Characterization of L1CAM expression in human breast cancer. (A) ONCOMINE gene microarray database was explored for L1CAM gene expression in breast cancer and the results of Boersma et al.  were displayed by different stages. COPA analysis yielded a score at 1.95, ranking L1CAM 125th at 75% outlier among 12,427 measured genes on mRNA level (http://www.oncomine.org/). (B) Quantitative analysis of transmigration assay between MDA-MB-231 and MDA-MB-468 cells. Each cell suspension (105 cells) was plated into the upper chamber of Transwell inserts precoated with LN on the underside, and allowed to migrate for 12 h at 37°C. Cells that migrated to the backside of the insert were stained with crystal violet and counted from five random views. Data are mean ± SEM of three independent experiments. **, p < 0.01. (C) L1CAM expression level examined by RT-PCR and western blot analysis in MDA-MB-435, MDA-MB-231 and MDA-MB-468 cells. Beta-actin and β-tubulin were internal controls for each assay respectively. DNA band markers and protein molecular weight markers are shown as indicated. (D) Immunostaining of L1CAM in MDA-MB-231 and MDA-MB-468 cells observed by confocal microscopy. Fixed and permeablized staining with polyclonal antibody NCAM-L1 (C-20) (upper panel) or live staining with monoclonal antibody UJ127 for L1CAM (lower panel) are shown in red. Nuclei stained with bisbenzimide are shown as blue.