STAT1 Promotes KRAS Colon Tumor Growth and Susceptibility to Pharmacological Inhibition of Translation Initiation Factor eIF4A.
Fiche publication
Date publication
décembre 2016
Journal
Molecular cancer therapeutics
Auteurs
Membres identifiés du Cancéropôle Est :
Dr DESAUBRY Laurent
Tous les auteurs :
Wang S, Darini C, Désaubry L, Koromilas AE
Lien Pubmed
Résumé
The transcription factor STAT1 displays antitumor functions for certain forms of cancer via immunoregulatory and cell-autonomous pathways. Paradoxically, STAT1 can promote the survival of different tumor types treated with chemotherapeutic drugs through mechanisms that are not clearly defined. Herein, we demonstrate that STAT1 displays prosurvival effects in human KRAS colon tumor cells by regulating pathways that converge on the initiation of mRNA translation. Specifically, STAT1 increases PI3K class IB signaling and promotes the downregulation of the programmed cell death protein 4 (PDCD4), a protein with tumor-suppressive properties. PDCD4 downregulation by STAT1 increases the activity of the translation initiation factor eIF4A, which facilitates the cap-independent translation of mRNAs encoding for the antiapoptotic XIAP and BCL-XL in colon tumors with mutated but not normal KRAS Genetic inactivation of STAT1 impairs the tumorigenic potency of human KRAS colon tumor cells and renders them resistant to the antitumor effects of the pharmacologic inhibition of eIF4A in culture and immunodeficient mice. Our data demonstrate an important connection between mRNA translation and KRAS tumorigenesis under the control of STAT1, which can determine the susceptibility of KRAS tumors to pharmacologic inhibition of mRNA translation initiation. Mol Cancer Ther; 15(12); 3055-63. ©2016 AACR.
Référence
Mol. Cancer Ther.. 2016 Dec;15(12):3055-3063