University of Southern California

University College London

Epigenomics Ag

Peter W Laird

Kathleen D Danenberg

Mihaela Campan

Daniel J Weisenberger

Kimberly D Siegmund

Martin Widschwendter

Cindy A Carroll

Cindy A Eads

Peter A Jones

Allen S Yang

Hui-Lee Wong

Binh N Trinh

Tiffany I Long

Tifany I Long

Particular aspects provide novel, high-throughput methods to quantify DNA methylation (e.g., at a single-base resolution) in an allele-specific manner. The methods comprise use of an allele-specific sequence polymorphism (e.g., allele-specific single nucleotide polymorphism; SNP) in sufficient proximity to a CpG methylation site to provide for distinguishing the methylation levels between two alleles. In particular aspects, after bisulfite modification, the genomic DNA region is PCR-amplified, and the product subjected to allele-specific pyrosequencing, and the percentage of methylation determined based on the percentage of cytosine to thymidine conversion. In further embodiments, MethyLight&#x2122; is used after bisulfite treatment. The inventive methodology has, for example, substantial utility for affording quantitative analyses in the regulation of analyses of X-inactivation, the allele-specific expression of genes (e.g., in the immune system) and junk DNA, etc., and in classifying an individual as to whether they have loss of imprinting (LOI).

High throughput method of DNA methylation haplotyping

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.

DNA methylation analysis by digital bisulfite genomic sequencing and digital methylight

Preferred aspects provide novel high-throughput, sensitive methods (e.g., real-time PCR-based (MethyLight&#x2122;) reactions) for detection and/or measurement of global genomic 5-methylcytosine content, based on measurement of DNA methylation of Alu, LINE-1 repetitive sequences, and the chromosome 1 centromeric satellite alpha and juxtacentromeric satellite 2 repeat sequences. Additional aspects provide sensitive methods for determining the amount of a DNA (e.g., in formalin-fixed, paraffin-embedded tissues). Combined (mean) use of Alu and Sat2 repeat methylation measurements provides for a surprisingly close correlation with global genomic 5-methylcytosine content measurements obtained by HPLC. Methylation of Alu repeats was determined to be closely associated with HPLC-based global methylation levels, as was methylation of satellite 2 and LINE-1 global genomic 5-methylcytosine content. The assays provide surrogate markers for global genomic 5-methylcytosine content analyzes, and have substantial utility for high-throughput and population-based studies (e.g., genetic and dietary influences on global DNA methylation, folate deficiency, MTHFR gene polymorphisms, etc).

High throughput methods comprising analysis of repetitive element DNA methylation

In particular aspects, stem-cell polycomb group (PcG) targets are more likely to have cancer-specific promoter DNA methylation than non-targets, indicating a stem-cell origin of cancer, where reversible gene repression is replaced by permanent silencing, locking the cell into a perpetual state of self-renewal and predisposition to subsequent malignant transformation. Exemplary aspects provide methods for identifying preferred DNA methylation markers for a cellular proliferative disorder and/or cancer and markers for developmental lineages and/or stages, based on identifying PcG protein or PcG repressive complex genomic target loci within a precursor cell (e.g., stem or progenitor cell) population, and determining, in cells of the proliferative disorder and/or cancer or cell of the particular developmental lineages and/or stages, a characteristic methylation status of the PcG target loci. Additional aspects provide methods for validating and/or monitoring a precursor cell (e.g., stem cell) population. Diagnostic and prognostic methods for ovarian and breast cancer are provided.

DNA methylation markers based on epigenetic stem cell signatures in cancer

Particular embodiments provide novel and clinically useful DNA methylation predictors of hormone receptor status, and predictors of response to endocrine (e.g., hormonal) and non-endocrine breast cancer therapy. The ESR1 gene, encoding the estrogen receptor (ER) alpha proved to be the preferred predictor of progesterone receptor (PR) status, while methylation of the PGR gene, encoding PR, was the preferred predictor of ER status. ESR1 methylation outperformed hormone receptor status as a predictor of clinical response in patients treated with antiestroges (e.g., tamoxifen), while promoter methylation of the CYP1B1 gene, encoding a tamoxifen and estradiol metabolizing cytochrome P450, predicted response differentially in tamoxifen-treated and non-treated patients. High levels of promoter methylation of the ARH1 gene, encoding a RAS-related small G-protein, were shown to be preferred predictors of better survival in patients who had not received tamoxifen therapy.

Association of the DNA methylation profile of the CYP1B1 gene with response to adjuvant therapy in breast cancer

There is disclosed an improved high-throughput and quantitative process for determining methylation patterns in genomic DNA samples based on amplifying modified nucleic acid, and detecting methylated nucleic acid based on amplification-dependent displacement of specifically annealed hybridization probes. Specifically, the inventive process provides for treating genomic DNA samples with sodium bisulfite to create methylation-dependent sequence differences, followed by detection with fluorescence-based quantitative PCR techniques. The process is particularly well suited for the rapid analysis of a large number of nucleic acid samples, such as those from collections of tumor tissues.

Process for high-throughput DNA methylation analysis

Particular aspects confirm the existence of a CpG island methylator phenotype (CIMP) in colorectal cancer, and provide novel validated DNA methylation markers associated with CIMP. Additional aspects provide novel methods and compositions for: determining CIMP status in colorectal cancers, determining the relationship between CIMP status and other molecular features of the cancers (e.g., BRAF mutation, KRAS mutation and MSI status); determining the relationship between CIMP status and other variables (e.g., age, sex, tumor location, family history, race, country of origin, tumor characteristics (including, tumor type, tumor grade, invasive margin characteristics, lymphocyte infiltration characteristics, direct spread, lymph node spread, venous spread and type of residual adjacent polyp, if present)); and determining, between subgroups defined by CIMP status and BRAF mutations, effects of selected risk factors (e.g., body mass index, smoking history, alcohol intake, dietary folate intake, folate metabolic enzyme polymorphisms and history of hormonal use).

Growing community of inventors

South Pasadena, CA, United States of America

Peter W Laird