FYI....
---------- Forwarded message ----------
From: Peterson, Katherine (NIH/NEI) [E] <[email protected]>
Date: Tue, Jul 8, 2014 at 12:53 PM
Subject: Reminder July Microarray Users' SIG journal club tomorrow
Greetings Chippers,
This is to remind you that the Microarray SIG journal club will meet
tomorrow to review a paper from Andrew Jaffe and Rafael Irizarry about
measuring gene expression values in samples that may be quite
heterogeneous. Here are the details:
When: Wednesday July 9, 2014 at 11:00 a.m.
Where: NIH Library, Building 10, Bethesda, in the media room.
What: Andrew Jaffe and Rafael Irizarry
Accounting for cellular heterogeneity is critical in epigenome-wide
association studies
Genome Biology 2014, 15:R31
Abstract: Background
Epigenome-wide association studies of human disease and other quantitative
traits are becoming increasingly common. A series of papers reporting
age-related changes in DNA methylation profiles in peripheral blood have
already been published. However, blood is a heterogeneous collection of
different cell types, each with a very different DNA methylation profile.
Results
Using a statistical method that permits estimating the relative proportion
of cell types from DNA methylation profiles, we examine data from five
previously published studies, and find strong evidence of cell composition
change across age in blood. We also demonstrate that, in these studies,
cellular composition explains much of the observed variability in DNA
methylation. Furthermore, we find high levels of confounding between
age-related variability and cellular composition at the CpG level.
Conclusions
Our findings underscore the importance of considering cell composition
variability in epigenetic studies based on whole blood and other
heterogeneous tissue sources. We also provide software for estimating and
exploring this composition confounding for the Illumina 450k microarray.
All are welcome, a good time is sure to be had by all.
Cheers,
Katherine
