Amino acid requirements of normal and malignant human cells in tissue culture

Three tissue culture cell lines deriving from normal human tissue (liver, conjunctiva, and intestine) and two lines deriving from human cancer [KB (nasopharynx), and J-111 (monocytic leukemia)] have been examined with respect to their amino acid requirements in comparison with those of a HeLa cell and a mouse fibroblast. With the possible exception of tryptophan, all seven cell lines required the same amino acids (arginine, cystine, glutamine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tyrosine, valine); and in the absence of any one of these 12, cytopathogenic changes developed which culminated in the death of the cell. The provision of non-essential amino acids, purines, pyrimidines, and NH4+ had a glutamine-sparing effect, but did not eliminate the need for this amino acid. Extremely high and nonphysiological concentrations of glutamic acid (20 mM) did, however, substitute for glutamine. It is not yet clear whether tryptophan is similarly essential for survival and growth, or whether it is merely growth stimulatory for some of the five cell lines here studied. The concentration of the individual amino acids necessary for optimum growth varied somewhat among the six strains; but there were not significant or consistent differences in this respect between the lines deriving from normal and from malignant tissues.