Journal: Cancer Cell

Article Title: An Evolutionarily Conserved Function of Polycomb Silences the MHC Class I Antigen Presentation Pathway and Enables Immune Evasion in Cancer

doi: 10.1016/j.ccell.2019.08.008

Figure Lengend Snippet: A Whole Genome CRISPR Screen Identifies a Critical Role for PRC2 in Silencing MHC-I Expression in Cancer Cells (A) CRISPR screen. K-562 cells were mutagenized by infection with a pooled lentiviral library comprising 220,000 sgRNA and MHC-I high cells were enriched by three successive sorts using fluorescence-activated cell sorting. (B) Cell surface MHC-I in K-562 cells following incubation ± IFN-γ 10 ng/mL for 24 h. (C) Bubble plots show the top 1,000 enriched genes identified in the CRISPR screen. PRC2 genes indicated in red. p values calculated using the RSA algorithm ( Konig et al., 2007 ). (D and E) EED KO K-562 cells were transduced with a lentiviral vector encoding either EED cDNA or GFP (vector, V) and analyzed by flow cytometry (D) and immunoblot (E). (F) mRNA expression (reads per kilobase of transcript per million mapped reads) of MHC-I genes in 920 cancer cell lines in the Cancer Cell Line Encyclopedia. Each dot represents an individual cancer cell line, clustered by tumor type (log 2 scale, black line indicates median). See also Figure S1 and .

Article Snippet: The screen was performed using the Bassik Human CRISPR KO Library (a gift from Michael Bassik, Addgene 101296-101934).

Techniques: CRISPR, Expressing, Infection, Fluorescence, FACS, Incubation, Transduction, Plasmid Preparation, Flow Cytometry, Western Blot