S100A4 mediated cell invasion and metastasis of esophageal squamous cell carcinoma via the regulation of MMP-2 and E-cadherin activity.

It is well documented that S100A4 is upregulated in a large amount of invasive tumors and plays a pivotal role in tumor invasion and metastasis. However, the precise role and mechanism S100A4 exerts in the invasion and metastasis of esophageal squamous cell carcinoma (ESCC) have not been fully elucidated to date. Our data demonstrated that S100A4 was overexpressed in human ESCC tissues, especially in ESCC with poor differentiation, deep invasion and lymph node metastasis. Subsequently, the knockdown of S100A4 by RNAi in ESCC cell line (EC-1) could reduce cell invasion, metastasis and proliferation ability in vitro. Most importantly, S100A4 regulated MMP-2 positively and E-cadherin negatively in vivo and in vitro to some extent. Our results suggest that S100A4 is an important factor in the invasion, metastasis and proliferation of ESCC and may control invasion and metastasis at least in part through the regulation of MMP-2 and E-cadherin activity. S100A4 may serve as a biomarker for progression of ESCC and a potential molecular target for biotherapy of ESCC.

[Inhibitory effect and molecular mechanism of silencing S100A4 gene on the growth of transplanted tumor of human esophageal carcinoma EC-1 cells in nude mice].

OBJECTIVE: To study the effect of S100A4siRNA on tumor growth of xenografted human esophageal squamous cell carcinoma (ESCC) cell line EC1 in nude mice and explore its related molecular mechanism. METHODS: The xenografted tumor model was established in nude mice, and S100A4siRNA chemically synthesized was used to transfect the xenografted nude mice. The tumor growth was observed. The mRNA and protein expressions of S100A4, MMP-2 and E-cadherin in tumor after transfection with S100A4siRNA were detected by RT-PCR and immunohistochemistry. RESULTS: The tumor volume of S100A4siRNA transfection group was lower than that of nonsense siRNA transfection group and blank control group (P < 0.05), and tumor inhibitive ratio of S100A4siRNA group was higher than that of nonsense siRNA transfection group (P < 0.05). Furthermore, the mRNA and protein expressions of S100A4, MMP-2 in S100A4siRNA group were lower than those in nonsense siRNA group and control group (P < 0.05), the mRNA and protein expressions of E-cadherin in S100A4siRNA group were higher than those in nonsense siRNA group and control group (P < 0.05). CONCLUSION: S100A4siRNA could effectively lead to growth inhibition of xenografted human esophageal tumor in nude mice, with down regulation of MMP-2 and up regulation of E-cadherin, which provides theoretical basis for molecular therapy of ESCC.

[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.

[Expression of S100A4 in esophageal squamous cell carcinoma and its relation to tumor invasion and metastasis].

OBJECTIVE: To study the role of S100A4 in the carcinogenesis, development, invasion and metastasis of esophageal squamous cell carcinoma. METHODS: Immunohistochemistry was used to detect the expressions of S100A4, MMP-2 and E-cadherin proteins in 100 cases of surgically resected esophageal squamous cell carcinoma specimens. RT-PCR and Western blot were used to detect the expressions of S100A4 mRNA and protein in esophageal squamous cell carcinoma line EC-1 and TE-1. Boyden-chamber model in vitro was utilized to detect the invasion ability of EC-1 and TE-1 cells. RESULTS: The positivity rate of S100A4 protein was 52.0% was in esophageal carcinoma tissues, significantly higher than that in normal tissues (26.0%) (P<0.01). The expression of S100A4 was related to tumor grading, invasive depth and lymph node metastasis (P<0.05). In esophageal carcinoma, the expression of S100A4 was positively correlated to MMP-2 expression (P<0.01), but inversely to E-cadherin expression (P<0.05). The expressions of S100A4 mRNA (0.894-/+0.021) and protein (0.897-/+0.053) in EC-1 cells were significantly higher than those in TE-1 (0.812-/+0.040 and 0.645-/+0.089, respectively, P<0.01), and the invasion ability of EC-1 cells was significantly higher than that of TE-1 cells (91.00-/+17.44 vs 61.80-/+11.10, P<0.01). CONCLUSION: The overexpression of S100A4 in esophageal squamous cell carcinoma tissue and highly invasive EC-1 cells may contribute to the carcinogenesis, development, invasion and metastasis of esophageal squamous cell carcinoma.