Fig. 8

Hypomethylation of four sites in Fgfr4 in tumors induced by MWCNTs and amosite asbestos. A Partial alignment of bisulfite sequences in control peritoneal tissues along the promoter region of Fgfr4, showing frequent methylation of all four sites: a CpG (− 266CpG), 2 sequence variations (− 226T > C; − 124T > C), and a non-CpG site (-117CpT). Methylated cytosines (blue boxes) are not converted into uracil by bisulfite treatment and remain unchanged. In contrast, similar alignment of bisulfite sequences in clones from tumors induced by MWCNT D did not show these frequently methylated sites. Instead, there is a high frequency of methylated cytosines in non-CpG sites. B Sequence electropherograms showing the four methylated sites in clones from a control peritoneal tissue (BF3). C Methylation frequency for the four sites in tumors and control tissues