[Integration of DNA oscillatory vector pSV neo to genome of NIH3T3: importance in investigations of transformation with c-Ha-ras oncogene].

Main aim of this study was evaluation of application of stable clones of transforming cells, containing DNA of plasmid vector for the investigation of oncogenes. Plasmid vector was constructed basing on pSV2neo vector, containing activated oncogene c-Ha-ras-1, derived from pT 24-C3 which was followed by evaluation of phenotypic and genetic changes in standard line of NIH3T3 mouse fibroblast line after transfection with constructed plasmid. After two weeks of culture in selective conditions, transformants resistant to geneticin were obtained and analysis of clones was performed after transfection with constructed vector containing ras oncogene and after transfection pSV2neo. Analysis of efficiency of cloning and transformation basing on growth independent from placement and morphology and investigation of karyotypes demonstrated similar irregularities in both investigated groups and subchromosomal aberrations of NIH3T3 cells were even more frequent than in initial lines of NIH3T3 cells. Southern hybridization with pSV2neo-ras probe demonstrated that only restrictive DNA fragments, obtained by Pst1 enzyme contain copies of neo in cell genomes. Integration of gene cf geneticin-resistance increases thus normally unstable genetically NIH3T3 cells.