REVERSIBLE INHIBITION OF GROWTH OF B16 MELANOMA-CELLS BY DECREASED AMINO-ACID NUTRITION

The effect of limited amino acid nutrition upon the growth of B16 melanoma cells was investigated. It was observed that the cells in Basal Medium Eagle do not proliferate and are inhibited predominantly in the G1 phase of cell cycle. The cells which were inhibited in growth for 7 or 12 days in Basal Medium Eagle were able to commence proliferation when transferred to Eagle's Minimal Essential Medium containing higher concentration of amino acids. The proliferating cells were found to be more evenly distributed throughout all phases of the cell cycle. The reversible inhibition of growth of B16 melanoma cells was caused by decreased concentrations of amino acids and not by their depletion in the culture medium. The B16 melanoma cells which are known to be capable of highly autonomous growth in the absence of extracellular hormones and growth factors have appeared to be sensitive to nutritional inadequacy.