ONX0912 exerts antiproliferative effects on primary WM cells as well as on IgM-secreting low-grade lymphoma cells. (A-B) DNA synthesis was measured by thymidine uptake assay in BCWM.1 (A) and IgM-secreting cell lines, RL and MEC.1 (B), and treated with ONX0912 (1-500nM) for 24, 48, and 72 hours (A) or for 48 hours (B). (C) BCWM.1 cells were treated with ONX0912 (10-50nM) for 24 hours, and cell-cycle profiling was performed by propidium iodide staining and flow cytometric analysis. (D) BCWM.1 cells were cultured with ONX0912 (10-20-50nM) for 12 hours. Whole-cell lysates were subjected to Western blotting using anti–cyclin D1, –cyclin D2, –cyclin E, -p21^waf1/cip1, -p27^kip1, and –β-actin.