Netrin-1 is a chemoattractant for DCC-expressing glioblastoma cells.

(A,B) Addition of 100 ng/ml netrin-1 to the bottom compartment (NB) of the transfilter microchemotaxis assay significantly increased U87 cell migration compared to control (medium alone). NB: netrin-1 bottom; NTB: netrin-1 top and bottom; NB DCC_FB: netrin-1 bottom, DCC function-blocking antibody top and bottom. Similar results were obtained in assays lasting (A) 16 hours and (B) 48 hours. (C) Netrin-1 in the bottom compartment had no effect on the migration of U343 or U373 cells. (D) U343 cells transfected with a DCC expression construct (U343D control) reduced their rate of migration relative to the parental line (U343P). Increased migration of DCC-transfected U343 cells was evoked by netrin-1 in the bottom compartment (U343D NB), but not uniform netrin-1 (NTB). DCC_FB blocked this response (U343D DCC_FB). (F) Transfection of U373 cells with DCC produced responses similar to U343 cells, which mimic those seen in DCC expressing U87 cells. Number of cells migrated is per 10X objective field. 16 hr assays in all panels except (B). * p<0.05 vs. control (A,B), U343P (D) or U373P (E). § p<0.05 vs. U343D control (E) or U373D control (F).