Identification of a novel human cancer/testis gene MAEL that is regulated by DNA methylation

The mouse maelstrom (MAEL) gene has been found to be expressed in male germ cells and to play a role in spermatogenesis. Here, we cloned the human MAEL gene by digital differential display and found that, among human tissues, MAEL is only expressed in the testis, but it is also expressed in various cancer cell lines. The transcription start site of the MAEL gene is 74-bp upstream of the start codon. The region from −216 to +150 is the basal promoter of the MAEL gene, and a CpG island (−295 to +148) is located in this region. Treatment with the demethylating agent 5′-Aza-2-Deoxycytidine significantly upregulated MAEL expression. These results suggest that MAEL is a novel cancer/testis-associated gene and is regulated by DNA methylation.