Dynamic aspects of neural tumor gangliosides.

Gangliosides are important cell surface molecules in tumors of the nervous system. Initially thought of particularly as diagnostic disease markers, the biological properties and in vivo roles of tumor gangliosides have been recognized more recently. The latter affect the formation and progression of tumors of many types, including neural tumors. This chapter focuses on a prominent and almost universal dynamic property of tumor cells, the rapid synthesis and shedding of gangliosides, and consequences on the host response to tumors. In contemporary terms, these effects are understood to be functional properties of tumor cells affecting normal cells in the tumor microenvironment. Some of the most comprehensive studies have been possible in the human neuroectodermal tumors, neuroblastomas, including first observations of the shedding and activities of human tumor gangliosides. Citing other selected examples from tumors of different types, the impact and mechanisms of action of tumor gangliosides in facilitating tumor formation and progression will be delineated, leading to consideration of clinical relevance and therapeutic implications.