Effect of the expression of matrix metalloproteases and their tissue inhibitors on survival of patients with resectable colorectal cancer

The paradoxical role of matrix metalloproteinase-11 in cancer

The microenvironment surrounding the tumor affects biological processes, such as cell proliferation, angiogenesis, apoptosis, and invasion. Therefore, the ability to change these environments is an important attribute for tumor cells to obtain specific functions necessary for growth and metastasis. Matrix metalloproteinases (MMPs) are zinc-dependent proteolytic metalloenzymes that facilitate protease-dependent tumor progression by degrading extracellular matrix (ECM) proteins, releasing cytokines, growth factors, and other cell surface molecules. As one of the most widely studied MMPs, MMP-11 is an important protease that is expressed in cancer cells, stromal cells, and the adjacent microenvironment. MMP-11 has a dual effect on tumors. On one hand, MMP-11 promotes tumor development by inhibiting apoptosis and promoting the migration and invasion of cancer cells in the early stage. On the other hand, in animal models, MMP-11 has a protective effect on tumor growth and metastasis at an advanced stage. Based on current findings regarding the importance of MMP-11 in altering the tumor microenvironment, there is a need to further understand how stromal cells and the ECM regulate tumor progression, which may result in the re-examination of MMPs as drug targets for cancer and other diseases. In this review, we summarize the dual role of MMP-11 in cancer and its potential clinical significance.

Relationship between Metalloprotease-7 and -14 and Tissue Inhibitor of Metalloprotease 1 Expression by Mucosal Stromal Cells and Colorectal Cancer Development in Inflammatory Bowel Disease

Colorectal carcinoma (CRC) associated with inflammatory bowel disease (IBD) is an example of an inflammation-related cancer. Matrix metalloproteases (MMP) are known to be associated with both processes. The aim of the study was to compare the expression of MMP-7, MMP-14 and tissue inhibitor of metalloproteases-1 (TIMP-1) in sporadic CRC- and IBD-associated CRC, and to compare the expression in inflamed and non-inflamed colonic tissue samples from IBD patients without or with associated CRC. An immunohistochemical study of MMP-7, -14 and TIMP-1 was performed on sporadic CRC (n = 86), IBD-associated CRC (n = 23) and colorectal mucosa of non-tumor samples from IBD patients without (n = 47) and with (n = 23) associated CRC. These factors were more frequently expressed by cancer-associated fibroblasts (CAF) from IBD-associated CRC than by CAF from CRC not associated with IBD. Regarding the inflamed tissue of IBD patients, Crohn’s disease (CD) patients with CRC development showed a higher expression of MMP-14 by fibroblasts and by mononuclear inflammatory cells (MICs) than CD patients without CRC development. In non-inflamed tissue samples, MMP-7 associated with fibroblasts and MICs, and TIMP-1 associated with MICs, were more frequently expressed in CD patients with CRC development than in CD patients without CRC development. Our data suggest that these factor expressions by stromal cells may be biological markers of CRC development risk in IBD patients.

Crosstalk among colon cancer-derived exosomes, fibroblast-derived exosomes, and macrophage phenotypes in colon cancer metastasis

Cellular crosstalk is an important mechanism in the pathogenesis of inflammatory disorders and cancers. One significant means by which cells communicate with each other is through the release of exosomes. Exosomes are extracellular vesicles formed by the outward budding of plasma membranes, which are then released from cells into the extracellular space. Many studies have suggested that microvesicles released by colon cancer cells initiate crosstalk and modulate the fibroblast activities and macrophage phenotypes. Interestingly, crosstalk among colon cancer cells, macrophages and cancer-associated fibroblasts maximizes the mechanical composition of the stromal extracellular matrix (ECM). Exosomes contribute to cancer cell migration and invasion, which are critical for colon cancer progression to metastasis. The majority of the studies on colorectal cancers (CRCs) have focused on developing exosomal biomarkers for the early detection and prediction of CRC prognosis. This study highlights the crosstalk among colon cancer-derived exosomes, macrophage phenotypes and fibroblasts during colon cancer metastasis.

Toll-Like Receptor 4 and Matrix Metalloproteases 11 and 13 as Predictors of Tumor Recurrence and Survival in Stage II Colorectal Cancer

Current clinical-pathologic stratification factors do not allow clear identification of high-risk stage II colorectal cancer (CRC) patients. Therefore, the identification of additional prognostic markers is desirable. Toll-like receptor (TLR)-4 is activated during tumorigenesis and matrix metalloproteases (MMPs) are involved in invasion and metastasis. We aimed to evaluate the expression and clinical relevance of TLR4, MMP11 and MMP13 for patients with stage II CRC. Immunohistochemistry was used to study the expression of TLR4, MMP11 and MMP13 in 96 patients with stage II CRC. We measured the global expression and the expression by different cell types (tumor cells, cancer-associated fibroblasts (CAFs) and mononuclear inflammatory cells (MICs)). The potential relationship between expressions of factors and different prognostic variables were evaluated. Our results show significant relationships between either TLR4 expression by tumor cells and MMP11 expression by CAFs and high risk of tumor recurrence. In addition, the concurrence of age ≥ 75 years and the non-expression of MMP11 by CAFs identify a subgroup of patients with a good prognosis. Our results show that TLR4 expression by tumor cells and MMP11 expression by CAFs may to improve the identification of patients with stage II CRC with a high-risk of relapse.

Role of DDX3 in the pathogenesis of inflammatory bowel disease

When crypt stem cells of the gastrointestinal tract become injured, the result is increased synthesis of pro-inflammatory cytokines and matrix metalloproteinases by their progeny – the colonic epithelium. Chronic inflammation of the gastrointestinal tract is a characteristic of inflammatory bowel disease, which includes Crohn’s Disease and Ulcerative Colitis. In our ongoing investigation to decipher the characteristic functions of a RNA helicase gene, DDX3, we identified high DDX3 expression by immunohistochemistry of colon biopsy samples, which included chronic/mild Morbus Crohn, active Morbus Crohn, Chronic/mild Colitis Ulcerosa and active Colitis Ulcerosa in epithelium and stromal compartments. We used a small molecule inhibitor of DDX3, RK-33, on two human colonic epithelial cell lines, HCEC1CT and HCEC2CT and found that RK-33 was able to decrease expression of MMP-1, MMP-2, MMP-3, and MMP-10. Moreover, forced differentiation of a human colonic cancer cell line, HT29, resulted in decreased DDX3 levels, indicating that DDX3 contributes to the modulation of colonic epithelium differentiation. In conclusion, our results revealed novel functions of DDX3 in inflammatory bowel disease and indicate a potential for using RK-33 as a systemic therapy to promote not only differentiation of transformed colonic epithelium but also to reduce MMP expression and thus elicit a decreased inflammatory response.

Matrix metalloproteases expression in different histological types of colorectal polyps

INTRODUCTION

Colorectal carcinoma (CC) may begin as benign polyps, which may be classified in different histological types with a different risk to develop cancer. Matrix metalloproteases (MMPs) are able to degrade all components in the extracellular matrix and are important tissue-remodeling enzymes and key elements in tumor invasion and metastasis. The aim of this study was to investigate the expression and clinical relevance of MMPs in different histological types of colorectal polyps.

METHODS

The expression levels of MMP-1, 2, 7, 9, 11, 13 and 14 were analyzed by real-time PCR, Western-blot and immunohistochemistry in 50 patients with different histological types of colorectal polyps, 28 of which developed CC.

RESULTS

The results indicate that hyperplastic polyps had the lowest levels of MMP-1 and MMP-7, tubular polyps showed higher levels of both MMP-7 and MMP-14, and tubulovillous adenoma showed higher levels of MMP-1, MMP-7 and MMP-14.

CONCLUSION

MMP expression was decreased in hyperplastic, tubular and tubulovillous adenoma polyps from patients who developed CC. Our findings suggest that MMP expression may be a pathological marker of colorectal polyps and for cancer susceptibility, which may improve strategies for CC prevention based on screening colonoscopy.

Knockdown of inhibitor of growth protein 2 inhibits cell invasion and enhances chemosensitivity to 5-FU in human gastric cancer cells

BACKGROUND

The inhibitor of growth (ING) family is involved in multiple cellular functions, but the role of ING2 in gastric cancer progression is unclear.

AIM

To investigate the effects of ING2 gene knockdown on chemosensitivity to 5-fluorouracil (5-FU) in human gastric cancer cells and its possible mechanisms.

METHODS

Short hairpin RNA (shRNA) targeting ING2 (shING2) was transfected into MGC-803 cells using Lipofectamine 2000, and stable transfection cell lines were established using G418. Cell viability, cell cycle distribution, cell apoptosis, and invasive ability were measured to determine the influence of ING2 knockdown on cell biologic characteristics. Messenger RNA (mRNA) and protein levels of ING2, cyclin D1, NF-kappaB/p65, and several matrix metalloproteinases (MMPs) were determined by use of real-time polymerase chain reaction (PCR) or Western blotting, respectively.

RESULTS

Our results showed that ING2 knockdown induced cell apoptosis and inhibited cell viability significantly (P < 0.05). Additionally, ING2 knockdown induced a specific G0/G1 arrest. Furthermore, the suppression of ING2 could enhance the chemosensitivity of gastric cancer cells to 5-FU significantly. Moreover, knockdown of ING2 expression significantly reduced cellular metastatic ability and expression of MMPs in MGC-803 cells. The expression of cyclin D1 and NF-kappaB/p65 was also markedly inhibited in MGC-803/shING2 cells compared with control cells.

CONCLUSIONS

ING2 not only plays an essential role in the growth and invasion of MGC-803 cells but also represents a potential approach to chemosensitization therapy in human gastric cancer.

The behavior of matrix metalloproteinases and their inhibitors in colorectal cancer

Matrix metalloproteinases (MMPs) play an important role in the degradation of extracellular matrix components crucial for tumor growth, invasion and metastasis. MMPs are controlled by natural inhibitors called tissue inhibitors of metalloproteinases (TIMPs). We and others have demonstrated that MMPs and TIMPs are especially important in the process of tumor invasion, progression and the metastasis of colorectal cancer (CRC). It has been proposed that MMPs and TIMPs might play a part not only in tumor invasion and initiation of metastasis but also in carcinogenesis from colorectal adenomas. Several recent studies demonstrated that high preoperative serum or plasma MMP-2, MMP-9 and TIMP-1 antigen levels are strong predictive factors for poor prognosis in patients with CRC and their determination might be useful for identification of patients with higher risk for cancer recurrence. MMP-9 and TIMP-1 have significant potential tumor marker impact in CRC. Their diagnostic sensitivity is consistently higher than those of conventional biomarkers. The pharmacological targeting of CRC by the development of a new generation of selective inhibitors of MMPs, that is highly specific for certain MMPs, is a promising and challenging area for the future.