DETECTION AND DISTRIBUTION OF HEAT-SHOCK-PROTEIN-27 AND HEAT-SHOCK-PROTEIN-90 IN HUMAN BENIGN AND MALIGNANT PROSTATIC TISSUE

Objective To determine whether it is possible to predict the behaviour of prostate tumours by identifying cellular characteristics, specific ally specific heat shock proteins (HSPs). Materials and methods An imm unohistochemical study staining for HSP 27 and 90 was undertaken on 15 benign and 13 malignant samples of freshly frozen prostatic tissue ob tained from patients with a similar age range in each group (benign, m ean age 71.6 years, range 61-86; malignant, mean age 72.7 years, range 58-87), Gleason scores for the tumours ranged from 2 to 8. Results Co nsistent patterns of cytoplasmic staining were seen in all sections of tissue from benign prostatic hyperplasia (BPH). The stroma stained st rongly positive for HSP 27, but negatively for HSP 90 and glandular ep ithelium showed positive apical staining for both HSPs, Stromal patter ns in prostatic carcinoma tissue were similar to that of BPH tissue fo r both HSP 27 and 90. Areas of prostatic intra-epithelial neoplasia st ained as strongly as did adjacent areas of BPH. For HSP 27, there was varied staining of individual epithelial cells, suggesting cellular he terogeneity, with an apparent reduction in staining with increasing Gl eason score and invasiveness. For HSP 90, this pattern was less marked , with a predominance for positive staining throughout all grades of c arcinoma. Conclusions The distribution of HSPs, primarily HSP 27, may aid in identifying different cell populations within prostatic carcino mas and thus help forecast biological behaviour.