Using the methylome to identify aggressive Barrett’s esophagus

Abbreviated Name
UMIABE (William Grady Supplement 2012)s
Lead Investigator
Grady, WilliamFred Hutchinson Cancer Center
Coordinating Investigator
University of Michigan
Involved Investigators

Abstact

No abstract availalbe.

Aims

Aim 1: To characterize the genome-wide methylation status of various histological subtypes of esophageal tissues: Aim 1a: To determine the methylome of BE, BE+LGD, BE+HGD, and EAC. Aim 1b: To determine if a panel of methylated genes can be used to distinguish BE, BE+LGD, BE+HGD, and EAC. 1) 1st quarter 1. Request tissue samples from EDRN biorepository 2. Obtain tissues from biorepository and assess quality 3. Extract DNA from tissue samples and treat with sodium bisulfite 2) 2nd quarter 1. Run HumanMethylation450 arrays using tissue samples 2. Analyze data and identify methylated genes that are specific for BE, BE+LGD, BE+HGD, and EAC 3) 3rd quarter 1. Develop pyrosequencing assays and/or MethyLight assays for candidate genes identified from array studies 2. Organize DNA samples in Grady lab tissue collection and bisulfite treat DNA samples 3. Assess methylation state of candidate genes in independent tissue set available in Grady lab 4. Identify methylated genes that show highest specificity for BE, BE+LGD, BE+HGD, and EAC 4) 4th quarter 1. Continue to assess methylation state of candidate genes in independent tissue set available in Grady lab 2. Continue to identify methylated genes that show highest specificity for BE, BE+LGD, BE+HGD, and EAC 3. Determine best methylated gene(s) to be used to identify aggressive BE vs. indolent BE Aim 2: To conduct a pilot study to determine if methylated genes can be used to identify aggressive BE vs. indolent BE. 1) 1st quarter 1. Arrange to obtain tissue samples from EDRN for initial analysis of methylated gene biomarkers. This will be run on samples from 33 patients 2. Begin enrollment of study subjects and collection of tissues from these additional study subjects enrolled in EDRN GLNE study 2) 2nd quarter 1. Continue enrollment and tissue collection of samples from EDRN GLNE study 2. Perform histologic quality assessment of tissues obtained from the initial patient cohort (N=33) 2 3. Begin DNA extraction and bisulfite treatment of DNA samples 3) 3rd quarter 1. Run HumanMethylation450 arrays using tissue samples from initial patient cohort 2. Analyze data and identify methylated genes that are specific for aggressive BE vs. indolent BE 3. Develop pyrosequencing assays and/or MethyLight assays for candidate genes identified from array studies 4. Run pyrosequencing assays and/or Methylight assays on DNA samples from array studies to validate array results 5. Identify methylated genes that have the highest specificity for aggressive BE vs. indolent BE 4) 4th quarter 1. Analyze samples from initial patient cohort using best candidate genes for identifying aggressive BE vs. indolent BE 2. Obtain tissue samples from additional patients in EDRN GLNE study, assess quality of samples, and extract DNA 3. Bisulfite treatment of DNA from tissue samples from 2nd patient cohort. 4. Assess best candidate genes in 2nd patient cohort to determine if results can be valid

Analytic Method

Statistical Analysis: Dr. Chao-Jen Wong will direct the statistical analysis. We will assess genomewide methylation patterns using HumanMethylation450 arrays in matched aggressive BE and indolent BE cases. We will subsequently identify methylated gene profiles that are significantly methylated (ß value >0.5) in tissues from both these groups using the selection criteria as described in Aim 1. Next, we will compare candidate methylated genes identified in Aim 1 between the aggressive BE and indolent BE groups using two-sided two sample t-test to identify transcripts deregulated specifically in the aggressive BE population. Methylated genes will then be prioritized based on their consistent methylation pattern in BE, HGD or EAC lesions in Aim 1. Finally, those methylated genes will be considered as candidate biomarkers associated with aggressive BE, and will be subsequently validated in an independent cohort of patients in future studies. 3) Power Analysis: Given the small initial sample size, we will initially assess for trends indicating a methylated gene is a potential aggressive BE biomarker. In year 2, Dr Wong will conduct a power analysis when we know how many people with aggressive vs. indolent BE have been collected.

Publications

  • No publications available at this time for this protocol.

Biomarkers

  • No biomarkers available at this time for this protocol.

Data Collections

  • No data collections available at this time for this protocol.
 Team Project
Start Date
Jul 1 2012
Estimated Finish Date
Jun 30 2014
Protocol ID
360
Protocol Type
Collaboration
Field of Research
Hypermethylation
Collaborative Group
G.I. and Other Associated Cancers Research Group
Cancer Types
  • Malignant neoplasm of esophagus
Phased Status
1

Associated Forms