<p>NF-κB mediates transcriptional regulation crucial to many biological functions, and elevated NF-κB activity leads to autoimmune and inflammatory diseases, as well as cancer. Since highly aggressive breast cancers have few therapeutic molecular targets, clarification of key molecular mechanisms of NF-κB signaling would facilitate the development of more effective therapy. In this report, we show that Tob, a member of the Tob/BTG family of antiproliferative proteins, acts as a negative regulator of the NF-κB signal in breast cancer. Studies with 35 human breast cancer cell lines reveal that Tob expression is negatively correlated with NF-κB activity. Analysis of The Cancer Genome Atlas (TCGA) database of clinical samples reveals an inverse correlation between Tob expression and NF-κB activity. Tob knockdown in human breast cancer cells promoted overactivation of NF-κB upon TNF-α treatment, whereas overexpression of Tob inhibited TNF-α stimulation-dependent NF-κB activation. Mechanistically, Tob associates with the TNF receptor complex I and consequently inhibits RIPK1 polyubiquitylation, leading to possible prevention of overwhelming activation of NF-κB.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Tob negatively regulates NF-κB activation in breast cancer through its association with the TNF receptor complex

  • Miho Tokumasu,
  • Atsuko Sato,
  • Taku Ito-Kureha,
  • Mizuki Yamamoto,
  • Nao Ohmine,
  • Kentaro Semba,
  • Jun-ichiro Inoue,
  • Tadashi Yamamoto

摘要

NF-κB mediates transcriptional regulation crucial to many biological functions, and elevated NF-κB activity leads to autoimmune and inflammatory diseases, as well as cancer. Since highly aggressive breast cancers have few therapeutic molecular targets, clarification of key molecular mechanisms of NF-κB signaling would facilitate the development of more effective therapy. In this report, we show that Tob, a member of the Tob/BTG family of antiproliferative proteins, acts as a negative regulator of the NF-κB signal in breast cancer. Studies with 35 human breast cancer cell lines reveal that Tob expression is negatively correlated with NF-κB activity. Analysis of The Cancer Genome Atlas (TCGA) database of clinical samples reveals an inverse correlation between Tob expression and NF-κB activity. Tob knockdown in human breast cancer cells promoted overactivation of NF-κB upon TNF-α treatment, whereas overexpression of Tob inhibited TNF-α stimulation-dependent NF-κB activation. Mechanistically, Tob associates with the TNF receptor complex I and consequently inhibits RIPK1 polyubiquitylation, leading to possible prevention of overwhelming activation of NF-κB.