Prostate Adenocarcinoma: Correlation between mRNA expression and DNA methylation
Maintained by Richard Park (Boston University/Harvard Medical School)
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 = 53. Number of gene expression samples = 53. Number of methylation samples = 53.

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 = 53

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
--- | --- | --- | --- | --- | --- | --- | --- | ---
cg12368065 | PCA3 | 9 | 78569192 | -0.95 | 0 | 0 | 11.7624 | 0.562105
cg05165378 | ZNF655 | 7 | 98993675 | -0.93 | 0 | 0 | 9.0207 | 0.392419
cg12045875 | DDX43 | 6 | 74161315 | -0.92 | 0 | 0 | NA | 0.723686
cg07775813 | SPESP1 | 15 | 67010422 | -0.92 | 0 | 0 | 5.5345 | 0.739741
cg04676799 | CDO1 | 5 | 115180837 | -0.92 | 0 | 0 | 7.1776 | 0.840959
cg10132157 | PARP6 | 15 | 70351722 | -0.91 | 0 | 0 | 8.3182 | 0.309907
cg14619949 | F2RL1 | 5 | 76151925 | -0.91 | 0 | 0 | 9.6157 | 0.652898
cg24040502 | NLRP2 | 19 | 60169622 | -0.91 | 0 | 0 | NA | 0.766200
cg24819835 | CD38 | 4 | 15389109 | -0.91 | 0 | 0 | 8.3144 | 0.478399
cg25002788 | SPON2 | 4 | 1156873 | -0.91 | 0 | 0 | 13.0547 | 0.622400
cg05991820 | ECHDC3 | 10 | 11825167 | -0.9 | 0 | 0 | 7.7743 | 0.506761
cg04860563 | TP63 | 3 | 191007164 | -0.9 | 0 | 0 | 8.4164 | 0.837612
cg11619216 | LOC100130933 | 17 | 71153675 | -0.89 | 0 | 0 | NA | 0.675312
cg05253480 | IL17RE | 3 | 9919537 | -0.89 | 0 | 0 | 6.6345 | 0.585171
cg09677945 | DNAJC15 | 13 | 42495657 | -0.88 | 0 | 0 | 7.5735 | 0.563094
cg21482265 | LOC654433 | 2 | 113709233 | -0.88 | 0 | 0 | NA | 0.710262
cg00120825 | PEX10 | 1 | 2328598 | -0.88 | 0 | 0 | 10.5621 | 0.592277
cg03977657 | LAMB3 | 1 | 207892370 | -0.88 | 0 | 0 | 9.0190 | 0.599245
cg18404205 | SP8 | 7 | 20789354 | -0.88 | 0 | 0 | 7.0046 | 0.519742
cg02251567 | AMT | 3 | 49434944 | -0.87 | 0 | 0 | 7.2873 | 0.575650
cg01106989 | GSTA4 | 6 | 52966418 | -0.87 | 0 | 0 | 9.3350 | 0.595655
cg01923218 | CCDC67 | 11 | 92703536 | -0.87 | 0 | 0 | 3.7034 | 0.415413
cg01844235 | RAB36 | 22 | 21817969 | -0.87 | 0 | 0 | 7.9822 | 0.459733
cg08834057 | KCNG3 | 2 | 42571582 | -0.87 | 0 | 0 | 6.3550 | 0.854574
cg15302379 | KAZALD1 | 10 | 102811838 | -0.87 | 0 | 0 | 7.3435 | 0.665011
cg20911718 | NYNRIN | 14 | 23937331 | -0.87 | 0 | 0 | 8.1225 | 0.736848

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/PRAD/1841559/0.GDAC_MethylationPreprocess.Finished/PRAD.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/PRAD/1768840/0.mRNAseq_preprocessor.Finished/PRAD.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.

- Analysis Results (MD5 checksum)

- Auxiliary Data (MD5 checksum)

- MAGE-TAB File (MD5 checksum)

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