OBJECTIVETo investigate the effects of E-cadherin on the biologic behavior of SUM149, an inflammatory breast cancer cell line.

METHODSSUM149 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.

RESULTSWhereas 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.

CONCLUSIONIn this cell line model, down-regulation of E-cadherin can inhibit the ability of invasion of this inflammatory breast cancer cell line.