Exploring the relationship between autophagy and Gefitinib resistance in NSCLC by silencing PDLIM5 using ultrasound-targeted microbubble destruction technology

BACKGROUND: Ultrasound-targeted microbubble destruction (UTMD) technology is a new drug and gene delivery strategy. This study investigates novel ultrasound (US) sensitive siRNA-loaded nanobubbles (siRNA-NBs) to explore the relationship between PDLIM5 mediated autophagy and drug resistance development using epidermal growth factor tyrosine kinase inhibitors (EGFR-TKIs) in the treatment of non-small cell lung cancer (NSCLC). METHODS: US sensitive siRNA-NBs were designed to inhibit the expression of PDLIM5 in gefitinib-resistant human NSCLC PC9GR cells in vitro. The expression of autophagy-related proteins (P62 and LC3-II/I) and autophagosomes in PC9GR cells after PDLIM5 gene silencing were explored. RESULTS: US-sensitive PDLIM5-targeted siRNA-NBs were effectively delivered into PC9GR cells, inhibiting PDLIM5 expression, increasing LC3-II/I and p62 expressions and increasing autophagosomes in PC9GR cells in vitro. CONCLUSIONS: Using UTMD, US-sensitive siRNA-NBs have the potential as an ideal delivery vector to mediate highly effective RNA interference for NSCLC cells. Furthermore, PDLIM5 plays a role in the autophagy-mediated resistance in gefitinib-resistant PC9GR cells.