Cytidine deaminase (CDA) (CDA)

Cytidine deaminase (CDA) is a ubiquitous enzyme that plays a central role in the pyrimidine salvage pathway by catalyzing the hydrolytic deamination of cytidine and deoxycytidine into uridine and deoxyuridine [12, 19]. This process is essential for maintaining the balance of the intracellular nucleotide pool required for DNA and RNA synthesis and for regulating replication stress [19, 25]. In clinical oncology, CDA is a critical determinant of the metabolic fate of several nucleoside analog chemotherapeutics, including gemcitabine, cytarabine, and decitabine, which it converts into inactive metabolites [1, 2, 15]. High levels of CDA activity are frequently linked to chemoresistance in various solid and hematological malignancies, whereas genetic or epigenetic CDA deficiency can lead to severe, life-threatening systemic toxicity due to impaired drug clearance [1, 11, 18]. Consequently, CDA is both a predictive biomarker for treatment response and a therapeutic target; CDA inhibitors like cedazuridine are co-administered with nucleoside analogs to enhance their oral bioavailability and clinical efficacy [14, 15, 17].

Other names

Cytidine aminohydrolase [12]CDD [12, 19]CD [19]

Cytidine deaminase (CDA) catalyzes the hydrolytic deamination of cytidine and deoxycytidine to uridine and deoxyuridine [12, 19]. Drugs targeting this enzyme, such as the inhibitor cedazuridine, work by preventing the metabolic inactivation of nucleoside analogs (e.g., decitabine, gemcitabine), thereby increasing their systemic exposure, half-life, and therapeutic efficacy [14, 15, 17]. Additionally, CDA is involved in the metabolic activation of the prodrug capecitabine [1, 11].