FUNCTIONAL NERVE GROWTH-FACTOR RECEPTOR IN VON RECKLINGHAUSEN NEUROFIBROMATOSIS - AN IMMUNOCYTOCHEMICAL AND SHORT-TERM CULTURE STUDY

Immunocytochemistry reveals 75 kDa low affinity type nerve growth fact or receptor (NGFR) on the cell membrane of human neurofibroma cells of von Recklinghausen disease in vivo and in vitro. NGF-immunoreactivity is detected in the primary and cultured tumor cells. Growth augmentat ion of cultured neurofibroma cells by exogenous NGF is also confirmed. Phosphotyrosine-immunoreactivity is demonstrated by immunocytochemist ry in the in vivo and in vitro neurofibroma cells suggesting possible phosphorylation of tyrosine residue in the NGFR or a cellular protein downstream of signal transduction through the ligand receptor system. These results indicate human neurofibroma cells possess functional NGF R and the growth is potentiated through the NGF-NGFR system in the par acrine and/or autocrine fashion.