去氢骆驼蓬碱通过PTEN/Akt/MDM2信号通路抑制胃癌细胞COX-2表达

目的探讨PTEN基因/Akt/小鼠双微体基因(MDM2)信号通路在去氢骆驼蓬碱(harmine,HM)抑制胃癌细胞COX-2表达中的作用。方法构建PTEN(PTEN-siRNA)、Akt(Akt-siRNA)和MDM2(MDM2-siRNA)小干扰RNA,分别转染胃癌细胞株SGC-7901和MKN-45,Western blot检测HM干预前后PTEN、p-Akt、p-MDM2和COX-2表达。结果 HM诱导PTEN表达,抑制Akt、MDM2磷酸化和COX-2表达。敲减PTEN基因有效地阻断了HM抑制Akt、MDM2磷酸化和COX-2表达的作用,敲减Akt基因可协同HM抑制MDM2磷酸化和COX-2表达,敲减MDM2基因可协同HM抑制COX-2表达。结论 HM可能通过PTEN/Akt/MDM2信号通路,下调胃癌细胞COX-2表达。     

Survivin在B细胞淋巴瘤中的表达及其与细胞凋亡和预后的关系

目的探讨survivin在B细胞淋巴瘤表达及其与细胞凋亡和预后的关系。方法应用TdT介导的dUTP缺口末端标记(TUNEL)技术和免疫组织化学链霉菌抗生物素蛋白-过氧化酶连接法(SP法),检测43例B细胞淋巴瘤中细胞凋亡和survivin蛋白的表达水平。结果survivin在B细胞非霍奇金淋巴瘤表达的阳性率为44.2％(19/43);中度和高度侵袭性淋巴瘤中survivin表达与凋亡指数降低明显相关(P<0.025);弥漫性大B细胞淋巴瘤(DLBCL)中survivin基因的表达高于惰性淋巴瘤(P<0.002);survivin过表达者的平均生存时间明显短于阴性者(P=0.013)。结论 survivin基因的异常表达而引起的凋亡抑制可能在B细胞非霍奇金淋巴瘤,尤其是DLBCL的发生进展中有一定的作用;survivin表达可能是B细胞非霍奇金淋巴瘤的一个新的预后不良因子。     

干扰PTEN基因表达影响人正常胃黏膜上皮细胞系GES-1增殖和凋亡

目的：探讨PTEN对体外培养的人胃黏膜上皮细胞系GES-1增殖凋亡的影响及其磷酸化通路研究。方法：体外培养GES-1细胞,构建针对PTEN基因的shRNA慢病毒载体,感染GES-1细胞系,干扰PTEN的表达,实验分为空白对照组、慢病毒阴性对照组和干扰PTEN实验组;荧光显微镜、实时荧光定量PCR和免疫印迹法检测其感染效率;CCK8测定GES-1细胞的增殖,流式细胞术测定细胞的周期和凋亡;实时荧光定量PCR检测GES-1的PTEN、Akt、ERK的mRNA表达水平;Western blot检测GES-1的Akt和磷酸化Akt（p-Akt）,ERK1/2及磷酸化ERK1/2（p-ERK1/2）表达。结果：干扰PTEN的慢病毒成功感染GES-1,降低了PTEN基因的转录和翻译水平。与空白对照组相比,PTEN表达降低后使G₀/G₁期的细胞比率减低,而G₂/M和S期细胞比率增高,同时凋亡细胞减少,促进GES-1的增殖而抑制其凋亡。p-Akt和p-ERK1/2表达显著上调（P<0.05）,而对GES-1的Akt和ERK的mRNA及总蛋白表达没有影响（P>0.05）。结论：抑癌基因PTEN可以通过促进Akt和ERK的磷酸化,调节GES-1细胞下游的相关凋亡和信号通路,进而调节GES-1的增殖和凋亡。     

环磷酰胺和异环磷酰胺Balb/c小鼠肝脏毒性的基因表达谱

目的利用毒理基因芯片技术研究环磷酰胺和异环磷酰胺肝脏毒性效应的分子机制。方法利用构建的小鼠毒理基因芯片和环磷酰胺及异环磷酰胺致Balb/c小鼠肝毒性动物模型,观察不同时相点小鼠肝脏基因表达谱变化,结合层次聚类和生物信息数据库检索对差异表达基因进行初步功能分析。结果两种药物作用后引发小鼠肝脏多种基因表达改变,分析发现类似的表达谱变化趋势如蛋白质生物合成相关基因上调,抗氧化相关基因失衡,免疫调节、细胞增殖及凋亡相关基因异常改变等均存在于两种药物组,提示两种药物存在多种共同的肝毒性效应机制。结论环磷酰胺和异环磷酰胺有共同的肝脏毒性分子机制。     

基于微流控芯片技术橙皮苷抗肺肿瘤作用机制研究

目的探究橙皮苷诱导人肺癌细胞A549凋亡的作用机制。方法基于微流控芯片技术采用Hoechst 33342/PI染色法检测橙皮苷对肺癌细胞A549凋亡坏死的影响;流式细胞术检测橙皮苷对肺癌细胞周期及凋亡的影响;实时荧光定量PCR技术检测相关基因VEGF、PI3K及PTEN的表达;Western blot技术检测橙皮苷诱导肺癌细胞中PI3K-Akt信号通路相关蛋白PI3K、Akt、PTEN及凋亡蛋白Bcl-2、周期蛋白Cyclin B1的表达。结果橙皮苷作用于细胞G_0/G_1期及S期,阻滞细胞分裂,并呈现浓度依赖性诱导肺癌细胞凋亡,其细胞凋亡坏死率由正常对照组的(6.7±0.6)%增至(27.9±1.1)%;经橙皮苷诱导后的肺癌细胞中VEGF和PI3K基因表达相对降低,抑癌基因PTEN表达相对增加。Western blot结果显示,经橙皮苷诱导的肺癌细胞中凋亡蛋白Bcl-2及周期蛋白Cyclin B1相对表达降低,PI3K-Akt信号通路蛋白Akt表达量与对照组比较明显减少,PI3K蛋白表达量相对增加,PTEN表达量无明显变化。结论橙皮苷可能是通过干扰PI3K-Akt信号通路,阻碍肿瘤细胞的分裂并促进凋亡蛋白的产生,从而诱导肺癌细胞A549凋亡。     

阿托伐他汀对谷氨酸引起大鼠神经元损伤保护作用机制的研究

目的探讨阿托伐他汀对谷氨酸所致培养大鼠皮层神经元损伤保护作用的机制。方法 MTT法测定细胞存活率;Hoechst33258核染色观察细胞凋亡的形态学改变;Western blot检测活性的半胱氨酸天冬氨酸蛋白酶-3(caspase-3)和钙蛋白酶Ⅰ蛋白表达水平。结果谷氨酸(100μmol.L-1)可使神经元细胞存活率下降,细胞凋亡百分比明显增加,活性的caspase-3和钙蛋白酶Ⅰ蛋白表达增加。阿托伐他汀明显对抗谷氨酸诱导的神经元存活率下降及细胞凋亡百分比增加,同时明显抑制活性的caspase-3和钙蛋白酶Ⅰ蛋白表达增加。磷酯酰肌醇-3激酶(phos-phoinositide3-kinase,PI3K)/磷酸化蛋白激酶B(protein ki-nase B,Akt)通路特异性阻断剂LY294002(10μmol.L-1)能抑制阿托伐他汀对抗谷氨酸引起神经元细胞存活率下降,细胞凋亡百分比增加及活性caspase-3和钙蛋白酶Ⅰ蛋白表达增加的作用。结论阿托伐他汀能够明显对抗谷氨酸引起的皮层神经元损伤作用,这种作用可能与激活PI3K/Akt信号转导通路有关。     

天花粉蛋白诱导人宫颈癌HeLa细胞凋亡的分子机制研究

目的利用基因芯片技术研究天花粉蛋白对人宫颈癌HeLa细胞基因表达谱的影响,以深入探讨其作用的分子机制。方法提取药物处理前后HeLa细胞总RNA并逆转录成cDNA,在获得的cDNA上分别标记CY3和CY5两种荧光物质,然后与BiostarH-Ⅰ表达谱芯片杂交,扫描后对获得的数据用GenePixPro3·0软件分析。结果两组间存在差异性表达基因78条,其中与细胞凋亡密切相关的NOP56、TN-FSF10、CASP9、DFFB等62条基因表达上调,与细胞黏附及细胞间相互作用相关的COL9A3、MGST3、LGALS3BP等16条基因表达下调。结论天花粉蛋白可以引起HeLa细胞中多个基因的表达改变,基因芯片技术进一步揭示了其诱导HeLa细胞凋亡的作用机制。     

基因芯片技术分析肝癌细胞系Bel-7402、Hep-3B与胎儿肝细胞基因表达差异

目的 研究肝癌细胞系的基因表达概况,寻找在肝癌细胞系及胎儿肝细胞中差异表达基因.方法 应用基因芯片技术检测肝癌细胞系Bel-7402、Hep-3B与胎儿肝细胞的全基因组序列,分析其基因表达差异.结果 在检测的54614个探针组中,Bel-7402、Hep-3B 2株肝癌细胞与胎儿肝脏细胞相比表达共同上调2倍及2倍以上的有1452个基因;表达下调2倍及2倍以上的有2054个基因.涉及凋亡、细胞黏附、细胞周期等多种生物学过程,钙离子信号通路、G蛋白信号通路等多种信号通路.结论 肝癌的发生、发展是由数千个癌症相关基因异常表达,进而引起多种生物功能异常的综合过程,对这些表达异常基因的综合分析,可以为阐明肝癌的发生机制提供重要的线索.     

B小细胞淋巴瘤患者化疗期间自尊及生活质量相关性研究

恶性淋巴瘤包括霍奇金淋巴瘤和非霍奇金淋巴瘤[1],非霍奇金淋巴瘤绝大多数为B细胞来源[2].由于肿瘤对机体的影响及化疗对机体的副作用,患者较易形成一系列的异常心理状态,常表现为不同程度的负性情绪,继而引起自尊及生活质量的改变.本研究通过对89例B小细胞淋巴瘤化疗患者自尊及生活质量进行调查,探讨其临床意义,旨在为临床合理治疗及干预提供理论依据.     

雷公藤甲素对Wistar大鼠免疫毒性相关基因表达的影响

目的应用基因芯片技术研究雷公藤甲素对大鼠胸腺全基因表达谱的影响,从基因水平探讨雷公藤甲素引起免疫抑制毒性的潜在分子作用机制。方法 Wistar大鼠,连续28 d ig给予雷公藤甲素0.5和1.0 mg·kg-1以及环孢素A 20 mg·kg-1(阳性对照),进行T细胞依赖抗体反应检测、免疫器官组织病理学检查和胸腺组织基因芯片实验。结果与溶媒对照组相比,雷公藤甲素0.5和1.0 mg·kg-1组和环孢素A组大鼠血清中T细胞依赖抗体应答水平均受到了显著抑制。组织病理学检查发现,雷公藤甲素1.0 mg·kg-1使胸腺皮髓质淋巴细胞数量轻度减少,环孢素A使胸腺髓质皮质化。基因芯片检测结果显示,雷公藤甲素1.0 mg·kg-1给药第7天引起422个显著差异表达基因,其基因功能主要涉及DNA依赖的细胞转录调节、核转运、微管蛋白复合体装配、核小体装配、线粒体DNA转录、氨基酸转运和线粒体DNA复制等。KEGG通路分析发现差异表达基因主要参与移植排斥和自身免疫性疾病等多个与免疫抑制相关的基因表达调控途径。结论雷公藤甲素1.0 mg·kg-1能够引起大鼠胸腺基因表达谱的显著性改变,其免疫毒性的主要机制可能是通过下调免疫毒性相关基因的表达,抑制淋巴细胞的增殖。     

Ursolic acid-induced apoptosis in K562 cells involving upregulation of PTEN gene expression and inactivation of the PI3K/Akt pathway

Ursolic acid (UA), a pentacyclic triterpenoid derived from a variety of medicinal plants, exhibits potent anticancer activity against many types of cancer cells. However, the anticancer mechanism of UA is not clearly understood. Suppression of phosphatase and a tensin homolog deleted on chromosome 10 (PTEN) gene expression leading to activation of the phosphatidylinositol-3-OH kinase (PI3K)/Akt pathway has been observed in many cancers including leukemia, making the PTEN gene and PI3K/Akt pathway a central target for cancer therapy. Here, we demonstrated that UA was able to inhibit growth, induce apoptosis in a human chronic myelogenous leukemia cell line (K562 cells) via upregulation of PTEN gene expression, inhibit Akt kinase activity, change mitochondrial transmembrane potential and reduce the release of cytochrome c and the activity of caspases. These results suggest that UA may elicit its strong antitumor effects via upregulation of the PTEN gene and inhibition of the PI3K/Akt pathway.     

甲基转移酶SETDB2对肝癌侵袭迁移的影响及其机制研究

摘要：目的 检测甲基转移酶SETDB2对肝癌侵袭转移的影响并探讨其机制。方法 应用Western blot、免疫组 化以及 Real-time PCR 等方法检测 37 例肝癌及对应癌旁组织标本中 SETDB2 蛋白及 mRNA 表达情况。将靶向 SETDB2 的短发卡 RNA（sh-SETDB2）和空载体（sh-NC）分别转染至人肝癌 MHCC97H 细胞构建稳转细胞系,应用 Tanswell侵袭实验、细胞划痕实验检测2组细胞的侵袭和迁移能力。通过基因芯片检测敲低SETDB2后表达有变化 的基因。敲低SETDB2后,运用Real-time PCR检测PTEN的mRNA的表达变化以及Western blot检测PTEN和组蛋白 H3第9位赖氨酸的三甲基化（H3K9me3）的表达变化,CHIP 检测H3K9me3在PTEN 的启动子区域的变化。在敲低 SETDB2的同时敲低PTEN的表达,Tanswell侵袭实验检测细胞侵袭能力的变化。结果 （1）Western blot和Real-time PCR的结果均表明肝癌组织中SETDB2蛋白及mRNA表达水平均高于癌旁组织;SETDB2表达的高低与肝癌组织学 分级和TNM分期有关。（2）转染sh-SETDB2的MHCC97H细胞的侵袭和迁移能力均明显低于sh-NC组。（3）基因芯 片、Western blot以及Real-time PCR等实验结果显示敲低SETDB2后PTEN表达上调。（4）在敲低SETDB2后H3K9me3 表达下调,PTEN启动子区域的H3K9me3减少。（5）与敲低SETDB1组相比,敲低SETDB2的同时敲低PTEN后细胞的 侵袭能力恢复。结论 SETDB2通过下调PTEN的表达促进肝癌细胞的侵袭迁移。     

Induction of steroid sulfatase expression in PC-3 human prostate cancer cells by insulin-like growth factor II

Human steroid sulfatase (STS) plays an important role in regulating the formation of biologically active estrogens and may be a promising target for treating estrogen-mediated carcinogenesis. The molecular mechanism of STS gene expression, however, is still not clear. Growth factors are known to increase STS activity but the changes in STS expression have not been completely understood. To determine whether insulin-like growth factor (IGF)-II can induce STS gene expression, the effects of IGF-II on STS expression were studied in PC-3 human prostate cancer cells. RT-PCR and Western blot analysis showed that IGF-II treatment significantly increased the expression of STS mRNA and protein in concentration- and time-dependent manners. To understand the signaling pathway by which IGF-II induces STS gene expression, the effects of specific PI3-kinase/Akt and NF-κB inhibitors were determined. When the cells were treated with IGF-II and PI3-kinase/Akt inhibitors, such as LY294002, wortmannin, or Akt inhibitor IV, STS expression induced by IGF-II was significantly blocked. Moreover, we found that NF-κB inhibitors, such as MG-132, bortezomib, Bay 11-7082 or Nemo binding domain (NBD) binding peptide, also strongly prevented IGF-II from inducing STS gene expression. We assessed whether IGF-II activates STS promoter activity using transient transfection with a luciferase reporter. IGF-II significantly stimulated STS reporter activity. Furthermore, IGF-II induced expression of 17β-hydroxysteroid dehydrogenase (HSD) 1 and 3, whereas it reduced estrone sulfotransferase (EST) gene expression, causing enhanced estrone and β-estradiol production. Taken together, these results strongly suggest that IGF-II induces STS expression via a PI3-kinase/Akt–NF-κB signaling pathway in PC-3 cells and may induce estrogen production and estrogen-mediated carcinogenesis.     

TP53基因沉默介导PI3K/PTEN/AKT信号通路对肾透明细胞癌侵袭转移的调控机制

目的探讨肿瘤蛋白p53基因(TP53)沉默介导PI3K/PTEN/AKT信号通路对肾透明细胞癌侵袭转移的调控机制。方法取60例肾透明细胞癌组织标本,免疫组化分析TP53蛋白在肾透明细胞癌组织中的表达;取人肾透明细胞癌细胞株RLC-310进行细胞培养;细胞转染表达载体分为空白组(A组)、阴性对照组(B组)、sh TP53组(C组)、PTEN抑制剂bpv组(D组)、phen+sh TP53组(E组)。采用实时荧光定量PCR(qRT-PCR)和Western Blot检测各组细胞TP53、同源性磷酸酶-张力蛋白(PTEN)、磷脂酰肌醇-3-激酶(PI3K)、AKT的m RNA和蛋白表达水平;CCK-8法检测各组细胞增殖能力;划痕愈合试验检测各组细胞的迁移能力;Transwell侵袭试验检测各组细胞的侵袭能力。结果TP53蛋白在肾透明细胞癌组织中高表达(P<0.05);与A组和B组相比,C组的TP53,PI3K,AKT m RNA和蛋白表达水平显著下降,PTEN m RNA和蛋白表达水平均显著上升,且细胞增殖能力、迁移率、侵袭率均显著下降(P<0.05);D组TP53,PI3K,AKT m RNA和蛋白表达水平显著上升,PTEN m RNA和蛋白表达水平显著下降,且细胞增殖能力、迁移率、侵袭率均显著上升(P<0.05);同时,E组TP53下降(P<0.05),而其他指标与A组和B组相当(P>0.05)。结论沉默TP53基因抑制PI3K/PTEN/AKT信号通路,从而抑制肾透明细胞癌细胞浸润转移功能,并可逆转phen诱导的肾透明细胞癌细胞浸润转移。     

野马追总黄酮的体内外抗乳腺癌活性及机制研究

目的 探究野马追总黄酮(TFE)的体内外抗乳腺癌活性及相关的作用机制。方法 MTT法检测TFE对乳腺癌细胞(MCF-7、T47D、MDA-MB-231、MDA-MB-468)和人正常乳腺上皮细胞MCF-10A增殖的影响;流式细胞术检测TFE对乳腺癌细胞周期和凋亡的影响;吖啶橙(AO)染色法检测TFE对细胞自噬的影响;Western blot检测细胞周期、凋亡、自噬相关蛋白的变化,以及PI3K/Akt信号通路相关蛋白的变化;建立MDA-MB-231细胞的裸鼠移植瘤模型,观察TFE的体内抗肿瘤活性。结果 TFE能明显抑制乳腺癌细胞增殖,并呈剂量依赖性,而对人正常乳腺上皮细胞无显著的抑制作用;TFE能增加G₂/M期细胞比例,上调p-cdc-2蛋白表达,下调cdc-2和Cyclin B1蛋白表达;TFE能显著增加乳腺癌细胞凋亡比例,上调促凋亡蛋白Bad和Bax表达,下调抗凋亡蛋白Bcl-2表达;TFV能够诱导乳腺癌细胞产生自噬,自噬相关蛋白LC3-II表达上升,p62表达降低;TFE能够抑制显著抑制PI3K和Akt的磷酸化水平;TFE能够在体内抑制裸鼠肿瘤的体积。结论 TFE通过抑制PI3K/Akt信号通路,阻滞细胞周期、诱导凋亡和自噬,进而在体内外抑制乳腺癌细胞的生长。     

Suppression of human lung cancer cell proliferation and metastasis in vitro by the transducer of ErbB-2.1 (TOB1)

Aim:

To investigate the effects of the transducer of ErbB-2.1 (TOB1) on the proliferation, migration and invasion of human lung cancer cells in vitro.

Methods:

Human lung cancer cell lines (95-D, A549, NCI-H1299, NCI-H1975, NCI-H661, NCI-H446, NCI-H1395, and Calu-3) and the normal human bronchial epithelial (HBE) cell line were tested. The expression levels of TOB1 in the cells were determined with Western blot and RT-PCR analyses. TOB1-overexpressing cell line 95-D/TOB1 was constructed using lipofectamine-induced TOB1 recombinant plasmid transfection and selective G418 cell culture. The A549 cells were transcend-transfected with TOB1-siRNA. MTT assay, flow cytometry and Western blot analysis were used to examine the effects of TOB1 on cancer cell proliferation and wound healing. Transwell invasive assay was performed to evaluate the effects of TOB1 on cancer cell migration and invasion. The activity of MMP2 and MMP9 was measured using gelatin zymography assay.

Results:

The expression levels of TOB1 in the 8 human lung cancer cell lines were significantly lower than that in HBE cells. TOB1 overexpression inhibited the proliferation of 95-D cells, whereas TOB1 knockdown with TOB1-siRNA promoted the growth of A549 cells. Decreased cell migration and invasion were detected in 95-D/TOB1 cells, and the suppression of TOB1 enhanced the metastasis in A549 cells. TOB1 overexpression not only increased the expression of the phosphatase and tensin homolog (PTEN), an important tumor suppressor, but also regulated the downstream effectors in the PI3K/PTEN signaling pathway, including Akt, ERK1/2, etc. In contrast, decreased expression of TOB1 oppositely regulated the expression of these factors. TOB1 also regulates the gelatinase activity of MMP2 and MMP9 in lung cancer cells.

Conclusion:

The results demonstrate that the PI3K/PTEN pathway, which is essential for carcinogenesis, angiogenesis, and metastasis, may be one of the possible signaling pathways for regulation of proliferation and metastasis of human lung cancer cells by TOB1 in vitro.     

PI3K/Akt抑制剂CCT128930抑制人脐静脉血管内皮细胞增殖与血管生成的实验研究

目的探讨一类新的PI3K/Akt抑制剂CCT128930对人脐静脉血管内皮细胞(HUVEC)增殖与血管生成的影响。方法采用MTT法检测CCT128930对HUVEC存活的影响;流式细胞术分析细胞周期变化;AnnexinⅤ-FITC试剂盒检测细胞凋亡;体外小管形成实验观察CCT128930对HUVEC体外小管形成的影响;免疫印迹法检测蛋白表达水平。结果CCT128930可通过阻滞细胞于G1期而抑制HUVEC的增殖,且抑制作用呈剂量依赖性,但对HUVEC的凋亡无影响;HUVEC经CCT128930处理后,体外小管形成能力受到明显抑制;低浓度的CCT128930抑制内皮细胞中VEGF的表达,但对Akt的磷酸化水平无影响。结论 CCT128930能够抑制HUVEC的增殖与血管生成,其抑制血管生成活性可能与其调控VEGF的表达水平相关。     

Gecko Proteins Exert Anti-Tumor Effect against Cervical Cancer Cells Via PI3-Kinase/Akt Pathway

Anti-tumor activity of the proteins from Gecko (GP) on cervical cancer cells, and its signaling mechanisms were assessed by viable cell counting, propidium iodide (PI) staining, and Western blot analysis. GP induced the cell death of HeLa cells in a dose-dependent manner while it did not affect the viability of normal cells. Western blot analysis showed that GP decreased the activation of Akt, and co-administration of GP and Akt inhibitors synergistically exerted anti-tumor activities on HeLa cells, suggesting the involvement of PI3-kinase/Akt pathway in GP-induced cell death of the cancer cells. Indeed, the cytotoxic effect of GP against HeLa cells was inhibited by overexpression of constituvely active form of Akt in HeLa cells. The candidates of the functional proteins in GP were analyzed by Mass-spectrum. Taken together, our results suggest that GP elicits anti-tumor activity against HeLa cells by inhibition of PI3-kinase/Akt pathway.