Murine and human MSC response to forodesine and dGuo. MSCs were treated without or with forodesine and dGuo for 48 hours. The apoptosis was measured by DIOC₆ assay (A), dGTP accumulation was analyzed (B), GTP and ATP levels were quantitated (C-D), and the global RNA and protein synthesis were measured (E). Data in panel A represent mean + SD from 3 independent experiments and data in panels B through E represent mean + SEM from 5 independent experiments. M indicates M210B4; F, forodesine; and N, NKtert.