YY1 expression in PDAC tissues and cell lines. (a, b) qRT-PCR analysis of YY1 expression in five normal pancreas tissues and 108 pairs of PDAC tissue and adjacent tissue. YY1 expression in the normal pancreas tissues was low, but was slightly higher in the tissue adjacent to PDAC tumors and significantly higher in the PDAC tumors themselves. Of the 108 paired tissues, YY1 expression was higher in the cancer tissue than in the adjacent tissues in 86 cases (p < 0.05). (c) A boxplot showing the qRT-PCR results of YY1 mRNA expression in the 108 cancer tissue, 108 adjacent tissue and five normal pancreas tissues (mean ± SD: 1.01 ± 1.01, 0.38 ± 0.43 and 0.03 ± 0.01, respectively). The bottom and the top edges of the box mark the lower boundary and upper boundary of the 95% confidence interval (CI) for the mean. The center horizontal line is drawn at the sample mean. The center vertical lines drawn from the boxes extend to the minimum and the maximum. (d) qRT-PCR analysis of YY1 expression in six PDAC cell lines. (e) Western blotting of YY1 expression in six PDAC cell lines. (f) A boxplot showing the immunohistochemistry (IHC) results of YY1 protein expression in the 108 cancer tissue, 108 adjacent tissue and five normal pancreas tissues. (g) IHC showing the location of YY1 in PDAC samples. Scale bar, 100 μm. (** represents p < 0.01, # represents p < 0.001, compared with the control group).