BACKGROUND: 72 Kilodalton (kd) type IV collagenase is a matrix metalloproteinase that specifically cleaves type IV collagen molecules. The enzyme has been postulated to have an important role in the invasion and spread of malignant tumors. EXPERIMENTAL DESIGN: In situ hybridization was used to study the expression of the 72 kd type IV collagenase mRNA in 24 benign, 2 semimalignant, and 15 malignant ovarian tumors and in 5 metastases of ovarian serous adenocarcinomas. The results were correlated with the expression of the mRNA for the alpha 1(IV) chain of type IV collagen and with the corresponding immunohistochemical distribution of the enzyme. RESULTS: The results showed that the more malignant an ovarian tumor was, the more clearly mRNA expressions for both 72 kd type IV collagenase and the alpha 1(IV) chain could be detected in tumor cells. The expression of both types of mRNAs was localized within the cells of tumor stroma and occurred mainly in fibroblasts and vascular endothelial cells. Epithelial tumor cells only rarely expressed these mRNAs. Immunohistochemical stainings localized the 72 kd collagenase as well to the stromal cells as to the epithelial cells of both benign and malignant tumors. CONCLUSIONS: The findings indicate that genes for the 72 kd type IV collagenase and for its substrate are simultaneously active in the same cells of the tumor stroma. The difference in the in situ hybridization and immunohistochemical findings could be explained by a possible variation in the metabolic balance between synthesis and accumulation of the protein in different cell types. It can also be proposed that the activity of the 72 kd type IV collagenase would be mediated through a receptor-like mechanism present on epithelial cells which could bind the 72 kd type IV collagenase synthesized elsewhere. There is also a possibility that the gelatinolytic activity of the mesenchymally synthesized 72 kd type IV collagenase would be consumed to degrade extracellular matrix proteins other than basement membranes.
The expression of tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) was studied in eight malignant fibrous histiocytomas (MFH) and in eight dermatofibromas (DF) using in situ hybridization methods (ISH). Immunohistochemical stainings were also performed using corresponding antibodies to TIMP-1 and TIMP-2. In ISH the neoplastic cells of MFHs showed a high level of expression for both TIMP-1 and TIMP-2 mRNAs. The cells usually expressed similarly both TIMPs, except for osteoclast-like giant cells, which showed a distinct signal for TIMP-2 but not for TIMP-1. A distinctly lower level of both TIMP-1 and TIMP-2 mRNAs was seen in DFs. Immunohistochemical stainings were concordant with the results obtained by ISH. The findings suggest that the behavior of MFHs and DFs is not directly or solely dependent on the quantity of type IV collagenase inhibitors. The increased TIMP synthesis in MFHs might represent a chaotic response of malignant cells to increased matrix degradation. Alternatively, it may reflect a deranged communication between type IV collagenases and TIMPs in malignant tissues.
BACKGROUND: Previous studies have shown that matrix metalloproteinase-2 (MMP-2) (a 72-kilodalton Type IV collagenase/gelatinase A) is associated with breast carcinoma, but to the authors' knowledge there are no reports showing that it is prognostic for overall survival. METHODS: Expression of the immunoreactive protein for MMP-2 was evaluated in tissue sections from primary breast carcinomas of 177 patients with a monoclonal antibody to MMP-2 using an immunohistochemical technique. RESULTS: Approximately 84% of the samples were MMP-2 positive, with 22% being strongly positive. Positive MMP-2 immunostaining was prognostic for shortened survival. After 10 years 56% of the patients with tumors that were strongly positive for MMP-2 were alive, whereas 88% of patients with an MMP-2 negative tumor and 70% of patients with weakly or moderately positive tumors were still alive (chi-square test = 7.4; P
OBJECTIVE: Expression of the immunoreactive protein of matrix metalloproteinase 2 (MMP-2) was studied in cervical tumors representing various stages of cell atypia and differentiation. In this study, we evaluated whether the expression of MMP-2 is an early or late event in the process of dedifferentiation and cancer progression. METHODS: Paraffin tissue sections from 60 cervical neoplasias including 38 cervical intraepithelial neoplasias (CINs) and 22 early-stage (stage IB and IIA) squamous cervical carcinomas were studied with respect to the expression of MMP-2 protein by using immunoperoxidase staining. RESULTS: The staining pattern of MMP-2 in the CIN lesions usually differed from that in squamous carcinoma. Latent MMP-2 protein localized, in most of the cases, to the periphery of the CIN cells, but was diffuse in the cytoplasm of the carcinoma cells. No correlation was found between overexpression of MMP-2 protein and degree of dysplasia, nor was there any association between MMP-2 and human papillomavirus (HPV). High scores for MMP-2 were observed only in histologically higher-grade early-stage cervical carcinomas. The lymph node metastases derived from high-MMP-2-score primary tumors were also positive for MMP-2. No correlation between MMP-2 staining and clinical course or prognosis was found. CONCLUSIONS: MMP-2 expression is an early event during dedifferentiation and malignant transformation in cervical neoplasias. The pattern of staining is different in CIN than in squamous carcinoma cells, in which overexpression may correlate with the degree of anaplasia.
Uveal melanoma is the most common primary intraocular tumour. Once haematogenous metastasis has occurred, there is no cure for the disease and there is an obvious need for new biological prognostic markers to estimate the risk of metastasis. In this study, the expression of matrix metalloproteinase-2 (MMP-2) was characterized immunohistochemically in 29 human uveal melanomas. Enzyme-linked immunoassays and gelatin zymographies were assessed in order to quantify the expression of gelatinases A and B, as well as the tissue inhibitor of metalloproteinases (TIMPs), in the vitreous body. A total of 49 per cent of the uveal melanomas displayed a positive immunoreaction for MMP-2 in melanoma cells, the epithelioid cells showing the most frequent staining. There was no correlation between the positivity of MMP-2 staining and the size of the primary tumour, gender or age. The expression of MMP-2 was associated with a dismal prognosis: the 5-year overall survival rate for MMP-2-positive cases was significantly inferior to that of the MMP-2 negative cases, 49 per cent vs. 86 per cent, respectively (p=0.02). A patient group at high risk of metastatic disease was identified; only 38 per cent of patients with a MMP-2-positive non-spindle cell uveal melanoma survived for 5 years. The analyses of MMPs or TIMPs in the vitreous body had no prognostic value. Positive immunostaining for MMP-2 was observed in the retinal pigment epithelium, corneal epithelium, and fibroblasts in the ciliary body and choroid. It is concluded that immunohistochemical analysis of MMP-2 may help to predict a risk of metastasis in uveal melanoma.
Matrix metalloproteinases play an important role in the invasion of tumor cells and the progression of cancer. The 72 kDa type IV collagenase, a matrix metalloproteinase 2 (MMP-2) has been shown to contribute to the invasion and metastasis in diverse malignant neoplasms. OBJECT: To elaborate the potential role of MMP-2 in brain tumor invasion we studied the expression and localization of this enzyme protein in 101 brain tumors representing different types of brain neoplasms. For the first time, we also correlated the expression of MMP-2 protein to patient survival. METHODS: Using immunohistochemistry and a monoclonal antibody specific for MMP-2 we found that MMP-2 protein was primarily localized in tumor cells and vasculature cells as well as inflammatory cells. The expression of MMP-2 was absent or negligible in benign tumors (pilocytic astrocytoma and meningioma). Thirty-three percent (6/18) of astrocytomas, 38% (3/8) of anaplastic astrocytomas, 14% (1/7) of anaplastic oligodendrogliomas, 54% (19/35) of glioblastomas and 100% (6/6) of metastatic brain tumors were positive for MMP-2. A correlation between MMP-2 expression and survival was found in malignant brain tumors. The mean survival of patients with an MMP-2 negative tumor was 36 months, when it was only 7-14 months in patients with an MMP-2 positive tumor. CONCLUSIONS: Our data suggest that MMP-2 is associated with histological malignancy and poor survival in brain tumors.
Radiation-induced fibrosis is a common side-effect of cancer treatment. The pathophysiological events leading to fibrosis are not known in detail. We analysed the effect of therapeutic irradiation on human skin collagen synthesis, skin thickness, gelatinases and their inhibitors. Twenty randomly chosen women who had been treated for breast cancer with surgery and radiation therapy participated in the study. In each patient, the irradiated skin area was compared with a corresponding non-treated skin area. Suction blister fluid (SBF) and serum samples were analysed for the aminoterminal propeptides of type I and type III procollagens (PINP and PIIINP), tissue inhibitors of matrix metalloproteinases (MMPs) 1 and 2 (TIMP-1 and TIMP-2) and MMP-9 and MMP-2/TIMP-2 complex. Skin biopsies were analysed for PINP and immunohistochemical staining was used for PIIINP. In irradiated skin, PINP, PIIINP, TIMP-1 and MMP-2/TIMP-2 complex levels in SBF and the number of PINP-positive fibroblasts in tissue sections were significantly higher in comparison with non-treated skin. The levels of TIMP-2 in irradiated and non-irradiated skin were similar. MMP-9 could not be detected in SBF with the assay used. The serum levels of MMP-9 were higher in the treated subjects than the reference values. The serum values of PINP, PIIINP, TIMP-1, TIMP-2 and MMP-2/TIMP-2 complex were not significantly affected. These results indicate increased local collagen synthesis and accumulation of connective tissue in irradiated skin. The marked upregulation of collagen synthesis as a result of irradiation offers a possibility to treat this complication with compounds such as topical steroids which downregulate collagen synthesis.
Cytotrophoblasts of early placenta invade the decidual membrane, gestational endometrium, and spiral arteries during early pregnancy. Unlike tumor invasion, this physiological invasion is well controlled, although its molecular mechanisms are largely unknown. We have previously shown that cytotrophoblasts synthesize significant mRNAs for 72-KD Type IV collagenase, laminin, and Type IV collagen, proteins implicated in extracellular matrix turnover and migration. In this study we used in situ hybridization and immunohistochemistry to investigate the mRNA expression pattern of 92-KD Type IV collagenase and the matix metalloproteinase inhibitors TIMP-1, TIMP-2, and TIMP-3 in early human placenta and decidual membrane. mRNAs for 92-KD Type IV collagenase, TIMP-1, TIMP-2, and TIMP-3 were found in the cells of cytotrophoblastic columns, the endothelial and fibroblastic stromal cells of villi, and the large decidualized cells of decidual membrane. TIMP-1 expression was notably accentuated in the fibroblasts of fibrotic villi. In the decidual membrane, the signals for 92-KD Type IV collagenase and TIMP-1 mRNA were particularly strong around the glandular structures. The trophoblastic epithelium of villi and the epithelial cells of decidual glands showed a signal for 92-KD Type IV collagenase and TIMP-2, but not for TIMP-1 or TIMP-3. The coincidental expression of the proteolytic 92-KD Type IV collagenase and inhibitors TIMP-1, TIMP-2, and TIMP-3 generally in the same cells suggests that the activity of 92-KD Type IV collagenase, which is regulated by TIMPs, plays an important role in placental tissue organization and in the invasion of trophoblastic cells into the uterine wall.