Prostate cancer (PC) is one of the most common male cancers worldwide. Until now, there is no consensus about using urinary metabolomic profiling as novel biomarkers to identify PC. In this study, urine samples from 50 PC patients and 50 non-cancerous individuals (control group) were collected. Based on ¹H nuclear magnetic resonance (¹H-NMR) analysis, 20 metabolites were identified. Subsequently, principal component analysis (PCA), partial least squares-differential analysis (PLS-DA) and ortho-PLS-DA (OPLS-DA) were applied to find metabolites to distinguish PC from the control group. Furthermore, Wilcoxon test was used to find significant differences between the two groups in metabolite urine levels. Guanidinoacetate, phenylacetylglycine, and glycine were significantly increased in PC, while L-lactate and L-alanine were significantly decreased. The receiver operating characteristics (ROC) analysis revealed that the combination of guanidinoacetate, phenylacetylglycine, and glycine was able to accurately differentiate 77% of the PC patients with sensitivity = 80% and a specificity = 64%. In addition, those three metabolites showed significant differences in patients stratified for Gleason score 6 and Gleason score ≥7, indicating potential use to detect significant prostate cancer. Pathway enrichment analysis using the KEGG (Kyoto Encyclopedia of Genes and Genomes) and the SMPDB (The Small Molecule Pathway Database) revealed potential involvement of KEGG “Glycine, Serine, and Threonine metabolism” in PC. The present study highlights that guanidinoacetate, phenylacetylglycine, and glycine are potential candidate biomarkers of PC. To the best knowledge of the authors, this is the first study identifying guanidinoacetate, and phenylacetylglycine as potential novel biomarkers in PC.

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.