Elevated insulin-like growth factor 1 receptor, hepatocyte growth factor receptor and telomerase protein expression in mild ulcerative colitis

Coptisine inhibits esophageal carcinoma growth by modulating pyroptosis via inhibition of HGF/c-Met signaling

Esophageal carcinoma is a highly prevalent malignancy worldwide. The present study aimed to investigate the mechanism by which the natural compound coptisine affects pyroptosis in esophageal squamous cell carcinoma (ESCC). The expression of c-Met in ESCC patients was assessed by immunohistochemical analysis of tissue microarrays. Natural drugs that bind to c-Met were identified by screening and molecular docking. The effect of coptisine on the proliferation of ESCC cells was detected by CCK-8 and colony formation assays. Cell cycle progression and cell apoptosis were detected by flow cytometry. The levels of mRNAs related to pyroptosis and miR-21 after coptisine treatment were assessed via real-time quantitative PCR. The effect of pyroptosis was evaluated by reactive oxygen species level detection and transmission electron microscopy (TEM) analysis. The expression of proteins related to pyroptosis and the HGF/c-Met pathway was detected by western blotting. A xenograft tumor model was established, and the inhibitory effect of coptisine was evaluated by observing tumor growth. The results showed that the highly expressed protein c-Met in esophageal cancer could bind with coptisine. Coptisine inhibited c-Met phosphorylation and proliferation in ESCC cells. Furthermore, coptisine inhibited the expression of downstream proteins of the HGF/c-Met signaling pathway and induced ROS generation. Tumor xenograft experiments demonstrated that coptisine effectively inhibited tumor growth by reducing the levels of pyroptosis-associated proteins. In conclusion, these findings indicate that inhibition of the HGF/c-Met signaling pathway suppresses pyroptosis to enhance the antitumor effect of coptisine in ESCC and support the potential use of coptisine for EC treatment.

Mechanisms of Insulin Signaling as a Potential Therapeutic Method in Intestinal Diseases

Gastrointestinal diseases are becoming a growing public health problem. One of them is inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD). The incidence of IBD is increasing in developing countries and declining in developed countries, affecting people of all ages. Researchers have been exploring new treatment options including insulin signaling pathways in the inflammation of the gastrointestinal tract. It seems that a better understanding of the mechanism of IGF-1, GLP-1 and TL1A on the gut microbiota and inflammation may provide new advances in future therapeutic strategies for patients with IBD, but also other intestinal diseases. This review aims to synthesize insights into the effects of GLP, IGF and anti-TL1A on inflammation and the gut microbiota, which may enable their future use in therapy for people with intestinal diseases.

The Influence of TEP1 and TERC Genetic Variants on the Susceptibility to Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease of the central nervous system. According to recent studies, cellular senescence caused by telomere shortening may contribute to the development of MS.

AIM OF THE STUDY

Our aim was to determine the associations of TEP1 rs1760904, rs1713418, TERC rs12696304, rs35073794 gene polymorphisms with the occurrence of MS.

METHODS

The study included 200 patients with MS and 230 healthy controls. Genotyping of TEP1 rs1760904, rs1713418 and TERC rs12696304, rs35073794 was performed using RT-PCR. The obtained data were analysed using the program "IBM SPSS Statistics 29.0". Haplotype analysis was performed using the online program "SNPStats".

RESULTS

The TERC rs12696304 G allele of this SNP is associated with 1.4-fold lower odds of developing MS (p = 0.035). TERC rs35073794 is associated with approximately 2.4-fold reduced odds of MS occurrence in the codominant, dominant, overdominant, and additive models (p < 0.001; p < 0.001; p < 0.001; p < 0.001, respectively). Haplotype analysis shows that the rs1760904-G-rs1713418-A haplotype is statistically significantly associated with 1.75-fold increased odds of developing MS (p = 0.006). The rs12696304-C-rs35073794-A haplotype is statistically significantly associated with twofold decreased odds of developing MS (p = 0.008). In addition, the rs12696304-G-rs35073794-A haplotype was found to be statistically significantly associated with 5.3-fold decreased odds of developing MS (p < 0.001).

CONCLUSION

The current evidence may suggest a protective role of TERC SNP in the occurrence of MS, while TEP1 has the opposite effect.

MicroRNA‑200a suppresses migration and invasion and enhances the radiosensitivity of NSCLC cells by inhibiting the HGF/c‑Met signaling pathway

Hepatocyte growth factor (HGF), an activator of the c‑Met signaling pathway, is involved in tumor invasiveness, metastasis and radiotherapy resistance. In the present study, a novel HGF regulatory pathway in lung cancer involving micro-RNAs (miRNAs/miR) is described. Immunohistochemical staining and western blot analyses demonstrated that HGF was upregulated and associated with miR‑200a downregulation in non‑small cell lung cancer (NSCLC) samples compared with normal lung tissues. The association between HGF and miR‑200a was associated with the degree of tumor malignancy and cell migration and invasion. miR‑200a negatively regulated HGF expression by targeting the 3'‑untranslated region of the HGF mRNA. miR‑200a overexpression induced HGF downregulation, decreased NSCLC cell migration and invasion, promoted apoptosis, and decreased cell survival in A549 and H1299 cells in response to ionizing radiation. The present results revealed a previously uncharacterized role of miRNA‑200a in regulating tumor malignancy and radiosensitivity by suppressing HGF expression, a key factor in the HGF/c‑Met pathway.

Relation of the IGF/IGF1R system to autophagy in colitis and colorectal cancer

Metabolic syndrome (MetS), as a chronic inflammatory disorder has a potential role in the development of inflammatory and cancerous complications of the colonic tissue. The interaction of DNA damage and inflammation is affected by the insulin-like growth factor 1 receptor (IGF1R) signaling pathway. The IGF1R pathway has been reported to regulate autophagy, as well, but sometimes through a bidirectional context. Targeting the IGF1R-autophagy crosstalk could represent a promising strategy for the development of new antiinflammatory and anticancer therapies, and may help for subjects suffering from MetS who are at increased risk of colorectal cancer. However, therapeutic responses to targeted therapies are often shortlived, since a signaling crosstalk of IGF1R with other receptor tyrosine kinases or autophagy exists, leading to acquired cellular resistance to therapy. From a pharmacological point of view, it is attractive to speculate that synergistic benefits could be achieved by inhibition of one of the key effectors of the IGF1R pathway, in parallel with the pharmacological stimulation of the autophagy machinery, but cautiousness is also required, because pharmacologic IGF1R modulation can initiate additional, sometimes unfavorable biologic effects.

Is insulin-like growth factor 1 (IGF-1) system an attractive target inflammatory bowel diseases? Benefits and limitation of potential therapy

Inflammatory bowel diseases (IBD) are chronic gastrointestinal disorders with unknown etiology, whose incidence dramatically increased over the past 50 years. Currently available strategies for IBD treatment, such as biological therapies, corticosteroids, and immunosuppressive agents are effective, but their side effects and economic costs cannot be ignored. Better understanding of IBD etiology and new therapeutics are thus needed. The aim of this paper is to briefly discuss IGF-1 dependent functions, with particular focus on IGF-1 use in IBD therapy. Data collection was based on records found in medical literature. Data analysis included records published between 1984 and 2014. The IGF-1 system is involved in major physiological functions, such as cell proliferation and metabolism, and growth promotion. Most importantly IGF-1 has anti-inflammatory properties and its use in IBD treatment can be recommended. However, potential IGF-1 therapy has some limitations, which include aggravation of fibrosis in Crohn's patients and facilitated transformation to malignancy. Taken into consideration their possible side effects, IGF-1 analogs and recombinants are nonetheless a promising target for IBD therapy for a specific group of patients. Further studies, at the clinical level are thus recommended.

Sparse Modeling Reveals miRNA Signatures for Diagnostics of Inflammatory Bowel Disease

The diagnosis of inflammatory bowel disease (IBD) still remains a clinical challenge and the most accurate diagnostic procedure is a combination of clinical tests including invasive endoscopy. In this study we evaluated whether systematic miRNA expression profiling, in conjunction with machine learning techniques, is suitable as a non-invasive test for the major IBD phenotypes (Crohn's disease (CD) and ulcerative colitis (UC)). Based on microarray technology, expression levels of 863 miRNAs were determined for whole blood samples from 40 CD and 36 UC patients and compared to data from 38 healthy controls (HC). To further discriminate between disease-specific and general inflammation we included miRNA expression data from other inflammatory diseases (inflammation controls (IC): 24 chronic obstructive pulmonary disease (COPD), 23 multiple sclerosis, 38 pancreatitis and 45 sarcoidosis cases) as well as 70 healthy controls from previous studies. Classification problems considering 2, 3 or 4 groups were solved using different types of penalized support vector machines (SVMs). The resulting models were assessed regarding sparsity and performance and a subset was selected for further investigation. Measured by the area under the ROC curve (AUC) the corresponding median holdout-validated accuracy was estimated as ranging from 0.75 to 1.00 (including IC) and 0.89 to 0.98 (excluding IC), respectively. In combination, the corresponding models provide tools for the distinction of CD and UC as well as CD, UC and HC with expected classification error rates of 3.1 and 3.3%, respectively. These results were obtained by incorporating not more than 16 distinct miRNAs. Validated target genes of these miRNAs have been previously described as being related to IBD. For others we observed significant enrichment for IBD susceptibility loci identified in earlier GWAS. These results suggest that the proposed miRNA signature is of relevance for the etiology of IBD. Its diagnostic value, however, should be further evaluated in large, independent, clinically well characterized cohorts.

Resveratrol inhibits collagen I synthesis by suppressing IGF-1R activation in intestinal fibroblasts

AIM: To investigate whether resveratrol (3,4,5-trihydroxy-trans-stilbene) inhibits collagen I synthesis induced by insulin growth factor-1 (IGF-1) in intestinal fibroblasts, and to explore the possible molecular mechanisms.

METHODS: Male Sprague-Dawley rats were randomly divided into two groups: a control group and a 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis group. After 21 d of TNBS administration, the degree of inflammation and fibrosis in colon was measured by HE staining and Masson’s trichrome staining. Western blotting was used to examine collagen I, IGF-1 and silent information regulator 1 (SIRT1) protein expression in colitis tissues. Western blotting and quantitative real-time polymerase chain reaction were used to characterize collagen I protein and col1a2 mRNA expression in mouse intestinal fibroblasts and CCD-¹⁸Co cells treated with IGF-1. A MEK inhibitor (U0126) was used to determine whether IGF-1-induced collagen I expression was mediated by extracellular signal-regulated kinase 1/2 (ERK1/2)-dependent mechanism. Effects of resveratrol on collagen I protein level, insulin growth factor-1 receptor (IGF-1R) and ERK1/2 phosphorylation levels were also examined after IGF-1 treatment in fibroblasts. To evaluate whether SIRT1 was necessary for the anti-fibrosis effect of resveratrol, cells were transfected with SIRT1-specific small interfering RNAs, wild-type SIRT1, and deacetylase-inactive mutant SIRT1.

RESULTS: Collagen I and IGF-1 expression was increased, and SIRT1 expression was decreased (0.67 ± 0.04 vs 1.05 ± 0.07, P < 0.001) in TNBS-induced colitis compared with the control group. In vitro, IGF-1 could induce collagen I expression, mainly through the ERK 1/2 signal pathway. Resveratrol reduced basal and IGF-1-induced collagen I gene and protein expression in intestinal fibroblasts. Overexpression of wild-type SIRT1, not deacetylase-inactive mutant SIRT1, decreased expression of collagen I induced by IGF-1. Moreover, silencing SIRT1 restored collagen I expression in fibroblasts challenged with resveratrol. However, disruption of SIRT1 did not influence the anti-fibrotic effects of resveratrol and IGF-1-induced collagen I expression. Further analysis revealed that resveratrol significantly decreased phosphorylation of IGF-1R and its downstream signaling molecules by inhibiting IGF-1 binding to its receptor.

CONCLUSION: Our data suggest that resveratrol effectively inhibits collagen I synthesis in IGF-1-stimulated fibroblasts, partly by inhibiting IGF-1R activation, and SIRT1 is also responsible for the process.

Reduced hTERT protein levels are associated with DNA aneuploidy in the colonic mucosa of patients suffering from longstanding ulcerative colitis

Longstanding ulcerative colitis (UC) is a disease of chronic inflammation of the colon. It is associated with the development of colorectal cancer through a multistep process including increasing degrees of dysplasia and DNA-ploidy changes. However, not all UC patients will develop these characteristics even during lifelong disease, and patients may therefore be divided into progressors who develop dysplasia or cancer, and non-progressors who do not exhibit such changes. In the present study, the amount of hTERT, the catalytic subunit of the enzyme telomerase, was estimated by using peroxidase immunohistochemistry (IHC) in a set of progressor and non-progressor UC colectomies. The protein levels in the colonic mucosa of the progressors and non-progressors were compared, and further comparisons between different categories of dysplastic development and to DNA-ploidy status within the progressors were made. Levels of hTERT were elevated in the colonic mucosa of the progressors and non-progressors when compared to non-UC control samples, but no difference was observed between the hTERT levels in the mucosa of progressors and non-progressors. The levels of hTERT associated with levels of Ki67 to a significant degree within the non-progressors. hTERT expression in lesions with DNA-aneuploidy were decreased as compared to diploid lesions, when stratified for different classes of colonic morphology. Our results indicate an association between hTERT protein expression and aneuploidy in UC-progressor colons, and also a possible protective mechanism in the association between hTERT and Ki67, against development of malignant features within the mucosa of a UC-colon.

Telomere shortening correlates to dysplasia but not to DNA aneuploidy in longstanding ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a chronic, inflammatory bowel disease which may lead to dysplasia and adenocarcinoma in patients when long-lasting. Short telomeres have been reported in mucosal cells of UC patients. Telomeres are repetitive base sequences capping the ends of linear chromosomes, and protect them from erosion and subsequent wrongful recombination and end-to-end joining during cell division. Short telomeres are associated with the development of chromosomal instability and aneuploidy, the latter being risk factors for development of dysplasia and cancer. Specifically, the abrupt shortening of one or more telomeres to a critical length, rather than bulk shortening of telomeres, seems to be associated with chromosomal instability.

METHODS

We investigated possible associations between dysplasia, aneuploidy and telomere status in a total of eight lesions from each of ten progressors and four nonprogressors suffering from longstanding UC. We have analyzed mean telomere length by qPCR, as well as the amount of ultra-short telomeres by the Universal STELA method.

RESULTS

An increased amount of ultra-short telomeres, as well as general shortening of mean telomere length are significantly associated with dysplasia in longstanding UC. Furthermore, levels of ultra-short telomeres are also significantly increased in progressors (colons harbouring cancer/dysplasia and/or aneuploidy) compared to nonprogressors (without cancer/dysplasia/aneuploidy), whereas general shortening of telomeres did not show such associations.

CONCLUSIONS

Our data suggest that ultra-short telomeres may be more tightly linked to colorectal carcinogenesis through development of dysplasia in UC than general telomere shortening. Telomere status was not seen to associate with DNA aneuploidy.

Epithelial-to-mesenchymal and mesenchymal-to-epithelial transitions in the colon

Epithelial-to-mesenchymal and mesenchymal-to-epithelial transitions are well established biological events which have an important role in not just normal tissue and organ development, but in the pathogenesis of diseases. Increasing evidence has established their presence in the human colon during colorectal carcinogenesis and cancer invasion, chronic inflammation-related fibrosis and in the course of mucosal healing. A large body of evidence supports the role for transforming growth factor-β and its downstream Smad signaling, the phosphatidylinositol 3'-kinase/Akt/mTOR axis, the Ras-mitogen-activated protein kinase/Snail/Slug and FOXC2 pathway, and Hedgehog signaling and microRNAs in the development of colorectal cancers via epithelial-to-mesenchymal transition. C-met and Frizzled-7, among others, seem to be the principle effectors of mesenchymal-to-epithelial transition, hence have a role not just in mucosal regeneration but in the progression of colonic wall fibrosis. Here we discuss a role for these pathways in the initiation and development of the transition events. A better understanding of their induction and regulation may lead to the identification of pathways and factors that could be potent therapeutic targets. The inhibition of epithelial-to-mesenchymal transition using mTOR kinase inhibitors targeting the ATP binding pocket and which inhibit both mTORC1 and mTORC2, RNA aptamers or peptide mimetics, such as a Wnt5A-mimetic, may all be useful in both cancer treatment and delaying fibrosis, while the induction of mesenchymal-to-epithelial transition in induced pluripotent stem cells may enhance epithelial healing in the case of severe mucosal damage. The preliminary results of the current studies are promising, but more clinical investigations are needed to develop new and safe therapeutic strategies for diseases of the colon.

Physiological and pathological role of local and immigrating colonic stem cells

The latest avenue of research is revealing the existence of and role for the colonic stem cells in the physiological renewal of the mucosa and in pathological circumstances where they have both positive and negative effects. In the case of human colon, different levels of stem cell compartments exist. First, the crypt epithelial stem cells, which have a role in the normal crypt epithelial cell dynamics and in colorectal carcinogenesis. Close to the crypts, the second layer of stem cells can be found; the local subepithelial stem cell niche, including the pericryptic subepithelial myofibroblasts that regulate the epithelial cell differentiation and have a crucial role in cancer progression and chronic inflammation-related fibrosis. The third level of stem cell compartment is the immigrating bone-marrow-derived stem cells, which have an important role in wound healing after severe mucosal inflammation, but are also involved in cancer invasion. This paper focuses on stem cell biology in the context of physiological and pathological processes in the human colon.

UDCA slows down intestinal cell proliferation by inducing high and sustained ERK phosphorylation

Ursodeoxycholic acid (UDCA) attenuates colon carcinogenesis in humans and in animal models by an unknown mechanism. We investigated UDCA effects on normal intestinal epithelium in vivo and in vitro to identify the potential chemopreventive mechanism. Feeding of mice with 0.4% UDCA reduced cell proliferation to 50% and suppressed several potential proproliferatory genes including insulin receptor substrate 1 (Irs-1). A similar transcriptional response was observed in the rat intestinal cell line IEC-6 which was then used as an in vitro model. UDCA slowed down the proliferation of IEC-6 cells and induced sustained hyperphosphorylation of ERK1/ERK2 kinases which completely inhibited the proproliferatory effects of EGF and IGF-1. The hyperphosphorylation of ERK1 led to a transcriptional suppression of the Irs-1 gene. Both, the hyperphosphorylation of ERK as well as the suppression of Irs-1 were sufficient to inhibit proliferation of IEC-6 cells. ERK1/ERK2 inhibition in vitro or ERK1 elimination in vitro or in vivo abrogated the antiproliferatory effects of UDCA. We show that UDCA inhibits proliferation of nontransformed intestinal epithelial cells by inducing a sustained hyperphosphorylation of ERK1 kinase which slows down the cell cycle and reduces expression of Irs-1 protein. These data extend our understanding of the physiological and potentially chemopreventive effects of UDCA and identify new targets for chemoprevention.

Effect of ageing on colonic mucosal regeneration

The physiologic and pathologic cellular and molecular changes occurring with age in the human colon affect both the inflammatory process leading to mucosal injury and the regenerative capacity of the epithelium. On the one hand, age-related telomere shortening and inflamm-ageing may lead to the development of colonic inflammation, which results in epithelial damage. On the other hand, the altered migration and function of regenerative stem cells, the age-related methylation of mucosal healing-associated genes, together with the alterations of growth factor signaling with age, may be involved in delayed mucosal regeneration. The connections of these alterations to the process of ageing are not fully known. The understanding and custom-tailored modification of these mechanisms are of great clinical importance with regard to disease prevention and modern therapeutic strategies. Here, we aim to summarize the age-related microscopic and molecular changes of the human colon, as well as their role in altered mucosal healing.

Isolated lymphoid follicles in colon: switch points between inflammation and colorectal cancer?

Gut-associated lymphoid tissue is supposed to play a central role in both the organization of colonic repair mechanisms and colorectal carcinogenesis. In inflammatory conditions, the number, diameter and density of isolated lymphoid follicles (ILFs) increases. They are not only involved in immune surveillance, but their presence is also indispensable in normal mucosal regeneration of the colon. In carcinogenesis, ILFs may play a dual role. On the one hand they may support tumor growth and the metastatic process by vascular endothelial growth factor receptor signaling and producing a specific cytokine and cellular milieu, but on the other hand their presence is sometimes associated with a better prognosis. The relation of ILFs to bone marrow derived stem cells, follicular dendritic cells, subepithelial myofibroblasts or crypt formation, which are all involved in mucosal repair and carcinogenesis, has not been directly studied. Data about the putative organizer role of ILFs is scattered in scientific literature.

Oxazolone-induced over-expression of focal adhesion kinase in colonic epithelial cells of colitis mouse model

We examined the change of protein tyrosine kinases (PTKs) expression levels in colonic epithelial cells isolated from mice in which colitis was induced by oxazolone administration, using the monoclonal antibody YK34, which cross-reacts with a wide variety of PTKs. We identified focal adhesion kinase (FAK) and found the expression level increased due to the induction of colitis. Furthermore, we found that there was a positive correlation between FAK expression and the severity of colitis. Also, FAK expression localized in the colonic epithelium but not in the lamina propria, implying FAK functions in epithelial cells during colitis formation and/or wound repairing.

Regeneration associated growth factor receptor and epithelial marker expression in lymphoid aggregates of ulcerative colitis

OBJECTIVE

Mesenchymal-epithelial transition may have crucial role in mucosal regeneration, hence we assayed epithelial growth factor receptor (EGFR), insulin-like growth factor receptor-1 (IGF1R), hepatocyte-derived growth factor receptor (HGFR), CDX2 and cytokeratin (CK) expression in lymphoid aggregates (LA) of ulcerative colitis (UC).

MATERIAL AND METHODS

Tissue microarrays (TMAs) made of biopsy samples from 20 mildly, 20 moderately and 20 severely active UC, 12 non-specific colitis (NSC) and 20 healthy colon were prepared, and immunolabelled with anti-EGFR, -IGF1R, -HGFR, -CDX2, -CK antibodies. After virtual microscopic evaluation, one-way ANOVA and correlation analysis were performed. For validation, TaqMan real-time RT-PCR was performed by using RNA from laser microdissected LA from 10 healthy colon and 10 endoscopically active UC biopsies.

RESULTS

The number of LA was in tight positive correlation with the severity of inflammation (r=0.9). The number of EGFR/HGFR positive subepithelial cells was found to be significantly elevated in severe (21.6+/-2.1%/21.3+/-1.9%), moderate (14.3+/-1.7%/14.6+/-1.6%) and mild (7.2+/-1.6%/7.4+/-1.3%) inflammation compared to healthy colon mucosa (2.6+/-1.4%/2.4+/-1.03%) (p < 0.005). Some alterations were found between UC and NSC samples regarding EGFR and HGFR expression. IGF1R immunoreactive cells were only found in a trace number in all cases. Increasing trend of CDX2 and CK positive subepithelial cells was found in active UC, but it was not in significant correlation with the severity of inflammation.

CONCLUSION

EGFR and HGFR positive subepithelial cells in LA may be involved in the induction of the regenerative mucosal processes. The presence of CDX2/CK positive subepithelial cells suggests that mesenchymal-to-epithelial transition may be located to lymphoid aggregates.

The possible role of isolated lymphoid follicles in colonic mucosal repair

The continuous reformation and rapid repair of the colonic mucosa is essential for avoiding the aggregation of pernicious mutations induced by bacterial, toxic, or mitogenic factors. Gut-associated lymphoid tissue is supposed to play a central role in the organization of the repair mechanisms. In inflammatory conditions, the number, the diameter and the density of isolated lymphoid follicles (ILFs) are increasing. They are involved not just in immune surveillance, but their presence is also indispensable in normal mucosal regeneration of the colon. The relation of ILFs to the components of mucosal renewal such as bone marrow derived stem cells, follicular dendritic cells, subepithelial myofibroblasts or crypt formation has not been directly studied, and data about their putative organizer role are scattered in scientific literature. Whether they act as a regenerative pool containing stem cells in case of mucosal damage, or they are responsible only for the optimal cytokine milieu for the differentiation of immigrating stem cells is a question under debate. Our aim is to review the relation of ILFs to the different elements of colonic mucosal repair.

Carcinogenesis in IBD: potential targets for the prevention of colorectal cancer

In patients with IBD, chronic colonic inflammation increases the risk of colorectal cancer, perhaps because inflammation predisposes these tissues to genomic instability. Carcinogenesis in the inflamed colon seems to follow a different sequence of genetic alterations than that observed in sporadic cancers in the uninflamed colon. In this Review, we focus on the genetic alterations in colitis-associated colorectal cancer that contribute to the acquisition of the essential hallmarks of cancer, and on how those alterations differ from sporadic colorectal cancers. Our intent is to provide a conceptual basis for categorizing carcinogenetic molecular abnormalities in IBD, and for understanding how cancer-preventive therapies might target reversal of acquired abnormalities in specific biochemical pathways.

[mRNA expression analysis and classification of colonic biopsy samples using oligonucleotide and cDNA microarray techniques]

Despite tremendous progress in the past few decades, certain important aspects regarding the diagnosis, therapy, and follow-up of colorectal cancer still remain unsolved. In our work we searched for biomarkers of the development of colorectal carcinoma, and performed gene expression analysis for colorectal disease classification. We have established that the oligonucleotide microarray analyses of biopsy samples wholly fulfil the Affymetrix quality requirements, are highly standard and reproducible and the Taqman microfluidic card system is suitable for high-throughput, quick and cost efficient real-time-PCR validation of gene expression changes. We have shown that the sequential overexpression of osteopontin and osteonectin mRNAs and proteins significantly correlates with the progression of the colorectal adenoma-dysplasia-carcinoma sequence. We have identified and validated ten novel markers with continuously increasing mRNA expression in line with the adenoma-dysplasia-carcinoma transition. We have identified the top 27, 13 and 10 genes associated with adenoma, colorectal cancer, and inflammatory bowel diseases.

Matrix metalloproteinase-9 expression in the normal mucosa-adenoma-dysplasia-adenocarcinoma sequence of the colon

It has been proposed that matrix metalloproteinases (MMPs) play a role in tumor invasion. We determined protein expression of matrix metalloproteinase-9 (MMP-9) in colorectal cancer (CRC), corresponding normal mucosa and colorectal adenomas. For confirmation of immunohistochemical results MMP-9 TaqMan RT-PCR analysis was performed. Expression of MMP-9 was determined on paraffin embedded biopsy sections by immunohistochemistry in 31 CRC patients (from cancer tissue and corresponding normal mucosa) and in 30 patients with adenoma (nine adenomas with high grade of dysplasia). MMP-9 immunostaining was determined semi-quantitatively. For Taqman RT-PCR analyses normal mucosa (n = 5), adenoma without (n = 6) and with high grade dysplasia (n = 7) and CRC (n = 10) were investigated. Statistical analysis with ANOVA, LSD test and correlation analysis were performed. P value of <0.05 was considered significant. The MMP-9 expression in CRC was significantly higher compared to adenomas or the normal mucosa (P = 0.001). Significantly higher expression of MMP-9 has been observed in adenomas with high grade dysplasia compared to other adenomas or normal colon (P < 0.001). Diffuse strong MMP-9 expression was present in tumor as well as in stromal cells. In adenoma samples, dysplastic epithelial cells showed moderate intensive cytoplasmic MMP-9 expression, with a clear-cut differentiation between dysplastic and non-dysplastic areas. Staining intensity correlated with the grade of CRC. We demonstrate a significantly higher expression of MMP-9 in adenoma with high grade dysplasia-CRC sequence as compared to normal tissue. The over-expression of MMP-9 strongly suggests its association with colorectal carcinogenesis.