Edible safety requirements and assessment standards for agricultural genetically modified organisms.

This paper describes the background, principles, concepts and methods of framing the technical regulation for edible safety requirement and assessment of agricultural genetically modified organisms (agri-GMOs) for Shenzhen Special Economic Zone in the People's Republic of China. It provides a set of systematic criteria for edible safety requirements and the assessment process for agri-GMOs. First, focusing on the degree of risk and impact of different agri-GMOs, we developed hazard grades for toxicity, allergenicity, anti-nutrition effects, and unintended effects and standards for the impact type of genetic manipulation. Second, for assessing edible safety, we developed indexes and standards for different hazard grades of recipient organisms, for the influence of types of genetic manipulation and hazard grades of agri-GMOs. To evaluate the applicability of these criteria and their congruency with other safety assessment systems for GMOs applied by related organizations all over the world, we selected some agri-GMOs (soybean, maize, potato, capsicum and yeast) as cases to put through our new assessment system, and compared our results with the previous assessments. It turned out that the result of each of the cases was congruent with the original assessment.     

乙型肝炎病毒C基因启动子变异检测方法的建立

目的 建立乙型肝炎病毒（HBV）C基因启动子（BCP）变异的限制性片断长度多态性（RFLP）检测方法,更好地了解BCP变异的发生与乙型病毒性肝炎（乙肝）的病情、预后以及治疗的影响。方法 结合引物设计软件Primer Premier5.0,选定保守区域,设计了2对最佳引物,建立了HBV BCP变异检测PCR-RFLP的实验方法。结果 对34例不同乙肝患者进行BCP变异检测发现：肝硬化（LC）组和慢性乙型肝炎（CHB）组中发生变异的例数明显高于无症状感染者（Asl）（χ2值分别为6.39和3.98,P〈0.05）。并且HBeAg（-）组发生变异的例数明显高于HBeAg（＋）组（χ2=4.60,P〈0.05）,结论该方法操作简便、敏感度与特异性高、结果 可靠,并可用于较大范围调查该变异株的流行情况,为临床进一步诊断和治疗提供了科学的依据,同时对人们进一步了解HBVBCP变异的发病机制具有重要意义。     

Construction of a Targeting Adenoviral Vector Carrying Survivin Promoter for Expressing EGFP Gene in Laryngeal Carcinoma Cell Line Hep-2

In gene therapy for any type of malignancy, tumor specificity is of utmost importance. Here we constructed the adenoviral vector bringing EGFP gene under the control of survivin promoter for evaluation of the possibility of target gene therapy in laryngeal carcinoma. First, Survivin promoter （SP） was amplified by PCR in the replace of CMV promoter in the plasmid pShuttle. Enhanced green fluorescent protein gene （EGFP） digested from the plasmid pEGFP-CI was cloned into plasmid pShuttle. Further two genes were cloned to Adeno-X Viral DNA. The recombinant adenoviral plasmid was transferred to HEK293 cells by lipofectamine. After titrating the virus, the laryngeal carcinoma cells （Hep-2） were transfected by the adenovirus and the expression of EGFP gene was detected. The recombinant Ad-SP-EGFP was correctly constructed and confirmed by restriction endonuclease analysis and DNA sequencing. After Hep-2 cells were transfected by the virus, RT-PCR showed that survivin mRNA was transcribed from the tumor cells. Western blot and fluorescent microscope showed EGFP protein was expressed in transgene Hep-2 cells. Present results suggest that survivin promoter may provide a new promising tool for target gene therapy of human malignancies.     

人端粒酶逆转录酶启动子在裸鼠中增强人喉癌对基因放射治疗的敏感性

目的 探索人端粒酶逆转录酶启动子(hTERTp)介导自杀基因辣根过氧化酶(HRP)-吲哚乙酸(IAA)系统联合射线,对相同来源而放射敏感性不同的人喉癌移植瘤模型的治疗作用.方法 建立相同来源而放射敏感性不同的人喉癌(Hep-2和Hep-2R细胞)移植瘤模型,并分为联合治疗组(A组和AR组)、基因治疗组(B组和BR组)、单纯放射组(C组和CR组)和对照组(D组和DR组).瘤内注射脂质体包裹的质粒phTERTp-HRP,腹腔内注射IAA从并联合放疗30 Gy,观察对移植瘤生长的抑制作用.应用原位末端转移酶标记技术(TUNEL)检测肿瘤细胞的凋亡情况;应用AP法检测瘤内HRP蛋白的表达.结果 裸鼠移植瘤生长以联合治疗组最慢,以对照组最快.A组的肿瘤抑制率为54.8%,B组为10.0%,C组为31.9%,AR组为52.7%,BR组为24.8%,CR组为17.0%.A组和AR组可见大量肿瘤细胞坏死和凋亡,凋亡指数分别为16.6%±1.3%和17.6%±1.3%,高于其他组(P<0.05).B组的HRP蛋白表达率(21.9%±5.7%)低于BR组和(33.3%±8.9%),辐射诱导后,A组和AR组的HRP蛋白表达率分别增加2.1和1.6倍(P<0.05).结论 在不同放射敏感性的喉癌移植瘤模型中,hTERTp能被射线诱导,并根据瘤内端粒酶活性增强HRP基因的表达.hTERTp·HRP-IAA系统通过诱导肿瘤细胞凋亡和引起细胞坏死,抑制裸鼠移植瘤生长,并与射线协同作用,起到放射增敏作用.     

MAL promoter hypermethylation as a novel prognostic marker in gastric cancer

T-lymphocyte maturation associated protein, MAL, has been described as a tumour-suppressor gene with diagnostic value in colorectal and oesophageal cancers, and can be inactivated by promoter hypermethylation. The aim of this study was to analyse the prevalence of MAL promoter hypermethylation and the association with mRNA expression in gastric cancers and to correlate methylation status to clinicopathological data. Bisulphite-treated DNA isolated from formalin-fixed and paraffin-embedded samples of 202 gastric adenocarcinomas and 22 normal gastric mucosae was subjected to real-time methylation-specific PCR (Q-MSP). Two regions within the MAL promoter (M1 and M2) were analysed. In addition, 17 frozen gastric carcinomas and two gastric cancer cell lines were analysed both by Q-MSP and real-time RT–PCR. Methylation of M1 and M2 occurred in 71 and 80% of the gastric cancers, respectively, but not in normal gastric mucosa tissue. Hypermethylation of M2, but not M1, correlated with significantly better disease-free survival in a univariate (P=0.03) and multivariate analysis (P=0.03) and with downregulation of expression (P=0.01). These results indicate that MAL has a putative tumour-suppressor gene function in gastric cancer, and detection of promoter hypermethylation may be useful as a prognostic marker.     

广东地区人群CYP2C9基因启动子区-1189C/T位点的多态性

目的:检测中国广东地区人群CYP2C9基因启动子区-1189C/T位点的多态性并调查其等位基因及基因型频率.方法:提取152例广东药学院新生外周血基因组DNA,PCR扩增含CYP2C9基因-1189C/T位点的DNA片段,用MboⅡ酶切PCR产物,通过聚丙烯酰胺凝胶电泳-银染判断基因型.结果:在检测的152例样本中,CYP2C9基因-1189C/T位点基因型:C/C 21例、C/T 82例、T/T 49例,其相应的频率分别为0.14、0.54、0.32,符合Hardy-Weinberg平衡;等位基因-1189C和-1189T的频率分别为0.41和0.59,与日本人群和西班牙人群相比,差异没有统计学意义.结论:本研究建立了一种基于PCR-RFLP的简单、快速、灵敏的检测CYP2C9基因-1189C/T位点多态性的方法;CYP2C9基因-1189C/T位点多态性在中国广东地区人群中极为常见,是一个较好的遗传标志.     

Prothrombotic gene polymorphisms and atherothrombotic cerebral infarction

OBJECTIVES: To test the hypothesis whether risk genotypes of the prothrombotic gene polymorphisms (I/D 4G5G PAI-1, G1691A factor V point mutation, factor VII Arg/Gln353) are risk factors for ACI in the Slovene population. The study sought an association between the insertion/deletion 4G/5G-plasminogen activator inhibitor 1 (PAI-1) gene polymorphism, the 1691G-A factor V point mutation or the arg353-to-gln factor VII gene polymorphism and atherothrombotic cerebral infarction (ACI). MATERIAL AND METHODS: Ninety-six Slovene patients who suffered ACI were compared with 115 control subjects clinically free of cerebrovascular disease. Insertion/deletion 4G/5G PAI-1 gene polymorphism, 1691G-A factor V point mutation and arg353-to-gln polymorphism in the factor VII were determined using polymerase chain reaction. RESULTS: The 4G4G genotype of 4G5G PAI-1 gene polymorphism was less frequent in cases (21.9%) than in controls (35.6%; OR = 0.5, 95% CI = 0.3-1; P = 0.033). No association was found either between the factor V point mutation (1691G-A) or the RR genotype of the factor VII Arg/Gln353 gene polymorphism and the risk of ACI using univariate analysis. CONCLUSION: The 4G/4G-PAI-1 genotype might be a protective factor against ACI, whereas the factor V point mutation (1691G-A) and the factor VII Arg/Gln353 gene polymorphism have not proved to be risk factors for ACI.     

异种移植转基因用含粘附分子-2启动子的人CD59 重组基因的构建

目的：构建含人粘附分子－2（ICAM－2）启动子的人补体调节蛋白CD59重组基因,并钭其用于异种器官移植转基因。方法：利用PCR方法从人血基因组扩增得到ICAM－2启动子、CD59基因的第一内含子片段,经电泳分离、切胶回收纯化得到上述片段,分别双酶、单酶切这两条片段,纯化回收备用;双酶切pcDNA3-CD59真核表达载体,经电泳分离,切胶回收纯化得到不含病毒启动子、含筛选基因Neo的一段pcDNA3-CD59cDNA作为载体序列;ICAM－2启动子片段先与载体进行定向克隆连接反应后转化细菌,阳性转化蓖质粒抽提及酶切鉴定,得到pcDNA3-ICAM2-CD59质粒;再单酶切此质粒,纯化该载体与CD59第一内含子片段连接,转化细菌、抽提质粒,用脂质体将该质粒转染猪血管内皮细菌,流式细胞仪检测CD59蛋白表达。结果：得到pcDNA3-Enhancer-ICAM2-CD59质粒,以EcoR I消化此重组质粒,产生5．5及0．5kb两片段,以Hind Ⅲ消化重组质粒,得到5．45及0．55kb两片段,以Kpn I/Hind Ⅲ双酶切质粒时,出现5．0、0．55、0．4kb 3条片段,对插入子分别进行测序,上述结果完全符合设计要求及正确序列。流式细胞仪检测重组基因表达阳性。结论：含人ICAM－2启动子的CD59重组基因表达载体获得成功,该重组基因构建成功为转基因应用奠定了基础。