Abstract Mutant p53 (mtp53) is an oncogene that drives cancer cell proliferation. We found that mtp53 associates with the promoters of numerous nucleotide metabolism genes (NMG). Mtp53 knockdown reduced NMG expression and substantially depleted nucleotide pools. Decreased GTP levels correlated with reduced activation of GTP dependent proteins (GTPases) and reduced invasiveness. Addition of exogenous GTP restored the invasiveness of mtp53 knockdown cells, suggesting that mtp53 promotes invasion by increasing GTP. Additionally, mtp53 creates a dependency on the nucleotide salvage pathway enzyme deoxycytidine kinase (dCK) for the maintenance of a proper balance in dNTP pools required for proliferation. These data indicate that mtp53 harboring cells have acquired a synthetic sick or lethal phenotype relationship with the nucleotide salvage pathway. Finally, elevated expression of NMG correlates with mutant p53 status and poor prognosis in breast cancer patients. Thus, mtp53's control of nucleotide biosynthesis has both a driving and sustaining role in cancer development. Citation Format: Luis A. Martinez, Madhusudhan Kollareddy. Regulation of nucleotide metabolism by mutant p53 contributes to its gain-of-function activities. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2108. doi:10.1158/1538-7445.AM2015-2108