Updates on the hepatocyte growth factor/c-Met axis in hepatocellular carcinoma and its therapeutic implications

Cinobufacini Inhibits Survival and Metastasis of Hepatocellular Carcinoma via c-Met Signaling Pathway

OBJECTIVE

To investigate the anti-tumor effects of cinobufacini (CINO) on hepatocellular carcinoma (HCC) induced by des-gamma-carboxy-prothrombin (DCP) and to uncover the underlying mechanisms.

METHODS

The inhibitory effect of CINO on HCC cell proliferation was evaluated using the cell counting kit-8 method, and the apoptosis rate was quantified using flow cytometry. Immunofluorescence and Western blot analyses were used to investigate the differential expression of proteins associated with cell growth, apoptosis, migration, and invasion pathways after CINO treatment. The therapeutic potential of CINO for HCC was confirmed, and the possibility of combining cinobufacini with c-Met inhibitor for the treatment of primary HCC was further validated by in vivo experiments.

RESULTS

Under the induction of DCP, CINO inhibited the activity of HCC cells, induced apoptosis, and inhibited migration and invasion. Upon the induction of DCP, CINO regulated c-Met activation and the activation of the phosphatidylinositol-3 kinase/protein kinase B (PI3K/AKT) and mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK) pathways. In a mouse model of HCC, CINO exhibited significant antitumor effects by inhibiting the phosphorylation of c-Met and the downstream PI3K/AKT and MEK/ERK pathways in tumor tissues.

CONCLUSIONS

CINO inhibited HCC cell growth, promoted apoptosis, and suppressed HCC cell invasion and migration by targeting c-Met and PI3K/AKT and MEK/ERK signaling pathways under DCP induction.

Activated Gab1 drives hepatocyte proliferation and anti-apoptosis in liver fibrosis via potential involvement of the HGF/c-Met signaling axis

Chronic liver diseases are caused by hepatic viral infection, chemicals, and metabolic stress. The protein Grb2-associated binder 1 (Gab1) binds to various growth factor receptors, and triggers cell differentiation/survival signaling pathways. To identify signaling molecules involved in the progression of liver diseases, we performed reverse-phase protein microarray (RPMA)-based screening of hepatocytes isolated from humanized mice after acute HCV infection. Acute viral infection in humanized liver mice significantly decreased the level of hepatocyte p-Gab1. Moreover, hepatoma cells upon HCV infection decreased Gab1 mRNA at later times of infection (D3 to D5) and p-Gab1 level was inversely related to the production of TGF-β. In contrast, the level of p-Gab1 was increased in CCL4-induced fibrotic liver. Hepatoma cells showed elevation of p-Gab1, along with an increase in STAT3 and ERK activation, upon treatment with HGF (ligand of HGF receptor/c-Met) and CCL4. In Gab1 knockdown hepatoma cells, cell proliferative signaling activity was reduced but the level of activated caspase-3 was increased. These findings suggest that hepatocyte Gab1 expression may play a role in promoting liver fibrosis progression by triggering ERK activation and inhibiting apoptosis. It implies that the Gab1-mediated signaling pathway would be a promising therapeutic target to treat chronic liver diseases.

Targeting the PI3K/pAKT/mTOR/NF-κB/FOXO3a signaling pathway for suppressing the development of hepatocellular carcinoma in rats: Role of the natural remedic Suaeda vermiculata forssk

Liver malignancy is well recognized as a prominent health concern, with numerous treatment options available. Natural products are considered a renewable source, providing inspiring chemical moieties that could be used for cancer treatment. Suaeda vermiculata Forssk has traditionally been employed for management of hepatic conditions, including liver inflammation, and liver cirrhosis, as well as to improve general liver function. The findings of our earlier study demonstrated encouraging in vivo hepatoprotective benefits against liver injury generated by paracetamol and carbon tetrachloride. Additionally, Suaeda vermiculata Forssk exhibited cytotoxic activities in vitro against Hep-G2 cell lines and cell lines resistant to doxorubicin. The present investigation aimed to examine the potential in vivo hepatoprotective efficacy of Suaeda vermiculata Forssk extract (SVE) against hepatocellular carcinoma induced by diethylnitrosamine (DENA) in rats. The potential involvement of the PI3K/AKT/mTOR/NF-κB pathway was addressed. Sixty adult male albino rats were allocated into five groups randomly (n = 10). First group received a buffer, whereas second group received SVE only, third group received DENA only, and fourth and fifth groups received high and low doses of SVE, respectively, in the presence of DENA. Liver toxicity and tumor markers (HGFR, p-AKT, PI3K, mTOR, NF-κB, FOXO3a), apoptosis markers, and histopathological changes were analyzed. The current results demonstrated that SVE inhibited PI3K/AKT/mTOR/NF-κB pathway as well as increased expression of apoptotic parameters and FOXO3a levels, which were deteriorated by DENA treatment. Furthermore, SVE improved liver toxicity markers and histopathological changes induced by DENA administration. This study provided evidence for the conventional hepatoprotective properties attributed to SV and investigated the underlying mechanism by which its extract, SVE, could potentially serve as a novel option for hepatocellular carcinoma (HCC) treatment derived from a natural source.

NETs induce ferroptosis of endothelial cells in LPS-ALI through SDC-1/HS and downstream pathways

BACKGROUND

Extracellular neutrophil extracellular traps (NETs) play an important role in acute lung injury (ALI), but their mechanisms are still unclear. The aim of this study is to explore the effects of NETs on endothelial glycocalyx/HGF/cMET pathway and ferroptosis in ALI and elucidate their potential mechanisms.

METHODS

Plasma was collected from healthy and sepsis patients to test for differences in neutrophil elastase (NE) expression of NETs components. In addition, LPS-ALI mice and endothelial cell injury models were established, and NETs were disrupted by siPAD4 (a driver gene for NETs) and sivelestat (an inhibitor of the NETs component) in the mice and by sivelestat in the endothelial cell injury models, and the effects of NETs on the SDC-1/HS/HGF/cMET pathway were studied. To verify the relationship between NETs and ferroptosis, Fer1, a ferroptosis inhibitor, was added as a positive control to observe the effect of NETs on ferroptosis indicators.

RESULTS

The expression level of NE was significantly higher in the plasma of sepsis patients. In ALI mice, intervention in the generation of NETs reduced pulmonary vascular permeability, protected the integrity of SDC-1/HS and promoted the downstream HGF/cMET pathway. In addition, sivelestat also improved the survival rate of mice, decreased the serious degree of ferroptosis. In the endothelial cells, the results were consistent with those of the ALI mice.

CONCLUSION

The study indicates that inhibiting the production of NETs can protect the normal conduction of the SDC-1/HS/HGF/cMET signalling pathway and reduce the severity of ferroptosis.

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.

Emerging therapies targeting growth factors in hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) is a primary liver cancer that commonly arises in the background of chronic liver inflammation and/or cirrhosis. Chronic liver inflammation results in the production of different growth factors, remodeling of the microenvironment architecture into fibrosis, and eventually carcinogenesis. Overexpression of some growth factors has been associated with worse prognosis in patients with HCC. Targeted therapies against growth factors may disrupt cell signaling and the mechanisms that allow for cell survival (e.g. angiogenesis, proliferation, metastases).

AREAS COVERED

We herein review potential growth factor targets of HCC and the limited research that exists regarding targeted therapy of these ligands and their receptors. We performed an extensive literature search to investigate preclinical studies, clinical research, and clinical trials.

EXPERT OPINION

Systemic therapy for patients with HCC is continuing to evolve. Anti-angiogenic therapy holds the most promise among targeted therapy for growth factors among patients with HCC. Improving our understanding of growth factors in HCC will hopefully lead to the development of new targeted therapies and strategies for combination therapies with immune checkpoint inhibitors.

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.

Epithelial cell adhesion molecule (EpCAM) regulates HGFR signaling to promote colon cancer progression and metastasis

BACKGROUND

Epithelial cell adhesion molecule (EpCAM) is known to highly expression and promotes cancer progression in many cancer types, including colorectal cancer. While metastasis is one of the main causes of cancer treatment failure, the involvement of EpCAM signaling in metastatic processes is unclear. We propose the potential crosstalk of EpCAM signaling with the HGFR signaling in order to govern metastatic activity in colorectal cancer.

METHODS

Immunoprecipitation (IP), enzyme-linked immunosorbent assay (ELISA), and fluorescence resonance energy transfer (FRET) was conducted to explore the extracellular domain of EpCAM (EpEX) and HGFR interaction. Western blotting was taken to determine the expression of proteins in colorectal cancer (CRC) cell lines. The functions of EpEX in CRC were investigated by proliferation, migration, and invasion analysis. The combined therapy was validated via a tail vein injection method for the metastasis and orthotopic colon cancer models.

RESULTS

This study demonstrates that the EpEX binds to HGFR and induces downstream signaling in colon cancer cells. Moreover, EpEX and HGF cooperatively mediate HGFR signaling. Furthermore, EpEX enhances the epithelial-to-mesenchymal transition and metastatic potential of colon cancer cells by activating ERK and FAK-AKT signaling pathways, and it further stabilizes active β-catenin and Snail proteins by decreasing GSK3β activity. Finally, we show that the combined treatment of an anti-EpCAM neutralizing antibody (EpAb2-6) and an HGFR inhibitor (crizotinib) significantly inhibits tumor progression and prolongs survival in metastatic and orthotopic animal models of colon cancer.

CONCLUSION

Our findings illuminate the molecular mechanisms underlying EpCAM signaling promotion of colon cancer metastasis, further suggesting that the combination of EpAb2-6 and crizotinib may be an effective strategy for treating cancer patients with high EpCAM expression.

Silencing CircEIF3I/miR-526b-5p Axis Epigenetically Targets HGF/c-Met Signal to Hinder the Malignant Growth, Metastasis and Angiogenesis of Hepatocellular Carcinoma

BACKGROUND

Hepatocyte growth factor (HGF)/c-mesenchymal-epithelial transition factor (c-Met) is important for the diagnosis and prognosis of hepatocellular carcinoma (HCC). Circular RNAs (circRNAs) are key regulators of HCC progression, and this study focused on circRNA eukaryotic translation initiation factor 3 subunit I (circEIF3I) with HGF/c-Met in HCC.

METHODS

Levels of circEIF3I, microRNA (miR)-526b-5p, HGF, E-cadherin, N-cadherin, and Vimentin were detected by Gene Expression Omnibus database, quantitative PCR and western blotting. Cell functions were measured by detecting cell growth (cell proliferation assay with WST-1 and EdU, colony formation assay, flow cytometry, caspase 3 activity assay, and nude mouse tumorigenicity assay), metastasis (transwell assay and western blotting), angiogenesis (endothelial tube formation assay). Molecular interaction was determined dual-luciferase reporter assay, RNA immunoprecipitation, and Pearson correlation analysis.

RESULTS

Expression of circEIF3I was upregulated in HCC tissues. Knockdown of circEIF3I suppressed cell proliferation epithelial-mesenchymal transition, migration, invasion and tube formation ability but promoted apoptosis of HCC cells. CircEIF3I could sponge miR-526b-5pto regulate downstream HGF. Functionally, circEIF3I regulation in HCC cell progression was associated with miR-526b-5p sponging function and HGF upregulation could attenuate tumor-inhibiting roles of miR-526b-5p. HCC tumor growth was delayed by interfering circEIF3I.

CONCLUSION

CircEIF3I was an oncogenic circRNA in HCC-, and interfering circEIF3I exhibited anti-HCC activity via circEIF3I-miR-526b-5p-HGF/c-Met pathway.

Engineering the Tumor Immune Microenvironment through Minimally Invasive Interventions

The tumor microenvironment (TME) is a unique landscape that poses several physical, biochemical, and immune barriers to anti-cancer therapies. The rapidly evolving field of immuno-engineering provides new opportunities to dismantle the tumor immune microenvironment by efficient tumor destruction. Systemic delivery of such treatments can often have limited local effects, leading to unwanted offsite effects such as systemic toxicity and tumor resistance. Interventional radiologists use contemporary image-guided techniques to locally deliver these therapies to modulate the immunosuppressive TME, further accelerating tumor death and invoking a better anti-tumor response. These involve local therapies such as intratumoral drug delivery, nanorobots, nanoparticles, and implantable microdevices. Physical therapies such as photodynamic therapy, electroporation, hyperthermia, hypothermia, ultrasound therapy, histotripsy, and radiotherapy are also available for local tumor destruction. While the interventional radiologist can only locally manipulate the TME, there are systemic offsite recruitments of the immune response. This is known as the abscopal effect, which leads to more significant anti-tumoral downstream effects. Local delivery of modern immunoengineering methods such as locoregional CAR-T therapy combined with immune checkpoint inhibitors efficaciously modulates the immunosuppressive TME. This review highlights the various advances and technologies available now to change the TME and revolutionize oncology from a minimally invasive viewpoint.

Cytokines and Hepatocellular Carcinoma: Biomarkers of a Deadly Embrace

Hepatocellular carcinoma (HCC) represents a worldwide health matter with a major care burden, high prevalence, and poor prognosis. Its pathogenesis mainly varies depending on the underlying etiological factors, although it develops from liver cirrhosis in the majority of cases. This review summarizes the role of the most interesting soluble factors as biomarkers for early diagnosis and as recommended targets for treatment in accordance with the new challenges in precision medicine. In the premalignant environment, inflammatory cells release a wide range of cytokines, chemokines, growth factors, prostaglandins, and proangiogenic factors, making the liver environment more suitable for hepatocyte tumor progression that starts from acquired genetic mutations. A complex interaction of pro-inflammatory (IL-6, TNF-α) and anti-inflammatory cytokines (TGF-α and -β), pro-angiogenic molecules (including the Angiopoietins, HGF, PECAM-1, HIF-1α, VEGF), different transcription factors (NF-kB, STAT-3), and their signaling pathways are involved in the development of HCC. Since cytokines are expressed and released during the different stages of HCC progression, their measurement, by different available methods, can provide in-depth information on the identification and management of HCC.

Fangchinoline abrogates growth and survival of hepatocellular carcinoma by negative regulation of c-met/HGF and its associated downstream signaling pathways

Among all cancers, hepatocellular carcinoma (HCC) remains a lethal disease with limited treatment options. In this study, we have analyzed the possible inhibitory effects of Fangchinoline (FCN) on c-Met, a protein known to regulate the rapid phosphorylation of downstream signals, as well as mediate aberrant growth, metastasis, survival, and motility in cancer. FCN inhibited the activation of c-Met and its downstream signals PI3K, AKT, mTOR, MEK, and ERK under in vitro settings. Moreover, c-Met gene silencing lead to suppression of PI3K/AKT/mTOR and MEK/ERK signaling pathways, and induced apoptotic cell death upon exposure to FCN. In addition, FCN markedly inhibited the expression of the various oncogenic proteins such as Bcl-2/xl, survivin, IAP-1/2, cyclin D1, and COX-2. In vivo studies in HepG2 cells xenograft mouse model showed that FCN could significantly attenuate the tumor volume and weight, without affecting significant loss in the body weight. Similar to in vitro studies, expression level of c-Met and PI3K/AKT/mTOR, MEK/ERK signals was also suppressed by FCN in the tissues obtained from mice. Therefore, the novel findings of this study suggest that FCN can potentially function as a potent anticancer agent against HCC.

CD44v6+ Hepatocellular Carcinoma Cells Maintain Stemness Properties through Met/cJun/Nanog Signaling

Cancer stem cells (CSCs) are characterized by their self-renewal and differentiation abilities. CD44v6 is a novel CSC marker that can activate various signaling pathways. Here, we hypothesized that the HGF/Met signaling pathway promotes stemness properties in CD44v6+ hepatocellular carcinoma (HCC) cells via overexpression of the transcription factor, cJun, thus representing a valuable target for HCC therapy. Magnetic activated cell sorting was used to separate the CD44v6+ from CD44v6- cells, and Met levels were regulated using lentiviral particles and the selective Met inhibitor, PHA665752. An orthotopic liver xenograft tumor model was used to assess the self-renewal ability of CD44v6+ cells in immunodeficient NOD/SCID mice. Luciferase reporter and chromatin immunoprecipitation assays were also conducted using cJun-overexpressing 293 T cells to identify the exact binding site of cJun in the Nanog promoter. Our data demonstrate that CD44v6 is an ideal surface marker of liver CSCs. CD44v6+ HCC cells express higher levels of Met and possess self-renewal and tumor growth abilities. Xenograft liver tumors were smaller in nude mice injected with shMet HCC cells. Immunohistochemical analysis of liver tissue specimens revealed that high Met levels in HCC cells were associated with poor patient prognosis. Further, a cJun binding site was identified 1700 bp upstream of the Nanog transcription start site and mutation of the cJun binding site reduced Nanog expression. In conclusion, the HGF/Met signaling pathway is important for maintenance of stemness in CD44v6+ HCC cells by enhancing expression of cJun, which binds 1700 bp upstream of the Nanog transcription start site.

Custom gene expression panel for evaluation of potential molecular markers in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related mortality worldwide. It is a highly heterogeneous disease with poor prognosis and limited treatment options, which highlights the need for reliable biomarkers. This study aims to explore molecular markers that allow stratification of HCC and may lead to better prognosis and treatment prediction.

MATERIALS AND METHODS

We studied 20 candidate genes (HCC hub genes, potential drug target genes, predominant somatic mutant genes) retrieved from literature and public databases with potential to be used as the molecular markers. We analysed expression of the genes by RT-qPCR in 30 HCC tumour and adjacent non-tumour paired samples from Vietnamese patients. Fold changes in expression were then determined using the 2^-∆∆CT method, and unsupervised hierarchical clustering was generated using Cluster v3.0 software.

RESULTS

Clustering of expression data revealed two subtypes of tumours (proliferative and normal-like) and four clusters for genes. The expression profiles of the genes TOP2A, CDK1, BIRC5, GPC3, IGF2, and AFP were strongly correlated. Proliferative tumours were characterized by high expression of the c-MET, ARID1A, CTNNB1, RAF1, LGR5, and GLUL1 genes. TOP2A, CDK1, and BIRC5 HCC hub genes were highly expressed (> twofold) in 90% (27/30), 83% (25/30), and 83% (24/30) in the tissue samples, respectively. Among the drug target genes, high expression was observed in the GPC3, IGF2 and c-MET genes in 77% (23/30), 63% (19/30), and 37% (11/30), respectively. The somatic mutant Wnt/ß-catenin genes (CTNNB1, GLUL and LGR5) and TERT were highly expressed in 40% and 33% of HCCs, respectively. Among the HCC marker genes, a higher percentage of tumours showed GPC3 expression compared to AFP expression [73% (23/30) vs. 43% (13/30)].

CONCLUSION

The custom panel and molecular markers from this study may be useful for diagnosis, prognosis, biomarker-guided clinical trial design, and prediction of treatment outcomes.

The study of direct and indirect effects of radiofrequency ablation on tumor microenvironment in liver tumor animal model

Background

Direct and indirect effects of radiofrequency ablation (RFA) on tumor microenvironment of the liver tumor have been noted, which was reported to be related to a variety of tyrosine protein kinase or cytokinetic pathway, but have not been thoroughly investigated and conclusive.

Purpose

To elucidate direct and indirect effects of RFA on tumor microenvironment in the liver tumor model, and to explore the role of the specific inhibitor in tumor growth by targeting the key pathway of RFA.

Materials and methods

One hundred and ten mice with H22 liver tumor were used in animal experiments. Eighty-four mice were randomized into three groups: control, direct RFA and indirect RFA (a block slide was inside the middle of the tumor). The growth rate of the residual tumor after RFA was calculated (n = 8 each group) and the pathologic changes at different time points (6 h, 24 h, 72 h and 7d after RFA) were evaluated (n = 5 in each subgroup). After semi-quantitative analysis of the pathological staining, the most significant marker after RFA was selected. Then, the specific inhibitor (PHA) was applied with RFA and the tumor growth and pathological changes were evaluated and compared with RFA alone. The Kruskal-Wallis test was used for evaluating the significance of different treatments in the pathological positive rate of specific markers in tumor. The two-way analysis of variance was used to determine the significance of treatment in tumor growth or body weight.

Results

The growth rate of the residual tumor in the direct RFA group was faster than the indirect RFA group (P = 0.026). The pathological analysis showed the expression of HSP70 (73 ± 13% vs 27 ± 9% at 24 h, P < 0.001), SMA (70 ± 18% vs 18 ± 7% at 6 h, P < 0.001) and Ki-67 (51 ± 11% vs 33 ± 14% at 7d, P < 0.001) in the direct RFA group was higher than those in the indirect RFA group after RFA. On the other hand, the expression of c-Met (38 ± 11% vs 28 ± 9% at 24 h, P = 0.01), IL-6 (41 ± 10% vs 25 ± 9% at 24 h, P < 0.001) and HIF-α (48 ± 10% vs 28 ± 8% at 24 h, P < 0.001) in the indirect RFA group was higher than those in the direct RFA group. And the expression of c-Met increased mostly in both direct and indirect RFA group compared to the baseline (53 and 65% at 72 h). Then the specific inhibitor of c-Met-PHA was applied with RFA. The growth rate of the tumor was significantly slower in the RFA + PHA group than the RFA alone group (1112.9 ± 465.6 mm³ vs 2162.7 ± 911.1 mm³ at day 16, P = 0.02).

Conclusion

Direct and indirect effects of RFA on tumor microenvironment changed at different time points and resulted in increased residual tumor growth in the animal model. It can be potentially neutralized with specific inhibitor of related pathways, such as tyrosine-protein kinase c-Met.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09730-x.

Antibody-drug conjugate as targeted therapeutics against hepatocellular carcinoma: preclinical studies and clinical relevance

An antibody-drug conjugate (ADC) is an advanced chemotherapeutic option with immense promises in treating many tumor. They are designed to selectively attack and kill neoplastic cells with minimal toxicity to normal tissues. ADCs are complex engineered immunoconjugates that comprise a monoclonal antibody for site-directed delivery and cytotoxic payload for targeted destruction of malignant cells. Therefore, it enables the reduction of off-target toxicities and enhances the therapeutic index of the drug. Hepatocellular carcinoma (HCC) is a solid tumor that shows high heterogeneity of molecular phenotypes and is considered the second most common cause of cancer-related death. Studies show enormous potential for ADCs targeting GPC3 and CD24 and other tumor-associated antigens in HCC with their high, selective expression and show potential outputs in preclinical evaluations. The review mainly highlights the preclinical evaluation of different antigen-targeted ADCs such as MetFab-DOX, Anti-c-Met IgG-OXA, Anti CD 24, ANC-HN-01, G7mab-DOX, hYP7-DCand hYP7-PC, Anti-CD147 ILs-DOX and AC133-vcMMAF against hepatocellular carcinoma and its future relevance.

P53 is a risk factor of de-novo hepatitis C-related hepatocellular carcinoma treated with direct-acting antivirals: a case-control study

BACKGROUND

The mechanisms underlying de-novo hepatocellular carcinoma (HCC) after direct-acting antivirals (DAAs) is still under investigation. This work aims to study P53 and hepatocyte growth factor (HGF) as possible diagnostics of de-novo hepatocellular carcinoma (HCC) following DAAs in comparison to alpha-fetoprotein (AFP).

METHOD

This case-control study included 166 patients with liver cirrhosis divided into group-1: patients without HCC (n = 50), group-2: patients with de-novo HCC following DAAs, and achieved sustained virological response (n = 50), and group-3: patients with HCC without DAAs (n = 66). P53 antibody and HGF were determined using a quantitative sandwich enzyme immunoassay technique (Cusabio Co, Houston, USA).

RESULTS

Patients with HCC showed significantly higher HGF. Patients with de-novo HCC following DAAs had significantly higher P53 than HCC without DAAs (P < 0.0001). The multiple logistic regression analysis showed that the P53 levels were significantly associated with susceptibility to de-novo HCC (P value = 0.004). The best overall formula was constructed for HCC diagnosis by entering significant markers into the regression model. A three markers model was developed = (1.22 + AFP X 0.002 + HGF X 0.001 + P53 X 0.001). The medians (percentiles) of combined three markers were 1.8 (1.0-2.1) in liver cirrhosis and 2.2 (2.0-2.9) in all HCC (P < 0.00001). The AUC of combined markers was greater than a single marker. The AUC was 0.87 to differentiate HCC from liver cirrhosis; AUC 0.91 to differentiate de-novo HCC after DAAs from liver cirrhosis.

CONCLUSION

P53 may serve as a diagnostic marker for de-novo HCC after DAAs therapy. HGF may serve as a diagnostic marker for HCC but not specific for de-novo HCC after DAAs therapy.

Liver Fibrosis-From Mechanisms of Injury to Modulation of Disease

The Transregional Collaborative Research Center "Organ Fibrosis: From Mechanisms of Injury to Modulation of Disease" (referred to as SFB/TRR57) was funded for 13 years (2009-2021) by the German Research Council (DFG). This consortium was hosted by the Medical Schools of the RWTH Aachen University and Bonn University in Germany. The SFB/TRR57 implemented combined basic and clinical research to achieve detailed knowledge in three selected key questions: (i) What are the relevant mechanisms and signal pathways required for initiating organ fibrosis? (ii) Which immunological mechanisms and molecules contribute to organ fibrosis? and (iii) How can organ fibrosis be modulated, e.g., by interventional strategies including imaging and pharmacological approaches? In this review we will summarize the liver-related key findings of this consortium gained within the last 12 years on these three aspects of liver fibrogenesis. We will highlight the role of cell death and cell cycle pathways as well as nutritional and iron-related mechanisms for liver fibrosis initiation. Moreover, we will define and characterize the major immune cell compartments relevant for liver fibrogenesis, and finally point to potential signaling pathways and pharmacological targets that turned out to be suitable to develop novel approaches for improved therapy and diagnosis of liver fibrosis. In summary, this review will provide a comprehensive overview about the knowledge on liver fibrogenesis and its potential therapy gained by the SFB/TRR57 consortium within the last decade. The kidney-related research results obtained by the same consortium are highlighted in an article published back-to-back in Frontiers in Medicine.

The Emerging Role of c-Met in Carcinogenesis and Clinical Implications as a Possible Therapeutic Target

Background

c-MET is a receptor tyrosine kinase receptor (RTK) for the hepatocyte growth factor (HGF). The binding of HGF to c-MET regulates several cellular functions: differentiation, proliferation, epithelial cell motility, angiogenesis, and epithelial-mesenchymal transition (EMT). Moreover, it is known to be involved in carcinogenesis. Comprehension of HGF-c-MET signaling pathway might have important clinical consequences allowing to predict prognosis, response to treatment, and survival rates based on its expression and dysregulation. Discussion. c-MET represents a useful molecular target for novel engineered drugs. Several clinical trials are underway for various solid tumors and the development of new specific monoclonal antibodies depends on the recent knowledge about the definite c-MET role in each different malignance. Recent clinical trials based on c-MET molecular targets result in good safety profile and represent a promising therapeutic strategy for solid cancers, in monotherapy or in combination with other target drugs.

Conclusion

The list of cell surface receptors crosslinking with the c-MET signaling is constantly growing, highlighting the importance of this pathway for personalized target therapy. Research on the combination of c-MET inhibitors with other drugs will hopefully lead to discovery of new effective treatment options.

Survival of HT29 cancer cells is influenced by hepatocyte growth factor receptor inhibition through modulation of self-DNA-triggered TLR9-dependent autophagy response

HGFR activation drives the malignant progression of colorectal cancer, and its inhibition displays anti-autophagic activity. The interrelated role of HGFR inhibition and TLR9/autophagy signaling in HT29 cancer cells subjected to modified self-DNA treatments has not been clarified. We analyzed this complex interplay with cell metabolism and proliferation measurements, TLR9, HGFR and autophagy inhibitory assays and WES Simple Western blot-based autophagy flux measurements, gene expression analyses, immunocytochemistry, and transmission electron microscopy. The overexpression of MyD88 and caspase-3 was associated with enhanced HT29 cell proliferation, suggesting that incubation with self-DNAs could suppress the apoptosis-induced compensatory cell proliferation. HGFR inhibition blocked the proliferation-reducing effect of genomic and hypermethylated, but not that of fragmented DNA. Lowest cell proliferation was achieved with the concomitant use of genomic DNA, HGFR inhibitor, and chloroquine, when the proliferation stimulating effect of STAT3 overexpression could be outweighed by the inhibitory effect of LC3B, indicating the putative involvement of HGFR-mTOR-ULK1 molecular cascade in HGFR inhibitor-mediated autophagy. The most intense cell proliferation was caused by the co-administration of hypermethylated DNA, TLR9 and HGFR inhibitors, when decreased expression of both canonical and non-canonical HGFR signaling pathways and autophagy-related genes was present. The observed ultrastructural changes also support the context-dependent role of HGFR inhibition and autophagy on cell survival and proliferation. Further investigation of the influence of the studied signaling pathways and cellular processes can provide a basis for novel, individualized anti-cancer therapies.

The prominence of potential biomarkers in the diagnosis and management of hepatocellular carcinoma: Current scenario and future anticipation

Hepatocellular carcinoma (HCC) is one of the most aggressive and truculent types of cancer. Early detection of HCC is a massive concern that can boost the overall survival rates of HCC patients. As a result, there is a continual quest for advancements in screening, diagnosis, and treatment strategies to enhance the prognosis at its early stages. However, the confluence of inflammation and cirrhosis hampers the early detection of HCC. The analysis of different types of biomarkers such as tissue biomarkers, serum biomarkers, protein biomarkers, autoantibody markers, and improved imaging techniques has played a vital role in ameliorating HCC monitoring responses. Therefore biomarkers that can identify HCC early with a high degree of sensitivity and specificity might be prodigiously serviceable in the diagnosis and treatment of this notorious disorder. This study offers an overview of the contemporary understanding of several types of biomarkers implicated in hepatocarcinogenesis and their applications in monitoring, diagnosis, and prognosis presage. In additament, we address the role of image techniques associated with HCC diagnosis.

Zinc Finger E-Box Binding Homeobox 1 Promotes Cholangiocarcinoma Progression Through Tumor Dedifferentiation and Tumor-Stroma Paracrine Signaling

BACKGROUND AND AIMS

Zinc finger E-box binding homeobox 1 (ZEB1) is a transcription factor that promotes metastatic and stem cell features, which has been associated with poor prognosis in cholangiocarcinoma (CCA), a desmoplastic cancer enriched in cancer-associated fibroblasts (CAFs). We aimed to define ZEB1 regulatory functions in malignant and stromal compartments of CCA.

APPROACH AND RESULTS

Bioinformatic and immunohistochemical analyses were performed to determine correlations between ZEB1 and markers of progressiveness in human intrahepatic CCA (iCCA). Gain-of-function and loss-of-function models were generated in CCA cells and liver myofibroblasts as a model of CAFs. Conditioned media (CM) was used to unravel tumor-stroma interplay. In vivo experiments were performed using a xenograft CCA model. ZEB1 expression in tumor cells of human iCCA was associated with undifferentiated tumor and vascular invasion. In vitro, ZEB1 promoted epithelial-mesenchymal transition and stemness in tumor cells, leading to cell migration and spheroid formation. In vivo, ZEB1-overexpressing CCA cells formed larger tumors with more abundant stroma. Expression of cellular communication network factor 2 (CCN2, encoding connective tissue growth factor [CTGF]) was increased in tumor cells from ZEB1-overexpressing xenografts and correlated with ZEB1 expression in human tumors. In vitro, CM from ZEB1-overexpressing tumor cells or recombinant CTGF induced myofibroblast proliferation. ZEB1 was also expressed by CAFs in human CCA, and its expression correlated with CCN2 in myofibroblasts and CCA stroma. In mice, cotransplantation of CCA cells with ZEB1-depleted myofibroblasts reduced CCA progressiveness compared to CCA cells/ZEB1-expressing myofibroblasts. Furthermore, ZEB1 controls the expression of paracrine signals (i.e., HGF and IL6) in tumor cells and myofibroblasts.

CONCLUSIONS

ZEB1 plays a key role in CCA progression by regulating tumor cell-CAF crosstalk, leading to tumor dedifferentiation and CAF activation.

Novel Pyridine Bioisostere of Cabozantinib as a Potent c-Met Kinase Inhibitor: Synthesis and Anti-Tumor Activity against Hepatocellular Carcinoma

Two novel bioisosteres of cabozantinib, 3 and 4, were designed and synthesized. The benzene ring in the center of the cabozantinib structure was replaced by trimethylpyridine (3) and pyridine (4), respectively. Surprisingly, the two compounds showed extremely contrasting mesenchymal-epithelial transition factor (c-Met) inhibitory activities at 1 μM concentration (4% inhibition of 3 vs. 94% inhibition of 4). The IC₅₀ value of compound 4 was 4.9 nM, similar to that of cabozantinib (5.4 nM). A ligand-based docking study suggested that 4 includes the preferred conformation for the binding to c-Met in the conformational ensemble, but 3 does not. The anti-proliferative activity of compound 4 against hepatocellular carcinoma (Hep3B and Huh7) and non-small-cell lung cancer (A549 and H1299) cell lines was better than that of cabozantinib, whereas 3 did not show a significant anti-proliferative activity. Moreover, the tumor selectivity of compound 4 toward hepatocellular carcinoma cell lines was higher than that of cabozantinib. In the xenograft chick tumor model, compound 4 inhibited Hep3B tumor growth to a much greater extent than cabozantinib. The present study suggests that compound 4 may be a good therapeutic candidate against hepatocellular carcinoma.

Immunologic markers and risk of hepatocellular carcinoma in hepatitis B virus- and hepatitis C virus-infected individuals

BACKGROUND

Clinical and experimental studies suggest immunologic proteins contribute to hepatocellular carcinoma (HCC) development.

AIM

To evaluate circulating immunologic markers and HCC risk.

METHODS

From a Taiwanese cohort of chronically hepatitis B virus (HBV)-infected individuals followed over time (REVEAL-HBV), we sampled 175 who developed HCC, 117 cirrhosis only, and 165 non-cirrhotic controls. From a similar Taiwanese cohort of chronically hepatitis C virus (HCV)-infected individuals (REVEAL-HCV), we included 94 individuals who developed HCC, 68 cirrhosis only and 100 non-cirrhotic controls. We compared pre-diagnostic plasma levels of 102 markers in HCC cases to non-cirrhotic and cirrhotic controls using polytomous logistic regression. A priori markers included insulin-like growth factor binding protein-3 (IGFBP-3), intercellular adhesion molecule 1 (ICAM-1) and interleukin 6 (IL-6). P-values for other markers were corrected for multiple testing (false discovery rate = 10%).

RESULTS

In both REVEAL-HBV and REVEAL-HCV, increasing levels of ICAM-1 were associated with increased risk of HCC compared to non-cirrhotic controls (P-trend 0.02 and 0.001, respectively). In both REVEAL-HBV and REVEAL-HCV, two novel markers [C-X-C motif chemokine 11 (CXCL11) and hepatocyte growth factor (HGF)] were positively associated [strongest odds ratio_{quartile 4 versus 1} (OR) 4.55 for HGF in HCV], while two [complement factor H related 5 (CFHR5) and stem cell factor (SCF)] were negatively associated (strongest OR_Q4vQ1 0.14 for SCF in HCV) with development of HCC compared to non-cirrhotic controls.

CONCLUSIONS

We confirmed the association for ICAM-1 and identified 4 additional proteins associated with HBV- and HCV-related HCC. These findings highlight the importance of immunologic processes in HBV- and HCV-related HCC.

Second-line cabozantinib after sorafenib treatment for advanced hepatocellular carcinoma: a subgroup analysis of the phase 3 CELESTIAL trial

Objective

In the phase 3 CELESTIAL trial, cabozantinib improved overall survival (OS) and progression-free survival (PFS) compared with placebo in patients with previously treated advanced hepatocellular carcinoma (HCC). This subgroup analysis evaluated cabozantinib in patients who had received sorafenib as the only prior systemic therapy.

Methods

CELESTIAL randomised (2:1) patients with advanced HCC and Child–Pugh class A liver function to treatment with cabozantinib (60 mg daily) or placebo. Eligibility required prior treatment with sorafenib, and patients could have received ≤2 prior systemic regimens. The primary endpoint was OS. Outcomes in patients who had received sorafenib as the only prior therapy were analysed by duration of prior sorafenib (<3 months, 3 to <6 months and ≥6 months).

Results

Of patients who had received only prior sorafenib, 331 were randomised to cabozantinib and 164 to placebo; 136 patients had received sorafenib for <3 months, 141 for 3 to <6 months and 217 for ≥6 months. Cabozantinib improved OS relative to placebo in the overall second-line population who had received only prior sorafenib (median 11.3 vs 7.2 months; HR=0.70, 95% CI 0.55 to 0.88). This improvement was maintained in analyses by prior sorafenib duration with longer duration generally corresponding to longer median OS—median OS 8.9 vs 6.9 months (HR=0.72, 95% CI 0.47 to 1.10) for prior sorafenib <3 months, 11.5 vs 6.5 months (HR=0.65, 95% CI 0.43 to 1.00) for 3 to <6 months and 12.3 vs 9.2 months (HR=0.82, 95% CI 0.58 to 1.16) for ≥6 months. Cabozantinib also improved PFS in all duration subgroups. Safety data were consistent with the overall study population.

Conclusion

Cabozantinib improved efficacy outcomes versus placebo in the second-line population who had received only prior sorafenib irrespective of duration of prior sorafenib treatment, further supporting the utility of cabozantinib in the evolving treatment landscape of HCC.

Clinical trial number

NCT01908426.

Association between the HGF/c‑MET signaling pathway and tumorigenesis, progression and prognosis of hepatocellular carcinoma (Review)

Hepatocellular carcinoma (HCC) is one of the most aggressive and lethal malignancies with a rising incidence, and is characterized by rapid progression, frequent metastasis, late diagnosis, high postoperative recurrence and poor prognosis. Therefore, novel treatment strategies for HCC, particularly advanced HCC, are urgently required. The hepatocyte growth factor (HGF)/c‑mesenchymal‑epithelial transition receptor (c‑MET) axis is a key signaling pathway in HCC and is strongly associated with its highly malignant features. Available treatments based on HGF/c‑MET inhibition may prolong the lifespan of patients with HCC; however, they do not achieve the desired therapeutic effects. The aim of the present article was to review the basic knowledge regarding the role of the HGF/c‑MET signaling pathway in HCC, and examine the association between the HGF/c‑MET signaling pathway and the tumorigenesis, progression and prognosis of HCC.

Higher cMET dependence of sacral compared to clival chordoma cells: contributing to a better understanding of cMET in chordoma

Chordomas are rare slow growing, malignant bone tumors of the axial skeleton with no approved medical treatment. As the majority of chordomas express cMET and its ligand, HGF, and crosstalks between EGFR and MET-signaling exist, we aimed to explore cMET activity in chordoma cell lines and clinical samples. We investigated nine chordoma patients and four chordoma cell lines for cMET expression. Two clival and two sacral chordoma cell lines were tested for chromosomal abnormalities of the MET gene locus; we studied the influence of HGF on the autocrine secretion and migration behavior, as well as protein expression and phosphorylation. Two MET/ALK inhibitors were investigated for their effects on cell viability, cell cycle, cyclin alterations, apoptosis, and downstream signaling pathways. Moderate and strong expression of membrane and cytoplasmic cMET in chordoma patients and cell lines used, as well as concentration-dependent increase in phospho cMET expression after HGF stimulation in all four chordoma cell lines was shown. U-CH2, MUG-Chor1, and UM-Chor1 are polysomic for MET. Chordoma cell lines secreted EGF, VEGF, IL-6, and MMP9 upon HGF-stimulation. Sacral cell lines showed a distinct HGF-induced migration. Both inhibitors dose-dependently inhibited cell growth, induce apoptosis and cell-cycle arrest, and suppress downstream pathways. Heterogeneous responses obtained in our in vitro setting indicate that cMET inhibitors alone or in combination with other drugs might particularly benefit patients with sacral chordomas.

High glucose induced c-Met activation promotes aggressive phenotype and regulates expression of glucose metabolism genes in HCC cells

Hepatocellular carcinoma (HCC) is strongly associated with metabolic dysregulations/deregulations and hyperglycemia is a common metabolic disturbance in metabolic diseases. Hyperglycemia is defined to promote epithelial to mesenchymal transition (EMT) of cancer cells in various cancers but its molecular contribution to HCC progression and aggressiveness is relatively unclear. In this study, we analyzed the molecular mechanisms behind the hyperglycemia-induced EMT in HCC cell lines. Here, we report that high glucose promotes EMT through activating c-Met receptor tyrosine kinase via promoting its ligand-independent homodimerization. c-Met activation is critical for high glucose induced acquisition of mesenchymal phenotype, survival under high glucose stress and reprogramming of cellular metabolism by modulating glucose metabolism gene expression to promote aggressiveness in HCC cells. The crucial role of c-Met in high glucose induced EMT and aggressiveness may be the potential link between metabolic syndrome-related hepatocarcinogenesis and/or HCC progression. Considering c-Met inhibition in hyperglycemic patients would be an important complementary strategy for therapy that favors sensitization of HCC cells to therapeutics.

Critical signaling pathways governing hepatocellular carcinoma behavior; small molecule-based approaches

Hepatocellular carcinoma (HCC) is the second leading cause of death due to cancer. Although there are different treatment options, these strategies are not efficient in terms of restricting the tumor cell's proliferation and metastasis. The liver tumor microenvironment contains the non-parenchymal cells with supportive or inhibitory effects on the cancerous phenotype of HCC. Several signaling pathways are dis-regulated in HCC and cause uncontrolled cell propagation, metastasis, and recurrence of liver carcinoma cells. Recent studies have established new approaches for the prevention and treatment of HCC using small molecules. Small molecules are compounds with a low molecular weight that usually inhibit the specific targets in signal transduction pathways. These components can induce cell cycle arrest, apoptosis, block metastasis, and tumor growth. Devising strategies for simultaneously targeting HCC and the non-parenchymal population of the tumor could lead to more relevant research outcomes. These strategies may open new avenues for the treatment of HCC with minimal cytotoxic effects on healthy cells. This study provides the latest findings on critical signaling pathways governing HCC behavior and using small molecules in the control of HCC both in vitro and in vivo models.

Long non-coding RNA RP11-284P20.2 promotes cell proliferation and invasion in hepatocellular carcinoma by recruiting EIF3b to induce c-met protein synthesis

A newly identified lncRNA designated as RP11-284P20.2 has been identified to be up-regulated in hepatocellular carcinoma (HCC), but its role in HCC remain poorly understood. Quantitative PCR and immunocytochemical analysis were performed using the HCC tissues to identify the potential interaction partners of RP11-284P20.2. Moreover, RP11-284P20.2 was knocked down in HCC cell lines, HepG2 and SMMC7721, to investigate the influence of this lncRNA on cell growth properties. Additionally, RNA fluorescence in situ hybridization and immunofluorescence, RNA immunoprecipitation, and RNA pull-down assays were performed to determine the interaction of RP11-284P20.2 with c-met mRNA and eukaryotic translation initiation factor 3b (EIF3b). Silencing RP11-284P20.2 inhibited cell viability, migration, invasion, and colony formation, and increased apoptosis. Overexpression of c-met abolished these effects of RP11-284P20.2 in HCC cells. Histopathological examination showed that HCC tissues with high RP11-284P20.2 expression had higher c-met protein level than that in HCC tissues with low RP11-284P20.2 expression. However, there was no positive correlation between the expression levels of RP11-284P20.2 and c-met mRNA. RP11-284P20.2 knockdown led to a decease in c-met protein expression level, but did not affect the c-met mRNA expression level. These data suggest that RP11-284P20.2 regulates c-met protein expression level, which is independent of c-Met mRNA expression level. It was also confirmed that RP11-284P20.2 has high affinity toward both c-met mRNA and EIF3b protein, and hence RP11-284P20.2 probably recruits EIF3b protein to c-met mRNA and further facilitates its translation. RP11-284P20.2 promotes cell proliferation and invasion in hepatocellular carcinoma by recruiting EIF3b to induce c-met protein synthesis.

Loss of Apc Cooperates with Activated Oncogenes to Induce Liver Tumor Formation in Mice

Hepatocellular carcinoma (HCC) and hepatoblastoma are the major types of primary liver cancer in adulthood and childhood, respectively. Wnt/β-catenin signaling deregulation is one of the most frequent genetic events in hepatocarcinogenesis. APC regulator of WNT signaling pathway (APC) encodes an inhibitor of the Wnt cascade and acts as a tumor suppressor. Germline defects of the APC gene lead to familial adenomatous polyposis, and its somatic mutations occur in multiple tumor types. However, the contribution of APC in hepatocarcinogenesis remains unclear. Therefore, APC mutations and expression patterns were examined in human HCC and hepatoblastoma samples. Whether loss of Apc alone or in cooperation with other oncogenes triggers liver tumor development in vivo was also investigated. sgApc alone could not drive liver tumor formation, but synergized with activated oncogenes (YapS127A, TazS89A, and c-Met) to induce hepatocarcinogenesis. Mechanistically, Apc deletion induced the activation of β-catenin and its downstream targets in mouse liver tumors. Furthermore, Ctnnb1 ablation or TCF4-mediated transcription blockade completely prevented liver tumor formation, indicating the requirement of a functional β-catenin pathway for loss of Apc-driven hepatocarcinogenesis. This study shows that a subset of HCC patients with loss-of-function APC mutations might benefit from therapeutic strategies targeting the Wnt/β-catenin pathway.

Identification of novel CD44v6-binding peptides that block CD44v6 and deliver a pro-apoptotic peptide to tumors to inhibit tumor growth and metastasis in mice

CD44v6, a splice variant of the cell surface glycoprotein CD44, acts as a co-receptor for c-Met and is upregulated in tumors with high metastatic potential.

Methods: We screened a phage-displayed peptide library for peptides that selectively bind to CD44v6-overexpressing cells and exploited them to block CD44v6 and deliver a pro-apoptotic peptide to tumors for cancer therapy.

Results: CNLNTIDTC (NLN) and CNEWQLKSC (NEW) peptides bound preferentially to CD44v6-high cells than to CD44v6-low cells. The binding affinities of NLN and NEW to CD44v6 protein were 253 ± 79 and 85 ± 18 nM, respectively. Peptide binding to CD44v6-high cells was inhibited by the knockdown of CD44v6 gene expression and competition with an anti-CD44v6 antibody. A pull-down assay with biotin-labeled peptides enriched CD44v6 from cell lysates. NLN and NEW induced CD44v6 internalization and inhibited hepatocyte growth factor-induced c-Met internalization, c-Met and Erk phosphorylation, and cell migration and invasion. In mice harboring tumors, intravenously administered NLN and NEW homed to the tumors and inhibited metastasis to the lungs. When combined with crizotinib, a c-Met inhibitor, treatment with each peptide inhibited metastatic growth more efficiently than each peptide or crizotinib alone. In addition, KLAKLAKKLAKLAK pro-apoptotic peptide guided by NLN (NLN-KLA) or NEW (NEW-KLA) killed tumor cells and inhibited tumor growth and metastasis. No significant systemic side effects were observed after treatments.

Conclusions: These results suggest that NLN and NEW are promising metastasis-inhibiting peptide therapeutics and targeting moieties for CD44v6-expressing metastases.

Anti-neoplastic Effect of Ginkgolide C through Modulating c-Met Phosphorylation in Hepatocellular Carcinoma Cells

Ginkgolide C (GGC) derived from Ginkgo biloba, has been reported to exhibit various biological functions. However, the anti-neoplastic effect of GGC and its mechanisms in liver cancer have not been studied previously. Hepatocyte growth factor (HGF)/c-mesenchymal-epithelial transition receptor (c-Met) pathway can regulate tumor growth and metastasis in hepatocellular carcinoma (HCC) cells. This study aimed to evaluate the anti-neoplastic effect of GGC against HCC cells and we observed that GGC inhibited HGF-induced c-Met and c-Met downstream oncogenic pathways, such as PI3K/Akt/mTOR and MEK/ERK. In addition, GGC also suppressed the proliferation of expression of diverse tumorigenic proteins (Bcl-2, Bcl-xL, Survivin, IAP-1, IAP-2, Cyclin D1, and COX-2) and induced apoptosis. Interestingly, the silencing of c-Met by small interfering RNA (siRNA) mitigated c-Met expression and enhanced GGC-induced apoptosis. Moreover, it was noted that GGC also significantly reduced the invasion and migration of HCC cells. Overall, the data clearly demonstrate that GGC exerts its anti-neoplastic activity through modulating c-Met phosphorylation and may be used as an effective therapy against HCC.

HGF/c-Met Axis: The Advanced Development in Digestive System Cancer

Numerous studies have indicated that abnormal activation of the HGF/c-Met signaling pathway can lead to cell proliferation, invasiveness, and metastasis of cancers of the digestive system. Moreover, overexpression of c-Met has been implicated in poor prognosis of patients with these forms of cancer, suggesting the possibility for HGF/c-Met axis as a potential therapeutic target. Despite the large number of clinical and preclinical trials worldwide, no significant positive success in the use of anti-HGF/c-Met treatments on cancers of the digestive system has been achieved. In this review, we summarize advanced development of clinical research on HGF/c-Met antibody and small-molecule c-Met inhibitors of cancers of the digestive system and provide a possible direction for future research.

Chinese herbal formula QHF inhibits hepatocellular carcinoma metastasis via HGF/c-Met signaling pathway

Hepatocellular Carcinoma (HCC) is one of the most common malignant tumors, and high recurrence and metastasis are the major obstacles to successful treatment of HCC. Traditional Chinese medicine has little known and unique advantages in the treatment of HCC. Previous studies have confirmed that Chinese herbal formula Qingrejiedu (clears away heat and toxins), Huoxuehuayu (promotes blood flow to remove stasis) and Fuzhengguben (strengthens healthy qi and root) (QHF) has a significant effect on patients with advanced HCC, improves the quality of life and prolongs the survival time of patients significantly. In this study, we investigated the effect of QHF on proliferation, migration and invasion of human high metastatic hepatocellular carcinoma cell line HCCLM3 and its underlying mechanism. The results from our in vitro experiments showed that QHF has the ability to inhibit the proliferation by inducing G2/M phase cell cycle arrest and induce apoptosis. Moreover, QHF can also inhibit migration and invasion of HCCLM3 cells and the expression of the p-c-Met protein in HCCLM3 cells was down-regulated. c-Met is closely related to the metastasis of HCC, then we constructed a stable transfected cell line HepG2-met with high expression of c-Met by transfection. Further study in vivo revealed that c-Met gene will promote the growth of tumors and lung metastases in nude mice, and QHF intervention can reduce tumor lung metastases by inhibiting the HGF/c-Met signaling pathway. In conclusion, our study reveals that QHF can inhibit the proliferation, migration and invasion of HCCLM3, and this effect may be related to inhibiting HGF/c-Met signaling pathway.

SIX4 promotes hepatocellular carcinoma metastasis through upregulating YAP1 and c-MET

Metastasis is the main reason for high mortality in hepatocellular carcinoma (HCC) patients and the molecular mechanism remains unclear. Therefore, it is important to elucidate the mechanism underlying HCC metastasis. Here, we report a novel role of SIX homeobox 4 (SIX4), one of the SIX gene family, in promoting HCC metastasis. The elevated expression of SIX4 was positively correlated with loss of tumor encapsulation, microvascular invasion, higher TNM stage, and poor prognosis in human HCC. SIX4 expression was an independent and significant risk factor for the recurrence and survival in HCC patients. Upregulation of SIX4 promoted HCC invasion and metastasis, whereas downregulation of SIX4 decreased HCC invasion and metastasis. SIX4 transactivated Yes1 associated transcriptional regulator (YAP1) and MET proto-oncogene, receptor tyrosine kinase (MET) expression through directly binding to their promoters. Knockdown of YAP1 and c-MET inhibited SIX4-medicated HCC metastasis, while the stable overexpression of YAP1 and c-MET reversed the decreased metastasis induced by SIX4 knockdown. Hepatocyte growth factor (HGF), the specific ligand of c-MET, upregulated SIX4 expression through ERK/NF-κB pathway. Knockdown of SIX4 significantly decreased HGF-enhanced HCC metastasis. In human HCC tissues, SIX4 expression was positively correlated with nuclear YAP1, c-MET and HGF expression. Patients with positive coexpression of SIX4/ nuclear YAP1, SIX4/c-MET or HGF/SIX4 had the poorest prognosis. Moreover, the combination treatment of YAP1 inhibitor Verteporfin and c-MET inhibitor Capmatinib significantly suppressed SIX4-mediated HCC metastasis. In conclusion, SIX4 is a prognostic biomarker in HCC patients and targeting the HGF-SIX4-c-MET positive feedback loop may provide a promising strategy for the treatment of SIX4-driven HCC metastasis.

Identification of P-Rex1 in the Regulation of Liver Cancer Cell Proliferation and Migration via HGF/c-Met/Akt Pathway

Background

Rho-GTPases and their activators, guanine nucleotide exchange factors (GEFs), are increasingly being recognized as essential mediators of oncogenic signaling. Although it is known that P-Rex1, a member of the Dbl family of GEFs for the Rac small GTPase, contributes to the migration of cancer cells, its exact role in liver cancer and the underlying mechanisms remain unclear.

Materials and Methods

Public datasets from the Gene Expression Omnibus database (GEO) and clinical liver cancer samples were analyzed to explore the expression of P-Rex1. P-Rex1 knockdown and overexpression cell lines were established using a recombinant lentiviral transfection system. BrdU and colony formation assays were performed to determine cell viability. Migratory capacity was analyzed using a transwell migration assay and an in vitro wound-healing assay. Nude mice bearing subcutaneous xenograft tumors were established to determine the effects of P-Rex1 on tumorigenesis in vivo. The role of P-Rex1 in hepatocarcinogenesis was determined through Western blot and co-immunoprecipitation.

Results

Induced expression of endogenous P-Rex1 was identified in liver cancer tumors when compared with adjacent nonmalignant tissues from clinical data. In response to HGF treatment, P-Rex1-knockdown cells displayed reduced proliferation and migration in vitro as well as reduced xenograft tumor growth in vivo. Overexpression of P-Rex1 promoted liver cancer cell proliferation and migration. P-Rex1 primarily acts as a downstream effector of GPCR signaling. This study demonstrated that downregulation of P-Rex1 led to a significant decrease in the phosphorylation of Akt and Erk1/2 by reducing the phosphorylation of the tyrosine kinase receptor c-Met. Furthermore, a physical association between P-Rex1 and c-Met was observed after HGF treatment, suggesting that P-Rex1 may be involved in the HGF/c-Met signaling pathway.

Conclusion

These results support the role of P-Rex1 as a novel player in liver cancer, which suggest that targeting P-Rex1 may provide a potential strategy for liver cancer treatment.

Five gene signatures were identified in the prediction of overall survival in resectable pancreatic cancer

Background

Although genes have been previously detected in pancreatic cancer (PC), aberrant genes that play roles in resectable pancreatic cancer should be further assessed.

Methods

Messenger RNA samples and clinicopathological data corrected with PC were downloaded from The Cancer Genome Atlas (TCGA). Resectable PC patients were randomly divided into a primary set and a validation set. Univariable Cox regression analysis, lasso-penalized Cox regression analysis, and multivariable Cox analysis were implemented to distinguish survival-related genes (SRGs). A risk score based on the SRGs was calculated by univariable Cox regression analysis. A genomic-clinical nomogram was established by integrating the risk score and clinicopathological data to predict overall survival (OS) in resectable PC.

Results

Five survival-related genes (AADAC, DEF8, HIST1H1C, MET, and CHFR) were significantly correlated with OS in resectable PC. The resectable PC patients, based on risk score, were sorted into a high-risk group that showed considerably unfavorable OS (p < 0.001) than the low-risk group, in both the primary set and the validation set. The concordance index (C-index) was calculated to evaluate the predictive performance of the nomogram were respectively in the primary set [0.696 (0.608–0.784)] and the validation set [0.682 (0.606–0.758)]. Additionally, gene set enrichment Analysis discovered several meaningful enriched pathways.

Conclusion

Our study identified five prognostic gene biomarkers for OS prediction and which facilitate postoperative molecular target therapy for the resectable PC, especially the nomic-clinical nomogram which may be used as an effective model for the postoperative OS evaluation and also an optimal therapeutic tool for the resectable PC.

Heparan Sulfate Proteoglycan Signaling in Tumor Microenvironment

In the last few decades, heparan sulfate (HS) proteoglycans (HSPGs) have been an intriguing subject of study for their complex structural characteristics, their finely regulated biosynthetic machinery, and the wide range of functions they perform in living organisms from development to adulthood. From these studies, key roles of HSPGs in tumor initiation and progression have emerged, so that they are currently being explored as potential biomarkers and therapeutic targets for cancers. The multifaceted nature of HSPG structure/activity translates in their capacity to act either as inhibitors or promoters of tumor growth and invasion depending on the tumor type. Deregulation of HSPGs resulting in malignancy may be due to either their abnormal expression levels or changes in their structure and functions as a result of the altered activity of their biosynthetic or remodeling enzymes. Indeed, in the tumor microenvironment, HSPGs undergo structural alterations, through the shedding of proteoglycan ectodomain from the cell surface or the fragmentation and/or desulfation of HS chains, affecting HSPG function with significant impact on the molecular interactions between cancer cells and their microenvironment, and tumor cell behavior. Here, we overview the structural and functional features of HSPGs and their signaling in the tumor environment which contributes to tumorigenesis and cancer progression.

The Role of Receptor Tyrosine Kinases in Lassa Virus Cell Entry

The zoonotic Old World mammarenavirus Lassa (LASV) causes severe hemorrhagic fever with high mortality and morbidity in humans in endemic regions. The development of effective strategies to combat LASV infections is of high priority, given the lack of a licensed vaccine and restriction on available treatment to off-label use of ribavirin. A better understanding of the fundamental aspects of the virus's life cycle would help to improve the development of novel therapeutic approaches. Host cell entry and restriction factors represent major barriers for emerging viruses and are promising targets for therapeutic intervention. In addition to the LASV main receptor, the extracellular matrix molecule dystroglycan (DG), the phosphatidylserine-binding receptors of the Tyro3/Axl/Mer (TAM), and T cell immunoglobulin and mucin receptor (TIM) families are potential alternative receptors of LASV infection. Therefore, the relative contributions of candidate receptors to LASV entry into a particular human cell type are a complex function of receptor expression and functional DG availability. Here, we describe the role of two receptor tyrosine kinases (RTKs), Axl and hepatocyte growth factor receptor (HGFR), in the presence and absence of glycosylated DG for LASV entry. We found that both RTKs participated in the macropinocytosis-related LASV entry and, regardless of the presence or absence of functional DG, their inhibition resulted in a significant antiviral effect.

lncRNA HOTAIR overexpression induced downregulation of c-Met signaling promotes hybrid epithelial/mesenchymal phenotype in hepatocellular carcinoma cells

Background

Epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET) are both reversible processes, and regulation of phenotypical transition is very important for progression of several cancers including hepatocellular carcinoma (HCC). Recently, it is defined that cancer cells can attain a hybrid epithelial/mesenchymal (hybrid E/M) phenotype. Cells with hybrid E/M phenotype comprise mixed epithelial and mesenchymal properties, they can be more resistant to therapeutics and also more capable of initiating metastatic lesions. However, the mechanisms regulating hybrid E/M in HCC are not well described yet. In this study, we investigated the role of the potential crosstalk between lncRNA HOTAIR and c-Met receptor tyrosine kinase, which are two essential regulators of EMT and MET, in acquiring of hybrid E/M phenotype in HCC.

Methods

Expression of c-Met and lncRNA HOTAIR were defined in HCC cell lines and patient tissues through HCC progression. lncRNA HOTAIR was overexpressed in SNU-449 cells and its effects on c-Met signaling were analyzed. c-Met was overexpressed in SNU-398 cells and its effect on HOTAIR expression was analyzed. Biological significance of HOTAIR/c-Met interplay was defined in means of adhesion, proliferation, motility behavior, invasion, spheroid formation and metastatic ability. Effect of ectopic lncRNA HOTAIR expression on phenotype was defined with investigation of molecular epithelial and mesenchymal traits.

Results

In vitro and in vivo experiments verified the pivotal role of lncRNA HOTAIR in acquisition of hybrid E/M phenotype through modulating expression and activation of c-Met and its membrane co-localizing partner Caveolin-1, and membrane organization to cope with the rate limiting steps of metastasis such as survival in adhesion independent microenvironment, escaping from anoikis and resisting to fluidic shear stress (FSS) in HCC.

Conclusions

Our work provides the first evidence suggesting a role for lncRNA HOTAIR in the modulation of c-Met to promote hybrid E/M phenotype. The balance between lncRNA HOTAIR and c-Met might be critical for cell fate decision and metastatic potential of HCC cells.

The Function of the HGF/c-Met Axis in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide, leading to a large global cancer burden. Hepatocyte growth factor (HGF) and its high-affinity receptor, mesenchymal epithelial transition factor (c-Met), are closely related to the onset, progression, and metastasis of multiple tumors. The HGF/c-Met axis is involved in cell proliferation, movement, differentiation, invasion, angiogenesis, and apoptosis by activating multiple downstream signaling pathways. In this review, we focus on the function of the HGF/c-Met axis in HCC. The HGF/c-Met axis promotes the onset, proliferation, invasion, and metastasis of HCC. Moreover, it can serve as a biomarker for diagnosis and prognosis, as well as a therapeutic target for HCC. In addition, it is closely related to drug resistance during HCC treatment.

Crosstalk Mechanisms Between HGF/c-Met Axis and ncRNAs in Malignancy

Several lines of evidence have confirmed the magnitude of crosstalk between HGF/c-Met axis (hepatocyte growth factor and its high-affinity receptor c-mesenchymal-epithelial transition factor) and non-coding RNAs (ncRNAs) in tumorigenesis. Through activating canonical or non-canonical signaling pathways, the HGF/c-Met axis mediates a range of oncogenic processes such as cell proliferation, invasion, apoptosis, and angiogenesis and is increasingly becoming a promising target for cancer therapy. Meanwhile, ncRNAs are a cluster of functional RNA molecules that perform their biological roles at the RNA level and are essential regulators of gene expression. The expression of ncRNAs is cell/tissue/tumor-specific, which makes them excellent candidates for cancer research. Many studies have revealed that ncRNAs play a crucial role in cancer initiation and progression by regulating different downstream genes or signal transduction pathways, including HGF/c-Met axis. In this review, we discuss the regulatory association between ncRNAs and the HGF/c-Met axis by providing a comprehensive understanding of their potential mechanisms and roles in cancer development. These findings could reveal their possible clinical applications as biomarkers for therapeutic interventions.

Assessment of liver cancer biomarkers

Liver cancer is the third cause of cancer-related deaths in the world. It is primarily divides into two main types, namely hepatocellular carcinoma (HC) and cholangiocarcinoma (IC). Due to the increasing number of patients with liver cancer and the high mortality rate, early diagnosis of the disease can be helpful in treatment, but most patients are diagnosed atlate stages of HC. The aim of this study is to screen and provide an overview on candidate biomarkers related to primary liver cancer to introduce the critical ones. In this study, various biomarkers related to the diagnosis of primary liver cancer have been studied. Accordingly, biomarkers are divided into different groups as blood biomarkers classified as serum and plasma biomarkers, tissue biomarkers, microRNA biomarkers, proteomic biomarkers and altered genes. Previous researches have focused on liver cells and bile ducts, the surround cellular environment, how cells differentiate, and the types of genes expressed in liver cancer. Some even have focused on the origin of tumor cells and how they differentiate and develop. In all these studies, the expression of specific proteins and genes in liver cancer has been considered. Based on available sources, biomarkers can be considered as candidates to diagnose and prognosis of various types of primary liver cancer, from sources such as blood, tissue, mic-RNA, proteome and genes. However, more investigations are required to introduce a biomarker for precise detection of early liver cancer.

Thermal Ablation Induces Transitory Metastatic Growth by Means of the STAT3/c-Met Molecular Pathway in an Intrahepatic Colorectal Cancer Mouse Model

Background Systemic protumorigenic effects have been noted after radiofrequency ablation (RFA) of normal liver and have been linked to an interleukin 6/signal transducer and activator of transcription 3 (STAT3)/hepatocyte growth factor (HGF)/tyrosine-protein kinase Met (c-Met)/vascular endothelial growth factor (VEGF) cytokinetic pathway. Purpose To elucidate kinetics of RFA protumorigenic effects on intrahepatic metastatic implantation and growth and determine potential molecular targets for pharmacologic suppression of these effects. Materials and Methods An intrahepatic metastasis model was established by implanting CT26 and MC38 tumor cells into 216 7-8-week-old male Balb/C and C57BL6 mice, respectively, by means of splenic injection. Between June 2017 and March 2019, mice underwent tumor injection, followed 24 hours later by either standardized RFA (70°C ± 1, 5 minutes, 1-cm tip) or a sham procedure (needle placement without heating) (12 animals per arm, n = 48). Next, RFA or sham procedures were performed, followed by splenic tumor cell injection at 1 day, 3 days, or 7 days later (six animals per arm, n = 72). Finally, PHA-665752 and S3I-201 were used to block c-Met or STAT3, respectively, prior to either RFA or sham treatment (six animals per arm, n = 96). Livers were harvested at 14 days for CT26 and 21days for MC38 for tumor quantification. Ki-67 and CD34 immunohistochemistry measured proliferative indexes and microvascular density, respectively. Data were compared with analysis of variance and the two-tailed Student t test. Results RFA performed after tumor cell injection induced increased metastatic tumor number (103 ± 45 vs 52 ± 44 [CT26], P = .009 and 87 ± 51 vs 39 ± 20 [MC38], P = .007), cellular proliferation (P < .001 for both), and intratumoral neovascularization (P < .001 for both), compared with the sham procedure. Tumor cell injection performed 1 day and 3 days after RFA also increased these indexes (P < .05), while no difference was demonstrated for cell injection 7 days after RFA (P > .05). Adjuvant c-Met or STAT3 inhibition reduced intrahepatic metastatic parameters after RFA to baseline (P < .03), equivalent to the sham group (P > .05). Conclusion Radiofrequency ablation of normal liver promotes intrahepatic metastatic implantation and increased growth over a short-lived (1-3 days) temporal window in animal models. This phenomenon can be potentially neutralized with specific inhibition of pathways including hepatocyte growth factor/tyrosine-protein kinase Met and signal transducer and activator of transcription 3. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Nikolic in this issue.

C7 peptide inhibits hepatocellular carcinoma metastasis by targeting the HGF/c-Met signaling pathway

Hepatocellular carcinoma (HCC), characterized by a high rate of metastasis and recurrence after surgery, is caused by malignant proliferation of hepatocytes with epigenetic and/or genetic mutations. In particular, abnormal activation of the hepatocyte growth factor (HGF)-/c-mesenchymal-epithelial transition receptor (c-Met) axis is closely associated with HCC metastasis. Unfortunately, effective treatments or drugs that target the HGF/c-Met signaling pathway are still in the research pipeline. Here, a c-Met inhibitor named the C7 peptide, which can inhibit both HGF and c-Met, can significantly inhibit HGF-induced (but not EGF-induced) cell migration and suppress the phosphorylation of c-Met, Akt and Erk1/2. Moreover, the C7 peptide can also significantly suppress tumor metastasis in nude mice and the phosphorylation of c-Met. Together, our current findings, demonstrated that the C7 peptide can inhibit HGF-induced cancer cell migration and invasion through the inhibition of Akt and Erk1/2. Identification of a peptide that can block HGF/c-Met signaling provides new insight into the mechanism of HCC and future clinical treatments.

Hepatocellular carcinoma: Therapeutic advances in signaling, epigenetic and immune targets

Hepatocellular carcinoma (HCC) remains a global medical burden with rising incidence due to chronic viral hepatitis and non-alcoholic fatty liver diseases. Treatment of advanced disease stages is still unsatisfying. Besides first and second generation tyrosine kinase inhibitors, immune checkpoint inhibitors have become central for the treatment of HCC. New modalities like epigenetic therapy using histone deacetylase inhibitors (HDACi) and cell therapy approaches with chimeric antigen receptor T cells (CAR-T cells) are currently under investigation in clinical trials. Development of such novel drugs is closely linked to the availability and improvement of novel preclinical and animal models and the identification of predictive biomarkers. The current status of treatment options for advanced HCC, emerging novel therapeutic approaches and different preclinical models for HCC drug discovery and development are reviewed here.

MET overexpression and activation favors invasiveness in a model of anaplastic thyroid cancer

In thyroid cancers, MET receptor overexpression has been associated with higher risk of metastatic progression. In this study, it was shown that the anaplastic thyroid cancer (ATC)-derived TTA1 cell line overexpressed MET. By using FISH and relative quantification by qPCR, it was demonstrated that this overexpression resulted from a MET amplification with more than 20 copies. As expected, MET overexpression led to its constitutive activation and upregulated signaling towards the MAPK, PI3K/AKT, STAT3 and NF-κB pathways. Since the usual feature of MET-amplified cell lines is the "MET addiction" for their cell proliferation, the effect of the highly selective ATP competitive MET inhibitor PHA665752 was analyzed. While PHA665752 strongly inhibited the MAPK pathway, it did not reduce cell proliferation in TTA1 cells (IC₅₀ = 4100 nM). This resistance to PHA665752 of the TTA1 cell line was demonstrated to be related to EGFR-MET functional cross-talk and PI3K/AKT and NF-κB signaling. Nevertheless, PHA665752 suppressed the anchorage-independent growth capacity of the TTA1 cell line and reduced cell migration and invasion in a transwell assay. The role of activated MET in these neoplastic properties of the TTA1 cells was also proved with si-MET-RNA targeting. Thus, this work highlights the TTA1 cell line as the first model of MET amplification in an ATC cell line, which leads to MET constitutive activation and underlies its neoplastic properties. Besides being a useful model for MET inhibitors screening, the TTA1 cell line also supports the argument for searching for MET amplification in ATC, as it could have therapeutic implications.