IGF-Ⅱ、IGF-1R、IGFBP-3在结直肠癌中的表达及诊断价值研究

目的：探讨结直肠癌中IGF-Ⅱ、IGF-1R以及IGFBP-3等的阳性表达及诊断价值。方法：收集我院45例结直肠癌、33例炎性息肉、40例腺瘤以及35例正常肠粘膜组织予以免疫组织化学SP法进行IGF—Ⅱ、IGF—1R以及IGFBP-3检测,并统计结直肠腺瘤不同组织类型和结直肠癌不同Dukes分期的阳性表达差异。结果：结直肠癌组织中IGF—Ⅱ、IGF—1R以及IGFBP-3表达均呈高阳性率,并且显著高于其他3组（P〈0．05）。结直肠腺瘤管状、混合型、绒毛状等不同组织类型IGF-Ⅱ、IGF—1R以及IGFBP-3表达阳性率呈逐渐增高趋势,绒毛状腺瘤显著高于其他两型（P〈0．05）。45例结直肠癌中,Dukes分期A、B两期显著低于C期和D期,比较差异具有显著性（P〈0．05）。结论：IGF—Ⅱ、IGF-1R以及IGFBP-3可能在结直肠腺瘤发生、发展及进展为结直肠癌的过程中起一定作用,对结直肠癌早期诊断具有一定价值。     

Clinical Significance of Frizzled Homolog 3 Protein in Colorectal Cancer Patients

Frizzled homolog 3 receptor was up-regulated in several gastrointestinal cancers such as esophageal and gastric cancers. Moreover, frizzled homolog 3 has recently reported to be expressed in colorectal adenoma specimens. In the present study, we investigated the clinical significance of frizzled homolog 3 protein in colorectal cancer patients. Using immunocytochemical staining, frizzled homolog 3 expression was examined in 186 colorectal cancer specimens, 79 colorectal adenoma specimens, 133 colorectal polyp specimens, 127 colorectal cancer specimens with lymph node and/or distant metastasis, 310 specimens of various non-colorectal cancer metastatic carcinomas and 40 specimens with simultaneous occurrence of colorectal cancer, colorectal adenoma and colorectal polyp. Statistical analysis was used to correlate frizzled homolog 3 protein expression to the clinicohistopathological factors, recurrence/metastasis and survival after follow-up for 42 months in colorectal cancer patients. Frizzled homolog 3 protein was expressed in 100% colorectal cancer specimens, 89% colorectal adenoma specimens, 75% colorectal polyp specimens and 69% normal colorectal epithelial tissues. Moreover, frizzled homolog 3 immunocytochemical scores were highly correlated with colorectal cancer progression. Furthermore, frizzled homolog 3 was expressed in a comparatively lower percentage of metastatic hepatocellular carcinoma and metastatic renal clear cell carcinoma with focal and very weak staining than other metastatic tumor types. On the other hand, the frizzled homolog 3 immunocytochemical scores of colorectal adenomas with synchronous colorectal carcinomas were significantly higher than those of pure colorectal adenomas. Statistical analysis showed that frizzled homolog 3 immunocytochemical scores were associated with Dukes stage and lymph node status. Finally, stratified groups of colorectal cancer patients had significant differences in their recurrence/metastasis and survival. In conclusion, the present large-scale study has clearly showed that frizzled homolog 3 protein can generate clinically important information for colorectal cancer patients.     

Colon cancer specific nuclear matrix protein alterations in human colonic adenomatous polyps

Most colon cancers arise within preexisting adenomatous polyps or adenomas. The slow evolution from the non-invasive premalignant lesion, the adenomatous polyp, to invasive cancer supports a strategy of early detection. Recently, we identified unique nuclear matrix proteins (NMPs) specific for colon cancer (CC2, CC3, CC4, CC5). Most of the NMPs identified are common to all cell types, but several identified NMPs are tissue and cell line specific. The objective of this study is to describe and characterize the NMP profile of premalignant adenomatous colon polyps. Specifically when in the adenoma-carcinoma sequence four specific colon cancer NMPs, previously described, appear. Using two-dimensional (2-D) gel analysis 20 colon polyps (one juvenile polyp, six tubular adenoma (TA), seven tubulovillous adenoma (TVA), six TVA with focal high-grade dysplasia (HGD), were analyzed for the presence of four (CC2, CC3, CC4, CC5) specific NMPs. CC2 was not seen in any of the premalignant polyps. CC5 was present in only two premalignant TVA with HGD and in one TA. CC3 and CC4 were present in most adenomas. None of the NMPs were seen in the juvenile polyp, which is not considered to be a precursor of colon cancer. CC2 and CC5 are NMPs expressed at the junction of an advanced adenoma and invasive colorectal cancer. CC3 and CC4 are expressed earlier in the evolution of adenomatous polyps. Development of an assay to these proteins may serve as a new method for early detection of colorectal cancer.     

Association between family history of malignant neoplasm with colorectal adenomatous polyp in 40s aged relative person

PurposeWe assessed the association between a family history of malignancy and risk of colorectal adenoma among individuals aged 40–49 years.MethodsThe study population consisted of subjects, aged in their 40s, who underwent colonoscopy. Their family histories of cancer were collected with a self-administered questionnaire. A logistic regression model was used to assess the association between a family history of cancer and the risk of colorectal polyp.ResultsIn total, 2275 participants were included in the study. Univariate analysis showed that old age, male sex, current cigarette smoking, BMI > 25 kg/m², and a family history of colorectal cancer (CRC) were risk factors for the development of sporadic colorectal adenomatous polyps in these patients. A multivariate analysis showed that a family history of CRC or kidney cancer was associated with adenoma development. A family history of CRC was also a risk factor for advanced and multiple adenoma.ConclusionsThis study shows that a family history of CRC is a risk factor for advanced and multiple colorectal adenoma in people in their 40s. These results support earlier screening for colorectal neoplasms in individuals with a family history of CRC.     

Variation in Blood and Colorectal Epithelia’s Key Trace Elements Along with Expression of Mismatch Repair Proteins from Localized and Metastatic Colorectal Cancer Patients

Colorectal cancer (CRC) is an increasingly common medical issue affecting millions worldwide, and contribution of the body’s trace elements to CRC is arguable. The concentrations and buffered status of selenium, iron, copper, zinc, and phosphorus in blood and large intestinal tissues of CRC patients are, respectively, variable and vital for cell physiology. The aim of this study was to assess selenium, iron, copper, zinc, and phosphorus variations in blood and colorectal epithelia along with examining the expression of mismatch repair proteins in CRC patients with/without metastasis for potential diagnosis/therapy. Concentrations of selenium, iron, copper, zinc, and phosphorus in blood of healthy versus CRC patients and colorectal epithelia (adenocarcinomatous versus non-adenocarcinomatous/control) were measured in 40 CRC patients (55.87 ± 11.9 years old) with/without metastasis before surgery using ICP-OES. Mismatch repair (MMR) protein expression was analyzed through histopathological/immunohistochemistry assays, which was sparse in 5 CRC patient’s colorectal tissues (12%). Compared with healthy individuals, blood and colorectal tissue’s levels of phosphorus, copper, and iron were significantly higher in the CRC patients, and more pronounced in metastatic CRC patients; conversely, blood and colorectal tissue’s selenium levels were significantly lower in metastatic patients. Unlike blood zinc, cancerous colorectal tissue’s zinc concentration was significantly lower in CRC patients compared to healthy control cohorts. There was no significant difference on the measured elements in samples from CRC patients with MMR⁻ compared to CRC patients with MMR⁺. Receiver operating characteristic analysis revealed a correlation of blood iron, zinc, copper, and phosphorus to CRC, and inappropriately low levels of blood and colorectal selenium correlated with exacerbated metastasis. Altered levels of selenium, iron, copper, zinc, and phosphorus in vivo may impact the pathogenesis and detection of CRC, and their diagnostic/therapeutic potential in CRC would be revealing.

     

结肠腺瘤发生的危险因素及和幽门螺杆菌感染的相关性分析

目的:分析结肠腺瘤发生的危险因素及和幽门螺杆菌(Hp)感染的相关性。方法:选择我院2018年6月～2018年12月收治的180例结肠腺瘤患者,同时选择我院接受结肠镜检查无异常者152例作为对照组。收集和比较两组患者的一般资料,采用14C尿氮呼气试验检测Hp的感染情况,多因素Logistic回归分析结肠腺瘤发生的危险因素。结果:多因素Logistic逐步回归分析结果显示男性、年龄、体质指数24 kg/m~2、腹型肥胖、饮酒、吸烟、喜食红肉、喜食果蔬、高脂血症、糖尿病、粪便隐血阳性、肿瘤家族史及Hp阳性是结肠腺瘤发生的危险因素,喜食果蔬为其发生的保护因素。HP阳性率组腺瘤1 cm、腺瘤数目多发、左结肠率高于Hp阴性组(P0.05);Hp阳性组和Hp阴性组肠腺瘤患者腺瘤蒂部分型、腺瘤病理类型比较差异无统计学意义(P0.05)。结论:结肠腺瘤的发生和多种危险因素有关,其中Hp感染可增加结肠腺瘤发生发展风险,临床应将此类高危人群作为结肠腺瘤的重点筛查对象,以降低结肠癌的潜在发生风险。     

结肠息肉镜下特征、病理分型及癌变规律分析

目的:探讨结肠息肉镜下特征、病理类型及血清学特点与癌变的相关性。方法:收集我院2011年6月~2013年6月肠镜证实的640名结肠息肉患者资料。对年龄、性别、息肉特征(部位、大小、数量、分型、病理等)分析,并将息肉者癌胚抗原与健康人比较。结果:检出息肉1144枚;年龄在41岁~60岁的占52.9%;发生在乙状结肠和直肠的占47.3%;多发及多部位息肉比例为56.9%和46.9%;腺瘤样息肉占87%;随年龄、息肉体积增加,癌变率增加;无蒂息肉癌变率高于有蒂息肉;两组血清癌胚抗原值差异有统计学意义。结论:结肠息肉多发生在乙状结肠和直肠;以腺瘤息肉为主;癌变与年龄、腺瘤大小、形态、病理类型有关。癌胚抗原可能在腺瘤样息肉的筛查及监测癌变存在意义。     

Adipokines and Obesity Are Associated with Colorectal Polyps in Adult Males: A Cross-Sectional Study

Background

Obesity increases the risk of colon cancer. It is also known that most colorectal cancers develop from adenomatous polyps. However, the effects of obesity and adipokines on colonic polyp formation are unknown.

Methods

To determine if BMI, waist circumference or adipokines are associated with colon polyps in males, 126 asymptomatic men (48–65 yr) were recruited at time of colonoscopy, and anthropometric measures as well as blood were collected. Odds ratios were determined using polytomous logistic regression for polyp number (0 or ≥3) and polyp type (no polyp, hyperplastic polyp, tubular adenoma).

Results

41% of the men in our study were obese (BMI ≥30). The odds of an obese individual having ≥3 polyps was 6.5 (CI: 1.3–33.0) times greater than those of a lean (BMI<25) individual. Additionally, relative to lean individuals, obese individuals were 7.8 (CI: 2.0–30.8) times more likely to have a tubular adenoma than no polyp. As BMI category increased, participants were 2.9 (CI: 1.5–5.4) times more likely to have a tubular adenoma than no polyps. Serum leptin, IP-10 and TNF-α were significantly associated with tubular adenoma presence. Serum leptin and IP-10 were significantly associated with increased likelihood of ≥3 polyps, and TNF-α showed a trend (p = 0.09).

Conclusions

Obese men are more likely to have at least three polyps and adenomas. This cross-sectional study provides evidence that colonoscopy should be recommended for obese, white males.     

Serum levels of selenium, manganese, copper, and iron in colorectal cancer patients

This article describes a study in which four trace elements (Se, Mn, Cu, and Fe) were analyzed in the blood serum of the patients with colorectal cancer from the Moravian region of the Czech Republic. Atomic absorption spectrometry with graphite furnace atomization was used for analysis of selenium and manganese and with flame atomization for analysis of copper and iron. The observed serum concentrations in adenocarcinoma colorectal patients of selenium were significantly lower (41.8 ± 11.6 μg/L) and those of manganese (16.3 ± 4.5 μg/L) and iron (2.89 ± 1.23 mg/L) were significantly higher as compared to the age-matched control group. Copper serum content (0.95 ± 0.28 mg/L) did not significantly differ as compared to healthy population.     

Serum selenium level in patients with colorectal cancer

Serum selenium levels were determined by fluorometric procedure in 37 patients of both sexes suffering from colorectal cancer. The diagnosis was verified with histopathological examination during surgical treatment. The values found were 46.8±11.2 μg/L. The control group consisted of 230 healthy persons from the same environment as the group of patients. The values found were 64.2±11.5 μg/L. The results of this study are compared with the results of the other research groups analyzing the level of selenium in colorectal cancer.     

Plasma glycoprotein profiling for colorectal cancer biomarker identification by lectin glycoarray and lectin blot

Colorectal cancer (CRC) remains a major worldwide cause of cancer-related morbidity and mortality largely due to the insidious onset of the disease. The current clinical procedures utilized for disease diagnosis are invasive, unpleasant, and inconvenient; hence, the need for simple blood tests that could be used for the early detection of CRC. In this work, we have developed methods for glycoproteomics analysis to identify plasma markers with utility to assist in the detection of colorectal cancer (CRC). Following immunodepletion of the most abundant plasma proteins, the plasma N -linked glycoproteins were enriched using lectin affinity chromatography and subsequently further separated by nonporous silica reversed-phase (NPS-RP)-HPLC. Individual RP-HPLC fractions were printed on nitrocellulose coated slides which were then probed with lectins to determine glycan patterns in plasma samples from 9 normal, 5 adenoma, and 6 colorectal cancer patients. Statistical tools, including principal component analysis, hierarchical clustering, and Z-statistics analysis, were employed to identify distinctive glycosylation patterns. Patients diagnosed with colorectal cancer or adenomas were shown to have dramatically higher levels of sialylation and fucosylation as compared to normal controls. Plasma glycoproteins with aberrant glycosylation were identified by nano-LC-MS/MS, while a lectin blotting methodology was used to validate proteins with significantly altered glycosylation as a function of cancer progression. The potential markers identified in this study for diagnosis to distinguish colorectal cancer from adenoma and normal include elevated sialylation and fucosylation in complement C3, histidine-rich glycoprotein, and kininogen-1. These potential markers of colorectal cancer were subsequently validated by lectin blotting in an independent set of plasma samples obtained from 10 CRC patients, 10 patients with adenomas, and 10 normal subjects. These results demonstrate the utility of this strategy for the identification of N -linked glycan patterns as potential markers of CRC in human plasma, and may have the utility to distinguish different disease states.     

Predictors of Colorectal Polyp Recurrence after the First Polypectomy in Private Practice Settings: A Cohort Study

Background

Supplementary observational data in the community setting are required to better assess the predictors of colorectal polyp recurrence and the effectiveness of colonoscopy surveillance under real circumstances.

Aim

The goal of this study was to identify patient characteristics and polyp features at baseline colonoscopy that are associated with the recurrence of colorectal polyps (including hyperplastic polyps) among patients consulting private practice physicians.

Patients and Methods

This cohort study was conducted from March 2004 to December 2010 in 26 private gastroenterology practices (France). It included 1023 patients with a first-time diagnosis of histologically confirmed polyp removed during a diagnostic or screening colonoscopy. At enrollment, interviews were conducted to obtain data on socio-demographic variables and risk factors. Pathology reports were reviewed to abstract data on polyp features at baseline colonoscopy. Colorectal polyps diagnosed at the surveillance colonoscopy were considered as end points. The time to event was analyzed with an accelerated failure time model assuming a Weibull distribution.

Results

Among the 1023 patients with colorectal polyp at baseline, 553 underwent a surveillance colonoscopy. The mean time interval from baseline colonoscopy to first surveillance examination was 3.42 (standard deviation, 1.45) years. The recurrence rates were 50.5% and 32.9% for all polyps and adenomas, respectively. In multivariate models, the number of polyps at baseline was the only significant predictor for both polyp recurrence (hazard ratio [HR] 1.19, 95% CI 1.06 to 1.33), and adenoma recurrence (HR 1.17, 95% CI 1.03 to 1.34).

Conclusion

The efficacy of surveillance colonoscopy in community gastroenterology practice compared favorably with academic settings. This study provides further evidence that the number of initial colorectal polyps is useful for predicting the risk of polyp recurrence, even in the community setting.     

Detection of cancer clones in human colorectal adenoma as revealed by increased DNA instability and other bio-markers

An immunohistochemical differential staining of cancerous cells with anti-cytidine antibody after denaturation of nuclear DNA by acid hydrolysis with 2N HCl at 30 degrees C for 20 min (DNA-instability test) has been used as a marker for malignancy. The test was applied to bioptic tissues of human colorectal polyps assessed histopathologically as hyperplastic polyp (11 cases), tubular adenoma of mild (68 cases), moderate (102 cases), and severe (46 cases) dysplasia, and adenocarcinoma (30 cases). The serial sections of the same tissues were also subjected to immunohistochemical staining for Ki67, p53, DNA-fragmentation factor 45 (DFF45) and vascular endothelial growth factor (VEGF). The DNA-instability test was positive in 30 (100%) adenocarcinoma cases, 46 (100%) severe dysplasia adenoma cases, 36 (35.29%) moderate dysplasia adenoma cases, and 8 (11.76%) mild dysplasia adenoma cases, indicating malignancy. All hyperplastic polyps were negative to the DNA-instability test. Furthermore, the percentage of glands positive in the DNA-instability test steadily increased in going from mild (10%), to moderate (35%), to severe (100%) dysplasia, and adenocarcinoma (100%). All other biological markers tested in the present study showed significantly higher values in those adenoma glands that were positive to the DNA-instability test, irrespective of the dysplasia grade, as compared to the markers in the adenoma glands that were negative to DNA instability testing. Furthermore, the former values were comparable to those in adenocarcinoma. The results indicate that cancer cell clones are already present at the adenoma stages showing positivity to DNA instability testing, enhanced proliferative activity, p53 mutation and induction of DFF45 and VEGF, at a time when the degree of morphological atypia are not yet large enough for them to be identified as cancer. These factors promote cancer cell proliferation, produce heterogeneous subclones due to DNA instability, enhance their survival by escaping apoptosis, and provide abundant nutrients by neovascularization during the early-stage progression of colorectal cancer.     

Disparity Expression of Notch1 in Benign and Malignant Colorectal Diseases

Background and Objectives

Although there was growing evidence supporting the hypothesis that Notch1 was one of the few candidate genes linked with colorectal cancer (CRC) susceptibility, the precise level of Notch1 protein expression in benign and malignant colorectal diseases was still unknown. Our study has investigated the Notch1 expression in benign and malignant colorectal diseases as well as to investigate the role and clinicopathological significance of aberrant expression of Notch1 in CRC.

Methods

The protein expression of Notch1 was examined by immunohistochemistry in 901 clinical specimens with colorectal diseases, including 220 patients with ulcerative colitis, 232 patients with colorectal adenoma and 449 patients with colorectal cancer. Associations between the expression of Notch1 and various clinicopathological features, as well as survival status, were studied.

Results

Cytoplasmic Notch1 was expressed in 7.7% of patients with ulcerative colitis, 14.7% of patients with colorectal adenoma and 58.0% of patients with colorectal cancer, respectively. Colorectal cancer patients with high expression levels of Notch1 showed lower overall survival (OS) and disease-free survival (DFS) rates than those patients with low Notch1 expression.

Conclusions

Expression level of Notch1 was gradually increased from precancerous lesions to cancer. It might play as an oncogene in the CRC development, and might be potentially used as a biomarker for prognosis of CRCs.     

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.     

大肠息肉的危险因素分析

目的：探讨大肠息肉在人群中的年龄、性别、病理类型的分布,并探讨体质量指数、吸烟饮酒、血脂水平、相关疾病、饮食习惯及运动状况对大肠息肉发生的影响。方法：选择2011年4月至2013年4月在海军总医院进行电子结肠镜检查的542例患者,将结肠镜检查发现大肠息肉并住院治疗的患者纳入息肉组,将内镜检查无明显异常的患者纳入对照组。比较两组患者的体质量指数、吸烟饮酒、血脂水平、相关疾病、饮食习惯及运动状况等。结果：大肠息肉人群中男性多于女性,40岁以上高发,超重及肥胖者达55．56％;经常饮酒、较少进食蔬菜、水果、粗纤维食物、运动量少及患有高脂血症、高血压、糖尿病、脂肪肝、胆系疾病者易发大肠息肉。结论：高体质量指数、吸烟、高血脂水平、相关疾病、不良饮食习惯、运动量小是大肠息肉发生的危险因素。     

大肠息肉的危险因素分析

目的:探讨大肠息肉在人群中的年龄、性别、病理类型的分布,并探讨体质量指数、吸烟饮酒、血脂水平、相关疾病、饮食习惯及运动状况对大肠息肉发生的影响。方法:选择2011年4月至2013年4月在海军总医院进行电子结肠镜检查的542例患者,将结肠镜检查发现大肠息肉并住院治疗的患者纳入息肉组,将内镜检查无明显异常的患者纳入对照组。比较两组患者的体质量指数、吸烟饮酒、血脂水平、相关疾病、饮食习惯及运动状况等。结果:大肠息肉人群中男性多于女性,40岁以上高发,超重及肥胖者达55.56%;经常饮酒、较少进食蔬菜、水果、粗纤维食物、运动量少及患有高脂血症、高血压、糖尿病、脂肪肝、胆系疾病者易发大肠息肉。结论:高体质量指数、吸烟、高血脂水平、相关疾病、不良饮食习惯、运动量小是大肠息肉发生的危险因素。     

Evidence that a polymorphism within the 3′UTR of glutathione peroxidase 4 is functional and is associated with susceptibility to colorectal cancer

Low selenium (Se) status has been associated with increased risk of colorectal cancer (CRC). Se is present as the amino acid selenocysteine in selenoproteins, such as the glutathione peroxidases. Se incorporation requires specific RNA structures in the 3' untranslated region (3'UTR) of the selenoprotein mRNAs. A single nucleotide polymorphism (SNP) occurs at nucleotide 718 (within the 3'UTR) in the glutathione peroxidase 4 gene. In the present study, Caco-2 cells were transfected with constructs in which type 1 iodothyronine deiodinase coding region was linked to the GPx4 3'UTR with either C or T variant at position 718. Higher reporter activity was observed in cells expressing the C variant compared to those expressing the T variant, under either Se-adequate or Se-deficient conditions. In addition, a disease association study was carried out in cohorts of patients with either adenomatous polyps, colorectal adenocarcinomas and in healthy controls. A higher proportion of individuals with CC genotype at the GPx4 T/C 718 SNP was present in the cancer group, but not in the polyp group, compared with the control group (P < 0.05). The present data demonstrate the functionality of the GPx4 T/C 718 SNP and suggest that T genotype is associated with lower risk of CRC.     

An immunohistochemical study and review of potential markers of human intestinal M cells

M cells are found in intestinal follicle associated epithelium. Studies into the physiological and pathological roles of human M cells have been hampered by the lack of well-substantiated, specific markers for these cells. A critical literature review suggests the following molecules may potentially serve as such markers: CK7, FcaR (CD89), S100, CD1a, CD21, CD23, sialyl Lewis A, and cathepsin E. Normal ileum, appendix and colorectum were studied using paraffin-embedded, formalin-fixed tissue and immunohistochemistry for these 8 markers. Cathepsin E immunohistochemistry was also performed on cases of colorectal adenocarcinoma, colorectal adenoma, colorectal hyperplastic/metaplastic polyp, lymphocytic colitis, collagenous colitis, pseudomembranous colitis and active ulcerative colitis. Of the 8 markers tested, only cathepsin E appeared to be specific to follicle associated epithelium (expressed by cells with and without M cell morphology) and follicular crypt epithelium; this specificity was limited to the colorectum. Focal epithelial expression of cathepsin E was seen in adenocarcinoma, adenoma, hyperplastic/metaplastic polyp, ulcerative colitis and pseudomembranous colitis. In conclusion, cathepsin E is a specific marker of normal colorectal follicle associated epithelium and follicular crypt epithelium though is not specific to M cells within these compartments. None of the other 7 markers studied is exclusively expressed by human M cells.     

Colorectal adenoma and cancer detection based on altered methylation pattern of SFRP1, SFRP2, SDC2, and PRIMA1 in plasma samples

Aberrant methylation is one of the most frequent epigenetic alterations that can contribute to tumor formation. Cell-free DNA can originate from tumor tissue; therefore, the evaluation of methylation markers in cell-free DNA can be a promising method for cancer screening. Our aim was to develop a panel of biomarkers with altered methylation along the colorectal adenoma-carcinoma sequence in both colonic tissue and plasma. Methylation of selected CpG sites in healthy colonic (n = 15), adenoma (n = 15), and colorectal cancer (n = 15) tissues was analyzed by pyrosequencing. MethyLight PCR was applied to study the DNA methylation of SFRP1, SFRP2, SDC2, and PRIMA1 gene promoters in 121 plasma and 32 biopsy samples. The effect of altered promoter methylation on protein expression was examined by immunohistochemistry. Significantly higher (P < 0.05) DNA methylation levels were detected in the promoter regions of all 4 markers, both in CRC and adenoma tissues compared with healthy controls. Methylation of SFRP1, SFRP2, SDC2, and PRIMA1 promoter sequences was observed in 85.1%, 72.3%, 89.4%, and 80.9% of plasma samples from patients with CRC and 89.2%, 83.8%, 81.1% and 70.3% from adenoma patients, respectively. When applied as a panel, CRC patients could be distinguished from controls with 91.5% sensitivity and 97.3% specificity [area under the curve (AUC) = 0.978], while adenoma samples could be differentiated with 89.2% sensitivity and 86.5% specificity (AUC = 0.937). Immunohistochemical analysis indicated decreasing protein levels of all 4 markers along the colorectal adenoma-carcinoma sequence. Our findings suggest that this methylation biomarker panel allows non-invasive detection of colorectal adenoma and cancer from plasma samples.