Journal
CANCER RESEARCH
Volume 81, Issue 12, Pages 3295-3308Publisher
AMER ASSOC CANCER RESEARCH
DOI: 10.1158/0008-5472.CAN-20-3564
Keywords
-
Categories
Funding
- National Cancer Institute [1U01-CA196408]
- National Heart Lung and Blood Institute [T32-HL072752]
- Medical Research Funds from the Department of Veteran Affairs
- National Institutes of Health (NIH) [CA-16042, AI-28697]
- NIH/NCATS [UL1TR001881]
Ask authors/readers for more resources
Loss of LKB1 leads to increased secretion of ELR+ CXC chemokines in NSCLC, promoting the enrichment of G-MDSCs and immunosuppression. Treatment with ATRA enhances tumor sensitivity to PD-1 blockade, suggesting a potential strategy for overcoming immunotherapy resistance in LKB1-deficient NSCLC.
LKB1 inactivating mutations are commonly observed in patients with KRAS-mutant non-small cell lung cancer (NSCLC). Although treatment of NSCLC with immune checkpoint inhibitors (ICI) has resulted in improved overall survival in a subset of patients, studies have revealed that co-occurring KRAS/LKB1 mutations drive primary resistance to ICIs in NSCLC. Effective therapeutic options that overcome ICI resistance in LKB1-mutant NSCLC are limited. Here, we report that loss of LKB1 results in increased secretion of the C-X-C motif (CXC) chemokines with an NH2-terminal Glu-Leu-Arg (ELR) motif in premalignant and cancerous cells, as well as in genetically engineered murine models (GEM M) of NSCLC. Heightened levels of ELR+ CXC chemokines in LKB1-deficient murine models of NSCLC positively correlated with increased abundance of granulocytic myeloid-derived suppressor cells (G-MDSC) locally within the tumor microenvironment and systemically in peripheral blood and spleen. Depletion of G-MDSCs with antibody or functional inhibition via all-trans-retinoic acid (ATRA) led to enhanced antitumor T-cell responses and sensitized LKB1-deficent murine tumors to PD-1 blockade. Combination therapy with anti-PD-1 and ATRA improved local and systemic T-cell proliferation and generated tumor-specific immunity. Our findings implicate ELR+ CXC chemokine-mediated enrichment of G-MDSCs as a potential mediator of immunosuppression in LKB1-deficient NSCLC and provide a rationale for using ATRA in combination with anti-PD-1 therapy in patients with LKB1-deficient NSCLC refractory to ICIs. Significance: These findings show that accumulation of myeloid-derived suppressor cells in LKB1-deficient non-small cell lung cancer can be overcome via treatment with all-trans-retinoic acid, sensitizing tumors to immunotherapy.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available