Cytoplasmic suppression of tumor progression in reconstituted cells

This report details studies of whether mouse NIH/3T3 TG^r karyoplasts that are exposed to benzo[a]pyrene epoxide(trans) (BPDE) can progress to tumorigenicity when they are rescued with either mouse B10mtJ CAP^r tumorigenic (experiment 1) or nontumorigenic (experiment 2) cytoplasts. The mitochondrial DNA of the B10mtJ cells has restriction fragment length differences that allow distinction from the mitochondrial DNA of the NIH/3T3 cells. The reconstructed clones in experiment 1 were all tumorigenic, while those from experiment 2 were all nontumorigenic. The clones in both experiments were passaged for an equivalent time. These findings reflect the presence of factors in mouse cytoplasm capable of suppressing the tumor phenotype of NIH/3T3-BPDE treated karyoplasts when rescued at an early stage of progression.     

树突状细胞体外诱导抗肿瘤血管内皮细胞特异性免疫的研究

目的:探讨肿瘤内皮细胞抗原负载的树突状细胞(DC)诱导的细胞毒性T淋巴细胞(CTL)的特异性杀伤效应。方法:采用肿瘤细胞的培养上清诱导人脐静脉血管内皮细胞(HUVEC)增殖,制备肿瘤血管衍生的内皮细胞(TdEC)。用RTPCR检测肿瘤内皮标志物(TEM)的表达。制备TdEC的冻融抗原,负载从外周血中扩增的DC,用MTS比色法检测DC刺激自体淋巴细胞增殖的效应;用LDH法检测DC诱导的CTL的特异性杀伤效应。结果:TdEC可表达TEM1和TEM8。负载TdEC抗原的DC,可显著刺激自体淋巴细胞增殖。由其诱导的CTL对TdEC具有特异性的杀伤作用。在效靶比为20∶1和10∶1时,杀伤率分别为33%和27%,高于对照组的14%和10%。结论:TdEC抗原负载的DC,在体外可有效地诱导CTL产生,并特异性地杀伤TdEC。     

Histamine release induced by histone and related morphological changes in mast cells

When isolated rat peritoneal mast cells were exposed to histone mixture, both histamine release and degranulation were evoked rapidly and dose-dependently at concentrations higher than 1 g/ml in a Ca-free medium. All of the histone subfractions (H1, H2A, H2B, H3 and H4) induced histamine release from mast cells in a Ca-free medium and, as in the case of histone mixture, the amount of histamine release was reduced by addition of Ca²⁺. By means of high-voltage electron microscopy, at least three types of degranulation were observed in mast cells exposed to histone mixture: (1) microfilament-associated degranulation, (2) extrusion of granules with the surrounding membrane, and (3) mass degranulation.     

人Egr-1启动子的克隆及其在肿瘤细胞中的辐射诱导反应

目的:克隆人Egr-1基因的启动子, 插入荧光素酶报告基因载体中, 并检测电离辐射对其活性的影响.方法:采用PCR技术从人乳腺癌细胞系MCF-7基因组中扩增出Egr-1启动子, 将其克隆到pGL3-basic载体中;将重组质粒转染人肿瘤细胞, 测定Egr-1启动子在不同辐射条件下转录活性的改变.结果:成功构建了Egr-1启动子的荧光素酶报告基因;在不同剂量的γ射线照射后, Egr-1的启动子活性均明显高于未照射组;在同一剂量照射后48 h, Egr-1的启动子活性达峰值.结论:本实验构建的Egr-1启动子具有辐射激活的功能, 为进一步研究放射-基因治疗奠定了基础.     

鼠脾细胞肿瘤坏死因子的诱生和检测

本文报道采用Ｅ．ｃｏｌｉ ＬＰＳ刺激ＡＬＢ／Ｃ小鼠脾细胞诱生ＴＮＦ的最适条件，并用人ＴＮＦ ＥＬＩＳＡ方法检测小鼠ＴＮＦ。结果显示：脾细胞经ＬＰＳ刺激２ｈ就可在上清液中测出ＴＮＦ，１２ｈ达高峰，ＬＰＳ最适刺激浓度为１０＾－２μｇ／ｍｌ，ＴＮＦ产量依赖于脾细胞的浓度。     

Induction of nestin synthesis in rat brain cells by ischemic damage

Nestin, an intermediate filament protein, is known to be expressed in proliferating and provisional cells in the forming mammalian brain, disappearing on differentiation. The aim of the present work was to identify the morphological types and locations of cells regaining the ability to synthesize nestin after transient total brain ischemia in rats. Transient ischemia was found to be followed by the induction of nestin synthesis in astrocytes in the damaged area; these cells acquired structural features not characteristic of the adult brain, and these persisted in the long term. Nestin synthesis was also induced in proliferation-capable undifferentiated cells in the subventricular zone. The acquisition by astrocytes of some of the phenotypic features of immature glial cells, however, does not provide grounds for the notion that they were transformed into neural stem cells. Director: Corresponding Member of the Russian Academy of Medical Sciences Professor V. A. Otellin Director: Professor S. A. Polenov Director: Professor N. N. Petrishchev __________ Translated from Morfologiya, Vol. 131, No. 1, pp. 23–26, January–February, 2007.     

Induction of avian tumor viruses in normal cells by physical and chemical carcinogens

Avian tumor viruses were induced in normal chicken cells treated with ionizing radiations or chemical carcinogens and mutagens. The induced leukosis viruses possess a buoyant density, DNA polymerase, polypeptides, and 70S RNA typical of avian tumor viruses. Induced leukosis viruses act as helper agents for the defective Bryan high titer strain of Rous sarcoma virus and with one exception belong to subgroup E as judged by host-range, interference, and neutralization patterns. Induction of leukosis viruses was successful in chicken cells lacking the “natural” group specific (gs) antigen of the avian tumor viruses as well as in cells carrying this antigen. This observation indicates that the viral genome is present in gs⁺ and in gs⁻ cells. Therefore, the chromosomal locus which controls the presence of natural gs antigen in chicken cells does not represent the viral genome itself but regulates its expression in normal cells. These findings have implications for the origin of RNA tumor viruses and for theories of carcinogenesis.     

锂诱导肿瘤细胞凋亡及其机理初探

研究微量元素锂在体外对肿瘤细胞系凋亡的诱导作用。方法在细胞培养体系中加入ＬｉＣｌ进行诱导，以流式细胞分析，ＤＮＡ电流分析及细胞形态变为指标检测凋亡，并用ｍＲＮＡ狭缝杂交和Ｗｅｓｔｅｒｎｂｌｏｔ测定凋亡相关基因的改变。加入大分子合成抑制或第二信使相关药物观察对锂诱凋亡的影响。     

Induction of a novel morphological response in Chinese hamster ovary cells by pertussis toxin.

Exposing Chinese hamster ovary cells in culture to pertussis toxin resulted in a novel clustered growth pattern. The specificity of the response for pertussis toxin was shown by neutralization of the activity with specific anti-toxin antibody, heat lability (80 degrees C for 15 min), and absence of such activity by culture media from nontoxigenic Bordetella species. Although a lag of at least 16 h was required before clustered growth was seen, exposure to the toxin for as little as 10 min resulted in a full response 24 h later. The morphological effect appeared to be independent of the cyclic AMP-mediated cell elongation elicited by the heat-labile enterotoxin from Vibrio cholerae in that the pertussis toxin effect was seen in both the presence and absence of elongation. Although the mechanism by which this effect is mediated remains to be determined, it is already providing a useful in vitro assay for pertussis toxin.     

神经酰胺介导粒细胞凋亡机理初探

目的 观察神经酰胺对ＨＬ－６０及中性粒细胞（ＰＭＮ）凋亡产生的影响,探讨其在粒细胞发生过程中可能的调节作用。方法：采用ＤＮＡ凝胶电泳,流式细胞术,光镜及ＲＴ－ＰＣＲ等技术对细胞进行凋亡鉴定及相关基因ｂｃｌ－２,ｃ－ｍｙｃ,ｍＲＮＡ表达分析。结果 神经酰胺（ｃ２－ｃｅｒａｍｉｄｅ）肿瘤坏死因子（ＴＮＦα）及长春新碱（Ｖｉｎｃｒｉｓｔｉｎｅ）均可不同程度地诱导ＨＬ－６０及成熟ＰＭＮ产生凋亡,ＣＰＫ激活     

Induction of metallothionein synthesis in cultured cells by substances released from endotoxin-activated macrophages

The involvement of macrophages in the induction of metallothionein (MT) synthesis by bacterial endotoxin was studied in vitro. Rat peritoneal macrophages were incubated with endotoxin. The incubation medium from endotoxin-activated macrophages accelerated MT synthesis by human hepatic Chang cells. However, the incubation medium from non-activated macrophages did not. Endotoxin added to the culture medium of Chang cells was ineffective in inducing MT synthesis. The contents of zinc, copper and cadmium, which are primary inducers of MT, in the incubation medium of macrophages in the presence of endotoxin were not different from those in the absence of endotoxin. These results suggest that MT synthesis is induced by endotoxin-treated macrophages.