Management of hepatocellular carcinoma

Circ_TEX2 Functions as a Tumor Suppressor in Hepatoma via miR-96-5p/SPRED1 Axis

Circular RNAs (circRNAs) have been shown to have a vital effect on hepatoma progression. The purpose of this study was to explore the function and mechanism of circRNA testis expressed 2 (circ_TEX2, circ_0004913) in hepatoma pathogenesis. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect circ_TEX2, miR-96-5p, and sprouty-related EVH1 domain containing 1 (SPRED1) expression. Western blot analyzed the proliferating cell nuclear antigen (PCNA), SPRED1, and the apoptosis-related protein levels. 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), and colony formation assays were used to test cell proliferation. Cell migration and invasion were analyzed by transwell assay, and cell apoptosis was detected by flow cytometry. Dual-luciferase reporter assay was done to analyze the target relationship between miR-96-5p and circ_TEX2 or SPRED1. The effects of circ_TEX2 on tumor growth in vivo were verified by xenograft model experiment and immunohistochemistry assay. The levels of circ_TEX2 and SPRED1 were down-regulated in hepatoma tissues and cells, and miR-96-5p expression was up-regulated. Overexpression of circ_TEX2 could inhibit the proliferation, migration, and invasion and boost cell apoptosis of hepatoma cells. Circ_TEX2 affected SPRED1 expression by sponging miR-96-5p. The overexpression of miR-96-5p could overturn the influence of circ_TEX2 up-regulation on malignant behaviors of hepatoma cells, and reduced SPRED1 expression could reverse the function of miR-96-5p knockdown on hepatoma cell malignant behaviors. Circ_TEX2 could suppress the growth of xenograft tumors in vivo. Our study demonstrates the tumor-suppressive role of circ_TEX2 in hepatoma through miR-96-5p/SPRED1 axis, suggesting that strategies directed toward restoring the production of circ_TEX2 might have a therapeutic value for hepatoma treatment.

Regulation of TREM1-Mediated Inflammation in Hepatocellular Carcinoma Cells

Hepatocellular carcinoma (HCC), accounting for more than 90% of cases of primary liver cancer, is the third most common cause of cancer-related death worldwide. Chronic inflammation precedes the development of cirrhosis and HCC. TREM (triggering receptor expressed on myeloid cell)-1 is an inflammatory marker and amplifier of inflammation that signals through PI3K and ERK1/2 to activate transcription factors, resulting in increased secretion of pro-inflammatory cytokines, causing chronic inflammation and predisposing the liver to carcinogenesis. Thus, targeting TREM-1 in HCC might be a potential therapeutic target. A low level of vitamin D has been associated with chronic inflammation and poor prognosis in HCC. Thus, we evaluated the effect of vitamin D on TREM-1 expression in the HCC cell line. Additionally, the effects of high mobility group box-1, lipopolysaccharide, and transcription factor PU.1 on the expression of TREM-1 in normal liver cells and HCC cells have been investigated in the presence and absence of vitamin D. The results showed increased expression of TREM-1 in HCC cells and with IL-6, TNF-α, LPS, and rHMGB-1 and decreased expression with calcitriol. Calcitriol also attenuated the effect of IL-6, TNF-α, LPS, and rHMGB-1 on TREM-1. Calcitriol treatment attenuated the proliferation, migration, and invasion of HCC cells. These results (in vitro) provide molecular and biochemical evidence that calcitriol significantly attenuates the expression of mediators of inflammation, and thus might be used therapeutically together with conventional treatment to delay the progression of HCC. Additionally, the negative regulation of TREM-1 by PU.1 suggests PU.1 as a potential therapeutic target.

Diffuse Recurrence of Hepatocellular Carcinoma After Liver Resection: Transarterial Chemoembolization (TACE) Combined With Sorafenib Versus TACE Monotherapy

This study aims to compare the effectiveness and complications of transarterial chemoembolization (TACE) combined with sorafenib (S-TACE) and TACE monotherapy in HCC patients with diffuse recurrence (DR). This retrospective study was approved by our hospital ethics committee, and all patients provided informed consent. We retrospectively enrolled 356 DR patients from January 2005 to December 2014, who underwent either S-TACE or TACE monotherapy. Treatment complications, overall survival (OS) and progression-free survival (PFS) were evaluated. Survival curves were constructed using the Kaplan-Meier method and compared using a log-rank test. Our results found a significant difference between S-TACE and TACE monotherapy in the PFS and OS of HCC patients with early diffuse recurrence (EDR) (p=0.011 and 0.049, respectively). Patients with late diffuse recurrence (LDR) who underwent S-TACE had longer OS (median 24.0 vs. 16.0 months; p=0.044) compared with those in the TACE monotherapy group. Subgroup analysis revealed that S-TACE therapy resulted in higher OS of EDR patients with tumors > 5 cm and HBV-DNA >100 (p=0.036 and 0.035, respectively), compared with patients given TACE monotherapy. S-TACE therapy also resulted in better OS in LDR patients with AFP≥400 ng/ml, AFP<400 ng/ml, TB<28 g/L, TB>28 g/L, and a maximum tumor diameter < 5 cm (p=<0.001, 0.042, <0.001, <0.001, and <0.001, respectively). The rate of major complications in patients who underwent S-TACE was not significantly different to those who underwent TACE monotherapy (33.5% vs. 28.2%, p= 0.69). Overall, patients given S-TACE had better OS in both EDR and LDR patients, but only EDR patients had better PFS.

Piperlongumine, a Novel TrxR1 Inhibitor, Induces Apoptosis in Hepatocellular Carcinoma Cells by ROS-Mediated ER Stress

Hepatocellular carcinoma (HCC) is the sixth most common cancer and the third leading cause of cancer-related deaths globally. Despite advances in diagnosis and treatment, the incidence and mortality of HCC continue to rise. Piperlongumine (PL), an alkaloid isolated from the fruit of the long pepper, is known to selectively kill tumor tissues while sparing their normal counterparts. However, the killing effects of PL on HCC and the underlying mechanism of PL are not clear. We report that PL may interact with thioredoxin reductase 1 (TrxR1), an important selenocysteine (Sec)-containing antioxidant enzyme, and induce reactive oxygen species (ROS)-mediated apoptosis in HCC cells. Our results suggest that PL induces a lethal endoplasmic reticulum (ER) stress response in HCC cells by targeting TrxR1 and increasing intracellular ROS levels. Notably, PL treatment reduces TrxR1 activity and tumor cell burden in vivo. Additionally, TrxR1 is significantly upregulated in existing HCC databases and available HCC clinical specimens. Taken together, these results suggest PL as a novel anticancer candidate for the treatment of HCC. More importantly, this study reveals that TrxR1 might be an effective target in treating HCC.

Downregulation of DcR3 sensitizes hepatocellular carcinoma cells to TRAIL-induced apoptosis

Decoy receptor 3 (DcR3) has been recently described as an antiapoptosis and prometastasis factor since it can competitively bind to FasL, TL1A, and LIGHT, and it is highly expressed in many malignant tumors. Downregulation of DcR3 can promote tumor cell apoptosis and inhibit metastasis. A previous study demonstrated that reduction of DcR3 could induce tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis in pancreatic cancer cells. However, whether such an effect is seen in hepatocellular carcinoma (HCC) remains to be explored. This study was designed to investigate the sensitivity of HCC cells to TRAIL after silencing DcR3, and this was done by evaluating the expression of DcR3 in HCC cells and the effect on TRAIL-mediated apoptosis after downregulation of DcR3. Our data showed that DcR3 was highly expressed in HepG2, BEL-7402, Hep3B, Huh-7, MHCC97H, and SMCC7721 cell lines compared with normal liver cell line LO-2. Both HepG2 and BEL-7402 were tolerant to TRAIL-mediated apoptosis, and the tolerance was negatively correlated to the expression of DcR3. Silencing of DcR3 with shRNA and treatment with TRAIL induced obvious apoptosis in HepG2 and BEL-7402, with more cancer cells found in the G1 phase. SiDcR3 combined with TRAIL could induce activation of caspases-3, -8, and -9, raise the expression of the apoptotic protein Bax, and reduce the expression of antiapoptotic proteins (Bcl-2, Mcl-1, Bcl-XL, IAP-2, and survivin). Caspase-8 inhibitor Ac-IETD-CHO significantly decreased the activation of caspase cascade, indicating that the extrinsic pathway may have a vital role in the apoptotic events induced by SiDcR3/TRAIL. Furthermore, our results showed that the TRAIL death receptor 5 (DR5) was upregulated and that DR5 neutralizing antibody abrogated the effect of SiDcR3. Our results demonstrated that downregulation of DcR3 could enhance TRAIL-mediated apoptosis in HCC through the death receptor pathway. In the future, this might be useful as a clinical treatment method of liver cancer.

Complete response to sorafenib in a patient with recurrent hepatocellular carcinoma

Partial hepatectomy is still the treatment of choice aiming at a cure for patients with hepatocellular carcinoma (HCC), provided that the patient can tolerate the treatment. For patients with multiple recurrent HCC after partial hepatectomy which cannot be treated by re-hepatectomy or local ablative therapy, the prognosis is extremely poor. Sorafenib is a molecular-targeted agent which has been demonstrated in two global phase III randomized controlled trials to show survival benefit for advanced HCC. Here, we present a 56-year-old patient with HCC who showed complete clinical response after sorafenib was used for tumor recurrence which developed 3 mo after partial hepatectomy. There was no evidence of progression of disease for 60 mo till now after continuous treatment with sorafenib.

An anthraquinone derivative, emodin sensitizes hepatocellular carcinoma cells to TRAIL induced apoptosis through the induction of death receptors and downregulation of cell survival proteins

Recombinant tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is currently under clinical trials for cancer, however many tumor cells, including hepatocellular carcinoma (HCC) develop resistance to TRAIL-induced apoptosis. Hence, novel agents that can alleviate TRAIL-induced resistance are urgently needed. In the present report, we investigated the potential of emodin to enhance apoptosis induced by TRAIL in HCC cells. As observed by MTT cytotoxicity assay and the externalization of the membrane phospholipid phosphatidylserine, we found that emodin can significantly potentiate TRAIL-induced apoptosis in HCC cells. When investigated for the mechanism(s), we observed that emodin can downregulate the expression of various cell survival proteins, and induce the cell surface expression of both TRAIL receptors, death receptors (DR) 4 as well as 5. In addition, emodin increased the expression of C/EBP homologous protein (CHOP) in a time-dependent manner. Knockdown of CHOP by siRNA decreased the induction of emodin-induced DR5 expression and apoptosis. Emodin-induced induction of DR5 was mediated through the generation of reactive oxygen species (ROS), as N-acetylcysteine blocked the induction of DR5 and the induction of apoptosis. Also, the knockdown of X-linked inhibitor of apoptosis protein by siRNA significantly reduced the sensitization effect of emodin on TRAIL-induced apoptosis. Overall, our experimental results clearly indicate that emodin can indeed potentiate TRAIL-induced apoptosis through the downregulation of antiapoptotic proteins, increased expression of apoptotic proteins, and ROS mediated upregulation of DR in HCC cells.

Pancreatic injury after major hepatectomy: a study in a porcine model

PURPOSE

The aim of this study was to investigate the pathophysiology of pancreatitis after major hepatectomy.

METHODS

The study used ten female pigs. Three served as sham animals (sham group) and were killed after laparotomy to obtain normal tissue samples. Seven animals were subjected to major hepatectomy (70-75%), using the Pringle maneuver for 150 min, after constructing a portacaval side-to-side anastomosis (hepatectomy group). Duration of reperfusion was 24 h.

RESULTS

Pancreatic tissue sampled 24 h after reperfusion had increased necrosis and edema in comparison to sham group and to tissue sampled at 12 h. Tissue malondialdehyde (MDA) did not differ significantly between samples at 12 and 24 h but was increased in the hepatectomy group in comparison to sham animals. Percentage increase in portal MDA content during reperfusion was greater at 12 h of reperfusion in comparison to the increase after 24 h. Portal pressure increased significantly after 12 h of reperfusion. Serum amylase and C-peptide increased during reperfusion in comparison to baseline levels.

CONCLUSIONS

The findings suggest that intraoperative portal congestion is not the only cause of the development of pancreatitis after major hepatectomy. The oxidative markers suggest that reactive oxygen species produced during vascular control may be responsible as well.

An unusual complication following transarterial chemoembolization: acute myocardial infarction

Transarterial chemoembolization has been widely used to treat unresectable hepatocellular carcinoma. Various complications have been reported, but they have not included acute myocardial infarction. Acute myocardial infarction results mainly from coronary artery occlusion by plaques that are vulnerable to rupture or from coronary spasm, embolization, or dissection of the coronary artery. It is associated with significant morbidity and mortality. We present a case report that describes a patient with hepatocellular carcinoma who underwent transarterial chemoembolization and died subsequently of acute myocardial infarction. To our knowledge, there has been no previous report of this complication induced by transarterial chemoembolization for hepatocellular carcinoma. This case illustrates the need to be aware of acute myocardial infarction when transarterial chemoembolization is planned for the treatment of hepatocellular carcinoma, especially in patients with underlying coronary artery disease.

Percutaneous ablation for small hepatocellular carcinoma

Hepatocellular carcinoma is increasingly detected at small size, usually 5 cm or smaller in diameter. For small hepatocellular carcinoma, percutaneous ablation is a potentially curative treatment. Ethanol injection is able to achieve a complete response of 70-80% and a 5-year survival of 40-60% in the treatment of hepatocellular carcinoma of 3 cm or less. Radiofrequency ablation has emerged as the more powerful alternative method. Randomized controlled trials show that radiofrequency ablation offers a higher complete response at fewer treatment sessions and better survival compared with ethanol injection. Microwave ablation has been demonstrated to be equivalent to radiofrequency ablation in both local efficacy and long-term outcome. Laser ablation is mainly applied in clinical settings in Europe. Nowadays, percutaneous ablation is commonly accepted as the best option for patients with small hepatocellular carcinoma who are not candidates for surgical resection or liver transplantation. However, whether it can compete with surgery as the first-line treatment has long been debated. There are some retrospective studies and only a few randomized controlled trials to compare the two modalities. The currently available data are not robust enough to draw a solid conclusion. This review article provides an overview of the current status of percutaneous ablation in management of small hepatocellular carcinoma and also focuses on comparison with surgical resection.

Embolotherapy in the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) ranks fifth in frequency of cancers worldwide. The incidence of HCC in the United States is rising, primarily due to the number of patients who were infected by hepatitis in the 1960s and 1970s coupled with the rising migrant population from Asia, where hepatitis is widely prevalent. Up to 80% of the patients present with multicentric HCC and advanced liver disease or comorbidities that restrict the option of resection or liver transplantation. The dual blood supply (arterial and portal) to the liver with predominantly arterial supply to the tumor has made embolotherapy a cornerstone in the management of inoperable HCC. The techniques have become refined not only due to the development of microcatheter angiographic capabilities, but also in the ability to deliver a wide variety of therapeutic agents to these tumors. This article reviews the fundamental principles of bland embolization, chemoembolization, and radioembolization in the management of HCC.

Role and support for hepatologists at liver transplant programs in the United States

Liver transplantation has evolved into a successful option for patients with end-stage liver disease. Transplant hepatologists are involved in the management of patients with end-stage liver disease both before and after liver transplantation. The goals of this study were to evaluate the roles that transplant hepatologists play at liver transplantation programs in the United States and the demand for and institutional support provided for these physicians. A web-based questionnaire was sent via e-mail to the medical directors of all 108 United Network for Organ Sharing-recognized liver transplant programs during the fall of 2006. Follow-up e-mails were sent and phone calls were made to those not completing the survey within 4 weeks. The survey was completed by 72 (67%) medical directors. The average number of liver transplants performed per center was 62, and a broad range of program sizes were represented. The number of transplant hepatologists increased in proportion to the number of transplants performed on an annual basis but lagged behind the number of surgeons and transplant coordinators. On average, 33 liver transplants were performed per year per transplant hepatologist. Transplant hepatologists were involved in all aspects of pretransplant and posttransplant care at all but 10% of these institutions; they provided virtually all pretransplant care at all of these programs and all long-term posttransplant care at 45% of these programs. Overall, 94% of liver transplant programs provided direct salary support and/or ancillary personnel for their transplant hepatologists. Despite this, over half of transplant hepatologists and 75% of those that received no direct salary support performed endoscopic procedures on a regular basis. Eighty-one percent of programs were recruiting additional transplant hepatologists. In conclusion, although the vast majority of transplant hepatologists receive institutional support, this support appears to be inadequate. The current shortage of transplant hepatologists is likely to increase if appropriate support mechanisms are not implemented.

Targeting of VX2 rabbit liver tumor by selective delivery of 3-bromopyruvate: a biodistribution and survival study

The aim of this study was to determine the biodistribution and tumor targeting ability of (14)C-labeled 3-bromopyruvate ([(14)C]3-BrPA) after i.a. and i.v. delivery in the VX2 rabbit model. In addition, we evaluated the effects of [(14)C]3-BrPA on tumor and healthy tissue glucose metabolism by determining (18)F-deoxyglucose (FDG) uptake. Last, we determined the survival benefit of i.a. administered 3-BrPA. In total, 60 rabbits with VX2 liver tumor received either 1.75 mM [(14)C]3-BrPA i.a., 1.75 mM [(14)C]3-BrPA i.v., 20 mM [(14)C]3-BrPA i.v., or 25 ml of phosphate-buffered saline (PBS). All rabbits (with the exception of the 20 mM i.v. group) received FDG 1 h before sacrifice. Next, we compared survival of animals treated with i.a. administered 1.75 mM [(14)C]3-BrPA in 25 ml of PBS (n = 22) with controls (n = 10). After i.a. infusion, tumor uptake of [(14)C]3-BrPA was 1.8 +/- 0.2% percentage of injected dose per gram of tissue (%ID/g), whereas other tissues showed minimal uptake. After i.v. infusion (1.75 mM), tumor uptake of [(14)C]3-BrPA was 0.03 +/- 0.01% ID/g. After i.a. administration of [(14)C]3-BrPA, tumor uptake of FDG was 26 times lower than in controls. After i.v. administration of [(14)C]3-BrPA, there was no significant difference in tumor FDG uptake. Survival analysis showed that rabbits treated with 1.75 mM 3-BrPA survived longer (55 days) than controls (18.6 days). Intra-arterially delivered 3-BrPA has a favorable biodistribution profile, combining a high tumor uptake resulting in blockage of FDG uptake with no effects on healthy tissue. The local control of the liver tumor by 3-BrPA resulted in a significant survival benefit.

In vivo and in vitro anti-tumor effects of β-elemene liposome

AIM: To investigate the inhibitory effects of β-elemene liposome on digestive tumors in vitro and in vivo.

METHODS: Five digestive tumor cell lines and one human lung embryonic fibroblast cell line were used to test the IC₅₀ values of β-elemene liposome in vitro by cell culture. H22-bearing Kunming mice were treated with injection of β-elemene liposome through the tail vein at 20, 40 or 80 mg/kg to establish solid and ascites tumor models. Mice treated with glucose or elemene emulsion served as negative or positive controls, respectively. The anti-tumor effects, survival and side effects of β-elemene liposome observed and compared between different groups.

RESULTS: IC₅₀ values of β-elemene liposome and elemene emulsion for the five digestive tumor cell lines were from 34.1 ± 4.5 to 51.4 ± 4.2 mg/L and 41.5 ± 4.7 mg/L to 82.3 ± 8.8 mg/L, respectively, and IC₅₀ of the former was half of the later. In solid tumor models, the inhibitory rates of 80-, 40- or 20-mg/kg β-elemene liposome and elemene emulsion were 47.4%-50.8%, 38.2%-45.0%, 23.2%-28.2% and 21.8%-43.0%, respectively, and the average tumor weights were lower than those in the glucose control group (t > 4.09, P < 0.05). In ascites tumor models, the survival time was 51.3%-153.0% longer in β-elemene liposome or emulsion group than that in the glucose control group (t > 7.92, P < 0.05). Furthermore, the survival time in 80- or 40-mg/kg β-elemene liposome group was longer than that in elemene emulsion group (t > 4.64, P < 0.05). The stimulating symptoms and phlebitis of tail vein generated by injection of β-elemene liposome were slighter than those by elemene emulsion.

CONCLUSION: β-elemene liposome has greater ability to inhibit tumor growth and relieve side effects than elemene emulsion.