Fig 2.

Telomere-elongated PC-3 cells without hTERT overexpression. (A) Western blot analysis (upper panel) and TRAP assay (bottom panel) at population doubling (PD) 50. DAT-hTERT and wild-type hTERT with loxP (LhTERTL) elevated telomerase activity. After the introduction of Cre at PD 40, only endogenous hTERT and telomerase activities were detected in PC-3/LhTERTL/cre+ cells. (B) Telomere Southern blot analysis. PC-3/DAT-hTERT cells did not have elongate telomeres despite enhanced telomerase activity. PC-3/LhTERTL cells had elongated telomeres, which were maintained even after shutdown of the transgene until at least PD 80. (C) Combined immunofluorescence and FISH at PD 50, just before subcutaneous injection. Most cells showed the expected patterns of hTERT and telomere signal intensities.