Figure 4

Nuclear iASPP expression was increased in prostate cancer samples with a high level of TP53 expression. (a) iASPP expression in human prostate cancer samples was greater in both wild-type p53 (<30% nuclei expressing TP53) and mutant p53 (>30% nuclei expressing TP53) samples compared with benign prostate epithelium (P<0.05). Although the number of mutant p53 prostate cancer samples was small (n=5) compared with the number of wild-type p53 samples (n=195) we observed that the nuclear iASPP expression was higher in mutant p53 samples compared with wild-type p53 samples. (b) TP53 and iASPP expression in cells within the leading edge of locally invading pT3a prostate cancer was compared with other areas of the sample. TP53 expression was greatest in invading prostate cancer cells within the leading edge. iASPP expression was higher in prostate cancer cells with high TP53 expression, compared with cancer cells with low TP53 expression, in capsular-invading and intra-prostatic areas of tumour. Arrow depicts direction of invasion into the prostate capsule. (c) Nuclear iASPP is co-expressed with nuclear TP53 in DU145 prostate cancer cells at the invasive margin in organotypic co-cultures. (d) Immunoprecipitation of TP53 probed with anti-iASPP and anti-TP53 antibodies demonstrated that iASPP interacts with mutant TP53