Mutational analysis of driver genes defines the colorectal adenoma: in situ carcinoma transition.

A large proportion of colorectal carcinomas (CRC) evolve from colorectal adenomas. However, not all individuals with colonic adenomas have a risk of CRC substantially higher than those of the general population. The aim of the study was to determine the differences or similarities of mutation profile among low- and high-grade adenomas and in situ carcinoma with detailed follow up. We have investigated the mutation spectrum of well-known genes involved in CRC (such as APC, BRAF, EGFR, NRAS, KRAS, PIK3CA, POLE, POLD1, SMAD4, PTEN, and TP53) in a large, well-defined series of 96 adenomas and in situ carcinomas using a high-throughput genotyping technique. Besides, the microsatellite instability and APC and MLH1 promoter methylation were studied as well. We observed a high frequency of pathogenic variants in the studied genes. The APC, KRAS and TP53 mutation frequencies were slightly lower in adenoma samples than in in situ carcinoma samples. Further, when we stratified mutation frequency based on the grade, the frequency distribution was as follows: low-grade adenoma-high-grade adenomas-in situ carcinoma: APC gene 42.9-56.0-54.5%; KRAS gene 32.7-32.0-45.5%; TP53 gene 8.2-20.0-18.2%. The occurrence of KRAS mutation was associated with the presence of villous histology and methylation of the APC promoter was significantly associated with the presence of POLE genetic variations. However, no association was noticed with the presence of any singular mutation and occurrence of subsequent adenoma or CRC. Our data supports the multistep model of gradual accumulation of mutations, especially in the driver genes, such as APC, TP53 and KRAS.

A head-to-head comparison of 4-L polyethylene glycol and low-volume solutions before colonoscopy: which is the best? A multicentre, randomized trial.

PURPOSE: The purpose of this study is to compare the efficacy and tolerability of polyethylene glycol (PEG) to sodium picosulfate/magnesium citrate (SPMC) and low-volume polyethylene glycol/ascorbic acid (PEGA) in a single- or split-dose regimen for colonoscopy bowel preparation. METHODS: This was a prospective, randomized, endoscopist-blinded, multicentre study. Outpatients received either PEG or SPMC or PEGA in a single or a split dose before the colonoscopy. Quality and tolerability of the preparation and complaints during preparation were recorded. RESULTS: Nine hundred seventy-three patients were analysed. Satisfactory bowel cleansing (Aronchick score 1 + 2) was more frequent when a split dose was used irrespective of the solution type (PEG 90.1 vs 68.8%, PEGA 86.0 vs 71.6%, SPMC 84.3 vs 60.2%, p < 0.001). SPMC was the best tolerated followed by PEGA (p < 0.006) and PEG as the worst (p < 0.001). Tolerability did not correlate with the regimen and amount of the solution used. Female gender is associated with a higher incidence of nausea, vomiting and pain (p < 0.029). CONCLUSIONS: Both PEG, PEGA and SPMC are fully comparable in terms of colonic cleansing when used in similar regimens. The split-dose preparation is more effective in all agents. SPMC and PEGA are better tolerated than PEG. The preparation regimen and/or the volume do not affect tolerability.

Inflammation regulates 11ß-hydroxysteroid dehydrogenase type 1 differentially in specific compartments of the gut mucosal immune system.

The bioavailability of glucocorticoids is modulated by enzyme 11ß-hydroxysteroid dehydrogenase type 1 (11HSD1), which catalyzes the conversion of inactive 11-oxo-glucocorticoids to active 11-hydroxy-glucocorticoids cortisol and corticosterone and is regulated by pro-inflammatory cytokines. Our aim was to assess the effect of colitis on the expression of 11HSD1 in specific microanatomical compartments of the mucosal immune system. Using qRT-PCR we quantified the expression of 11HSD1 and cytokines in the colon, mesenteric lymph nodes (MLN) and spleen of mice with colitis. Microsamples of the MLN cortex, paracortex and medulla, colonic crypt epithelium (CCE), lamina propria and isolated intestinal lymphoid follicles (ILF) were harvested by laser microdissection, whereas splenic and MLN lymphocytes by flow cytometry. Colitis increased 11HSD1 in the CCE, ILF, and MLN cortex but not in the lamina propria and the MLN paracortex and medulla. Expression of IL-4, IL-21 and TNFα was increased in both the cortex of MLN and ILF, whereas IL-1ß and IL-10 were only increased in the follicles. No positive effect was observed in the case of IFNγ and TGFß. 11HSD1 was positively correlated with TNFα and less strongly with IL-21, IL-1ß, and IL-4. Colitis also upregulated the 11HSD1 expression of T cells in the spleen and MLN. The study demonstrates the stimulatory effect of inflammation on local glucocorticoid metabolism only in particular compartments of the mucosal immune system. The correlation between cytokines and 11HSD1 in the ILF and MLN cortex indicates that pro-inflammatory cytokines may amplify glucocorticoid signals in inductive compartments of the mucosal immune system.

[Effective bowel preparation before coloscopy - low-volume PEG in the divided dose regimen]. / Efektivní príprava streva pred koloskopií - nízkoobjemový PEG v deleném rezimu.

INTRODUCTION: The good and safe bowel cleansing is key to the success of coloscopy. The standard preparation involves 4 l polyethylene glycol (PEG). Now the combination of PEG and ascorbic acid (PEGA) of half the volume is available. Besides the type of product also the time factors which are not clarified, play a role during the bowel preparation. The aim of the study was to compare the efficiency and tolerance of both the agents and evaluate the effect of the time regimen of preparation. METHODS: 380 individuals were included in the evaluation in 4 cohorts which used 4 l PEG (Fortrans) in a single dose or split into 3 + 1 l and PEG + ascorbic acid (Moviprep) split into 1 + 1 l or 2 l one day before examination. RESULTS: There was no difference between the agents as to the quality of bowel preparation, when they were used in the same regimen. The bowel cleansing was better in both cases in the divided dose regimen (p < 0.001), and it was inversely proportional to the length of preparation (p = 0.003) and directly proportional to the length of time between the end of preparation and coloscopy (p < 0.001). PEGA was better tolerated (p < 0.028), regardless of the preparation regimen. CONCLUSION: PEG and PEGA are similarly efficient in the bowel preparation before coloscopy provided they are used in a similar regimen. The best results are reached when the preparation is divided into 2 days. PEGA is better tolerated than PEG, regardless of the used regimen. The quality of bowel cleansing is affected by the length of preparation (optimally up to 12 hours) and the time elapsed from the preparation until examination (up to 8 hours).

Synchronous gastric and sebaceous cancers, a rare manifestation of MLH1-related Muir-Torre syndrome.

Muir-Torre syndrome (MTS), a rare variant of the hereditary non polyposis colorectal cancer syndrome, is an autosomal dominant genodermatosis characterised by coincidence of sebaceous gland neoplasms (sebaceous adenoma, epithelioma, or carcinoma) and at least one internal malignancy. The underlying cause of MTS is a germline mutation in DNA mismatch repair genes MSH2, MLH1 and MSH6. We report the case of a 52-year-old caucasian woman with the development of metachronous colon cancer at the age of 38 years, uterine cancer at the age of 43 years, and unique occurrence of synchronous gastric and sebaceous carcinomas related to germline point mutation c. 2194A>T in the last exon of MLH1 gene, resulting in truncated protein in C-terminal region p. Lys732X due to premature stop codon. This mutation, not previously reported in MTS, disrupts the function of MutL complexes presumably by preventing the interaction with PMS1/PMS2 and impairing the endonuclease active site. This case points out the importance of sebaceous neoplasia, especially sebaceous adenocarcinoma, as cutaneous markers of MTS for timely implementation of cancer screening programs.

[Zdenek Maratka and his share in the founding of the Czech Gastroenterological Society and its journal. Gastroenterological Society in Czech and Slovac republics]. / Zdenek Maratka a jeho podíl na zalození Ceské gastroenterologické spolecnosti a jejího casopisu. Gastroenterologická spolecnost v Cechách a na Slovensku.

Zdenek Maratka (1914-2010) was a leading person in a Czech and Slovak gastroenterology in spite of the infavourable approach of the official communist policy to him.. He was one of the founders of gastroenterology in Czechoslovakia. He had been habilitated in 1948 for thesis Ulcerative colitis. Maratka stood at the first steps of foundation of Czech Gastroenterology Society very soon after the WW2 and followed with the preparation as a secretary ge-neral of the 8th ASNEMGE Congress in Prague 1968 and as a president the 1st Congress of Endoscopy in the very optimistic atmosphere of ,,Prague Spring". He was nominated or elected by several international gastroenterology organisations, during 1976-1980 had been President of ESGE. He started with editoring of Czech gastroenterology Association journal as a member of editorial board and had been its main editor between 1969-1999. His well appreciated novelty in the magazine was a short remarks in one or two sentences from the world scientific literature which appeared in every copy. As an editor emeritus he supported the quality of the journal by many advices and contributions including articles.

Expression of 11ß-hydroxysteroid dehydrogenase type 2 is deregulated in colon carcinoma.

Although the effects of glucocorticoids on proliferation, differentiation and apoptosis are well known, and steroid hormones have been identified to play a role in pathogenesis and the development of various cancers, limited data are available regarding the relationship between the local metabolism of glucocorticoids and colorectal adenocarcinoma (CRC) formation. Glucocorticoid metabolism is determined by 11ß-hydroxysteroid dehydrogenases type 1 and 2 (11HSD1, 11HSD2), which increase the local concentration of cortisol due to the reduction of cortisone, or decrease this concentration due to the oxidation of cortisol. The objective of this study was to evaluate the extent of 11HSD1 and 11HSD2 mRNA in pre-malignant colorectal polyps and in CRC. The specimens were retrieved from patients by endoscopic or surgical resection and the expression of 11HSD1 and 11HSD2 was measured by real-time PCR. The polyps were of the following histological types: hyperplastic polyps and adenomas with low- or high-grade dysplasia. The neoplastic tissue of CRC obtained during tumor surgery was also studied. It was found that 11HSD2 was not only downregulated in CRC but already in the early stages of neoplastic transformation (adenoma with low-grade dysplasia). In contrast, the level of 11HSD1 was significantly increased in CRC but not in pre-malignant polyps. The results demonstrate that the downregulation of 11HSD2 gene expression is a typical feature of the development of colorectal polypous lesions and their transformation into CRC.

Local metabolism of glucocorticoids and its role in rat adjuvant arthritis.

11beta-Hydroxysteroid dehydrogenase 1 (11HSD1) regulates local glucocorticoid activity and plays an important role in various diseases. Here, we studied whether arthritis modulates 11HSD1, what is the role of pro-inflammatory cytokines in this process and whether altered local metabolism of glucocorticoids may contribute to the feedback regulation of inflammation. Adjuvant arthritis increased synovial 11HSD1 mRNA and 11-reductase activity but treatments with tumor necrosis factor alpha (TNF-alpha) and interleukin 1beta (IL-1beta) antagonists etanercept and anakinra reduced 11HSD1 upregulation. Treatment with carbenoxolone, an 11HSD inhibitor, increased expression of TNF-alpha, cyclooxygenase 2, and osteopontin mRNA without any changes in the plasma levels of corticosterone. Similar changes were observed when arthritic rats were treated with RU486, an antagonist of GR. This study suggests that arthritis upregulates synovial 11HSD1, this upregulation is controlled by TNF-alpha and IL-1beta and that the increased supply of local corticosterone might contribute to feedback regulation of inflammation.

Expression profiles of proliferative and antiapoptotic genes in sporadic and colitis-related mouse colon cancer models.

Elevated levels of survivin, telomerase catalytic subunit (TERT), integrin-linked kinase (ILK), cyclooxygenase 2 (COX-2), inducible nitric oxide synthase (iNOS) and the regulatory factors c-MYB and Tcf-4 are often found in human cancers including colorectal cancer (CRC) and have been implicated in the development and progression of tumorigenesis. The aim of this study was to determine the expression of these genes in mouse models of sporadic and colitis-associated CRC. To address these issues, we used qRT-PCR approach to determine changes in gene expression patterns of neoplastic cells (high-grade dysplasia/intramucosal carcinoma) and surrounding normal epithelial cells in A/J and ICR mouse strains using laser microdissection. Both strains were injected with azoxymethane and ICR mice were also given drinking water that contained 2% dextran sodium sulphate. In both sporadic (A/J mice) and colitis-associated (ICR mice) models of CRC, the levels of TERT mRNA, COX-2 mRNA and Tcf-4 mRNA were higher in neoplastic cells than in surrounding normal epithelial cells. In contrast, survivin mRNA was upregulated only in neoplastic cells from A/J mice and ILK mRNA was upregulated only in neoplastic cells from ICR mice. However, the expression of iNOS mRNA was similar in normal and neoplastic cells in both models and c-MYB mRNA was actually downregulated in neoplastic cells compared with normal cells in both models. These findings suggest that the genetic background and/or the molecular mechanisms of tumorigenesis associated with genotoxic insults and colonic inflammation influence the gene expression of mTERT, COX-2, Tcf-4, c-MYB, ILK and survivin in colon epithelial neoplasia.

Enhanced expression of proproliferative and antiapoptotic genes in ulcerative colitis-associated neoplasia.

BACKGROUND: Inflammatory bowel diseases including long-standing ulcerative colitis (UC) have an increased risk of evolving into colorectal cancer (CRC). The overexpression of some proproliferative and antiapoptotic genes, such as survivin, telomerase catalytic subunit (hTERT), integrin-linked kinase (ILK), and regulatory factors c-MYB and Tcf-4, has been implicated in the development and progression of several human malignancies including CRC. METHODS: In this study we analyzed the expression alterations of these markers and proinflammatory enzymes cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS) during the transition of colonic mucosa from chronic inflammation to epithelial neoplasia in biopsies of UC patients using quantitative real-time polymerase chain reaction and immunohistochemistry; additionally, we compared the expression profiles of this gene panel in samples of patients with CRC after tumor resection and in human tumor xenografts of SW620 malignant colonic cells. RESULTS: The transcript levels of survivin, c-MYB, COX-2, iNOS, and Tcf-4 showed a statistically significant increase during neoplastic transformation of UC patient colonic mucosa, whereas hTERT and ILK were not elevated. In contrast, the specimens of CRC showed upregulated expression of not only survivin, c-MYB, Tcf-4, COX-2, and iNOS but also hTERT. A similar expression profile was observed in human tumor xenografts in which all transcripts with the exception of c-MYB were upregulated. CONCLUSIONS: These results suggest that telomerase and ILK activation occurs during the later stages of carcinoma progression, whereas upregulation of survivin, c-MYB, and Tcf-4 is a feature of the early stage of development of neoplasia, and thus, they might serve as early indicators for UC-associated colorectal carcinogenesis.

11beta-hydroxysteroid dehydrogenase 1 and 2 expression in colon from patients with ulcerative colitis.

BACKGROUND AND AIM: 11beta-hydroxysteroid dehydrogenase (11betaHSD) is an enzyme responsible for the interconversion of active 11beta-hydroxysteroids (cortisol) into biologically inactive 11-oxosteroids (cortisone). The isoform 11betaHSD1 operates predominantly as a reductase converting cortisone to cortisol, whereas 11betaHSD2 catalyzes oxidation of cortisol to cortisone. This mechanism of peripheral metabolism of glucocorticoids has been suggested to be involved in increasing the availability of anti- inflammatory glucocorticoids as a response to inflammatory stimuli. The aim of this study therefore was to investigate the impact of inflammatory bowel disease on the expression of colonic 11betaHSD1 and 11betaHSD2. METHODS: Quantitative real-time RT-PCR was used to assess messenger RNA for 11betaHSD1 and 11betaHSD2 in bioptic samples taken from patients with ulcerative colitis and in healthy controls, and in colon of rats with colitis induced by dextran sulfate sodium (DSS). Rat colonic fragments were used for assessment of local metabolism of glucocorticoids. RESULTS: In both human and rat specimens colitis up-regulated the expression of colonic 11betaHSD1 mRNA and down-regulated 11betaHSD2 mRNA. A similar pattern was observed at the level of local metabolism of corticosterone. Oxidation of corticosterone to 11-dehydrocorticosterone was decreased and reduction of 11-dehydrocorticosterone to corticosterone was increased in colonic tissue of rats with DSS-colitis. CONCLUSIONS: Colonic inflammation induces local glucocorticoid activation via 11betaHSD1 and impairs glucocorticoid inactivation via 11betaHSD2. The observed changes indicate a role for local metabolism of glucocorticoids in the control of colonic inflammation.

Expression of 11beta-hydroxysteroid dehydrogenase types 1 and 2 in colorectal cancer.

Glucocorticoid hormones have been reported to operate as regulators of cell proliferation and differentiation and to inhibit growth of several colon tumors and adenocarcinoma cell lines. The glucocorticoid action is regulated, in part, at the pre-receptor level through the expression of isoforms of 11beta-hydroxysteroid dehydrogenase (11betaHSD1, 11betaHSD2) which are responsible for the interconversion of hormonally active cortisol to cortisone. Since both of these isoforms are expressed in the mammalian colon, we examined whether 11betaHSD1 and 11betaHSD2 are expressed in human colorectal cancer and whether their expression differs between neoplastic and autologous non-neoplastic tissue. We provide evidence that both isoforms of 11betaHSD are expressed in the colon adenocarcinoma, but their expression is not identical in neoplastic and non-neoplastic tissue. There is a significant decrease of 11betaHSD2 mRNA abundance and enzyme activity in neoplastic tissue. In contrast, 11betaHSD1 activity and mRNA abundance are increased in some but not all tumor samples. The results demonstrate that (1) neoplastic transformation is associated with decreasing steady-state levels of 11betaHSD2 mRNA and enzyme activity and in some cases also with increasing expression of 11betaHSD1, and (2) colorectal tumor cells have a decreased capability of autocrine inactivation of glucocorticoids.