Figure 5
p63-expressing prostate tumors do not invariably silence GSTP1. (a) A representative p63-expressing tumor with high GSTP1 protein expression by immunohistochemistry and concomitant lack of hypermethylation at the CpG island of the GSTP1 gene by bisulfite sequencing (case A, bottom). (b) This p63-expressing tumor shows lack of GSTP1 expression, consistent with hypermethylation at the GSTP1 locus by bisulfite sequencing at levels comparable with usual-type adenocarcinoma controls (case B, bottom). (c) This p63-expressing tumor is admixed with usual-type p63-negative carcinoma and shows mixed GSTP1 protein expression. Bisulfite sequencing in this case shows hypermethylation of the GSTP1 locus at levels similar to usual-type adenocarcinomas (case C, bottom). Red bar indicates genomic location of the bisulfite sequencing amplicon; yellow bar indicates region of differential methylation between normal prostatic epithelium and usual-type adenocarcinoma; green bar indicates promoter associated CpG island. All images are at × 100 magnification.
