Fig. 4
Induction of p21 protein is crucial for SELENBP1-mediated G0/G1 phase cell cycle arrest. a UMUC3 (Vector) and UMUC3 (HA-SELENBP1) cells were collected at day 4 as described in “Fig. 3c”, and subjected to flow cytometry assay following the staining of propidium iodide. b Cell lysates of stable transfectants UMUC3 (Vector), UMUC3 (HA-SELENBP1), T24T (Vector) and T24T (HA-SELENBP1) were extracted and subjected to immunoblotting assay for determining expression levels of G0/G1 phase arrest-associated regulatory proteins. GAPDH was used as a loading control. Densitometric quantification of p21 (relative to GAPDH) is shown under each blot. c HCT116 WT and HCT116 p21−/− cells were transfected with empty vector or HA-SELENBP1, each along with pGIPZ, and stable transfectants were established under the selection of puromycin. Cell lysates of these stable transfectants were extracted and then subjected to immunoblotting assay with anti-SELENBP1, anti-p21 or anti-GAPDH antibodies. d Anchorage-independent cell growth of stable transfectants described in “c” was determined by soft agar assay. Representative images of colonies were visualized under an inverted microscope (×40 magnification; left panel) and relative numbers of colonies were calculated on day 12 (right panel). The asterisk (*) indicates a significant difference in comparison to that of control transfectants (p < 0.05)