Analysis of retinoblastoma gene expression in human prostate tissue

The retinoblastoma (RB) gene has been reported to be deleted in a number of human cancers including urologic tumors. In the present study, we used polymerase chain reaction (PCR) employing total RNA extracted from snap-frozen tumor specimens of ten benign prostatic hyperplasia and nine cancer specimens to test for the presence of a short sized mRNA transcript to screen for point mutations at the exon–intron boundaries between exons 13 and 23. None of the tissue entered in the study showed any evidence of an aberrant short sized mRNA. In addition, we used DNA-PCR to investigate deletional changes within exons 13 and 17 in an additional 5 benign lesions and 18 adenocarcinomas of the prostate but failed to demonstrate any deletions within exons 13 and 17 at the DNA levels in these cancer specimens. Furthermore, we examined the immunostaining patterns for the RB protein in the benign and malignant glands but found no significant difference between the two groups. We therefore concluded that, in contrast to other human tumors, the RB gene is not commonly altered in cancer of the prostate.