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 probes per gene are displayed. Total number of matched samples = 262. Number of gene expression samples = 262. Number of methylation samples = 262.

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 = 262

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
--- | --- | --- | --- | --- | --- | --- | --- | ---
cg16666160 | NR5A1 | 9 | 127269631 | -0.89 | 0 | 0 | NA | 0.927134
cg19580810 | RAB25 | 1 | 156031182 | -0.88 | 0 | 0 | 9.731 | 0.455644
cg02665570 | LYPLAL1 | 1 | 219347340 | -0.86 | 0 | 0 | 6.731 | 0.367931
cg10236239 | SULT1C4 | 2 | 108994514 | -0.85 | 0 | 0 | NA | 0.405697
cg04089739 | C3 | 19 | 6719980 | -0.8 | 0 | 0 | 14.514 | NA
cg18059223 | NLRP2 | 19 | 55478588 | -0.8 | 0 | 0 | NA | 0.639802
cg09886641 | SPESP1 | 15 | 69223018 | -0.79 | 0 | 0 | NA | 0.802474
cg27235662 | CLDN16 | 3 | 190105986 | -0.78 | 0 | 0 | 8.176 | 0.297871
cg24333473 | ZNF597 | 16 | 3493428 | -0.78 | 0 | 0 | 5.135 | 0.364959
cg20848130 | GJC2 | 1 | 228337776 | -0.77 | 0 | 0 | 6.134 | 0.591419
cg24235633 | LOC440356 | 16 | 29875177 | -0.77 | 0 | 0 | NA | 0.646337
cg24691453 | S100A4 | 1 | 153518384 | -0.76 | 0 | 0 | 10.515 | 0.696922
cg22424746 | VTCN1 | 1 | 117753313 | -0.76 | 0 | 0 | 10.557 | 0.447990
cg23234999 | MKRN3 | 15 | 23811205 | -0.76 | 0 | 0 | NA | 0.625430
cg24421410 | HLA-DMA | 6 | 32920220 | -0.76 | 0 | 0 | 10.735 | 0.513755
cg27246571 | HAL | 12 | 96389588 | -0.75 | 0 | 0 | NA | 0.757698
cg11584936 | BNIPL | 1 | 151009588 | -0.75 | 0 | 0 | 6.946 | 0.429844
cg09407859 | CES3 | 16 | 66995461 | -0.75 | 0 | 0 | 6.817 | 0.490075
cg00186701 | TSPYL5 | 8 | 98290510 | -0.75 | 0 | 0 | 9.763 | 0.355246
cg16150435 | C6orf15 | 6 | 31080529 | -0.75 | 0 | 0 | NA | 0.639590
cg02082342 | VSIG2 | 11 | 124622373 | -0.75 | 0 | 0 | NA | 0.581157
cg25023994 | BANK1 | 4 | 102711773 | -0.75 | 0 | 0 | NA | 0.354966
cg21488617 | DNALI1 | 1 | 38022586 | -0.74 | 0 | 0 | 8.955 | 0.288949
cg15937958 | CXCL17 | 19 | 42947133 | -0.74 | 0 | 0 | 8.507 | 0.478644
cg27583102 | KLK5 | 19 | 51456055 | -0.74 | 0 | 0 | 10.226 | 0.425993
cg10590292 | BIN2 | 12 | 51717674 | -0.74 | 0 | 0 | 6.655 | 0.908610

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/OV-TP/2282784/0.GDAC_MethylationPreprocess.Finished/OV-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/OV-TP/2282617/0.mRNAseq_preprocessor.Finished/OV-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.

- Analysis Results (MD5 checksum)

- Auxiliary Data (MD5 checksum)

- MAGE-TAB File (MD5 checksum)

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