Simona Nanni, Michela Narducci, Linda Della Pietra, Fabiola Moretti, Annalisa Grasselli, Piero De Carli, Ada Sacchi, Alfredo Pontecorvi, Antonella Farsetti
Effect of the selective aromatase inhibitor letrozole on the interaction between ERs and the hTERT-ERE and on telomerase activity. (a) LNCaP cells were cultured for 16 hours in the absence (lanes 2 and 3) or the presence of E2 (10–7 M, lanes 4 and 5) or T (10–7 M) (lanes 6–9) with (lanes 3, 5, and 9) or without the nonsteroidal aromatase inhibitor letrozole (1 μM) added 1 hour before hormone addition. Nuclear extracts (5 μg) were then prepared and incubated with a 32P-labeled oligonucleotide encompassing the proximal hTERT-ERE. Reaction in the presence of anti-AR (αAR) or anti–ER-β (αERβ) Ab’s are shown in lanes 7 and 8, respectively. Lane 1 corresponds to probe incubated without nuclear extracts. Migration of a slower migrating complex is indicated (arrow). (b) Extracts (0.1 μg) from LNCaP cells treated for 4 hours with R1881 (10–8 M) or T (10–7 M) with or without the nonsteroidal aromatase inhibitor letrozole (1 μM) added 1 hour before ligand addition were assayed for telomerase activity by TRAP.