Role of cell adhesion molecule L1 like in the inhibition of the metastasis of esophageal squamous cell carcinoma / 中华消化杂志

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 (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.

High level of L1CAM predicting poor prognosis in hepatocellular carcinoma patients / 重庆医学

Objective To investigate the clinical significance and prognostic value of PKD3 expression in human hepatocellu-lar carcinoma (HCC)after hepatectomy.Methods We analyzed mRNA expression of L1CAM in 1 10 HCCs by quantitative real-time PCR (qRT-PCR)and western blot,and the relationship among the overall survival of HCCs.Results The relative protein and mRNA expression level of L1CAM was up-regulated in HCCs comparing with adjacent non tumor liver tissues (P <0.01).L1CAM expression in the well-differentiated group was higher than that in the poor-differentiated group (P < 0.01 ).The expression of L1CAM mRNA was significantly correlated with tumor differentiation and TNM stage (P <0.05).The prognosis of patients with high expression L1CAM was poor (P <0.01).Conclusion L1CAM expression is related to occurrence and development of HCCs and may predict the prognosis of HCCs after hepatectomy.

Homophilic interaction of the L1 family of cell adhesion molecules

Homophilic interaction of the L1 family of cell adhesion molecules plays a pivotal role in regulating neurite outgrowth and neural cell networking in vivo. Functional defects in L1 family members are associated with neurological disorders such as X-linked mental retardation, multiple sclerosis, low-IQ syndrome, developmental delay, and schizophrenia. Various human tumors with poor prognosis also implicate the role of L1, a representative member of the L1 family of cell adhesion molecules, and ectopic expression of L1 in fibroblastic cells induces metastasis-associated gene expression. Previous studies on L1 homologs indicated that four N-terminal immunoglobulin-like domains form a horseshoe-like structure that mediates homophilic interactions. Various models including the zipper, domain-swap, and symmetry-related models are proposed to be involved in structural mechanism of homophilic interaction of the L1 family members. Recently, cryo-electron tomography of L1 and crystal structure studies of neurofascin, an L1 family protein, have been performed. This review focuses on recent discoveries of different models and describes the possible structural mechanisms of homophilic interactions of L1 family members. Understanding structural mechanisms of homophilic interactions in various cell adhesion proteins should aid the development of therapeutic strategies for L1 family cell adhesion molecule-associated diseases.

A chimeric antibody to L1 cell adhesion molecule shows therapeutic effect in an intrahepatic cholangiocarcinoma model

Intrahepatic cholangiocarcinoma (ICC), a malignant tumor derived from the intrahepatic bile duct epithelium, has a poor prognosis and is refractory to conventional chemotherapy and radiation therapy. Thus, there is an urgent need to develop new effective therapeutic strategies for this disease. We previously found that L1 cell adhesion molecule (L1CAM) plays an important role in tumor progression of ICC, and we generated a murine mAb, A10-A3 (IgG1), that binds to the Ig1 domain of L1CAM. In the present study, we further characterized A10-A3, constructed a chimeric A10-A3 antibody (cA10-A3) containing the constant regions of human IgG1, and evaluated the therapeutic potential in a human ICC xenograft nude mice model. The affinities (K D) of A10-A3 and cA10-A3 for soluble L1CAM were 1.8 nM and 1.9 nM, respectively, as determined by competition ELISA. A10-A3 inhibited L1CAM homophilic binding and was slowly internalized into the tumor cells, but it did not significantly inhibit proliferation of ICC cells in vitro. cA10-A3 mediated antibody-dependent cell-mediated cytotoxicity in vitro and displayed anti-tumor activity in the ICC animal model. These results suggest that the humanized A10-A3 antibody may have potential as an anticancer agent for the treatment of ICC.