茶为伴 乐晚年

饮茶可以提神益智,增加营养,还可以延缓衰老,消除疲劳,促进新陈代谢,并有维持心脏,血管、胃肠等正常机能的功能。对保持口腔卫生、预防老年性白内障。减肥、美容．抗衰老以及抑制癌细胞的生长等都有一定作用。     

人结肠腺癌细胞HCT－8绿色荧光标记肿瘤模型的建立

目的 筛选表达绿色荧光蛋白基因的人的单克隆结肠腺癌细胞系,为体内监测肿瘤的早期生长建立一种新的肿瘤动物模型.方法 以脂质体2000介导chicken β-actin-GF-P-NEO转染人结肠腺癌细胞HCT-8,经梯度浓度G418筛选获得稳定表达绿色荧光蛋白的细胞克隆并扩大培养.BALB/CA-nu裸鼠皮下接种1×106个发光细胞使其成瘤,活体荧光成像系统观察肿瘤的生长情况.结果获得了稳定表达GFP的人结肠腺癌细胞株,将其接种到裸鼠体内可成瘤,利用活体成像系统观察了肿瘤的生长过程.肿瘤的发光随着观察时间的延长而增加.结论 绿色荧光蛋白能够在人结肠腺癌细胞HCT-8中长期稳定表达,用绿色荧光蛋白标记的人结肠腺癌细胞HCT-8建立的裸鼠肿瘤模型为进一步研究结肠肿瘤和相应的药物筛选提供了一种简便、可行的新方法 .     

Destruction of gastric cancer cells to mesothelial cells by apoptosis in the early peritoneal metastasis

This study examined the mechanism by which the gastric cancer cells lead to early peritoneal metastasis. HMrSV5 cells, a human peritoneal mesothelial cell line, were co-incubated with the supernatants of gastric cancer cells. Morphological changes of HMrSV5 cells were observed. The cell damage was quantitatively determined by MTT assay. The apoptosis of HMrSV5 cells was observed under transmission electron microscope. Acridine orange/ethidium bromide-stained condensed nuclei was detected by fluorescent microscopy and flow cytometry. The expressions of Bcl-2 and Bax was immunochemically evaluated. The results showed that conspicuous morphological changes of apoptosis were observed in HMrSV5 cells 24 h after treatment with the supernatants of gastric cancer cells. The supematants could induce apoptosis of HMrSV5 cells in a time-dependent manner. The supernatants could up-regulate the expression of Bax and suppress that of Bcl-2 in HMrSV5 cells. These findings demonstrated that gastric cancer cells can induce the apoptosis of HPMCs through supernatants in the early peritoneal metastasis, The abnormal expressions of Bcl-2 and Bax may contribute to the apoptosis. Anti-apoptosis drugs promise to be adjuvant chemotherapeutic agents in the treatment of peritoneal metastasis of gastric cancer.     

肼屈嗪与丙戊酸对胆管癌细胞QBC_（939）中P16、RASSF1A基因表达的协同作用

目的 探讨利用甲基化酶抑制剂(肼屈嗪)和组蛋白脱乙酰化酶抑制剂(丙戊酸)干预胆管癌细胞后,对P16和RASSFIA基因表达的影响.方法 将胆管癌细胞QBC939分为4组,丙戊酸组、肼屈嗪组、两药合用组以及空白组,分别以相应药物(终浓度10 mmol/L)作用48 h.空白组加入等量的含10%血清的RPMI 1640培养液.利用PCR、Westernblot和甲基化特异性PCR检测处理后的P16、RASSF1A基因及蛋白的表达和它们启动子区甲基化状态.结果 空白组P16基因及蛋白微量表达,RASSF1A基因及蛋白无表达;单用丙戊酸不能使两基因mRNA及蛋白表达增加,而单用肼屈嗪可以增加两基因mRNA及蛋白表达,两种药物合用使两基因mRNA及蛋白表达量明显高于单用一种药物组(均P<0.01);单用肼屈嗪、两药合用分别可使P16基因和RASSF1A基因启动子区部分和完全去甲基化,而单用丙戊酸无此效果.结论 两种药物在恢复沉默抑癌基因表达上有协同作用,有望成为胆管癌治疗的新选择.     

Chitosan/pshRNA plasmid nanoparticles targeting MDR1 gene reverse paclitaxel resistance in ovarian cancer cells

In order to investigate the effect of chitosan/pshRNA plasmid nanoparticles targeting MDR1 genes on the resistance of A2780/TS cells to paclitaxel, chitosan/pshRNA plasmid nanoparti- cles were synthesized by means of a complex coacervation technique and transfected into A2780/TS cells. The cells transfected with MDRl-targeted chitosan/pshRNA plasmid nanoparticles were experimental cells and the cells transfected with chitosan/pGPU6/GFP/Neo no-load plasmid nanoparticles served as negative control cells. Morphological features of the nanoparticles were observed under transmission electron microscope （TEM）. MDR1 mRNA expression was assessed by RT-PCR. Half-inhibitory concentration （IC50） ofpaclitaxel for A2780/TS cells was determined by MTT method. TEM showed that the nanoparticles were round-shaped, smooth in surface and the diameters varied from 80 to 120 nm. The MDR1 mRNA in the transfected cells was significantly decreased by 17.6%, 27.8% and 52.6% on the post-transfection day 2, 4 and 7 when compared with that in A2780/TS cells control （P〈0.05）. MTT assay revealed that the relative reversal efficiency was increased over time and was 29.6%, 51.2% and 61.3% respectively in the transfected cells 2, 4, 7 days after transfection and IC_50 （0.197±0.003, 0.144±0.001, 0.120±0.004） were decreased with difference being significant when compared with that in A2780/TS （0.269±0.003） cells control （P〈0.05）. It was concluded that chitosan/pshRNA plasmid nanoparticles targeting MDR1 can effectively reverse the paclitaxel resistance in A2780/TS cells in a time-dependent manner.     

S100蛋白和GFAP在腺样囊性癌中的表达及与嗜神经侵袭的关系

目的 观察S100蛋白和GFAP在腺样囊性癌中的表达情况,探讨其与腺样囊性癌嗜神经侵袭间的关系.方法采用免疫组化方法对45例腺样囊性癌以及正常腮腺组织中的S100蛋白和GFAP进行检测.结果 45例腺样囊性癌中,有34例出现癌细胞包绕或侵袭神经现象,11例无此类现象,S100蛋白和GFAP在嗜神经现象组的阳性率分别为100%(34/34)、94.14%(32/34),在非嗜神经现象组阳性率为90.91%(10/11)、45.45%(5/11).两组间S100蛋白阳性率无明显差异(P>0.05),GFAP阳性率比较差异明显,P<0.01.结论 S100蛋白和GFAP在腺样囊性癌中均过表达,但GFAP在两组间差异明显,可能与腺样囊性癌嗜神经侵袭的关系密切.     

miR-375-3p过表达的甲状腺乳头状癌细胞增殖和侵袭能力变化

目的 探讨miR-375-3p过表达后甲状腺乳头状癌细胞增殖和侵袭能力以及PI3K/AKT/EMT信号通路相关蛋白的变化。方法 取人甲状腺上皮细胞系Nthy-ori3-1和人甲状腺乳头状癌细胞系TPC-1、BHP5-16、BHP2-7、K-1,采用RT-qPCR法检测细胞miR-375-3p表达。以四种甲状腺乳头状癌细胞中miR-375-3p表达最低的细胞为研究对象,将其分为转染组和阴性对照组,转染组通过转染miR-375-3p模拟物miR-375-3p-mimics上调细胞中miR-375-3p表达,阴性对照组转染阴性对照序列scramble。采用MTT法检测两组细胞增殖能力,Transwell实验观察细胞侵袭能力,Western blotting法检测细胞PI3K/AKT信号通路相关蛋白p-PI3K、p-AKT和上皮间质转化（EMT）相关蛋白E钙黏蛋白（E-cadherin）、N钙黏蛋白（N-cadherin）、波形蛋白（Vimentin）表达。取甲状腺乳头状癌细胞,随机分为阴性对照组、miR-375-3p过表达组和miR-375-3p过表达+IGF-1组,miR-375-3p过表...     

上调miR-181a-5p对宫颈癌细胞增殖、凋亡能力的影响及相关机制

目的 研究上调微小RNA(miR)-181a-5p对宫颈癌细胞增殖、凋亡能力的影响及相关机制。方法 宫颈癌细胞株经过培养、转染后,分为miR-181a-5p上调组、miR-181a-5p下调组、宫颈癌组,miR-181a-5p及细胞增殖相关基因的表达采用荧光定量-聚合酶链反应(PCR)进行检测,观察3组细胞增殖、凋亡能力,凋亡相关蛋白表达及信号通路相关蛋白表达采用Western印迹进行检测。结果 miR-181a-5p上调组miR-181a-5p、半胱氨酸天冬氨酸蛋白水解酶(Caspase)-3、B细胞淋巴瘤(Bcl)-2相关蛋白(Bax)表达明显高于宫颈癌组和miR-181a-5p下调组,增殖细胞核抗原(PCNA)、肿瘤增殖抗原(Ki)67、Bcl-2、磷脂酰肌醇-3激酶(PI3K)、蛋白激酶B(Akt)表达明显低于宫颈癌组和miR-181a-5p下调组(P<0.05);miR-181a-5p下调组miR-181a-5p、Caspase-3、Bax表达明显低于宫颈癌组,PCNA、Ki67、Bcl-2、PI3K、Akt表达明显高于宫颈癌组(P<0.05)。在24、48、72...     

红树林内生真菌来源dicerandrol A及其对肝癌HepG2细胞的增殖抑制作用和机制的初步研究

摘要：目的 研究红树林植物大红树内生真菌Phomopsis asparagi DHS-48发酵提取物中的化学成分及其对肝癌HepG2细胞 的抑制作用,并初步探讨其作用机制。方法 通过反复硅胶柱色谱、Sephadex LH-20柱色谱等方法进行分离纯化,根据理化性 质、波谱数据并结合参考文献鉴定化合物DD-38的结构;用不同浓度DD-38处理HepG2细胞,采用MTT比色法检测其对HepG2 细胞增殖的抑制作用;平板克隆形成实验检测HepG2细胞克隆形成能力;细胞划痕实验观察HepG2细胞细胞的体外迁移能力; Annexin V/PI双染流式细胞术检测细胞凋亡;Western blot检测β-catenin的表达水平。结果 通过1H NMR、13C NMR及MS等波谱 学方法,结合相关文献数据,鉴定化合物结构为：dicerandrol A(DD-38);MTT实验显示,DD-38对HepG2细胞的增殖具有明显 抑制作用,存在时间和剂量依赖性(P<0.05,P<0.01);根据细胞增殖率得出24 h时HepG2细胞的IC50为(4.8273±0.2216) μmol/L; 平板克隆形成实验显示,DD-38明显降低了HepG2细胞的克隆形成能力,具有剂量依赖性(P<0.01);细胞划痕实验表明DD-38可 以显著降低HepG2细胞的迁移能力(P<0.01),加药24 h后,细胞迁移率从77.09%±2.16%降低到12.14%±5.32%;流式细胞术检 测实验显示,DD-38可促进HepG2细胞凋亡,凋亡率存在剂量依赖性;Western blot实验显示,DD-38可抑制β-catenin蛋白在细胞 质和细胞核中的表达(P<0.05和P<0.01)。结论 DD-38可抑制HepG2细胞的增殖、迁移和克隆形成,促进细胞凋亡,其机制可能 与抑制Wnt/β-catenin信号通路活化有关。