There are no effective therapies for malignant brain tumors, the number one killer among children with cancer. In order to develop effective therapies, the mechanisms that control tumor growth must be understood. Accelerated growth of a variety of neural tumors has been correlated with overexpression of receptors for the epidermal growth factor (EGF) or fibroblast growth factor (FGF). The overexpression of these growth factor receptors is thought to result in autocrine growth of the tumors. Ganglioside GM3 is able to specifically inhibit cell growth and tyrosine specific kinase activity associated with the receptors for these growth factors. It is our hypothesis that GM3 mediates its effects by binding directly to the receptor protein, and that it inhibits receptor activation and signal transduction. The overall aim of this proposal is to understand the mechanism of GM3 inhibition and to make use of this mechanism for possible therapeutic applications in brain tumors. To accomplish these goals we will: l) generate deletion and point mutations of the EGF receptor and stably express these mutant receptors in mammalian cells; 2) determine if exogenously added GM3 will effect the growth and protein tyrosine kinase activity of these mutant receptors; 3) determine if GM3 interacts directly with the EGF receptor in these cells; and 4) examine the mechanism of GM3 inhibition of the EGF and FGF receptors. The long term goal of this research is to understand how changes in ganglioside composition may influence the growth behavior of brain tumors. The altered expression of gangliosides is a phenomenon found in virtually all tumors. The possibility that ganglioside GM3 may interact directly with the EGF receptor suggests that it may be possible to exploit this mechanism of inhibition for future therapeutic applications in brain tumors. It may be possible to block signal transduction of these growth factor receptors in brain tumors by gangliosides, thus reducing the autocrine growth advantage that these tumors may attain by receptor overexpression. This project is one of four sections of an Interactive Research Project Grant (IRPG) application, Glycobiology of Brain Tumors, to the National Cancer Institute (PA-93-078). The overall goals of this interactive project are: l) test the hypothesis that brain tumor gangliosides may play a key role in tumor development and progression; and 2) modulate their expression by several complementary approaches.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
7R01NS033383-04
Application #
2547355
Study Section
Physiological Chemistry Study Section (PC)
Program Officer
Jacobs, Tom P
Project Start
1994-08-01
Project End
1999-07-31
Budget Start
1997-08-01
Budget End
1999-07-31
Support Year
4
Fiscal Year
1996
Total Cost
Indirect Cost
Name
Children's Memorial Hospital (Chicago)
Department
Type
DUNS #
City
Chicago
State
IL
Country
United States
Zip Code
60611
Meuillet, E J; Mania-Farnell, B; George, D et al. (2000) Modulation of EGF receptor activity by changes in the GM3 content in a human epidermoid carcinoma cell line, A431. Exp Cell Res 256:74-82
Mayanil, C S; George, D; Mania-Farnell, B et al. (2000) Overexpression of murine Pax3 increases NCAM polysialylation in a human medulloblastoma cell line. J Biol Chem 275:23259-66
Meuillet, E J; Kroes, R; Yamamoto, H et al. (1999) Sialidase gene transfection enhances epidermal growth factor receptor activity in an epidermoid carcinoma cell line, A431. Cancer Res 59:234-40
Rebbaa, A; Chou, P M; Vucic, I et al. (1999) Expression of bisecting GlcNAc in pediatric brain tumors and its association with tumor cell response to vinblastine. Clin Cancer Res 5:3661-8
Meuillet, E J; Bremer, E G (1998) Growth factor receptors as targets for therapy in pediatric brain tumors. Pediatr Neurosurg 29:1-13
Yamamoto, H; Kaneko, Y; Rebbaa, A et al. (1997) alpha2,6-Sialyltransferase gene transfection into a human glioma cell line (U373 MG) results in decreased invasivity. J Neurochem 68:2566-76
Rebbaa, A; Yamamoto, H; Saito, T et al. (1997) Gene transfection-mediated overexpression of beta1,4-N-acetylglucosamine bisecting oligosaccharides in glioma cell line U373 MG inhibits epidermal growth factor receptor function. J Biol Chem 272:9275-9
Rebbaa, A; Yamamoto, H; Moskal, J R et al. (1996) Binding of erythroagglutinating phytohemagglutinin lectin from Phaseolus vulgaris to the epidermal growth factor receptor inhibits receptor function in the human glioma cell line, U373 MG. J Neurochem 67:2265-72
Rebbaa, A; Hurh, J; Yamamoto, H et al. (1996) Ganglioside GM3 inhibition of EGF receptor mediated signal transduction. Glycobiology 6:399-406