PCK2 induces gefitinib resistance by suppresses ferroptosis in non-small cell lung cancer.

ABSTRACT

OBJECTIVES: This study aimed to explore the involvement of phosphoenolpyruvate carboxykinase 2 (PCK2) in gefitinib-resistant non-small cell lung cancer (NSCLC) cells and assess its feasibility as a therapeutic target against gefitinib resistance. METHODS: Gefitinib-resistant cell lines, PC9GR and HCC827GR, were generated through progressive exposure of parental cells to escalating concentrations of gefitinib. Transcriptomic analysis encompassed the treatment of PC9 and PC9GR cells with gefitinib or vehicle, followed by RNA extraction, sequencing, and subsequent bioinformatic analysis. Cell viability was determined via CCK-8 assay, while clonogenic assays assessed colony formation. Apoptosis was detected utilizing the Annexin V-FITC/7AAD kit. Iron ion concentrations were quantified using FerroOrange. mRNA analysis was conducted through quantitative RT-PCR. Western blotting was employed for protein analysis. H&E and immunohistochemical staining were performed on tumor tissue sections. RESULTS: The results revealed that depletion or inhibition of PCK2 significantly enhanced gefitinib's efficacy in inducing cell growth arrest, apoptosis, and ferroptosis in resistant NSCLC. Moreover, PCK2 knockdown led to the downregulation of key ferroptosis-related proteins, GPX4 and SLC7A11, while upregulating ASCL4. Conversely, overexpression of PCK2 in gefitinib-sensitive cells rendered resistance to gefitinib. In vivo experiments using a gefitinib-resistant xenograft model demonstrated that PCK2 silencing not only reduced tumor growth but also considerably increased the anti-tumor effect of gefitinib. CONCLUSIONS: In conclusion, our study presents compelling evidence indicating that PCK2 plays a pivotal role in gefitinib resistance in NSCLC. The modulation of ferroptosis-related proteins and the involvement of Akt activation further elucidate the mechanisms underlying this resistance. Consequently, PCK2 emerges as a promising therapeutic target for overcoming gefitinib resistance in NSCLC, offering a new avenue for the development of more effective treatment strategies.