The pIRES-p21 (Waf1) , pIRES-p27 (Kip1) , and pIRES-p21 (Waf1) -p27 (Kip1) genes were transfected into MCF-7 cells by lipofection. 
lipofection
The effect on proliferation was evaluated by MTT assay and clone-formation assay. 
MTT assay
The effect on proliferation was evaluated by MTT assay and clone-formation assay. 
clone-formation assay
Cell cycle and apoptosis were analyzed by flow cytometry.  Apoptosis was tested by flow cytometry and TUNEL assay. 
flow cytometry
Centrosome duplication was detected by use of indirect immunofluorescence microscopy.



indirect immunofluorescence microscopy