Background:Radiofrequency ablation (RFA) is an effective therapy for hepatocellular
carcinoma (HCC). However, incomplete radiofrequency ablation (IRFA) can promote the progression
of residual cancer cells, which is a serious problem in the clinical application of RFA. Therefore,
it is of great significance to explore the mechanism and countermeasures of the progression
of residual tumors after IRFA. Our previous study confirmed that IRFA can activate the hypoxia/
autophagy pathway of residual tumors in mice and then induce the proliferation of residual tumor
cells. Additionally, we found a metal ruthenium complex [Ru(bpy)2(ipad)](ClO4)2 (Ru, where
bpy = 2,2’-bipyridine and ipad = 2-(anthracene-9,10-dione-2-yl)imidazo[4,5-f][1,10]phenanthroline)
can effectively inhibit hypoxia-inducible factor (HIF-1α) and has good anti-tumor effect in a
hypoxic environment; however, whether Ru could suppress the proliferation of residual tumor
cells after IRFA is unknown.Objective:This study intends to evaluate the effect of Ru in suppressing the proliferation of residual
hepatocellular carcinoma after IRFA in a mice model.Methods:The Hepa1-6 xenograft mouse model was established in C57BL/6 mice to simulate clinical
IRFA. H&E staining was used to evaluate the biosafety of major organs in the treated mice.
TUNEL assay was employed to assess the antitumor effect. Immunohistochemically and immunofluorescence
staining was performed to detect the expression of HIF-1α and autophagy-related
proteins. The ELISA assay was used to examine the cytokines of interferon-gamma (IFN-γ)
and interleukin 10 (IL-10).Results:Our findings revealed that the residual tumor relapsed via the HIF-1α/LC3B/P62 autophagy-
related pathway after IRFA, while Ru could suppress this process. In addition, it was demonstrated
that Ru could effectively activate the immune system of the mice and reverse the tumor immune
suppression microenvironment after IRFA.Conclusion:The ruthenium complex Ru could suppress the proliferation of residual hepatocellular
carcinoma cells after IRFA in the mice model. This study introduces a novel approach that
combines the use of ruthenium complexes with IRFA, offering a potential solution to address the
reoccurrence of residual liver cancer following IRFA in clinical settings.