Kidney Renal Clear Cell Carcinoma: Correlation between mRNA expression and DNA methylation
(primary solid tumor cohort)
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 = 272. Number of gene expression samples = 480. Number of methylation samples = 272.

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 = 272

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
cg18653451 CCDC8 19 46917018 -0.85 0 0 7.398 0.333792
cg06797068 DDX43 6 74104600 -0.84 0 0 NA 0.763134
cg21550016 LOC654433 2 113992930 -0.83 0 0 5.592 0.814305
cg13234544 CCDC146 7 76911877 -0.83 0 0 9.375 0.802902
cg21583694 TGFBI 5 135365401 -0.83 0 0 13.644 0.692844
cg08450017 CXCR6 3 45984838 -0.82 0 0 6.802 0.771341
cg13714749 FAM83F 22 40391489 -0.8 1.7e-51 1.1e-51 NA 0.639235
cg25258033 RNASET2 6 167368657 -0.79 0 0 12.050 0.538502
cg15518883 SIT1 9 35650561 -0.79 0 0 5.871 0.774634
cg12792363 LGALS12 11 63274030 -0.79 0 0 NA 0.676514
cg05564251 SP140 2 231090640 -0.78 0 0 6.139 0.788377
cg14580211 C5orf62 5 150161299 -0.78 0 0 10.154 0.688519
cg12705353 WDR66 12 122356852 -0.78 0 0 5.971 0.509052
cg12044599 PTPRCAP 11 67206308 -0.78 0 0 7.809 0.826618
cg02358862 CORO1A 16 30197211 -0.77 0 0 10.235 0.716514
cg12472603 MXRA7 17 74705806 -0.76 0 0 11.999 0.724828
cg00939684 TMEM204 16 1599150 -0.76 0 0 9.750 0.634316
cg15694715 TMEM25 11 118402280 -0.76 0 0 8.154 NA
cg06532379 ALPK3 15 85360319 -0.76 0 0 9.793 0.458423
cg14467840 S100A1 1 153600972 -0.76 0 0 9.273 0.619745
cg22512531 CRTAM 11 122709551 -0.76 0 0 5.289 0.859525
cg07383757 TRPC2 11 3647654 -0.76 0 0 NA 0.499989
cg25391117 C1QTNF3 5 34043284 -0.76 0 0 8.203 0.641813
cg16927606 TMEM149 19 36233324 -0.75 0 0 7.343 0.651827
cg09419670 LOC253039 9 123605666 -0.75 0 0 8.073 0.283096
cg00903584 PTPN7 1 202128682 -0.75 0 0 7.554 0.698672
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/KIRC-TP/2401631/0.GDAC_MethylationPreprocess.Finished/KIRC-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/KIRC-TP/2398230/0.mRNAseq_preprocessor.Finished/KIRC-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.