15 May 2024 in Science Translational Medicine
Apart from their killer identity, natural killer (NK) cells have integral roles in shaping the tumor microenvironment. Through immune gene deconvolution, the present study revealed an interplay between NK cells and myeloid-derived suppressor cells (MDSCs) in nonresponders of immune checkpoint therapy. Given that the mechanisms governing the outcome of NK cell–to–myeloid cell interactions remain largely unknown, we sought to investigate the cross-talk between NK cells and suppressive myeloid cells. Upon contact with tumor-experienced NK cells, monocytes and neutrophils displayed increased expression of MDSC-related suppressive factors along with increased capacities to suppress T cells. These changes were accompanied by impaired antigen presentation by monocytes and increased ER stress response by neutrophils. In a cohort of patients with sarcoma and breast cancer, the production of interleukin-6 (IL-6) by tumor-infiltrating NK cells correlated with S100A8/9 and arginase-1 expression by MDSCs. At the same time, NK cell–derived IL-6 was associated with tumors with higher major histocompatibility complex class I expression, which we further validated with b2m -knockout (KO) tumor mice models. Similarly in syngeneic wild-type and IL-6 KO mouse models, we then demonstrated that the accumulation of MDSCs was influenced by the presence of such regulatory NK cells. Inhibition of the IL-6/signal transducer and activator of transcription 3 (STAT3) axis alleviated suppression of T cell responses, resulting in reduced tumor growth and metastatic dissemination. Together, these results characterize a critical NK cell–mediated mechanism that drives the development of MDSCs during tumor immune escape.
2 August 2021 in Nature Biomedical Engineering
30 June 2026 in Nature Communications
Despite promising development as emerging "off-the-shelf" therapeutics against cancer, natural killer (NK) cells still faced considerable challenges in the solid tumor microenvironment (TME), including poor penetrance and immuno-suppression. Here, we employ spatial and single-cell transcriptomics to reveal a role for Nur77 in NK cell-mediated immunity against hepatocellular carcinoma (HCC). Orthogonal analysis of human and mouse HCC tumors indicate that the expression of NR4A1, encoding Nur77, is associated with NK cell proliferation, activation of the immunostimulatory AP-1 gene regulons, and better disease-free survival in HCC. Conditional ablation of Nr4a1 in NK cells perturbs their homeostasis and accelerates tumor progression in multiple tumor models. Conversely, the agonistic activation of Nur77 in NK cells ex-vivo or in-vivo enhances their anti-tumor functions. Mechanistically, downstream functional assays confirm that Nur77 activation attenuates CD36 expression in NK cells and confers resistance against oxLDL-mediated immunosuppression in the TME. Collectively, our findings highlight the potential of harnessing Nur77 agonism in improving NK cell-based immunotherapy against HCC.
6 December 2025 in Biochemical Pharmacology
JMJessica Javiera Conejeros Monsalve
Jessica Javiera Conejeros Monsalve
+10
Breast and ovarian cancers remain among the most lethal malignancies affecting women worldwide. Despite advances in standard therapies, drug resistance and high relapse rates continue to undermine long-term treatment outcomes. To address these challenges, we re-evaluated five previously identified drug candidates (FLIX1-FLIX5), all of which are effective at nanomolar concentrations in breast and ovarian cancer cell lines. Among them, FLIX3 (Albacarcin V) and FLIX4 exhibited the most potent cytotoxicity, with IC50 values below 50 nM across multiple cell lines. Notably, FLIX3 also exhibited nanomolar-range efficacy in drug-resistant, patient-derived samples from triple-negative breast cancer (TNBC) and ovarian cancer. In a zebrafish model, FLIX3 effectively eliminated cancer cells within its safety window. ATAC-Seq analysis revealed that both compounds induce significant epigenetic alterations. Proteome Integral Solubility Alteration (PISA) and cellular thermal shift assay (CETSA) identified EPLIN (Epithelial Protein Lost in Neoplasm) as the top target of FLIX3 but not FLIX4. EPLIN was previously identified as the primary target of FLIX5. Its re-emergence as the dominant target of FLIX3 highlights its potential as a broadly applicable therapeutic target. Collectively, these findings support the continued development of EPLIN-targeting compounds as promising agents for treating aggressive and drug-resistant breast and ovarian cancers.