Nasopharyngeal carcinoma (NPC) is a common tumor in the head and neck. There are a high incidence of NPC in south of China. Its pathogenesis is not very clear. It may be related to a variety of factors. In recent years, epigenesis of gene attracted much attention from researchers. Abnormality of DNA methylation is an important mechanism of epigenetic regulation. Methylation status of gene promoter is related to gene activity [
1,
2]. DNA methylation plays an important role in tumorigenesis. CpG island methylation of tumor suppressor gene resulted in inactivation of the gene transcription has become an important part of cancer epigenetics research. Multiple tumor suppressor genes inactivated by promoter CpG island methylation have been found in a variety of tumor tissues and cells. Such as promoter hypermethylation and BRCA1 inactivation in sporadic breast and ovarian tumors [
3], hypermethylation of the APC (adenomatous polyposis coli) gene promoter region is involved in human colorectal carcinoma [
4], incidence and functional consequences of hMLH1 promoter hypemethylation in colorectal carcinoma[
5], hypermethylation around the promoter may be a mechanism of E-cadherin inactivation in human carcinomas [
6]. The transcription factor SOX11 is one of members of the SRY box-containing (SOX) family emerging as important transcriptional regulators, which as a whole controls cell fate and differentiation [
7]. Twenty SOX genes have been identified in mouse and human genomes. All SOX genes contain a DNA-binding high mobility group (HMG) domain and protein specific domains implicated in activation and repression of gene transcription [
8]. It has been found that SOX11 plays an important role in the development of nervous system and adult neurogenesis [
9,
10]. SOX11 up-regulation has been detected in various types of solid tumors, such as gliomas and epithelial ovarian tumors [
11,
12]. Vegliante found that SOX11 expression is related to methylation of SOX11 gene promoter in lymphoid neoplasms [
13].
In the present study, we have performed on methylation of SOX11 gene, inclouding DNA methylation in the tissues of nasopharyngeal carcinoma and DNA demethylation in the CNE2 cell line (human nasopharyngeal carcinoma cell line). The findings shows that weak expression of SOX11 is related to methylation of SOX11 gene promoter in the tissues of nasopharyngeal carcinoma, and SOX11 re-expression is associated with demethylation of SOX11 gene by 5-aza-2'-deoxycytidine treated in CNE2 cells.