Design of EBVTK substrates to eradicate EBV+ tumors

描述(申请人提供)：疱疹病毒的独特性质 复制酶使抗病毒药物的开发成为可能 仅在受病毒感染的细胞中转化为细胞毒性化合物。一定的 这些蛋白构成了细胞毒基因治疗(HSV-1TK和 更昔洛韦)。尽管疱疹病毒EBV编码类似的基因，但表达 在永生/致瘤感染期间保持沉默。然而，EBV转变为 B细胞可通过多种途径诱导表达复制蛋白 化学/生物制剂，提示在体内诱导TK是可行的 可以开发出摧毁EB病毒感染的肿瘤的药物。一种治疗方案 阿格丁酸酯诱导EBV-TK和更昔洛韦治疗EBV相关性恶性肿瘤 因此，为实现TK介导的杀伤作用而发展起来的。然而，实验证明 验证方案令人惊讶地发现更昔洛韦是一个很差的 基于竞争、磷酸化和差异的EBVTK底物 细胞毒性试验。HSV-1 TK是一种多核苷激酶，而EBV-1 TK 磷酸化胸腺嘧啶核苷。我们的第一阶段目标是合成和表征 胸苷(5-取代尿嘧啶)类似物，初步研究表明 以EBV-TK依赖的方式有效地杀伤细胞。综合方案是 描述。将对核苷进行系统分析，以便(1)通过 EBV-TK对细胞TK-1、TK-2或核苷酶无效(2) 通过宿主聚合酶进入细胞DNA，产生不可逆的 抑制EBV-TK+细胞的复制。成功的候选人将进入 第二阶段。 建议的商业应用：不可用

DESCRIPTION (provided by applicant): The unique properties of aherpesvirus replicative enzymes have permitted development of antiviral drugs that are converted to cytotoxic compounds exclusively in virus-infected cells. Certain of these proteins form the basis for cytotoxic gene therapy (HSV-1TK and ganciclovir). Although the gherpesvirus EBV encodes similar genes, expression is silent during immortalizing/tumorigenic infection. However, EBV-transformed B-cells can be induced to express replicative proteins by various chemical/biological agents, suggesting TK induction in vivo is feasible and that drugs destroying EBVinfected tumors can be developed. A protocol to treat EBV-associated malignancies with Argbutyrate to induce EBV-TK and ganciclovir to effect TK-mediated killing was therefore developed. However, experiments to validate the protocol surprisingly revealed that ganciclovir was a poor substrate for EBVTK based on competition, phosphorylation and differential cytoxicity assays. HSV-1 TK is a polynucleoside kinase, whereas EBV TK phosphorylates thymidine. Our Phase-I goal is to synthesize and characterize thymidine (5-substituted uracil) analogs that preliminary studies suggest will effectively kill cells in an EBV-TK-dependent manner. Synthetic schemes are described. Nucleosides will be systematicalily analyzed for (1) recognition by EBV-TK but not cellular TK- 1, TK-2 or nucleoside kinases (2) effective incorporation into cellular DNA by host polymerases, producing irreversible inhibition of replication in EBV-TK+ cells. Successful candidates will enter Phase II. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE