cyclin-d1 and brucine

It has been proven that Cyclin D1 and Cyclin E are the important positive regulators of cell cycle, they are closely related to the tumor proliferation. The aim of this study is to explore the relationship between Brucine and the proliferation in human lung cancer cell line PC-9, and the effect of it on the expression of Cyclin D1 and Cyclin E.. PC-9 cells were divided to 4 groups: the normal control group, the DMSO control group (2‰), the 150 μM Brucine group, and the 300 μM Brucine group. The proliferation rate of PC-9 cells was determined by The CellTiter-Glo Luminescent Cell Viability Assay and Colony Formation assay. The change of cell cycle was detected by Flow cytome try. Expressions of cell cycle regulators Cyclin D1, Cyclin E mRNA were determined by qRT-PCR. Protein expression of cell cycle regulators Cyclin D1, Cyclin E were determined by Western blot.. Compared with the control, Brucine remarkably inhibited the proliferation of PC-9 cells in a dose- and time-dependent manner (P<0.01); Flow cytome try showed that Brucine blocked the cell cycle of PC-9 cells at G0/G1, and the differences were statistically significant (P<0.01); qRT-PCR showed that the expression of Cyclin D1, Cyclin E mRNA were down-regulated; Western blot showed that the protein expression of Cyclin D1, Cyclin E were down-regulated.. Brucine can inhibit the proliferation of human lung cancer cell line PC-9 mainly by blocking the cell cycle at G0/G1 via down-regulating the expression of Cyclin D1, Cyclin E.. 背景与目的 已有的研究表明：Cyclin D1和Cyclin E是细胞周期中重要的正性调控因子，其高表达与肿瘤的增殖密切相关。本研究旨在探讨马钱子碱（Brucine）对人肺癌细胞株PC-9增殖的影响，及其与Cyclin D1和Cyclin E表达的影响。方法 将PC-9细胞分为4组：空白对照组、DMSO对照组（2‰）、150 μM Brucine组、300 μM Brucine组。CellTiter-Glo发光法、平板克隆形成实验观察该药对PC-9细胞增殖的影响，流式细胞仪检测细胞周期，qRT-PCR检测细胞周期相关基因Cyclin D1、Cyclin E mRNA的表达，Western blot检测细胞周期相关基因Cyclin D1、Cyclin E蛋白的表达。结果 与对照组比较，CellTiter-Glo发光法、平板克隆形成实验结果显示：Brucine可以抑制人肺癌细胞株PC-9的增殖，并呈时间-剂量依赖性（P<0.01）；流式结果显示对细胞周期的影响主要是阻滞PC-9细胞于G0/G1期；qRT-PCR结果显示Cyclin D1、Cyclin E mRNA的表达下调；Western blot结果显示Brucine使Cyclin D1、Cyclin E的表达降低。结论 Brucine能明显抑制人肺癌细胞株PC-9的增殖，机制主要与其通过下调Cyclin D1、Cyclin E表达，进而阻滞细胞周期有关。

Topics: Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Cyclin E; Down-Regulation; Drugs, Chinese Herbal; Gene Expression Regulation, Neoplastic; Growth Inhibitors; Humans; Lung Neoplasms; Strychnine

We evaluated the effects of brucine on N-nitrosodiethylamine (DENA)-induced hepatocarcinogenesis in rats. Initiation of hepatocarcinogenesis was done by intraperitoneal injection of diethylnitrosamine (DENA) followed by promotion with phenobarbital. The rats were exposed to dietary brucine for 4 weeks prior to initiation, and the treatment was continued for 22 consecutive weeks. Brucine decreased the incidence, total number, multiplicity, size and volume of preneoplastic hepatic nodules in a dose-dependent manner. Administration of DENA induced hepatocellular carcinoma (HCC), as evidenced by changes in histopathological architecture, increased activity of cytochrome P450, decreased activity of glutathione Stransferase (GST) as well as decreased antioxidant status, enhanced lipid peroxidation, increased liver marker enzymes. Western blot analysis showed decreased expression of cyclin D1 and Bcl-2 with activation of caspase-3 and increased expression of Bax. Immunohistochemical demonstrated the decreased expression of the PCNA and VEGF. These results indicate that brucine prevents lipid peroxidation and hepatic cell damage and also protects the antioxidant system in DENA-induced hepatocarcinogenesis.

Topics: Alkylating Agents; Animals; Anticarcinogenic Agents; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Cyclin D1; Diethylnitrosamine; Female; Gene Expression Regulation; Immunohistochemistry; Lipid Peroxidation; Liver Neoplasms, Experimental; Phenobarbital; Proliferating Cell Nuclear Antigen; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Strychnine; Vascular Endothelial Growth Factor A