and GLN on intestinal stem cells (ISCs). METHODS: The in vitro and in vivo effects of GH and/or GLN on ISCs were evaluated by observing the ability of ISCs to form organoids in a Matrigel culture system. The expression levels of stemness and differentiation markers in ISCs and organoids were assessed using quantitative real-time polymerase chain reaction, immunofluorescence assay, and immunohistochemistry staining. RESULTS: In vitro administration of GH activated the stemness of ISCs, whereas GLN enhanced the expression of chromogranin A and Muc2, which are differentiation markers in enteroendocrine and goblet cells, respectively. Administration of GH or GLN in mice showed that GH, but not GLN, upregulated the proliferative activity of ISCs with increased formation of crypt organoids. In addition, GH increased the expression of Lgr5 and GLN enhanced expression of Muc2 in the crypt fractions of the intestines in mice. CONCLUSION: These results suggest that GH mainly enhances proliferative activities, whereas GLN promotes the differentiation potential of ISCs.

Highly Accurate Identification of Cystic Precursor Lesions of Pancreatic Cancer Through Targeted Mass Spectrometry: A Phase IIc Diagnostic Study.

Purpose Pancreatic cystic lesions are common incidental findings on imaging, but up to half may be forerunners of pancreatic cancer. Therefore, accurate differential diagnosis is crucial for correct patient management. Unfortunately, currently available diagnostic methods cannot robustly identify premalignant and malignant pancreatic cystic lesions. Methods Cyst fluid samples obtained by routine endoscopic ultrasound-guided aspiration were used for the analyses. In a cohort of 24 patients, eight biomarker candidates for malignant potential and high-grade dysplasia/cancer were identified by an explorative proteomic approach. Subsequently, a quantitative analysis, using 30 heavy-labeled peptides from the biomarkers and parallel reaction monitoring mass spectrometry, was devised, tested in a training cohort of 80, and prospectively evaluated in a validation cohort of 68 patients. End points were surgical pathology diagnosis/clinical follow-up. Diagnostic assessments were blinded to mass spectrometry results. Results The optimal set of markers for detecting malignant potential was a panel of peptides from mucin-5AC and mucin-2, which could discriminate premalignant/malignant lesions from benign with an accuracy of 97% (95% CI, 89% to 99%) in the validation cohort. This result compared favorably with the accuracy of standard analyses: cyst fluid carcinoembryonic antigen (61%; 95% CI, 46% to 74%; P < .001) and cytology (84%; 95% CI, 71% to 92%; P = .02). A combination of proteins mucin-5AC and prostate stem-cell antigen could identify high-grade dysplasia/cancer with an accuracy of 96% (95% CI, 90% to 99%), and detected 95% of malignant/severely dysplastic lesions, compared with 35% and 50% for carcinoembryonic antigen and cytology ( P < .001 and P = .003, respectively). Conclusion Targeted mass spectrometry analysis of just three cyst fluid biomarkers provides highly accurate identification and assessment of cystic precursors to pancreatic adenocarcinoma. Additional studies should determine whether the method can facilitate timely cancer diagnosis, successful intervention, and prevention.

Intake of Fish Oil Specifically Modulates Colonic Muc2 Expression in Middle-Aged Rats by Suppressing the Glycosylation Process.

SCOPE: Dietary fats have been shown to affect gut microbiota composition and aging gene expression of middle-aged rats at a normal dose, but little is known about such an effect on gut barrier. In this study, the changes in colonic Muc2 expression are investigated and the underlying mechanism is also proposed. METHODS AND RESULTS: 36 middle-aged Sprague-Dawley rats are assigned to one of the diets containing soybean oil, lard, or fish oil (4%). The rats are fed for 5 weeks and then goblet cells, Muc2 expression, and inflammatory cytokines in the colon are measured. Proteome analysis is performed. Compared with the lard and soybean oil diet groups, intake of fish oil decreases the number of goblet cells, and inhibits Muc2 and TLRs expression in the colon of middle-aged rats, which would impair mucus barrier. Several key enzymes involved in glycosylation process, including Agr2, Gale, Gne, Pmm2, Pdxdc1, Plch1, Pfkp, Cmpk1, and Rexo2, show the lowest abundance in the fish oil diet group. CONCLUSION: Intake of fish oil at a normal dose downregulates colonic Muc2 expression. This negative effect of fish oil may involve the suppression of mucin glycosylation process.

EVALUATION OF ENEMAS CONTAINING SUCRALFATE IN TISSUE CONTENT OF MUC-2 PROTEIN IN EXPERIMENTAL MODEL OF DIVERSION COLITIS.

BACKGROUND: The effects of topical application of sucralfate (SCF) on the tissue content of MUC-2 protein have not yet been evaluated in experimental models of diversion colitis. AIM: To measure the tissue content of MUC-2 protein in the colonic mucosa diverted from fecal stream submitted to the SCF intervention. METHODS: Thirty-six rats underwent derivation of intestinal transit through proximal colostomy and distal mucous fistula. The animals were divided into three groups which were submitted application of enemas with saline, SCF 1 g/kg/day and SCF 2 g/kg/day. Each group was divided into two subgroups, according to euthanasia was done after two or four weeks. The colitis diagnosis was established by histopathological study and the inflammatory intensity was evaluated by previously validated scale. The MUC-2 protein was identified by immunohistochemistry and the tissue content was measured computerized morphometry). RESULTS: The application of enemas with SCF in the concentration of 2 g/kg/day reduced inflammatory score of the segments that were diverted from fecal stream. The content of MUC-2 in diverted colon of the animals submitted to the intervention with SCF, independently of intervention period and the used concentration, was significantly greater than animals submitted to the application of enemas containing saline (p< 0.01). The content of MUC-2 after the intervention with SCF in the concentration of 2 g/kg/day was significantly higher when compared to the animals submitted to the application containing SCF at concentration of 1.0 g/kg/day (p<0.01). The tissue content of MUC-2 reached the highest values after intervention with SCF in the concentration of 2 g/kg/day for four weeks (p<0.01). Conclusion: The preventive application of enemas containing SCF reduces the inflammatory score and avoids the reduction of tissue content of MUC-2, suggesting that the substance is a valid therapeutic strategy to preserve the mucus layer that covers the intestinal epithelium.

Evaluation of enemas containing sucralfate in tissue content of muc-2 protein in experimental model of diversion colitis / Avaliação de enemas com sucralfato no conteúdo tecidual da proteina muc-2 em colite de exclusão experimental

ABSTRACT Background: The effects of topical application of sucralfate (SCF) on the tissue content of MUC-2 protein have not yet been evaluated in experimental models of diversion colitis. Aim: To measure the tissue content of MUC-2 protein in the colonic mucosa diverted from fecal stream submitted to the SCF intervention. Methods: Thirty-six rats underwent derivation of intestinal transit through proximal colostomy and distal mucous fistula. The animals were divided into three groups which were submitted application of enemas with saline, SCF 1 g/kg/day and SCF 2 g/kg/day. Each group was divided into two subgroups, according to euthanasia was done after two or four weeks. The colitis diagnosis was established by histopathological study and the inflammatory intensity was evaluated by previously validated scale. The MUC-2 protein was identified by immunohistochemistry and the tissue content was measured computerized morphometry). Results: The application of enemas with SCF in the concentration of 2 g/kg/day reduced inflammatory score of the segments that were diverted from fecal stream. The content of MUC-2 in diverted colon of the animals submitted to the intervention with SCF, independently of intervention period and the used concentration, was significantly greater than animals submitted to the application of enemas containing saline (p< 0.01). The content of MUC-2 after the intervention with SCF in the concentration of 2 g/kg/day was significantly higher when compared to the animals submitted to the application containing SCF at concentration of 1.0 g/kg/day (p<0.01). The tissue content of MUC-2 reached the highest values after intervention with SCF in the concentration of 2 g/kg/day for four weeks (p<0.01). Conclusion: The preventive application of enemas containing SCF reduces the inflammatory score and avoids the reduction of tissue content of MUC-2, suggesting that the substance is a valid therapeutic strategy to preserve the mucus layer that covers the intestinal epithelium.

RESUMO Racional: Os efeitos da aplicação tópica de sucralfato (SCF) no conteúdo tecidual da proteína mucina-2 (MUC-2) ainda não foram avaliados em modelos experimentais de colite de exclusão. Objetivo: Mensurar o conteúdo tecidual da proteína MUC-2 na mucosa cólica sem trânsito intestinal submetida à intervenção com SCF. Método : Trinta e seis ratos foram submetidos à derivação intestinal por colostomia proximal terminal e fístula mucosa distal. Foram divididos em três grupos segundo recebessem clisteres contendo solução fisiológica (SF), SCF 1 g/kg/dia e SCF 2 g/kg/dia. Cada grupo foi dividido em dois subgrupos, segundo a eutanásia ser realizada após duas ou quatro semanas. O diagnóstico de colite foi estabelecido por estudo histopatológico e a intensidade inflamatória foi avaliada por escala validada. A expressão tecidual da MUC-2 foi identificada por imunoistoquímica e seu conteúdo mensurado por morfometria computadorizada. Resultados: A aplicação de clisteres com SCF na concentração de 2 g/kg/dia reduziu a intensidade inflamatória no cólon sem trânsito fecal. O conteúdo tecidual de MUC-2 no cólon sem trânsito dos animais submetidos à intervenção com SCF, independente do tempo de intervenção e da concentração utilizada, foi maior quando comparado aos animais tratados com SF (p<0,01). O conteúdo de MUC-2 após a intervenção com SCF na concentração de 2 g/kg/dia foi maior quando comparado aos animais submetidos à intervenção com concentração menor (p<0,01). O conteúdo de MUC-2 foi maior após intervenção com SCF na concentração de 2 g/kg/dia por quatro semanas (p<0,01). Conclusão: A aplicação preventiva de clisteres com SCF reduz o grau de inflamação e preserva o conteúdo tecidual de MUC-2, em segmentos desprovidos de trânsito intestinal, mostrando-se uma estratégia terapêutica válida para preservar a camada de muco que recobre o epitélio intestinal.

Physical and chemical characteristics of mucin secreted by pseudomyxoma peritonei (PMP).

Background: Pseudomyxoma peritonei (PMP) is a rare disease with excess intraperitoneal mucin secretion. Treatment involves laparotomy, cytoreduction and chemotherapy that is very invasive with patients often acquiring numerous compromises. Hence a mucolytic comprising of bromelain and N-acetyl cystein has been developed to solubilise mucin in situ for removal by catherization. Owing to differences in mucin appearance and hardness, dissolution varies. Therefore the current study investigates the inter-mucin physical and chemical characteristics, in order to reformulate an effective mucolytic for all mucin. Method: PMP mucin, from the three categories (soft, semi hard and hard mucin) was solubilised and then various physical characteristics such as turbidity, density, kinematic viscosity were measured. The water content and the density of solid mucin were also determined. This was followed by the determination of sialic acid, glucose, lipid, Thiol (S-S and S-H) content of the samples. Lastly, the distribution of MUC2, MUC5B and MUC5AC was determined using western blot technique. Results: Both turbidity and kinematic viscosity and sialic acid content increased linearly as the hardness of mucin increased. However, density, hydration, protein, glucose, lipid and sulfhydryl and disulphide content decreased linearly as hardness of mucin increased. The distribution ratio of mucins (MUC2:MUC5B:MUC5AC) in soft mucin is 2.25:1.5:1.0, semi hard mucin is 1:1:1 and hard mucin is 3:2:1. Conclusion: The difference in texture and hardness of mucin may be due to cellular content, hydration, glucose, protein, lipids, thiol and MUC distribution. Soft mucin is solely made of glycoprotein whilst the others contained cellular materials.

Is mucin a determinant of peritoneal dissemination of gastrointestinal cancer? Analysis of mucin depletion in two preclinical models

Background. Mucinous gastrointestinal cancers may indicate a higher propensity for widespread peritoneal seeding than their non-mucinous counterparts. We hypothesized that mucin content of gastrointestinal cancer cells and tumors is an indicator of cell viability and a determinant of the peritoneal tumor burden and tested our hypothesis in relevant experimental models. Methods. MKN45 and LS174T models of human gastrointestinal cancer were treated with known mucin-depleting agents in vitro and in vivo, their mucin production was evaluated with Western blot immunohistochemistry, PAS staining and ELISA, and its correlation with cell viability and peritoneal tumor burden was analyzed. Results. A relationship was found between the viability of cancer cells and their mucin levels in vitro. In agreement, when treated animal models were categorized into low- and high-burden groups (based on the weight and number of the peritoneal nodules), tumoral mucin levels were found to be significantly higher in the latter group. Conclusions. Tumoral mucin is apparently among the factors that dictate the pattern and extent of the peritoneal spread of gastrointestinal cancer, where it allows for enhanced dissemination and redistribution. If further tested and validated, our hypothesis could lay the basis for the development of novel mucin-targeted strategies (AU)

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Immunohistochemical expression of mucin antigens in gallbladder adenocarcinoma: MUC1-positive and MUC2-negative expression Is associated with vessel invasion and shortened survival.

Mucins play pivotal roles in influencing cancer biology, for example affecting carcinoma invasion, aggressiveness and/or metastatic potential. Our aim is to investigate the significance of expression profiles of two mucins in particular, MUC1 and MUC2, their correlations with various clinicopathological features, and prognosis in gallbladder adenocarcinoma (GBAC). We performed immunohistochemistry from patients with surgically resected GBAC, using antibodies against mucin core proteins MUC1/DF3 and MUC2/Ccp58 in 81 paraffin-embedded tumor samples. MUC1 or MUC2 expression was considered to be high when ≥ 20% or 10% of the GBAC cells showed positive staining, respectively. High MUC1 expression was revealed to have a significant relationship to the presence of pathologically lymphatic and vascular invasion, and regional lymph node metastasis. By contrast, high MUC2 expression showed a significant correlation with pathologically perineural invasion, T stage ≥ 3, and post-operative recurrence. Moreover, MUC1 showed significantly positive co-expression and potentially complementary correlations with MUC2. Multivariate analyses demonstrated that the high MUC1 expression group had significantly shorter disease-specific survival times. However, the combination of both high MUC1 and MUC2 expression did not predict worse outcome in GBACs. Therefore, although each mucin has a somewhat important role in the pathogenesis of GBAC progression, MUC1 can independently predict vessel invasion and poor prognosis in patients with GBAC. The detection of MUC1 might well offer a useful parameter for providing clinical management and treatment against postsurgical GBACs.

Differential Expression of ß-Catenin, EGFR, CK7, CK20, MUC1, MUC2, and CDX2 in Intestinal and Pancreatobiliary-Type Ampullary Carcinomas.

INTRODUCTION: The purpose of this study was to associate immunohistochemical expression of ß-catenin, EGFR, CK7, CK20, MUC1, MUC2, and CDX2 in ampullary adenocarcinomas with the type of differentiation and prognosis. METHODS: Forty-seven patients with ampullary adenocarcinoma who underwent pancreatoduodenectomy with curative intent from 1997 to 2014 were included in this study. Nine patients with perioperative death were included in the association analysis but excluded from survival analysis. All tumors were classified as intestinal or pancreatobiliary type, according to histologic criteria, and immunohistochemically stained against the aforementioned markers. RESULTS: Eighteen carcinomas were classified as intestinal type and 29 carcinomas as pancreatobiliary type. Univariate analysis revealed that CK20 and CDX2 expression correlates with intestinal type, whereas MUC1 positivity indicates pancreatobiliary type. A marginally significant trend was shown for intestinal-type tumors toward larger size and more frequent MUC2 expression. Using multivariate analysis CK20 ( P = .003) and MUC1 ( P = .004) were identified as independent predictors of the intestinal and pancreatobiliary types, respectively. Mean and median survival was 90.3 and 55 months, respectively. Overall 5-year survival rate was 48%. On univariate survival analysis, overall survival was adversely influenced by the number of infiltrated lymph nodes, elevated Ca19-9 serum levels, jaundice, poor differentiation, T4 stage, N1 stage, TNM stage III, and CDX2 immunonegativity. Multivariate analysis identified TNM stage as the only independent prognostic factor in ampullary adenocarcinoma ( P = .048). CONCLUSIONS: Immunoreactivity against CK20 and MUC1 in ampullary carcinomas is a useful adjunct to histologic examination in determining histotype. None of the immunohistochemical markers studied had prognostic significance.