Journal: bioRxiv
Article Title: CRISPR activation screens map the genomic landscape of cancer glycome remodeling
doi: 10.1101/2025.05.26.656133
Figure Lengend Snippet: A) K-562-dCas9-CRISPRa cells were transduced with two different sgRNAs targeting the CD24 promoter region. After selection with puromycin, cells were stained with Siglec-10-Fc as in 1B and with a fluorescent antibody against CD24. Representative flow cytometry plots for both stains are shown. B) THP-1 cells were stained with Siglec-10-Fc as in 1B and a fluorescent antibody against CD24. Representative flow cytometry plots for both stains are shown. C) OCI-AML-2-Cas9 cells were lentivirally transduced with an sgRNA targeting MGAT1 to generate a polyclonal cell population containing WT and MGAT1 KO cells. Cells were then co-stained with Siglec-10-Fc and the lectin L-PHA (5 μg/mL), which binds to complex N-linked glycans. Representative staining is indicated on the flow cytometry plot. D) Graph indicates MFI of Siglec-10-Fc staining in the WT (L-PHA+) and MGAT1 KO (L-PHA-) populations. E) OCI-AML-2-Cas9 cells were lentivirally transduced with an sgRNA targeting C1GALT1. Cells were co-stained with Siglec-10-Fc and the lectin DBA, which binds to exposed α-GalNAc. Representative staining is indicated on the flow cytometry plot. F) Graph indicates MFI of Siglec-10-Fc staining in the WT (DBA-) and C1GALT1 KO (DBA+) populations. G) Pathway diagram indicates the enzymes involved in 2,3-linked and 2,6-linked sialylation of N-linked glycans. ST3GAL4, ST3GAL6 and ST6GAL1 were all strong hits in the Siglec-10 screen. H) The heat map indicates the average mRNA expression of key glycosyltransferase hits in cell lines derived from B-ALL, T-ALL, AML and multiple myeloma. mRNA expression values were extracted from DepMap and the Human Protein Atlas. I) OCI-AML-2-Cas9 cells were transduced an sgRNAs against ST3GAL4. Cells were then stained with fluorescently labeled Siglec-10-Fc. A representative flow cytometry plot is shown. J) The MFI of Siglec-10 staining in OCI-AML-2 WT and ST3GAL4 KO cells is indicated. MFI is internally normalized to the WT cell line. K) MM1S-Cas9 cells were transduced an sgRNAs against ST6GAL1. ST6GAL1 KO cells were isolated by FACS using the lectin SNA. Cells were then stained with fluorescently labeled Siglec-10-Fc. A representative flow cytometry plot is shown. L) The MFI of Siglec-10 staining in MM1S WT and ST6GAL1 KO cells is indicated. MFI is internally normalized to the WT cell line. M) K-562-CRISPRa cells were transduced and stained as in 4C . A representative flow cytometry plot is shown comparing Siglec-10-Fc staining in cells transduced with a non-targeting (NT) sgRNA to cells within the “CD44 High” expression gate. N) The MFI of Siglec-10-Fc staining in NT cells vs. “CD44 High” cells is shown. MFI is internally normalized to the WT cell line. O) K-562 CRISPRa cells were transduced with an sgRNA against CSPG4 and co-stained with Sig10-Fc and a CSPG4 antibody as in 4C . A representative flow cytometry plot is shown comparing Siglec-10-Fc staining in cells transduced with a non-targeting (NT) sgRNA to cells within the “CSPG4 High” expression gate. P) The MFI of Siglec-10 staining in NT cells vs. “CSPG4 High” cells is shown. MFI is internally normalized to the WT cell line. Statistical significance was determined using a two-tailed t-test. ** indicates p<0.01, * indicates p<0.05. Mean values plotted, error bars indicate SEM.
Article Snippet: The CRISPRa-v2 library (top 5 sgRNAs/gene) containing 104,535 sgRNAs was purchased from Addgene (Pooled Library 83978).
Techniques: Transduction, Selection, Staining, Flow Cytometry, Expressing, Derivative Assay, Labeling, Isolation, Two Tailed Test