Exosomes-transmitted miR-7 reverses gefitinib resistance by targeting YAP in non-small-cell lung cancer

Area of Science:

• Molecular Biology
• Oncology
• Biochemistry

Background:

• Epidermal growth factor receptor (EGFR) T790M mutations are a primary cause of resistance to tyrosine kinase inhibitors (TKIs).
• The specific role of microRNA-7 (miR-7) in the development of T790M-mediated resistance remains largely uncharacterized.

Purpose of the Study:

• To investigate the role of miR-7 in acquired resistance to EGFR TKIs.
• To explore the potential of exosomal miR-7 as a therapeutic strategy against T790M resistance mutations.

Main Methods:

• Comparative analysis of miR-7 levels in resistant and sensitive lung cancer cell lines.
• In vitro studies involving exosome-mediated transfer of miR-7 mimics.
• In vivo experiments using GW4869 to inhibit exosomal miR-7.
• Analysis of serum exosomal miR-7 levels in healthy controls and lung cancer patients.

Main Results:

• miR-7 levels were significantly lower in gefitinib-resistant H1975 cells compared to gefitinib-sensitive PC9 cells.
• Overexpression of miR-7 induced apoptosis in H1975 cells upon gefitinib treatment.
• Exosomes transferred miR-7 mimics from PC9 to H1975 cells, reversing gefitinib resistance by targeting YAP.
• Inhibition of exosomal miR-7 increased chemoresistance in vivo.
• Serum exosomal miR-7 was higher in healthy controls than in lung cancer patients.

Conclusions:

• Exosomal miR-7 can reverse gefitinib resistance in EGFR T790M-mutated lung cancer by targeting YAP.
• Serum exosomal miR-7 levels correlate with treatment response and survival in lung cancer patients.
• Exosomal miR-7 represents a promising biomarker and therapeutic target for overcoming TKI resistance.