Qici Sanling Decoction Suppresses Glutamine Consumption and Bladder Cancer Cell Growth through Inhibiting c-Myc Expression

Traditional Chinese medicine (TCM) is widely used as an alternative therapy for cancer treatment in China. Glutamine catabolism plays an important role in cancer development. Qici Sanling decoction (QCSL) suppresses bladder cancer growth. However, the association between QCSL and glutamine catabolism remains unknown. In this study, different doses of QCSL were applied to T24 cells, followed by the measurements of cell viability and apoptosis using CCK-8 and Annexin V/PI assay, respectively. Furthermore, glutamine consumption was detected using the glutamine assay kit. QCSL was observed to inhibit cell growth and induced cell apoptosis in a dose-dependent manner. Analysis of glutamine consumption revealed that QCSL suppressed glutamine consumption in T24 cells. Furthermore, QCSL decreased the mRNA and protein levels of c-Myc, GLS1, and SLC1A5. All these effects induced by QCSL could be alleviated by c-Myc overexpression, indicating c-Myc was involved in the protective role of QCSL in bladder cancer. In addition, QCSL was found to inhibit tumor growth in the xenograft tumor model. The similar results were obtained in tumor samples that protein levels of c-Myc, GLS1, and SLC1A5 were decreased upon treatment with QCSL. In conclusion, QCSL suppresses glutamine consumption and bladder cancer cell growth through inhibiting c-Myc expression.