Role of the Stem Cell Factor/c-kit Complex in Neurofibrormatosis

摘要

This constitutes an addendum to the final report for grant number DAMD17-93-J-3035. The final report already submitted covered research performed from September 22, 1993 through September 21, 1996, whereas this addendum covers research performed from September 22, 1996 through September 21, 1997. Two conditions of Schwann cell hyperplasia occur at increased incidence in NF1 patients: neurofibromas and malignant schwannomas. We continued investigations of the Kit/ stem cell factor complex in hyperplasias of these cells. In the request for no-cost extension, several experiments were listed to be completed. These included testing conditioned media provided from Dr. Nancy Rattner from wild-type and NF1 knockout mice, testing paraffin sections of malignant schwannomas provided by Dr. Viskochil, and testing various malignant neural tumors for the Kit/SCF complex. Conditioned medium from Schwann cells of NF1 knockout mice failed to convert mast cells to a connective tissue phenotype, as compared to wild-type Schwann cells, suggesting less soluble stem cell factor from the NF1 knockout Schwann cells. We also found that most neural tumors express mRNA for Kit, and also for stem cell factor.