Synergistic Inhibitory Effect of Gliquidone Against Cisplatin-Resistant Human Lung Adenocarcinoma

Cisplatin (CDDP) can combat various types of cancers, employing a multifaceted approach against these malignant diseases. Despite its efficacy, resistance to CDDP remains a significant clinical challenge, often resulting in treatment failure and disease progression. Currently, efforts are underway to unravel the mechanisms of CDDP drug resistance in cancer treatment. The elevated presence of glutathione S-transferase pi-1 (GSTP1-1) within tumor cells plays a pivotal role in the development of resistance toward the effects of CDDP. GSTP1-1 contributes to detoxification by conjugating glutathione (GSH) to CDDP, reducing its accumulation and effectiveness in the tumor cells. In this study, the efficacy of gliquidone, an antidiabetic drug, demonstrated its capacity to impede tumor cell proliferation in both lung cancer A549 cell lines and A549/CDDP cell lines. This was achieved by suppressing the expression of GSTP1-1 within tumor cells (IC₅₀: 16.8 ± 0.8 μM). Furthermore, through the establishment of a nude mouse model featuring lung adenocarcinoma A549/CDDP cell transplantation tumors, gliquidone demonstrated a significant therapeutic effect on the mice tumors, while avoiding discernible side effects. These findings suggest that gliquidone could potentially be repurposed as an adjunct therapy in CDDP-resistant lung cancer.