[Effect of calmodulin antagonist EBB on invasion of human fibrosarcoma cell HT1080].

OBJECTIVE: To investigate the potential effect of EBB, a calmodulin antagonist, on invasion of human fibrosarcoma cells HT1080. METHODS: The antitumor effect of EBB was assessed by 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Activities of matrix metalloproteinase (MMP)-2 and MMP-9 were measured by Zymogrophy analysis. The mRNA levels, of MMP-2, MMP-9, and tissue inhibitor of metalloproteinases (TIMP)-1 were evaluated by reverse transcriptionpolymerase chain reaction (RT-PCR). Transwell chamber assay was applied to measure the effect of EBB on the invasion of HT1080 cells. RESULTS: Calmodulin antagonist EBB inhibited the proliferation of HT1080 cells with an IC50 of (8.2 +/- 1.2) microg/ml. EBB down-regulated the activities of MMP-2 and MMP-9, and down-regulated the mRNA levels of MMP-2 and MMP-9, while up-regulated the mRNA levels of TIMP-1. The invasive ability of HT1080 cells was decreased to (31.13 +/- 2.265)%, (59.91 +/- 2.566)%, and (71.58 +/- 0.5960)% after exposure of the cells with 2, 5, and 10 microg/ml EBB, respectively. CONCLUSION: Treatment with calmodulin antagonist EBB is effective in suppressing tumor invasion. The possible mechanism is the down-regulation of MMPs.