Journal: Cell Reports Medicine
Article Title: CRISPR screens in the context of immune selection identify CHD1 and MAP3K7 as mediators of cancer immunotherapy resistance
doi: 10.1016/j.xcrm.2025.102565
Figure Lengend Snippet: Reduced CHD1 and MAP3K7 expression enhances anti-tumor immunity and correlates with clinical response to immune checkpoint blockade (A) Chd1 and Map3k7 dKO B16-F10 tumor cells have a higher frequency of spontaneous rejection. Engraftment rates of NT gRNA-harboring or dKO B16-F10 cells injected subcutaneously into syngeneic C57BL/6 mice at day 9 post-injection. Data represent four independent experiments. Two-sided Fisher’s exact test; ∗ P = 0.015. (B) Chd1 and Map3k7 dKO B16-F10 tumors grow more slowly in vivo . Endpoint tumor mass of successfully engrafted B16-F10 NT gRNA and dKO tumors in mice treated with intraperitoneal anti-PD-1 and anti-CTLA-4 immune checkpoint blockade (ICB) or isotype (Iso.) control. Data represent the mean ± SD from three independent experiments. Unpaired, two-tailed Student’s t test; n = 25 NT NT iso.; n = 18 NT NT ICB; n = 33 dKO iso.; n = 21 dKO ICB. ∗∗∗ P = 0.0002, ∗∗ P = 0.0025 NT NT iso. versus NT NT ICB, ∗∗ P = 0.0094 dKO iso versus dKO ICB, ∗ P = 0.01. (C) Tumor regressions are more frequent in Chd1 and Map3k7 dKO B16-F10 tumors treated with ICB. Subcutaneous tumors were measured using calipers, and tumors with a decrease in volume were considered regressions. Data are pooled from three independent experiments. NT NT ICB versus dKO ICB, two-sided Fisher’s exact test; ∗ P = 0.0176. (D) Improved immunotherapy response in Chd1 and Map3k7 dKO B16-F10 tumors. Growth curves of subcutaneously engrafted B16-F10 NT NT gRNA or dKO tumors ± ICB. Data represent the mean ± SEM and are representative of three independent experiments. Two-way analysis of variance (ANOVA); ∗ P = 0.0094; ∗∗ P = 0.0019. dKO Iso n = 6, dKO ICB n = 5, NT NT Iso n = 4, NT NT ICB n = 6. (E) Heightened anti-tumor immunity in Chd1 and Map3k7 dKO B16-F10 tumors treated with ICB. Immunoprofiling of subcutaneous tumors at the endpoint (days 15–17). Relative abundance of intratumoral conventional CD4 + T cells, CD8 + T cells, regulatory T cells (T regs ), and the CD8 + T cells:T reg ratio, as well as the surface expression of the activation marker CD44 on CD8 + T cells, was assessed by flow cytometry. MFI, mean fluorescence intensity. Data represent the mean ± SD and are pooled from three independent experiments. One-way ANOVA; ∗∗∗∗ P < 0.0001; ∗∗∗ P < 0.0005; ∗∗ P < 0.01; ∗ P < 0.05; ns = not significant. NT NT Iso. n = 22 or n = 23 for CD8 analysis. NT NT ICB n = 20 or n = 19 for Tconv. analysis. dKO Iso. n = 25 or n = 27 for CD8 analysis. dKO ICB n = 17 or n = 16 for CD8:Treg or n = 18 for CD44 analysis. (F) Correlation of CHD1 and MAP3K7 mRNA expression in prostate cancers expressed as log2 fragments per kilobase of transcript per million (FMPK). Spearman’s rank correlation, R = 0.67, P = 1.54e−16. (G) Reduced expression of CHD1 and MAP3K7 in lung cancer and melanoma is associated with clinical response to ICB. Boxplot displaying tumor CHD1 and MAP3K7 mRNA expression (adjusted transcripts per million; adj. TPM) and clinical responses to ICB in patients from the Hartwig Medical Foundation. Significance was assessed using the Wilcoxon signed-rank test, and n denotes the number of patients. Boxplots represent the median and interquartile range (IQR), and whiskers indicate the lowest and highest values within 1.5 × IQR. CB, clinical benefit; NCB, no clinical benefit.
Article Snippet: Anti-human PD-1 , BioXCell , Cat.# BP0146; RRID: AB_2894808.
Techniques: Expressing, Injection, In Vivo, Control, Two Tailed Test, Activation Assay, Marker, Flow Cytometry, Fluorescence