Correlation between mRNA expression and DNA methylation
Cervical Squamous Cell Carcinoma (Primary solid tumor)
23 May 2013  |  analyses__2013_05_23
Maintainer Information
Citation Information
Maintained by Richard Park (Boston University/Harvard Medical School)
Cite as Broad Institute TCGA Genome Data Analysis Center (2013): Correlation between mRNA expression and DNA methylation. Broad Institute of MIT and Harvard. doi:10.7908/C11Z42DR
Overview
Introduction

The role of general epigenetic mechanisms in carcinogenesis and tumor aggressiveness is well documented: CpG island hyper-methylation silences tumor suppressor genes, whereas hypo-methylation promotes the transcriptional activation of oncogenes and induces chromosomal instability. This pipeline calculates and identifies correlations between DNA methylation and gene expression profiles using the available array technologies.

Summary

The top 25 correlated methylation probes per gene are displayed. Total number of matched samples = 116. Number of gene expression samples = 116. Number of methylation samples = 134.

Results
Correlation Histogram

Figure 1.  Histogram of methylation correlation values. n is the number of matched samples between Level 3 CpG site methylation and Level 3 gene expression arrays. Number of Matched Samples = 116

Qvalue Summary Plots

Figure 2.  Plot 1. The estimated pi_0 versus the tuning parameter lambda. Plot 2. The q-values versus the p-values. Plot 3. The number of significant tests versus each q-value cutoff. Plot 4. The number of expected false positives versus the number of significant tests.The first is a plot of the estimate of pi_0 versus its tuning parameter lambda. In most cases, as lambda gets larger, the bias of the estimate decreases, yet the variance increases. Comparing your estimate of pi_0 to this plot allows one to guage its quality. The remaining three plots show how many tests are significant, as well as how many false positives to expect for each q-value cut-off.

Negative Correlation between Methylation and Gene Expression

Table 1.  Get Full Table Top 25 most negatively correlated methylation probes. Correlation Coefficient: See Methods & Data below. Pval and Qval: P- and Q-values of the correlation coefficient. Expression Mean: mean detection level of gene expression probes. Methylation Mean: mean detection level of CpG methylation probes.

Meth_Probe Gene Chrom Position Corr_Coeff Pval Qval Expr_Mean Meth_Mean
cg12889195 LOC654433 2 113992843 -0.93 0 0 6 0.76
cg15167155 ZNF347 19 53662499 -0.88 0 0 4.7 0.39
cg24040502 NLRP2 19 55477810 -0.88 0 0 7.5 0.65
cg10263370 ZNF502 3 44754102 -0.88 0 0 4.6 0.38
cg02876237 ZNF614 19 52531528 -0.88 0 0 6.3 0.23
cg16246961 ZNF256 19 58459139 -0.87 0 0 4.8 0.3
cg25451874 ZNF569 19 37958444 -0.87 0 0 5.3 0.35
cg12950007 ZNF528 19 52900970 -0.87 0 0 5.1 0.48
cg18113994 ZNF134 19 58125867 -0.86 6.4e-36 1.1e-35 5.4 0.36
cg24392574 CALML5 10 5541423 -0.86 0 0 8.5 0.72
cg10157975 ZNF304 19 57862442 -0.86 0 0 6.5 0.18
cg11595155 ZNF570 19 37960414 -0.86 0 0 3.7 0.28
cg14732998 ZNF793 19 37997831 -0.85 0 0 5 0.38
cg09643186 GPX2 14 65409452 -0.85 0 0 8.1 0.59
cg24415565 LOC148189 19 28284988 -0.85 0 0 3.6 0.29
cg12360029 ZNF665 19 53696623 -0.85 0 0 2 0.48
cg09260640 ZNF419 19 57999177 -0.85 0 0 5.8 0.41
cg23484599 PAX6 11 31831137 -0.85 0 0 6.6 0.65
cg22956410 ZNF586 19 58281117 -0.84 0 0 6.4 0.32
cg23504474 ZNF682 19 20149886 -0.84 0 0 3.7 0.5
cg21168622 ZNF350 19 52489831 -0.84 0 0 6.1 0.48
cg13101072 FAM50B 6 3849818 -0.84 0 0 6.8 0.53
cg24724633 ZFP82 19 36909413 -0.84 2.3e-32 3.8e-32 4.5 0.46
cg08332658 ZNF681 19 23941408 -0.84 0 0 4 0.45
cg08170294 FOXJ1 17 74134843 -0.84 0 0 6.6 0.63
cg04181321 ZNF71 19 57106852 -0.84 0 0 6.4 0.24
Methods & Data
Input

Methylation Array Platforms: Illumina Infinium HumanMethylation27, Illumina DNA Methylation OMA002, Illumina DNA Methylation OMA003

  • methylation file = /xchip/cga/gdac-prod/tcga-gdac/jobResults/GDAC_MethylationPreprocess/CESC-TP/3527692/CESC-TP.meth.by_min_expr_corr.data.txt

Gene Expression Platforms: Agilent 244K Gene Expression G4502A-07-1, Agilent 244K Gene Expression G4502A-07-2, Agilent 244K Gene Expression G4502A-07-3, Affymetrix Human Exon 1.0 ST Array, Affymetrix HT Human Genome U133 Array

  • gene expression file = /xchip/cga/gdac-prod/tcga-gdac/jobResults/mRNAseq_preprocessor/CESC-TP/3352998/CESC-TP.uncv2.mRNAseq_RSEM_normalized_log2.txt

Correlation Coefficient

Level 3 methylation and gene expression arrays were paired on the basis of Entrez Gene ID concordance. The association between CpG site methylation and the level of expression of the corresponding genes was determined by calculating a correlation measure between the two platforms.

  • correlation measure = Spearman

Download Results

This is an experimental feature. The full results of the analysis summarized in this report can be downloaded from the TCGA Data Coordination Center.