ABSTRACT
Matriptase is a cell-surface trypsin-like serine protease of epithelial origin, which cleaves and activates proteins including hepatocyte growth factor/scatter factor and proteases such as uPA, which are involved in the progression of various cancers. Here we report a fragment-linking approach, which led to the discovery of O-(3-carbamimidoylphenyl)-l-serine amides as potent matriptase inhibitors. The co-crystal structure of one of the potent inhibitors, 6 in complex with matriptase catalytic domain validated the working hypothesis guiding the development of this congeneric series and revealed the structural basis for matriptase inhibition. Replacement of a naphthyl group in 6 with 2,4,6-tri-isopropyl phenyl resulted in 10 with improved matriptase inhibition, which exhibited significant primary tumor growth inhibition in a mouse model of prostate cancer. Compounds such as 10, identified using a fragment-linking approach, can be explored further to understand the role of matriptase as a drug target in cancer and inflammation.
Subject(s)
Amides/chemistry , Serine Endopeptidases/chemistry , Serine Proteinase Inhibitors/chemistry , Amides/chemical synthesis , Amides/pharmacokinetics , Animals , Binding Sites , Catalytic Domain , Crystallography, X-Ray , Half-Life , Kinetics , Male , Mice , Molecular Docking Simulation , Protein Binding , Serine/chemistry , Serine Endopeptidases/metabolism , Serine Proteinase Inhibitors/chemical synthesis , Serine Proteinase Inhibitors/pharmacokinetics , Structure-Activity RelationshipABSTRACT
Hepsin, a type II transmembrane serine protease, is upregulated in prostate cancer and known to be involved in the progression of metastasis. Here we report a structure-guided approach, which resulted in the discovery of 2-aryl/pyridin-2-yl-1H-indole derivatives as potent and selective inhibitors of hepsin. Potent and selective inhibition of hepsin by compound 8 is likely due to interactions of the amidine group at the S1 site with the cyclohexyl ring from the 2-aryl group projecting towards the S1' site and the tert-hydroxyl group interacting with His57 side-chain as revealed by X-ray crystallography. Compounds 8 and 10, showed Ki of 0.1 µM for hepsin, and exhibited inhibition of invasion and migration of hepsin-overexpressing cell line. Compounds described here could serve as useful tool reagents to investigate the role of hepsin as a potential therapeutic target in cancer.
Subject(s)
Antineoplastic Agents/pharmacology , Cyclohexanes/pharmacology , Indoles/pharmacology , Pyridines/pharmacology , Serine Endopeptidases/metabolism , Serine Proteinase Inhibitors/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Cell Line, Tumor , Cell Movement/drug effects , Cyclohexanes/chemical synthesis , Humans , Indoles/chemical synthesis , Mice , Microsomes, Liver/metabolism , Molecular Docking Simulation , Neoplasm Invasiveness , Pyridines/chemical synthesis , Serine Proteinase Inhibitors/chemical synthesisABSTRACT
Matriptase is a serine protease implicated in cancer invasion and metastasis. Expression of matriptase is frequently dysregulated in human cancers and matriptase has been reported to activate latent growth factors such as hepatocyte growth factor/scatter factor, and proteases such as urokinase plasminogen activator suggesting that matriptase inhibitors could have therapeutic potential in treatment of cancer. Here we report a structure-based approach which led to the discovery of selective and potent matriptase inhibitors with benzene as central core having 1,3,5 tri-substitution pattern. X-ray crystallography of one of the potent analogs in complex with matriptase revealed strong hydrogen bonding and salt-bridge interactions in the S1 pocket, as well as strong CH-π contacts between the P2/P4 cyclohexyl and Trp215 side-chain. An additional interaction of the pendant amine at cyclohexyl with Gln175 side-chain results in substantial improvement in matriptase inhibition and selectivity against other related serine proteases. Compounds 15 and 26 showed tumor growth inhibition in a subcutaneous DU-145 prostate cancer mouse model. These compounds could be useful as tools to further explore the biology of matriptase as a drug target.
Subject(s)
Antineoplastic Agents/pharmacology , Benzamides/pharmacology , Benzene/pharmacology , Cell Proliferation/drug effects , Cyclohexanes/pharmacology , Drug Discovery , Prostatic Neoplasms/pathology , Serine Endopeptidases/chemistry , Serine Proteinase Inhibitors/pharmacology , Amino Acid Sequence , Animals , Antineoplastic Agents/chemistry , Benzamides/chemistry , Benzene/chemistry , Binding Sites , Crystallography, X-Ray , Cyclohexanes/chemical synthesis , Humans , Male , Mice , Mice, SCID , Models, Molecular , Molecular Sequence Data , Prostatic Neoplasms/drug therapy , Sequence Homology, Amino Acid , Serine Proteinase Inhibitors/chemistry , Structure-Activity RelationshipABSTRACT
Matriptase belongs to trypsin-like serine proteases involved in matrix remodeling/degradation, growth regulation, survival, motility, and cell morphogenesis. Herein, we report a structure-based approach, which led to the discovery of sulfonamide and amide derivatives of pyridyl bis(oxy)benzamidine as potent and selective matriptase inhibitors. Co-crystal structures of selected compounds in complex with matriptase supported compound designing. Additionally, WaterMap analyses indicated the possibility of occupying a distinct pocket within the catalytic domain, exploration of which resulted in >100-fold improvement in potency. Co-crystal structure of 10 with matriptase revealed critical interactions leading to potent target inhibition and selectivity against other serine proteases.