Mitochondrial-Targeting MET Kinase Inhibitor Kills Erlotinib-Resistant Lung Cancer Cells

Area of Science:

• Oncology
• Molecular Biology
• Drug Discovery

Background:

• Epidermal Growth Factor Receptor (EGFR) tyrosine kinase inhibitors (TKIs) are standard treatments for EGFR-mutated non-small cell lung cancer.
• Acquired resistance to EGFR TKIs often involves bypass signaling pathways, notably MET amplification and overexpression.
• Activated MET protein has been found in the mitochondria of resistant lung cancer cells, suggesting a role in TKI resistance.

Purpose of the Study:

• To investigate the potential of targeting mitochondrial MET to overcome EGFR TKI resistance in lung cancer.
• To synthesize and evaluate a novel MET inhibitor conjugated with a mitochondrial targeting moiety.

Main Methods:

• Development of a triphenylphosphonium (TPP)-conjugated MET kinase inhibitor (PHA665752).
• Assessment of the TPP-TKI conjugate's localization in mitochondria of EGFR TKI-resistant HCC827 lung cancer cells.
• Evaluation of the conjugate's effect on MET phosphorylation in the mitochondrial inner membrane.
• Determination of the conjugate's cytotoxicity and apoptogenic activity.

Main Results:

• The TPP-TKI conjugate rapidly localized to the mitochondria of MET-overexpressing, erlotinib-resistant HCC827 cells.
• The conjugate partially suppressed MET phosphorylation at Y1234/Y1235 in the mitochondrial inner membrane.
• The TPP-TKI conjugate exhibited comparable cytotoxicity and apoptosis-inducing effects to the parent compound.

Conclusions:

• Mitochondrial MET is a viable target for overcoming EGFR TKI resistance in lung cancer.
• A TPP-TKI conjugate can effectively target mitochondrial MET.
• Targeting mitochondrial MET with TPP-TKI conjugates offers a promising strategy to restore chemosensitivity in resistant lung cancers.