New molecularly targeted therapies against advanced hepatocellular carcinoma: From molecular pathogenesis to clinical trials and future directions

Biomacromolecular carriers based hydrophobic natural products for potential cancer therapy

Cancer is the second leading cause of death worldwide. It was estimated that 90 % of cancer-related deaths were attributable to the development of multi-drug resistance (MDR) during chemotherapy, which results in ineffective chemotherapy. Hydrophobic natural products plays a pivotal role in the field of cancer therapy, with the potential to reverse MDR in tumor cells, thereby enhancing the efficacy of tumor therapy. However, their targeted delivery is considered a major hurdle in their application. The advent of numerous approaches for encapsulating bioactive ingredients in the nanodelivery systems has improved the stability and targeted delivery of these biomolecules. The manuscript comprehensively analyses the nanodelivery systems of bioactive compounds with potential cancer therapy applications, including liposomes, emulsions, solid lipid nanoparticles (NPs), and polymeric NPs. Then, the advantages and disadvantages of various nanoagents in the treatment of various cancer types are critically discussed. Further, the application of multiple-compbine delivery methods to overcome the limitations of single-delivery have need critically analyzed, which thus could help in the designing nanodrug delivery systems for bioactive compounds in clinical settings. Therefore, the review is timely and important for development of efficient nanodelivery systems involving hydrophobic natural products to improve pharmacokinetic properties for effective cancer treatment.

Hepatocellular Carcinoma: Old and Emerging Therapeutic Targets

Liver cancer, predominantly hepatocellular carcinoma (HCC), globally ranks sixth in incidence and third in cancer-related deaths. HCC risk factors include non-viral hepatitis, alcohol abuse, environmental exposures, and genetic factors. No specific genetic alterations are unequivocally linked to HCC tumorigenesis. Current standard therapies include surgical options, systemic chemotherapy, and kinase inhibitors, like sorafenib and regorafenib. Immunotherapy, targeting immune checkpoints, represents a promising avenue. FDA-approved checkpoint inhibitors, such as atezolizumab and pembrolizumab, show efficacy, and combination therapies enhance clinical responses. Despite this, the treatment of hepatocellular carcinoma (HCC) remains a challenge, as the complex tumor ecosystem and the immunosuppressive microenvironment associated with it hamper the efficacy of the available therapeutic approaches. This review explores current and advanced approaches to treat HCC, considering both known and new potential targets, especially derived from proteomic analysis, which is today considered as the most promising approach. Exploring novel strategies, this review discusses antibody drug conjugates (ADCs), chimeric antigen receptor T-cell therapy (CAR-T), and engineered antibodies. It then reports a systematic analysis of the main ligand/receptor pairs and molecular pathways reported to be overexpressed in tumor cells, highlighting their potential and limitations. Finally, it discusses TGFβ, one of the most promising targets of the HCC microenvironment.

Hepatocellular carcinoma: signaling pathways, targeted therapy, and immunotherapy

Hepatocellular carcinoma (HCC) is the most common primary liver cancer with a high mortality rate. It is regarded as a significant public health issue because of its complicated pathophysiology, high metastasis, and recurrence rates. There are no obvious symptoms in the early stage of HCC, which often leads to delays in diagnosis. Traditional treatment methods such as surgical resection, radiotherapy, chemotherapy, and interventional therapies have limited therapeutic effects for HCC patients with recurrence or metastasis. With the development of molecular biology and immunology, molecular signaling pathways and immune checkpoint were identified as the main mechanism of HCC progression. Targeting these molecules has become a new direction for the treatment of HCC. At present, the combination of targeted drugs and immune checkpoint inhibitors is the first choice for advanced HCC patients. In this review, we mainly focus on the cutting-edge research of signaling pathways and corresponding targeted therapy and immunotherapy in HCC. It is of great significance to comprehensively understand the pathogenesis of HCC, search for potential therapeutic targets, and optimize the treatment strategies of HCC.

Influence of Pterostilbene on Gene Expression in Liver Cancer: An In Silico Analysis

Background Liver cancer, in particular, is a serious threat to global health and has few viable treatments. One natural molecule that shows potential in cancer therapy is pterostilbene, especially for hepatocellular carcinoma (HCC). The molecular details of pterostilbene's interactions with liver cancer are uncovered in this study using an in silico method. Methodology This study determines the differentially expressed genes (DEGs) in HCC and the way pterostilbene affects them using data from Gene Expression Omnibus (GEO) datasets. To identify the intricate linkages and possible treatment targets, network pharmacology, protein-protein interaction (PPI) analysis, and pathway enrichment investigations were performed. Results The study revealed complex relationships between pterostilbene and liver cancer, identified important DEGs in HCC, and showed enriched pathways. Pterostilbene shows promise as a target for therapeutic approaches in HCC due to its modulation of important signaling pathways. Conclusions This work offers an extensive knowledge of pterostilbene's potential in liver cancer, despite intrinsic computational limitations. In addition to the importance of experimental validation, the pathways and DEGs that have been found provide insightful information for future investigation, highlighting the ongoing research that is necessary to create targeted therapeutics for HCC.

ReGeNNe: genetic pathway-based deep neural network using canonical correlation regularizer for disease prediction

MOTIVATION

Common human diseases result from the interplay of genes and their biologically associated pathways. Genetic pathway analyses provide more biological insight as compared to conventional gene-based analysis. In this article, we propose a framework combining genetic data into pathway structure and using an ensemble of convolutional neural networks (CNNs) along with a Canonical Correlation Regularizer layer for comprehensive prediction of disease risk. The novelty of our approach lies in our two-step framework: (i) utilizing the CNN's effectiveness to extract the complex gene associations within individual genetic pathways and (ii) fusing features from ensemble of CNNs through Canonical Correlation Regularization layer to incorporate the interactions between pathways which share common genes. During prediction, we also address the important issues of interpretability of neural network models, and identifying the pathways and genes playing an important role in prediction.

RESULTS

Implementation of our methodology into three real cancer genetic datasets for different prediction tasks validates our model's generalizability and robustness. Comparing with conventional models, our methodology provides consistently better performance with AUC improvement of 11% on predicting early/late-stage kidney cancer, 10% on predicting kidney versus liver cancer type and 7% on predicting survival status in ovarian cancer as compared to the next best conventional machine learning model. The robust performance of our deep learning algorithm indicates that disease prediction using neural networks in multiple functionally related genes across different pathways improves genetic data-based prediction and understanding molecular mechanisms of diseases.

AVAILABILITY AND IMPLEMENTATION

https://github.com/divya031090/ReGeNNe.

Therapeutic options in hepatocellular carcinoma: a comprehensive review

Hepatocellular carcinoma (HCC) is a chronic liver disease that is highly fatal if not detected and treated early. The incidence and death rate of HCC have been increasing in recent decades despite the measures taken for preventive screening and effective diagnostic and treatment strategies. The pathophysiology of HCC is multifactorial and highly complex owing to its molecular and immune heterogeneity, and thus the gap in knowledge still precludes making choices between viable therapeutic options and also the development of effective regimens. The treatment of HCC demands multidisciplinary approaches and primarily depends on tumor stage, hepatic functional reserve, and response to treatment by patients. Although curative treatments are limited but critical in the early stages of cancer, there are numerous palliative treatments available for patients with intermediate and advanced-stage HCC. In recent times, the use of combination therapy has succeeded over the use of monotherapy in the treatment of HCC by achieving effective tumor suppression, increasing survival rate, decreasing toxicity, and also aiding in overcoming drug resistance. This work focuses on reviewing the current and emerging treatment strategies for HCC.

ZNF655 promotes the progression of hepatocellular carcinoma through PSMB8

Hepatocellular carcinoma (HCC) is a type of liver cancer that is associated with high mortality rates. This study aims to investigate the role of ZNF655, a member of the zinc finger protein family, in the development of HCC. Immunohistochemical staining analysis was conducted to evaluate the expression of ZNF655 in HCC patient samples. Lentivirus-mediated ZNF655 knockdown was established in HCC cell lines (BEL-7402 and HCCLM3). The effects of ZNF655 on different aspects of HCC cell behavior such as proliferation, apoptosis, cycle, migration and tumor formation were examined. Downstream targets of ZNF655 in HCC were identified and verified through loss/gain-of-function experiments. Clinically, ZNF655 expression was elevated in HCC and increased with the severity of the disease. Functionally, inhibition of ZNF655 expression reduced the progression of HCC cells by decreasing proliferation, causing apoptosis, arresting cell cycle retention in G2, suppressing migration, and attenuating tumor formation in mice. Mechanistically, the proteasome subunit beta type-8 (PSMB8) was found to be co-expressed with ZNF655 in HCC, and PSMB8 knockdown weakened the promotion of ZNF655 overexpression on HCC. In summary, these findings suggest that ZNF655 promotes the progression of HCC through PSMB8, and inhibition of its expression may be a promising therapeutic target for HCC.

Masitinib Inhibits Hepatitis A Virus Replication

The hepatitis A virus (HAV) infection causes acute hepatitis. HAV also induces acute liver failure or acute-on-chronic liver failure; however, no potent anti-HAV drugs are currently available in clinical situations. For anti-HAV drug screening, more convenient and useful models that mimic HAV replication are needed. In the present study, we established HuhT7-HAV/Luc cells, which are HuhT7 cells stably expressing the HAV HM175-18f genotype IB subgenomic replicon RNA harboring the firefly luciferase gene. This system was made by using a PiggyBac-based gene transfer system that introduces nonviral transposon DNA into mammalian cells. Then, we investigated whether 1134 US Food and Drug Administration (FDA)-approved drugs exhibited in vitro anti-HAV activity. We further demonstrated that treatment with tyrosine kinase inhibitor masitinib significantly reduced both HAV HM175-18f genotype IB replication and HAV HA11-1299 genotype IIIA replication. Masitinib also significantly inhibited HAV HM175 internal ribosomal entry-site (IRES) activity. In conclusion, HuhT7-HAV/Luc cells are adequate for anti-HAV drug screening, and masitinib may be useful for the treatment of severe HAV infection.

Exosomes from Ub‑HBcAg‑overexpressing dendritic cells induce T‑lymphocyte differentiation and enhance cytotoxic T‑lymphocyte activity

Hepatitis B virus (HBV) infection is a major public health concern. The clearance of HBV may involve cytotoxic T-lymphocyte (CTL) activity and T helper type 1 reactions. Exosomes generated from dendritic cells (DCs) can induce immunological responses capable of eradicating viruses. However, exosomes loaded with antigens have not yet demonstrated therapeutic potential in HBV infection. Therefore, the present study aimed to investigate the antiviral effects of DC-derived exosomes (Dexs) loaded with ubiquitinated HBV core antigen (Dexs-Ub-HBcAg). Murine bone marrow-derived DCs were loaded with a recombinant lentivector encoding the ubiquitinated form of HBcAg. High-purity Dexs were generated using differential velocity centrifugation. Splenic T-lymphocytes were stimulated with Dexs-Ub-HBcAg and the specific T-cell-mediated immune responses were examined. Cytokine expression was analyzed using enzyme-linked immunosorbent assays. T-lymphocyte proliferation was detected using a Cell Counting Kit-8 assay and HBcAg-specific CTL activity was determined using a lactate dehydrogenase release assay. The results revealed that Dexs-Ub-HBcAg effectively stimulated T-cell proliferation and induced the activation of antigen-specific CTLs to exhibit HBcAg-specific CTL immune responses in vitro. These results suggest the potential of Dexs-Ub-HBcAg for development as a future therapeutic option for the elimination of HBV.

Plant-derived natural products and combination therapy in liver cancer

Liver cancer is one of the malignant cancers globally and seriously endangers human health because of its high morbidity and mortality. Plant-derived natural products have been evaluated as potential anticancer drugs due to low side effects and high anti-tumor efficacy. However, plant-derived natural products also have defects of poor solubility and cumbersome extraction process. In recent years, a growing numbers of plant derived natural products have been used in combination therapy of liver cancer with conventional chemotherapeutic agents, which has improved clinical efficacy through multiple mechanisms, including inhibition of tumor growth, induction of apoptosis, suppression of angiogenesis, enhancement of immunity, reversal of multiple drug resistance and reduction of side effects. The therapeutic effects and mechanisms of plant-derived natural products and combination therapy on liver cancer are reviewed to provide references for developing anti-liver-cancer strategies with high efficacy and low side effects.

New Insights into the Structural Requirements of Isatin-Derived Pro-Apoptotic Agents against Acute Myeloid Leukemia

Searching for bioactive compounds within the huge chemical space is like trying to find a needle in a haystack. Isatin is a unique natural compound which is endowed with different bio-pertinent activities, especially in cancer therapy. Herein, we envisaged that adopting a hybrid strategy of isatin and α,β-unsaturated ketone would afford new chemical entities with strong chemotherapeutic potential. Of interest, compounds 5b and 5g demonstrated significant antiproliferative activities against different cancer genotypes according to NCI-60 screening. Concomitantly, their IC₅₀ against HL-60 cells were 0.38 ± 0.08 and 0.57 ± 0.05 µM, respectively, demonstrating remarkable apoptosis and moderate cell cycle arrest at G1 phase. Intriguingly, an impressive safety profile for 5b was reflected by a 37.2 times selectivity against HL-60 over PBMC from a healthy donor. This provoked us to further explore their mechanism of action by in vitro and in silico tools. Conclusively, 5b and 5g stand out as strong chemotherapeutic agents that hold clinical promise against acute myeloid leukemia.

Dendritic cell combination therapy reduces the toxicity of triptolide and ameliorates colitis in murine models

Triptolide (TP) exerts a promising effect in the treatment of ulcerative colitis (UC). However, its toxicity seriously hinders its application in the clinic. Previous studies indicated that dendritic cells (DCs) are the main target through which TP exerts its immunoregulatory effect. Thus, we designed an approach to target DCs in vitro to avoid the direct exposure of organs to TP. Our results revealed that DCs pretreated with TP (DCTP) exerted satisfactory therapeutic effects in mice with colitis, resulting in improved colonic inflammation and alleviated local lesion damage. In addition, no obvious toxicity was observed. DCTP also reshaped the immune milieu by decreasing CD4⁺ T cell numbers and increasing regulatory T cell numbers in the spleen, mesenteric lymph nodes, peripheral blood and colon; these effects were further confirmed in vitro. Downregulation of CD80/86, ICAM-1, MHCI, TLR2/4, TNF-α, and IL-6 expression and upregulation of programmed cell death ligand 1 (PDL1) and IL-10 expression were observed, indicating that DCs were converted into tolerogenic DCs. In conclusion, DCTP can effectively reduce toxicity and alleviate colonic inflammation and local lesion damage in mice with colitis. The immune mechanism underlying the effects of DCTP included the conversion of DCs into tolerogenic DCs and the alteration of T cell differentiation to produce immunoinhibitory rather than immunostimulatory T cells.

Expression of Podoplanin in Hepatocellular Carcinoma in a Sample of Egyptian Population – Immunohistopathological Study

BACKGROUND: Hepatocellular carcinoma (HCC) is a highly incident malignancy with a dreadful prognosis. It evolves through a multistep process, with a contribution from different stromal cells like cancer associated fibroblasts. Podoplanin is a glycoprotein that influences epithelial mesenchymal interplay facilitating the tumor invasion. AIM: The aim of the study was to evaluate the immunohistochemical expression of Podoplanin in HCC in cancer associated fibroblasts (CAFs) and malignant hepatocytes as well as assessing the lymphovascular density, and correlating them with the clinicopathological parameters. METHODS: Sixty formalin-fixed paraffin-embedded HCC tissue blocks were retrieved from the pathology Department of the National Hepatology and Tropical Medicine Research Institute and Kasr Al-aini Hospital during the period of January 2012 till December 2019. The specimens were obtained through partial or total hepatectomy inclusion criteria included HCC cases obtained through resection type biopsy and those having no history of pre-operative cancer therapy, while cases with insufficient data, core biopsy, and marked necrosis were excluded from the study. Tumor tissue blocks were immunostained for Podoplanin and its expression was interpreted in lymphatic vessels, CAFs, and malignant hepatocytes. RESULTS: Podoplanin expression in CAFs and malignant hepatocytes was detected in the majority of HCC cases (81.7%) and (88.3%), respectively. The malignant hepatocytes showed increased expression of Grade 1 immunostaining (36.7%). High lymphovascular density was detected over the majority of the cases (73.3%). Podoplanin expression was significantly correlated with higher mean age, male gender, presence of viral infection, cirrhosis, and higher tumor grade. Unifocal tumor mass, tumor size <5 cm, and presence of invasion showed a significant correlation with Podoplanin in malignant hepatocytes and CAFs for the formers and the later, respectively. CONCLUSION: Podoplanin is highly expressed in HCC, which could be used as a prognostic marker for lymphangiogenesis. Furthermore, within the malignant hepatocytes and CAFs suggesting a role in hepatocellular tumorigenesis. Podoplanin targeted therapy can be investigated to slow down the tumor progression and metastasis.

Chemotherapeutic Drug-Regulated Cytokines Might Influence Therapeutic Efficacy in HCC

Hepatocellular carcinoma (HCC), the most common type of liver cancer, is the second leading cause of cancer-related mortality worldwide. Processes involved in HCC progression and development, including cell transformation, proliferation, metastasis, and angiogenesis, are inflammation-associated carcinogenic processes because most cases of HCC develop from chronic liver damage and inflammation. Inflammation has been demonstrated to be a crucial factor inducing tumor development in various cancers, including HCC. Cytokines play critical roles in inflammation to accelerate tumor invasion and metastasis by mediating the migration of immune cells into damaged tissues in response to proinflammatory stimuli. Currently, surgical resection followed by chemotherapy is the most common curative therapeutic regimen for HCC. However, after chemotherapy, drug resistance is clearly observed, and cytokine secretion is dysregulated. Various chemotherapeutic agents, including cisplatin, etoposide, and 5-fluorouracil, demonstrate even lower efficacy in HCC than in other cancers. Tumor resistance to chemotherapeutic drugs is the key limitation of curative treatment and is responsible for treatment failure and recurrence, thus limiting the ability to treat patients with advanced HCC. Therefore, the capability to counteract drug resistance would be a major clinical advancement. In this review, we provide an overview of links between chemotherapeutic agents and inflammatory cytokine secretion in HCC. These links might provide insight into overcoming inflammatory reactions and cytokine secretion, ultimately counteracting chemotherapeutic resistance.

Conventional and hybrid nanoparticulate systems for the treatment of hepatocellular carcinoma: An updated review

Hepatocellular carcinoma (HCC) is considered a serious malignancy which affects a large number of people worldwide. Despite the presence of some diagnostic techniques for HCC, the fact that its symptoms somehow overlap with other diseases causes it to be diagnosed at a late stage, hence negatively affecting the prognosis of the disease. The currently available treatment strategies have many shortcomings such as high cost, induction of serious side effects as well as multiple drug resistance, hence resulting in therapeutic failure. Accordingly, nanoformulations have been developed in order to overcome the clinical challenges, enhance the therapeutic efficacy, and elicit chemotherapy tailor-ability. Hybrid nanoparticulate carriers in particular, which are composed of two or more drug vehicles with different physicochemical characteristics combined together in one system, have been recently reported to advance nanotechnology-based therapies. Therefore, this review sheds the light on HCC, and the role of nanotechnology and hybrid nanoparticulate carriers as well as the latest developments in the use of conventional nanoparticles in combating this disease.

PAF enhances cancer stem cell properties via β-catenin signaling in hepatocellular carcinoma

Increasing proofs have declared that liver cancer stem cells (CSCs) are the main contributors to tumor initiation, metastasis, therapy resistance, and recurrence of hepatocellular carcinoma (HCC). However, the molecular mechanisms underlying CSCs regulation remain largely unclear. Recently, PCNA-associated factor (PAF) was identified to play a key role in maintaining breast cancer cell stemness, but its role in liver cancer stem cells has not been declared yet. Herein, we found that both mRNA and protein expression levels of PAF were significantly higher in HCC tissues and cell lines than normal controls. CSC-enriched hepatoma spheres displayed an increase in PAF expression compared to monolayer-cultured cells. Both loss-of-function and gain-of-function experiments revealed that PAF enhanced sphere formation and the percentage of CD133+ or EpCAM+ cells in HCCLM3 and Huh7 cells. In the xenograft HCC tumor model, tumor initiation rates and tumor growth were suppressed by knockdown of PAF. Mechanistically, PAF can amplify the self-renewal of liver CSCs by activating β-catenin signaling. Taken together, our results demonstrate that PAF plays a crucial role in maintaining the hepatoma cell stemness by β-catenin signaling.Abbreviations: CSCs: cancer stem cells; HCC: hepatocellular carcinoma; PAF: pCNA-associated factor.

Cytokine-induced killer cells carrying recombinant oncolytic adenovirus expressing p21Ras scFv inhibited liver cancer

Background: Oncolytic adenovirus-mediated gene therapy is an emerging strategy for cancer treatment. However, oncolytic adenoviruses are mainly administered locally at tumor site. Intravenous administration of oncolytic adenovirus for cancer gene therapy is a problem that needs to be solved urgently.

Methods: We constructed recombinant oncolytic adenovirus KGHV500 carrying anti-p21Ras scFv and employed CIK cells to deliver KGHV500. TUNEL, wound healing, MTT, and Transwell invasion assays were used to determine the anti-tumor efficacy of KGHV500 on liver cancer cells in vitro. Nude mouse xenograft model was used to examine the anti-tumor efficacy of CIK cells combined with KGHV500 in vivo. Furthermore, KGHV500 accumulation in different organs was detected to assess the safety.

Results: KGHV500 inhibited the migration, proliferation, invasion, and induced the apoptosis of liver cancer cells. CIK cells carrying KGHV500 reached tumor site and exerted much better anti-tumor efficacy than CIK cells or KGHV500 alone in nude mouse xenograft model. Moreover, we detected KGHV500 and anti-p21Ras scFv in different organs of nude mice, with little effects on the organs.

Conclusions: We develop a novel strategy for the treatment of Ras-driven liver cancer by combining CIK cells with oncolytic adenovirus expressing anti-p21Ras scFv. Intravenous injection of CIK cells carrying KGHV500 in vivo significantly inhibits tumor growth, has little effect on normal organs, and is relatively safe.

Radiolabeled Peptide Probes for Liver Cancer Imaging

Liver cancer/Hepatocellular Carcinoma (HCC) is a leading cause of cancer death and represents an important cause of mortality worldwide. Several biomarkers are overexpressed in liver cancer, such as Glypican 3 (GPC3) and Epidermal Growth Factor Receptor (EGFR). These biomarkers play important roles in the progression of tumors and could serve as imaging and therapeutic targets for this disease. Peptides with adequate stability, receptor binding properties, and biokinetic behavior have been intensively studied for liver cancer imaging. A great variety of them have been radiolabeled with clinically relevant radionuclides for liver cancer diagnosis, and many are promising imaging and therapeutic candidates for clinical translation. Herein, we summarize the advancement of radiolabeled peptides for the targeted imaging of liver cancer.

Clinical Significance of Adverse Events for Patients with Unresectable Hepatocellular Carcinoma Treated with Lenvatinib: A Multicenter Retrospective Study

We sought to investigate the clinical profile(s) associated with the discontinuation of lenvatinib (LEN) due to severe adverse events (DLSAE) in patients with unresectable hepatocellular carcinoma (HCC). This retrospective study enrolled 177 patients with HCC treated with LEN. Independent factors associated with DLSAE were advanced age, albumin-bilirubin (ALBI) grade 2, fatigue grade ≥ 3, and appetite loss ≥ 2. The overall survival (OS) in the group that did not require DLSAE was significantly longer compared to the group that did require DLSAE (median survival time (MST): not reached vs. 12.8 months, p < 0.001). Moreover, advanced age was the most important variable for DLSAE in a decision tree analysis. Hypertension and hand-foot-skin-reaction (HFSR) were also significantly associated with longer survival, and the occurrence of hypertension was the earliest predictor for improved prognosis, while appetite loss and development of grade ≥ 3 fatigue were predictive of a poor prognosis. We concluded that the appearance of hypertension has potential as an early surrogate marker to predict improved prognosis. Moreover, careful management to avoid discontinuation of treatment leads to longer survival in patients receiving LEN.

Peptide vaccine as an adjuvant therapy for glypican-3-positive hepatocellular carcinoma induces peptide-specific CTLs and improves long prognosis

There is no established postoperative adjuvant therapy for hepatocellular carcinoma (HCC), and improvement of patient prognosis has been limited. We conducted long‐term monitoring of patients within a phase II trial that targeted a cancer antigen, glypican‐3 (GPC3), specifically expressed in HCC. We sought to determine if the GPC3 peptide vaccine was an effective adjuvant therapy by monitoring disease‐free survival and overall survival. We also tracked GPC3 immunohistochemical (IHC) staining, CTL induction, and postoperative plasma GPC3 for a patient group that was administered the vaccine (n = 35) and an unvaccinated patient group that underwent surgery only (n = 33). The 1‐y recurrence rate after surgery was reduced by approximately 15%, and the 5‐y and 8‐y survival rates were improved by approximately 10% and 30%, respectively, in the vaccinated group compared with the unvaccinated group. Patients who were positive for GPC3 IHC staining were more likely to have induced CTLs, and 60% survived beyond 5 y. Vaccine efficacy had a positive relationship with plasma concentration of GPC3; high concentrations increased the 5‐y survival rate to 75%. We thus expect GPC3 vaccination in patients with HCC, who are positive for GPC3 IHC staining and/or plasma GPC3 to induce CTL and have significantly improved long‐term prognosis.

Weekends-Off Lenvatinib for Unresectable Hepatocellular Carcinoma Improves Therapeutic Response and Tolerability toward Adverse Events

Background: Although lenvatinib has become the standard therapy for hepatocellular carcinoma (HCC), the high incidence rate of adverse events (AEs) is an issue. This study aimed to clarify the AEs of lenvatinib and the therapeutic impact of five days-on/two days-off administration (i.e., weekends-off strategy) for lenvatinib. Methods: We retrospectively assessed the therapeutic effects and AEs of 135 patients treated with lenvatinib, and the improvement of tolerability and therapeutic efficacy of 30 patients treated with the weekends-off strategy. We also evaluated lenvatinib-induced vascular changes in tumors and healthy organs using a mouse hepatoma model. Results: The incidence rates of any grade and grade ≥ 3 AEs were 82.1% and 49.6%. Fatigue was the most important AE since it resulted in dose reduction and discontinuation. Of the 30 patients who received weekends-off lenvatinib, 66.7% tolerated the AEs. Although 80.8% of the patients showed progression after dose reduction, the therapeutic response improved in 61.5% of the patients by weekends-off lenvatinib. Notably, weekends-off administration significantly prolonged the administration period and survival (p < 0.001 and p < 0.05). The mouse hepatoma model showed that weekends-off administration contributed to recovery of vascularity in the organs. Conclusion: Weekends-off administration of lenvatinib was useful to recover the therapeutic response and tolerability toward AEs.

Activation of extracellular signal-regulated kinase is associated with hepatocellular carcinoma with aggressive phenotypes

AIM

Sorafenib inhibits multiple kinase signaling pathways, including the rat sarcoma virus (Ras)/rapidly accelerated fibrosarcoma (Raf)/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway, and is a promising therapy for hepatocellular carcinoma (HCC). However, the role of ERK activation in HCC remains unclear. This study was designed to investigate the potential link between ERK activation and aggressive HCC phenotypes.

METHODS

We evaluated nuclear ERK expression by immunohistochemistry in 154 resected HCC nodules from 136 patients. We then investigated the associations of ERK expression with the clinicopathological characteristics of HCC, c-MET expression, and the molecular subclass biomarkers Ki-67, keratin 19 (KRT19, CK19, or K19), and sal-like protein 4. Multivariate Cox regression analysis was carried out to determine independent prognostic factors for overall survival and recurrence-free survival. The effects of ERK activation by hepatocyte growth factor (HGF) on eight HCC cell lines were further examined.

RESULTS

High-level nuclear expression of ERK was observed in 20 (13%) of 154 nodules and was significantly associated with higher serum alpha-fetoprotein levels (P = 0.034), poorer differentiation (P = 0.003), a higher Ki-67 index (P < 0.001), high-level expression of c-MET (P = 0.008), KRT19 (P = 0.002), or sal-like protein 4 (P < 0.001), and shorter overall survival (multivariate hazard ratio 3.448; P = 0.028) and recurrence-free survival (multivariate hazard ratio 2.755; P = 0.004). HCC cells treated with hepatocyte growth factor showed enhanced cell proliferation together with ERK activation and upregulated KRT19 expression, both of which were inhibited by sorafenib.

CONCLUSIONS

High-level ERK activation is associated with a KRT19-positive highly proliferative subtype of HCC with a dismal prognosis. These findings support the key role of the hepatocyte growth factor/c-MET/ERK axis in HCC progression.

Molecular Signaling Pathways and Therapeutic Targets in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a complex biological process and is often diagnosed at advanced stages with no effective treatment options. With advances in tumor biology and molecular genetic profiling, several different signaling pathways and molecular mechanisms have been identified as responsible for initiating and promoting HCC. Targeting these critical pathways, which include the receptor tyrosine kinase pathways, the Ras mitogen-activated protein kinase (Ras/Raf/MAPK), the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR), the Wnt/β-catenin signaling pathway, the ubiquitin/proteasome degradation and the hedgehog signaling pathway has led to the identification of novel therapeutics for HCC treatment. In this review, we elaborated on our current understanding of the signaling pathways involved in the development and initiation of HCC and anticipate the potential targets for therapeutic drug development.

Long noncoding RNA 91H overexpression contributes to the growth and metastasis of HCC by epigenetically positively regulating IGF2 expression

BACKGROUND & AIMS

Long noncoding RNA 91H is transcribed from the H19/IGF2 locus and contributes to the development of breast and oesophagus cancers by regulating the expression of IGF2, but the regulation mechanism remains poorly characterized. Here, we explored the role of 91H in hepatocellular carcinoma (HCC) and the mechanism of IGF2 expression regulation by 91H.

METHODS

Firstly, the expression of 91H was analysed in HCC by quantitative RT-PCR, the association of 91H with survival was evaluated by the Kaplan-Meier method and the effect of 91H on the growth and invasion of HCC was investigated by the in vitro and in vivo studies. Then, the association of 91H with the expression of IGF2 was evaluated in HCC tissues, and the effect of 91H on the expression of IGF2 was investigated by 91H knockdown. Finally, the binding of RBBP5 to 91H and the binding of RBBP5, activating H3K4me3 mark and repressive H3K27me3 mark to the P3 and P4 promoters of IGF2 gene were studied by RIP and ChIP respectively.

RESULTS

The overexpression of 91H was found in HCC and in association with the growth, metastasis and shorter survival time of HCC. The knockdown of 91H down-regulated the IGF2 expression in HCC, and the mechanism was correlated with the decreased enrichment of RBBP5 and H3K4me3 and increased enrichment of H3K27me3 at the bivalent P3 and P4 promoters.

CONCLUSIONS

The overexpression of 91H promotes tumour growth and metastasis, and is associated with a poor prognosis of HCC at least partially by positively regulating the expression of IGF2 through bivalent histone modification changes characterized by H3K4me3 and H3K27me3 at the P3 and P4 promoters.

miR-664b-5p Inhibits Hepatocellular Cancer Cell Proliferation Through Targeting Oncogene AKT2

Background: miR-664b-5p accelerates the development of certain cancers, but the role of miR-664b-5p in hepatocellular carcinoma (HCC) has been less reported. Therefore, the authors aimed to study the role of miR-664b-5p in HCC progression. Materials and Methods: miR-664b-5p expression in liver cancer and adjacent tissues, and in HepG2 and SUN-475 cells, was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Relationship between miR-664b-5p and AKT2 was predicted by TargetScan and confirmed by dual-luciferase reporter assay, and gene or protein expressions were determined by performing qRT-PCR and Western blotting. The viability and apoptosis, and the migration and invasion of HepG2 and SUN-475 cells were determined by CCK-8 assay and flow cytometry, and transwell assay, respectively. Results: Downregulated miR-664b-5p was observed in hepatocellular cancer tissues. Functional analyses revealed that miR-664b-5p mimic suppressed viability, migration, and invasion, but promoted apoptosis in HepG2 and SUN-475 cells. AKT2 was a target of miR-664b-5p, whose mimics inhibited the expression of AKT2. However, upregulated AKT2 promoted viability, migration, and invasion, but inhibited apoptosis in HepG2 and SUN-475 cells, and such effects were reversed by miR-664b-5p mimics. Conclusions: miR-664b-5p acts as a cancer suppressor through negatively regulating AKT2 expression in HepG2 and SUN-475 cells, suggesting that miR-664b-5p could be a protective target for HCC patients.

Ramucirumab as a second line therapy for advanced HCC: a significant achievement or a wasted opportunity for personalised therapy?

The second line treatment of hepatocellular carcinoma (HCC) has recently become an exciting area of interest since new emerging options have demonstrated survival benefits versus placebo. Unfortunately, predictive biomarkers are unavailable for these treatments. Ramucirumab, a monoclonal antibody against VEGFR-2, has demonstrated overall survival superiority against placebo as a second line therapy for patients with AFP > 400 ng/ml in the recent REACH-2 trial. This review will provide the current updated knowledge regarding the HCC cancerogenesis and angiogenic VEGF/VEGFR-2 pathways and the clinical development of ramucirumab in advanced HCC. This study will also critically assess the gaps in a previous negative phase III trial that tested other potentially useful treatments and suggest ways to modernise clinical trials and personalise therapy for advanced HCC.

Treatment with a new benzimidazole derivative bearing a pyrrolidine side chain overcomes sorafenib resistance in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major cause of cancer-related death worldwide. Currently, sorafenib is the standard first-line drug for patients with advanced HCC. However, long-term exposure to sorafenib often results in reduced sensitivity of tumour cells to the drug, leading to acquired resistance. Therefore, developing new compounds to treat sorafenib resistance is urgently needed. Although benzimidazole and its derivatives have been reported to exert antimicrobial and antitumour effects, the anti-drug resistance potential of these molecules is still unknown. In this study, we established sorafenib-resistant (SR) cell lines and an acquired sorafenib resistance xenograft model. We showed that treatment with a benzimidazole derivative bearing a pyrrolidine side chain (compound 9a) inhibited the proliferation of SR cells by blocking the phosphorylation of AKT, p70S6 and the downstream molecule RPS6. In addition, caspase 3/PARP-dependent apoptotic signals were induced in 9a-treated cells. Regarding epithelial-mesenchymal transition (EMT) activities, 9a treatment significantly suppressed the migration of SR cells. In particular, the levels of EMT-related transcription factors (snail, slug and twist) and mesenchymal markers (vimentin and N-cadherin) were downregulated. In the acquired sorafenib resistance xenograft model, compound 9a administration decreased the growth of tumours with acquired sorafenib resistance and the expression of the HCC markers α-fetoprotein, glypican 3 and survivin. In conclusion, treatment with this compound may be a novel therapeutic strategy for patients with sorafenib resistance.

Cetuximab and epirubicin HCl-combined application as a possibility to treat both parental and epirubicin HCl-resistant liver cancer cells

BACKGROUND AND AIMS

Targeted chemotherapeutics such as cetuximab can cause many side effects such as skin toxicity when used in high concentrations. In addition, cancer cells can develop resistance to some of the anticancer agents during treatment. The lack of the desired success in chemotherapy and the development of resistance to chemotherapeutics, such as epirubicin HCl, suggest that there is a need for combined therapies. The combination of targeted chemotherapeutics and conventional chemotherapy drugs may lead to the emergence of new strategies in the treatment of cancer. In this study, cytotoxic, antiproliferative, cell cycle inhibitive, oxidative stress generation, and apoptotic effects and effect mechanisms of cetuximab alone and together with epirubicin HCl on parental liver cancer cells (P-Hep G2) and epirubicin HCl-resistant liver cancer cells (R-Hep G2) were investigated.

MATERIALS

Cytotoxic effects of cetuximab alone and with epirubicin-HCl on cells were determined by Cell Titer-Blue® Cell Viability and Lactate Dehydrogenase Activity tests. Cell cycle distributions and apoptosis were detected by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Cetuximab with epirubicin HCl treatment increased the cytotoxic effect on both cells. Caspase-3/7 activity increased 3 and 1.5 times in comparison with control group in P-Hep G2 and R-Hep G2 cells, respectively, after treating with cetuximab alone, whereas the increase was found to be approximately 4.7 and 2.5 times when cetuximab was treated with epirubicin HCl in P-Hep G2 and R-Hep G2 cells, respectively. Both cetuximab alone and together with epirubicin HCl treatments caused increases in Bax/Bcl-2 ratio in both cells.

DISCUSSION

Treatment of cetuximab with epirubicin HCl to P-Hep G2 and R-Hep G2 cells was found to be more effective in cytotoxic effect and inducing apoptosis comparison to cetuximab alone treatment. In addition, combination treatment showed different effects on pro-apoptotic/anti-apoptotic genes expression according to cells drug resistance properties.

Design and synthesis of phthalazine-based compounds as potent anticancer agents with potential antiangiogenic activity via VEGFR-2 inhibition

In the designed compounds, either a biarylamide or biarylurea moiety or an N-substituted piperazine motif was linked to position 1 of the phthalazine core. The anti-proliferative activity of the synthesised compounds revealed that eight compounds (6b, 6e, 7b, 13a, 13c, 16a, 16d and 17a) exhibited excellent broad spectrum cytotoxic activity in NCI 5-log dose assays against the full 60 cell panel with GI₅₀ values ranging from 0.15 to 8.41 µM. Moreover, the enzymatic assessment of the synthesised compounds against VEGFR-2 tyrosine kinase showed the significant inhibitory activities of the biarylureas (12b, 12c and 13c) with IC₅₀s of 4.4, 2.7 and 2.5 μM, respectively, and with 79.83, 72.58 and 71.6% inhibition of HUVEC at 10 μM, respectively. Additionally, compounds (7b, 13c and 16a) were found to induce cell cycle arrest at S phase boundary. Compound 7b triggered a concurrent increase in cleaved caspase-3 expression level, indicating the apoptotic-induced cell death.

INPP4B inhibits cell proliferation, invasion and chemoresistance in human hepatocellular carcinoma

Background: Inositol polyphosphate 4-phosphatase type II (INPP4B) has been identified as a negative regulator of phosphatidyl inositol 3-kinase (PI3K)/Akt signaling in human several cancers. However, the expression, clinical significance and biological function of INPP4B in human hepatocellular carcinoma (HCC) clinical tissues and cell lines are little known.

Materials and methods: We evaluated the expression of INPP4B in 86 cases of paired human HCC samples by immunohistochemistry, and the clinical significance of INPP4B expression was analyzed. The expression of INPP4B in five HCC cell lines was detected through using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot analyses. The role of INPP4B gene on HCC cell proliferation, apoptosis, migration, invasion as well as epithelial-to-mesenchymal transition (EMT) and chemoresistance was examined via INPP4B mammalian expression vector and small interfering RNA (siRNA) transfection in vitro. Western blot analysis was used to explore the downstream molecules modulated by INPP4B.

Results: Immunohistochemistry analysis revealed that INPP4B was significantly downregulated in HCC tissues compared with the corresponding normal tissues. The rate of INPP4B-positive staining was markedly lower in metastatic samples than in those of non-metastatic samples. Univariate analysis showed that INPP4B expression was indicated to have a marked association with histological grades, tumor size and tumor metastasis. Moreover, INPP4B overexpression suppressed cell proliferation, migration, invasion and EMT, but induced cell apoptosis and chemosensitivity in human HCC cell lines. In contrast, INPP4B knockdown had the opposite effects on the biological behaviors of HCC cells. Furthermore, INPP4B was found to inhibit the activation of PI3K/Akt signaling in HCC cells.

Conclusion: Our findings suggest that INPP4B is a tumor suppressing gene in human HCC, and might act as a novel therapeutic target for HCC patients.

Ponatinib Inhibits Proliferation and Induces Apoptosis of Liver Cancer Cells, but Its Efficacy Is Compromised by Its Activation on PDK1/Akt/mTOR Signaling

Ponatinib is a multi-target protein tyrosine kinase inhibitor, and its effects on hepatocellular carcinoma cells have not been previously explored. In the present study, we investigated its effects on hepatocellular carcinoma cell growth and the underlying mechanisms. Toward SK-Hep-1 and SNU-423 cells, ponatinib induces apoptosis by upregulation of cleaved caspase-3 and -7 and promotes cell cycle arrest in the G1 phase by inhibiting CDK4/6/CyclinD1 complex and phosphorylation of retinoblastoma protein. It inhibits the growth-stimulating mitogen-activated protein (MAP) kinase pathway, the phosphorylation of Src on both negative and positive regulation sites, and Jak2 and Stat3 phosphorylation. Surprisingly, it also activates the PDK1, the protein kinase B (Akt), and the mechanistic target of rapamycin (mTOR) signaling pathway. Blocking mTOR signaling strongly sensitizes cells to inhibition by ponatinib and makes ponatinib a much more potent inhibitor of hepatocellular carcinoma cell proliferation. These findings demonstrate that ponatinib exerts both positive and negative effects on hepatocellular cell proliferation, and eliminating its growth-stimulating effects by drug combination or potentially by chemical medication can significantly improve its efficacy as an anti-cancer drug.

Prospects for immunotherapy as a novel therapeutic strategy against hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly aggressive malignant disease, with a poor clinical prognosis. Many standard therapies are often considered for HCC treatment today; however, these conventional therapies often fail to achieve sufficiently effective clinical results. Today, HCC therapy is set to undergo a major revolution, owing to rapid developments in cancer immunotherapy, particularly immune checkpoint inhibitor therapy. Cancer immunotherapy is a novel and promising treatment strategy that differs significantly from conventional therapies in its approach to achieve antitumor effects. In fact, many cancer immunotherapies have been tested worldwide and shown to be effective against various types of cancer; HCC is no exception to this trend. For example, we identified a specific cancer antigen called glypican-3 (GPC3) and performed clinical trials of GPC3-targeted peptide vaccine immunotherapy in patients with HCC. Here, we present an overview of the immune mechanisms for development and progression of HCC, our GPC3-based immunotherapy, and immune checkpoint inhibitor therapy against HCC. Finally, we discuss the future prospects of cancer immunotherapy against HCC. We believe that this review and discussion of cancer immunotherapy against HCC could stimulate more interest in this promising strategy for cancer therapy and help in its further development.

Integrated analysis of multiple receptor tyrosine kinases identifies Axl as a therapeutic target and mediator of resistance to sorafenib in hepatocellular carcinoma

BACKGROUND

Aberrant activation of Axl is implicated in the progression of hepatocellular carcinoma (HCC). We explored the biologic significance and preclinical efficacy of Axl inhibition as a therapeutic strategy in sorafenib-naive and resistant HCC.

METHODS

We evaluated Axl expression in sorafenib-naive and resistant (SR) clones of epithelial (HuH7) and mesenchymal origin (SKHep-1) using antibody arrays and confirmed tissue expression. We tested the effect of Axl inhibition with RNA-interference and pharmacologically with R428 on a number of phenotypic assays.

RESULTS

Axl mRNA overexpression in cell lines (n = 28) and RNA-seq tissue datasets (n = 373) correlated with epithelial-to-mesenchymal transition (EMT). Axl was overexpressed in HCC compared to cirrhosis and normal liver. We confirmed sorafenib resistance to be associated with EMT and enhanced motility in both HuH7-SR and SKHep-1-SR cells documenting a 4-fold increase in Axl phosphorylation as an adaptive feature of chronic sorafenib treatment in SKHep-1-SR cells. Axl inhibition reduced motility and enhanced sensitivity to sorafenib in SKHep-1SR cells. In patients treated with sorafenib (n = 40), circulating Axl levels correlated with shorter survival.

CONCLUSIONS

Suppression of Axl-dependent signalling influences the transformed phenotype in HCC cells and contributes to adaptive resistance to sorafenib, providing a pre-clinical rationale for the development of Axl inhibitors as a measure to overcome sorafenib resistance.

A Phase I Study of Combination Therapy with Sorafenib and 5-Fluorouracil in Patients with Advanced Hepatocellular Carcinoma

Background and aims

Sorafenib is the first molecular targeted drug approved for the treatment of advanced hepatocellular carcinoma (HCC) and is a potent small molecule inhibitor of multiple kinases. Combination therapy with sorafenib and other cytotoxic agents for HCC may result in additive anticancer activity. The purpose of this phase I study was to investigate the safety and tolerability of combination therapy with sorafenib and 5-fluorouracil (5-FU) and to determine the optimum dose of 5-FU for a phase II trial.

Methods

This phase I study used a conventional 3 + 3 dose-escalation design. The primary endpoint was to determine the maximum tolerated dose (MTD) of 5-FU in combination with sorafenib and to determine the recommended dosage (RD) for phase II. The secondary endpoints evaluated were toxicity and the tumor response rate. All patients received 800 mg of sorafenib daily and three different dosages of 5-FU (250, 350, and 450 mg/m²/day) for 20 days by intravenous infusion in 1 month as one cycle.

Results

Twelve patients with advanced HCC were evaluated. The MTD of 5-FU in combination with sorafenib was 450 mg/m²/day, and 350 mg/m²/day was selected as the RD for a phase II study. Thrombocytopenia, stomatitis, and hand-foot skin reaction were observed as grade 3 adverse events. Nine patients achieved stable disease (75%), and three patients (25%) were judged to have progressive disease. The disease control rate was 75%.

Conclusions

Combination therapy with sorafenib and 5-FU appears to be well tolerated and may have the potential to be an option for advanced HCC.

Role of Systemic Therapy and Future Directions for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is an aggressive tumor that often arises in the setting of liver cirrhosis. Although early-stage disease is often amenable for surgical resection, transplant, or locoregional therapies, many patients are diagnosed at an advanced stage or have poor liver reserve. Systemic therapy is the mainstay of treatment for these patients. At present, the only approved therapy for the treatment of advanced disease is the tyrosine multikinase inhibitor sorafenib. Candidacy for treatment is based on liver reserve. Novel agents for the treatment of this disease are urgently needed. In this article, we review systemic therapy trials and upcoming data for the treatment of HCC.

microRNA-608 inhibits human hepatocellular carcinoma cell proliferation via targeting the BET family protein BRD4

Over-expression of the bromodomain and extraterminal (BET) family protein BRD4 is associated with hepatocellular carcinoma (HCC) progression. In the present study, we indentified a novel putative anti-BRD4 microRNA: microRNA-608 ("miR-608"). In HepG2 cells and primary human HCC cells, over-expression of miR-608, using a lentiviral construct, induced BRD4 downregulation and proliferation inhibition. Conversely, transfection of the miR-608 inhibitor increased BRD4 expression to promote HepG2 cell proliferation. Our results suggest that BRD4 is the primary target gene of miR-608 in HepG2 cells. shRNA-mediated knockdown or CRSIPR/Cas9-mediated knockout of BRD4 mimicked and overtook miR-608's actions in HepG2 cells. Furthermore, introduction of a 3'-untranslated region (3'-UTR) mutant BRD4 (UTR-A1718G) blocked miR-608-induced c-Myc downregulation and proliferation inhibition in HepG2 cells. In vivo, HepG2 xenograft tumor growth was significantly inhibited after expressing miR-608 or BRD4 CRSIPR/Cas9-KO construct. Importantly, BRD4 mRNA was upregulated in human HCC tissues, which was correlated with downregulation of miR-608. Together, we conclude that miR-608 inhibits HCC cell proliferation possibly via targeting BET family protein BRD4.

Variant 2 of KIAA0101, antagonizing its oncogenic variant 1, might be a potential therapeutic strategy in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most lethal malignant tumors worldwide and effective therapies, including molecular therapy, remain elusive. Our previous work demonstrates that oncogenic KIAA0101 transcript variant (tv) 1 promotes HCC development and might be a HCC therapeutic target. However, the function of another KIAA0101 variant, KIAA0101 tv2, remains unknown. In this study, we reported that KIAA0101 tv2 was highly expressed in adjacent non-tumorous liver tissues (NTs) compared to HCC tissues. In vivo and in vitro results showed that KIAA0101 tv2 decreased cell survival, colony formation, tumor xenografts, migration, and invasion, as well as induced cell cycle arrest and apoptosis. Interestingly, it could inhibit the function of KIAA0101 tv1 by partially down-regulating KIAA0101 tv1, acting similar to KIAA0101 tv1 short hairpin RNA (shRNA). Further studies illustrated that KIAA0101 tv2 could increase the activity of p53 by competing with KIAA0101 tv1 for P53 binding. In conclusion, KIAA0101 tv2 exerts anti-tumor activity in HCC and acts as an endogenous competitor of tumor-associated KIAA0101 tv1. KIAA0101 tv2 has a potential to work as a therapeutic drug targeting the KIAA0101 tv1 in HCC.

Resistance a major hindrance to chemotherapy in hepatocellular carcinoma: an insight

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer mortality, accounting for almost 90% of total liver cancer burden. Surgical resection followed by adjuvant and systemic chemotherapy are the most meticulously followed treatment procedures but the complex etiology and high metastatic potential of the disease renders surgical treatment futile in majority of the cases. Another hindrance to the scenario is the acquired resistance to drugs resulting in relapse of the disease. Hence, to provide insights into development of novel therapeutic targets and diagnostic biomarkers, this review focuses on the various molecular mechanisms underlying chemoresistance in HCC. We have provided a comprehensive summary of the various strategies adopted by HCC cells, extending from apoptosis evasion, autophagy activation, drug expulsion to epigenetic transformation as modes of therapy resistance. The role of stem cells in imparting chemoresistance is also discussed. Furthermore, the review also focuses on how this knowledge might be exploited for the development of an effective, prospective therapy against HCC.

Sunitinib Induces NK-κB-dependent NKG2D Ligand Expression in Nasopharyngeal Carcinoma and Hepatoma Cells

Multitargeted tyrosine kinase inhibitors (MTKIs) have been shown to combine with natural killer (NK) cell adoptive transfer for the treatment in various cancers. MTKIs sensitize cancer cells to NK cell therapy through upregulation of nature killer group 2 member D ligands (NKG2DLs) on tumor cells. However, the molecular mechanism of MTKIs-mediated upregulation of NKG2DLs is still unknown. In this study, we confirmed sunitinib induced downregulation of its targets, such as vascular endothelial growth factor, platelet-derived growth factor, and c-kit in multiple-drug-resistant nasopharyngeal carcinoma cell line CNE2/DDP and hepatoma cell line HepG2. Then, we further showed sunitinib induced cell proliferation inhibition, apoptosis, and DNA damage in CNE2/DDP and HepG2 cells. Coculture experiments showed that sunitinib-treated CNE2/DDP and HepG2 cells were able to increase the activation and cytotoxicity of NK cells. Quantitative polymerase chain reaction results showed that sunitinib upregulated NKG2DLs, apoptotic genes, DNA damage repair genes, and nuclear factor (NF)-κβ family genes. Silencing of NF-κβ1, NF-κβ2, or RelB (NF-κβ pathway) inhibited sunitinib-induced upregulation of NKG2DLs. Taken together, we concluded that sunitinib upregulated NKG2DLs through NF-κβ signaling noncanonical pathway which might mediate higher cytotoxic sensitivity of CNE2/DDP and HepG2 cells to NK cells.

miR-155-5p modulates malignant behaviors of hepatocellular carcinoma by directly targeting CTHRC1 and indirectly regulating GSK-3β-involved Wnt/β-catenin signaling

Background

Hepatocellular carcinoma (HCC) remains one of the most lethal cancers. MicroRNA-155 (miR-155) and collagen triple helix repeat containing 1 (CTHRC1) were found to be involved in hepatocarcinogenesis, but their detailed functions in HCC are unclear. Here, we aimed to investigate the underlying role of miR-155-5p and CTHRC1 in HCC.

Methods

miR-155-5p and CTHRC1 expression levels were detected by qRT-PCR, IHC and WB in HCC patients and cell lines. Dual-luciferase assay, qRT-PCR and WB were used to validate the target interaction between miR-155-5p and CTHRC1. Biological behaviors, including apoptosis, cell cycle progression, and cell proliferation, invasion and migration, were measured by flow cytometry, CCK-8 assay and Transwell tests. A xenograft model was established to examine the effects of miR-155-5p and CTHRC1 on tumor formation. WB was finally utilized to identify the role of GSK-3β-involved Wnt/β-catenin signaling in HCC growth and metastasis.

Results

Our results showed that miR-155-5p and CTHRC1 were down-regulated and up-regulated, respectively, in HCC patients and cell lines. Dual-luciferase assay verified that CTHRC1 was the direct target of miR-155-5p. Moreover, elevated miR-155-5p expression promoted apoptosis but suppressed cell cycle progression and cell proliferation, invasion and migration in vitro and facilitated tumor formation in vivo; elevated CTHRC1 expression abolished these biological effects. Additionally, miR-155-5p overexpression increased metastasis- and anti-apoptosis-related protein expression and decreased pro-apoptosis-related protein expression, while forced CTHRC1 expression conserved the expression of these proteins.

Conclusion

Altogether, our data suggested that miR-155-5p modulated the malignant behaviors of HCC by targeting CTHRC1 and regulating GSK-3β-involved Wnt/β-catenin signaling; thereby, miR-155-5p and CTHRC1 might be promising therapeutic targets for HCC patients.

Imaging the expression of glypican-3 in hepatocellular carcinoma by PET

The glypican-3 (GPC3) receptor is overexpressed in hepatocellular carcinoma (HCC) and is a potential diagnostic and therapeutic target. GPC3-targeted molecular imaging will be helpful to differentiate diagnosis and guide therapy. In the present study, we will develop a novel PET probe for imaging the expression of GPC-3. L5 (sequence: RLNVGGTYFLTTRQ), a GPC3 targeting peptide, was labeled with 5-carboxyfluorescein (FAM) and ¹⁸F-fluoride. Cell binding tests were performed to identify the binding specificity of FAM-L5 and ¹⁸F radiolabeled peptide. MicroPET/CT imaging was used to determine the potential of a novel PET tracer for visualizing HCC tumors with a high expression of GPC3. In vitro binding tests showed that the uptake of FAM-L5 in HepG2 cells (high expression of GPC3) was significantly higher than that of HL-7702 cells (negative expression of GPC3) (mean fluorescent intensity: 14,094 ± 797 vs. 2765 ± 314 events, t = 32.363, P = 0.000). Confocal fluorescent imaging identified that FAM-L5 accumulated where the GPC3 receptor was located. A novel PET tracer (¹⁸F-AlF-NODA-MP-6-Aoc-L5) was successfully labeled by chelation chemistry. In vitro cell uptake studies showed that ¹⁸F-AlF-NODA-MP-6-Aoc-L5 can bind to HepG2 tumor cells and was stable in PBS and mouse serum stability tests. MicroPET/CT showed that HepG2 tumors could be clearly visualized with a tumor/muscle ratio of 2.46 ± 0.53. However, the tumor/liver ratio was low (0.93 ± 0.16) due to the high physiological uptake in the liver. This study demonstrates that FAM and the ¹⁸F-labeled L5 peptide can selectively target HCC with a high expression of GPC3 in vitro and in vivo. ¹⁸F-AlF-NODA-MP-C6-L5 has the potential to be a GPC3 target tracer but requires some chemical modifications to achieve a high enough tumor/liver ratio for detection of the tumor in the liver.

Increased expression of Forkhead box M1 transcription factor is associated with clinicopathological features and confers a poor prognosis in human hepatocellular carcinoma

AIM

Forkhead Box M1 (FoxM1) is a proliferation-specific transcription factor. In this study, we aimed to elucidate the clinicopathological and prognostic values of FoxM1 expression in human hepatocellular carcinoma (HCC) and correlate FoxM1 expression with various etiologies of liver diseases. We also investigated its therapeutic value in HCC.

METHODS

We investigated the expression of FoxM1 in tumor tissues and adjacent non-tumor tissues of 79 Japanese HCC patients by quantitative real-time reverse transcription-polymerase chain reaction analysis. Depletion by siRNA or specific inhibition by siomycin A were also used to investigate the effect of FoxM1 inhibition on stem-like features of human HCC cells.

RESULTS

Quantitative real-time reverse transcription-polymerase chain reaction analysis showed that tumor tissues displayed an approximately 14-fold increase in FoxM1 expression compared with adjacent non-tumor tissues. Interestingly, the expression levels of FoxM1in tumor tissues did not depend on the etiology of liver disease. The expression of FoxM1 in tumor tissues was associated with serum α-fetoprotein level, maximum tumor size, histological grade, TNM staging, and portal involvement. Kaplan-Meier analysis indicated that the high FoxM1 expression (≥median) group had a poor prognosis compared with the low FoxM1 expression (<median) group. Using multivariate analysis, the expression of FoxM1 in tumor tissues was shown to be an independent prognostic factor that affected overall survival and disease-free survival. Furthermore, FoxM1 inhibition by siRNA or siomycin A reduced spheroid colony formation of HCC cells in vitro.

CONCLUSION

Our data suggest that FoxM1 might be a prognostic biomarker and a promising therapeutic target for HCC.

Fibrinogen and D-dimer levels elevate in advanced hepatocellular carcinoma: High pretreatment fibrinogen levels predict poor outcomes

AIM

Plasma fibrinogen and D-dimer have been reported to predict survival in several types of malignancies. The aim of this study is to investigate their predictive value in patients with hepatocellular carcinoma (HCC).

METHODS

We retrospectively analyzed plasma fibrinogen and D-dimer levels from 252 subjects: control (n = 20), hepatitis (n = 20), cirrhosis (n = 20), and HCC (n = 192) subjects. The clinical involvement and prognostic value of fibrinogen and D-dimer was analyzed in HCC subjects. To confirm the effects of tumor on hypercoagulability and fibrinolysis, fibrinogen and D-dimer levels were measured in nude mice following HCC inoculation.

RESULTS

Fibrinogen decreased and D-dimer increased in cirrhosis subjects relative to other groups. In HCC subjects, elevated fibrinogen and D-dimer levels were significantly associated with adverse tumor features (increased size, stage, and grade) and systemic inflammation. Patients with HCC with either elevated fibrinogen or D-dimer levels had significantly higher 3-year tumor recurrence rates (65% vs. 41%, P < 0.001 for fibrinogen; 67% vs. 40%, P = 0.011 for D-dimer) and significantly lower 3-year overall survival rates (57% vs. 79%, P < 0.001 for fibrinogen; 56% vs. 80%, P = 0.001 for D-dimer). After multivariate analysis, elevated fibrinogen levels remained an independent predictor of poor prognosis in HCC patients. Finally, elevated levels of fibrinogen and D-dimer were confirmed in nude mice following tumor inoculation.

CONCLUSION

The fibrinogen and D-dimer levels, elevating after carcinogenesis, may serve as simple but effective predictors of adverse tumor profiles and outcomes in HCC.

Dendritic cell-derived exosomes elicit tumor regression in autochthonous hepatocellular carcinoma mouse models

BACKGROUND & AIMS

Dendritic cell (DC)-derived exosomes (DEXs) form a new class of vaccines for cancer immunotherapy. However, their potency in hepatocellular carcinoma (HCC), a life-threatening malignancy with limited treatment options in the clinic that responds poorly to immunotherapy, remains to be investigated.

METHODS

Exosomes derived from α-fetoprotein (AFP)-expressing DCs (DEX_AFP) were investigated in three different HCC mouse models systemically. Tumor growth and microenvironment were monitored.

RESULTS

DEX_AFP elicited strong antigen-specific immune responses and resulted in significant tumor growth retardation and prolonged survival rates in mice with ectopic, orthotopic and carcinogen-induced HCC tumors that displayed antigenic and pathological heterogeneity. The tumor microenvironment was improved in DEX_AFP-treated HCC mice, demonstrated by significantly more γ-interferon (IFN-γ)-expressing CD8⁺ T lymphocytes, elevated levels of IFN-γ and interleukin-2, and fewer CD25⁺Foxp3⁺ regulatory T (Treg) cells and decreased levels of interleukin-10 and transforming growth factor-β in tumor sites. Lack of efficacy in athymic nude mice and CD8⁺ T cell-depleted mice showed that T cells contribute to DEX_AFP-mediated antitumor function. Dynamic examination of the antitumor efficacy and the immune microenvironment in DEX_AFP-treated orthotopic HCC mice at different time-points revealed a positive correlation between tumor suppression and immune microenvironment.

CONCLUSIONS

Our findings provide evidence that AFP-enriched DEXs can trigger potent antigen-specific antitumor immune responses and reshape the tumor microenvironment in HCC mice and thus provide a cell-free vaccine option for HCC immunotherapy. Lay summary: Dendritic cell (DC)-derived exosomes (DEXs) form a new class of vaccines for cancer immunotherapy. However, their potency in hepatocellular carcinoma (HCC) remains unknown. Here, we investigated exosomes from HCC antigen-expressing DCs in three different HCC mouse models and proved their feasibility and capability of treating HCC, and thus provide a cell-free vaccine for HCC immunotherapy.

Cabozantinib in the treatment of hepatocellular carcinoma

Despite clinical studies with different mechanisms of action, no new systemic therapies were approved for hepatocellular carcinoma (HCC) between sorafenib in 2007 and regorafenib in 2017. This is an area of interest to improve outcomes and quality of life. Cabozantinib is oral, small-molecule tyrosine kinase inhibitor that primarily targets MET, VEGFR2, AXL and RET, with additional effect on KIT and FLT3. Cabozantinib is approved for progressive metastatic medullary thyroid cancer and previously treated renal cell carcinoma, and is in development for multiple solid tumors. Given positive results from a Phase II study, cabozantinib is under evaluation in a Phase III randomized controlled trial for patients with advanced HCC previously treated with sorafenib. It has been granted orphan drug status in the USA for this indication. This review summarizes the development of cabozantinib in HCC.

The role of autophagy in hepatocellular carcinoma: friend or foe

Autophagy is an evolutionarily conserved lysosome-dependent catabolic process which degrades cell’s components in order to recycle substrates to exert optimally and adapt to tough circumstances. It is a critical cellular homeostatic mechanism with stress resistance, immunity, antiaging, and pro-tumor or anti-tumor effects. Among these, the role of autophagy in cancer is the most eye-catching that is not immutable but dynamic and highly complex. Basal autophagy acts as a tumor suppressor by maintaining genomic stability in normal cells. However, once a tumor is established, unbalanced autophagy will contribute to carcinoma cell survival under tumor microenvironment and in turn promote tumor growth and development. The dynamic role of autophagy can also apply on hepatocellular carcinoma (HCC). HCC is a highly malignant cancer with high morbidity and poor survival rate. Decline or overexpression of autophagic essential genes such as ATG7, ATG5 or Beclin 1 plays a key role in the occurrence and development of HCC but the exact mechanisms are still highly controversial. Signaling pathways or molecules involving in autophagy, for example PI3K/AKT/mTOR pathway, ERK/MAPK pathway, PERK pathway, p53, LncRNA PTENP1 (Long non-coding RNA PTENP1), microRNA-375 and so on, occupy an important position in the complex role of autophagy in HCC. Here, we discuss the dynamic role, the signaling pathways and the potential prognostic and therapy value of autophagy in HCC.

Promising new strategies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer death worldwide. It usually arises based on a background of chronic liver diseases, defined as the hypercarcinogenic state. The current treatment options for HCC ranging from locoregional treatments to chemotherapies, including sorafenib, effectively regulate the limited sizes and numbers of the nodules. However, these treatments remain unsatisfactory because they have insufficient antitumor effects on the large and numerous nodules associated with HCC and because of a high recurrence rate in the surrounding inflamed liver. To develop novel and promising therapies with higher antitumor effects, recent progress in identifying molecular targets and developing immunological procedures for HCC are reviewed. The molecular targets discussed include the intracellular signaling pathways of protein kinase B/mammalian target of rapamycin and RAS/RAF/mitogen-activated protein kinase, Wnt/β-catenin and glutamine synthetase, insulin-like growth factor, signal transducer and activator of transcription 3, nuclear factor-κB and telomerase reverse transcriptase, and c-MET. Immunological studies have focused mainly on target identification, T cells, natural killer cells, dendritic cells, natural killer T cells, and vaccine development.

The multifaceted role of podoplanin expression in hepatocellular carcinoma

The role of podoplanin in hepatocellular carcinoma (HCC) is not clear yet. The aim of our study was to evaluate the expression of podoplanin in HCC and to determine its role in hepatocarcinogenesis. We performed immunohistochemistry with monoclonal D2-40 antibody, on paraffin-embedded tissue sections of 72 patients diagnosed with HCC. Lymphatic vessels density (LVD) was increased in patients who had vascular invasion at the time of diagnosis (P=0.018) and in those with associated cirrhosis (P=0.006). Tumor cells showing podoplanin expression were correlated with histological grade (P=0.040). Podoplanin-expressing cancer associated fibroblasts (CAFs) were correlated with both LVD (P=0.019) and tumor cells (P=0.015). Our results sustain the dual role of podoplanin in HCC by its involvement in both HCC tumorigenesis, lymphatic neovascularization and tumor invasion invasiveness. A possible crosstalk between epithelial and stromal tumor cells in HCC tumor microenvironment may be mediated by podoplanin, but this hypothesis needs further studies to elucidate this interrelation.