TREM1 is Essential for Maintaining Stemness of Liver Cancer Stem-Like Cells in Hepatocellular Carcinoma

Arsha SreekumarAshwin AjithKenza MamouniDaniel D HoruzskoAnatolij Horuzsko^*

• Georgia Cancer Center, Augusta University, Augusta, United States

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and a leading cause of cancer-related mortality worldwide. While Triggering Receptor Expressed on Myeloid Cells 1 (TREM1) is recognized for amplifying inflammation in the tumor microenvironment (TME), its tumorintrinsic role remains poorly defined. Our flow cytometry analysis showed that TREM1 is highly expressed in CD133⁺EpCAM⁺ liver cancer stem-like cells (LCSLCs), a subpopulation critical for HCC initiation, metastasis, recurrence, and therapy resistance. Using CRISPR-Cas9-mediated knockout models, we observed that TREM1 loss significantly impairs proliferation, migration and promotes apoptosis in HCC cells. In LCSLCs, TREM1 silencing reduced clonogenic ability and spheroid formation capacity, highlighting TREM1's crucial role in maintaining their self-renewal capabilities and stemness. In cell line-derived xenograft (CDX) models, TREM1-deficient LCSLCs exhibited markedly reduced tumorigenicity. Transcriptomic analysis revealed that TREM1 knockout in LCSLCs triggers distinct context-dependent gene expression changes in nuclear and extracellular pathways. Pharmacological inhibition of TREM1 using VJDT recapitulated the tumor-suppressive effects in vivo. Together, our findings establish TREM1 as a critical tumor-intrinsic regulator of LCSLC survival and tumorigenic potential, independent of its immunomodulatory role in the TME. Targeting TREM1 may thus represent a promising dual-action therapeutic strategy to disrupt both cancer stem-like cell function and the pro-inflammatory tumor milieu in HCC.