Correlations between copy number and mRNAseq expression
Mesothelioma (Primary solid tumor)
28 January 2016  |  analyses__2016_01_28
Maintainer Information
Citation Information
Maintained by TCGA GDAC Team (Broad Institute/MD Anderson Cancer Center/Harvard Medical School)
Cite as Broad Institute TCGA Genome Data Analysis Center (2016): Correlations between copy number and mRNAseq expression. Broad Institute of MIT and Harvard. doi:10.7908/C1CZ36KC
Overview
Introduction

A TCGA sample is profiled to detect the copy number variations and expressions of genes. This pipeline attempts to correlate copy number and Rnaseq data of genes across samples to determine if the copy number variations also result in differential expressions. This report contains the calculated correlation coefficients based on measurements of genomic copy number (log2) values and RNAseq expression of the corresponding feature across patients. High positive/low negative correlation coefficients indicate that genomic alterations result in differences in the expressions of mRNAseq the genomic regions transcribe.

Summary

The correlation coefficients in 10, 20, 30, 40, 50, 60, 70, 80, 90 percentiles are 931, 1820.2, 2457, 3063, 3668, 4271, 4892.2, 5546.8, 6270.4, respectively.

Results
Correlation results

Number of genes and samples used for the calculation are shown in Table 1. Figure 1 shows the distribution of calculated correlation coefficients and quantile-quantile plot of the calculated correlation coefficients against a normal distribution. Table 2 shows the top 20 features ordered by the value of correlation coefficients.

Table 1.  Counts of mRNAseq and number of samples in copy number and expression data sets and common to both

Category Copy number Expression Common
Sample 87 87 87
Genes 24776 18209 15557

Figure 1.  Summary figures. Left: histogram showing the distribution of the calculated correlations across samples for all Genes. Right: QQ plot of the calculated correlations across samples. The QQ plot is used to plot the quantiles of the calculated correlation coefficients against that derived from a normal distribution. Points deviating from the blue line indicate deviation from normality.

Table 2.  Get Full Table Top 20 features (defined by the feature column) ranked by correlation coefficients

Locus ID Gene Symbol Cytoband cor p-value q-value
79886 CAAP1 9p21.2 0.8723 0 0
9373 PLAA 9p21.2 0.856 0 0
80173 IFT74 9p21.2 0.8526 0 0
9878 TOX4 14q11.2 0.8497 0 0
286319 TUSC1 9p21.2 0.8389 0 0
11193 WBP4 13q14.11 0.8253 0 0
84893 FBXO18 10p15.1 0.8243 0 0
53407 STX18 4p16.3 0.8207 0 0
10425 ARIH2 3p21.31 0.8099 0 0
57862 ZNF410 14q24.3 0.8081 0 0
9117 SEC22C 3p22.1 0.805 0 0
51409 HEMK1 3p21.2 0.8049 0 0
7375 USP4 3p21.31 0.8024 0 0
122553 TRAPPC6B 14q21.1 0.8019 0 0
8846 ALKBH1 14q24.3 0.7981 0 0
7323 UBE2D3 4q24 0.7963 0 0
4292 MLH1 3p22.2 0.7937 0 0
79947 DHDDS 1p36.11 0.793 0 0
6908 TBP 6q27 0.7925 0 0
79892 MCMBP 10q26.11 0.7915 0 0
Methods & Data
Input

Gene level (TCGA Level III) mRNAseq expression data and copy number data of corresponding gene derived by GISTIC pipelinePearson correlation coefficients were calculated for each pair of genes shared by the two data sets across all the samples that were common. The input file "MESO-TP.uncv2.mRNAseq_RSEM_normalized_log2.txt " is generated in the pipeline mRNAseq_Preprocess in the stddata run.

Correlation across sample

Pairwise correlations between the log2 copy numbers and expressions of each gene across samples were calculated using Pearson correlation.

Download Results

In addition to the links below, the full results of the analysis summarized in this report can also be downloaded programmatically using firehose_get, or interactively from either the Broad GDAC website or TCGA Data Coordination Center Portal.