Skin Cutaneous Melanoma: Correlation between mRNAseq expression and clinical features
(WT cohort)
Maintained by Juok Cho (Broad Institute)
Overview
Introduction

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

Summary

Testing the association between 18110 genes and 6 clinical features across 21 samples, statistically thresholded by Q value < 0.05, 4 clinical features related to at least one genes.

  • 2 genes correlated to 'AGE'.

    • TRIM54|57159 ,  WWP2|11060

  • 9 genes correlated to 'GENDER'.

    • RPS4Y1|6192 ,  PRKY|5616 ,  KDM5D|8284 ,  DDX3Y|8653 ,  USP9Y|8287 ,  ...

  • 2 genes correlated to 'LYMPH.NODE.METASTASIS'.

    • C12ORF61|283416 ,  C12ORF27|283460

  • 3 genes correlated to 'NEOPLASM.DISEASESTAGE'.

    • ZNF484|83744 ,  ZNF558|148156 ,  ZNF468|90333

  • No genes correlated to 'Time to Death', and 'PRIMARY.SITE.OF.DISEASE'.

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=2 older N=0 younger N=2
PRIMARY SITE OF DISEASE ANOVA test   N=0        
GENDER t test N=9 male N=7 female N=2
LYMPH NODE METASTASIS ANOVA test N=2        
NEOPLASM DISEASESTAGE ANOVA test N=3        
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) 4.9-78.4 (median=13.8)
  censored N = 3
  death N = 9
     
  Significant markers N = 0
Clinical variable #2: 'AGE'

2 genes related to 'AGE'.

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

AGE Mean (SD) 59.43 (14)
  Significant markers N = 2
  pos. correlated 0
  neg. correlated 2
List of 2 genes significantly correlated to 'AGE' by Spearman correlation test

Table S3.  Get Full Table List of 2 genes significantly correlated to 'AGE' by Spearman correlation test

SpearmanCorr corrP Q
TRIM54|57159 -0.8846 0 0
WWP2|11060 -0.8391 1.995e-06 0.0361

Figure S1.  Get High-res Image As an example, this figure shows the association of TRIM54|57159 to 'AGE'. P value = 0 with Spearman correlation analysis. The straight line presents the best linear regression.

Clinical variable #3: 'PRIMARY.SITE.OF.DISEASE'

No gene related to 'PRIMARY.SITE.OF.DISEASE'.

Table S4.  Basic characteristics of clinical feature: 'PRIMARY.SITE.OF.DISEASE'

PRIMARY.SITE.OF.DISEASE Labels N
  DISTANT METASTASIS 3
  REGIONAL CUTANEOUS OR SUBCUTANEOUS TISSUE (INCLUDES SATELLITE AND IN-TRANSIT METASTASIS) 4
  REGIONAL LYMPH NODE 14
     
  Significant markers N = 0
Clinical variable #4: 'GENDER'

9 genes related to 'GENDER'.

Table S5.  Basic characteristics of clinical feature: 'GENDER'

GENDER Labels N
  FEMALE 11
  MALE 10
     
  Significant markers N = 9
  Higher in MALE 7
  Higher in FEMALE 2
List of 9 genes differentially expressed by 'GENDER'

Table S6.  Get Full Table List of 9 genes differentially expressed by 'GENDER'

T(pos if higher in 'MALE') ttestP Q AUC
RPS4Y1|6192 13.49 7.546e-10 1.36e-05 1
PRKY|5616 12.2 1.427e-09 2.57e-05 1
KDM5D|8284 16.05 2.512e-09 4.52e-05 1
DDX3Y|8653 14.27 3.078e-09 5.53e-05 1
USP9Y|8287 17.13 3.233e-09 5.81e-05 1
ZFY|7544 11.85 1.172e-08 0.000211 1
TSIX|9383 -8.18 2.614e-07 0.0047 1
UTY|7404 11.13 8.731e-07 0.0157 1
XIST|7503 -7.53 1.814e-06 0.0326 1

Figure S2.  Get High-res Image As an example, this figure shows the association of RPS4Y1|6192 to 'GENDER'. P value = 7.55e-10 with T-test analysis.

Clinical variable #5: 'LYMPH.NODE.METASTASIS'

2 genes related to 'LYMPH.NODE.METASTASIS'.

Table S7.  Basic characteristics of clinical feature: 'LYMPH.NODE.METASTASIS'

LYMPH.NODE.METASTASIS Labels N
  N0 11
  N1 1
  N1A 1
  N1B 3
  N2B 1
  N3 2
     
  Significant markers N = 2
List of 2 genes differentially expressed by 'LYMPH.NODE.METASTASIS'

Table S8.  Get Full Table List of 2 genes differentially expressed by 'LYMPH.NODE.METASTASIS'

ANOVA_P Q
C12ORF61|283416 2.362e-07 0.00428
C12ORF27|283460 1.064e-06 0.0193

Figure S3.  Get High-res Image As an example, this figure shows the association of C12ORF61|283416 to 'LYMPH.NODE.METASTASIS'. P value = 2.36e-07 with ANOVA analysis.

Clinical variable #6: 'NEOPLASM.DISEASESTAGE'

3 genes related to 'NEOPLASM.DISEASESTAGE'.

Table S9.  Basic characteristics of clinical feature: 'NEOPLASM.DISEASESTAGE'

NEOPLASM.DISEASESTAGE Labels N
  STAGE I 4
  STAGE IA 1
  STAGE II 1
  STAGE IIB 2
  STAGE IIC 3
  STAGE III 1
  STAGE IIIA 1
  STAGE IIIB 1
  STAGE IIIC 4
     
  Significant markers N = 3
List of 3 genes differentially expressed by 'NEOPLASM.DISEASESTAGE'

Table S10.  Get Full Table List of 3 genes differentially expressed by 'NEOPLASM.DISEASESTAGE'

ANOVA_P Q
ZNF484|83744 3.012e-07 0.00544
ZNF558|148156 3.506e-07 0.00633
ZNF468|90333 6.185e-07 0.0112

Figure S4.  Get High-res Image As an example, this figure shows the association of ZNF484|83744 to 'NEOPLASM.DISEASESTAGE'. P value = 3.01e-07 with ANOVA analysis.

Methods & Data
Input
  • Expresson data file = SKCM-WT.uncv2.mRNAseq_RSEM_normalized_log2.txt

  • Clinical data file = SKCM-WT.clin.merged.picked.txt

  • Number of patients = 21

  • Number of genes = 18110

  • Number of clinical features = 6

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

This is an experimental feature. The full results of the analysis summarized in this report can be downloaded from the TCGA Data Coordination Center.

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)