Fig. 2. Effect of TGF-ß1 treatment on hTERT expression. (a) hTERT transcription in HaCaT (upper gel) and HaCaT-myc cells (lower gel) after TGF-ß1 treatment. hTERT total mRNA expression was measured by RT-PCR using primers 1784S and 1928A (Ulaner et al., 1998). (b) hTERT splicing after TGF-ß1 treatment. RT-PCR was carried out with primers TERT-HT2026F and TERT-HT2482R (Kilian et al., 1997). fl, full length; , splice; ß, ß splice. (c) hTERT expression in HaCaT-TERT cells: RT-PCR as in (b), but to remain in the exponential phase only 30 cycles of amplification were performed. The endogenous and ß splice variants are not detectable owing to high expression of the exogenous hTERT transcript. Untransfected HaCaT cells (control and treated with TGF-ß1 for 96 hours) were amplified under the same conditions and included for comparison of the expression level of the endogenous with the exogenous gene and as control for the TGF-ß1 activity.