title: Identification of PRTFDC1 silencing and aberrant promoter methylation of GPR150, ITGA8 and HOXD11 in ovarian cancers.
abstract: Methylated promoter CpG islands (CGIs) can be used to find novel tumor-suppressor genes and disease markers. In this study, to identify promoter CGIs aberrantly methylated in human ovarian cancers, we performed a genome-wide screening for differentially methylated DNA fragments using methylation-sensitive-representational difference analysis (MS-RDA). MS-RDA isolated 185 DNA fragments specifically methylated in an ovarian cancer cell line (ES-2), compared with a normal human ovarian surface epithelial cell line (HOSE6-3), and 33 of them were derived from putative promoter CGIs. Ten ovarian cancer cell lines were analyzed by methylation-specific PCR, and seven (GPR150, LOC222171, PRTFDC1, LOC339210, ITGA8, C9orf64 and HOXD11) of the 33 CGIs were methylated in one or more of the cell lines. Their downstream genes were barely expressed in cell lines without unmethylated DNA molecules by quantitative reverse-transcription-PCR. Demethylation of methylated cell lines with 5-aza-2'-deoxycytidine restored expression of two genes (PRTFDC1 and C9orf64). In primary ovarian cancers, CGIs of GPR150 (in 4 of 15 cancers), ITGA8 (2/15), PRTFDC1 (1/15), and HOXD11 (1/15) were methylated. Silencing of PRTFDC1 was revealed here for the first time, and aberrant methylation of GPR150, ITGA8 and HOXD11 could be candidate tumor markers.
authors.affiliation: Carcinogenesis Division, National Cancer Center Research Institute, Japan.
authors.forename: Li-yi
authors.initials: LY
authors.lastname: Cai
authors.forename: Masanobu
authors.initials: M
authors.lastname: Abe
authors.forename: Shun-ichiro
authors.initials: S
authors.lastname: Izumi
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Imura
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Yasugi
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Ushijima
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics*; D045744:Cell Line, Tumor; D018899:CpG Islands / Q000235:genetics*; D019175:DNA Methylation; D017931:DNA Primers; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D023281:Genomics / Q000379:methods; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D039001:Integrin alpha Chains / Q000235:genetics; D010051:Ovarian Neoplasms / Q000235:genetics*; D043562:Receptors, G-Protein-Coupled / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; D017931:DNA Primers; C489493:HOXD11 protein, human; D018398:Homeodomain Proteins; D039001:Integrin alpha Chains; D043562:Receptors, G-Protein-Coupled