Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Nucleosides Nucleotides Nucleic Acids. 2020;39(10-12):1347-1358. doi: 10.1080/15257770.2020.1720234. Epub 2020 Mar 19.
Thymidine kinase 1 (TK1) and deoxycytidine kinase (dCK) are required for the activation of thymidine and deoxycytidine analogs used in antiviral and anticancer therapies. Many anticancer drugs cause oxidative stress, and the rise of GSSG and other reactive oxygen species may lead to alteration in gene expression, protein, nucleic acids and lipid modifications. Here, we investigated the effects of oxidative stress and nucleoside analog on the expression and activity of TK1 and dCK. Treatment with GSSG resulted in glutathionylation of dCK and dGK but not TK1 and Dm-dNK, and glutathionylation led to increased dCK activity but decreased dGK activity. Treatment with hydrogen peroxide resulted in induction of TK1, however, the TK1 activity did not correlate with TK1 protein levels, indicating that TK1 protein was inactive. The cellular expression of dCK, however, was reduced but dCK activity was not affected at concentration ≤ 4 mM. Treatment with TFT or 5FdU resulted in downregulation of both TK1 and dCK. However, araC and dFdC treatment led to increased dCK protein but decreased dCK activity. In contrast, both TK1 protein and activity were upregulated after araC and dFdC treatment. Doxorubicin treatment led to upregulation of the TK1 but downregulation of dCK. In conclusion TK1 and dCK expression and activity are apparently affected by oxidative stress and treatment by nucleoside analogs. These results demonstrate the pharmacokinetic importance of characterizing the expression and activity of TK1 and dCK during chemotherapy with thymidine and deoxycytidine analogs in order to optimize their efficacy.
胸苷激酶 1（TK1）和脱氧胞苷激酶（dCK）是用于抗病毒和抗癌治疗的胸苷和脱氧胞苷类似物激活所必需的。许多抗癌药物会引起氧化应激，GSSG 和其他活性氧物质的增加可能导致基因表达、蛋白质、核酸和脂质修饰的改变。在这里，我们研究了氧化应激和核苷类似物对 TK1 和 dCK 表达和活性的影响。GSSG 的处理导致 dCK 和 dGK 的谷胱甘肽化，但不导致 TK1 和 Dm-dNK 的谷胱甘肽化，谷胱甘肽化导致 dCK 活性增加，但 dGK 活性降低。H2O2 的处理导致 TK1 的诱导，然而，TK1 活性与 TK1 蛋白水平无关，表明 TK1 蛋白无活性。然而，dCK 的细胞表达减少，但 dCK 活性在浓度≤4 mM 时不受影响。用 TFT 或 5FdU 处理导致 TK1 和 dCK 的下调。然而，阿糖胞苷和地氟胞苷处理导致 dCK 蛋白增加但 dCK 活性降低。相比之下，阿糖胞苷和地氟胞苷处理后，TK1 蛋白和活性均上调。多柔比星处理导致 TK1 的上调和 dCK 的下调。总之，氧化应激和核苷类似物处理明显影响 TK1 和 dCK 的表达和活性。这些结果表明，在使用胸苷和脱氧胞苷类似物进行化疗期间，表征 TK1 和 dCK 的表达和活性对于优化其疗效具有药代动力学重要性。
