Figure 5.

Telomerase downregulation decreases the proliferation of breast cancer cells. (A) The cumulative population doublings was calculated for each 96 h ((log (total number of cells counted at the day of passage) − log (number of cells initially seeded at the previous passage))/log2). The monitoring period of proliferation potential is 9 weeks after transduction. The experiment was repeated three times. (B) Immunodetection of Ki-67, p53, p-p53, and p21 was performed using Western blot in MCF7 and MDA-MB-231 cells on the 21st-day. 0.1 μM DOX; 8h treatment, followed by densitometry analysis (C). (*) p < 0.05; (**) p < 0.01; (***) p < 0.001 relative to shRNA Control. Densitometry analysis was performed out of three scanned membranes from 3 independent experiments. (D) Analysis of the biochemical-aging marker, the enzyme β-galactosidase (SA-β-Gal). Cells were subjected to hTERT downregulation, and the effect was assessed after 21 days from transduction. A typical result out of 2 replicates was demonstrated (arrows indicate green/β-galactosidase signal), magnification 100×, scale bars 100 μm.