Correlation between mRNA expression and DNA methylation
Cervical Squamous Cell Carcinoma (Primary solid tumor)
22 February 2013  |  analyses__2013_02_22
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/C1W37THG
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 = 97. Number of gene expression samples = 97. Number of methylation samples = 97.

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 = 97

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 6.183 0.741696
cg02876237 ZNF614 19 52531528 -0.9 0 0 6.189 0.225938
cg10263370 ZNF502 3 44754102 -0.88 0 0 4.515 0.381248
cg15167155 ZNF347 19 53662499 -0.87 0 0 NA 0.394342
cg11595155 ZNF570 19 37960414 -0.87 0 0 3.676 0.281914
cg12048031 ZNF256 19 58459283 -0.87 0 0 4.804 0.381041
cg25451874 ZNF569 19 37958444 -0.87 0 0 5.265 0.347880
cg10157975 ZNF304 19 57862442 -0.86 0 0 6.520 0.170652
cg24040502 NLRP2 19 55477810 -0.86 0 0 7.715 0.639319
cg07697981 ZNF134 19 58125678 -0.86 8.3e-30 1.2e-29 5.496 0.382337
cg12950007 ZNF528 19 52900970 -0.86 0 0 5.047 0.479009
cg16601893 ZNF738 19 21541793 -0.86 0 0 6.282 0.324056
cg05017253 ZNF350 19 52490211 -0.85 0 0 6.013 0.285953
cg09260640 ZNF419 19 57999177 -0.85 0 0 5.802 0.408913
cg04181321 ZNF71 19 57106852 -0.85 0 0 6.404 0.246878
cg14732998 ZNF793 19 37997831 -0.85 0 0 4.926 0.378627
cg22956410 ZNF586 19 58281117 -0.85 0 0 6.308 0.311540
cg24415565 LOC148189 19 28284988 -0.84 0 0 NA 0.286051
cg13252583 ZFP82 19 36909831 -0.84 1.7e-27 2.5e-27 4.419 0.438402
cg17853707 ZNF91 19 23578260 -0.84 0 0 5.698 0.393136
cg23484599 PAX6 11 31831137 -0.84 0 0 6.481 0.662937
cg03695666 ZNF607 19 38210224 -0.84 0 0 5.976 0.288426
cg08332658 ZNF681 19 23941408 -0.84 0 0 NA 0.456446
cg23504474 ZNF682 19 20149886 -0.84 0 0 3.523 0.507339
cg14059257 KRT7 12 52628105 -0.83 0 0 11.906 0.478661
cg20607331 ZNF549 19 58038621 -0.83 0 0 4.586 0.493626
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/2660899/0.GDAC_MethylationPreprocess.Finished/CESC-TP.meth.for_correlation.filtered_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/2587666/0.mRNAseq_preprocessor.Finished/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.