茵陈蒿对实验性食道肿瘤大鼠P53和cdk2表达的影响

为研究中药菌陈蒿的抗肿瘤作用机理,观察了菌陈蒿水煎剂对实验性食道肿瘤大鼠病变组织P^53和cdb2表达的影响。结果表明,肿瘤大鼠食道组织P^53,cdk2表达增高,而饮用菌陈蒿水剪水煎剂各组P^53,cdk2的表达均不同程度受到抑制,提示菌陈蒿水煎剂对P^53,cdk2的表达有下调作用。     

Anticancer properties of novel aminoacetonitrile derivative monepantel (ADD 1566) in pre-clinical models of human ovarian cancer

Monepantel (MPL) is a new anthelmintic agent approved for the treatment of nematode infections in farm animals. As a nematicide, it acts through a nematode-specific nicotinic receptor subtype which explains its exceptional safety in rodents and mammals. In the present study, we evaluated its potential as an anticancer agent. In vitro treatment of epithelial ovarian cancer cells with MPL resulted in reduced cell viability, inhibition of cell proliferation and suppression of colony formation. Proliferation of human ovarian surface epithelial cells and other non-malignant cells were however minimally affected. MPL-induced inhibition was found to be independent of the acetylcholine nicotinic receptor (nAChR) indicating that, its target in cancer cells is probably different from that in nematodes. Analysis of MPL treated cells by flow cytometry revealed G1 phase cell cycle arrest. Accordingly, MPL treated cells expressed reduced levels of cyclins D1 and A whereas cyclin E2 expression was enhanced. Consistent with a G1 phase arrest, cellular levels of cyclin dependent kinases (CDKs) 2 and 4 were lower, whereas expression of CDK inhibitor p27^kip was increased. In cells expressing the wild-type p53, MPL treatment led to increased p53 expression. In line with these results, MPL suppressed cellular thymidine incorporation thus impairing DNA synthesis and inducing cleavage of poly (ADP-ribose) polymerase (PARP-1). Combined these pre-clinical findings reveal for the first time the anticancer potential of monepantel.     

肾细胞癌中转录因子E2F-1表达的意义

目的探讨转录因子E2F-1在肾癌中的表达及其临床意义。方法应用免疫组化方法检测E2F-1在48例肾癌组织和12例正常肾组织中表达；应用DNA图像定量分析技术进行肾癌中DNA含量检测和细胞周期分析。结果肾癌组织中E2F-1阳性表达率为72．9％，显著高于正常肾组织的41．7％（P〈O．05）；E2F-1表达与肾癌的临床分期、肿瘤大小、淋巴结转移、DNA含量和S期细胞比率均密切相关，但与肾癌病理类型无显著相关性。结论E2F-1异常高表达在肾癌发病机制中起着重要作用，对肾癌生物学行为有-定的预测评估价值。     

Effects of different concentrations of celecoxib on proliferation and cell cycle of SH-SY-5Y cells and its mechanisms*★ In vitro study

BACKGROUND： Highly selective cyclooxygenase-2 （COX-2） inhibitors have recently been approved for the treatment of colon cancer, breast cancer, urinary bladder cancer, and skin cancer. For the highly selective COX-2 celecoxib, the mechanism of action for inhibiting neuroblastoma cells is still uncertain.
OBJECTIVE： To observe the influence of different celecoxib concentrations on proliferation and cell cycle of SH-SY-5Y cells in vitro and to reveal potential COX-2-independent mechanisms of celecoxib on SH-SY-5Y cells.
DESIGN： Controlled experiment.
SETTING： Department of Hematology, Affiliated Hospital of the Qingdao Medical College, Qingdao University, Shandong Province. MATERIALS： The study was performed at the Cerebrovascular Disease Institute of Shandong Province and the Laboratory of Molecular Biology, Affiliated Hospital of Qingdao Medical College, Qingdao University between September 2006 and June 2007. The SH-SY-5Y cell line was obtained from the Department of Molecular Biology, Qingdao Medical College, Qingdao University. Celecoxib was obtained from Pfizer Pharmaceuticals LLC, USA. Coulter DNA PREP reagent kit was purchased from Beckman Coulter, Inc. The antibodies against human CyclinD1, P21, and P16 were purchased from Santa Cruz Biotechnology. METHODS： SH-SY-5Y cells were treated with different concentrations of celecoxib （10, 20, 40, and 80 la mol/L） for 48 hours and comprised the experimental groups. The same concentrations of DMSO （dimethyl sulphoxide） treatment for 48 hours served as the control group.
MAIN OUTCOME MEASURES： ① Cellular morphology of cells pre-treated and post-treated with celecoxib by inverted microscopy. ② Methabenzthiazuron assay was used to measure cell proliferation. ③ Cell cycle was measured by flow cytometry after incubation with different celecoxib concentrations for 48 hours. ④CyclinD1, P16, and P21 protein expression was detected by Western blot analysis. RESULTS： ① Cellular morphology： The shape of SH-SY-5Y cells pre-treated     

Regulation of G1 cyclin-dependent kinases in liver regeneration

The liver serves as a suitable model for studying tissue regeneration. Although various growth factors have been implicated in the promotion of this process, their precise role in liver regeneration remains to be elucidated. Whatever the extracellular signals may be, they all converge on cell cycle regulators in the nucleus, where the sequential activation of cyclin-dependent kinases (Cdk) takes place. The activities of Cdk are regulated positively through their association with cognate cyclins, and negatively via interactions with Cdk inhibitors. In this review article, our recent data as well as results of previous reports on how these cell cycle regulators trigger and/or terminate the process of liver regeneration are summarized. The authors believe that ‘knockout’ mice, in which specific genes are deleted, will be useful for providing further insight into the positive and negative regulation of liver regeneration.     

Differential expression of cell proliferation regulatory proteins in B- and T-lineage acute lymphoblastic leukaemias

In order to better understand the molecular background of differences between the clinical picture of T- and B-lineage ALLs, we studied the expression of several proteins involved in the regulation of cell proliferation in bone marrow blast cells from 30 cases of previously untreated acute lymphoblastic leukaemia (ALL); 14 cases were T- and 16 B-cell lineage ALLs. We studied several cyclin-dependent kinases (cdk1, cdk2, cdk4, cdk6) and cyclins (cyclin A, cyclin B1, cyclin D3 and cyclin E). We also studied proliferating cell nuclear antigen (PCNA) and Bcl-2 expression, the latter protein known to be involved in the prolonged survival of B-lineage ALL blasts. Proteins obtained from cell lysates were resolved on polyacrylamide gel followed by immunodetection and densitometry of specific bands. Expression of cdk1 and PCNA, markers of proliferative activity, was significantly higher in T- than in B-lineage ALL. Cdk6, which was highly correlated to PCNA, was also higher in T-cell ALL. In contrast, B-lineage ALL displayed a higher expression of anti-apoptotic protein Bcl-2. We hypothesize that those particularities may reflect differential roles of cell multiplication and apoptosis in the neoplastic proliferation of B- and T-lineage ALL.     

p-MAPK、cyclinD1和p53蛋白在大肠癌中的表达及其相关性

目的：检测ｐ－ＭＡＰＫ、ｃｙｃｌｉｎＤ１和ｐ５３蛋白在大肠癌中的表达，并探讨其相关性。方法：免疫组织化学Ｓ－Ｐ法。结果：１４０例大肠癌中ｐ－ＭＡＰＫ、ｃｙｃｌｉｎＤ１和ｐ５３蛋白的阳性表达率分别为９２．９％（１３０／１４０）、８７．１％（１２２／１４０）和６６．４％（９３／１４０）；５０例相应癌旁肠粘膜中阳性表达率分别为４．０％（２／５０）、６．０％（３／５０）和２．０％（１／５０）。三者阳性表达     

MCMV影响神经干细胞cyclins表达和细胞周期进程的体外实验研究

目的:观察鼠巨细胞病毒(MCMV)感染对体外培养神经干细胞(NSCs)细胞周期进程和cyclins表达的影响,探讨MCMV感染致脑发育异常的机制。方法:本实验体外分离、培养和鉴定BABL/C胎鼠NSCs,以感染复数(MOI)为5,1和0.1的MCMVsmith毒株感染NSCs并于感染后1,2,3,4,5,6d收集细胞,采用Cyclin/DNA双参数流式细胞术检测感染细胞cyclinA,cyclinB1,cyclinD1,cyclinE的表达和细胞周期时相的动态变化,观察MC-MV对感染NSCs细胞周期进程的影响。结果:体外分离培养的NSCs呈球样生长,神经干细胞特异性标记Nestin表达阳性,并可进一步分化为GFAP阳性的星形胶质细胞和NF-200阳性的神经元;各感染组cyclinA,cyclinB1,cy-clinD1和cyclinE的表达均上调,其中MOI=0.1表达逐渐上升,在第6d达峰值,MOI=1组表达高峰在第4d,MOI=5组表达高峰在第3d;感染组G0/G1期细胞比率减少,S期和G2/M期细胞比率增加,其变化趋势与cyclins的表达基本一致,并随MOI的增加变化越明显。结论:Cyclin/DNA多参数流式细胞术可用于NSCs细胞周期的分析;MCMV可通过上调cyclinA,cyclinB1,cyclinD1,cyclinE的表达来影响NSCs细胞周期进程,并与MOI存在一定量效依赖关系;MCMV感染可诱导NSCs从G0/G1期进入S期,出现S期和G2/M期偏移和阻滞,影响NSCs细胞周期进程,这可能是CMV抑制NSCs增殖并导致先天性脑发育异常的重要机制之一。     

Apelin-13促大鼠血管平滑肌细胞增殖的PKC-ERK1/2信号通路研究

目的研究G蛋白偶联受体APJ(血管紧张素受体样受体或称血管紧张素受体AT1相关的受体蛋白,putativere-ceptor protein related to the angiotensin receptor AT1)的内源性配体apelin-13通过PKC-ERK1/2-Cyclins信号通路促进大鼠血管平滑肌细胞(vascular smooth muscle cells,VSMCs)增殖的影响。方法培养SD大鼠胸主动脉VSMCs,Western blot检测p-ERK1/2、ERK1/2、细胞周期蛋白CyclinD1和CyclinE的表达,四噻唑蓝比色法观察PKC阻断剂GF109203X对apelin-13促大鼠VSMCs增殖的影响。结果Apelin-13剂量依赖性和时间依赖性地促进大鼠VSMCsp-ERK1/2表达增加,对ERK1/2表达没有明显影响,GF109203X可明显抑制apelin-13诱导的细胞增殖及p-ERK1/2、CyclinD1和CyclinE的表达。结论Apelin-13促进大鼠VSMCs增殖可能与ape-lin-APJ-PKC-ERK1/2-Cyclins信号通路有关。