Sorafenib for Treatment of Hepatocellular Carcinoma: A Survival Analysis From the South American Liver Research Network

Changing epidemiology of hepatocellular carcinoma in South America: A report from the South American liver research network

INTRODUCTION AND OBJECTIVES

Most epidemiological data on hepatocellular carcinoma (HCC) originate from resource-rich countries. We have previously described the epidemiology of HCC in South America through the South American Liver Research Network. Here, we provide an update on the changing epidemiology of HCC in the continent seven years since that report.

MATERIALS AND METHODS

We evaluated all cases of HCC diagnosed between 2019 to 2021 in centers from six countries in South America. A templated, retrospective chart review of patient characteristics at the time of HCC diagnosis, including basic demographic, clinical and laboratory data, was completed. Diagnosis of HCC was made radiologically or histologically for all cases via institutional standards.

RESULTS

Centers contributed to a total of 339 HCC cases. Peru accounted for 37% (n=125) of patients; Brazil 16% (n=57); Chile 15% (n=51); Colombia 14% (n=48); Argentina 9% (n=29); and Ecuador 9% (n=29). The median age at HCC diagnosis was 67 years (IQR 59-73) and 61% were male. The most common risk factor was nonalcoholic fatty liver disease (NAFLD, 37%), followed by hepatitis C (17%), alcohol use disorder (11%) and hepatitis B (12%). The majority of HCCs occurred in the setting of cirrhosis (80%). HBV-related HCC occurred at a younger age compared to other causes, with a median age of 46 years (IQR 36-64).

CONCLUSIONS

We report dramatic changes in the epidemiology of HCC in South America over the last decade, with a substantial increase in NAFLD-related HCC. HBV-related HCC still occurs at a much younger age when compared to other causes.

Summary of key guidelines for locoregional treatment of HCC in Asia, Europe, South and North America

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide accounting for over 800,000 new cases in 2018, with the highest incidence in Asia and Africa where hepatitis B is the most common risk factor. In Europe, Japan, and the United States, hepatitis C chronic alcohol abuse and non-alcoholic fatty liver disease are more common risk factors. Five-year survival is low, less than 20% worldwide. HCC is a particularly challenging disease to treat because therapeutic options and prognosis must also consider hepatitis or cirrhosis independent of the malignancy. Locoregional therapies (LRT) including ablation, arterially directed therapy and external beam radiation are the preferred treatments for patients with good performance status, unresectable disease limited to the liver and preserved liver function. In practice, patients with portal vein tumor thrombus and limited extrahepatic disease may also be considered candidates for LRT. There are several guidelines developed by expert panels provide recommendations on treating this challenging disease including the Barcelona Clinic Liver Cancer, European Association for the Study of the Liver, European Society for Medical Oncology, American Association for the Study of the Liver Diseases, and the National Comprehensive Cancer Network. The purpose of this paper is to review the guidelines as they are applied clinically in regions with high incidence of HCC.

Non-alcoholic fatty liver disease-related hepatocellular carcinoma: Is there a role for immunotherapy?

Hepatocellular carcinoma (HCC) is among the most common cancers and it is a major cause of cancer-related deaths. Non-alcoholic fatty liver disease (NAFLD) affects approximately one fourth of individuals worldwide and it is becoming one of the most important causes of HCC. The pathogenic mechanisms leading to NAFLD-related HCC are complex and not completely understood. However, metabolic, fibrogenic, oncogenic, inflammatory and immunological pathways seem to be involved. First-line therapy of advanced HCC has recently undergone major changes, since the combination of atezolizumab and bevacizumab was proven to increase survival when compared to sorafenib. Other immune-oncology drugs are also demonstrating promising results in patients with advanced HCC when compared to traditional systemic therapy. However, initial studies raised concerns that the advantages of immunotherapy might depend on the underlying liver disease, which seems to be particularly important in NAFLD-related HCC, as these tumors might not benefit from it. This article will review the mechanisms of NAFLD-related hepatocarcinogenesis, with an emphasis on its immune aspects, the efficacy of traditional systemic therapy for advanced NAFLD-related HCC, and the most recent data on the role of immunotherapy for this specific group of patients, showing that the management of this condition should be individualized and that a general recommendation cannot be made at this time.

Determination of the pH dependence, substrate specificity, and turnovers of alternative substrates for human ornithine aminotransferase

Hepatocellular carcinoma (HCC) is the most common primary cancer of the liver and occurs predominantly in patients with underlying chronic liver diseases. Over the past decade, human ornithine aminotransferase (hOAT), which is an enzyme that catalyzes the metabolic conversion of ornithine into an intermediate for proline or glutamate synthesis, has been found to be overexpressed in HCC cells. hOAT has since emerged as a promising target for novel anticancer therapies, especially for the ongoing rational design effort to discover mechanism-based inactivators (MBIs). Despite the significance of hOAT in human metabolism and its clinical potential as a drug target against HCC, there are significant knowledge deficits with regard to its catalytic mechanism and structural characteristics. Ongoing MBI design efforts require in-depth knowledge of the enzyme active site, in particular, pKa values of potential nucleophiles and residues necessary for the molecular recognition of ligands. Here, we conducted a study detailing the fundamental active-site properties of hOAT using stopped-flow spectrophotometry and X-ray crystallography. Our results quantitatively revealed the pH dependence of the multistep reaction mechanism and illuminated the roles of ornithine α-amino and δ-amino groups in substrate recognition and in facilitating catalytic turnover. These findings provided insights of the catalytic mechanism that could benefit the rational design of MBIs against hOAT. In addition, substrate recognition and turnover of several fragment-sized alternative substrates of hOATs, which could serve as structural templates for MBI design, were also elucidated.

Rational Design, Synthesis, and Mechanism of (3S,4R)-3-Amino-4-(difluoromethyl)cyclopent-1-ene-1-carboxylic Acid: Employing a Second-Deprotonation Strategy for Selectivity of Human Ornithine Aminotransferase over GABA Aminotransferase

Human ornithine aminotransferase (hOAT) is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that contains a similar active site to that of γ-aminobutyric acid aminotransferase (GABA-AT). Recently, pharmacological inhibition of hOAT was recognized as a potential therapeutic approach for hepatocellular carcinoma. In this work, we first studied the inactivation mechanisms of hOAT by two well-known GABA-AT inactivators (CPP-115 and OV329). Inspired by the inactivation mechanistic difference between these two aminotransferases, a series of analogues were designed and synthesized, leading to the discovery of analogue 10b as a highly selective and potent hOAT inhibitor. Intact protein mass spectrometry, protein crystallography, and dialysis experiments indicated that 10b was converted to an irreversible tight-binding adduct (34) in the active site of hOAT, as was the unsaturated analogue (11). The comparison of kinetic studies between 10b and 11 suggested that the active intermediate (17b) was only generated in hOAT and not in GABA-AT. Molecular docking studies and pK_a computational calculations highlighted the importance of chirality and the endocyclic double bond for inhibitory activity. The turnover mechanism of 10b was supported by mass spectrometric analysis of dissociable products and fluoride ion release experiments. Notably, the stopped-flow experiments were highly consistent with the proposed mechanism, suggesting a relatively slow hydrolysis rate for hOAT. The novel second-deprotonation mechanism of 10b contributes to its high potency and significantly enhanced selectivity for hOAT inhibition.

Echinacea purpurea suppresses the cell survival and metastasis of hepatocellular carcinoma through regulating the PI3K/Akt pathway

Echinacea purpurea (L.) Moench (Ep) is widely used as a kind of dietary supplements, and possesses various pharmacological activities, including immunomodulatory, anti-inflammatory, antitumor effects. However, the inhibitory effects of Ep on the growth and metastasis of hepatocellular carcinoma (HCC) is unclear. Here, the preventive effect and potential mechanism of Ep on HCC was elucidated by systems pharmacology and molecular docking. The results showed that Ep could significantly ameliorate HCC-induced tumor growth and migration in vivo and in vitro. System pharmacology results indicated that 180 genes associated with HCC were regarded as the potential therapeutic targets of Ep, mainly involved in metabolic pathways, cancer pathways, proteoglycans in cancer and PI3K/Akt signaling pathway, which might be a crucial pathway in HCC EMT. A herb-component-target-pathway network was constructed to reveal the interactions between Ep and HCC. Finally, predicted PI3K/Akt pathway was further validated by molecular docking and western blot experiment. This study showed that Ep ameliorates HCC-induced tumor cell survival and migration in mice via the regulation of the PI3K/Akt pathway. Thus, Ep might be a potential new strategy to prevent the growth and metastasis of HCC.

Echinacea in hepatopathy: A review of its phytochemistry, pharmacology, and safety

BACKGROUND

Echinacea, one of the most popular herbs with double function of immunity and anti-inflammatory activity, has now attracted much interest for a possible alternative for the treatment of hepatopathy. This review is aimed at providing a comprehensive overview of Echinacea regarding its chemical composition, pharmacological action against various hepatopathy, and safety.

METHODS

A comprehensive search of published articles was conducted to focus on original publications related to Echinacea and hepatopathy till the end of 2020 using various literature databases, including China National Knowledge Infrastructure, PubMed, and Web of Science database.

RESULTS

Echinacea exhibited excellent activities in resisting a variety of hepatopathy induced by different causes in preclinical experiments and clinical trials by regulating cell proliferation and apoptosis, antioxidant defense mechanism, voltage-gated sodium channels, lipid metabolism, circadian rhythm, p38 MAPK signaling pathway, JNK signaling pathway, Nrf2/HO-1 signaling pathway, PI3K/AKT signaling pathway, and Akt/GSK3 beta signaling pathways. The high efficacy of Echinacea is related to its immunomodulatory and anti-inflammatory activities. The main ingredients of Echinacea include caffeic acid derivatives, alkylamides, and polysaccharides, which have been well established in preclinical studies of liver diseases. Studies on acute and subacute toxicity show that Echinacea preparations are well-tolerated herbal medicines.

CONCLUSION

Echinacea may offer a novel potential strategy for clinical prevention and treatment of liver diseases and related diseases. Extensive studies are necessary to identify the underlying mechanisms and establish future therapeutic potentials of this herb. Well-designed clinical trials are still warranted to confirm the safety and effectiveness of Echinacea for hepatopathy.

Remarkable and Unexpected Mechanism for (S)-3-Amino-4-(difluoromethylenyl)cyclohex-1-ene-1-carboxylic Acid as a Selective Inactivator of Human Ornithine Aminotransferase

Human ornithine aminotransferase (hOAT) is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that was recently found to play an important role in the metabolic reprogramming of hepatocellular carcinoma (HCC) via the proline and glutamine metabolic pathways. The selective inhibition of hOAT by compound 10 exhibited potent in vivo antitumor activity. Inspired by the discovery of the aminotransferase inactivator (1S,3S)-3-amino-4-(difluoromethylene)cyclopentane-1-carboxylic acid (5), we rationally designed, synthesized, and evaluated a series of six-membered-ring analogs. Among them, 14 was identified as a new selective hOAT inactivator, which demonstrated a potency 22× greater than that of 10. Three different types of protein mass spectrometry approaches and two crystallographic approaches were employed to identify the structure of hOAT-14 and the formation of a remarkable final adduct (32') in the active site. These spectral studies reveal an enzyme complex heretofore not observed in a PLP-dependent enzyme, which has covalent bonds to two nearby residues. Crystal soaking experiments and molecular dynamics simulations were carried out to identify the structure of the active-site intermediate 27' and elucidate the order of the two covalent bonds that formed, leading to 32'. The initial covalent reaction of the activated warhead occurs with *Thr322 from the second subunit, followed by a subsequent nucleophilic attack by the catalytic residue Lys292. The turnover mechanism of 14 by hOAT was supported by a mass spectrometric analysis of metabolites and fluoride ion release experiments. This novel mechanism for hOAT with 14 will contribute to the further rational design of selective inactivators and an understanding of potential inactivation mechanisms by aminotransferases.

A Combined Antitumor Strategy Mediated by a New Targeted Nanosystem to Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the main causes of cancer-related death. Sorafenib, which is the first-line therapy for this disease, is associated with reduced therapeutic efficacy that could potentially be overcome by combination with selumetinib. In this context, the main goal of this work was to develop a new nanosystem, composed of a polymeric core coated by a lipid bilayer containing the targeting ligand GalNAc, to specifically and efficiently co-deliver both drugs into HCC cells, in order to significantly increase their therapeutic efficacy.

METHODS

The physicochemical characterization of hybrid nanosystems (HNP) and their components was performed by dynamic light scattering, zeta potential, matrix-assisted laser desorption ionization - time of flight mass spectroscopy, and transmission electron microscopy. Cellular binding, uptake and specificity of HNP were evaluated through flow cytometry and confocal microscopy. The therapeutic activity was evaluated namely through: cell viability by the Alamar Blue assay; cell death by flow cytometry using FITC-Annexin V; caspases activity by luminescence; mitochondrial membrane potential by flow cytometry; and molecular target levels by Western blot.

RESULTS

The obtained data show that these hybrid nanosystems present high stability and loading capacity of both drugs, and suitable physicochemical properties, namely in terms of size and surface charge. Moreover, the generated formulation allows to circumvent drug resistance and presents high specificity, promoting great cell death levels in HCC cells, but not in non-tumor cells. This potentiation of the antitumor effect of co-loaded drugs was carried out by an increased programmed cell death, being associated with a strong reduction in the mitochondrial membrane potential, a significant increase in the activity of caspases 3/7 and caspase 9, and much greater number of annexin V-positive cells.

CONCLUSION

The developed formulation resulted in a high and synergistic antitumor effect, revealing a translational potential to improve therapeutic approaches against HCC.

Sorafenib treatment by Child-Pugh score in Latin American patients with hepatocellular carcinoma

Aim: To evaluate sorafenib treatment in Latin American patients with unresectable hepatocellular carcinoma in the real-world GIDEON study. Patients & methods: Sorafenib administration, safety and efficacy were analyzed by Child-Pugh status. Results: Of 90 evaluable patients (37% Child-Pugh A, 46% Child-Pugh B and 3% Child-Pugh C at study entry), 97% started sorafenib at 800 mg/day. Patients with Child-Pugh B7 had the longest median treatment duration of sorafenib (33.1 weeks). Sorafenib-related adverse events occurred in 58% of patients with Child-Pugh A (21% grade 3/4) and 46% with Child-Pugh B (7% grade 3/4). Conclusion: Sorafenib had a similar safety profile across patients with Child-Pugh A and B and is a treatment option for both groups.

Development of Formulation Methods and Physical Characterization of Injectable Sodium Selenite Nanoparticles for the Delivery of Sorafenib tosylate

Background: Sorafenib is the first oral therapeutic agent to show the activity against human hepatocellular carcinoma. Sorafenib leads to severe toxicity due to the multiple-dose regimen. Reducing the overall dose of sorafenib through injectable dosage form to release sustainably is of therapeutically more important to combat drug-induced toxicity.

Objective: The purpose of this study was to formulate and evaluate the physical parameters of sorafenib-loaded Sodium Selenite Nanoparticles (SSSNP).

Methods: Two different methods: chemical crosslinking and solvent evaporation were applied for the formulation of nanoparticles using various crosslinkers such as formaldehyde, magnesium sulfate, tripolyphosphate, dextran sulfate, and aluminum hydroxide. Physical characterization was performed with zeta potential analysis, polydispersity index, particle size and scanning electron microscopic studies for morphological analysis for all the formulated nanoparticles developed using the chemical crosslinking technique based ionic interaction.

Results: Tripolyphosphate was selected as an ideal crosslinker and used for nanoparticle formulation with the solvent evaporation technique. Based on the physical characterization, SSSNP was formulated successfully with the solvent evaporation technique using tripolyphosphate as a cross-linker. The zeta potential of SSSNP was -37.5 mV, PDI was approximately 0.3 to 0.4, and the observed size (diameter) was in the range of 208 nm to 0.2 µm. Furthermore, the particles were smooth in morphology and appeared as crystals.

Conclusion: The novel injectable sorafenib loaded sodium selenite nanoparticle dosage form will serve better than conventional oral dosage form to elicit a safe therapeutic effect.

BRAZILIAN SOCIETY OF HEPATOLOGY UPDATED RECOMMENDATIONS FOR DIAGNOSIS AND TREATMENT OF HEPATOCELLULAR CARCINOMA

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. The Brazilian Society of Hepatology (SBH) published in 2015 its first recommendations about the management of HCC. Since then, new data have emerged in the literature, prompting the governing board of SBH to sponsor a single-topic meeting in August 2018 in São Paulo. All the invited experts were asked to make a systematic review of the literature reviewing the management of HCC in subjects with cirrhosis. After the meeting, all panelists gathered together for the discussion of the topics and the elaboration of updated recommendations. The text was subsequently submitted for suggestions and approval of all members of the Brazilian Society of Hepatology through its homepage. The present manuscript is the final version of the reviewed manuscript containing the recommendations of SBH.

A Remarkable Difference That One Fluorine Atom Confers on the Mechanisms of Inactivation of Human Ornithine Aminotransferase by Two Cyclohexene Analogues of γ-Aminobutyric Acid

Human ornithine aminotransferase (hOAT), a pyridoxal 5'-phosphate-dependent enzyme, plays a critical role in the progression of hepatocellular carcinoma (HCC). Pharmacological selective inhibition of hOAT has been shown to be a potential therapeutic approach for HCC. Inspired by the discovery of the nonselective aminotransferase inactivator (1R,3S,4S)-3-amino-4-fluoro cyclopentane-1-carboxylic acid (1), in this work, we rationally designed, synthesized, and evaluated a novel series of fluorine-substituted cyclohexene analogues, thereby identifying 8 and 9 as novel selective hOAT time-dependent inhibitors. Intact protein mass spectrometry and protein crystallography demonstrated 8 and 9 as covalent inhibitors of hOAT, which exhibit two distinct inactivation mechanisms resulting from the difference of a single fluorine atom. Interestingly, they share a similar turnover mechanism, according to the mass spectrometry-based analysis of metabolites and fluoride ion release experiments. Molecular dynamics (MD) simulations and electrostatic potential (ESP) charge calculations were conducted, which elucidated the significant influence of the one-fluorine difference on the corresponding intermediates, leading to two totally different inactivation pathways. The novel addition-aromatization inactivation mechanism for 9 contributes to its significantly enhanced potency, along with excellent selectivity over other aminotransferases.

Celastrol Enhances the Anti-Liver Cancer Activity of Sorafenib

Background

Sorafenib, a multiple-target-point kinase inhibitor, has been used as a standard treatment for advanced liver cancer and has shown therapeutic benefits. However, resistance often occurs, prompting the need for identification of synergizing agents. Celastrol is a major active ingredient of Tripterygium wilfordii, which can increase the antitumor effect of traditional antitumor drugs. This work focused on the sensitization of liver cancers in use of celastrol combined with sorafenib.

Material/Methods

The IC50 values of sorafenib and celastrol on cancer cells were determined through MTT assays. The effects of sorafenib on AKT signaling and VEGF levels in sorafenib-treated cancer cells were analyzed by Western blotting and ELISA, respectively. After combined treatment with celastrol and sorafenib, the survival rate of tumor cells was determined by MTT and clonogenic assays, and the apoptosis rate was also determined by flow cytometry. In addition, the in vivo antitumor activity of celastrol combined with sorafenib was evaluated in Hepa1-6 tumor-bearing mice.

Results

Sorafenib treatment induced the compensatory activation of the AKT pathway and autocrine VEGF in hepatoma cells, which could be reversed by celastrol. Furthermore, celastrol enhanced the growth inhibition and apoptosis induction of cancer cells by sorafenib both in vitro and in vivo and reduced the dosage of sorafenib needed.

Conclusions

Celastrol enhances the antitumor activity of sorafenib in HCC tumor cells by suppressing the AKT pathway and VEGF autocrine system.

Role of Natural Phenolics in Hepatoprotection: A Mechanistic Review and Analysis of Regulatory Network of Associated Genes

The liver is not only involved in metabolism and detoxification, but also participate in innate immune function and thus exposed to frequent target Thus, they are the frequent target of physical injury. Interestingly, liver has the unique ability to regenerate and completely recoup from most acute, non-iterative situation. However, multiple conditions, including viral hepatitis, non-alcoholic fatty liver disease, long term alcohol abuse and chronic use of medications can cause persistent injury in which regenerative capacity eventually becomes dysfunctional resulting in hepatic scaring and cirrhosis. Despite the recent therapeutic advances and significant development of modern medicine, hepatic diseases remain a health problem worldwide. Thus, the search for the new therapeutic agents to treat liver disease is still in demand. Many synthetic drugs have been demonstrated to be strong radical scavengers, but they are also carcinogenic and cause liver damage. Present day various hepatic problems are encountered with number of synthetic and plant based drugs. Nexavar (sorafenib) is a chemotherapeutic medication used to treat advanced renal cell carcinoma associated with several side effects. There are a few effective varieties of herbal preparation like Liv-52, silymarin and Stronger neomin phages (SNMC) against hepatic complications. Plants are the huge repository of bioactive secondary metabolites viz; phenol, flavonoid, alkaloid etc. In this review we will try to present exclusive study on phenolics with its mode of action mitigating liver associated complications. And also its future prospects as new drug lead.