GOLPH3 inhibition overcomes cisplatin resistance by restoring the glutathione/reactive oxygen species balance in the A549 non‑small cell lung cancer cell line

Cisplatin resistance is common in non‑small cell lung cancer (NSCLC); however, the molecular mechanisms remain unclear. The present study aimed to identify a new function of Golgi phosphoprotein 3 (GOLPH3) in NSCLC‑associated cisplatin resistance. Using A549 human NSCLC cells and the cisplatin‑resistant variant, stable cell lines with GOLPH3 knockdown or overexpression were established using lentiviral vectors. Through Cell Counting Kit‑8 and EdU assays, it was revealed that knockdown of GOLPH3 significantly enhanced cisplatin sensitivity in NSCLC cells. Specifically, flow cytometric analysis showed that GOLPH3 knockdown promoted apoptosis and G₂‑phase cell cycle arrest in A549 cells. Mechanistically, intracellular reactive oxygen species (ROS) and glutathione (GSH) levels were measured using assay kits, and it was demonstrated that GOLPH3 knockdown decreased intracellular GSH levels, and further attenuated intracellular cisplatin efflux and GSH/ROS imbalance. In addition, tumor‑sphere formation assays verified that GOLPH3 knockdown mitigated the stem cell‑like phenotype of NSCLC cells. In conclusion, the present findings indicated the relevance of GOLPH3 in NSCLC‑associated cisplatin resistance, and thus targeting GOLPH3 may be developed into a combination therapy to overcome cisplatin resistance.