New Insight into Therapies Targeting Angiogenesis in Hepatocellular Carcinoma

To construct and validate a risk score model of angiogenesis-related genes to predict the prognosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors with high morbidity and mortality worldwide. Angiogenesis is essential for HCC progression and metastasis. Some angiogenesis-related genes promote this process, whereas other antiangiogenic genes inhibit HCC growth and metastasis. Therefore, finding new potential biomarkers for HCC prognosis prediction and treatment is essential. Public RNAseq and clinical data from TCGA and GEO database, download angiogenesis-related genes from the GeneCards, MSigDB database, through the single factor analysis of Cox, LASSO build risk score-Cox regression analysis model and external validation verified from the GEO. Cox regression analysis, Kaplan Meier (KM) curve, ROC curve, and decision-curve analysis will be used to evaluate and examine the risk score prediction effect of the model. GSVA analysis was used to assess the variation of gene sets between groups, and ClBERSOFT, ESTIMATE, and TIMER databases were used to analyze the immune infiltration in the single-cell level analysis of gene expression differences between cells. Finally, in the three pairs of HCC tissues and tissue adjacent to carcinoma by real-time fluorescent quantitative PCR (qRT_PCR) and western blotting (WB) to evaluate angiogenesis-related genes (ATP2A3 AEBP1 PNMA1, PLAT) expression level in HCC, and AEBP1 was knocked out in HCCLM3 cells, which is to study AEBP1 biological function in HCC. We established a prognostic risk assessment model based on 13 significant genes associated with HCC prognosis by Cox analysis and LASSO-Cox regression analysis. The median was used to divide these patients into high-risk and low-risk groups, and the prognosis of the high-risk group was worse than that of the low-risk group. Through the multivariate Cox regression analysis, it was found that the risk score was an independent predictor of overall survival (OS). The GSVA analysis suggested that the predicted high-risk population showed higher activity in the purine, pyrimidine, and riboflavin metabolic pathways. Compared with the low-risk group, the tumor microenvironment in the high-risk group showed a reduction in the number of cells promoting anti-tumor immunity and an increase in the number of cells inhibiting anti-tumor immunity, as well as a reduction in overall immune infiltration and matrix components. On the single-cell level, it was confirmed that the key genes (AEBP1, ATP2A3, PLAT, and PNMA1) expressed differently between liver cancer and adjacent tissue cell groups. Finally, qRT_PCR and WB results showed that ATP2A3, AEBP1, PNMA1, and PLAT were highly expressed in liver cancer tissue compared to adjacent tissue, and the proliferation, migration, and invasion of HCCLM3 cells were inhibited after knocking out AEBP1. We constructed novel risk score models as prognostic biomarkers for HCC, which has the potential to guide the development of more personalized treatment strategies for HCC patients. In addition, AEBP1 is a potential therapeutic target for HCC.

Idarubicin-loaded chitosan nanobubbles to improve survival and decrease drug side effects in hepatocellular carcinoma

BACKGROUND

Drug delivery strategies using chitosan nanobubbles (CS-NBs) could be used to reduce drug side effects and improve outcomes in hepatocellular carcinoma (HCC) treatment. To enhance their action, a targeting agent, such as the humanized anti-GPC3 antibody GC33 (condrituzumab), could be attached to their surface. Here, we investigated the use of idarubicin-loaded CS-NBs for HCC treatment and a GC33-derived minibody (that we named 4A1) to enhance CS-NB delivery.

METHODS

Various CS-NB formulations were prepared with or without 4A1 conjugation and idarubicin loading.

RESULTS

CS-NBs had a positive charge and a diameter of about 360 nm. In in-vitro experiments using the HCC-like HUH7 cell line, CS-NBs showed a cytotoxic effect once loaded with idarubicin. In-vivo biodistribution in HUH7 tumor-bearing xenograft mice demonstrated that CS-NBs can accumulate in the tumor mass. This effect was enhanced by 4A1 conjugation (p = 0.0317). In HUH7 tumor-bearing xenograft mice, CS-NBs loaded with idarubicin and conjugated or not conjugated with 4A1 were both able to slow tumor growth, to increase mouse survival time compared to free idarubicin (p = 0.00044 and 0.0018, respectively) as well as to reduce drug side effects.

CONCLUSIONS

CS-NBs loaded with idarubicin can be a useful drug delivery strategy for HCC treatment.

Molecular docking and in vivo/in vitro studies of a novel thiadiazole Schiff base as a hepatoprotective drug against angiogenesis induced by breast cancer

Two new thiadiazole imidazolium salicylidene Schiff bases (TISSBs) were successfully synthesized, and their structures were analyzed comprehensively using spectroscopic techniques. The results of the MTT assay showed that TISSB2 was the safest and most effective anti-breast cancer agent. The anti-angiogenic activity of TISSB2 was evaluated using in vivo tests in Ehrlich ascites carcinoma (EAC)-bearing Swiss albino mice. The degree of angiogenesis was assessed by measuring the levels of vascular endothelial growth factor (VEGF), tumor necrosis factor-α (TNF-α), and transforming growth factor-β1 (TGF-β1). The results of biochemical, immunohistochemical, and histopathological examinations indicated that TISSB2 could restore the normal functional indices of the injured liver, as evident from the downregulated TGF-β1, TNF-α, and VEGF levels reverting to normal values. Moreover, in the molecular docking study, TISSB2 exhibited stronger interactions with VEGFR-2 and NF-κB proteins, with binding affinity scores of -11.79 and -9.25 kcal mol-1, respectively. These stronger interactions involved H-bonding, ionic bonds, and hydrophobic π-interactions. Overall, TISSB2 can be a promising therapeutic option for the treatment of EAC-induced tumour angiogenesis.

A Novel Liver Cancer-Selective Histone Deacetylase Inhibitor Is Effective against Hepatocellular Carcinoma and Induces Durable Responses with Immunotherapy

Hepatocellular carcinoma (HCC) progression is facilitated by gene-silencing chromatin histone hypoacetylation due to histone deacetylase (HDAC) activation. However, inhibiting HDACs-an effective treatment for lymphomas-has shown limited success in solid tumors. We report the discovery of a class of HDAC inhibitors (HDACi) that demonstrates exquisite selective cytotoxicity against human HCC cells. The lead compound STR-V-53 (3) showed a favorable safety profile in mice and robustly suppressed tumor growth in orthotopic xenograft models of HCC. When combined with the anti-HCC drug sorafenib, STR-V-53, showed greater in vivo efficacy. Moreover, STR-V-53 combined with anti-PD1 therapy increased the CD8+ to regulatory T-cell (Treg) ratio and survival in an orthotopic HCC model in immunocompetent mice. This combination therapy resulted in durable responses in 40% of the mice. Transcriptomic analysis revealed that STR-V-53 primed HCC cells to immunotherapy through HDAC inhibition, impaired glucose-regulated transcription, impaired DNA synthesis, upregulated apoptosis, and stimulated the immune response pathway. Collectively, our data demonstrate that the novel HDACi STR-V-53 is an effective anti-HCC agent that can induce profound responses when combined with standard immunotherapy.

Case report: Translational treatment of unresectable intrahepatic cholangiocarcinoma: Tislelizumab, Lenvatinib, and GEMOX in one case

Background

Intrahepatic cholangiocellular carcinoma (ICC) is one of the most common invasive malignancies. Currently, ICC is treated with radical surgical resection. However, the majority of patients are diagnosed at an advanced stage, making surgery ineligible for them.

Case presentation

We present a case of advanced ICC, which could not undergo radical surgery due to tumor invasion of liver blood vessels. The gemcitabine and oxaliplatin (GEMOX) regimen combined with Tislelizumab immunotherapy and Lenvatinib targeted therapy for 8 cycles resulted in significant tumor shrinkage significantly and the vascular invasion disappeared. CA19-9 levels were reduced to normal levels. Partial remission and successful tumor transformation were achieved. The patient underwent a successful radical surgical resection, including cholecystectomy, resection of liver segments IV, V, and VIII, as well as a regional lymphatic dissection procedure, resulting in complete pathological remission.

Conclusion

Tumor-free surgical margins (R0) resection of patients with advanced ICC after combination of immune, targeted and chemotherapy is rare, and there are almost no cases of complete postoperative remission. The GEMOX regimen in combination with Tislelizumab and Lenvatinib has a good antitumor efficacy and safety profile, and may be a feasible and safe translational treatment option for advanced ICC.

A Novel Liver Cancer-Selective Histone Deacetylase Inhibitor Is Effective Against Hepatocellular Carcinoma and Induces Durable Responses with Immunotherapy

Hepatocellular cancer (HCC) progression is facilitated by gene-silencing chromatin histone hypoacetylation due to histone deacetylases (HDACs) activation. However, inhibiting HDACs, an effective treatment for lymphomas, has shown limited success in solid tumors. We report the discovery of a class of HDAC inhibitors (HDACi) that demonstrates exquisite selective cytotoxicity against human HCC cells. The lead compound STR-V-53 (3) showed favorable safety profile in mice and robustly suppressed tumor growth in orthotopic xenograft models of HCC. When combined with the anti-HCC drug sorafenib, STR-V-53 showed greater in vivo efficacy. Moreover, STR-V-53 combined with anti-PD1 therapy increased the CD8+ to regulatory T-cell (Treg) ratio and survival in an orthotopic HCC model in immunocompetent mice. This combination therapy resulted in durable responses in 40% of the mice. Collectively, our data demonstrate that the novel HDACi STR-V-53 is an effective anti-HCC agent that can induce profound responses when combined with standard immunotherapy.

Case Report: Camrelizumab combined with gemcitabine and oxaliplatin in the treatment of advanced intrahepatic cholangiocarcinoma: a case report and literature review

Intrahepatic cholangiocarcinoma (ICC) is one of the most common invasive malignant tumors, with a 5-year survival rate of less than 5%. Currently, radical surgical resection is the preferred treatment for ICC. However, most patients are only diagnosed at an advanced stage and are therefore not eligible for surgery. Herein, we present a case of advanced ICC in which radical surgery was not possible due to tumor invasion of the second porta hepatis and right hepatic artery. Six treatment cycles with a gemcitabine and oxaliplatin (GEMOX) regimen combined with camrelizumab immunotherapy achieved a partial response and successful tumor conversion, as tumor invasion of the second porta hepatis and right hepatic artery was no longer evident. The patient subsequently underwent successful radical surgical resection, including hepatectomy, caudate lobe resection, and cholecystectomy combined with lymph node dissection. Cases of patients with advanced ICC undergoing surgical resection after combined immunotherapy and chemotherapy are rare. The GEMOX regimen combined with camrelizumab demonstrated favorable antitumor efficacy and safety, suggesting that it might be a potential feasible and safe conversion therapy strategy for patients with advanced ICC.

Current insights into the hepatic microenvironment and advances in immunotherapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and shows high global incidence and mortality rates. The liver is an immune-tolerated organ with a specific immune microenvironment that causes traditional therapeutic approaches to HCC, such as chemotherapy, radiotherapy, and molecular targeted therapy, to have limited efficacy. The dramatic advances in immuno-oncology in the past few decades have modified the paradigm of cancer therapy, ushering in the era of immunotherapy. Currently, despite the rapid integration of cancer immunotherapy into clinical practice, some patients still show no response to treatment. Therefore, a rational approach is to target the tumor microenvironment when developing the next generation of immunotherapy. This review aims to provide insights into the hepatic immune microenvironment in HCC and summarize the mechanisms of action and clinical usage of immunotherapeutic options for HCC, including immune checkpoint blockade, adoptive therapy, cytokine therapy, vaccine therapy, and oncolytic virus-based therapy.

Angiogenesis in hepatocellular carcinoma: mechanisms and anti-angiogenic therapies

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-associated death worldwide. Angiogenesis, the process of formation of new blood vessels, is required for cancer cells to obtain nutrients and oxygen. HCC is a typical hypervascular solid tumor with an aberrant vascular network and angiogenesis that contribute to its growth, progression, invasion, and metastasis. Current anti-angiogenic therapies target mainly tyrosine kinases, vascular endothelial growth factor receptor (VEGFR), and platelet-derived growth factor receptor (PDGFR), and are considered effective strategies for HCC, particularly advanced HCC. However, because the survival benefits conferred by these anti-angiogenic therapies are modest, new anti-angiogenic targets must be identified. Several recent studies have determined the underlying molecular mechanisms, including pro-angiogenic factors secreted by HCC cells, the tumor microenvironment, and cancer stem cells. In this review, we summarize the roles of pro-angiogenic factors; the involvement of endothelial cells, hepatic stellate cells, tumor-associated macrophages, and tumor-associated neutrophils present in the tumor microenvironment; and the regulatory influence of cancer stem cells on angiogenesis in HCC. Furthermore, we discuss some of the clinically approved anti-angiogenic therapies and potential novel therapeutic targets for angiogenesis in HCC. A better understanding of the mechanisms underlying angiogenesis may lead to the development of more optimized anti-angiogenic treatment modalities for HCC.

Quercetin activates vitamin D receptor and ameliorates breast cancer induced hepatic inflammation and fibrosis

Aims

To explore the hepatoprotective role of quercetin and its novel molecular mechanism of action on breast cancer associated hepatic inflammation and fibrosis via Vitamin D receptor (VDR).

Main methods

We used Ehrlich Ascites Carcinoma (mouse mammary carcinoma) model for our in-vivo experiments and human breast cancer cell lines for in-vitro assays. We inoculated 1.5 × 10⁶ Ehrlich ascites carcinoma cells into female Swiss albino mice. Quercetin (50 mg/kg) was administered intraperitoneally for 15 days. Liver enzymes activity was determined using a spectrophotometric assay. The hallmarks of inflammation and fibrosis were determined using Immunohistochemistry. The effect of quercetin on tumor formation was elucidated using human breast cancer cell lines and chick chorioallantoic membrane assay. Docking study was performed to explore the binding mode of quercetin with VDR.

Key findings

In EAC tumor-bearing mice, cell numbers, tumor volume, body weight and liver weight were dramatically increased, while they significantly decreased in mice treated with quercetin. Additionally, the peritoneal neo-angiogenesis was also significantly suppressed in the quercetin-treated mice, compared to the control. In addition, quercetin treated EAC tumor bearing mice had lower levels of liver enzymes, decreased hepatic inflammation and fibrosis compared with EAC tumor bearing mice. Docking study confirmed VDR-quercetin interaction. Furthermore, in-vitro assays and chick chorioallantoic membrane assay revealed the Vitamin D mimicking effect of quercetin.

Significance

Dietary flavonoid, quercetin could act as a promising therapeutic drug to suppress the breast cancer induced tumor angiogenesis, hepatic inflammation, and fibrosis possibly via activation of VDR.

High Procalcitonin, C-Reactive Protein, and α-1 Acid Glycoprotein Levels in Whole Blood Samples Could Help Rapid Discrimination of Active Tuberculosis from Latent Tuberculosis Infection and Healthy Individuals

Tuberculosis (TB) management is important for prompt discrimination of latent TB infection (LTBI) from active TB and proper treatment. Whole blood Interferon-gamma (IFN-γ) release assay (IGRA) is used to diagnose LTBI based on the secretion of IFN-γ by T-cells in the whole blood by using a specific antigen of Mycobacterium tuberculosis. However, the ability of IGRA to distinguish active TB from LTBI is considerably limited. Distinguishing active TB from LTBI is necessary to identify indicators that can be used to effectively manage TB and develop diagnostic methods. In the present study, we used a Luminex multiplex bead array (a bead-based antibody−antigen sandwich method). The whole blood level of acute phase proteins (APPs), such as endoglin (ENG), procalcitonin (PCT), C-reactive protein (CRP), and α1-acid glycoprotein (AGP), in active TB, LTBI, and healthy individuals were analyzed and quantified. The APP test results for the serum and whole blood samples showed that the levels of PCT, CRP, and AGP were significantly increased (p < 0.0500; area under curve = 0.955) in active TB. The level of these markers in the whole blood of active TB, LTBI, and healthy individuals could provide data for effective diagnosis and treatment of TB.

MYBL1 induces transcriptional activation of ANGPT2 to promote tumor angiogenesis and confer sorafenib resistance in human hepatocellular carcinoma

Angiogenesis is considered as an important process in tumor growth, metastasis of hepatocellular carcinoma (HCC) and associated with cancer progression, suggesting that an important research and development field of clinical molecular targeted drugs for HCC. However, the molecular mechanisms underlying tumor angiogenesis in HCC remains elusive. In the current study, we demonstrate that upregulation of AMYB proto-oncogene-like 1 (MYBL1) was associated with high endothelial vessel (EV) density and contributed to poor prognosis of HCC patient. Functionally, MYBL1 overexpressing enhanced the capacity of HCC cells to induce tube formation, migration of HUVECs, neovascularization in CAMs, finally, enhanced HCC cells metastasis, while silencing MYBL1 had the converse effect. Furthermore, HCC cells with high MYBL1 expression were more resistance to sorafenib treatment. We observed that CD31 staining was significantly increased in tumors formed by MYBL1-overexpressing cells but decreased in MYBL1-silenced tumors. Mechanistically, MYBL1 binds to the ANGPT2 promoter and transcriptionally upregulate ANGPT2 mRNA expression. Strikingly, treatment with monoclonal antibody against ANGPT2 significantly inhibited the growth of MYBL1-overexpressing tumors and efficiently impaired angiogenesis. Furthermore, the histone post-translational factors: protein arginine methyltransferase 5 (PRMT5), MEP50, and WDR5 were required for MYBL1-mediated ANGPT2 upregulation. Importantly, we confirmed the correlation between MYBL1 and ANGPT2 expression in a large cohort of clinical HCC samples and several published datasets in pancreatic cancer, esophageal carcinoma, stomach adenocarcinoma, and colon cancer. Our results demonstrate that MYBL1 upregulated the ANGPT2 expression, then induced angiogenesis and confer sorafenib resistance to HCC cells, and MYBL1 may represent a novel prognostic biomarker and therapeutic target for patients with HCC.

Myocardial Ischemia Related to Common Cancer Therapy-Prevention Insights

Modern antineoplastic therapy improves survival and quality of life in cancer patients, but its indisputable benefits are accompanied by multiple and major side effects, such as cardiovascular ones. Endothelial dysfunction, arterial spasm, intravascular thrombosis, and accelerated atherosclerosis affect the coronary arteries, leading to acute and chronic coronary syndromes that negatively interfere with the oncologic treatment. The cardiac toxicity of antineoplastic agents may be mitigated by using adequate prophylactic measures. In the absence of dedicated guidelines, our work provides the most comprehensive, systematized, structured, and up-to-date analyses of the available literature focusing on measures aiming to protect the coronary arteries from the toxicity of cancer therapy. Our work facilitates the implementation of these measures in daily practice. The ultimate goal is to offer clinicians the necessary data for a personalized therapeutic approach for cancer patients receiving evidence-based oncology treatments with potential cardiovascular toxicity.

Therapeutic approach for digestive system cancers and potential implications of exercise under hypoxia condition: what little is known? a narrative review

BACKGROUND

Cancer, like other chronic pathologies, is associated with the presence of hypoxic regions due to the uncontrolled cell growth. Under this pathological hypoxic condition, various molecular signaling pathways are activated to ensure cell survival, such as those that govern angiogenesis, erythropoiesis, among others. These molecular processes are very similar to the physiological response caused by exposure to altitude (natural hypobaric systemic hypoxia), the use of artificial hypoxia devices (systemic normobaric simulated hypoxia) or the delivery of vascular occlusion to the extremities (also called local hypoxia by the blood flow restriction technique). "Tumor hypoxia" has gained further clinical importance due to its crucial role in both tumor progression and resistance to treatment. However, the ability to manipulate this pathway through physical exercise and systemic hypoxia-mediated signaling pathways could offer an important range of therapeutic opportunities that should be further investigated.

METHODS

This review is focused on the potential implications of systemic hypoxia combined with exercise in digestive system neoplasms prognosis. Articles included in the review were retrieved by searching among the three main scientific databases: PubMed, Scopus, and Embase.

FINDINGS

The findings of this review suggest that exercise performed under systemic hypoxic conditions could have a positive impact in prognosis and quality of life of the population with digestive system cancers.

CONCLUSIONS

Further studies are needed to consider this paradigm as a new potential intervention in digestive oncological population.

Safety of ramucirumab treatment in patients with advanced hepatocellular carcinoma and elevated alpha-fetoprotein

INTRODUCTION

Hepatocellular carcinoma (HCC) is the second most common cause of cancer-induced deaths worldwide, and limited therapeutic options are available for patients with advanced disease. Ramucirumab, a monoclonal antibody that blocks the vascular endothelial growth factor (VEGF) receptor-2, is the first biomarker-selected systemic agent with therapeutic efficacy, tolerability, and favorable patient-reported outcomes in patients with advanced HCC and elevated serum α-fetoprotein levels ≥400 ng/mL, who are resistant or intolerant to sorafenib therapy. However, treatment-induced adverse events (AEs), such as hypertension, proteinuria, bleeding, thromboembolism, and gastrointestinal perforation remain challenging and potentially fatal concerns.

AREAS COVERED

This review discusses the published or ongoing studies and subgroup analyses on ramucirumab therapy in patients with advanced HCC. We present information on the risks of ramucirumab-induced common or rare AEs and their management.

EXPERT OPINION

Ramucirumab toxicity secondary to VEGF inhibition is similar to the AEs that are known to be associated with other VEGF-blocking antibodies. Common AEs can be safely treated using conventional measures; however, rare and potentially fatal AEs necessitate close monitoring. With regard to the safety profile, more promising ramucirumab-containing combination therapies are likely to pave the future path for effective HCC treatment.

Recent advances in systemic therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common and lethal malignant tumors in the world. Therapeutic options for advanced HCC are limited. Systemic treatment, especially with conventional cytotoxic drugs, is usually ineffective. For more than a decade, sorafenib has been the only systemic drug that has been proven to be clinically effective for treating advanced HCC. However, over the past three years, the rapid progress of molecular targeted therapies has dramatically changed the treatment landscape for advanced HCC. Immune checkpoint therapies are now being incorporated into HCC therapies, and their combination with molecular targeted therapy is emerging as a tool to enhance the immune response. In this review, we summarize the development and progress of molecular targeted agents and immunotherapies in HCC.

Potential therapeutic strategies to combat HCC

Hepatocellular carcinoma (HCC) is a complex, life threatening and most common neoplasm in the world. HCC tumors are genetically and phenotypically heterogeneous and involve various molecular mechanisms and stimulation of several signaling pathways such as Vascular Endothelial Growth Factor, Epidermal Growth Factor Receptors (EGFR), Insulin growth factor, Ras/extracellular signal-stimulated kinase, mammalian goal of rapamycin (mTOR), c-mesenchymal-epithelial transition factor-1 (c-Met), Hedgehog, Wnt and apoptotic signaling. Lately, in patient's multi-kinase cascade blockers such as sorafenib, selumetinib and regorafenib have increased survival rate of progressive HCC. This development presents a step forward towards the therapy of liver cancer infection and attests that molecular systemic rehabilitations can be useful in HCC treatment. The development of these systemic therapeutic agents has further expanded the research area for surplus molecular mediators to auxiliary increase cure rate of patients. This article reviews the complete consideration of focus on cascades, current enduring clinical tests by means of HCC therapeutic mediators, and imminent prospects in the cure of HCC.

Revealing the suppressive role of protein kinase C delta and p38 mitogen-activated protein kinase (MAPK)/NF-κB axis associates with lenvatinib-inhibited progression in hepatocellular carcinoma in vitro and in vivo

Nuclear factor-kappa B (NF-κB), an oncogenic transcription factor, modulates tumor formation and progression by inducing the expression of oncogenes involved in proliferation, survival, angiogenesis, and metastasis. Oral multikinase inhibitors, such as sorafenib, regorafenib, and lenvatinib have been used for the treatment of hepatocellular carcinoma (HCC). Both sorafenib and regorafenib were shown to abolish the NF-κB-mediated progression of HCC. However, the effect of lenvatinib on NF-κB-mediated progression of HCC is ambiguous. Therefore, the primary purpose of the present study was to evaluate the inhibitory effect of lenvatinib and its inhibitory mechanism on the NF-κB-mediated progression of HCC in vitro and in vivo. Here, we used two HCC cell lines to identify the cytotoxicity, apoptosis and metastasis effect of lenvatinib. We also applied a Hep3B-bearing animal model to investigate the therapeutic efficacy of lenvatinib on in vivo model. An NF-κB translocation assay, NF-κB reporter gene assay, a Western blotting assay and immunohistochemistry staining were used to investigate the underlying mechanism by which lenvatinib acts on HCC. In this study, we demonstrated that lenvatinib induced extrinsic/intrinsic apoptosis and suppressed the metastasis of HCC both in vitro and in vivo. Lenvatinib may also suppress NF-κB translocation and activation. We also found both protein kinase C delta (PKC-δ) and p38 mitogen-activated protein kinase (MAPK) inactivation participated in lenvatinib-reduced NF-κB signaling. In conclusion, this study reveals that the suppression of PKC-δ, and the p38 MAPK/NF-κB axis is associated with the lenvatinib-inhibited progression of HCC in vitro and in vivo.

Establishment of a 3D model of tumor-driven angiogenesis to study the effects of anti-angiogenic drugs on pericyte recruitment

Hepatocellular carcinoma (HCC), as a well-vascularized tumor, has attracted increasing attention in antiangiogenic therapies. Notably, emerging studies reveal that the long-term administration of antiangiogenic drugs induces hypoxia in tumors. Pericytes, which play a vital role in vascular stabilization and maturation, have been documented to be associated with antiangiogenic drug-induced tumor hypoxia. However, the role of antiangiogenic agents in regulating pericyte behavior still remains elusive. In this study, by using immunostaining analysis, we first demonstrated that tumors obtained from HCC patients were highly angiogenic, in which vessels were irregularly covered by pericytes. Therefore, we established a new 3D model of tumor-driven angiogenesis by culturing endothelial cells, pericytes, cancer stem cells (CSCs) and mesenchymal stem cells (MSCs) with microcarriers in order to investigate the effects and mechanisms exerted by antiangiogenic agents on pericyte recruitment during tumor angiogenesis. Interestingly, microcarriers, as supporting matrices, enhanced the interactions between tumor cells and the extracellular matrix (ECM), promoted malignancy of tumor cells and increased tumor angiogenesis within the 3D model, as determined by qRT-PCR and immunostaining. More importantly, we showed that zoledronic acid (ZA) reversed the inhibited pericyte recruitment, which was induced by sorafenib (Sora) treatment, through fostering the expression and activation of ErbB1/ErbB2 and PDGFR-β in pericytes, in both an in vitro 3D model and an in vivo xenograft HCC mouse model. Hence, our model provides a more pathophysiologically relevant platform for the assessment of therapeutic effects of antiangiogenic compounds and identification of novel pharmacological targets, which might efficiently improve the benefits of antiangiogenic treatment for HCC patients.

Role of Virus-Related Chronic Inflammation and Mechanisms of Cancer Immune-Suppression in Pathogenesis and Progression of Hepatocellular Carcinoma

Simple Summary

Hepatocellular carcinoma pathogenesis is dependent on a chronic inflammation caused by several factors, including hepatotropic viruses, such as HCV and HBV. This chronic inflammation is established in the context of the immunotolerogenic environment peculiar of the liver, in which the immune system can be stimulated by HCV and HBV viral antigens. This complex interaction can be influenced by direct-acting antiviral drug treatments, capable of (almost totally) rapidly eradicating HCV infection. The influence of anti-viral treatments on HCC pathogenesis and progression remains to be fully clarified.

Abstract

Hepatocellular carcinoma (HCC) can be classified as a prototypical inflammation-driven cancer that generally arises from a background of liver cirrhosis, but that in the presence of nonalcoholic steatohepatitis (NASH), could develop in the absence of fibrosis or cirrhosis. Tumor-promoting inflammation characterizes HCC pathogenesis, with an epidemiology of the chronic liver disease frequently encompassing hepatitis virus B (HBV) or C (HCV). HCC tumor onset and progression is a serial and heterogeneous process in which intrinsic factors, such as genetic mutations and chromosomal instability, are closely associated with an immunosuppressive tumor microenvironment (TME), which may have features associated with the etiopathogenesis and expression of the viral antigens, which favor the evasion of tumor neoantigens to immune surveillance. With the introduction of direct-acting antiviral (DAA) therapies for HCV infection, sustained virological response (SVR) has become very high, although occurrence of HCC and reactivation of HBV in patients with co-infection, who achieved SVR in short term, have been observed in a significant proportion of treated cases. In this review, we discuss the main molecular and TME features that are responsible for HCC pathogenesis and progression. Peculiar functional aspects that could be related to the presence and treatment of HCV/HBV viral infections are also dealt with.

Recent advances of immunotherapy for biliary tract cancer

Introduction: Biliary tract cancer (BTC) is a heterogeneous group of aggressive malignancies comprising intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma, gallbladder cancer, and ampulla of Vater cancer. Although recent years have witnessed the emergence of novel treatment targets, medical therapy remains a compelling challenge in these hepatobiliary malignancies. In order to provide more effective treatment options, immune checkpoint inhibitors (ICIs) are currently under investigation in advanced BTC, with controversial results reported so far.Areas covered: This review provides an overview regarding current scenario of ICIs and immune-based combinations in advanced BTC, where several novel treatments are currently being developed, some of which have suggested interesting efficacy in recent clinical trials. In addition, we provide a report of ongoing Phase I to III clinical trials assessing ICIs and new immunotherapeutic strategies for advanced BTC.Expert opinion: Although immunotherapy has revolutionized the treatment landscape of several hematological and solid tumors, the role of ICIs and immune-based combinations in advanced BTC is still unclear. Despite ICI monotherapy has reported limited efficacy in this setting, the durable responses observed in sporadic cases suggest that testing patients for MMR, MSI, TMB, and PD-L1 expression is warranted. Results of currently ongoing trials are highly awaited.

The Role of Endoglin in Hepatocellular Carcinoma

Endoglin (CD105) is a type-1 integral transmembrane glycoprotein and coreceptor for transforming growth factor-β (TGF-β) ligands. The endoglin/TGF-β signaling pathway regulates hemostasis, cell proliferation/migration, extracellular matrix (ECM) synthesis and angiogenesis. Angiogenesis contributes to early progression, invasion, postoperative recurrence, and metastasis in hepatocellular carcinoma (HCC), one of the most widespread malignancies globally. Endoglin is overexpressed in newly formed HCC microvessels. It increases microvessel density in cirrhotic and regenerative HCC nodules. In addition, circulating endoglin is present in HCC patients, suggesting potential for use as a diagnostic or prognostic factor. HCC angiogenesis is dynamic and endoglin expression varies by stage. TRC105 (carotuximab) is an antibody against endoglin, and three of its clinical trials were related to liver diseases. A partial response was achieved when combining TRC105 with sorafenib. Although antiangiogenic therapy still carries some risks, combination therapy with endoglin inhibitors or other targeted therapies holds promise.

Angiogenesis in the progression from liver fibrosis to cirrhosis and hepatocelluar carcinoma

Introduction: Persistent inflammation and hypoxia are strong stimulus for pathological angiogenesis and vascular remodeling, and are also the most important elements resulting in liver fibrosis. Sustained inflammatory process stimulates fibrosis to the end-point of cirrhosis and sinusoidal portal hypertension is an important feature of cirrhosis. Neovascularization plays a pivotal role in collateral circulation formation of portal vein, mesenteric congestion, and high perfusion. Imbalance of hepatic artery and portal vein blood flow leads to the increase of hepatic artery inflow, which is beneficial to the formation of nodules. Angiogenesis contributes to progression from liver fibrosis to cirrhosis and hepatocellular carcinoma (HCC) and anti-angiogenesis therapy can improve liver fibrosis, reduce portal pressure, and prolong overall survival of patients with HCC. Areas covers: This paper will try to address the difference of the morphological characteristics and mechanisms of neovascularization in the process from liver fibrosis to cirrhosis and HCC and further compare the different efficacy of anti-angiogenesis therapy in these three stages. Expert opinion: More in-depth understanding of the role of angiogenesis factors and the relationship between angiogenesis and other aspects of the pathogenesis and transformation may be the key to enabling future progress in the treatment of patients with liver fibrosis, cirrhosis, and HCC.

Cooperative Role of Thrombopoietin and Vascular Endothelial Growth Factor-A in the Progression of Liver Cirrhosis to Hepatocellular Carcinoma

Primary thrombopoietic mediator thrombopoietin (THPO) is mainly produced by the liver; it may act as a growth factor for hepatic progenitors. Principal angiogenesis inducer vascular endothelial growth factor-A (VEGF-A) is critical for the complex vascular network within the liver architecture. As a cross-regulatory loop between THPO and VEGF-A has been demonstrated in the hematopoietic system, the two growth factors were hypothesized to cooperatively contribute to the progression from liver cirrhosis (LC) to hepatocellular carcinoma (HCC). The mRNA and protein expression levels of THPO, VEGF-A, and their receptors were examined, compared, and correlated in paired cancerous and LC tissues from 26 cirrhosis-related HCC patients, using qRT-PCR and immunohistochemistry. THPO and VEGF-A were alternatively silenced by small interfering RNA (siRNA) in human liver cancer cell lines Huh7 and HepG2. THPO and VEGF-A expressions significantly increased in tumor versus LC tissues. HCC and paired LC cells expressed similar levels of THPO receptor (R), whereas vascular endothelial growth factor receptor (VEGFR) -1 and VEGFR-2 levels were higher in HCC than in corresponding LC tissue samples. A significant linear correlation emerged between THPO and VEGF-A transcripts in HCC and, at the protein level, THPO and THPOR were significantly correlated with VEGF-A in tumor tissues. Both HCC and LC expressed similar levels of gene and protein hypoxia inducible factor (HIF)-1α. Positive cross-regulation occurred with the alternative administration of siRNAs targeting THPO and those targeting VEGF-A in hypoxic liver cancer cell lines. These results suggest THPO and VEGF-A might act as interdependently regulated autocrine and/or paracrine systems for cellular growth in HCC. This might be clinically interesting, since new classes of THPOR agonistic/antagonistic drugs may provide novel therapeutic options to correct the frequent hemostatic abnormality seen in HCC patients.

The role of hypoxia in the tumor microenvironment and development of cancer stem cell: a novel approach to developing treatment

Hypoxia is a common feature of solid tumors, and develops because of the rapid growth of the tumor that outstrips the oxygen supply, and impaired blood flow due to the formation of abnormal blood vessels supplying the tumor. It has been reported that tumor hypoxia can: activate angiogenesis, thereby enhancing invasiveness and risk of metastasis; increase survival of tumor, as well as suppress anti-tumor immunity and hamper the therapeutic response. Hypoxia mediates these effects by several potential mechanisms: altering gene expression, the activation of oncogenes, inactivation of suppressor genes, reducing genomic stability and clonal selection. We have reviewed the effects of hypoxia on tumor biology and the possible strategiesto manage the hypoxic tumor microenvironment (TME), highlighting the potential use of cancer stem cells in tumor treatment.

Immune Checkpoint Inhibitors in the Treatment of HCC

Hepatocellular carcinoma (HCC) is the typical inflammation-induced neoplasia. It often prospers where a chronic liver disease persists, thus leading a strong rationale for immune therapy. Several immune-based treatments, including immune checkpoint inhibitors (ICI), cytokines, adoptive cell transfer, and vaccines, have been tested in the treatment of HCC. In this review, we summarize the role of the ICI in HCC patients in various sets of treatment. As for advanced HCC, the anti-Programmed cell Death protein 1 (PD1) antibodies and the anti-Cytotoxic T-Lymphocyte Antigen 4 (CTLA-4) antibodies have been examined in patients with enthusiastic results in phase I-II-III studies. Overall, this led the Food and Drug Administration (FDA) to approve pembrolizumab, nivolumab, and nivolumab + ipilimumab in the second-line setting. The anti- Programmed Death-Ligand 1 (PDL-1) antibodies have also been evaluated. Thanks to the results obtained from phase III IMbrave study, atezolizumab + bevacizumab is now the standard of care in the first-line advanced setting of HCC. As for localized HCC, the putative immunological effect of locoregional therapies led to evaluate the combination strategy with ICI. This way, chemoembolization, ablation with radiofrequency, and radioembolization combined with ICI are currently under study. Likewise, the study of adjuvant immunotherapy following surgical resection is underway. In addition, the different ICI has been studied in combination with other ICI as well as with multikinase inhibitors and anti-angiogenesis monoclonal antibody. The evidence available suggests that combining systemic therapies and locoregional treatments with ICI may represent an effective strategy in this context.

Diarylureas as Antitumor Agents

The diarylurea is a scaffold of great importance in medicinal chemistry as it is present in numerous heterocyclic compounds with antithrombotic, antimalarial, antibacterial, and anti-inflammatory properties. Some diarylureas, serine-threonine kinase or tyrosine kinase inhibitors, were recently reported in literature. The first to come into the market as an anticancer agent was sorafenib, followed by some others. In this review, we survey progress over the past 10 years in the development of new diarylureas as anticancer agents.

Microvasculature in hepatocellular carcinoma: An ultrastructural study

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most vascularized tumor types, and is characterized by development of heterogeneous immature vessels with increased permeability. Here, we analyzed morphology and vascular permeability-related structures in endothelial cells of HCC microvessels.

METHODS

Small (Type I) and large (Type II) peritumoral blood microvessels were assessed in HCC-bearing mice. By transmission electron microscopy, endothelial cell cytoplasm area, free transport vesicles, vesiculo-vacuolar organelles and clathrin-coated vesicles were measured.

RESULTS

The phenotypic changes in the HCC microvessels included presence of sinusoidal capillarization, numerous luminal microprocesses and abnormal luminal channels, irregular dilatations of interendothelial junctions, local detachment of basement membranes and widened extracellular space. Endothelial cells Type I microvessels showed increased vesicular trafficking-related structures.

CONCLUSION

Ultrastructural characteristics of microvessels Type I can associate with HCC new-formed microvessels. The morphological changes observed in HCC microvessels might explain the increased transcellular and paracellular permeability in HCC endothelial cells.

Design, synthesis, biological evaluation, and modeling studies of novel conformationally-restricted analogues of sorafenib as selective kinase-inhibitory antiproliferative agents against hepatocellular carcinoma cells

Sorafenib is one of the clinically used anticancer agents that inhibits several kinases. In this study, novel indole-based rigid analogues of sorafenib were designed and synthesized in order to enhance kinase selectivity and hence minimize the side effects associated with its use. The target compounds possess different linkers; urea, amide, sulfonamide, or thiourea, in addition to different terminal aryl moieties attached to the linker in order to investigate their impact on biological activity. They were tested against Hep3B, Huh7, and Hep-G2 hepatocellular carcinoma (HCC) cell lines to study their potency. Among all the tested target derivatives, compound 1h exerted superior antiproliferative potency against all the three tested HCC cell lines compared to sorafenib. Based on these preliminary results, compound 1h was selected for further biological and in silico investigations. Up to 30 μM, compound 1h did not inhibit 50% of the proliferation of WI-38 normal cells, which indicated promising selectivity against HCC cells than normal cells. In addition, compound 1h exerted superior kinase selectivity than sorafenib. It is selective for VEGFR2 and VEGFR3 angiogenesis-related kinases, while sorafenib is a multikinase inhibitor. Superior kinase selectivity of compound 1h to sorafenib can be attributed to its conformationally-restricted indole nucleus and the bulky N-methylpiperazinyl moiety. Western blotting was carried out and confirmed the ability of compound 1h to inhibit VEGFR2 kinase inside Hep-G2 HCC cells in a dose-dependent pattern. Compound 1h induces apoptosis and necrosis in Hep-G2 cell line, as shown by caspase-3/7 and lactate dehydrogenase (LDH) release assays, respectively. Moreover, compound 1h is rather safe against hERG. Thus, we could achieve a more selective kinase inhibitor than sorafenib with retained or even better antiproliferative potency against HCC cell lines. Furthermore, molecular docking and dynamic simulation studies were carried out to investigate its binding mode with VEGFR2 kinase. The molecule has a unique orientation upon binding with the kinase.

Morphological Analysis of Blood Capillaries and Transport Function of Endothelial Cells in Hepatocellular Carcinoma-29

Hepatocellular carcinoma is characterized by the pronounced vascularization, high levels of vascular endothelial growth factors, and intensive angiogenesis. Caveola-mediated endocytosis and clathrin-dependent endocytosis contribute to internalization of various growth factors, thus affecting blood supply to the tumor and neoangiogenesis. We performed a quantitative analysis of blood vessels in the tumor and evaluated the basal levels of endocytosis-associated vesicular structures in the endothelial cells of the hepatocellular carcinoma-29. The numbers of blood vessels and clathrin-coated vesicles in endothelial cells in the tumor tissue were significantly higher than in normal tissue. The association between clathrin-dependent endocytosis in the endotheliocytes of the capillaries and tumor angiogenesis can provide the basis for the development of new molecular targets for antiangiogenic antitumor therapy.

Programmable Synthetic Protein Circuits for the Identification and Suppression of Hepatocellular Carcinoma

Precisely identifying and killing tumor cells are diligent pursuits in oncotherapy. Synthesized gene circuits have emerged as an intelligent weapon to solve these problems. Gene circuits based on post-transcriptional regulation enable a faster response than systems based on transcriptional regulation, which requires transcription and translation, showing superior safety. In this study, synthetic-promoter-free gene circuits possessing two control layers were constructed to improve the specific recognition of tumor cells. Using split-TEV, we designed and verified the basic control layer of protein-protein interaction (PPI) sensing. Another orthogonal control layer was built to sense specific proteins. Two layers were integrated to generate gene circuits sensing both PPI and specific proteins, forming 10 logic gates. To demonstrate the utility of this system, the circuit was engineered to sense alpha-fetoprotein (AFP) expression and the PPI between YAP and 14-3-3σ, the matching profile of hepatocellular carcinoma (HCC). Gene-circuit-loaded cells distinguished HCC from other cells and released therapeutic antibodies, exhibiting in vitro and in vivo therapeutic effects.

Glucose Metabolism and Oxidative Stress in Hepatocellular Carcinoma: Role and Possible Implications in Novel Therapeutic Strategies

Hepatocellular carcinoma (HCC) metabolism is redirected to glycolysis to enhance the production of metabolic compounds employed by cancer cells to produce proteins, lipids, and nucleotides in order to maintain a high proliferative rate. This mechanism drives towards uncontrolled growth and causes a further increase in reactive oxygen species (ROS), which could lead to cell death. HCC overcomes the problem generated by ROS increase by increasing the antioxidant machinery, in which key mechanisms involve glutathione, nuclear factor erythroid 2-related factor 2 (Nrf2), and hypoxia-inducible transcription factor (HIF-1α). These mechanisms could represent optimal targets for innovative therapies. The tumor microenvironment (TME) exerts a key role in HCC pathogenesis and progression. Various metabolic machineries modulate the activity of immune cells in the TME. The deregulated metabolic activity of tumor cells could impair antitumor response. Lactic acid-lactate, derived from the anaerobic glycolytic rate of tumor cells, as well as adenosine, derived from the catabolism of ATP, have an immunosuppressive activity. Metabolic reprogramming of the TME via targeted therapies could enhance the treatment efficacy of anti-cancer immunotherapy. This review describes the metabolic pathways mainly involved in the HCC pathogenesis and progression. The potential targets for HCC treatment involved in these pathways are also discussed.

Immune Phenotype and Immune Checkpoint Inhibitors for the Treatment of Human Hepatocellular Carcinoma

Immunotherapies are promising approaches for treating hepatocellular carcinomas (HCCs) refractory to conventional therapies. However, a recent clinical trial of immune checkpoint inhibitors (ICIs) revealed that anti-tumor responses to ICIs are not satisfactory in HCC cases. Therefore, it is critical to identify molecular markers to predict outcome and develop novel combination therapies that enhance the efficacy of ICIs. Recently, several attempts have been made to classify HCC based on genome, epigenome, and transcriptome analyses. These molecular classifications are characterized by unique clinical and histological features of HCC, as well immune phenotype. For example, HCCs exhibiting gene expression patterns with proliferation signals and stem cell markers are associated with the enrichment of immune infiltrates in tumors, suggesting immune-proficient characteristics for this type of HCC. However, the presence of activating mutations in β-catenin represents a lack of immune infiltrates and refractoriness to ICIs. Although the precise mechanism that links the immunological phenotype with molecular features remains controversial, it is conceivable that alterations of oncogenic cellular signaling in cancer may lead to the expression of immune-regulatory molecules and result in the acquisition of specific immunological microenvironments for each case of HCC. Therefore, these molecular and immune characteristics should be considered for the management of HCC using immunotherapy.

Angiopoietin-2 induces angiogenesis via exosomes in human hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and is a highly vascularized solid tumor. Angiopoietin-2 (ANGPT2) has been described as an attractive target for antiangiogenic therapy. Exosomes are small extracellular vesicles secreted by most cell types and contribute to cell-to-cell communication by delivering functional cargo to recipient cells. The expression of ANGPT2 in tumor-derived exosomes remains unknown.

Methods

We detected the ANGPT2 expression in HCC-derived exosomes by immunoblotting, enzyme-linked immunosorbent assay and immunogold labeling, then observed exosomal ANGPT2 internalization and recycling by confocal laser scanning microscopy, co-immunoprecipitation and immunoblotting. We used two HCC cell lines (Hep3B and MHCC97H) to overexpress ANGPT2 by lentivirus infection or knockdown ANGPT2 by the CRISPR/Cas system, then isolated exosomes to coculture with human umbilical vein endothelial cells (HUVECs) and observed the angiogenesis by Matrigel microtubule formation assay, transwell migration assay, wound healing assay, cell counting kit-8 assay, immunoblotting and in vivo tumorigenesis assay.

Results

We found that HCC-derived exosomes carried ANGPT2 and delivered it into HUVECs by exosome endocytosis, this delivery led to a notable increase in angiogenesis by a Tie2-independent pathway. Concomitantly, we observed that HCC cell-secreted exosomal ANGPT2 was recycled by recipient HUVECs and might be reused. In addition, the CRISPR-Cas systems to knock down ANGPT2 significantly inhibited the angiogenesis induced by HCC cell-secreted exosomal ANGPT2, and obviously suppressed the epithelial-mesenchymal transition activation in HCC.

Conclusions

Taken together, these results reveal a novel pathway of tumor angiogenesis induced by HCC cell-secreted exosomal ANGPT2 that is different from the classic ANGPT2/Tie2 pathway. This way may be a potential therapeutic target for antiangiogenic therapy.

LOXL2 upregulates hypoxia‑inducible factor‑1α signaling through Snail‑FBP1 axis in hepatocellular carcinoma cells

Lysyl oxidase‑like 2 (LOXL2), a member of the lysyl oxidase gene family, is involved in the progression of hepatocellular carcinoma progression and metastasis. Increased expression of LOXL2 has been identified in several types of cancer, including hepatocellular carcinoma. Recently, LOXL2 has been reported to promote epithelial‑mesenchymal transition by reducing E‑cadherin expression via the upregulation of Snail expression. The present study provided evidence demonstrating that LOXL2 inhibited the expression of fructose‑1, 6‑biphosphatase (FBP1) and enhanced the glycolysis of Huh7 and Hep3B hepatocellular carcinoma cell lines in a Snail‑dependent manner. Overexpression of the point‑mutated form of LOXL2 [LOXL2(Y689F)], which lacks enzymatic activity, does not affect the expression of Snail1 or FBP1. Notably, targeting extracellular LOXL2 of Huh7 cells with a therapeutic antibody was unable to abolish its regulation on the expression of Snail and FBP1. Knockdown of LOXL2 also interrupted the angiogenesis of Huh7 and Hep3B cells, and this effect could be rescued by the overexpression of Snail. Furthermore, upregulation of hypoxia‑inducible factor 1α (HIF‑1α) and vascular endothelial growth factor (VEGF) expression was observed in Huh7 and Hep3B cells expressing wild‑type LOXL2. Notably, the selective LOXL2 inhibitor LOXL2‑IN‑1 could upregulate the expression of FBP1 and inhibit the expression of Snail, HIF‑1α and VEGF in HCC cells, but not in FBP1‑knockdown cells. The results of the present study indicated that the intracellular activity of LOXL2 upregulated HIF‑1α/VEGF signaling pathways via the Snail‑FBP1 axis, and this phenomenon could be inhibited by LOXL2 inhibition. Collectively, these findings further support that LOXL2 exhibits an important role in the progression of hepatocellular carcinoma and implicates LOXL2 as a potential therapeutic agent for the treatment of this disease.

Targeting Receptor Tyrosine Kinase VEGFR-2 in Hepatocellular Cancer: Rational Design, Synthesis and Biological Evaluation of 1,2-Disubstituted Benzimidazoles

In this study, a novel series of 1,2-disubstituted benzo[d]imidazoles was rationally designed as VEGFR-2 inhibitors targeting hepatocellular carcinoma. Our design strategy is two-fold; it aimed first at studying the effect of replacing the 5-methylfuryl moiety of the well-known antiangiogenic 2-furylbenzimidazoles with an isopropyl moiety on the VEGFR-2 inhibitory activity and the cytotoxic activity. Our second objective was to further optimize the structures of the benzimidazole derivatives through elongation of the side chains at their one-position for the design of more potent type II-like VEGFR-2 inhibitors. The designed 1,2-disubstituted benzimidazoles demonstrated potent cytotoxic activity against the HepG2 cell line, reaching IC₅₀ = 1.98 μM in comparison to sorafenib (IC₅₀ = 10.99 μM). In addition, the synthesized compounds revealed promising VEGFR-2 inhibitory activity in the HepG2 cell line, e.g., compounds 17a and 6 showed 82% and 80% inhibition, respectively, in comparison to sorafenib (% inhibition = 92%). Studying the effect of 17a on the HepG2 cell cycle demonstrated that 17a arrested the cell cycle at the G2/M phase and induced a dose-dependent apoptotic effect. Molecular docking studies of the synthesized 1,2-disubstituted benzimidazoles in the VEGFR-2 active site displayed their ability to accomplish the essential hydrogen bonding and hydrophobic interactions for optimum inhibitory activity.

Molecular therapies for HCC: Looking outside the box

Over the past decade, sorafenib has been the only systemic agent with proven clinical efficacy for patients with unresectable hepatocellular carcinoma (HCC). Recently, lenvatinib was shown to be non-inferior to sorafenib, while regorafenib, cabozantinib, and ramucirumab were shown to be superior to placebo in patients failing sorafenib. In addition, trials of immune checkpoint inhibitors reported encouraging efficacy signals. However, apart from alpha-fetoprotein, which is used to select patients for ramucirumab, no biomarkers are available to identify patients that may respond to a specific treatment. Different synergisms have been postulated based on the potential interplay between antiangiogenic drugs and immunotherapy, with several clinical trials currently testing this hypothesis. Indeed, encouraging preliminary results of phase I studies of bevacizumab plus atezolizumab and lenvatinib plus pembrolizumab have led to the design of ongoing phase III trials, including both antiangiogenics and immune checkpoint inhibitors in the front-line setting. Other important phase II studies have tested molecular therapies directed against different novel targets, such as transforming growth factor-beta, MET (hepatocyte growth factor receptor), and fibroblast growth factor receptor 4. These studies integrated translational research with the aim of better defining the biological tumour profile and identifying tumour and blood biomarkers that select patients who may really benefit from a specific molecular therapy. Importantly, good safety profiles make these drugs suitable for future combinations. In this review, we discuss the most recent data on novel combination strategies and targets, as well as looking ahead to the future role of molecular therapies in the treatment of patients with advanced HCC.