特异性siRNA沉默TDGF-1基因表达对乳腺癌细胞迁移侵袭的影响

Impacts of specific TDGF-1 gene silience by siRNA on invasion and migration of human breast cancer cell

目的 探讨RNA干扰（RNA interference,RNAi）沉默TDGF-1基因表达对乳腺癌细胞侵袭的影响.方法 根据TDGF-1基因序列特点设计3个小干扰RNA（small interfering RNA,siRNA）后,转染人乳腺癌MDA-MB-468细胞,用荧光实时定量RT-PCR筛选出效果最好的siRNA.以该siRNA转染处理乳腺癌MDA-MB-468细胞后,分别采用实时定量RT-PCR和western blot检测TDGF-1基因mRNA和蛋白水平,以划痕试验方法评测癌细胞迁移能力;用Boyden模型观察癌细胞侵袭能力.结果 根据TDGF-1基因序列特点设计的3个siRNA均能抑制TDGF-1基因mRNA水平,以S1效果最好.S1 siRNA转染组TDGF-1 mRNA和蛋白水平明显下调,且呈浓度和时间依赖性（P＜0.001,P＜0.001）.体外试验发现,TDGF-1 siRNA转染可有效抑制乳腺癌细胞集落生长、侵袭和迁移能力,且与浓度相关（P＜0.005,P＜0.005,P＜0.005）.结论 TDGF-1在乳腺癌细胞迁移、侵袭中起着重要的作用;采用TDGF-1 siRNA转染可抑制乳腺癌细胞侵袭.

Objective To study the impact of TDGF-1 gene silience by small interfering RNA（siRNA）on the invasion and migration of human breast cancer cell. Methods 3 siRNA fragments were designed according to the characteristic of TDGF-1 gene sequence and the most appropriate siRNA was selected by fluorescence real-time quantitative RT-PCR method. After the human breast cancer cell line MDA-MB-468 was transfected by the selected TDGF-1 siRNA, mRNA and protein of TDGF-1 were determined by real time quantitative RT-PCR and western blot respectively. The migration and invasion ability of the cancer cell were evaluated by wound-healing assay and Boyden chamber model respectively. Results siRNA could down-regulate the level of mRNA and protein of TDGF-1 in a dose-and time-dependent manner. In vitro experiment showed that TDGF-1 siRNA transfection can effectively inhibit the clonal growth, invasion and migration of breast cancer cell in a dose-dependent manner. Conclusions TDGF-1 gene may play an important role in the migration and invasion of human breast cancer cells. siRNA transfection can inhibit the invasion of human breast cancer cells.