Increased neurite development and plasminogen activator expression by exposure of human neuroblastoma cells to a plasminogen‐deficient growth medium

Growth of human neuroblastoma strain SK-N-SH in a plasminogen-deficient medium results in about a 40% increase in the number of differentiated cells (cells with a neurite-like process at least 50 micrometers in length) and about a five-fold increase in the amount of plasminogen activator liberated per cell. Plasminogen deficiency has no effect on the growth rate of SK-N-SH cells. These results are consistent with the hypothesis that plasminogen activator is involved in neuroblast development.