Sulforaphane overcomes T790M-mediated gefitinib resistance in vitro through epithelial-mesenchymal transition

Area of Science:

• Molecular Biology
• Cancer Research
• Pharmacology

Background:

• Acquired resistance to gefitinib, often mediated by the T790M mutation, is a significant challenge in non-small cell lung cancer (NSCLC) treatment.
• Epithelial-mesenchymal transition (EMT) is implicated in acquired resistance to tyrosine kinase inhibitors like gefitinib.

Purpose of the Study:

• To investigate the efficacy of sulforaphane (SFN) in overcoming gefitinib resistance in lung cancer cell lines harboring the T790M mutation.
• To elucidate the mechanisms underlying SFN's effects, including its impact on EMT and key signaling pathways.

Main Methods:

• Utilized gefitinib-resistant PC-9/AB11 cells (T790M mutation) and parental PC-9 cells.
• Assessed antiproliferative activity using CCK-8 assays.
• Analyzed cell cycle arrest and apoptosis via flow cytometry.
• Evaluated drug interactions using the combination index method.
• Determined changes in EMT-related proteins and signaling pathways (EGFR, AKT, ERK) by Western blot analysis.

Main Results:

• Gefitinib-resistant PC-9/AB11 cells exhibited T790M mutation and EMT characteristics.
• The combination of gefitinib and SFN demonstrated dose-dependent antiproliferative effects and induced cell cycle arrest and apoptosis specifically in PC-9/AB11 cells.
• Synergistic effects were linked to the reversal of EMT (changes in E-cadherin, claudin-1, vimentin, N-cadherin) and modulation of EGFR, p-EGFR, p-AKT, and p-ERK signaling.

Conclusions:

• SFN effectively overcomes T790M-mediated gefitinib resistance in vitro by targeting EMT.
• The combination of gefitinib and SFN presents a promising therapeutic strategy for lung cancer patients with acquired resistance due to the T790M mutation.