Of FACT complex and oxidative stress response: a KEAP1/NRF2-dependent novel mechanism sustaining hepatocellular carcinoma progression

CBL0137 activates ROS/BAX signaling to promote caspase-3/GSDME-dependent pyroptosis in ovarian cancer cells

Curaxin CBL0137 was designed to regulate p53 and nuclear factor-κB simultaneously and exhibits antitumor activity by inhibiting tumor cell proliferation and inducing apoptosis in multiple cancers. However, whether CBL0137 can induce pyroptosis has not yet been reported. This study demonstrated that CBL0137 induces caspase-3/gasdermin E (GSDME)-dependent pyroptosis via the reactive oxygen species (ROS)/BAX pathway. In ovarian cancer cells, CBL0137 inactivated the chromatin remodeling complex which could facilitate chromatin transcription, leading to the decreased transcription of antioxidant genes and oxidation and causing increased ROS levels. BAX was recruited on the mitochondrial membrane by mitochondrial ROS and induced the release of cytochrome c to cleave caspase-3. This led to the cleavage of the N-terminal of GSDME to form pores on the cell membrane and induced pyroptosis. Results of in vivo experiments revealed that CBL0137 also had anti-tumor effects on ovarian cancer cells in vivo. Our study outcomes reveal the mechanisms and targets of CBL0137 inducing pyroptosis in ovarian cancer cells and indicate that CBL0137 is a promising therapeutic agent for ovarian cancer.

Upregulated SSB Is Involved in Hepatocellular Carcinoma Progression and Metastasis through the Epithelial-Mesenchymal Transition, Antiapoptosis, and Altered ROS Level Pathway

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors with high morbidity and mortality. Therefore, finding new diagnostic and therapeutic targets is vital for HCC patients. Recent studies have shown that dysregulation of RNA-binding proteins is often associated with cancer progression. Several studies have reported that the RNA-binding protein SSB can promote cancer occurrence and progression and is linked to tumor epithelial-mesenchymal transition (EMT), which could be a new diagnostic marker and therapeutic target. However, the expression and function of SSB in HCC remain to be elucidated. Therefore, this study is aimed at clarifying the expression and biological function of SSB in HCC through bioinformatics analysis combined with in vitro experiments. We found that SSB is highly expressed in HCC and is associated with the poor prognosis of HCC patients, and it can serve as an independent unfavorable prognostic factor. Knockdown of SSB can inhibit the growth of HCC cells in vitro, increase the level of apoptosis and the expression of pro-apoptosis-related proteins, and decrease the expression of antiapoptotic proteins. Meanwhile, SSB knockdown reduced HCC cell invasiveness, and the expression of EMT-related proteins changed significantly. We also found that the gene SSB was associated with the level of oxidative stress in liver cancer cells, and the level of intracellular reactive oxygen species (ROS) increased after knockdown of SSB. The results of bioinformatics analysis also showed that high expression of SSB may affect the effect of checkpoint blockade (ICB) therapy. In conclusion, we found that SSB is highly expressed in HCC and that upregulated SSB can promote the proliferation and metastasis of HCC through antiapoptotic, altered intracellular oxidative stress level, and EMT pathways, which can serve as a new diagnostic marker and therapeutic target, and patients with high SSB expression may not have obvious ICB therapy effect.

Chemopreventive and hepatoprotective effects of genistein via inhibition of oxidative stress and the versican/PDGF/PKC signaling pathway in experimentally induced hepatocellular carcinoma in rats by thioacetamide

Objective

Genistein is a recognized isoflavone present in soybeans with antioxidant, anti-inflammatory, antiangiogenic and antitumor activities. This study aimed to test ability of genistein in modulating versican/platelet derived growth factor (PDGF) axis in HCC.

Methods

HCC was experimentally induced in male Sprague-Dawley rats then treated with 25 or 75 mg/kg genistein. Antioxidant activities of genistein was assessed by measuring the gene expression of Nrf2 and the hepatic levels of malondialdehyde (MDA), superoxide dismutase (SOD) and reduced glutathione. Expression of versican, PDGF, protein kinase C (PKC) and ERK-1 protein was assessed by Western blotting and immunostaining.

Results

HCC induced an elevation in oxidative stress, PDGF, versican, PKC and ERK protein expression levels. Genistein significantly reduced an HCC-induced increase in oxidative stress. Moreover, genistein dose-dependently reduced HCC-induced elevation of PDGF, versican, PKC and ERK protein expression levels. Moreover, genistein helped retain a normal hepatocyte structure and reduced fibrous tissue deposition, especially in high dose.

Conclusions

Genistein exerted antitumor and antioxidant effects and therefore suppress HCC development via inhibition of the PDGF/versican bidirectional axis, suppressing both ERK1 and PKC as downstream regulators. Therefore, genistein is a potential novel therapeutic candidate for improving the outcome of patients with HCC.

Nrf2 signaling promotes cancer stemness, migration, and expression of ABC transporter genes in sorafenib-resistant hepatocellular carcinoma cells

Background and aim

As a multiple tyrosine kinase inhibitor, sorafenib is widely used to treat hepatocellular carcinoma (HCC), but patients frequently face resistance problems. Because the mechanism controlling sorafenib-resistance is not well understood, this study focused on the connection between tumor characteristics and the Nrf2 signaling pathway in a sorafenib-resistant HCC cell line.

Methods

A sorafenib-resistant HCC cell line (Huh7) was developed by increasing the dose of sorafenib in the culture medium until the target concentration was reached. Cell morphology, migration/invasion rates, and expression of stemness-related and ATP-binding cassette (ABC) transporter genes were compared between sorafenib-resistant Huh7 cells and parental Huh7 cells. Next, a small interfering RNA was used to knock down Nrf2 expression in sorafenib-resistant Huh7 cells, after which cell viability, stemness, migration, and ABC transporter gene expression were examined again.

Results

Proliferation, migration, and invasion rates of sorafenib-resistant Huh7 cells were significantly increased relative to the parental cells with or without sorafenib added to the medium. The expression levels of stemness markers and ABC transporter genes were up-regulated in sorafenib-resistant cells. After Nrf2 was knocked down in sorafenib-resistant cells, cell migration and invasion rates were reduced, and expression levels of stemness markers and ABC transporter genes were reduced.

Conclusion

Nrf2 signaling promotes cancer stemness, migration, and expression of ABC transporter genes in sorafenib-resistant HCC cells.

Efficacy of Sorafenib Combined with Interventional Therapy on Primary Liver Cancer Patients and Its Effect on Serum AFP, VEGF, and GGT

Objective

To explore the efficacy of sorafenib combined with interventional therapy on primary liver cancer (PLC) patients and its effect on serum AFP, VEGF, and GGT.

Methods

120 PLC patients admitted to our hospital from January 2016 to January 2020 were selected as the research object and divided into group A and group B according to the admission order, with 60 cases each. Interventional therapy was performed to both groups, and sorafenib was given to group A additionally to compare their treatment effect, survival, adverse reaction rate (ARR), and serum AFP, VEGF, and GGT levels.

Results

After treatment, group A obtained significantly higher objective remission rate (ORR) and disease control rate (DCR) (p < 0.05), higher one-year survival rate and two-year survival rate (p < 0.05), lower ARR of skin reactions, gastrointestinal reactions, hepatorenal reactions, and hyperbilirubinemia (p < 0.05), and lower serum AFP, VEGF, and GGT levels (p < 0.001).

Conclusion

The combination of sorafenib and interventional therapy can inhibit the growth and migration of PLC, improve the immune function, prolong the survival period of patients, and lower ARR, so it should be promoted in practice.

SRXN1 stimulates hepatocellular carcinoma tumorigenesis and metastasis through modulating ROS/p65/BTG2 signalling

Sulfiredoxin 1 (SRXN1) is a pivotal regulator of the antioxidant response in eukaryotic cells. However, the role of SRXN1 in hepatocellular carcinoma (HCC) is far from clear. The present study aims to elucidate whether SRXN1 participates in tumorigenesis and metastasis of HCC and to determine the molecular mechanisms. We found that SRXN1 expression was up-regulated in HCC tissue samples and correlated with poor prognosis in HCC patients. We also observed that SRXN1 knockdown by transient siRNA transfection inhibited HCC cell proliferation, migration and invasion. Overexpression of SRXN1 increased HCC cell migration and invasion. B-cell translocation gene 2 (BTG2) was identified as a downstream target of SRXN1. Mechanistic studies revealed that SRXN1-depleted reactive oxygen species (ROS) modulated migration and invasion of HCC cells. In addition, the ROS/p65/BTG2 signalling hub was found to regulate the epithelial-mesenchymal transition (EMT), which mediates the pro-metastasis role of SRXN1 in HCC cells. In vivo experiments showed SRXN1 promotes HCC tumour growth and metastasis in mouse subcutaneous xenograft and metastasis models. Collectively, our results revealed a novel pro-tumorigenic and pro-metastatic function of SRXN1 in HCC. These findings demonstrate a rationale to exploit SRXN1 as a therapeutic target effectively preventing metastasis of HCC.