E4F1 knockdown leads to reduction of TERT promoter transcription and telomerase activity in 575A cells. (A) mRNA expression data of TERT and target genes following 48 + 72 h (48-h virus transduction, 72-h puromycin selection) post-shRNA knockdown in 575A, with shGFP as control. Data shown as mean of values from three biological replicates. (B) Representative western blot image following 48 + 72 h post-shRNA knockdown in 575A, with shGFP as control. (C) ddPCR-TRAP assay measuring telomerase activity following 48 + 72 h post-shRNA knockdown in 575A, with shGFP as control. Telomerase-negative U2OS and Saos2 were used as negative controls. Positive droplets quantified are labeled in blue. (D) Quantification of data in C; data shown as mean of values from three biological replicates. All statistical significance was calculated using a two-sampled t-test, and the degree of significance is indicated as follows: (*) P < 0.05, (**) P < 0.01, (***) P < 0.001.
