胸腺上皮肿瘤组织中基质金属蛋白酶-2活性与Ⅰ型膜型基质金属蛋白酶 mRNA表达的相关性

目的探讨胸腺瘤和胸腺癌中基质金属蛋白酶（MMP）-2、Ⅰ型膜型（MT1）-MMP、金属蛋白酶组织抑制剂（TIMP）-2mRNA的表达和MMP-2蛋白活性的关系。方法分别用real-time逆转录．聚合酶链反应（RT-PCR,Taqman法）、明胶酶谱法和Filmin situ gelatin-Zymography（FIZ）对正常的胸腺组织（2例）、胸腺瘤（12例）和胸腺癌（2例）患者的新鲜肿瘤组织中MMP-2、MT1-MMP、TIMP-2mRNA的表达,pro-MMP-2的活性率及活性蛋白的定位进行测定。结果MMP-2、MT1-MMP及TIMP-2mRNA在Ⅰ期与Ⅱ期和Ⅲ期与Ⅳ期中的表达差异均无统计学意义（P〉0．05）,在Ⅰ～Ⅱ期与Ⅲ～Ⅳ期和胸腺癌3组中差异均有统计学意义（P〈0．01）。在AB、B1型（混合型和淋巴细胞为主型）与B2、B3型（皮质型和多角细胞为主型）以及胸腺癌3组中差异均有统计学意义（P〈0．05）。MMP-2的蛋白活性率（MMP-2／pro—MMP-2＋MMP-2）在Ⅰ～Ⅱ期、Ⅲ～Ⅳ期和胸腺癌各组中差异有统计学意义（P〈0．05）,在AB、B1型与B2、B3型以及胸腺癌各组中的差异均具有统计学意义（P〈0．05）。胸腺瘤各期及各型中MT1-MMP、TIMP-2mRNA与MMP-2蛋白活性表达均呈正相关,且相关程度相似（r=0．7235、r=0．7647、P〈0．005）。MMP-9的蛋白表达在各组间差异均无统计学意义。结论MMP-2、MT1-MMP及TIMP-2的mRNA表达与胸腺瘤临床分期、病理分型相关,MMP-2的活性与MT1-MMP和TIMP-2的表达升高正相关。推测MT1-MMP通过TIMP-2对MMP-2的激活起促进作用。     

Cell membrane-associated MT1-MMP-dependent activation of pro-MMP-2 in A375 melanoma cells.

Matrix metalloproteinases (MMPs), a family of zinc-dependent endopeptidases, can degrade extracellular matrix components under physiological conditions and during cancer invasion and metastasis. Among the MMPs, the 72 kDa type IV collagenase MMP-2 (gelatinase A) is activated in a membrane-associated manner by an activation complex composed of membrane type 1 matrix metalloproteinase (MT1-MMP), tissue inhibitor of matrixmetalloproteinase-2 (TIMP-2), and pro-MMP-2 in the presence of alphavbeta3 integrin receptor. The activation of pro-MMP-2 correlates with increased occurrence of metastases. Increased MMP-2 activity has been demonstrated in many human tumors. In the present communication, we studied cell surface-associated activation of MMP-2 (72 kDa collagenase type IV) in the moderately metastatic human melanoma cell line A375. RESULTS: Activation of purified 72 kDa collagenase type IV, pro-MMP-2 from cervical cancer tissue homogenate and from serum-free culture medium of HT1080 cells grown in presence of concanavalin A, by A375 cells, was shown by gelatin zymography. A375 cells activated only pro-MMP-2 from purified MMP-9/MMP-2 mixture indicating that the activation is specific for MMP-2. Activation of MMP-2 and purified collagenase type IV by A375 membrane fraction and membrane extract was also demonstrated by gelatin zymography. When A375 cells were first incubated with anti-MT1-MMP polyclonal antibody, activation of collagenase type IV was significantly decreased, indicating that membrane-associated MMP-2 activation is MT1-MMP-mediated. Immunocytochemistry showed MT1-MMP localization at focal adhesion sites. The presence of the components of activation complex-MT1-MMP and integrin alphavbeta3-were confirmed by Western blot, cell adhesion assay, and integrin subunit assay. CONCLUSION: Our experimental findings furnish another example of the unique membrane-associated MMP-2 activation mechanism in A375 melanoma cells and clearly indicate the role of MT1-MMP in MMP-2 activation. The information could help in developing new therapies designed to interfere with MMP activation and management of cancer and metastases.     

Cell membrane-associated MT1-MMP dependent activation of MMP-2 in SiHa (human cervical cancer) cells.

Among the soluble MMPs, MMP-2 (gelatinase A) is particularly important in the invasive property of tumor cells. Cell membrane-associated MMP-2 activation is one of the challenging areas in tumor biology. In the present communication, we studied the membrane dependent activation of MMP-2 in SiHa cells. METHODS: Activation of pro-MMP-2 by membrane fraction, membrane extract, and live SiHa cells was studied by gelatin zymography. The role of MT1-MMP in MMP-2 activation was studied by incubating SiHa cells and cell membrane fractions with anti-MT1-MMP antibody. RESULTS: Activation of purified pro-MMP-2 by membrane fraction isolated from SiHa cells, by SiHa cell membrane extract and by SiHa cells, pro-MMP-2 from Con A treated HT-1080 conditioned medium by SiHa cells, and pro-MMP-2 from serum free culture medium of SiHa cells and cervical tissue homogenate by SiHa cell membrane fraction was shown by gelatin zymography. SiHa membrane fraction activated only pro-MMP-2 from purified MMP-9/MMP-2 mixture, indicating that the activation is specific for MMP-2. Inhibition of MMP-2 activation in the presence of anti-MT1-MMP antibody strongly indicated that the cell membrane mediated MMP-2 activation is MT1-MMP dependent. Immunocytochemistry of SiHa cells demonstrated expression of MT1-MMP at focal points. Invasion assay showed that invasiveness of anti-MT1-MMP antibody treated SiHa cells through Matrigel was drastically reduced compared to control SiHa cells. CONCLUSIONS: Our findings furnish an example of the cell membrane-associated MT1-MMP mediated MMP-2 activation in SiHa cells and suggest that this MT1-MMP mediated MMP-2 activation is of importance in tumor invasion and metastasis. This MT1-MMP mediated MMP-2 activation on tumor cell surface could be a realistic target for managing metastatic diseases.     

Matrix metalloproteinase-2 from bronchial epithelial cells induces the proliferation of subepithelial fibroblasts

BACKGROUND: In bronchial asthma, subepithelial fibrosis in the conducting airways is associated with increased numbers of subepithelial fibroblasts. OBJECTIVE: This study examined the hypothesis that MMP-2 from airway epithelial cells induces the proliferation of subepithelial fibroblasts. METHODS: Using primary bronchial epithelial cells MMP-2, MT1-MMP and TIMP-2 mRNA expression were assessed by Northern blotting and RT-PCR. Primary bronchial epithelial cells transfected with constructs encoding pro-MMP-2 and MT1-MMP (MMP-14). RESULTS: Transfected cells showed enhanced expression of the appropriate mRNA species by RT-PCR and enhanced MMP-2 or MT1-MMP activity by zymography. Active MMP-2 levels in epithelial supernatants were increased most by cotransfection with pro-MMP-2 and MT1-MMP encoding constructs. By measuring tritiated thymidine incorporation, supernatants from transfected cells were found to enhance DNA synthesis of primary airway fibroblast cultures compared with controls. There was a strong correlation (r = 0.9, P < 0.01) between MMP-2 levels in epithelial cell conditioned media and fibroblast proliferation as indicated by DNA synthesis. The MMP inhibitor 1,10-phenanthroline attenuated the increased proliferation, while the addition of exogenous purified MMP-2 alone also increased fibroblast proliferation. CONCLUSIONS: Our results support a role for MMP-2 in mediating cross-talk between epithelial cells and myofibroblasts.     

(-)Epigallocatechin-3-gallate directly inhibits MT1-MMP activity,leading to accumulation of nonactivated MMP-2 at the cell surface

Consumption of green tea has been associated with prevention of cancer development, metastasis, and angiogenesis. Given the crucial role of the matrix metallo-proteinase-2 (MMP-2) on the degradation of the extracellular matrix instrumental to invasion, we examined the effect of the main flavanol present, (-)epigallocatechin-3-gallate (EGCG), on membrane-type 1 MMP (MT1-MMP), the receptor/activator of MMP-2. In-solution fluorimetric assay with activated MT1-MMP and gelatin-zymography with MT1-MMP catalytic domain alone and pro-MMP-2 activation by the same domain revealed dose-dependent inhibition of MT1-MMP at EGCG concentrations slightly lower than that reported to inhibit MMP-2 and MMP-9. Cytofluorimetry and immunolocalization revealed that EGCG does not impair MT1-MMP/TIMP-2/MMP-2 presence on the cell membrane. In the membrane extract of HT-1080 human fibrosarcoma cells, 10 micro M EGCG caused a strong increase in MT1-MMP level and accumulation of pro-MMP-2 while leaving activated MMP-2 unchanged. EGCG thus exerts inhibition of MT1-MMP, which restrains activation of MMP-2; this may confer the antiangiogenic and antimetastatic activity associated with green tea.     

Increased MMP-2 activity during intervertebral disc degeneration is correlated to MMP-14 levels

Intervertebral disc (IVD) degeneration is associated with the increased expression of several matrix metalloproteinases (MMPs), in particular MMP-2. However, little is known about the actual activity of MMP-2 in healthy and degenerated discs, or what mechanisms are involved in its activation. A major activation pathway involves complex formation with MMP-14 and a tissue inhibitor of metalloproteinases-2 (TIMP-2). In a series of 56 human IVDs, obtained at autopsy and graded according to the Thompson score (I-V), we analysed whether MMP-2 activity was increased in different stages of IVD degeneration and to what extent activation was related to the production of MMP-14 and TIMP-2. MMP-2 activation and production were quantified by gelatin zymography. Immunohistochemical staining of MMP-14 and TIMP-2 was quantified with a video overlay-based system. A positive correlation was observed between the amount of active MMP-2 and pro-MMP-2 and degeneration grade (p < 0.001, correlation coefficient (CC) 0.557; and p < 0.001, CC 0.556, respectively). MMP-2 activity correlated positively with MMP-14 and less strongly with TIMP-2 (p = 0.001, CC 0.436; and p = 0.03, CC 0.288, respectively). Moreover, immunopositivity for MMP-14 correlated to degeneration grade (p = 0.002, CC 0.398). IVD degeneration was associated with the activity of MMP-2 and the correlation of its activation with MMP-14 production suggests MMP-14 activates MMP-2 during degeneration. As MMP-14 is capable of activating several other enzymes that are also thought to be involved in IVD degeneration, it may be a key mediator of the degenerative process.     

Gelatin zymography and substrate cleavage assays of matrix metalloproteinase-2 in breast carcinoma cells overexpressing membrane type-1 matrix metalloproteinase

Gelatin zymography is the common method for examining matrix metalloproteinase-2 (MMP-2) in cells and media samples. Activation of the latent MMP-2 zymogen involves its binding to the cell surface MT1-MMP*TIMP-2 (membrane type-1 matrix metalloproteinase/tissue inhibitor of matrix metalloproteinase-2) complex with subsequent cleavage of proMMP-2 by TIMP-2-free adjacent MT1-MMP. This is followed by autolytic maturation of the activation intermediate and the release of the mature MMP-2 species from cell surfaces into the extracellular milieu. To observe the MMP-2 activation pathway in more detail, proMMP-2-deficient MCF7 breast carcinoma cells expressing MT1-MMP were incubated with excess proMMP-2 to saturate the available MT1-MMP*TIMP-2 surface receptors. After removal of the unbound material, the kinetics of proMMP-2 activation and MMP-2 release from cells into media was monitored by gelatin zymography and substrate cleavage. Our observations demonstrate that gelatin zymography is insufficient for providing meaningful information about the status of MMP-2. The proteolytically competent mature MMP-2 moiety alone, but not in its complex with TIMP-2, was released from the cells. In tissue culture conditions, the enzyme's proteolytic activity was suppressed in the next 30 to 60 minutes by tissue inhibitors of MMPs, especially by TIMP-1. The picture emerges that there is a likely temporal regulation of MMP-2 activity by TIMPs in tumor cells. These relatively rapid changes of the MMP-2 status cannot be detected by gelatin zymography. Additional studies are needed to examine the significance of this phenomenon in vivo.     

Expression of MT-1 MMP, MMP2, MMP9 and TIMP2 mRNAs in ductal carcinoma in situ and invasive ductal carcinoma of the breast

We investigated the expression of membrane type-1 (MT1)-MMP, MMP2, MMP9 and TIMP2 mRNAs and their roles in ductal carcinoma in situ (DCIS) and T1 and T2 invasive ductal carcinoma of the breast. We further compared these two types of carcinomas for differences in microvessel density, and expression of angiogenic factors and CD44std. MT1-MMP, MMP2, MMP9 and TIMP2 mRNA were expressed in both DCIS and invasive ductal carcinomas. Expression rates of MT1-MMP, MMP2, MMP9 and TIMP2 mRNAs were not statistically different between DCIS and invasive ductal carcinomas, nor did they differ statistically when grouped by tumor size, histologic grade or nuclear grade of invasive ductal carcinoma. Microvessel density and expression of VEGF and TGF-beta1 were not statistically different between DCIS and invasive ductal carcinoma. CD44std expression was significantly increased in DCIS compared to invasive ductal carcinoma (p < 0.05) and it was also significantly increased in lower clinical stage, histologic grade and nuclear grade of invasive ductal carcinoma (p < 0.05). Axillary node metastasis was significantly correlated with MT1-MMP mRNA, VEGF and TGF-beta1 expression (p < 0.05) and MT1-MMP mRNA was positively correlated with VEGF expression and TIMP2 mRNA (p < 0.05). In summary, patterns of MMP mRNA expression in DCIS and invasive ductal carcinoma suggest that the invasive potential of breast carcinoma is already achieved before morphologically overt invasive growth is observed. As MT1-MMP mRNA expression is significantly correlated with axillary nodal metastasis, it may be useful as a prognostic indicator of invasive ductal carcinoma. Considering the positive correlation of MT1-MMP mRNA and TIMP2mRNA expression, our finding supports a role for TIMP2 in tumor growth, as well as the utility of CD44std as a prognostic indicator of breast cancer.     

The metalloproteinase inhibitor TIMP-2 is down-regulated by androgens in LNCaP prostate carcinoma cells

Tissue inhibitors of metalloproteinases (TIMPs) have been shown to perform several biological functions in tumor promotion, principally by their action of inhibiting matrix metalloproteinases (MMPs) at different steps of the metastatic process. In particular, TIMP-2 is involved in a functional complex with the membrane-type 1 (MT1) MMP to convert the secreted MMP-2 progelatinase into the fully active proteolytic enzyme. We used the human, androgen-sensitive prostate carcinoma cell line LNCaP in coculture with the human osteosarcoma cell line OHS to experimentally address the possibility of androgen-dependent regulatory effects on the functional MT1-MMP/TIMP-2/MMP-2 complex upon interaction between prostate carcinoma and osteoblastic cells in metastasis of prostate cancer to bone. In the LNCaP cells a gradual, time-dependent decline in TIMP-2 mRNA expression was observed in the presence of the synthetic androgen analogue R1881 (100 nM), reaching ∼25% of the control level after 48 h of incubation. Consistent with this, the accumulation of secreted TIMP-2 in media from R1881-treated cells was significantly inhibited already after 3 h. Neither MMP-2 gelatinolytic activity nor expression of MT1-MMP was detected in LNCaP cells. In contrast, the OHS cells showed membrane-associated MT1-MMP expression as well as MMP-2 secretion. However, R1881 treatment of the LNCaP/OHS coculture model did not seem to change the overall proteolytic activity of the MT1-MMP/TIMP-2/MMP-2 complex. Hormonal control of TIMP-2 expression in prostate carcinoma cells has not been previously reported, but whether such regulation has any functional role in the development of osteoblastic metastases in prostate cancer is still unclear. This revised version was published online in July 2006 with corrections to the Cover Date.     

High levels of MMP-2, MMP-9, MT1-MMP and TIMP-2 mRNA correlate with poor survival in ovarian carcinoma

The object of this study was to analyze the potential association between the expression of MMP-2, MMP-9, MT1-MMP and TIMP-2, and disease outcome in advanced-stage ovarian carcinomas. Sections from 70 paraffin-embedded blocks (36 primary ovarian carcinomas and 34 metastatic lesions) from 45 patients diagnosed with advanced stage ovarian carcinomas (FIGO stages III–IV) were studied using mRNA in situ hybridization (ISH) technique. Patients were divided retrospectively in two groups based on disease outcome. Long-term survivors (21 patients) and short-term survivors (24 patients) were defined using a double cut-off of 36 months for disease-free survival (DFS) and 60 months for overall survival (OS). Mean follow-up period for patients that were diagnosed with advanced-stage carcinoma was 70 months. The mean values for DFS and OS were 109 and 125 months for long-term survivors, as compared to 3 and 21 months for short-term survivors, respectively. Intense mRNA signals were detected more frequently in tumor cells of short-term survivors with use of all four probes. Comparable findings were observed in peritumoral stromal cells with ISH for MMP-2, MMP-9 and TIMP-2 mRNA. Notably, primary tumors with intense mRNA signal for TIMP-2 (No = 14) were uniformly associated with a fatal outcome. In univariate analysis of primary tumors, mRNA levels of TIMP-2 in stromal cells (P = 0.0002), as well as for MMP-9 (P = 0.012) and TIMP-2 (P = 0.02) in tumor cells, correlated with poor outcome. In univariate analysis of metastatic lesions, mRNA levels of TIMP-2 in stromal cells (P = 0.031), as well as for MMP-2 (P = 0.027) and MT1-MMP (P = 0.008) in tumor cells, correlated with poor outcome. Interestingly, the presence of MT1-MMP in stromal cells correlated with longer survival (P = 0.025). In a multivariate analysis of ISH results for primary tumors, TIMP-2 levels in stromal cells (P = 0.006) and MMP-9 levels in tumor cells (P = 0.011) retained their predictive value. We conclude that MMP-2, MMP-9, MT1-MMP and TIMP-2 are valid markers of poor survival in advanced-stage ovarian carcinoma. This revised version was published online in July 2006 with corrections to the Cover Date.     

Differential expression patterns of MMPs and their role in the invasion of epithelial premalignant tumors and invasive cutaneous squamous cell carcinoma

Co-expression of several members of the matrix metalloproteinase (MMP) family is characteristic of human malignant tumors. MMP-2, MMP-9, TIMP-2, and MT1-MMP are thought to be involved in the process of destruction of basement membranes and stromal invasion by neoplastic epithelial cells. In this study, we investigated the expression and role of MMPs in cutaneous oncogenesis. Tissue microarray consisting of 62 squamous cell carcinomas (SCC), 32 Bowen's disease (BD) samples, 25 normal epidermis samples were obtained for the study. MMP-2,-9, MT1-MMP and TIMP-2 proteins were examined by immunohistochemical staining and mRNA level was detected by quantitative RT-PCR in fresh tissues consisting of 5 cutaneous SCCs and paired normal epidermis samples. Gelatinase activity of MMP-2 and MMP-9 was investigated by gelatin zymography and protein levels of MT1-MMP and TIMP-2 were measured by western blot in 2 human SCC cell lines. The invasive property was evaluated with invasion assays using Transwell filters. SCC exhibited significantly increased MMP-2, MT1-MMP and decreased TIMP-2 mRNA and protein expression compared to that of the normal epithelium. Immunohistochemical staining revealed that MT1-MMP was strongly expressed on the invasive front of SCCs, whereas BD exhibited higher expression around the dyskeratotic cells in the epithelium. In comparison with the expression observed in BD, SCC exhibited significantly increased MMP-2 expression. In addition, high MMP-2 and MT1-MMP expression and low TIMP-2 expression had a significant positive correlation with the invasiveness of SCC cell lines in vitro. Our results revealed significantly increased MT1-MMP and MMP-2 expression and decreased TIMP-2 expression in cutaneous SCC, and the expression correlated with the invasiveness of SCC cell lines. Therefore, the expression of these factors in cutaneous tumors may serve as an indicator of tumor aggressiveness and invasion.     

Upregulated MT1-MMP/TIMP-2 axis in the TSU-Pr1-B1/B2 model of metastatic progression in transitional cell carcinoma of the bladder

Muscle invasive transitional cell carcinoma (TCC) of the bladder is associated with a high frequency of metastasis, resulting in poor prognosis for patients presenting with this disease. Models that capture and demonstrate step-wise enhancement of elements of the human metastatic cascade on a similar genetic background are useful research tools. We have utilized the transitional cell carcinoma cell line TSU-Pr1 to develop an in vivo experimental model of bladder TCC metastasis. TSU-Pr1 cells were inoculated into the left cardiac ventricle of SCID mice and the development of bone metastases was monitored using high resolution X-ray. Tumor tissue from a single bone lesion was excised and cultured in vitro to generate the TSU-Pr1-B1 subline. This cycle was repeated with the TSU-Pr1-B1 cells to generate the successive subline TSU-Pr1-B2. DNA profiling and karyotype analysis confirmed the genetic relationship of these three cell lines. In vitro, the growth rate of these cell lines was not significantly different. However, following intracardiac inoculation TSU-Pr1, TSU-Pr1-B1 and TSU-Pr1-B2 exhibited increasing metastatic potential with a concomitant decrease in time to the onset of radiologically detectable metastatic bone lesions. Significant elevations in the levels of mRNA expression of the matrix metalloproteases (MMPs) membrane type 1-MMP (MT1-MMP), MT2-MMP and MMP-9, and their inhibitor, tissue inhibitor of metalloprotease-2 (TIMP-2), across the progressively metastatic cell lines, were detected by quantitative PCR. Given the role of MT1-MMP and TIMP-2 in MMP-2 activation, and the upregulation of MMP-9, these data suggest an important role for matrix remodeling, particularly basement membrane, in this progression. The TSU-Pr1-B1/B2 model holds promise for further identification of important molecules.     

Expression of MMP-2 and MMP-9, their inhibitors, and the activator MT1-MMP in primary breast carcinomas.

Enhanced expression of the type IV collagenases MMP-2 and MMP-9, or lack of their inhibitors TIMP-1 and TIMP-2, has been associated with tumour invasion and metastatic potential in several experimental models. Regulation of enzyme activity is clearly a key step in tumour invasion, and recently a potent activator of MMP-2, the membrane-associated MT1-MMP, has been described and characterized. Using an immunohistochemical approach, this study has examined the expression and distribution of the type IV collagenases, their inhibitors, and the activator MT1-MMP, in a series of 79 infiltrating ductal carcinomas (IDCs), 8 tubular carcinomas, and 27 infiltrating lobular carcinomas (ILCs). MMP-2 and MT1-MMP were expressed in more than 90 per cent of all carcinomas, with predominantly stromal and tumour cell cytoplasmic staining. However, reactivity localized on tumour cell membranes was recorded for MMP-2 in 34 per cent of cases with a monoclonal antibody and 55 per cent of cases with a polyclonal antibody, and for MT1-MMP in 68 per cent of tumours. In each case, this pattern of staining was significantly associated with the presence of lymph node metastasis (p=0.001, p=0. 008, and p=0.1, respectively). Both tumour cell and stromal staining was observed for TIMP-2, but there was no correlation with metastatic status. The 92 kD gelatinase MMP-9 was expressed by 68 per cent of carcinomas, either in the stromal compartment or by tumour cells. There was a highly significant correlation between the expression pattern of MMP-9 and tumour type, with ILCs displaying greater frequency and more homogeneous cytoplasmic staining than IDCs (p=0.0004). Staining for TIMP-1 was seen in the stroma and also in relation to small blood vessels, with more than 90 per cent of tumours showing this staining pattern using a polyclonal antibody. This study indicates distinct patterns of expression for different MMPs and demonstrates the potential importance of the MMP-2/MT1-MMP system in breast tumour progression. The association of MMP-9 with the infiltrating lobular phenotype may reveal novel mechanisms of control for this metalloproteinase.