Adaptive resistance to lorlatinib via EGFR signaling in ALK-rearranged lung cancer

Area of Science:

• Oncology
• Molecular Biology
• Cancer Research

Background:

• Advanced Anaplastic Lymphoma Kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) often shows incomplete responses to tyrosine kinase inhibitors due to adaptive resistance.
• Understanding the mechanisms of adaptive resistance to specific inhibitors, such as lorlatinib, is critical for improving patient outcomes.

Purpose of the Study:

• To investigate the mechanisms of adaptive resistance to lorlatinib in ALK-rearranged NSCLC.
• To identify therapeutic strategies to overcome this resistance.

Main Methods:

• Analysis of signaling pathways involved in lorlatinib resistance.
• In vitro studies using lung cancer cell lines.
• In vivo xenograft models in mice.

Main Results:

• Epidermal Growth Factor Receptor (EGFR) signaling, activated by heparin-binding EGF-like growth factor via c-Jun, mediates adaptive resistance to lorlatinib.
• EGFR inhibition enhances lorlatinib-induced apoptosis by suppressing Bcl-xL, thereby halting cancer cell proliferation.
• Combination therapy with an EGFR inhibitor and lorlatinib significantly suppressed tumor regrowth in xenograft models.

Conclusions:

• EGFR signaling plays a key role in the adaptive resistance of ALK-rearranged NSCLC to lorlatinib.
• Combined EGFR and ALK inhibition represents a promising therapeutic strategy to overcome resistance and prevent tumor recurrence in ALK-rearranged NSCLC.