Figure 3.

iE2 cells maintain normal diploid karyotypes and dependence on cytokines and hormone for proliferation even after long-term ex vivo expansion. (a–c) G-banding of iE2 cells at days 109, 159, and 275 of expansion showed normal karyotypes. At least 20 metaphases were examined for each sample. (d) Growth factor elimination experiments started at day 124 of iE2 expansion culture showed that the continuous survival and proliferation of iE2 cells is dependent on the combinational act of SCF (S), Epo (E), and Dexamethasone (D), while IGF-1 (I) and IL-3 (3) are not required for iE2 proliferation. Error bars represent standard deviation of three repeats.