The cellular immortalization process: relevant issues for the generation of cell substrates for production of...

Although non-immortalized primary cultures have been widely used, and continue to be used, for the production of biological materials, there are many instances where the use of immortalized cell lines presents a significant saving in effort as well as cost. Furthermore, circumstances can often arise where the cell substrate must be engineered to a degree which cannot be achieved in primary cultures; in such cases the use of immortalized cells would be a necessity. The downside of using immortalized cells is that the vast majority of currently available immortalized cell lines display malignant phenotypes, which in many cases can limit their usefulness for the production of biologicals. In this review we will explore the biological basis of the immortalization process, as well as recent advances in our ability to engineer immortalization using well-defined interventions.