Skip to Content
MilliporeSigma
  • Cancer Cells Employ Nuclear Caspase-8 to Overcome the p53-Dependent G2/M Checkpoint through Cleavage of USP28.

Cancer Cells Employ Nuclear Caspase-8 to Overcome the p53-Dependent G2/M Checkpoint through Cleavage of USP28.

Molecular cell (2020-01-27)
Ines Müller, Elwira Strozyk, Sebastian Schindler, Stefan Beissert, Htoo Zarni Oo, Thomas Sauter, Philippe Lucarelli, Sebastian Raeth, Angelika Hausser, Nader Al Nakouzi, Ladan Fazli, Martin E Gleave, He Liu, Hans-Uwe Simon, Henning Walczak, Douglas R Green, Jiri Bartek, Mads Daugaard, Dagmar Kulms
ABSTRACT

Cytosolic caspase-8 is a mediator of death receptor signaling. While caspase-8 expression is lost in some tumors, it is increased in others, indicating a conditional pro-survival function of caspase-8 in cancer. Here, we show that tumor cells employ DNA-damage-induced nuclear caspase-8 to override the p53-dependent G2/M cell-cycle checkpoint. Caspase-8 is upregulated and localized to the nucleus in multiple human cancers, correlating with treatment resistance and poor clinical outcome. Depletion of caspase-8 causes G2/M arrest, stabilization of p53, and induction of p53-dependent intrinsic apoptosis in tumor cells. In the nucleus, caspase-8 cleaves and inactivates the ubiquitin-specific peptidase 28 (USP28), preventing USP28 from de-ubiquitinating and stabilizing wild-type p53. This results in de facto p53 protein loss, switching cell fate from apoptosis toward mitosis. In summary, our work identifies a non-canonical role of caspase-8 exploited by cancer cells to override the p53-dependent G2/M cell-cycle checkpoint.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Mowiol® 4-88, Mw ~31,000
Sigma-Aldrich
MISSION® esiRNA, targeting human TP53
Sigma-Aldrich
Anti-NOXA antibody produced in rabbit, affinity isolated antibody, buffered aqueous solution
Sigma-Aldrich
Anti-phospho-Histone H3 (pSer10) antibody produced in rabbit, IgG fraction of antiserum, buffered aqueous solution
Sigma-Aldrich
MISSION® esiRNA, targeting human USP28