Clonal Transitions and Phenotypic Evolution in Barrett's Esophagus.

BACKGROUND & AIMS: Barrett's esophagus (BE) is a risk factor for esophageal adenocarcinoma but our understanding of how it evolves is poorly understood. We investigated BE gland phenotype distribution, the clonal nature of phenotypic change, and how phenotypic diversity plays a role in progression. METHODS: Using immunohistochemistry and histology, we analyzed the distribution and the diversity of gland phenotype between and within biopsy specimens from patients with nondysplastic BE and those who had progressed to dysplasia or had developed postesophagectomy BE. Clonal relationships were determined by the presence of shared mutations between distinct gland types using laser capture microdissection sequencing of the mitochondrial genome. RESULTS: We identified 5 different gland phenotypes in a cohort of 51 nondysplastic patients where biopsy specimens were taken at the same anatomic site (1.0-2.0 cm superior to the gastroesophageal junction. Here, we observed the same number of glands with 1 and 2 phenotypes, but 3 phenotypes were rare. We showed a common ancestor between parietal cell-containing, mature gastric (oxyntocardiac) and goblet cell-containing, intestinal (specialized) gland phenotypes. Similarly, we have shown a clonal relationship between cardiac-type glands and specialized and mature intestinal glands. Using the Shannon diversity index as a marker of gland diversity, we observed significantly increased phenotypic diversity in patients with BE adjacent to dysplasia and predysplasia compared to nondysplastic BE and postesophagectomy BE, suggesting that diversity develops over time. CONCLUSIONS: We showed that the range of BE phenotypes represents an evolutionary process and that changes in gland diversity may play a role in progression. Furthermore, we showed a common ancestry between gastric and intestinal-type glands in BE.

Lessons from recent medical history: an obsolete anti-reflux device in an older patient with variable gastrointestinal symptoms.

A frail 93-year-old lady presented with delirium, on a background of heart failure, cerebrovascular disease, constipation and osteoporosis. A computed tomography (CT) pulmonary angiography, undertaken due to persistent hypoxia, identified no pathology aside from an unusual appearance of the left hypochondrium, necessitating further elucidation with CT abdomen. This unexpectedly reported the presence of a gastric band, leading us to consider possible misidentification. Perusing her General Practitioner (GP) records demonstrated that she underwent surgical insertion of an Angelchik prosthesis in 1984. Angelchik prostheses were anti-reflux devices used for a short period, before falling from favour due to increasing evidence around late developing complications. A collateral history from family revealed that this patient had experienced multiple longstanding symptoms including bloating, reflux and constipation, potentially linked to her prosthesis, a previously unestablished link.

Current concepts in tumour-derived organoids.

Cancer comprises a collection of highly proliferative and heterogeneous cells growing within an adaptive and evolving tumour microenvironment. Cancer survival rates have significantly improved following decades of cancer research. However, many experimental and preclinical studies do not translate to the bedside, reflecting the challenges of modelling the complexities and multicellular basis of human disease. Organoids are novel, complex, three-dimensional ex vivo tissue cultures that are derived from embryonic stem cells, induced pluripotent stem cells or tissue-resident progenitor cells, and represent a near-physiological model for studying cancer. Organoids develop by self-organisation, and can accurately represent the diverse genetic, cellular and pathophysiological hallmarks of cancer. In addition, co-culture methods and the ability to genetically manipulate these organoids have widened their utility in cancer research. Organoids thus offer a new and exciting platform for studying cancer and directing personalised therapies. This review aims to highlight how organoids are shaping the future of cancer research.

Novel biomarkers for risk stratification of Barrett's oesophagus associated neoplastic progression-epithelial HMGB1 expression and stromal lymphocytic phenotype.

BACKGROUND: The incidence of oesophageal adenocarcinoma is increasing globally. Barrett's oesophagus (BO) is a pre-malignant condition with no biomarker to risk stratify those at highest risk of dysplasia and malignant transformation. METHODS: Subcellular epithelial protein (HMGB1, p53, RUNX3) expression, alongside expression of CD20, CD4, CD8 and Foxp3 to characterise stromal B lymphocyte, and helper, cytotoxic and regulatory T-lymphocyte cell infiltrate, respectively, was assessed by immunohistochemistry in 218 human tissue samples including normal oesophageal/gastric biopsies (n = 39), BO (non-dysplasia, dysplasia, non-dysplastic background from progressors to dysplasia or cancer, n = 121) and oesophageal adenocarcinoma (n = 58). RESULTS: There is a dynamic subcellular epithelial expression of HMGB1 (loss of nuclear, emergence of cytoplasmic), associated with epithelial p53 expression and differential immune cell phenotype in oesophageal neoplastic progression. We identify a protein signature and lymphocyte infiltrate in non-dysplastic BO when progressive disease (dysplasia or adenocarcinoma) is present but not histologically represented in the biopsied field. There is a dynamic stromal lymphocytic infiltrate in oesophageal neoplastic progression. CONCLUSIONS: This data reveals novel insights into the microenvironment of BO and progression towards cancer and identifies a novel high-risk biomarker of disease progression to aid surveillance strategies to identify early progression and impact future incidence of oesophageal cancer.

CXCR2 inhibition suppresses acute and chronic pancreatic inflammation.

Pancreatitis is a significant clinical problem and the lack of effective therapeutic options means that treatment is often palliative rather than curative. A deeper understanding of the pathogenesis of both acute and chronic pancreatitis is necessary to develop new therapies. Pathological changes in pancreatitis are dependent on innate immune cell recruitment to the site of initial tissue damage, and on the coordination of downstream inflammatory pathways. The chemokine receptor CXCR2 drives neutrophil recruitment during inflammation, and to investigate its role in pancreatic inflammation, we induced acute and chronic pancreatitis in wild-type and Cxcr2(-/-) mice. Strikingly, Cxcr2(-/-) mice were strongly protected from tissue damage in models of acute pancreatitis, and this could be recapitulated by neutrophil depletion or by the specific deletion of Cxcr2 from myeloid cells. The pancreata of Cxcr2(-/-) mice were also substantially protected from damage during chronic pancreatitis. Neutrophil depletion was less effective in this model, suggesting that CXCR2 on non-neutrophils contributes to the development of chronic pancreatitis. Importantly, pharmacological inhibition of CXCR2 in wild-type mice replicated the protection seen in Cxcr2(-/-) mice in acute and chronic models of pancreatitis. Moreover, acute pancreatic inflammation was reversible by inhibition of CXCR2. Thus, CXCR2 is critically involved in the development of acute and chronic pancreatitis in mice, and its inhibition or loss protects against pancreatic damage. CXCR2 may therefore be a viable therapeutic target in the treatment of pancreatitis.

Prophylactic Versus Endoscopy-driven Treatment of Crohn's Postoperative Recurrence: A Retrospective, Multicentric, European Study [PORCSE Study].

BACKGROUND AND AIMS: No consensus exists on optimal strategy to prevent postoperative recurrence [POR] after ileocaecal resection [ICR] for Crohn's disease [CD]. We compared early medical prophylaxis versus expectant management with treatment driven by findings at elective endoscopy 6-12 months after ICR. METHODS: A retrospective, multicentric, observational study was performed. CD patients undergoing first ICR were assigned to Cohort 1 if a biologic or immunomodulator was [re]started prophylactically after ICR, or to Cohort 2 if no postoperative prophylaxis was given and treatment was started as reaction to elective endoscopic findings. Primary endpoint was rate of endoscopic POR [Rutgeerts >i1]. Secondary endpoints were severe endoscopic POR [Rutgeerts i3/i4], clinical POR, surgical POR, and treatment burden during follow-up. RESULTS: Of 346 included patients, 47.4% received prophylactic postoperative treatment [proactive/Cohort 1] and 52.6% did not [reactive/Cohort 2]. Endoscopic POR [Rutgeerts >i1] rate was significantly higher in Cohort 2 [41.5% vs 53.8%, OR 1.81, p = 0.039] at endoscopy 6-12 months after surgery. No significant difference in severe endoscopic POR was found [OR 1.29, p = 0.517]. Cohort 2 had significantly higher clinical POR rates [17.7% vs 35.7%, OR 3.05, p = 0.002] and numerically higher surgical recurrence rates [6.7% vs 13.2%, OR 2.59, p = 0.051]. Cox proportional hazards regression analysis showed no significant difference in time to surgical POR of proactive versus expectant/reactive approach [HR 2.50, p = 0.057]. Quasi-Poisson regression revealed a significantly lower treatment burden for immunomodulator use in Cohort 2 [mean ratio 0.53, p = 0.002], but no difference in burden of biologics or combination treatment. CONCLUSIONS: The PORCSE study showed lower rates of endoscopic POR with early postoperative medical treatment compared with expectant management after first ileocaecal resection for Crohn's disease.

QuPath Algorithm Accurately Identifies MLH1-Deficient Inflammatory Bowel Disease-Associated Colorectal Cancers in a Tissue Microarray.

Current methods for analysing immunohistochemistry are labour-intensive and often confounded by inter-observer variability. Analysis is time consuming when identifying small clinically important cohorts within larger samples. This study trained QuPath, an open-source image analysis program, to accurately identify MLH1-deficient inflammatory bowel disease-associated colorectal cancers (IBD-CRC) from a tissue microarray containing normal colon and IBD-CRC. The tissue microarray (n = 162 cores) was immunostained for MLH1, digitalised, and imported into QuPath. A small sample (n = 14) was used to train QuPath to detect positive versus no MLH1 and tissue histology (normal epithelium, tumour, immune infiltrates, stroma). This algorithm was applied to the tissue microarray and correctly identified tissue histology and MLH1 expression in the majority of valid cases (73/99, 73.74%), incorrectly identified MLH1 status in one case (1.01%), and flagged 25/99 (25.25%) cases for manual review. Qualitative review found five reasons for flagged cores: small quantity of tissue, diverse/atypical morphology, excessive inflammatory/immune infiltrations, normal mucosa, or weak/patchy immunostaining. Of classified cores (n = 74), QuPath was 100% (95% CI 80.49, 100) sensitive and 98.25% (95% CI 90.61, 99.96) specific for identifying MLH1-deficient IBD-CRC; κ = 0.963 (95% CI 0.890, 1.036) (p < 0.001). This process could be efficiently automated in diagnostic laboratories to examine all colonic tissue and tumours for MLH1 expression.

Subcellular Epithelial HMGB1 Expression Is Associated with Colorectal Neoplastic Progression, Male Sex, Mismatch Repair Protein Expression, Lymph Node Positivity, and an 'Immune Cold' Phenotype Associated with Poor Survival.

New treatment targets are needed for colorectal cancer (CRC). We define expression of High Mobility Group Box 1 (HMGB1) protein throughout colorectal neoplastic progression and examine the biological consequences of aberrant expression. HMGB1 is a ubiquitously expressed nuclear protein that shuttles to the cytoplasm under cellular stress. HMGB1 impacts cellular responses, acting as a cytokine when secreted. A total of 846 human tissue samples were retrieved; 6242 immunohistochemically stained sections were reviewed. Subcellular epithelial HMGB1 expression was assessed in a CRC Tissue Microarray (n = 650), normal colonic epithelium (n = 75), adenomatous polyps (n = 52), and CRC polyps (CaP, n = 69). Stromal lymphocyte phenotype was assessed in the CRC microarray and a subgroup of CaP. Normal colonic epithelium has strong nuclear and absent cytoplasmic HMGB1. With progression to CRC, there is an emergence of strong cytoplasmic HMGB1 (p < 0.001), pronounced at the leading cancer edge within CaP (p < 0.001), and reduction in nuclear HMGB1 (p < 0.001). In CRC, absent nuclear HMGB1 is associated with mismatch repair proteins (p = 0.001). Stronger cytoplasmic HMGB1 is associated with lymph node positivity (p < 0.001) and male sex (p = 0.009). Stronger nuclear (p = 0.011) and cytoplasmic (p = 0.002) HMGB1 is associated with greater CD4+ T-cell density, stronger nuclear HMGB1 is associated with greater FOXP3+ (p < 0.001) and ICOS+ (p = 0.018) lymphocyte density, and stronger nuclear HMGB1 is associated with reduced CD8+ T-cell density (p = 0.022). HMGB1 does not directly impact survival but is associated with an 'immune cold' tumour microenvironment which is associated with poor survival (p < 0.001). HMGB1 may represent a new treatment target for CRC.

Endoscopically placed venting gastrostomy can be a safe and effective palliative intervention in benign and malignant gastrointestinal obstruction.

Introduction: Chronic gastrointestinal obstruction can precipitate a constellation of symptoms including nausea, vomiting, abdominal distension and pain that negatively impact on health-related quality of life. Decompression via venting gastrostomy can offer symptomatic relief but safety and efficacy data are sparse. This study characterises the diverse venting percutaneous endoscopic gastrostomy (vPEG) cohort at our tertiary referral centre and defines the safety and efficacy of this procedure. Methods: Patients undergoing vPEG between May 2012 and June 2020 were identified from a prospectively maintained database and demographic, procedure-related and mortality data were extracted. Retrospective analysis of case notes provided data on patient symptoms. Last follow-up was May 2021. Results: 27 patients (median age 63, range 18-90 years) underwent vPEG insertion. The majority of vPEGs were for patients with obstruction secondary to locally advanced or metastatic malignancy (n=21/27, 77.8%). Six procedures were performed for benign disease (n=6/27, 22.2%). No patients developed the recognised serious complications of bleeding, perforation or peritonitis from vPEG insertion. Symptoms of nausea (p=0.006), vomiting (p<0.001), abdominal distension (p<0.001) and abdominal pain (p=0.002) were improved following vPEG. Pain beyond the expected postprocedural discomfort was associated with a lower number of days survived postprocedure (p=0.026). Conclusion: vPEG can be a safe and efficacious palliative intervention for benign and malignant chronic gastrointestinal obstruction. Severe postprocedural pain should be promptly investigated to exclude a potential complication. A defined clinical strategy for assessing and managing these patients would facilitate wider recognition of the benefits of vPEG and improve the safety profile in centres with more limited experience.

c-MET immunohistochemical expression in sporadic and inflammatory bowel disease associated lesions.

BACKGROUND: Post-colonoscopy colorectal cancer (CRC) rates for patients with inflammatory bowel disease (IBD) are unacceptably high. During colonoscopy, an intravenous fluorescent anti-c-MET probe may improve endoscopic detection of lesions. However, c-MET expression in IBD lesions is poorly defined, limiting translational studies. AIM: To comprehensively define c-MET expression in sporadic and IBD-associated colorectal carcinogenesis. METHODS: c-MET expression was immunohistochemically assessed in 319 formalin-fixed paraffin-embedded tissue specimens, colonoscopically or surgically retrieved between 1994-2017. Tissue included: 30 normal colorectal biopsies, 30 hyperplastic polyps (HP), 31 sessile serrated lesions (SSL), 55 tubular/tubulovillous adenomas with low (TA-LGD, n = 32) or high grade dysplasia (TA-HGD, n = 23), 26 sporadic (s)-CRCs, 16 quiescent IBD biopsies, 11 active/inflamed IBD biopsies, 18 IBD-associated dysplastic lesions (IBD-dys), and 102 IBD-CRCs. Expression was scored by two independent observers as: 0 = absent, 1 = weak, 2 = moderate or 3 = strong. Mann-Whitney U and Kruskal-Wallis tests were used to assess significance. RESULTS: Positive epithelial cytoplasmic and membranous c-MET expression was observed in all tissues, indicating there is ubiquitous expression in the colorectum. c-MET expression was weak in normal colonic epithelium compared with each of the sporadic colonic lesions, including TA-LGD (P < 0.001), TA-HGD (P = 0.004), HP (P < 0.001), SSL (P < 0.001), and s-CRC (P < 0.001). Specifically, in sporadic (non-IBD) lesions, expression was stronger in TA-LGD compared with normal mucosa (P < 0.001), and stronger in s-CRC compared with TA-HGD (P = 0.004). However, there was no significant difference between TA-LGD and TA-HGD (P = 0.852). Further, there was no difference in c-MET expression between HP and SSL (P = 0.065). In IBD, expression was weaker in quiescent colonic mucosa compared with inflamed colonic mucosa (P < 0.001). There was no difference between inflamed colonic mucosa and IBD-dys (P = 0.512) or IBD-CRC (P = 0.296). However, expression was stronger in IBD-dys (P < 0.001) and IBD-CRC (P < 0.001) compared with quiescent IBD colonic mucosa. CONCLUSION: The characterisation of c-MET expression suggest that an intravenous probe may improve the endoscopic detection of lesions in both non-IBD patients and IBD patients with quiescent disease.

Interleukin-27 Regulates the Function of the Gastrointestinal Epithelial Barrier in a Human Tissue-Derived Organoid Model.

A treatment with direct healing effects on the gastrointestinal epithelial barrier is desirable for inflammatory bowel disease (IBD). Interleukin-27 (IL-27) is an immunoregulatory cytokine, and oral delivery is an effective treatment in murine models of IBD. We aimed to define IL-27 effects on the human gastrointestinal epithelial barrier. We characterised gene and protein expression of permeability mediators in a human colon-derived organoid model. Functional permeability was determined in an organoid-derived 2D monolayer by transepithelial electrical resistance. IL-27 effects on epithelial innate immune responses were assessed through expression of cytokines, anti-microbial peptides and MUC genes. IL-27 effects on wound healing and proliferation were determined in human colon epithelial cell lines. IL-27 led to restoration of permeability regulation following inflammatory cytokine insult (p = 0.001), associated with differential expression of tight junction mediators with decrease in claudin 2 (p = 0.024) and increase in claudin 4 (p < 0.001), E-cadherin (p < 0.001) and zona occludens (p = 0.0014). IL-27 evoked differential gene expression of epithelial-derived innate immune responses (reduced IL1B and IL18, and increased IL33, HBD1, MUC1 and MUC2; p < 0.012). IL-27 induced epithelial barrier wound healing through restitution (p < 0.001), and increased proliferation (p < 0.001) following injury. Overall, IL-27 provokes mucosal healing of the human gastrointestinal epithelial barrier.

Inflammatory Bowel Disease-Associated Colorectal Cancer: Translational Risks from Mechanisms to Medicines.

The cumulative impact of chronic inflammation in patients with inflammatory bowel diseases predisposes to the development of inflammatory bowel disease-associated colorectal cancer [IBD-CRC]. Inflammation can induce mutagenesis, and the relapsing-remitting nature of this inflammation, together with epithelial regeneration, may exert selective pressure accelerating carcinogenesis. The molecular pathogenesis of IBD-CRC, termed the 'inflammation-dysplasia-carcinoma' sequence, is well described. However, the immunopathogenesis of IBD-CRC is less well understood. The impact of novel immunosuppressive therapies, which aim to achieve deep remission, is mostly unknown. Therefore, this timely review summarizes the clinical context of IBD-CRC, outlines the molecular and immunological basis of disease pathogenesis, and considers the impact of novel biological therapies.

Colonic epithelial cathelicidin (LL-37) expression intensity is associated with progression of colorectal cancer and presence of CD8+ T cell infiltrate.

Colorectal cancer (CRC) remains a leading cause of cancer mortality. Here, we define the colonic epithelial expression of cathelicidin (LL-37) in CRC. Cathelicidin exerts pleotropic effects including anti-microbial and immunoregulatory functions. Genetic knockout of cathelicidin led to increased size and number of colorectal tumours in the azoxymethane-induced murine model of CRC. We aimed to translate this to human disease. The expression of LL-37 in a large (n = 650) fully characterised cohort of treatment-naïve primary human colorectal tumours and 50 matched normal mucosa samples with associated clinical and pathological data (patient age, gender, tumour site, tumour stage [UICC], presence or absence of extra-mural vascular invasion, tumour differentiation, mismatch repair protein status, and survival to 18 years) was assessed by immunohistochemistry. The biological consequences of LL-37 expression on the epithelial barrier and immune cell phenotype were assessed using targeted quantitative PCR gene expression of epithelial permeability (CLDN2, CLDN4, OCLN, CDH1, and TJP1) and cytokine (IL-1ß, IL-18, IL-33, IL-10, IL-22, and IL-27) genes in a human colon organoid model, and CD3+ , CD4+ , and CD8+ lymphocyte phenotyping by immunohistochemistry, respectively. Our data reveal that loss of cathelicidin is associated with human CRC progression, with a switch in expression intensity an early feature of CRC. LL-37 expression intensity is associated with CD8+ T cell infiltrate, influenced by tumour characteristics including mismatch repair protein status. There was no effect on epithelial barrier gene expression. These data offer novel insights into the contribution of LL-37 to the pathogenesis of CRC and as a therapeutic molecule.

Ulcerative colitis: Recent advances in the understanding of disease pathogenesis.

Inflammatory bowel diseases are common, complex, immune-mediated conditions with a sharply rising global prevalence. While major advances since 2000 have provided strong mechanistic clues implicating a de-regulation in the normal interaction among host genetics, immunity, microbiome, and the environment, more recent progress has generated entirely new hypotheses and also further refined older disease concepts. In this review, we focus specifically on these novel developments in the pathogenesis of ulcerative colitis.

Gastropexy can be as safe as conventional percutaneous endoscopic gastrostomy (PEG), and biomarkers do not predict short-term or long-term outcomes: a 7-year follow-up audit.

OBJECTIVE: Gastrostomy facilitates artificial enteral feeding but controversy exists around associated morbidity and mortality. This study aimed to report short and long-term outcomes, and identify parameters associated with overall survival. METHODS: A 7-year follow-up audit was undertaken at Aberdeen Royal Infirmary, UK. All patients undergoing endoscopic gastrostomy insertion October 2011-September 2018 were included. Last follow-up was February 2019. Clinical data were prospectively collected. Blood results were retrospectively obtained from electronic records. Statistical analysis was with IBM SPSS V.25. RESULTS: 691 procedures were performed over the 7-year period (520 traditional pull-through percutaneous endoscopic gastrostomy (PEG) and 171 gastropexy procedures to facilitate gastrostomy). Frequency of complications (gastrointestinal bleeding, perforation and peritonitis) was low (each n=1). Overall 7-day and 30-day mortality was 2.2% and 8.4%, respectively. One-year mortality reached 47.6%. There was no difference in survival between PEG and gastropexy procedures (p=0.410). Multivariate analysis reported increased age (p<0.001), increased alkaline phosphatase (p<0.001) and clinical indication (p=0.002) as independently associated with an increased hazard of death. Only age was moderately predictive of mortality (area under the curve 0.74, 95% CI 0.70 to 0.78, p<0.001) in the PEG group. Clinical indication was the only parameter independently associated with mortality in the gastropexy cohort (p=0.003). CONCLUSION: Endoscopic gastrostomy placement can be safe with a low mortality and low risk of serious complications. Blood markers were not associated with short-term or long-term outcomes. Gastropexy to facilitate gastrostomy is a safe alternative to traditional pull-through PEG procedures. Future work should consider quality of life outcomes to assess the benefit of gastrostomy from a patient perspective.