FIG. 5.

p53 null and p53 wild-type tumors have different gene expression profiles. (A) Hierarchial clustering of normal liver tissue and tumor samples using 532 genes that most strongly discriminate between the two classes. The sample marked by an asterisk (*) shows data from a small p53 null tumor that clusters with normal tissue from p53 null livers, indicating possible contamination with normal tissue. The genes present in the cluster are identified in Table S1 in the supplemental data. (B) Analysis of clustering of p53 null and p53 wild-type tumors using 100 genes that most strongly discriminate between the two tumor groups. The genes present in the cluster are identified in Table S2 in the supplemental data. (C) Confirmation of differential expression by RT-PCR. RT-PCR assays demonstrating elevated expression of cathepsin E, Igf2, and H19 genes in p53 null tumors relative to p53 wild-type tumors.