Figure 2.

In tumor cell lines with strongly active p90RSK, MDM2-mediated p53 degradation is controlled by p90RSK. (A) A549, A375 and LNCaP cells were incubated with 10 μM BI-D1870 for the indicated times. The efficiency of the inhibition was confirmed by anti-phospho-S102 YB1 antibody. The immunoblot was checked by anti-p53, anti-MDM2 and anti-phospho-S166 antibodies, and anti-tubulin antibody was used for normalization. (B) A549, A375 and LNCaP cells were seeded in culture medium with 2 μM wortmannin for the indicated times. The efficiency of wortmannin was confirmed by using anti-phospho-T308 AKT antibody. The immunoblot was checked using anti-p53, anti-MDM2 and anti-phospho-S166 MDM2 antibodies, and normalization was carried out by immunoblotting with anti-tubulin antibody. (C) A549, A375 and LNCaP cells were seeded in culture medium with BI-D1870 to a 4 µM final concentration for the indicated times (h). The efficiency of the BI-D1870 was confirmed with anti-phospho-S102 YB1 antibody. The immunoblot was checked using anti-p53, anti-MDM2 and anti-phospho-S166 MDM2 antibodies and then normalized using tubulin. All presented experiments were repeated three times with consistent results.