Peroxisomal branched chain fatty acid β-oxidation pathway is upregulated in prostate cancer

Overexpression of α-methylacyl-CoA racemase (AMACR), an enzyme involved in branched chain fatty acid β-oxidation, in prostate cancer has been reported. Here, we report that an enzyme downstream from AMACR in the peroxisomal branched chain fatty acid β-oxidation pathway - D-bifunctional protein (DBP) - is also upregulated in prostate cancer at both mRNA and protein levels, accompanied by increased enzymatic activity. Furthermore, our data suggest that pristanoyl-CoA oxidase (ACOX3), which is expressed at extremely low level in other human organs studied including the liver, might contribute significantly to peroxisomal branched chain fatty acid β-oxidation in human prostate tissue and some prostate cancer cell lines. In contrast to these results for peroxisomal enzymes, no significant expression changes of mitochondrial fatty acid β-oxidation enzymes were observed in prostate cancer tissues through comprehensive quantitative RT-PCR screening. These data for the first time provide evidence for the selective over-activation of peroxisomal branched chain fatty acid β-oxidation in prostate cancer, emphasizing a new metabolic change during prostate oncogenesis.