Expression and localization of matrix-degrading metalloproteinases during colorectal tumorigenesis

Preclinical Evaluation of a Novel Small Molecule LCC-21 to Suppress Colorectal Cancer Malignancy by Inhibiting Angiogenic and Metastatic Signatures

Colorectal cancer (CRC) is one of the most common cancers, and it frequently metastasizes to the liver and lymph nodes. Despite major advances in treatment modalities, CRC remains a poorly characterized biological malignancy, with high reported cases of deaths globally. Moreover, cancer stem cells (CSCs) and their microenvironment have been widely shown to promote colon cancer development, progression, and metastasis. Therefore, an understanding of the underlying mechanisms that contribute to the maintenance of CSCs and their markers in CRC is crucial in efforts to treat cancer metastasis and develop specific therapeutic targets for augmenting current standard treatments. Herein, we applied computational simulations using bioinformatics to identify potential theranostic markers for CRC. We identified the overexpression of vascular endothelial growth factor-α (VEGFA)/β-catenin/matrix metalloproteinase (MMP)-7/Cluster of Differentiation 44 (CD44) in CRC to be associated with cancer progression, stemness, resistance to therapy, metastasis, and poor clinical outcomes. To further investigate, we explored in silico molecular docking, which revealed potential inhibitory activities of LCC-21 as a potential multitarget small molecule for VEGF-A/CTNNB1/MMP7/CD44 oncogenic signatures, with the highest binding affinities displayed. We validated these finding in vitro and demonstrated that LCC-21 inhibited colony and sphere formation, migration, and invasion, and these results were further confirmed by a Western blot analysis in HCT116 and DLD-1 cells. Thus, the inhibitory effects of LCC-21 on these angiogenic and onco-immunogenic signatures could be of translational relevance as potential CRC biomarkers for early diagnosis.

Matrix metalloproteinase 7 contributes to intestinal barrier dysfunction by degrading tight junction protein Claudin-7

Background

Previous studies implicated matrix metalloproteinases (MMPs), such as MMP-7, in inflammatory bowel diseases (IBD) by showing increased activity during inflammation of the gut. However, the pathophysiological roles of MMP-7 have not been clearly elucidated.

Methods

The expression of MMP-7 was assessed in colonic biopsies of patients with ulcerative colitis (UC), in rodents with experimental colitis, and in cell-based assays with cytokines. Wild-type and MMP-7-null mice treated with dextran sulfate sodium (DSS) or trinitrobenzene sulfonic acid were used for determining the pro-inflammatory function(s) of MMP-7 in vivo.

Results

MMP-7 was highly expressed in patients with UC and in rodents with experimental colitis. IL-1β, IL-4, IL-13, TNFα, or lipopolysaccharide enhanced MMP-7 expression in human colonic epithelial cells, rat colonic smooth muscle cells, and THP-1-derived macrophages. Active MMP-7 degraded tight junction protein Claudin-7 in epithelial cells, cleaved recombinant Claudin-7 in cell-free system, and increased Caco-2 monolayer permeability. Immunostaining of colon biopsies revealed up-regulation of MMP-7 and reduction of Claudin-7 in UC patients. Compared to wild-type mice, Mmp7-/- mice had significantly less inflammation in the colon upon DSS insult. DSS-induced alterations in junction proteins were mitigated in Mmp7-/- mice, suggesting that MMP-7 disrupts the intestinal barrier. MMP-7 antibody significantly ameliorated colonic inflammation and Claudin-7 reduction in 2 different rodent models of colitis.

Summary

MMP-7 impairs intestinal epithelial barrier by cleavage of Claudin-7, and thus aggravating inflammation. These studies uncovered Claudin-7 as a novel substrate of MMP-7 in the intestinal epithelium and reinforced MMP-7 as a potential therapeutic target for IBD.

Targeting matrix metalloproteinase MMP3 greatly enhances oncolytic virus mediated tumor therapy

In cancer, the extracellular matrix is extensively remodeled during chronic inflammation, thus affecting cell transcription, differentiation, migration and cell-cell interactions. Matrix metalloproteinases can degrade the extracellular matrix of tumor tissues and take important roles in disease progression. Numerous efforts to develop cancer treatments targeting matrix metalloproteinases have failed in clinical trials owing to the ineffectiveness and toxicity of the applied inhibitors. In this study, we investigated the potential of targeting matrix metalloproteinases and oncolytic virus combination in cancer therapy. We found that MMP3 expression was upregulated in various cancers and MMP3 expression in the tumor cells, but not in other tissues, was important for tumor growth and metastasis. Single treatment of colon cancer with multiple MMP3 inhibitors was not effective in mice. Nevertheless, the therapeutic effect of MMP3 was greatly improved by combination with an oncolytic virus. A potential mechanism of MMP3 in regulating tumor cell proliferation and invasion was mediated via Erk1/2 an NF-κB signaling. This study reveals that MMP3 is a promising target and the combined treatment with oncolytic virus is a potential strategy for cancer therapy.

Dysplastic Aberrant Crypt Foci: Biomarkers of Early Colorectal Neoplasia and Response to Preventive Intervention

The discovery of aberrant crypt foci (ACF) more than three decades ago not only enhanced our understanding of how colorectal tumors form, but provided new opportunities to detect lesions prior to adenoma development and intervene in the colorectal carcinogenesis process even earlier. Because not all ACF progress to neoplasia, it is important to stratify these lesions based on the presence of dysplasia and establish early detection methods and interventions that specifically target dysplastic ACF (microadenomas). Significant progress has been made in characterizing the morphology and genetics of dysplastic ACF in both preclinical models and humans. Image-based methods have been established and new techniques that utilize bioactivatable probes and capture histologic abnormalities in vivo are emerging for lesion detection. Successful identification of agents that target dysplastic ACF holds great promise for intervening even earlier in the carcinogenesis process to maximize tumor inhibition. Future preclinical and clinical prevention studies should give significant attention to assessing the utility of dysplastic ACF as the earliest identifiable biomarker of colorectal neoplasia and response to therapy.See all articles in this Special Collection Honoring Paul F. Engstrom, MD, Champion of Cancer Prevention.

MMP7 as a potential biomarker of colon cancer and its prognostic value by bioinformatics analysis

ABSTRACT

Colon cancer is one of the most common cancers in the world. To identify the candidate genes in the carcinogenesis and progression of colon cancer, the microarray datasets GSE10950, GSE44861 and GSE74602 were downloaded from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) were identified, and functional enrichment analyses were performed. A total of 176 DEGs were identified, consisting of 55 genes upregulated and 121 genes downregulated in colon cancer tissues compared to non-cancerous tissues. The DEGs were mainly enriched in mineral absorption, nitrogen metabolism and complement and coagulation cascades. By using STRING database analysis, we constructed a coexpression network composed of 140 nodes and 280 edges for the DEGs with a combined score >0.4 and a significant interaction relation. Thirteen hub genes were identified, and poor OS of patients was only associated with high expression of Matrix Metallopeptidase 7 (MMP7), which may be involved in the carcinogenesis, invasion or recurrence of colon cancer. In conclusion, we propose that the DEGs and hub genes identified in the present study may be regarded as diagnostic biomarkers for colon cancer. Moreover, the overexpression of MMP7 may correlate with poor prognosis.

Antiparkinson Drug Benztropine Suppresses Tumor Growth, Circulating Tumor Cells, and Metastasis by Acting on SLC6A3/DAT and Reducing STAT3

Tumor growth, progression, and therapy resistance are crucial factors in the prognosis of cancer. The properties of three-dimensional (3D) tumor-like organoids (tumoroids) more closely resemble in vivo tumors compared to two-dimensionally cultured cells and are therefore effectively used for assays and drug screening. We here established a repurposed drug for novel anticancer research and therapeutics using a 3D tumoroid-based screening system. We screened six pharmacologically active compounds by using an original tumoroid-based multiplex phenotypic screening system with a matrix metalloproteinase 9 (MMP9) promoter-driven fluorescence reporter for the evaluation of both tumoroid formation and progression. The antiparkinson drug benztropine was the most effective compound uncovered by the screen. Benztropine significantly inhibited in vitro tumoroid formation, cancer cell survival, and MMP9 promoter activity. Benztropine also reduced the activity of oncogenic signaling transducers and trans-activators for MMP9, including STAT3, NF-κB, and β-catenin, and the properties of cancer stem cells/cancer-initiating cells. Benztropine and GBR-12935 directly targeted the dopamine transporter DAT/SLC6A3, whose genetic alterations such as amplification were correlated with poor prognosis for cancer patients. Benztropine also inhibited the tumor growth, circulating tumor cell (CTC) number, and rate of metastasis in a tumor allograft model in mice. In conclusion, we propose the repurposing of benztropine for anticancer research and therapeutics that can suppress tumor progression, CTC, and metastasis of aggressive cancers by reducing key pro-tumorigenic factors.

A Reporter System Evaluates Tumorigenesis, Metastasis, β-catenin/MMP Regulation, and Druggability

Cancer invasion, metastasis, and therapy resistance are the crucial phenomena in cancer malignancy. The high expression of matrix metalloproteinase 9 (MMP9) is a biomarker as well as a causal factor of cancer invasiveness and metastatic activity. However, a regulatory mechanism underlying MMP9 expression in cancer is not clarified yet. In addition, a new strategy for anticancer drug discovery is becoming an important clue. In the present study, we aimed (i) to develop a novel reporter system evaluating tumorigenesis, invasiveness, metastasis, and druggability with a combination of three-dimensional tumoroid model and Mmp9 promoter and (ii) to examine pharmacological actions of anticancer medications using this reporter system. High expression and genetic amplification of MMP9 were found in colon cancer cases. We found that proximal promoter sequences of MMP9 in murine and human contained conserved binding sites for transcription factors β-catenin/TCF/LEF, glucocorticoid receptor (GR), and nuclear factor kappa-B (NF-κB). The murine Mmp9 promoter (-569 to +19) was markedly activated in metastatic colon cancer cells and additionally activated by tumoroid formation and by β-catenin signaling stimulator lithium chloride. The Mmp9 promoter-driven fluorescent reporter cells enabled the monitoring of activities of MMP9/gelatinase, tumorigenesis, invasion, and metastasis in syngeneic transplantation experiments. We also demonstrated pharmacological actions as follows: dexamethasone and hydrocortisone, steroidal medications binding to GR, inhibited the Mmp9 promoter but did not inhibit tumorigenesis. On the contrary, antimetabolite 5-fluorouracil, a gold standard for colon cancer chemotherapy, inhibited tumoroid formation but did not inhibit Mmp9 promoter activity. Notably, antimalaria medication artesunate inhibited both tumorigenesis and the Mmp9 promoter in vitro, potentially through inhibition of β-catenin/TCF/LEF signaling. Thus, this novel reporter system enabled monitoring tumorigenesis, invasiveness, metastasis, key regulatory signalings such as β-catenin/MMP9 axis, and druggability. Impact Statement Cancer invasion and metastasis have been shown to be driven by matrix metalloproteinase 9 (MMP9), whose expression mechanism is not clarified yet. In addition, a new strategy for anticancer drug discovery is becoming important. We established a novel reporter system evaluating tumorigenesis, invasiveness, metastasis, and druggability with a combination of three-dimensional (3D) tumoroid model and Mmp9 promoter. Using this reporter system, we demonstrated pharmacological actions of anticancer medications such as antimetabolite 5-fluorouracil (5-FU) and antimalaria medication artesunate (ART), which inhibited both tumorigenesis and β-catenin/MMP regulatory signaling. Our study impacts the translational fields of oncology, drug discovery, and organoid model.

Tracing the path of cancer initiation: the AA protein-based model for cancer genesis

Background

Cancer is a defiant disease which cure is still far from being attained besides the colossal efforts and financial means deployed towards that end. The continuing setbacks encountered with today’s arsenal of anti-cancer drugs and cancer therapy modalities; show the need for a radical approach in order to get to the root of the problem. And getting to the root of cancer initiation and development leads us to challenge the present dogmas surrounding the pathogenesis of this disease.

Results

This comprehensive analysis brings to light the following points: (i) Cancer with its plethora of genetic and cellular symptoms could originate from one major event switching a cell from normalcy-to-malignancy; (ii) The switching event is postulated to involve a pathological breakup of a non-mutated protein, called here AA protein, resulting in the acquisition of new cellular functions present only in cancer cells; (iii) Following this event, DNA mutations begin to accumulate as secondary events to ensure perpetuity of cancer. Supporting arguments for this protein-based model come mainly from these observations: (i) The AA protein-based model reconciles together the clonal-and-stem cell theories into one inclusive model; (ii) The breakup of a normal protein could be behind the cancer-linked inflammation symptom; (iii) Cancer hallmarks are but adaptive traits, earned as a result of the switch from normalcy-to-malignancy.

Conclusions

Adaptation of cancer cells to their microenvironment and to different anti-cancer drugs is deemed here as the ultimate cancer hallmark, that needs to be understood and controlled. This adaptive power of cancer cells parallels that of bacteria also known with their resistance to a large range of substances in nature and in the laboratory. Consequently, cancer development could be viewed as a backward walk on the line of Evolution. Finally this unprecedented analysis demystifies cancer and puts the finger on the core problem of malignancy while offering ideas for its control with the ultimate goal of leading to its cure.

Imaging Matrix Metalloproteases in Spontaneous Colon Tumors: Validation by Correlation with Histopathology

The use of fluorescent probes in conjunction with white-light colonoscopy is a promising strategy for improving the detection of precancerous colorectal lesions, in particular flat (sessile) lesions that do not protrude into the lumen of the colon. We describe a method for determining the sensitivity and specificity of an enzymatically activated near-infrared probe (MMPSense680) for the detection of colon lesions in a mouse model (APC^+/Min-FCCC) of spontaneous colorectal cancer. Fluorescence intensity correlates directly with the activity of matrix metalloproteinases (MMPs). Overexpression of MMPs is an early event in the development of colorectal lesions. Although the probe employed serves as a reporter of the activity of MMPs, our method can be applied to any fluorescent probe that targets an early molecular event in the development of colorectal tumors.

Curcumin suppresses colon cancer cell invasion via AMPK-induced inhibition of NF-κB, uPA activator and MMP9

Curcumin, an active nontoxic ingredient of turmeric, possesses potent anti-inflammatory, antioxidant and anti-cancer properties; however, the molecular mechanisms of curcumin are not fully understood. The transcription factor nuclear factor-κB (NF-κB) is key in cellular processes, and the expression/activation of urokinase-type plasminogen activator (uPA) and matrix metalloproteinase-9 (MMP9) are crucial for cell invasion. The present study investigated the hypothesis that curcumin inhibits colon cancer cell invasion by modulating NF-κB-mediated expression and activation of uPA and MMP9. Human colon cancer SW480 and LoVo cells were treated with various concentrations of curcumin. Curcumin was demonstrated to dose-dependently inhibit the adhesion and proliferation ability of LoVo and SW480 cells using Transwell and MTT assays, respectively. In addition, curcumin activated 5' AMP-activated protein kinase (AMPK) and suppressed p65 NF-κB phosphorylation, as shown by western blot analysis. Compound C, a potent AMPK inhibitor, abolished curcumin-induced inhibition of NF-κB, uPA and MMP9, suggesting that AMPK activation is responsible for curcumin-mediated NF-κB, uPA and MMP9 inhibition. The binding activity of NF-κB to DNA was examined and western blotting and quantitative polymerase reaction was performed to detect the effect of curcumin on the expression of uPA and MMP9. The present results revealed that curcumin significantly decreased the expression of uPA and MMP9 and NF-κB DNA binding activity. Furthermore, curcumin decreased the level of the p65 subunit of NF-κB binding to the promoter of the gene encoding uPA and MMP9, which suppressed transcriptional activation of uPA and MMP9. Overall, the present data suggest that curcumin inhibits colon cancer cell invasion via AMPK activation and subsequent inhibition of p65 NF-κB, uPA and MMP9. The therapeutic potential of curcumin for colon cancer metastasis required additional study.

Tissue Inhibitor of Metalloproteinase-1 Is Confined to Tumor-Associated Myofibroblasts and Is Increased With Progression in Gastric Adenocarcinoma

The tissue inhibitor of metalloproteinase-1 (TIMP-1) inhibits the extracellular matrix-degrading activity of several matrix metalloproteinases, thereby regulating cancer cell invasion and metastasis. Studies describing the expression pattern and cellular localization of TIMP-1 in gastric cancer are, however, highly discordant. We addressed these inconsistencies by performing immunohistochemistry and in situ hybridization analyses in a set of 49 gastric cancer lesions to reexamine the TIMP-1 localization. In addition, we correlated these findings to clinicopathological parameters. We show that strong expression of TIMP-1 protein and mRNA was observed in a subpopulation of stromal fibroblast-like cells at the periphery of the cancer lesions. In a few cases, a small fraction of cancer cells showed weak expression of TIMP-1 protein and mRNA. The stromal TIMP-1-expressing cells were mainly tumor-associated myofibroblasts. In the normal-appearing mucosa, scattered TIMP-1 protein was only found in chromogranin A positive cells. TIMP-1-positive myofibroblasts at the invasive front of the tumors were more frequently seen in intestinal than in diffuse histological subtype cases (p=0.009). A significant trend to a higher number of cases showing TIMP-1 staining in myofibroblasts with increasing tumor, node, metastasis (TNM) stage was also revealed (p=0.041). In conclusion, tumor-associated myofibroblasts are the main source of increased TIMP-1 expression in gastric cancer.

Tissue inhibitor of matrix metalloproteinase-1 expression in colorectal cancer liver metastases is associated with vascular structures

Metastatic growth by colorectal cancer cells in the liver requires the ability of the cancer cells to interact with the new microenvironment. This interaction results in three histological growth patterns of liver metastases: desmoplastic, pushing, and replacement. In primary colorectal cancer several proteases, involved in the degradation of extracellular matrix components, are up‐regulated. In liver metastases, their expression is growth pattern dependent. Tissue inhibitor of matrix metalloproteinase‐1 (TIMP‐1) is a strong prognostic marker in plasma from colorectal cancer patients, with significant higher levels in patients with metastatic disease. We therefore wanted to determine the expression pattern of TIMP‐1 in primary colorectal cancers and their matching liver metastases. TIMP‐1 mRNA was primarily seen in α‐smooth‐muscle actin (α‐SMA)‐positive cells. In all primary tumors and liver metastases with desmoplastic growth pattern, TIMP‐1 mRNA was primarily found in α‐SMA‐positive myofibroblasts located at the invasive front. Some α‐SMA‐positive cells with TIMP‐1 mRNA were located adjacent to CD34‐positive endothelial cells, identifying them as pericytes. This indicates that TIMP‐1 in primary tumors and liver metastases with desmoplastic growth pattern has dual functions; being an MMP‐inhibitor at the cancer periphery and involved in tumor‐induced angiogenesis in the pericytes. In the liver metastases with pushing or replacement growth patterns, TIMP‐1 was primarily expressed by activated hepatic stellate cells at the metastasis/liver parenchyma interface. These cells were located adjacent to CD34‐positive endothelial cells, suggesting a function in tumor‐induced angiogenesis. We therefore conclude that TIMP‐1 expression is growth pattern dependent in colorectal cancer liver metastases. © 2015 The Authors. Molecular Carcinogenesis published by Wiley Periodicals, Inc.

Pair-wise comparison analysis of differential expression of mRNAs in early and advanced stage primary colorectal adenocarcinomas

OBJECTIVES

To characterise the mRNA expression patterns of early and advanced stage colorectal adenocarcinomas of Malaysian patients.

DESIGN

Comparative expression analysis.

SETTING AND PARTICIPANTS

We performed a combination of annealing control primer (ACP)-based PCR and reverse transcription-quantitative real-time PCR for the identification of differentially expressed genes (DEGs) associated with early and advanced stage primary colorectal tumours. We recruited four paired samples from patients with colorectal cancer (CRC) of Dukes' A and B for the preliminary differential expression study, and a total of 27 paired samples, ranging from CRC stages I to IV, for subsequent confirmatory test. The tumouric samples were obtained from the patients with CRC undergoing curative surgical resection without preoperative chemoradiotherapy. The recruited patients with CRC were newly diagnosed with CRC, and were not associated with any hereditary syndromes, previously diagnosed cancer or positive family history of CRC. The paired non-cancerous tissue specimens were excised from macroscopically normal colonic mucosa distally located from the colorectal tumours.

PRIMARY AND SECONDARY OUTCOME MEASURES

The differential mRNA expression patterns of early and advanced stage colorectal adenocarcinomas compared with macroscopically normal colonic mucosa were characterised by ACP-based PCR and reverse transcription-quantitative real-time PCR.

RESULTS

The RPL35, RPS23 and TIMP1 genes were found to be overexpressed in both early and advanced stage colorectal adenocarcinomas (p<0.05). However, the ARPC2 gene was significantly underexpressed in early colorectal adenocarcinomas, while the advanced stage primary colorectal tumours exhibited an additional overexpression of the C6orf173 gene (p<0.05).

CONCLUSIONS

We characterised two distinctive gene expression patterns to aid in the stratification of primary colorectal neoplasms among Malaysian patients with CRC. Further work can be done to assess and compare the mRNA expression levels of these identified DEGs between each CRC stage group, stages I-IV.

Matrix metalloproteinase-13 expression in the progression of colorectal adenoma to carcinoma : Matrix metalloproteinase-13 expression in the colorectal adenoma and carcinoma

Most colorectal carcinomas (CRCs) are considered to arise from conventional adenoma based on the concept of the adenoma-carcinoma sequence. Matrix metalloproteinases (MMPs) are known to be overexpressed as normal mucosa progresses to adenomas and carcinomas. There has been little previous investigation about MMP-13 expression in adenoma-carcinoma sequence. In this study, we aimed to investigate the immunohistochemical expression of MMP-13 in colorectal adenoma and CRC specimens using tissue microarray (TMA) technique. A total of 40 cases of CRC associated with adenoma were collected from files of the Pathology laboratory at Mansoura Gastroenterology Center between January 2007 and January 2012. Sections from TMA blocks were prepared and stained for MMP-13. Immunoreactivity to MMP-13 staining was localized to the cytoplasm of mildly, moderately, and severely dysplatic cells of adenomas and CRC tumor cells that were either homogenous or heterogeneous. There was no significant difference in MMP-13 expression between adenomas and CRCs either non-mucinous or mucinous. Adenomas with high MMP-13 expression were significantly associated with moderate to marked degree of inflammatory cellular infiltrate and presence of familial adenomatous polyps. In conclusion, MMP-13 may be a potential biological marker of early tumorigenesis in the adenoma-carcinoma sequence.

β,β-carotene 15,15'-monooxygenase and its substrate β-carotene modulate migration and invasion in colorectal carcinoma cells

BACKGROUND

β,β-Carotene 15,15'-monooxygenase (BCMO1) converts β-carotene to retinaldehyde. Increased β-carotene consumption is linked to antitumor effects. Retinoic acid reduces the invasiveness in cancer, through inhibition of matrix metalloproteinases (MMPs). In our studies of a mouse model that develops intestinal tumors after low dietary folate, we found reduced BCMO1 expression in normal preneoplastic intestine of folate-deficient tumor-prone mice.

OBJECTIVE

Our goal was to determine whether BCMO1 expression could influence transformation potential in human colorectal carcinoma cells, by examining the effect of BCMO1 modulation on cellular migration and invasion, and on expression of MMPs.

DESIGN

LoVo colon carcinoma cells were transfected with BCMO1 small interfering RNA (siRNA) or scrambled siRNA. Migration and invasion were measured, and the expression of BCMO1, MMP7, and MMP28 was assessed by quantitative reverse-transcriptase polymerase chain reaction. These variables were also measured after treatment of cells with retinoic acid, 5-aza-2'-deoxycytidine, folate-depleted/high-methionine medium, and β-carotene.

RESULTS

Retinoic acid decreased the migration, invasion, and expression of MMP28 mRNA. Transfection of cells with BCMO1 siRNA inhibited BCMO1 expression, enhanced migration and invasion, and increased expression of MMP7 and MMP28. 5-Aza-2'-deoxycytidine decreased, whereas folate-depleted/high-methionine medium increased invasiveness. β-Carotene increased BCMO1 expression and reduced invasiveness with a decrease in expression of MMP7 and MMP28.

CONCLUSIONS

Inhibition of BCMO1 expression is associated with increased invasiveness of colon cancer cells and increased expression of MMP7 and MMP28. β-Carotene can upregulate BCMO1 and reverse these effects. These novel associations suggest a critical role for BCMO1 in cancer and provide a mechanism for the proposed antitumor effects of β-carotene.

Extracellular calcium-sensing receptor/PTH knockout mice colons have increased Wnt/β-catenin signaling, reduced non-canonical Wnt signaling, and increased susceptibility to azoxymethane-induced aberrant crypt foci

Epidemiological evidence suggests increased dietary calcium and dairy products reduce the onset of colon cancer. To understand a role of the colonic extracellular calcium-sensing receptor (CaSR) in calcium-mediated chemoprevention of colon cancer, we induced formation of aberrant crypt foci (ACF) caused by azoxymethane (AOM) injection in 'rescued' CaSR-/PTH- (C-/P-) double knockout colons compared with colons from control CaSR+/PTH+ (C+/P+) mice. C-/P- colonic epithelia had increased Wnt/β-catenin signaling as evidenced by 3-8-fold increases in Wnt3a, CyclinD1, and MMP-7 proteins compared with C+/P+ colonic epithelia. The C-/P- colonic epithelia had reduced Wnt5a and Ror2, and a three-fold increase in TNFR1 compared with C+/P+ epithelia. The C-/P- colons and small intestine had extensive neutrophil infiltration with myeloperoxidase (MPO) levels 18-fold higher then C+/P+ small intestine and colon. Saline-injected C-/P- colons had the same number of ACF/cm(2) as C+/P+ colons, which were injected with AOM. However, there were eight times more ACF/cm(2) in the C-/P- injected with AOM compared with C+/P+ colons, which received AOM. Together our results suggest both inflammation and Wnt/β-catenin signaling are increased in the epithelia of 'rescued' CaSR/PTH double knockout colons, and the capacity for non-canonical Wnt signaling through Wnt5a/Ror2 engagement is reduced. The loss of the colonic CaSR increased the number of ACF/cm(2) in response to AOM injection, suggesting colonic CaSR may mediate the chemoprotective effect of increased dietary calcium against colorectal cancer observed in humans.

Immunohistochemical expression of matrix metalloproteinase-7 in human colorectal adenomas using specified automated cellular image analysis system: a clinicopathological study

BACKGROUND/AIM

To evaluate the immunohistochemical expression of matrix metalloproteinase-7 (MMP-7) in colorectal adenomas, and to correlate this expression with different clinicopathological parameters.

PATIENTS AND METHODS

The study was retrospectively designed. Thirty three paraffin blocks from patients with colorectal adenoma and 20 samples of non-tumerous colonic tissue taken as control group were included in the study. MMP-7 expression was assessed by immunohistochemistry method. The scoring of immunohistochemical staining was conducted utilizing a specified automated cellular image analysis system (Digimizer).

RESULTS

The frequency of positive immunohistochemical expression of MMP-7 was significantly higher in adenoma than control group (45.45% versus 10%) (P value < 0.001). Strong MMP-7 staining was mainly seen in adenoma cases (30.30%) in comparison with control (0%) the difference is significant ( P < 0.001). The three digital parameters of MMP-7 immunohistochemical expression (Area (A), Number of objects (N), and intensity (I)) were significantly higher in adenoma than control. Mean (A and I) of MMP-7 showed a significant correlation with large sized adenoma (≥ 1cm) ( P < 0.05), also a significant positive correlation of the three digital parameters (A, N, and I) of MMP-7 expression with villous configuration and severe dysplasia in colorectal adenoma had been identified ( P < 0.05).

CONCLUSION

MMP-7 plays an important role in the growth and malignant conversion of colorectal adenomas as it is more likely to be expressed in advanced colorectal adenomatous polyps with large size, severe dysplasia and villous histology. The use of automated cellular image analysis system (Digmizer) to quantify immunohistochemical staining yields more consistent assay results, converts semi-quantitative assay to a truly quantitative assay, and improves assay objectivity and reproducibility.

The role of the tumor microenvironment in regulating angiogenesis

The tumor-associated stroma has been shown to play a significant role in cancer formation. Paracrine signaling interactions between epithelial tumor cells and stromal cells are a key component in the transformation and proliferation of tumors in several organs. Whereas the intracellular signaling pathways regulating the expression of several pro- and antiangiogenic proteins have been well characterized in human cancer cells, the intercellular signaling that takes place between tumor cells and the surrounding tumor-associated stroma has not been as extensively studied with regard to the regulation of angiogenesis. In this chapter we define the key players in the regulation of angiogenesis and examine how their expression is regulated in the tumor-associated stroma. The resulting analysis is often seemingly paradoxical, underscoring the complexity of intercellular signaling within tumors and the need to better understand the environmental context underlying these signaling mechanisms.

Production of recombinant human matrix metalloproteinase 7 (Matrilysin) with potential role in tumor invasion by refolding from Escherichia coli inclusion bodies and development of sandwich ELISA of MMP-7

Metastatic potential of prostate cancer is thought to correlate with the degradation of basement membrane components by matrix metalloproteinases (MMPs). The MMP-7 (matrilysin) gene is overexpressed in prostate cancer as well as colorectum and brain cancer. In order to clarify the relation of MMP-7 to clinical stages of prostate cancer, recombinant human MMP-7 was produced to prepare antibodies for immunohistochemistry and immunoassay. Preproform of human MMP-7 was produced in Escherichia coli as inclusion bodies that could be solubilized and refolded to yield an activatable proenzyme. PreproMMP-7 (Mr 31,000) solubilized from inclusion bodies was converted to proMMP-7 (Mr 30,000) during the refolding steps. The refolded proMMP-7 was purified to about 80% homogeneity as MMP-7 by sequential ion-exchange and molecular-sieve chromatography. The active, mature form of MMP-7 (Mr 20,000) could be produced from proforms of MMP-7 by treatment with p-aminophenylmercuric acetate. Activated MMP-7 was shown to have proteolytic activity to fibronectin, casein, and diazotized, denatured collagen (Azocoll). Specific activity, as assayed with the denatured collagen as substrate, was measured to be about 3,100 units/mg protein of mature enzyme. Using recombinant proMMP-7 as antigen, monoclonal and polyclonal antibodies were prepared. A sandwich ELISA was developed using monoclonal antibody as the capture antibody and rabbit anti-proMMP-7 polyclonal IgG conjugated with biotin as the detection antibody; MMP-7 at 10 ng/ml was significantly detectable. The assay system is applicable on the measurement of MMP-7 levels in the clinical and pathologic specimens including serum from patients with different stages in malignancy of prostate cancer. These antibodies are useful for the retrospective analyses of prostate cancer on the basis of immunohistochemical evaluation.

Application of MMP-7 and MMP-10 in assisting the diagnosis of malignant pleural effusion

BACKGROUND

Matrix metalloproteinases (MMP) are proteolytic enzymes that are essentially involved in turnover of the extracellular matrix (ECM). The aim was to investigate the diagnostic value of MMP-7 and MMP-10 as tumor markers in pleural effusion (PE) and evaluate the value of combining MMP-7, MMP-10 and carcinoembryonic antigen (CEA) assays as diagnostic aids for malignant cells.

MATERIALS AND METHODS

A total of 179 patients with PE (87 malignant and 92 benign) were included in this study. The levels of MMP-7 and MMP-10 were measured using ELISA.

RESULTS

Values for MMP-7 and MMP-10 were significantly higher in malignant PE than those in benign PE (P<0.01). Among all variables evaluated, logistic regression found that MMP-7 and MMP-10 were significantly correlated with the presence of malignant disease (P<0.01). Analysis of receiver operating characteristics (ROC) curves showed that the area under the curve of MMP-10 (0.806) was significantly larger than that of MMP-7 (0.771) and CEA (0.789) (P<0.01). With parallel interpretation, the combination of MMP-10 and CEA achieved the higher sensitivity of 94.6%. The combination of MMP-7 and CEA in serial interpretation was able to boost the specificity to 95.7%. The combination of MMP-7, MMP-10 and CEA produced better sensitivity, specificity, PPV and NPV than MMP-7 and MMP-10 alone.

CONCLUSION

MMP-7 and MMP-10 in PE may represent helpful adjuncts to conventional diagnostic tools in ruling out malignancy as a probable diagnosis, thus guiding the selection of patients who might benefit from further invasive procedures.

Multiple antitumor effects of picropodophyllin in colon carcinoma cell lines: clinical implications

Although colorectal cancer can be successfully treated by conventional strategies such as chemo/radiotherapy and surgery, a substantial number of cases, in particular those with liver metastases, remain incurable. Therefore, novel treatment approaches are warranted. The IGF-1R and its ligands, mainly IGF-1 and IGF-2, have been suggested to play pivotal roles in proliferation, survival and migration of adenocarcinoma cells of the colon/rectum. Therefore, interference with IGF-1R-mediated signaling may represent a therapeutic option for this malignancy. In this study, semi-quantitative RT-PCR analyses of 48 paired, colorectal cancer patient samples showed significant overexpression of tumor IGF-1R and IGF-2 mRNA. There was also an overexpression of MMP-7, which was significantly correlated with histopathological parameters. Based on these findings, the effect of the IGF-1R-inhibitory cyclolignan picropodophyllin (PPP) was assessed in the four colon carcinoma cell lines HT-29, HCT-116, DLD-1 and CaCO-2. PPP strongly and dose-dependently inhibited proliferation and migration in all cell lines. However, when exposed to 0.5 μM PPP, only HT-29 showed a net decrease of viable cells as compared with the cell number at the beginning of the experiment, a finding that coincided with decreased expression/phosphorylation of IGF-1R, AKT and ERK. This cell line also exhibited PPP-induced downregulation of MMP-7 and MMP-9. Similar to the DLD-1 and HCT-116 cell lines, HT-29 also showed substantial cell detachment in response to PPP. Although a net reduction of cells by PPP seems to require a synchronized downregulation of IGF-1R, AKT and ERK1/2, part of the antitumor effect may be explained by other, possibly IGF-1R-unrelated mechanism(s). Such a multitude of inhibitory effects of PPP in colon cancer cells together with its low toxicity in vivo makes it a promising drug candidate in the treatment of this disease.

Detection of colorectal adenomas using a bioactivatable probe specific for matrix metalloproteinase activity

A significant proportion of colorectal adenomas, in particular those that lack an elevated growth component, continue to escape detection during endoscopic surveillance. Elevation of the activity of matrix metalloproteinases (MMPs), a large family of zinc endopeptidases, in adenomas serves as a biomarker of early tumorigenesis. The goal of this study was to assess the feasibility of using a newly developed near-infrared bioactivatable probe (MMPSense 680) that reports the activity of a broad array of MMP isoforms to detect early colorectal adenomas. Adenomatous polyposis coli (Apc)(+/Min-FCCC) mice that spontaneously develop multiple colorectal adenomas were injected with MMPSense 680, and the colons were imaged in an IVIS Spectrum system ex vivo. Image analyses were correlated with histopathologic findings for all regions of interest (ROIs). The biochemical basis of fluorescent signal was investigated by immunohistochemical staining of MMP-7 and -9. A strong correlation (Kendall = 0.80) was observed between a positive signal and the presence of pathologically confirmed colonic adenomas; 92.9% of the 350 ROIs evaluated were classified correctly. The correlation between two independent observers was 0.87. MMP-7 expression was localized to epithelial cells of adenomas and microadenomas, whereas staining of MMP-9 was found in infiltrating polymorphonuclear leukocytes within the adenomas. MMPSense 680 identifies colorectal adenomas, both polypoid and nonpolypoid, in Apc(+/Min-FCCC) mice with high specificity. Use of this fluorescent probe in combination with colonoscopy could aid in preventing colorectal neoplasias by providing new opportunities for early detection and therapeutic intervention.

Application of near-infrared fluorescence imaging using a polymeric nanoparticle-based probe for the diagnosis and therapeutic monitoring of colon cancer

BACKGROUND

Early and accurate detection of adenomatous colonic polyps is a major concern in the prevention of colon cancer. Near-infrared fluorescence (NIRF) imaging with optical probes targeting specific peptides enables the noninvasive visualization and characterization of lesions. Matrix metalloproteinases (MMPs) are known to play an important role in tumorigenesis and tumor progression.

AIM

To investigate the effectiveness of NIRF imaging, with a novel MMP-activatable probe based on a polymeric nanoparticle platform, in the colon cancer models.

METHODS

We used an azoxymethane (AOM)-induced mouse colon cancer model resembling human sporadic colon cancer and an MMP-positive xenograft tumor model. MMP expression was evaluated by Western blotting, real-time PCR, and immunohistochemical staining. NIRF imaging was performed with a novel MMP-activatable probe, an MMP-inactivatable probe, and saline. In addition, we observed the change of NIRF signal intensity after intratumoral administration of an MMP-inhibitor.

RESULTS

Multiple tumors with various sizes developed in AOM-treated mouse colons, progressing from adenomas to adenocarcinomas, with MMP expression progressively increasing in the normal-adenoma-adenocarcinoma sequence. In mice injected with the MMP-activatable probe, the NIRF signal also increased in this sequence and was highly correlated with MMP expression (p < 0.001). Tumor-background-ratios (TBR) of adenocarcinoma to adjacent normal mucosa by a novel probe were significantly higher than that of adenoma (p < 0.001). In both the AOM and xenograft models, NIRF signals of tumors decreased after treatment with an MMP-inhibitor.

CONCLUSIONS

NIRF imaging using a polymeric nanoparticle-based probe may be useful for detecting early stage disease and for assessing treatment response.

Post-translational modifications of the extracellular matrix are key events in cancer progression: opportunities for biochemical marker development

The aim of this review is to discuss the potential usefulness of a novel class of biochemical markers, designated neoepitopes. Neoepitopes are post-translational modifications (PTMs) of proteins and are derived by processes, such as protease cleavage, citrullination, nitrosylation, glycosylation and isomerization. Each PTM results from a specific local physiological or pathobiological process. Identification of each modification to a tissue-specific protein may reveal a unique disease-specific biochemical marker. During cancer metastasis, the host tissue is extensively degraded and replaced by cancer-associated extracellular matrix (ECM) proteins. Furthermore, severe cellular stress and inflammation, caused by cancer, results in generation of PTMs, which will be distributed throughout the ECM. This gives rise to release of protein-specific fragments to the circulation. Here we highlight the importance of remodeling of the ECM in cancer and the generation of PTMs, which may be cancer specific and reflect disease progression; thus having potential for biochemical marker development.

Active matrix metalloproteinase-2 activity discriminates colonic mucosa, adenomas with and without high-grade dysplasia, and cancers

Pathologic assessment of colorectal adenomas, a complex task with significant interobserver variability, typically defines the scheduling of surveillance colonoscopies after removal of adenomas. We have characterized the activity levels of pro-matrix metalloproteinase-2, active matrix metalloproteinase-2, and matrix metalloproteinase-9 in colorectal adenomas and carcinomas as potential markers of pathologic progression during colorectal tumorigenesis. Endogenous fully activated matrix metalloproteinase-2, in particular, has been studied less frequently in adenomas due to difficulties in detection. For this report, tissues (n = 119) from 51 individuals were extracted and assayed on gelatin zymograms with digital standardization to nanogram quantities of purified active controls. Resulting data were assessed by graphical and multinomial logit regression analyses to test whether matrix metalloproteinase-2 or matrix metalloproteinase-9 activities could discriminate among 4 different types of colorectal tissue (normal mucosa, adenomas with or without high-grade dysplasia, and invasive carcinomas). Active matrix metalloproteinase-2 successfully discriminated among these tissue categories. Median activity for active matrix metalloproteinase-2 increased in a stepwise fashion with pathologic progression from normal mucosa to adenoma without high-grade dysplasia to adenoma with high-grade dysplasia to cancer. Although pro-matrix metalloproteinase-2 and pro-matrix metalloproteinase-9 activities could discriminate to some extent among tissue categories, those effects did not contribute additional information. Active matrix metalloproteinase-2 activity correlated significantly with histopathologic assessment of colorectal tissues. The ability of active matrix metalloproteinase-2 to distinguish adenomas with high-grade dysplasia from adenomas without high-grade dysplasia may be particularly useful in predicting future colorectal cancer risk for an individual, thus optimizing scheduling of surveillance colonoscopies.

Matrilysin-1 (MMP7) cleaves galectin-3 and inhibits wound healing in intestinal epithelial cells

BACKGROUND

Galectin-3 is an animal lectin that has been implicated in wound healing and is decreased in inflammatory bowel disease (IBD). Matrix metalloproteinase-7 (MMP7), also known as matrilysin-1, a protease shown to cleave extracellular matrix proteins, is highly expressed in IBD tissues, especially at the leading edge of gastrointestinal ulcers. The ability of MMP7 to cleave galectin-3 and influence wound healing has not been reported previously. The aim was to determine whether MMP7 cleaves galectin-3 and modulates wound healing in intestinal epithelial cells.

METHODS

The cleaved fragments of galectin-3 were identified by N-terminal sequencing and mass spectrometry. Western blotting was used to detect the cleaved galectin-3 products in a colonic epithelial cell line (T84 cells). Cell migration was studied by the in vitro scratch method.

RESULTS

We demonstrate for the first time that MMP7 cleaves galectin-3 in vitro, resulting in three cleaved fragments (20.2 kDa, 18.9 kDa, and 15.5 kDa). Exogenous treatment of T84 cells with recombinant MMP7 resulted in the appearance of secreted galectin-3 cleavage fragments in the supernatant. MMP7 inhibited cell migration and resulted in wound retraction and the addition of MMP7 to galectin-3 abrogated the wound healing and cell migration induced by galectin-3.

CONCLUSIONS

We have demonstrated that galectin-3 is a substrate for MMP7. Cleavage of galectin-3 may be one mechanism by which MMP7 inhibits wound healing. This study has significance in understanding delayed wound healing in chronic intestinal diseases like intestinal ulcers and IBD, where MMP7 protein expression is elevated with a decreased galectin-3 protein expression.

Near-infrared fluorescence imaging using a protease-specific probe for the detection of colon tumors

BACKGROUND/AIMS

Early tumor detection is crucial for the prevention of colon cancer. Near-infrared fluorescence (NIRF) imaging using a target-activatable probe may permit earlier disease detection. Matrix metalloproteinases (MMPs) participate in tumorigenesis and tumor growth. The aim of this study was to determine whether NIRF imaging using an MMP-activatable probe can detect colon tumors at early stages.

METHODS

WE UTILIZED TWO MURINE COLON CANCER MODELS: a sporadic colon cancer model induced by azoxymethane (AOM), and a colitis-associated cancer model induced by a combination of AOM and dextran sodium sulfate (DSS). Colonic lesions were analyzed by histologic examination, Western blotting, immunohistochemical staining, and NIRF imaging using an MMP-activatable probe.

RESULTS

Multiple variable-sized tumors developed in both models and progressed from adenomas to adenocarcinomas over time. At the early stage of the AOM/DSS model, diffuse inflammation was observed within the tumors. MMP expression increased progressively through normal, inflammation, adenoma, and adenocarcionoma stages. NIRF signal intensities were strongly correlated with each tumor stage from adenoma to adenocarcinoma. NIRF imaging also distinguished tumors from inflamed mucosa.

CONCLUSIONS

NIRF imaging using a protease-activatable probe may be a useful tool for early tumor detection. This approach could translate to improve the endoscopic detection of colon tumors, especially in patients with inflammatory bowel disease.

Cellular sources of MMP-7, MMP-13 and MMP-28 in ulcerative colitis

OBJECTIVE

Matrix metalloproteinases (MMPs) are considered the predominant proteases in the pathogenesis of mucosal ulcerations associated with inflammatory bowel disease (IBD). Whether the malignancy associated MMP-7 and MMP-13 or the recently cloned MMP-28 convey a certain meaning for intestinal homeostasis and pathogenesis of IBD is currently unknown. We therefore set off to analyze regulation patterns and cellular origins of these MMPs in mucosal tissues of patients with ulcerative colitis (UC).

MATERIAL AND METHODS

Biopsy samples of affected and healthy tissues were obtained from 35 Norwegian patients with UC. RNA was quantified by quantitative real-time polymerase chain reaction to study MMP gene expression in both pathological and healthy mucosal specimens. Cellular origins were determined by immunohistology using surrogate markers for inflammation, neovascularization, and epithelial structures. Protein expression of MMP-7 and MMP-13 was quantified using enzyme-linked immunosorbent assay.

RESULTS

MMP-7 and MMP-13 gene expression was significantly increased in UC affected colonic mucosa whereas MMP-28 showed a decreased expression in inflamed mucosa. Endothelial cells and infiltrating leukocytes were identified as the major cellular sources of MMP-7 and MMP-13 in UC. Enterocytes represented the major cellular source of MMP-28 in healthy and inflamed mucosa.

CONCLUSIONS

MMP-7 and MMP-13 expression in inflammatory and endothelial cells indicate a role of these MMPs for both colitis associated neoangiogenesis and inflammatory changes. Decreased MMP-28 expression in UC is most likely the result of colitis associated epithelial destruction and loss of cryptal architecture.

MMP-7 as a prognostic marker in colorectal cancer

Matrix metalloproteinase-7 is capable of degrading many extracellular matrix proteins and cellular adhesions. In many malignancies, it is overexpressed, and it plays a role in cancer progression by enhancing tumor invasion and thereby metastatic potential. The purpose of this study was to evaluate the association between MMP-7 tissue expression and prognosis in colorectal cancer. From 623 patients who underwent surgery for colorectal cancer, surgical specimens were collected into tissue array blocks and stained by immunohistochemistry for MMP-7. Specimens from 545 patients were suitable for analysis. In specimens from 105 patients (19.3%), MMP-7 scored as high; in 103 (18.9%), as moderate; and in 134 (24.9%), as mild. In 203 cases (37.2%), immunoreactivity was negative. A significant correlation appeared between MMP-7 immunoexpression and tumor differentiation. High MMP-7 positivity associated with poor prognosis during a 5-year follow-up. During longer follow-up, the differences in survival between groups disappeared. MMP-7 is a potential target for tumor therapy, which should be evaluated in clinical trials.

Laminin induces matrix metalloproteinase-9 expression and activation in human cervical cancer cell line (SiHa)

PURPOSE

Interaction between cell surface integrin receptors and extracellular matrix (ECM) components plays an important role in cell survival, proliferation and migration including tumor development and invasion. Matrix metalloproteinases (MMP) are a family of metalloproteinases capable of digesting ECM and facilitate cell migration. Binding of ECM to integrins initiates signaling cascades modulating expression and activity of different MMPs. The present study investigates whether laminin-mediated signaling modulates matrix metalloproteinases (MMP) expression and activity in human cervical cancer cell (SiHa).

METHODS

Western blot, immunocytochemistry, ELISA, zymography, RT-PCR, EMSA and wound-healing assay were used.

RESULTS

Culture of SiHa cells on laminin (LN)-coated surface induces MMP-9 expression and activation. Wound-healing assay showed that SiHa cells migrate much faster on laminin-coated surface than that of control. LN-induced MMP-9 expression and activation was appreciably reduced with treatment of extracellular signal-regulated kinase (ERK) inhibitor, phosphatidylinositol-3-kinase (PI-3K) inhibitor and anti-α2 antibody. Phosphorylation of focal adhesion kinase (FAK), ERK, and PI-3K was increased upon LN stimulation. LN induces nuclear translocation of PI-3K and nuclear factor kappa B (NF-κB). LN increases DNA-binding activity of NF-κB and activator protein-1 (AP-1) to MMP-9 promoter.

CONCLUSIONS

Our findings indicate laminin-induced MMP-9 expression and activation possibly via α2β1 integrin-mediated signaling involving FAK, PI-3K, ERK followed by transcriptional upregulation of MMP-9.

Molecular interactions in cancer cell metastasis

Metastasis, the process by which cancer cells leave the primary tumour, disseminate and form secondary tumours at anatomically distant sites, is a serious clinical problem as it is disseminated disease, which is often impossible to eradicate successfully, that causes the death of most cancer patients. Metastasis results from a complex molecular cascade comprising many steps, all of which are interconnected through a series of adhesive interactions and invasive processes as well as responses to chemotactic stimuli. In spite of its clinical significance, it remains incompletely understood. This review provides an overview of some of the molecular interactions that are critical to metastasis. It summarises the principle molecular players in the major steps of the metastatic cascade. These are: (1) tumour angiogenesis, (2) disaggregation of tumour cells from the primary tumour mass, mediated by cadherins and catenins, (3) invasion of, and migration through, the basement membrane (BM) and extracellular matrix (ECM) surrounding the tumour epithelium, and subsequent invasion of the BM of the endothelium of local blood vessels. This is mediated through integrins and proteases, including urokinase form of plasminogen activator (uPA), matrix metalloproteinases (MMPs) and cathepsins, (4) intravasation of the tumour cells into the blood vessels prior to hematogeneous dissemination to distant sites, (5) adhesion of the circulating tumour cells to the endothelial cell lining at the capillary bed of the target organ site. This occurs through adhesive interactions between cancer cells and endothelial cells involving selectins, integrins and members of the immunoglobulin superfamily (IgSF), (6) invasion of the tumour cells through the endothelial cell layer and surrounding BM (extravasation) and target organ tissue and (7) the development of secondary tumour foci at the target organ site.

Fecal cyclooxygenase 2 plus matrix metalloproteinase 7 mRNA assays as a marker for colorectal cancer screening

We previously reported that fecal cyclooxygenase 2 (COX-2) mRNA assay, detecting COX-2 mRNA in feces, is useful for identifying subjects with colorectal cancer (CRC). To further improve the sensitivity, we evaluated the usefulness of the combination of COX-2 mRNA and matrix metalloproteinase 7 (MMP-7) mRNA assays as a marker of CRC. The study cohort included 62 patients with CRC and 29 control patients without colorectal neoplasia. RNA was isolated from routinely collected fecal samples. The expression levels of COX-2 and MMP-7 mRNAs were determined by nested reverse transcription-PCR. PCR conditions were optimized where the specificity of fecal COX-2 and MMP-7 mRNA assay result in 100%. The sensitivity of each fecal assay was 87% [95% confidence interval (95% CI), 76-94%] and 65% (95% CI, 51-76%) for CRC, respectively. The sensitivity of fecal RNA test (either marker being positive) was high for CRC (90%; 95% CI, 80-96%). The sensitivity of the fecal RNA test was also high (93%; 95% CI, 80-98%) in patients with stage I or II who are often cured by surgical resection. The fecal RNA test using COX-2 and MMP-7 mRNAs improved the sensitivity to detect CRC without decreasing the specificity. These results suggest that the fecal RNA test would be a promising approach for CRC screening, although larger clinical investigations are indicated.

Correlation between the immunohistochemical expressions of MMP-1, MMP-7 and VEGF and prognostic factors in colorectal adenocarcinoma

PURPOSE: To analyze the expression of metalloproteinase-1, metalloproteinase-7 and vascular endothelial growth factor (VEGF) in colorectal adenocarcinoma, and to correlate these with the clinical-pathological prognostic factors. METHODS: Tumor tissue from 82 patients was fixed in formalin and embedded in paraffin blocks. These samples were analyzed by means of the streptavidin-biotin immunohistochemical method, using the tissue microarray technique. Marker positivity was evaluated using categorical scores that determined cutoff percentages of stained tumor cells. Protein tissue expression was correlated with the variables of degree of cell differentiation, staging, disease-free interval, recurrence, survival and specific mortality. The Fisher exact and Kaplan-Meier tests were used to assess associations between the markers and the study variables. The log-rank and Wilcoxon tests were used to assess the significance of differences between curves of disease-free interval and survival. RESULTS: All tumors were positive for metalloproteinase-1; 50 (61%) were positive and 32 (39%) were negative for metalloproteinase-7; and 60 (74.1%) were positive and 21 (25.9%) were negative for VEGF. Correlation of marker expression, both in groups and individually, did not show statistical significance in relation to the degree of cell differentiation, staging, disease-free interval, survival or specific mortality. Recurrence showed a statistically significant correlation with positive expression of the three markers, when analyzed as a group (p = 0.038). CONCLUSION: The associated expression of metalloproteinase-1, metalloproteinase-7 and VEGF in colorectal adenocarcinoma is related to the incidence of disease recurrence.

Requirement of cell cycle and apoptosis regulator 1 for target gene activation by Wnt and beta-catenin and for anchorage-independent growth of human colon carcinoma cells

Aberrant Wnt signaling promotes oncogenesis by increasing cellular levels of beta-catenin, which associates with DNA-bound transcription factors and activates Wnt target genes. However, the molecular mechanism by which beta-catenin mediates gene expression is still poorly understood. Here, we show that cell cycle and apoptosis regulator 1 (CCAR1), which was recently shown to function as a transcriptional coactivator for nuclear receptors, also interacts with beta-catenin and enhances the ability of beta-catenin to activate expression of transiently transfected reporter genes. Furthermore, association of CCAR1 with the promoter of an endogenous Wnt/beta-catenin target gene in a colon cancer cell line depends on the presence of beta-catenin. Depletion of CCAR1 inhibits expression of several Wnt/beta-catenin target genes and suppresses anchorage-independent growth of the colon cancer cell line. Thus, CCAR1 is a novel component of Wnt/beta-catenin signaling that plays an important role in transcriptional regulation by beta-catenin and that, therefore, may represent a novel target for therapeutic intervention in cancers involving aberrantly activated Wnt/beta-catenin signaling.

Andrographolide could inhibit human colorectal carcinoma Lovo cells migration and invasion via down-regulation of MMP-7 expression

Andrographolide (Andro), a diterpenoid lactone isolated from a traditional herbal medicine Andrographis paniculata, is known to possess multiple pharmacological activities. In our previous study, Andro had been shown to have potent anti-cancer activity against human colorectal carcinoma Lovo cells by inhibiting cell-cycle progression. To further investigate the mechanism for the anti-cancer properties of Andro, it was used to examine the effect on migration and invasion of Lovo cells. The results of wound-healing assay and in vitro transwell assay revealed that Andro inhibited dose-dependently the migration and invasion of Lovo cells under non-cytotoxic concentrations. Using zymographic assay and RT-PCR, the results revealed that Andro diminished the activity and the mRNA and protein levels of MMP-7, but not MMP-2 or MMP-9. The down-regulation of MMP-7 appeared to be via the inactivation of activator protein-1 (AP-1) since the treatment with Andro suppressed the nuclear protein level of AP-1, which was accompanied by a decrease in DNA-binding level of the factor. Taken together, these results indicated that Andro reduces the MMP-7-mediated cellular events in Lovo cells, and provided a new mechanism for its anti-cancer activity.

Matrix metalloproteinase 7 is required for tumor formation, but dispensable for invasion and fibrosis in SMAD4-deficient intestinal adenocarcinomas

Expression of matrix metalloproteinase 7 (MMP7) is increased in the human colorectal carcinomas, and correlates with malignant progression. However, its contribution to colon cancer pathogenesis is not understood thoroughly. To investigate the roles of MMP7 in colon cancer progression, we introduced an Mmp7 knockout mutation into the cis-Apc/Smad4 mutant mouse, a model of invasive colon cancer in which SMAD4-dependent TGF-beta family signaling is inactivated. We demonstrate here that lack of MMP7 reduces the number and size of tumors in the cis-Apc/Smad4 mice. On the other hand, MMP7-deficiency does not affect the depth of tumor invasion, number of stromal fibroblasts or levels of extracellular matrix components in the tumors. These results indicate that MMP7 is required for tumor formation, but not for the invasion or fibrosis of the colon cancer whose SMAD4-dependent TGF-beta family signaling is blocked.

Biology and potential clinical implications of tissue inhibitor of metalloproteinases-1 in colorectal cancer treatment

Colorectal cancer (CRC) is the second leading cause of cancer-related death in the industrialized world. About half of "curatively" resected patients develop recurrent disease within the next 3-5 years despite the lack of clinical, histological and biochemical evidence of remaining overt disease after resection of the primary tumour. Availability of validated biological markers for early detection, selection for adjuvant therapy, prediction of treatment efficacy and monitoring of treatment efficacy would most probably increase survival. Tissue inhibitor of metalloproteinases-1 (TIMP-1) may be such a marker. TIMP-1 inhibits the proteolytic activity of metalloproteinases, which are centrally involved in tumour invasion and metastases. However, in clinical investigations high tumour tissue or plasma levels of TIMP-1 have shown a strong and independent association with a shorter survival time in CRC patients, suggesting that TIMP-1 could have a tumour-promoting function. Furthermore, measurement of plasma TIMP-1 has been shown to be useful for disease detection, with a high sensitivity and high specificity for early-stage colon cancer. This review describes some basic information on the current knowledge of the biology of TIMP-1 as well as the potential use of TIMP-1 as a biological marker in the management of CRC patients.

In vitro method for diagnosing and monitoring renal cell carcinoma using matrix metalloprotease-7 as humoral biomarker

Matrix metalloprotease (MMP)-7 is associated with malignant aggressiveness and prognosis in various cancers. In renal cell carcinoma (RCC) tissues, it has been reported that MMP-7 is overexpressed in cancer cells and on newly formed vascular endothelial cells, and it is associated with cancer cell invasion and metastasis. From these facts, the possibility exists that measurement of blood MMP-7 levels is useful marker in diagnosis and monitoring or prediction of prognosis in patients with RCC. MMP-7 is secreted in its precursor form and it can be activated by endoproteases. Furthermore, MMP-7 is composed of various domains and fragments. Reliable method and objection is needed to investigate the usefulness of MMP-7 as a human biomarker of RCC.

Prognostic significance of matrix metalloproteinases-1, -2, -7 and -13 and tissue inhibitors of metalloproteinases-1, -2, -3 and -4 in colorectal cancer

Strong expression of many matrix metalloproteinases (MMPs) has been related to poor survival of colorectal cancer (CRC) patients. The expression of tissue inhibitors of metalloproteinases (TIMPs) has been associated with both a beneficial and a poor outcome and there is thus a need to further clarify the significance of MMPs and TIMPs in CRC. The prognostic significance of 4 MMPs and TIMPs in CRC was evaluated. Formalin-fixed, paraffin-embedded tissue arrayed samples of 351 patients with primary colon or rectal cancer of Dukes' stages A-D were selected for immunohistochemical staining of MMP-1, -2, -7 and -13, and TIMP-1, -2, -3 and -4. High expression of MMP-2 in the malignant epithelium as well as in the surrounding stroma was associated with reduced survival of colon cancer patients. Strong epithelial and stromal cytoplasmic staining of TIMP-3 was associated with a longer survival in rectal cancer patients, and here the interobserver variation for evaluating the degree of staining was lower than for epithelial staining. Strong stromal cytoplasmic staining of TIMP-4 predicted longer survival of rectal cancer patients. Multivariate analysis showed that stromal cytoplasmic TIMP-3 staining was the only marker of independent prognostic value. MMP-2 might be a useful prognostic marker in colon cancer, and TIMP-3 and TIMP-4 in rectal cancer, but the findings associated with stromal staining should be interpreted with some caution. Different biologic behavior or different genetic development may explain the differences between colon and rectal cancers regarding the expression of MMP-2, TIMP-3 and TIMP-4.

Achaete-scute homolog-1 linked to remodeling and preneoplasia of pulmonary epithelium

The basic helix-loop-helix protein achaete-scute homolog-1 (ASH1) is involved in lung neuroendocrine (NE) differentiation and tumor promotion in SV40 transgenic mice. Constitutive expression of human ASH-1 (hASH1) in mouse lung results in hyperplasia and remodeling that mimics bronchiolization of alveoli (BOA), a potentially premalignant lesion of human lung carcinomas. We now show that this is due to sustained cellular proliferation in terminal bronchioles and resistance to apoptosis. Throughout the airway epithelium the expression of anti-apoptotic Bcl-2 and c-Myb was increased and Akt/mTOR pathway activated. Moreover, the expression of matrix metalloproteases (MMPs) including MMP7 was specifically enhanced at the bronchiolo-alveolar duct junction and BOA suggesting that MMPs play a key role in this microenvironment during remodeling. We also detected MMP7 in 70% of human BOA lesions. Knockdown of hASH1 gene in human lung cancer cells in vitro suppressed growth by increasing apoptosis. We also show that forced expression of hASH1 in immortalized human bronchial epithelial cells decreases apoptosis. We conclude that the impact of hASH1 is not limited to cells with NE phenotype. Rather, constitutive expression of hASH1 in lung epithelium promotes remodeling through multiple pathways that are commonly activated during lung carcinogenesis. The collective results suggest a novel model of BOA formation via hASH1-induced suppression of the apoptotic pathway. Our study yields a promising new preclinical tool for chemoprevention of peripheral lung carcinomas.

MMP-7 (matrilysin) expression in human brain tumors

Matrix metalloproteinases (MMP) which degrades protein components of the extra-cellular matrix and basement membrane seems to be largely involved in cancer invasiveness. MMP proteolitic activity essentially comes from stromal cells but matrilysin (MMP-7) is produced by the tumor itself. Thus, MMP-7 is investigated to address the particular invasive behavior of human glioma. Both MMP-7 mRNA and protein were clearly identified in human glioma. MMP-7 mRNA expression was highly variable within our glioma population. When analyzing MMP-7 mRNA expression in different primary brain tumors, we found highly variable levels of expression not related to their invasive behavior. In successive biopsies obtained in the same patients with glioblastoma, MMP-7 mRNA was quantified and appeared variable, but intra-individual variations were lower than inter-individual differences. With a xenograft model of U87 human tumors in RAG2/gamma(c) immune-deficient mice, the strict tumor origin of MMP-7 was shown. Additionally, MMP-7 expression by U87 cells which is low in culture was stimulated by these cells while forming tumors and the level of expression was higher when the tumor cells were implanted within the brain. These data provide some consistent information about cross-talk occurring between the tumor and the surrounding stroma to regulate MMP-7 expression.

Matrix metalloproteinase-7-catalyzed release of HB-EGF mediates deoxycholyltaurine-induced proliferation of a human colon cancer cell line

Prior evidence indicates that bile acids stimulate colon cancer cell proliferation by muscarinic receptor-induced transactivation of epidermal growth factor receptors (EGFR). To explore further the mechanism underlying this action, we tested the hypothesis that bile acids activate a matrix metalloproteinase (MMP) that catalyzes release of an EGFR ligand. Initial studies showed that non-selective MMP inhibitors blocked the actions of deoxycholyltaurine (DCT), thereby indicating a role for MMP-catalyzed release of an EGFR ligand. DCT-induced cell proliferation was reduced by increasing concentrations of EGFR kinase inhibitors, by antibodies to the ligand binding domain of EGFR, by neutralizing antibodies to heparin binding-EGF-like growth factor (HB-EGF) and by CRM197, an inhibitor of HB-EGF release. These findings and our observations with more selective MMP inhibitors suggested that MMP-7, an enzyme known to release HB-EGF, plays a key role in mediating bile acid-induced H508 colon cancer cell proliferation. We observed that recombinant HB-EGF and MMP-7 mimicked both the signaling and proliferative actions of bile acids. Strikingly, reducing MMP-7 expression with either neutralizing antibody or small interfering RNA attenuated the actions of DCT. MMP-7 expression in H508 cells was confirmed using quantitative reverse transcription PCR. DCT stimulated a greater than 10-fold increase in MMP-7 gene transcription. Co-localization of pro-MMP-7 and pro-HB-EGF at the cell surface (immunofluorescence microscopy) was demonstrated, indicating proximity of the enzyme to its substrate. These findings provide strong evidence that in H508 human colon cancer cells, DCT-induced transactivation of EGFR is mediated by MMP-7-catalyzed release of the EGFR ligand HB-EGF.

Auraptene decreases the activity of matrix metalloproteinases in dextran sulfate sodium-induced ulcerative colitis in ICR mice

Previously we reported that auraptene was a potent suppressant for matrix metalloproteinase (MMP)-7 expression in HT-29 human colon cancer cells. In the present study, we examined the effects of auraptene on MMP-2, -7, and -9 expression in colonic mucosa from dextran sulfate sodium (DSS)-induced ulcerative colitis mice. Auraptene remarkably suppressed the DSS-induced gelatinolytic activity of MMP-7 as well as the expression of MMP-2 and -9, suggesting that it might be useful in anti-metastatic therapies via the targeting of MMPs.

Genetic polymorphisms of MMP1, MMP3 and MMP7 gene promoter and risk of colorectal adenoma

Background

Matrix metalloproteinases (MMP) have been shown to play a role in colorectal cancer (CRC). More recently, MMP1, MMP3 and MMP7 functional gene promoter polymorphisms have been found to be associated with CRC occurrence and prognosis. To document the role of MMP polymorphisms in the early step of colorectal carcinogenesis, we investigated their association with colorectal adenoma risk in a case-control study comprising 295 patients with large adenomas (LA), 302 patients with small adenomas (SA) and 568 polyp-free (PF) controls.

Methods

Patients were genotyped using automated fragment analysis for MMP1 -1607 ins/del G and MMP3 -1612 ins/delA (MMP3.1) polymorphisms and allelic discrimination assay for MMP3 -709 A/G (MMP3.2) and MMP7 -181 A/G polymorphisms. Association between MMP genotypes and colorectal adenomas was first tested for each polymorphism separately and then for combined genotypes using the combination test. Adjustment on relevant variables and estimation of odds ratios were performed using unconditional logistic regression.

Results

No association was observed between the polymorphisms and LA when compared to PF or SA. When comparing SA to PF controls, analysis revealed a significant association between MMP3 -1612 ins/delA polymorphism and SA with an increased risk associated with the 6A/6A genotype (OR = 1.67, 95%CI: 1.20–2.34). Using the combination test, the best association was found for MMP3.1-MMP1 (p = 0.001) with an OR of 1.88 (95%CI: 1.08–3.28) for the combined genotype 2G/2G-6A/6A estimated by logistic regression.

Conclusion

These data show a relation between MMP1 -1607 ins/del G and MMP3 -1612 ins/delA combined polymorphisms and risk of SA, suggesting their potential role in the early steps of colorectal carcinogenesis.

Role of matrix metalloproteinase-7 in colorectal adenomas

Matrix metalloproteinases (MMPs) degregade and remodel the extracellular matrix. They are known to be overexpressed as normal mucosa progresses to adenomas and carcinomas. In our prospective study we measured the overexpression of MMP-7 immunohistochemically in various types of colonic adenomas. Although MMP-7 has already been shown to be overexpressed in various types of colonic adenomas, tubular versus villous adenomas had not been further seperated to date. Seventy-six patients had either normal mucosa (n=15) or tubular (n=32), tubulovillous (n=16), or villous (n=13) colonic adenoma. MMP-7 expression was classified into three categories, as negative, weakly stained, or strongly stained, depending on the percentage of cells stained. Each adenoma was graded according to the percentage of strongly stained areas in the adenoma as G0, G1, G2, or G3. Sixty-nine percent of villous adenomas showed grade 3 staining of MMP-7, versus none of the tubular adenomas. G0 and G1 staining was not detected in the villous adenomas. The results of the study show that the degrees of overexpression of the three subtypes of colonic adenomas were statistically significantly different. In conclusion, MMP-7 overexpression is thought to be an early event in the adenoma-carcinoma pathway.