title: DNAase I encapsulated in liposomes can induce neoplastic transformation of Syrian hamster embryo cells in culture.
abstract: We have used liposomes to deliver DNAase I inside normal Syrian hamster embryo (SHE) cells. We showed the entrance of DNAase I inside the cell by dose-dependent cytotoxicity; and the entrance of DNAase I into the nucleus by the induction of chromosomal aberrations and somatic mutation at the HPRT locus (but not at the Na+/K+ ATPase locus). The induction of neoplastic transformation in cultures treated by DNAase I-in-liposomes was manifested by increased saturation density, colony formation at low seeding density, colony formation in 1% serum and 0.3% agar, and tumorigenicity in 100% of injected animals. The acquisition of anchorage-independent growth became apparent only after 39-57 posttreatment population doublings. Thus damage to DNA alone can initiate the neoplastic transformation process; but for full expression of the neoplastic phenotypes, a long progression time is required for the acquisition of anchorage-independent growth and tumorigenicity.
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002471:Cell Transformation, Neoplastic; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D006224:Cricetinae; D003850:Deoxyribonuclease I / Q000494:pharmacology*; D004622:Embryo, Mammalian; D007621:Karyotyping; D008081:Liposomes; D008647:Mesocricetus; D009154:Mutation; D010641:Phenotype
chemical_list: D008081:Liposomes; D003850:Deoxyribonuclease I