正常的和转化的C3H小鼠胚胎成纤维细胞neu基因结构的初步研究

应用ＰＣＲ－ＳＳＣＰ技术并结合Ｓｏｕｔｈｅｒｎ印迹杂交从基因水平对正常和￣３Ｈ－ＴｄＲ恶性转化小鼠胚胎成纤维细胞ＮＣ３Ｈ１０和ＴＣ３Ｈ１０中ｎｅｕ基因进行研究。Ｓｏｕｔｈｅｒｎ印迹杂交结果表明恶性转化的ＴＣ３Ｈ１０细胞ｎｅｕ基因出现重排和扩增,ＳＳＣＰ分析未发现ＴＣ３Ｈ１０细胞ｎｅｕ基因跨膜区突变。上述结果说明ＴＣ３Ｈ１０细胞ｎｅｕ基因结构异常可能在跨膜区外,ｎｅｕ基因异常在￣３Ｈ－ＴｄＲ诱导的细胞恶性转化过程中可能有重要的作用,ＥＧＦ可促进ｎｅｕ基因表达增高,研究发现在ＥＧＦ持续作用下,ＮＣ３Ｈ１０细胞ｎｅｕ基因甲基化水平无显著变化,说明ＥＧＦ可能是通过其它途径调控ｎｅｕ基因表达增高的,排除了ＥＧＦ通过改变ｎｅｕ基因甲基化水平而调控ｎｅｕ基因表达的可能性。     

生长抑素对羟自由基损伤的人胃粘膜上皮细胞系GES—1的影响

目的和方法：采用人胃粘膜上皮细胞系ＧＥＳ１细胞传代培养技术,利用Ｆｅ２＋与Ｈ２Ｏ２反应生成的羟自由基（ｈｙｄｒｏｘｙｌｒａｄｉｃａｌ,ＯＨ·）建立细胞损伤模型,探讨ＯＨ·损伤人胃粘膜细胞的机制,观察生长抑素（ｓｏｍａｔｏｓｔａｔｉｎ,ＳＳ）对ＧＥＳ１细胞抗ＯＨ·损伤的影响。结果：（１）ＯＨ·可直接损伤ＧＥＳ１细胞,表现为细胞存活率下降而细胞乳酸脱氢酶（ｌａｃｔａｔｅｄｅｈｙｄｒｏｇｅｎａｓｅ,ＬＤＨ）漏出量增多;预先在细胞培养液中加入ＯＨ·特异性清除剂二甲基亚砜（５ｍｍｏｌ／Ｌ）,可预防该损伤。预先加入ＳＳ（０．０１ｍｇ／Ｌ,０．１ｍｇ／Ｌ,１．０ｍｇ／Ｌ,１０ｍｇ／Ｌ）对细胞存活率和细胞ＬＤＨ漏出量无影响;（２）加入ＯＨ·后,细胞丙二醛（ＭＤＡ）、氧化型谷胱甘肽（ＧＳＳＧ）含量上升而还原型谷胱甘肽（ＧＳＨ）含量下降。以ＳＳ０．１ｍｇ／Ｌ,１．０ｍｇ／Ｌ,１０ｍｇ／Ｌ预处理,可部分减轻上述改变。结论：ＯＨ·可直接损伤ＧＥＳ１细胞,其机制与破坏细胞的巯基稳态及加重细胞的脂质过氧化程度有关;ＳＳ可通过维持细胞的巯基稳态,部分减轻ＯＨ·所致的ＧＥＳ１细胞脂质过氧化程度。     

人乳头状瘤病毒18E6E7和TPA协同诱发人胚食管上皮细胞恶性转化的研究

为了研究病毒和促癌物在食管癌中的作用,用带有人乳头状瘤病毒１８型Ｅ６Ｅ７片段的载体腺病毒感染人胚食管上皮细胞,然后加ＴＰＡ协同作用,观察细胞转化。将人胚食管切碎与ＨＰＶ１６Ｅ６Ｅ７ＡＡＶ同孵育２小时,在１０％小牛血清的１９９培养液培养和传代,形成永生化细胞株,即人胚食管上皮细胞汕头株,实验分现代化组：一组ＳＨＥＥ细胞在传代至第５和１３代时,两次在培养基中加入ＴＰＡ５ｎｇ／ｍｌ,每次诱导２周,所获得     

小偃麦部分双二倍体及其异附加系异源染色体的GISH分析

应用ＴＩＳＨ对小偃麦部分双二倍体ＴＡＦ４６（２ｎ＝８ｘ＝５６）及其衍生的６个二体异附加系的中间偃麦草染色体组种类进行了分析、鉴定。以拟鹅冠草（Ｐｓ．ｓｔｒｉｇｏｓａ）ＤＮＡ为探针的分析结果表明,ＴＡＦ４６所含有的中间偃麦草染色体组为合成染色体组,即６条Ｓｔ组染色体和８条Ｅ组染色体。在其衍生的二体异附加系中,Ｌ４和Ｌ７含有Ｓｔ组染色体,Ｌ１、Ｌ２、Ｌ３、Ｌ５含有Ｅ组染色体。ＴＡＦ４６所含有的中间偃麦草染色体的部分同源群依次为ＩＥ（Ｌ３）、２Ｓｔ（Ｌ６）、３Ｅ（Ｌ２）、４Ｓｔ（Ｌ４）、５Ｅ（Ｌ５）、６Ｓｔ（Ｌ７）、７Ｅ（Ｌ１）。     

人巨细胞病毒转化作用的研究进展

人巨细胞病毒（ＨＣＭＶ）属于ＤＮＡ肿瘤病毒,有３个可导致细胞恶性转化的形态转化区,另有病毒即刻早期（ＩＥ）基因的编码产物对细胞生长进行调探。本文最后探讨了病毒导致细胞恶性转化的可能机制。     

人生长激素基因逆转录病毒载体的构建及其对3T3和ES细胞的转化与表达

为了研究生长激素基因在异源细胞中的表达,构建了携带人生长激素基因（ｈＧＨ）的逆转录病毒载体ｐＩＮＳ－ＧＨ,并将其导入小鼠成纤维细胞３Ｔ３和小鼠胚胎干细胞（ＥＳ细胞）ＣＣＥ中。ｐＩＮＳ－ＧＨ转化３Ｔ３细胞,获得了高效表达的克隆,即用放射免疫法检测到克隆培养基中有大量的人生长激素蛋白富积,如ＧＨＳＮＣ２０,富积率高达３７８４ｎｇ／ｍｌ,而且外源基因的整合很稳定。不同的３Ｔ３转化克隆的表达率有显著的差异,Ｓｏｕｔｈｅｒｎ杂交的结果表明,这种差异与外源基因整合的拷贝数无关。ｐＩＮＳ－ＧＨ转化ＣＣＥ细胞没有获得明显表达的克隆,而且外源基因的整合也不稳定。转化的ＥＳ细胞克隆总ＤＮＡ的Ｓｏｕｔｈｅｒｎ杂交结果表明,ｈＧＨ基因的确整合到细胞基因组中。目前尚未发现明显的外源ＤＮＡ重排的迹象。     

钙通道阻滞剂对肾上腺素能受体激动剂促血管平滑肌细胞增值的抑制

本工作观察到１０－６—１０－５ｍｏｌ／Ｌ去甲肾上腺素（ＮＥ）和１０－７—１０－５ｍｏｌ／Ｌ异丙基肾上腺素（ＩＳＯ）可明显促进离体培养的血管平滑肌细胞（ＶＳＭＣ）的增殖和ＤＮＡ的合成,并呈剂量依赖效应,该效应可为相应的受体阻断剂ｐｈｅｎｔｏｌａｍｉｎｅ（１０－６ｍｏｌ／Ｌ）和ｐｒｏｐｔａｎｏｌｏｌ（１０－５ｍｏｌ／Ｌ）所抑制;ｎｉｆｅｄｉｐｉｎｅ（１０－６ｍｏｌ／Ｌ）和ｖｅｒａｒｏｍｉｌ（１０－６ｍｏｌ／Ｌ）分别与同样浓度的ＮＥ同时加入细胞培养液中,其细胞计数和３Ｈ－ＴｄＲ掺入率分别较单用ＮＥ时显著降低（Ｐ＜０．０１）,ｎｉｆｅｄｉｐｉｎｅ与ｖｅｒａｐａｍｉｌ亦明显抑制ＩＳＯ促ＶＳＭＣ增殖的作用。     

氧化HDL_2在大鼠肝窦状隙细胞内代谢

大鼠肝窦状隙细胞培养结果显示：氧化高密度脂蛋白２（ｏｘ－ＨＤＬ２）对异硫氰酸荧光素（ＦＩＴＣ）荧光标记ｏｘ－ＨＤＬ２的细胞结合有竞争抑制作用,而ＨＤＬ２则无。细胞内吞ＦＩＴＣ－ｏｘ－ＨＤＬ２的荧光强度（ＦＳ）和［３Ｈ］ＣＥ－ｏｘ－ＨＤＬ２（ｒ－ｏｘ－ＨＤＬ２）的放射强度分别是内吞ＦＩＴＣ－ＨＤＬ２的４５．５％和ｒＨＤＬ２的６１．４％。内吞ＦＳ主要存在于三氯醋酸（ＴＣＡ）沉淀部分,而放射强度主要存在于ＴＣＡ上清液部分。细胞释放的ＦＳ和放射活性分别是内吞量的６７．７％和１０．９％,且主要存在于ＴＣＡ可沉淀部分。结果提示：（１）大鼠肝窦状隙细胞可能存在着ｏｘ－ＨＤＬ受体,该受体不同于ＨＤＬ受体。（２）ｏｘ－ＨＤＬ２在细胞内代谢方式与ＨＤＬ２相似,均没有经历溶酶体分解途径。在细胞内载脂蛋白与胆固醇酯（ＣＥ）组分经历一个解离过程。细胞截留大部分ＣＥ后,将载脂蛋白（Ａｐｏ）与剩余ＣＥ重组成脂蛋白并以逆向胞饮方式释放到胞外。（３）氧化修饰减弱ＨＤＬ２逆向转运胆固醇能力     

戊型肝炎病毒(HEV)合成肽及基因重组抗原免疫反应性研究

用ＯＲＦ２、ＯＲＦ３合成肽抗原（１～１０号）及基因工程重组的ＯＲＦ２抗原（１和２号）分别建立了酶联免疫方法（ＥＩＡ）,检测６０份戊型肝炎病人血清中ＨＥＶＩｇＧ及ＩｇＭ１０个合成肽抗原（Ｓｐ１－Ｓｐ１０）及２个重组抗原（Ｒｅ１、Ｒｅ２）,均和ＨＥＶ阳性血清发生特异反应,但阳性率和反应强度差别很大。以Ｒｅ１（ＯＲＦ２,４０２～６６０）检测的抗体阳性率最高,为９６．７％（５８／６０）;Ｓｐ６（ＯＲＦ３,８８～１２３）次之,为９３．３％（５６／６０）;以上两种抗原混合使用阳性率为１００％（６０／６０）。Ｓｐ６、Ｒｅ１及这两种抗原混合使用检测抗ＨＥＶＩｇＭ,阳性率分别为１８．３％（１１／６０）、６６．７％（４０／６０）和６６．７％（４０／６０）。研究结果表明：合成肽６号（Ｓｐ６）及重组抗原１号（Ｒｅ１）是制备戊肝抗体诊断试剂的理想抗原。     

人主动脉硫酸乙酰肝素蛋白聚糖对培养的人血管壁细胞生长的作用

通过培养的人主动脉平滑肌细胞（ｈＡＳＭＣ）及脐静脉内皮细胞（ｈＵＶＥＣ）,应用＾３Ｈ－ＴｄＲ参入、Ｎｏｒｔｈｅｒｎ ｂｌｏｔ分析、逆转录多聚酶链反应（ＲＴ－ＰＣＲ）、放射免疫分析（ＲＩＡ）、和紫外比色法等技术观察了人主动脉中硫酸乙酰肝素蛋白聚糖（ＨＳＰＧ）对ｈＡＳＭＣ和ｈＵＶＥＣ ＤＮＡ合成的作用及对血小板源生长因子（ＰＧＤＦ）、ＰＧＤＦ受体、转化生长因子β（ＴＧＦ－β）、内皮素－１（ＥＴ－１）或     

人乳头状瘤病毒协同60钴照射促进食管上皮细胞恶性转化

为探明人乳头状瘤病毒(HPV)和促癌剂对食管上皮致癌作用,人胚食管上皮细胞转染HPV协同60钴(60Co)放射观察其恶性转化.用HPV18E6E7AAV转染的人胚食管上皮(SHEE),培养至13代,分为4组,实验组分别用60Co2、4、8Gy照射,每周1次共4周;SHEE未经照射为对照组.细胞形态用相差显微镜观察;细胞DNA合成和定量用3H-TdR掺入和用流式细胞仪分析;染色体众数用常规方法分析;致瘤性用软琼脂培养和裸小鼠接种;HPVDNA用PCR检测.经60Co照射后细胞呈凋亡和坏死(危象期).8周后SHEE 4Gy组细胞增殖,增殖指数(34%)和3H-TdR摄入增高,软琼脂培养和裸鼠接种出现致瘤性.对照组SHEE组细胞增殖指数24%,伴有少数3H-TdR掺入,裸鼠未成瘤.染色体众数:对照组,58～62;4Gy组,63～65;两组HPV18E6E7 PCR呈阳性条带.此结果表明,用HPV18E6E7协同60Coγ射线可以使人胚食管上皮恶性转化,60Co γ射线有加速食管上皮细胞恶性转化作用.     

Amplification of the Y chromosome in three murine tumor cell lines transformed in vivo by different human prostate cancers

Summary Conventional and molecular cytogenetic analyses of three murine cancer cell lines that had been induced in male athymic mice by the injection of three different human prostate cancer cell lines revealed selective amplification of the Y chromosome. In particular, analysis of metaphase and interphase nuclei by fluorescence in situ hybridization (FISH) with the mouse Y chromosome-specific DNA painting probe revealed the presence of various numbers of Y chromosomes, ranging from one to eight, with a large majority of nuclei showing two copies (46.5–60.1%). In Interphase nuclei, the Y chromosomes showed distinct morphology, allowing identification irrespective of whether the preparations were treated for 15 min or for 5 h with Colcemid, a chemical known to cause chromosome condensation. However, FISH performed on human lymphocyte cultures with chromosome-specific DNA painting probes other than the Y chromosome did not reveal condensed chromosome morphology in interphase nuclei even after 12 h of Colcemid treatment. Our FISH results indicate that (1) the Y chromosome is selectively amplified in all three cell lines; (2) the mouse Y chromosome number is comparable in both interphase and metaphase cells; (3) the Y chromosome number varies between one and eight, with a large majority of cells showing two or three copies in most interphase nuclei; (4) the condensation of the Y chromosome is not affected by the duration of Colcemid treatment but by its inherent DNA constitution; and (5) the number of copies of the Y chromosome is increased and retained not only in human prostate tumor cell lines but also in murine tumors induced by these prostate tumor cell lines.     

Genomic imbalances are confined to non-proliferating cells in paediatric patients with acute myeloid leukaemia and a normal or incomplete karyotype

Leukaemia is often associated with genetic alterations such as translocations, amplifications and deletions, and recurrent chromosome abnormalities are used as markers of diagnostic and prognostic relevance. However, a proportion of acute myeloid leukaemia (AML) cases have an apparently normal karyotype despite comprehensive cytogenetic analysis. Based on conventional cytogenetic analysis of banded chromosomes, we selected a series of 23 paediatric patients with acute myeloid leukaemia and performed whole genome array comparative genome hybridization (aCGH) using DNA samples derived from the same patients. Imbalances involving large chromosomal regions or entire chromosomes were detected by aCGH in seven of the patients studied. Results were validated by fluorescence in situ hybridization (FISH) to both interphase nuclei and metaphase chromosomes using appropriate bacterial artificial chromosome (BAC) probes. The majority of these copy number alterations (CNAs) were confirmed by FISH and found to localize to the interphase rather than metaphase nuclei. Furthermore, the proliferative states of the cells analyzed by FISH were tested by immunofluorescence using an antibody against the proliferation marker pKi67. Interestingly, these experiments showed that, in the vast majority of cases, the changes appeared to be confined to interphase nuclei in a non-proliferative status.     

Transfer of mink genes into mouse cells by means of isolated lipid-encapsulated nuclei

Summary A method for gene transfer by means of interphase nuclei encapsulated within lipid membranes was developed. The method was based on passage of interphase nuclei through a layer of organic solvents containing phospholipids. Evidence was obtained indicating that the nuclei become surrounded by a protective phospholipid membrane: measurements of bound labelled or non-labelled phospholipids; decrease in the permeability of lipid-encapsulated nuclei for high molecular compounds; visualization by direct electron microscopy. Lipid-encapsulated nuclei of mink fibroblasts were used for transformation of mutant mouse LMTK^- cells (deficient for thymidine kinase). The frequency of occurrence of HAT-resistant colonies/recipient cell was 1.9x10^-5. Biochemical analysis of 14 independent clones demonstrated that they all contained TK1 of mink origin. Analysis of 15 other biochemical markers located on 12 of the mink chromosomes revealed the activities of mink galactokinase (a syntenic marker) in 5 transformed clones, and that of mink aconitase-1 (the marker of mink chromosome 12) in 1 clone. No cytogenetically visible donor chromosomes were identified in the transformed clones. Nine transformed clones were tested for the stability of the TK⁺ phenotype; of these, the phenotype was expressed stably in 3 and unstably in 6. The method suggested is similar to the gene transfer procedure using total DNA. Its advantage is in ensuring efficient gene transfer and donor DNA integrity.     

Detection of retinoblastoma gene copy number in metaphase chromosomes and interphase nuclei by fluorescence in situ hybridization.

Fluorescence in situ hybridization (FISH) was applied to detect the copy number of the retinoblastoma (RB1) tumor suppressor gene in metaphase chromosomes and interphase nuclei. We used 14 lambda phage clones spanning the whole RB1 gene region as a probe and obtained a specific hybridization signal in normal metaphase chromosomes at 13q14. Normal interphase nuclei showed two RB1 signals in about 90% of cases, whereas two cell lines with cytogenetically defined deletions involving the RB1 gene showed only one hybridization signal in about 80% of the nuclei. Analogous changes were detected in metaphase chromosomes. Multicolor FISH with subsets of the phage clones allowed visualization of subregions within the 200-kb gene in interphase nuclei. Analysis of clinical breast cancer samples showed that most of the cells contained two copies of the RB1 gene, even when restriction fragment length polymorphism analysis showed loss of heterozygosity (LOH) at the RB1 locus. This indicates that LOH at the RB1 locus in breast cancer cells probably involves mechanisms other than physical deletion.     

An Evaluation of the Frequency of Spontaneous Aneuploidy in Human Somatic Cells Using the Technology of Interphase Cytogenetics

The frequency of spontaneous aneuploidy of the four autosomes and both sex chromosomes in the interphase nuclei of cultured and noncultured lymphocytes from clinically healthy men was examined by use of two-color fluorescent in situ hybridization (FISH). It was shown that in noncultured cells from the individuals examined autosomal nullisomies were practically not detected (the frequency 0 to 0.01%). At the same time, the frequency of such cells with either Y, or X nullisomy was at least an order of magnitude higher (about 0.15%). This frequency was comparable with the level of Y- or X-disomic cells, and also with autosomal monosomies, precluding from consideration of X-nullisomic cells as hybridization artifact. During lymphocyte cultivation, a statistically significant increase in the total frequency of Y- or X-nullisomic cells was observed already after the first cell division cycle. Thus, interphase FISH analysis is a sufficiently sensitive method enabling detection of higher, compared to the autosomes, loss of sex chromosomes in the process of cell division, a phenomenon observed during replicative cell aging, as well as during natural aging of the organism. Male cells with the de novo lost single X chromosome, probably, switch to apoptosis and do not survive during further life of a cell population. The frequency of total aneuploidy in human somatic cells with the correction for the resolution capacity of the interphase FISH analysis was estimated to be 5.62 and 6.90% for noncultured and cultured cells, respectively. This aneuploidy level is close to that in spermatozoa. The data obtained can serve as the basis for the examination of the aneugenic (aneuploidy-inducing) genotoxic effects and for the analysis of interindividual genetic instability.     

Molecular Cytogenetic Characteristics of Chromosome Imbalance in Spontaneous Human Abortion Cells with Low Proliferative Activity in Vitro

Karyotyping of noncultivated cells of 60 first-trimester spontaneous abortions (blighted ovum and missed abortions) was carried out using fluorescence in situ hybridization (FISH) with centromere-specific DNA probes for all chromosomes of the karyotype. Conventional cytogenetic study of these abortions was impossible because of cell culture failures. The algorithm is proposed for molecular cytogenetic FISH analysis of interphase karyotypes. Chromosome abnormalities were found in 32 fetuses (53.3%). In groups of missed abortions and blighted ovum, the frequency of numerical chromosome abnormalities was 50 and 60%, respectively. Both the numerical chromosome abnormalities typical of spontaneous human abortions (autosomal trisomies, sex chromosome aneuploidy, and polyploidy) and a relatively rare type of genomic imbalance unidentifiable by standard cytogenetic analysis (autosomal monosomies 7, 15, 21, and 22 in mosaic state) were observed. The frequency of these type of chromosome abnormalities comprised 19% of all known karyotype abnormalities determined in spontaneously aborted embryos. Note that the level of confined placental mosaicism in embryos with low cell proliferative activity was 25%, which is substantially higher than the corresponding parameter (1–2%) determined by prenatal diagnosis of chromosome abnormalities in developing embryos. The results of interphase FISH analysis of cells with low proliferative activity in vitro suggest that the pathology of early fetal development and missed abortion in humans are associated with a wider spectrum of chromosome abnormalities.     

Combined Fluorescent-Chromogenic In Situ Hybridization for Identification and Laser Microdissection of Interphase Chromosomes

Chromosome territories constitute the most conspicuous feature of nuclear architecture, and they exhibit non-random distribution patterns in the interphase nucleus. We observed that in cell nuclei from humans with Down Syndrome two chromosomes 21 frequently localize proximal to one another and distant from the third chromosome. To systematically investigate whether the proximally positioned chromosomes were always the same in all cells, we developed an approach consisting of sequential FISH and CISH combined with laser-microdissection of chromosomes from the interphase nucleus and followed by subsequent chromosome identification by microsatellite allele genotyping. This approach identified proximally positioned chromosomes from cultured cells, and the analysis showed that the identity of the chromosomes proximally positioned varies. However, the data suggest that there may be a tendency of the same chromosomes to be positioned close to each other in the interphase nucleus of trisomic cells. The protocol described here represents a powerful new method for genome analysis.     

Interphase fluorescence in situ hybridization mapping: a physical mapping strategy for plant species with large complex genomes

The chromatin in interphase nuclei is much less condensed than are metaphase chromosomes, making the resolving power of fluorescence in situ hybridization (FISH) two orders of magnitude higher in interphase nuclei than on metaphase chromosomes. In mammalian species it has been demonstrated that within a certain range the interphase distance between two FISH sites can be used to estimate the linear DNA distance between the two probes. The intephase mapping strategy has never been applied in plant species, mainly because of the low sensitivity of the FISH technique on plant chromosomes. Using a CCD (charge-coupled device) camera system, we demonstrate that DNA probes in the 4 to 8 kb range can be detected on both metaphase and interphase chromosomes in maize. DNA probes pA1-Lc and pSh2.5·SstISalI, which contain the maize locia1 andsh2, respectively, and are separated by 140 kb, completely overlapped on metaphase chromosomes. However, when the two probes were mapped in interphase nuclei, the FISH signals were well separated from each other in 86% of the FISH sites analyzed. The average interphase distance between the two probes was 0.50 µm. This result suggests that the resolving power of interphase FISH mapping in plant species can be as little as 100 kb. We also mapped the interphase locations of another pair of probes, ksu3/4 and ksu16, which span theRp1 complex controlling rust resistance of maize. Probes ksu3/4 and ksu16 were mapped genetically approximately 4 cM apart and their FISH signals were also overlapped on metaphase chromosomes. These two probes were separated by an average of 2.32 µm in interphase nuclei. The possibility of estimating the linear DNA distance between ksu3/4 and ksu16 is discussed.