title: Regulation of high molecular weight-melanoma associated antigen (HMW-MAA) gene expression by promoter DNA methylation in human melanoma cells.
abstract: The human high molecular weight-melanoma associated antigen (HMW-MAA) is a membrane-bound chondroitin sulfate proteoglycan that is variably expressed in a high percentage of melanoma cell lines and tumors. Since the mechanism(s) regulating HMW-MAA expression has(ve) not been defined, in this study, we have examined whether promoter DNA methylation regulates the level of HMW-MAA expression. In melanoma cell lines, the level of HMW-MAA mRNA and protein expression is coordinately regulated, implicating a transcriptional control mechanism. Consistent with a role for regulation by DNA methylation, we have found that a dense CpG island flanks the human HMW-MAA gene transcriptional start site. Methylation-specific PCR and sodium bisulfite DNA sequencing analyses indicate that the HMW-MAA promoter is heavily methylated in melanoma cell lines, melanoma lesions and normal lymphocytes that do not express HMW-MAA; in contrast, the HMW-MAA promoter is not methylated in melanoma cell lines and tumors that express this antigen. In addition, HMW-MAA expression is markedly induced in HMW-MAA-negative melanoma cell lines by incubation with the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine. In summary, our results establish DNA methylation as a key regulator of HMW-MAA expression by human melanoma cells. This information represents a useful background to optimize immunotherapeutic strategies targeting HMW-MAA.
authors.affiliation: Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
authors.forename: W
authors.initials: W
authors.lastname: Luo
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.forename: T
authors.initials: T
authors.lastname: Kageshita
authors.forename: S
authors.initials: S
authors.lastname: Wakasugi
authors.forename: A R
authors.initials: AR
authors.lastname: Karpf
authors.forename: S
authors.initials: S
authors.lastname: Ferrone
mesh_terms: D000951:Antigens, Neoplasm / Q000235:genetics*; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000037:antagonists & inhibitors; D000077209:Decitabine; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008545:Melanoma / Q000235:genetics* / Q000556:secondary; D011401:Promoter Regions, Genetic / Q000235:genetics*; D014407:Tumor Cells, Cultured / Q000187:drug effects; D000099216:Chondroitin Sulfate Proteoglycan 4
chemical_list: D000951:Antigens, Neoplasm; D001374:Azacitidine; D015254:DNA Modification Methylases; D000077209:Decitabine; D004791:Enzyme Inhibitors; D000099216:Chondroitin Sulfate Proteoglycan 4