Gelatinases (MMP-2 and -9) and their natural inhibitors as prognostic indicators in solid cancers

Prognostic significance of matrix metalloproteinase-9 (MMP-9) in epithelial ovarian cancer

OBJECTIVE

We investigated the expression of matrix metalloproteinase-9 (MMP-9) and its relation to clinicopathologic factors and survival and also to previously analyzed expressions of CD44 and hyaluronan in epithelial ovarian cancer.

METHODS

The expression of MMP-9 was analyzed immunohistochemically in 292 primary tumors and their 31 metastases.

RESULTS

A low proportion of strong MMP-9 expression in cancer cells and high stromal MMP-9 expression correlated with advanced stage of the tumor (p=0.003, p=0.02, respectively). Stromal MMP-9 expression significantly correlated with hyaluronan positivity (p<0.0005), whereas MMP-9 did not correlate with CD44. In univariate analysis, a longer 10-year disease-related survival (DRS) was found in patients with a high proportion of MMP-9 or strong MMP-9 expression in cancer cells (p=0.02, p=0.05, respectively). However, high stromal expression of MMP-9 indicated short DRS (p=0.01). In multivariate analysis of all patients, MMP-9 expressing cancer or stromal cells were not independent prognostic factors, while in FIGO stage I patients a high percentage of MMP-9 positive cancer cells was associated with long DRS (p=0.008).

CONCLUSION

These data suggest that MMP-9 has a dual role in tumor progression, acting against tumor advancement when in tumor epithelium and promoting tumor progression while in the stroma.

MMP-2 expression associates with CA 125 and clinical course in endometrial carcinoma

OBJECTIVE

Matrix metalloproteinases have long been associated with aggressive behavior of several malignancies, but their role in endometrial cancer has not been conclusively established. This study aimed to evaluate the roles of matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) as prognostic factors in endometrial carcinoma and their association with CA 125 and other conventional prognostic markers.

METHODS

The MMP-2 and MMP-9 immunoreactive proteins were evaluated from primary tumors of endometrial carcinoma in 266 specimens by using a specific monoclonal antibody in immunohistochemical stainings. The median follow-up time was 79 months.

RESULTS

Expression of the MMP-2 and MMP-9 proteins was found in 88% and 70% of the primary tumors, respectively. Positive MMP-2 immunostaining was associated with a shortened recurrence-free (P=0.04) and cancer-specific survival (P=0.05). MMP-2 negativity was linked with a favorable prognosis; only one patient developed recurrent disease and died during the follow-up. Preoperative serum levels of CA 125 were higher in the patients presenting with tumors positive for MMP-2 than in those with negative immunostaining (P=0.03).

CONCLUSIONS

We suggest that MMP-2 is linked with biologically aggressive nature of this cancer type. It seems that MMP-2, but not MMP-9, has some prognostic value in endometrial carcinoma. However, the conventional prognostic markers are superior to MMP-2 in assessing aggressive behavior and cancer-specific survival in endometrial cancer.

MMP-2 but not MMP-9 associated with COX-2 and survival in gastric cancer

BACKGROUND AND AIM

Matrix metalloproteinases (MMPs) MMP-2 and MMP-9 can degrade type IV collagen of extracellular matrix and basal membranes. As cyclo-oxygenase-2 (COX-2) has been shown to activate MMPs, creating one of the COX-2-promoted pathways of tumour growth and metastasis, the prognostic role of MMP-2 and MMP-9 in gastric cancer was assessed and their association with COX-2 expression was evaluated.

MATERIALS AND METHODS

Samples were collected from 342 consecutive patients operated on for gastric cancer, of which 315 were acceptable for MMP-2, MMP-9 and COX-2 immunohistochemistry. Specimens were stained with specific antibodies, evaluated and categorised by two interpreters, and then correlated with clinical data and survival.

RESULTS

Epithelial MMP-2 immunoreactivity was associated with male sex, high stage, advanced penetration depth, non-curative surgery, high COX-2 expression and poor survival. Stromal MMP-2 expression correlated with high stage, intestinal type and non-curative surgery whereas MMP-9 correlated only with intestinal type. Stage, intent of surgery and COX-2 were independent prognostic factors.

CONCLUSIONS

Epithelial MMP-2 expression in gastric cancer is associated with aggressive forms, COX-2 and poor survival, although MMP-2 was not an independent prognostic factor. In gastric cancer tumour growth is apparently induced by COX-2, and invasion is mediated by MMP-2.

Cell-surface association between matrix metalloproteinases and integrins: role of the complexes in leukocyte migration and cancer progression

Leukocyte motility is known to be dependent on both β2-integrins and matrix metalloproteinases MMP-2/-9 or gelatinases, which mediate leukocyte adhesion and the proteolysis needed for invasion, respectively. Gelatinases not only play an important role in cell migration, tissue remodeling, and angiogenesis during development, but are also involved in the progression and invasiveness of many cancers, including leukemias. The concept that MMPs associate with integrins, as well as their importance in some physiologic and pathologic conditions, has been advanced previously but has not been examined on leukocytes. This review will examine mainly the function of the MMP-integrin complexes in normal leukocyte migration and the effect of integrin and broad-spectrum MMP inhibitors in tumor progression.

Fibronectin increases matrix metalloproteinase 9 expression through activation of c-Fos via extracellular-regulated kinase and phosphatidylinositol 3-kinase pathways in human lung carcinoma cells

Enhanced expression of matrix metalloproteinase-9 (MMP-9) is associated with human lung tumor invasion and/or metastasis. We have demonstrated that fibronectin (FN), a matrix glycoprotein, stimulates human non-small cell lung carcinoma (NSCLC) cell proliferation. The current study examines the effect of FN on MMP-9 expression in NSCLC cells. We show that FN increases MMP-9 protein, mRNA expression, and gelatinolytic activity in NSCLC cells. The integrin alpha5beta1 mediated the effects of FN because alpha5 small interfering RNA blocked FN-stimulated MMP-9 protein expression, and also abrogated FN-induced phosphorylation of ERK and phosphatidylinositol 3-kinase (PI3K) signals. The inhibitor of ERK, PD98095, and of PI3K, wortmannin, but not that of protein kinase A, H89, of Rho kinase, Y-27632, of mTOR, rapamycin, or of JNK, SP600125, prevented FN-induced MMP-9 gelatinolytic activity and gene expression. FN enhanced MMP-9 gene promoter activity; however, there was no response to FN in DNA constructs with an AP-1 site mutation. FN increased AP-1 DNA binding activity, and this was abrogated by cyclic AMP response element decoy oligonucleotides, which also diminished FN-induced MMP-9 promoter activity. FN increased the expression of the AP-1 subunit c-Fos protein, but not in the presence of PD98095 and wortmannin. The AP-1 inhibitor, nordihydroguaiaretic acid, and a c-Fos small interfering RNA eliminated the effect of FN on MMP-9 expression. This study indicates that FN, by binding to the integrin alpha5beta1 receptor, stimulates the expression of MMP-9 through increased AP-1/DNA binding and c-Fos protein expression via ERK and PI3K signaling pathways. The data unveils a novel mechanism by which FN could promote NSCLC cell invasion and metastasis.

Low serum level of pro-matrix metalloproteinase 2 correlates with aggressive behavior in breast carcinoma

Malignant tumors that are capable of invading surrounding structures and metastasizing possess certain capacities to cross tissue barriers. Matrix metalloproteinases (MMPs), especially gelatinases and their inhibitor molecules, are known to affect the extracellular matrix turnover, and the proteolytic imbalance due to the abnormal expression of these enzymes eventually leads to cancer progression. This has been well documented at the tissue level. In this study, the different forms of the circulating MMP-2 have been studied in the preoperative sera of 71 patients with breast carcinoma. A quantitative enzyme-linked immunosorbent assay was performed for total proMMP-2, proMMP-2-tissue inhibitor of metalloproteinase 2 (TIMP-2) complex, and free active MMP-2. It is shown here, for the first time, that the total proMMP-2 levels in the serum correlate inversely with node positivity, high stage of the disease, and high nuclear grade of the breast tumor. An association with the levels of lower free active MMP-2 and tumor recurrence is also demonstrated. Interestingly, the tumor tissue expression of MMP-2 had an inverse correlation with proMMP-2-TIMP-2 complex levels in the serum. In conclusion, the levels of the total proMMP-2 correlate inversely with tumor burden, whereas free active MMP-2 might be associated with survival. This could indicate that the prognostic value of the circulating forms of MMP-2 is not congruent with the prognostic information obtained from tissue expression. This is further supported by the inverse correlation of the proMMP-2-TIMP-2 complex and MMP-2 tissue expression in the tumor. Therefore, the different forms of circulating metalloproteinases need to be evaluated further to explore their full potential for clinical use.

Matrix metalloproteinases and tumor metastasis

Functions of individual matrix metalloproteinases (MMPs) differentially expressed by tumor cells and stromal cells, are finely regulated by their spatial as well as temporal interactions with distinct cellular and extracellular components of the tumor microenvironment and also distant pre-metastatic sites. Certain aspects of MMP involvement in tumor metastasis such as tumor-induced angiogenesis, tumor invasion, and establishment of metastatic foci at the secondary site, have received extensive attention that resulted in an overwhelming amount of experimental and observational data in favor of critical roles of MMPs in these processes. In particular, dependency of tumor angiogenesis on the activity of MMPs, especially that of MMP-9, renders this step possibly the most effective target of synthetic MMP inhibitors. MMP functioning in other stages of metastasis, including the escape of individual tumor cells from the primary tumor, their intravasation, survival in circulation, and extravasation at the secondary site, have not yet received enough consideration, resulting in insufficient or controversial data. The major pieces of evidence that are most compelling and clearly determine the role and involvement of MMPs in the metastatic cascade are provided by molecular genetic studies employing knock-out or transgenic animals and tumor cell lines, modified to overexpress or downregulate a specific MMP. Findings from all of these studies implicate different functional mechanisms for both tumor and stromal MMPs during distinct steps of the metastatic cascade and indicate that MMPs can exhibit pro-metastatic as well as anti-metastatic roles depending on their nature and the experimental setting. This dual function of individual MMPs in metastasis has become a major focus of this review.

Bcl-w promotes gastric cancer cell invasion by inducing matrix metalloproteinase-2 expression via phosphoinositide 3-kinase, Akt, and Sp1

Given a previous report that Bcl-w is expressed in gastric cancer cells, particularly in those of an infiltrative morphology, we investigated whether Bcl-w expression influences the invasiveness of gastric cancer cells. To accomplish this, Bcl-w was overexpressed in adherent types of gastric adenocarcinoma cell lines, and this was found to result in an increase in their migratory and invasive potentials. These effects were not induced when Bcl-2 was overexpressed in the same cell types. Consistently, Bcl-w, but not Bcl-2, overexpression increased matrix metalloproteinase-2 (MMP-2) expression, and synthetic or natural inhibitors of MMP-2 abolished Bcl-w-induced cell invasion. Bcl-w overexpression also activated phosphoinositide 3-kinase (PI3K), Akt, and Sp1, and the blocking effects of each of these components using pharmacologic inhibitors, dominant-negative mutants, or small interfering RNA abolished the ability of Bcl-w to induce MMP-2 and cell invasion. The inhibition of PI3K/Akt signaling also prevented Sp1 activation. Overall, our data suggest that Bcl-w, which was previously shown to enhance gastric cancer cell survivability, also promotes their invasiveness by inducing MMP-2 expression via the sequential actions of PI3K, Akt, and Sp1.

Amber force field implementation, molecular modelling study, synthesis and MMP-1/MMP-2 inhibition profile of (R)- and (S)-N-hydroxy-2-(N-isopropoxybiphenyl-4-ylsulfonamido)-3-methylbutanamides

Ab initio calculations (B3LYP/Lanl2DZ level of theory) were performed in this study to determine all the structural and catalytic zinc parameters required in order to study MMPs and their complexes with hydroxamate inhibitors by means of the AMBER force field. The parameters thus obtained were used in order to study the docking of some known MMPi (Batimastat, CGS 27023A and Prinomastat) and our previously described inhibitor a which had shown an inhibitory activity for MMP-1, and -2, with the aim of explaining the different selectivity. On this basis the two enantiomers (R)-b and (S)-b were designed and synthesized, as more potent MMP-2 inhibitors than our previously described inhibitor a. Between these two enantiomers the eutomer (R)-b proved to be 24.7 times and 15.3 times more potent than CGS 27023A and the parent compound a on MMP-2, maintaining a higher index of MMP-2/MMP-1 selectivity compared with CGS 27023A and the more potent inhibitor Prinomastat. The hydroxamate (R)-b can be considered as a progenitor of a new class of biphenylsulfonamido-based inhibitors that differ from compound a in the presence of an alkyl side chain on the C alpha atom, and show different potency and selectivity profiles on the two MMPs considered.

Activation of phosphatidylinositol 3-kinase signaling by a mutant thyroid hormone beta receptor

Activation of the phosphatidylinositol 3-kinase (PI3K)-AKT/protein kinase B signaling pathway has been associated with multiple human cancers. Recently we showed that AKT is activated in both the thyroid and metastatic lesions of a mouse model of follicular thyroid carcinoma [thyroid hormone beta receptor (TRbeta)(PV/PV) mice]. This TRbeta(PV/PV) mouse harbors a knock-in mutant TRbeta gene (TRbetaPV mutant) that spontaneously develops thyroid cancer and distant metastasis similar to human follicular thyroid cancer. Here we show that in thyroid tumors, PV mutant bound significantly more to the PI3K-regulatory subunit p85alpha, resulting in a greater increase in the kinase activity than did TRbeta1 in wild-type mice. By GST pull-down assays, the ligand-binding domain of TR was identified as the interaction site with p85alpha. By confocal fluorescence microscopy, p85alpha was shown to colocalize with TRbeta1 or PV mainly in the nuclear compartment of cultured tumor cells from TRbeta(PV/PV) mice, but cytoplasmic p85alpha/PV or p85alpha/TRbeta1 complexes were also detectable. Further biochemical analysis revealed that the activation of the PI3K-AKT-mammalian target of the rapamycin-p70(S6K) pathway was observed in both the cytoplasmic and nuclear compartments, whereas the activation of the PI3K-integrin-linked kinase-matrix metalloproteinase 2 pathway was detected mainly in the extranuclear compartments. These results suggest that PV, via the activation of p85alpha, could act to affect PI3K downstream signaling in both the nuclear and extranuclear compartments, thereby contributing to thyroid carcinogenesis. Importantly, the present study unveils a mechanism by which a mutant TR acts to activate PI3K activity via protein-protein interactions.

Detection of gelatinase B activity in serum of gastric cancer patients

AIM: To determine the proteolytic activity and expression of gelatinase B in serum of gastric cancer patients and their correlation with the stage of the tumor.

METHODS: Sera from 23 patients who underwent surgery for primary gastric cancer as the experimental group and from 11 as the control group were used to determine the proteolytic activity and its inhibition by EDTA and 1,10-phenanthroline. Gelatinase B activity was detected by SDS polyacrylamide gel electrophoresis (SDS-PAGE) and SDS-PAGE zymography.

RESULTS: Proteolytic enzyme activity was increased in gastric cancer patients when compared to the control group (P<0.05). The proteinases were determined to be metalloproteinases upon inhibition test with specific metalloproteinase inhibitors 1,10-phenanthroline (P<0.05) and EDTA (P <0.01). SDS-PAGE and SDS-PAGE zymography revealed gelatinase B (proMMP-9) activity and its molecular mass of 92 ku.

CONCLUSION: Proteinase activity is overexpressed in serum of gastric cancer patients. Gelatinase B in serum plays an important role in the progression of gastric cancer. ProMMP-9 can be used as a marker for invasiveness of gastric cancer.

Inflammation dampened by gelatinase A cleavage of monocyte chemoattractant protein-3

Tissue degradation by the matrix metalloproteinase gelatinase A is pivotal to inflammation and metastases. Recognizing the catalytic importance of substrate-binding exosites outside the catalytic domain, we screened for extracellular substrates using the gelatinase A hemopexin domain as bait in the yeast two-hybrid system. Monocyte chemoattractant protein-3 (MCP-3) was identified as a physiological substrate of gelatinase A. Cleaved MCP-3 binds to CC-chemokine receptors-1, -2, and -3, but no longer induces calcium fluxes or promotes chemotaxis, and instead acts as a general chemokine antagonist that dampens inflammation. This suggests that matrix metalloproteinases are both effectors and regulators of the inflammatory response.