Correlations between copy number and mRNAseq expression
Liver Hepatocellular Carcinoma (Primary solid tumor)
22 February 2013  |  analyses__2013_02_22
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 (2013): Correlations between copy number and mRNAseq expression. Broad Institute of MIT and Harvard. doi:10.7908/C1PV6HK0
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 911.1, 2196, 2981, 3735.4, 4447, 5136, 5863.7, 6624, 7482.9, 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 97 34 34
Genes 23778 17911 17822

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
55290 BRF2 8p11.23 0.9082 1.19904086659517e-13 6.98583604312216e-10
22827 PUF60 8q24.3 0.9047 2.1493917756743e-13 6.98583604312216e-10
84060 RBM48 7q21.2 0.9039 2.40696351738734e-13 6.98583604312216e-10
3551 IKBKB 8p11.21 0.8887 2.26374474721069e-12 4.92762443217e-09
91782 CHMP7 8p21.3 0.8864 3.08508774082838e-12 5.37239147508151e-09
526 ATP6V1B2 8p21.3 0.8796 7.51043671698426e-12 8.85667386906161e-09
57226 LYRM2 6q15 0.8796 7.44537764774122e-12 8.85667386906161e-09
8881 CDC16 13q34 0.8789 8.13749068129255e-12 8.85667386906161e-09
84513 PPAPDC1B 8p11.23 0.8769 1.04489750185621e-11 1.01088398683039e-08
220064 ORAOV1 11q13.3 0.8743 1.42437173167309e-11 1.24020501059281e-08
80778 ZNF34 8q24.3 0.8715 2.00288674534477e-11 1.46166742912801e-08
57798 GATAD1 7q21.2 0.8714 2.02524663706072e-11 1.46166742912801e-08
51763 INPP5K 17p13.3 0.8707 2.18984830269164e-11 1.46166742912801e-08
9694 TTC35 8q23.1 0.8701 2.3502089163685e-11 1.46166742912801e-08
57805 KIAA1967 8p21.3 0.8635 4.94559948549522e-11 2.8270523290214e-08
5537 PPP6C 9q33.3 0.863 5.19497778128652e-11 2.8270523290214e-08
8451 CUL4A 13q34 0.8591 7.92530485682619e-11 4.05916954176579e-08
51362 CDC40 6q21 0.8575 9.39719413395323e-11 4.54564828333613e-08
28998 MRPL13 8q24.12 0.8563 1.067881338912e-10 4.6864777542202e-08
889 KRIT1 7q21.2 0.8562 1.07648112646075e-10 4.6864777542202e-08
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.

Correlation across sample

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

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.