HEPATOCYTE GROWTH-FACTOR AND C-MET IN BENIGN AND MALIGNANT PERIPHERAL-NERVE SHEATH TUMORS

Hepatocyte growth factor (HGF), secreted by mesenchymal cells, has ple iotropic biological activities on several cell types. HGF and its rece ptor, the c-met proto-oncogene product (c-MET) have been implicated in the genesis and progression of several carcinomas and sarcomas. It ha s been suggested that MET/HGF autocrine signaling may contribute to tu morigenesis in sarcomas. HGF has been recently found to be a mitogen f or rat Schwann cells and to be present in neurofibromas in NF1 patient s. In this investigation, we assessed the immunoreactive patterns of H GF and MET in benign and malignant peripheral nerve sheath tumors (PNS T) using archival formalin-fixed tissue. The standard avidin-biotin-pe roxidase method was used. All benign tumors were negative with HGF. Ei ght cases of MPNST were positive with both HGF and MET. In some malign ant PNST, positivity with both ligand and the receptor may be indicati ve of an autocrine mediated signal transduction and may implicate HGF/ MET in tumor progression. Immunoreactivity with MET was strikingly gre ater in MPNST in contrast to benign PNST; this finding may prove to be helpful in distinguishing some histologically low-grade MPNST from ce llular and atypical benign PNST. Copyright (C) 1997 by W.B. Saunders C ompany.