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  • The EMBO Journal (2009) 28, 843 - 853
  • doi:10.1038/emboj.2009.32

Published online: 12 February 2009

ASK1 and ASK2 differentially regulate the counteracting roles of apoptosis and inflammation in tumorigenesis

Takayuki Iriyama1,9, Kohsuke Takeda1, Hiromi Nakamura1, Yoshifumi Morimoto1, Takumi Kuroiwa1, Junya Mizukami1, Tsuyoshi Umeda1, Takuya Noguchi1, Isao Naguro1, Hideki Nishitoh1, Kaoru Saegusa1, Kei Tobiume2, Toshiki Homma3, Yutaka Shimada4, Hitoshi Tsuda5, Satoshi Aiko6, Issei Imoto7, Johji Inazawa7, Kazuhiro Chida8, Yoshimasa Kamei9, Shiro Kozuma9, Yuji Taketani9, Atsushi Matsuzawa1 and Hidenori Ichijo1

  1. Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, CREST, Japan Science and Technology Corporation, and Strategic Approach to Drug Discovery and Development in Pharmaceutical Sciences, Center of Excellence (COE) Program, Bunkyo-ku, Tokyo, Japan
  2. Department of Mucosal Immunology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan
  3. Central Research Laboratory, Kissei Pharmaceutical Co. Ltd., Nagano, Japan
  4. Department of Surgery and Science, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, Toyama, Japan
  5. Department of Basic Pathology, National Defense Medical College, Saitama, Japan
  6. Department of Surgery, National Defense Medical College, Saitama, Japan
  7. Department of Molecular Cytogenetics, Medical Research Institute and School of Biomedical Science, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
  8. Department of Animal Resource Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
  9. Department of Obstetrics and Gynecology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan

Correspondence to:

Hidenori Ichijo, Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, CREST, Japan Science and Technology Corporation, and Strategic Approach to Drug Discovery and Development in Pharmaceutical Sciences, Center of Excellence (COE) Program, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan. Tel.: 81 3 5841 4859; Fax: 81 3 5841 4778; E-mail: ichijo@mol.f.u-tokyo.ac.jp

Received 23 August 2008; Accepted 21 January 2009

Apoptosis and inflammation generally exert opposite effects on tumorigenesis: apoptosis serves as a barrier to tumour initiation, whereas inflammation promotes tumorigenesis. Although both events are induced by various common stressors, relatively little is known about the stress-induced signalling pathways regulating these events in tumorigenesis. Here, we show that stress-activated MAP3Ks, ASK1 and ASK2, which are involved in cellular responses to various stressors such as reactive oxygen species, differentially regulate the initiation and promotion of tumorigenesis. ASK2 in cooperation with ASK1 functioned as a tumour suppressor by exerting proapoptotic activity in epithelial cells, which was consistent with the reduction in ASK2 expression in human cancer cells and tissues. In contrast, ASK1-dependent cytokine production in inflammatory cells promoted tumorigenesis. Our findings suggest that ASK1 and ASK2 are critically involved in tumorigenesis by differentially regulating apoptosis and inflammation.

  • Keywords:

    • apoptosis,
    • ASK1,
    • inflammation,
    • MAP kinase,
    • reactive oxygen species