Mapping Tyrosine Kinases Based on a TK Activity-Representing Peptide Library Reveals a Role for SRC in H1975 Drug...

Area of Science:

• Biochemistry
• Oncology
• Proteomics

Background:

• Tyrosine kinases (TKs) are critical targets in cancer therapy, with numerous TK inhibitors approved.
• Cancer drug resistance, often due to kinome reprogramming, limits the long-term efficacy of TK inhibitors.
• Monitoring TK activity is essential for understanding and overcoming drug resistance mechanisms.

Purpose of the Study:

• To develop and validate a novel strategy for directly inferring TK activities.
• To investigate TK activity heterogeneity in non-small cell lung cancer (NSCLC) cell lines.
• To assess TK activity responses to EGFR inhibitor AZD9291 and identify resistance mechanisms.

Main Methods:

• Development of a TK activity-representing peptide library-based multiple reaction monitoring (TARPL-MRM) strategy.
• Assay of 87 human TKs by quantifying 301 phosphorylation sites.
• Application of the TARPL-MRM strategy to NSCLC cell lines, including analysis of resistance to AZD9291.

Main Results:

• Demonstrated heterogeneity of TK activity across different NSCLC cell lines.
• Assessed the dynamic changes in TK activities in response to AZD9291 treatment.
• Identified SRC activity as crucial for acquired resistance in H1975 cells and suggested SRC inhibition as a potential strategy to overcome resistance.

Conclusions:

• The TARPL-MRM strategy provides a powerful tool for direct inference of TK activities.
• This approach can reveal insights into cancer drug resistance mechanisms, such as acquired resistance to EGFR inhibitors in NSCLC.
• The strategy holds potential for clinical diagnostics and the discovery of novel therapeutic targets for cancer treatment.