Apoptotic effects of oridonin on t(8;21) leukemic cells. (A) Morphologic changes in Kasumi-1 (top panel) and fresh leukemic (bottom panel) cells untreated or treated with oridonin. Stainings were analyzed using an Olympus BX51 research microscope equipped with a 100×/1.30 numerical aperture (NA) oil objective (Olympus, Tokyo, Japan). Images were processed using Adobe Photoshop CS (Adobe Systems, San Jose, CA). Original magnification, ×1000. (B) Expression of annexin V on Kasumi-1 cells treated with oridonin at indicated concentrations. (C) In situ TdT labeling of Kasumi-1 cells. (Top panel) control; (bottom panel) Kasumi-1 cells treated with 2 μM oridonin for 48 hours. Images were visualized and processed using the equipment described for panel A. (D) Cell cycle analysis showing sub-G1 content in cells treated with 2 μM oridonin. (Top panel) control; (bottom panel) Kasumi-1 cells treated with 2 μM oridonin for 48 hours. (E) DNA fragmentation in Kasumi-1 cells treated with 2 μM oridonin for 48 hours. (F) PI-negative Rh123-positive (PI [−] Rh123 [+]) cells are decreased upon oridonin treatment; in particular, the inhibition was greater using oridonin treatment at 5 μM for 48 hours. (G) Effects of oridonin on casp-3, PARP, Bcl-2, survivin, NFκB, and Fas-L. β-Actin is used as a loading control. Error bars represent SD of experiments.