title: Aberrant promoter methylation of insulin-like growth factor binding protein-3 gene in human cancers.
abstract: Insulin-like growth factor binding protein-3 (IGFBP-3) is postulated to be a mediator of growth suppression signals. Here, we examined the methylation status of IGFBP-3 to correlate to clinicopathological factors in human cancers. The methylation status of IGFBP-3 was determined by bisulfite DNA sequencing and was correlated with expression semi-quantified by real-time RT-PCR to develop a methylation-specific PCR (MSP) assay for IGFBP-3. Using the MSP assay, we examined the methylation status of IGFBP-3 in gastric cancer (GC), colorectal cancer (CRC), breast cancer (BC) and malignant mesothelioma (MM). IGFBP-3 methylation was detected in 6 of 13 (46%) and 16 of 24 (67%) GC cell lines and tumors, respectively; 4 of 8 (50%) and 15 of 26 (58%) CRC cell lines and tumors, respectively; 3 of 11 (27%) and 7 of 39 (18%) BC cell lines and tumors, respectively and 1 of 5 (20%) and 18 of 56 (32%) MM cell lines and tumors, respectively. Interestingly, the methylation status of MM specimens from Japanese patients (75%, 12 out of 16 patients) was significantly higher than those from the USA (15%, 6 out of 40 patients) (p < 0.0001), suggesting the presence of ethnic differences in the IGFBP-3 methylation status. We also found that IGFBP-3 methylation was preferentially present in GCs arising in the lower-third of the stomach (p = 0.079). In summary, our results showed that IGFBP-3 methylation played an important role in the silencing of its expression, suggesting that IGFBP-3 may act as a tumor suppressor gene in several human cancers examined.
authors.affiliation: Department of Cancer and Thoracic Surgery, Shikata Laboratory, Advanced Science Research Center, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
authors.forename: Kunitoshi
authors.initials: K
authors.lastname: Tomii
authors.forename: Kazunori
authors.initials: K
authors.lastname: Tsukuda
authors.forename: Shinichi
authors.initials: S
authors.lastname: Toyooka
authors.forename: Hideaki
authors.initials: H
authors.lastname: Dote
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hanafusa
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Asano
authors.forename: Minoru
authors.initials: M
authors.lastname: Naitou
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Doihara
authors.forename: Takumi
authors.initials: T
authors.lastname: Kisimoto
authors.forename: Hideki
authors.initials: H
authors.lastname: Katayama
authors.forename: Harvery I
authors.initials: HI
authors.lastname: Pass
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Date
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Shimizu
mesh_terms: D024506:5' Flanking Region / Q000235:genetics; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000235:genetics / Q000473:pathology; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation; D017931:DNA Primers / Q000235:genetics; D004273:DNA, Neoplasm / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D019073:HT29 Cells; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000235:genetics*; D009369:Neoplasms / Q000235:genetics / Q000473:pathology*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013274:Stomach Neoplasms / Q000235:genetics / Q000473:pathology
chemical_list: D017931:DNA Primers; D004273:DNA, Neoplasm; D018972:Insulin-Like Growth Factor Binding Protein 3; D012333:RNA, Messenger