title: Inhibitors of HGFA, Matriptase, and Hepsin Serine Proteases: A Nonkinase Strategy to Block Cell Signaling in Cancer.
abstract: Hepatocyte growth factor activators (HGFA), matriptase, and hepsin are S1 family trypsin-like serine proteases. These proteases proteolytically cleave the single-chain zymogen precursors, pro-HGF (hepatocyte growth factor), and pro-MSP (macrophage stimulating protein) into active heterodimeric forms. HGF and MSP are activating ligands for the oncogenic receptor tyrosine kinases (RTKs), c-MET and RON, respectively. We have discovered the first substrate-based ketothiazole inhibitors of HGFA, matriptase and hepsin. The compounds were synthesized using a combination of solution and solid-phase peptide synthesis (SPPS). Compounds were tested for protease inhibition using a kinetic enzyme assay employing fluorogenic peptide substrates. Highlighted HGFA inhibitors are Ac-KRLR-kt (5g), Ac-SKFR-kt (6c), and Ac-SWLR-kt (6g) with K is = 12, 57, and 63 nM, respectively. We demonstrated that inhibitors block the conversion of native pro-HGF and pro-MSP by HGFA with equivalent potency. Finally, we show that inhibition causes a dose-dependent decrease of c-MET signaling in MDA-MB-231 breast cancer cells. This preliminary investigation provides evidence that HGFA is a promising therapeutic target in breast cancer and other tumor types driven by c-MET and RON.
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Alvin J. Siteman Cancer Center, and Department of Medicine, Oncology Division, Washington University School of Medicine , 660 South Euclid Avenue, St. Louis, Missouri 63110, United States.
authors.forename: Zhenfu
authors.initials: Z
authors.lastname: Han
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Alvin J. Siteman Cancer Center, and Department of Medicine, Oncology Division, Washington University School of Medicine , 660 South Euclid Avenue, St. Louis, Missouri 63110, United States.
authors.forename: Peter K W
authors.initials: PK
authors.lastname: Harris
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Alvin J. Siteman Cancer Center, and Department of Medicine, Oncology Division, Washington University School of Medicine , 660 South Euclid Avenue, St. Louis, Missouri 63110, United States.
authors.forename: Darin E
authors.initials: DE
authors.lastname: Jones
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Alvin J. Siteman Cancer Center, and Department of Medicine, Oncology Division, Washington University School of Medicine , 660 South Euclid Avenue, St. Louis, Missouri 63110, United States.
authors.forename: Ryan
authors.initials: R
authors.lastname: Chugani
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Alvin J. Siteman Cancer Center, and Department of Medicine, Oncology Division, Washington University School of Medicine , 660 South Euclid Avenue, St. Louis, Missouri 63110, United States.
authors.forename: Tommy
authors.initials: T
authors.lastname: Kim
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Alvin J. Siteman Cancer Center, and Department of Medicine, Oncology Division, Washington University School of Medicine , 660 South Euclid Avenue, St. Louis, Missouri 63110, United States.
authors.forename: Manjula
authors.initials: M
authors.lastname: Agarwal
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Alvin J. Siteman Cancer Center, and Department of Medicine, Oncology Division, Washington University School of Medicine , 660 South Euclid Avenue, St. Louis, Missouri 63110, United States.
authors.forename: Wei
authors.initials: W
authors.lastname: Shen
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Alvin J. Siteman Cancer Center, and Department of Medicine, Oncology Division, Washington University School of Medicine , 660 South Euclid Avenue, St. Louis, Missouri 63110, United States.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Wildman
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Alvin J. Siteman Cancer Center, and Department of Medicine, Oncology Division, Washington University School of Medicine , 660 South Euclid Avenue, St. Louis, Missouri 63110, United States.
authors.forename: James W
authors.initials: JW
authors.lastname: Janetka
keywords: HGF; HGFA; MSP; RON; breast cancer; c-MET; cell signaling; growth factor; hepsin; inhibitor; ketothiazole; kinase; matriptase; peptidomimetic; serine protease; solid-phase peptide synthesis