Assignment of the human deoxycytidine kinase (DCK) gene to chromosome 4 band q13. 3-q21. 1

The enzyme deoxycytidine kinase (DCK) is the key enzyme of the salvage pathway for pyrimidine synthesis. It is responsible for the phosphorylation of deoxycytidine and several deoxycytidine analogues that are used as antimetabolites in the treatment of human cancers. For instance, the cytotoxic activity of 1-[beta]-D-arabinofuranosylcytosine (AraC), used in the chemotherapy of acute myeloid leukemia (AML), is dependent on its phosphorylation by DCK. The occurrence of clinical AraC resistance, which is usually marked by functional DCK deficiency, is one of the major obstacles in the successful treatment of AML. The cDNA sequence of the DCK gene was published and, more recently, mutational inactivation of the DCK gene has been described as a possible cause of DCK deficiency. In this study the authors report on the chromosomal localization of the DCK gene by means of fluorescence in situ hybridization. 6 refs., 2 figs.