Neuroblastoma--an overview of laboratory studies aimed at inducing tumor regression by initiation of differentiation or administration of antitumor drugs.

Experimental laboratory investigations aimed at inducing tumor regression are reviewed critically. Possible interference with tumor growth by induction of differentiation has stimulated studies employing cell lines in vitro and in vivo of murine and, more recently human origin. The diverse range of agents proving effective inducers has facilitated studies of morphological and biochemical differentiation. However, the precise molecular events involved are still unclear, and any therapeutic potential for differentiation-induction therapy remains uncertain. Drug sensitivity testing for agents specifically effective against neuroblastoma centered initially on the murine C1300 tumor. More recently human neuroblastomas, grown in tissue culture or as xenografts, have been employed, and preliminary reports are available of direct cloning of neuroblastomas from clinical specimens. These preclinical chemotherapy studies are reviewed, and prospects for laboratory investigations of potential clinical relevance are highlighted.