title: Examination of IGF2 and H19 loss of imprinting in bladder cancer.
abstract: Loss of imprinting (LOI) is a common epigenetic event in cancer and may serve as an early biomarker in some cancers. To obtain a better understanding of LOI, we studied 41 bladder tumors and their adjacent normal bladder mucosa. We found 2/9 (22.2%) cases that displayed LOI of IGF2 and 2/16 (12.5%) that had LOI of H19, as determined by the evaluation of mRNA for biallelic expression. In addition, we examined allele-specific methylation of the differentially methylated regions (DMR) of IGF2 and H19 using a new allele-specific pyrosequencing assay. We found that DNA methylation changes were a common finding (21/30, 70%) in the DMR regions, but could not clearly link DNA methylation changes with LOI as measured by biallelic expression. LOI and allele-specific DNA methylation changes are present in bladder cancer; however, a better understanding of the biology of LOI and its relationship to DNA methylation changes is needed before its use as an epigenetic biomarker.
authors.affiliation: Division of Hematology, University of Southern California/Norris Comprehensive Cancer Center, Los Angeles, California 90033, USA.
authors.forename: Hyang-Min
authors.initials: HM
authors.lastname: Byun
authors.forename: Hui-Lee
authors.initials: HL
authors.lastname: Wong
authors.forename: Elliott Aaron
authors.initials: EA
authors.lastname: Birnstein
authors.forename: Erika M
authors.initials: EM
authors.lastname: Wolff
authors.forename: Gangning
authors.initials: G
authors.lastname: Liang
authors.forename: Allen S
authors.initials: AS
authors.lastname: Yang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D044127:Epigenesis, Genetic; D015972:Gene Expression Regulation, Neoplastic; D018392:Genomic Imprinting; D006801:Humans; D007335:Insulin-Like Growth Factor II / Q000096:biosynthesis*; D007413:Intestinal Mucosa / Q000473:pathology; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000096:biosynthesis*; D001743:Urinary Bladder / Q000473:pathology*; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; C094335:H19 long non-coding RNA; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D007335:Insulin-Like Growth Factor II