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.
Subject(s)
CRISPR-Cas Systems , Cyclooxygenase 2 , Drug Resistance, Neoplasm , Immunotherapy , Lung Neoplasms , Proto-Oncogene Proteins p21(ras) , Animals , Lung Neoplasms/genetics , Lung Neoplasms/immunology , Lung Neoplasms/pathology , Lung Neoplasms/therapy , Lung Neoplasms/drug therapy , Cyclooxygenase 2/metabolism , Cyclooxygenase 2/genetics , Mice , Proto-Oncogene Proteins p21(ras)/genetics , Humans , Drug Resistance, Neoplasm/genetics , Immunotherapy/methods , Dinoprostone/metabolism , Adenocarcinoma of Lung/immunology , Adenocarcinoma of Lung/genetics , Adenocarcinoma of Lung/drug therapy , Adenocarcinoma of Lung/pathology , Adenocarcinoma of Lung/therapy , Tumor Microenvironment/immunology , Immune Checkpoint Inhibitors/pharmacology , Immune Checkpoint Inhibitors/therapeutic use , Cell Line, Tumor , Mice, Inbred C57BL , FemaleABSTRACT
In this study, the impact of the apolipoprotein B mRNA-editing catalytic subunit-like (APOBEC) enzyme APOBEC3B (A3B) on epidermal growth factor receptor (EGFR)-driven lung cancer was assessed. A3B expression in EGFR mutant (EGFRmut) non-small-cell lung cancer (NSCLC) mouse models constrained tumorigenesis, while A3B expression in tumors treated with EGFR-targeted cancer therapy was associated with treatment resistance. Analyses of human NSCLC models treated with EGFR-targeted therapy showed upregulation of A3B and revealed therapy-induced activation of nuclear factor kappa B (NF-κB) as an inducer of A3B expression. Significantly reduced viability was observed with A3B deficiency, and A3B was required for the enrichment of APOBEC mutation signatures, in targeted therapy-treated human NSCLC preclinical models. Upregulation of A3B was confirmed in patients with NSCLC treated with EGFR-targeted therapy. This study uncovers the multifaceted roles of A3B in NSCLC and identifies A3B as a potential target for more durable responses to targeted cancer therapy.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Animals , Mice , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/genetics , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , Mutation , Up-Regulation/genetics , ErbB Receptors/genetics , ErbB Receptors/metabolism , Cytidine Deaminase/genetics , Minor Histocompatibility Antigens/genetics , Minor Histocompatibility Antigens/metabolismABSTRACT
In the process of epithelial-mesenchymal transition (EMT), epithelial cancer cells transdifferentiate into mesenchymal-like cells with high motility and aggressiveness, resulting in the spread of tumor cells. Immune cells and inflammation in the tumor microenvironment are the driving factors of EMT, but few studies have explored the core targets of the interaction between EMT and tumor immune cells. We analyzed thousands of cases of gastric cancer and gastric tissue specimens of TCGA, CPTAC, GTEx and analyzing QPCR and IHC data of 56 gastric cancer patients in SYSU Gastric Cancer Research Center. It was known that EMT has an important connection with the infiltration of NK cells, and that the expression of vinculin may be the target of the phenomenon. The increased expression of vinculin is closely related to the aggressiveness and distant metastasis of cancer, which affects the survival prognosis of the patient. Moreover, through in vitro experiments under 3D conditions, we found that vinculin, cell invasion and metastasis are clearly linked. VCL can affect EMT and tumor immunity by regulating EPCAM gene expression. The role and mechanism of action of vinculin have been controversial, but this molecule may downregulate EpCAM (epithelial cellular adhesion molecule) and its own role in gastric cancer through DNA methylation, causing NK cells to enrich into tumor cells and kill tumor cells. At the same time, it promotes the occurrence of EMT, which in turn causes tumor metastasis and thus poorer prognosis.
