The miR-200 family is increased in dysplastic lesions in ulcerative colitis patients.
ABSTRACT: 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.
Project description:MicroRNAs are dysregulated in various cancers including colorectal cancer, and are potential useful biomarkers of disease development. We used next generation sequencing to investigate miRNA expression profiles in low- and high-grade intraepithelial dysplastic polyps from pigs carrying a mutation in the adenomatous polyposis coli tumour suppressor (APC1311 , orthologous to human APC1309 ) that model an inherited predisposition to colorectal cancer, familial adenomatous polyposis. We identified several miRNAs and their isomiRs significantly (P < 0.05) differentially expressed between low and high-grade intraepithelial dysplastic polyps. Of these, ssc-let-7e, ssc-miR-98, ssc-miR-146a-5p, ssc-miR-146b, ssc-miR-183 and ssc-miR-196a were expressed at higher level and ssc-miR-126-3p at lower level in high-grade intraepithelial dysplastic polyps. Functional miRNA target analysis revealed significant (P < 0.001) over-representation of cancer-related pathways, including 'microRNAs in cancer', 'proteoglycans in cancer', 'pathways in cancer' and 'colorectal cancer'. This is the first study to reveal miRNAs associated with premalignant transformation of colon polyps.
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:Leukoplakia is the most common precursor lesion of oral squamous cell carcinoma (OSCC). Currently, the risk of progression to OSCC is assessed based on histopathologic examination alone. However, this method fails to identify the subset of microscopically innocuous leukoplakia that ultimately transforms to OSCC. The aim of this study was to determine if microRNAs (miRNAs) can be utilized to identify non- and low-grade dysplastic oral lesions at risk for cancer progression. A retrospective study of genome-wide miRNA expression level analyses was performed in the training cohort (n=20) using deep sequencing formalin-fixed paraffin embedded incisional biopsy tissues from patients with oral leukoplakic lesions diagnosed with non- or low-grade dysplasia and known clinical outcome. The promising miRNA candidates were then evaluated in the validation cohort (n=80) using quantitative real-time PCR (qRT-PCR). Four promising miRNAs-208b-3p, 204-5p, 129-2-3p and 3065-5p were identified. Combining these four miRNAs as a panel with age and histologic diagnosis (p<0.004), our final model had a predictive value for the area under the receiver operating characteristic (ROC) curve (AUC) of 0.792, sensitivity of 76.9% and specificity of 73.7% to accurately identify non- and low-grade dysplastic lesions at risk of cancer progression, which is a significant improvement over histopathologic examination alone (AUC of 0.645). While further investigation is needed, discovery of predictive markers that can accurately identify histologically innocuous oral lesions at high risk for progression to OSSC will significantly improve clinical outcome by means of early intervention.
Project description:Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide and is derived from an accumulation of genetic and epigenetic changes. This study explored potential prognostic markers in CRC via the construction and in-depth analysis of a competing endogenous RNA (ceRNA) network, which was generated through a three-step process. First, we screened candidate hub genes in CRC as the primary gene markers to survey their related regulatory non-coding RNAs, miRNAs. Second, the interacting miRNAs were used to search for associated lncRNAs. Thus, candidate RNAs were first constructed into ceRNA networks based on close associations with miRNAs. Further analysis at the isomiR level was also performed for each miRNA locus to understand the detailed expression patterns of the multiple variants. Finally, RNAs were performed an in-depth analysis of expression correlations, which contributed to further screening and validation of potential RNAs with close correlations to each other. Using this approach, nine hub genes, 13 related miRNAs, and 29 candidate lncRNAs were collected and used to construct the ceRNA network. Further in-depth analysis identified the MFAP5-miR-200b-3p-AC005154.6 axis as a potential prognostic marker in CRC. MFAP5 and miR-200b-3p have previously been reported to play important roles in tumorigenesis. These RNAs showed potential prognostic values, and the combination of them may have more sensitivity than using them alone. In conclusion, MFAP5, miR-200b-3p, and AC005154.6 may have potential prognostic value in CRC and may provide a prognostic reference for this patient population.
Project description:Ulcerative Colitis (UC) is a type of inflammatory bowel disease, considered as an important disease of gastrointestinal tract having a huge impact on the health of the patient. Prolonged inflammation of colon in UC patients increases the risk of developing colorectal cancer. MiRNA are reported as a connecting link between inflammation and cancer. Differential miRNA expression is reported in Crohn's disease (CD) patients involving various regions of the gastrointestinal tract. The current study was performed to dissect out the site specific miRNA expression in the colon biopsy samples of UC patients from Northern India.Biopsy samples were collected from UC patients and healthy controls from Rectosigmoid Area (RS) and Ascending Colon (AC). MiRNA expression was compared between patients with RS and AC using a microarray platform. Differential expression was further validated by Real Time PCR analysis. Demographic and pathological data of UC -associated CRC patients was collected from the hospital database and analyzed for assessing the site of cancer.Upon analysis of data generated on a microarray platform and qRT PCR revealed that the expression of six miRNAs hsa-miR-146b-5p, hsa-miR-335-3p, hsa-miR-342-3p, hsa-miR-644b-3p, hsa-miR-491-3p, hsa-miR-4732-3p were downregulated in patients where RS was involved as compared to AC. The expression of hsa-miR-141-3p was upregulated in patients where RS region was involved as compared to AC. Analysis of the registered UC patient's database from the hospital revealed that the site of CRC was predomimnantly the rectosigmoid region of the colon in most of the cases.This is the first study to show the differential expression of miRNA involving different sites of colon in UC patients. Taking our data and previous reports into consideration, we propose that differential miRNA expression during UC perhaps contribute in the development of UC-associated CRC at the rectosigmoid area.
Project description:Metastasis is a major threat to colorectal cancer (CRC) patients. We have reported that peroxiredoxin-2 (PRDX2) is associated with CRC invasion and metastasis. However, the mechanisms regulating PRDX2 expression remain unclear. We investigate whether microRNAs (miRNAs) regulate PRDX2 expression in CRC progression.Quantitative real-time polymerase chain reaction (qPCR) was used to measure microRNA-200b-3p (miR-200b-3p) expression. Immunohistochemistry (IHC) was performed to detect c-Myc and PRDX2 protein levels in CRC tissue samples (n = 97). Western blot was used to quantify PRDX2, c-Myc, AKT2/GSK3? pathway-associated proteins and epithelial-mesenchymal transition (EMT)-related proteins in CRC cells. Luciferase reporter assays were used to analyze the interaction between miR-200b-3p and 3'untranslated region (3'UTR) of PRDX2 mRNA and AKT2 mRNA as well as c-Myc and the miR-200b-3p promoter. Chromatin immunoprecipitation (ChIP) assay was used to evaluate binding of c-Myc to the miR-200b-3p promoter. Invasive assay and metastatic model were used to assess invasive and metastatic capacities of CRC cells in vitro and in vivo. Moreover, drug-induced apoptosis was measured by flow cytometry.We found that miR-200b-3p was significantly downregulated, whereas c-Myc and PRDX2 were upregulated in metastatic CRC cells and CRC tissues compared to their counterparts. An inverse correlation existed between c-Myc and miR-200b-3p, and between miR-200b-3p and PRDX2. We also found that PRDX2 was a target of miR-200b-3p. Importantly, overexpression of nontargetable PRDX2 eliminated the suppressive effects of miR-200b-3p on proliferation, invasion, EMT, chemotherapeutic resistance and metastasis of CRC cells. Moreover, c-Myc bound to the promoter of miR-200b-3p and repressed its transcription. In turn, miR-200b-3p disrupted the stability of c-Myc protein by inducing c-Myc protein threonine 58 (T58) phosphorylation and serine 62 (S62) dephosphorylation via AKT2/GSK3? pathway.Our findings reveal that the c-Myc/miR-200b/PRDX2 loop regulates CRC progression and its disruption enhances tumor metastasis and chemotherapeutic resistance in CRC.
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 and study aims? Ulcerative colitis (UC) and Crohn's disease (CD) have higher risk of colorectal cancer (CRC). Guidelines recommend dysplasia surveillance with dye-spraying chromoendoscopy (DCE). The aim of this systematic review and meta-analysis was to review all randomized clinical trials (RCTs) available and compare the efficacy of different endoscopic methods of surveillance for dysplasia in patients with UC and CD. Methods? Databases searched were Medline, EMBASE, Cochrane and SCIELO/LILACS.?It was estimated the risk difference (RD) for dichotomous outcomes (number of patients diagnosed with one or more dysplastic lesions, total number of dysplastic lesions diagnosed and number of dysplastic lesions detected by targeted biopsies) and mean difference for continuous outcomes (procedure time). Results? This study included 17 RCTs totaling 2,457 patients. There was superiority of DCE when compared to standard-definiton white light endoscopy (SD-WLE). When compared with high-definition (HD) WLE, no difference was observed in all outcomes (number of patients with dysplasia (RD 0.06; 95?% CI [-0.01, 0.13])). Comparing other techniques, no difference was observed between DCE and virtual chromoendoscopy (VCE - including narrow-band imaging [NBI], i-SCAN and flexible spectral imaging color enhancement), in all outcomes except procedure time (mean difference, 6.33 min; 95?% CI, 1.29, 11.33). DCE required a significantly longer procedure time compared with WLE (mean difference, 7.81 min; 95?% CI, 2.76, 12.86). Conclusions? We found that dye-spraying chromoendoscopy detected more patients and dysplastic lesions than SD-WLE. Although no difference was observed between DCE and HD-WLE or narrow-band imaging, the main outcomes favored numerically dye-spraying chromoendoscopy, except procedure time. Regarding i-SCAN, FICE and auto-fluorescence imaging, there is still not enough evidence to support or not their recommendation.
Project description:Ulcerative colitis (UC) patients have a greater risk of developing colorectal cancer through inflammation-dysplasia-carcinoma sequence of transformation. The histopathological diagnosis of dysplasia is therefore of critical clinical relevance, but dysplasia may be difficult to distinguish from inflammatory changes. A proteomic pilot study on 5 UC colorectal dysplastic patients highlighted proteins differentially distributed between paired dysplastic, inflammatory and normal tissues. The best candidate marker was selected and immunohistochemistry confirmation was performed on AOM/DSS mouse model lesions, 37 UC dysplasia, 14 UC cancers, 23 longstanding UC, 35 sporadic conventional adenomas, 57 sporadic serrated lesions and 82 sporadic colorectal cancers. Differential proteomics found 11 proteins significantly more abundant in dysplasia compared to inflammation, including Solute carrier family 12 member 2 (SLC12A2) which was confidently identified with 8 specific peptides and was below the limit of quantitation in both inflammatory and normal colon. SLC12A2 immunohistochemical analysis confirmed the discrimination of preneoplastic and neoplastic lesions from inflammatory lesions in mice, UC and in sporadic contexts. A specific SLC12A2 staining pattern termed “loss of gradient” reached 89% sensitivity, 95% specificity and 92% accuracy for UC-dysplasia diagnosis together with an inter-observer agreement of 95.24% (multirater κfree of 0.90; IC95%: 0.78 – 1.00). Such discrimination could not be obtained by Ki67 staining. This specific pattern was also associated with sporadic colorectal adenomas and cancers. We found a specific SLC12A2 immunohistochemical staining pattern in precancerous and cancerous colonic UC-lesions which could be helpful for diagnosing dysplasia and cancer in UC and non-UC patients.
Project description:Targeted molecular probes have been used to detect sporadic colonic dysplasia during confocal laser endomicroscopy (CLE) with promising results. This is a feasibility pilot study aiming to assess the potential role of CLE combined with a fluorescent-labeled peptide to stain and detect dysplasia associated with Ulcerative Colitis.A phage-derived heptapeptide with predicted high binding affinity for dysplastic tissue, was synthesized and labeled with fluorescein. Eleven lesions with suspected dysplasia at endoscopy were excised from nine patients with long-standing ulcerative colitis. Specimens were sprayed with the peptide and examined by CLE. The CLE images were then compared to the corresponding histological sections.At definitive histology, 4 lesions were diagnosed as inflammatory polyps, 6 as dysplastic lesions and one as invasive cancer. In inflammatory polyps, the fluorescence signal came from peri-cryptal spaces and crypt lumen due to passive accumulation of the peptide in these areas. Dysplasia was associated with active binding of the peptide to dysplastic colonocytes.Ex vivo staining of ulcerative colitis-associated dysplasia using a fluorescent labeled molecular probe and CLE is feasible. In vivo studies on larger populations are required to evaluate the safety and the effective contribution of molecular probes in cancer surveillance of ulcerative colitis.