Apoptosis induction and ERK/NF-κB inactivation are associated with magnolol-inhibited tumor progression in hepatocellular carcinoma in vivo.

Although hepatitis B and/or hepatitis C virus were recognized as major risk factor for the development of hepatocellular carcinoma (HCC), certain occupational, environmental, and lifestyle factors also play key roles in HCC tumorigenesis. Moreover, in molecular signaling route, extracellular signal-regulated kinase (ERK)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling was found to be overexpressed and linked to poor prognosis in HCC. Thus, to identify possible nature compound that can suppress ERK/NF-κB may be benefit to HCC patient. Magnolol, a natural compound derived from herbal plant Magnolia officinalis, has been recognized as a liver protection and antitumor reagent. However, whether magnolol-inhibited HCC progression correlates with disruption of ERK/NF-κB signaling is remained unclear. In this studies, we performed SK-Hep1/luc2 HCC bearing animal model to investigate the anticancer efficacy and mechanism of magnolol on tumor progression. Tumor size and tumor growth rate were dramatically suppressed after treatment of magnolol. In addition, expression of phospho-ERK (p-ERK), NF-κB p65 (Ser536), and tumor progression-associated proteins, such as matrix metallopeptidase 9 (MMP-9), vascular endothelial growth factor (VEGF), X-linked inhibitor of apoptosis protein (XIAP), and CyclinD1 were all significantly decreased by magnolol. Most important, major extrinsic and intrinsic apoptosis signaling factors, including active caspase-8 and caspase-9 were both enhanced by magnolol. This study indicated that apoptosis induction through extrinsic/intrinsic pathways and blockage of ERK/NF-κB activation were associated with magnolol-inhibited tumor progression in HCC in vivo.

Proteomic analysis of plasma from rats following total parenteral nutrition-induced liver injury.

Total parenteral nutrition (TPN) is provided as the primary nitrogen source to manage patients with intestinal failure who were not able to sustain themselves on enteral feeds. The most common complication of long-term TPN use is hepatitis. A proteomic approach was used to identify proteins that are differentially expressed in the plasma of rats following TPN-related acute liver injury. Six male rats were randomly assigned to either the saline infusion control group or the TPN infusion group. Our results demonstrate that TPN infusion in rats resulted in hepatic dysfunction and hepatocyte apoptosis. Five proteins that were differentially expressed between TPN infusion and normal rats were determined and validated in vivo. Fascinatingly, the proteomic differential displays, downregulated proteins included peroxiredoxin 2 (PRDX2), alpha-1-antiproteinase (A1AT), and fibrinogen gamma chain (FIBG), which were involved in oxidative stress, inflammatory respondence and cells apoptosis. After TPN infusion, two protein spots showed increased expression, namely, the glucagon receptor (GLR) protein and apolipoprotein A-1 (APOA1), which may mediate the effects of TPN administration on glycogen and lipid metabolism. In this study, proteomic analysis suggested TPN-related acute liver injury could be involved in limiting cellular protection mechanisms against oxidative stress-induced apoptosis. On the basis of the results, we also give molecular evidences replying TPN-related hepatitis.

Glycyrrhizin represses total parenteral nutrition-associated acute liver injury in rats by suppressing endoplasmic reticulum stress.

Total parenteral nutrition (TPN) is an artificial way to support daily nutritional requirements by bypassing the digestive system, but long-term TPN administration may cause severe liver dysfunction. Glycyrrhizin is an active component of licorice root that has been widely used to treat chronic hepatitis. The aim of this study is to investigate the hepatoprotective effect of glycyrrhizin on TPN-associated acute liver injury in vivo. Liver dysfunction was induced by intravenous infusion of TPN at a flow rate of 20 mL/kg/h for three h in Sprague Dawley rats. The rats were pretreated with Glycyrrhizin (1, 3 and 10 mg/kg intravenously). After receiving TPN or saline (control group) for three h, the rats were sacrificed, blood samples were collected for biochemical analyses and liver tissue was removed for histopathological and immunohistochemical examination. We found that aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TB) and triglyceride (TG) levels were significantly increased in the TPN group without glycyrrhizin pretreatment and decreased in the glycyrrhizin-pretreated TPN group in a dose-dependent manner. The stained liver sections showed that glycyrrhizin relieved acute liver injury. The upregulation of serum protein biomarkers of reactive nitrogen species, including nitrotyrosine and inducible NO synthase (iNOS), were attenuated by glycyrrhizin pretreatment. Levels of endoplasmic reticulum (ER) stress factors, such as phosphorylation of JNK1/2, p38 MAPK and CHOP, were decreased by glycyrrhizin pretreatment. In summary, our results suggest that glycyrrhizin decreases TPN-associated acute liver injury factors by suppressing endoplasmic reticulum stress and reactive nitrogen stress.

Lenvatinib Synergistically Promotes Radiation Therapy in Hepatocellular Carcinoma by Inhibiting Src/STAT3/NF-κB-Mediated Epithelial-Mesenchymal Transition and Metastasis.

PURPOSE: This study suggested that lenvatinib may incapacitate hepatocellular carcinoma (HCC) to radiation treatment by abrogating radiation-induced Src/signal transducer and the activator of transcription 3 signaling (STAT3)/nuclear factor-κB (NF-κB) to escalate radiation-induced extrinsic and intrinsic apoptosis. These findings uncover the role of targeting Src and its arbitrating epithelial-mesenchymal transition (EMT), which could increase the anti-HCC efficacy of radiation therapy (RT). Lenvatinib and sorafenib are multikinase inhibitors used to treat HCC. Lenvatinib is noninferior to sorafenib in the therapeutic response in HCC. However, whether lenvatinib intensifies the anti-HCC efficacy of RT is ambiguous. Several oncogenic kinases and transcription factors, such as Src, STAT3, and NF-κB, enhance the radiosensitivity of cancers. Therefore, we aimed to investigate the roles of the Src/STAT3/NF-κB axis in HCC after RT treatment and assessed whether targeting Src by lenvatinib may enhance the effectiveness of RT. METHODS AND MATERIALS: Hep3B, Huh7, HepG2, and SK-Hep1 HCC cells and 2 types of animal models were used to identify the efficacy of RT combined with lenvatinib. Cellular toxicity, apoptosis, DNA damage, EMT/metastasis regulation, and treatment efficacy were validated by colony formation, flow cytometry, Western blotting, and in vivo experiments, respectively. Knockdown of Src by siRNA was also used to validate the role of Src in RT treatment. RESULTS: Silencing Src reduced STAT3/NF-κB signaling and sensitized HCC to radiation. Lenvatinib reversed radiation-elicited Src/STAT3/NF-κB signaling while enhancing the anti-HCC efficacy of radiation. Both lenvatinib and siSrc promoted the radiation effect of cell proliferation on suppression, inhibition of the invasion ability, and induction of apoptosis in HCC. Lenvatinib also alleviated radiation-triggered oncogenic and EMT-related protein expression. CONCLUSIONS: Our findings uncovered the role of the Src/STAT3/NF-κB regulatory axis in response to radiation-induced toxicity and confirmed Src as the key regulatory molecule for radiosensitization of HCC evoked by lenvatinib.

Effect of renal impairment on mortality of patients with cirrhosis and spontaneous bacterial peritonitis.

BACKGROUND & AIMS: The effects of end-stage renal disease (ESRD) on the mortality of patients with cirrhosis and spontaneous bacterial peritonitis (SBP) have not been determined. METHODS: We collected data from Taiwan's National Health Insurance Database on 2592 patients with cirrhosis who were hospitalized with SBP from January 1 to December 31, 2004. Patients were matched with individuals from a national mortality database; 30-day and 1-year mortalities were calculated for each group and compared to calculate hazard ratios (HRs). RESULTS: Of the patients with cirrhosis and SBP, 300 (11.5%) had renal function impairment. Of these, 145 had acute renal failure, 70 had ESRD, and 75 had chronic kidney disease. Overall, 30-day and 1-year mortality were 21.3% and 51.7%, respectively. After adjusting for age, sex, and underlying comorbidities, HRs for 30-day mortality from renal function impairment, acute renal failure, ESRD, and chronic kidney disease were 3.00, 4.68, 1.93, and 1.37, respectively. The HRs for 1-year mortality from renal function impairment, acute renal failure, ESRD, and chronic kidney disease were 2.03, 2.78, 1.70, and 1.37, respectively. The adjusted HRs for 30-day and 1-year mortality of patients with acute renal failure were 2.6 and 1.6, respectively, compared with patients with ESRD. CONCLUSIONS: Acute renal failure is a better determinant of 30-day and 1-year mortality than renal function impairment in cirrhotic patients with SBP.

The role of oxidative stress response revealed in preconditioning heat stimulation in skeletal muscle of rats.

BACKGROUND: Our previous study showed that preconditioned local somatothermal stimulation (LSTS) protected subsequent ischemia-reperfusion injury of the skeletal muscle. The exact mechanisms of LSTS preconditioning remain unknown. The aim of this study was to test the hypothesis stating that heat stimulation induces free radical production, increases enzymatic scavenging activity, and subsequently enhances the expression of heat shock protein 70 (HSP-70) in skeletal muscles. MATERIALS AND METHODS: After LSTS was applied onto the left quarter ventral abdomen muscle of male Sprague-Dawley rats, the underling muscles were collected at the intervals of baseline, 5-, 15-, 30-, and 60-min after LSTS. The time-dependent profiles of free radical production and enzymatic scavenging activity were measured. The influence of nitric oxide (NO) on HSP-70 expression was evaluated by pretreatment of an NO synthase inhibitor. RESULTS: The concentrations of reactive oxygen species, NO metabolites, and malondialdehyde increased significantly 5 min after LSTS, whereas the scavenging activity reduced to the lowest level 5 min (dismutase) and 15 min (catalase and glutathione) after LSTS. Expression of HSP-70 was significantly lower in the LSTS with NO synthase inhibitor group than in the LSTS group. CONCLUSIONS: LSTS induces oxidative stress and the scavenging response in the underlying skeletal muscle, which might explain the possible mechanisms of LSTS preconditioning-induced muscle plasticity.

Inactivation of AKT/ERK Signaling and Induction of Apoptosis Are Associated With Amentoflavone Sensitization of Hepatocellular Carcinoma to Lenvatinib.

BACKGROUND/AIM: AKT/ERK signaling transduction and anti-apoptosis effects have both been recognized as important mediators of hepatocellular carcinoma (HCC) progression. Targeting AKT/ERK signaling and mediating apoptosis may be beneficial for alleviating HCC growth. Lenvatinib, a tyrosine kinase inhibitor, has been approved by the FDA to treat HCC since 2018 as a monotherapy with limited efficacy. Amentoflavone, a biflavonoid in natural plants, has been shown to have the potential to suppress HCC progression in previous studies. Whether the combination of lenvatinib and amentoflavone may show superior HCC suppression is unclear. MATERIALS AND METHODS: We used MTT, flow cytometry and western blotting assays to identify the role of lenvatinib and amentoflavone in both Hep3B and Huh7 cells. RESULTS: We found that amentoflavone enhances the suppressive effect of AKT/ERK signaling induced by lenvatinib and, thus, sensitizes HCC to lenvatinib. The intrinsic/extrinsic apoptosis pathways induced by lenvatinib were also boosted by amentoflavone. CONCLUSION: Amentoflavone sensitization of HCC to lenvatinib is associated with AKT/ERK inactivation and apoptosis induction.

DNA damage and NF-κB inactivation implicate glycyrrhizic acid-induced G1 phase arrest in hepatocellular carcinoma cells.

Hepatocellular carcinoma (HCC) is the most frequently occurring liver malignancy in Asia. Glycyrrhizic acid is known to reduce the risk of HCC formation in patients with chronic hepatitis C. To identify whether glycyrrhizic acid may play a role in anti-HCC therapy as an adjuvant is important. However, the inhibitory effect of glycyrrhizic acid on cell cycle progression in HCC cells and the mechanism of such have not been fully elucidated. This study used the comet assay, cell cycle analysis, immunofluorescence staining, the TUNEL assay, and Western blotting to identify the anti-HCC role of glycyrrhizic acid. Glycyrrhizic acid may induce DNA damage, apoptosis, activation of ATM, and expression of p21, and p27 in HCC cells. In addition, glycyrrhizic acid may also induce G1 phase arrest and suppress NF-κB-mediated Cyclin D1 expression. DNA damage and NF-κB inactivation may be associated with glycyrrhizic acid-induced G1 phase arrest in HCC cells.

Sorafenib Induces Apoptosis and Inhibits NF-κB-mediated Anti-apoptotic and Metastatic Potential in Osteosarcoma Cells.

BACKGROUND/AIM: Sorafenib, an oral multi-kinase inhibitor, has been shown to improve the outcome of patients with osteosarcoma (OS). However, the anti-OS effect and mechanism of sorafenib has not yet been fully understood. The main purpose of this study was to investigate the effect of sorafenib on apoptotic signaling and Nuclear Factor-κB (NF-κB)-mediated anti-apoptotic and metastatic potential in OS in vitro. MATERIALS AND METHODS: The effect of sorafenib on apoptotic signaling transduction, anti-apoptotic, and metastatic potential of OS U-2 cells was verified with flow cytometry, trans-well invasion/migration, and western blotting assay. RESULTS: Sorafenib induced the extrinsic and intrinsic apoptotic pathways. In addition, sorafenib reduced the invasion and migration ability of OS cells, induced NF-κB activation, and the expression of anti-apoptotic proteins and metastasis-associated proteins encoded by NF-κB target genes. CONCLUSION: Sorafenib led to stimulation of extrinsic/intrinsic apoptotic pathways and NF-κB inactivation in U-2 OS cells.

Regorafenib suppresses epidermal growth factor receptor signaling-modulated progression of colorectal cancer.

Active epidermal growth factor receptors (EGFR) signaling mediates the progression of colorectal cancer (CRC) through activation of downstream kinases and transcription factors. The increased expression of EGFR was associated with worse prognosis in patients with metastatic CRC (mCRC). Regorafenib, the oral kinase inhibitor approved for the treatment of mCRC, has been shown to reduce activation of downstream kinases of EGFR signal pathway in hepatocellular carcinoma and osteosarcoma. However, whether EGFR inactivation was participates in regorafenib-inhibited progression of CRC still remaining ambiguous. The major purpose of present study was to verify effect of regorafenib on EGFR signaling-mediated progression of CRC. Here, we investigated the effect of regorafenib or erlotinib (EGFR inhibitor) on tumor cell growth, invasion ability, apoptotic, and EGFR signal transduction in CRC in vitro and in vivo. Our results indicated regorafenib reduced EGF-induced EGFR and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activity. Both regorafenib and erlotinib significantly reduced cell invasion ability, activation of protein kinase C-δ (PKCδ), protein kinase B (AKT), extracellular signal-regulated kinases (ERK), and NF-κB. Regorafenib can trigger the inhibition of tumor cell growth and the induction of apoptosis through extrinsic/intrinsic apoptosis pathways. In addition, the expression of NF-κB-mediated proteins involved in tumor progression was also suppressed by regorafenib treatment. Taken together, regorafenib acts as a inhibitor of EGFR signaling that attenuated the activation of EGFR and EGFR related downstream signaling cascades in CRC. Our results suggested that the suppression of EGFR signaling was associated with regorafenib-inhibited progression of CRC.

Glycyrrhizic Acid Modulates Apoptosis through Extrinsic/Intrinsic Pathways and Inhibits Protein Kinase B- and Extracellular Signal-Regulated Kinase-Mediated Metastatic Potential in Hepatocellular Carcinoma In Vitro and In Vivo.

A previous study presented that glycyrrhizic acid as the hepatoprotective agent inhibits total parenteral nutrition-associated acute liver injury in rats. However, the anticancer effect and mechanism of glycyrrhizic acid in human hepatocellular carcinoma (HCC) is ambiguous. The purpose of the present study was to investigate the effect of glycyrrhizic acid on apoptosis dysregulation and metastatic potential in HCC in vitro and in vivo. Both SK-Hep1 and Hep3B cells were treated with different concentrations of glycyrrhizic acid for 24 or 48h. SK-Hep1/luc2 tumor-bearing mice were treated with vehicle or glycyrrhizic acid (50mg/kg/day by intraperitoneal injection) for 7 days. Tumor cells growth, apoptotic, and metastatic signaling transduction were evaluated by using MTT assay, digital caliper, bioluminescence imaging (BLI), flow cytometry, western blotting assay, and immunohistochemistry (IHC) staining. The results demonstrated glycyrrhizic acid significantly inhibits tumor cell growth, cell invasion, and expression of AKT (Ser473), extracellular-signal-regulated kinase (ERK), epidermal growth factor receptor (EGFR) phosphorylation, anti-apoptotic and metastatic proteins in HCC in vitro and in vivo. Glycyrrhizic acid also significantly triggered apoptosis and extrinsic/intrinsic apoptotic signaling transduction. In addition, PD98059 (ERK inhibitor) and LY294002 (AKT inhibitor) obviously reduced cell invasion and expression of metastasis-associated proteins. Taken together, these results indicated that glycyrrhizic acid induces apoptosis through extrinsic/intrinsic apoptotic signaling pathways and diminishes EGFR/AKT/ERK-modulated metastatic potential in HCC in vitro and in vivo.

Oral or intravenous proton pump inhibitor in patients with peptic ulcer bleeding after successful endoscopic epinephrine injection.

AIMS: We aimed to assess the clinical effectiveness of oral vs. intravenous (i.v.) regular-dose proton pump inhibitor (PPI) after endoscopic injection of epinephrine in patients with peptic ulcer bleeding. METHODS: Peptic ulcer patients with active bleeding, nonbleeding visible vessels, or adherent clots were enrolled after successful endoscopic haemostasis achieved by epinephrine injection. They were randomized to receive either oral rabeprazole (RAB group, 20 mg twice daily for 3 days) or i.v. omeprazole (OME group, 40 mg i.v. infusion every 12 h for 3 days). Subsequently, the enrolled patients receive oral PPI for 2 months (rabeprazole 20 mg or esomeprazole 40 mg once daily). The primary end-point was recurrent bleeding up to 14 days. The hospital stay, blood transfusion, surgery and mortality within 14 days were compared as well. RESULTS: A total of 156 patients were enrolled, with 78 patients randomly allocated in each group. The two groups were well matched for factors affecting the clinical outcomes. Primary end-points (recurrent bleeding up to 14 days) were reached in 12 patients (15.4%) in the OME group and 13 patients (16.7%) in the RAB group [95% confidence interval (CI) of difference -12.82, 10.22]. All the rebleeding events occurred within 3 days of enrolment. The two groups were not different in hospital stay, volume of blood transfusion, surgery or mortality rate (1.3% of the OME group and 2.6% of the RAB group died, 95% CI of difference -5.6, 3.0). CONCLUSIONS: Oral rabeprazole and i.v. regular-dose omeprazole are equally effective in preventing rebleeding in patients with high-risk bleeding peptic ulcers after successful endoscopic injection with epinephrine.

Amentoflavone Enhances the Therapeutic Efficacy of Sorafenib by Inhibiting Anti-apoptotic Potential and Potentiating Apoptosis in Hepatocellular Carcinoma In Vivo.

BACKGROUND/AIM: In a previous study, we showed that amentoflavone promotes sorafenib-induced apoptosis in hepatocellular carcinoma (HCC) cells in vitro. However, whether amentoflavone augments anticancer efficacy of sorafenib in HCC in vivo is unknown. The aim of the present study was to verify the anticancer effect of amentoflavone combined with sorafenib in HCC in vivo. MATERIALS AND METHODS: HCC SK-Hep1 tumor-bearing mice were treated with vehicle, sorafenib, amentoflavone, or combination for 14 days, respectively. Effect of sorafenib, amentoflavone, or their combination on tumor growth, anti-apoptotic potential, apoptotic signaling and general toxicity were evaluated with digital caliper, immunohistochemistry staining and body weight. RESULTS: Our results demonstrated that amentoflavone significantly enhanced sorafenib-inhibited tumor growth and expression of ERK/AKT phosphorylation and anti-apoptotic proteins compared to single-agent treatment. Additionally, amentoflavone also triggered sorafenib-induced apoptosis through extrinsic and intrinsic apoptotic pathways. CONCLUSION: Amentoflavone boosts therapeutic efficacy of sorafenib through blockage of anti-apoptotic potential and induction of apoptosis in HCC in vivo.

Regorafenib inhibits tumor progression through suppression of ERK/NF-κB activation in hepatocellular carcinoma bearing mice.

Regorafenib has been demonstrated in our previous study to trigger apoptosis through suppression of extracellular signal-regulated kinase (ERK)/nuclear factor-κB (NF-κB) activation in hepatocellular carcinoma (HCC) SK-Hep1 cells in vitro However, the effect of regorafenib on NF-κB-modulated tumor progression in HCC in vivo is ambiguous. The aim of the present study is to investigate the effect of regorafenib on NF-κB-modulated tumor progression in HCC bearing mouse model. pGL4.50 luciferase reporter vector transfected SK-Hep1 (SK-Hep1/luc2) and Hep3B 2.1-7 tumor bearing mice were established and used for the present study. Mice were treated with vehicle or regorafenib (20 mg/kg/day by gavage) for 14 days. Effects of regorafenib on tumor growth and protein expression together with toxicity of regorafenib were evaluated with digital caliper and bioluminescence imaging (BLI), ex vivo Western blotting immunohistochemistry (IHC) staining, and measurement of body weight and pathological examination of liver tissue, respectively, in SK-Hep1/luc2 and Hep3B 2.1-7 tumor bearing mice. The results indicated regorafenib significantly reduced tumor growth and expression of phosphorylated ERK, NF-κB p65 (Ser536), phosphorylated AKT, and tumor progression-associated proteins. In addition, we found regorafenib induced both extrinsic and intrinsic apoptotic pathways. Body weight and liver morphology were not affected by regorafenib treatment. Our findings present the mechanism of tumor progression inhibition by regorafenib is linked to suppression of ERK/NF-κB signaling in SK-Hep1/luc2 and Hep3B 2.1-7 tumor bearing mice.

Amentoflavone Inhibits ERK-modulated Tumor Progression in Hepatocellular Carcinoma In Vitro.

BACKGROUND/AIM: A previous study indicated that amentoflavone inhibits tumor growth of breast cancer. However, the anti-cancer effects and mechanism of amentoflavone in hepatocellular carcinoma (HCC) have not been elucidated. The aim of the present study was to verify the effect of amentoflavone on tumor progression in HCC. MATERIALS AND METHODS: HCC SK-Hep1 cells were treated with different concentrations of amentoflavone or 10 µM PD98059 (extracellular signal-regulated kinases (ERK) inhibitor) for 48 h, respectively, and then cell viability, NF-κB activation, levels of tumor progression-associated proteins, and cell invasion were evaluated with 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), NF-κB reporter gene assay, western blotting, and cell invasion assay. RESULTS: The results demonstrated that both amentoflavone and PD98059 not only significantly reduced cell viability, NF-κB activation, and cell invasion, but also inhibited the expression of tumor progression-associated proteins. In addition, we found that amentoflavone suppresses ERK phosphorylation. CONCLUSION: The results of the present study suggest that amentoflavone down-regulates ERK-modulated tumor progression in HCC.

Amentoflavone Inhibits Metastatic Potential Through Suppression of ERK/NF-κB Activation in Osteosarcoma U2OS Cells.

AIM: The study goal was to investigate effect of amentoflavone on nuclear factor-κB (NF-κB)-modulated metastatic mechanism in osteosarcoma U2OS cells. U2OS cells were treated with amentoflavone, NF-κB inhibitor, protein kinase B (PKB or AKT) inhibitor or mitogen-activated protein kinase (MAPK) inhibitor. Change of cell viability, NF-κB activation, expression of metastasis-associated proteins, signal transduction, and cell migration and invasion were evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, NF-κB reporter gene assay, western blotting, and cell migration and invasion assays. The results demonstrated that inhibition of activation of extracellular signal-regulated kinases (ERK) was a key point for suppression of NF-κB-modulated metastatic mechanism. Amentoflavone significantly inhibited NF-κB activation, ERK phosphorylation, expression of metastasis-associated proteins, and cell migration and invasion. Our findings indicate that amentoflavone reduces metastatic potential through suppression of ERK and NF-κB activation in osteosarcoma U2OS cells.

Regorafenib induces extrinsic and intrinsic apoptosis through inhibition of ERK/NF-κB activation in hepatocellular carcinoma cells.

The aim of the present study was to investigate the role of NF-κB inactivation in regorafenib-induced apoptosis in human hepatocellular carcinoma SK-HEP-1 cells. SK-HEP-1 cells were treated with different concentrations of the NF-κB inhibitor 4-N-[2-(4-phenoxyphenyl)ethyl]quinazoline-4,6-diamine (QNZ) or regorafenib for different periods. The effects of QNZ and regorafenib on cell viability, expression of NF-κB-modulated anti-apoptotic proteins and apoptotic pathways were analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, western blotting, DNA gel electrophoresis, flow cytometry and NF-κB reporter gene assay. Inhibitors of various kinases including AKT, c-Jun N-terminal kinase (JNK), P38 and extracellular signal-regulated kinase (ERK) were used to evaluate the mechanism of regorafenib-induced NF-κB inactivation. The results demonstrated that both QNZ and regorafenib significantly inhibited the expression of anti-apoptotic proteins and triggered extrinsic and intrinsic apoptosis. We also demonstrated that regorafenib inhibited NF-κB activation through ERK dephosphorylation. Taken all together, our findings indicate that regorafenib triggers extrinsic and intrinsic apoptosis through suppression of ERK/NF-κB activation in SK-HEP-1 cells.