Colorectal dysplasia in chronic inflammatory bowel disease: pathology, clinical implications, and pathogenesis

Histopathological Evaluation of Pouch Neoplasia in IBD and Familial Adenomatous Polyposis

BACKGROUND

IPAA is often required for patients with ulcerative colitis or familial adenomatous polyposis after colectomy. This procedure reduces but does not completely eliminate the risk of neoplasia.

OBJECTIVE

This study focuses on the histopathology of neoplasia in the ileal pouch, rectal cuff, and anal transition zone.

DATA SOURCES

We performed a MEDLINE search for English-language studies published between 1981 and 2022 using the PubMed search engine. The terms "ileal pouch-anal anastomosis," "pouchitis," "pouch dysplasia," "pouch lymphoma," "pouch squamous cell carcinoma," "pouch adenocarcinoma," "pouch neoplasia," "dysplasia of rectal cuff," and "colitis-associated dysplasia" were used.

STUDY SELECTION

Human studies of neoplasia occurring in the pouch and para-pouch were selected, and the full text was reviewed. Comparisons were made within and across studies, with key concepts selected for inclusion in this article.

CONCLUSIONS

Neoplasia in the pouch is a rare complication in patients with IPAA. Annual endoscopic surveillance is recommended for familial adenomatous polyposis patients and ulcerative colitis patients with a history of prior dysplasia or carcinoma. In familial adenomatous polyposis, dysplastic polyps of the pouch are visible and readily amenable to endoscopic removal; however, glandular dysplasia in the setting of ulcerative colitis may be invisible on endoscopy. Therefore, random biopsies and adequate tissue sampling of the pouch and rectal cuff are recommended in this setting. The histological diagnosis of IBD-associated dysplasia can be challenging and should be confirmed by at least 1 expert GI pathologist. See video from the symposium.

Stable Dietary Ora-Curcumin Formulation Protects from Experimental Colitis and Colorectal Cancer

Inflammatory bowel disease (IBD) is a chronic gut disorder that also elevates the risk of colorectal cancer (CRC). The global incidence and severity of IBD are rising, yet existing therapies often lead to severe side effects. Curcumin offers potent anti-inflammatory and chemotherapeutic properties. However, its clinical translation is hindered by rapid metabolism, as well as poor water solubility and stability, which limits its bioavailability. To address these challenges, we developed OC-S, a water-soluble and colon-targeted curcumin formulation that protects against colitis in mice. The current study advances OC-S as a dietary supplement by establishing its stability and compatibility with various commercial dietary products. Further, OC-S exhibited specific binding to inflamed colon tissue, potentially aiding in targeted drug retention at the inflammation site in colitis with diarrhea symptoms. We further investigated its efficacy in vivo and in vitro using a murine model of colitis and tumoroids from APCmin mice. OC-S significantly reduced colitis severity and pro-inflammatory cytokine expression compared with curcumin, even at very low doses (5 mg/kg/day). It also demonstrated higher anti-proliferative activity in CRC cells and colon cancer tumoroids vs. curcumin. Overall, this study demonstrated that OC-S effectively targets and retains water-soluble curcumin at the inflamed colon sites, while showing promise in addressing both colitis and colorectal cancer, which potentially paves the way for OC-S to advance into clinical development as a dietary product for both IBD and CRC.

Pathology and Clinical Significance of Inflammatory Bowel Disease-Associated Colorectal Dysplastic Lesions

Timely diagnosis and effective management of colorectal dysplasia play a vital role in preventing mortality from colorectal cancer in patients with chronic inflammatory bowel disease. This review provides a contemporary overview of the pathologic and endoscopic classification of dysplasia in inflammatory bowel disease, their roles in determining surveillance and management algorithms, and emerging diagnostic and therapeutic approaches that might further enhance patient management.

Hyper Mucinous Proliferations in the Mucosa of Patients with Inflammatory Bowel Disease: Histological Lesions with a Real Potential for Neoplastic Evolution?

BACKGROUND AND AIMS

Mucin disfunction is a critical event in the pathogenesis of inflammatory bowel disease (IBD). Although hyper mucinous conditions have a still debated implication in the clinical evolution of this disorder, hyper mucinous villous proliferations were found to have a preneoplastic biologic potential. We studied morphologic and immunophenotypic characteristics of these lesions in ileocolonic resections for IBD to add evidence about the evolutive potential of these lesions in samples with well oriented wall structures.

METHODS

Morphologic characteristics of bowel samples from 20 patients resected for IBD and with raised lesions at gross examination were studied and sections from cases with hyper mucinous lesions were stained with the following antibodies: Ki 67, p21, and p27, which were employed to evaluate the characteristics of the proliferative and differentiative activity of the epithelial structures; mismatch repair proteins and p53 have been studied as proteins implicated in carcinogenesis in IBD-affected mucosa; mucins subtypes in hyper mucinous structures were evaluated with MUC-2 and MUC-6. The results in 11 cases of saplings were that they harbored hyper mucinous proliferations. The occurrence of hyper mucinous structures was not related to dysplastic lesions, pseudo pyloric metaplasia, subtype of disease, or activity. In only one of our cases, mild cytologic atypia in the proliferative compartment was detected. Proliferation markers (Ki 67, p53) were expressed in the proliferative compartments of mucosal crypts and antiproliferative proteins p21 and p27 were expressed in differentiated epithelium. MMR proteins expression was limited to the proliferative compartment of the hyper mucinous projections. Mucin subtypes distribution was regular in the epithelium of hyper mucinous proliferations.

CONCLUSIONS

The present monocentric retrospective study was conducted on surgical samplings with well oriented crypts. Collected data show that hyper mucinous features are frequent occurrences in raised lesions in IBD patients. In hyper mucinous proliferations of the selected cases, the status of the proliferative cycle, the expression of the proteins most frequently involved in carcinogenetic pathways of mucosa affected by IBD, and the mucins subtypes expression have no evident anomalies. Findings are not consistent with the increased risk of neoplastic evolution observed in other studies; rather, they suggest a hyperplastic nature. However, the capacity of hyper mucinous raised lesions for neoplastic evolution should be ruled out with more extensive prospective studies to identify functional defects that could explain the hypothesized neoplastic potential.

Claudin-2 protects against colitis-associated cancer by promoting colitis-associated mucosal healing

Patients with inflammatory bowel disease (IBD) are susceptible to colitis-associated cancer (CAC). Chronic inflammation promotes the risk for CAC. In contrast, mucosal healing predicts improved prognosis in IBD and reduced risk of CAC. However, the molecular integration among colitis, mucosal healing, and CAC remains poorly understood. Claudin-2 (CLDN2) expression is upregulated in IBD; however, its role in CAC is not known. The current study was undertaken to examine the role for CLDN2 in CAC. The AOM/DSS-induced CAC model was used with WT and CLDN2-modified mice. High-throughput expression analyses, murine models of colitis/recovery, chronic colitis, ex vivo crypt culture, and pharmacological manipulations were employed in order to increase our mechanistic understanding. The Cldn2KO mice showed significant inhibition of CAC despite severe colitis compared with WT littermates. Cldn2 loss also resulted in impaired recovery from colitis and increased injury when mice were subjected to intestinal injury by other methods. Mechanistic studies demonstrated a possibly novel role of CLDN2 in promotion of mucosal healing downstream of EGFR signaling and by regulation of Survivin expression. An upregulated CLDN2 expression protected from CAC and associated positively with crypt regeneration and Survivin expression in patients with IBD. We demonstrate a potentially novel role of CLDN2 in promotion of mucosal healing in patients with IBD and thus regulation of vulnerability to colitis severity and CAC, which can be exploited for improved clinical management.

Colorectal dysplasia in chronic inflammatory bowel disease: a contemporary consensus classification and interobserver study

The clinical management of patients with dysplasia in chronic inflammatory bowel disease (IBD) is currently guided by Riddell et al.'s grading system (negative, indefinite, low grade, high grade) from 1983 which was based primarily on nuclear cytoarchitectural characteristics. Although most dysplasia in IBD resembles sporadic adenomas morphologically, other distinctive potential cancer precursors in IBD have been described over time. Recognizing the need for a updated comprehensive classification for IBD-associated dysplasia, an international working group of pathologists with extensive clinical and research experience in IBD devised a new classification system and assessed its reproducibility by having each participant assess test cases selected randomly from a repository of electronic images of potential cancer precursor lesions. The new classification system now encompasses three broad categories and nine sub-categories: 1) intestinal dysplasia (tubular/villous adenoma-like, goblet cell deficient, crypt cell, traditional serrated adenoma-like, sessile serrated lesion-like and serrated NOS), 2) gastric dysplasia (tubular/villous and serrated), and 3) mixed intestinal-gastric dysplasia. In the interobserver analysis, 67% of the diagnoses were considered definitive and achieved substantial inter-rater agreement. The key distinctions between intestinal and gastric lesions and between serrated and non-serrated lesions achieved substantial and moderate inter-rater agreement overall, respectively, however, the distinctions among certain serrated sub-categories achieved only fair agreement. Based on the Riddell grading system, definite dysplasia accounted for 86% of the collective responses (75% low grade, 11% high grade). Based on these results, this new classification of dysplasia in IBD can provide a sound foundation for future clinical and basic IBD research.

A network pharmacology approach and experimental validation to investigate the anticancer mechanism and potential active targets of ethanol extract of Wei-Tong-Xin against colorectal cancer through induction of apoptosis via PI3K/AKT signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Wei-Tong-Xin (WTX), derives from the Chinese herbal decoction (CHD) of Wan-Ying-Yuan in ancient China, has been shown to be effective therapeutic herbal decoction for treating gastrointestinal diseases. Present studies have demonstrated that WTX had potential to alleviate the symptoms of gastrointestinal inflammation, gastric ulcer and improve gastric motility.

AIM OF THE STUDY

The study primarily focused on exploring the therapeutic effect and possible pharmacological mechanism of WTX on colorectal cancer (CRC) based on network pharmacology, in vitro and in vivo experiments.

MATERIALS AND METHODS

Firstly, colorectal cancer and WTX associated with targets were searched from GeneCards database and TCM Systems Pharmacology Database and Analysis Platform (TCMSP) respectively. The protein-protein interaction (PPI) network also was constructed to screening key targets. In addition, the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were applied to predict the underlying biological function and mechanism involving in the anti-colorectal cancer effect of WTX. Next, CCK-8, colony formation and transwell assays were performed to verify the influence of proliferation and metastasizing ability of HCT116 cells after treated with WTX. Cell cycle, apoptosis and reactive oxygen species (ROS) were analysis by flow cytometry. Hoechst 33258 staining was conducted to observe nuclear morphology changes. Protein expression of apoptosis and PI3K/AKT signaling as well as mRNA expression of ferroptosis and apoptosis were determined by Western Blotting and RT-qPCR. The effects of WTX and LY294002 combination on the PI3K/Akt/mTOR signaling pathway were measured by Western Blotting. Finally, the xenograft tumor mouse model was established by subcutaneous injection of CT26 cells to measure tumors volume and weight. Hematoxylin and eosin (HE) staining and immunohistochemical analysis were used to observe the pathological changes and the protein expression in tumor tissues.

RESULTS

There were 286 potential treatment targets from 130 bioactive compounds in WTX, 1349 CRC-related targets were identified. Eleven core targets (TP53, AKT1, STAT3, JUN, TNF, HSP90AA1, IL-6, MAPK3, CASP3, EGFR, MYC) were found by PPI network analysis constructed of 142 common targets. The results of KEGG enrichment displayed PI3K/AKT signaling pathway as core pathway. After the treatment of WTX, the inhibitory of viability, metastases and cell cycle arrest at G2/M phase were observed in HCT116 cells. Moreover, WTX induced an increase in the expression of apoptosis proteins (Bak, cytochrome c, cleaved caspase-9/caspase-9 and cleaved caspase-3/caspase-3) and the levels of ROS and MDA, a decrease in the expression of PI3K/AKT signaling related proteins (PI3K, p-PI3K, p-AKT/AKT and p-mTOR/mTOR) and the level of SOD. WTX treatment significantly reduced the tumor weight, increased cleaved caspase-3 positive area and decreased that of ki67 in xenograft mouse model.

CONCLUSION

Through a network pharmacology approach and in vitro experiments, we predicted and verified the effect of WTX on colorectal cancer cells mainly depended on the regulation of intrinsic apoptosis via PI3K/AKT signaling pathway, and further animal experiments proved that WTX has a good anti-colon cancer effect in vivo.

Oral Lingzhi or Reishi Medicinal Mushroom Ganoderma lucidum (Agaricomycetes) Spore Powder Ameliorates Murine Colitis by Inhibiting Key Kinases Phosphorylation in MAPK Pathway

The compound ganoderma lucidum spore powder (GLSP) has emerged as an anti-inflammatory and anti-oxidative regulator. In this study, we explored the roles of GLSP against dextran sulfate sodium (DSS)-induced mouse colitis that can mimic human inflammatory bowel disease (IBD). GLSP was administered by oral gavage at a dosage of 150 mg/kg/day to the acute colitis mice induced by DSS. The DSS-induced mouse weight loss, colonic shortening, diarrhea and bloody stool were observably alleviated after GLSP treatment. The lesion of macroscopic and microscopic signs of the disease was reduced significantly and DSS-induced gut barrier dysfunction was restored via increasing the level of claudin-1, ZO1, Occu, and ZO2 with GLSP. Meanwhile, the levels of IL-6, TNF-α, IL-1β, and IL-18 in the colon were reduced in the GLSP-treated groups. In addition, phosphorylation of the MAPKs ERK1/2, p38, and AKT was suppressed after GLSP treatment. All these results demonstrated that GLSP owned a protective effect on DSS-induced colitis by inhibition of MAPK pathway, which provides a promising therapeutic approach for the treatment of colitis.

Optimising inflammatory bowel disease surveillance and dysplasia management-Where do we stand?

Patients with longstanding extensive colitis are at an increased risk of developing colorectal cancer (CRC), and are therefore enrolled into colonoscopy screening programmes with the aim of detecting pre-cancerous dysplastic change. However, current surveillance programs face multiple limitations relating to low levels of patient enrolment, missed lesions resulting in interval cancers, and uncertainties in the management of dysplasia. Patient counselling regarding the endoscopic and surgical management options of dysplastic lesions can prove particularly challenging, due to the variable risk of progression to cancer. In this review, we discuss the histopathological diagnosis of inflammatory bowel disease (IBD)-associated dysplasia, describe the techniques to maximise dysplasia detection, and present a standardised multi-disciplinary approach to managing patients with dysplasia. The challenges presented by this patient cohort highlight the clear clinical need for further research into the development and validation of non-invasive markers of CRC risk in IBD patients undergoing surveillance.

Characteristics and Outcomes of Left-sided Ulcerative Colitis With a Cecal/Periappendiceal Patch of Inflammation

Ulcerative colitis (UC) is characterized by continuous mucosal inflammation of the rectum, extending uninterrupted to a variable portion of the colon proximally. However, in some patients with distal colitis, a distinct pattern of skip inflammation (so-called patch) involves the cecum and/or appendiceal orifice, but data on this entity are contradictory, and its significance and prognosis are still debated. We identified 102 adult cases of left-sided UC with a cecal/periappendiceal patch and compared them to 102 controls (left-sided UC only) along clinicopathologic characteristics and disease outcomes. In multivariate analysis, patients with a patch were younger (median age: 31 vs. 41 y; P =0.004) and more likely to have rectosigmoid involvement only (58.8% vs. 28.4%; P <0.001), compared with patients without a patch. During follow-up, patients with a patch were more likely to be eventually diagnosed with Crohn disease (CD) (9.8% vs. 1.0%; P =0.022) and to show proximal extension of inflammation (35.6% vs. 10.0%; P =0.021), but showed no differences in rates of neoplasia, colectomy, or pharmacotherapy escalation. Kaplan-Meier analysis confirmed that patients with a biopsy diagnosis of cecal/periappendiceal patch were more likely to show proximal disease extension ( P <0.001) and to be diagnosed with CD ( P =0.008). In conclusion, cecal/periappendiceal skip inflammation in left-sided UC occurs more often in younger patients and in those with rectosigmoid involvement and is associated with proximal disease extension and, in a small fraction of cases, change of diagnosis to CD. However, it does not portend increased risk of neoplasia, pharmacotherapy escalation, or subsequent colectomy, compared with patients with left-sided UC only.

The novel role of glucocorticoid-induced leucine zipper as a marker of mucosal healing in inflammatory bowel diseases

Glucocorticoid-induced leucin zipper (GILZ) mediates the effects of glucocorticoids in immune cells, but little is known about its role in both the gastro-intestinal (GI) mucosa and inflammatory bowel diseases (IBD) in humans. To investigate the GILZ protein expression profile in the GI tract, mucosal biopsies from 80 patients were retrospectively enrolled in this study and subdivided into three groups: 1) patients without clinical-endoscopic and histological evidence of IBD; 2) IBD patients; 3) patients with chronic atrophic gastritis (CAG) and Barrett esophagus (BE), both characterized by intestinal metaplasia (IM). GILZ expression was assessed by immunohistochemical and immunofluorescence methods. Our results showed that GILZ protein was strongly expressed in the secretory cells in healthy mucosa. GILZ expression was reduced in goblet cells in active disease, whereas it was restored in quiescent diseases. Conversely, entero-endocrine cells were not involved in such inflammation-driven dynamics, as GILZ expression remained detectable in active disease. Moreover, GILZ was expressed in IM, but was limited to CAG, and was not detected in BE. In summary, GILZ acts as a secretory protein in the GI mucosa in healthy, hyperplastic and metaplastic conditions. Its secretion by goblet cells is mostly affected by neutrophils mucosal infiltration and seems to be directly related to active mucosal inflammation in IBD. Overall, our findings suggest that GILZ is a suitable molecule to be considered as a histological marker of mucosal healing.

Colorectal cancer screening and surveillance in patients with inflammatory bowel disease in 2021

The detection of dysplasia in patients with inflammatory bowel disease (IBD) continues to be important given the increased risk of colorectal cancer in this population. Therefore, in 2017, we performed a review and update of the recommendations for the management and follow-up of patients with IBD based on the clinical practice guidelines of various scientific societies. The present manuscript focuses on new aspects of the detection, follow-up, and management of dysplasia according to the latest studies and recommendations. While chromoendoscopy with targeted biopsy continues to be the technique of choice for the screening and detection of dysplasia in IBD, the associated difficulties mean that it is now being compared with other techniques (virtual chromoendoscopy), which yield similar results with less technical difficulties. Furthermore, the emergence of new endoscopy techniques that are still being researched but seem promising (e.g., confocal laser endomicroscopy and full-spectrum endoscopy), together with the development of devices that improve endoscopic visualization (e.g., Endocuff Vision), lead us to believe that these approaches can revolutionize the screening and follow-up of dysplasia in patients with IBD. Nevertheless, further studies are warranted to define the optimal follow-up strategy in this patient population.

Small Intestinal Adenocarcinomas Arising in Enteritis Cystica Profunda With Metaplasia: A Report of 2 Cases

Enteritis cystica profunda (ECP) is an uncommon benign condition arising after mucosal damage. We describe 2 cases of small intestinal adenocarcinomas associated with ECP at the distal ileum, one in a background of active Crohn ileitis (case 1), the other 22 years after pelvic radiation therapy (case 2). Both patients presented with small bowel obstruction and received ileocectomy. Macroscopic examination identified an indurated/strictured area in the distal ileum. Histologically, both cases showed a low-grade tubuloglandular adenocarcinoma arising in a background of chronic ischemic stricture and ECP lined by flat cuboidal cells with mild cytologic atypia resembling pancreatobiliary-type epithelium. There was no conventional dysplasia in the surface or adjacent mucosa. Immunohistochemically, both ECP with metaplasia and invasive carcinomas were diffusely positive for CK7 and CK19, while focally positive for CDX2 or CK20. Both cases showed normal wild-type p53 expression. Case 2 was also mismatch repair protein proficient, with membranous β-catenin staining, and retained nuclear SMAD4 expression. In summary, the 2 cases uniquely exhibits "enteritis-metaplasia-carcinoma" sequence, which has not been reported before. This process appears to bypass conventional dysplasia, be slow and indolent, independent of p53, APC/β-catenin, and SMAD4/TGFβ signaling pathways.

Label-Free Quantitative Phase Imaging Reveals Spatial Heterogeneity of Extracellular Vesicles in Select Colon Disorders

Three-dimensional (3D) imaging and quantitative analysis of extracellular vesicles (EVs) remain largely unexplored, mainly because of limitations in detection techniques. In this study, EVs from patients diagnosed with colorectal cancer (CRC) and ulcerative colitis were examined. To investigate the spatial heterogeneity and 3D refractive index (RI) distribution of single EVs, a label-free digital holographic tomography technique was used at a submicrometer spatial resolution. The presented image-processing algorithms were used in quantitative analysis with digital staining and 3D visualization, the determination of the EV size distribution and extraction of fractions with different RIs. Reconstructed 3D RI distributions revealed variations in the spatial heterogeneity of EVs related to tissue specificity, such as CRC, normal colonic mucosa, and ulcerative colitis, as well as the isolation procedures used. The RI values of EVs isolated from solid tissues of frozen CRC samples were also dependent on the tumor grade and cancer cell proliferation. The simultaneous examination of cell culture models confirmed the association of the RI of EVs with the tumor grade. 3D-RI data analysis generates new perspectives with the optical, contact-free, label-free examination of the individual EVs. Depending on the specific tissue and isolation method, EVs exhibit significant spatial heterogeneity. The optical parameters of single EVs enabled their classification into two unique subgroups with different RI values.

Molecular characterization of ulcerative colitis-associated colorectal carcinomas

Patients with ulcerative colitis (UC) are at increased risk for developing colorectal cancer (CRC). In contrast to sporadic colorectal tumorigenesis, TP53 mutations occur early in the progression from inflamed colonic epithelium to dysplasia to CRC, and are sometimes readily detectable in inflamed, (yet) non-dysplastic mucosa. Here, we analyzed formalin-fixed paraffin-embedded tissue samples from 19 patients with long-standing UC (median 18 years, range 3 to 34) who had developed CRC as a consequence of chronic inflammation of the large bowel. We performed microsatellite instability testing, copy number analysis by array-based comparative genomic hybridization, mutation analysis by targeted next generation sequencing (48-gene panel) and TP53 immunostaining. The results were compared to The Cancer Genome Atlas (TCGA) data on sporadic CRC. All UC-CRC lesions in our cohort were microsatellite stable. Overall, genomic imbalances of UC-CRCs showed patterns of chromosomal aneuploidies characteristic for sporadic CRC with the exception of gains of chromosome arm 5p (12 of 23 UC-CRC, 52%), which are rare in sporadic CRCs from TCGA (21 of 144, 15%; FDR adjusted P = 0.006). UC-CRCs showed a predilection for TP53 alterations, which was the most frequently mutated gene in our cohort (20 of 23, 87%). Interestingly, spatially separated tumor lesions from individual patients tended to harbor distinct TP53 mutations. Similar to CRCs arising in a background of Crohn's colitis, the genetic landscape of UC-CRCs was characterized by TP53 mutations and chromosomal aneuploidies including gains of chromosome arm 5p. Both alterations harbor the potential for early detection in precursor lesions, thus complementing morphologic diagnosis.

Molecular profiling of the intestinal mucosa and immune cells of the colon by multi-parametric histological techniques

The impact of the post-mortem interval (PMI) on the optical molecular characteristics of the colonic mucosa and the gut-associated lymphoid tissue (GALT) were examined by multi-parametric measurements techniques. Inflammatory cells were identified by immunohistochemical staining. Molecular parameters were estimated using the Raman spectroscopy (RS) and Fourier Transform Infrared (FTIR) spectroscopic imaging. The 3D refractive index (3D-RI) distributions of samples were determined using the digital holographic tomography. The distribution of immune cells between post-mortem (PM) and normal controls did show significant differences for CD4 (P = 0.0016) or CD8 (P < 0.0001), whose expression level was decreased in PM cases. No association was found between individual PMI values and inflammatory cell distribution. However, there was a tendency for a negative correlation between CD4⁺ cells and PMI (r = - 0.542, P = 0.032). The alterations ongoing in post-mortem tissue may suggest that PMI has a suppressive effect on the effector properties of the cell-mediated immunity. Moreover, it was confirmed that spectroscopic and digital holotomographic histology are also a useful technique for characterization of the differences in inflammation of varying intensity and in GALT imaging in a solid tissue. Anatomical location of immune cells and methods of tissue fixation determine the molecular and optical parameters of the examined cases.

Clinicopathologic Characteristics and Neoplasia Risk of Colorectal Inflammatory Polyposis in Inflammatory Bowel Disease

CONTEXT.—

Inflammatory polyps (IPs) in inflammatory bowel disease may have been associated in the past with increased neoplasia risk. Additionally, colonic mucosa in filiform polyposis and giant inflammatory polyposis may be difficult to visualize during endoscopic surveillance, perhaps contributing to early colectomy in these patients.

OBJECTIVE.—

To examine the clinicopathologic characteristics and significance of IPs and inflammatory polyposis in inflammatory bowel disease.

DESIGN.—

We identified 336 resections from inflammatory bowel disease patients (212 [63.1%] male; mean age, 40.3 years; 175 [52.1%] with ulcerative colitis), including 78 with rare/few (<10) IPs, 141 with multiple (≥10) IPs, and 117 with inflammatory polyposis (including 30 with filiform polyposis/giant inflammatory polyposis) and compared them with 100 controls without IPs along various parameters, including overall and occult (unexpected) dysplasia.

RESULTS.—

There was no increased neoplasia in resections with IPs compared with controls, given similar age, disease duration, degree of inflammation, anatomical extent of colitis, prevalence of primary sclerosing cholangitis, and tissue sampling. Increasing numbers of IPs and inflammatory polyposis were significantly associated in multivariate analysis with ulcerative and indeterminate colitis (P = .003) and shorter disease duration (P = .01), but also, and independently, with lower rates of dysplasia overall, including all grades (P = .001) and advanced neoplasia (P = .04). There were no instances of occult dysplasia (any grade) among inflammatory polyposis cases.

CONCLUSIONS.—

These findings support the conclusion that the presence of IPs per se, and inflammatory polyposis in particular (including filiform polyposis and giant inflammatory polyposis), should not be considered an independent risk factor for the development of neoplasia in inflammatory bowel disease patients, outside the context of disease duration and inflammatory burden.

Interplay of stromal tumor-infiltrating lymphocytes, normal colonic mucosa, cancer-associated fibroblasts, clinicopathological data and the immunoregulatory molecules of patients diagnosed with colorectal cancer

A total of 94 patients with colorectal cancer (CRC) were included in this study. Lymphocytic infiltration of CD45⁺ cells in the normal colon was more pronounced than that in the paired tumor stroma (p = 0.0008). The mean immunoscore of CD45⁺TILs was decreased in CRC compared with the controls (p = 0.0010). The percentage of CD3⁺ cells was higher in stage II than in stage IV (p = 0.0218) and showed a negative correlation with the TNM classification (r = -0.2867, p = 0.0109). The number of stromal CD4⁺TILs was higher in stage I than in stage III (p = 0.0116) and IV (p = 0.0104), and there was a negative correlation between this number and the stage (r = -0.3708, p = 0.0008). There was a positive correlation between the Ki-67 and CD45⁺ (r = 0.2468, p = 0.0294), CD3⁺ (r = 0.3822, p = 0.0006), and CD4⁺ cells (r = 0.5465, p < 0.0001). The levels of cancer-associated fibroblast (CAF) markers such as α-SMA, thrombin and fibronectin were significantly higher in CRC than in normal colonic mucosa. The immunohistochemical expression of α-SMA was negatively correlated with TILs, while fibronectin showed positive coexpression. A higher number of cells expressing IL-2Rα, PD-L1, CD33 and CD14 were found in colorectal adenocarcinomas than in controls. The number of CD14⁺ cells was also dependent on the TNM stage (p = 0.0444) and tumor budding (p = 0.0324). These findings suggest a suppressive impact of CRC on the adaptive immune response and emphasize the importance of CAFs in regulating tumor immunity.

Epithelial TLR4 Signaling Activates DUOX2 to Induce Microbiota-Driven Tumorigenesis

BACKGROUND & AIMS

Chronic colonic inflammation leads to dysplasia and cancer in patients with inflammatory bowel disease. We have described the critical role of innate immune signaling via Toll-like receptor 4 (TLR4) in the pathogenesis of dysplasia and cancer. In the current study, we interrogate the intersection of TLR4 signaling, epithelial redox activity, and the microbiota in colitis-associated neoplasia.

METHODS

Inflammatory bowel disease and colorectal cancer data sets were analyzed for expression of TLR4, dual oxidase 2 (DUOX2), and NADPH oxidase 1 (NOX1). Epithelial production of hydrogen peroxide (H₂O₂) was analyzed in murine colonic epithelial cells and colonoid cultures. Colorectal cancer models were carried out in villin-TLR4 mice, carrying a constitutively active form of TLR4, their littermates, and villin-TLR4 mice backcrossed to DUOXA-knockout mice. The role of the TLR4-shaped microbiota in tumor development was tested in wild-type germ-free mice.

RESULTS

Activation of epithelial TLR4 was associated with up-regulation of DUOX2 and NOX1 in inflammatory bowel disease and colorectal cancer. DUOX2 was exquisitely dependent on TLR4 signaling and mediated the production of epithelial H₂O₂. Epithelial H₂O₂ was significantly increased in villin-TLR4 mice; TLR4-dependent tumorigenesis required the presence of DUOX2 and a microbiota. Mucosa-associated microbiota transferred from villin-TLR4 mice to wild-type germ-free mice caused increased H₂O₂ production and tumorigenesis.

CONCLUSIONS

Increased TLR4 signaling in colitis drives expression of DUOX2 and epithelial production of H₂O₂. The local milieu imprints the mucosal microbiota and imbues it with pathogenic properties demonstrated by enhanced epithelial reactive oxygen species and increased development of colitis-associated tumors. The inter-relationship between epithelial reactive oxygen species and tumor-promoting microbiota requires a 2-pronged strategy to reduce the risk of dysplasia in colitis patients.

βII spectrin (SPTBN1): biological function and clinical potential in cancer and other diseases

βII spectrin, the most common isoform of non-erythrocyte spectrin, is a cytoskeleton protein present in all nucleated cells. Interestingly, βII spectrin is essential for the development of various organs such as nerve, epithelium, inner ear, liver and heart. The functions of βII spectrin include not only establishing and maintaining the cell structure but also regulating a variety of cellular functions, such as cell apoptosis, cell adhesion, cell spreading and cell cycle regulation. Notably, βII spectrin dysfunction is associated with embryonic lethality and the DNA damage response. More recently, the detection of altered βII spectrin expression in tumors indicated that βII spectrin might be involved in the development and progression of cancer. Its mutations and disorders could result in developmental disabilities and various diseases. The versatile roles of βII spectrin in disease have been examined in an increasing number of studies; nonetheless, the exact mechanisms of βII spectrin are still poorly understood. Thus, we summarize the structural features and biological roles of βII spectrin and discuss its molecular mechanisms and functions in development, homeostasis, regeneration and differentiation. This review highlight the potential effects of βII spectrin dysfunction in cancer and other diseases, outstanding questions for the future investigation of therapeutic targets. The investigation of the regulatory mechanism of βII spectrin signal inactivation and recovery may bring hope for future therapy of related diseases.

Diagnostic interobserver variability in Crohn's disease- and ulcerative colitis-associated dysplasia: a multicenter digital survey from the IG-IBD Pathologists Group

BACKGROUND

Crohn's disease (CD) and ulcerative colitis, two forms of inflammatory bowel disease (IBD), are chronic and relapsing conditions of the gastrointestinal tract both characterized by long lasting chronic inflammation and increased risk of dysplasia and colorectal cancer (CRC). The aim of our study was to evaluate the interobserver agreement about IBD-associated dysplasia among pathologists belonging to the Italian Group for Inflammatory Bowel Diseases (IG-IBD P).

METHODS

The present multicenter survey was performed using telepathology, supported by an open source E-learning platform. Biopsy specimens from 30 colonoscopies and from 20 patients were included. The glass slides of any case, including clinical and endoscopic data, were digitalized and uploaded on the E-learning platform. All the digital slides were grouped in 54 diagnostic "blocks". Blinded histopathological evaluation on all the digital slides was performed by 20 gastrointestinal pathologists. Closed-ended questions about (1) the occurrence of IBD; (2) the classification of IBD (as UC or CD); (3) the presence of active versus quiescent disease; (4) the presence of dysplasia; (5) the possible association of dysplasia with the sites of disease (dysplasia-associated lesion or mass-DALM vs adenoma-like mass-ALM); (6) the grading of dysplasia according to the ECCO guidelines (negative, indefinite, low grade, high grade categories) and (7) the presence of associated serrated features, were proposed in each case. Inter-observer agreement was evaluated by mean agreement percentage and kappa statistic, when suitable.

RESULTS

The diagnosis of IBD was confirmed in 19 of 20 patients, 17 of 19 being classified as UC, 2 as CD. The mean interobserver agreement percentages about (1) the evidence of IBD, (2) the presence of either UC or CD and (3) the activity grading resulted to be 80%, 69% and 86%, respectively. Dysplasia was detected in 8/20 patients, with moderate agreement between pathologists (mean 72%, k 0.48). Particularly, low grade dysplasia was found in 13 biopsies (combined k 0.38), whereas high grade dysplasia in 8 (combined k 0.47). When the endoscopic and histopathological data were combined, features consistent with DALM were found in 6 of 20 patients with low grade dysplasia and those consistent with ALM in 2 patients with low grade dysplasia in a single biopsy (mean agreement: 86%). An associated serrated pattern was discovered in 4 patients (7 biopsies).

CONCLUSIONS

Our study showed moderate interobserver agreement about the histopathological detection and classification of IBD-associated dysplasia. Further efforts should be undertaken to integrate the histopathological data with both the ancillary tests and molecular investigations.

Methylation patterns in dysplasia in inflammatory bowel disease patients

Background and aims: Inflammatory Bowel Disease (IBD) with colonic involvement increases colorectal cancer risk. However, the distinction between IBD related and sporadic dysplasia in IBD patients is difficult. Some data favors the importance of abnormal DNA methylation in IBD-related carcinogenesis. We aimed to define methylation patterns in patients with colonic cancer or dysplasia diagnosis following an IBD diagnosis.Methods: Multicentric cross-sectional study-91 samples from colonic mucosa with/without dysplasia from 9 patients with IBD-related dysplasia/cancer and 26 patients with IBD and sporadic dysplasia/cancer were included. Methylation patterns of CpG islands in the promoter regions of 67 genes were studied by Methylation-specific Multiplex Ligation-dependent Probe Amplification.Results: Mean age at IBD diagnosis: 42 ± 16 years;at dysplasia diagnosis: 56 ± 14 years. Twenty-ninepatients had ulcerative colitis. Twenty-five patients had at least 1 lesion endoscopically described as adenoma-like, 4 at least 1 non-adenoma like, 3 had cancer and 3 had dysplasia in flat mucosa. No patient had both adenoma-like and non-adenoma-like lesions. Patients with an IBD-related lesion were significantly younger at IBD diagnosis (p = .003) and at dysplasia/cancer diagnosis (p = .039). Promoter methylation of IGF2, RARB, ESR1, CHFR, CDH13, WT1, GATA5, WIF1genes was significantly associated to dysplasia/cancer; methylation of MSH6, TIMP3 was significantly associated to IBD-related dysplasia/cancer. Promoter methylation of MSH6, MSH3, RUNX3, CRABP1, TP73, RARB, CDH13, PAX5, WT1, THBS1, TP53, SFRP1, WIF1, APAF1, BCL2 genes was significantly associated to active IBD.Conclusions: Methylation analysis, namely of MSH6, may contribute to the classification of dysplastic lesions in IBD- to be further tested in prospective studies.

Newly recognized non-adenomatous lesions associated with enteric carcinomas in inflammatory bowel disease - Report of six rare and unique cases

It is the current view that the inflammatory bowel disease (IBD)-associated precancerous lesions may be adenomatous (with classic cytologic dysplasia) and non-adenomatous (without frank cytologic dysplasia), and the latter ones are in various histomorphologies including serrated, mucinous, eosinophilic (goblet cell deficient), and differentiated (dysplasia with terminal epithelial differentiation) types. By retrospectively reviewing the surgically resected IBD-associated colorectal and ileal carcinomas (×53), analyzing the background epithelial changes/lesions in the mucosa surrounding and adjacent to invasive carcinomas, and testing the key molecular profile (KRAS, BRAF, PIK3CA, NRAS, p53, mismatch repair proteins, and SAT-B2) known to be involved in colorectal carcinogenesis, we identified 6 representative, rare and unique cases, in which non-adenomatous lesions were clearly in vicinity and in transition to invasive carcinomas. Furthermore, we identified certain colonic carcinoma-related molecular alterations, and thus further confirmed the neoplastic nature of various non-adenomatous lesions. It was also revealed that non-adenomatous lesions are heterogeneous in both morphology and molecular alterations, and that it is common to have more than one type of lesions be associated with a carcinoma. Moreover, mixed focal adenomatous dysplasia was common, which may be the necessary step in the malignant transformation of the non-adenomatous lesions.

Surgical Management of Dysplasia and Cancer in Inflammatory Bowel Disease

Patients with inflammatory bowel disease are at an increased risk of cancer secondary to long-standing intestinal inflammation. Surgical options must take into account the significant risk of synchronous disease at other colonic sites. Ileal pouch anal anastomosis is a viable option for patients with ulcerative colitis, but this should be restricted to early cancers that are unlikely to require preoperative or postoperative radiation treatment.

Inflammatory bowel disease- and Barrett's esophagus-associated neoplasia: the old, the new, and the persistent struggles

Early diagnosis of and adequate therapy for premalignant lesions in patients with inflammatory bowel disease (IBD) and Barrett's esophagus (BE) has been shown to decrease mortality. Endoscopic examination with histologic evaluation of random and targeted biopsies remains the gold standard for early detection and adequate treatment of neoplasia in both these diseases. Although eventual patient management (including surveillance and treatment) depends upon a precise histologic assessment of the initial biopsy, accurately diagnosing and grading IBD- and BE-associated dysplasia is still considered challenging by many general as well as subspecialized pathologists. Additionally, there are continuing updates in the literature regarding the diagnosis, surveillance, and treatment of these disease entities. This comprehensive review discusses the cancer risk, detailed histopathological features, diagnostic challenges, and updates as well as the latest surveillance and treatment recommendations in IBD- and BE-associated dysplasia.

Chemopreventive Effects of Edible Canna (Canna edulis Kerr.) Against Colorectal Carcinogenesis: Effects on Expression of Adenomatous Polyposis Coli and Inducible Nitric Oxide Synthase in Rat Inflammatory Model

Objective:

Dietary high fibre and calcium intake has been suggested to reduce colorectal cancer risk. However, there is limited information available regarding the potential of edible canna (Ganyong), with high dietary fibre and calcium content, to act as a preventive agent for colorectal cancer. This experimental study was conducted to investigate the preventive effect of Ganyong in reducing colorectal carcinogenesis with attention to effects on adenomatous polyposis coli (APC) and inducible nitric oxide synthase (iNOS) expression.

Methods:

Thirty male Wistar rats were divided into 5 equal groups; a normal control group without azoxymethane/dextran sodium sulphate (AOM/DSS) induction and Ganyong, a ‘cancer’ control group with AOM/DSS induction only, and three treatment groups with AOM/DSS induction and different percentages (5%, 10% and 20%) of Ganyong. Paraffin-embedded sections of rat colon tissue were analysed by haematoxylin-eosin and immunohistochemical staining against antibodies against APC and iNOS. Variation in rates of APC and iNOS expression were analyzed using the Kruskal-Wallis test followed by the Dunn’s test (SPSS statistic version 24). P<0.05 was considered statistically significant.

Results:

AOM/DSS induction increased the expression of APC (p=0.013) and iNOS (p=0.013) compared to the normal control group. APC expression in the treated groups was lower than in the ‘cancer’ control group (p=0.049), especially in the 10% Ganyong group (p=0.02). In contrast, there was no significant variation among the treated groups regarding iNOS expression. Histopathological features of the colon supported the data for APC and iNOS expression.

Conclusion:

This study indicated potential chemopreventive effects of Ganyong reducing expression of factors contributing to colorectal carcinogenesis.

Chitin, chitinases, and chitin lectins: Emerging roles in human pathophysiology

Chitin is a simple β-linked repeating sugar polymer prominent in the building block structures of a wide variety of organisms, from the yeast cell wall to the exoskeleton and shells of arthropods and other forms of invertebrate life. It had previously been assumed that vertebrates did not contain chitins. However, chitin and chitinases are now documented to occur in vertebrate tissues. Chitin, chitinases and particularly chitinase-like proteins are involved in important human pathologies, though the mechanisms by which these function is unknown. These chitinase-like proteins bind to chitin and function as chitin lectins in that they bind to chitin but have lost the ability to degrade it. Emphasis is placed on one of the chitinase-like proteins, CHI3L1, that has acquired wide clinical importance. The purpose of this review is to place an array of bewildering observations associated with various human disorders into a framework, particularly the pathologies of the human gastro-intestinal tract. A reasonably cohesive story may eventually emerge.

The Mbd4 DNA glycosylase protects mice from inflammation-driven colon cancer and tissue injury

Much of the global cancer burden is associated with longstanding inflammation accompanied by release of DNA-damaging reactive oxygen and nitrogen species. Here, we report that the Mbd4 DNA glycosylase is protective in the azoxymethane/dextran sodium sulfate (AOM/DSS) mouse model of inflammation-driven colon cancer. Mbd4 excises T and U from T:G and U:G mismatches caused by deamination of 5-methylcytosine and cytosine. Since the rate of deamination is higher in inflamed tissues, we investigated the role of Mbd4 in inflammation-driven tumorigenesis. In the AOM/DSS assay, Mbd4-/- mice displayed more severe clinical symptoms, decreased survival, and a greater tumor burden than wild-type (WT) controls. The increased tumor burden in Mbd4-/- mice did not arise from impairment of AOM-induced apoptosis in the intestinal crypt. Histopathological analysis indicated that the colonic epithelium of Mbd4-/- mice is more vulnerable than WT to DSS-induced tissue damage. We investigated the role of the Mbd4-/- immune system in AOM/DSS-mediated carcinogenesis by repeating the assay on WT and Mbd4-/- mice transplanted with WT bone marrow. Mbd4-/- mice with WT bone marrow behaved similarly to Mbd4-/- mice. Together, our results indicate that the colonic epithelium of Mbd4-/- mice is more vulnerable to DSS-induced injury, which exacerbates inflammation-driven tissue injury and cancer.

Interorgan regulation of Drosophila intestinal stem cell proliferation by a hybrid organ boundary zone

The molecular identities and regulation of cells at interorgan boundaries are often unclear, despite the increasingly appreciated role of organ boundaries in disease. Using Drosophila as a model, we here show that a specific population of adult midgut organ-boundary intestinal stem cells (OB-ISCs) is regulated by the neighboring hindgut, a developmentally distinct organ. This distinct OB-ISC control occurs through proximity to a specialized transition zone between the endodermal midgut and ectodermal hindgut that shares molecular signatures of both organs, which we term the hybrid zone (HZ). During homeostasis, proximity to the HZ restrains OB-ISC proliferation. However, injury to the adult HZ/hindgut drives upregulation of unpaired-3 cytokine, which signals through a Signal transducer and activator of transcription (STAT) protein to promote cell division only in OB-ISCs. If HZ disruption is severe, hyperplastic OB-ISCs expand across the interorgan boundary. Our data suggest that interorgan signaling plays an important role in controlling OB-ISCs in homeostasis and injury repair, which is likely to be crucial in prevention of disease.

Oleuropein Decreases Cyclooxygenase-2 and Interleukin-17 Expression and Attenuates Inflammatory Damage in Colonic Samples from Ulcerative Colitis Patients

Oleuropein (OLE) is the major phenolic secoiridoid of olive tree leaves, and its antioxidant and anti-inflammatory activities have been demonstrated in in vitro and in vivo animal models. The aim of this study was to investigate the activity of OLE in the colonic mucosa from patients with ulcerative colitis (UC). Biopsies obtained during colonoscopy from 14 patients with active UC were immediately placed in an organ culture chamber and challenged with lipopolysaccharide from Escherichia coli (EC-LPS) at 1 μg/mL in the presence or absence of 3 mM OLE. The expression of cyclooxygenase (COX)-2 and interleukin (IL)-17 was assessed in total protein extracts from treated colonic biopsies by Western blotting. Levels of IL-17 were also measured in culture supernatant by ELISA. A microscopic evaluation of the cultured biopsies was performed by conventional histology and immunohistochemistry. The expression of COX-2 and IL-17 were significantly lower in samples treated with OLE + EC-LPS compared with those treated with EC-LPS alone (0.80 ± 0.15 arbitrary units (a.u.) vs. 1.06 ± 0.19 a.u., p = 0.003, and 0.71 ± 0.08 a.u. vs. 1.26 ± 0.42 a.u., p = 0.03, respectively) as were the levels of IL-17 in culture supernatants of OLE + EC-LPS treated colonic samples (21.16 ± 8.64 pg/mL vs. 40.67 ± 9.24 pg/mL, p = 0.01). Histologically, OLE-treated colonic samples showed an amelioration of inflammatory damage with reduced infiltration of CD3, CD4, and CD20 cells, while CD68 numbers increased. The anti-inflammatory activity of OLE was demonstrated in colonic biopsies from UC patients. These new data support a potential role of OLE in the treatment of UC.

Clonal evolution of colorectal cancer in IBD

Optimizing the management of colorectal cancer (CRC) risk in IBD requires a fundamental understanding of the evolutionary process underpinning tumorigenesis. In IBD, clonal evolution begins long before the development of overt neoplasia, and is probably accelerated by the repeated cycles of epithelial wounding and repair that are characteristic of the condition. Here, we review the biological drivers of mutant clone selection in IBD with particular reference to the unique histological architecture of the intestinal epithelium coupled with the inflammatory microenvironment in IBD, and the unique mutation patterns seen in IBD-driven neoplasia when compared with sporadic adenomas and CRC. How these data can be leveraged as evolutionary-based biomarkers to predict cancer risk is discussed, as well as how the efficacy of CRC surveillance programmes and the management of dysplasia can be improved. From a research perspective, the longitudinal surveillance of patients with IBD provides an under-exploited opportunity to investigate the biology of the human gastrointestinal tract over space and time.

Investigation of malignant transformation of sporadic adenomas of colon by fluorimetry

In this work, biochemical changes in sporadic adenoma during progression to colon cancer have been detected by spectral techniques. It is shown that spectra of all types of adenomas as well as adenocarcinoma have two maxima at 265 ÷ 270 nm and at 330 ÷ 340 nm. The first maximum is primarily defined by tryptophan containing peptides. The second maximum of the spectra is in the main defined by collagen presence in stroma of tumors and normal mucosa. Progression of precancer lesions to advanced cancer leads to increase of NADH concentration impacting on the second maximum of spectra. At the time, the spectra of both AC differ from each other by widths of the second maximum. For well-differentiated AC, the second maximum is wider. It gives reason to suggest that two fluorophores impact on its intensity. These fluorophores can be NADH and vitamin B₆. Correlation between microscopical and spectral results can allow to use fluorimetry for detail diagnostics and investigation of colon cancer development.

Radiation and SN38 treatments modulate the expression of microRNAs, cytokines and chemokines in colon cancer cells in a p53-directed manner

Aberrant expression of miRNAs, cytokines and chemokines are involved in pathogenesis of colon cancer. However, the expression of p53 mediated miRNAs, cyto- and chemokines after radiation and SN38 treatment in colon cancer remains elusive. Here, human colon cancer cells, HCT116 with wild-type, heterozygous and a functionally null p53, were treated by radiation and SN38. The expression of 384 miRNAs was determined by using the TaqMan® miRNA array, and the expression of cyto- and chemokines was analyzed by Meso-Scale-Discovery instrument. Up- or down-regulations of miRNAs after radiation and SN38 treatments were largely dependent on p53 status of the cells. Cytokines, IL-6, TNF-α, IL-1β, Il-4, IL-10, VEGF, and chemokines, IL-8, MIP-1α were increased, and IFN-γ expression was decreased after radiation, whereas, IL-6, IFN-γ, TNF-α, IL-1β, Il-4, IL-10, IL-8 were decreased, and VEGF and MIP-1α were increased after SN38 treatment. Bioinformatic analysis pointed out that the highly up-regulated miRNAs, let-7f-5p, miR-455-3p, miR-98, miR-155-5p and the down-regulated miRNAs, miR-1, miR-127-5p, miR-142-5p, miR-202-5p were associated with colon cancer pathways and correlated with cyto- or chemokine expression. These miRNAs have the potential for use in colon cancer therapy as they are related to p53, pro- or anti-inflammatory cyto- or chemokines after the radiation and SN38 treatment.

Microarray analysis of differentially-expressed genes and linker genes associated with the molecular mechanism of colorectal cancer

Colorectal cancer (CRC) is one of the most prevalent malignancies worldwide and remains the third leading cause of cancer-associated mortality. The present study aimed to fully elucidate the pathogenesis of CRC and identify associated genes in tumor development. Microarray GSE44076, GSE41328 and GSE44861 datasets were downloaded from the Gene Expression Omnibus database and integrated with meta-analysis. Differentially-expressed genes (DEGs) were identified from CRC samples compared with adjacent non-cancerous controls using the Limma package in R, followed by functional analysis using the Database for Annotation, Visualization, and Integrated Discovery online tool. A protein-protein interaction (PPI) network of DEGs and linker genes was constructed using NetBox software and modules were also mined. Functional annotation was performed for modules with a maximum number of nodes. Subsequent to meta-analysis to pool the data, one dataset that included 327 samples involved in 11,081 genes was obtained. A total of 697 DEGs were identified between CRC samples and adjacent non-cancerous controls. In the PPI network, modules 1 and 5 contained the maximum number of nodes. Collagen, type I, α1 (COL1A1), COL1A2 and matrix metallopeptidase 9 (MMP9) in module 1 and UDP-glucose 6-dehydrogenase (UGDH), aldehyde dehydrogenase 1 family, member A1 (ALDH1A1), fatty acid binding protein 4 (FABP4) and monoglyceride lipase (MGLL) in module 5 exhibited a high degree of connectivity. Functional analysis indicated that the genes in module 1 were involved in extracellular matrix (ECM)-associated functions and that the genes in module 5 were involved in metabolism-related functions. Overall, significant DEGs and linker genes, namely COL1A1, COL1A2, MMP9, UGDH, ALDH1A1, FABP4 and MGLL, play a crucial role in the development of CRC via regulating the ECM and cell metabolism.

In Vivo 19F MR Imaging Cell Tracking of Inflammatory Macrophages and Site-specific Development of Colitis-associated Dysplasia

Purpose To investigate whether the magnitude of in vivo fluorine 19 (¹⁹F) magnetic resonance (MR) imaging signal is associated with subsequent development of colitis-associated dysplasia after in situ fluorination of inflammatory macrophages in a mouse model of inflammatory bowel disease (IBD). Materials and Methods Experiments were approved by the institutional animal care and use committee. Mice in the experimental group (n = 10) were administered azoxymethane and dextran sulfate sodium to induce colitis-associated dysplasia. Five mice were in the noninduced control group. Animals were injected with a commercially available perfluorocarbon and were examined in vivo with an 11.7-T MR imager for up to 110 days. Colons were then harvested followed by high-spatial-resolution ex vivo MR imaging. Multiple colon segments with or without ¹⁹F signal were histologically graded and were correlated with ¹⁹F signal intensity by using a Spearman correlation test. The signal intensity in mice with colitis-associated dysplasia was compared with that in control mice with a two-tailed Mann-Whitney U test. Results Patchy distributions of ¹⁹F signal intensity in the colon wall were seen on in vivo and ex vivo images, representing chronic inflammation as shown by immunohistochemistry. Histologic scores of inflammation and site-specific development of colitis-associated dysplasia in the descending colon showed good correlation with normalized ¹⁹F signal intensity (r = 0.88, P = .033 for the ascending colon; r = 0.82, P = .006 for the descending colon). A significantly (P = .002) higher normalized ¹⁹F signal-to-noise ratio was found at sites that developed dysplasia (mean, 0.58 ± 0.09 [standard deviation]) as compared with sites that did not (mean, 0.17 ± 0.22). Conclusion ¹⁹F MR imaging cell tracking of macrophages can be used to assess local inflammation in a mouse model of IBD. The resulting local ¹⁹F signal intensity, representing the magnitude of inflammation, has a positive correlation with the development of colitis-associated dysplasia. ^© RSNA, 2016 Online supplemental material is available for this article.

Loss of intestinal O-glycans promotes spontaneous duodenal tumors

Mucin-type O-glycans, primarily core 1- and core 3-derived O-glycans, are the major mucus barrier components throughout the gastrointestinal tract. Previous reports identified the biological role of O-glycans in the stomach and colon. However, the biological function of O-glycans in the small intestine remains unknown. Using mice lacking intestinal core 1- and core 3-derived O-glycans [intestinal epithelial cell C1galt1(-/-);C3GnT(-/-) or double knockout (DKO)], we found that loss of O-glycans predisposes DKO mice to spontaneous duodenal tumorigenesis by ∼1 yr of age. Tumor incidence did not increase with age; however, tumors advanced in aggressiveness by 20 mo. O-glycan deficiency was associated with reduced luminal mucus in DKO mice before tumor development. Altered intestinal epithelial homeostasis with enhanced baseline crypt proliferation characterizes these phenotypes as assayed by Ki67 staining. In addition, fluorescence in situ hybridization analysis reveals a significantly lower bacterial burden in the duodenum compared with the large intestine. This phenotype is not reduced with antibiotic treatment, implying O-glycosylation defects, rather than bacterial-induced inflammation, which causes spontaneous duodenal tumorigenesis. Moreover, inflammatory responses in DKO duodenal mucosa are mild as assayed with histology, quantitative PCR for inflammation-associated cytokines, and immunostaining for immune cells. Importantly, inducible deletion of intestinal O-glycans in adult mice leads to analogous spontaneous duodenal tumors, although with higher incidence and heightened severity compared with mice with O-glycans constitutive deletion. In conclusion, these studies reveal O-glycans within the small intestine are critical determinants of duodenal cancer risk. Future studies will provide insights into the pathogenesis in the general population and those at risk for this rare but deadly cancer.

Gastrointestinal stem cells in health and disease: from flies to humans

The gastrointestinal tract of complex metazoans is highly compartmentalized. It is lined by a series of specialized epithelia that are regenerated by specific populations of stem cells. To maintain tissue homeostasis, the proliferative activity of stem and/or progenitor cells has to be carefully controlled and coordinated with regionally distinct programs of differentiation. Metaplasias and dysplasias, precancerous lesions that commonly occur in the human gastrointestinal tract, are often associated with the aberrant proliferation and differentiation of stem and/or progenitor cells. The increasingly sophisticated characterization of stem cells in the gastrointestinal tract of mammals and of the fruit fly Drosophila has provided important new insights into these processes and into the mechanisms that drive epithelial dysfunction. In this Review, we discuss recent advances in our understanding of the establishment, maintenance and regulation of diverse intestinal stem cell lineages in the gastrointestinal tract of Drosophila and mice. We also discuss the field's current understanding of the pathogenesis of epithelial dysfunctions.

Serrated colorectal polyps in inflammatory bowel disease

Serrated colorectal polyps, which, besides hyperplastic polyps, comprise sessile serrated adenomas/polyps and traditional serrated adenomas, are presumptive precursors of at least 20% of sporadic colorectal carcinomas; however, their significance in patients with inflammatory bowel disease is unclear. We retrospectively evaluated 78 serrated polyps, removed over a 14-year period from 6602 inflammatory bowel disease patients undergoing endoscopic surveillance, with respect to morphologic, clinicopathologic, and molecular features, and compared rates of advanced neoplasia (high-grade dysplasia and carcinoma) development following the index serrated polyp diagnosis to reference inflammatory bowel disease cohorts without serrated polyps. Serrated polyps negative for dysplasia, which morphologically resembled sporadic sessile serrated adenoma/polyps, occurred mainly in females, in the proximal colon, and contained BRAF mutations. Serrated polyps with low-grade dysplasia resembled sporadic traditional serrated adenomas and occurred mainly in males, in the distal colon, and contained KRAS mutations. Serrated polyps indefinite for dysplasia were morphologically heterogeneous, but similar to serrated polyps positive for low-grade dysplasia with respect to male predominance, left-sided location, and KRAS mutation rates. Rates of prevalent neoplasia associated with serrated polyps positive for low-grade dysplasia, indefinite for dysplasia, and negative for dysplasia were 76, 39, and 11%, respectively (P<0.001). Actuarial 10-year rates of incident advanced neoplasia after an initial diagnosis of serrated polyp positive for low-grade dysplasia, indefinite for dysplasia, and negative for dysplasia were 17, 8, and 0%, respectively, the first and last being significantly different (P=0.02) and comparable to those of corresponding reference populations of inflammatory bowel disease patients with and without low-grade dysplasia at baseline, respectively. We conclude that in serrated polyps from inflammatory bowel disease patients, dysplasia grade correlates with morphology, sex, anatomic location, BRAF and KRAS mutation status, prevalent conventional neoplasia, and rates of advanced neoplasia development.

Fiber-bundle microendoscopy with sub-diffuse reflectance spectroscopy and intensity mapping for multimodal optical biopsy of stratified epithelium

Early detection of structural or functional changes in dysplastic epithelia may be crucial for improving long-term patient care. Recent work has explored myriad non-invasive or minimally invasive "optical biopsy" techniques for diagnosing early dysplasia, such as high-resolution microendoscopy, a method to resolve sub-cellular features of apical epithelia, as well as broadband sub-diffuse reflectance spectroscopy, a method that evaluates bulk health of a small volume of tissue. We present a multimodal fiber-based microendoscopy technique that combines high-resolution microendoscopy, broadband (450-750 nm) sub-diffuse reflectance spectroscopy (sDRS) at two discrete source-detector separations (374 and 730 μm), and sub-diffuse reflectance intensity mapping (sDRIM) using a 635 nm laser. Spatial resolution, magnification, field-of-view, and sampling frequency were determined. Additionally, the ability of the sDRS modality to extract optical properties over a range of depths is reported. Following this, proof-of-concept experiments were performed on tissue-simulating phantoms made with poly(dimethysiloxane) as a substrate material with cultured MDA-MB-468 cells. Then, all modalities were demonstrated on a human melanocytic nevus from a healthy volunteer and on resected colonic tissue from a murine model. Qualitative in vivo image data is correlated with reduced scattering and absorption coefficients.

Properties and Clinical Relevance of Speckle-Type POZ Protein in Human Colorectal Cancer

BACKGROUND

The aims of this study are to evaluate the effect of Speckle-type POZ protein (SPOP) in colorectal cancer (CRC) patients and explore its significance in the prognosis.

METHODS

We used immunohistochemistry to detect the expression of SPOP in CRC. Moreover, this result was further confirmed at the protein and messenger RNA (mRNA) level in paired CRC specimens and matched adjacent noncancerous colon tissues by Western blotting and real-time quantitative PCR (qRT-PCR), respectively. Furthermore, we evaluate the effects of SPOP on CRC cell proliferation and migration in vitro. The Kaplan-Meier method and log-rank test were employed to compare the overall survival between SPOP low expression group and SPOP high expression group. Correlation of survival with clinicopathologic parameters, including SPOP level, was investigated with multivariate analyses.

RESULTS

We confirmed frequent SPOP downregulation in both mRNA (P = 0.0286) and protein (P = 0.004) levels in CRC tissues as compared to matched adjacent nontumorous tissues. Besides, the downregulated SPOP expression in CRC tissues was significantly correlated to poor differentiation (P = 0.013), distant metastasis (P = 0.003), gross type (P < 0.001), and high TNM stage (P = 0.002). Kaplan-Meier survival analysis showed that low SPOP expression exhibited a significant correlation with poor prognosis for CRC patients. Overexpression of SPOP in CRC cell lines significantly suppressed cell proliferation, migration, and clone formation. In contrast, SPOP knockdown dramatically promoted cell proliferation, migration, and clone formation in vitro. In addition, overexpression of SPOP increased E-cadherin and suppressed vimentin in HCT116 cells and silencing of SPOP reversed all these biomarkers. Furthermore, SPOP significantly downregulated MMP2 and MMP7 protein levels in HCT116 cell lines.

CONCLUSION

Our results suggest that SPOP plays a pivotal role in colorectal cancer (CRC) through mesenchymal-epithelial transition and MMPs, and it may be a potential therapeutic target in colorectal cancer.

Risk for colorectal neoplasia in patients with inflammatory bowel disease and mucosa indefinite for dysplasia

BACKGROUND

The management of colonic epithelial changes indefinite for dysplasia (IND) in patients with inflammatory bowel disease (IBD) remains controversial because of a paucity of published outcome data.

METHODS

We analyzed data from 93 patients with IBD who were IND and 52 IBD patients without dysplasia (controls) from the Department of Anatomic Pathology database at the Cleveland Clinic from 1989 to 2004. Pathology reports, histologic slides, clinical features, and outcomes were reviewed.

RESULTS

Twenty-two patients (23.7%) had surgical resections within 6 months of the IND assignment; of these, 6 had dysplasia (27.3%; 1 low-grade dysplasia and 5 high-grade dysplasia [HGD]). The remaining 71 patients received regular colonoscopy examinations for a mean period of 98.6 months; 18 patients developed dysplasia or carcinoma (25.2%; 10 low-grade dysplasia, 5 HGD, and 3 colorectal cancer). There was a mean interval of 53.9 months between an IND assignment and identification of dysplasia or carcinoma. Histology review of 59 cases revealed 3.2 cases per 100 person-years for neoplasia (low-grade dysplasia, HGD, or colorectal cancer) and 1.5 cases per 100 person-years for advanced neoplasia (HGD or colorectal cancer); these values were higher than those for controls (1.9 cases per 100 person-years for neoplasia and 0.7 cases per 100 person-years for advance neoplasia; P = 0.1 and P = 0.2, respectively, for IND versus controls). Patients aged more than 44 years when they were found to be IND were more likely than younger patients to develop neoplasia (hazard ratio, 6.7; P = 0.01).

CONCLUSIONS

Patients with IBD and IND are at significant risk for colorectal dysplasia and cancer. These patients should be closely followed.

Small bowel adenocarcinomas complicating Crohn's disease are associated with dysplasia: a pathological and molecular study

BACKGROUND

Crohn's disease (CD) is associated with an increased risk of small bowel adenocarcinoma (SBA). However, there are no guidelines for the screening and early diagnosis of SBA. Colorectal cancer associated with chronic colitis arises from dysplasia. High-risk patients benefit from surveillance colonoscopies aimed to detect dysplasia. The dysplasia-carcinoma sequence remains poorly documented in CD-associated SBA. Moreover, molecular data about SBA complicating CD and associated dysplasia are very limited. We therefore assessed dysplasia and several key molecular markers of carcinogenesis in SBA and dysplasia developed in patients with CD.

METHODS

Forty-five SBA complicating CD and 4 specimens with dysplasia without SBA were screened. In SBA, we looked for dysplasia and determined their pathological characteristics (type, grade, distribution). We also stained for mismatch repair proteins (MLH1, MSH2, MSH6, PMS2), p53, β-catenin, and p16 and looked for KRAS, BRAF and PIK3CA mutations.

RESULTS

All neoplastic lesions, except 1 lesion, were found in inflamed mucosal areas. Dysplasia was found in 20 of 41 patients with SBA (49%). Dysplasia was flat or raised, low grade or high grade, and adjacent or distant to concomitant SBA. Molecular markers of SBA carcinogenesis complicating CD were similar to those observed in chronic colitis-related colorectal cancer (KRAS, BRAF, p53, MSI), although differences were observed for β-catenin and p16. No PIK3CA mutations were observed.

CONCLUSIONS

These results suggest that there is an inflammation-dysplasia-adenocarcinoma sequence in at least half of CD-related SBA, similar to what is observed in chronic colitis-related colorectal cancer and may have implications for the prevention and treatment of this cancer.

Histological evaluation in ulcerative colitis

This review summarizes diagnostic problems, challenges and advances in ulcerative colitis (UC). It emphasizes that, although histopathological examination plays a major role in the diagnosis and management of UC, it should always be interpreted in the context of clinical, endoscopic, and radiological findings. Accurate diagnosis requires knowledge of the classic morphological features of UC, as well as a number of atypical pathological presentations that may cause mis-classification of the disease process, either in resection or biopsy specimens. These atypical pathological presentations include rectal sparing and patchiness of disease at initial presentation of UC in pediatric patients or in the setting of medically treated UC, cecal or ascending colon inflammation in left-sided UC, and backwash ileitis in patients with severe ulcerative pancolitis. Loosely formed microgranulomas, with pale foamy histiocytes adjacent to a damaged crypt or eroded surface, should not be interpreted as evidence of Crohn's disease. Indeterminate colitis should only be used in colectomy specimens as a provisional pathological diagnosis. Patients with UC are at risk for the development of dysplasia and carcinoma; optimal outcomes in UC surveillance programs require familiarity with the diagnostic criteria and challenges relating to UC-associated dysplasia and malignancy. Colon biopsy from UC patients should always be evaluated for dysplasia based on cytological and architectural abnormalities. Accurate interpretation and classification of dysplasia in colon biopsy from UC patients as sporadic adenoma or UC-related dysplasia [flat, adenoma-like, or dysplasia-associated lesion or mass (DALM)] requires clinical and endoscopic correlation. Isolated polypoid dysplastic lesions are considered to be sporadic adenoma if occurring outside areas of histologically proven colitis, or adenoma-like dysplasia if occurring in the diseased segment. Recent data suggest that such lesions may be treated adequately by polypectomy in the absence of flat dysplasia in the patient. UC patients with DALM or flat high-grade dysplasia should be treated by colectomy because of the high probability of adenocarcinoma. The natural history of low-grade dysplasia (LGD) is more controversial: while multifocal LGD, particularly if detected at the time of initial endoscopic examination, is treated with colectomy, unifocal flat LGD detected during surveillance may be managed by close follow-up with increased surveillance. The surveillance interval and treatment options for UC patients with dysplasia are reviewed in detail.

Inflammatory cues acting on the adult intestinal stem cells and the early onset of cancer (review)

The observation that cancer often arises at sites of chronic inflammation has prompted the idea that carcinogenesis and inflammation are deeply interwoven. In fact, the current literature highlights a role for chronic inflammation in virtually all the steps of carcinogenesis, including tumor initiation, promotion and progression. The aim of the present article is to review the current literature on the involvement of chronic inflammation in the initiation step and in the very early phases of tumorigenesis, in a type of cancer where adult stem cells are assumed to be the cells of origin of neoplasia. Since the gastrointestinal tract is regarded as the best-established model system to address the liaison between chronic inflammation and neoplasia, the focus of this article will be on intestinal cancer. In fact, the anatomy of the intestinal epithelial lining is uniquely suited to study adult stem cells in their niche, and the bowel crypt is an ideal developmental biology system, as proliferation, differentiation and cell migration are all distributed linearly along the long axis of the crypt. Moreover, crypt stem cells are regarded today as the most likely targets of neoplastic transformation in bowel cancer. More specifically, the present review addresses the molecular mechanisms whereby a state of chronic inflammation could trigger the neoplastic process in the intestine, focusing on the generation of inflammatory cues evoking enhanced proliferation in cells not initiated but at risk of neoplastic transformation because of their stemness. Novel experimental approaches, based on triggering an inflammatory stimulus in the neighbourhood of adult intestinal stem cells, are warranted to address some as yet unanswered questions. A possible approach, the targeted transgenesis of Paneth cells, may be aimed at 'hijacking' the crypt stem cell niche from a status characterized by the maintenance of homeostasis to local chronic inflammation, with the prospect of initiating neoplastic transformation in that site.

Diagnostic utility of TP53 and cytokeratin 7 immunohistochemistry in idiopathic inflammatory bowel disease-associated neoplasia

Long-standing inflammatory bowel disease is associated with increased risk of developing colorectal adenocarcinoma. Significant intra- and inter-observers' variability exists in histologic interpretation of dysplasia in surveillance biopsies. In this study, we evaluated the utility of a panel of immunohistochemical markers in diagnosing inflammatory bowel disease-associated neoplasia. We reviewed 39 colectomy specimens with inflammatory bowel disease-associated neoplasia. In these 39 cases, we identified 172 foci of interest (5 normal, 58 negative for dysplasia, 15 indefinite for dysplasia, 59 low-grade dysplasia, 18 high-grade dysplasia, and 17 invasive adenocarcinoma). They were subjected to immunohistochemistry for TP53 and CK7. Logistic regression was used to evaluate their association with the presence of dysplasia. Receiver operating characteristic curves were used to determine the optimal cutoffs and assess the diagnostic performance of TP53 and CK7. Both TP53 nuclear staining and CK7 immunoreactivity gradually increased in the progression of inflammatory bowel disease-associated neoplasia (P<0.0001). CK7 immunoreactivity increased along with the increase of inflammation severity (P=0.0002) as well as reactive changes (P=0.04) in the colonic mucosa. But TP53 nuclear staining was independent of either feature. When both TP53>8% and CK7>30% as identified from logistic regression and receiver operating characteristic curves were used to diagnose dysplasia, the specificity achieved as high as 95%. When either TP53>8% or CK7>30% was used to diagnose dysplasia, the sensitivity achieved was 82%. Our results suggested that a combination of CK7 and TP53 immunohistochemistry may be helpful in diagnosing inflammatory bowel disease-associated dysplasia in difficult cases.

Risk of colorectal cancer in patients with acute myocardial infarction and stroke: a nationwide cohort study

BACKGROUND

An association between colorectal cancer and acute myocardial infarction (AMI) and stroke has been suggested, but evidence is conflicting.

METHOD

We conducted a population-based cohort study (1978-2010) of the association between AMI/stroke and colorectal cancer by linking nationwide Danish registries. We calculated standardized incidence ratios (SIR) of colorectal cancer after AMI/stroke as the ratios of observed to expected incidence.

RESULTS

A total of 297,523 patients with AMI (median age, 69.4 years; 64% men) were followed for a median of 3.1 years (range, 0-33 years) and 4,387 developed colorectal cancer [SIR, 1.08; 95% confidence interval (CI), 1.05-1.11; P < 0.001]. In the first year of follow-up, the SIR was 1.85 (95% CI, 1.73-1.98; P < 0.001), whereas it was 0.98 (95% CI, 0.95-1.02; P = 0.318) in the second and subsequent years. We followed 246,998 patients with stroke (median age, 72.4 years; 52% men) for a median of 2.9 years (range, 0-33 years) and 3,035 developed colorectal cancer (SIR, 1.04; 95% CI, 1.00-1.07; P = 0.053). In the first year of follow-up, the SIR was 1.42 (95% CI, 1.31-1.53; P < 0.001), whereas it was 0.96 (95% CI, 0.93-1.00; P = 0.072) thereafter. We found no difference between the SIRs for ischemic and hemorrhagic stroke. The increased one-year relative risks for AMI and stroke corresponded to a 0.3% absolute risk.

CONCLUSIONS

Our findings reflect detection of occult cancer at the time of the vascular event. The lack of increased risk after one year suggests that an association based on shared risk factors or chronic inflammation is unlikely.

IMPACT

In patients with AMI/stroke, the diagnostic workup including screening for colorectal cancer should follow that of the general population.

Precancerous lesions in inflammatory bowel disease

Reduction of mortality from colorectal cancer is a prime goal in the clinical management of patients with extensive, longstanding ulcerative colitis and colonic Crohn's disease. The cornerstone of current cancer prevention efforts is endoscopic surveillance for colorectal dysplasia, or intraepithelial neoplasia, the direct histological precursor of cancer. A diagnosis of dysplasia provides a reliable indicator of heightened cancer risk and an end-point for colonoscopic surveillance allowing most patients to undergo prophylactic colectomy before the development of incurable cancer. This article reviews the classification, pathological criteria and clinical implications of colorectal dysplasia, current recommendations for the performance of surveillance colonoscopy, recent technical advances in colonoscopic imaging to enhance the detection of dysplasia, and a summary of the molecular genetic events implicated in its development.

Abnormal expression of GADD45B in human colorectal carcinoma

Background

GADD45B is a member of the growth arrest DNA damage-inducible gene family associated with cell growth control, apoptosis, and DNA damage repair response. The aim of this study is to detect the role of GADD45B in colorectal carcinoma (CRC); the area not studied in depth to date.

Methods

The mRNA and protein levels of GADD45B were examined by Real-Time quantitative PCR (RT-qPCR) and immunohistochemistry (IHC) in CRC tissues and adjacent noncancerous tissues (ANCT). Over-expression plasmids and SiRNA were used to regulate GADD45B expression in CRC cell lines in vitro and flow cytometry and Western blotting were used to detect apoptotic changes.

Results

The mRNA and protein levels of GADD45B were significantly higher in CRC tissues than those in ANCT (P<0.05). Up-regulation of GADD45B was also correlated with relapse and death of CRC patients (P<0.05). The Kaplan-Meier survival curves indicated that disease-free survival (DFS) was significantly worse in CRC patients who showed GADD45B overexpression. A Cox multivariate analysis revealed that GADD45B overexpression and TNM stage were significant factors affecting patients’ survival. On the other hand, as a tumor suppressor gene, GADD45B amplified from normal colorectal tissues could induce apoptosis in CRC cell lines and may be associated with the p53-mediated apoptotic pathways.

Conclusion

GADD45B, a tumor suppressor gene potentially through the p53-mediated apoptotic pathways, is paradoxically overexpressed in CRC and as such may play an unappreciated role in tumorigenesis. The exact mechanism of GADD45B inactivation and overexpression requires further investigation. GADD45B could be a potential therapeutic target for CRC treatment in future.