A zinc chelator inhibiting gelatinases exerts potent in vitro anti-invasive effects

Novel Suppressive Effects of Ketotifen on Migration and Invasion of MDA-MB-231 and HT-1080 Cancer Cells

The high mortality rates associated with cancer reflect the metastatic spread of tumor cells from the site of their origin. Metastasis, in fact, is the cause of 90% of cancer deaths. Therefore, considerable effort is being made to inhibit metastasis. In the present study, we screened ketotifen for anti-migratory and anti-invasive activities against MDA-MB-231 breast cancer and HT-1080 fibrosarcoma cancer cells. Cancer cell migration and invasion were measured using multi-well chambers. Additionally, western blots were used to examine the effects of ketotifen on the expressions of CDC42, Rho, Rac, and matrix metalloproteinase 9 (MMP-9). The results showed that ketotifen dose-dependently suppressed the migration and invasion of MDA-MB-231 and HT-1080 cells. Ketotifen also suppressed the expressions of CDC42, Rac, and Rho, which, significantly, are involved in MDA-MB-231 and HT-1080 cancer cell migration. Moreover, ketotifen suppressed the expression and activity of MMP-9, which is involved in degradation of the extracellular matrix leading to invasion. The overall data suggested that ketotifen suppresses the migration and invasion of MDA-MB-231 and HT-1080 cancer cells via inhibition of CDC42, Rac, Rho, and MMP-9 expression.

The lipophilic metal chelators DP-109 and DP-460 are neuroprotective in a transgenic mouse model of amyotrophic lateral sclerosis

One of the hypotheses for the development of familial amyotrophic lateral sclerosis (ALS) is that mutations in the superoxide dismutase 1 enzyme lead to aberrant properties of the copper within the active site of the enzyme which then causes increased oxidative damage. The lipophilic metal chelators DP-109 and DP-460 which chelate calcium, copper, and zinc were tested in the G93A-transgenic ALS mouse model. Both compounds significantly extended survival, DP-109 (5 mg/kg/day) by 10%, DP-460 (10 mg/kg/day) by 9%. While the effect on survival was relatively small, chelator treatment also improved motor performance, dramatically reduced cell loss in the lumbar spinal cord and decreased reactive astrocytosis and microgliosis. Markers of oxidative damage, tumor necrosis factor (TNF)-alpha and alpha-synuclein were reduced in the lumbar spinal cord of G93A mice treated with DP-109 or DP-460 as compared with vehicle-treated animals. Furthermore, the treatment induced protein expression of the transcription factor hypoxia inducible factor-1alpha and mRNA levels of vascular endothelial growth factor as a corresponding target gene. In line with previous studies using metal chelators in the G93A animal model, our results suggest that these compounds have neuroprotective capacities in ALS.

Ageladine A: an antiangiogenic matrixmetalloproteinase inhibitor from the marine sponge Agelas nakamurai

A novel MMP inhibitor, ageladine A (1) with antiangiogenic activity was isolated from a marine sponge Agelas nakamurai. Structure 1 was determined by a combination of spectroscopic and chemical methods to be an unprecedented structure of 4-(4,5-dibromo-1H-pyrrol-2-yl)]-1H-imidazo[4,5-c]pyridin-2-amine.

Development of new assays and improved procedures for the purification of recombinant human chymase

Chymase mediates a major alternative way of angiotensin II production from angiotensin I beside angiotensin converting enzyme in the final step of the renin-angiotensin system. This enzyme is also involved in other physio-pathological processes such as angiogenesis, atherosclerosis and inflammation. Several purification attempts of natural or recombinant chymase were reported in the literature. Most of these reports were not successful in obtaining the recombinant enzyme in a highly active form and in large quantity. In the present study, we describe a facile route for the purification of the human recombinant chymase. Chymase being produced as inactive prochymase, to be cathepsin C-activated, newly raised anti-chymase Ig were used to follow the purification. In order to complete the available tools for the search of chymase inhibitors, we developed and assessed a new 96-well plate based assay for the measurement of enzyme activity, as well as a low throughput, HPLC-based one. The assays used an original derivative of angiotensin I, or the native hormone. Chymase was produced in CHO cells and appropriately matured. The amount of enzyme obtained at the end of the process is compatible with the medium-throughput screening (up to 10,000 points per day), about 800 microg x L(-1) of culture medium with a specific activity of 6.16 mmol of angiotensin I cleaved per minute per mg of protein. All the biological and technical tools are now available for the discovery of new classes of chymase inhibitors.

Physico-chemical and biological analysis of true combinatorial libraries

Combinatorial libraries offer new sources of compounds for the research of pharmacological agents such as receptor ligands, enzyme inhibitors or substrates and antibody-binding epitopes. The present review stresses the main roles played by both physico-chemical analysis, particularly when complex mixture of compounds are synthesized as libraries, and biological analysis from which active compounds are identified. After a brief discussion of semantic problems related to the designation of the product mixtures, the physico-chemical analysis of mixtures is reviewed with special emphasis on mass spectrometric techniques. These methods are able both to give a representative view of a library composition and to identify single critical compounds in large libraries. Then the biological screening of such combinatorial libraries is critically discussed with respect to the power and limitations of the methods used for the identification of the active components. Special attention is given to the complex process of library deconvolution. It is pointed out that while combinatorial techniques have evolved towards sophisticated high-tech methods, simple and robust biochemical tests should be used to deconvolute. From a large panel of published examples, a set of trends are identified which should help investigators to choose the most appropriate assay for the discovery of new entities.