中文摘要：

目的通过抑制Cullin4B（简称为CUIAB）在神经胶质母细胞瘤U87和U251细胞中的表达，探讨CUL4B在神经胶质母细胞瘤形成中的作用及其机制。方法体外实验设立3组，分别为空白对照组、Lv-shCon组以及Lv-shCUL4B组；体内实验设立2组，分别为Lv-shCon组和Lv-shCUL4B组。采用CUL4BsiRNA构建慢病毒并感染U87和U251细胞株，以下调细胞中CUL4B的表达。通过实时定量PCR（qPCR）和Westernblot方法检测各组细胞中CUL4B的表达。以MTF法和细胞集落形成实验分别检测细胞增殖能力和集落形成能力。通过Transwell实验检测细胞的迁移能力。采用流式细胞术进行细胞周期分析。以Westernblot方法检测细胞周期和细胞迁移的相关调控因子的表达。建立U87和U251细胞移植瘤裸鼠模型，观察各组动物的瘤体生长情况。结果qPCR和Westernblot结果表明，与空白对照组和Lv-shCon组相比，Lv-shCUL4B组U87细胞和U251细胞的CUIAB表达均下降（均P〈0．01）。MTF实验表明，与空白对照组相比，Lv-shCUL4B组的生长均明显受到抑制，U87细胞的增殖能力降低了63．7％，U251细胞降低了45．5％（均P〈0．01）。与空白对照组和Lv．shCon组相比，Lv-shCUL4B组U87和U251细胞集落均数均减少（均P〈0．01）。Transwell实验结果显示，U87和U251细胞Lv-shCUIAB组发生迁移的能力均低于空白对照组和Lv-shCon组（均P〈0．01）。流式细胞仪检测结果显示，与空白对照组及Lv-shCon组相比，U87和U251细胞Lv-shCUL4B组处于G1期的比例上升，处于S期的比例下降。与空白对照组和Lv-shCon组相比，U87和U251细胞Lv．shCUL4B组CyclinD1和MMP-9的表达水平下降（均P〈0．01），p16（INK4A）和PTEN的表达水平升高（均P〈0．01）。体内实验结果表明，与Lv-shCon组相比，Lv-shCUL4B组U87细胞种植裸鼠的肿瘤重量下降57．7％，U251细胞种植裸鼠的肿瘤重量下降75．4％（均P〈0．01）。结论CUL4B低表?

英文摘要：

Objective To study the relationship between CUL4B and glioblastoma by inhibiting the expression of CUL4B in U87 and U251 cells. Methods Three groups were set for in vivo experiments including control group , antisense sequence group （ Lv-shCon ） and CUIAB group （ Lv-shCUIAB ） ; and 2 groups were divided for in vitro experiments including Lv-shCon and Lv-shCUL4B groups. U87 and U251 cells were transduced with shRNA-expressing lentivirus （Lv-shCon or Lv-shCUL4B ）, respectively. Endogenous expression of CUIAB was detected by quantitative real-time PCR and Western blot. The cell proliferation assay, colony formation assay , Transwell assay and cell cycle analysis were then conducted. Furthermore, U87 and U251 plantation model were set up in nude mice. Results The expression levels of CUL4B were significantly reduced in Lv-shCUL4B groups in U87 and U251 cells, in contrast to uninfected （Con） and Lv-shCon groups （ all P 〈 0. 01 ）. MTT experimental results showed that the growth of Lv-shCUIAB cells was significantly inhibited and U87 and U251 cells decreased by 63.7% and 45.5%, respectively （all P 〈 0. 01 ）. The colony formation experiment results demonstrated that the cell colony numbers in U87 cells control group and Lv-shCon group measured an average of 150, while in the Lv- shCUIAB group there were less than 30 colonies. For U251 cells, the control group and Lv-shCon group had an average of 200 cell colonies, and the Lv-shCUL4B group had less than 40 colonies. Compared with the control group and Lv - shCon group, migration ability of Lv - shCUL4B group in U87 and U251 cells decreased significantly（all P 〈0.05 ）. The cell cycle distribution of U87 and U251 cells was detected by flow cytometry. The results showed that the U251 cells in the G1 phase accounted for 50. 0% in the control group, while the percentages was 52. 0% and 82. 0% in the Lv-shCon and Lv-shCUIAB groups, respectively. Ten percentage of the U87 cells were 10. 0% in phase S in Lv-shCUIAB group, in contrast with 40. 0%