کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2514415 | 1118466 | 2008 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Effect of AZT on thymidine phosphorylation in cultured H9c2, U-937, and Raji cell lines Effect of AZT on thymidine phosphorylation in cultured H9c2, U-937, and Raji cell lines](/preview/png/2514415.png)
3′-Azido-3′-deoxythymidine (AZT) has been shown to be a potent inhibitor of thymidine kinase 2 in work from this laboratory. Inhibition results in decreased salvage of thymidine to TTP, which may lead to depletion of the TTP pool and result in the mitochondrial dysfunction and mt-DNA depletion observed with AZT toxicity. The effect of AZT on thymidine phosphorylation in growing cells expressing thymidine kinase 1 has not been shown. Three cell lines were used in these experiments: H9c2, derived from rat cardiomyoblasts; U-937, derived from human monocytes; and Raji, derived from human lymphoblasts. AZT inhibited growth in a concentration-dependent manner in U-937 cells, but not the other cell lines. The phosphorylation of [3H]-thymidine or [3H]-AZT was determined during log growth. All cell lines salvaged and phosphorylated thymidine to TTP, with TTP the major product. The U-937 cells had a much more active salvage pathway than the other cells. All cell lines phosphorylated AZT to the triphosphate, but the major product was AZTMP. The AZT inhibition of growth of the U-937 cells did not correlate with levels of the phosphorylated AZT. In contrast, pro-drug AZT was shown to inhibit thymidine phosphorylation in all lines with 50% inhibition concentrations (IC50) ranging from 4.4 to 21.9 μM. Since the U-937 cells expressed higher activity of the salvage pathway than the other cell lines, the U-937 cells may rely more heavily on the salvage pathway for TTP synthesis, accounting for AZT inhibition of growth.
Journal: Biochemical Pharmacology - Volume 75, Issue 8, 15 April 2008, Pages 1610–1615