Figure 5.

MDM2 stabilization is associated with p90RSK activation in primary melanomas and primary lung tumors. (A) Formalin-fixed, paraffin-embedded normal (N) and tumor (T) tissue samples were stained using an immunohistochemical technique for RSK phosphorylation. To this end, normal (N) or tumor (T) tissue samples were incubated with anti-pRSK antibodies. A diffuse cytoplasmic/nuclear positivity for pRSK characterized the T samples; in contrast, N samples present a reduction in the percentage of positive cells or only a weak positivity. For each tumor type (lung, melanoma and prostate), we show two representative images of different samples related to the samples (both T and N) shown in Supplementary Tables S1 and S2. 40× magnification. (B) Formalin-fixed, paraffin-embedded normal (N) and tumor (T) tissue samples were stained using an immunohistochemical technique for MDM2 and pRSK. Each tissue sample (both T and N) was stained with anti-MDM2 and anti-pRSK antibodies. Diffuse cytoplasmic/nuclear evident detection for pRSK is evident in tumor samples (T), while samples from normal lung and skin tissues (N) were less positive. Diffuse nuclear positivity to MDM2 staining, indicating its nuclear accumulation, characterizes the T samples, while the corresponding N samples are negative. Representative images of the samples indicated in Supplementary Tables S1 and S2 are shown. 40× magnification.