Thymidine kinase (EC 2.7.1.21 ) catalyzes the phosphorylation of thymidine to deoxythymidine monophosphate.
General function
Cell death/survival, DNA Replication, Enzyme, Transferase
Comment
Cellular localization
Cytoplasmic
Comment
Ovarian function
Comment
Demeter A, et al reported differences in thermostability of thymidine kinase isoenzymes in normal ovary and ovarian carcinoma.
Thymidine kinase 1 (TK 1 EC. 2.7.1.21) the most specific and cell-cycle regulated salvage enzyme for pyrimidine nucleoside supply of DNA synthesis is a promising target to rationally designed chemo- and other therapies. The present study was undertaken to compare the heat stability of TK isoenzymes of both normal ovarian and epithelial ovarian cancer cells. Tissue extracts of epithelial ovarian carcinomas (N = 7) and normal ovaries (N = 9) were analyzed for thymidine kinase activity using the polyethyleneimine-cellulose disc radioassay. The TK activity in extracts of ovarian carcinomas was 12-fold higher than in extracts of normal ovaries. The TK activity of malignant ovarian cells was much higher but more unstable (t1/2 = 36 minutes) than the enzyme isolated from healthy ovaries (t1/2 = 82 minutes). This profound difference in thermostability might provide the molecular background for hyperthermia combined with chemotherapy as a promising treatment for ovarian malignancies.