Studies on apoptosis in bone tumor cells induced by 153Sm

The apoptosis in human bone tumor cells induced by internal irradiation with ^153Sm was studied. The morphological changes in bone tumor cells were observed by electronic and fluorescent microscopy, as well as DNA agarose gel eletrophoresis. DNA chain fragmentation, microautoradiographic tracing and the inhibition rate of proliferation in bone tumor cells exposed to ^153Srn with different duration time were examined. It was demonstrated that the bone tumor cells exposed to ^153Sm displayed nuclear fragmentation, pyknosis, margination of condensed chromatin, and formation of membrane bounded apoptotic bodies, whereas the percentage of DNA chain fragmentation of bone tumor cells increases in direct proportion to the duration of irradiation with ^153Sm, as well as DNA ladder formation in apoptotic cells. Also a marked inhibition effect of proliferation in bone tumor cells after exposure with ^153Sm was observed.     

Fluorescence microscopic morphology and inhibition rate studies on apoptosis of osteosarcoma cells induced by 153Sm

The apoptosis of osteosarcoma cells treated with irradiation by ^153Sm－EDTMPwas studied,The morphological changes in osteosarcoma cells were observed by fluorescence microscopy,It was found that osteosarcoma cells exposed with ^153Sm－EDTMP displayed significant nuclear fragmentation and marked pyknosis ,With the prolongation of observing period,the membrane bound apoptotic bodies formation was observed,It should be noted,that with the lenghening of irradiation time by ^153Sm－EDTMP,the inhibiton rate of proliferation of osteosarcoma cells increased progressively.     

DNA gel electrophoretic and microaut oradiographic studies on apoptosis in bone tumor cells after exposure with ^153Sm—EDTMP

The apoptosis in bone tumor cells is studied after ^153Sm-EDTMP irradiation.Fragmented DNA is analyzed by agarose gel electrophoresis.Experimental observations show that 153Sm-EDTMP exposure induces the internucleosomal DNA damage in bone tumor cells the DNA ladder pattern formation in bone tumor cells is show.At the same time,the microautoradiographic study indicates that ^153Sm-EDTMP could permeate through cell membrane and duisplays membrane-seeking condensation in bone tumor cells.Soon afterwards ^153Sm-EDTMP could be phagocytized by the tuymor cells and distributed in cytoplasm as well as nucleus in the form of phagosome.with the prolongation of observing time,the membrane-bounded apoptotic bodies are observed.     

153Sm-EDTMP诱发骨肉瘤细胞凋亡的荧光显微镜形态和增生抑制研究

通过荧光显微镜观察,发现骨肉瘤细胞受到＾１５３Ｓｍ内照射作用后,可诱发明显的核断裂和核固缩,以及以凋亡小体形成为特征的瘤细胞凋亡。同时揭示,经＾１５３Ｓｍ－ＥＤＴＭＰ辐照后可呈现出对骨肉瘤细胞的增生抑制效应。并随着辐射时间的延长,增生抑制率亦随之增升。     

Chromatin and DNA chain fragmentation studies on apoptosis in immune cells induced by ^235U and radioprotection of IL—2 or IL—6

The apoptosis in human acute lymphoblastic leukemia cell line Molt-4 cell and macrophage cell line Ana-1 cell are studied after internal irradiation with enriched uranium 235U.The cumulative absorption dose of ^235U in cultural cells through different periods are estimated.The fluorescence microscopic observations indicate that Molt-4 and Ana-1 immune cells internally irradiated by ^235U displayed significant chromatin fragmentation and marked pyknosis in immune cells nuclei.as well as DNA chain fragmentation and apoptotic bodies formation.It should be noted that DNA chain fragmentation induced by ^235U may be inhibited statistically by IL-2(interleukin-2)or IL-6 treatment.     

浓缩~(235)U诱发免疫细胞凋亡的电镜和琼脂糖凝胶电泳研究

研究了浓缩235U内照射诱发人淋巴细胞白血病细胞株Molt－4细胞和巨噬细胞株Ana－1细胞的细胞调亡。估算了浓缩235U在不同阶段培养细胞中的辐射累积吸收剂量。通过电镜对免疫细胞的形态观察，发现Molt－4和Ana－1细胞在受235U内照射作用下可呈现核染质边聚，DNA链断裂和膜包裹的凋亡小体形成。对Molt－4和Ana－1细胞的DNA抽提，进行DNA琼脂糖凝胶电泳也显示出阶梯状条带形成的细胞调亡特征。从而证实了浓缩235U内照射可导致免疫细胞Molt－4和Ana－1细胞的凋亡发生。     

放射性核素153Sm诱导不同肿瘤细胞凋亡及相关基因表达研究

采用细胞抑制率实验、光镜、电镜、流式细胞仪和免疫组化方法研究了^153Sm作用于前列腺癌PC—3细胞、乳腺癌ER—75—30细胞和肺癌A549细胞后对细胞的抑制作用，诱导肿田细胞凋亡的时间剂量效应关系和周期依赖性以及凋亡相关基因bcl—2和bax蛋白在其中的表达情况。结果显示，^153Sm对3种肿田细胞有明显的杀伤作用，能诱导肿田细胞产生凋亡的形态学变化，并且随着浓度的增大和时间的延长，凋亡率增加，且呈时间剂量和周期依赖性。比1—2表达减弱，bax表达增强，细胞阻滞于G2／M期，bcl—2和bax基因均参与^153Sm诱导细胞凋亡过程。3种细胞对^153Sm的敏感性由高到低依次为PC—3细胞、ER—75—30细胞和A549细胞。     

DNA gel electrophoretic and microautoradiographicstudies on apoptosisin bone tumor cells afterexposure with 153Sm-EDTMP

The apoptosis in bone tumorcells is studied after ¹⁵³Sm-EDTMP irradiation. Fragmented DNA is analyzed byagarose gel electrophoresis.Experimental observations show that ¹⁵³Sm-EDTMPexposureinduces the internucleosomal DNA damage in bone tumor cells the DNAladder patternformation in bone tumor cells is shown. At the same time,the microautoradiographic studyindicates that ¹⁵³153Sm-EDTMP could permeate through cell membrane and displaysmembrane-seeking condensation in bone tumor cells. Soon afterwards ¹⁵³Sm-EDTMPcould be phagocytized by the tumor cells and distributed in cytoplasm as well as nucleusin the form of phagosome. With the prolongation of observing time, the membrane-boundedapoptotic bodies are observed.     

线粒体DNA减少在氡及其子体致人支气管上皮细胞凋亡中的作用

使用溴化乙锭(Ethidium bromide,EtBr)诱导方法构建线粒体数目减少支气管上皮细胞(Human bronchia epithelia with mitochondrial DNA knock-down,ρ?HBE)模型并进行长期氡照射,用克隆形成法测定氡照射后HBE细胞的增殖能力,用流式细胞仪进行细胞凋亡和线粒体膜电位的检测。结果发现,氡照射后,与线粒体DNA数量正常的HBE细胞(ρ+HBE)相比较,ρ?HBE细胞存活分数明显增高,虽然早期凋亡率明显低于正常细胞,但是总凋亡率增加,同时线粒体膜电位也显著降低。结果提示,氡照射后引起的线粒体减少HBE细胞增殖能力提高与总凋亡率的减少有关,并且与线粒体膜电位的变化相关。