The aim of the present study was to assess the differential immunoexpression of neurofibromin in benign and malignant peripheral nerve sheath tumors (PNST) from Neurofibromatosis type l (NF1) patients. Two polyclonal antibodies raised against peptides corresponding to residues 2798-2818 and 509-528 of the NF1 gene product, that specifically recognize the 250 kd NF1 gene product were used. Using enzymatic antigen enhancement these antibodies were applied to formalin-fixed, paraffin-embedded tissue sections. Neurofibromin immunoreactivity was seen in normal dorsal root ganglia, Schwärm cells, keratinocytes, melanocytes, CNS neurons and oligodendrocytes. 38 PNST from 25 NF1 patients were examined. 7/7 malignant PNST immunoexpressed neurofibromin, as detected with both antibodies. 26β1 benign neurofibromas were also positive while immunoreactivity was not detected in 5 benign tumors. Double immunolabelling with S-100 demonstrated neurofibromin within Schwann cells. Immunoabsorption of primary antibodies with corresponding peptides eliminated labelling. Our results negate the concept that malignancy within NF1 tumors is a consequence of neurofibromin deficiency and thus raises additional questions regarding the role of this molecule in the pathogenesis of NF1.
|Original language||English (US)|
|State||Published - 1996|
ASJC Scopus subject areas
- Molecular Biology