RESUMO
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.
RESUMO
BACKGROUND: Doxorubicin is a significant drug for the treatment of breast cancer, but its cardiotoxicity is an obvious obstacle. Previously, we confirmed that ruthenium complex (Δ-Ru1) and doxorubicin (Δ-Ru1/Dox) combination had a synergistic effect in MCF-7 cells, but its biological effect in vivo is unknown. PURPOSES: To find a way to overcome the toxicity of doxorubicin and build MCF-7 xenograft tumor mouse model to test whether this potential combination has better efficacy and less toxicity. METHODS: The tumor model of nude mice was established to verify the synergistic antitumor effect of the drug combination in vivo. H&E staining was used to detect the toxicity of major organs in mice. Sirius red staining and transmission electron microscopy were used to detect cardiotoxicity. Prussian blue was used to measure iron accumulation in heart tissue. TUNEL staining was used to detect the antitumor effect in vivo. Immunohistochemical staining was used to detect the expression of iron death-related pathway proteins. High-throughput sequencing techniques were used to determine the molecular mechanism of ferroptosis. RESULTS: Histopathological analysis of tumor tissues indicated that the Δ-Ru1/Dox combination significantly promoted tumor cell apoptosis. Doxorubicin damaged cardiac tissue by inducing fibrosis and iron accumulation, but it was reversed by the Δ-Ru1/Dox combination treatment. Further exploration found that doxorubicin could regulate iron accumulation in the ferroptosis pathway and the expression of lipid peroxidation-related proteins, including upregulation of Tf, DMT1, and HO-1, and downregulation of Nrf2, SLC7A11, and GPX4. CONCLUSION: Δ-Ru1/Dox combination synergistically inhibits tumor growth, and it can significantly reduce and alleviate the toxic side effects of doxorubicin, especially cardiac injury.