Objective To investigate telomere reduction and telomerase activity in
human transitional cell carcinomas (TCCs) of the bladder, using prima
ry tissue preparations, and their relationship to the clinicopathologi
cal properties of the TCC. Materials and methods Tumour tissues were o
btained from 21 patients together with apparently normal urothelia as
controls. The mean telomere length of each sample was determined using
southern blot analysis with an oligonucleotide probe (TTAGGG)(4) and
telomerase activity was semi-quantified using a polymerase chain react
ion based assay. Results The mean (se) telomere length was 6.6 (0.7) k
b in tumour tissues and 11.5 (0.4) kb in apparently normal urothelia a
djacent to the tumour (P < 0.001). Furthermore, it was 8.9 (1.4) kb an
d 3.4 (0.9) kb in superficial and invasive tumours (P = 0.002), respec
tively. Telomerase activity was detected in all 13 of the tumour tissu
es examined, with no relationship to telomere reduction, while it was
undetectable in any of the control tissues. Conclusions In human TCCs,
telomere length was reduced in tumour tissue, more so in superficial
than in invasive tumours. Telomerase was detectable only in tumour tis
sues and its activity was unrelated to telomere reduction.