[Identification of speckle type BTB/POZ protein mutation regulated key metabolic pathways by cell based proteomics...

Speckle type BTB/POZ protein (SPOP) is one of the most frequently mutated protein in prostate cancer. In this study, proteomics and metabolomics were integrated to study the effects of SPOP mutation on metabolism. First, LNCaP control (CON), SPOP wild-type (SPOP_WT), and SPOP mutation (SPOP_Y87N and SPOP_F133L) cells were subjected to a metabolomics study. The metabolomics data of LNCaP CON, SPOP_WT, SPOP_Y87N, and SPOP_F133L cells were evaluated by partial least squares-discriminant analysis (PLS-DA). Four groups could be clearly differentiated with an explanation ability of R²X=0.512, R²Y=0.616 and predictive ability of Q²=0.475. Totally, 36 differential metabolites were defined with variable importance for the projection (VIP) value > 1. Then, the 36 metabolites were subjected to one-way ANOVA analysis. Fumaric acid, malic acid, citric acid, aspartic acid, and asparagine were increased in LNCaP SPOP mutation cells compared to that in LNCaP SPOP_WT cells. Using a proteomics study, 909 differential proteins were found in LNCaP SPOP_Y87N and SPOP_F133L cells. MetaboAnalyst 3.0 was used to enrich metabolic pathways by using differential metabolites. KOBAS 3.0 was used to enrich metabolic pathways by using differential proteins. Both metabolomics and proteomics analysis showed that the tricarboxylic acid (TCA) cycle and aminoacyl-tRNA biosynthesis were significantly changed. To validate these findings, gas chromatography-mass spectrometry (GC-MS)-based metabolomics was performed in Du145 SPOP knock-out cells. The results indicated that the TCA cycle was activated in Du145 SPOP knock-out cells. Collectively, this study found that SPOP mutation significantly promoted TCA cycle in prostate cancer cells.