The inhibitory effect of transthyretin gene on growth of human hepatoma cells

Transthyretin(TTR) gene was highly expressed in normal liver and it has been found to be deleted in part of DNA samples from human hepatic cancer.Its mRNA expression was suppressed in most hepatoma samples.In order to study the biological effect of TTR gene on the growth of hepatoma cells,a recombinant vector containing TTR cDNA was constructed by pCMV,then it was transfected into hepatoma cell lines SMMC-7721 and Q3.It has been demonstrated that the inhibition of growth rate of TTR cDNA transfected hepatoma cells was about 50% in strength compared with that of the control.This inhibition was further enhanced when the transfected hepatoma cells were treated with all-trans retinoic acid.Hepatoma cells of cell lines PLC/PRF/5,SMMC-7721 and Q3 as well as hepatoma cells SMMC-7721 transfected with pCMV or pCMV-TTR were analyzed for TTR expression by Northern hybridization.The low level of TTR expression was found in both hepatoma cell lines and in SMMC-7721 cells transfected with pCMV alone.However,a remarkable TTR mRNA expression was observed in hepatoma SMMV-7721 cells transfected with pCMV-TTR.It seems possible that TTR gene might be a candidate of cancer suppressor gene for human hepatic cancer.     

A stage—specific protein factor binding to a CACCC motif in both human β—globin gene promoter and 5‘—HS2 region

The DNaseI hypersensitive site 2 (HS2) of human β-globin locus control region(LCR) is required for the high level expression of human β-globin genes.In the present study,a stage-specific protein factor (LPF-β) was identified in the nuclear extract prepared from mouse fetal liver at d 18 of gestation,which could bind to the HS2 region of human β-globin LCR.We also found that the shift band of LPF-β factor could be competed by human β-globin promoter.However,it couldn‘t be competed by human ε-globin promoter or by human ^Aγ-globin promoter.Furthermore,our data demonstrated that the binding-sequence of LPF-β factor is 5‘CACACCCTA 3‘,which is located at the HS2 region of β-LCR(from-10845 to-10853 bp)and human β-globin promoter(from-92 to -84 bp).We speculated that these regions containing the CACCC box in both the human β-globin promoter and HS2 might function as stage selector elements in the regulation of human β-globin switching and the LPF-β factor might be a stage-specific protein factor involved in the regulation of human β-globin gene expression.     

基因转移的DNA病毒方法

在基因治疗中,作为基因转移的载体,迄今几乎都用逆转录病毒,但是在某些情况下,ＤＮＡ病毒作为载体具有明显的优越性,本对腺相关病毒、腺病毒和疱疹病毒作为外源基因载体进行了简要的讨论。     

载脂蛋白A—I基因表达及调控

载脂蛋白Ａ－Ｉ是血浆中高密度脂蛋白的主要蛋白成份,十多年来其基因结构已清楚,并在染色体上得以定位。目前ＡｐｏＡ－Ｉ基因在原核,真核细胞以及转基因鼠中均已获表达,对于该基因的调控机理正在深入研究。本就以上几方面的进展加以综述。     

血型糖蛋白及其变种基因发生的分子机理

人红细胞膜血型糖蛋白α和δ组成ＭＮＳｓ血型系统抗原。该系统ＧＰＡ,ＧＰＢ和ＧＰＥ的基因结构已经阐明。在人群中,该系统显示了结构多态性,并具有许多α和δ基因杂化产生的变种,而不等交换与基因转换则可能是该系统进行演变和这种变种产生的分子机理。     

高等植物的泛肽素基因及其基因表达

高等植物的泛肽素基因及其基因表达印莉萍,刘兴军,林忠平（首都师范大学生物系北京１０００３７）（中科院植物所北京１０００４４）ＵＢＩＯＵＩＴＩＮＧＥＮＥＡＨＤＪＤＳＧＥＮＥＥＸＰＲＥＳＳＩＯＮＩＮＨＩＧＨＥＲＰＬＡＮＴＳ￥ＹｉｎＬｉ－ｐｉｎｇ;ＬｉｕＸ...     

植物基因转移及其应用前景

植物基因转移及其应用前景刘金元（山东省农科院原子能应用研究所,济南）自从１９７４年Ｖａｎｌａｒｅｂｅｋｅｔ［１２］等人在根癌农杆菌中发现一种与双子叶植物肿瘤诱导有关的质粒,随后Ｃｈｉｌｔｏｎ［７］等人又从分子水平证实了该质粒中的一个ＤＮＡ片段（Ｔ－Ｄ...     

植物──病原物互作中的基因类型和功能

植物──病原物互作中的基因类型和功能何晨阳,王金生（南京农业大学植保系南京２１００１４）１植物－病原物互作中的基因对基因关系植物－病原物相互关系有亲和性互作和不亲和性互作二种类型。在亲和性互作中,病原物致病,植物感病;在不亲和互作中,病原物不致病（无...     

用平截末端使大豆根瘤菌苹果酸脱氨酶基因插入失活及电激法转化

本实验用平截末端连接法把卡那霉素抗性基因插入到大豆根瘤菌（Ｂｒａｈｙｒｈ;ｚｏｂｉｕｍｊａｐｏｎｉｃｕｍ）１１０的苹果酸脱氢酶（ｍｄｈ）基因中,致使ｍｄｈ基因失活,再通过电激法把这一重组基因转入大豆根瘤菌（Ｂｒａｈｙｒｈｉｚｏｂｉｕｍｊａｐｏｎｉｃｕｍ）２１４３中,进而探讨ｍｄｈ基因失活对大豆固氮作用的影响。