Table 2.

p16 CpG methylation sequencing analysisa

Stage of cellsHMEC6HMEC9
ClonebCpG methylationcClonebCpG methylationc
Early passage without E6Passage 3NDd
 Clone A0
 Clone B1
 Clone C1
 Clone D0
After M0 escape with E6Passage 12Passage 16
 Clone A6 Clone A8
 Clone B6 Clone B9
 Clone C14 Clone C10
 Clone D10 Clone D7
Later passage with E6Passage 25Passage 42
 Clone A19 Clone A17
 Clone B20 Clone B28
 Clone C25 Clone C9
 Clone D19 Clone D18
Later passage with E6/E7NDPassage 32
 Clone A0
 Clone B0
 Clone C0
 Clone D0
  • a Methylation in the p16 CpG island region from −159 to +135 (according to the numbering system of Hara et al. (21), with +1 being the translational start site), which contains 35 CpG dinucleotides.

  • b Each clone represents an individual PCR product.

  • c Each value is the number of methylated sites out of the 35 CpG sites.

  • d ND, not done.