Objective Chemotherapy is one of the important therapeutic approaches for cancer treatment. However, the emergence of multidrug resistance and side effects significantly limit its application. To address these challenges, chemotherapy is often combined with other drugs or therapies. Among the 13 human fucosyltransferases (FUTs) identified, FUT8 (alpha-(1,6)-fucosyltransferase) is the only enzyme responsible for core fucosylation. Core fucosylation plays an important role in cancer occurrence, metastasis and chemotherapy resistance, making the suppression of FUT8 a potential strategy for reversing multidrug resistance. This study aims to evaluate the feasibility of combining the small molecule FUT8 inhibitor 2FF (2-deoxy-2-fluoro-L-fucose) with the clinical chemotherapeutic drug doxorubicin (DOX) for treating malignant tumors.Methods The human hepatocellular carcinoma cell line HepG2 and mouse colon cancer cell line CT26 cells were treated with 2FF, DOX or their combination and core fucosylation levels were assessed using Lectin Blot. HepG2 and CT26 cells were exposed to 50 μmol/L 2FF for 72 h, followed by treatment with a gradient concentration of DOX for 24 h. Cell viability and IC₅₀ values were determined via the CCK-8 assay. Transwell invasion assays were conducted to evaluate the combited effect of 2FF and DOX on the invasion ability of HepG2 cells. Flow cytometry was performed to analyze the impact of 2FF, DOX and their combination on membrane PD-L1 expression of HepG2 cells. To assess the in vivo effect, 6 to 8 week old female BALB/c mice (20-25 g), were subcutaneously injected with 1×10⁶ CT26 cells into the right axilla (four groups, six mice in each group). After the average tumor volume reached 100 mm³, mice were treated with DOX, 2FF, their combination, or saline (mock group) every other day. DOX was administanted intraperitoneally (2 mg/kg), 2FF intravenously (5 mg/kg), and the combination group, received the both treatment. Tumor size was measured every other day using a vernier caliper.Results This study demonstrated that DOX upregulates the core fucosylation level in HepG2 and CT26 cells,while 2FF effectively inhibits this DOX-induced effect. Furthermone, 2FF enhanced the sensitivity of HepG2 and CT26 cells to DOX. The combination of 2FF and DOX synergistically inhibited the invasion ability of HepG2 cells, and enhanced the anti-tumor efficacy of CT26 subcutaneous tumor model in BALB/c mice. However the combination thertment led to weight loss in mice. In addition, DOX increased the cell surface PD-L1 expression in HepG2 cells, which was effectively suppressed by 2FF.Conclusion The FUT8 inhibitor 2FF effectively suppresses DOX-induced upregulation of core fucosylation and PD-L1 levels in tumor cells, and 2FF synergistically enhances the anticancer efficacy of DOX.