TGFβ1/integrin β3 positive feedback loop contributes to acquired EGFR TKI resistance in EGFR-mutant lung cancer

Area of Science:

• Oncology
• Molecular Biology
• Drug Resistance

Background:

• Acquired resistance to Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors (EGFR TKIs), including third-generation osimertinib, limits long-term efficacy in EGFR-mutant lung cancer.
• Understanding novel molecular mechanisms of acquired resistance is crucial for developing effective therapeutic strategies.

Purpose of the Study:

• To investigate novel molecular mechanisms underlying acquired resistance to EGFR TKIs in EGFR-mutant lung cancer.
• To identify and characterize a new molecular loop contributing to acquired resistance.
• To evaluate the therapeutic potential of targeting this loop.

Main Methods:

• Utilized in vitro and in vivo EGFR-mutant lung cancer models with acquired resistance to EGFR TKIs.
• Assessed the expression levels of TGFβ1 and integrin β3.
• Investigated the mechanistic relationship between TGFβ1 and integrin β3, including feedback loop formation.
• Evaluated the impact of interrupting the TGFβ1/integrin β3 loop on acquired resistance and EGFR TKI efficacy.

Main Results:

• EGFR TKIs significantly increased TGFβ1 and integrin β3 expression in resistant lung cancer models.
• A positive feedback loop was identified where TGFβ1 induced and activated integrin β3, and overexpressed integrin β3 induced and activated TGFβ1.
• Interruption of the TGFβ1/integrin β3 loop markedly delayed acquired resistance and enhanced EGFR TKI efficacy.

Conclusions:

• The study demonstrates a novel TGFβ1/integrin β3 positive feedback loop as a key mechanism driving acquired resistance to EGFR TKIs in EGFR-mutant lung cancer.
• This TGFβ1/integrin β3 loop represents a new therapeutic target for overcoming acquired resistance and improving treatment outcomes.