Serum-free culture of insulin-secreting clonal cells from a hamster insulinoma.

We experimented with a wide range of serum-free media to find the best one for culturing insulinoma cells from the Syrian golden hamster, cell line In-R1-I10. Optimum cell growth came with a mixture of equal proportions of Dulbecco's modified Eagle's medium and Ham's F-12, supplemented with 10(-6) M insulin, 10 micrograms/ml transferrin, and 10(-9) M triiodothyronine (what we labeled DF-ITT medium). In addition to testing different varieties of basal media, we also experimented with different concentrations of known stimulants of cell proliferation, including transferrin, ferrous sulfate, insulin, epidermal growth factor, triiodothyronine, hydrocortisone, monoethanolamine, prolactin, proteose peptone, and selenium. Cells cultured in DF-ITT medium grew as well as those in serum-containing medium for 94 consecutive generations. Their insulin secreting capacity was maintained. The substitution of epidermal growth factor (10 ng/ml) for the insulin did not reduce either the growth rate or the insulin secreting capacity of the culture cells.