Related Experiment Video
Updated: Sep 19, 2025
An Oncogenic Hepatocyte-Induced Orthotopic Mouse Model of Hepatocellular Cancer Arising in the Setting of Hepatic Inflammation and Fibrosis
Published on: September 12, 2019
Targeting SIX2 as a novel sensitization strategy of sorafenib treatment on advanced hepatocellular carcinoma through
Junren Lu1, Daming Cai2, Long Qian2
1State Key Laboratory of Pharmaceutical Biotechnology, Department of General Surgery, Nanjing Drum Tower Hospital, Drum Tower Clinical Medical College, Nanjing Medical University, Nanjing, China.
Abstract:
Sorafenib is the main treatment for advanced hepatocellular carcinoma (HCC), but drug resistance limits its effectiveness. Evidence increasingly indicates that, in addition to targeting tyrosine kinases, sorafenib also induces ferroptosis. However, current studies have not fully clarified the relationship between ferroptosis and sorafenib treatment sensitivity. Our bioinformatics analysis identified that SIX Homeobox 2 (SIX2), known for maintaining cellular stemness via the Wnt signaling pathway, was significantly upregulated in sorafenib-resistant tissues. Overexpression and knockdown experiments revealed that altering SIX2 expression affected HCC cell sensitivity to sorafenib and involved the ferroptosis pathway, suggesting a regulatory role for SIX2 in ferroptosis. RNA sequencing and CUT&Tag analysis showed that SIX2 directly regulated methyltransferase 9 (METTL9) expression. Co-immunoprecipitation (Co-IP) assays confirmed that METTL9 bound to SLC7A11, enhancing its stability and reducing degradation, thus regulating ferroptosis. Importantly, the role of SIX2 in ferroptosis operated independently of the classical glutathione peroxidase 4 (GPX4) pathway. In vitro studies further supported these findings, demonstrating that SIX2 knockdown increased sorafenib-induced ferroptosis in HCC, while METTL9 overexpression largely counteracted the effects of SIX2 knockdown. In mouse models, overexpression of SIX2 increased tumor resistance to sorafenib. Our findings suggest that modulating the ferroptosis pathway through SIX2 could enhance sorafenib sensitivity. This study provides the first evidence that SIX2 influences ferroptosis via the METTL9-SLC7A11 axis, thereby sensitizing HCC cells to sorafenib. Reducing SIX2 expression could thus represent a promising strategy to improve the efficacy of sorafenib in advanced HCC.
Insights
SIX Homeobox 2 (SIX2) promotes resistance to sorafenib in liver cancer by inhibiting ferroptosis. Targeting SIX2 enhances sorafenib effectiveness by reactivating ferroptosis, offering a new treatment strategy for hepatocellular carcinoma.
Area of Science:
- Oncology
- Molecular Biology
- Biochemistry
Background:
- Sorafenib is a primary treatment for advanced hepatocellular carcinoma (HCC), but drug resistance is a major clinical challenge.
- Sorafenib's mechanism involves tyrosine kinase inhibition and induction of ferroptosis, a form of regulated cell death.
- The precise role of ferroptosis in sorafenib sensitivity and resistance in HCC remains incompletely understood.
Purpose of the Study:
- To investigate the relationship between SIX Homeobox 2 (SIX2) and sorafenib resistance in hepatocellular carcinoma.
- To elucidate the molecular mechanisms by which SIX2 influences sorafenib sensitivity, particularly through the ferroptosis pathway.
- To explore the therapeutic potential of targeting the SIX2-mediated ferroptosis axis to overcome sorafenib resistance.
Main Methods:
- Bioinformatics analysis to identify differentially expressed genes in sorafenib-resistant HCC tissues.
- In vitro experiments including gene overexpression, knockdown, RNA sequencing, and CUT&Tag assays.
- Co-immunoprecipitation (Co-IP) assays and in vivo mouse models to validate findings.
Main Results:
- SIX2 was significantly upregulated in sorafenib-resistant HCC and its modulation affected HCC cell sensitivity to sorafenib via the ferroptosis pathway.
- SIX2 directly regulated methyltransferase 9 (METTL9) expression, which in turn stabilized SLC7A11, a key regulator of ferroptosis.
- SIX2-mediated ferroptosis occurred independently of the glutathione peroxidase 4 (GPX4) pathway; SIX2 knockdown enhanced sorafenib-induced ferroptosis, while METTL9 overexpression counteracted this effect. SIX2 overexpression increased tumor resistance in mouse models.
Conclusions:
- SIX2 promotes sorafenib resistance in HCC by suppressing ferroptosis through the METTL9-SLC7A11 axis.
- Targeting SIX2 or modulating the METTL9-SLC7A11 pathway offers a potential strategy to enhance sorafenib efficacy in advanced HCC.
- Reducing SIX2 expression could improve treatment outcomes for patients with sorafenib-resistant hepatocellular carcinoma.
More Related Videos
Related Concept Videos
02:57Targeted Cancer Therapies
There are several types of targeted therapies against...
02:50Combination Therapies and Personalized Medicine
The combination of the drug acetazolamide and sulforaphane is a good example of combination therapy to treat cancer. The cells in the interior of a large tumor often die due to the hypoxic and...