A single nucleotide polymorphism chip-based method for combined genetic and epigenetic profiling: validation in decitabine therapy and tumor/normal comparisons.
Progress on several unresolved issues in cancer epigenetics will benefit from rapid and standardized methods for profiling DNA methylation genome-wide. In the area of epigenetic therapy, the demethylating drug decitabine (5-aza-2'-deoxycytidine) is increasingly used to treat acute myelogenous leukemia and myelodysplastic syndrome, but the mechanisms of its anticancer activity have remained unclear. Given the clinical efficacy of decitabine and the uncertainties about its mode of action, it will be useful to optimize methods for following DNA methylation as a biochemical response in individual patients. Here, we describe a single nucleotide polymorphism (SNP) chip-based method (MSNP) for profiling DNA methylation. Using this procedure, the extent of demethylation in bone marrow aspirates from patients with leukemia receiving decitabine can be assessed genome-wide using commercially available (Affymetrix) SNP chips. We validated the accuracy of MSNP by comparing the results with combined bisulfite restriction analysis and by sequencing cloned PCR products from bisulfite-converted DNA. We further validated MSNP in a Wilms' tumor/normal kidney comparison, comparing the results with methylation-sensitive Southern blotting. MSNP simultaneously detects aberrations in DNA copy number and loss of heterozygosity, making it a generally useful approach for combined genetic and epigenetic profiling in tissue samples from cancer patients.
Institute for Cancer Genetics, Columbia University Medical Center, 1150 St. Nicholas Avenue, New York, NY 10032, USA.
Eric
E
Yuan
Fatemeh
F
Haghighi
Susan
S
White
Ramiro
R
Costa
Julie
J
McMinn
Kathy
K
Chun
Mark
M
Minden
Benjamin
B
Tycko
D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use*; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D015139:Blotting, Southern; D019175:DNA Methylation / Q000187:drug effects*; D004273:DNA, Neoplasm / Q000235:genetics; D000077209:Decitabine; D044127:Epigenesis, Genetic; D018628:Gene Dosage; D006801:Humans; D007680:Kidney Neoplasms / Q000188:drug therapy / Q000235:genetics*; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D020641:Polymorphism, Single Nucleotide; D015203:Reproducibility of Results; D013447:Sulfites / Q000737:chemistry; D009396:Wilms Tumor / Q000188:drug therapy / Q000235:genetics*
D000964:Antimetabolites, Antineoplastic; D004273:DNA, Neoplasm; D013447:Sulfites; D000077209:Decitabine; D001374:Azacitidine; C042345:hydrogen sulfite