Overexpression of Bmi-1 in immortalized esophageal epithelial cell line and esophageal carcinoma cell lines. Expression of Bmi-1 protein (A), mRNA (B and C) in immortalized esophageal epithelial cell line (NE-3) and esophageal carcinoma cell lines (108CA, Kyse 140, Eca-109 and TE-1) analyzed by Western blot (A), RT-PCR (B) or real-time PCR (C). N was a normal esophageal tissue. Expression level was normalized by α-Tubulin or GAPDH. Error bars represent standard deviations (SD) calculated from three parallel experiments.