title: Identification and Characterization of Separase Inhibitors (Sepins) for Cancer Therapy.
abstract: Separase is an endopeptidase that cleaves cohesin subunit Rad21, facilitating the repair of DNA damage during interphase and the resolution of sister chromatid cohesion at anaphase. Separase activity is negatively regulated by securin and Cdk1-cyclin B in vivo. Separase overexpression is reported in a broad range of human tumors, and its overexpression in mouse models results in tumorigenesis. To elucidate further the mechanism of separase function and to test if inhibition of overexpressed separase can be used as a strategy to inhibit tumor-cell proliferation, small-molecule inhibitors of separase enzyme are essential. Here, we report a high-throughput screening for separase inhibitors (Sepins). We developed a fluorogenic separase assay using rhodamine 110-conjugated Rad21 peptide as substrate and screened a small-molecule compound library. We identified a noncompetitive inhibitor of separase called Sepin-1 that inhibits separase enzymatic activity with a half maximal inhibitory concentration (IC50) of 14.8 µM. Sepin-1 can inhibit the growth of human cancer cell lines and breast cancer xenograft tumors in mice by inhibiting cell proliferation and inducing apoptosis. The sensitivity to Sepin-1 in most cases is positively correlated to the level of separase in both cancer cell lines and tumors.
authors: Texas Children's Cancer Center, and Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
authors: Nenggang
authors: N
authors: Zhang
authors: Texas Children's Cancer Center, and Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
authors: Kathleen
authors: K
authors: Scorsone
authors: Texas Children's Cancer Center, and Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
authors: Gouqing
authors: G
authors: Ge
authors: Texas Children's Cancer Center, and Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
authors: Caterina C
authors: CC
authors: Kaffes
authors: Lester & Sue Smith Breast Center, and Departments of Molecular and Cellular Biology and Radiology, Baylor College of Medicine, Houston, TX, USA.
authors: Lacey E
authors: LE
authors: Dobrolecki
authors: Texas Children's Cancer Center, and Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
authors: Malini
authors: M
authors: Mukherjee
authors: Lester & Sue Smith Breast Center, and Departments of Molecular and Cellular Biology and Radiology, Baylor College of Medicine, Houston, TX, USA.
authors: Michael T
authors: MT
authors: Lewis
authors: Texas Children's Cancer Center, and Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
authors: Stacey
authors: S
authors: Berg
authors: IBT, Texas A&M Health Science Center, Houston, TX, USA.
authors: Clifford C
authors: CC
authors: Stephan
authors: Texas Children's Cancer Center, and Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA pati@bcm.edu nzhang@bcm.edu.
authors: Debananda
authors: D
authors: Pati
mesh_terms: D000818:Animals; D000906:Antibodies / Q000737:chemistry; D000970:Antineoplastic Agents / Q000737:chemistry*; D017209:Apoptosis; D001943:Breast Neoplasms / Q000473:pathology; D018797:Cell Cycle Proteins; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004249:DNA Damage; D004268:DNA-Binding Proteins; D004195:Disease Models, Animal; D005260:Female; D057166:High-Throughput Screening Assays; D006801:Humans; D006868:Hydrolysis; D020128:Inhibitory Concentration 50; D020714:Maximum Tolerated Dose; D051379:Mice; D008856:Microscopy, Fluorescence; D009368:Neoplasm Transplantation; D009369:Neoplasms / Q000188:drug therapy* / Q000201:enzymology* / Q000473:pathology; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism; D010455:Peptides / Q000737:chemistry; D010750:Phosphoproteins / Q000737:chemistry; D012235:Rhodamines / Q000737:chemistry; D064247:Separase / Q000037:antagonists & inhibitors*
chemical_list: D000906:Antibodies; D000970:Antineoplastic Agents; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D010455:Peptides; D010750:Phosphoproteins; C429022:RAD21 protein, human; D012235:Rhodamines; C049025:rhodamine 110; D064247:Separase
keywords: Separase; breast cancer; high-throughput screening; small-molecular inhibitors