title: Lack of imprinting of three human cyclin-dependent kinase inhibitor genes.
abstract: Genomic imprinting is an epigenetic modification in the germline leading to parental allele-specific gene expression in somatic cells. We have previously found that imprinted genes can be abnormally expressed or silenced in tumors and that the cyclin-dependent kinase inhibitor (CKI) CDKN1C (p57KIP2) is normally imprinted, with preferential expression of the maternal allele. Here we analyze the imprinting status of three additional CKIs, the abnormal expression and/or chromosomal localization of which has been implicated in human malignancy: CDKN1A, CDKN1B, and CDKN2C. Allele-specific expression was examined by reverse transcription-PCR, using primers that span transcribed polymorphisms as well as exon/intron boundaries, to distinguish cDNA products from genomic DNA. Biallelic expression was observed for all three genes in both fetal and adult tissues. Thus, genomic imprinting is not a generalized feature of CKIs.
authors.affiliation: Department of Molecular Biology & Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
authors.forename: G J
authors.initials: GJ
authors.lastname: Cost
authors.forename: J S
authors.initials: JS
authors.lastname: Thompson
authors.forename: B A
authors.initials: BA
authors.lastname: Reichard
authors.forename: J Y
authors.initials: JY
authors.lastname: Lee
authors.forename: A P
authors.initials: AP
authors.lastname: Feinberg
mesh_terms: D000328:Adult; D000483:Alleles; D002352:Carrier Proteins / Q000235:genetics*; D018797:Cell Cycle Proteins; D050763:Cyclin-Dependent Kinase Inhibitor p18; D050759:Cyclin-Dependent Kinase Inhibitor p21; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors*; D016213:Cyclins / Q000235:genetics*; D004791:Enzyme Inhibitors; D005656:Fungal Proteins / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007173:Imprinting, Psychological; D008869:Microtubule-Associated Proteins / Q000235:genetics*; D020409:Molecular Motor Proteins; D012150:Polymorphism, Restriction Fragment Length; D012333:RNA, Messenger / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D025521:Tumor Suppressor Proteins
chemical_list: C493956:CDKN1A protein, human; C493971:CDKN2C protein, human; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D050763:Cyclin-Dependent Kinase Inhibitor p18; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004791:Enzyme Inhibitors; D005656:Fungal Proteins; C075341:KIP2 protein, S cerevisiae; D008869:Microtubule-Associated Proteins; D020409:Molecular Motor Proteins; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases