Figure 2. Transcripts levels of BRCA1, CTSL, and 53BP1 in growth-arrested and cycling human fibroblasts. (A) Quantitation of BRCA1 transcripts levels by qRT-PCR in human fibroblasts expressing telomerase (BJ+hTERT) either growing asynchronously, growth arrested by contact inhibition, or released from the growth arrest. Relative expression is compared in all conditions between cells incubated in water as control and cells incubated with 10 μM E64. (B) Quantitation of CTSL transcripts levels as in (A). (C) Quantitation of 53BP1 transcripts levels as in (A). **Represents P value of statistical significance (P ≤ 0.05) of that sample compared with all the other samples in the experiment. The complete statistical analysis of all the samples under the different conditions is shown in supplemental information.