Figure 3 from CRISPR–Cas9 Screening Identifies KRAS-Induced COX2 as a Driver of Immunotherapy Resistance in Lung Cancer

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posted on 2024-07-15, 07:20 authored by Jesse Boumelha, Andrea de Castro, Nourdine Bah, Hongui Cha, Sophie de Carné Trécesson, Sareena Rana, Mona Tomaschko, Panayiotis Anastasiou, Edurne Mugarza, Christopher Moore, Robert Goldstone, Phil East, Kevin Litchfield, Se-Hoon Lee, Miriam Molina-Arcas, Julian Downward

COX2/PGE2 signaling hinders response to ICB in mouse and human lung adenocarcinoma. A, Kaplan–Meier survival of mice treated intraperitoneally with 200 μg anti-PD1 after orthotopic transplantation of KPAR or Ptgs2^−/− cells, n = 6–8 per group. Analysis of survival curves was carried out using the log-rank (Mantel–Cox) test. B, Quantification and representative IHC staining of CD8⁺ T cells in KPAR or Ptgs2^−/− orthotopic tumors on day 7 after treatment with anti-PD1 or corresponding isotype control (IgG). Scale bar, 100 μm. C, Percentage of CD69⁺ CD8⁺ T cells in KPAR or Ptgs2^−/− tumors treated as shown in B. D, Frequency of PD1⁺, LAG3⁺, and TIM3⁺ CD8⁺ T cells in KPAR or Ptgs2^−/− tumors treated as shown in B. E, Heatmap showing hierarchical clustering of KPAR or Ptgs2^−/− tumors treated as shown in B based on mRNA expression of antitumor immunity genes assessed by qPCR. F, Baseline COX-IS levels in responder (R) and nonresponder (NR) ICB-treated patients with lung adenocarcinoma. G, Progression-free survival of patients with lung adenocarcinoma treated with ICB, stratified into highest and lowest quartile based on COX-IS expression. H, Multivariate Cox regression analysis for the indicated variables in patients with lung adenocarcinoma following ICB treatment. CTx, chemotherapy. Error bars represent 95% confidence interval (CI) boundaries. Data are represented as mean ± SEM for B–D, n = 5–9 per group. Statistics were calculated using two-tailed Student t test (F) or one-way ANOVA, FDR 0.05 (B–D). ns, not significant; *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001.

Funding

HORIZON EUROPE European Research Council (ERC)

Cancer Research UK (CRUK)

Medical Research Foundation

Wellcome Trust (WT)

'la Caixa' Foundation ('la Caixa')

History

ARTICLE ABSTRACT

Oncogenic KRAS impairs antitumor immune responses. As effective strategies to combine KRAS inhibitors and immunotherapies have so far proven elusive, a better understanding of the mechanisms by which oncogenic KRAS drives immune evasion is needed to identify approaches that could sensitize KRAS-mutant lung cancer to immunotherapy. In vivo CRISPR–Cas9 screening in an immunogenic murine lung cancer model identified mechanisms by which oncogenic KRAS promotes immune evasion, most notably via upregulation of immunosuppressive COX2 in cancer cells. Oncogenic KRAS potently induced COX2 in both mouse and human lung cancer, which was suppressed using KRAS inhibitors. COX2 acted via prostaglandin E2 (PGE2) to promote resistance to immune checkpoint blockade (ICB) in lung adenocarcinoma. Targeting COX2/PGE2 remodeled the tumor microenvironment by inducing proinflammatory polarization of myeloid cells and influx of activated cytotoxic CD8+ T cells, which increased the efficacy of ICB. Restoration of COX2 expression contributed to tumor relapse after prolonged KRAS inhibition. These results provide the rationale for testing COX2/PGE2 pathway inhibitors in combination with KRASG12C inhibition or ICB in patients with KRAS-mutant lung cancer.Significance: COX2 signaling via prostaglandin E2 is a major mediator of immune evasion driven by oncogenic KRAS that promotes immunotherapy and KRAS-targeted therapy resistance, suggesting effective combination treatments for KRAS-mutant lung cancer.