Question: GSEA following DESeq2
2
gravatar for sup230
11 months ago by
sup23030
sup23030 wrote:

Hi Biostars

I am trying to use GSEA GUI from broad institute to do gene set analysis on RNA seq data. I have been reading many posts and researched GSEA website about the DEseq2->GSEA workflow and here is what I understood from it.

So if I used DEseq2 package to get a list of DE genes and if I would like to run preranked GSEA function,

  1. get a table with the list of genes on the row and log2FoldChange, p-value, and adj p-values on the column
  2. order the gene list by a metric -log10(p-value)*sign(logFC) and create rank file (.rnk) in R
  3. load this file to GSEA software and run GSEApreranked after choosing required and basic fields (making sure enrichment statistic is "classic")

Am I on the right track in understanding this workflow?

gsea rna-seq deseq2 R • 1.8k views
ADD COMMENTlink modified 11 months ago by geek_y8.6k • written 11 months ago by sup23030
2

As you use R pipeline, I recommend to use R implementation of pre-ranked GSEA: either through fgsea package or clusterprofiler/DOSE interface. It's the same method but much faster.

Answering your question, I normally use stat column of DESeq2 results, but your metric should also work fine.

ADD REPLYlink written 11 months ago by assaron140
1
gravatar for geek_y
11 months ago by
geek_y8.6k
geek_y8.6k wrote:

Looks good. I would always recommend to do in your own way and get feedback. The -log10(p-value)*sign of the fold change is been used in published papers,so there is no problem with it.

ADD COMMENTlink modified 11 months ago • written 11 months ago by geek_y8.6k

thanks for clarifying! Could you elaborate a little bit on taking p-value (unadjusted) vs. FDR-adjusted pvalue for metric calculation, and if I use metric =(sign of log2FC)*(-log10(pval)), what is the appropriate parameter for scoring scheme (classic vs weighted (p=1))? How should I decide to use classic or weighted scheme? Thanks for your input in advance!

ADD REPLYlink modified 11 months ago • written 11 months ago by sup23030

are you doing this for the purpose of cross checking the significance of the set of genes selected by DESeq2?

ADD REPLYlink written 4 months ago by Uday Madappa40
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