COMPARISON OF TELOMERASE ACTIVITY IN PROSTATE CANCER, PROSTATIC INTRAEPITHELIAL NEOPLASIA AND BENIGN PROSTATIC HYPERPLASIA

摘要

BACKGROUND: Telomerase is a reverse transcriptase enzyme that synthesizes telomeric DNA on chromosome ends. The enzyme is important for the immortalization of cancer cells because it maintains the telomeres. METHODS: Telomerase activity (TA) was measured by fluorescence-based telomeric repeat amplification protocol (FTRAP) assay in prostate carcinoma and benign prostatic hyperplasia (BPH). RESULTS: TA was present in 91.4% of 70 prostate cancers, 68.8% of 16 prostatic intraepithelial neoplasia (PIN), 43.3% of 30 BPH*, 21.4% of 14 atrophy and 20% of 15 normal samples adjacent to tumor. There was not any significant correlation between TA, histopathological tumor stage or gleason score. In contrast to high TA in the BPH* tissue from the cancer-bearing gland, only 6.3% of 32 BPH specimens from patients only diagnosed with BPH were telomerase activity- positive. CONCLUSIONS: These results indicate that TA is present in most prostate cancers. The high rate of TA in tissue adjacent to tumor may be attributed either to early molecular alteration of cancer that was histologically unapparent, or to the presence of occult cancer cells. Our findings suggest that the re-expression of telomerase activity could be one step in the transformation of BPH to PIN.