逆转录病毒及对生物制品污染的安全问题

自80年代发现引起人类淋巴细胞白血病和艾滋病等疾病的病源体都属于逆转录病毒以来,大量文献对逆转录病毒及其逆转录酶的研究进行了报道.随着人们越来越重视生物制品的外来因子污染问题[1],而对于生物制品如疫苗等的生产用动物源细胞基质逆转录病毒的安全检测一直是WHO以及药品监管部门关注的重点.本文就这方面的研究进展作一综述.     

高中生物学中与DNA有关的6类酶

高中生物学中涉及到与DNA有关的6类酶：DNA酶、解旋酶、DNA聚合酶、逆转录酶、限制性核酸内切酶和DNA连接酶。通过查阅文献,对这6类酶的有关知识作一综述,并提出了相应教学建议,以期对同行的教学提供帮助。     

PinX1的原核表达、纯化及其与hTERT的相互作用简

目的：原核表达人Pin2/TRF1结合蛋白X1（PinX1）,确定该蛋白与人端粒酶逆转录酶（hTERT）催化亚基的相互作用。方法：用PCR方法从乳腺文库中扩增PinX1基因的编码序列,克隆至pET-32a载体构建重组质粒pHis-PinX1,经双酶切鉴定后转化大肠杆菌BL21并进行诱导表达,SDS-PAGE和Western印迹检测His-PinX1的表达;用His磁珠纯化His-PinX1,在人肾胚细胞293T内检测His-PinX1与hTERT的相互作用。结果：扩增得到980bp的PinX1基因;Western印迹检测表明,相对分子质量约57x10。的His-PinX1获得表达,且纯化的His-PinX1与hTERT具有相互作用。结论：表达并纯化得到了与hTERT相互作用的His-PinX1,为深入研究PinX1的功能奠定了基础。     

苦参素联合富硒酵母干预大鼠肝癌变进程中TERT表达的变化

目的：探讨大鼠肝脏端粒酶逆转录酶（TERT）在肝癌演进及药物干预中表达的变化。方法：在建立大鼠肝癌变模型的基础上,用苦参素联合富硒酵母（OMT＋Se）对其进行干预。分别在诱癌2．4、6、8、10、12、14、16和18周处死大鼠。病理分级后用免疫组化和Westernblot法,分别显示大鼠肝端粒酶逆转录酶（TERT）表达的变化。结果：诱癌组’IERT表达在诱癌各时期均显著高于对照组（P〈0．05,P〈O．01）。干预组TERT在腺瘤样增生期（AH）和非典型性腺瘤样增生期（AAH）的表达均显著低于诱癌组（P〈0．05）。结论：OMT＋Se的联合干预抑制了癌变进程中TERT的表达,可在一定程度上延缓和推迟肝癌的发生发展。     

Cloning and Sequence Analysis of Genome from the Inner Mongolia Strain of the Endogenous Betaretroviruses （enJSRV）

In order to amplify the complete genome of enJSRV from the strain of Inner Mongolia （enJSRV-NM）, we used enJSRV-specific and JSRV-specific DNA probes in dot blot hybridization. Seven pairs of primers were designed based on Genbank sequences. Seven fragments were obtained by PCR and were cloned into the PMD19-T vectors. The recombinant plasmids were sequenced and analyzed. The results showed that the genome was 7 942 bp in length and contained four overlapping open reading frames corresponding to the gag, pro, pol and env genes as well as an additional open reading frame （orf-x） that overlaps the 3＇ end of the pol gene. The nucleotide acid sequences of the enJSRV-NM loci were compared with the sequences of South Africa enJS56A1 strain （Accession No.AF153615） and USA JSRV21 strain （Accession No. AF105220）. The nucleotide acid identities were 99.2% and 92.3% respectively. Two zinc fingers were found in the NC region in the predicted amino acid sequence. However, the YXXM motif, which is a reliable molecular marker for the infectious exogenous virus, was not found in the TM region. It was found that the enJSRV-NM region was 90%-98% identical at the amino acid level to its exogenous infectious counterparts in most of the retroviral genome. This is the first nucleotide sequence of enJSRV reported in P.R China. The resource work has provided a wide range of information useful not only for expression genomics and annotation of genomic DNA sequence, but also for further research on the clinical diagnosis of OPA.     

利用逆转录酶的聚合酶链式反应检测外周血中的肿瘤细胞

本文就RT－PCR技术检测外周血中肿瘤细胞的基本原理及其在黑色素瘤,肝癌,乳腺癌,结直肠癌,前列腺癌等检测中的应用加以综述。     

端粒酶逆转录酶基因的结构特点及转录调控

调节端粒酶活性的最主要成份是端粒酶逆转录酶（hTERT) ,它往往在肿瘤发生的早期巳表达,故对其研究具有重大的临床意义,近年hTERT基因启动子区巳克隆鉴定,研究发现在其核心启动子区含有多个转录因子结合位点,体内外的转录因子结合在这些位点和“CPG岛”甲基化、组蛋白去乙酰化以及hTERT转录变异体的自身调节等构成了对hTERT基因转录调控的复杂系统。研究hTERT基因的转录调控将对肿瘤的发生发展、诊断和治疗提供重要的帮助。