Effects of imatinib and/or As₄S₄ on BCR-ABL oncoprotein and PTK activity in K562 cells and primary CML cells. (A) Western blot analysis of BCR-ABL of K562 cells after 48 hours of treatment. (B) PTK activity of K562 cells and primary BMMNCs from CML-AP patients. Analysis was performed after treatment with As₄S₄ and/or imatinib for 24 hours and 48 hours (n = 3, mean ± SD). Statistical analysis using a one-side paired t test (^*, P < .05 versus control; ▴, P < .01 versus control; ☆, P < .05 versus imatinib, As₄S₄ group, and control; ⋆, P < .01 versus imatinib, As₄S₄ group, and control; #, P < .05 versus imatinib, As₄S₄ group, and P < .01 versus control). CON indicates control; I 0.2, 0.2 μM imatinib; I 0.25, 0.25 μM imatinib; A2, 2 μM As₄S₄; A2.5, 2.5 μM As₄S₄; I 0.2A2, 0.2 μM imatinib and 2 μM As₄S₄; and I 0.25A2.5, 0.25 μM imatinib and 2.5 μM As₄S₄.