Dose response of insects to malignant transformed cells

Abstract

Graded doses of cell suspensions of an embryonic cockroach cell line in its 290th passage were injected into the hemoceles of hosts of the homologous species,Blattella germanica, of different ages. All insects injected with viable cells suffered paralysis, progressive loss of appendages, and premature death. The time of death depended on the number of cells inoculated. Histological studies of the afflicted insects showed that the injected cells were metastatic and invasive, producing tumors, especially in the fat body. Tumors were transplantable and malignant in secondary hosts. Tumors were not produced by cell-free spent medium, or homogenized or sonicated cell breis. The cause of paralysis and loss of appendages was not known, although large aggregations of the injected cells could be seen in the leg musculature in the thorax. Cells were recovered from the tumors and grown again in culture. The line was predominantly diploid (62%) with some heteroploid cells (38%).