Transfection and transformation of human and animal cells by recombinant DNA vectors: issues relevant to use of these substrates for the production of biologicals.

This paper reviews some of the issues relevant to the effect of oncogene or recombinant DNAs in both in vivo and in vitro models. Many studies of directly injected DNAs alone, with mediators of DNA uptake, or as the initiator in a multi-stage tumor progression model, showed that the DNAs were only rarely (if at all) tumorigenic. Conclusions from these and other in vitro experiments were that single oncogenes transfected into human cells did not generally convert those cells to a malignant phenotype, suggesting that additional genetic insult(s) or other factors were needed. These data, in concert with other observations and standard methods for product purification, imply that recombinant DNAs or oncogenes in cell lines pose little or no risk in the production of biologicals.