中文摘要：

目的：利用合成的小分子干扰RNA（siRNA）转染人支气管上皮细胞16HBE,观察LBH（limb-bud and heart） 基因表达下调对16HBE细胞周期及相关基因表达的影响.方法：脂质体2000转染靶向LBH 基因的siRNA到16HBE细胞,荧光定量RT-PCR检测siRNA转染后LBH基因表达,流式细胞术检测LBH基因沉默后16HBE 细胞周期的改变,荧光定量RT-PCR及Western blotting检测LBH基因沉默后细胞周期素E1和E2表达水平.结果：50 nmol/L siRNA转染16HBE细胞48 h后, LBH基因的表达水平只有对照组的14%;siRNA转染16HBE细胞48 h,其G1期细胞百分率比对照组减少9.28%,而S期细胞百分比增加14.08%;16HBE细胞在50 nmol/L siRNA的转染后,细胞周期素E2的表达水平为对照组的2倍,而细胞周期素E1的表达没有发生明显改变.结论：靶向于LBH基因的siRNA能有效沉默16HBE细胞中LBH基因的表达,LBH基因的表达下调促进了16HBE细胞周期G1/S期的进展;细胞周期素E2的表达上调参与了LBH沉默导致的细胞周期G1/S期的进展.

英文摘要：

AIM： To investigate the effect of small interfering RNA （siRNA） on limb -bud and heart （LBH） gene expression in 16HBE cells, and further to observe the change of 16HBE cell cycle after knocking down of LBH gene. METHODS： Synthetical siRNA targeting LBH gene was transfected into 16HBE cells by the method of lipofectamine 2000. The mRNA expression of LBH was examined by real time RT - PCR. The cell cycle was assayed by flow cytometry. The expression of cyelin El and E2 was also detected by real time RT - PCR and Western blotting. RESULTS： The expression of LBH gene decreased by 86% in 16HBE cells transfected with 50 nmol/L of siRNA for 48 h. After transfected with siRNA for 48 h, 16HBE cells in G1 phase decreased by 9. 28% and the cells in S phase increased by 14. 08%. The expression level of cyclin E2 in 16HBE cells transfected with siRNA was twice higher than that of the negative control cells. CONCLUSION： Sequence - specific siRNA targeting LBH is capable of suppressing LBH gene expression in 16HBE cells. Down - regulation of LBH expression in 16HBE cells may promote the progress of cell cycle, and up - regulation of cyclin E2 expression plays a role in the process of G1/S phase.