The prognostic significance and potential mechanism of DBF4 zinc finger in hepatocellular carcinoma

DBF4 zinc finger (DBF4) is a critical component involved in DNA replication and cell proliferation. It acts as a positive regulator of the cell division cycle 7 kinase. In this study, our investigation encompassed the impact of DBF4 on hepatocellular carcinoma (HCC) progression and delved into the potential mechanisms. We utilized open-access databases like TCGA and GEO to analyze the association between DBF4 and 33 different tumor types. We also conducted immunohistochemistry experiments to validate the expression of DBF4 in HCC, STAD, COAD, READ, PAAD, and LGG. Furthermore, we employed lentiviral transduction to knockdown DBF4 in HLF and SMMC cells, as well as to overexpress DBF4 in Huh7 cells. Subsequently, we evaluated the impact of DBF4 on proliferation, migration, and invasion of hepatocellular carcinoma cells. RNA Sequencing and KEGG pathway enrichment analysis were also conducted to identify potential pathways, which were further validated through WB experiments. Finally, pathway inhibitor was utilized in rescue experiments to confirm whether DBF4 exerts its effects on tumor cells via the implicated pathway. Our findings revealed that DBF4 exhibited significant expression levels in nearly all examined tumors, which were further substantiated by the results of immunohistochemistry analysis. High DBF4 expression was correlated with poor overall survival (OS), disease-specific survival (DSS), progression-free interval (PFI), disease-free interval (DFI), relapse-free interval (RFI) in majority of tumor types, particularly in patients with HCC. In vitro experiments demonstrated that inhibition of DBF4 impaired the proliferative, migratory, and invasive abilities of HCC cells, whereas overexpression of DBF4 promoted these phenotypes. Sequencing results indicated that DBF4 may induce these changes through the ERBB signaling pathway. Further experimental validation revealed that DBF4 activates the ERBB signaling pathway, leading to alterations in the JNK/STAT, MAPK, and PI3K/Akt signaling pathways, thereby impacting the proliferative, migratory, and invasive abilities of tumor cells. Lastly, treatment of Huh7 cells overexpressing DBF4 with the ERBB2 inhibitor dacomitinib demonstrated the ability of ERBB2 inhibition to reverse the promoting effect of DBF4 overexpression on the proliferative, migratory, and invasive abilities of HCC cells. DBF4 plays a pivotal oncogenic role in HCC by promoting the ERBB signaling pathway and activating its downstream PI3K/Akt, JNK/STAT3, and MAPK signaling pathways. DBF4 may serve as a prognostic biomarker for patients with HCC.

DBF4; ERBB2; Hepatocellular carcinoma; Invasion; Migration; Prognosis; Proliferation.