[Effect of KISS-1 on invasive potential and proliferation of esophageal squamous carcinoma cell line EC-1].

Objective: To investigate the effect of KISS-1 expression on the potential of invasion and proliferation of esophageal squamous carcinoma cell EC-1.

Methods: Protein and mRNA expressions of KISS-1 were evaluated by Western blot and RT-PCR in four esophageal carcinoma cell lines (EC-1, Eca109, EC9706 and TE-1). Using liposome-mediated transfection, an eukaryotic expression vector (pcDNA3.1-KISS-1) of KISS-1 gene was transfected into EC-1 cells. Boyden chamber model, MTT and clone formation assay were used to detect the potential of invasion and proliferation.

Results: Western blot and RT-PCR showed a baseline low level of expression of KISS-1 protein (0.715 +/- 0.109) and mRNA (0.670 +/- 0.176) in EC-1 cells. pcDNA3.1-KISS-1 expression vector was successfully transfected into EC-1 cells. Western blot and RT-PCR showed that the expression of KISS-1 protein (1.143 +/- 0.218) and mRNA (0.877 +/- 0.162) in EC-1 cells transfected with pcDNA3.1-KISS-1 were significantly higher than those transfected with the control vector pcDNA3.1 (0.745 +/- 0.130, 0.685 +/- 0.128; t = 3.850, 2.481, P < 0.05) and the control cells (0.855 +/- 0.184, 0.677 +/- 0.138; t = 2.275, 2.306, P < 0.05). Boyden chamber analysis showed that the invasiveness of the cells transfected with KISS-1 at 24 h (91.8 +/- 11.7), 48 h (117.8 +/- 11.1) and 72 h (139.2 +/- 11.8) were significantly reduced than that of the cells transfected with the control vector pcDNA3.1 (118.1 +/- 14.7, 141.7 +/- 13.2, 162.2 +/- 22.7; t = 3.153, 4.215, 3.569, P < 0.01) and the control cells (112.2 +/- 15.6, 138.1 +/- 13.0, 162.3 +/- 14.0; t = 4.154, 3.797, 2.702, P < 0.05). MTT showed that the proliferation potential of cells after transfection with KISS-1 at 48 h (0.517 +/- 0.127) and 72 h (0.394 +/- 0.137) were significantly reduced than that of cells transfected with the control vector pcDNA3.1 (0.636 +/- 0.186, 0.513 +/- 0.150; t = 2.054, 2.709, P < 0.05) and the control cells (0.646 +/- 0.135, 0.511 +/- 0.153; t = 2.276, 2.205, P < 0.05). Clone formation assay suggested that cells transfected with KISS-1 (157.2 +/- 36.4) showed significantly decreased clone formation than cells transfected with the control vector pcDNA3.1 (236.3 +/- 78.1; t = 3.441, P < 0.01) and the control cells (242.5 +/- 48.6; t = 2.250, P < 0.05).

Conclusion: KISS-1 gene inhibits the potential of invasion and proliferation of EC-1 cells.