Significant telomere reduction in human superficial transitional cell carcinoma

Objective To investigate telomere reduction and telomerase activity in human transitional cell carcinomas (TCCs) of the bladder, using primary tissue preparations, and their relationship to the clinicopathological properties of the TCC. Materials and methods Tumour tissues were obtained 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 reaction based assay. Results The mean (se) telomere length was 6.6 (0.7) kb in tumour tissues and 11.5 (0.4) kb in apparently normal urothelia adjacent to the tumour (P < 0.001). Furthermore, it was 8.9 (1.4) kb and 3.4 (0.9) kb in superficial and invasive tumours (P = 0.002), respectively. Telomerase activity was detected in all 13 of the tumour tissues 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 tissues and its activity was unrelated to telomere reduction.