Increased expression of Schwannoma-derived growth factor (SDGF) mRNA in rat tumor cells: Involvement of SDGF in the growth promotion of rat gliomas

Abstract

Schwannoma-derived growth factor (SDGF) is a member of the epidermal growth factor (EGF) family, having mitogenic activity on rat astrocytes, fibroblasts and Schwann cells. The SDGFgene is significantly expressed in the newborn rat lung and in the adult rat sciatic nerve. However, except for one rat schwannoma cell line, from which SDGF and its cDNA were isolated, nothing is known about SDGF expression in established tumor cell lines. We examined the expression level of the SDGF gene in a variety of rat tumor cell lines by Northern blotting and found that it was increased in I I of 25 established lines. The most abundant SDGF mRNA, which was about 50-fold higher than in the newborn rat lung, was expressed in rat liver adenoma dRLa74 cells. In rat glioma cell lines, such as C6,9L and T9, and in the rat hepatoma dRLh84 and H411E cells, the SDGF expression level was about 10-fold higher than in the newborn rat lung. In 8 of 13 cell lines expressing SDGF mRNA, the EGF receptor (EGFR) gene, the product of which is re- o 1996 Wiley-Liss, Inc.

Antiangiogenic Drugs Synergize with a Membrane Macrophage Colony-Stimulating Factor-Based Tumor Vaccine to Therapeutically Treat Rats with an Established Malignant Intracranial Glioma

“…1B). T9/9L gliomas produce proangiogenic factors such as VEGF, PLGF, SDGF, and IL-8, also known as cytokine-induced neutrophil chemoattractants (10,24,25), which stimulate endothelial cell growth. DMBI and oxindole from 0.25 to 1.0 g/ml both significantly inhibited MS1 endothelial cells (Fig.…”