GZ17-6.02 and Pemetrexed Interact to Kill Osimertinib-Resistant NSCLC Cells That Express Mutant ERBB1 Proteins

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Non-small cell lung cancer (NSCLC) remains a leading cause of cancer-related deaths worldwide.
• Epidermal Growth Factor Receptor (EGFR) inhibitors are standard treatments, but resistance, especially to osimertinib, is a significant clinical challenge.
• Understanding the molecular mechanisms of novel therapeutic combinations is crucial for overcoming treatment resistance.

Purpose of the Study:

• To elucidate the molecular mechanisms underlying the efficacy of the novel therapeutic GZ17-6.02 in non-small cell lung cancer (NSCLC) cells.
• To investigate the synergistic effects of GZ17-6.02 with EGFR inhibitors and pemetrexed in various NSCLC models, including osimertinib-resistant cells.
• To identify the key signaling pathways and molecular events modulated by these drug combinations.

Main Methods:

• Investigated drug interactions between GZ17-6.02, EGFR inhibitors (erlotinib, afatinib, osimertinib), and pemetrexed in NSCLC cell lines.
• Utilized gene knockdown (ATM, AMPKα1, eIF2α, Beclin1, ATG5, BAX, BAK) and protein expression analysis (mTOR, AKT, MEK1, BCL-XL, caspase 9) to dissect molecular pathways.
• Assessed effects on autophagy (autophagosome formation and flux), cell signaling (ATM, AMPK, mTOR, ERK, AKT, c-SRC), and expression of immune-related markers (PD-L1, IDO1, MHCA).

Main Results:

• GZ17-6.02 synergized with EGFR inhibitors in mutant EGFR NSCLC but not in osimertinib-resistant cells.
• GZ17-6.02 combined with pemetrexed demonstrated efficacy in mutant ERBB1, mutant RAS, and EGFR inhibitor-resistant NSCLC.
• The combination activated ATM, AMPK, and ULK1, inactivated mTORC1/2, ERK, AKT, and c-SRC, induced autophagy, reduced HDAC2/3 expression, and modulated PD-L1, IDO1, ODC, and MHCA levels.

Conclusions:

• The combination of GZ17-6.02 and pemetrexed warrants consideration for treating osimertinib-resistant NSCLC.
• The observed molecular mechanisms involve the activation of autophagy-related pathways and modulation of key signaling cascades.
• Targeting these pathways may offer a novel therapeutic strategy for overcoming resistance to current NSCLC treatments.