Abstract: Objectives To investigate the regulating role of Neuregulin-1 (Nrg1) on cell adhesion molecule L1 expression and its effects on the migration of U87-MG cells. Methods Cells were administered with recombinant Nrg1α (rNrg1α) for 24 hours (h) and 48 h, and RT-PCR was used to investigate the mRNA levels of L1. Cells were then treated with rNrg1α and rNrg1β at 2.5 nmol/L for 48 h, and Western blot was applied to study the expression of L1 in response to Nrg1. siRNA targeting Nrg1 was also applied to study its effects on L1 expression. In addition, cells treated with Nrg1 siRNA was also subjected to wound healing assay. Immunofluorescence staining was used to study Nrg1α/β and L1 expression in cells on the wound edge. Results Administration of Nrg1α at 2.5 nmol/L can appartently increase the L1 mRNA levels at 24 h and 48 h time points. In addition, both 2.5 nmol/L of Nrg1α and Nrg1β can significantly increase the protein level of L1 at 48 h (p＜0.01 and p＜0.05, respectively). siRNA targeting Nrg1 for 48 h can appartently reduce the expression of Nrg1, accompanied with the reduction of L1 levels. Wound healing assay indicated that downregulating Nrg1 expression not only reduced the expression of L1 in cells on the wound edge, but also reduced cell migration, as was indicated by the wound space with a higher width. Conclusions Nrg1 can regulate L1 expression in human glioblastoma U87-MG cells, which may partially contribute to cell migration.

Key words: Key words：neuregulin (Nrg1), cell adehsion molecule L1, U87-MG cell line, cell migration