Cathepsin B is a lysosomal cysteine protease that is implicated in a number ofphysiological processes, including protein turnover in lysosomes. Changes inits expression are associated with a variety of pathological processes, including cancer. Due to the structural feature, termed the occluding loop, cathepsin B differs from other cysteine proteases in possessing both, endopeptidase and exopeptidase activity. Here we investigated the impact of both cathepsin B activities on intracellular and extracellular collagen IV degradation and tumour cell invasion using new selective synthetic inhibitors,2-{[(8-hydroxy-5-nitroquinoline-7-yl)methyl]amino}-acetonitrile (1), 8-(4-methylpiperidin-1-yl)-5-nitroquinoline (2) and 7-[(4-methylpiperidin-1-yl)methyl]-5-nitroquinolin-8-ol (3). All three compounds (5 microm) reduced extracellular degradation of collagen IV by MCF-10A neoT cells by 45-70% as determined by spectrofluorimetry and they (50 microm) attenuated intracellular collagen IV degradation by 40-60% as measured with flow cytometry. Furthermore, all three compounds (5 microm) impaired MCF-10A neoT cell invasion by 40-80% as assessed by measuring electrical impedance in real time. Compounds 1 and 3 (5 microm), but not compound 2, significantly reduced the growth of MMTV-PyMT multicellular tumour spheroids. Collectively, these data suggest that the efficient strategy to impair harmful cathepsin B activity in tumour progression may include simultaneous and potent inhibition of cathepsin B endopeptidase and exopeptidase activities.
COBISS.SI-ID: 3979633
Human cathepsin B is a cysteine protease with many house-keeping functions, such as intracellular proteolysis within lysosomes. Its increased activity and expression have been strongly associated with many pathological processes, including cancers. We present here the design and synthesis of novel derivatives of nitroxoline as inhibitors of cathepsin B. These were prepared either by omitting the pyridine part, or by modifying positions 2, 7, and 8 of nitroxoline. All compounds were evaluated for their ability to inhibit endopeptidase and exopeptidase activities of cathepsin B. For the most promising inhibitors, the ability to reduce extracellular and intracellular collagen IV degradation was determined, followed by their evaluation in cell-based in vitro models of tumor invasion. The presented data show that we have further defined the structural requirements for cathepsin B inhibition by nitroxoline derivatives and provided additional knowledge that could lead to non-peptidic compounds with usefulness against tumor progression.
COBISS.SI-ID: 4477553
Lysosomal cysteine peptidase cathepsin B, involved in multiple processes associated with tumor progression, is validated as a target for anti-cancer therapy. Nitroxoline, a known antimicrobial agent, is a potent and selective inhibitor of cathepsin B, hence reducing tumor progression in vitro and in vivo. In order to further improve its anti-cancer properties we developed a number of derivatives using structure-based chemical synthesis. Of these, the 7-aminomethylated derivative (compound 17) exhibited significantly improved kinetic properties over nitroxoline, inhibiting cathepsin B endopeptidase activity selectively. In the present study, we have evaluated its anti-cancer properties. It was more effective than nitroxoline in reducing tumor cell invasion and migration, as determined in vitro on two-dimensional cell models and tumor spheroids, under either endpoint or real time conditions. Moreover, it exhibited improved action over nitroxoline in impairing tumor growth in vivo in LPB mouse fibrosarcoma tumors in C57Bl/6 mice. Taken together, the addition of a 2-(ethylamino)acetonitrile group to nitroxoline at position 7 significantly improves its pharmacological characteristics and its potential for use as an anti-cancer drug.
COBISS.SI-ID: 4360305
Over the past years, the organometalled compounds, including ruthenium, gained a lot of attention as anticancer agents. We report on clioquinol-ruthenium complex [Ru(eta6-p-cymene)(Cq)Cl] as a potent inhibitor of cathepsin B, a lysosomal cysteine peptidase, involved in tumour cell invasion and metastasis. In the low micromolar concentration range, clioquinol-ruthenium complex did not exhibit cytotoxic effects on MCF-10A neoT and U-87 MG cells; it did, however, significantly reduced their ability for extracellular matrix degradation and invasiveness in two independent cell-based models, measuring either electrical impedance in real time or the growth of multicellular tumour spheroids implanted in Matrigel, a model representing the extracellular matrix. These results establish ruthenium based organometallic compounds as promising candidates for further pre-clinical studies as anticancer therapeutics.
COBISS.SI-ID: 4164977