体内TIMP-3基因电转染治疗人前列腺癌裸鼠移植瘤的研究

目的 研究肌肉内基因电转染对前列腺肿瘤的抑制作用。方法 人前列腺癌细胞系PC-3M裸鼠皮下移植成瘤，TIMP-3质粒扩增后，通过电子穿孔仪（脉冲时值20ms，电场强度200V／cm）将质粒（15μg）转入裸鼠胫前肌。结果 肌肉内TIMP-3电转染后，肿瘤生长受到抑制。较单纯TIMP-3肌肉内注射和空质粒（PCDNA-3质粒）肌肉内电转染有显著差异。结论 肌肉内基因电转染，对前列腺癌有全身抗肿瘤作用。     

HepG2细胞电转染条件的优化

目的优化HepG2细胞电转染条件,进一步提高HepG2细胞的转染效率。方法采用电穿孔方法将pcDNA3．1-EGFP导入HepG2细胞中,在500μL电转染体系中,在不同电场强度、细胞数目、脉冲频率、脉冲时间、电转质粒数目、电转缓冲液、培养基血清浓度条件下,分别将pcDNA3．1-EGFP质粒电转染HepG2细胞,检测不同条件下细胞存活率和转染率。结果电转前4℃孵育电转体系混合液10min,方波电转条件在1个电脉冲、电压270V、细胞数为2×10^6个、质粒20μg、脉冲时间20ms、电转缓冲液为优化缓冲液、电转后置于37℃、含15％FBS的DMEM高糖培养基中培养48h,可获得高转染率（60．68±1．87）％。结论优化电穿孔法的电转染条件能够有效提高HepG2细胞的电转染效率。本研究为外源基因电转染HepG2细胞提供了可靠的试验参数。     

蚊抗药性相关糜蛋白酶基因稳定转染细胞系的建立与表达鉴定

目的 建立抗药性相关糜蛋白酶基因稳定转染细胞系。方法 采用PCR方法，以淡色库蚊抗药性品系CD-NA文库为模板，扩增出抗药性品系高表达的糜蛋白酶基因编码区；经T／A克隆测序鉴定后，亚克隆到真核表达载体piEl-3，构建重组昆虫细胞表达载体piEl-3／chy，经酶切和PCR鉴定后，与带有筛选标记的piEl-neo质粒共转染蚊细胞C6／36，通过G418选择培养，建立转染细胞系；用RT-PCR、Westernblotting鉴定糜蛋白酶基因的转录表达。结果 成功构建了真核表达载体piE1-3／chy，证明糜蛋白酶基因已转入C6／36细胞，建立了稳定转染细胞系，表达产物分子质量单位约30ku，与理论值相符。结论 稳定转染细胞系的建立和基因表达为进一步研究糜蛋白酶基因与抗药性的关系奠定了基础。     

强心复脉方含药血清对乳鼠受损窦房结细胞动作电位的影响

目的研究强心复脉方含药血清对乳鼠受损窦房结细胞动作电位的影响。方法分离培养Wistar乳鼠窦房结细胞,分为6组:正常组、模型组、100μl含药血清组、200μl含药血清组、300μl含药血清组、空白血清组。除正常组外,其余各组均模拟缺血-再灌注制备细胞损伤模型。采用膜片钳技术在电流钳模式下记录各组细胞自发性动作电位,测量各组细胞复极至20%、50%、90%动作电位时程(APD20、APD50、APD90)、最大舒张电位(MDP)及动作电位幅值(APA)。结果于造模后细胞外液分别加入100μl、200μl、300μl强心复脉方含药血清,与模型组比较,100μl含药血清组、200μl含药血清组、300μl含药血清组APD20缩短,分别为[(77.2±5.5)ms vs.(35.7±7.1)ms]、[(77.2±5.5)ms vs.(50.1±7.5)ms]、[(77.2±5.5)ms vs.(39.7±4.3)ms],差别均具有统计学意义(P均0.01);APD50缩短,分别为[(147.5±5.1)ms vs.(90.6±5.8)ms]、[(147.5±5.1)ms vs.(111.0±4.1)ms]、[(147.5±5.1)ms vs.(109.0±2.4)ms],差别均具有统计学意义(P均0.05)。与正常组比较,经缺血-再灌注造模后(模型组)细胞的MDP上升,APA减小,为[(-61.9±5.4)m V vs.(-54.5±4.6)m V],[(84.7±5.0)m V vs.(71.4±4.7)m V],差异均具有显著性统计学意义(P均0.01)。于造模后细胞外液分别加入100μl、200μl、300μl强心复脉方含药血清,与模型组比较,各组MDP值无明显改变,无统计学意义(P均0.05)。100μl含药血清组和300μl含药血清组APA均较模型组增大,分别为[(83.2±5.9)m V vs.(71.4±4.7)m V]和[(82.2±6.4)m V vs.(71.4±4.7)m V],差异均具有显著统计学意义(P均0.01)。结论强心复脉方含药血清能缩短乳鼠受损窦房结细胞动作电位的APD20、APD50,增大APA,缩短动作电位时程,进而加快细胞自发性搏动频率。     

外源P53对人肺癌细胞生长的抑制

目的 观察外源性野生型Ｐ５３基因对有Ｐ５３基因突变的人肺癌细胞系生长的影响。方法 用多聚酶链反应－单链多肽性及ＤＮＡ测序，选择Ｐ５３突变的人肺癌巨细胞系８０１－Ｄ。构建野生型Ｐ５３表达质粒ＰＺｉＰｎｅｏＳＶ－Ｐ５３。用基因枪介导外源基因。经新霉素筛选得到转染细胞系８０１－Ｄ－Ｐ５３。用ＰＣＲ检测外源基因，观察转染细胞恶性生长的变化。结果 转染细胞８０１－Ｄ－Ｐ５３体外长期传代有Ｎｅｏ基因及外性ＰＴ     

外源性野生型p53基因对人肺癌细胞生长的抑制

目的观察外源性野生型ｐ５３基因对有ｐ５３基因突变的人肺癌细胞系生长的影响。方法用多聚酶链反应单链构象多态性及ＤＮＡ测序，选择ｐ５３基因突变的人肺巨细胞癌系８０１Ｄ为受体细胞。构建野生型ｐ５３表达质粒ＰＺＩＰｎｅｏＳＶｐ５３。用基因枪介导外源基因。建立转染细胞系８０１Ｄｐ５３。用聚合酶链反应检测外源基因，观察转染细胞恶性生长的变化。结果转染细胞系８０１Ｄｐ５３体外长期传代有ｎｅｏ基因及外源ｐ５３基因存在，转染细胞生长明显受到抑制，克隆形成抑制率达９６％，裸鼠异种移植致瘤性降低，肿瘤生长明显缓慢。结论外源性野生型ｐ５３经基因枪导入有ｐ５３基因突变的人肺癌细胞后可长期存在于转染细胞中，且明显抑制转染细胞的恶性生长     

重组DNA甲基化酶1表达质粒对结肠癌细胞相关基因表达的影响

目的 分析DNA甲基化酶1(DNMT1)基因的真核表达质粒对人结肠癌细胞肿瘤相关基因的表达影响。方法 分别构建并转染含有人正义和反义DNMT1的真核表达质粒入结肠癌SW1116细胞，PCR和限制性内切酶证实转染结果，以Western印迹法分析各组细胞DNMT1蛋白的表达情况。定量PCR检测hMLH1、hMSH2及c—myc、p16^INK4A基因的表达。结果 经G418筛选得到稳定转染DNMT1基因的结肠癌细胞系，且分别在该转染有正义和反义质粒的细胞系中，DNMT1蛋白表达上调和下调。同时发现转染正义DNMT1的细胞中hMLH1、hMSH2及c—myc的表达降低，而转染反义DNMT1的细胞中hMSH2的表达明显增强。各组细胞p16^INK4A基因的表达差异不明显。结论 DNMT1基因调控人结肠癌细胞中肿瘤相关基因的表达。     

野生型p53对人肺癌细胞体内生长的抑制作用

观察外源性野生型ｐ５３基因对有Ｐ５３基因突变的人肺癌细胞系８０１－Ｄ体内生长的抑制作用。将转染了ｐ５３基因之细胞８０１－Ｄ－ｐ５３及转染ｐＺＩＰ之８０１－Ｄ－ｐＺＩＰ和母系细胞，接种裸小鼠皮下，以观察ｐ５３对癌细胞肿瘤源性的影响。瘤内注射或腹腔注射脂质体包裹的ｐ５３基因治疗荷人肺癌８０１－Ｄ细胞之裸小鼠，观察对肿瘤细胞体内生长的抑制作用。转染ｐ５３之８０１－Ｄ－ｐ５３细胞肿瘤源性显著降低，３／４移     

p16、p53、p21基因对肺癌细胞增殖的影响

目的 观察肿瘤抑制基因ｐ１６,ｐ５３及细胞周期信赖激酶抑制物ｐ２１基因单独或联合应用时对肺癌细胞增殖的影响。方法 应用十八酰基胺阳离子脂质体介导ｐ１６,ｐ５３,ｐ２１基因单独或共转染到非小细胞肺癌细胞系Ａ５４９和小细胞肺癌细胞系ＳＨ７７,观察转染后１,３,５日该细胞增殖的活力。采用四甲基偶氮唑 盐微量酶反应比色法（ＭＴＴ法）测定吸光度（Ａ）,以检测细胞增殖活力,结果 Ａ５４９细胞系：Ａ均值分别为：     

160例成人HIV感染者/AIDS患者机会性感染与CD4+之间关系分析

目的：分析中国成人艾滋病病毒（HIV）感染者／艾滋病（AIDS）患者机会性感染发生的频率与CD4^ 细胞数之间的关系。方法：对1990－2001年在北京佑安医院就诊的160例成人HIV感染者／AIDS患者CD4^ 、CD8^ 进行跟踪分析。结果：（1）CD4^ ＞500个／μl66人次（12．7％），CD4^ 为200个／μl-500个／μl212人次（41．1％），CD4^ ＜200个／μl234人次（45．3％）。在CD4^ ＜个200／μl中，CD4^ ＜100个／μl128人次（24．8％），CD4^ ＜50个／μl89人次（17．2％）。（2）CD4^ ＞200个／μl时，共发生机会性感染33人次（15．6％）。CD4^ ＜200个／μl时，共发生机会性感染170人次（72．6％），CD4^ 为100个／μl0－200个／μl之间发生机会性感染42人次（39．6％），CD4^ ＜100个／μl发生机会性感染128人次（98．4％），其中CD4^ ＜50个／μl发生机会性感染87人次（97．8％）。结论：中国成人HIV感染者／AIDS患者在CD4^ ＞200个/μl时机会性感染出现频率较少，CD4^ ＜200个／μl时机会性感染的频率明显增加，CD4^ ＜100个／μl和＜50个／μl时，感染率约为100％。     

A forest-based approach to identifying gene and gene gene interactions

Multiple genes, gene-by-gene interactions, and gene-by-environment interactions are believed to underlie most complex diseases. However, such interactions are difficult to identify. Although there have been recent successes in identifying genetic variants for complex diseases, it still remains difficult to identify gene-gene and gene-environment interactions. To overcome this difficulty, we propose a forest-based approach and a concept of variable importance. The proposed approach is demonstrated by simulation study for its validity and illustrated by a real data analysis for its use. Analyses of both real data and simulated data based on published genetic models show the effectiveness of our approach. For example, our analysis of a published data set on age-related macular degeneration (AMD) not only confirmed a known genetic variant (P value = 2E-6) for AMD, but also revealed an unreported haplotype surrounding single-nucleotide polymorphism (SNP) rs10272438 on chromosome 7 that was significantly associated with AMD (P value = 0.0024). These significance levels are obtained after the consideration for a large number of SNPs. Thus, the importance of this work is twofold: it proposes a powerful and flexible method to identify high-risk haplotypes and their interactions and reveals a potentially protective variant for AMD.     

RFamide-related peptide gene is a melatonin-driven photoperiodic gene

In seasonal species, various physiological processes including reproduction are organized by photoperiod via melatonin, but the mechanisms of melatonin action are still unknown. In birds, the peptide gonadotropin-inhibiting hormone (GnIH) has been shown to have inhibitory effects on reproductive activity and displays seasonal changes of expression. Here we present evidence in mammals that the gene orthologous to GnIH, the RFamide-related peptide (RFRP) gene, expressed in the mediobasal hypothalamus, is strongly regulated by the length of the photoperiod, via melatonin. The level of RFRP mRNA and the number of RFRP-immunoreactive cell bodies were reduced in sexually quiescent Syrian and Siberian hamsters acclimated to short-day photoperiod (SD) compared with sexually active animals maintained under long-day photoperiod (LD). This was contrasted in the laboratory Wistar rat, a non-photoperiodic breeder, in which no evidence for RFRP photoperiodic modulation was seen. In Syrian hamsters, the reduction of RFRP expression in SD was independent from secondary changes in gonadal steroids. By contrast, the photoperiodic variation of RFRP expression was abolished in pinealectomized hamsters, and injections of LD hamsters with melatonin for 60 d provoked inhibition of RFRP expression down to SD levels, indicating that the regulation is dependent on melatonin. Altogether, these results demonstrate that in these hamster species, the RFRP neurons are photoperiodically modulated via a melatonin-dependent process. These observations raise questions on the role of RFRP as a general inhibitor of reproduction and evoke new perspectives for understanding how melatonin controls seasonal processes via hypothalamic targets.     

HLA基因、CC10基因和结节病

结节病是一种多器官系统受累的肉芽肿性疾病,常侵犯肺部、双肺门淋巴结。其病因目前尚不清楚,本文仅就有关结节病相关基因研究中的两个基因HLA基因、CC10基因和结节病的关系作一简要综述。     

Evidence for gene recombination in FCGR3 gene variants

Background and Objectives  The genes encoding the Fcγ receptors (FcγR) IIIa and IIIb ( FCGR3A and FCGR3B ) are clustered on chromosome 1 band q23–24 and exhibit allelic polymorphism. We investigated the molecular basis of additional new FCGR3 genomic variation.
Materials and Methods  A segment shared by FCGR3A and FCGR3B containing the polymorphic nucleotide positions 141, 147, 227, 266, and 277 in exon 3 was cloned and sequenced from genomic DNA of 30 donors and 3 bacterial artificial chromosome (BAC) clones. A mixture consisting of isolated FCGR3B * 2 - and FCGR3A - plasmids was cloned and sequenced as well. Additionally, nucleotide databases were screened for clones with variant FCGR3 sequences.
Results  A total of 12 FCGR3 variants defined by the polymorphic positions were detected in whole blood genomic DNA from 23 of 24 FCGR3B * 2 and/or FCGR3B * 3 positive donors, the DNA from two of three BAC clones and in the DNA mixture of isolated FCGR3B * 2 - and FCGR3A - plasmids.
Conclusion  Nucleotide exchanges of the variants were non-random and resulted from two alternative nucleotides present in one of the polymorphic position of the basic FCGR3 forms. Polymerase chain reaction (PCR) artefacts cannot be excluded as origin of new variants, but there is strong evidence that at least two variants are the result of a somatic recombination.     

The ovalbumin gene: Cloning of the natural gene

The structural ovalbumin DNA sequences are not contiguous and are separated by multiple "intervening regions" in native chicken DNA. EcoRI, a restriction endonuclease that does not cleave the structural ovalbumin DNA sequences, digests the natural ovalbumin gene into three distinct fragments of 2.4, 1.8, and 9.5 kilobase pairs in length by cleaving within these "intervening regions." The 2.4-kilobase pair fragment contains only about 450 nucleotide pairs of coding sequence, with the rest being intervening sequences. This DNA fragment was cloned in bacteria by using the certified EK2 vector lambdagtWES.lambdaB after enrichment from total EcoRI-digested chicken DNA by a combination of RPC-5 column chromatography and preparative agarose gel electrophoresis. Five out of approximately 20,000 recombinant phage plaques were capable of hybridizing with a (32)P-labeled Hha I fragment of a recombinant plasmid pOV230 containing the entire structural ovalbumin gene. DNA amplified in these recombinant phages, lambdagtWES.OV2.4, was shown to contain the same restriction endonuclease cleavage sites as in the 2.4-kilobase pair EcoRI fragment previously determined by restriction mapping of total genomic chicken DNA. The intervening sequences were allowed to hybridize with excess total chicken DNA and oviduct nuclear RNA after nick-translation. They were found to be unique chicken DNA sequences, and appeared to be transcribed in their entireties during gene expression. Like the structural gene sequences, the expression of the intervening sequences is also inducible by steroid hormones.     

Sex-based differences in gene transmission and gene expression.

The higher prevalence of certain diseases among women suggests involvement of genetic mechanisms linked to the sex chromosomes or of sex-limited gene expression that may be developmentally or hormonally regulated. Analysis of genetic markers and gene expression patterns provides the means for testing hypotheses related to these mechanisms.     

Antiangiogenic gene therapy for hepatocellular carcinoma using angiostatin gene

Recent studies have reported that antiangiogenic gene delivery into cancer cells inhibits growth of certain tumors in vivo. Hepatocellular carcinoma (HCC) is a hypervascular cancer, and antiangiogenic gene therapy might be suitable for HCC. In the present study, we investigated the antiangiogenic effects of angiostatin gene transduction into HCC both in vitro and in vivo. Angiostatin gene was cloned into a pSecTag2B mammalian expression vector to construct pSecTag2B-ANG. pSecTag2B or pSecTag2B-ANG were transfected into an HCC cell line, PLC/PRF/5, and then stable transfectants were obtained by Zeocin selection. pSecTag2B or pSecTag2B-ANG transfection did not alter the expression of vascular endothelial growth factor (VEGF), a potent angiogenic stimulator, or pigment epithelium-derived factor (PEDF), an angiogenic inhibitor, in PLC/PRF/5 cells. However, conditioned media (CM) derived from pSecTag2B-ANG-transfected PLC/PRF/5 cells (CM-ANG) suppressed the proliferation and migration of human umbilical vein endothelial cells (HUVEC) by 35% and 50%, respectively, relative to their effects on nontransfected cells. In in vivo experiments, pSecTag2B-ANG stable transfected (CM-Mock) and nontransfected cells (CM-N) were mixed at various proportions and the mixed cells were subcutaneously implanted into athymic mice. Suppression of tumor growth was noted in mice implanted with angiostatin gene-transfected cells, and such suppression was proportional with the percentage of transfected cells. Analysis of the vascular density in these tumors showed that the tumor growth suppression effect of angiostatin gene correlated with suppression of tumor vascularity. In conclusion, antiangiogenic gene therapy using angiostatin gene is potentially suitable for the treatment of patients with HCC.