Figure 1

Bisulfite-modified sequencing analysis of p16 INK4a 5' CpG island in cervical carcinomas and cervical cancer cell lines. A. Schematic representation of the p16 INK4a 5' region: broken arrow indicates the location of the translation start site; figures above horizontal line indicate the numbers of CpG dinucleotides relative to the translation start site; vertical lines indicate Hpa II recognition sites; horizontal arrows indicate positions of primers for MSP analysis [30], + indicates MSP-positive samples; each row of circles represents a sequence of total PCR product generated from bisulfite-treated DNA of tumor (T) and normal adjacent tissue (N) or sequence of cloned PCR product (cl), one clone out 5 identical clones is presented; figures on the left side of scheme indicate specimen numbers; open circles – unmethylated cytosine, gray circles – partially methylated cytosine, black circles – methylated cytosine, triangles – status of cytosine is not detected. B. Chromatograms showing CpG-dinucleotides with unmethylated and partially methylated cytosines in some normal and tumor tissues. Numbers of CpG-dinucleotides and samples are indicated, as in A.