Sortilin exhibits tumor suppressor-like activity by limiting EGFR transduction function

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Lung cancer is a leading cause of cancer death globally, often driven by mutated epidermal growth factor receptor (EGFR).
• While EGFR inhibitors show initial promise, therapeutic resistance frequently develops, limiting long-term efficacy.
• EGFR functions as a transcription factor, promoting oncogenic drivers that contribute to treatment resistance.

Purpose of the Study:

• To investigate the role of sortilin in regulating EGFR signaling and its potential impact on lung cancer.
• To explore the relationship between sortilin, EGFR, and oncogenic drivers like cMYC.
• To determine if sortilin expression can predict patient response to anti-EGFR therapies.

Main Methods:

• Utilized genome-wide chromatin binding assays to identify interactions between sortilin and EGFR.
• Analyzed the binding of sortilin to gene regulatory elements, including those associated with cMYC.
• Correlated sortilin expression levels with the efficacy of anti-EGFR therapies in lung adenocarcinoma models.

Main Results:

• Sortilin was identified as a regulator of cytoplasmic EGFR, attenuating its signal transduction.
• Sortilin was found to interact with gene regulatory elements occupied by EGFR.
• Sortilin also binds to regulatory elements of cMYC, suggesting a tumor suppressor-like function.
• Sortilin expression levels showed potential as a predictive biomarker for anti-EGFR therapy response.

Conclusions:

• Sortilin plays a role in modulating EGFR activity and may possess tumor suppressor functions in lung cancer.
• The interaction of sortilin with EGFR and cMYC regulatory elements provides a molecular mechanism for its activity.
• Sortilin expression is a potential predictive biomarker for the efficacy of anti-EGFR treatments in lung adenocarcinoma.