Figure 3

(A&B): Gel shift analysis showing levels of active AP-1 DNA binding complexes present in HPV-positive and HPV-negative esophageal cancer biopsies. (A) γ³²P-labelled double stranded AP-1 oligonucleotides were co-incubated with 10 μg of nuclear protein extracts from HPV16 positive (C1), HPV negative (C2) esophageal tumor biopsies and corresponding normal adjacent tissues (N1, N2), analyzed on a 4.5% PAGE. The intensities of the bands were quantified as indicated in methods. Nuclear extracts of HeLa cells, which constitutively express active AP-1, was used as positive control. (B) Mean fold change in AP-1 binding activity in HPV negative and HPV positive esophageal cancer with respect to normal adjacent control tissues. Error bars indicate standard deviation, p-value 0.02 as compared to HPV negative tumor tissue. Arrows indicate the position of specific retarded bands.