Retinoic acid-induced neuronal differentiation regulates expression of mRNAs for neurotrophins and neurotrophin receptors in a human embryonal carcinoma cell line NTera2

The expression of mRNAs for neurotrophins and neurotrophin receptors was examined in NTera2/cl.D1 (NT2) human embryonal carcinoma cells at various stages of retinoic acid (RA)-induced neuronal differentiation using reverse transcription-polymerase chain reaction and southern blot analysis in order to investigate the biological role of neurotrophins in the human neuronal differentiation. The expression of high steady levels of BDNF, NT-3, NT-4, and low-affinity NGF receptor mRNAs was observed in both untreated NT2 cells and NT2-derived differentiated neurons induced by RA treatment. The lower levels of expression of NGF, trkA, trkB, and trkC mRNAs were identified in untreated NT2 cells and their expression was elevated markedly following 4 week treatment with RA. The increased expression of NGF, trkB, and trkC mRNAs were stable in NT2-derived differentiated neurons, while the expression of trkA mRNA was reduced substantially in these cells. These results indicate that mRNAs for a battery of neurotrophins and their receptors are coexpressed in NT2 cells and their expression is regulated by RA-induced neuronal differentiation.