Correlation between miRseq expression and clinical features
Brain Lower Grade Glioma (Primary solid tumor)
22 February 2013 | analyses__2013_02_22
Maintainer Information
Citation Information
doi:10.7908/C1TQ5ZR3
Maintained by Juok Cho (Broad Institute)
Cite as Broad Institute TCGA Genome Data Analysis Center (2013): Correlation between miRseq expression and clinical features. Broad Institute of MIT and Harvard. doi:10.7908/C1TQ5ZR3
Overview
Introduction

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

Summary

Testing the association between 564 genes and 6 clinical features across 207 samples, statistically thresholded by Q value < 0.05, 3 clinical features related to at least one genes.

- 4 genes correlated to 'Time to Death'.

- HSA-MIR-346 , HSA-MIR-10A , HSA-MIR-155 , HSA-MIR-15B

- 1 gene correlated to 'AGE'.

- HSA-MIR-34A

- 38 genes correlated to 'HISTOLOGICAL.TYPE'.

- HSA-MIR-1262 , HSA-MIR-23A , HSA-MIR-3074 , HSA-MIR-186 , HSA-MIR-455 , ...

- No genes correlated to 'GENDER', 'KARNOFSKY.PERFORMANCE.SCORE', and 'RADIATIONS.RADIATION.REGIMENINDICATION'.

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=4 | shorter survival | N=3 | longer survival | N=1
AGE | Spearman correlation test | N=1 | older | N=1 | younger | N=0
GENDER | t test | N=0 |  |  |  |
KARNOFSKY PERFORMANCE SCORE | Spearman correlation test | N=0 |  |  |  |
HISTOLOGICAL TYPE | ANOVA test | N=38 |  |  |  |
RADIATIONS RADIATION REGIMENINDICATION | t test | N=0 |  |  |  |

Clinical variable #1: 'Time to Death'

4 genes related to 'Time to Death'.

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

Time to Death | Duration (Months) | 0-211.2 (median=13.4)
| censored | N = 156
| death | N = 50
| Significant markers | N = 4
| associated with shorter survival | 3
| associated with longer survival | 1

List of 4 genes significantly associated with 'Time to Death' by Cox regression test

Table S2. Get Full Table List of 4 genes significantly associated with 'Time to Death' by Cox regression test

| HazardRatio | Wald_P | Q | C_index
--- | --- | --- | --- | ---
HSA-MIR-346 | 0.52 | 1.496e-08 | 8.4e-06 | 0.278
HSA-MIR-10A | 1.47 | 2.097e-08 | 1.2e-05 | 0.726
HSA-MIR-155 | 1.86 | 1.812e-07 | 1e-04 | 0.743
HSA-MIR-15B | 1.65 | 4.626e-05 | 0.026 | 0.755

Figure S1. Get High-res Image As an example, this figure shows the association of HSA-MIR-346 to 'Time to Death'. four curves present the cumulative survival rates of 4 quartile subsets of patients. P value = 1.5e-08 with univariate Cox regression analysis using continuous log-2 expression values.

Clinical variable #2: 'AGE'

One gene related to 'AGE'.

Table S3. Basic characteristics of clinical feature: 'AGE'

AGE | Mean (SD) | 43.22 (13)
| Significant markers | N = 1
| pos. correlated | 1
| neg. correlated | 0

List of one gene significantly correlated to 'AGE' by Spearman correlation test

Table S4. Get Full Table List of one gene significantly correlated to 'AGE' by Spearman correlation test

| SpearmanCorr | corrP | Q
--- | --- | --- | ---
HSA-MIR-34A | 0.294 | 1.715e-05 | 0.00967

Figure S2. Get High-res Image As an example, this figure shows the association of HSA-MIR-34A to 'AGE'. P value = 1.72e-05 with Spearman correlation analysis. The straight line presents the best linear regression.

Clinical variable #3: 'GENDER'

No gene related to 'GENDER'.

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

GENDER | Labels | N
| FEMALE | 89
| MALE | 118
| Significant markers | N = 0

Clinical variable #4: 'KARNOFSKY.PERFORMANCE.SCORE'

No gene related to 'KARNOFSKY.PERFORMANCE.SCORE'.

Table S6. Basic characteristics of clinical feature: 'KARNOFSKY.PERFORMANCE.SCORE'

KARNOFSKY.PERFORMANCE.SCORE | Mean (SD) | 88.48 (10)
| Significant markers | N = 0

Clinical variable #5: 'HISTOLOGICAL.TYPE'

38 genes related to 'HISTOLOGICAL.TYPE'.

Table S7. Basic characteristics of clinical feature: 'HISTOLOGICAL.TYPE'

HISTOLOGICAL.TYPE | Labels | N
| ASTROCYTOMA | 63
| OLIGOASTROCYTOMA | 54
| OLIGODENDROGLIOMA | 89
| Significant markers | N = 38

List of top 10 genes differentially expressed by 'HISTOLOGICAL.TYPE'

Table S8. Get Full Table List of top 10 genes differentially expressed by 'HISTOLOGICAL.TYPE'

| ANOVA_P | Q
--- | --- | ---
HSA-MIR-1262 | 1.118e-13 | 6.3e-11
HSA-MIR-23A | 1.786e-10 | 1.01e-07
HSA-MIR-3074 | 4.807e-10 | 2.7e-07
HSA-MIR-186 | 2.377e-08 | 1.33e-05
HSA-MIR-455 | 5.934e-08 | 3.32e-05
HSA-MIR-21 | 6.207e-08 | 3.47e-05
HSA-MIR-219-1 | 1.086e-07 | 6.06e-05
HSA-MIR-28 | 2.638e-07 | 0.000147
HSA-MIR-576 | 3.058e-07 | 0.00017
HSA-MIR-1226 | 5.125e-07 | 0.000284

Figure S3. Get High-res Image As an example, this figure shows the association of HSA-MIR-1262 to 'HISTOLOGICAL.TYPE'. P value = 1.12e-13 with ANOVA analysis.

Clinical variable #6: 'RADIATIONS.RADIATION.REGIMENINDICATION'

No gene related to 'RADIATIONS.RADIATION.REGIMENINDICATION'.

Table S9. Basic characteristics of clinical feature: 'RADIATIONS.RADIATION.REGIMENINDICATION'

RADIATIONS.RADIATION.REGIMENINDICATION | Labels | N
| NO | 103
| YES | 104
| Significant markers | N = 0

Methods & Data
Input

- Expresson data file = LGG-TP.miRseq_RPKM_log2.txt

- Clinical data file = LGG-TP.clin.merged.picked.txt

- Number of patients = 207

- Number of genes = 564

- 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

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

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

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.

- Analysis Results (MD5 checksum)

- Auxiliary Data (MD5 checksum)

- MAGE-TAB File (MD5 checksum)

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] Lehmann and Romano, Testing Statistical Hypotheses (3E ed.), New York: Springer. ISBN 0387988645 (2005)
[4] Howell, D, Statistical Methods for Psychology. (5th ed.), Duxbury Press:324-5 (2002)
[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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