Fig. 6.

HDAC4 inhibition upregulates NEDD9 expression and promotes breast cancer cells migration. a ChIP assay of recruitment of Ac-H3K9 to the nedd9 promoter region was observed after cells treatment with LBH589. b Western blotting analysis of NEDD9 expression after cells transfected with indicated siRNA or treated with HDAC4 specific inhibitor tasquinimod. MCF-7 and MDA-MB-231 cells were transfected with two independent HDAC4 siRNAs, then NEDD9 mRNA levels (c), nedd9 promoter ChIP assay (d), nedd9 promoter luciferase activity (e) and cells migration ability (f) were examined. Scale bar, 200 μm. g Invasion ability was restored when HDAC4 was depleted by siRNA in NEDD9 knockdown cells. Scale bar, 200 μm. h Schematic diagram depicting the regulation of NEDD9 in breast tumor cells by HDAC4 inhibition contributes to breast metastasis. Results are expressed as mean ± SD. Two-tailed Student’s t-tests were performed. */#p < 0.05, **/##p < 0.01, ***/###p < 0.001