Fig. 7: Phosphorylation of DAB2IP at its Thr531 and Thr546 sites promotes SAC activation, k-MT attachment and inhibits PCa tumorigenesis. | Oncogene

Fig. 7: Phosphorylation of DAB2IP at its Thr531 and Thr546 sites promotes SAC activation, k-MT attachment and inhibits PCa tumorigenesis.

From: Mitotic phosphorylation of tumor suppressor DAB2IP maintains spindle assembly checkpoint and chromosomal stability through activating PLK1-Mps1 signal pathway and stabilizing mitotic checkpoint complex

Fig. 7

A C4-2 Neo, D2, and D2 2A (T531A/T546A) cells were treated with 50 ng/ml nocodazole for 16 h. Mitotic index was determined by chromosome spread assay (three independent experiments, n ≥ 1000 in each group; error bars, s.e.m; ***P < 0.001 as compared with Neo and D2 2 A cells). B C4-2 Neo, D2, and D2 2A cells were exposed to different concentrations of paclitaxel for 48 h and MTT assay was performed. Results were obtained from three independent experiments (means ± SD; ***P < 0.001 as compared with control and D2 2A cells). C, D Decreased kinetochore localization of BubR1 in phosphoryl-deficient DAB2IP-expressing PCa cells. Representative images showing BubR1 colocalization with kinetochores (Crest) in C4-2 Neo, D2, and D2 2A cells. C4-2 cells were fixed and immunostained with anti-BubR1 and Crest antibodies (C). Colocalization of BubR1 with Crest antibody-stained structures (kinetochores) was detected under a fluorescence microscope. Scale bar, 5 μm. Quantification of BubR1 levels (normalized by Crest) on prometaphase kinetochores in C4-2 cells expressing different DAB2IP statuses (D). (***P < 0.001 as compared with control and D2 2A cells). E Inter-distance of paired kinetochores at metaphase in C4-2 Neo, D2, and D2 2A cells. F Average inter-kinetochore distances of C4-2 Neo, D2 and D2 2A cells. To quantify inter-kinetochore distances, all images were acquired as Z-stack with 0.4 μm spacing using a ×63 objective. At least 100 kinetochores were analyzed in each cell lines. Error bars represent SD (***P < 0.001 as compared with control and D2 2A cells). G, H The phosphorylation of DAB2IP on its Thr531 and Thr546 is essential to suppress tumor growth in vivo. (n = 5; **P < 0.01 as compared with C4-2 D2 cells).

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