Genome-wide maps of methylations in experimental lingual carcinogenesis

To identification of genome wide DNA methylation profiling during lingual tumorigenesis, tongue cancer was induced by oral delivery of 4-nitroquinoline-1-oxide (4NQO) at a dose of 50mg/L for 16weeks in C57BL/6J female mice. Nine samples of lingual mucosa from 0 (encoded as C in experiment), 12 (encoded as M in experiment) and 28 (encoded as E in experiment) week, which were supposed as normality, early and advanced stage during lingual tumorigenesis, were harvested for methylated DNA Immunoprecipitation sequencing. Illumina HiSeq 2000 was used to obtain DNA methylation profiles across 16023 CpG Islands including 26600 promoters and 21625 genebodies in murine tongue samples. Samples included 3 normal lingual mucosa,3 lingual mucosa with hyperplasia, mild and moderate dysplasia, 3 lingual mucosa with carcinoma in situ and invasive cancer. DNA from the 9 samples were fragmented and methylated DNA were immunoprecipitated by anti-5-methylcytosine antibody. The samples were sequenced by Illumina HiSeq 2000.