[7] Amplification of genes in somatic mammalian cells

Publisher Summary This chapter describes the experience from the laboratory with techniques employed to generate resistance phenomena as a result of gene amplification. The experience has focused primarily on resistance to methotrexate and amplification of the dihydrofolate reductase gene in Chinese hamster ovary and mouse 3T6 cells. Ones anticipate that experience may prove useful to other investigators working on very different systems. However, it is likely that the mechanisms by which drug treatments alter cell metabolism or kill cells differ with the particular treatment undertaken. The chapter describes the effects of various treatments on cell physiology are critical in studying amplification processes. It emphasizes on the variability of cells in culture, particularly with respect to phenomena such as gene amplification, where the process under investigation necessarily involves genome instability. Even cell lines carded for long periods in the same laboratory without apparent change must be repeatedly subcloned and characterized.