Decoding the ubiquitin network: molecular mechanisms and therapeutic vulnerabilities for precision...

Area of Science:

• Molecular Biology
• Cancer Research
• Biochemistry

Background:

• Radiotherapy resistance is a significant clinical hurdle, often driven by tumor adaptation via complex molecular networks.
• The ubiquitin system plays a crucial role in regulating various cellular processes, including DNA repair, metabolism, and immune responses, which are implicated in radioresistance.
• Understanding the ubiquitin system's role is key to developing novel strategies to overcome radiotherapy resistance.

Purpose of the Study:

• To review how the ubiquitin system orchestrates radiotherapy resistance.
• To explore the mechanisms by which the ubiquitin code and its crosstalk with other post-translational modifications contribute to resistance.
• To identify vulnerabilities within these resistance mechanisms that can be exploited for radio-sensitization.

Main Methods:

• Review of existing literature on the ubiquitin system and radiotherapy resistance.
• Analysis of the role of ubiquitin chain topology (e.g., K48 vs. K63 linkages) in regulating DNA repair, metabolism, and immune evasion.
• Examination of the interplay between ubiquitination and other post-translational modifications (phosphorylation, SUMOylation, acetylation).

Main Results:

• The ubiquitin system regulates radiotherapy resistance through spatiotemporal control of DNA repair fidelity, metabolic reprogramming, and immune evasion.
• Ubiquitin modifications, including monoubiquitylation and diverse chain topologies, modulate chromatin dynamics and DNA damage responses.
• Ubiquitination critically influences cancer metabolism, affecting processes like ferroptosis, hypoxia adaptation, and nutrient flux, presenting targetable vulnerabilities.
• Targeting E3 ligases and deubiquitinases (DUBs) shows preclinical promise but faces challenges like redundancy and toxicity.

Conclusions:

• The ubiquitin system offers unique advantages for therapeutic intervention due to its dynamic reversibility and diverse signaling mechanisms.
• Targeted degradation technologies like PROTACs provide novel ways to disrupt radioresistance networks.
• Integrating mechanistic insights with biomarker-guided strategies, ubiquitin-targeting agents are poised to become essential in next-generation radiotherapy.