The Journal of Practical Medicine ›› 2026, Vol. 42 ›› Issue (8): 1397-1406.doi: 10.3969/j.issn.1006-5725.2026.08.013

• Treatise:Mechanism Exploration • Previous Articles    

Regorafenib synergy with irinotecan targets the proliferation, apoptosis and migration of hepatocellular carcinoma cells under hypoxia

Shuo HE1,Jun ZHANG1,2()   

  1. 1.Department of Pathology,Guizhou Medical University,Guiyang 550004,Guizhou,China
    2.Department of Pathology,Affiliated Hospital of Guizhou Medical University,Guiyang 550004,Guizhou,China
  • Received:2025-11-05 Online:2026-04-25 Published:2026-04-28
  • Contact: Jun ZHANG E-mail:junzhang1216@sina.com

Abstract:

Objective This study investigates the mechanism of combination therapy of Regorafenib and Irinotecan in hepatocellular carcinoma under hypoxic conditions and aims to provide a new therapeutic strategy for anticancer drugs combination to improve outcomes. Methods The median inhibitory concentration (IC50) of drugs against hepatocellular carcinoma cells under normoxic and hypoxic conditions were determined, dose-response curves were plotted to evaluate the sensitivity to Oxaliplatin Regorafenib and Irinotecan. Combined effects of different concentrations of Regorafenib and Irinotecan on hepatocellular carcinoma cells were analyzed using CompuSyn and SynergyFinder 3.0 software. The impacts on cell death rates were determined via flow cytometry. The effects on cell proliferation were determined using EdU proliferation assays. The influences on cell migration were assessed through Transwell and wound healing assays. The alterations of relevant proteins in signaling pathways were detected by Western blot experiments. Results Hypoxia had no significant effect on the IC50 values of Regorafenib and Irinotecan. Compared to Oxaliplatin, both agents can overcome hypoxia-induced treatment tolerance. Under hypoxic conditions, Regorafenib and Irinotecan exhibited synergistic effects with a combination index (CI values) < 1 and a ZIP synergy score > 10. Compared to regorafenib and irinotecan groups, the combination of Regorafenib and Irinotecan significantly increased the cells proportion in SubG1 phase (P < 0.000 1) and exhibited combined inhibitory effects on cell migration (P < 0.000 1). Under hypoxic conditions, Irinotecan increased the proportion of proliferating cells (P < 0.000 1), which significantly decreased upon combination with Regorafenib (P < 0.000 1), accompanied by reduced intracellular CyclinD1 levels (P < 0.000 1) Under hypoxic conditions, Irinotecan upregulated HIF-1α expression and activated ERK1/2 signaling (P < 0.000 1), combination with Regorafenib modulated Irinotecan-mediated expression or activation (P < 0.000 1), and the combination therapy downregulated AKT and ERK1/2 signaling activity (P < 0.001). Conclusions Under hypoxic conditions, the combination of Regorafenib and Irinotecan overcomes hypoxia-induced treatment tolerance, promotes hepatocellular carcinoma cell death, and inhibits hepatocellular carcinoma cell proliferation and migration. This synergistic effect may be associated with the suppression of HIF-1α and CyclinD1 expression, as well as the downregulation of AKT and ERK1/2 phosphorylation levels in hepatocellular carcinoma cells.

Key words: regorafenib, irinotecan, oxaliplatin, hypoxia, hepatocellular carcinoma

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