Differential methylation of CpG islands within the dermo1 gene promoter in several cancer cell lines.

Inactivation of tumor-related genes by promoter hypermethylation is a common epigenetic event in the development of variety of tumors. Dermo1 (also called twist2) is a novel cancer-related gene which belongs to the basic helix-loop-helix (bHLH) transcription factor family. Herein, we report that dermo1 expression was sporadically abrogated in human cancer cells by transcriptional silencing associated with CpG island promoter hypermethylation. Direct sequencing of bisulfite-modified DNA from a panel of seven human cancer cell lines (HL60, Molm14, MV4-11, RS4:11, MDM-BA231, H358, and H1299) revealed that CpG dinucleotides in the dermo1 promoter were methylated. RT-PCR results demonstrated that dermo1 CpG island hypermethylation was accompanied by a low basal dermo1 expression level. Our data implicate dermo1 as a tumor suppressor gene and a valuable molecular marker for human cancer.