Figure 1. THP-1 cells stably expressing wild-type K5 have increased growth rate, which is serum dependent.

THP-1 cell lines were seeded at 0.1 x 10⁶ cells/ml in RPMI media supplemented with (A) 10% FBS or (B) 5% and 0.5% FBS, as indicated, in triplicates. Viable cell numbers and averages were determined for each day. (C) Equal numbers of indicated THP-1 cell line in medium with either 10% FBS (top panel) or 0.5% FBS (bottom panel), were examined for cell cycle profile, as described in the Methods, at three days post-seeding. Results are representative of three independent experiments. (D) Each of the indicated THP-1 cells was seeded in triplicate at 0.1 x 10⁶ cells/ml in medium containing the indicated serum concentration. Five days post-seeding cells were examined for apoptosis. The percentage of cells doubly stained for Annexin V and propidium iodide are indicated.