FGF19 and cancer

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.

Integrated characterization of hepatobiliary tumor organoids provides a potential landscape of pharmacogenomic interactions

Despite considerable efforts to identify human liver cancer genomic alterations that might unveil druggable targets, the systematic translation of multiomics data remains challenging. Here, we report success in long-term culture of 64 patient-derived hepatobiliary tumor organoids (PDHOs) from a Chinese population. A divergent response to 265 metabolism- and epigenetics-related chemicals and 36 anti-cancer drugs is observed. Integration of the whole genome, transcriptome, chromatin accessibility profiles, and drug sensitivity results of 64 clinically relevant drugs defines over 32,000 genome-drug interactions. RUNX1 promoter mutation is associated with an increase in chromatin accessibility and a concomitant gene expression increase, promoting a cluster of drugs preferentially sensitive in hepatobiliary tumors. These results not only provide an annotated PDHO biobank of human liver cancer but also suggest a systematic approach for obtaining a comprehensive understanding of the gene-regulatory network of liver cancer, advancing the applications of potential personalized medicine.

Sex Dimorphic Effects of Bile Acid Metabolism in Liver Cancer in Mice

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) is a male-dominant disease, but targeted sex hormone therapies have not been successful. Bile acids are a potential liver carcinogen and are biomolecules with hormone-like effects. A few studies highlight their potential sex dimorphism in physiology and disease. We hypothesized that bile acids could be a potential molecular signature that explains sex disparity in HCC.

METHODS & RESULTS

We used the farnesoid X receptor knockout (FxrKO) mouse model to study bile acid-dependent HCC. Temporal tracking of circulating bile acids determined more than 80% of FxrKO females developed spontaneous cholemia (ie, serum total bile acids ≥40 μmol/L) as early as 8 weeks old. Opposingly, FxrKO males were highly resistant to cholemia, with ∼23% incidence even when 26 weeks old. However, FxrKO males demonstrated higher levels of deoxycholate than females. Compared with males, FxrKO females had more severe cholestatic liver injury and further aberrancies in bile acid metabolism. Yet, FxrKO females expressed more detoxification transcripts and had greater renal excretion of bile acids. Intervention with CYP7A1 (rate limiting enzyme for bile acid biosynthesis) deficiency or taurine supplementation either completely or partially normalized bile acid levels and liver injury in FxrKO females. Despite higher cholemia prevalence in FxrKO females, their tumor burden was less compared with FxrKO males. An exception to this sex-dimorphic pattern was found in a subset of male and female FxrKO mice born with congenital cholemia due to portosystemic shunt, where both sexes had comparable robust HCC.

CONCLUSIONS

Our study highlights bile acids as sex-dimorphic metabolites in HCC except in the case of portosystemic shunt.

A phase Ib/II study of BLU-554, a fibroblast growth factor receptor 4 inhibitor in combination with CS1001, an anti-PD-L1, in patients with locally advanced or metastatic hepatocellular carcinoma

OBJECTIVE

Targeted therapy combined with immunotherapy has become the main treatment option for hepatocellular carcinoma (HCC). This trial assessed the safety and efficacy of fibroblast growth factor receptor 4 inhibitor (BLU-554) in combination with the anti-PD-L1 monoclonal antibody (CS1001) in patients with locally advanced or metastatic HCC.

PATIENTS AND METHODS

This Phase Ib/II trial enrolled patients with locally advanced or metastatic HCC who were FGF19-positive. The patients were intravenously administered with CS1001 (1200 mg) every three weeks and orally administered with BLU-554 (600 mg) daily. The primary endpoint was objective response rate (ORR), as assessed according to RECISTv1.1.

RESULTS

Four patients were treated with BLU-554 combined with CS1001. The trial revealed a 50% ORR and 100% DCR. The main adverse reactions that were attributed to BLU-554 in combination with CS1001 were diarrhoea, liver function impairments and skin rashes. Only one patient had immune-related adverse reactions.

CONCLUSION

Preliminary data showed that BLU-554 in combination with CS1001 is safe and effective for treatment of patients with locally advanced or metastatic HCC.

Phase 1 dose escalation study of FGFR4 inhibitor in combination with pembrolizumab in advanced solid tumors patients

OBJECTIVE

Inhibition of fibroblast growth factor (FGF) 19-FGF Receptor 4 (FGFR4) signaling demonstrates potent anticancer activity. EVER4010001 is a highly selective FGFR4 inhibitor and pembrolizumab is approved for the treatment of several solid tumors. This study determined the maximum tolerated dose (MTD), recommended Phase 2 dose (RP2D), pharmacokinetics, safety, and preliminary efficacy of EVER4010001 plus pembrolizumab in patients with advanced solid tumors.

METHODS

This Phase 1, multicenter, open-label study enrolled 19 Asian-Chinese patients (57.9% male: median age 58 years) with advanced solid tumors. For "3+3" dose escalation, 3-6 patients received treatment at each dose level (EVER4010001 40, 60, 80, or 100 mg twice daily [BID] plus pembrolizumab 200 mg every 3 weeks).

RESULTS

At the data cutoff (August 12, 2021), no dose-limiting toxicities (DLTs) were reported at 40 mg-80 mg. At 100 mg, 2 (40.0%) patients had 3 DLTs within the 28-day DLT observation period after first administration. Median time to peak EVER4010001 concentration (T_max ) was 0.55-1.03 hours. Mean terminal EVER4010001 half-life (T_1/2 ) was 4.00-4.92 hours. The area under the concentration-time curve (AUC_0-t ) and maximum observed concentration (C_max ) ranged from 2370.87-5475.77 hour*ng/ml and 606.07-1348.86 ng/ml, respectively. The most common EVER4010001-related treatment-emergent adverse events were diarrhea (94.7%), increased aspartate aminotransferase (57.9%), and increased alanine aminotransferase (47.4%).

CONCLUSION

Eighty milligrams BID was the MTD and RP2D for EVER4010001 plus pembrolizumab. Efficacy results were promising, and no new safety risks were reported, justifying the Phase 2 portion of this study.

Integration of Pharmacokinetics, Pharmacodynamics, Safety, and Efficacy into Model-Informed Dose Selection in Oncology First-in-Human Study: A Case of Roblitinib (FGF401)

Model-informed dose selection has been drawing increasing interest in oncology early clinical development. The current paper describes the example of FGF401, a selective fibroblast growth factor receptor 4 (FGFR4) inhibitor, in which a comprehensive modeling and simulation (M&S) framework, using both pharmacometrics and statistical methods, was established during its first-in-human clinical development using the totality of pharmacokinetics (PK), pharmacodynamic (PD) biomarkers, and safety and efficacy data in patients with cancer. These M&S results were used to inform FGF401 dose selection for future development. A two-compartment population PK (PopPK) model with a delayed 0-order absorption and linear elimination adequately described FGF401 PK. Indirect PopPK/PD models including a precursor compartment were independently established for two biomarkers: circulating FGF19 and 7α-hydroxy-4-cholesten-3-one (C4). Model simulations indicated a close-to-maximal PD effect achieved at the clinical exposure range. Time-to-progression was analyzed by Kaplan-Meier method which favored a trough concentration (C_trough )-driven efficacy requiring C_trough above a threshold close to the drug concentration producing 90% inhibition of phospho-FGFR4. Clinical tumor growth inhibition was described by a PopPK/PD model that reproduced the dose-dependent effect on tumor growth. Exposure-safety analyses on the expected on-target adverse events, including elevation of aspartate aminotransferase and diarrhea, indicated a lack of clinically relevant relationship with FGF401 exposure. Simulations from an indirect PopPK/PD model established for alanine aminotransferase, including a chain of three precursor compartments, further supported that maximal target inhibition was achieved and there was a lack of safety-exposure relationship. This M&S framework supported a dose selection of 120 mg once daily fasted or with a low-fat meal and provides a practical example that might be applied broadly in oncology early clinical development.

Isoform-specific inhibition of FGFR signaling achieved by a de-novo-designed mini-protein

Cellular signaling by fibroblast growth factor receptors (FGFRs) is a highly regulated process mediated by specific interactions between distinct subsets of fibroblast growth factor (FGF) ligands and two FGFR isoforms generated by alternative splicing: an epithelial b- and mesenchymal c-isoforms. Here, we investigate the properties of a mini-protein, mb7, developed by an in silico design strategy to bind to the ligand-binding region of FGFR2. We describe structural, biophysical, and cellular analyses demonstrating that mb7 binds with high affinity to the c-isoforms of FGFR, resulting in inhibition of cellular signaling induced by a subset of FGFs that preferentially activate c-isoforms of FGFR. Notably, as mb7 blocks interaction between FGFR with Klotho proteins, it functions as an antagonist of the metabolic hormones FGF19 and FGF21, providing mechanistic insights and strategies for the development of therapeutics for diseases driven by aberrantly activated FGFRs.

Park et al. show that a de-novo-designed mini-protein, mb7, can specifically recognize c-isoforms of FGFRs. By masking the regions of FGFR that are critical for the FGFR activation, mb7 can potently inhibit cellular signaling by a subset of FGFs that preferentially activate FGFR c-isoform signaling.

A Novel Secreted Protein-Related Gene Signature Predicts Overall Survival and Is Associated With Tumor Immunity in Patients With Lung Adenocarcinoma

Secreted proteins are important proteins in the human proteome, accounting for approximately one-tenth of the proteome. However, the prognostic value of secreted protein-related genes has not been comprehensively explored in lung adenocarcinoma (LUAD). In this study, we screened 379 differentially expressed secretory protein genes (DESPRGs) by analyzing the expression profile in patients with LUAD from The Cancer Genome Atlas database. Following univariate Cox regression and least absolute shrinkage and selection operator method regression analysis, 9 prognostic SPRGs were selected to develop secreted protein-related risk score (SPRrisk), including CLEC3B, C1QTNF6, TCN1, F2, FETUB, IGFBP1, ANGPTL4, IFNE, and CCL20. The prediction accuracy of the prognostic models was determined by Kaplan–Meier survival curve analysis and receiver operating characteristic curve analysis. Moreover, a nomogram with improved accuracy for predicting overall survival was established based on independent prognostic factors (SPRrisk and clinical stage). The DESPRGs were validated by quantitative real-time PCR and enzyme-linked immunosorbent assay by using our clinical samples and datasets. Our results demonstrated that SPRrisk can accurately predict the prognosis of patients with LUAD. Patients with a higher risk had lower immune, stromal, and ESTIMATE scores and higher tumor purity. A higher SPRrisk was also negatively associated with the abundance of CD8⁺ T cells and M1 macrophages. In addition, several genes of the human leukocyte antigen family and immune checkpoints were expressed in low levels in the high-SPRrisk group. Our results provided some insights into assessing individual prognosis and choosing personalized treatment modalities.

An Update on Novel Pharmacological Agents for Primary Sclerosing Cholangitis

INTRODUCTION

: Primary sclerosing cholangitis (PSC) is a rare chronic cholestatic liver disease with heterogeneous phenotypes that may lead to liver transplantation and/or end-stage liver disease. Its multifactorial etiopathogenesis remains uncertain, but gut-liver axis and bile composition and excretion are widely demonstrated to influence the immune-mediated fibrogenic reactive cascade.

AREAS COVERED

: Different experimental therapeutic options are under investigation, mainly aiming at modulating bile acids excretion, limiting inflammatory-cascade reactions, and changing intestinal microbiota composition; none of them yet demonstrated to prolong transplant free survival.

This review provides a comprehensive description of the experimental drugs recently tested and/or currently under investigation. A bibliographical search was performed in Pubmed, MEDLINE, EMBASE, OVID and clinicaltrial.gov until July 2021.

EXPERT OPINION

: The heterogeneity and poor prevalence of PSC, its uncertain pathophysiology, and the lack of surrogate endpoints are the major challenges in drug discovery. Strategies that synergistically target microbiota, bile acids, and liver fibrosis are needed. In parallel, we must enhance biomarker discovery to develop surrogate endpoints, as biochemical markers' fluctuations over the time hamper their effectiveness. Magnetic resonance cholangiopancreatography tools that accurately measure bile duct changes represent a potential, novel marker for disease monitoring. A collaboration between academia, research consortia, patient's associations and industry is required.

Fibroblast Growth Factor 19 Induced Changes in Non-malignant Cholangiocytes

BACKGROUND AND AIMS

Fibroblast growth factor (FGF)19 has been implicated in the pathogenesis of murine hepatocellular carcinoma. Whether it plays a role in the development or course of human cholangiocarcinoma remains to be determined. The aim of this study was to determine whether prolonged exposure to FGF19 results in the transformation of non-malignant human cholangiocytes into cells with malignant features.

METHODS

Human SV-40 transfected non-malignant H69 cholangiocytes were cultured with FGF19 (0-50 ng/mL) for 6 weeks, followed by 6 weeks with medium alone. Cell proliferation, invasion, stem cell surface markers, oncofetoprotein expression, state of differentiation, epithelial-mesenchymal transition (EMT) and interleukin (IL)-6 expression were documented at various time intervals throughout the 12-week period.

RESULTS

FGF19 exposure was associated with significant increases in cell proliferation, de-differentiation, EMT and IL-6 expression. However, each of these effects returned to baseline or control values during the 6-week FGF19 free follow-up period. The remaining cell properties remained unaltered.

CONCLUSIONS

Six weeks of FGF19 exposure did not result in the acquisition of permanent malignant features in non-malignant, human cholangiocytes.

Design, synthesis and biological evaluation of quinazoline derivatives as potent and selective FGFR4 inhibitors

Aberrant activation of the fibroblast growth factor 19-fibroblast growth factor receptor 4 (FGF19-FGFR4) signaling pathway has been proved to promote hepatocellular carcinoma (HCC) proliferation. It is assumed that the first FGFR4 inhibitor BLU9931 did not enter clinical studies, presumably due to its rapid metabolism in liver microsomes. Here, we report the development of series of quinazoline derivatives based on FGFR4 inhibitor BLU9931 through structural modification of its solvent region pocket to minimize its potential metabolic liability. Among them, compound 35a exhibited comparable or superior kinase inhibitory activity (IC50 = 8.5 nM) and selectivity in cells. More importantly, compound 35a improved liver microsomes stability compared to BLU9931. Cellular mechanistic studies demonstrated that 35a induced apoptosis via the FGFR4 signaling pathway blockage. In addition, the computational simulation revealed the possible binding mode to FGFR4 protein, which provides a plausible explanation of high potent and metabolic stability.

Treatment of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by progressive fibro-stenotic strictures and destruction of the biliary tree. Currently, there is no effective treatment which can delay its progression or ameliorate the transplant-free survival. Moreover, a major chontroversy in PSC is whether to use UDCA. More recently, novel pharmacological agents emerged aiming at: i) modulation of bile composition; ii) immunomodulation; iii) targeting the gut microbiome; iv) targeting fibrosis. Successful PSC therapy, however, will be most likely a personalized combination of different drugs plus endoscopic treatment. This review aims at offering an overview on the experimental pharmacological strategies currently exploited for PSC treatment.

Aberrant FGFR4 signaling worsens nonalcoholic steatohepatitis in FGF21KO mice

Background: Nonalcoholic steatohepatitis (NASH) is the most severe form of non-alcoholic fatty liver disease (NAFLD) and a potential precursor of hepatocellular carcinoma (HCC). In our previous studies, we found that endocrine fibroblast growth factor 21 (FGF21) played a key role in preventing the development of NASH, however, the FGF15/19 mediated-FGFR4 signaling worsened NASH and even contributed to the NASH-HCC transition. The aim of this study is to determine whether FGF15/FGFR4 signaling could alleviate or aggravate NASH in the FGF21KO mice.

Methods: NASH models were established in FGF21KO mice fed with high fat methionine-choline deficient (HFMCD) diet to investigate FGF15/FGFR4 signaling during early stage NASH and advanced stage NASH. Human hepatocytes, HepG2 and Hep3B cells, were cultured with human enterocytes Caco-2 cells to mimic gut-liver circulation to investigate the potential mechanism of NASH development.

Results: Significant increase of FGF15 production was found in the liver of the NASH-FGF21KO mice, however the increased FGF15 protein was unable to alleviate hepatic lipid accumulation. In contrast, up-regulated FGF15/19/FGFR4 signaling was found in the FGF21KO mice with increased NASH severity, as evident by hepatocyte injury/repair, fibrosis and potential malignant events. In in vitro studies, blockage of FGFR4 by BLU9931 treatment attenuated the lipid accumulation, up-regulated cyclin D1, and epithelial-mesenchymal transition (EMT) in the hepatocytes.

Conclusion: The increased FGF15 in NASH-FGF21KO mice could not substitute for FGF21 to compensate its lipid metabolic benefits thereby to prevent NASH development. Up-regulated FGFR4 signaling in NASH-FGF21KO mice coupled to proliferation and EMT events which were widely accepted to be associated with carcinogenic transformation.

Role of FGF15 in Hepatic Surgery in the Presence of Tumorigenesis: Dr. Jekyll or Mr. Hyde?

The pro-tumorigenic activity of fibroblast growth factor (FGF) 19 (FGF15 in its rodent orthologue) in hepatocellular carcinoma (HCC), as well as the unsolved problem that ischemia-reperfusion (IR) injury supposes in liver surgeries, are well known. However, it has been shown that FGF15 administration protects against liver damage and regenerative failure in liver transplantation (LT) from brain-dead donors without tumor signals, providing a benefit in avoiding IR injury. The protection provided by FGF15/19 is due to its anti-apoptotic and pro-regenerative properties, which make this molecule a potentially beneficial or harmful factor, depending on the disease. In the present review, we describe the preclinical models currently available to understand the signaling pathways responsible for the apparent controversial effects of FGF15/19 in the liver (to repair a damaged liver or to promote tumorigenesis). As well, we study the potential pharmacological use that has the activation or inhibition of FGF15/19 pathways depending on the disease to be treated. We also discuss whether FGF15/19 non-pro-tumorigenic variants, which have been developed for the treatment of liver diseases, might be promising approaches in the surgery of hepatic resections and LT using healthy livers and livers from extended-criteria donors.

Novel Regulatory Factors and Small-Molecule Inhibitors of FGFR4 in Cancer

Fibroblast growth factor receptor 4 (FGFR4) is a tyrosine kinase receptor that is a member of the fibroblast growth factor receptor family and is stimulated by highly regulated ligand binding. Excessive expression of the receptor and its ligand, especially FGF19, occurs in many types of cancer. Abnormal FGFR4 production explains these cancer formations, and therefore, this receptor has emerged as a potential target for inhibiting cancer development. This review discusses the diverse mechanisms of oncogenic activation of FGFR4 and highlights some currently available inhibitors targeting FGFR4.

Advances of Fibroblast Growth Factor/Receptor Signaling Pathway in Hepatocellular Carcinoma and its Pharmacotherapeutic Targets

Hepatocellular carcinoma (HCC) is a type of primary liver cancer with poor prognosis, and its incidence and mortality rate are increasing worldwide. It is refractory to conventional chemotherapy and radiotherapy owing to its high tumor heterogeneity. Accumulated genetic alterations and aberrant cell signaling pathway have been characterized in HCC. The fibroblast growth factor (FGF) family and their receptors (FGFRs) are involved in diverse biological activities, including embryonic development, proliferation, differentiation, survival, angiogenesis, and migration, etc. Data mining results of The Cancer Genome Atlas demonstrate high levels of FGF and/or FGFR expression in HCC tumors compared with normal tissues. Moreover, substantial evidence indicates that the FGF/FGFR signaling axis plays an important role in various mechanisms that contribute to HCC development. At present, several inhibitors targeting FGF/FGFR, such as multikinase inhibitors, specific FGFR4 inhibitors, and FGF ligand traps, exhibit antitumor activity in preclinical or early development phases in HCC. In this review, we summarize the research progress regarding the molecular implications of FGF/FGFR-mediated signaling and the development of FGFR-targeted therapeutics in hepatocarcinogenesis.

Investigation of Covalent Warheads in the Design of 2-Aminopyrimidine-based FGFR4 Inhibitors

Covalent kinase inhibitors are rapidly emerging as a class of therapeutics with clinical benefits. Herein we report a series of selective 2-aminopyrimidine-based fibroblast growth factor receptor 4 (FGFR4) inhibitors exploring different types of cysteine-targeting warheads. The structure-activity relationship study revealed that the chemically tuned warheads α-fluoro acrylamide, vinylsulfonamide, and acetaldehyde amine were suitable as covalent warheads for the design of selective FGFR4 inhibitors. Compounds 6a, 6h, and 6i selectively suppressed FGFR4 enzymatic activity with IC₅₀ values of 53 ± 18, 45 ± 11, and 16 ± 4 nM, respectively, while sparing FGFR1/2/3. X-ray crystal structure and MALDI-TOF studies demonstrated that compound 6h bearing the α-fluoro acrylamide binds to FGFR4 with an irreversible binding mode, whereas compound 6i with an acetaldehyde amine binds to FGFR4 with a reversible covalent mode. 6h and 6i might provide some fundamental structural information for the rational design of new selective FGFR4 inhibitors.

The impact of FGF19/FGFR4 signaling inhibition in antitumor activity of multi-kinase inhibitors in hepatocellular carcinoma

FGF19/FGFR4 autocrine signaling is one of the main targets for multi-kinase inhibitors (MKIs). However, the molecular mechanisms underlying FGF19/FGFR4 signaling in the antitumor effects to MKIs in hepatocellular carcinoma (HCC) remain unclear. In this study, the impact of FGFR4/ERK signaling inhibition on HCC following MKI treatment was analyzed in vitro and in vivo assays. Serum FGF19 in HCC patients treated using MKIs, such as sorafenib (n = 173) and lenvatinib (n = 40), was measured by enzyme-linked immunosorbent assay. Lenvatinib strongly inhibited the phosphorylation of FRS2 and ERK, the downstream signaling molecules of FGFR4, compared with sorafenib and regorafenib. Additional use of a selective FGFR4 inhibitor with sorafenib further suppressed FGFR4/ERK signaling and synergistically inhibited HCC cell growth in culture and xenograft subcutaneous tumors. Although serum FGF19^high (n = 68) patients treated using sorafenib exhibited a significantly shorter progression-free survival and overall survival than FGF19^low (n = 105) patients, there were no significant differences between FGF19^high (n = 21) and FGF19^low (n = 19) patients treated using lenvatinib. In conclusion, robust inhibition of FGF19/FGFR4 is of importance for the exertion of antitumor effects of MKIs. Serum FGF19 levels may function as a predictive marker for drug response and survival in HCC patients treated using sorafenib.

FGF401 and vinorelbine synergistically mediate antitumor activity and vascular normalization in FGF19-dependent hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a lethal cancer with limited therapeutic options, and standard therapy with sorafenib provides only modest survival benefits. Fibroblast growth factor 19 (FGF19) has been proposed as a driver oncogene, and targeting its receptor, FGFR-4, may provide a better alternative to standard therapy for patients with FGF19-driven tumors. Sixty-three HCC patient-derived xenograft (PDX) models were screened for FGF19 expression. Mice bearing high and low FGF19-expressing tumors were treated with FGF401 and/or vinorelbine, and the antitumor activity of both agents was assessed individually and in combination. Tumor vasculature and intratumoral hypoxia were also examined. High FGF19 expression was detected in 14.3% (9 of 63) of the HCC models tested and may represent a good target for HCC treatment. FGF401 potently inhibited the growth of high FGF19-expressing HCC models regardless of FGF19 gene amplification. Furthermore, FGF401 inhibited the FGF19/FGFR-4 signaling pathway, cell proliferation, and hypoxia, induced apoptosis and blood vessel normalization and prolonged the overall survival (OS) of mice bearing high FGF19 tumors. FGF401 synergistically acted with the microtubule-depolymerizing drug vinorelbine to further suppress tumor growth, promote apoptosis, and prolong the OS of mice bearing high FGF19 tumors, with no evidence of increased toxicity. Our study suggests that a subset of patients with high FGF19-expressing HCC tumors could benefit from FGF401 or FGF401/vinorelbine treatment. A high level of FGF19 in a tumor may serve as a potential biomarker for patient selection.

The drugs FGF401 and vinorelbine, when working together synergistically, could be effective in treating those liver cancers driven by the activity of the fibroblast growth factor 19 (FGF19) protein. The drugs’ effects on human tumors grafted into mice were studied by an international research team led by Hung Huynh at the National Cancer Centre in Singapore. FGF401 is a small molecule that inhibits the activity of the receptor protein that the FGF19 growth factor interacts with to promote some cancers. Vinorelbine disrupts protein microtubules required for the cell division that allows cancer cells to multiply. In combination, the drugs achieved significantly enhanced anti-cancer effects which can now be tested in clinical trials. The research also uncovered new details of FGF401’s therapeutic actions, including its ability to restore healthy blood vessel formation.

Inflammatory Markers in Suction Blister Fluid: A Comparative Study Between Interstitial Fluid and Plasma

Background

Biomarker analysis allows for the detection and prediction of disease as well as health monitoring. The use of interstitial fluid (ISF) as a matrix for biomarkers has recently gained interest. This study aimed to compare levels of inflammatory markers in ISF from suction blister fluid (SBF) and plasma.

Methods

Plasma and SBF were collected from 18 healthy individuals. Samples were analyzed for 92 inflammation-related protein biomarkers by Proximity Extension Assay (PEA). Protein profiles in the two matrices were compared using traditional and multivariate statistics.

Results

Out of 92 targeted proteins, 70 were successfully quantified in both plasma and SBF. Overall, plasma and SBF displayed distinct protein profiles with up to 40-fold difference in abundance of specific proteins. The levels of 25 proteins were significantly correlated between plasma and SBF and several of these were recognized as potential markers to monitor health using ISF.

Conclusions

Skin ISF and plasma have unique protein profiles but many inflammatory markers are proportionally related between the matrices at the individual level. ISF is a promising biofluid for the monitoring of biomarkers in clinical studies and routine analyses.

Dual Role of MSC-Derived Exosomes in Tumor Development

Mesenchymal stem cells (MSCs) are a class of adult stem cells derived from the mesoderm. They can self-renew, have multidirectional differentiation potential, and can differentiate into a variety of mesenchymal tissues. MSCs can produce a large number of exosomes, which can mediate information exchange and transmission between cells in the tumor microenvironment under conditions of rest or stress. Recent studies have reported conflicting findings regarding the effect of MSC-derived exosomes on tumors. Some studies have suggested that MSC-derived exosomes can promote tumor growth and metastasis, but others have reported that they can inhibit tumor cell growth. Here, we investigate the two sides of the debate regarding the effect of MSC-derived exosomes on tumors and analyze the reasons for the divergent findings.

Dissecting the Role of the FGF19-FGFR4 Signaling Pathway in Cancer Development and Progression

Fibroblast growth factor (FGF) receptor 4 (FGFR4) belongs to a family of tyrosine kinase receptor. FGFR4 is highly activated in certain types of cancer and its activation is closely associated with its specific ligand, FGF19. Indeed, FGF19-FGFR4 signaling is implicated in many cellular processes including cell proliferation, migration, metabolism, and differentiation. Since active FGF19-FGFR4 signaling acts as an oncogenic pathway in certain types of cancer, the development and therapeutic evaluation of FGFR4-specific inhibitors in cancer patients is a topic of significant interest. In this review, we aim to provide an updated overview of currently-available FGFR4 inhibitors and their ongoing clinical trials, as well as upcoming potential therapeutics. Further, we examined the possibility of enhancing the therapeutic efficiency of FGFR4 inhibitors in cancer patients. We also discussed the underlying molecular mechanisms of oncogenic activation of FGFR4 by FGF19.

The Race to Bash NASH: Emerging Targets and Drug Development in a Complex Liver Disease

Nonalcoholic steatohepatitis (NASH) is a severe form of nonalcoholic fatty liver disease (NAFLD) characterized by liver steatosis, inflammation, and hepatocellular damage. NASH is a serious condition that can progress to cirrhosis, liver failure, and hepatocellular carcinoma. The association of NASH with obesity, type 2 diabetes mellitus, and dyslipidemia has led to an emerging picture of NASH as the liver manifestation of metabolic syndrome. Although diet and exercise can dramatically improve NASH outcomes, significant lifestyle changes can be challenging to sustain. Pharmaceutical therapies could be an important addition to care, but currently none are approved for NASH. Here, we review the most promising targets for NASH treatment, along with the most advanced therapeutics in development. These include targets involved in metabolism (e.g., sugar, lipid, and cholesterol metabolism), inflammation, and fibrosis. Ultimately, combination therapies addressing multiple aspects of NASH pathogenesis are expected to provide benefit for patients.

Serum fibroblast growth factor 19 serves as a potential novel biomarker for hepatocellular carcinoma

Background

Abnormal autocrine fibroblast growth factor 19 (FGF19) production has been observed in several types of cancers, including hepatocellular carcinoma (HCC). In this study, we investigated the potential of serum FGF19 as a novel tumor marker of HCC based on a sandwich enzyme-linked immunosorbent assay (ELISA).

Methods

The serum FGF19 levels of 304 patients with HCC was measured by ELISA. The serum levels of existing markers, including alpha-fetoprotein (AFP) and des-gamma-carboxy prothrombin (DCP) were determined by chemiluminescence enzyme immunoassay. Both diagnostic value of FGF19 and its changes after curative ablation therapy was further examined.

Results

The median FGF19 levels in controls, chronic liver disease patients, and primary HCC patients, were 78.8 pg/mL, 100.1 pg/mL, and 214.5 pg/mL, respectively. The subsequent receiver operating characteristic curves (ROC) successfully determined an optimal cut-off value of 200.0 pg/mL. The area under the ROC curve (AUC) of FGF19 for HCC detection was comparable to those of AFP and DCP. Of importance, FGF19 showed higher sensitivity for the detection of small HCC (solitary cancer with diameter < 20 mm) than those of existing markers. In addition, 43 out of 79 cases (54.4%) with normal AFP and DCP (so-called “double negative HCC”) exhibited serum FGF19 level ≥ 200 pg/mL. In 45 HCC patients treated with curative ablation therapy, serum FGF19 levels changed from 257.4 pg/mL to 112.0 pg/mL after the treatment.

Conclusion

Our findings reveal that FGF19 can be a potential novel biomarker for HCC. Although FGF19 is not necessarily a substitute for existing markers, it may help improve the prognosis in HCC patients owing to its resourceful use in various aspects of HCC management and treatment.

Metabolic Messengers: fibroblast growth factor 15/19

Fibroblast growth factor (FGF) 15 in mice and its human orthologue FGF19 (together denoted FGF15/19) are gut hormones that control homeostasis of bile acids and glucose during the transition from the fed to the fasted state. Apart from its central role in the regulation of bile acid homeostasis, FGF15/19 is now recognized as a transversal metabolic coordinator at the crossroads of the gut, liver, brain and white adipose tissue. Dysregulation of FGF15/19 signalling may contribute to the pathogenesis of several diseases affecting the gut-liver axis and to metabolic diseases. Here, we provide an overview of current knowledge of the physiological roles of the enterokine FGF15/19 and highlight commonalities and differences between the two orthologues. We also discuss the putative therapeutic potential in areas of unmet medical need-such has cholestatic liver diseases and non-alcoholic steatohepatitis, for which FGF19 is being tested in ongoing clinical trials-as well as the possibility of using FGF19 for the treatment of obesity and type II diabetes.

Bile Acid Sequestration by Cholestyramine Mitigates FGFR4 Inhibition-Induced ALT Elevation

The FGF19- fibroblast growth factor receptor (FGFR4)-βKlotho (KLB) pathway plays an important role in the regulation of bile acid (BA) homeostasis. Aberrant activation of this pathway has been described in the development and progression of a subset of liver cancers including hepatocellular carcinoma, establishing FGFR4 as an attractive therapeutic target for such solid tumors. FGF401 is a highly selective FGFR4 kinase inhibitor being developed for hepatocellular carcinoma, currently in phase I/II clinical studies. In preclinical studies in mice and dogs, oral administration of FGF401 led to induction of Cyp7a1, elevation of its peripheral marker 7alpha-hydroxy-4-cholesten-3-one, increased BA pool size, decreased serum cholesterol and diarrhea in dogs. FGF401 was also associated with increases of serum aminotransferases, primarily alanine aminotransferase (ALT), in the absence of any observable adverse histopathological findings in the liver, or in any other organs. We hypothesized that the increase in ALT could be secondary to increased BAs and conducted an investigative study in dogs with FGF401 and coadministration of the BA sequestrant cholestyramine (CHO). CHO prevented and reversed FGF401-related increases in ALT in dogs in parallel to its ability to reduce BAs in the circulation. Correlation analysis showed that FGF401-mediated increases in ALT strongly correlated with increases in taurolithocholic acid and taurodeoxycholic acid, the major secondary BAs in dog plasma, indicating a mechanistic link between ALT elevation and changes in BA pool hydrophobicity. Thus, CHO may offer the potential to mitigate elevations in serum aminotransferases in human subjects that are caused by targeted FGFR4 inhibition and elevated intracellular BA levels.

Characterization of FGF401 as a reversible covalent inhibitor of fibroblast growth factor receptor 4

Biochemical and structural studies provide information on the mode of action of FGF401 as a selective, reversible covalent inhibitor of FGFR4.

Suppression of Hepatic Bile Acid Synthesis by a non-tumorigenic FGF19 analogue Protects Mice from Fibrosis and Hepatocarcinogenesis

Critical regulation of bile acid (BA) pool size and composition occurs via an intensive molecular crosstalk between the liver and gut, orchestrated by the combined actions of the nuclear Farnesoid X receptor (FXR) and the enterokine fibroblast growth factor 19 (FGF19) with the final aim of reducing hepatic BA synthesis in a negative feedback fashion. Disruption of BA homeostasis with increased hepatic BA toxic levels leads to higher incidence of hepatocellular carcinoma (HCC). While native FGF19 has anti-cholestatic and anti-fibrotic activity in the liver, it retains peculiar pro-tumorigenic actions. Thus, novel analogues have been generated to avoid tumorigenic capacity and maintain BA metabolic action. Here, using BA related Abcb4^-/- and Fxr^-/- mouse models of spontaneous hepatic fibrosis and HCC, we explored the role of a novel engineered variant of FGF19 protein, called FGF19-M52, which fully retains BA regulatory activity but is devoid of the pro-tumoral activity. Expression of the BA synthesis rate-limiting enzyme Cyp7a1 is reduced in FGF19-M52-treated mice compared to the GFP-treated control group with consequent reduction of BA pool and hepatic concentration. Treatment with the non-tumorigenic FGF19-M52 strongly protects Abcb4^-/- and Fxr^-/- mice from spontaneous hepatic fibrosis, cellular proliferation and HCC formation in terms of tumor number and size, with significant reduction of biochemical parameters of liver damage and reduced expression of several genes driving the proliferative and inflammatory hepatic scenario. Our data bona fide suggest the therapeutic potential of targeting the FXR-FGF19 axis to reduce hepatic BA synthesis in the control of BA-associated risk of fibrosis and hepatocarcinoma development.

Blocking FGFR4 exerts distinct anti-tumorigenic effects in esophageal squamous cell carcinoma

Background

The FGFR family can be activated by FGFs and plays important roles in regulating cell growth, differentiation, migration, and angiogenesis. Recent studies have suggested that FGFR4 could regulate several processes, including tumor progression. Esophageal squamous cell carcinoma (ESCC) is a malignancy with high global occurrence. However, the molecule mechanism and the potential roles of FGFR4 in ESCC remain unknown.

Methods

Immunohistochemistry and Western blotting were used to detect FGFR4 expression in ESCC samples and cell lines. Cell counting kit‐8, and clonogenic, transwell, flow cytometric, and tumor xenograft in nude mice assays were utilized to determine the effect of blocking FGFR4 in proliferation, invasion, migration, and apoptosis of ESCC cells.

Results

FGFR4 is frequently overexpressed in ESCC tissue and cell lines. in vitro assays have shown that blocking FGFR4 by a specific blocker, H3B‐6527, significantly decreases proliferation, invasion, and migration, and alters epithelial‐mesenchymal transition markers in ESCC cells. In addition, FGFR4 blockade is associated with the induction of apoptosis and affects PI3K/Akt and MAPK/ERK pathways. Moreover, FGFR4 blockade could significantly inhibit the growth of xenograft tumors in vivo.

Conclusion

Our findings suggest that blocking FGFR4 significantly suppresses the malignant behaviors of ESCC and indicate that FGFR4 is a potential target for the treatment of ESCC.

Bile acid homeostasis in gastrointestinal and metabolic complications of cystic fibrosis

With the improved treatment of the pulmonary complications of cystic fibrosis (CF), gastrointestinal problems have become more important in the morbidity in CF. A hallmark of the gastrointestinal phenotype of CF, apart from pancreatic insufficiency, is a disruption of bile acid homeostasis. Bile acid homeostasis is important for many gastrointestinal processes including fat absorption, inflammation, microbial composition, as well as regulation of whole body energy metabolism. This review describes the impairment of bile acid homeostasis in CF, its possible consequences for gastrointestinal and metabolic complications and its potential as a target for therapy.

Up-regulation of FGF15/19 signaling promotes hepatocellular carcinoma in the background of fatty liver

Background

Upregulated fibroblast growth factor 19 (FGF19) expression in human hepatocellular carcinoma (HCC) specimens is associated with tumor progression and poor prognosis. Nonalcoholic steatohepatitis (NASH) patients are at high risk for malignant transformation into HCC.

Methods

A steatohepatitis-HCC model was established in male C57L/J mice treated with N-nitrosodiethylamine (DEN) and high-fat diet (HFD). A mouse HCC cell line (Hepa1–6) and a mouse hepatocyte line (FL83B) were used to elucidate the mechanism by free fatty acids (FFA) treatment. FGF15, the mouse orthologue of FGF19, and it receptor fibroblast growth factor receptor4 (FGFR4) as well as co-receptor β-klotho were studied. FGF19 signaling was also studied in human samples of HCC with steatohepatitis.

Results

HCC incidence and tumor volume were significantly increased in the DEN+HFD group compared to that in the DEN+control diet (CD) group. Increased levels of FGF15/FGFR4/β-klotho, aberrant epithelial–mesenchymal transition (EMT) and Wnt/β-catenin signaling were detected in DEN+HFD mice. Blockage of the FGF15 signal can attenuate cell migration ability and aberrant EMT and Wnt/β-catenin signaling.

Conclusions

Up-regulated FGF15/FGFR4 signaling promoted the development of HCC by activation of EMT and Wnt/β-catenin signaling in the lipid metabolic disorder microenvironment. Further investigation of FGF19/FGFR4 signaling is important for potential early diagnosis and therapeutic targeting in HCC patients.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0781-8) contains supplementary material, which is available to authorized users.

Fibroblast growth factors 19 and 21 in acute liver damage

Currently there are very few pharmacological options available to treat acute liver injury. Because its natural exposure to noxious stimuli the liver has developed a strong endogenous hepatoprotective capacity. Indeed, experimental evidence exposed a variety of endogenous hepatic and systemic responses naturally activated to protect the hepatic parenchyma and to foster liver regeneration, therefore preserving individual's survival. The fibroblast growth factor (FGF) family encompasses a range of polypeptides with important effects on cellular differentiation, growth survival and metabolic regulation in adult organisms. Among these FGFs, FGF19 and FGF21 are endocrine hormones that profoundly influence systemic metabolism but also exert important hepatoprotective activities. In this review, we revisit the biology of these factors and highlight their potential application for the clinical management of acute liver injury.

Fibroblast growth factor receptor 4 (FGFR4) and fibroblast growth factor 19 (FGF19) autocrine enhance breast cancer cells survival

Basal-like breast cancer is an aggressive tumor subtype with poor prognosis. The discovery of underlying mechanisms mediating tumor cell survival, and the development of novel agents to target these pathways, is a priority for patients with basal-like breast cancer. From a functional screen to identify key drivers of basal-like breast cancer cell growth, we identified fibroblast growth factor receptor 4 (FGFR4) as a potential mediator of cell survival. We found that FGFR4 mediates cancer cell survival predominantly via activation of PI3K/AKT. Importantly, a subset of basal-like breast cancer cells also secrete fibroblast growth factor 19 (FGF19), a canonical ligand specific for FGFR4. siRNA-mediated silencing of FGF19 or neutralization of extracellular FGF19 by anti-FGF19 antibody (1A6) decreases AKT phosphorylation, suppresses cancer cell growth and enhances doxorubicin sensitivity only in the FGFR4⁺/FGF19⁺ breast cancer cells. Consistently, FGFR4/FGF19 co-expression was also observed in 82 out of 287 (28.6%) primary breast tumors, and their expression is strongly associated with AKT phosphorylation, Ki-67 staining, higher tumor stage and basal-like phenotype. In summary, our results demonstrated the presence of an FGFR4/FGF19 autocrine signaling that mediates the survival of a subset of basal-like breast cancer cells and suggest that inactivation of this autocrine loop may potentially serve as a novel therapeutic intervention for future treatment of breast cancers.

Alteration in the serum concentrations of FGF19, FGFR4 and βKlotho in patients with thyroid cancer

INTRODUCTION

βKlotho (βKL) is known to act as co-receptor for fibroblast growth factor receptor 4 (FGFR4) which is the main cognate receptor for fibroblast growth factor 19 (FGF19). Dysregulation of this FGF19/FGFR4/βKL signaling axis has been implicated in the pathogenesis of several cancers. However, its role in the pathogenesis of thyroid cancer has not been determined.

MATERIALS AND METHODS

The aim of this study was to assess FGF19, FGFR4 and βKL concentrations in a group of 36 patients with papillary thyroid cancer (PTC), 11 patients with follicular thyroid cancer (FTC), 9 patients with anaplastic thyroid cancer (ATC) and a group of 19 subjects with multinodular nontoxic goiter (MNG). The control group consisted of 20 healthy volunteers. Serum FGF19, FGFR4 and βKL concentrations were measured using specific ELISA methods.

RESULTS

Significantly lower concentrations of βKL and higher concentrations of FGF19 were found in patients with PTC, FTC and ATC as compared with MNG group and controls. An elevation of FGFR4 serum concentration was observed in all thyroid cancer groups in comparison to MNG group and controls; however, in FTC group it was statistically insignificant. A positive correlation was found between βKL and FGFR4 concentrations in PTC patients. The levels of βKL, FGF19 and FGFR4 did not differ significantly between MNG group and healthy controls.

CONCLUSIONS

Our results indicate that a disrupted FGF19/FGFR4/βKL signaling pathway may play a role in the development of thyroid cancers. However, further studies are needed to elucidate the molecular mechanism of the neoplastic transition of thyroid epithelial cells.

Up-regulation of fibroblast growth factor 19 and its receptor associates with progression from fatty liver to hepatocellular carcinoma

Background

Human fibroblast growth factor 19 (FGF19), its receptor (FGFR4) and EpCAM play an important role in cell proliferation, differentiation, motility, and overexpression have been linked to hepatocellular carcinoma (HCC). The aim of this study was to evaluate the FGF19 signals responsible for the progression of HCC arising from fatty liver.

Results

FGF19 level was significantly increased in the HCC patients' serum compared to non-HCC controls. The IHC results demonstrated significant increases of protein expressions of FGF19, FGFR4 and EpCAM in specimens with fatty liver, NASH, cirrhosis, and HCC compared to healthy liver tissue. There was a significant positive correlation between the protein expressions (FGF19, FGFR4, and EpCAM) and histopathologic changes from FL to HCC. Furthermore, FGF19 was positively correlated with FGFR4 and with EpCAM.

Materials and Methods

FGF19 protein levels in serum and tissues were determined by ELISA assay. The FGFR4, and EpCAM expression and tissue distribution were further evaluated by immunohistochemical staining in tissue array samples. FGF19, FGFR4 and EpCAM expressions between the different histologic stages of fatty liver steatohepatitis-cirrhosis-HCC carcinogenesis sequence were compared to healthy hepatic tissue.

Conclusions

Overexpression of FGF19/FGFR4 significantly correlated with EpCAM as a marker of hepatic cancer stem cells within the fatty liver-steatosis-cirrhosis-HCC sequence.

Impact

This is the first study to elucidate FGF19/FGFR4 signaling in favor of HCC cells developing as indicated by increased EpCAM within the carcinogenesis sequence from fatty liver to hepatocellular carcinoma. Our study has the potential to yield novel and cost effective screening strategies for HCC patients.

FGF19 promotes epithelial-mesenchymal transition in hepatocellular carcinoma cells by modulating the GSK3β/β- catenin signaling cascade via FGFR4 activation

Compelling evidence suggests that the epithelial-mesenchymal transition (EMT) correlates with aggressiveness of tumors and poor survival. FGF19 has been shown to be involved in EMT in cholangiocarcinoma and colorectal cancer, however, molecular mechanisms underlying FGF19-induced EMT process in hepatocellular carcinoma (HCC) remain largely unknown. Here, we show the expression of FGF19 is significantly elevated and negatively associated with the expression of E-cadherin in HCC tissues and cell lines. Ectopic FGF19 expression promotes EMT and invasion in epithelial-like HCC cells through repression of E-cadherin expression, whereas FGF19 knockdown enhances E-cadherin expression and hence diminishes EMT traits in mesenchymal-like HCC cells, suggesting FGF19 exerts its tumor progressing functions as an EMT inducer. Interestingly, depletion of FGF19 cannot abrogate EMT traits in the presence of GSK3β inhibitors. Furthermore, FGF19-induced EMT can be markedly attenuated when FGFR4 is knocked out. These observations clearly indicate that FGFR4/GSK3β/β-catenin axis may play a pivotal role in FGF19-induced EMT in HCC cells. As FGF19 and its specific receptor FGFR4 are frequently amplified in HCC cells, selective targeting this signaling node may lend insights into a potential effective therapeutic approach for blocking metastasis of HCC.

Genome-wide copy number variation pattern analysis and a classification signature for non-small cell lung cancer

The accurate classification of non-small cell lung carcinoma (NSCLC) into lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) is essential for both clinical practice and lung cancer research. Although the standard WHO diagnosis of NSCLC on biopsy material is rapid and economic, more than 13% of NSCLC tumors in the USA are not further classified. The purpose of this study was to analyze the genome-wide pattern differences in copy number variations (CNVs) and to develop a CNV signature as an adjunct test for the routine histopathologic classification of NSCLCs. We investigated the genome-wide CNV differences between these two tumor types using three independent patient datasets. Approximately half of the genes examined exhibited significant differences between LUAD and LUSC tumors and the corresponding non-malignant tissues. A new classifier was developed to identify signature genes out of 20 000 genes. Thirty-three genes were identified as a CNV signature of NSCLC. Using only their CNV values, the classification model separated the LUADs from the LUSCs with an accuracy of 0.88 and 0.84, respectively, in the training and validation datasets. The same signature also classified NSCLC tumors from their corresponding non-malignant samples with an accuracy of 0.96 and 0.98, respectively. We also compared the CNV patterns of NSCLC tumors with those of histologically similar tumors arising at other sites, such as the breast, head, and neck, and four additional tumors. Of greater importance, the significant differences between these tumors may offer the possibility of identifying the origin of tumors whose origin is unknown.

Discovery and optimization of selective FGFR4 inhibitors via scaffold hopping

Introduction of a Michael acceptor on a flexible scaffold derived from pan-FGFR inhibitors has successfully yielded a novel series of highly potent FGFR4 inhibitors with selectivity over FGFR1. Due to reduced lipophilicity and aromatic ring count, this series demonstrated improved solubility and permeability. However, plasma instability and fast metabolism limited its potential for in vivo studies. Efforts have been made to address these problems, which led to the discovery of compound (-)-11 with improved stability, CYP inhibition, and good activity/selectivity for further optimization.

Targeted Therapy for Hepatocellular Carcinoma

Hepatocellular cancer (HCC) is a leading cause of cancer death worldwide, and most patients who are diagnosed with HCC are ineligible for curative local therapy. The targeted agent sorafenib provides modest survival benefits in the setting of advanced disease. Novel systemic treatment options for HCC are sorely needed. In this review, we identify and categorize the drugs and targets that are in various phases of testing for use against HCC. We also focus on the potential for combining these agents with radiotherapy. This would help identify directions for future study that are likely to yield positive findings and improve outcomes for patients with HCC.

Novel bile acid therapeutics for the treatment of chronic liver diseases

Recent developments in understanding the role of bile acids (BAs) as signalling molecules in human metabolism and inflammation have opened new avenues in the field of hepatology research. BAs are no longer considered as simple molecules helping in fat digestion but as agents with real therapeutic value in treating complex autoimmune and metabolic liver diseases. BAs and their receptors such as farnesoid X receptor, transmembrane G protein-coupled receptor 5 and peroxisome proliferator-activated receptor have been identified as novel targets for drug development. Some of these novel pharmaceuticals are already in clinical evaluation with the most advanced drugs having reached phase III trials. Chronic liver diseases such as primary biliary cholangitis, primary sclerosing cholangitis and nonalcoholic fatty liver disease, for which there is no or limited pharmacotherapy, are most likely to gain from these developments. In this review we discuss recent and the most relevant basic and clinical research findings related to BAs and their implications for novel therapy for chronic liver diseases.

Obeticholic acid for the treatment of primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is characterized by progressive nonsuppurative destruction of small bile ducts, resulting in intrahepatic cholestasis, fibrosis and ultimately end-stage liver disease. Timely intervention with ursodeoxycholic acid is associated with excellent survival, although approximately one-third of all patients fail to achieve biochemical response, signifying a critical need for additional therapeutic strategies. Obeticholic acid (OCA) is a potent ligand of the nuclear hormone receptor farnesoid X receptor (FXR). Activation of FXR inhibits bile acid synthesis and protects against toxic accumulation in models of cholestasis and facilitates hepatic regeneration in preclinical studies. Data from recent Phase II and III controlled trials suggest a therapeutic impact of OCA in PBC biochemical nonresponders, as evidenced by change in proven laboratory surrogates of long-term outcome. Dose-dependent pruritus is a common adverse effect, but may be overcome through dose-titration. Longer term studies are needed with focus on safety and long-term clinical efficacy.

FXR Primes the Liver for Intestinal FGF15 Signaling by Transient Induction of β-Klotho

The bile acid (BA)-sensing nuclear receptor, farnesoid X receptor (FXR), regulates postprandial metabolic responses, including inhibition of BA synthesis, by inducing the intestinal hormone, fibroblast growth factor (FGF)15 (FGF19 in human). In this study, we tested a novel hypothesis that FXR not only induces intestinal FGF15 but also primes the liver for effectively responding to the signal by transcriptional induction of the obligate coreceptor for FGF15, β-Klotho (βKL). Activation of FXR by a synthetic agonist, GW4064, in mice increased occupancy of FXR and its DNA-binding partner, retinoid X receptor-α, at FGF15-signaling component genes, particularly βKL, and induced expression of these genes. Interestingly, mRNA levels of Fgfr4, the FGF15 receptor, were not increased by GW4064, but protein levels increased as a result of βKL-dependent increased protein stability. Both FGF receptor 4 and βKL protein levels were substantially decreased in FXR-knockout (KO) mice, and FGF19 signaling, monitored by phosphorylated ERK, was blunted in FXR-KO mice, FXR-KO mouse hepatocytes, and FXR-down-regulated human hepatocytes. Overexpression of βKL in FXR-lacking hepatocytes partially restored FGF19 signaling and inhibition by FGF19 of Cyp7a1, which encodes the rate-limiting BA biosynthetic enzyme. In mice, transient inductions of intestinal Fgf15 and hepatic βKL were temporally correlated after GW4064 treatment, and pretreatment of hepatocytes with GW4064 before FGF19 treatment enhanced FGF19 signaling, which was abolished by transcriptional inhibition or βKL down-regulation. This study identifies FXR as a gut-liver metabolic coordinator for FGF15/19 action that orchestrates transient induction of hepatic βKL and intestinal Fgf15/19 in a temporally correlated manner.

High Expression of FGFR4 Enhances Tumor Growth and Metastasis in Nasopharyngeal Carcinoma

Background: FGF receptor (FGFR) family can be activated by FGFs and play important roles in regulating cell growth, differentiation, migration and angiogenesis. Recent studies suggested that FGFR4 could regulate several processes including tumor progression. Nasopharyngeal carcinoma (NPC) is a malignancy with a high occurrence in Southeast Asia and Southern China. However, the molecule mechanism and the potential roles of FGFR4 in NPC remain unknown

Methods: Immunohistochemistry and western blot were used to investigate the expression of FGFR4 in NPC samples. Then we used statistical analysis to evaluate the diagnostic value and the associations of FGFR4 expression with clinical parameters. In vitro studies, the effects of FGFR4 on proliferation and migration of NPC cell line CNE2 were measured by the starvation-refeeding experiment, CCK8 assay, wounding healing assay and transwell migration assay. The changes of the epithelial-mesenchymal transition (EMT) markers in CNE2 cells after knocking down the expression of FGFR4 were measured by Western blot and immunofluorescence analysis.

Results: FGFR4 was overexpressed in NPC as compared with the inflammatory tissues. High expression of FGFR4 was correlated with Ki67 expression, clinical stages and prognosis in NPC patients (P<0.05).While in vitro, the upregulation of FGFR4 was accompanied with CNE2 cells released from serum starvation. Moreover, it could increase cell proliferation and migration by regulating EMT markers in CNE2 cells.

Conclusion: Our data suggested that FGFR4 might induce NPC progression and act as a potential therapeutic target in NPC.

Increased Expression of FGF19 Contributes to Tumor Progression and Cell Motility of Human Thyroid Cancer

OBJECTIVE

Numerous reports indicate a role for aberrant expression of fibroblast growth factor 19 (FGF19) in tumor development and progression, and several drugs have been developed to target it. The aim of this study was to investigate the clinical significance of FGF19 and examine whether it plays any roles in progression of thyroid cancer.

STUDY DESIGN

Translation research.

SETTING

Navy General Hospital of Chinese PLA, China.

SUBJECTS AND METHODS

Expression patterns of FGF19 protein in 100 paired formalin-fixed and paraffin-embedded cancerous and adjacent noncancerous tissues from patients with thyroid cancer were detected by immunohistochemistry. Then, in vitro migration and invasion assays of siRNA-targeted FGF19-transfected cells were performed.

RESULTS

Positive immunostaining of FGF19 protein expression was localized in cytoplasm with or without membrane of malignant cells and was observed in 82 (82.0%) of 100 patients with thyroid cancer. Statistically, the expression level of FGF19 protein in thyroid cancer tissues was significantly higher than that in normal tissues. In addition, FGF19 overexpression was significantly associated with the advanced tumor node metastasis staging (P = .008), the presence of extrathyroidal invasion (P = .01), lymph nodes metastasis (P = .01), and distant metastasis (P = .02). Furthermore, knockdown of FGF19 by transfection of siRNA-FGF19 could efficiently suppress the migration and invasion abilities of thyroid cancer cells in vitro.

CONCLUSION

Our data revealed that the increased expression of FGF19 might be involved in the malignant behaviors of thyroid cancer, highlighting its potential as a molecular marker for early diagnosis and as a possible target for therapeutic intervention of this disease.