Development of matrix metalloproteinase inhibitors in cancer therapy

Specific Inhibitor of Matrix Metalloproteinase Decreases Tumor Invasiveness After Radiofrequency Ablation in Liver Tumor Animal Model

Objective

To determine whether the specific inhibitor of matrix metalloproteinase (MMP)-batimastat (BB-94)-could decrease the progression of liver tumor after radiofrequency ablation (RFA) and achieve better therapeutic efficacy in an animal model.

Methods

In vitro experiments, the proliferation of H22 liver tumor cells was detected by CCK 8 assay and cell migration was detected by Transwell method. In vivo experiments, H22 murine liver tumors were used. First, 32 mice with one tumor were randomized into four groups (n = 8 each group): control (PBS only), RFA alone (65°C, 5 min), BB-94 (30 mg/kg), RFA+BB-94. The growth rate of the residual tumor and the end point survival were calculated and the pathologic changes were evaluated. Secondly, a total of 48 tumors in 24 animals (paired tumors) were randomized into three groups (n = 8 each group): control, RFA alone, RFA+BB-94. Each mouse was implanted with two tumors subcutaneously, one tumor was treated by RFA and the other was evaluated for distant metastasis after applying BB-94.

Results

In vitro, the proliferation assay demonstrated higher proliferation ability after heat treatment (0.82 ± 0.07 vs 1.27 ± 0.08, P = 0.008), and it could be inhibited by BB-94 (1.27 ± 0.08 vs 0.67 ± 0.06, P = 0.001). In the cell migration assay, the H22 cells demonstrated enhanced tumor invasiveness in the heat group than the control group (33.7 ± 2.1 vs 19.7 ± 4.9, P = 0.011). And it could be significantly suppressed after BB-94 incubation (33.7 ± 2.1 vs 23.0 ± 4.6, P = 0.009). With one tumor animal, the growth rate of the residual tumor in the BB-94+RFA group was slower than that in the RFA alone group (P = 0.003). And combination of BB-94 could significantly prolong the survival of the mice (40.3 ± 1.4d vs 47.1 ± 1.3d, P = 0.002). The expression of CD31 and VEGF at the coagulation margin were decreased after combined with BB-94. With two tumors animal, the growth of metastasis tumor in the BB-94+RFA group was slower than that in the RFA group (P < 0.001).

Conclusion

BB-94 combined with RFA reduced the invasiveness of the liver tumor and improved the end-point survival. Our data suggested that targeting the MMP process with the specific inhibition could help to increase overall ablation efficacy.

Prediction of MMP-9 inhibitory activity of N-hydroxy-α-phenylsulfonylacetamide derivatives by pharmacophore based modeling and 3-D QSAR studies

Matrix metalloproteinase-9 (MMP-9), also known as gelatinase B, is a MMP that is strongly associated with multiple cellular processes including proliferation, angiogenesis, and metastasis. Various studies have shown that N-hydroxy-α-phenylsulfonylacetamide (HPSAs) derivatives are promising and selective for the MMP-9 inhibition. In the present study, we have selected and reported 80 HPSAs derivatives as inhibitors of MMP-9 and performed structure-based 3-dimensional quantitative structure-activity relationship (3D-QSAR) studies to elucidate the important structural elements responsible for binding affinity. Developed pharmacophore models; QSAR model I contains 2 hydrogen-bond acceptors (A), 2 hydrogen-bond donors (D), and 1 aromatic ring (R) and QSAR model II contains 3 hydrogen-bond acceptors (A), 1 positive ionic (P), and 1 aromatic ring (R). The statistical results of QSAR models (I and II) such as good correlation coefficient (0.61 for I and 0.63 for II), good predictive power (0.84 and 0.77 for I and II, respectively) with low standard deviation (SD\0.3 for both) strongly suggest that the developed models are virtuous for the future prediction of MMP-9 inhibitory activity of HPSAs derivatives. The geometry and features of pharmacophore were expected to be useful for further design and development of selective MMP-9 inhibitors.

Inhibition of extracellular matrix production and remodeling by doxycycline in smooth muscle cells

Alterations in the extracellular matrix (ECM) production and remodeling of smooth muscle cells (SMCs) have been implicated in processes related to the differentiation in atherosclerosis. Due to the anti-atherosclerotic properties of the tetracyclines, we aimed to investigate whether cholesterol supplementation changes the effect of doxycycline over the ECM proteins synthesis and whether isoprenylated proteins and Rho A protein activation are affected. SMC primary culture isolated from chicks exposed to atherogenic factors in vivo (a cholesterol-rich diet, SMC-Ch), comparing it with control cultures isolated after a standard diet (SMC-C). After treatment with 20 nM doxycycline, [H³]-proline and [H³]-mevalonate incorporation were used to measure the synthesis of collagen and isoprenylated proteins, respectively. Real-time PCR was assessed to determine col1a2, col2a1, col3a1, fibronectin, and mmp2 gene expression and the pull-down technique was applied to determine the Rho A activation state. A higher synthesis of collagens and isoprenylated proteins in SMC-Ch than in SMC-C was determined showing that doxycycline inhibits ECM production and remodeling in both SMC types of cultures. Moreover, preliminary results about the effect of doxycycline on protein isoprenylation and Rho A protein activation led us to discuss the possibility that membrane G-protein activation pathways could mediate the molecular mechanism.

Diphlorethohydroxycarmalol Suppresses Ultraviolet B-Induced Matrix Metalloproteinases via Inhibition of JNK and ERK Signaling in Human Keratinocytes

Skin aging is the most readily observable process involved in human aging. Ultraviolet B (UVB) radiation causes photo-oxidation via generation of reactive oxygen species (ROS), thereby damaging the nucleus and cytoplasm of skin cells and ultimately leading to cell death. Recent studies have shown that high levels of solar UVB irradiation induce the synthesis of matrix metalloproteinases (MMPs) in skin fibroblasts, causing photo-aging and tumor progression. The MMP family is involved in the breakdown of extracellular matrix in normal physiological processes such as embryonic development, reproduction, and tissue remodeling, as well as in disease processes such as arthritis and metastasis. We investigated the effect of diphlorethohydroxycarmalol (DPHC) against damage induced by UVB radiation in human skin keratinocytes. In UVB-irradiated cells, DPHC significantly reduced expression of MMP mRNA and protein, as well as activation of MMPs. Furthermore, DPHC reduced phosphorylation of ERK and JNK, which act upstream of c-Fos and c-Jun, respectively; consequently, DPHC inhibited the expression of c-Fos and c-Jun, which are key components of activator protein-1 (AP-1, up-regulator of MMPs). Additionally, DPHC abolished the DNA-binding activity of AP-1, and thereby prevented AP-1-mediated transcriptional activation. These data demonstrate that by inactivating ERK and JNK, DPHC inhibits induction of MMPs triggered by UVB radiation.

Mycobacterium indicus pranii (Mw) inhibits invasion by reducing matrix metalloproteinase (MMP-9) via AKT/ERK-1/2 and PKCα signaling: A potential candidate in melanoma cancer therapy

Invasion and metastasis via induction of matrix metalloproteinases are the main causes of death in melanoma cancer. In this study, we investigated the inhibitory effects of heat killed saprophytic bacterium Mycobacterium indicus pranii (Mw) on B16F10 melanoma cell invasion. Mw reported to be an immunomodulator has antitumor activity however, its effect on cancer cell invasion has not been studied. Highly invasive B16F10 melanoma was found sensitive to Mw which downregulated MMP-9 expression. Mw treatment inhibited nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) transcriptional activity and respective DNA binding to MMP-9 promoter. Moreover, Mw also overcame the promoting effects of PMA on B16F10 cell invasion. Mw decreased PMA-induced transcriptional activation of NF-κB and AP-1 by inhibiting phosphorylation of AKT and ERK-1/2. Furthermore, Mw strongly suppressed PMA-induced membrane localization of protein kinase C α (PKCα) since PKCα inhibition caused a marked decrease in PMA-induced MMP-9 secretion as well as AKT/ERK-1/2 activation. These results suggest that Mw may be a promising anti-invasive agent as it blocks tumor growth and inhibits B16F10 cell invasion by reducing MMP-9 activation through inhibition of PKCα/ AKT/ ERK-1/2 phosphorylation and NF-κB/AP-1 activation.

Combined aberrant expression of N-Myc downstream-regulated gene 2 and CD24 is associated with disease-free survival and overall survival in patients with hepatocellular carcinoma

Background

N-Myc downstream-regulated gene 2 (NDRG2), as a tumor suppressor, has been demonstrated to inhibit tumor invasion and migration of hepatocellular carcinoma (HCC) by reducing the expression of CD24, which has been identified as a prognostic factor for HCC patients. However, the clinical significance of combined NDRG2 and CD24 expression in HCC remains unclear. Thus, the aim of the current study was to investigate the relationship of NDRG2 and CD24 expression with clinicopathological parameters and patients’ survival.

Methods

Immunohistochemistry was performed to detect the expression and subcellular localizations of NDRG2 and CD24 proteins in 130 pairs of HCC and adjacent nonneoplastic liver tissues.

Results

NDRG2 protein was strongly expressed in the cytoplasm and plasma membrane of hepatocytes in adjacent nonneoplastic liver tissues, whereas its immunostaining was weak or negative in HCC tissues. In contrast, CD24 protein exhibited the cytoplasm immunostaining in tumor cells of HCC tissues but showed negative expression in adjacent nonneoplastic liver tissues. The statistical analysis also showed that the expression levels of NDRG2 and CD24 proteins in HCC tissues were respectively lower and higher than those in adjacent nonneoplastic liver tissues significantly (both P < 0.001). In addition, there was an inverse correlation between NDRG2 expression and CD24 expression in HCC tissues (P = 0.02). Moreover, combined NDRG2 downregulation and CD24 upregulation (NDRG2-low/CD24-high) more frequently occurred in HCC tissues with high serum AFP (P = 0.03), advanced tumor stage (P = 0.001) and high tumor grade (P = 0.02). Furthermore, HCC patients with NDRG2-low/CD24-high expression showed shortest 5-year disease-free survival and 5-year overall survival (both P < 0.001) of four groups (NDRG2-low/CD24-high, NDRG2-low/CD24-low, NDRG2-high/CD24-high, NDRG2-high/CD24-low). Of note, the multivariate survival analysis showed that the combined aberrant expression of NDRG2 and CD24 proteins was an independent prognostic factor for both 5-year disease-free survival and 5-year overall survival (both P = 0.01) in HCC.

Conclusions

These findings suggest that the downregulation of NDRG2 combined with the upregulation of CD24 may play a synergistic role in the occurrence and progression of HCC. A combined detection of NDRG2/CD24 expression may benefit us in determining the prognosis in patients with HCC.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_209

Discovery of potent inhibitor for matrix metalloproteinase-9 by pharmacophore based modeling and dynamics simulation studies

Matrix metalloproteinase-9 (MMP-9) is an attractive target for anticancer therapy. In the present study ligand based pharmacophore modeling was performed to elucidate the structural elements for a diverse class of MMP-9 inhibitors. The pharmacophore model was validated through Güner-Henry (GH) scoring method. The final pharmacophore model consisted of three hydrogen bond acceptors (HBA), and two ring aromatic regions (RA). This model was utilized to screen the natural compound database to seek novel compounds as MMP-9 inhibitors. The identified hits were validated using molecular docking and molecular dynamics simulation studies. Finally, one compound named Hinokiflavone from Juniperus communis had high binding free energy of -26.54kJ/mol compared with the known inhibitors of MMP-9. Cytotoxicity for hinokiflavone was evaluated by MTT assay. Inhibition of MMP-9 in the presence of hinokiflavone was detected by gelatin zymography and gelatinolytic inhibition assay. Results revealed that the natural compounds derived based on the developed pharmacophore model would be useful for further design and development of MMP-9 inhibitors.

Implication of MMP-9 and urokinase plasminogen activator (uPA) in the activation of pro-matrix metalloproteinase (MMP)-13

We examined whether the expression and activation of pro-matrix metalloproteinase (MMP)-1 varies from that of pro-MMP-13 in the joint fluid of osteoarthritis (OA) and rheumatoid arthritis (RA) patients. To do this, joint fluid was collected from 34 RA and 34 OA patients. The collagenase (pro-MMP-1 and MMP-13, total MMP-1, and MMP-13), gelatinase (total MMP-2 and MMP-9), stromelysin (total MMP-3), matrilysin (total MMP-7), uPA, and tissue inhibitor of MMP (TIMP) levels were measured by ELISA. The level of total MMP-1 in RA joint fluids was similar to that of the OA joint fluid. In contrast, the level of total MMP-13 in the RA group was significantly higher than that of the OA group. Among various MMPs (MMP-2, MMP-3, MMP-7, and MMP-9), only MMP-9 was strongly associated with total MMP-13 in both RA and OA. The level of uPA was also strongly associated with MMP-13 in RA but not OA, while the level of TIMP-1 and TIMP-2 was not significantly different between RA and OA. In conclusion, MMP-9 and uPA might be involved in the activation of pro-MMP-13 through unknown mechanisms in arthritic diseases.

Andrographolide could inhibit human colorectal carcinoma Lovo cells migration and invasion via down-regulation of MMP-7 expression

Andrographolide (Andro), a diterpenoid lactone isolated from a traditional herbal medicine Andrographis paniculata, is known to possess multiple pharmacological activities. In our previous study, Andro had been shown to have potent anti-cancer activity against human colorectal carcinoma Lovo cells by inhibiting cell-cycle progression. To further investigate the mechanism for the anti-cancer properties of Andro, it was used to examine the effect on migration and invasion of Lovo cells. The results of wound-healing assay and in vitro transwell assay revealed that Andro inhibited dose-dependently the migration and invasion of Lovo cells under non-cytotoxic concentrations. Using zymographic assay and RT-PCR, the results revealed that Andro diminished the activity and the mRNA and protein levels of MMP-7, but not MMP-2 or MMP-9. The down-regulation of MMP-7 appeared to be via the inactivation of activator protein-1 (AP-1) since the treatment with Andro suppressed the nuclear protein level of AP-1, which was accompanied by a decrease in DNA-binding level of the factor. Taken together, these results indicated that Andro reduces the MMP-7-mediated cellular events in Lovo cells, and provided a new mechanism for its anti-cancer activity.

Inhibition of angiogenesis and invasion in malignant gliomas

Malignant gliomas confer a dismal prognosis. As the molecular events that underlie tumor angiogenesis are elucidated, angiogenesis inhibition is emerging as a promising therapy for recurrent and newly diagnosed tumors. Data from animal studies suggest that angiogenesis inhibition may promote an invasive phenotype in tumor cells. This may represent an important mechanism of resistance to antiangiogenic therapies. Recent studies have begun to clarify the mechanisms by which glioma cells detach from the tumor mass, remodel the extracellular matrix and infiltrate normal brain. An array of potential therapeutic targets exists. Combination therapy with antiangiogenic and novel anti-invasion agents is a promising approach that may produce a synergistic antitumor effect and a survival benefit for patients with these devastating tumors.

A rapid and simple HPLC-UV method for the determination of inhibition characteristics of farnesyl transferase inhibitors

Ras proteins play an important role in the development of cancer. Farnesyl transferase inhibitors (FTIs) block the first obligatory post-translational step for activation, prenylation, of Ras proteins. To find new potent FTIs, rapid enzyme activity assays are required to reduce FTI development time. Most assays to date are based on radioactive labelled substrates. We developed a new, in vitro, farnesyl transferase assay based on gradient chromatography coupled to UV detection. Unfarnesylated and farnesylated H-Ras proteins were resolved on a C18 wide-pore HPLC column and their concentrations were determined with use of a calibration curve of unfarnesylated H-Ras. The assay was used to investigate inhibition characteristics of FTIs. The IC50 values of the FTIs L778,123 and SCH66336 were 4.2 nm and 78 microm, respectively. This assay could support the screening and development of FTIs to obtain rapid insights into their inhibitory properties.

Constitutive mobilization of CD34+ cells into the peripheral blood in idiopathic myelofibrosis may be due to the action of a number of proteases

Idiopathic myelofibrosis (IM) is characterized by increased numbers of CD34+ cells in the peripheral blood (PB). We explored the possible mechanisms underlying this abnormal trafficking of CD34+ cells. Plasma levels of neutrophil elastase (NE), total and active matrix metalloproteinase 9 (MMP-9), and soluble vascular cell adhesion molecule-1 (sVCAM-1) were dramatically increased in IM. The absolute number of CD34+ cells in the PB was correlated with the levels of sVCAM-1. Marked elevations of the levels of NE but not total and active MMP-9 as well as MMP-2 were detected in media conditioned by IM mononuclear cells (MNCs) as compared with that of healthy volunteers. IM MNC-conditioned media, however, was shown by zymographic analysis to contain increased gelatinolytic activity corresponding to the molecular weight of MMP-9. IM MNC-conditioned media also exhibited a greater ability to cleave VCAM-1 and c-kit in vitro, consistent with the biologic actions of NE. In addition, the increased ability of IM PB CD34+ cells to migrate through a reconstituted basement membrane was diminished by several inhibitors of MMP-9 activity, indicating that these cells express increased levels of this MMP. These data indicate that a proteolytic environment exists in IM which might result in the sustained mobilization of CD34+ cells.

Carnosol inhibits the invasion of B16/F10 mouse melanoma cells by suppressing metalloproteinase-9 through down-regulating nuclear factor-kappaB and c-Jun

Carnosol, a constant constituent of Rosmarinus officinalis extracts, is a phenolic diterpene shown to have antioxidant and anticarcinogen properties. In our studies, carnosol inhibited the invasion of highly metastatic mouse melanoma B16/F10 cells in vitro. First, the antimetastatic potentials of carnosol were examined by soft agar colony formation assay. Second, carnosol dose-dependently inhibited B16/F10 cell migration and invasion by in vitro transwell assay. Third, the decreasing activity of metalloproteinase was observed by zymographic assay. The result revealed that the treatment of carnosol could diminish the activity of MMP-9 more than MMP-2. Next, we analyzed the amounts of MMP-9 and MMP-2 proteins in the cells. The data indicated MMP-9 protein was also suppressed by carnosol in the same manner. In accordance with the above data, the results of reverse transcriptase polymerase chain reaction (RT-PCR) analysis showed a reduced level of MMP-9 mRNA. Furthermore, carnosol significantly inhibited the tyrosine phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, AKT, p38, JNK and inhibition of activation of transcription factors NFkappa-B and c-Jun. These results lead us to conclude that carnosol could restrict the invasive ability of B16/F10 mouse melanoma cells by reducing MMP-9 expression and activity through suppressing (ERK) 1/2, AKT, p38, and JNK signaling pathway and inhibition of NF-kappaB and AP-1 binding activity. Taken together, these results indicate that carnosol targets MMP-mediated cellular events in cancer cells and provides a new mechanism for its anticancer activity.

Chemically modified tetracyclines as inhibitors of matrix metalloproteinases

Matrix metalloproteinases belong to a diverse group of enzymes that are not only involved in restructuring the extracellular matrix, but also play a major role in various pathophysiological conditions by virtue of their complicated expression, activation, and regulation processes. They have been widely implicated to function as major contenders in cancer progression, frequently due to their role in invasion, proliferation and metastasis. MMP inhibitors have been specifically designed to target these altered activities of MMPs, mostly by means of inhibiting their function and by diminishing their increased expression in various disease states, particularly cancer. Tetracyclines and chemically modified tetracyclines (CMTs) have been rationally designed to inhibit the activity of MMPs and thus decrease the potential risk of spread of tumor cells to distant sites by invasion and metastasis. Pre-clinical and early clinical data for one of these CMTs, COL-3 (formerly CMT-3) indicate considerable potential for this group of anticancer agents. Further testing and rational modifications of these CMT analogues might lead to new anticancer agents.

A sensitive method for determination of COL-3, a chemically modified tetracycline, in human plasma using high-performance liquid chromatography and ultraviolet detection

COL-3, 6-deoxy-6-desmethyl-4-desdimethylamino-tetracycline, is a matrix metalloproteinase inhibitor currently in clinical development. A HPLC-UV method to quantitate COL-3 in human plasma was developed. COL-3 was extracted from plasma using solid-phase extraction cartridges. COL-3 is separated on a Waters Symmetry Shield RP8 (3.9 mm x150 mm, 5 microm) column with EDTA (0.001 M) in sodium acetate (0.01 M, pH 3.5)-acetonitrile mobile phase using a gradient profile at a flow rate of 1 ml/min for 22 min. Carryover was eliminated by using an extended needle wash of methanol:acetonitrile:dichloromethane (1:1:1, v/v/v). Detection of COL-3 and the internal standard, chrysin, was observed at 350 nm. COL-3 and chrysin elute at 8.9 and 9.9 min, respectively. The lower limit of quantitation in human plasma of COL-3 was 75 ng/ml, linearity was observed from 75 to 10,000 ng/ml. A 30,000 ng/ml sample that was diluted 1:50 with plasma was accurately quantitated. This method is rapid, widely applicable, and suitable for quantifying COL-3 in patient samples enabling further clinical pharmacology characterization of COL-3.

A Molecular Basis for the Selectivity of Thiadiazole Urea Inhibitors with Stromelysin-1 and Gelatinase-A from Generalized Born Molecular Dynamics Simulations

Matrix metalloproteinases (MMPs) represent a potentially important class of therapeutic targets for the treatment of diseases such as cancer. Selective inhibition of MMPs will be required given the high sequence identity across the family and the discovery that individual MMPs also regulate the natural angiogenesis inhibitor angiostatin. In this study, we have used computational methods to model the selectivity for six thiadiazole urea inhibitors with stromelysin-1 and gelatinase-A, two homologous MMPs that have been implicated in breast cancer. From continuum Generalized Born molecular dynamics (GB-MD) and MM-GBSA analysis, we estimated ligand free energies of binding using 200 snapshots obtained from a short 40 ps simulation of the relevant protein-ligand complex. The MM-GBSA free energies, computed from the continuum GB-MD trajectories, show strong correlation with the experimental affinities (r(2) = 0.74); prior studies have employed explicit water MD simulations. Including estimates for changes in solute entropy in the binding calculations slightly diminishes the overall correlation with experiment (r2 = 0.71). Notably, in every case, the simulation results correctly predict that a given ligand will bind selectively to stromelysin-1 over gelatinase-A which is gratifying given the high degree of structural homology between the two proteins. The increased selectivity for stromelysin-1 appears to be driven by (1) increased favorable van der Waals interactions, (2) increased favorable Coulombic interactions, and (3) decreased unfavorable total electrostatic energies (Coulombic plus desolvation).