title: Evaluation of MYB promoter methylation in salivary adenoid cystic carcinoma.
abstract: The transcription factor MYB was recently proposed to be a promising oncogene candidate in salivary gland adenoid cystic carcinoma (ACC). However, the up-regulation of MYB in ACC could not be explained solely by deletion of its 3' end. It is widely accepted that the promoter methylation status can regulate the transcription of genes, especially in human cancers. Therefore, it is important to know whether MYB promoter demethylation could explain the over-expression of MYB in ACC. By using the Methprimer program, we identified nine CpG islands in the promoter of MYB. All of these CpG islands were located within the -864 to +2082 nt region relative to the transcription start site of MYB. We then used bisulfite genomic sequencing to evaluate the methylation levels of the CpG islands of MYB in 18 primary ACC tumors, 13 normal salivary gland tissues and nine cancer cell lines. Using cell lines, we also determined the relative MYB expression levels and correlated these with the methylation levels. With bisulfite genomic sequencing, we found no detectable methylation in the CpG islands of MYB in either ACC or normal salivary gland tissues. There was a variable degree of MYB expression in the cell lines tested, but none of these cell lines demonstrated promoter methylation. Promoter hypomethylation does not appear to explain the differential expression of MYB in ACC. An alternative mechanism needs to be proposed for the transcriptional control of MYB in ACC.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors.forename: Chunbo
authors.initials: C
authors.lastname: Shao
authors.forename: Weiliang
authors.initials: W
authors.lastname: Bai
authors.forename: Jacqueline C
authors.initials: JC
authors.lastname: Junn
authors.forename: Mamoru
authors.initials: M
authors.lastname: Uemura
authors.forename: Patrick T
authors.initials: PT
authors.lastname: Hennessey
authors.forename: David
authors.initials: D
authors.lastname: Zaboli
authors.forename: David
authors.initials: D
authors.lastname: Sidransky
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Califano
authors.forename: Patrick K
authors.initials: PK
authors.lastname: Ha
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003528:Carcinoma, Adenoid Cystic / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D018899:CpG Islands / Q000502:physiology; D019175:DNA Methylation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011401:Promoter Regions, Genetic; D012468:Salivary Gland Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D014157:Transcription Factors