Bioflavonoids as DNA Topoisomerase II Poisons

描述（由申请方提供）：双氢吡喃是有效的拓扑异构酶II毒药，被认为对成人具有化学预防作用。 然而，它们也与子宫内急性髓性白血病（AML）的发生有关。 该提案的总体目标是进一步确定生物素改变人类拓扑异构酶II的催化活性的机制及其在致癌起始中的潜在作用。 本研究的具体目的是：（1）通过体外酶学研究，阐明双胍改变人II型拓扑异构酶催化功能的机制，这些酶学研究用于检测DNA切割和连接。 将采用诱变和NMR研究来确定生物素对酶的相互作用位点。 (2)通过使用siRNA确定拓扑异构酶II α和β在介导生物素在人细胞中的细胞毒性和遗传毒性作用中的作用。 将通过克隆和PCR方法检查每种亚型在培养的人细胞中类生物素诱导的MIL基因易位起始中的作用。 该项目将进一步加深我们对联苯双酯的化学预防和细胞毒性特性的理解，并可能导致这些化合物作为化疗剂的利用。

DESCRIPTION (provided by applicant): Bioflavonoids are potent topoisomerase II poisons and are believed to be chemopreventative in adults. However, they have also been implicated in the initiation of acute myeloid leukemia's (AMLs) in utero. The overall goal of this proposal is to further define the mechanism by which bioflavonoids alter the catalytic activity of human topoisomerase II and their potential role in the initiation of carcinogenesis. The specific aims for this proposal are to: (1) Delineate the mechanism by which bioflavonoids alter the catalytic function of human type II topoisomerases via in vitro enzymological studies that are used to examine DNA cleavage and ligation. Mutagenesis and NMR studies will be employed to define the site of interaction of bioflavonoids on the enzyme. (2) Determine the role of topoisomerase II alpha and beta in mediating the cytotoxic and genotoxic effects of bioflavonoids in human cells by using siRNA. The role of each isoform in the initiation of bioflavonoid-induced MIL gene translocations in cultured human cells will be examined via cloning and PCR approaches. This project will further our understanding of the chemopreventative and cytotoxic properties of bioflavonoids and potentially lead to the utilization of these compounds as chemotherpeutic agents.