中文摘要：

目的：特异性下调子宫内膜癌细胞中的ERα基因，探讨E胁亚型表达在子宫内膜癌侵袭中的作用。方法：将ERa的小干扰RNA（siRNA-small interfering RNA）转染子宫内膜癌细胞HEC-1B，通过RT-PCR和Western blot证实ERα基因的有效阻断。通过transwell小室法检测下调ERa基因表达前后HEC-1B细胞的侵袭能力；应用RT-PCR检测转染前后细胞MMP-2、MMP-9、TIMP-1和TIMP-2 mRNA表达水平的变化；Western blot及明胶酶谱分别检测细胞分泌TIMP-1、TIMP-2、MMP-2和MMP-9蛋白的水平。结果：（1）将ERα-siRNA转染HEC-1B细胞后，转染效率大于90％，ERα mRNA及蛋白的表达水平均明显下调（分别为72％，67％）；（2）下调ERα基因表达后，肿瘤细胞的侵袭能力下降（P〈0．05）；在mRNA水平和蛋白水平均可检测到ERα-siRNA组细胞的MMP-2、MMP-9表达下降（P〈0．05），TIMP-1、TIMP-2表达增加（P〈0．05）。结论：使用ERα-siRNA能够有效地阻断ERa基因表达；子宫内膜癌细胞中，17β-雌二醇对MMPs／TIMPs具有调节作用，这种作用可通过ERα介导；ERα表达水平影响子宫内膜癌细胞的侵袭能力。

英文摘要：

Objective：To knock down the expression of ERα gene by RNAi and to inves-tigate the change in the capacity of invasion of endometrial carcinoma. Methods： （1） Validated ERα-siRNA was transfected into endometrial carcinoma cell line HEC-1B cells. RT-PCR and Western blot were used to confirm the effeciency; （2）Invasiveness of HEC-1B cells before and after knocking down ERα gene was detected by matrix metrigel invasion assay. Expression of MMP-2,MMP-9,TIMP-1 ,TIMP-2 mRNA was detected by RT-PCR. Western blot and gelatin zymography were used to measure TIMP-1/TIMP-2 and MMP-2/MMP-9 protein expression, respectively. Results：（1）ERα mRNA and protein expression in HEC-1B cells was significantly knocked down after transfection（knocked down by 72% and 67% ,respectively） ; （2）The invasiveness of HEC-1B cells significantly decreased after ERα were knocked down. The mRNA expression of MMP-2, MMP-9 as well as protein expression was decreased after ERa knocked down. However, TIMP-1, TIMP-2 expression was enhanced. Conclusion： Transfection with ERα-siRNA can effectively down-regulate human ERα gene expression. The invasive ability of endometrial carcinoma cells is affected by ERα. MMPs/TIMPs can be regulated by 17-β estradiol via ERα.