Analysis of TAp73-Dependent Signaling via Omics Technologies

Transactivation-proficient (TA) p73 is a transcription factor belonging to the p53 family, which regulates a variety of biological processes, including neurogenesis, differentiation, apoptosis, and DNA damage checkpoint response. In the present study, we adopted multiple Omics approaches, based upon the simultaneous application of metabolomics, lipidomics, and proteomics, in order to dissect the intracellular pathways activated by p73. As cellular model, we utilized a clone of the human osteosarcoma SAOS-2 cell line that allows the expression of TAp73alpha in an inducible manner. We found that TAp73alpha promoted mitochondrial activity (accumulation of metabolic intermediates and up-regulation of proteins related to the Krebs cycle), boosted glutathione homeostasis, increased arginine-citrulline-NO metabolism, altered purine synthesis, and promoted the pentose phosphate pathway toward NADPH accumulation for reducing and biosynthetic purposes. Indeed, lipid metabolism was driven toward the accumulation and oxidation of long-chain fatty acids with pro-apoptotic potential. In parallel, the expression of TAp73alpha was accompanied by the dephosphorylation of key proteins of the mitotic spindle assembly checkpoint. In conclusion, the obtained results confirm existing evidence from transcriptomics analyses and suggest a role for TAp73alpha in the regulation of cellular metabolism, cell survival, and cell growth.