Hypoxia enhances the phosphorylation and cytotoxicity of ganciclovir and zidovudine in Kaposi's sarcoma-associated herpesvirus-infected cells
Hypoxia enhances the phosphorylation and cytotoxicity of ganciclovir and zidovudine in Kaposi's sarcoma-associated herpesvirus-infected cells
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DOI：
10.1158/0008-5472.can-07-0939
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发表时间：
2007-07-15
期刊：
影响因子：
11.2
通讯作者：
Yarchoan, Robert
中科院分区：
文献类型：
--
作者：
Davis, David A.;Singer, Kathleen E.;Yarchoan, Robert
原发性渗出性淋巴瘤(PEL)是一种罕见的由卡波西肉瘤相关疱疹病毒(KSHV)引起的B细胞淋巴瘤。PEL对标准的细胞毒性化疗反应不佳，预示着存活率很低。因此，迫切需要新的有效治疗方案。已知KSHV编码两个裂解基因ORF36(磷酸转移酶)和ORF21(胸苷激酶)，分别可磷酸化更昔洛韦和叠氮胸苷。在这里，我们探索了这些基因是否可以作为PEL的治疗靶点。PEL出现在胸腔和其他提供低氧环境的积液中。根据Northern印迹分析，PEL细胞暴露在低氧环境中上调了ORF36和ORF21的表达。利用一种新的非放射性反相高效液相色谱/质谱法分离和定量更昔洛韦和叠氮胸苷的磷酸化形式，我们发现暴露在低氧下的PEL细胞产生了这些药物的毒性三磷酸盐。此外，我们发现缺氧增加了更昔洛韦和叠氮胸苷在PEL细胞中的细胞毒性，但对疱疹病毒阴性的CA46细胞没有明显的影响。这些发现可能在开发PEL或其他KSHV相关恶性肿瘤的有效治疗方法方面具有临床应用价值。
Primary effusion lymphoma (PEL) is a rare B-cell lymphoma caused by Kaposi's sarcoma-associated herpesvirus (KSHV). PEL is poorly responsive to standard cytotoxic chemotherapy and portends a poor survival. Consequently, new effective treatment options are urgently needed. It is known that KSHV encodes two lytic genes, ORF36 (phosphotransferase) and KSHV ORF21 (thymidine kinase), which can phosphorylate ganciclovir and azidothymidine, respectively. Here, we have explored whether these genes can be used as therapeutic targets for PEL. PEL arises in pleural spaces and other effusions that provide a hypoxic environment. Based on Northern blot analysis, exposure of PEL cells to hypoxia up-regulated the expression of both ORF36 and ORF21. Using a newly developed nonradioactive reverse-phase high-performance liquid chromatography/mass spectrometry method to separate and quantify the phosphorylated forms of ganciclovir and azidothymidine, we found that PEL cells exposed to hypoxia produced increased amounts of the toxic triphosphates of these drugs Moreover, we found that hypoxia increased the cell toxicity of ganciclovir and azidothymidine in PEL cells but had no significant effect on the herpesvirus-negative cell line CA46. These findings may have clinical applicability in the development of effective therapies for PEL or other KSHV-related malignancies.