Objective:To investigate the role and mechanism of F-box protein 28(FBXO28)in regulating hypoxia-inducible factor 1α(HIF-1α)expression and downstream oxidative stress-related genes in hepatocellular carcinoma(HCC)invasion.Methods:Human liver cell line THLE-2 and HCC cell line MHCC-LM3 were cultured.MHCC-LM3 cells were transfected to establish FBXO28 overexpression(oe-FBXO28 group),FBXO28 knockdown(si-FBXO28 group),and corresponding control groups(NC-oe group,NC-si group).Transfection efficiency was validated via quantitative real-time polymerase chain reaction(qRT-PCR).Cell proliferation was as-sessed using Cell Counting Kit-8(CCK-8)and 5-ethynyl-2'-deoxyuridine(EdU)staining.Apoptosis and cell cycle were analyzed by flow cytometry.Migration and invasion were evaluated using Transwell assays.Western blot was performed to detect epithelial-mesenchy-mal transition(EMT)-related proteins(E-cadherin,N-cadherin,Vimentin),PI3K/AKT pathway activity,and expression of HIF-1α,Kelch-like ECH-associated protein 1(KEAP1),NAD(P)H quinone dehydrogenase 1(NQO1),and glutathione peroxidase 2(GPX2).Tumor-bearing nude mice models were established by subcutaneous injection of oe-FBXO28,si-FBXO28,NC-oe,or NC-si MHCC-LM3 cells to monitor tumor growth.Hematoxylin-eosin(HE)staining was used for histopathological analysis,and immunohisto-chemistry was applied to assess HIF-1α,KEAP1,and PI3K expression in tumor tissues.Results:FBXO28 mRNA was significantly downregulated in MHCC-LM3 compared to THLE-2(P<0.05).In the oe-FBXO28 group,CCK-8 absorbance,EdU-positive rate,mi-grating/invading cell counts,N-cadherin,Vimentin,phosphorylated PI3K(p-PI3K),phosphorylated AKT(p-AKT),HIF-1α,and the levels of oxidative stress markers(KEAP1,NQO1,GPX2)were significantly reduced(P<0.05),while apoptosis rate and E-cadherin expression were increased compared to the NC-oe group(P<0.05).Conversely,the si-FBXO28 group showed opposite trends(P<0.05).Tumor volume and weight decreased in oe-FBXO28 group mice,with downregulated HIF-1α,KEAP1,and PI3K expression(P<0.05),whereas si-FBXO28 group mice exhibited the opposite(P<0.05).Conclusion:FBXO28 inhibits HCC cell invasion by suppressing HIF-1α and oxidative stress,thereby downregulating EMT progression,and represents a potential therapeutic target for HCC treatment.