title: Roles of Kunitz domains in the anti-invasive effect of hepatocyte growth factor activator inhibitor type 1 in human glioblastoma cells.
abstract: Hepatocyte growth factor activator inhibitor type 1 (HAI-1) is a membrane-bound serine proteinase inhibitor having two extracellular Kunitz-type proteinase inhibitor domains (KD) namely KD-1 and KD-2. It efficiently inhibits hepatocyte growth factor activator, matriptase, hepsin, prostasin and trypsin. We have previously reported that the expression of HAI-1 suppresses the in vitro invasive capability of human glioblastoma cells. In this study we examined the role of each KD in the anti-invasive effect of HAI-1. Engineered over-expression of the mature membrane-form HAI-1 suppressed in vitro fibrin gel invasion of two human glioblastoma cell lines, U251 and YKG-1. The migratory activity on type IV collagen was also suppressed by the HAI-1 expression. These effects were not affected by the deletion of intracytoplasmic domain of HAI-1. A truncated secreted form of HAI-1 also suppressed in vitro invasion of the cells, indicating that the extracellular portion of HAI-1 was responsible for the anti-invasive effect. To determine the roles of each KD in the anti-invasive effect of HAI-1 in vitro, we constructed expression plasmids for HAI-1 with or without mutation at the P1 position of the reactive site of each KD. The results revealed that the proteinase inhibitor activity of N-terminal KD (KD-1) is responsible for the anti-invasion effect of HAI-1.
authors.affiliation: Section of Neursurgery, Department of Neuroscience and Section of Oncopathology and Regenerative Biology, Department of Pathology, Facullty of Medicine, University of Miyazaki, Miyazaki, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Miyata
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Fukushima
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Kohama
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Hideo
authors.initials: H
authors.lastname: Takeshima
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kataoka
mesh_terms: D020816:Amino Acid Motifs; D005909:Glioblastoma / Q000473:pathology*; D006801:Humans; D009361:Neoplasm Invasiveness; D017434:Protein Structure, Tertiary / Q000502:physiology; D053491:Proteinase Inhibitory Proteins, Secretory / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D015842:Serine Proteinase Inhibitors / Q000502:physiology*; D014407:Tumor Cells, Cultured
chemical_list: D053491:Proteinase Inhibitory Proteins, Secretory; C109149:SPINT1 protein, human; D015842:Serine Proteinase Inhibitors