<i>In Vitro</i> Experiments on the Effects of Mouse Sarcomas 180 and 37 on the Spinal and Sympathetic Ganglia of the Chick Embryo

Abstract

Summary Small fragments of mouse Sarcomas 180 and 37 were placed at a distance of 1–2 mm. from spinal or sympathetic ganglia of a chick embryo in a hanging-drop tissue culture. Under this condition the ganglion produces precociously, within 24 hours, an excessive number of nerve fibers which grow very straight radially in all directions, forming a dense “halo” around the ganglion. Their density decreases, and their length increases, with increasing distance from the sarcoma. In addition, the migration of spindle cells from the ganglia is inhibited by the sarcomas. Mouse Sarcoma 1 has a similar, but milder, effect. Mouse adenocarcinoma dbrB and mouse neuroblastoma C1300 do not stimulate nerve growth. Control experiments with heart tissue from chick embryos were entirely negative, but heart tissue of fetal mice was found to have a mild stimulating effect. However, in the latter instance, the growth pattern is very different from that found in the presence of sarcomas and very similar to that found in normal, isolated ganglia. Sarcomas have no effect on spinal cord fibers. It is concluded that the mouse sarcomas tested produce a diffusible agent which strongly promotes the nerve fiber outgrowth of ganglia. The results obtained in vitro are compared to previous results obtained by intra-embryonic transplantation of the same sarcomas, and the conclusion is reached that the in vitro and the in vivo effects on the spinal and sympathetic ganglia are due to the same agent.