Fig. 3.

Stimulation of WNT signaling promotes proliferation of MM cells. (A) Exogenous Wnt3a promotes proliferation of MM cells. The MM cell lines UM1, OPM1, and NCI H929 were cultured in the presence of L cell-conditioned medium (open bars) or conditioned medium derived from Wnt3a-transfected L cells (Wnt3a CM, filled bars) and [³H]thymidine incorporation was measured after 1, 2, and 3 days of culture. Error bars represent SD of triplicate measurements. (B) Purified Wnt3a promotes proliferation of MM cells. Cells were cultured in the absence (open bars) or presence (filled bars) of purified Wnt3a (100 ng/ml) in serum-free medium. [³H]thymidine incorporation was measured after 2 days of culture. (C) LiCl stimulation promotes proliferation of MM cells. Cell were cultured in the absence (open bars) or presence (filled bars) of 2 mM LiCl in serum-free medium. [³H]Thymidine incorporation was measured after 3 days of culture. (D) β-catenin S33Y promotes proliferation of MM cells. Cells were transfected with empty vector (open bars) or with β-catenin S33Y (filled bars) and [³H]thymidine incorporation was measured after 2 days of culture.