EZH2蛋白在食管上皮永生化细胞系和恶性转化细胞系中的表达

目的研究EZH2蛋白在食管上皮永生化细胞系(SHEE)和恶性转化细胞系(SHEEC)中的表达。方法采用免疫细胞化学染色、免疫印迹分析和流式细胞术检测两种细胞系EZH2蛋白的表达。结果两种细胞EZH2蛋白染色均呈阳性,阳性反应定位于细胞核,部分细胞胞浆也有阳性着色。免疫印迹分析表明SHEEC细胞和SHEE细胞的总蛋白、核蛋白在分子质量约90ku的位置均出现特异性印迹条带。SHEE细胞中EZH2蛋白的表达强于SHEEC细胞(P<0.05)。流式细胞术显示EZH2蛋白在两种细胞中均有表达,两者的平均荧光强度无明显差别;阳性细胞率均较高,其中SHEE细胞阳性率高于SHEEC细胞。结论EZH2蛋白在SHEE细胞和SHEEC细胞中高表达可能参与了它们的恶性改变;而EZH2蛋白在两种细胞系中的差异表达可能与细胞的分化程度及来源于胚胎食管上皮细胞相关。     

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.     

反义封闭NGAL基因表达对SHEEC食管癌细胞微丝骨架的影响

为了研究反义封闭NGAL基因表达对SHEEC食管癌细胞微丝骨架以及肿瘤细胞生物学行为的影响,以不同长度NGAL基因片段反义表达载体和硫代修饰反义寡核苷酸单链片段转染SHEEC食管癌细胞,通过G418筛选,建立一系列旨在封闭SHEEC食管癌细胞NGAL基因表达的亚细胞克隆.在细胞内F-肌动蛋白(F-actin)及DNA荧光双标记基础上,通过流式细胞术、激光共聚焦显微镜扫描术等技术手段检测封闭反义NGAL基因表达后, SHEEC食管癌细胞中F-actin和DNA含量、F-actin形态结构以及肿瘤细胞生物学行为的变化特征.结果显示,反义封闭NGAL基因表达后,SHEEC食管癌细胞F-actin的含量明显降低,与永生化食管上皮细胞SHEE相近,但细胞分裂增殖指数未见明显变化.表明反义封闭NGAL基因表达对SHEEC食管癌细胞的微丝骨架有明显影响,而对SHEEC食管癌细胞的分裂增殖影响不明显.激光共聚焦显微镜扫描观测显示,反义封闭NGAL基因表达可使SHEEC食管癌细胞F-actin分布均匀,F-actin小体减少,细胞间连接重新建立,结构较紧密,主要形态结构特征与SHEE细胞趋于一致.提示反义封闭NGAL基因表达可对SHEEC食管癌细胞的微丝骨架F-actin产生明显影响,推测癌细胞的微丝骨架F-actin可能是NGAL基因在SHEEC食管癌细胞中发挥功能的一种作用环节.     

人食管癌细胞株PTEN的激光共聚焦扫描显微镜检测

目的对人胚食管上皮永生化细胞株SHEE、SHEEMT、食管癌细胞株EC8712中PTEN表达情况进行定量比较和定位观察.方法采用激光共聚焦扫描显微镜光学切片和荧光探针的双重标记技术对三株细胞中PTEN的表达和分布情况进行检测.结果人食管癌细胞中PTEN主要表达在细胞浆和细胞核,在人胚食管癌上皮永生化细胞株SHEE、SHEEMT主要表达在细胞浆,食管癌细胞EC8712中细胞核表达增多,差异有统计学意义(P<0.01);PTEN在三种细胞株中表达强弱顺序为SHEE>SHEEMT>EC8712,差异有统计学意义(P<0.01).结论PTEN在SHEE、SHEEMT和EC8712分化程度不同的细胞株中均表达,表达和分布位置与分化程度相关.     

人乳头状瘤病毒诱导食管上皮永生化细胞的双相分化

研究中期永生化食管上皮细胞的表型,细胞遗传学和部份基因的改变,以阐明癌前病变的特征,SHEE是该院人人乳头状瘤病毒HPV18E6E7诱导的永生化上皮,传至61代已开始有少量细胞恶性转化。对永生化中期31代细胞用相差显微镜检查细胞形态改变和细胞生长状态（细胞接触和锚定生长）;流式细胞仪检测细胞周期;做染色体众数分析;多重PCR检查c-myc,p53,bcl-2和ras等基因。免疫组化检查细胞角蛋白和鬼臼毒素荧光标记检查肌动蛋白F（F－actin)。软琼脂培养的集落细胞接种SCID小鼠检查成瘤性。Western blot方法检测细胞内HPVE6表达蛋白。结果：培养细胞有两种不同分化形态,分化差的基底细胞和分化好的鳞状上皮;前者角蛋白和F－actin极少,后者含量丰富;细胞接触抑制和锚锭生长特性减弱,分析100个细胞染色体众数分二干系,56条（占30％）和61条（占24％）染色体,核型分析属上超二倍体,亚三倍体,多重PCR检查：c-myc,p53基因上调,bcl-2和ras基因阳性。用优选生长在软琼脂上的克隆细胞接种SCID小鼠,未成瘤;HPV18E6表达蛋白阳性。以HPV18E6E7诱导的食管永生化上皮31代细胞形态出现了双向分化,根据其形态表型,双染色体众数的细胞遗传学改变和某些癌基因上调等特性,可以认为SHEE31细胞是外处于癌前改变。     

近平滑念珠菌的形态转换观察

目的观察近平滑念珠菌在不同培养基的形态转换现象,以及温度对其形态转换的影响。方法收集近平滑念珠菌正常人皮肤携带株及临床致病株和标准株,接种于改良Lee培养基和含桃红B的YPD培养基,观察其不同形态转换,以及温度变化对光滑(W)与皱褶(O)形态转换的影响。结果近平滑念珠菌在Lee培养基和含桃红B的YPD培养基上,均可以出现多种形态以及一定频率W-O转换现象。在观察W向O形态转换过程中发现,与25℃培养温度相比,37℃条件下光滑菌落形态占更多的比例。结论近平滑念珠菌体外培养时存在形态转换及W-O转换现象,且于37℃时更易保持光滑形态。含桃红B的YPD培养基也可以用于基本的W-O形态转换观察。     

ROCK抑制剂Y27632对小胶质细胞炎性分泌的影响

目的观察ROCK抑制剂Y27632对小胶质细胞活化及其炎性分泌的作用。方法采用小胶质细胞系BV2细胞复苏后传代培养,分为对照组和Y27632干预组;在0、3h、6h、18h和24h收取细胞和细胞培养基;采用免疫荧光细胞染色测定各组BV2细胞上Ibal的表达,ELISA法测定各组培养基中IL-1B和TNF-α的浓度变化。结果Y27632可明显改变BV2细胞形态,干预组细胞比对照组细胞的胞体更大,细胞突起增多增长,细胞形态改变在干预6h时最为显著。与对照组相比,Y27632干预后BV2细胞分泌的IL-1β和TNF-α降低,在18h时抑制效果最为显著（P〈0．01）。结论ROCK抑制剂Y27632可诱导BV2细胞活化及炎性分泌降低,提示Rho／ROCK信号通路在小胶质细胞活化及炎性因子分泌中发挥了重要作用。     

中华绒螯蟹血细胞原代培养条件的优化

比较了几种常见血细胞培养基(L-15、2×L-15、3×L-15、M199和RMPI-1640)对中华绒螯蟹(Eriocheir sinensis)血细胞原代培养中细胞形态以及存活率的影响,以及在筛选获得的最佳培养基中添加不同比例胎牛血清(FBS)(0%、5%、10%和15%),进一步观察了血清对中华绒螯蟹血细胞培养效果的比较。结果表明,3×L-15培养基培养效果较好,所培养的细胞形态相对完整,数量较多,培养至96 h时血细胞存活率仍大于60%;而其他4种培养基效果较差,培养12 h存活率均低于50%,且细胞形态结构变化明显。以3×L-15培养基为基础,添加不同比例胎牛血清后发现,对细胞存活有显著影响,存活率明显降低。因此,不添加血清的3×L-15培养基对中华绒螯蟹血细胞的生长较为适宜。     

前列腺癌干细胞的分离及鉴定

前列腺癌DU145细胞在普通培养基中培养至对数生长期,无血清培养基重悬细胞培养至形成球状体,以细胞三维(3D)培养和二维(2D)培养方法分离前列腺癌类干细胞,观察细胞球的形成及其生长情况,通过CCK-8细胞增殖实验和细胞划痕修复实验检测所分离细胞的增殖能力,结果显示前列腺癌DU145细胞在普通培养基中呈长梭形贴壁生长,无血清培养基培养72 h形成大量细胞球聚集体,细胞3D培养分离的细胞球的透明度和形态比2D培养分离的细胞好,3D培养分离细胞的增殖能力和划痕修复能力明显强于2D培养分离细胞.因此,细胞3D培养技术联合无血清培养基有利于前列腺癌干细胞的分离.     

不同培养基对干细胞-胰岛复合物培养后形态和功能的影响

探讨3种培养基对干细胞包被胰岛形态和功能的影响。间充质干细胞(mesenchymal stem cells,MSCs)、内皮祖细胞(endothelial progenitor cells,EPCs)、新生猪胰岛细胞(neonatal porcine islet cell clusters,NICCs)混合后分别用NICC培养基(A组)、MSC培养基(B组)、EPC培养基(C组)培养,观察各组中NICCs形态、分泌功能、基因表达水平及混合细胞凋亡率。C组破碎细胞数量明显比A、B两组少,凋亡率低,胰岛素和胰高血糖素基因的mRNA相对表达量高(P0.05)。EPC培养基对NICCs的保护作用最优。     

人乳头状瘤病毒诱导人胚食管上皮永生化细胞恶性转化

为了证实ＨＰＶ１８Ｅ６Ｅ７基因诱导的人胚食管上皮永生化细胞（ＳＨＥＥ）６１代（ＳＨＥＥ６１）部份细胞（ＳＨＥＥ６１Ａ）已经恶性转化,以寻找监控细胞早期恶性转化的方法。对培养的ＳＨＥＥ第１０代（ＳＨＥＥ１０）和６１代（ＳＨＥＥ６１）细胞,用光学是为微镜和电子显微镜观察细胞形态及生长形式;用流工细胞仪分析细胞周期;用染色体Ｇ带核型分析和间期核染色体１、７、８号着丝粒探针荧光原位杂交９ＦＩＳＨ）检测细胞     

细胞内F-actin的聚合与解聚对肝癌Bel-7402细胞的影响

目的：为探讨癌细胞内F—actin的解聚与聚合对癌细胞的形态、迁移、侵入的影响。方法：利用激光共聚焦显微镜对贴附培养的人肝癌：Bel-7402细胞形态及其细胞内F-actin进行观察;使用流式细胞仪对贴附的Bel一7402细胞及其脱落细胞与Cyt—B处理后Bel-7402细胞内F-actin的含量进行分析。结果：Bel-7402细胞在培养的过程中,癌细胞形态伸展,出现侵入性生长,细胞内F-actin聚合形成粗大的贯通细胞内的F-actin束,F-acfin含量增高;癌细胞在生长过程中,常出现重叠生长,细胞变圆,F_actin解聚变短,F-acfin小体增高,细胞有脱落的趋势,其脱落细胞内的F-actin含量低于贴附细胞。结论：人肝癌：Bel-7402细胞内F-actin的聚合可增加癌细胞的贴附和侵入性：细胞内F-actin的解聚,及Gactin重新聚合形成F-aefin小体可影响到癌细胞脱落及迁移。     

1 alpha, 25-dihydroxyvitamin D3 specific regulation of growth, morphology, and fibronectin in a human osteosarcoma cell line

The ability of the hormonally active vitamin D metabolite, 1 alpha, 25-dihydroxyvitamin D3, to affect cell growth, morphology and fibronectin production has been examined using the MG-63 human osteosarcoma cell line. Hormone treatment reduced cell growth rate, saturation density and [3H]thymidine incorporation. Inhibition was specific for 1 alpha, 25-dihydroxyvitamin D3 relative to other vitamin D metabolites (1 alpha, 25-dihydroxyvitamin D3 greater than 25-dihydroxyvitamin D3 greater than 24R,25-dihydroxyvitamin D3 greater than D3), antagonized by high concentrations of serum and readily reversed by removal of 1 alpha, 25-dihydroxyvitamin D3 from the culture medium. Hormone treatment also increased cell associated alkaline phosphatase activity up to twofold and altered morphology such that treated cells were more spread out on the culture dish and contained more cytoplasmic processes. Significantly, 1 alpha, 25-dihydroxyvitamin D3 increased cellular and medium concentrations of fibronectin, a glycoprotein known to be involved in cellular adhesiveness. MG-63 cells contain a specific 1 alpha, 25-dihydroxyvitamin D3 receptor which may mediate these responses.     

Establishment and characterization of immortalized cell lines from rat parotid glands

Summary This study reports for the first time the establishment of immortalized cell lines from normal adult rat parotid glands. The freshly prepared cellular clumps obtained from parotid glands of isoproterenol-treated rats were incubated in 0.2% trypsin solution without EDTA. These clumps were transfected with plasmid vectors pSV ₃ ^neo and pSV ₅ ^neo by electroporation and calcium phosphate-Co-DNA-precipitation techniques. The untransfected and transfected cellular clumps were plated in precoated dishes containing modified MCDB-153 medium. Epithelial cells grew from the clumps that were attached. All epithelial cells from untransfected culture died within 6 to 8 wk. Two cell lines which were isolated from transfected cultures subsequently grew on regular tissue culture dishes. One of them, which was isolated from pSV ₅ ^neo transfected cultures, exhibited non-epithelial cell morphology, but at confluency, many cells mature to acinar-like cells containing numerous granules. The other cell line (2RS), which was isolated from pSV ₃ ^neo transfected culture, contained cells of non-epithelial and epithelial morphology. During the initial phase of the growth, MCDB-153 medium was essential; however, at a later time, RPMI medium was better than MCDB-153 or F12 medium for maintaining morphology and growth of these cells. The immortalized cells grew in RPMI with a doubling time of about 25 h, synthesize T-antigen,α-amylase mRNAs of 1176 and 702 bp, andα-amylase and were non-tumorigenic. These amylase-producing cells can be a useful model to study the mechanisms of regulation of growth and differentiation in these cells.     

Injury to primary cultures of rat heart endothelial cells by hypoxia and glucose deprivation

Primary cultures of rat heart endothelial cells were subjected to simulated conditions of ischemia: hyposia and glucose deprivation for 4 and 24 hr. Cellular injury was evaluated by measuring changes in viability, total protein, cellular morphology, and leakage of cytoplasmic enzymes from the cells into the culture medium. Deprivation of oxygen and glucose for 4 or 24 hr did not lethally injure the cells as noted by no change in cell viability, morphology, and total protein when compared to controls. However, reversible or non-lethal cellular injury was produced as reflected by a significant release of lactate dehydrogenase (LDH) from the cells into the medium after treatment with hypoxia and glucose deprivation for 4 or 24 hr. When the cultures were deprived of glucose, but were oxygenated, cellular injury was not evident after 24 hr. Deprivation of oxygen but not glucose resulted in significant loss of LDH after 4 or 24 hr. When the cultures were allowed to recover after oxygen and glucose deprivation in complete medium containing 1000 mg glucose per 1 and a normal atmosphere of 20% O2, they had levels of LDH leakage comparable to those of control cultures.     

Testosterone-induced responsiveness to androgen in Shionogi mouse carcinoma cells

Primary cell cultures from an androgen-dependent mouse mammary carcinoma, the Shionogi-SC 115 tumor, were cultured in the presence or absence of testosterone (50 nM). Characteristic changes in cellular morphology and cell growth were observed according to the presence or absence of the androgen. In testosterone-containing medium, cells formed individual clones, piling up one over another and showed no contact inhibition, whereas in the absence of the androgen, cells had a flattened morphology, they grew in a monolayer and cell multiplication was reduced. The testosterone-dependent changes were observed in culture as long as cells were maintained in androgen-containing medium. Only a few (3-5) days of culture in the absence of testosterone rendered cells irreversibly unresponsive to the androgen, and they could no longer produce tumours after inoculation in the host animal. Cellular proteins were analysed after culture in the presence or absence of testosterone. After [35S]methionine labelling of cells and SDS-PAGE of the cytosol, several proteins were specifically synthesized in the presence of testosterone, predominantly a 45 kD protein, which was not seen in the absence of the androgen. Conversely, a protein of 35 kD present in absence of the hormone disappeared in the presence of testosterone. The anti-androgen cyproterone acetate inhibited the characteristic cellular morphology, cell proliferation and protein synthesis observed in the presence of the the androgen. The antiprogestin and anti-glucocorticosteroid RU 486 also showed limited anti-androgen activity. The concentration of specific androgen receptor-binding sites did not change significantly after 3 months of culture with or without testosterone, i.e., in responsive and unresponsive cells.     

Control of dimorphism in a biochemical variant of Candida albicans

The cellular morphology of a biochemical variant of Candida albicans could be controlled by the ratio of carbon dioxide to oxygen in the culture system or by individual amino acids. Predominantly pseudohyphal morphology was observed (i) at a CO(2) to O(2) ratio of 2:1 and (ii) without the addition of carbon dioxide, when either glycine, d- or l-ornithine, l-serine, l-methionine, l-phenylalanine, or l-tyrosine was the sole nitrogen source in the culture medium. When ammonium chloride, ammonium sulfate, l-glutamic acid, l-glutamine, or l-proline was the nitrogen source, yeastlike growth was observed in the presence or absence of CO(2). More adenosylmethionine was present in pseudohyphal than in yeastlike cells, and pseudohyphal cell wall preparations contained less methionine than cell walls from the yeastlike form. These results suggest a correlation between sulfur amino acid metabolism and dimorphism.