Ovarian Serous Cystadenocarcinoma: 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 probe(s) per gene are displayed. Total number of matched samples = 522 Number of gene expression samples = 525 Number of methylation samples = 539

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 = 522

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 probe(s) per gene. Correlation Coefficient: See Methods & Data below. Expression Mean and Expression Variance: median and variance of gene expression levels of gene expression probes associated with the gene. Methylation Mean and Methylation Variance: median and variance of methylation levels of CpG methylation probes associated with the gene.

Meth_Probe Gene Chrom Position Corr_Spearman Pval_Spearman Qval Expr_Mean Meth_Mean
cg19580810 RAB25 1 154297806 -0.84 0 0 1.5 0.47309
cg22424746 VTCN1 1 117554836 -0.73 0 0 2.1 0.44659
cg04089739 C3 19 6670980 -0.72 0 0 4.9 0.62062
cg09243900 RAB25 1 154297468 -0.71 0 0 1.5 0.36874
cg25023994 BANK1 4 102930796 -0.7 0 0 -1.2 0.36731
cg17612991 C3 19 6672016 -0.69 0 0 4.9 0.45364
cg24691453 S100A4 1 151785008 -0.69 0 0 3.7 0.67366
cg21488617 DNALI1 1 37795173 -0.69 0 0 -0.2 0.31081
cg00332153 BANK1 4 102931033 -0.68 0 0 -1.2 0.48832
cg27583102 KLK5 19 56147867 -0.68 0 0 1.1 0.44702
cg00186701 TSPYL5 8 98359686 -0.68 0 0 2.3 0.36521
cg00929855 HSPA1A 6 31891343 -0.64 0 0 4 0.34318
cg27235662 CLDN16 3 191588680 -0.64 0 0 0.68 0.31210
cg06537829 UBB 17 16224701 -0.64 3e-61 7.6e-60 6.1 0.21168
cg08471713 MEOX1 17 39094419 -0.64 0 0 -0.56 0.68646
cg01420388 FBXO2 1 11636841 -0.63 0 0 -0.4 0.54210
cg14467840 S100A1 1 151867596 -0.62 0 0 1.7 0.35504
cg07717632 C9orf167 9 139292452 -0.62 0 0 -0.94 0.31447
cg23352695 EVI2A 17 26672937 -0.62 0 0 0.093 NA
cg10315334 CCL5 17 31231445 -0.61 0 0 -0.11 0.75266
cg11394785 LTC4S 5 179153696 -0.61 0 0 -0.81 0.37789
cg03662459 IL11RA 9 34644290 -0.61 0 0 0.12 0.62789
cg04237003 C11orf9 11 61278578 -0.61 0 0 -1 0.64174
cg16937611 SERPINA5 14 94117855 -0.61 0 0 0.55 0.67312
cg22627427 C11orf9 11 61279074 -0.61 0 0 -1 0.72274
cg01570885 FAM50B 6 3794271 -0.6 0 0 -0.054 0.45708
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_MergeDataFilesPipeline/OV/670713/1.GDAC_MergeDataFiles.Finished/OV.methylation__humanmethylation27__jhu_usc_edu__Level_3__within_bioassay_data_set_function__data.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/GDAC_mRNA_Preprocess_Median/OV/718821/0.GDAC_mRNA_Preprocess_Median.Finished/OV.medianexp.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.

Meta
  • Maintainer = Richard Park