人载脂蛋白B基因3′端高可变区不同等位基因在真核细胞中对基因表达调控的作用

为探讨人载脂蛋白B基因3'端高可变区（hypervariableregion，HVR）不同等位基因对真核细胞基因表达调控的作用．选取在正常人群中分本最广的HVE36小等位基因和在冠心病病人中分布占优势的大等位基因HVE44，分别克隆进含荧光素酶基因的pGL2－promoter及pGL2－control质粒中，转染Hela细胞和HepG2细胞．结果发现，在不同的细胞系中插入HVE44等位基因的重组质位表达均高于插入HVE36的重组质粒的表达。表明载脂蛋白B基因3'端高可变区不同等位基因具有调控基因表达的作用，HVE44大等位基因可上调细胞内的基因表达，这或许是以HVE44等大等位基因为主体的动脉粥样硬化患者体内载脂蛋白B升高的原因之一．

The Role of Different 3' End of Variable Number of Tandemly Repeat Alleles from Apolipoprotein B Gene in the Expression and Regulation of Gene

Aim The present pater is to study the effect of different 3'end of variable number of tandemly repeat (VNTR) alleles from human apoliopoprotein B gene on eukarytic expression and regulation. Methods HVE36 allele distributed widely in nor- mal Population and HVE44 allele distributed mainly in patients with atherosclerosis were cloned into plasmids of luciferase reporter vecters pGL2-promoter and PGL2-control. Then the recombinants were transfect- ed iuto Hela and HepG2 cell lines.Results The level of expression of pGL2-control plasmid inserted with WE44 allele was 4 times than those of the recombinant with HVE36. The level of expression of pGL2-promoter plasmid inserted by HVE44 is 1. 7 times than those in plasmid inserted by HVE36 allele in Hela cell line, In HepG2 cell line, the level of expression of pGL2-control recombinant with HVE44 is 3. 05 times of those in HVE36 recombi- mant. But in PGL2-promoter system, the level of expression of recombinant with HVE44 alleles is 2.1 time than those in HVE36 recombinant. In differ- ent cell lines, the expression level of recombinant with HVE44 was much higher than those of HVE36 recom- binant. Conclusioas Different 3'VNTR alleles have regula-tory role in gene expression and HVE44 allele can pos-itively regulate the eukarytic expression, which may be one of causes of higher apolipoprotein B level in atherosclerosis patients with VNTR-big alleles like HVE44. More investigations are carried out for regu- latory mechanism of the 3'-end nontranslation region.