OCT4-transduced breast cells (OTBCs) underwent an immortalization process. (a) OTBCs overcame cellular senescence. The histogram quantifies β-galactosidase-positive cells in the OTBCs-86L1 and OTBCs-48L1 lines. Data were normalized to the parental cell lines p86 and p48 and represent the mean ± standard deviation (SD) of three independent experiments (*P ≤0.01). (b) Telomerase mRNA levels are upregulated in OTBCs relative to the parental p86 and p48 lines. The SUM159PT breast cancer cell line was used as a positive telomerase gene expression control. Samples were normalized to the parental p86 and p48 lines. Bar graphs represent the mean ± SD of three independent experiments. (c) OTBCs downregulate p16Ink4a mRNA levels as assessed by quantitative real-time polymerase chain reaction. The p16Ink4a levels in OTBCs were normalized to the parental lines. Bar graphs represent the mean ± SD of three independent experiments. hTERT, human telomerase reverse transcriptase.
Beltran et al. Breast Cancer Research 2011 13:R94 doi:10.1186/bcr3019