脊髓小脑共济性失调2型家系永生细胞株的建立及遗传稳定性检测

目的 建立伴帕金森氏病症状的脊髓小脑共济性失调2型家系永生细胞株,提供永久性的实验研究材料.方法 采用EB病毒加入环胞霉素A的转化细胞技术,建立了该家系的永生细胞株.并检测传代细胞与家系血液中的微卫星标记有无改变,确定细胞株的遗传稳定性.结果 成功建立此家系25株永生细胞株,所检测的微卫星位点未发生变化.结论 所建永生细胞株染色体核型检测无异常,转化细胞株与血液中的微卫星的遗传稳定性无差异.     

建立不同民族永生细胞株质量控制方法的探讨

目的以建立普米族、独龙族和怒族永生细胞为基础,探讨EB病毒转化细胞、细胞培养、冻存、复苏以及支原体检测等建立永生细胞株的技术要点及质量检测方法.方法采用EB病毒转化技术建立3个民族永生细胞株;培养法和PCR法对细胞株进行支原体污染检测;染色体G显带及核型分析细胞株的遗传稳定性.结果成功建立了3个民族B淋巴细胞永生细胞株,转化率分别为98%、86%和76%.对已建株保存的3个民族的永生细胞进行复苏培养,复苏成活率为100%.支原体污染检测均为阴性.染色体计数和G带分析显示,细胞株经早期传代培养后,仍然保持二倍体特征,未发现染色体结构畸变.结论本研究中传代培养、细胞冻存、细胞复苏和支原体污染防范等一整套技术过程是满足建库要求的.同时为大规模永生细胞库的建立和进行相应的质量监测提供了科学的依据.另外,本研究还对一些影响转化的因素和可能的机理进行了探讨.     

表达HPA抗原的细胞株稳定性及应用的研究

建立血小板特异性抗原永生化细胞株,为血小板免疫学及血小板交叉配型提供永久的研究材料。采用EB病毒(Ep-stein-Barr virus)转化技术,把携带血小板特异性稀有抗原外周血淋巴细胞转化成永生化淋巴母细胞株。结果:成功地建立了13个稀有血小板特异性稀有抗原建立了永久细胞株,所有的细胞株传代、冻存和复苏的成功率为100%,细胞传至30代没有发现基因突变。由所建的细胞株抽提的DNA样本,分发给第14届国际血小板免疫学研究会做为参比试剂,34个国际实验室基因分型鉴定结果的一致率为97.85%。采用EB病毒转化技术,能成功地血小板特异性抗原外周血淋巴细胞转化成永生化细胞淋巴母细胞株,细胞株稳定传代,并可用作为参比试剂。     

儿童原发性免疫缺陷病患者EBV转化的B淋巴母细胞系的建立及应用

目的: 建立原发性免疫缺陷病人外周血永生化B细胞系,保存原发性免疫缺陷病人特有的基因组资源,为进一步研究原发性免疫缺陷病提供丰富实验材料.方法: 采用密度梯度离心法分离PBMC,加入环孢菌素A、 EB病毒共培养以转化外周血淋巴细胞.结果: 成功建立14例原发性免疫缺陷病人外周血永生化B细胞系,建株成功率100%;对已建立的永生细胞株冻存和复苏,成功率为100%;转化前后制备细胞染色体和G显带核型分析无明显改变.结论: 经EB病毒成功转化外周血B淋巴细胞为永生细胞株,为进一步开展原发性免疫缺陷病的基础研究提供了资料.     

中国遗传性耳聋大家系永生细胞系的建立与保存

目的建立我国遗传性耳聋大家系患者永久淋巴母细胞株以研究核基因结构对线粒体DNA突变的修饰效应.方法采用EB病毒转化外周血淋巴细胞同时加环孢霉素A法,建立该大家系永生细胞系,其中患者14例,配偶及正常同胞18例:男性17例,女性15例.结果建株成功率达到90%以上,对已建立的永生细胞株经复苏和冻存的成功率为100%.细胞染色体制备及G显带核型分析正常.结论通过建立永生细胞系保存这一具有重要研究价值的家系遗传资源,为在细胞和分子水平上进一步开展遗传性耳聋的基础研究提供了宝贵的资料.     

罗伯逊易位型21三体永生淋巴细胞株的建立

目的建立并鉴定13／21易位与21／21罗伯逊易位21三体永生淋巴细胞株,为21三体罗伯逊易位的遗传学研究提供实验材料。方法筛查获得易位型21三体患者并收集外周血,培养B95-8细胞制备EB病毒感染液,采用EB病毒转化法获得永生淋巴细胞株,对第10、15、20代细胞进行G显带染色体分析。结果筛检出1例罕见的13／21易位与4例121／21罗伯逊易位型21三体患儿并成功建立永生淋巴细胞株,传代至第10、15、20代细胞的核型无显著差异。结论明病毒转化法可用于易位型21三体永生淋巴细胞株的建立,早期转化的细胞可为该病的研究提供实验基础。     

细胞永生化对线粒体DNA拷贝数的影响

目的探讨EB病毒转化形成的永生细胞对线粒体DNA突变比例及拷贝数的影响。方法随机选择23位携带线粒体A3243G突变的患者,采集静脉血7ml,其中2ml提取总DNA,为对照组;5ml用EB病毒转化成为永生细胞,提取总DNA,为实验组。采用Taqman探针联合扩增受阻突变体系定量聚合酶链反应(ARMS-q PCR)方法检测线粒体A3243G突变比例和拷贝数。运用配对t检验进行统计分析。结果实验组的线粒体A3243G突变比例与对照组无明显差异;实验组的野生型线粒体DNA拷贝数,突变型线粒体DNA拷贝数和总线粒体DNA拷贝数与对照组比较,均无明显差异。结论 EB病毒转化对线粒体DNA数量上无明显影响,证实了通过EB病毒转化建立的永生细胞株可以长久保存线粒体DNA,为线粒体相关疾病的研究提供充足的实验材料。     

男性性腺发育不全患者外周血淋巴细胞永生细胞系的建立

目的建立男性性腺发育不全患者外周血永生细胞系以保存性腺发育不全患者特有的基因组资源,为进一步探讨性腺发育不全的发生机理提供材料.方法收集40例男性性腺发育不全患者的外周血样品,采用EB病毒转化技术,把患者外周血B淋巴细胞转化成永生淋巴母细胞系;用遗传学方法检测其建系前后的遗传稳定性.结果建系成功40例,所有建成的细胞系冻存后复苏成功率100%,核型和DNA分析表明建系前后遗传是稳定的.结论性腺发育不全患者永生细胞系的建立,为进一步研究性腺发育不全导致的不育症分子水平发病机理提供随时可取的实验材料.     

端粒酶与前列腺癌

端粒是真核细胞染色体末端的特殊结构.端粒的不断缩短或丢失可阻止细胞的增殖.端粒酶是一种RNA依赖的DNA多聚酶,可以合成端粒DNA的重复片段与细胞永生化密切相关.研究发现,大多数肿瘤组织细胞中可检测到端粒酶活性,其被认为在肿瘤发生中起重要作用.本文主要综述端粒酶的主要特性及其在前列腺癌中的潜在作用.     

中华民族永生细胞库的建立

目的 为保存中国不同民族基因组，完整建立中国各民族永生细胞库，供永久性研究需要。方法 按照严格的采样标准和“知情同意”原则，采集不同民族群体外周血样，利用EB病毒转化B淋巴细胞为永生细胞的技术，建立中国各民族永生细胞库。结果 已建立了47个民族70个群体（含民族支系）的3982株永生细胞株，并保存了7210份DNA样本。建立了较为成熟和稳定的利用EB病毒转化B淋巴细胞为永生细胞的技术。结论 这是目前规模最大的较为完整的中国国家级中国各民族永生细胞库，可供永久性研究需要。已向国内多家人类基因组相关单位提供了细胞株和 DNA，进行相关研究。     

Study on the genetic stability of immortalized cell line of lymphocyte cell transformed by EB virus after long subculture process]

OBJECTIVE: To study the genetic stability of an immortalized cell line transformed by Epstein-Barr virus (EBV) after long subculture process. METHODS: In the present study, the genetic stability including chromosome diploidy, karyotypes and microsatellite DNA were evaluated with chromosome banding techniques and microsatellite DNA detection. The telomerase activity of the immortalized cell line was detected by using the telomerase assay kit. RESULTS: From passage 1 to 30, there were no change of the diploidy, karyotypes of chromosome and microsatellite DNA, and the telomerase activity is negative. CONCLUSION: This study indicates that the immortalized cell line remains stable genetically within limited passages.     

Clonal chromosomal aberrations accompanied by strong telomerase activity in immortalization of human B-lymphoblastoid cell lines transformed by Epstein-Barr virus

Human B-lymphoblastoid cell lines transformed by Epstein-Barr (EBV-LCLs) are considered to be immortalized, although most of them show a normal diploid karyotype. Recently, we and others have shown that only part of EBV-LCLs is immortalized by developing strong telomerase activity that stabilizes the telomeres. In this study, we investigated the change in karyotypes during immortalization. All the eight immortalized cell lines developed clonal chromosomal aberrations accompanied by the development of strong telomerase activity. Interestingly, abnormal chromosomes were not shared among the immortalized cell lines. These results strongly suggest that chromosomal rearrangements and induction of strong telomerase activity are two events that take place in parallel in the process of immortalization of EBV-LCLs, and indicate that EBV-LCLs are clearly divided into two distinct groups, pre-immortal cell lines mostly with a normal diploid karyotype and post-immortal cell lines with a clonally abnormal karyotype.     

Immortalization of human uterine leiomyoma and myometrial cell lines after induction of telomerase activity: molecular and phenotypic characteristics

In vitro model systems for studying uterine leiomyomas are limited in that human-derived leiomyoma cells grow poorly in culture compared with normal myometrial cells and begin to senesce early, at approximately passage 10 in our studies. To our knowledge, a good in vitro human-derived cell culturing system for leiomyomas does not exist. In an attempt to fill this void, we have immortalized a uterine leiomyoma cell line by inducing telomerase activity, which allows cells to bypass their normal programmed senescence. Telomerase activity was induced by infecting the target (uterine leiomyoma and normal myometrial) cells with a retroviral vector containing hTERT, the gene for the catalytic subunit of telomerase. Subsequent analysis by RT-PCR and the telomeric repeat amplification protocol assay confirmed expression of the inserted gene and induction of telomerase activity in leiomyoma and myometrial cells. Analysis of cells for estrogen receptor-alpha and progesterone receptor proteins by Western blotting showed no change in expression of these proteins between the immortalized and parental leiomyoma and myometrial cells. Both immortalized and parental myometrial and leiomyoma cells expressed the smooth muscle-specific cytoskeletal protein alpha-actin and were negative for mutant p53 protein as evidenced by immunocytochemical staining. The immortalized leiomyoma and myometrial cells showed no anchorage-independent growth, with the exception of a small subpopulation of immortalized leiomyoma cells at a higher passage that did form two to three small colonies (per 50,000 cells) in soft agar. None of the immortalized cells were tumorigenic in nude mice. In conclusion, our data show the successful insertion of the hTERT gene into leiomyoma and myometrial cells and the immortalization of these cell lines without phenotypic alteration from the parental cell types (up to 200 population doublings). These cells should help to advance research in understanding the molecular pathways involved in the conversion of a normal myometrial cell to a leiomyoma cell and the mechanisms responsible for the growth of uterine leiomyomas. Answers to these questions will undoubtedly lead to the development of more effective treatment and intervention regimens for clinical cases of uterine leiomyoma.     

Reconsideration of senescence, immortalization and telomere maintenance of Epstein-Barr virus-transformed human B-lymphoblastoid cell lines

We review recent data on senescence and immortalization of human B-lymphoblastoid cell lines (LCLs) transformed by the Epstein-Barr virus (EBV). Although EBV-transformed LCLs are generally believed to be immortalized, a series of recent studies, including ours, provided strong evidence that they are mostly mortal and have non-malignant properties, except for a small proportion of LCLs that are immortalized by developing a strong telomerase activity. A large proportion of mortal LCLs have exceptionally long lifespans. Some of them have a lifespan over 150 population-doubling levels, keeping a relatively constant telomere length in spite of the absence of a detectable telomerase activity, suggesting that they maintain telomeres by a pathway other than that using telomerase. Here we propose a model of an alternative pathway to maintain telomeres of such long-lived mortal LCLs by exploiting extra-chromosomal telomere repeat DNA, which was recently found by us.     

HPV 16 YY1位点突变株诱导的永生化细胞系具有部分转化细胞特征

目的 检测ＨＰＶ １６ ＹＹ１位点突变株诱导的包皮角原细胞永生化细胞系的生物学特性。方法 提取永生化细胞株蛋白,以Ｗｅｓｔｅｒｎ ｂｌｏｔ检测细胞内源性ｐ５３蛋白含量;以ＴＲＡＰ法检测细胞中端粒体酶活性;将永生化细胞系接种于含有１０％ＦＣＳ的软琼脂培养基,观测细胞的软琼脂生长能力。结果 Ｗｅｓｔｅｒｎ ｂｌｏｔ检测结果显示４株永生化细胞系中ｐ５３均为阴性;端粒体酶活性均为阳性,并且随着细胞传代活性     

A comparative study of telomerase activity and malignant phenotype in multistage carcinogenesis of esophageal epithelial cells induced by human papillomavirus.

To examine certain characteristics of multistep carcinogenesis, we studied telomerase activity and malignant phenotypes in the immortal, premalignant and malignant stages of esophageal epithelial cells induced by HPV. An immortalized human fetal esophageal epithelial cell line (SHEE) was induced by E6E7 genes of human papillomavirus (HPV) type 18. Cells in the 10th passage, (SHEE10), 31st passage (SHEE31), 61st passage (SHEE61) and SHEE61A which were selected and expanded from anchorage-independent growth colonies of SHEE61, were examined as follows: cell morphology by electron-microscopy; the cell cycle by flow cytometry, telomerase activity by TRAP assay, tumorigenic detection including anchorage-independent growth by soft agar culture and tumor formation by inoculating cells into SCID and nude mice, and detection of HPV18 E6E7 oncoprotein by Western blot. The morphology of the SHEE10 cells exhibited good differentiation, the SHEE60 and SHEE61A cells were relatively poorly differentiated, and the SHEE31 cells were differentiated in two distinct ways. The telomerase was activated in SHEE31, SHEE61 and SHEE61A, but not in SHEE10 cells. SHEE61 and SHEE61A cells were weakened in contact-inhibition and increased in anchorage-independent growth. Inoculated into SCID and nude mice, the cells of the earlier two passages could not develop tumors; the SHEE61 developed one tumor in four SCID mice, but not in nude mice, and the SHEE61A cells developed tumors in both strains of immunodeficient mice. HPV18 E6E7 DNA detection by Western blotting was positive in all cell passages. In the process of carcinogenesis by HPV, the cells of SHEE31 are in an immortalized state with telomerase activity. The fact that SHEE61 cells remained immortalized and also demonstrated anchorage-independent growth, reveals premalignant character; the cells of SHEE61A exhibited malignant transformation with tumor formation in mice. The results revealed that the telomerase activity, anchorage-independent growth and tumor formation in nude mice are the indicators for immortalization, premalignancy and malignancy, respectively.     

人端粒酶反转录酶重组绿色荧光表达载体转染椎间盘正常髓核细胞

背景：椎间盘髓核细胞分离培养困难,老化较快,迫切需要一种标准细胞株用于实验研究。 目的：探讨人端粒酶反转录酶重组绿色荧光表达载体的构建及其转染正常髓核细胞构建永生化细胞的可行性研究。 方法：通过目的基因克隆、真核表达质粒中目的基因序列测定、目的基因真核表达质粒的构建、转染人端粒酶反转录酶表达检测等步骤进行实验。 结果与结论：构建出人端粒酶反转录酶重组绿色荧光表达载体,成功转染正常髓核细胞并在细胞中稳定表达。结果表明运用人端粒酶反转录酶转染椎间盘髓核细胞构建永生化细胞是一种可行的方法。