Ginsenoside Rh2 as a novel PIN1 inhibitor disrupting the cancer stem cell-like phenotype in non-small cell lung cancer.

BACKGROUND

The widespread issue of drug resistance remains a major obstacle in the treatment of lung cancer, particularly non-small cell lung cancer (NSCLC), making the development of novel adjuvant therapeutic strategies an urgent priority. Cancer stem cells (CSCs) are key drivers of drug resistance and metastasis, and the development of therapies targeting CSCs holds potential to overcome resistance to chemotherapy or targeted therapy in NSCLC. This study investigated the mechanisms by which ginsenoside Rh2 (G-Rh2) targeted CSCs and enhanced the efficacy of gefitinib (GF).

METHODS

This study systematically examined the anti-tumor mechanisms of G-Rh2 using an integrated experimental approach. Flow cytometry, tumor sphere formation assays, and reverse transcription quantitative polymerase chain reaction (RT-qPCR) were employed to assess the effects of G-Rh2 on CSC formation and function. Protein microarray screening, combined with analysis of epithelial-mesenchymal transition (EMT) markers, lactate production assays, and co-immunoprecipitation (co-IP), were used to identify and validate the key molecular target of G-Rh2 as prolyl isomerase PIN1. Profiling of glycolytic metabolites demonstrated that the regulation of glucose metabolism by G-Rh2 is PIN1-dependent. Co-IP, immunofluorescence, and Western blotting were used to elucidate the mechanistic role of PIN1. Cell proliferation and apoptosis assays were conducted to evaluate the sensitizing effect of G-Rh2 on GF treatment. A xenograft mouse model was used to evaluate the effect of G-Rh2 on tumor growth and GF efficacy.

RESULTS

G-Rh2 inhibited CSC-like properties in NSCLC cells, reduced tumor metastasis, and enhanced sensitivity to both chemotherapy and GF treatment. It modulated glucose metabolism in a PIN1-dependent manner to exert its anti-NSCLC effects. Mechanistically, G-Rh2 was found to bind to PIN1, disrupting the PIN1-PGK1 interaction. This disruption reduced PIN1-dependent mitochondrial translocation, leading to the PDHK1 phosphorylation at the T338 site and upregulating the expression of the PDH complex. Consequently, G-Rh2 enhanced the mitochondrial conversion of pyruvate to acetyl-CoA, promoted oxidative phosphorylation, and suppressed tumor aerobic glycolysis. In vivo studies further demonstrated that G-Rh2 increased GF sensitivity through modulation of the PIN1/PGK1 signaling pathway, ultimately inhibiting the malignant growth and metastasis of NSCLC.

CONCLUSIONS

G-Rh2, as a PIN1-targeting agent, inhibited CSC traits in NSCLC by modulating the PIN1/PGK1 axis, thereby enhancing the sensitivity to GF treatment.