{
  "abstract": "Background Retinoic acid receptor responder 2 (RARRES2) is among the most significantly downregulated genes in prostate cancer (PCa) across multiple independent transcriptomic analyses. 1 2 Our integrative analysis of TCGA, Oncomine, and Prostate Cancer Biorepository Network data from human prostate samples shows a progressive decline in RARRES2 expression with malignant progression (unpublished). RARRES2 encodes Chemerin, a chemoattractant protein predominantly secreted by fibroblasts. Emerging evidence, including ongoing studies, suggests a critical role for Chemerin in mediating lymphocyte recruitment and shaping antitumor immunity via its receptor, Chemokine-like receptor 1 (CMKLR1), expressed on NK cells and various innate cells.3 4 Recent studies highlight the relevance of NK cell infiltration in the prostate TME as a promising axis for immunotherapeutic intervention.5 This study investigates the contribution of the Chemerin-CMKLR1 axis to functional and phenotypic modulation of human NK cells, beyond its known chemotactic role in PCa.Methods Following negative selection, enriched human NK cells were assessed for early signaling using calcium flux assays with recombinant human chemerin (rhChemerin) and the CMKLR1 antagonist α-NETA. NK cells were exposed to rhChemerin or control conditions alone, in tumor-conditioned media, or co-cultured with PCa cell lines, followed by functional assays measuring cytotoxicity and proliferation over time. To characterize transcriptomic changes without added cytokines, bulk RNA sequencing was performed on chemerin-treated NK cells from three healthy donors cultured for 24 hours. In parallel, in vivo studies in immunodeficient mice evaluated NK cell survival, expansion, and cytotoxic activity after rhChemerin treatment.Results We observed that rhChemerin increased calcium flux signaling in primary human NK cells and the NK-92 cell line, an effect reversed by α-NETA. In vitro proliferation assays showed that chemerin-treated primary NK cells from multiple donors exhibited significantly greater proliferation by day 13, both alone and combined with rhIL-2, compared to untreated controls. Chemerin treatment also enhanced persistence of adoptively transferred NK cells in vivo. Bulk RNA sequencing of rhChemerin-treated NK cells revealed increased oxidative phosphorylation and fatty acid metabolism, along with activation of inflammatory pathways including TNFα/NFκB and IL-6/JAK/STAT3 signaling, engagement of stress response mechanisms, and a pronounced proinflammatory transcriptional signature.Conclusions These functional changes in NK cells following Chemerin exposure indicate an important role for the Chemerin-CMKLR1 axis in promoting NK cell responses beyond chemotaxis, potentially enhancing anti-tumor activity in PCa. These results support further exploration of Chemerin as a strategy to boost NK cell recruitment and effector function within the TME.Acknowledgements We thank Dr. Todd Fehniger for providing LRS chambers for our study. We thank the Alvin J. Siteman Cancer Center at Washington University School of Medicine, Barnes-Jewish Hospital in St. Louis, MO., for the use of the Immunomonitoring Laboratory and Genome Technology Access Center, which provided Flow cytometry and RNA-seq service. The Siteman Cancer Center is supported in part by an NCI Cancer Center Support Grant #P30 CA091842.References Stamey TA, Warrington JA, Caldwell MC, Chen Z, Fan Z, Mahadevappa M, et al. Molecular genetic profiling of Gleason grade 4/5 prostate cancers compared to benign prostatic hyperplasia. J Urol. 2001;166(6):2171-7.Lin PC, Giannopoulou EG, Park K, Mosquera JM, Sboner A, Tewari AK, et al. Epigenomic alterations in localized and advanced prostate cancer. Neoplasia. 2013;15(4):373-83.Rennier K, Shin WJ, Krug E, Virdi G, Pachynski RK. Chemerin reactivates PTEN and suppresses PD-L1 in tumor cells via modulation of a novel CMKLR1-mediated signaling cascade. Clin Cancer Res. 2020;26(18):5019-35.Pachynski RK, Zabel BA, Kohrt HE, Tejeda NM, Monnier J, Swanson CD, et al. The chemoattractant chemerin suppresses melanoma by recruiting natural killer cell antitumor defenses. J Exp Med. 2012;209(8):1427-35.Zorko NA, Makovec A, Elliott A, Kellen S, Lozada JR, Arafa AT, et al. Natural killer cell infiltration in prostate cancers predict improved patient outcomes. Prostate Cancer Prostatic Dis. 2025;28(1):129-37.Ethics Approval Animal procedures were reviewed and approved by the Washington University IACUC and performed in an AAALAC-accredited facility. Human NK cells were isolated from leukocyte reduction system chambers obtained from pre-consented healthy male volunteers aged 50 to 70 years, with a median age of 60, through the Fehniger Laboratory at Washington University for research purposes.",
  "authors": [
    {
      "affiliations": [
        "Washington University School of Medicine, St. Louis, MO, USA"
      ],
      "name": "Kavita Rawat"
    },
    {
      "affiliations": [
        "Washington University School of Medicine, St. Louis, MO, USA"
      ],
      "name": "Sara McCoy"
    },
    {
      "affiliations": [
        "Washington University School of Medicine, St. Louis, MO, USA"
      ],
      "name": "Michelle Becker-Hapak"
    },
    {
      "affiliations": [
        "Washington University School of Medicine, St. Louis, MO, USA"
      ],
      "name": "Wilbur Song"
    },
    {
      "affiliations": [
        "Washington University School of Medicine, St. Louis, MO, USA"
      ],
      "name": "Russell K Pachynski"
    }
  ],
  "title": "810 Chemerin-CMKLR1 axis modulates NK cell functional responses in prostate cancer",
  "uid": "c8a751cb-ae71-5d2b-b95c-0ddbbe1b4770"
}