• Open Access

ALEX1 suppresses colony formation ability of human colorectal carcinoma cell lines

Authors

  • Hiroyoshi Iseki,

    1. Department of Digestive Surgery, Saitama International Medical Center, Saitama Medical University, Saitama, Japan
    2. Project Research Division, Saitama Medical University, Saitama, Japan
    3. Division of Functional Genomics and Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
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  • Akihiko Takeda,

    Corresponding author
    1. Project Research Division, Saitama Medical University, Saitama, Japan
    • Department of Digestive Surgery, Saitama International Medical Center, Saitama Medical University, Saitama, Japan
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  • Toshiwo Andoh,

    1. Project Research Division, Saitama Medical University, Saitama, Japan
    2. Division of Functional Genomics and Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
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  • Koki Kuwabara,

    1. Project Research Division, Saitama Medical University, Saitama, Japan
    2. Department of Gastrointestinal and General Surgery, Saitama Medical Center, Saitama Medical University, Kawagoe, Japan
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  • Norio Takahashi,

    1. Project Research Division, Saitama Medical University, Saitama, Japan
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  • Igor V. Kurochkin,

    1. Genome and Gene Expression Data Analysis Division, Bioinformatics Institute, Matrix, Singapore
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  • Hideyuki Ishida,

    1. Department of Gastrointestinal and General Surgery, Saitama Medical Center, Saitama Medical University, Kawagoe, Japan
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  • Yasushi Okazaki,

    Corresponding author
    1. Division of Functional Genomics and Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
    • Department of Digestive Surgery, Saitama International Medical Center, Saitama Medical University, Saitama, Japan
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  • Isamu Koyama

    1. Department of Digestive Surgery, Saitama International Medical Center, Saitama Medical University, Saitama, Japan
    2. Project Research Division, Saitama Medical University, Saitama, Japan
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To whom correspondence should be addressed.

E-mail: cox2vegf@yahoo.co.jp

Abstract

Arm protein lost in epithelial cancers, on chromosome X (ALEX; also known as armadillo repeat containing, X-linked [ARMCX]) is a novel subgroup within the armadillo (ARM) family, which has several ARM repeat domains. The biological function of classical ARM family members such as β-catenin is well understood, but that of the ALEX/ARMCX family members is largely unknown. Here we evaluate the effects of ALEX1 overexpression on in vitro colony formation ability and expression of ALEX1 mRNA in human colorectal tumor. Overexpression of ALEX1 suppressed the anchorage-dependent and -independent colony formation of human colorectal carcinoma cell lines by the study of stable clones of HCT116 cells expressing ALEX1 protein. Bisulfite genomic sequencing revealed that the promoter region of ALEX1 gene was highly methylated in both HCT116 and SW480 cells in comparison with PANC-1 and MCF-7 cells, which express endogenous ALEX1 mRNA, indicating the capability of promoter methylation to silence ALEX1 gene in HCT116 and SW480 cells. Our current findings suggest that overexpression of ALEX1 play a negative role in human colorectal tumorigenesis. (Cancer Sci 2012; 103: 1267–1271)

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