摘要目的 探讨细胞黏附样分子L1(CALL)在食管鳞状细胞癌发生、发展中的作用.方法 纳入2007年7月至2010年12月行食管癌根治术的100例食管鳞状细胞癌患者,获取其食管鳞状细胞癌组织和对应的癌旁正常组织.采用组织微阵列技术,应用免疫组织化学ABC法检测组织中CALL的表达情况.建立CALL过表达的食管癌细胞株,采用细胞划痕实验、Transwell侵袭实验验证CALL对细胞迁移、侵袭的影响,应用纤丝状肌动蛋白(F-actin)染色分析CALL对肌动蛋白微丝的影响.统计学方法采用卡方检验、Fisher确切概率法、多因素分析、t检验.结果 CALL在食管鳞状细胞癌组织中的正常表达率为56％(56/100),低于癌旁正常组织的95％(95/100),差异有统计学意义(x2=41.114,P＜0.01).CALL蛋白质表达在不同分化程度、病理T分期、淋巴结转移、TNM分期的食管鳞状细胞癌患者中差异均有统计学意义(x2=13.702、5.317、21.453,Fisher确切概率法;P均＜0.05).CALL蛋白质表达下调的食管鳞状细胞癌患者5年疾病相关生存率为0(0/49),低于CALL蛋白质正常表达者的25.5％(13/51),差异有统计学意义(x2=43.338,P＜0.01);CALL蛋白质表达下调组中位生存期为1 7个月,正常表达组为3 8个月.CALL蛋白质表达是疾病特异性生存率的独立危险因素[风险比(HR) =0.353,95％CI 0.188～0.666,P=0.001].细胞划痕实验显示,划痕后24 h CALl过表达组CALL k30细胞较对照组Vec k30细胞迁移能力弱.Transwell侵袭实验显示,CALL k30细胞附着于膜下表面的迁移细胞数为44.000±13.748,少于对照组Vec k30细胞的154.333±25.007,差异有统计学意义(t=5.136,P=0.036).F actin染色结果显示,CALL-k30细胞中肌动蛋白微丝数量为234.667±65.1 1 8,低于Vec-k30细胞中的597.000±119.929,差异有统计学意义(t=4.707,P=0.042).结论 CALL通过抑制F-actin微丝形成减弱食管癌细胞的迁移和侵袭能力,其表达异常可能在食管鳞状细胞癌的发生、发展和预后中有重要作用.

abstractsObjective 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 (x2=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 (x2=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 (x2 =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.