FIG. 2.

Snk/Plk2 is a p53 target gene in response to DNA-damaging agents. (a) hSnk/Plk2 mRNA expression after ionizing radiation in the normal human diploid lymphoblastoid cell line 2184D. 2184D cells were untreated or exposed to irradiation at 5 or 10 Gy, and total RNA was harvested 10 h after treatment. mRNA levels were determined by a TaqMan real-time quantitative RT-PCR assay. All expression levels were normalized to GAPDH in each well and are defined as the increases for samples relative to the level for untreated 2184D cells. (b) HCT116 Neo and E6 cells and H460 Neo and E6 cells were untreated or treated with adriamycin (0.2 μg/ml) (A), 0.2 μM etoposide (E), or 50 J/m² (UV), and total RNA was harvested 10 h after treatment. Northern blotting was performed for Snk/Plk2. An ethidium stain of the RNA confirms equivalent loading. (c) (Left panel) Mouse M3 lymphoma cells expressing mutant p53 (37°C) or wild-type p53 (32°C) were untreated or treated with adriamycin (0.2 μg/ml) and harvested after 10 h. Northern blotting was performed for mSnk/Plk2. (Right panel) Three mutant p53-expressing colon (SW480), ovarian (SKOV3), and breast cancer cell lines (SKBR3) were infected with either Ad-LacZ or Ad-p53, and total RNA was harvested 10 h after infection. Northern blotting was performed for Snk/Plk2. An ethidium stain of the RNA confirms equivalent loading.