The use of telomerase activity for the detection of prostatic cancer cells after prostatic massage.
OBJECTIVE
Prostate cancer is the most commonly diagnosed cancer in the United States. The diagnosis or followup of prostate cancer in men older than 50 years is based on digital rectal examination, measurement of the free-to-total prostatic specific antigen ratio and transrectal ultrasound assisted needle biopsy of the prostate. We developed and evaluated a noninvasive method for diagnosing prostate cancer based on the measurement of telomerase activity after prostatic massage in fresh voided urine or after urethral washing.


METHODS
We obtained 36 specimens of cells after prostatic massage in the fresh voided urine of 16 patients who subsequently underwent radical prostatectomy and after urethral washing in 20 who underwent prostate needle biopsies. Ethylenediaminetetraacetic acid was immediately added to the collected urine or washing to a final concentration of 20 mM. After protein extraction by CHAPS buffer each specimen was tested for telomerase activity in a 2-step modified telomeric repeat amplification protocol assay. The 2 prostate cancer cell lines PC-3 and LNCaP with high telomerase activity were used as a positive control.


RESULTS
Telomerase activity was detected in 14 of 24 samples with known prostate cancer (sensitivity 58%). In contrast, no telomerase activity was found in the 12 cases without histological evidence of prostate tumor (specificity 100%). Eight of 9 poorly differentiated cancers expressed telomerase activity (89%), while only 6 of 15 well and moderately differentiated cancers showed telomerase activity (40%).


CONCLUSIONS
Our data illustrate that telomerase activity may be detected in voided urine or washing after prostatic massage in patients with prostate cancer. Sensitivity was higher for poorly differentiated tumors. This approach is not currently available for detecting prostate cancer in clinical practice. However, these results are promising and further studies are ongoing.
Meid
F H
FH
Institute of Pathology and Department of Urology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
Gygi
C M
CM
Leisinger
H J
HJ
Bosman
F T
FT
Benhattar
J
J
D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D006801:Humans; D008297:Male; D008405:Massage; D008875:Middle Aged; D021141:Nucleic Acid Amplification Techniques; D011467:Prostate / Q000201:enzymology*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D012334:RNA, Neoplasm / Q000652:urine; D019098:Telomerase / Q000032:analysis*; D014407:Tumor Cells, Cultured / Q000378:metabolism; D014556:Urine / Q000166:cytology
D014408:Biomarkers, Tumor; D012334:RNA, Neoplasm; D019098:Telomerase