A dose-finding and pharmacokinetic study of the matrix metalloproteinase inhibitor MMI270 (previously termed CGS27023A) with 5-FU and folinic acid

MMP9: A Tough Target for Targeted Therapy for Cancer

Having the capability to proteolyze diverse structural and signaling proteins, matrix metalloproteinase 9 (MMP9), one of the best-studied secretory endopeptidases, has been identified as a crucial mediator of processes closely associated with tumorigenesis, such as the extracellular matrix reorganization, epithelial to mesenchymal transition, cell migration, new blood vessel formation, and immune response. In this review, we present the current state of knowledge on MMP9 and its role in cancer growth in the context of cell adhesion/migration, cancer-related inflammation, and tumor microenvironment formation. We also summarize recent achievements in the development of selective MMP9 inhibitors and the limitations of using them as anticancer drugs.

Structure-based molecular insights into matrix metalloproteinase inhibitors in cancer treatments

Protease inhibitors are of considerable interest as anticancer agents. Matrix metalloproteinases (MMPs) were the earliest type of proteases considered as anticancer targets. The developments of MMP inhibitors (MMPIs) by pharmaceutical companies can be dated from the early 1980s. Thus far, none of the over 50 MMPIs entering clinical trials have been approved. This work summarizes the reported studies on the structure of MMPs and complexes with ligands and inhibitors, based on which, the authors analyzed the clinical failures of MMPIs in a structural biological manner. Furthermore, MMPs were systematically compared with urokinase, a protease-generating plasmin, which plays similar pathological roles in cancer development; the reasons for the clinical successes of urokinase inhibitors and the clinical failures of MMPIs are discussed.

Matrix metalloproteinase inhibitors (MMPIs) as attractive therapeutic targets: Recent progress and current challenges

Matrix metalloproteinase (MMP) plays an essential role in many physiological and pathological processes. An increase in MMP activity contributes to excessive degradation and remodeling of the extracellular matrix (ECM), which has been correlated with invasion and metastasis of tumors. Matrix metalloproteinase inhibitor (MMPI) has been developed as an attractive therapeutic target for decades, suggesting inspiring therapeutic effects in preclinical studies. However, achieving specificity remains an important challenge in the development of MMPIs, limiting their clinical application and bringing about the risk of biosafety. Nanomaterials can be used as alternative candidates for MMPI design, providing a new strategy for this problem. This report reviewed the research about MMPIs, summarized their MMPs activity regulation mechanisms, and discussed their failures in clinical trials. Furthermore, we outlined several schemes of MMPIs screening and design. Finally, we reviewed the therapeutic application prospects of MMPIs and discussed the remaining challenges and solutions, which may offer new insights for the development of MMPIs studies.

Attenuation of pulmonary injury by an inhaled MMP inhibitor in the endotoxin lung injury model

Acute respiratory distress syndrome (ARDS) is characterized by pulmonary edema and poor gas exchange resulting from severe inflammatory lung injury. Neutrophilic infiltration and increased pulmonary vascular permeability are hallmarks of early ARDS and precipitate a self-perpetuating cascade of inflammatory signaling. The biochemical processes initiating these events remain unclear. Typically associated with extracellular matrix degradation, recent data suggest matrix metalloproteinases (MMPs) are regulators of pulmonary inflammation. To demonstrate that inhalation of a broad MMP inhibitor attenuates LPS induced pulmonary inflammation. Nebulized CGS27023AM (CGS) was administered to LPS-injured mice. Pulmonary CGS levels were examined by mass spectroscopy. Inflammatory scoring of hematoxylin-eosin sections, examination of vascular integrity via lung wet/dry and bronchoalveolar lvage/serum FITC-albumin ratios were performed. Cleaved caspase-3 levels were also assessed. Differential cell counts and pulse-chase labeling were utilized to determine the effects of CGS on neutrophil migration. The effects of CGS on human neutrophil migration and viability were examined using Boyden chambers and MTT assays. Nebulization successfully delivered CGS to the lungs. Treatment decreased pulmonary inflammatory scores, edema, and apoptosis in LPS treated animals. Neutrophil chemotaxis was reduced by CGS treatment, with inhalation causing significant reductions in both the total number and newly produced bromodeoxyuridine-positive cells infiltrating the lung. Mechanistic studies on cells isolated from humans demonstrate that CGS-treated neutrophils exhibit decreased chemotaxis. The protective effect observed following treatment with a nonspecific MMP inhibitor indicates that one or more MMPs mediate the development of pulmonary edema and neutrophil infiltration in response to LPS injury. In accordance with this, inhaled MMP inhibitors warrant further study as a potential new therapeutic avenue for treatment of acute lung injury.

Mechanism and Inhibition of Matrix Metalloproteinases

Matrix metalloproteinases hydrolyze proteins and glycoproteins forming the extracellular matrix, cytokines and growth factors released in the extracellular space, and membrane-bound receptors on the outer cell membrane. The pathological relevance of MMPs has prompted the structural and functional characterization of these enzymes and the development of synthetic inhibitors as possible drug candidates. Recent studies have provided a better understanding of the substrate preference of the different members of the family, and structural data on the mechanism by which these enzymes hydrolyze the substrates. Here, we report the recent advancements in the understanding of the mechanism of collagenolysis and elastolysis, and we discuss the perspectives of new therapeutic strategies for targeting MMPs.

Vesicular systems employing natural substances as promising drug candidates for MMP inhibition in glioblastoma: A nanotechnological approach

Glioblastoma multiforme (GBM), one of the most lethal Brain tumors, characterized by its high invasive nature and increased mortality rates forms a major bottleneck in transport of therapeutics across the Blood Brain Barrier (BBB). Matrix metalloproteinases (MMPs) are classified as enzymes, which are found to be up regulated in the Glioma tumor microenvironment and thus can be considered as a target for inhibition for curbing GBM. Many chemotherapeutics and techniques have been employed for inhibiting MMPs till now but all of them failed miserably and were withdrawn in clinical trials due to their inability in restricting the tumor growth or increasing the overall survival rates. Thus, the quest for finding the suitable MMP inhibitor is still on and there is a critical need for identification of novel compounds which can alter the BBB permeability, restrain tumor growth and prevent tumor recurrence. Currently, naturally derived substances are gaining widespread attention as tumor inhibitors and many studies have been reported by far highlighting their importance in restricting MMP expression thus serving as chemotherapeutics for cancer due to their minimal toxicity. These substances may serve as probable candidates for inhibiting MMP expression in GBM. However, targeting and delivering the inhibitor to its target site is an issue that needs to be overcome in order to attain maximum specificity and sustained release. The birth of nanotechnology served as a boon in delivering drugs to the most complicated areas thus paving way for Nano drug delivery. An efficient Nano carrier with ability to cross the BBB and competently kill the Glioma cells forms the prerequisite for GBM chemotherapy. Vesicular drug delivery systems are one such class of carriers, which have the capacity to release the drug at a predetermined rate at the target site thus minimizing any undesirable side effects. Exploiting vesicular systems as promising Nano drug carriers to formulate naturally derived substances, that can bypass the BBB and act as an inhibitor against MMPs in GBM is the main theme of this review.

Pharmacodynamic considerations in the use of matrix metalloproteinase inhibitors in cancer treatment

INTRODUCTION

Matrix metalloproteinases (MMPs) are classified in the family of zinc-dependent endopeptidases, which can degrade various components of an extracellular matrix and a basement membrane. Studies have demonstrated that MMPs relate to the development of malignant tumors and induce angiogenesis, resulting in the invasion and metastasis of tumor cells. MMPs are highly expressed in malignant tumors and are related to cancer patients' malignant phenotype and poor prognosis. Therefore, blocking the expression or activity of MMPs may be a promising strategy for cancer treatment.

AREAS COVERED

This study aimed to explain the MMP structure, regulatory mechanism, and carcinogenic effect; investigate the matrix metalloproteinase-inhibitors (MMPIs) that are currently used in clinical trials for cancer treatment; and summarize the trial results.

EXPERT OPINION

Currently, the results of clinical trials that have used MMPIs as anticancer agents are unsatisfactory. However, MMPs remain an attractive target for cancer treatment. For example, development of the specific peptide or antibodies in targeting the hemopexin domain of MMP-2 may be a new therapeutic direction. The design and development of MMPIs that have selectivity will be the primary focus in future studies.

Potential clinical applications of matrix metalloproteinase inhibitors and their future prospects

Matrix metalloproteinases (MMPs) are endopeptidases that are involved in extracellular matrix degradation. They are also implicated in a number of abnormal bioprocesses, such as tumor growth, invasion, and metastasis. Therefore, controlling MMP activities has generated considerable interest as a possible therapeutic target. The tissue inhibitors of metalloproteinases (TIMPs) are the major naturally occurring proteins that specifically inhibit MMPs and assist in maintaining the balance between extracellular matrix destruction and formation. However, TIMPs are probably not suitable for pharmacological applications due to their short half-lives in vivo. During the last few decades, synthetic MMP inhibitors (MMPIs) have undergone rapid clinical development in attempts to control MMP enzymatic activities in abnormal bioprocesses. Although studies with these agents have met with limited clinical success, the field of MMPIs is still expanding, and generation of highly effective and selective MMPIs might be a promising direction of this research area.

Matrix metalloproteinase-2 as a target for head and neck cancer therapy

INTRODUCTION

Matrix metalloproteinase (MMP)-2 is a zinc-dependent proteinase that is capable of cleaving all extracellular matrix (ECM) substrates. Degradation of the matrix is a key event in the progression, invasion, and metastasis of potentially malignant and malignant lesions of the head and neck. Therefore, blocking MMP-2 expression or activity may present a promising strategy for anticancer treatment.

AREAS COVERED

Current understanding of the molecular mechanisms that govern MMP-2 regulation and its tumorigenic effects, and that are involved in the initiation and progression of head and neck cancers, in particular the emerging role of MMP-2 in cell migration, which is a prerequisite for tumor metastasis. MMP-2 gene polymorphisms, cellular substrates, and interacting proteins are summarized. The current state of drugs that target this enzyme, either alone or in combination with other targeted agents are also discussed.

EXPERT OPINION

MMP-2 has long been a drug target. The current status of MMP-2 inhibitors as anticancer agents and their failure in the clinic is discussed in light of new data on the MMP-2s role as a cell surface transducer - data that may lead to the design and development of novel, MMP-2-targeting inhibitors.

Caffeoyl pyrrolidine derivative LY52 inhibits hepatocellular carcinoma invasion via suppressing matrix metalloproteinase-2

PURPOSE

In this study, we examined the effects of LY52, a caffeoyl pyrrolidine derivative designed to fit the S'1 active pocket of gelatinases, on the expressions of matrix metalloproteinases and invasion abilities of hepatocellular carcinoma cells.

METHODS

The effects of LY52 on the proliferations of HepG2 (hepatitis B virus (HBV) negative) and HepG2.2.15 (HBV-producing) cells were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Gelatin zymography was used to detect the effects of LY52 on matrix metalloproteinases expressions and Western blot was used to detect matrix metalloproteinase-2 expressions. Transwell chamber assay was used to detect the effects of LY52 on invasion of the cells.

RESULTS

Gelatin zymography and Western blot showed that matrix metalloproteinase-2 expressions were inhibited by LY52 in a dose-dependent manner, and inhibitory rates of LY52 on HepG2 cells were higher than on HepG2.2.15 cells. Transwell chamber showed that LY52 could significantly inhibit the invasion of both cells, although the inhibitory effects of LY52 on HepG2.2.15 cells were was not as obvious as on HepG2 cells.

CONCLUSIONS

These results suggested that LY52 might inhibit the invasion of hepatocellular carcinoma cells by suppressing matrix metalloproteinase-2, although the inhibitory effects of LY52 on HBV-negative cells were more obvious than that of HBV-infected cells.

Matrix metalloproteinase inhibitors: a critical appraisal of design principles and proposed therapeutic utility

Matrix metalloproteinases (MMPs) play an important role in tissue remodelling associated with various physiological and pathological processes, such as morphogenesis, angiogenesis, tissue repair, arthritis, chronic heart failure, chronic obstructive pulmonary disease, chronic inflammation and cancer metastasis. As a result, MMPs are considered to be viable drug targets in the therapy of these diseases. Despite the high therapeutic potential of MMP inhibitors (MMPIs), all clinical trials have failed to date, except for doxycycline for periodontal disease. This can be attributed to (i) poor selectivity of the MMPIs, (ii) poor target validation for the targeted therapy and (iii) poorly defined predictive preclinical animal models for safety and efficacy. Lessons from previous failures, such as recent discoveries of oxidative/nitrosative activation and phosphorylation of MMPs, as well as novel non-matrix related intra- and extracellular targets of MMP, give new hope for MMPI development for both chronic and acute diseases. In this article we critically review the major structural determinants of the selectivity and the milestones of past design efforts of MMPIs where 2-/3-dimensional structure-based methods were intensively applied. We also analyse the in vitro screening and preclinical/clinical pharmacology approaches, with particular emphasis on drawing conclusions on how to overcome efficacy and safety problems through better target validation and design of preclinical studies.

Anti-angiogenic drugs: from bench to clinical trials

Angiogenesis, the generation of new capillaries through a process of pre-existing microvessel sprouting, is under stringent control and normally occurs only during embryonic and post-embryonic development, reproductive cycle, and wound repair. However, in many pathological conditions (solid tumor progression, metastasis, diabetic retinopathy, hemangioma, arthritis, psoriasis and atherosclerosis among others), the disease appears to be associated with persistent upregulated angiogenesis. The development of specific anti-angiogenic agents arises as an attractive therapeutic approach for the treatment of cancer and other angiogenesis-dependent diseases. The formation of new blood vessels is a complex multi-step process. Endothelial cells resting in the parent vessels are activated by an angiogenic signal and stimulated to synthesize and release degradative enzymes allowing endothelial cells to migrate, proliferate and finally differentiate to give rise to capillary tubules. Any of these steps may be a potential target for pharmacological intervention. In spite of the disappointing results obtained initially in clinical trials with anti-angiogenic drugs, recent reports with positive results in phases II and III trials encourage expectations in their therapeutic potential. This review discusses the current approaches for the discovery of new compounds that inhibit angiogenesis, with emphasis on the clinical developmental status of anti-angiogenic drugs.

Stage-specific action of matrix metalloproteinases influences progressive hereditary kidney disease

BACKGROUND

Glomerular basement membrane (GBM), a key component of the blood-filtration apparatus in the in the kidney, is formed through assembly of type IV collagen with laminins, nidogen, and sulfated proteoglycans. Mutations or deletions involving alpha3(IV), alpha4(IV), or alpha5(IV) chains of type IV collagen in the GBM have been identified as the cause for Alport syndrome in humans, a progressive hereditary kidney disease associated with deafness. The pathological mechanisms by which such mutations lead to eventual kidney failure are not completely understood.

METHODS AND FINDINGS

We showed that increased susceptibility of defective human Alport GBM to proteolytic degradation is mediated by three different matrix metalloproteinases (MMPs)--MMP-2, MMP-3, and MMP-9--which influence the progression of renal dysfunction in alpha3(IV)-/- mice, a model for human Alport syndrome. Genetic ablation of either MMP-2 or MMP-9, or both MMP-2 and MMP-9, led to compensatory up-regulation of other MMPs in the kidney glomerulus. Pharmacological ablation of enzymatic activity associated with multiple GBM-degrading MMPs, before the onset of proteinuria or GBM structural defects in the alpha3(IV)-/- mice, led to significant attenuation in disease progression associated with delayed proteinuria and marked extension in survival. In contrast, inhibition of MMPs after induction of proteinuria led to acceleration of disease associated with extensive interstitial fibrosis and early death of alpha3(IV)-/- mice.

CONCLUSIONS

These results suggest that preserving GBM/extracellular matrix integrity before the onset of proteinuria leads to significant disease protection, but if this window of opportunity is lost, MMP-inhibition at the later stages of Alport disease leads to accelerated glomerular and interstitial fibrosis. Our findings identify a crucial dual role for MMPs in the progression of Alport disease in alpha3(IV)-/- mice, with an early pathogenic function and a later protective action. Hence, we propose possible use of MMP-inhibitors as disease-preventive drugs for patients with Alport syndrome with identified genetic defects, before the onset of proteinuria.

Recent advances in MMP inhibitor design

The search for an MMP inhibitor with anticancer efficacy is a nearly three-decade endeavor. This inhibitor is yet to be found. The reasons for this failure include shortcomings in the chemistry of these compounds (including broad MMP sub-type selectivity, metabolic lability, and toxicity) as well as the emerging, and arguably extraordinary, complexity of MMP cell (and cancer) biology. Together these suggest that the successful anticancer inhibitor must possess MMP selectivity against the MMP subtype whose involvement is critical, yet highly temporally (with respect to metastatic progression) and mechanistically (with respect to matrix degradation) regulated. This review summarizes the progression of chemical structure and mechanistic thinking toward these objectives, with emphasis on the disappointment, the perseverance, and the resilient optimism that such an inhibitor is there to be discovered.

The MMP-9 expression determined the efficacy of postoperative adjuvant chemotherapy using oral fluoropyrimidines in stage II or III colorectal cancer

BACKGROUND

The aim of this study was to determine any correlation between the efficacy of postoperative adjuvant chemotherapy using oral fluoropyrimidines and the matrix metalloproteinase 9 (MMP-9) expression in primary colorectal cancer tissues.

PATIENTS AND METHODS

The data on 307 patients with colorectal cancer at stage II or III, who underwent potentially curative resection with lymphadenectomy, were reviewed. Of these, 188 received postoperative administration of oral fluoropyrimidines such as UFT and 5'-DFUR (chemotherapy group), while the other 119 patients underwent surgery alone (surgery-alone group). Immunostaining for MMP-9 was performed using surgical specimens of all 307 primary tumors and 18 recurrent tumors.

RESULTS

Overall, MMP-9 was positively expressed in the primary tumor in 44% of patients. Multivariate analysis revealed that the MMP-9 expression was a worse prognostic factor with a second highest hazard ratio for recurrence. The disease-free survival rate in the chemotherapy group was significantly higher than that in the surgery-alone group. However, no significant difference in disease-free survival rate between the two groups was found in patients with a tumor positive for MMP-9. There was a strong positive correlation of MMP-9 expression between the primary tumors and the recurrent liver or lung tumors.

CONCLUSIONS

The efficacy of postoperative adjuvant chemotherapy using oral fluoropyrimidines such as UFT and 5'-DFUR may not be as great for patients with a tumor positive for MMP-9 having a greater risk to postoperative recurrence.

Efficacy of the MMP inhibitor MMI270 against lung metastasis following removal of orthotopically transplanted human colon cancer in rat

We have investigated the antitumor effects of synthetic MMP inhibitor MMI270 against postoperative lung metastasis from colon cancer in nude rat. The KM12SM human colon cancer cells were injected into the cecal wall, and at 5 weeks after the injection, the cecum was removed including the tumor. Then, 30 mg/kg of MMI270 was administered perorally twice per day for 2 or 4 weeks, either immediately after removal or after week 2 after the removal. At week 7 after the removal, lung metastasis was significantly inhibited by the early administration of MMI270 immediately after the tumor removal but not by the late administration. The survival rates were significantly higher in the rats treated by early administration of MMI270 compared to the survival rate in untreated rats. Moreover, no lung metastasis was detected in some rats with 24-weeks' survival treated by early administration. Lower microvessel density, lower PCNA Index and higher Apoptotic Index in the lung metastases of the rats treated with MMI270 were found compared to those in untreated rats. A beneficial effect of by early administration of MMI270 against postoperative lung metastases may be expected through inhibiting neovascularization of metastases in nude rat.