a, U251 cells were infected with a lentivirus carrying shRNA specific for βII-tubulin (shβII#1, shβII#2) or scrambled shRNA (shCtrl). 48hrs following the infection, U251 cells were harvested to examine protein levels of βI-, βII- and βIII-tubulin by western blotting. GAPDH was used as a loading control.
b–c, Cell cycle distribution of βII-tubulin deficient U251 cells and control U251 cells (with shCtrl) was analyzed by flow cytometry. The percentage of cells at G2/M phase among cells at metaphase was quantified (c).
d–e, U251 cells (βII-tubulin deficient cells and control cells) at metaphase of mitosis were immunostained for α-tubulin to examine spindle morphology (d). DAPI was used to counterstain cell nuclei. The percentage of cells with normal spindles or abnormal spindles (including multipolar, monopolar or distorted spindles) was quantified (e). scale bar: 15 μm.
f–g, Apoptosis in U251 cells (βII-tubulin deficient cells and control cells) was examined by flow cytometry after labelling with Annexin V and PI (f). The percentage of apoptotic cells (Annexin V+) was quantified (g).