Objective To investigate the role of cell adhesion molecule L1 like (CALL) in the genesis and development of esophageal squamous cell carcinoma (ESCC). Methods From July 2007 to December 2010, a total of 100 patients with ESCC who received radical resection of esophageal cancer were enrolled. The ESCC tissues and corresponding tumor-adjacent normal tissues were obtained. The expression of CALL was determined by tissue microarray technology and immunohistochemical staining. The CALL over-expressed esophageal cancer cell line was established. The effects of CALL on cell migration and invasion were detected by wound-healing assay and Transwell assay, respectively. The effects of CALL on actin microfilament was analyzed by filamentous actin (F-actin) staining. Chi-square test, Fisher′s exact test, multivariate analysis and t test were performed for statistical analysis. Results The positive expression rate of CALL in ESCC tissues was 56%(56/100), which was lower than that of tumor-adjacent normal tissues (95%, 95/100), and the difference was statistically significant (χ2=41.114, P<0.01). There were statistically significant differences in CALL expression at protein level among patients with ESCC of different differentiation degree, different pathological T stage, lymph node metastasis and different TNM stage (χ2=13.702, 5.317, 21.453, Fisher′s exact test; all P<0.05). The five-year disease related survival rate of ESCC patients with down-regulated expression of CALL was 0(0/49), which was lower than those with normal CALL expression (25.5%, 13/51), and the difference was statistically significant (χ2=43.338, P<0.01). The median survival time of CALL expression down-regulated group was 17 months, and that of normal expressed group was 38 months. CALL expression was an independent risk factor of disease special survival rate (hazard ratio (HR)=0.353, 95% confidence interval (CI) 0.188 to 0.666, P=0.001). The results of wound-healing assay showed that the migration ability of CALL overexpressed CALL-k30 cells was lower than that of Vec-k30 cells in control group on 24 hours after wound. The results of Transwell invasion test showed the number of migrating cells penetrating CALL-k30 cells attached to the inferior surface of the membrane was 44.000±13.748, which was less than that of the Vec-k30 cells (154.333±25.007), and the difference was statistically significant (t=5.136, P=0.036). The results of F-actin staining demonstrated that actin filaments of CALL-k30 cells was 234.667±65.118, which was lower than that of Vec-k30 cells (597.000±119.929), and the difference was statistically significant (t=4.707, P=0.042). Conclusions CALL lowers the migration and invasion abilities of esophageal cancer cells by inhibiting F-actin microfilaments. Its abnormal expression may play an important role in the genesis, development and prognosis of ESCC. Key words: Neural cell adhesion molecule L; Esophageal neoplasms; Carcinoma, squamous cell; Immunohistochemistry; Neoplasm metastasis; Tissue-microarray; F-actin
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