Fig. 1.

Methylation of PTPRO CpG island in primary human lung tumors. (A) Quantitative representation of the methylation profile of the CpG island of PTPRO in 43 pairs of primary lung tumors and matching adjacent normal tissues. (B) Bisulfite genomic sequencing of a representative set of primary lung tumors along with its matching normal tissue. The PTPRO CpG island was amplified from bisulfite-converted DNA by using nested primers, cloned into TA vector, and five randomly picked clones were subjected to automated sequencing. Each row of boxes represents an individual clone from the sample. The open and filled boxes represent unmethylated and methylated cytosines, respectively, in a specific clone. The numbers on top correspond to the position of the CpG with respect to the transcription start site (+1).