Early Development Of Colorectal Cancer Research Articles

Balanced regulation of ROS production and inflammasome activation in preventing early development of colorectal cancer.

Reactive oxygen species (ROS) production and inflammasome activation are the key components of the innate immune response to microbial infection and sterile insults. ROS are at the intersection of inflammation and immunity during cancer development. Balanced regulation of ROS production and inflammasome activation serves as the central hub of innate immunity, determining whether a cell will survive or undergo cell death. However, the mechanisms underlying this balanced regulation remain unclear. Mitochondria and NADPH oxidases are the two major sources of ROS production. Recently, NCF4, a component of the NADPH oxidase complex that primarily contributes to ROS generation in phagocytes, was reported to balance ROS production and inflammasome activation in macrophages. The phosphorylation and puncta distribution of NCF4 shifts from the membrane-bound NADPH complex to the perinuclear region, promoting ASC speck formation and inflammasome activation, which triggers downstream IL-18-IFN-γ signaling to prevent the progression of colorectal cancer (CRC). Here, we review ROS signaling and inflammasome activation studies in colitis-associated CRC and propose that NCF4 acts as a ROS sensor that balances ROS production and inflammasome activation. In addition, NCF4 is a susceptibility gene for Crohn's disease (CD) and CRC. We discuss the evidence demonstrating NCF4's crucial role in facilitating cell-cell contact between immune cells and intestinal cells, and mediating the paracrine effects of inflammatory cytokines and ROS. This coordination of the signaling network helps create a robust immune microenvironment that effectively prevents epithelial cell mutagenesis and tumorigenesis during the early stage of colitis-associated CRC.

In-Depth Proteomic Analysis of Paraffin-Embedded Tissue Samples from Colorectal Cancer Patients Revealed TXNDC17 and SLC8A1 as Key Proteins Associated with the Disease.

A deeper understanding of colorectal cancer (CRC) biology would help to identify specific early diagnostic markers. Here, we conducted quantitative proteomics on FFPE healthy, adenoma, and adenocarcinoma tissue samples from six stage I sporadic CRC patients to identify dysregulated proteins during early CRC development. Two independent quantitative 10-plex TMT experiments were separately performed. After protein extraction, trypsin digestion, and labeling, proteins were identified and quantified by using a Q Exactive mass spectrometer. A total of 2681 proteins were identified and quantified after data analysis and bioinformatics with MaxQuant and the R program. Among them, 284 and 280 proteins showed significant upregulation and downregulation (expression ratio ≥1.5 or ≤0.67, p-value ≤0.05), respectively, in adenoma and/or adenocarcinoma compared to healthy tissue. Ten dysregulated proteins were selected to study their role in CRC by WB, IHC, TMA, and ELISA using tissue and plasma samples from CRC patients, individuals with premalignant colorectal lesions (adenomas), and healthy individuals. In vitro loss-of-function cell-based assays and in vivo experiments using three CRC cell lines with different metastatic properties assessed the important roles of SLC8A1 and TXNDC17 in CRC and liver metastasis. Additionally, SLC8A1 and TXNDC17 protein levels in plasma possessed the diagnostic ability of early CRC stages.

Loss of EMI1 compromises chromosome stability and is associated with cellular transformation in colonic epithelial cell contexts.

Colorectal cancer (CRC) is still a leading cause of cancer deaths worldwide. Thus, identifying the aberrant genes and proteins underlying disease pathogenesis is critical to improve early detection methods and develop novel therapeutic strategies. Chromosome instability (CIN), or ongoing changes in chromosome complements, is a predominant form of genome instability. It is a driver of genetic heterogeneity found in ~85% of CRCs. Although CIN contributes to CRC pathogenesis, the molecular determinants underlying CIN remain poorly understood. Recently, EMI1, an F-box protein, was identified as a candidate CIN gene. In this study, we sought to determine the impact reduced EMI1 expression has on CIN and cellular transformation. Coupling siRNA-based silencing and CRISPR/Cas9 knockout clones with quantitative imaging microscopy we evaluated the impact reduced EMI1 expression has on CIN and cellular transformation in four colonic epithelial cell contexts. Quantitative imaging microscopy data revealed that reduced EMI1 expression induces increases in CIN phenotypes in both transient (siRNA) and constitutive (CRISPR/Cas9) cell models that are associated with increases in DNA damage and cellular transformation phenotypes in long-term studies. This study determined that reduced EMI1 expression induces CIN and promotes cellular transformation, which is consistent with a role in early CRC development.

Distinctive Lipid Characteristics of Colorectal Cancer Revealed through Non-targeted Lipidomics Analysis of Tongue Coating.

The metabolites and microbiota in tongue coating display distinct characteristics in certain digestive disorders, yet their relationship with colorectal cancer (CRC) remains unexplored. Here, we employed liquid chromatography coupled with tandem mass spectrometry to analyze the lipid composition of tongue coating using a nontargeted approach in 30 individuals with colorectal adenomas (CRA), 32 with CRC, and 30 healthy controls (HC). We identified 21 tongue coating lipids that effectively distinguished CRC from HC (AUC = 0.89), and 9 lipids that differentiated CRC from CRA (AUC = 0.9). Furthermore, we observed significant alterations in the tongue coating lipid composition in the CRC group compared to HC/CRA groups. As the adenoma-cancer sequence progressed, there was an increase in long-chain unsaturated triglycerides (TG) levels and a decrease in phosphatidylethanolamine plasmalogen (PE-P) levels. Furthermore, we noted a positive correlation between N-acyl ornithine (NAOrn), sphingomyelin (SM), and ceramide phosphoethanolamine (PE-Cer), potentially produced by members of the Bacteroidetes phylum. The levels of inflammatory lipid metabolite 12-HETE showed a decreasing trend with colorectal tumor progression, indicating the potential involvement of tongue coating microbiota and tumor immune regulation in early CRC development. Our findings highlight the potential utility of tongue coating lipid analysis as a noninvasive tool for CRC diagnosis.

Consensus molecular subtype transition during progression of colorectal cancer.

The consensus molecular subtype (CMS) classification divides colorectal cancer (CRC) into four distinct subtypes based on RNA expression profiles. The biological differences between CMSs are already present in CRC precursor lesions, but not all CMSs pose the same risk of malignant transformation. To fully understand the path to malignant transformation and to determine whether CMS is a fixed entity during progression, genomic and transcriptomic data from two regions of the same CRC lesion were compared: the precursor region and the carcinoma region. In total, 24 patients who underwent endoscopic removal of T1-2 CRC were included. Regions were subtyped for CMS and DNA mutation analysis was performed. Additionally, a set of 85 benign adenomas was CMS-subtyped. This analysis revealed that almost all benign adenomas were classified as CMS3 (91.8%). In contrast, CMS2 was the most prevalent subtype in precursor regions (66.7%), followed by CMS3 (29.2%). CMS4 was absent in precursor lesions and originated at the carcinoma stage. Importantly, CMS switching occurred in a substantial number of cases and almost all (six out of seven) CMS3 precursor regions showed a shift to a different subtype in the carcinoma part of the lesion, which in four cases was classified as CMS4. In conclusion, our data indicate that CMS3 is related to a more indolent type of precursor lesion that less likely progresses to CRC and when this occurs, it is often associated with a subtype change that includes the more aggressive mesenchymal CMS4. In contrast, an acquired CMS2 signature appeared to be rather fixed during early CRC development. Combined, our data show that subtype changes occur during progression and that CMS3 switching is related to changes in the genomic background through acquisition of a novel driver mutation (TP53) or selective expansion of a clone, but also occurred independently of such genetic changes. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Abstract P028: Methylation biomarkers for colorectal cancer early detection and survival prognostics impact gene expression and link to cancer-related biological pathways

Abstract Background: DNA methylation has been previously shown to have diagnostic and predictive potential for colorectal cancer (CRC). Aim of this study was to evaluate putative methylation markers in the context of early cancer development and diagnostics as well as further investigate the biological significance of these regions. Methods: Biomarker discovery was done by whole genome bisulfite sequencing (WGBS) of 88 CRC, 48 advanced adenoma (AA) and corresponding adjacent normal tissue (NAT) samples. Short-list of significantly hypermethylated regions (DMRs) was correlated to transcriptomics data from 512 CRC patients in The Cancer Genome Atlas (TCGA) cohort. Pathway enrichment for biological pathway analysis of the DMRs was done by using Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database. Survival analysis was performed using Kaplan–Meier method on sub-groups of patients divided by the methylation status of individual markers. Finally, individual marker significance of selected regions was evaluated by analyzing 26 plasma samples from early stage (stage I-IIA) CRC samples and 42 colonoscopy verified controls (CNT) with targeted methylation sequencing assay. Results: 4167 putative marker regions were identified from biomarker discovery with WGBS. Differential signal could be observed both between AA and NAT and CRC and NAT, while several of these regions were differentially methylated also between AA and CRC samples, indicating biological signal change with adenoma progression to cancer. 84 hypermethylated DMRs from several verification studies were further evaluated against transcriptome data from TCGA, where overlap for 69 genes was found. 19 of these genes showed a significant down- regulation (p< 0.05), indicating a link between hypermethylation and gene expression. 2 genes showed significant up-regulation (p< 0.05), which could indicate other epigenic processes to be in place. KEGG pathway analysis revealed that the top pathways involved were axonal guidance, ephrin receptor signaling, epithelial-mesenchymal transition and FGF signaling, which all play significant role in the context of cancer development and progression. Kaplan-Meier analysis showed significant correlation to patients 5- year survival prediction linked to 3 genes: FGF14 (p=0.025, HR = 1.75) DPY19L2P1 (p=0.012, HR = 1.86), PTPRO (p=0.046, HR = 1.63). Targeted sequencing analysis on plasma samples of patients with early stage (I-IIA) colorectal cancer and age and gender matching colonoscopy-verified controls, showed high individual marker accuracy with AUC= 0.78 for FGF14, AUC= 0.81 for DPY19L2P1 and AUC= 0.73 for PTPRO. Conclusions: Methylation markers have distinct signals in early development of CRC, with high individual accuracy for separating early-stage cancers from matching controls. These regions have impact on gene expression and can be linked to relevant biological pathways. Extending early detection potential of the markers to further prognostics and stratification, could lead to better outcomes and improved survival of the patients. Citation Format: Pol Canal Noguer, Alejandro Requena Bermejo, Francesco Mattia Mancuso, Juan Carlos Higareda, Marina Manrique López, Marko Chersicola, Pablo Pérez Martínez, Pablo Antonio Camino, Primoz Knap, Vivian Erklavec Zajec, Kristi Kruusmaa. Methylation biomarkers for colorectal cancer early detection and survival prognostics impact gene expression and link to cancer-related biological pathways. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr P028.

Genome-wide analysis of mRNA and microRNA expression in colorectal cancer and adjacent normal mucosa.

mRNA expression varies in human cancers. Such altered mRNA expression is negatively regulated by the expression of microRNAs (miRNAs), which play an important role in human tumorigenesis. According to this theory, inverse mRNA/miRNA expression may be a direct driver of cancer development, and certain genetic events may occur prior to the development of any discernible histological abnormalities. We examined the inverse expression between mRNAs and their corresponding miRNAs in colorectal cancer (CRC) and adjacent normal mucosa and performed pathway analysis to identify mRNA/miRNA networks. The cancer samples were divided into first (20 cases) and second (24 cases) cohorts, and 48 samples were obtained from two sections of the normal mucosa adjacent to the tumors from the second cohort. We investigated mRNAs with commonly altered expression in CRC and adjacent normal mucosa using isolated cancer glands and normal crypts from the first cohort, compared with that of distal normal crypts, using an array‐based method. As a result, significant inverse correlations between CEACAM1 and miRNA‐7114‐5p and between AK1 and miRNA‐6780‐5p were found in CRC and adjacent normal mucosa. We validated these correlations in the second cohort using RT‐PCR. To confirm these findings, transfection and immunohistochemical assays were also performed, which verified the inverse correlation between CEACAM1 and miRNA‐7114‐5p. Our findings suggest that the inverse correlations between the CEACAM1/miRNA‐7114‐5p and possibly AK1/miRNA‐6780‐5p pairs play an important role in early CRC development, and may help identify potential molecular targets for early detection of CRC.

MiRNome Profiling and Functional Analysis Reveal Involvement of hsa-miR-1246 in Colon Adenoma-Carcinoma Transition by Targeting AXIN2 and CFTR.

Regulatory changes occurring early in colorectal cancer development remain poorly investigated. Since the majority of cases develop from polyps in the adenoma-carcinoma transition, a search of early molecular features, such as aberrations in miRNA expression occurring prior to cancer development, would enable identification of potentially causal, rather than consequential, candidates in the progression of polyp to cancer. In the current study, by employing small RNA-seq profiling of colon biopsy samples, we described differentially expressed miRNAs and their isoforms in the adenoma-carcinoma transition. Analysis of healthy-adenoma-carcinoma sequence in an independent validation group enabled us to identify early deregulated miRNAs including hsa-miR-1246 and hsa-miR-215-5p, the expressions of which are, respectively, gradually increasing and decreasing. Loss-of-function experiments revealed that inhibition of hsa-miR-1246 lead to reduced cell viability, colony formation, and migration rate, thereby indicating an oncogenic effect of this miRNA in vitro. Subsequent western blot and luciferase reporter assay provided evidence of hsa-miR-1246 being involved in the regulation of target AXIN2 and CFTR genes’ expression. To conclude, the present study revealed possible involvement of hsa-miR-1246 in early colorectal cancer development and regulation of tumor suppressors AXIN2 and CFTR.

Enteric Glia Play a Critical Role in Promoting the Development of Colorectal Cancer.

Enteric glia are a distinct population of peripheral glial cells in the enteric nervous system that regulate intestinal homeostasis, epithelial barrier integrity, and gut defense. Given these unique attributes, we investigated the impact of enteric glia depletion on tumor development in azoxymethane/dextran sodium sulfate (AOM/DSS)-treated mice, a classical model of colorectal cancer (CRC). Depleting GFAP+ enteric glia resulted in a profoundly reduced tumor burden in AOM/DSS mice and additionally reduced adenomas in the ApcMin/+ mouse model of familial adenomatous polyposis, suggesting a tumor-promoting role for these cells at an early premalignant stage. This was confirmed in further studies of AOM/DSS mice, as enteric glia depletion did not affect the properties of established malignant tumors but did result in a marked reduction in the development of precancerous dysplastic lesions. Surprisingly, the protective effect of enteric glia depletion was not dependent on modulation of anti-tumor immunity or intestinal inflammation. These findings reveal that GFAP+ enteric glia play a critical pro-tumorigenic role during early CRC development and identify these cells as a potential target for CRC prevention.

A Systems Biology Approach to Identifying a Master Regulator That Can Transform the Fast Growing Cellular State to a Slowly Growing One in Early Colorectal Cancer Development Model.

Colorectal cancer (CRC) has been most extensively studied for characterizing genetic mutations along its development. However, we still have a poor understanding of CRC initiation due to limited measures of its observation and analysis. If we can unveil CRC initiation events, we might identify novel prognostic markers and therapeutic targets for early cancer detection and prevention. To tackle this problem, we establish the early CRC development model and perform transcriptome analysis of its single cell RNA-sequencing data. Interestingly, we find two subtypes, fast growing vs. slowly growing populations of distinct growth rate and gene signatures, and identify CCDC85B as a master regulator that can transform the cellular state of fast growing subtype cells into that of slowly growing subtype cells. We further validate this by in vitro experiments and suggest CCDC85B as a novel potential therapeutic target that may prevent malignant CRC development by suppressing stemness and uncontrolled cell proliferation.

An oligonucleotide-tagged microarray for routine diagnostics of colon cancer by genotyping KRAS mutations.

Colorectal cancer (CRC) is one of the most prevalent types of cancer, causing significant morbidity and mortality worldwide. CRC is curable if diagnosed at an early stage. Mutations in the oncogene KRAS play a critical role in early development of CRC. Detection of activated KRAS is of diagnostic and therapeutic importance. In this study, KRAS gene fragments containing mutations in codon12 were amplified by multiplex PCR using a 5'-Cy5-labeled reverse primer in combination with 3'-mutation-specific forward primers that were linked with four unique nucleotide-sequence tags at the 5'-end. The Cy5-labeled reverse primer was extended under PCR amplification to the 5'-end of the mutation-specific forward primers and thus included the complimentary sequence of the tag. PCR products were hybridized to tag-probes immobilized on various substrates and detected by a scanner. Our results indicate that all mutations at codon12 of KRAS derived from cancer cells and clinical samples could be unambiguously detected. KRAS mutations were accurately detected when the mutant DNA was present only in 10% of the starting mixed materials including wild-type genomic DNA, which was isolated from either cancer cells or spiked fecal samples. The immobilized tag-probes were stable under multiple thermal cycling treatments, allowing re-use of the tag-microarray and further optimization to solid PCR. Our results demonstrated that a novel oligonucleotide-tagged microarray system has been developed which would be suitable to be used for detection of KRAS mutations and clinical diagnosis of CRC.

Early gastric adenocarcinoma arising from a gastric adenoma in a patient with familial adenomatous polyposis syndrome

Familial adenomatous polyposis (FAP) is a rare hereditary syndrome characterized by multiple colorectal polyps and early development of colorectal cancer. Although FAP uniformly involves the large bowel, it may also produce lesions in the stomach and upper intestinal tract. Management of the risk of development of upper gastrointestinal cancer is one of the greatest challenges faced by clinicians involved in the care of polyposis families. We present the case of a 45-year-old woman with FAP who developed gastric cancer early post proctocolectomy. A gastric adenoma with moderate atypia was detected during the upper gastrointestinal endoscopic screening performed prior to the colorectomy. However, 14 months later, the gastric adenoma had progressed to early gastric cancer. In FAP patients living in East Asia, gastric adenoma is a high risk factor for gastric cancer and shows rapid progression. Therefore, it is important in FAP patients detected to have gastric adenomas, to perform upper gastrointestinal endoscopy in the short term and to resect any gastric adenomas, regardless of their tissue grade.

Age at diagnosis of inflammatory bowel disease influences early development of colorectal cancer in inflammatory bowel disease patients: a nationwide, long-term survey

BackgroundData on clinical characteristics of patients with inflammatory bowel disease (IBD)-related colorectal cancer (CRC) are scarce and mainly originate from tertiary referral centres. We studied patient and disease characteristics of IBD-related CRC in a nationwide IBD cohort in general hospitals. Main outcome parameters were time to develop CRC, and factors associated with early CRC development.MethodsAll IBD patients diagnosed with CRC between 1 January 1990 and 1 July 2006 were identified using a nationwide automated pathology database (PALGA). Patient charts were assessed to confirm diagnosis and collect clinical data. Early CRC was defined as CRC diagnosed less than 8 years after IBD diagnosis. Statistical analysis was performed using descriptive statistics, independent t tests, binary logistic regression and Cox-regression analysis.ResultsDiagnosis of IBD-related CRC was confirmed in 251 patients (171 ulcerative colitis, 77 Crohn’s disease, 3 unclassified colitis), 161 males (64 %). Median time from IBD diagnosis to CRC diagnosis was 12 years (IQR 4–20); 89 patients (35 %) developed early CRC. Type of IBD, gender, concomitant PSC, pseudopolyps, extent of inflammation, and medication use were not related to early CRC (p > 0.05). IBD diagnosis at older age (HR for 10 years older age 2.25; 95 % CI 1.92–2.63) was related to early CRC. Twenty-three patients (12 %) had been included in a surveillance programme prior to CRC diagnosis. Patients in the surveillance group had a significantly better tumor stage (p = 0.004).ConclusionsWe emphasize the problem of a high proportion of IBD-associated CRCs developing before the recommended start of surveillance. Therefore, we suggest that older age at IBD onset could be an additional factor to start surveillance in IBD patients.

Variations in hemoglobin before colorectal cancer diagnosis

We have conducted the present case-control study to examine whether long-term variations in blood hemoglobin (Hb) levels within the normal range could detect subtle gastrointestinal bleeding in the early development of colorectal cancer (CRC). A total of 1074 CRC cases aged 45-75 years that have been diagnosed with CRC and had normal Hb levels were frequency matched for age and sex with cancer-free individuals at a ratio of 10 controls per case. Our retrospective analysis indicates that starting from 4 years prior to cancer diagnosis, a progressive significant (P<0.001) decrement in Hb levels (0.28 g/dl per 6 months) was found among cases but not among controls. CRC patients were characterized in an on-going, long-term, logarithmic decrement in Hb levels. Such small changes within the normal Hb range could be missed by health providers, but automatically detected by computerized alert algorithms..

Identification of cancer‐associated proteins by proteomics and downregulation of β‐tropomyosin expression in colorectal adenoma and cancer

Elucidating the molecular mechanism underlying the development of adenoma, the major precursor lesion of colorectal cancer (CRC), would provide a basis for early detection, prevention as well as treatment of CRC. Using the highly sensitive 2-D DIGE method coupled with MS, we identified 24 differentially expressed proteins in adenoma tissues compared with matched normal colonic mucosa and CRC tissues. Fifteen proteins were downregulated and three proteins were upregulated in adenoma tissues when compared with individual-matched normal colonic mucosa. Five proteins were downregulated, while one protein was upregulated in adenoma tissues when compared with matched CRC tissues. A protein, β-tropomyosin (TM-β), recently suggested to be a biomarker of esophageal squamous carcinoma, was downregulated in both adenoma and CRC tissues. Additionally, the reduction in the level of TM-β in adenoma and CRC tissues was further validated by Western blotting (p<0.05) and RT-PCR (p<0.001). Our findings suggest that downregulation of TM-β is involved in the early development of CRC and that differentially expressed proteins might serve as potential biomarkers for detection of CRC.

Síndrome de Lynch: Caracterización genético clínica. Caso clínico

Hereditary non-polyposis colorectal cancer (HNPCC) or Lynch Syndrome is an autosomic dominant syndrome involving 596-1096 of colorectal cancer patients. Mutations in MLH1 and MSH2 genes account for most cases. These two genes participate in the DNA mismatch repair pathway. Therefore mutation carriers show microsatellite instability (MSI) in tumors. This syndrome is characterized by the early development of colorectal cancer (before 50 years) and an increased incidence of cancer in other organs. We report four siblings from a family diagnosed with HNPCC. All of them were subjected to colonic surgery for colorectal cancer Moreover, one patient developed an ampulloma after her colon surgery. The molecular-genetic analysis revealed three brothers with microsatellite instability in the tumor tissue, the absence of the MLH1 protein, and the presence of a germ line mutation localized in introm 15 of the MLH1 gene.

A novel missense MSH2 gene mutation in a patient of a Korean family with hereditary nonpolyposis colorectal cancer

Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant cancer-susceptible syndrome that predisposes to the early development of colorectal cancer. Germline mutations in DNA mismatch repair genes, particularly MLH1 and MSH2, are associated with the clinical phenotype of HNPCC. A previously unreported, novel missense mutation in exon 3 of the MSH2 gene (c.380A>T) was identified in the proband and a different missense mutation in exon 3 of MSH2 gene (c.505A>G) was noted in the mother, with a mutual splice mutation in intron 12 of the MSH2 gene in the proband, mother, and younger brother. Here, we report the clinical implications of a novel mutation in a patient with early-onset colorectal cancer and the significance of a common underlying splice site mutation occurring within a family with HNPCC.

Gastric Adenocarcinoma Arising from Fundic Gland Polyps in a Patient with Familial Adenomatous Polyposis Syndrome

Familial adenomatous polyposis (FAP) is a rare hereditary syndrome characterized by multiple colorectal polyps and early development of colorectal cancer. Although FAP uniformly involves the large bowel, it may also produce lesions in the stomach and upper intestinal tract. Fundic gland polyps are the most common gastric lesion in FAP. In the general population, these polyps are considered benign and have no malignant potential. However, in FAP patients, fundic gland polyps have been occasionally recognized as precursor lesions from which invasive cancer may develop. Herein, we present a case of gastric adenocarcinoma arising from fundic gland polyps in an FAP patient. We also review reported cases of gastric cancer in FAP and FAP variant patients in an effort to better understand the pathology, clinical course, and optimal screening and treatment strategies for this disease manifestation.

Differential Expression of Mimecan and Thioredoxin Domain–Containing Protein 5 in Colorectal Adenoma and Cancer: A Proteomic Study

Adenoma is the major precursor lesion of colorectal cancer, one of the most common cancers worldwide. The elucidation of the molecular mechanism underlying adenoma is essential for early detection, prevention, and intervention of colorectal cancer. Using a combination of two-dimensional gel electrophoresis and mass spectrometry, we identified 27 differentially expressed proteins in adenoma, compared with matched normal mucosa and cancer tissue. Seventeen proteins were upregulated and six downregulated in adenoma when compared with the same proteins in individual-matched normal mucosa. Four were downregulated, but none upregulated in adenoma when compared with the same proteins in matched cancer tissue. Two novel proteins, mimecan and thioredoxin domain-containing protein 5 (TXNDC5), were further validated by Western blot in 8 colorectal adenomas and 19 cancers that were matched with normal mucosa. All adenoma and cancer tissues did not express mimecan, but all normal mucosa did (P < 0.01). In contrast, TXNDC5 was significantly upregulated in colorectal adenoma and cancer tissues as compared with that in normal mucosa (P < 0.05). This study clearly demonstrated that absence of mimecan and upregulation of TXNDC5 are involved in the early development of colorectal cancer. Thus, the differentially expressed proteins might serve as potential biomarkers for colorectal cancer detection and intervention.

FAMILIAL ADENOMATOUS POLYPOSIS IN CHILDREN UNDER 10; PRESENTATION AND CLINICAL OUTCOME: WHO GOES TO COLECTOMY?

Background: Familial Adenomatous Polyposis (FAP) is an autosomal dominant inherited predisposition to early development of colorectal cancer (CRC) and increased risk of other, including extraintestinal, malignancies. Children aged less than 10 years are at a heightened risk of hepatoblastoma and may also present with polyps and rarely with CRC. Heirein we describe our experience as a multidisciplinary pediatric hereditary gastrointestinal polyposis clinic. Methods: A cross-sectional analysis including demographic, clinical presentation and course, gene mutation testing, endoscopic-histololgic findings and surgical outcome of all patients suspected or confirmed with FAP presenting in the first decade of life and followed by the multidisciplinary Pediatric Hereditary Polyposis Clinic at the University of Nebraska Medical Center and Creighton University. Results: 22 children (M;11) including 3 sibling pairs presented with suspected or confirmed FAP, 2 were discharged from follow up following negative APC gene mutation testing, all the rest continued to be tested for elevated ? αfetoprotein and ultrasound of the abdomen throughout the first decade of life. 12 patients presented with symptoms, 6 had de-novo FAP, 7 had gastrointestinal hemorrhage and went on to endoscopy, 4 patients were referred for colectomy, all 4 harbored APC gene mutation at codon 1309. The age at referral to colectomy was earlier for patients with 1309 mutation compared to patients who harbored other mutations or were untested (mean 8.6 years vs. 16 years P = 0.03). Conclusions: Children with FAP under the age of 10 may present presymptomatically for disease surveillance. De-novo and inherited FAP associated with APC gene mutation at codon 1309 entails a risk of a more aggressive phenotype; early colectomy may be indicated in children harboring this gene mutation.