Plasma MMP-1 Expression as a Prognostic Factor in Colon Cancer.

BACKGROUND: Matrix metalloproteinases (MMP) are involved in the local and distant invasiveness of colorectal cancer. This study investigates the prognostic value of circulating matrix metalloproteinase levels in patients with colon cancer. METHODS: A cohort of 152 patients was followed for more than 10 years. The correlation of plasma levels of MMP-1,-2, -7, -8, and -9 and survival was investigated. RESULTS: A high level of MMP-1 in circulating plasma was associated with a poorer prognosis in colon cancer (HR 2.0, 95% CI 1.1-3.9) in multivariate analysis regarding 5-year cancer-specific survival. This was further seen in regard of 10-year cancer-specific survival. CONCLUSIONS: Measurement of plasma MMP-1 concentration in patients planned for radical colon cancer surgery might be of importance when discussing prognosis and selection of patients for oncological treatment and postsurgery surveillance.

Levels of matrix metalloproteinases differ in plasma and serum - aspects regarding analysis of biological markers in cancer.

BACKGROUND: There are inconsistencies in the use of serum or plasma when analysing the matrix metalloproteinases (MMPs) as diagnostic or prognostic markers. The purpose of this study was to compare the concentration of MMP-1, -2, -7, -8, -9 and -13 in serum vs plasma samples. METHODS: Blood samples were obtained from sixty-five men and women. Samples were analysed for levels of MMPs in corresponding citrate plasma and serum. RESULTS: All MMPs expressed higher concentration in serum compared with plasma (P<0.01). There were no differences between genders. CONCLUSIONS: Present study demonstrated significant differences regarding concentrations of some MMPs using plasma vs serum. We conclude that future studies regarding MMPs as biological markers in cancer should consider the use of citrate plasma instead of serum.

Intestinal mucosal MMP-1 - a prognostic factor in colon cancer.

OBJECTIVE: There is evidence that transforming growth factor-ß1 (TGF-ß1) and matrix metalloproteinases (MMPs) play an important role in tumor invasion and progression in colorectal cancer. The aim of this study was to assess their utility in prediction of cancer-specific survival (CSS). MATERIALS AND METHODS: 136 patients undergoing curative surgery for colorectal carcinoma were prospectively included. Samples were taken from tumor and tumor-free intestinal mucosa and ELISA was used to assess protein levels in the tissues. Patients were followed for CSS. The median follow-up time for all included patients was 65 months (range: 45-92). The main outcome measure was CSS. RESULTS: T stage, lymph node involvement and high levels of MMP-1 as well as MMP-9 in tumor-free mucosa tissue were significantly associated with CSS in colon cancer in univariate analysis. This prognostic strength was maintained for MMP-1 and N-status in multivariate analysis. CONCLUSIONS: The results indicate that MMP-1 is independently associated with CSS in patients with colon cancer. Furthermore, a possible clinical implication is that MMP-1 protein expression in tumor-free mucosa could identify colon cancer patients with poor CSS in need of more intensified adjuvant treatment.

Stability of matrix metalloproteinase-9 as biological marker in colorectal cancer.

Matrix metalloproteinases (MMPs) are believed to be of importance in the growth and spread of colorectal cancer (CRC). MMP-9 level has been suggested as a biological predictor of prognosis in CRC as well as in other types of cancer such as breast and cervical cancer. The purpose of this study was to investigate the stability over time of MMP-9 in cryopreserved plasma, colorectal tumor tissue extract and macroscopically tumor-free colon mucosa tissue extract samples. Plasma and tissue samples were taken from patients at primary CRC surgery and analyzed for MMP-9. Aliquots of samples from the same patients were stored at - 80 °C pending analysis. These aliquots were analyzed using identical methods after storage periods of nine (plasma) and twelve (tissue) years. No significant difference in plasma MMP-9 concentration was seen between baseline samples and those after 9 years of cryopreservation (median values 9.9 and 9.7 ng/mL, respectively; p > 0.05). MMP-9 levels in the tumor-free tissue extracts had increased to baseline (median values 7.1 and 8.1 ng/mL, respectively; p < 0.01). MMP-9 levels in the tumor tissue extracts had also increased significantly (median values 89.9 and 133.5 ng/mL, respectively; p < 0.01). We have demonstrated that MMP-9 levels in frozen citrated plasma are stable if stored at - 80 °C, whereas MMP-9 levels in extracts from tumor tissue and tumor-free intestinal mucosa appear to increase with time. We conclude that MMP-9 levels in cryopreserved plasma may be considered stable over time and are thus suitable for comparison purposes in consecutive series.

Colorectal Cancer Cells Adhere to Traumatized Peritoneal Tissue in Clusters, An Experimental Study.

Purpose/Aim: Colorectal malignity is one of the most common forms of cancer. The finding of free intraperitoneal colorectal cancer cells during surgery has been shown to be associated with poor outcome. The aim of this study was to develop an experimental model designed to investigate adhesion of colorectal cancer cells to the peritoneal surface. MATERIALS AND METHODS: Two human experimental models were developed, the first using cultured mesothelial cells and the second consisting of an ex vivo model of peritoneal tissue. Both models were subjected to standardized trauma, following which labeled colorectal cancer cells (Colo205) were introduced. Adhesion of tumor cells was monitored using microscopy and detection of fluorochromes. RESULTS: The mesothelial cell layers and peritoneal membranes remained viable in culture medium for several weeks. In our experimental model, the tumor cells added were seen to adhere to the edges of the traumatized area in cluster formations. CONCLUSIONS: The use of human peritoneal tissue in an ex vivo model would appear to be a potentially useful tool for the study of interaction between human peritoneal membrane and free tumor cells. Experimental surgical trauma increases the ability of tumor cells to adhere to the peritoneal membrane. This ex vivo model should be useful in future studies on biological interactions between peritoneum and tumor cells in the search for novel forms of peritoneal cancer therapy.

TEP With Long-Term Resorbable Mesh in Patients With Indirect Inguinal Hernia.

BACKGROUND AND OBJECTIVES: The role of long-term degradable implants in reducing the risk of chronic postoperative pain after inguinal hernia repair is still unclear. A pilot study using a synthetic long-term resorbable mesh in Lichtenstein repair showed good results regarding pain and discomfort in patients with indirect inguinal hernia (IH) without recurrences, but higher recurrence rate in patients with direct inguinal hernia (DH). The purpose of this study was to assess the incidence of pain and early recurrence in patients with LIH surgically treated with the TEP technique using a long-term degradable mesh. This is the first human study to use long-term degradable mesh with the TEP approach. METHODS: This study was prospective, including 35 primary IHs surgically treated with TEP repair using TIGR Mesh (Novus Scientific Pte, Ltd, Singapore). At the 1-year follow-up recurrence was assessed by clinical examination and the incidence of pain or discomfort was assessed before and after surgery by Visual Analog Scale (VAS) and Inguinal Pain Questionnaire (IPQ). RESULTS: After 12 months, no patients had chronic pain. Only 1 (2.8%) patient reported pain using the VAS (score = 2), and 4 patients reported pain that could easily be ignored. All 4 patients reported less pain 1 year after the operation using both IPQ and VAS, compared with the preoperative assessment. One patient (2.8%) developed a recurrence 20 months after the primary operation. CONCLUSION: TEP repair using a synthetic long-term resorbable mesh was found to be safe and promising regarding pain and discomfort at 1-year follow-up in patients with IH. Longer follow-up is necessary to establish the risk of recurrence.

Role of matrix metalloproteinases in tumour invasion: immunohistochemistry of peritoneum from peritoneal carcinomatosis.

Colorectal cancer is one of the most common forms of cancer. Spread of tumour to the peritoneal cavity may lead to seeding of cancer cells that adhere to and invade the peritoneal membrane causing peritoneal carcinomatosis. Matrix metalloproteinases (MMPs) play an essential role in cancer cell invasion and dissemination. The aim of this study was to evaluate the morphology and presence of matrix metalloproteinases in peritoneal carcinomatosis. Biopsy samples of the parietal peritoneum were taken from patients undergoing cytoreductive surgery for peritoneal carcinomatosis. The samples were fixed in formalin, dehydrated and embedded in paraffin prior to cutting into 4-µm slices. Staining with haematoxylin/eosin was used for morphology studies, and MMP-1, MMP-2 and TIMP-1 levels were evaluated using immunohistochemistry and light microscopy. The microscopically tumour-free areas of the peritoneal membrane were thin compared to the peripheral invasion zone and the areas invaded by tumour. Peritoneum invaded by tumour was richly vascularised and contained inflammatory cells. MMP-1 was expressed in tumour-free peritoneum and in the invasion zone between tumour and peritoneal tissue, but not in tumour-invaded areas. MMP-2 and TIMP-1 were mostly expressed in the proximity of blood vessels and inflammatory cells in tumour-invaded areas, but was not seen in tumour-free areas. MMPs play an important role in the process of cancer cell invasion of the peritoneum in peritoneal carcinomatosis. The peripheral zone of the tumour appears to be of importance for tumour invasion.

An ex vivo model using human peritoneum to explore mesh-tissue integration.

Biological compatibility, in terms of implantation of foreign mesh material in hernia surgery, still needs experimental investigation. The present study develops an experimental model using human peritoneum to study the integration between tissue and different mesh material. The ex vivo model using peritoneal tissue was studied with different mesh material, and integration was monitored over time using microscopy. The peritoneal model could be kept viable in culture for several weeks. Cell migration was seen after 7-10 days in culture and could be further monitored over several weeks. The use of a human artificial model environment enabling the investigation of tissue/mesh integration has, to our knowledge, not been described previously. This proof-of-concept model was developed for the investigation of peritoneal biology and the integration between tissue and different mesh material. It has the potential to be useful in studies on other important biological mechanisms involving the peritoneum.

TGF-ß1 promotes transition of mesothelial cells into fibroblast phenotype in response to peritoneal injury in a cell culture model.

BACKGROUND: Peritoneal adhesions are a clinical problem. A key to the understanding of peritoneal adhesions is to study the healing of mesothelial cells within the peritoneal cavity following surgery. Transforming growth factor beta (TGF-ßs) affects this healing process. The aim of this study was to investigate the effects of different concentrations of TGF-ß1 on the healing rate and healing properties of mesothelial cells. MATERIALS AND METHODS: Human mesothelial cells from peritoneal fluid were collected, cultured and a mechanical wound was created. The restoration of the mesothelial surface with and without increasing concentrations of TGF-ß1 was monitored. RESULTS: The denuded area was restored within 24 h. The healing rate was most extensive between the first and second hour after the damage (61.9 ± 22.8 µm/h). No significant difference in healing rate were observed when increasing levels of TGF-ß1 were used. However, higher concentrations of TGF-ß1 increased cell size and the cells presented more fibroblast specific properties. Lower TGF-ß1 concentrations increased the number of proliferating cells. CONCLUSIONS: This study indicates the importance of high levels TGF-ß1 in mesothelial cell healing, mainly by changing the actual healing properties of the cells. Elevated levels of TGF-ß1 might promote mesothelial cell transition towards a more fibroblast-like appearance.