Synergistic antitumor effect of oroxylin A and donafenib in hepatocellular carcinoma through tumor protein p53 signaling pathway activation.

BACKGROUND: The clinical application of donafenib in advanced hepatocellular carcinoma (HCC) is restricted by its limited therapeutic efficacy and a variety of treatment-associated adverse events. These factors collectively underscore the need for more effective and well-tolerated therapeutic strategies.

AIM: To investigate the effects and underlying mechanisms of oroxylin A in combination with donafenib on HCC through in vivo and in vitro studies.

METHODS: The antitumor efficacy of oroxylin A, donafenib, and their combination was assessed in xenograft mouse models and MHCC-97H/PLC-PRF-5 cell lines. Tumor growth was monitored using fluorescence live imaging. Cell viability, colony formation, and apoptosis were assessed using Cell Counting Kit-8, clonogenic, and flow cytometry assays, respectively. Molecular mechanisms were investigated by assessing the expression of tumor protein p53 (TP53) signaling-related regulators via quantitative real-time polymerase chain reaction, western blot, and immunohistochemistry. Public datasets and Kaplan-Meier analysis were used to analyzed the relationship between their expression and patient survival.

RESULTS: The combination of oroxylin A and donafenib demonstrated superior anti-tumor efficacy in vivo compared to monotherapies, without inducing significant hepatorenal toxicity. The combination therapy demonstrated a stronger anti-proliferative and pro-apoptotic effects than two monotherapies in two HCC cell lines. Mechanistically, the drug combination synergistically activated the TP53 signaling pathway. Oroxylin A primarily targeted the cyclin-dependent kinase 9-murine double minute 2 (MDM2)/MDM4 axis to stabilize TP53, while donafenib suppressed the vascular endothelial growth factor receptor/B-rapidly accelerated fibrosarcoma proto-oncogene serine/threonine kinase axis to activate TP53. Clinical data has verified that the upregulation of key components of this pathway (TP53, MDM2, MDM4, and cyclin-dependent kinase 9) in patients with HCC is associated with a poor overall survival.

CONCLUSION: Oroxylin A and donafenib exert a synergistic anti-tumor effect in HCC by co-activating the TP53 signaling pathway through distinct but complementary molecular axes. This combination strategy presents a promising and viable therapeutic approach to overcome the limitations of donafenib monotherapy in the treatment of HCC.