Expression of ATF6 as a marker of pre-cancerous atypical change in ulcerative colitis-associated colorectal cancer: a potential role in the management of dysplasia.
ABSTRACT: Diagnosis of low-grade dysplasia (LGD) is important in the management of ulcerative colitis (UC), but it is often difficult to distinguish LGD from inflammatory regenerative epithelium. The unfolded protein response (UPR) is activated in inflammatory bowel disease and malignancies. We aimed to identify a UPR-related gene that is involved in the development of non-UC and UC-associated colorectal cancer (CRC), and to investigate whether the target gene is useful for the diagnosis of LGD.Using our microarray gene expression database of 152 CRCs, we identified activating transcription factor 6 (ATF6) as a target gene. Immunohistochemistry (IHC) of ATF6 were analyzed in 137 surgically resected CRCs, 95 endoscopically resected adenomas and pTis cancers, and 136 samples from 51 UC patients (93 colitis without neoplasia, 31 dysplasia, and 12 UC-associated CRC). The diagnostic accuracy of ATF6 and p53 as markers of LGD was assessed.ATF6 expression was detectable in all CRCs but not in normal colonic mucosa, was elevated with increase in cellular atypia (adenoma with moderate atypia < severe atypia < pTis CRC, p < 0.001), and higher in dysplasia and CRC than in non-neoplastic colitis (p < 0.001). Notably, the difference between colitis and LGD was significant. Compared to p53-IHC, ATF6-IHC had better diagnostic accuracy for distinguishing LGD from background inflammatory mucosa (sensitivity 70.8 vs. 16.7%, specificity 78.5 vs.71.0%, respectively).ATF6 was expressed in lesions undergoing pre-cancerous atypical change in both non-UC and UC-associated CRC and may be used to distinguish LGD from inflammatory regenerative epithelium in UC patients.
Project description:The aim of this study was to identify risk factors associated with development of high-grade dysplasia (HGD) or colorectal cancer (CRC) in ulcerative colitis (UC) patients diagnosed with low-grade dysplasia (LGD).Patients with histologically confirmed extensive UC, who were diagnosed with LGD between 1993 and 2012 at St Mark's Hospital, were identified and followed up to 1 July 2013. Demographic, endoscopic, and histological data were collected and correlated with the development of HGD or CRC.A total of 172 patients were followed for a median of 48 months from the date of initial LGD diagnosis (interquartile range (IQR), 15-87 months). Overall, 33 patients developed HGD or CRC (19.1% of study population; 20 CRCs) during study period. Multivariate Cox proportional hazard analysis revealed that macroscopically non-polypoid (hazard ratio (HR), 8.6; 95% confidence interval (CI), 3.0-24.8; P<0.001) or invisible (HR, 4.1; 95% CI, 1.3-13.4; P=0.02) dysplasia, dysplastic lesions ?1?cm in size (HR, 3.8; 95% CI, 1.5-13.4; P=0.01), and a previous history of "indefinite for dysplasia" (HR, 2.8; 95% CI, 1.2-6.5; P=0.01) were significant contributory factors for HGD or CRC development. Multifocal dysplasia (HR, 3.9; 95% CI, 1.9-7.8; P<0.001), metachronous dysplasia (HR, 3.5; 95% CI, 1.6-7.5; P=0.001), or a colonic stricture (HR, 7.4; 95% CI, 2.5-22.1; P<0.001) showed only univariate correlation to development of HGD or CRC.Lesions that are non-polypoid or endoscopically invisible, large (?1?cm), or preceded by indefinite dysplasia are independent risk factors for developing HGD or CRC in UC patients diagnosed with LGD.
Project description:BACKGROUND & AIMS:Little is known about outcomes of patients with ulcerative colitis with low-grade dysplasia (UC-LGD). We estimated the incidence of and risk factors for progression to colorectal cancer (CRC) in cohorts of patients with UC-LGD who underwent surveillance (surveillance cohort), and the prevalence of dysplasia-related findings among patients who underwent colectomy for UC-LGD (surgical cohort). METHODS:We performed a systematic literature review through June 1, 2016, to identify cohort studies of adults with UC-LGD. We estimated pooled incidence rates of CRC and risk factors associated with dysplasia progression in surveillance cohorts, and prevalence of synchronous advanced neoplasia (CRC and/or high-grade dysplasia) in surgical cohorts. RESULTS:In 14 surveillance cohort studies of 671 patients with UC-LGD (52 developed CRC), the pooled annual incidence of CRC was 0.8% (95% confidence interval [CI], 0.4-1.3); the pooled annual incidence of advanced neoplasia was 1.8% (95% CI, 0.9-2.7). Risk of CRC was higher when LGD was diagnosed by expert gastrointestinal pathologist (1.5%) than by community pathologists (0.2%). Factors significantly associated with dysplasia progression were concomitant primary sclerosing cholangitis (odds ratio [OR], 3.4; 95% CI, 1.5-7.8), invisible dysplasia (vs visible dysplasia; OR, 1.9; 95% CI, 1.0-3.4), distal location (vs proximal location; OR, 2.0; 95% CI, 1.1-3.7), and multifocal dysplasia (vs unifocal dysplasia; OR, 3.5; 95% CI, 1.5-8.5). In 12 surgical cohort studies of 450 patients who underwent colectomy for UC-LGD, 34 patients had synchronous CRC (pooled prevalence, 17%; 95% CI, 8-33). CONCLUSION:In a systematic review of the literature, we found that among patients with UC-LGD under surveillance, the annual incidence of progression to CRC was 0.8%; differences in rates of LGD diagnosis varied with pathologists' level of expertise. Concomitant primary sclerosing cholangitis, invisible dysplasia, distal location, and multifocal LGD are high-risk features associated with dysplasia progression.
Project description:INTRODUCTION:In patients with ulcerative colitis (UC), dysplasia develops in 10%-20% of cases. The persistence of low-grade dysplasia (LGD) in UC in 2 consecutive observations is still an indication for restorative proctocolectomy. Our hypothesis is that in the case of weak cytotoxic activation, dysplasia persists. We aimed to identify possible immunological markers of LGD presence and persistence. METHODS:We prospectively enrolled 112 UC patients who underwent screening colonoscopy (T0) who had biopsies taken from their sigmoid colon. Ninety of them had at least a second colonoscopy (T1) with biopsies taken in the sigmoid colon and 8 patients had dysplasia in both examinations suggesting a persistence of LGD in their colon. Immunohistochemistry and real time polymerase chain reaction for CD4, CD69, CD107, and CD8? messenger RNA (mRNA) expression and flow cytometry for epithelial cells expressing CD80 or HLA avidin-biotin complex were performed. Non-parametric statistics, receiver operating characteristic curves analysis, and logistic multiple regression analysis were used. RESULTS:Thirteen patients had LGD diagnosed at T0. The mucosal mRNA expression of CD4, CD69, and CD8? was significantly lower than in patients without dysplasia (P = 0.033, P = 0.046 and P = 0.007, respectively). A second colonoscopy was performed in 90 patients after a median follow-up of 17 (12-25) months and 14 of the patients were diagnosed with LGD. In these patients, CD8? mRNA expression at T0 was significantly lower in patients without dysplasia (P = 0.004). A multivariate survival analysis in a model including CD8? mRNA levels and age >50 demonstrated that both items were independent predictors of dysplasia at follow-up (hazard ratio [HR] = 0.47 [95% confidence interval [CI]: 0.26-0.86], P = 0.014, and HR = 13.32 [95% CI: 1.72-102.92], P = 0.013). DISCUSSION:These data suggest a low cytotoxic T cell activation in the colonic mucosa of UC patients who do not manage to clear dysplasia. Thus, low level of CD8? mRNA expression in non-dysplastic colonic mucosa might be considered in future studies about the decision making of management of LGD in UC.
Project description:BACKGROUND:It is unclear whether intensive surveillance protocols have resulted in a decreased incidence of colorectal cancer (CRC) in inflammatory bowel disease (IBD). AIMS:To determine the prevalence and characteristics of IBD associated high-grade dysplasia (HGD) or CRC that was undetected on prior colonoscopy. METHODS:This is a single-center, retrospective study from 1994 to 2013. All participants had a confirmed IBD diagnosis and underwent a colectomy with either HGD or CRC found in the colectomy specimen.The undetected group had no HGD or CRC on prior colonoscopies. The detected group had HGD or CRC identified on previous biopsies. RESULTS:Of 70 participants, with ulcerative colitis (UC) (n = 47), Crohn's disease (CD) (n = 21), and indeterminate colitis (n = 2), 29% (n = 20) had undetected HGD/CRC at colectomy (15 HGD and 5 CRC). In the undetected group, 75% had prior LGD, 15% had indefinite dysplasia, and 10% had no dysplasia (HGD was found in colonic strictures). Patients in the undetected group were more likely to have pancolitis (55 vs. 20%) and multifocal dysplasia (35 vs. 8%). The undetected group was less likely to have CRC at colectomy (25 vs. 62%). There was a trend toward right-sided HGD/CRC at colectomy (40 vs. 20%; p = 0.08). In addition, 84% of the lesions found in the rectum at colectomy were not seen on prior colonoscopy in the undetected group. CONCLUSIONS:The prevalence of previously undetected HGD/CRC in IBD found at colectomy was 29%. The high proportion of undetected rectal and right-sided HGD/CRC suggests that these areas may need greater attention during surveillance.
Project description:This study provides an overview of the largest and longest-running colonoscopic surveillance program for colorectal cancer (CRC) in patients with long-standing ulcerative colitis (UC).Data were obtained from medical records, endoscopy, and histology reports. Primary end points were defined as death, colectomy, withdrawal from surveillance, or censor date (1 January 2013).A total of 1,375 UC patients were followed up for 15,234 patient-years (median, 11 years per patient). CRC was detected in 72 patients (incidence rate (IR), 4.7 per 1,000 patient-years). Time-trend analysis revealed that although there was significant decrease in incidence of colectomy performed for dysplasia (linear regression, R=-0.43; P=0.007), IR of advanced CRC and interval CRC have steadily decreased over past four decades (Pearson's correlation, -0.99; P=0.01 for both trends). The IR of early CRC has increased 2.5-fold in the current decade compared with past decade (?(2), P=0.045); however, its 10-year survival rate was high (79.6%). The IR of dysplasia has similarly increased (?(2), P=0.01), potentially attributable to the recent use of chromoendoscopy that was twice more effective at detecting dysplasia compared with white-light endoscopy (?(2), P<0.001). CRCs were frequently accompanied by synchronous CRC or spatially distinct dysplasia (37.5%). Finally, the risk of CRC was not significantly different between "indefinite" or low-grade dysplasia (log-rank, P=0.78).Colonoscopic surveillance may have a significant role in reducing the risk of advanced and interval CRC while allowing more patients to retain their colon for longer. Given the ongoing risk of early CRC, patients with any grade of dysplasia who are managed endoscopically should be monitored closely with advanced techniques.
Project description:Inflammation plays a role in the progression to cancer and it is linked to the presence of senescent cells. Ulcerative colitis (UC) is a chronic inflammatory disease that predisposes to colorectal cancer. Tumorigenesis in this setting is associated with telomere shortening that can be observed in the nondysplastic epithelium of UC patients with high-grade dysplasia (HGD) or cancer (UC progressors). We hypothesized that a preneoplastic field of inflammation, telomere shortening, and senescence underlies tumor progression in UC progressors. Multiple biopsies of varying histologic grade were collected along the colon of nine UC progressors and analyzed for telomere length, DNA damage, senescence, p53, p16, and chronic and acute inflammation. Twenty biopsies from four UC nonprogressors and twenty-one biopsies from control individuals without UC were also analyzed. Short telomeres and increased DNA damage, senescence, and infiltrating leukocytes were observed in biopsies located less than 10 cm from HGD or cancer. Low-grade dysplasia (LGD) had the shortest telomeres along with the highest levels of senescence and infiltrating leukocytes, whereas HGD biopsies showed the opposite pattern. The expression of p16 and p53 was low in nondysplastic biopsies but progressively increased in LGD and HGD. In addition, high levels of infiltrating leukocytes were associated with telomere shortening, senescence, and reduced p53 expression. These results suggest that dysplasia arises in a preneoplastic field of chronic inflammation, which leads to telomere shortening, DNA damage, and senescence. Our findings argue that senescence acts as a tumor suppressor mechanism that is abrogated during the transition from LGD to HGD in UC.
Project description:OBJECTIVES:Inflammation-associated microsatellite alterations (also known as elevated microsatellite alterations at selected tetranucleotide repeats [EMAST]) result from IL-6-induced nuclear-to-cytosolic displacement of the DNA mismatch repair (MMR) protein MSH3, allowing frameshifts of dinucleotide or longer microsatellites within DNA. MSH3 also engages homologous recombination to repair double-strand breaks (DSBs), making MSH3 deficiency contributory to both EMAST and DSBs. EMAST is observed in cancers, but given its genesis by cytokines, it may be present in non-neoplastic inflammatory conditions. We examined ulcerative colitis (UC), a preneoplastic condition from prolonged inflammatory duration. METHODS:We assessed 70 UC colons without neoplasia, 5 UC specimens with dysplasia, 14 UC-derived colorectal cancers (CRCs), and 19 early-stage sporadic CRCs for microsatellite instability (MSI) via multiplexed polymerase chain reaction capable of simultaneous detection of MSI-H, MSI-L, and EMAST. We evaluated UC specimens for MSH3 expression via immunohistochemistry. RESULTS:UC, UC with dysplasia, and UC-derived CRCs demonstrated dinucleotide or longer microsatellite frameshifts, with UC showing coincident reduction of nuclear MSH3 expression. No UC specimen, with or without neoplasia, demonstrated mononucleotide frameshifts. EMAST frequency was higher in UC-derived CRCs than UC (71.4% vs 31.4%, P = 0.0045) and higher than early-stage sporadic CRCs (66.7% vs 26.3%, P = 0.0426). EMAST frequency was higher with UC duration >8 years compared with ?8 years (40% vs 16%, P = 0.0459). DISCUSSION:Inflammation-associated microsatellite alterations/EMAST are prevalent in UC and signify genomic mutations in the absence of neoplasia. Duration of disease and advancement to neoplasia increases frequency of EMAST. MSH3 dysfunction is a potential contributory pathway toward neoplasia in UC that could be targeted by therapeutic intervention.
Project description:Microarray analysis of promoter hypermethylation provides insight into the role and extent of DNA methylation in the development of colorectal cancer (CRC) and may be co-monitored with the appearance of driver mutations. Colonic biopsy samples were obtained endoscopically from 10 normal, 23 adenoma (17 low-grade (LGD) and 6 high-grade dysplasia (HGD)), and 8 ulcerative colitis (UC) patients (4 active and 4 inactive). CRC samples were obtained from 24 patients (17 primary, 7 metastatic (MCRC)), 7 of them with synchronous LGD. Field effects were analyzed in tissues 1 cm (n = 5) and 10 cm (n = 5) from the margin of CRC. Tissue materials were studied for DNA methylation status using a 96 gene panel and for KRAS and BRAF mutations. Expression levels were assayed using whole genomic mRNA arrays. SFRP1 was further examined by immunohistochemistry. HT29 cells were treated with 5-aza-2' deoxycytidine to analyze the reversal possibility of DNA methylation. More than 85% of tumor samples showed hypermethylation in 10 genes (SFRP1, SST, BNC1, MAL, SLIT2, SFRP2, SLIT3, ALDH1A3, TMEFF2, WIF1), whereas the frequency of examined mutations were below 25%. These genes distinguished precancerous and cancerous lesions from inflamed and healthy tissue. The mRNA alterations that might be caused by systematic methylation could be partly reversed by demethylation treatment. Systematic changes in methylation patterns were observed early in CRC carcinogenesis, occuring in precursor lesions and CRC. Thus we conclude that DNA hypermethylation is an early and systematic event in colorectal carcinogenesis, and it could be potentially reversed by systematic demethylation therapy, but it would need more in vitro and in vivo experiments to support this theory.
Project description:Methylation of specific microRNAs (miRNAs) often occurs in an age-dependent manner, as a field defect in some instances, and may be an early event in colitis-associated carcinogenesis. We aimed to determine whether specific mRNA signature patterns (MIR1, MIR9, MIR124, MIR137, MIR34B/C) could be used to identify patients with ulcerative colitis (UC) who are at increased risk for colorectal neoplasia.We obtained 387 colorectal tissue specimens collected from 238 patients with UC (152 without neoplasia, 17 with dysplasia, and 69 with UC-associated colorectal cancer [UC-CRC]), from 2 independent cohorts in Japan between 2005 and 2015. We quantified methylation of miRNAs by bisulfite pyrosequencing analysis. We analyzed clinical data to determine whether miRNA methylation patterns were associated with age, location, or segment of the colorectum (cecum, transverse colon, and rectum). Differences in tissue miRNA methylation and expression levels were compared among samples and associated with cancer risk using the Wilcoxon, Mann-Whitney, and Kruskal-Wallis tests as appropriate. We performed a validation study of samples from 90 patients without UC and 61 patients with UC-associated dysplasia or cancer to confirm the association between specific methylation patterns of miRNAs in non-tumor rectal mucosa from patients with UC at risk of UC-CRC.Among patients with UC without neoplasia, rectal tissues had significantly higher levels of methylation levels of MIR1, MIR9, MIR124, and MIR137 than in proximal mucosa; levels of methylation were associated with age and duration of UC in rectal mucosa. Methylation of all miRNAs was significantly higher in samples from patients with dysplasia or CRC compared with samples from patients without neoplasia. Receiver operating characteristic analysis revealed that methylation levels of miRNAs in rectal mucosa accurately differentiated patients with CRC from those without. Methylation of MIR137 in rectal mucosa was an independent risk factor for UC-CRC. Methylation patterns of a set of miRNAs (panel) could discriminate discriminate UC patients with or without dysplasia or CRC in the evaluation cohort (area under the curve, 0.81) and the validation cohort (area under the curve, 0.78).In evaluation and validation cohorts, we found specific miRNAs to be methylated in rectal mucosal samples from patients with UC with dysplasia or CRC compared with patients without neoplasms. This pattern also associated with patient age and might be used to identify patients with UC at greatest risk for developing UC-CRC. Our findings provide evidence for a field defect in rectal mucosa from patients with UC-CRC.
Project description:Colorectal cancer (CRC) is a life-threatening complication of ulcerative colitis (UC), and patients are routinely screened for the development of precancerous lesions (dysplasia). However, rates of CRC development in patients with confirmed low-grade dysplasia vary widely between studies, suggesting a large degree of heterogeneity between these lesions that is not detectable macroscopically. A better understanding of the underlying molecular changes that occur in dysplasia will help to identify lesions at higher risk of malignancy. MicroRNAs (miRNAs) post-transcriptionally regulate protein expression and cell-signalling networks. Aberrant miRNA expression is a feature of sporadic CRC but much less is known about the changes that occur in dysplasia and in UC.Comprehensive microRNA profiling was performed on RNA extracted from UC dysplastic lesions (n = 7) and UC controls (n = 10). The expression of miRNAs in UC post inflammatory polyps (n = 7) was also assessed. Candidate miRNAs were further validated by qPCR, and miRNA in situ hybridization. Serum levels of miRNAs were also assessed with a view to identification of non-invasive biomarkers of dysplasia.UC dysplasia was associated with a shift in miRNA expression profiles that was not seen in inflammatory polyps. In particular, levels of miR-200b-3p were increased in dysplasia, and this miRNA was localised to epithelial cells in dysplastic lesions and in UC cancers. No changes in miRNA levels were detected in the serum.UC-Dysplasia is linked to altered miRNA expression in the mucosa and elevated miR-200b-3p levels.