Reduced p53 Expression in Skin Tumors from <i>p19^Arf</i>-Deficient Mice

<div><p>(A) Western blot analysis of nuclear lysates from skin tumors from <i>p19^Arf (Arf)^+/+, p19^Arf+/−,</i> and <i>p19^Arf−/−</i> mice using p53-specific antibody. PA, papilloma; skin IR, irradiated normal skin</p> <p>(B) p53 immunostain of paraffin-embedded skin tumor sections from <i>p19^Arf+/+, p19^Arf+/−,</i> and <i>p19^Arf−/−</i> mice (arrows indicate positive stained cells) (top). p53 immunostain of irradiated papillomas (IR) from <i>p19^Arf+/+</i> and <i>p19^Arf−/−</i> mice (bottom). p53 is not detected in normal skin or tumors from <i>p19^Arf−/−</i> mice, but is induced by irradiation in both normal and tumor cells from <i>p19^Arf−/−</i> mice.</p>