Serum growth factor regulation of the paired-box transcription factor Pax-3 in neuronal cells.

Mutations in the murine Pax (paired-box)-3 gene results in a number of developmental abnormalities including a deficiency in sensory neurons. To determine the role that Pax-3 plays in neuronal cell development, we have studied the expression of Pax-3 in the ND7 neuronal cell line. Upon serum starvation, Pax-3 mRNA expression fell rapidly. Within 2 h of the removal of serum a 2-3-fold decrease in Pax-3 expression was observed and by 6 h Pax-3 mRNA expression was undetectable. Interestingly this decrease in Pax-3 expression could be reversed by the addition of serum growth factors. This rise in Pax-3 expression upon growth factor addition, was followed by an increase in cell proliferation and a reduction in neurite outgrowth, suggesting that Pax-3 may play a role in mediating cellular responses to these factors in neuronal cells.