Activation of the pyruvate dehydrogenase complex dictates tumour progression in prostate cancer

Metabolism in cancer serves to provide energy and key biomolecules that sustain cell growth, a process that is frequently accompanied by decreased mitochondrial use of glucose. Importantly, metabolic intermediates including mitochondrial metabolites are central substrates for post-translational modifications at the core of cellular signalling and epigenetics. However, the molecular means that coordinate the use of mitochondrial metabolites for anabolism and nuclear protein modification are poorly understood. Here, we unexpectedly found that genetic and pharmacological inactivation of Pyruvate Dehydrogenase A1 (PDHA1), a subunit of pyruvate dehydrogenase complex (PDC) that regulates mitochondrial metabolism16 inhibits prostate cancer development in different mouse and human xenograft tumour models. Intriguingly, we found that lipid biosynthesis was strongly affected in prostate tumours upon PDC inactivation. Mechanistically, we found that nuclear PDC controls the expression of Sterol regulatory element-binding transcription factor (SREBF) target genes by mediating histone acetylation whereas mitochondrial PDC provides cytosolic citrate for lipid synthesis in a coordinated effort to sustain anabolism. In line with the oncogenic function of PDC in prostate cancer, we find that PDHA1 and the PDC activator, Pyruvate dehydrogenase phospatase 1 (PDP1), are frequently amplified and overexpressed at both gene and protein level in these tumours. Taken together, our findings demonstrate that both mitochondrial and nuclear PDC sustains prostate tumourigenesis by controlling lipid biosynthesis thereby pointing at this complex as a novel target for cancer therapy. We evaluated that the PDHA1 knockdown in a series of human prostate cancer cell lines relying on elevates PDC activity induced growth arrest GEP analysis of mice Pdha1*pc-/pc-, mice Pten*pc-/pc- *Pdha1*pc-/pc- and mice Pten*pc-/pc- CTRL