Figure 6

FOXM1 positively regulated BICD2 expression, and BICD2 downregulation enhanced NVB-induced defects of the mitotic spindle. (a) The viability of NCI-H460 cells after thiostrepton treatment for 24 h was determined by MTT assay. (b) Effects of thiostrepton on the expression of FOXM1 and BICD2 for 24 h were analyzed by western blotting, and β-actin was served as the loading control. (c–f) BICD2 expression at mRNA and protein level was detected by altering the levels of FOXM1 in NCI-H460 cells by transfecting FOXM1 plasmid or siRNAs. (g, h) FOXM1 protein levels were analyzed by transfecting BICD2 plasmid or BICD2 siRNAs. (i) Mitotic spindle defects were observed by immunofluorescence assay in NCI-H460 cells following BICD2 deletion with or without 0.01 μM NVB treatment. Cells were immunostained with the antibody against β-tubulin (green) and the nucleus was stained with DAPI (blue), the mitotic cells were observed by confocal microscopy (× 100 magnification). (j) For each sample, at least 30 mitotic cells were captured in images. The data were expressed as mean±S.D. in triplicate using Student’s t-test (two-tailed). **P<0.01 and ***P<0.001. NS, no significant changes