中文摘要：

目的 研究上皮钙黏着蛋白（E-cadherin）对人炎性乳腺癌细胞系SUM149的生长、侵袭等生物学特性的影响。方法 应用脂质体法基因转染技术，将编码E-cadherin基因显性负调控突变体（H-2k^d-E-cadherin）质粒导入SUM149中，应用RT-PCR、流式细胞分析法筛选、鉴定出E-cadherin基因显性负调控突变体高表达的阳性克隆。观察转染前后人炎性乳腺癌细胞系SUM149生长、侵袭能力等特性的变化以及相关分子的改变。结果 RT-PCR及Western印迹法结果均显示，与对照组（未转染及空质粒组）相比，转染后高表达小鼠H-2k^d的阳性克隆细胞的内源性上皮钙黏着蛋白表达明显下调，其细胞生长速度增殖无明显变化，而体外侵袭能力分析显示其侵袭能力明显下降，进一步研究发现，基质金属蛋白酶MMP-1、MMP-9在mRNA水平明显下调；明胶酶谱分析也显示，MMP-9明显下调。结论 在E-cadherin高表达的人炎性乳腺癌细胞系SUM149中，其表达的下调可明显抑制其侵袭能力。

英文摘要：

Objective To investigate the effects of E-cadherin on the biologic behavior of SUM149, an inflammatory breast cancer cell line. Methods SUM149 cells were transfected with dominant-negative mutant E-cadherin expressing plasmid. The positive clones with higher expression of dominant-negative E-cadherin mutant were identified by RT-PCR and fluorescent flow cytometry method. The differences in cell growth, proliferation and invasion between positive clones and controls were compared. Results Whereas the proliferation of positive clones was of no change, compared with controls, the ability of invasion was decreased and the mRNA levels of MMP-1 and MMP-9 were downregulated. Gelatin zymography analysis also confirmed the decreasing expression of MMP-9 in the positive clones. Conclusion In this cell line model, clown-regulation of E-cadherin can inhibit the ability of invasion of this inflammatory breast cancer cell line.