{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,21]],"date-time":"2026-07-21T17:03:37Z","timestamp":1784653417277,"version":"3.55.0"},"reference-count":50,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,7,21]],"date-time":"2026-07-21T00:00:00Z","timestamp":1784592000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Genes"],"abstract":"<jats:p>Background\/Objectives: Colorectal liver metastases (CRLMs) are a major contributor to recurrence and mortality in colorectal cancer (CRC), with approximately a quarter of patients developing liver metastases over the course of the disease. Bone-marrow-derived myeloid lineages are sent into the circulatory system and colonize pre-metastatic niches, yet the transcriptional programs by which they establish a pro-metastatic microenvironment remain incompletely defined. Methods: Using an MC38 splenic-injection CRLM mouse model, we generated single-cell RNA sequencing (scRNA-seq) profiles of FACS-sorted CD11b+Gr1+ bone marrow myeloid cells, together with bulk RNA sequencing profiles of bone marrow and peripheral blood. Downstream analyses were performed in silico, including clustering and annotation, trajectory inference, cell\u2013cell communication analysis, weighted gene co-expression network analysis (WGCNA), and pathway enrichment, with subset specificity examined against a public dataset of E. coli (Escherichia coli)-infected mice. Results: Within the CD11b+Gr1+ compartment, a CCR2+ neutrophil-like population (Ly6g+S100a8\/9+) emerging during terminal differentiation was identified, which was enriched in CRLM mice but nearly absent in controls. Communication inference revealed an FN1-CD44 interaction involving mature neutrophils, which was associated with an epithelial\u2013mesenchymal transition signature and upregulation of Tgfb1 and Il1b. This subpopulation was not recovered in the infection dataset, suggesting relative specificity to CRLMs. Conclusions: Within the constraints of a splenectomized hepatic colonization model, integrated transcriptomic analysis highlighted a CCR2+ bone marrow neutrophil-like population as a candidate contributor to CRLM, challenging the view that CCR2+ pro-metastatic myeloid cells are exclusively monocytic and suggesting candidate biomarkers and therapeutic targets for further study.<\/jats:p>","DOI":"10.3390\/genes17070831","type":"journal-article","created":{"date-parts":[[2026,7,21]],"date-time":"2026-07-21T16:16:39Z","timestamp":1784650599000},"page":"831","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Single-Cell Profiling Identifies a CCR2+ Neutrophil-like Population Associated with Colorectal Cancer Liver Metastasis in a Murine Model"],"prefix":"10.3390","volume":"17","author":[{"given":"Zi-Jun","family":"Yan","sequence":"first","affiliation":[{"name":"Faculty of Hepato-Biliary-Pancreatic Surgery, The First Medical Center of Chinese People\u2019s Liberation Army (PLA) General Hospital, Beijing 100036, China"},{"name":"Department of Clinical Oncology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR 999077, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuan-Jie","family":"Yin","sequence":"additional","affiliation":[{"name":"Faculty of Hepato-Biliary-Pancreatic Surgery, The First Medical Center of Chinese People\u2019s Liberation Army (PLA) General Hospital, Beijing 100036, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu-Ting","family":"Wang","sequence":"additional","affiliation":[{"name":"Faculty of Hepato-Biliary-Pancreatic Surgery, The First Medical Center of Chinese People\u2019s Liberation Army (PLA) General Hospital, Beijing 100036, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xian-Qi","family":"Zhang","sequence":"additional","affiliation":[{"name":"Xiangya School of Basic Medical Sciences, Central South University, Changsha 410075, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiong-Hui","family":"Wang","sequence":"additional","affiliation":[{"name":"Faculty of Hepato-Biliary-Pancreatic Surgery, The First Medical Center of Chinese People\u2019s Liberation Army (PLA) General Hospital, Beijing 100036, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xi","family":"Chen","sequence":"additional","affiliation":[{"name":"Faculty of Hepato-Biliary-Pancreatic Surgery, The First Medical Center of Chinese People\u2019s Liberation Army (PLA) General Hospital, Beijing 100036, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cai-Ning","family":"Zhao","sequence":"additional","affiliation":[{"name":"Faculty of Hepato-Biliary-Pancreatic Surgery, The First Medical Center of Chinese People\u2019s Liberation Army (PLA) General Hospital, Beijing 100036, China"},{"name":"Department of Clinical Oncology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR 999077, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rong","family":"Liu","sequence":"additional","affiliation":[{"name":"Faculty of Hepato-Biliary-Pancreatic Surgery, The First Medical Center of Chinese People\u2019s Liberation Army (PLA) General Hospital, Beijing 100036, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Czauderna, C., Luley, K., von Bubnoff, N., and Marquardt, J.U. (2021). Tailored Systemic Therapy for Colorectal Cancer Liver Metastases. Int. J. Mol. Sci., 22.","DOI":"10.3390\/ijms222111780"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Engstrand, J., Nilsson, H., Str\u00f6mberg, C., Jonas, E., and Freedman, J. (2018). Colorectal cancer liver metastases\u2014A population-based study on incidence, management and survival. BMC Cancer, 18.","DOI":"10.1186\/s12885-017-3925-x"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1467","DOI":"10.1016\/S0140-6736(19)32319-0","article-title":"Colorectal cancer","volume":"394","author":"Dekker","year":"2019","journal-title":"Lancet"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"5971","DOI":"10.1158\/1078-0432.CCR-16-0460","article-title":"Role of the Microenvironment in Liver Metastasis: From Pre- to Prometastatic Niches","volume":"22","author":"Brodt","year":"2016","journal-title":"Clin. Cancer Res."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"e23187","DOI":"10.4161\/onci.23187","article-title":"Recruitment of myeloid cells to the tumor microenvironment supports liver metastasis","volume":"2","author":"Lim","year":"2013","journal-title":"Oncoimmunology"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1038\/s41575-019-0230-y","article-title":"Epigenetics of colorectal cancer: Biomarker and therapeutic potential","volume":"17","author":"Jung","year":"2020","journal-title":"Nat. Rev. Gastroenterol. Hepatol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"879897","DOI":"10.1155\/2014\/879897","article-title":"Increased levels of granulocytic myeloid-derived suppressor cells in peripheral blood and tumour tissue of pancreatic cancer patients","volume":"2014","author":"Khaled","year":"2014","journal-title":"J. Immunol. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"647684","DOI":"10.1155\/2012\/647684","article-title":"Metastatic behavior in melanoma: Timing, pattern, survival, and influencing factors","volume":"2012","author":"Tas","year":"2012","journal-title":"J. Oncol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1369","DOI":"10.1038\/ncb1507","article-title":"Tumour-mediated upregulation of chemoattractants and recruitment of myeloid cells predetermines lung metastasis","volume":"8","author":"Hiratsuka","year":"2006","journal-title":"Nat. Cell Biol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"21248","DOI":"10.1073\/pnas.1015855107","article-title":"Granulocyte-colony stimulating factor promotes lung metastasis through mobilization of Ly6G+Ly6C+ granulocytes","volume":"107","author":"Kowanetz","year":"2010","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"546","DOI":"10.1016\/j.ccell.2023.02.018","article-title":"Immune determinants of the pre-metastatic niche","volume":"41","author":"Patras","year":"2023","journal-title":"Cancer Cell."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"303","DOI":"10.1016\/j.immuni.2020.06.005","article-title":"Combinatorial Single-Cell Analyses of Granulocyte-Monocyte Progenitor Heterogeneity Reveals an Early Uni-potent Neutrophil Progenitor","volume":"53","author":"Kwok","year":"2020","journal-title":"Immunity"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1119","DOI":"10.1038\/s41590-020-0736-z","article-title":"Single-cell transcriptome profiling reveals neutrophil heterogeneity in homeostasis and infection","volume":"21","author":"Xie","year":"2020","journal-title":"Nat. Immunol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"829","DOI":"10.1002\/hep.26094","article-title":"Recruitment of a myeloid cell subset (CD11b\/Gr1mid) via CCL2\/CCR2 promotes the development of colorectal cancer liver metastasis","volume":"57","author":"Zhao","year":"2013","journal-title":"Hepatology"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/j.ccr.2007.12.004","article-title":"Abrogation of TGF beta signaling in mammary carcinomas recruits Gr-1+CD11b+ myeloid cells that promote metastasis","volume":"13","author":"Yang","year":"2008","journal-title":"Cancer Cell"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1564","DOI":"10.1016\/j.cell.2023.03.003","article-title":"Metastasis","volume":"186","author":"Gerstberger","year":"2023","journal-title":"Cell"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"13063","DOI":"10.1073\/pnas.1002372107","article-title":"Inactivation of chemokine (C-C motif) receptor 1 (CCR1) suppresses colon cancer liver metastasis by blocking accumulation of immature myeloid cells in a mouse model","volume":"107","author":"Kitamura","year":"2010","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Itatani, Y., Kawada, K., Inamoto, S., Yamamoto, T., Ogawa, R., Taketo, M.M., and Sakai, Y. (2016). The Role of Chemokines in Promoting Colorectal Cancer Invasion\/Metastasis. Int. J. Mol. Sci., 17.","DOI":"10.3390\/ijms17050643"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"485","DOI":"10.1038\/s41577-020-00490-y","article-title":"Myeloid-derived suppressor cells in the era of increasing myeloid cell diversity","volume":"21","author":"Veglia","year":"2021","journal-title":"Nat. Rev. Immunol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"9754","DOI":"10.1158\/0008-5472.CAN-08-1748","article-title":"TSU68 prevents liver metastasis of colon cancer xenografts by modulating the premetastatic niche","volume":"68","author":"Yamamoto","year":"2008","journal-title":"Cancer Res."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"484","DOI":"10.1038\/s41419-021-03698-5","article-title":"Inhibition of CCL7 derived from Mo-MDSCs prevents metastatic progression from latency in colorectal cancer","volume":"12","author":"Ren","year":"2021","journal-title":"Cell Death Dis."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"e1470729","DOI":"10.1080\/2162402X.2018.1470729","article-title":"Recruitment of CCR2+ tumor associated macrophage to sites of liver metastasis confers a poor prognosis in human colorectal cancer","volume":"7","author":"Grossman","year":"2018","journal-title":"Oncoimmunology"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"882","DOI":"10.1038\/s41419-021-04166-w","article-title":"TCF4 enhances hepatic metastasis of colorectal cancer by regulating tumor-associated macrophage via CCL2\/CCR2 signaling","volume":"12","author":"Tu","year":"2021","journal-title":"Cell Death Dis."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"3011","DOI":"10.1158\/0008-5472.CAN-19-0458","article-title":"Defining the Hallmarks of Metastasis","volume":"79","author":"Welch","year":"2019","journal-title":"Cancer Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1751","DOI":"10.1002\/art.39117","article-title":"CCR2 Expression in Neutrophils Plays a Critical Role in Their Migration into the Joints in Rheumatoid Arthritis","volume":"67","author":"Talbot","year":"2015","journal-title":"Arthritis Rheumatol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"234","DOI":"10.1164\/rccm.201003-0416OC","article-title":"Essential role of CCR2 in neutrophil tissue infiltration and multiple organ dysfunction in sepsis","volume":"183","author":"Souto","year":"2011","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1038\/s41577-021-00571-6","article-title":"Neutrophils in cancer: Heterogeneous and multifaceted","volume":"22","author":"Hedrick","year":"2022","journal-title":"Nat. Rev. Immunol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1038\/s41586-022-05400-x","article-title":"Liver tumour immune microenvironment subtypes and neutrophil heterogeneity","volume":"612","author":"Xue","year":"2022","journal-title":"Nature"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1422","DOI":"10.1016\/j.cell.2024.02.005","article-title":"Neutrophil profiling illuminates anti-tumor antigen-presenting potency","volume":"187","author":"Wu","year":"2024","journal-title":"Cell"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"234","DOI":"10.1038\/nrclinonc.2018.8","article-title":"Targeting the IL-6\/JAK\/STAT3 signalling axis in cancer","volume":"15","author":"Johnson","year":"2018","journal-title":"Nat. Rev. Clin. Oncol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"411","DOI":"10.1038\/nbt.4096","article-title":"Integrating single-cell transcriptomic data across different conditions, technologies, and species","volume":"36","author":"Butler","year":"2018","journal-title":"Nat. Biotechnol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"381","DOI":"10.1038\/nbt.2859","article-title":"The dynamics and regulators of cell fate decisions are revealed by pseudotemporal ordering of single cells","volume":"32","author":"Trapnell","year":"2014","journal-title":"Nat. Biotechnol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1408","DOI":"10.1038\/s41587-020-0591-3","article-title":"Generalizing RNA velocity to transient cell states through dynamical modeling","volume":"38","author":"Bergen","year":"2020","journal-title":"Nat. Biotechnol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"494","DOI":"10.1038\/s41586-018-0414-6","article-title":"RNA velocity of single cells","volume":"560","author":"Soldatov","year":"2018","journal-title":"Nature"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"H\u00e4nzelmann, S., Castelo, R., and Guinney, J. (2013). GSVA: Gene set variation analysis for microarray and RNA-seq data. BMC Bioinform., 14.","DOI":"10.1186\/1471-2105-14-7"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1088","DOI":"10.1038\/s41467-021-21246-9","article-title":"Inference and analysis of cell-cell communication using CellChat","volume":"12","author":"Jin","year":"2021","journal-title":"Nat. Commun."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Langfelder, P., and Horvath, S. (2008). WGCNA: An. R. package for weighted correlation network analysis. BMC Bioinform., 9.","DOI":"10.1186\/1471-2105-9-559"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1146\/annurev-med-051113-024537","article-title":"The JAK-STAT pathway: Impact on human disease and therapeutic intervention","volume":"66","author":"Schwartz","year":"2015","journal-title":"Annu. Rev. Med."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1083\/jcb.200109037","article-title":"Ras and TGF\u03b2 cooperatively regulate epithelial cell plasticity and metastasis: Dissection of Ras signaling pathways","volume":"156","author":"Janda","year":"2002","journal-title":"J. Cell Biol."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Capucetti, A., Albano, F., and Bonecchi, R. (2020). Multiple Roles for Chemokines in Neutrophil Biology. Front. Immunol., 11.","DOI":"10.3389\/fimmu.2020.01259"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1192","DOI":"10.1172\/JCI40310","article-title":"CCR2 mediates hematopoietic stem and progenitor cell trafficking to sites of inflammation in mice","volume":"120","author":"Si","year":"2010","journal-title":"J. Clin. Investig."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"11664","DOI":"10.1038\/srep11664","article-title":"CCR2 inhibition sequesters multiple subsets of leukocytes in the bone marrow","volume":"5","author":"Fujimura","year":"2015","journal-title":"Sci. Rep."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"676","DOI":"10.1038\/s41467-018-03080-8","article-title":"ACKR2 in hematopoietic precursors as a checkpoint of neutrophil release and anti-metastatic activity","volume":"9","author":"Massara","year":"2018","journal-title":"Nat. Commun."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"300","DOI":"10.1016\/j.ccr.2011.08.012","article-title":"Tumor entrained neutrophils inhibit seeding in the premetastatic lung","volume":"20","author":"Granot","year":"2011","journal-title":"Cancer Cell"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1016\/j.ccell.2021.01.009","article-title":"Neutrophils create a fertile soil for metastasis","volume":"39","author":"Kos","year":"2021","journal-title":"Cancer Cell"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"2159","DOI":"10.1182\/blood-2018-11-844548","article-title":"Neutrophil plasticity in the tumor microenvironment","volume":"133","author":"Giese","year":"2019","journal-title":"Blood"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/j.smim.2017.12.004","article-title":"Neutrophils and PMN-MDSC: Their biological role and interaction with stromal cells","volume":"35","author":"Zhou","year":"2018","journal-title":"Semin. Immunol."},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Toh, B., Wang, X., Keeble, J., Sim, W.J., Khoo, K., Wong, W.C., Kato, M., Prevost-Blondel, A., Thiery, J.P., and Abastado, J.P. (2011). Mesenchymal transition and dissemination of cancer cells is driven by myeloid-derived suppressor cells infiltrating the primary tumor. PLoS Biol., 9.","DOI":"10.1371\/journal.pbio.1001162"},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Tang, J., Yan, Z., Feng, Q., Yu, L., and Wang, H. (2021). The Roles of Neutrophils in the Pathogenesis of Liver Diseases. Front. Immunol., 12.","DOI":"10.3389\/fimmu.2021.625472"},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Fridlender, Z.G., Sun, J., Mishalian, I., Singhal, S., Cheng, G., Kapoor, V., Horng, W., Fridlender, G., Bayuh, R., and Worthen, G.S. (2012). Transcriptomic analysis comparing tumor-associated neutrophils with granulocytic myeloid-derived suppressor cells and normal neutrophils. PLoS ONE, 7.","DOI":"10.1371\/journal.pone.0031524"}],"container-title":["Genes"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4425\/17\/7\/831\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,21]],"date-time":"2026-07-21T16:22:03Z","timestamp":1784650923000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4425\/17\/7\/831"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,21]]},"references-count":50,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["genes17070831"],"URL":"https:\/\/doi.org\/10.3390\/genes17070831","relation":{},"ISSN":["2073-4425"],"issn-type":[{"value":"2073-4425","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,21]]}}}