Rejection of drug-treated tumor cells in the peritoneal cavity of mice

Abstract

Highly immunogenic sublines of L1210 and L5178Y leukemias were obtained in vivo following 6-8 transplant generations in (BALB/c × DBA/2)F 1 (CDF 1) mice treated with Dimethyl-triazenoimidazole-car☐amide (DIC). Tumor cells of parental or DIC-treated lymphoma lines were injected intraperitoneally in (CDF 1) mice. Progressive tumor growth or tumor growth and regression was monitored measuring the DNA synthesis in the peritoneal cavity of mice. The 125Iododeoxyuridine uptake method was employed ( Hofer and Hughes, 1970). Both parental and DIC-treated sublines showed rapid increase in DNA synthesis within 4 days after challenge. On day 8 no survivors were found in the groups of mice transplanted with parental tumors. A decline of DNA synthesis was observed in the cells collected from the peritoneum of animals challenged with the highly immunogenic DIC-treated sublines. On day 12 the DNA synthesis approached the values of background controls. Similar results were obtained when recipient mice were transplanted with untreated allogeneic lymphoma cells, incompatible for the entire H-2 complex. These data suggest that DIC-treated tumor sublines and H-2-incompatible allogeneic lymphoma cells are subjected to comparable rejection processes in the peritoneal cavity of mice.