---
title: "3.6 - TCGA.pipe: Running ELMER for TCGA data in a compact way"
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bibliography: bibliography.bib
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%\VignetteIndexEntry{"3.6 - TCGA.pipe: Running ELMER for TCGA data in a compact way"}
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---
# TCGA.pipe: Running ELMER for TCGA data in a compact way
`TCGA.pipe` is a function for easily downloading TCGA data from GDC using TCGAbiolinks package [@TCGAbiolinks]
and performing all the analyses in ELMER. For illustration purpose, we skip the downloading step.
The user can use the `getTCGA` function to download TCGA data or
use `TCGA.pipe` by including "download" in the analysis option.
The following command will do distal DNA methylation analysis and predict putative target genes, motif analysis and identify regulatory transcription factors.
```{r, fig.height = 6, eval = FALSE}
TCGA.pipe("LUSC",
wd = "./ELMER.example",
cores = parallel::detectCores()/2,
mode = "unsupervised"
permu.size = 300,
Pe = 0.01,
analysis = c("distal.probes","diffMeth","pair","motif","TF.search"),
diff.dir = "hypo",
rm.chr = paste0("chr",c("X","Y")))
```
TCGA.pipe: Mode argument
In this new version we added the argument `mode` in the `TCGA.pipe` function.
This will automatically set the `minSubgroupFrac` to the following values:
Modes available:
- `unsupervised`:
* Use 20% of each group to identify differently methylated regions (`minSubgroupFrac` = 0.2 in `get.diff.meth`)
* Use 40% of all samples to create Unmethytlated (U) and Methylated (M) groups in the other steps (the lowest quintile of samples is the U group and the highest quintile samples is the M group) (`minSubgroupFrac` = 0.4 in `get.pairs` and `get.TFs` functions)
- `supervised`:
* Use all samples in all functions and set Unmethytlated (U) and Methylated (M) one of the group selected in the analysis.
The `unsupervised` mode should be used when want to be able to detect a specific (possibly unknown) molecular subtype among tumor;
these subtypes often make up only a minority of samples, and 20\% was chosen as a lower bound for the purposes of statistical power.
If you are using pre-defined group labels, such as treated replicates vs. untreated replicated, use `supervised` mode (all samples),
For more information please read the analysis section of the vignette.
# Using mutation data to identify groups
We add in `TCGA.pipe` function (download step) the option to identify mutant samples to perform WT vs Mutant analysis.
It will download open [MAF file](https://docs.gdc.cancer.gov/Data/File_Formats/MAF_Format/)
from GDC database [@grossman2016toward], select a gene and identify the which are the mutant samples based on the following classification:
(it can be changed using the atgument `mutant_variant_classification`).
Mutations classification
| Argument | Description |
|------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Frame_Shift_Del | Mutant |
| Frame_Shift_Ins | Mutant |
| Missense_Mutation | Mutant |
| Nonsense_Mutation | Mutant |
| Splice_Site | Mutant |
| In_Frame_Del | Mutant |
| In_Frame_Ins | Mutant |
| Translation_Start_Site | Mutant |
| Nonstop_Mutation | Mutant |
| Silent | WT |
|3'UTR| WT |
|5'UTR| WT |
|3'Flank| WT |
|5'Flank| WT |
|IGR1 (intergenic region)| WT |
|Intron| WT |
|RNA| WT |
|Target_region| WT |
The arguments to be used are below:
`TCGA.pipe` mutation arguments
| Argument | Description |
|------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| genes | List of genes for which mutations will be verified. A column in the MAE with the name of the gene will be created with two groups WT (tumor samples without mutation), MUT (tumor samples w/ mutation), NA (not tumor samples)|
| mutant_variant_classification | List of GDC variant classification from MAF files to consider a samples mutant. Only used when argument gene is set.|
| group.col | A column defining the groups of the sample. You can view the available columns using: colnames(MultiAssayExperiment::colData(data)).|
| group1 | A group from group.col. ELMER will run group1 vs group2. That means, if direction is hyper, get probes hypermethylated in group 1 compared to group 2.|
| group2 | A group from group.col. ELMER will run group1 vs group2. That means, if direction is hyper, get probes hypermethylated in group 1 compared to group 2.|
Here is an example we TCGA-LUSC data is downloaded and we will compare TP53 Mutant vs
TP53 WT samples.
```{r, fig.height = 6, eval = FALSE}
TCGA.pipe("LUSC",
wd = "./ELMER.example",
cores = parallel::detectCores()/2,
mode = "supervised"
genes = "TP53",
group.col = "TP53",
group1 = "Mutant",
group2 = "WT",
permu.size = 300,
Pe = 0.01,
analysis = c("download","diffMeth","pair","motif","TF.search"),
diff.dir = "hypo",
rm.chr = paste0("chr",c("X","Y")))
```
# Session Info
```{r sessioninfo, eval=TRUE}
sessionInfo()
```
# Bibliography