Using the sensitive telomeric repeat amplification protocol assay, we
detected telomerase activity in 26 of 35 (74.3%) renal cell carcinomas
analyzed. Subdivision of the tumors according to telomerase activity
did not reveal an obvious association between the presence of telomera
se activity and histomorphological stage, grade, tumor size, or DNA pl
oidy. Furthermore, no association was found between telomerase activit
y and a distinct chromosomal aberration pattern; namely, loss of genet
ic material on the short arm of chromosome 3. Telomerase activity was
also detected in 6 of 35 (17.1%) normal corresponding renal tissue sam
ples, which seems interesting in light of the supposed biological role
of telomerase expression in carcinogenesis. Interestingly, telomerase
activity was detected in three of the four (75%) kidneys bearing non-
clear cell tumor types, whereas of the 31 kidneys with clear cell carc
inomas, telomerase activity was found in only 3 (9.7%) normal tissue s
amples. In addition, the two renal angiomyolipomas and one of the two
analyzed transitional cell carcinomas of the renal pelvis were telomer
ase negative.