Cytologic and Cytotoxic Changes Induced by Nucleic Acids.

Nucleic acids and protein prepared from Sarcoma 180, from Ehrlich ascites tumor, from NCTC 929 cells derived from strain L, and from normal mouse liver, when injected subcutaneously in mice with cultured viable NCTC 929 strain L cells, oc casionally induce cytologie atypia in the NCTC 929 cells, characterized by giant cells, abnormal cytoplasmic shapes and staining, large nuclei, and prominence of nuclear chromatin patterns. Cytologie atypia was not induced in mouse host cells adjacent to the site of nucleic acid injection. Histones without nucleic acids did not induce atypia in concomitantly injected viable NCTC 929 cells in the mouse. Injections of NCTC 929 cells alone did not present the same atypia as was seen when nucleic acids were injected with the NCTC 929 cells. Ascites tumor, mouse liver, and Sarcoma 180 nucleic acids and nucleic acids-protein were cytotoxic to NCTC 929 cells in tissue cultures at varying concentrations above 250 milligrams per milliliter of culture fluid. Cytotoxicity was produced by deoxyribonucleic acid, ribonucleic acid, or a mixture of both deoxyribonucleic acid and ribonucleic acid. The atypia induced in NCTC 929 cells in mice by nucleic acid-protein and the cytotoxicity produced by similar nucleic acid preparations acting upon NCTC 929 cells in tissue culture may be related.