Protein Instability Is Targetable in Mismatch Repair-Deficient Tumors

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Mismatch repair (MMR) is crucial for genomic stability.
• Deficiency in MMR leads to microsatellite instability and increased mutation rates.
• The downstream effects of MMR deficiency on protein homeostasis are not fully understood.

Purpose of the Study:

• To investigate the impact of MMR deficiency on proteome-wide protein stability.
• To identify specific protein aggregation patterns in MMR-deficient tumors.
• To explore the functional consequences of protein instability in these tumors.

Main Methods:

• Proteomic analysis of MMR-deficient and MMR-proficient tumor samples.
• Mass spectrometry-based quantification of protein levels and post-translational modifications.
• In vitro and in vivo models to assess protein aggregation and cellular stress responses.

Main Results:

• MMR-deficient tumors display significant proteome-wide protein instability.
• Increased levels of protein aggregation and hallmark features of cellular stress were observed.
• Specific pathways related to protein folding and degradation were dysregulated.

Conclusions:

• MMR deficiency drives widespread protein instability and aggregation, contributing to a unique tumor proteomic landscape.
• These findings suggest that protein homeostasis is a critical vulnerability in MMR-deficient cancers.
• Targeting protein aggregation pathways may offer novel therapeutic avenues for MMR-deficient tumors.