Gelsolin functions as a metasatsis suppressor in B16-BL6 mouse melanoma cells and requirement of the carboxyl-terminus for its effect

Authors

  • Hisakazu Fujita,

    Corresponding author
    1. Division of Cancer Gene Regulation, Research Section of Disease Control, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
    • Division of Cancer Gene Regulation, Research Section of Disease Control, Institute for Genetic Medicine, Hokkaido University, N15, W7, Kita-ku, Sapporo 060-0815, Japan
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    • Fax: +81-11-706-7869

  • Futoshi Okada,

    1. Division of Cancer Pathobiology, Research Section of Pathophysiology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
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  • Jun-ichi Hamada,

    1. Division of Cancer-Related Genes, Research Section of Molecular Pathogenesis, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
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  • Masuo Hosokawa,

    1. Division of Cancer Pathobiology, Research Section of Pathophysiology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
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  • Tetsuya Moriuchi,

    1. Division of Cancer-Related Genes, Research Section of Molecular Pathogenesis, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
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  • Richard Chikara Koya,

    1. Division of Cancer Gene Regulation, Research Section of Disease Control, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
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  • Noboru Kuzumaki

    1. Division of Cancer Gene Regulation, Research Section of Disease Control, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
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Abstract

Gelsolin, an actin-binding protein, is implicated as a critical regulator in cell motility. In addition, we have reported that cellular levels of gelsolin are decreased in various tumor cells, and overexpression of gelsolin by gene transfer suppresses tumorigenicity. We sought to assess the effects of gelsolin overexpression on metastasis and to determine the importance of a carboxyl-terminus that confers Ca2+ dependency on gelsolin for effects of its overexpression. Expression vectors with cDNA encoding either full-length wild-type or His321 mutant form, isolated from a flat revertant of Ras-transformed cells and a carboxyl-terminal truncate, C-del of gelsolin, were transfected into a highly metastatic murine melanoma cell line, B16-BL6. Expression of introduced cDNA in transfectants was confirmed using Western blotting, 2-dimensional gel electrophoresis and reverse transcription-polymerase chain reaction (RT-PCR). We characterized phenotypes of transfectants, such as growth rate, colony formation in soft agar, cell motility and metastasis formation in vivo. Transfectants expressing the wild-type, His321 mutant and C-del gelsolin exhibited reduced growth ability in soft agar. Although expression of integrin β1 or α4 on the cell surface of transfectants was not changed, wild-type and His321 mutant gelsolin, except for C-del gelsolin, exhibited retardation of cell spreading, reduced chemotatic migration to fibronectin and suppressed lung colonization in spontaneous metastasis assay. Gelsolin may function as a metastasis suppressor as well as a tumor suppressor gene. The carboxyl-terminus of gelsolin is important for retardation of cell spreading, reduced chemotasis and metastasis suppression. © 2001 Wiley-Liss, Inc.

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