TP53 is frequently altered by methylation, mutation, and/or deletion in acute lymphoblastic leukaemia

Different mechanisms, such as chromosomal rearrangements, deletions, mutations, and methylation/demethylation of the promoter regions of genes, have been shown to be involved in acute lymphoblastic leukaemia (ALL). These genetic and epigenetic alterations lead to the activation of protooncogenes or to inactivation of tumour suppressor genes promoting cell proliferation. One of the most frequently inactivated tumour suppressor genes is TP53, which is altered in 50% of human tumours. In this study, we have analysed: (1) the complete coding region, all intron-exon junctions and noncoding regions of exons 1-11 of TP53 by lexon-DGGE; (2) the methylation status of the 5' region of TP53 and (3) the deletion of one or both alleles of the gene by fluorescence in situ hybridisation (FISH) in 57 ALL patients. Using these techniques, we have found promoter methylation in 32% of the cases, missense mutations in 8.8%, and deletion of one allele in 7.5% of the samples, with TP53 being altered in 40% of the ALL samples studied in this series.     

Epigenetic inactivation of TSLC1 gene in nasopharyngeal carcinoma

Deletion of 11q23 is a common genetic aberration in nasopharyngeal carcinoma (NPC). Multiple candidate tumor suppressor genes (TSG) were mapped to this region but few of them were investigated in NPC. TSLC1 (tumor suppressor in lung cancer) is recently reported to be a putative TSG on 11q23. This gene was found to be inactivated by promoter hypermethylation in non-small cell lung carcinoma (NSCLC), liver cancer, and breast cancer. To study the role of TSLC1 gene in NPC tumorigenesis, we screened for mutations and aberrant methylation of TSLC1 gene in 5 NPC cell lines, 3 NPC xenografts, and 38 primary NPC cases. No somatic mutations of TSLC1 were detected in the NPC samples, but a 9-bp (CCACCACCA) deletion in exon 8 was found in a primary NPC and its corresponding blood sample. Bisulfite sequencing revealed aberrant methylation of TSLC1 promoter in four NPC cell lines. Loss of TSLC1 gene expression was found in two cell lines (HK-1 and CNE-2) with dense methylation. Expression of this gene was restored in these cell lines after treatment with demethylating agent 5-aza-2'-deoxycytidine. Our results showed that silencing of TSLC1 gene expression in NPC was associated with promoter hypermethylation. Promoter hypermethylation of TSLC1 gene was further illustrated in 34.2% (13/38) of primary NPCs. No aberrant promoter methylation was found in any of the four investigated normal nasopharyngeal epithelia. Frequent epigenetic inactivation of TSLC1 gene in NPC suggested that this gene is one of the target tumor suppressor genes of this endemic cancer.     

短发夹状RNA在人细胞诱导RNA干扰

背景与目的：RNA干扰是一种通过细胞内导入双链RNA而导致特异基因表达抑制的进化保守的转录后基因沉默现象,目前RNA干扰已成为研究基因功能的重要方法。本研究旨在利用DNA载体在细胞内产生短发夹状RNA(short hairpin RNAs,shRNA),通过这些shRNA来诱导RNA干扰(RNAm interference,RNAi),为基因功能分析提供新的实验手段。方法：利用双荧光素酶报告系统来检测DNA载体在细胞内产生的shRNA诱导RNAi的效果。比较该载体产生的shRNA在不同条件下的RNA干扰效果。结果：DNA载体产生的shRNA在人细胞能诱导RNAi,序列特异地抑制基因表达。抑制效果与所选基因靶位点高度相关。结论：shRNA在人细胞能诱导RNA干扰,序列特异地抑制基因表达,这一方法可用于基因功能分析。     

摔跤及柔道运动员的心率变异性特征

目的:通过和非运动训练人群比较,了解摔跤及柔道运动员心率变异性的特征.方法:选取男性摔跤及柔道运动员32名,设为实验组,高校男生32名,设为对照组.在静息状态下,对其常规5 min体表心电图进行时域、频域及非线性分析,获得心率变异性各相关指标数据.结果:实验组时域法各项指标(SDNN、RMSSD、SDSD、PNN50)均高于对照组,两组间有统计学差异;频域法显示TP、LF、VLF显著高于对照组,其他指标略高于对照组,但无统计学意义.结论:和非运动训练人群相比,摔跤及柔道运动员具有较大的心率变异性和更高的迷走神经和交感神经张力.     

Construction of Smac gene-containing and human prostate specific antigen promoter-regulated vector and its expression

To construct an eukaryotic expression vector containing Smac gene and study the expression efficiency and specificity of prostate specific antigen（PSA） enhancer/promoter in a possible targeted gene therapy scheme for prostate cancer. Methods： PSA enhancer （PSAE） and promoter （PSAP） sequences were amplified using PCR method. CMV and T7 promoters were deleted from pcDNA3.1-Smac and replaced by the two specific fragments to generate pPSAE-PSAP-Smac. After transfection into different cell lines, the status of cells was observed. And then, we determined the relative concentration of Smac mRNA in RT-PCR. Results： The recombinant plasmid of pPSAE-PSAP-Smac was successfully constructed. And only the prostate cancer cell line PC-3 was suppressed after transfection with pPSAE-PSAP-Smac. However, other nonprostate lines were not. Moreover, the concentration of Smac mRNA regulated by PSA promoter and enhancer was higher in comparison to the CMV promoter-driven control vectors. Conclusion： An expression vector containing the Smac gene （based on elements of the PSA gene regulatory sequences） has been developed and shown to function in prostate cancer cell lines which provides a solid platform for launching clinical studies.     

A new membrane-attack complex/perforin (MACPF) domain lethal toxin from the nematocyst venom of the Okinawan sea anemone Actineria villosa.

The Okinawan sea anemone Actineria villosa causes severe cases of stinging. We isolated the 60 kDa A. villosa toxin (AvTX-60A) as the major toxin from the isolated nematocysts of this species. AvTX-60A showed fatal toxicity to mice with intraperitoneal injection at a minimum lethal dose of less than 250 microg/kg. The N-terminal amino acid sequence was determined and the corresponding cDNA encoding AvTX-60A was sequenced. The deduced amino acid sequence of AvTX-60A showed high similarity with PsTX-60A, which had been isolated as one of the major toxins from the venomous sea anemone Phyllodiscus semoni. These sea anemone toxins are new members of the family of proteins containing membrane-attack complex/perforin (MACPF) domains, best known in pore forming proteins such as perforin. These are the first examples of MACPF domain proteins as toxins for prey acquisition or repelling predators in nature.     

植物源性转基因食品PCR检测技术研究

〔目的〕建立简便、快速、灵敏、特异的植物源性转基因食品DNA检测技术。〔方法〕针对转基因植物技术中载体上常用花椰菜花叶病毒的 3 5S启动子和根农杆菌的NOS终止子特异基因序列 ,设计合成特异的引物对 3 5s -f/ 3 5s-r、Nos -f/Nos -r ,利用基因PCR扩增技术检测植物源性转基因食品。〔结果〕引物对 3 5s -f/ 3 5s -r、Nos -f/Nos -r分别成功从转基因大豆中扩增出 195bp和 180bp特异的DNA带。采用引物对 3 5s -f/ 3 5s -r进行PCR时检测灵敏度为每反应 10 4分子 ;采用Nos -f/Nos -r时检测灵敏度为 2× 10 4分子。最低可以对 0 .1μg转基因大豆进行检测。〔结论〕基于 3 5S启动子和NOS终止子基因序列的PCR扩增技术是一种简便、快速、灵敏、特异的植物源性转基因食品DNA检测技术     

Egr-1基因启动子介导肿瘤基因放疗的研究进展

Egr-1基因是一种即刻早期基因，其启动子可感受自由基、电离辐射等理化刺激，继而诱导Egr-1基因或其下游基因表达。对转染了Egr-1基因启动子启动的肿瘤杀伤基因的肿瘤细胞．实施局部照射可诱导基因表达，通过射线与基因的双重作用杀伤肿瘤。此方法既解决了外源基因靶向表达的难题，又降低了照射剂量．减少了正常组织的损伤。     

在域中如何实现远程控制

本文介绍在域中如何实现系统远程控制,具体说明了如何配置Pcanywhere、域中实现远程安装、以及能够实现的一些功能。     

人内皮抑素在毕赤酵母中的组成型表达及其活性检测

为获得大量具有生物学活性的重组人内皮抑素(Endostatin),在毕赤酵母中进行组成型表达的研究。将由毕赤酵母偏爱密码子组成的Endostatin cDNA插入组成型载体pGAPZαA中,构建表达载体pGAPZαA-ENDO,并转化到毕赤酵母X-33中。重组菌株在甘油醛-3-磷酸脱氢酶(GAP)启动子的调控作用下,进行组成型表达Endostatin蛋白。重组人Endostatin产量达到102mg/L。Western blot显示:表达蛋白能与兔抗Endostatin的多克隆抗体特异性结合。纯化后的重组Endostatin具有抑制人血管内皮细胞系ECV-304细胞增殖的活性。利用毕赤酵母组成型表达系统能获得大量具有生物活性的Endostatin蛋白。