Crucial roles of thymidine kinase 1 and deoxyUTPase in incorporating the antineoplastic nucleosides trifluridine and 2'-deoxy-5-fluorouridine into DNA
| Autor: | Nozomu Tanaka, Kenichi Matsuo, Hiroyuki Ueno, Akiko Osada, Hiroyuki Okabe, Kei Oguchi, Tatsushi Yokogawa, Hiromi Kazuno, Keiji Ishida, Kazuki Sakamoto, Yukari Yamada |
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| Rok vydání: | 2015 |
| Předmět: |
Male
Cancer Research Antimetabolites Antineoplastic Pyrrolidines DNA polymerase Thymidylate synthase activity tipiracil hydrochloride Thymidine Kinase Substrate Specificity Equilibrative Nucleoside Transporter 1 chemistry.chemical_compound mental disorders Humans 5-fluorouracil Equilibrative-Nucleoside Transporter 2 Pyrophosphatases Thymidine kinase 1 Uracil Nucleotide salvage biology trifluridine DNA Neoplasm Articles HCT116 Cells TAS-102 Molecular biology Drug Combinations Oncology chemistry Biochemistry Thymidine kinase biology.protein Fluorouracil Thymidine Colorectal Neoplasms Nucleoside DNA Thymine |
| Zdroj: | International Journal of Oncology |
| ISSN: | 1791-2423 |
| Popis: | Trifluridine (FTD) and 2′-deoxy-5-fluorouridine (FdUrd), a derivative of 5-fluorouracil (5-FU), are antitumor agents that inhibit thymidylate synthase activity and their nucleotides are incorporated into DNA. However, it is evident that several differences occur in the underlying antitumor mechanisms associated with these nucleoside analogues. Recently, TAS-102 (composed of FTD and tipiracil hydrochloride, TPI) was shown to prolong the survival of patients with colorectal cancer who received a median of 2 prior therapies, including 5-FU. TAS-102 was recently approved for clinical use in Japan. These data suggest that the antitumor activities of TAS-102 and 5-FU proceed via different mechanisms. Thus, we analyzed their properties in terms of thymidine salvage pathway utilization, involving membrane transporters, a nucleoside kinase, a nucleotide-dephosphorylating enzyme, and DNA polymerase α. FTD incorporated into DNA with higher efficiency than FdUrd did. Both FTD and FdUrd were transported into cells by ENT1 and ENT2 and were phosphorylated by thymidine kinase 1, which showed a higher catalytic activity for FTD than for FdUrd. deoxyUTPase (DUT) did not recognize dTTP and FTD-triphosphate (F3dTTP), whereas deoxyuridine-triphosphate (dUTP) and FdUrd-triphosphate (FdUTP) were efficiently degraded by DUT. DNA polymerase α incorporated both F3dTTP and FdUTP into DNA at sites aligned with adenine on the opposite strand. FTD-treated cells showed differing nuclear morphologies compared to FdUrd-treated cells. These findings indicate that FTD and FdUrd are incorporated into DNA with different efficiencies due to differences in the substrate specificities of TK1 and DUT, causing abundant FTD incorporation into DNA. |
| Databáze: | OpenAIRE |
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