DNA METHYLATION ANALYSIS BY DIGITAL BISULFITE GENOMIC SEQUENCING AND DIGITAL METHYLIGHT

摘要

Provided are novel sensitive methylation assays referred to herein as Digital MethyLight, comprising stochastically distributing and compartmentalizing bisulfite-treated genomic DNA over multiple PCR reaction wells for detection of individually methylated DNA molecules in a large background of unmethylated DNA. Digital Bisulfite Genomic DNA Sequencing methods are also provided for high-resolution DNA methylation information without subcloning. Background signal and PCR contaminants are diluted, while the ratio of primer to methylated template DNA is kept high. Preferably, biological fluid (e.g., urine, blood-based (e.g., plasma and/or serum)) samples are analyzed for cancer diagnosis, prognosis and surveillance. Multiplexed PCR formats may be implemented to enhance when using small DNA amounts. Compositions and methods for diagnosis and/or prognosis of breast cancer, comprising the use of FOXE1, CLDN5 and/or RUNX3 gene markers are also provided (SEQ ID NOS: 17, 16 and 18, respectively for respective CpG island sequences), and in preferred embodiments plasma or serum samples are used.