去甲斑蝥素对人乳腺癌细胞MCF-7的杀伤效应及其可能机制

用１０μｇ／ｍＬ去甲斑蝥素（ＮＣＴＤ）作用于人乳腺癌细胞,以ＭＴＴ法、流式细胞仪、台盼蓝排斥法和透射电镜等方法分别观察ＮＣＴＤ对癌细胞的增殖抑制作用及对细胞周期和细胞凋亡的影响。结果表明：ＮＣＴＤ对乳腺癌细胞的杀伤作用有时间和剂量依赖性,药物作用２４ｈ后,Ｇ１期细胞减少,Ｇ２＋Ｍ期细胞明显增多,凋亡细胞百分比升高并可见到凋亡细胞的形态学变化。     

pEgr1-Trail重组质粒联合电离辐射对MCF-7细胞杀伤效应的实验研究

目的研究p Egr1-Trail重组质粒联合电离辐射对MCF-7细胞的杀伤效应,为增强肿瘤放疗效果提供实验证据.方法应用Annexin V-EGFP/PI双染法检测细胞凋亡;应用酶标仪检测细胞增殖;应用流式细胞仪检测细胞周期.结果不同处理组作用MCF-7细胞后24 h、不同剂量X射线照射后24 h后,各处理组MCF-7细胞的生长抑制率呈上升态势,生长抑制由弱到强的顺序为:2.0 Gy,p Egr1-Trail+0.5 Gy,5.0 Gy,p Egr1-Trail+1.0 Gy,p Egr1-Trail+2.0 Gy,Egr1-Trail+5.0 Gy.各处理组联合2.0 Gy X射线照射后6 h,细胞凋亡率开始上升,48 h达高峰,其中p Egr1-Trail+2.0 Gy组与其他各处理组比较差异具有统计学意义,且细胞凋亡最为显著(P0.05).在细胞周期方面,2.0 Gy X射线照后6 h各处理组S期细胞百分数呈现上升趋势,24 h达高峰;照后24 h,G_2+M期细胞百分数开始上升,且各处理组比较差异均具有统计学意义(P0.05);照后48 h,G_2+M期细胞百分数达到最高,依旧是p Egr1-Trail+2.0 Gy组上升最显著.结论 p Egr1-Trail重组质粒联合电离辐射作用于肿瘤细胞表现出协同杀伤效应,促凋亡作用强于单独X射照射组或p Egr1-Trail基因干预组.     

苦丁茶对MCF-7人乳腺癌细胞的体外抗癌效果

对市售的苦丁茶进行MCF-7人乳腺癌细胞体外抗癌效果和体内抗转移效果评价.通过MTT实验、DAPI荧光染色分析和RT-PCR分析说明其体外抗癌效果.200μg/mL苦丁茶(81%抑制率)水提物表现出对MCF-7人乳腺癌细胞较强的生长抑制效果.200μg/mL比100和50μg/mL苦丁茶水提物具有更强的细胞诱导凋亡效果,Bax,caspase-3和caspase-9的mRNA表达得到增强,Bcl-2表达减弱.苦丁茶水提物处理后炎症相关因子NF-κB,iNOS和COX-2表达减弱,展示了苦丁茶的抗炎特性.由此得出,一定质量浓度的苦丁茶具有良好的抗癌预防效果.     

小鼠B7—1cDNA克隆,测序,表达及其抗瘤效应的初步探讨

用反转录ＰＣＲ的方法,从ＢＡＬＢ／ｃ小鼠脾细胞中扩增出Ｂ７－１ｃＤＮＡ后,插入ｐｃＤＮＡ３质粒中构建成小鼠Ｂ７－１ｃＤＮＡ的真核表达载体ｐＣＤ－ｍＢ７．１,经酶切鉴定和序列分析证实此表达载体中插入的Ｂ７－１ｃＤＮＡ的序列与献报道一致。     

过表达maspin对人乳腺癌MCF-7细胞凋亡的影响

通过构建maspin表达质粒,在人乳腺癌MCF-7细胞中过表达maspin,研究maspin对MCF-7细胞增殖率及凋亡率的影响.MTT检测实验表明,过表达maspin能够剂量依赖性抑制MCF-7细胞的增殖率.采用TUNEL法和流式细胞术检测maspin对MCF-7细胞凋亡的影响,结果表明过表达maspin可促进MCF-7细胞凋亡进而抑制其增殖.     

人血小板生成素在COS—7细胞中的暂时表达

利用反转录ＰＣＲ获得的全长人ＴＰＯ ｃＤＮＡ克隆入真核表达载体ｐＭＡＭｎｅｏ的ＮｈｅＩ位点，用ＤＥＡＥ－Ｄｅｘｔｒａｎ法将其导入ＣＯＳ－７细胞中。。实验表明，所构建的表达质粒在ＣＯＳ－７细胞中转录水平表达，ｈＴＰＯ在真核系统中的稳定表达正在研究中。     

人乳腺癌细胞（MCF—7）相关抗原超微结构的定位观察

本文以二种免疫电镜法对人乳腺癌细胞系—MCF-7细胞肿瘤相关抗原进行定位观察: 1.直接免疫铁蛋白法。采用戊二醛二步结合法制备铁蛋白偶联人乳腺癌单克隆抗体6C_6B_1B_7A_(12)结合物,并以直接法对MCF-7细胞进行包埋前免疫染色。 2.间接免疫酶标电镜法。以6C_6B_1B_7A_(12)单克隆抗体为第一抗体,过氧化物酶标记兔抗小鼠IgG抗体的结合物为第二抗体对MCF-7细胞进行包埋前免疫染色。 电镜观察结果表明,该肿瘤相关抗原仅分布于MCF-7细胞表面。抗原的存在可能与细胞周期或细胞群体的变异性有关。     

双酚A类同系物的雌激素效应及对MCF-7细胞的毒性

双酚A(bisphenol A, BPA)及其类似物作为聚碳酸酯的主要合成原料, 一直是环境污染的重要问题, 其环境分布及人体暴露是当今科学研究的热点. 为评估环境中BPA 类物质的毒性效应, 采用MTT 比色法检测了7 种BPA 类同系物对人雌激素受体(estrogen receptor,ER)缺失乳腺癌细胞MCF-7(ER–) 增殖活性的影响. 通过检测细胞乳酸脱氢酶(lactate dehydrogenase, LDH)露出率评估了目标物对MCF-7 细胞膜的损伤, 结果表明, 在0.01～1.00 μmol/L 浓度范围内, 受试化合物对MCF-7 细胞的毒性较小, LDH 少量露出; 而在10 和100 μmol/L 浓度下, 细胞增殖受到显著抑制, 细胞膜通透性显著改变, LDH大量露出. 同时采用ER 基因双杂交酵母实验检验了这几种BPA 类同系物的雌激素效应大小, 通过Logistic 模型对曲线进行了拟合, 并以模型估算的半数透导活性(EC50) 评估了7 种BPA 类同系物的雌激素效应活性, 其大小依次为TDP>BPAF>4Cl-BPA>BPC>BPA>BPE>BPAP. 这说明其雌激素效应机制可能是通过和ER 结合而产生的.     

CdTe量子点对人乳腺癌细胞MCF 7/ADM的化学增敏作用及其机制研究

利用纳米材料CdTe量子点作为增敏剂, 四甲基偶氮唑蓝(MTT)法检测细胞活力的实验表明CdTe量子点增强了阿霉素对于MCF 7/ADM的毒性, 而对非耐药的MCF 7无增敏作用. 然后利用免疫印迹法和免疫荧光染色法检测发现CdTe量子点提高了MCF 7/ADM细胞的自噬水平, 且这种自噬水平的上调与化学增敏效应是相关的, 以上结果提示CdTe量子点通过诱导MCF 7/ADM细胞发生自噬, 增强耐药性细胞对DOX毒性的敏感性.     

人端粒酶催化亚单位(hTERT)特异性核酶对乳腺癌细胞MCF-7活性的作用及影响

目的 探讨端粒酶特异性核酶对乳腺癌细胞MCF-7端粒酶活性、增殖和凋亡的影响.方法 设计合成RZ基因,构建人端粒酶锤头状核酶真核表达质粒pcDNA3.1( )-hTERT-RZ,测序鉴定.提取MCF-7细胞总RNA,RT-PCR扩增靶基因的cDNA片段,插入载体pMD18-T并测序鉴定.将核酶重组体及hTERT载体体外转录,琼脂糖凝胶电泳检测Rz的切割活性.核酶载体转染乳腺癌细胞MCF-7,RT-PCR法检测核酶重组子转染效率及核酶转染细胞中hTERT mRNA的表达量,TRAP法测定细胞端粒酶活性,MTT法、流式细胞仪测定细胞增殖及凋亡.结果 测序表明peDNA3.1( )-hTERT-Rz和pMD18-T-hTERT构建成功.5%琼脂糖凝胶电泳表明体外转录出Rz和靶基因hTERT,Rz对靶基因hTERT具有切割活性.构建好的核酶真核表达载体转染乳腺癌MCF-7细胞.发现其潜伏期延长,对数生长期减缓,S期细胞比例降低,G1期细胞比例增高(P＜0.01).端粒酶活性检测发现端粒酶活性明显降低.结论 端粒酶催化亚单位特异性核酶对靶基因hTERT在体外和体内均有催化切割活性,该核酶在乳腺癌MCF-7细胞中抑制hTERT的表达和细胞增殖,为核酶应用于恶性肿瘤的基因治疗提供了实验依据和新型工具酶.     

The receptors and cells for mammalian taste

The emerging picture of taste coding at the periphery is one of elegant simplicity. Contrary to what was generally believed, it is now clear that distinct cell types expressing unique receptors are tuned to detect each of the five basic tastes: sweet, sour, bitter, salty and umami. Importantly, receptor cells for each taste quality function as dedicated sensors wired to elicit stereotypic responses.     

植物颗粒杀虫剂对玉米螟诱杀效果研究初报

用对玉米螟幼虫有诱食作用的食物引诱素和药用植物的粉碎物配合成型剂等原料制成的植物颗粒杀虫剂用于诱杀玉米螟幼虫实验，结果表明：玉米螟幼虫对植物颗粒杀虫剂有效强的趋向反应，植物颗粒杀虫剂对玉米螟幼虫有很强的毒杀作用，田间平均防效可达70.2%。植物颗粒杀虫剂对天敌无毒害，对环境无不良影响，是一种新型的高效、低毒植物源农药，此项研究为利用植物杀虫提供了一种新的方法和思路。     

Expression of PHGPx in mammalian cells and its antiviral effect against coxsackievirus group

To express human phospholipid hydroperoxide glutathione peroxidase (PHGPx) in eukaryotic cells and to study its antiviral effect against Coxsackievirus B3m (CVB3m) in vitro， PHGPx cDNA was amplified from a human testis library using specific primers and cloned into expression vector pcDNA3.1His. Expression of PHGPx was performed in COS-1 cells. The antiviral effect was studied by the treatment of HeLa cells with the recombinant PHGPx. Results showed that the activity of PHGPx expressed in COS-1 cells was 5-fold higher than that in control group, and it inhibited the cytopathic effect on HeLa cells caused by CVB3m. It can be concluded that recombinant PHGPx expressed in COS-1 cells has antiviral effect against CVB3m in vitro.     

低强度超声激活血卟啉对S180细胞的杀伤作用

为探讨低强度超声激活血卟啉对在体S180肉瘤细胞的杀伤作用，对荷瘤小鼠采用声动力疗法处理，分别从癌组织生长状况、显微结构及超微结构等方面进行研究。结果表明：超声激活血卟啉对肿瘤生长的抑制作用明显大于其他实验组，癌细胞在处理后的不同时间段，其显微结构及超微结构均表现出不同程度的损伤。     

The cells and logic for mammalian sour taste detection

Mammals taste many compounds yet use a sensory palette consisting of only five basic taste modalities: sweet, bitter, sour, salty and umami (the taste of monosodium glutamate). Although this repertoire may seem modest, it provides animals with critical information about the nature and quality of food. Sour taste detection functions as an important sensory input to warn against the ingestion of acidic (for example, spoiled or unripe) food sources. We have used a combination of bioinformatics, genetic and functional studies to identify PKD2L1, a polycystic-kidney-disease-like ion channel, as a candidate mammalian sour taste sensor. In the tongue, PKD2L1 is expressed in a subset of taste receptor cells distinct from those responsible for sweet, bitter and umami taste. To examine the role of PKD2L1-expressing taste cells in vivo, we engineered mice with targeted genetic ablations of selected populations of taste receptor cells. Animals lacking PKD2L1-expressing cells are completely devoid of taste responses to sour stimuli. Notably, responses to all other tastants remained unaffected, proving that the segregation of taste qualities even extends to ionic stimuli. Our results now establish independent cellular substrates for four of the five basic taste modalities, and support a comprehensive labelled-line mode of taste coding at the periphery. Notably, PKD2L1 is also expressed in specific neurons surrounding the central canal of the spinal cord. Here we demonstrate that these PKD2L1-expressing neurons send projections to the central canal, and selectively trigger action potentials in response to decreases in extracellular pH. We propose that these cells correspond to the long-sought components of the cerebrospinal fluid chemosensory system. Taken together, our results suggest a common basis for acid sensing in disparate physiological settings.