title: Microarray-based DNA methylation profiling: technology and applications.
abstract: This work is dedicated to the development of a technology for unbiased, high-throughput DNA methylation profiling of large genomic regions. In this method, unmethylated and methylated DNA fractions are enriched using a series of treatments with methylation sensitive restriction enzymes, and interrogated on microarrays. We have investigated various aspects of the technology including its replicability, informativeness, sensitivity and optimal PCR conditions using microarrays containing oligonucleotides representing 100 kb of genomic DNA derived from the chromosome 22 COMT region in addition to 12 192 element CpG island microarrays. Several new aspects of methylation profiling are provided, including the parallel identification of confounding effects of DNA sequence variation, the description of the principles of microarray design for epigenomic studies and the optimal choice of methylation sensitive restriction enzymes. We also demonstrate the advantages of using the unmethylated DNA fraction versus the methylated one, which substantially improve the chances of detecting DNA methylation differences. We applied this methodology for fine-mapping of methylation patterns of chromosomes 21 and 22 in eight individuals using tiling microarrays consisting of over 340 000 oligonucleotide probe pairs. The principles developed in this work will help to make epigenetic profiling of the entire human genome a routine procedure.
authors.affiliation: The Krembil Family Epigenetics Laboratory, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, Canada M5T 1R8.
authors.forename: Axel
authors.initials: A
authors.lastname: Schumacher
authors.forename: Philipp
authors.initials: P
authors.lastname: Kapranov
authors.forename: Zachary
authors.initials: Z
authors.lastname: Kaminsky
authors.forename: James
authors.initials: J
authors.lastname: Flanagan
authors.forename: Abbas
authors.initials: A
authors.lastname: Assadzadeh
authors.forename: Patrick
authors.initials: P
authors.lastname: Yau
authors.forename: Carl
authors.initials: C
authors.lastname: Virtanen
authors.forename: Neil
authors.initials: N
authors.lastname: Winegarden
authors.forename: Jill
authors.initials: J
authors.lastname: Cheng
authors.forename: Thomas
authors.initials: T
authors.lastname: Gingeras
authors.forename: Arturas
authors.initials: A
authors.lastname: Petronis
mesh_terms: D002874:Chromosome Mapping; D002891:Chromosomes, Human, Pair 21; D002892:Chromosomes, Human, Pair 22; D018899:CpG Islands; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D015894:Genome, Human; D023281:Genomics / Q000379:methods*; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D015203:Reproducibility of Results
chemical_list: D004247:DNA