Background/Aims: Lenvatinib resistance remains a critical barrier in advanced hepatocellular carcinoma (HCC) therapy. However, the underlying mechanisms and strategies for reversing resistance remain incompletely understood. Methods: Integrated transcriptomics of lenvatinib-resistant patient tumors and an acquired-resistance murine model identified a novel macrophage subpopulation. Functional validation employed CRISPR-SAM screening, conditioned medium (CM) assays, subcutaneous/orthotopic xenografts, patient-derived organoids (PDOs), and patient-derived xenografts (PDXs). Mechanistic studies included ChIP-qPCR, co-immunoprecipitation, and pharmacologic targeting. Clinical relevance was assessed in a retrospective cohort. Results: Resistant HCC exhibited significant enrichment of a COLEC12high TAM subset , which correlated with poor survival and treatment response. These TAMs secreted neuregulin-1 (NRG1) , activating HER2/HER3-AKT signaling in tumor cells to drive cancer stemness and lenvatinib resistance. Mechanistically, in TAMs COLEC12 sequestered STAT1 in the cytoplasm, preventing its phosphorylation, and thereby derepressing STAT3-mediated NRG1 transcription. Depletion of NRG1 reversed the stemness phenotypes and resensitized tumors to lenvatinib both in vitro and in vivo. Clinically, high NRG1 expression predicted an inferior lenvatinib response and shorter survival. Crucially, the bispecific anti-HER2/HER3 antibody zenocutuzumab restored lenvatinib efficacy in PDOs, PDXs, and murine models. Conclusions Our work establishes the COLEC12high TAM/NRG1 axis as a master regulator of therapeutic resistance and identifies NRG1 as a predictive biomarker, providing a clinically actionable strategy to overcome lenvatinib resistance in HCC.

0bjective To establish a standard curve method with more accuracy employed in fluorescence real-time PCR(RT-PCR)as a alternation of the general method.Methods β-actin and KLK11 plasmid DNA for quantitative standard curve were constructed in our study,and Plasmids of β-actin was employed as a internal control.After serial dilution these plasmid were used as DNA standard to obtained slope.Expression of these two genes in malignant prostate cancer cell line LNCAP were tested by real-time PCR,and we analyzed the RT-PCR results with two different methods and compared their accuracy.Results Thestandards curves made from these linear DNA standards showed good linearity (R2=0.991 and 0.992 for β-actin and KLK11 standards graphs),but also displayed a discrepancy in their PCR efficiency(β-actin 123% and KLK11 99%).There were different results after two different stand curve analytical method:the expression of KLK11 mRNA in LNCAP was downregulated in general standard curve method.In the new analytical method,howerer,KLK11 upregnlated for 4.46-fold.And there was a significant difference between aplification efficiency of targt gene and internal control gene(t=4.829,P<0.05).Conclusions Compared with general standard curve method,the new advanced standard curve method described here avoids an error which considers there is identical amplification efficiency between target gene and internal reference gene.It is considered to be a more correct analytical method in fluorescence real-time PCR.