Effect of TAT-NPM proteins on expression of genes controlling cell cycle, apoptosis, and inflammation. (A) Effect on negative regulators of cell-cycle progression. Primary MEFs were treated with BSA, TAT-NPM, or TAT-NPMΔC (30 μg/mL each) for 12 hours, and whole cell extracts or RNA were prepared for analyses of p53, p21^Waf1, p16^Ink4a, p19^Arf, and p27^KIP1 by immunoblotting (left and middle panels) or p16^Ink4a and p19^Arf mRNAs by RT-PCR (right panel). (B) Cells described in panel A were analyzed for expression of positive regulators of cell-cycle progression by immunoblotting. (C) Reduced levels of antiapoptotic proteins in cells treated with TAT-NPMΔC, as examined by immunoblot analysis of cell extracts described in panel A. (D) TAT-NPMΔC suppresses expression of inflammatory genes. Expression of genes encoding inflammatory genes was examined in BSA, TAT-NPM, and TAT-NPMΔC–treated cells stimulated with TNF-α (10 ng/mL) for 30 minutes. Cells were collected, total RNA was prepared, and gene expression was analyzed by real-time PCR and normalized to GAPDH mRNA. Results are means plus or minus SD of 3 independent experiments.