Correlation between mRNAseq expression and clinical features
Liver Hepatocellular Carcinoma (Primary solid tumor)
23 September 2013  |  analyses__2013_09_23
Maintainer Information
Citation Information
doi:10.7908/C1C24TRG
Maintained by Juok Cho (Broad Institute)
Cite as Broad Institute TCGA Genome Data Analysis Center (2013): Correlation between mRNAseq expression and clinical features. Broad Institute of MIT and Harvard. doi:10.7908/C1C24TRG
Overview
Introduction

This pipeline uses various statistical tests to identify mRNAs whose expression levels correlated to selected clinical features.

Summary

Testing the association between 17758 genes and 8 clinical features across 115 samples, statistically thresholded by Q value < 0.05, 7 clinical features related to at least one genes.

  • 1 gene correlated to 'AGE'.

    • PMS2L2|5380

  • 3 genes correlated to 'NEOPLASM.DISEASESTAGE'.

    • THNSL2|55258 ,  KCNT1|57582 ,  LOC399815|399815

  • 5 genes correlated to 'PATHOLOGY.T.STAGE'.

    • TFAP2A|7020 ,  RNF123|63891 ,  POLA2|23649 ,  CARKD|55739 ,  RBPJ|3516

  • 32 genes correlated to 'PATHOLOGY.N.STAGE'.

    • PI4KAP2|375133 ,  WARS2|10352 ,  AGPAT2|10555 ,  PRSS35|167681 ,  SFRS6|6431 ,  ...

  • 1 gene correlated to 'PATHOLOGY.M.STAGE'.

    • KCNT1|57582

  • 32 genes correlated to 'GENDER'.

    • XIST|7503 ,  ZFY|7544 ,  RPS4Y1|6192 ,  TSIX|9383 ,  PRKY|5616 ,  ...

  • 1 gene correlated to 'COMPLETENESS.OF.RESECTION'.

    • PGA5|5222

  • No genes correlated to 'Time to Death'

Results
Overview of the results

Complete statistical result table is provided in Supplement Table 1

Table 1.  Get Full Table This table shows the clinical features, statistical methods used, and the number of genes that are significantly associated with each clinical feature at Q value < 0.05.

Clinical feature Statistical test Significant genes Associated with                 Associated with
Time to Death Cox regression test   N=0        
AGE Spearman correlation test N=1 older N=1 younger N=0
NEOPLASM DISEASESTAGE ANOVA test N=3        
PATHOLOGY T STAGE Spearman correlation test N=5 higher stage N=3 lower stage N=2
PATHOLOGY N STAGE t test N=32 class1 N=23 class0 N=9
PATHOLOGY M STAGE ANOVA test N=1        
GENDER t test N=32 male N=18 female N=14
COMPLETENESS OF RESECTION ANOVA test N=1        
Clinical variable #1: 'Time to Death'

No gene related to 'Time to Death'.

Table S1.  Basic characteristics of clinical feature: 'Time to Death'

Time to Death Duration (Months) 0-113 (median=14.9)
  censored N = 61
  death N = 51
     
  Significant markers N = 0
Clinical variable #2: 'AGE'

One gene related to 'AGE'.

Table S2.  Basic characteristics of clinical feature: 'AGE'

AGE Mean (SD) 61.51 (14)
  Significant markers N = 1
  pos. correlated 1
  neg. correlated 0
List of one gene significantly correlated to 'AGE' by Spearman correlation test

Table S3.  Get Full Table List of one gene significantly correlated to 'AGE' by Spearman correlation test

SpearmanCorr corrP Q
PMS2L2|5380 0.4249 2.715e-06 0.0482

Figure S1.  Get High-res Image As an example, this figure shows the association of PMS2L2|5380 to 'AGE'. P value = 2.71e-06 with Spearman correlation analysis. The straight line presents the best linear regression.

Clinical variable #3: 'NEOPLASM.DISEASESTAGE'

3 genes related to 'NEOPLASM.DISEASESTAGE'.

Table S4.  Basic characteristics of clinical feature: 'NEOPLASM.DISEASESTAGE'

NEOPLASM.DISEASESTAGE Labels N
  STAGE I 43
  STAGE II 25
  STAGE III 2
  STAGE IIIA 25
  STAGE IIIB 2
  STAGE IIIC 5
  STAGE IV 1
  STAGE IVA 1
  STAGE IVB 1
     
  Significant markers N = 3
List of 3 genes differentially expressed by 'NEOPLASM.DISEASESTAGE'

Table S5.  Get Full Table List of 3 genes differentially expressed by 'NEOPLASM.DISEASESTAGE'

ANOVA_P Q
THNSL2|55258 1.577e-08 0.00028
KCNT1|57582 1.764e-08 0.000313
LOC399815|399815 1.988e-06 0.0353

Figure S2.  Get High-res Image As an example, this figure shows the association of THNSL2|55258 to 'NEOPLASM.DISEASESTAGE'. P value = 1.58e-08 with ANOVA analysis.

Clinical variable #4: 'PATHOLOGY.T.STAGE'

5 genes related to 'PATHOLOGY.T.STAGE'.

Table S6.  Basic characteristics of clinical feature: 'PATHOLOGY.T.STAGE'

PATHOLOGY.T.STAGE Mean (SD) 2.01 (0.97)
  N
  1 46
  2 28
  3 33
  4 7
     
  Significant markers N = 5
  pos. correlated 3
  neg. correlated 2
List of 5 genes significantly correlated to 'PATHOLOGY.T.STAGE' by Spearman correlation test

Table S7.  Get Full Table List of 5 genes significantly correlated to 'PATHOLOGY.T.STAGE' by Spearman correlation test

SpearmanCorr corrP Q
TFAP2A|7020 0.4561 5.504e-07 0.00977
RNF123|63891 -0.4383 1.073e-06 0.019
POLA2|23649 0.4353 1.299e-06 0.0231
CARKD|55739 -0.4244 2.532e-06 0.045
RBPJ|3516 0.4232 2.714e-06 0.0482

Figure S3.  Get High-res Image As an example, this figure shows the association of TFAP2A|7020 to 'PATHOLOGY.T.STAGE'. P value = 5.5e-07 with Spearman correlation analysis.

Clinical variable #5: 'PATHOLOGY.N.STAGE'

32 genes related to 'PATHOLOGY.N.STAGE'.

Table S8.  Basic characteristics of clinical feature: 'PATHOLOGY.N.STAGE'

PATHOLOGY.N.STAGE Labels N
  class0 73
  class1 3
     
  Significant markers N = 32
  Higher in class1 23
  Higher in class0 9
List of top 10 genes differentially expressed by 'PATHOLOGY.N.STAGE'

Table S9.  Get Full Table List of top 10 genes differentially expressed by 'PATHOLOGY.N.STAGE'

T(pos if higher in 'class1') ttestP Q AUC
PI4KAP2|375133 8.83 1.598e-10 2.54e-06 0.8995
WARS2|10352 8.95 3.243e-10 5.16e-06 0.9132
AGPAT2|10555 7.1 6.399e-10 1.02e-05 0.8082
PRSS35|167681 -7.33 3.03e-09 4.83e-05 0.8545
SFRS6|6431 7.04 7.369e-09 0.000117 0.7991
ATP5F1|515 6.42 1.409e-08 0.000224 0.7854
WNT5A|7474 6.76 1.501e-08 0.000239 0.7991
STAB2|55576 -6.63 2.319e-08 0.000369 0.7814
ARMCX3|51566 6.68 2.827e-08 0.00045 0.7717
CYTH4|27128 6.04 5.752e-08 0.000915 0.8037

Figure S4.  Get High-res Image As an example, this figure shows the association of PI4KAP2|375133 to 'PATHOLOGY.N.STAGE'. P value = 1.6e-10 with T-test analysis.

Clinical variable #6: 'PATHOLOGY.M.STAGE'

One gene related to 'PATHOLOGY.M.STAGE'.

Table S10.  Basic characteristics of clinical feature: 'PATHOLOGY.M.STAGE'

PATHOLOGY.M.STAGE Labels N
  M0 88
  M1 2
  MX 25
     
  Significant markers N = 1
List of one gene differentially expressed by 'PATHOLOGY.M.STAGE'

Table S11.  Get Full Table List of one gene differentially expressed by 'PATHOLOGY.M.STAGE'

ANOVA_P Q
KCNT1|57582 7.998e-11 1.42e-06

Figure S5.  Get High-res Image As an example, this figure shows the association of KCNT1|57582 to 'PATHOLOGY.M.STAGE'. P value = 8e-11 with ANOVA analysis.

Clinical variable #7: 'GENDER'

32 genes related to 'GENDER'.

Table S12.  Basic characteristics of clinical feature: 'GENDER'

GENDER Labels N
  FEMALE 44
  MALE 71
     
  Significant markers N = 32
  Higher in MALE 18
  Higher in FEMALE 14
List of top 10 genes differentially expressed by 'GENDER'

Table S13.  Get Full Table List of top 10 genes differentially expressed by 'GENDER'

T(pos if higher in 'MALE') ttestP Q AUC
XIST|7503 -13.76 2.615e-23 4.64e-19 0.9662
ZFY|7544 21.02 7e-20 1.24e-15 0.9947
RPS4Y1|6192 21.92 2.007e-19 3.56e-15 0.996
TSIX|9383 -12.15 6.692e-17 1.19e-12 0.9671
PRKY|5616 15.75 1.706e-15 3.03e-11 0.9927
DDX3Y|8653 18.92 1.447e-13 2.57e-09 0.9982
NLGN4Y|22829 13.8 3.923e-13 6.96e-09 0.985
KDM5D|8284 17.08 3.441e-12 6.11e-08 0.996
KDM5C|8242 -6.74 1.099e-09 1.95e-05 0.8182
BMP8B|656 -6.37 9.276e-09 0.000165 0.8075

Figure S6.  Get High-res Image As an example, this figure shows the association of XIST|7503 to 'GENDER'. P value = 2.62e-23 with T-test analysis.

Clinical variable #8: 'COMPLETENESS.OF.RESECTION'

One gene related to 'COMPLETENESS.OF.RESECTION'.

Table S14.  Basic characteristics of clinical feature: 'COMPLETENESS.OF.RESECTION'

COMPLETENESS.OF.RESECTION Labels N
  R0 91
  R1 10
  R2 1
  RX 8
     
  Significant markers N = 1
List of one gene differentially expressed by 'COMPLETENESS.OF.RESECTION'

Table S15.  Get Full Table List of one gene differentially expressed by 'COMPLETENESS.OF.RESECTION'

ANOVA_P Q
PGA5|5222 7.76e-07 0.0138

Figure S7.  Get High-res Image As an example, this figure shows the association of PGA5|5222 to 'COMPLETENESS.OF.RESECTION'. P value = 7.76e-07 with ANOVA analysis.

Methods & Data
Input

  • Expresson data file = LIHC-TP.uncv2.mRNAseq_RSEM_normalized_log2.txt

  • Clinical data file = LIHC-TP.clin.merged.picked.txt

  • Number of patients = 115

  • Number of genes = 17758

  • Number of clinical features = 8

Survival analysis

For survival clinical features, Wald's test in univariate Cox regression analysis with proportional hazards model (Andersen and Gill 1982) was used to estimate the P values using the 'coxph' function in R. Kaplan-Meier survival curves were plot using the four quartile subgroups of patients based on expression levels

Correlation analysis

For continuous numerical clinical features, Spearman's rank correlation coefficients (Spearman 1904) and two-tailed P values were estimated using 'cor.test' function in R

ANOVA analysis

For multi-class clinical features (ordinal or nominal), one-way analysis of variance (Howell 2002) was applied to compare the log2-expression levels between different clinical classes using 'anova' function in R

Student's t-test analysis

For two-class clinical features, two-tailed Student's t test with unequal variance (Lehmann and Romano 2005) was applied to compare the log2-expression levels between the two clinical classes using 't.test' function in R

Q value calculation

For multiple hypothesis correction, Q value is the False Discovery Rate (FDR) analogue of the P value (Benjamini and Hochberg 1995), defined as the minimum FDR at which the test may be called significant. We used the 'Benjamini and Hochberg' method of 'p.adjust' function in R to convert P values into Q values.

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.

References
[1] Andersen and Gill, Cox's regression model for counting processes, a large sample study, Annals of Statistics 10(4):1100-1120 (1982)
[2] Spearman, C, The proof and measurement of association between two things, Amer. J. Psychol 15:72-101 (1904)
[3] Howell, D, Statistical Methods for Psychology. (5th ed.), Duxbury Press:324-5 (2002)
[4] Lehmann and Romano, Testing Statistical Hypotheses (3E ed.), New York: Springer. ISBN 0387988645 (2005)
[5] Benjamini and Hochberg, Controlling the false discovery rate: a practical and powerful approach to multiple testing, Journal of the Royal Statistical Society Series B 59:289-300 (1995)
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