# scCATCH tutorial

#### Xin Shao

#### 2022-11-07

This package is a single cell Cluster-based auto-Annotation Toolkit for Cellular Heterogeneity (scCATCH) from cluster potential marker genes identification to cluster annotation based on evidence-based score by matching the potential marker genes with known cell markers in tissue-specific cell taxonomy reference database (CellMatch).

The scCATCH mainly includes two function `findmarkergene` and `findcelltype` to realize the automatic annotation for each identified cluster.

scCATCH can be used to annotate scRNA-seq data from tissue with cancer and without cancer.

### General usage

[1] For scRNA-seq data, we suggest to revise the gene symbols with `rev_gene()`. `geneinfo` is the system data.frame containing the information of human and mouse from NCBI gene(updated in June. 19, 2022). To use your own `geneinfo` data.frame, please refer to `demo_geneinfo` to build a new one, e.g., rat, zebrafish, Drosophila, C. elegans, etc.

    library(scCATCH)
    load(paste0(system.file(package = "scCATCH"), "/extdata/mouse_kidney_203.rda"))

    # demo_geneinfo
    demo_geneinfo()
    #>   symbol synonyms species
    #> 1   A1BG      A1B   Human
    #> 2   A1BG      ABG   Human
    #> 3  A2MP1     A2MP   Human
    #> 4   Aco1      Aco   Mouse

    # revise gene symbols
    mouse_kidney_203 <- rev_gene(data = mouse_kidney_203, data_type = "data", species = "Mouse", geneinfo = geneinfo)

[2] create scCATCH object with `createscCATCH()`. Users need to provide the normalized data and the cluster for each cell.

    obj <- createscCATCH(data = mouse_kidney_203, cluster = mouse_kidney_203_cluster)

[3] find highly expressed genes with `findmarkergene()`. Users need to provided the speices, tissue, or cancer information. `cellmatch` is the system data.frame containing the known markers of human and mouse. To use your own marker data.frame, please refer to `demo_marker` to build a new one, e.g., rat, zebrafish, Drosophila, C. elegans, etc.

    # demo_geneinfo
    demo_marker()
    #>   species tissue                cancer   condition   subtype1 subtype2
    #> 1   Human  Liver                Normal Normal cell         NA     CD4+
    #> 2   Human  Liver                Normal Normal cell         NA     CD8+
    #> 3   Human  Liver Hepatocellular Cancer Cancer cell         NA       NA
    #> 4   Human  Liver Hepatocellular Cancer Cancer cell Regulatory       NA
    #>    subtype3 celltype  gene               resource     pmid
    #> 1        NA   T Cell   CD4             Experiment 27781378
    #> 2        NA   T Cell  CD8A             Experiment 27781378
    #> 3 Exhausted   T Cell ABCG1 Single-cell sequencing 28622514
    #> 4        NA   T Cell  ACP5 Single-cell sequencing 28622514

    # find highly expressed genes
    obj <- findmarkergene(object = obj, species = "Mouse", marker = cellmatch, tissue = "Kidney")
    #> There are 1762 potential marker genes in CellMatch database for Mouse on Kidney.

[4] Evidence-based score and annotation for each cluster with `findcelltype()`

    obj <- findcelltype(object = obj)

    # Results is stored in obj
    obj@celltype
    #>   cluster
    #> 1       1
    #> 2       2
    #> 3       3
    #>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         cluster_marker
    #> 1                                                               Sdhd, Ckmt1, Rabac1, Clcn5, Kit, Clcnkb, Atp6v1b1, Pgrmc1, Atp6v0e, Eps8, Cpsf4l, Atp6ap1, Atp6v1e1, Epb41l2, Avpr1a, Uqcr11, Mdh1, Atp6v1c2, Slc26a4, Atp6v1d, Uqcrb, Hexb, Emb, Prkcd, Aco2, Alcam, Pros1, Guca2a, Atp6v0c, Slc4a9, Efhd1, Pam, Rgs2, Atp6v1g3, Mkks, Jag1, Edn3, Car2, Mme, Atp6v0d2, Ociad2, Stap1, Pcolce, Tmem213, Aldh1l1, Itpr2, Ctsc, Atp6ap2, Slc25a4, Plet1, Cox7a2, Car12, Gng11, Mif, Atp6v0b, Atp6v1h, Gadd45a, Etl4, Cox6b1, Fam13a, Slc43a2, Atp6v0a4, Rcan2, Ncoa7, S100g, Serpinb6b, Aqp6, Hepacam2, Oxgr1, Serpinb9, Wnk1, Foxi1, Chchd10, Tdrp, Spink8, Atp6v1a, 9130008F23Rik, Adgrf5, Pde1a, Kng2, Tmem117, Tmem61, Rhbg, Mindy1
    #> 2                                                                                                              Cav2, Scnn1g, Calm1, Gstt1, Aif1l, Fxyd4, Wdr1, Crip2, Crip1, Cav1, Ctsd, Pea15a, Stc1, Gata3, Dstn, Pls3, Sdc4, Serinc3, Wfdc2, Nudt4, Sptbn1, Btg2, Pgam2, Cdkl1, Fos, Clu, Fstl1, Aqp2, Krt7, Krt18, Ivns1abp, Myl12a, Anxa1, Ptp4a1, Atp1b1, Olfm1, Cst3, S100a11, Tbck, Calb1, Aqp3, Hacd4, Pdzk1ip1, Tmem52b, Arhgdib, Iqgap1, Scnn1b, Avpr2, Sorbs2, Adgrg1, Cdh16, Hsd11b2, Aplp2, Tpm1, Cdo1, Tspan8, R3hdm4, Btg1, Mcoln3, Kcne1, Arglu1, Npnt, Kcnj1, Tmem45b, S100a1, Cystm1, Cd24a, Cldn4, Tmem229a, Tmsb4x, Lgals3, Tacstd2, Junb, Phactr1, Blnk, Pcnp, Akr1c19, Adh1, S100a16, Apela, Btc, Neat1, Cavin1
    #> 3 Slc22a18, Gm2a, Slc7a7, Folr1, Rhoc, Apoe, Dnase1, Htra1, Cyba, Neu1, Slc47a1, Pipox, Igfbp4, Mapt, Sparc, Cxcl16, Timp3, Tcn2, Acox1, Akr1c21, Slc17a1, Slc34a1, Slc6a19, Ephx2, Cyp2d26, Miox, Cela1, Fhl1, Slc22a1, Mep1a, Lims2, Cndp2, Slc22a6, Fth1, Keg1, Acy3, Cyp2e1, Pecr, Dbi, Lrp2, Cat, Sord, Slc27a2, Pck1, Hao2, Hmgcs2, Bdh2, Ddah1, Ccdc107, Scp2, Akr1a1, Cda, Errfi1, Prom1, Khk, Tmem176b, Nox4, Fah, Acsm2, Msn, Ces1f, 4931406C07Rik, Slc37a4, Calml4, Pth1r, Guca2b, Xylb, Slc17a3, Pdzk1, Degs1, Ttc36, Lap3, Id1, Defb29, Tmem174, Ugt3a2, Cyp2j5, Slc22a30, Them7, Fut9, Tpt1, Slc4a4, Slc22a12, Ugt2b38, Kcnj15, Slc22a28, Glyat, Gpx1, Lgals1, Fbp1, Gm10804, Ass1, G6pc, Rida, Mettl26, Nat8f1, Selenop
    #>                           cell_type celltype_score
    #> 1 Collecting Duct Intercalated Cell           0.86
    #> 2    Collecting Duct Principal Cell           0.86
    #> 3              Proximal Tubule Cell           0.70
    #>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            celltype_related_marker
    #> 1                                  9130008F23Rik, Atp6v0d2, Atp6v1g3, Car2, Chchd10, Fam13a, Mif, Mme, Oxgr1, Slc25a4, Tmem61, Uqcrb, Aco2, Aldh1l1, Aqp6, Atp6ap1, Atp6ap2, Atp6v0a4, Atp6v0b, Atp6v0c, Atp6v0e, Atp6v1a, Atp6v1b1, Atp6v1c2, Atp6v1d, Atp6v1e1, Atp6v1h, Avpr1a, Car12, Ckmt1, Clcn5, Clcnkb, Cox6b1, Cox7a2, Cpsf4l, Efhd1, Emb, Eps8, Foxi1, Guca2a, Hepacam2, Hexb, Itpr2, Kit, Mdh1, Mkks, Ncoa7, Ociad2, Pam, Pde1a, Pgrmc1, Rcan2, Rgs2, S100g, Sdhd, Serpinb6b, Serpinb9, Slc26a4, Slc4a9, Tdrp, Tmem117, Tmem213, Uqcr11, Mindy1, Adgrf5
    #> 2                                                                                                                                                                                                                         Adgrg1, Apela, Aqp2, Aqp3, Avpr2, Cav1, Cav2, Cdh16, Cdo1, Cldn4, Fxyd4, Gstt1, Hsd11b2, Ivns1abp, Kcne1, Kcnj1, Npnt, Nudt4, Olfm1, Pdzk1ip1, Phactr1, Scnn1b, Scnn1g, Stc1, Tacstd2, Tbck, Tmem229a, Tmem45b, Tspan8, Wfdc2, Adh1, Aif1l, Akr1c19, Arhgdib, Atp1b1, Btc, Cdkl1, Ctsd, Cystm1, Fstl1, Krt18, Krt7, Lgals3, Neat1, Cd24a
    #> 3 4931406C07Rik, Acox1, Acsm2, Acy3, Akr1a1, Akr1c21, Ass1, Bdh2, Calml4, Cat, Ccdc107, Cda, Cela1, Ces1f, Cndp2, Cyp2d26, Cyp2e1, Cyp2j5, Defb29, Dnase1, Ephx2, Errfi1, Fah, Fbp1, Folr1, Fth1, Fut9, G6pc, Glyat, Gm10804, Gpx1, Guca2b, Hao2, Kcnj15, Keg1, Khk, Lap3, Lrp2, Mep1a, Miox, Neu1, Nox4, Pck1, Pdzk1, Pecr, Pipox, Scp2, Slc17a1, Slc17a3, Slc22a1, Slc22a12, Slc22a18, Slc22a28, Slc22a30, Slc22a6, Slc27a2, Slc34a1, Slc37a4, Slc47a1, Slc4a4, Slc6a19, Slc7a7, Sord, Tcn2, Them7, Tmem174, Ttc36, Ugt2b38, Ugt3a2, Xylb, Mettl26, Nat8f1, Rida
    #>                           PMID
    #> 1 29622724, 28851704, 29775597
    #> 2 29622724, 28851704, 29775597
    #> 3                     29622724

Note: There two methods to find marker genes. Set `use_method` `1` to compare with every other cluster and `2` to compare with other clusters together like the strategy in `Seurat`. Besides, when setting `use_method` `1`, users can set `comp_cluster`, it represent the number of clusters to compare. Default is to compare all other cluster for each cluster. Set it between 1 and length of unique clusters. More marker genes will be obtained for smaller `comp_cluster`.

    # The most strict condition to identify marker genes
    obj <- findmarkergene(object = obj, species = "Mouse", marker = cellmatch,tissue = "Kidney", use_method = "1")
    #> There are 1762 potential marker genes in CellMatch database for Mouse on Kidney.

    # The most loose condition to identify marker genes
    obj <- findmarkergene(object = obj, species = "Mouse", marker = cellmatch, tissue = "Kidney", use_method = "2")
    #> There are 1762 potential marker genes in CellMatch database for Mouse on Kidney.

    # Other conditions to identify marker genes
    obj <- findmarkergene(object = obj,species = "Mouse", marker = cellmatch, tissue = "Kidney", use_method = "1", comp_cluster = 1)
    #> There are 1762 potential marker genes in CellMatch database for Mouse on Kidney.

Moreover, users can adjust the `cell_min_pct`, `logfc`, and `pvalue` to identify the different marker genes.

### Custom usage

Users are allowed to use the custom `cellmatch` for cell type prediction when [1] users want to select different combination of tissues or cancers for annotation; [2] users want to add more marker genes to `cellmatch` for annotation; [3] users want to use markers from different species other than human and mouse. In this way, please set `if_use_custom_marker` `TRUE` in `findmarkergene()` function and do not need to set `species`,`tissue`, and `cancer`

[1] Different combination of tissues or cancers

    # Example
    cellmatch_new <- cellmatch[cellmatch$species == "Mouse" & cellmatch$tissue %in% c("Kidney", "Liver", "Lung", "Brain"), ]
    obj <- findmarkergene(object = obj, if_use_custom_marker = TRUE, marker = cellmatch_new)
    obj <- findcelltype(obj)

    # Example
    cellmatch_new <- cellmatch[cellmatch$species == "Mouse" & cellmatch$cancer %in% c("Lung Cancer", "Lymph node", "Renal Cell Carcinoma", "Prostate Cancer"), ]
    obj <- findmarkergene(object = obj, if_use_custom_marker = TRUE, marker = cellmatch_new)
    obj <- findcelltype(obj)

    # Example
    cellmatch_new <- cellmatch[cellmatch$species == "Mouse", ]
    cellmatch_new <- cellmatch[cellmatch$cancer %in% c("Lung Cancer", "Lymph node", "Renal Cell Carcinoma", "Prostate Cancer") | cellmatch$tissue %in% c("Kidney", "Liver", "Lung", "Brain"), ]
    obj <- findmarkergene(object = obj, if_use_custom_marker = TRUE, marker = cellmatch_new)
    obj <- findcelltype(obj)

[2] Add more marker genes to `cellmatch` for annotation

    # Example

    # cellmatch_new is provided by users
    # cellmatch_new <- rbind(cellmatch, cellmatch_new)

    # Then use the new cellmatch
    # a. define the species, tissue, and cancer
    obj <- findmarkergene(object = obj, species = "Mouse", marker = cellmatch_new, tissue = "Kidney")
    #> There are 1762 potential marker genes in CellMatch database for Mouse on Kidney.
    obj <- findcelltype(obj)

    # b. directly use custom cellmatch
    obj <- findmarkergene(object = obj, if_use_custom_marker = TRUE, marker = cellmatch_new)
    obj <- findcelltype(obj)

[3] Use markers from different species

    # Please refer to demo_marker to build a marker data.frame (new_cellmatch) for another species, e.g., rat
    # Then use the new marker
    obj <- findmarkergene(object = obj, species = "Rat", if_use_custom_marker = TRUE, marker = cellmatch_new, tissue = "Kidney")
    obj <- findcelltype(obj)

### About

Please refer to the scCATCH on GitHub for more information. Available tissues and cancers see the wiki page

### Cite

Shao et al., scCATCH:Automatic Annotation on Cell Types of Clusters from Single-Cell RNA Sequencing Data, iScience, Volume 23, Issue 3, 27 March 2020. doi: 10.1016/j.isci.2020.100882. PMID:32062421