Screen And Clone Of Methylative Difference DNA Fragments In Thyroid Cancer

Objective To investigate the aberrantly methylated status in human thyroid cancer.Methods (1) methylation-sensitive-representational difference analysis (MS-RDA)technique was employed to isolate the aberrantly methylated DNA fragments in thyroid cancer. (2)After they were cloned, these methylative difference fragments were analyzed with Blast tools.Results Following two successive competitive hybridization, 2 hypomethylativeand 1 hypermethylative genomic bands were identified. By sequencing, 3 hypo- and 5 hypermethylative DNA sequences were obtained. 5 DNA hypermathylative fragments showed low homology with any known gene of the total GenBank database. It's suggested that these fragments were from noval DNA sequences which were hypermethy-lated in thyroid cancer. 3 hypo- and 2 hypermathylative fragments were embodied by GenBank database. These fragments may provide new information for the research on pathogenesis of thyroid cancer.Conclusions By MS-RDA, we had cloned 8 DNA fragments which were meth-ylatively different in thyroid cancer. It is suggested that these fragments may playimportant roles in thyroid carcinogenesis.