Figure 7. Short-term IKKβca induced cell proliferation arrest is partially p21 dependent.

A: Comparisons of p21 protein levels in 7 dpi IKKβca MEFS, 7 dpi IKKβca IBIN-MEFs, 21 dpi IKKβca MEFs and 7 dpi BIP control MEFs. Western blots of whole cell lysates derived from the indicated cell populations were probed with anti-p21 Ab and with an anti-tubulin Ab as a protein reference control. B: Cell proliferation rates over a 1-5 day time period of 7 and 14 dpi IKKβca p21 (−/−) MEFs are compared to p21 (−/−) control cells infected with an empty BIP vector 7 dpi. Cells were seeded in quadruplicate and DNAs were quantified and shown as the mean ± s.e.m. Results on days 3 and 5 of 7 dpi IKKβca p21 (−/−) vs. 7 dpi BIP p21 (−/−) control cells were statistically significant (p values of 0.009). C: Sybr green real time PCR results for 2 induced and 5 repressed genes are shown as fold change values obtained with total cell RNAs prepared from 10 dpi IKKβca p21 (−/−) vs. p21 (−/−) control MEFs. Results were quantified as described in Materials and Methods and in the legend for Figures 2 and are averages of duplicate samples from one representative experiment out of two independent experiments producing similar results.