TUMOR CELL DEATH INDUCED BY INHIBITION OF REPLICATION

描述：许多用于癌症化疗的细胞毒性药物抑制DNA 在肿瘤细胞中复制并诱导细胞程序性死亡(凋亡)。 目前尚不清楚对DNA复制本身的抑制程度 负责抗癌药物诱导细胞死亡。细胞 用已知的抑制剂治疗可导致循环细胞的死亡 DNA复制的一种方式，如阿希迪克林，一种能抑制 DNA聚合酶α和德尔塔延长复制，或 含羞草素，一种植物氨基酸，可防止在 哺乳动物细胞。这个应用程序的主要目标是识别基因 以及与诱导细胞死亡有关的遗传途径 通过DNA复制的抑制剂。这些基因将通过 遗传抑制元件(GSE)、短cDNA的表达选择 通过编码主要作用来抑制基因表达的片段 多肽或抑制性反义RNA。中的GSE规范化库 逆转录病毒载体将被转导到HeLa细胞，而GSEs 保护细胞免受阿昔迪林或含羞草素诱导的细胞死亡 与世隔绝。这些GSE将根据它们的有效性、效果 关于细胞周期进程，保护细胞免受不同DNA的影响的能力 复制抑制物和细胞类型特异性。全长cDNA 与所选GSE对应的人类基因将被分离，并且 它们在细胞周期中的结构和表达模式将是 特色化的。被隔离的政府支持企业也将被测试其影响。 关于细胞对复制抑制化疗药物的反应， 确定基于复制的细胞毒性机制在 它们的抗肿瘤作用。

DESCRIPTION: Many cytotoxic drugs used in cancer chemotherapy inhibit DNA replication and induce programmed cell death (apoptosis) in tumor cells. It is unknown to what extent the inhibition of DNA replication per se is responsible for the induction of cell death by anticancer drugs. Cell death in cycling cells can be induced by treatment with known inhibitors of DNA replication, such as aphidicolin, a mycotoxin which inhibits elongation of replication by DNA polymerases alpha and delta, or mimosine, a plant amino acid which prevents initiation of replication in mammalian cells. The main goal of this application is to identify genes and genetic pathways that are involved in the induction of cell death by inhibitors of DNA replication. These genes will be identified through expression selection of genetic suppressor elements (GSE), short cDNA fragments that inhibit gene expression by encoding dominantly acting peptides or inhibitory antisense RNA. A normalized library of GSEs in a retroviral vector will be transduced into HeLa cells, and GSEs which protect cells from aphidicolin- or mimosine-induced cell death will be isolated. These GSEs will be characterized for their efficacy, effects on cell cycle progression, ability to protect cells against different DNA replication inhibitors and cell-type specificity. Full-length cDNAs for human genes corresponding to the selected GSEs will be isolated, and their structure and expression patterns in the cell cycle will be characterized. The isolated GSEs will also be tested for their effects on cellular response to replication-inhibiting chemotherapeutic drugs, to determine the role of replication-based mechanisms of cytotoxicity in their antitumor effect.