Enhanced Degradation of Misfolded Proteins Promotes Tumorigenesis

Publication date: 28 March 2017
Source:Cell Reports, Volume 18, Issue 13
Author(s): Liang Chen, Michael D. Brewer, Lili Guo, Ruoxing Wang, Peng Jiang, Xiaolu Yang
An adequate cellular capacity to degrade misfolded proteins is critical for cell survival and organismal health. A diminished capacity is associated with aging and neurodegenerative diseases; however, the consequences of an enhanced capacity remain undefined. Here, we report that the ability to clear misfolded proteins is increased during oncogenic transformation and is reduced upon tumor cell differentiation. The augmented capacity mitigates oxidative stress associated with oncogenic growth and is required for both the initiation and maintenance of malignant phenotypes. We show that tripartite motif-containing (TRIM) proteins select misfolded proteins for proteasomal degradation. The higher degradation power in tumor cells is attributed to the upregulation of the proteasome and especially TRIM proteins, both mediated by the antioxidant transcription factor Nrf2. These findings establish a critical role of TRIMs in protein quality control, connect the clearance of misfolded proteins to antioxidant defense, and suggest an intrinsic characteristic of tumor cells.

Graphical abstract

Teaser

A diminished cellular capacity to degrade misfolded proteins contributes to aging and neurodegeneration. Chen et al. report that a heightened degradation capacity promotes tumorigenesis. Upregulation of the proteasome and TRIM proteins in tumor cells supports enhanced degradation of misfolded proteins, which bolsters antioxidant defense during oncogenic growth.


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