锅柄式PCR及其在混合谱系白血病基因断裂区中的应用

Panhandle PCR and its Application in Mixed-Lineage Leukemia Genomic Breakpoint Cloning

染色体11q23的混合谱系白血病(MLL)基因的断裂点簇集群区(BCR)的转位,可引起婴儿急性白血病及与DNA拓扑异构酶Ⅱ抑制剂的生化治疗法相关的白血病。由于MLL基因包括大约30个不同的转位伴侣基因,几个断裂点所在的伴侣基因的序列还不清楚,因而对MLL基因断裂点的PCR克隆是很困难的。锅柄式PCR,即用已知5'端序列和未知的3'端伴侣基因序列以形似一个锅和一个柄的模板扩增断裂点基因DNA,是一种克隆MLL基因断裂区的新方法,可以扩增未知3'端序列的断裂点簇集群区。

Translocations involving a breakpoint cluster region （BCR） of the mixed-lineage leukemia （MLL） gene at chromosome band 11q23 are the most common molecular abnormalities in acute leukemias of infants and acute leukemias related to chemotherapy with DNA topoisomerase Ⅱ inhibitors. Molecular cloning of MLL genomic breakpoints by PCR has been difficult because MLL genomic breakpoints involve unknown parter genes. Panhandle PCR is a straightforward method that can amplify the breakpoints within the BCR with known 5＇ and unknown 3＇ sequences from a template schematically shaped like a pan with a handle.