Introduction

EnrichR [1][2] is a GSE (Gene Set Enrichment) method that infers biological knowledge by performing enrichment of input gene sets with curated biologically relevant prior databases that represent biological functions or functional pathways. The singleCellTK toolkit offers an easy to use interface to the EnrichR method and only requires the selection of input genes and the databases against which the genes should be tested.

To view detailed instructions on how to use the method from the toolkit, please select ‘Interactive Analysis’ for using enrichR in shiny application or ‘Console Analysis’ for using this method on R console from the tabs below:

Workflow Guide

An overall workflow guide on how to use EnrichR sub-tab is described below. This workflow guide assumes that the Single Cell Data has already been uploaded through the Import Single Cell Data tab.

  1. Select Cell Annotation & Pathway Analysis tab from the top menu.
  2. Select EnrichR option from the drop-down menu.

  1. Select if you want to upload a gene symbol file using the option Upload file or choose the Select Gene(s) option if you want to select genes from the already uploaded data.

  2. If Select Gene(s) option is selected, you can select the genes from the available data here. Alternatively, you can upload a gene file using the options specified in (9) and (10).

  3. Select databases to test the input genes against. Selecting ALL will test against all available databases and may take long time to compute.

  4. Press Run to start computation of enrichment scores.

  5. Once EnrichR computation is complete, results can be saved to local drive by pressing the Download Results button.

  6. Results are displayed in the table for genes that are significant (adjusted p value < 0.05).

  1. If Upload file option is selected in (3), additional options are displayed to upload the gene symbols file. The file path can be selected here.

  2. Once filed is selected in (9), options to select the parameters of the input file are displayed so the input file is correctly parsed.

1. Select genes and databases:

genes <- c("HES1", "PON2", "FBXO44", "DEK", "SOX4", "FBXL16")
databases <- enrichR::listEnrichrDbs()$libraryName

2. Run ‘enrichR’ using enrichRSCE function:

enrichRes <- enrichRSCE(inSCE = sce, glist = genes, db = databases)

The enrichRSCE function above, takes the following parameters:
inSCE: input SingleCellExperiment object
glist: vector of input gene names
db: a list of databases to test

3. Print results:

print(enrichRes)
Example
  # Load singleCellTK & pbmc3k example data
  library(singleCellTK)
  sce <- importExampleData(dataset = "pbmc3k")
  # Select genes
  genes <- c("HES1", "PON2", "FBXO44", "DEK", "SOX4", "FBXL16")
  # Fetch databases
  databases <- enrichR::listEnrichrDbs()$libraryName
  # Run enrichR
  enrichRes <- enrichRSCE(inSCE = sce, glist = genes, db = databases)
  # Print the first five results
  print(enrichRes[1:5, ])
##                     Database_selected                               Term
## 7750       LINCS_L1000_Chem_Pert_down LJP006 MCF10A 3H-withaferin-a-3.33
## 7751       LINCS_L1000_Chem_Pert_down      LJP006 MCF10A 3H-radicicol-10
## 5530         LINCS_L1000_Chem_Pert_up    LJP006 A375 24H-KIN001-043-1.11
## 4156 Genes_Associated_with_NIH_Grants                        R01GM072915
## 7752       LINCS_L1000_Chem_Pert_down       LJP006 A549 24H-BI-2536-0.37
##      Overlap P.value Adjusted.P.value Old.P.value Old.Adjusted.P.value
## 7750    3/68 7.0e-07        0.0013233           0                    0
## 7751    3/82 1.3e-06        0.0013233           0                    0
## 5530    3/91 1.8e-06        0.0040058           0                    0
## 4156     2/8 2.1e-06        0.0002791           0                    0
## 7752   3/119 4.1e-06        0.0027163           0                    0
##      Odds.Ratio Combined.Score          Genes
## 7750   306.6000       4325.556 PON2;HES1;SOX4
## 7751   252.0886       3413.374 PON2;HES1;SOX4
## 5530   226.2045       2991.617 PON2;HES1;SOX4
## 4156  1665.6667      21777.601       DEK;SOX4
## 7752   171.3621       2127.588 PON2;HES1;SOX4
##                                         link
## 7750                        https://clue.io/
## 7751                        https://clue.io/
## 5530                        https://clue.io/
## 4156 https://grants.nih.gov/grants/oer.htm\n
## 7752                        https://clue.io/

References

[1]
M. V. Kuleshov et al., Enrichr: a comprehensive gene set enrichment analysis web server 2016 update,” Nucleic acids research, vol. 44, no. W1, pp. W90–W97, Jul. 2016, doi: 10.1093/nar/gkw377.
[2]
E. Y. Chen et al., Enrichr: Interactive and collaborative HTML5 gene list enrichment analysis tool,” BMC Bioinformatics, vol. 14, no. 1, pp. 1–14, Apr. 2013, doi: 10.1186/1471-2105-14-128.