FGF19/FGFR4 signaling contributes to the resistance of hepatocellular carcinoma to sorafenib

Benja-ummarit induces ferroptosis with cell ballooning feature through ROS and iron-dependent pathway in hepatocellular carcinoma

ETHNOPHARMACOLOGICAL RELEVANCE

Benja-ummarit (BU), a traditional Thai herbal formula, has been prescribed by traditional Thai practitioners for the treatment of liver cancer. Clinical trials of BU have shown an increase in overall survival in hepatocellular carcinoma (HCC) patients, including stage 1-3 (with or without prior standard chemotherapy) and terminal stage. The clinical outcomes differ from those of other apoptosis-based conventional chemotherapies. The molecular mechanisms underlying the anti-cancer properties of BU remain unclear.

AIM OF STUDY

To investigate BU-induced ferroptosis through morphological and molecular analyses of HCC cell lines and HCC rat tissues.

METHODOLOGY

Cytotoxicity of BU extract in HepG2 and HuH-7 cells, with or without LX-2 in 2D and 3D cultures, was determined through MTT assay and by observing spheroid formation, respectively, as compared to sorafenib. Morphological changes and the cellular ultrastructure of the treated cells were evaluated by light microscopy and transmission electron microscopy (TEM), respectively. In addition, alterations in ferroptosis protein markers in both cell lines and rat liver tissue were determined using western blot analysis and immunohistochemical staining, respectively. To investigate the pathways mediating ferroptosis, cells were pretreated with an iron chelator to confirm the iron-dependent ferroptosis induced by the BU extract. Intracellular ROS, a mediator of ferroptosis, was measured using a scanning ion conductance microscope (SICM). SICM was also used to determine cellular stiffness. The lipid profiles of BU-treated cells were studied using LC-MS/MS.

RESULTS

The BU extract induced cell death under all HCC cell culture conditions. The BU-IC50 in HepG2 and HuH-7 were 31.24 ± 4.46 μg/mL and 23.35 ± 0.27 μg/mL, respectively as determined by MTT assay. In co-culture with LX-2, BU exhibited a similar trend of cytotoxicity in both HepG2 and HuH-7 cells. Light microscopy showed cell ballooning features with intact plasma membranes, and TEM microscopy showed mitochondrial swelling and reduced mitochondrial cristae in BU-treated cells. BU promotes intracellular iron levels by increasing DMT1 and NCOA4 expression and decreasing FTH1 expression. BU also suppressed the cellular antioxidant system by lowering CD98, NRF2, and GPX4 expression, and promoting KEAP1 expression. IHC results of HCC rat liver tissues showed the absence of DMT1 and high expression of GPX4 in the tumor area. Pre-treatment with an iron chelator partially restored cell viability and shifted the mode of cell death to a more apoptosis-like morphology in the BU-treated group. The SICM showed increased intracellular ROS levels and cellular stiffness 24 h after BU treatment. In more detail of BU-mediated ferroptosis, cellular lipid profiling revealed increased expression of 3 polyunsaturated lipids, which are highly susceptible to lipid peroxidation, in BU-treated cells.

DISCUSSION

Alterations in intracellular iron levels, ROS levels, and cellular lipid composition have been previously reported in cancer cells. Therefore, targeting the iron-dependent ROS pathway and polyunsaturated lipids via BU-induced ferroptosis may be more cancer-specific than apoptosis-based cancer drugs. These observations are in accordance with the clinical outcomes of BU. The ferroptosis-inducing mechanism of BU makes it an extremely promising novel drug candidate for the treatment of HCC.

HuR facilitates miR-93-5p-induced activation of MAP3K2 translation via MAP3K2 3'UTR ARE2 in hepatocellular carcinoma

MicroRNAs (miRNAs) can positively regulate gene expression through an unconventional RNA activation mechanism involving direct targeting 3' untranslated regions (UTRs). Our prior study found miR-93-5p activates mitogen-activated protein kinase kinase kinase 2 (MAP3K2) in hepatocellular carcinoma (HCC) via its 3'UTR. However, the underlying mechanism remains elusive. Here, we identified two candidate AU-rich element (ARE) motifs (ARE1 and ARE2) adjacent to the miR-93-5p binding site located within the MAP3K2 3'UTR using AREsite2. Luciferase reporter and translation assays validated that only ARE2 participated in MAP3K2 activation. Integrative analysis revealed that human antigen R (HuR), an ARE2-associated RNA-binding protein (RBP), physically and functionally interacted with the MAP3K2 3'UTR. Consequently, an HuR-ARE2 complex was shown to facilitate miR-93-5p-mediated upregulation of MAP3K2 expression. Furthermore, bioinformatics analysis and studies of HCC cells and specimens highlighted an oncogenic role for HuR and positive HuR-MAP3K2 expression correlation. HuR is also an enhancing factor in the positive feedback circuit comprising miR-93-5p, MAP3K2, and c-Jun demonstrated in our prior study. The newly identified HuR-ARE2 involvement enriches the mechanism of miR-93-5p-driven MAP3K2 activation and suggests new therapeutic strategies warranted for exploration in HCC.

Natural Polyphenol Delivered Methylprednisolone Achieve Targeted Enrichment for Acute Spinal Cord Injury Therapy

The strong anti-inflammatory effect of methylprednisolone (MP) is a necessary treatment for various severe cases including acute spinal cord injury (SCI). However, concerns have been raised regarding adverse effects from MP, which also severely limits its clinical application. Natural polyphenols, due to their rich phenolic hydroxyl chemical properties, can form dynamic structures without additional modification, achieving targeted enrichment and drug release at the disease lesion, making them a highly promising carrier. Considering the clinical application challenges of MP, a natural polyphenolic platform is employed for targeted and efficient delivery of MP, reducing its systemic side effects. Both in vitro and SCI models demonstrated polyphenols have multiple advantages as carriers for delivering MP: (1) Achieved maximum enrichment at the injured site in 2 h post-administration, which met the desires of early treatment for diseases; (2) Traceless release of MP; (3) Reducing its side effects; (4) Endowed treatment system with new antioxidative properties, which is also an aspect that needs to be addressed for diseases treatment. This study highlighted a promising prospect of the robust delivery system based on natural polyphenols can successfully overcome the barrier of MP treatment, providing the possibility for its widespread clinical application.

Outcomes in Patients with Macrotrabecular-Massive Subtype Hepatocellular Carcinoma Treated with Yttrium-90 Transarterial Radioembolization

PURPOSE

To compare the outcomes of yttrium-90 transarterial radioembolization (TARE) in patients with hepatocellular carcinoma (HCC) with and without macrotrabecular-massive (MTM) subtypes.

MATERIALS AND METHODS

Forty-one consecutive patients with HCC (male, 90.3%; mean age, 65.3 years [SD ± 10.7]) who underwent yttrium-90 TARE between September 2014 and January 2022 were grouped into the MTM-HCC (n = 17, 41.5%) and non-MTM-HCC (n = 24, 58.5%) groups based on their histopathological subtypes. Demographic, clinical, and radiological characteristics were compared. Survival, univariate, and multivariate analyses were performed, and prognostic factors were evaluated.

RESULTS

In MTM-HCC group, the rates of moderately to poorly differentiated tumors were significantly higher (13/17 vs 8/16, P = .007), and new intrahepatic/extrahepatic metastases were detected more frequently (12/17 vs 15/24, P = .038). Median overall survival (OS) in the cohort was 29 months (range, 17.1-40.9 months), whereas patients with MTM-HCC had a significantly shorter median OS (20 vs 44 months, P = .014). In univariate analysis, MTM-HCC subtype (hazard ratio [HR], 2.690; P = .021), the presence of satellite nodules (HR, 3.810; P = .004), and macrovascular invasion (HR, 3.321; P = .012) were identified as significant prognostic factors. In multivariate analysis, MTM-HCC subtype and macrovascular invasion were determined as independent poor prognostic factors (P = .038 and P = .012, respectively).

CONCLUSIONS

In patients with HCC treated with yttrium-90 TARE, both the rates of moderately to poorly differentiated histopathological classes and the development of intrahepatic or extrahepatic metastases were significantly higher in the MTM-HCC subtype. OS was worse in patients with MTM-HCC, and macrovascular invasion and MTM-HCC subtype were identified as independent poor prognostic factors.

Bromocriptine sensitivity in bromocriptine-induced drug-resistant prolactinomas is restored by inhibiting FGF19/FGFR4/PRL

PURPOSE

At present, various treatment strategies are available for pituitary adenomas, including medications, surgery and radiation. The guidelines indicate that pharmacological treatments, such as bromocriptine (BRC) and cabergoline (CAB), are important treatments for prolactinomas, but drug resistance is an urgent problem that needs to be addressed. Therefore, exploring the mechanism of drug resistance in prolactinomas is beneficial for clinical treatment.

METHODS

In our research, BRC-induced drug-resistant cells were established. Previous RNA sequencing data and an online database were used for preliminary screening of resistance-related genes. Cell survival was determined by Cell Counting Kit-8 (CCK-8) assay, colony formation assays and flow cytometry. Quantitative real-time polymerase chain reaction (qRT‒PCR), western blotting, immunohistochemistry, immunofluorescence and Co-immunoprecipitation (Co-IP) were used to assess the molecular changes and regulation. The therapeutic efficacy of BRC and FGFR4 inhibitor fisogatinib (FISO) combination was evaluated in drug-resistant cells and xenograft tumors in nude mice.

RESULTS

Consistent with the preliminary results of RNA sequencing and database screening, fibroblast growth factor 19 (FGF19) expression was elevated in drug-resistant cells and tumor samples. With FGF19 silencing, drug-resistant cells exhibited increased sensitivity to BRC and decreased intracellular phosphorylated fibroblast growth factor receptor 4 (FGFR4) levels. After confirming that FGF19 binds to FGFR4 in prolactinoma cells, we found that FGF19/FGFR4 regulated prolactin (PRL) synthesis through the ERK1/2 and JNK signaling pathways. Regarding the effect of targeting FGF19/FGFR4 on BRC efficacy, FISO and BRC synergistically inhibited the growth of tumor cells, promoted apoptosis and reduced PRL levels.

CONCLUSION

Overall, our study revealed FGF19/FGFR4 as a new mechanism involved in the drug resistance of prolactinomas, and combination therapy targeting the pathway could be helpful for the treatment of BRC-induced drug-resistant prolactinomas.

Mechanisms of drug resistance in HCC

HCC comprises ∼80% of primary liver cancer. HCC is the only major cancer for which death rates have not improved over the last 10 years. Most patients are diagnosed with advanced disease when surgical and locoregional treatments are not feasible or effective. Sorafenib, a multikinase inhibitor targeting cell growth and angiogenesis, was approved for advanced unresectable HCC in 2007. Since then, other multikinase inhibitors have been approved. Lenvatinib was found to be noninferior to sorafenib as a first-line agent. Regorafenib, cabozantinib, and ramucirumab were shown to prolong survival as second-line agents. Advances in immunotherapy for HCC have also added hope for patients, but their efficacy remains limited. A large proportion of patients with advanced HCC gain no long-term benefit from systemic therapy due to primary and acquired drug resistance, which, combined with its rising incidence, keeps HCC a highly fatal disease. This review summarizes mechanisms of primary and acquired resistance to therapy and includes methods for bypassing resistance. It addresses recent advancements in immunotherapy, provides new perspectives on the linkage between drug resistance and molecular etiology of HCC, and evaluates the role of the microbiome in drug resistance. It also discusses alterations in signaling pathways, dysregulation of apoptosis, modulations in the tumor microenvironment, involvement of cancer stem cells, changes in drug metabolism/transport, tumor hypoxia, DNA repair, and the role of microRNAs in drug resistance. Understanding the interplay among these factors will provide guidance on the development of new therapeutic strategies capable of improving patient outcomes.

Fibroblast Growth Factor Receptors and Ligands in Context of Bevacizumab Response in Ovarian Carcinoma: An Exploratory Analysis of AGO-OVAR11/ICON-7

With more novel drugs being approved for the treatment of ovarian carcinoma, the question remains to what extent patients benefit from antiangiogenic treatment with bevacizumab, either in combination with poly-(ADP-ribose) polymerase inhibitors or as single-agent maintenance. As fibroblast growth factor receptors and their ligands (FGFRs/FGFs) are key players in angiogenic signaling and have been linked to resistance to several drugs, we investigated the prognostic or predictive potential of FGFs/FGFRs signaling in the context of bevacizumab treatment within the prospective phase III AGO-OVAR11/ICON-7 study. FGFR1, FGFR2, FGFR3, FGFR4, FGF1, and FGF19 gene expressions were determined in 380 ovarian carcinoma tumor samples collected from German centers in the multicenter phase III AGO-OVAR11 trial/ICON-7 trial. All patients received carboplatin and paclitaxel, administered every 3 weeks for 6 cycles, and were randomized to bevacizumab. Expressions of FGFR1, FGFR2, FGF1, and FGF19 were associated with progression-free survival in both uni- and multivariate (FGFR1: HR, 1.6, P < .001; FGFR2: HR, 1.6, P = .002; FGF1: HR, 2.3, P < .001; and FGF19: HR, 0.7; P = .007) analysis. A signature built by FGFR1, FGFR4, and FGF19 defined a subgroup (n = 62) of patients that derived the greatest bevacizumab-associated improvement of progression-free survival (HR, 0.3; P = .004). In this exploratory analysis of a prospective randomized phase III trial, we provide evidence that the expression of FGFRs/FGFs might have independent prognostic values. An FGFR/FGF-based gene signature identified in our study appears to predict long-term benefit from bevacizumab. This observation is hypothesis-generating and requires validation on independent cohorts.

Targeting the FGF19-FGFR4 pathway for cholestatic, metabolic, and cancerous diseases

Human fibroblast growth factor 19 (FGF19, or FGF15 in rodents) plays a central role in controlling bile acid (BA) synthesis through a negative feedback mechanism. This process involves a postprandial crosstalk between the BA-activated ileal farnesoid X receptor and the hepatic Klotho beta (KLB) coreceptor complexed with fibrobalst growth factor receptor 4 (FGFR4) kinase. Additionally, FGF19 regulates glucose, lipid, and energy metabolism by coordinating responses from functional KLB and FGFR1-3 receptor complexes on the periphery. Pharmacologically, native FGF19 or its analogs decrease elevated BA levels, fat content, and collateral tissue damage. This makes them effective in treating both cholestatic diseases such as primary biliary or sclerosing cholangitis (PBC or PSC) and metabolic abnormalities such as nonalcoholic steatohepatitis (NASH). However, chronic administration of FGF19 drives oncogenesis in mice by activating the FGFR4-dependent mitogenic or hepatic regenerative pathway, which could be a concern in humans. Agents that block FGF19 or FGFR4 signaling have shown great potency in preventing FGF19-responsive hepatocellular carcinoma (HCC) development in animal models. Recent phase 1/2 clinical trials have demonstrated promising results for several FGF19-based agents in selectively treating patients with PBC, PSC, NASH, or HCC. This review aims to provide an update on the clinical development of both analogs and antagonists targeting the FGF19-FGFR4 signaling pathway for patients with cholestatic, metabolic, and cancer diseases. We will also analyze potential safety and mechanistic concerns that should guide future research and advanced trials.

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.

Establishment and Validation of Novel Prognostic Subtypes in Hepatocellular Carcinoma Based on Bile Acid Metabolism Gene Signatures Using Bulk and Single-Cell RNA-Seq Data

Hepatocellular carcinoma (HCC) is a highly detrimental cancer type and has limited therapeutic options, posing significant threats to human health. The development of HCC has been associated with a disorder in bile acid (BA) metabolism. In this study, we employed an integrative approach, combining various datasets and omics analyses, to comprehensively characterize the tumor microenvironment in HCC based on genes related to BA metabolism. Our analysis resulted in the classification of HCC samples into four subtypes (C1, C2a, C2b, and C3). Notably, subtype C2a, characterized by the highest bile acid metabolism score (BAMS), exhibited the highest survival probability. This subtype also demonstrated increased immune cell infiltration, lower cell cycle scores, reduced AFP levels, and a lower risk of metastasis compared to subtypes C1 and C3. Subtype C1 displayed poorer survival probability and elevated cell cycle scores. Importantly, the identified subtypes based on BAMS showed potential relevance to the gene expression of drug targets in currently approved drugs and those under clinical research. Genes encoding VEGFR (FLT4 and KDR) and MET were elevated in C2, while genes such as TGFBR1, TGFB1, ADORA3, SRC, BRAF, RET, FLT3, KIT, PDGFRA, and PDGFRB were elevated in C1. Additionally, FGFR2 and FGFR3, along with immune target genes including PDCD1 and CTLA4, were higher in C3. This suggests that subtypes C1, C2, and C3 might represent distinct potential candidates for TGFB1 inhibitors, VEGFR inhibitors, and immune checkpoint blockade treatments, respectively. Significantly, both bulk and single-cell transcriptome analyses unveiled a negative correlation between BA metabolism and cell cycle-related pathways. In vitro experiments further confirmed that the treatment of HCC cell lines with BA receptor agonist ursodeoxycholic acid led to the downregulation of the expression of cell cycle-related genes. Our findings suggest a plausible involvement of BA metabolism in liver carcinogenesis, potentially mediated through the regulation of tumor cell cycles and the immune microenvironment. This preliminary understanding lays the groundwork for future investigations to validate and elucidate the specific mechanisms underlying this potential association. Furthermore, this study provides a novel foundation for future precise molecular typing and the design of systemic clinical trials for HCC therapy.

FGF19/FGFR4 signaling contributes to hepatocellular carcinoma survival and immune escape by regulating IGF2BP1-mediated expression of PD-L1

Immune-checkpoint blockade (ICB) therapies have been widely used in clinical treatment of cancer patients, but only 20-30% of patients benefit from immunotherapy. Therefore, it is important to decipher the molecular mechanism of resistance to ICB and develop new combined treatment strategies. PD-L1 up-regulation in tumor cells contributes to the occurrence of immune escape. Increasing evidence shows that its transcription level is affected by multiple factors, which limits the objective response rate of ICB. Fibroblast growth factor 19 (FGF19), a member of the fibroblast growth factor family, is widely involved in the malignant progression of many tumors by binding to fibroblast growth factor receptor 4 (FGFR4). In this study, we confirmed that FGF19 acts as a driver gene in hepatocellular carcinoma (HCC) progression by binding to FGFR4. The up-regulation of FGF19 and FGFR4 in HCC is associated with poor prognosis. We found that FGF19/FGFR4 promoted the proliferation and invasion of HCC cells by driving IGF2BP1 to promote PD-L1 expression. Knockdown of FGFR4 significantly reduced the expression of IGF2BP1/PD-L1 and inhibited the proliferation and invasion of HCC cells. These biological effects are achieved by inhibiting the PI3K/AKT pathway. The combination of FGFR4 knockdown and anti-PD-1 antibody greatly suppressed tumor growth and enhanced the sensitivity of immunotherapy, highlighting the clinical significance of FGF19/FGFR4 activation in immunotherapy.

MicroRNAs as the critical regulators of tumor angiogenesis in liver cancer

Liver cancer is one of the most common malignancies in human digestive system. Despite the recent therapeutic methods, there is a high rate of mortality among liver cancer patients. Late diagnosis in the advanced tumor stages can be one of the main reasons for the poor prognosis in these patients. Therefore, investigating the molecular mechanisms of liver cancer can be helpful for the early stage tumor detection and treatment. Vascular expansion in liver tumors can be one of the important reasons for poor prognosis and aggressiveness. Therefore, anti-angiogenic drugs are widely used in liver cancer patients. MicroRNAs (miRNAs) have key roles in the regulation of angiogenesis in liver tumors. Due to the high stability of miRNAs in body fluids, these factors are widely used as the non-invasive diagnostic and prognostic markers in cancer patients. Regarding, the importance of angiogenesis during liver tumor growth and invasion, in the present review, we discussed the role of miRNAs in regulation of angiogenesis in these tumors. It has been reported that miRNAs mainly exert an anti-angiogenic function by regulation of tumor microenvironment, transcription factors, and signaling pathways in liver tumors. This review can be an effective step to suggest the miRNAs for the non-invasive early detection of malignant and invasive liver tumors.

Small Extracellular Vesicle-Derived vWF Induces a Positive Feedback Loop between Tumor and Endothelial Cells to Promote Angiogenesis and Metastasis in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a hypervascular malignancy by which its growth and dissemination are largely driven by the modulation of tumor-derived small extracellular vesicles (sEVs). Proteomic profiling of circulating sEVs of control individuals and HCC patients identifies von Willibrand factor (vWF) to be upregulated progressively along HCC stages. Elevated sEV-vWF levels are found in a larger cohort of HCC-sEV samples and metastatic HCC cell lines compared to their respective normal counterparts. Circulating sEVs of late-stage HCC patients markedly augment angiogenesis, tumor-endothelial adhesion, pulmonary vascular leakiness, and metastasis, which are significantly compromised by anti-vWF antibody. The role of vWF is further corroborated by the enhanced promoting effect of sEVs collected from vWF-overexpressing cells. sEV-vWF modulates endothelial cells through an elevated level of vascular endothelial growth factor A (VEGF-A) and fibroblast growth factor 2 (FGF2). Mechanistically, secreted FGF2 elicits a positive feedback response in HCC via the FGFR4/ERK1 signaling pathway. The co-administration of anti-vWF antibody or FGFR inhibitor significantly improves the treatment outcome of sorafenib in a patient-derived xenograft mouse model. This study reveals mutual stimulation between HCC and endothelial cells by tumor-derived sEVs and endothelial angiogenic factors, facilitating angiogenesis and metastasis. It also provides insights into a new therapeutic strategy involving blocking tumor-endothelial intercellular communication.

Ponatinib: An update on its drug targets, therapeutic potential and safety

Leukemia is a malignancy of the hematopoietic system, and as its pathogenesis has become better understood, three generations of tyrosine kinase inhibitors (TKIs) have been developed. Ponatinib is the third-generation breakpoint cluster region (BCR) and Abelson (ABL) TKI, which has been influential in the leukemia therapy for a decade. Moreover, ponatinib is a potent multi-target kinase inhibitor that acts on various kinases, such as KIT, RET, and Src, making it a promising treatment option for triple-negative breast cancer (TNBC), lung cancer, myeloproliferative syndrome, and other diseases. The drug's significant cardiovascular toxicity poses a significant challenge to its clinical use, requiring the development of strategies to minimize its toxicity and side effects. In this article, the pharmacokinetics, targets, therapeutic potential, toxicity and production mechanism of ponatinib will be reviewed. Furthermore, we will discuss methods to reduce the drug's toxicity, providing new avenues for research to improve its safety in clinical use.

FGF19/FGFR4-mediated elevation of ETV4 facilitates hepatocellular carcinoma metastasis by upregulating PD-L1 and CCL2

BACKGROUND & AIMS

Metastasis remains the major reason for the high mortality of patients with hepatocellular carcinoma (HCC). This study was designed to investigate the role of E-twenty-six-specific sequence variant 4 (ETV4) in promoting HCC metastasis and to explore a new combination therapy strategy for ETV4-mediated HCC metastasis.

METHODS

PLC/PRF/5, MHCC97H, Hepa1-6, and H22 cells were used to establish orthotopic HCC models. Clodronate liposomes were used to clear macrophages in C57BL/6 mice. Gr-1 monoclonal antibody was used to clear myeloid-derived suppressor cells (MDSCs) in C57BL/6 mice. Flow cytometry and immunofluorescence were used to detect the changes of key immune cells in the tumour microenvironment.

RESULTS

ETV4 expression was positively related to higher tumour-node-metastasis (TNM) stage, poor tumour differentiation, microvascular invasion, and poor prognosis in human HCC. Overexpression of ETV4 in HCC cells transactivated PD-L1 and CCL2 expression, which increased tumour-associated macrophage (TAM) and MDSC infiltration and inhibited CD8+ T-cell accumulation. Knockdown of CCL2 by lentivirus or CCR2 inhibitor CCX872 treatment impaired ETV4-induced TAM and MDSC infiltration and HCC metastasis. Furthermore, FGF19/FGFR4 and HGF/c-MET jointly upregulated ETV4 expression through the ERK1/2 pathway. Additionally, ETV4 upregulated FGFR4 expression, and downregulation of FGFR4 decreased ETV4-enhanced HCC metastasis, which created a FGF19-ETV4-FGFR4 positive feedback loop. Finally, anti-PD-L1 combined with FGFR4 inhibitor BLU-554 or MAPK inhibitor trametinib prominently inhibited FGF19-ETV4 signalling-induced HCC metastasis.

CONCLUSIONS

ETV4 is a prognostic biomarker, and anti-PD-L1 combined with FGFR4 inhibitor BLU-554 or MAPK inhibitor trametinib may be effective strategies to inhibit HCC metastasis.

IMPACT AND IMPLICATIONS

Here, we reported that ETV4 increased PD-L1 and chemokine CCL2 expression in HCC cells, which resulted in TAM and MDSC accumulation and CD8+ T-cell inhibition to facilitate HCC metastasis. More importantly, we found that anti-PD-L1 combined with FGFR4 inhibitor BLU-554 or MAPK inhibitor trametinib markedly inhibited FGF19-ETV4 signalling-mediated HCC metastasis. This preclinical study will provide a theoretical basis for the development of new combination immunotherapy strategies for patients with HCC.

Angiogenesis and Hepatocellular Carcinoma: From Molecular Mechanisms to Systemic Therapies

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy. The hypervascular nature of the majority of HCCs and the peculiar vascular derangement occurring during liver carcinogenesis underscore the importance of angiogenesis in the development and progression of these tumors. Indeed, several angiogenic molecular pathways have been identified as deregulated in HCC. The hypervascular nature and the peculiar vascularization of HCC, as well as deregulated angiogenic pathways, represent major therapeutic targets. To a large extent, intra-arterial locoregional treatments (transarterial-(chemo)embolization) rely on tumor ischemia caused by embolization of tumor feeding arteries, even though this may represent the "primum movens" of tumor recurrence through the activation of neoangiogenesis. Considering systemic therapies, the currently available tyrosine kinase inhibitors (sorafenib, regorafenib, cabozantinib and lenvatinib) and monoclonal antibodies (ramucirumab and bevacizumab, in combination with the anti-PD-L1, atezolizumab) primarily target, among others, angiogenic pathways. Considering the importance of angiogenesis in the pathogenesis and treatment of liver cancer, in this paper, we aim to review the role of angiogenesis in HCC, addressing the molecular mechanisms, available antiangiogenic therapies and prognostic biomarkers in patients receiving these treatments.

Target immune components to circumvent sorafenib resistance in hepatocellular carcinoma

Sorafenib, a multi-kinase inhibitor, has been approved for cancer treatment for decades, especially hepatocellular carcinoma (HCC). Although sorafenib produced substantial clinical benefits in the initial stage, a large proportion of cancer patients acquired drug resistance in subsequent treatment, which always disturbs clinical physicians. Cumulative evidence unraveled the underlying mechanism of sorafenib, but few reports focused on the role of immune subpopulations, since the immunological rationale of sorafenib resistance has not yet been defined. Here, we reviewed the immunoregulatory effects of sorafenib on the tumor microenvironment and emphasized the potential immunological mechanisms of therapeutic resistance to sorafenib. Moreover, we also summarized the clinical outcomes and ongoing trials in combination of sorafenib with immunotherapy, highlighted the immunotherapeutic strategies to improve sorafenib efficacy, and put forward several prospective questions aimed at guiding future research in overcoming sorafenib resistance in HCC.

Transcriptional regulation of NDUFA4L2 by NFIB induces sorafenib resistance by decreasing reactive oxygen species in hepatocellular carcinoma

Sorafenib is one a first-line therapeutic drugs for advanced hepatocellular carcinoma (HCC). However, only 30% of patients benefit from sorafenib due to drug resistance. We and other groups have revealed that nuclear factor I B (NFIB) regulates liver regeneration and carcinogenesis, but its role in drug resistance is poorly known. We found that NFIB was more upregulated in sorafenib-resistant SMMC-7721 cells compared to parental cells. NFIB knockdown not only sensitized drug-resistant cells to sorafenib but also inhibited the proliferation and invasion of these cells. Meanwhile, NFIB promoted the proliferation and invasion of HCC cells in vitro and facilitated tumor growth and metastasis in vivo. Knocking down NFIB synergetically inhibited tumor growth with sorafenib. Mechanically, gene expression profiling and subsequent verification experiments proved that NFIB could bind with the promoter region of a complex I inhibitor NDUFA4L2 and promote its transcription. Transcriptional upregulation of NDUFA4L2 by NFIB could thus inhibit the sorafenib-induced reactive oxygen species accumulation. Finally, we found that NFIB was highly expressed in HCC tissues, and high NFIB expression level was associated with macrovascular invasion, advanced tumor stage, and poor prognosis of HCC patients (n = 156). In summary, we demonstrated that NFIB could transcriptionally upregulate NDUFA4L2 to enhance both intrinsic and acquired sorafenib resistance of HCC cells by reducing reactive oxygen species induction.

CRISPR technology: A versatile tool to model, screen, and reverse drug resistance in cancer

BACKGROUND

Drug resistance is a serious challenge in cancer treatment that can render chemotherapy a failure. Understanding the mechanisms behind drug resistance and developing novel therapeutic approaches are cardinal steps in overcoming this issue. Clustered regularly interspaced short palindrome repeats (CRISPR) gene-editing technology has proven to be a useful tool to study cancer drug resistance mechanisms and target the responsible genes. In this review, we evaluated original research studies that used the CRISPR tool in three areas related to drug resistance, namely screening resistance-related genes, generating modified models of resistant cells and animals, and removing resistance by genetic manipulation. We reported the targeted genes, study models, and drug groups in these studies. In addition to discussing different applications of CRISPR technology in cancer drug resistance, we analyzed drug resistance mechanisms and provided examples of CRISPR's role in studying them. Although CRISPR is a powerful tool for examining drug resistance and sensitizing resistant cells to chemotherapy, more studies are required to overcome its disadvantages, such as off-target effects, immunotoxicity, and inefficient delivery of CRISPR/cas9 into the cells.

Circular RNA ITCH increases sorafenib-sensitivity in hepatocellular carcinoma via sequestering miR-20b-5p and modulating the downstream PTEN-PI3K/Akt pathway

BACKGROUNDS

Sorafenib-resistance leads to poor prognosis and high mortality in advanced hepatocellular carcinoma (HCC), and this study aims to investigate the functional role of a circular RNA ITCH (circITCH) in regulating the sorafenib-resistance of HCC and its underlying mechanisms.

METHODS

The expression of circITCH in HCC tissues and cell lines were detected by performing quantitative real-time polymerase chain reaction. Sorafenib-resistant HCC cells were transfected with PLCDH-circITCH to upregulate circITCH and intervened with sorafenib, and MTT assay, flow cytometry and transwell assay were used to test the cell viability, apoptosis and migration ability, respectively. The downstream target of circITCH were explored by using bioinformatic analysis, dual luciferase reporter system and Western blot.

RESULTS

CircITCH was significantly down-regulated in HCC tissues and cell lines, compared with their normal counterparts. Especially, in contrast with the sorafenib-sensitive HCC cells, continuous sorafenib treatment decreased the expression levels of circITCH in the sorafenib-resistant HCC cells. Overexpression of circITCH increased sorafenib-sensitivity, promoted cell apoptosis and reduced cell migration abilities in the sorafenib-resistant HCC cells. Mechanically, circITCH elevated PTEN expression to inactivate the PI3K/Akt signals through negatively regulating miR-20b-5p in HCC, and upregulating miR-20b-5p or inhibiting PTEN abolished the enhancing effect of circITCH overexpression on sorafenib-induced cytotoxicity in sorafenib-resistant HCC cells.

CONCLUSION

Taken together, this study proves that circITCH enhances sorafenib-sensitivity in sorafenib-resistant HCC cells via regulating the miR-20b-5p/PTEN/PI3K/Akt signaling cascade, which highlights the potential value of circITCH as a target for enhancing the sorafenib-sensitivity in HCC.

Blockade of NMT1 enzymatic activity inhibits N-myristoylation of VILIP3 protein and suppresses liver cancer progression

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Identification of the underlying mechanism of HCC progression and exploration of new therapeutic drugs are urgently needed. Here, a compound library consisting of 419 FDA-approved drugs was taken to screen potential anticancer drugs. A series of functional assays showed that desloratadine, an antiallergic drug, can repress proliferation in HCC cell lines, cell-derived xenograft (CDX), patient-derived organoid (PDO) and patient-derived xenograft (PDX) models. N-myristoyl transferase 1 (NMT1) was identified as a target protein of desloratadine by drug affinity responsive target stability (DARTS) and surface plasmon resonance (SPR) assays. Upregulation of NMT1 expression enhanced but NMT1 knockdown suppressed tumor growth in vitro and in vivo. Metabolic labeling and mass spectrometry analyses revealed that Visinin-like protein 3 (VILIP3) was a new substrate of NMT1 in protein N-myristoylation modification, and high NMT1 or VILIP3 expression was associated with advanced stages and poor survival in HCC. Mechanistically, desloratadine binds to Asn-246 in NMT1 and inhibits its enzymatic activity, disrupting the NMT1-mediated myristoylation of the VILIP3 protein and subsequent NFκB/Bcl-2 signaling. Conclusively, this study demonstrates that desloratadine may be a novel anticancer drug and that NMT1-mediated myristoylation contributes to HCC progression and is a potential biomarker and therapeutic target in HCC.

Reciprocal FGF19-GLI2 signaling induces epithelial-to-mesenchymal transition to promote lung squamous cell carcinoma metastasis

PURPOSE

Metastatic lung squamous cell carcinoma (LUSC) is one of the most common causes of cancer death worldwide. As yet, however, the molecular mechanism underlying LUSC metastasis remains elusive. In this study, we report a novel mechanism involving signaling interactions between FGF19 and GLI2 that could drive the progression of LUSC.

METHODS

The expression of FGF19 in human LUSC samples was assessed by immunohistochemistry. The concentration of FGF19 in serum samples was assessed by ELISA. RNA sequencing, scratch wound-healing, trans-well, GO analysis, GSEA, luciferase reporter, Western blotting, immunofluorescence and immunohistochemistry assays, as well as an animal model were used to investigate the molecular mechanism underlying FGF19 driven LUSC progression. The therapeutic effect of a GLI2 inhibitor was determined using both in vitro cellular and in vivo animal experiments.

RESULTS

We found that FGF19, a member of the fibroblast growth factor family, plays a crucial role in the invasion and metastasis of LUSC, and identified GLI2 as an important downstream effector of FGF19 involved in metastasis. Surprisingly, we found that FGF19 and GLI2 could reciprocally induce the expression of each other, and form a positive feedback loop to promote LUSC cell invasion and metastasis. These findings were corroborated by an association between a poor prognosis of LUSC patients and FGF19/GLI2 co-expression. In addition, we found that the GLI inhibitor GANT61 could effectively reduce FGF19-mediated LUSC invasion and metastasis.

CONCLUSION

Our data suggest that FGF19 may serve as a novel biomarker for predicting metastatic LUSC. Intervening with the FGF19-GLI2 feedback loop may be a strategy for the treatment of FGF19-driven LUSC metastasis.

FGF19-mediated ELF4 overexpression promotes colorectal cancer metastasis through transactivating FGFR4 and SRC

Background: Metastasis accounts for the high lethality of colorectal cancer (CRC) patients. Unfortunately, the molecular mechanism manipulating metastasis in CRC is still elusive. Here, we investigated the function of E74-like factor 4 (ELF4), an ETS family member, in facilitating CRC progression. Methods: The expression of ELF4 in human CRC samples and CRC cell lines was determined by quantitative real-time PCR, immunohistochemistry and immunoblotting. The migratory and invasive phenotypes of CRC cells were evaluated by in vitro transwell assays and in vivo metastatic models. The RNA sequencing was used to explore the downstream targets of ELF4. The luciferase reporter assays and chromatin immunoprecipitation assays were used to ascertain the transcriptional regulation related to ELF4. Results: We found elevated ELF4 was positively correlated with distant metastasis, advanced AJCC stages, and dismal outcomes in CRC patients. ELF4 expression was also an independent predictor of poor prognosis. Overexpression of ELF4 boosted CRC metastasis via transactivating its downstream target genes, fibroblast growth factor receptor 4 (FGFR4) and SRC proto-oncogene, non-receptor tyrosine kinase, SRC. Fibroblast growth factor 19 (FGF19) upregulated ELF4 expression through the ERK1/2/SP1 axis. Clinically, ELF4 expression had a positive correlation with FGF19, FGFR4 and SRC, and CRC patients who positively coexpressed FGF19/ELF4, ELF4/FGFR4, or ELF4/SRC exhibited the worst clinical outcomes. Furthermore, the combination of the FGFR4 inhibitor BLU-554 and the SRC inhibitor KX2-391 dramatically suppressed ELF4-mediated CRC metastasis. Conclusions: We demonstrated the essentiality of ELF4 in the metastatic process of CRC, and targeting the ELF4-relevant positive feedback circuit might represent a novel therapeutic strategy.

Targeted Therapy and Personalized Medicine

Targeted therapy and personalized medicine are novel emerging disciplines of cancer research intended for treatment and prevention. One of the most significant advancements in modern oncology is the shift from an organ-centric strategy to a personalized strategy guided by deep molecular analysis. This shift in view, which focuses on the tumour's precise molecular changes, has paved the way for individualized treatment. Researchers and clinicians are using targeted therapies to select the best treatment available based on the molecular characterization of malignant cancer. In the treatment of a cancer, personalized medicine entails the use of genetic, immunological, and proteomic profiling to provide therapeutic alternatives as well as prognostic information about cancer. In this book, targeted therapies and personalized medicine have been covered for specific malignancies, including latest FDA-approved targeted therapies and it also sheds light on effective anti-cancer regimens and drug resistance. This will help to enhance our ability to conduct individualized health planning, make early diagnoses, and choose optimal medications for each cancer patient with predictable side effects and outcomes in a quickly evolving era. Various applications and tools' capacity have been improved for early diagnosis of cancer and the growing number of clinical trials that choose specific molecular targets reflects this predicament. Nevertheless, there are several limitations that must need to be addressed. Hence, in this chapter, we will discuss recent advancements, challenges, and opportunities in personalized medicine for various cancers, with a specific emphasis on target therapies in diagnostics and therapeutics.

Implications of Withaferin A for the metastatic potential and drug resistance in hepatocellular carcinoma cells via Nrf2-mediated EMT and ferroptosis

Hepatocellular carcinoma (HCC) constitutes a major global health threat due to the high incidence and mortality. Sorafenib is known as the first-line medication for advanced HCC; however, it only extends the limited benefit for HCC patients as the development of acquired resistance. Withaferin A exerts broad pharmaceutical applications in several cancers. However, its effects on HCC cell metastatic potential and sorafenib resistance remain elusive. Here, we corroborated that Withaferin A greatly restrained cell viability, invasion, vasculogenic mimicry (VM) formation, and VE-cadherin levels in HepG2 and SNU449 cells. Moreover, Withaferin A sensitized sorafenib (SR)-resistant HCC cells to sorafenib. In striking contrast to the parental cells, lower ferroptosis was observed in SR-resistant cells as the lower ROS, MDA, and higher intracellular GSH levels in SR-resistant cells. Of interest, Withaferin A enhanced ferroptosis in SR-resistant cells, which was reversed by ferroptosis antagonist liproxstation-1. Notably, Withaferin A elevated Keap1 expression to mitigate Nrf2 signaling activation-mediated epithelial to mesenchymal transition (EMT) and ferroptosis-related protein xCT expression. Importantly, blockage of the Keap1/Nrf2 signaling overturned Withaferin A-evoked ferroptosis and facilitated sorafenib resistance. In addition, knockdown of Keap1 antagonized the inhibitory efficacy of Withaferin A on HCC cell viability, invasion, and VM formation. Consequently, Withaferin A may attenuate the metastatic potential and sorafenib resistance by regulating Keap1/Nrf2-associated EMT and ferroptosis. Thus, Withaferin A may serve as a promising agent for HCC therapy, especially for advanced HCC.

Drug resistance mechanism of kinase inhibitors in the treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer, and it usually occurs following chronic liver disease. Although some progress has been made in the treatment of HCC, the prognosis of patients with advanced HCC is not optimistic, mainly because of the inevitable development of drug resistance. Therefore, multi-target kinase inhibitors for the treatment of HCC, such as sorafenib, lenvatinib, cabozantinib, and regorafenib, produce small clinical benefits for patients with HCC. It is necessary to study the mechanism of kinase inhibitor resistance and explore possible solutions to overcome this resistance to improve clinical benefits. In this study, we reviewed the mechanisms of resistance to multi-target kinase inhibitors in HCC and discussed strategies that can be used to improve treatment outcomes.

Hepatocellular carcinoma subtypes based on metabolic pathways reveals potential therapeutic targets

Introduction

Hepatocellular carcinoma (HCC) is an aggressive malignancy with steadily increasing incidence rates worldwide and poor therapeutic outcomes. Studies show that metabolic reprogramming plays a key role in tumor genesis and progression. In this study, we analyzed the metabolic heterogeneity of epithelial cells in the HCC and screened for potential biomarkers.

Methods

The hepatic single-cell RNA sequencing (scRNA-seq) datasets of HCC patients and healthy controls were obtained from the Gene Expression Omnibus (GEO) database. Based on data intergration and measurement of differences among groups, the metabolic epithelial cell subpopulations were identified. The single-cell metabolic pathway was analyzed and the myeloid subpopulations were identified. Cell-cell interaction analysis and single-cell proliferation analysis were performed. The gene expression profiles of HCC patients were obtained from the GSE14520 dataset of GEO and TCGA-LIHC cohort of the UCSC Xena website. Immune analysis was performed. The differentially expressed genes (DEGs) were identified and functionally annotated. Tumor tissues from HCC patients were probed with anti-ALDOA, anti-CD68, anti-CD163, anti-CD4 and anti-FOXP3 antibodies. Results We analyzed the scRNA-seq data from 48 HCC patients and 14 healthy controls. The epithelial cells were significantly enriched in HCC patients compared to the controls (p = 0.011). The epithelial cells from HCC patients were classified into two metabolism-related subpopulations (MRSs) - pertaining to amino acid metabolism (MRS1) and glycolysis (MRS2). Depending on the abundance of these metabolic subpopulations, the HCC patients were also classified into the MRS1 and MRS2 subtype distinct prognoses and immune infiltration. The MRS2 group had significantly worse clinical outcomes and more inflamed tumor microenvironment (TME), as well as a stronger crosstalk between MRS2 cells and immune subpopulations that resulted in an immunosuppressive TME. We also detected high expression levels of ALDOA in the MRS2 cells and HCC tissues. In the clinical cohort, HCC patients with higher ALDOA expression showed greater enrichment of immunosuppressive cells including M2 macrophages and T regulatory cells.

Discussion

The glycolytic subtype of HCC cells with high ALDOA expression is associated with an immunosuppressive TME and predicts worse clinical outcomes, providing new insights into the metabolism and prognosis of HCC.

Spliceosomal profiling identifies EIF4A3 as a novel oncogene in hepatocellular carcinoma acting through the modulation of FGFR4 splicing

INTRODUCTION

Altered splicing landscape is an emerging cancer hallmark; however, the dysregulation and implication of the cellular machinery controlling this process (spliceosome components and splicing factors) in hepatocellular carcinoma (HCC) is poorly known. This study aimed to comprehensively characterize the spliceosomal profile and explore its role in HCC.

METHODS

Expression levels of 70 selected spliceosome components and splicing factors and clinical implications were evaluated in two retrospective and six in silico HCC cohorts. Functional, molecular and mechanistic studies were implemented in three cell lines (HepG2, Hep3B and SNU-387) and preclinical Hep3B-induced xenograft tumours.

RESULTS

Spliceosomal dysregulations were consistently found in retrospective and in silico cohorts. EIF4A3, RBM3, ESRP2 and SRPK1 were the most dysregulated spliceosome elements in HCC. EIF4A3 expression was associated with decreased survival and greater recurrence. Plasma EIF4A3 levels were significantly elevated in HCC patients. In vitro EIF4A3-silencing (or pharmacological inhibition) resulted in reduced aggressiveness, and hindered xenograft-tumours growth in vivo, whereas EIF4A3 overexpression increased tumour aggressiveness. EIF4A3-silencing altered the expression and splicing of key HCC-related genes, specially FGFR4. EIF4A3-silencing blocked the cellular response to the natural ligand of FGFR4, FGF19. Functional consequences of EIF4A3-silencing were mediated by FGFR4 splicing as the restoration of non-spliced FGFR4 full-length version blunted these effects, and FGFR4 inhibition did not exert further effects in EIF4A3-silenced cells.

CONCLUSIONS

Splicing machinery is strongly dysregulated in HCC, providing a source of new diagnostic, prognostic and therapeutic options in HCC. EIF4A3 is consistently elevated in HCC patients and associated with tumour aggressiveness and mortality, through the modulation of FGFR4 splicing.

Prognostic Role of Molecular and Imaging Biomarkers for Predicting Advanced Hepatocellular Carcinoma Treatment Efficacy

Simple Summary

Molecular biomarkers play a marginal role in clinical practice for hepatocellular carcinoma (HCC) diagnosis, surveillance and treatment monitoring. Radiological biomarker: alpha-fetoprotein is still a lone protagonist in this field. The potential role of molecular biomarkers in the assessment of prognosis and treatment results could reduce the health costs faced by standard radiology. The majority of efforts are oriented towards early HCC detection, but the field faces an important challenge to find adequate biomarkers for advanced HCC management.

Abstract

Hepatocellular carcinoma (HCC) is the sixth most common malignancy worldwide and the fourth cause of tumor-related death. Imaging biomarkers are based on computed tomography, magnetic resonance, and contrast-enhanced ultrasound, and are widely applied in HCC diagnosis and treatment monitoring. Unfortunately, in the field of molecular biomarkers, alpha-fetoprotein (AFP) is still the only recognized tool for HCC surveillance in both diagnostic and follow-up purposes. Other molecular biomarkers have little roles in clinical practice regarding HCC, mainly for the detection of early-stage HCC, monitoring the response to treatments and analyzing tumor prognosis. In the last decades no important improvements have been achieved in this field and imaging biomarkers maintain the primacy in HCC diagnosis and follow-up. Despite the still inconsistent role of molecular biomarkers in surveillance and early HCC detection, they could play an outstanding role in prognosis estimation and treatment monitoring with a potential reduction in health costs faced by standard radiology. An important challenge resides in identifying sufficiently sensitive and specific biomarkers for advanced HCC for prognostic evaluation and detection of tumor progression, overcoming imaging biomarker sensitivity. The aim of this review is to analyze the current molecular and imaging biomarkers in advanced HCC.

Combined inhibition of FGFR4 and VEGFR signaling enhances efficacy in FGF19 driven hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an aggressive liver malignancy that is difficult to treat with no approved biomarker based targeted therapies. FGF19-FGFR4 signaling blockade has been recently identified as a promising avenue for treatment of a subset of HCC patients. Using HCC relevant xenograft and PDX models, we show that Lenvatinib, an approved multi-kinase inhibitor, strongly enhanced the efficacy of FGFR4 inhibitor H3B-6527. This enhanced combination effect is not due to enhanced FGFR4 inhibition and it is likely due to cell non-autonomous VEGFR activity of Lenvatinib. This cell non-autonomous mode of action was further supported by strong in vivo combination efficacy with the mouse specific VEGFR2 antibody, DC101, which cannot cell-autonomously inhibit pathways in human xenografts. Mechanistic studies showed that the combination resulted in enhanced efficacy through increased anti-angiogenic and anti-tumorigenic activities. Overall, our results indicate that this combination can be a highly effective treatment option for FGF19 driven HCC patients, and provide preclinical validation of a combination that can be readily tested in the clinical setting.

Selenium nanoparticles overcomes sorafenib resistance in thioacetamide induced hepatocellular carcinoma in rats by modulation of mTOR, NF-κB pathways and LncRNA-AF085935/GPC3 axis

AIMS

The first-line treatment for advanced hepatocellular carcinoma (HCC) is the multikinase inhibitor sorafenib (SOR). Sofafenib resistance is linked to protein kinase B/ mammalian target of rapamycin (AKT/mTOR) and nuclear factor kappa B (NF-κB) activation, apoptosis inhibition and oxidative stress. This study investigated selenium nanoparticles (SeNps) to overcome SOR resistance in thioacetamide (TAA) induced HCC in rats.

MATERIALS AND METHODS

TAA (200 mg/kg/twice weekly, i.p.) was administered for 16 weeks to induce HCC.s. Rats were treated with oral SOR (10 mg/Kg daily), selenium, and SeNps (5 mg/kg three times/week) alone or in combination, for two weeks. Apoptosis, proliferation, angiogenesis, metastasis and drug resistance were assessed. Cleaved caspase 3 (C. CASP3), mTOR, and NF-κB were determined by western blotting. Expression of p53 gene and long-noncoding RNA-AF085935 was determined by qRT-PCR. Expression of B- Cell Leukemia/Lymphoma 2 (Bcl2), Bcl associated X protein (Bax)and glypican 3 (GPC3) was determined by enzyme-linked immunosorbent assay. Liver functions, antioxidant capacity, histopathology and CD34 immunohistochemistry were performed.

KEY FINDINGS

SOR/SeNps reversed TAA-induced HCC in rats, through reduction of oxidative stress, activation of p53, Bax and CASP3, and inhibition of Bcl2. SOR/SeNps ameliorated the HCC-induced effect on cell proliferation and drug resistance by targeting mTOR and NF-κB pathways. SOR/SeNps decreased CD34 immunostaining indicating a decrease in angiogenesis and metastasis. SOR/SeNps regulated HCC epigenetically through the lncRNA-AF085935/GPC3 axis.

SIGNIFICANCE

SOR/SeNps are a promising combination for tumor suppression and overcoming sorafenib resistance in HCC by modulating apoptosis, AKT/mTOR and NF-κB pathways, as well as CD34 and lncRNA-AF085935/GPC3 axis.

Macrotrabecular-Massive Hepatocellular Carcinoma: What Should We Know?

Hepatocellular carcinoma is one of the most common malignancies globally. Recently, a newly identified histological subtype, designated as "macrotrabecular-massive hepatocellular carcinoma" (MTM-HCC), has been associated with an aggressive phenotype and has received extensive attention. MTM-HCC was a strong independent prognostic predictor of early and overall recurrence because it is closely related to tumor molecular subclass, gene mutation, carcinogenesis pathways, and immunohistochemical markers. In addition, preoperative imaging examination can potentially provide an essential clue for diagnosing MTM-HCC, intratumor necrosis or ischemia is an independent predictor for MTM-HCC on Gd-EOB-DTPA enhanced MRI or CT. Early diagnosis and appropriate treatment of MTM-HCC could prove beneficial for preventing early recurrence and could improve outcomes.

Progress of targeted and immunotherapy for hepatocellular carcinoma and the application of next-generation sequencing

Hepatocellular carcinoma (HCC), leading cancer worldwide, has a high degree of genetic heterogeneity; next-generation sequencing (NGS) technology has contributed significantly to the discovery of driving genes as well as high-frequency mutations in HCC. The detection of gene alterations may allow us to predict prognosis and adverse drug reactions for individuals, paving the way for personalized medicine in HCC patients. In this review, we summarized the common systemic therapy regimens for HCC and the predictive efficacy of genetic biomarkers on the prognosis of patients under these treatments. Finally, we put forward a future perspective on the potential of NGS technology for the guidance of targeted therapy and immunotherapy in HCC.

DCZ0415, a small-molecule inhibitor targeting TRIP13, inhibits EMT and metastasis via inactivation of the FGFR4/STAT3 axis and the Wnt/β-catenin pathway in colorectal cancer

Thyroid receptor-interacting protein 13 (TRIP13), a protein of the AAA-ATPase family, is upregulated in various human cancers, including colorectal cancer (CRC). This study focused on the inhibition of TRIP13-induced CRC progression and signalling by DCZ0415, a small molecule targeting TRIP13. It demonstrated potent antitumour activity in TRIP13-deregulated cancer cell lines, regardless of their p53, KRAS, BRAF, epidermal growth factor receptor or microsatellite instability status. The treatment of CRC cells with DCZ0415 resulted in decreased cell proliferation, induced cell cycle arrest in the G2-M phase and increased apoptosis. DCZ0415 diminished xenograft tumour growth and metastasis of CRC in immunocompromised mice. DCZ0415 reduced expression of fibroblast growth factor receptor 4 (FGFR4), signal transducer and activator of transcription 3 (STAT3), and proteins associated with the epithelial-mesenchymal transition and nuclear factor kappa B (NF-κB) pathways in cells and xenografts exhibiting high expression of TRIP13. Additionally, DCZ0415 decreased cyclin D1, β-catenin and T-cell factor 1, leading to the inactivation of the Wnt/β-catenin pathway. In a syngeneic CRC model, DCZ0415 treatment induced an immune response by decreasing PD1 and CTLA4 levels and increasing granzyme B, perforin and interferon gamma. In sum, DCZ04145 inhibits the TRIP13-FGFR4-STAT3 axis, inactivates NF-κB and Wnt/β-catenin signalling, activates antitumour immune response and reduces the progression and metastasis of CRC. This study provides a rationale to evaluate DCZ0415 clinically for the treatment of a subset of CRCs that exhibit dysregulated TRIP13 and FGFR4.

CRISPR-Cas9-based genome-wide screening identified novel targets for treating sorafenib-resistant hepatocellular carcinoma: a cross-talk between FGF21 and the NRF2 pathway

The treatment of hepatocellular carcinoma (HCC) has been dominated by multikinase inhibitors for more than a decade. However, drug resistance can severely restrict the efficacy of these drugs. Using CRISPR/CAS9 genome library screening, we evaluated Kelch-like ECH-associated protein 1 (KEAP1) as a key regulator of sorafenib's susceptibility in HCC. We also investigated whether KEAP1's knockdown can stabilize nuclear factor (erythroid-derived 2)-like 2 (NRF2) protein levels that led to sorafenib's resistance, including an NRF2 inhibitor that can synergize with sorafenib to abolish HCC's growth in vitro and in vivo. Furthermore, we clarified that fibroblast growth factor 21 (FGF21) is an important downstream regulator of NRF2 in HCC. Intriguingly, we observed that FGF21 bound to NRF2 through the C-terminus of FGF21, thereby stabilizing NRF2 by reducing its ubiquitination and generating a positive feedback loop in sorafenib-resistant HCC. These findings, therefore, propose that targeting FGF21 is a promising strategy to combat HCC sorafenib's resistance.

Knockdown of AKR1C3 Promoted Sorafenib Sensitivity Through Inhibiting the Phosphorylation of AKT in Hepatocellular Carcinoma

Background

Sorafenib, which can induce ferroptosis, is a multikinase inhibitor for enhancing survival in advanced hepatocellular carcinoma (HCC). However, a considerable challenge for the treatment of HCC is sorafenib resistance. Therefore, targeting the relationship between sorafenib resistance and ferroptosis genes may provide a novel approach for the treatment of HCC.

Materials and Methods

We analyzed the gene expression and clinicopathological factors from The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC), International Cancer Genome Consortium (ICGC), and Gene Expression Omnibus (GEO) databases (GSE109211/GSE62813). The statistical analysis was conducted in R. Cell proliferation was assayed by MTT, cell colony-forming assay, and wound healing assay. Immunofluorescence assay and Western blot were used to evaluate the expression of AKT.

Results

Many ferroptosis-related genes were upregulated in the sorafenib-resistant group. Aldo-keto reductase 1C3 (AKR1C3) was highly expressed in sorafenib-resistant patients, and the high expression of AKR1C3 was associated with the poor prognosis of patients from the TCGA and ICGC databases. MTT and colony-forming assays showing AKR1C3 overexpression enhanced the proliferation of HCC cells and acute sorafenib resistance. Knockdown of AKR1C3 inhibited the proliferation of HCC cells and increased the drug sensitivity of sorafenib. Immunofluorescence assay and Western blot proved that AKR1C3 promoted the phosphorylation of AKT.

Conclusion

AKR1C3 can induce sorafenib resistance through promoting the phosphorylation of AKT in HCC. AKR1C3 inhibitors may be used in conjunction with sorafenib to become a better therapeutic target for HCC.

FGFR4 inhibitors for the treatment of hepatocellular carcinoma: a synopsis of therapeutic potential

INTRODUCTION

The mainstay pharmacological approaches to patients with hepatocellular carcinoma (HCC) are tyrosine kinase inhibitors, antiangiogenic agents, and immune checkpoint inhibitors in combination therapy. Aberrant signaling of fibroblast growth factor 19 (FGF19) and its corresponding receptor, fibroblast growth factor receptor 4 (FGFR4), are a driver of HCC cell growth and survival. However, the clinical potential of agents targeting aberrant FGF19/FGFR4 signaling has not been adequately explored.

AREAS COVERED

We evaluate the existing literature on aberrant signaling of FGF19/FGFR4 in HCC and address the recent preclinical and clinical advances of selective FGFR4 inhibitors in the treatment of advanced HCC. Our literature search was performed in September 2021 on clinical trials and ongoing studies published in journals or presented in conferences for cancer research.

EXPERT OPINION

Preclinical studies show selective FGFR4 inhibitors to be highly potent. These inhibitors also show promise in clinical trials and demonstrate manageable on-target side effects. An emphasis should be placed on the development of predictive biomarkers and on enhancing the understanding of primary and acquired resistance mechanisms. This will inspire rationale combination therapy strategies for testing in future clinical trials.

CRISPR/Cas9 in Gastrointestinal Malignancies

Gastrointestinal (GI) cancers such as colorectal cancer (CRC), gastric cancer (GC), esophageal cancer (EG), pancreatic duct adenocarcinoma (PDAC) or hepatocellular cancer (HCC) belong to the most commonly diagnosed types of cancer and are among the most frequent causes of cancer related death worldwide. Most types of GI cancer develop in a stepwise fashion with the occurrence of various driver mutations during tumor progression. Understanding the precise function of mutations driving GI cancer development has been regarded as a prerequisite for an improved clinical management of GI malignancies. During recent years, CRISPR/Cas9 has developed into a powerful tool for genome editing in cancer research by knocking in and knocking out even multiple genes at the same time. Within this review, we discuss recent applications for CRISPR/Cas9-based genome editing in GI cancer research including CRC, GC, EG, PDAC and HCC. These applications include functional studies of candidate genes in cancer cell lines or organoids in vitro as well as in murine cancer models in vivo, library screening for the identification of previously unknown driver mutations and even gene therapy of GI cancers.

Anti-cancer effects of 3,4-dihydropyrimido[4,5-d]pyrimidin-2(1H)-one derivatives on hepatocellular carcinoma harboring FGFR4 activation

Hepatocellular carcinoma (HCC) is disease with a high mortality rate and limited treatment options. Alterations of fibroblast growth factor receptor 4 (FGFR4) has been regarded as an oncogenic driver for HCC and a promising target for HCC therapeutics. Herein, we report that GNF-7, a multi-targeted kinase inhibitor, and its derivatives including SIJ1263 (IC₅₀ < 1 nM against FGFR4) are highly potent FGFR4 inhibitors and are capable of strongly suppressing proliferation of HCC cells and Ba/F3 cells transformed with wtFGFR4 or mtFGFR4. Compared with known FGFR4 inhibitors, both GNF-7 and SIJ1263 possess much higher (up to 100-fold) anti-proliferative activities via FGFR signaling blockade and apoptosis on HCC cells. Especially, SIJ1263 is 80-fold more potent (GI₅₀ = 24 nM) on TEL-FGFR4 V550E Ba/F3 cells than BLU9931, which suggests that SIJ1263 would be effective for overriding drug resistance. In addition, both substances strongly suppress migration/invasion and colony formation of HCC cells. It is worth noting that SIJ1263 is superior to GNF-7 with regards to the fact that activities of SIJ1263 are higher than those of GNF-7 in all assays performed in this study. Collectively, this study provides insight into designing highly potent FGFR4 inhibitors capable of potentially overcoming drug-resistance for the treatment of HCC patients.

FGF/FGFR-Dependent Molecular Mechanisms Underlying Anti-Cancer Drug Resistance

Simple Summary

Deregulation of the FGF/FGFR axis is associated with many types of cancer and contributes to the development of chemoresistance, limiting the effectiveness of current treatment strategies. There are several mechanisms involved in this phenomenon, including cross-talks with other signaling pathways, avoidance of apoptosis, stimulation of angiogenesis, and initiation of EMT. Here, we provide an overview of current research and approaches focusing on targeting components of the FGFR/FGF signaling module to overcome drug resistance during anti-cancer therapy.

Abstract

Increased expression of both FGF proteins and their receptors observed in many cancers is often associated with the development of chemoresistance, limiting the effectiveness of currently used anti-cancer therapies. Malfunctioning of the FGF/FGFR axis in cancer cells generates a number of molecular mechanisms that may affect the sensitivity of tumors to the applied drugs. Of key importance is the deregulation of cell signaling, which can lead to increased cell proliferation, survival, and motility, and ultimately to malignancy. Signaling pathways activated by FGFRs inhibit apoptosis, reducing the cytotoxic effect of some anti-cancer drugs. FGFRs-dependent signaling may also initiate angiogenesis and EMT, which facilitates metastasis and also correlates with drug resistance. Therefore, treatment strategies based on FGF/FGFR inhibition (using receptor inhibitors, ligand traps, monoclonal antibodies, or microRNAs) appear to be extremely promising. However, this approach may lead to further development of resistance through acquisition of specific mutations, metabolism switching, and molecular cross-talks. This review brings together information on the mechanisms underlying the involvement of the FGF/FGFR axis in the generation of drug resistance in cancer and highlights the need for further research to overcome this serious problem with novel therapeutic strategies.

The Saga of Endocrine FGFs

Fibroblast growth factors (FGFs) are cell-signaling proteins with diverse functions in cell development, repair, and metabolism. The human FGF family consists of 22 structurally related members, which can be classified into three separate groups based on their action of mechanisms, namely: intracrine, paracrine/autocrine, and endocrine FGF subfamilies. FGF19, FGF21, and FGF23 belong to the hormone-like/endocrine FGF subfamily. These endocrine FGFs are mainly associated with the regulation of cell metabolic activities such as homeostasis of lipids, glucose, energy, bile acids, and minerals (phosphate/active vitamin D). Endocrine FGFs function through a unique protein family called klotho. Two members of this family, α-klotho, or β-klotho, act as main cofactors which can scaffold to tether FGF19/21/23 to their receptor(s) (FGFRs) to form an active complex. There are ongoing studies pertaining to the structure and mechanism of these individual ternary complexes. These studies aim to provide potential insights into the physiological and pathophysiological roles and therapeutic strategies for metabolic diseases. Herein, we provide a comprehensive review of the history, structure–function relationship(s), downstream signaling, physiological roles, and future perspectives on endocrine FGFs.

CISD2 Promotes Resistance to Sorafenib-Induced Ferroptosis by Regulating Autophagy in Hepatocellular Carcinoma

Purpose

Sorafenib is a multi-kinase inhibitor that is used as a standard treatment for advanced hepatocellular carcinoma (HCC). However, the mechanism of sorafenib resistance in HCC is still unclear. It has been shown that CISD2 expression is related to the progression and poor prognosis of HCC. Here, we show a new role for CISD2 in sorafenib resistance in HCC.

Methods

Bioinformatic analysis was used to detect the expression of negative regulatory genes of ferroptosis in sorafenib-resistant samples. The concentration gradient method was used to establish sorafenib-resistant HCC cells. Western blot was used to detect the protein expression of CISD2, LC3, ERK, PI3K, AKT, mTOR, and Beclin1 in HCC samples. Quantitative real-time PCR (qPCR) was used to detect gene expression. CISD2 shRNA and Beclin1 shRNA were transfected to knock down the expression of the corresponding genes. Cell viability was detected by a CCK-8 assay. ROS were detected by DCFH-DA staining, and MDA and GSH were detected with a Lipid Peroxidation MDA Assay Kit and Micro Reduced Glutathione (GSH) Assay Kit, respectively. Flow cytometry was used to detect apoptosis and the levels of ROS and iron ions.

Results

CISD2 was highly expressed in HCC cells compared with normal cells and was associated with poor prognosis in patients. Knockdown of CISD2 promoted a decrease in the viability of drug-resistant HCC cells. CISD2 knockdown promoted sorafenib-induced ferroptosis in resistant HCC cells. The levels of ROS, MDA, and iron ions increased, but the change in GSH was not obvious. Knockdown of CISD2 promoted uncontrolled autophagy in resistant HCC cells. Inhibition of autophagy attenuated CISD2 knockdown-induced ferroptosis. The autophagy promoted by CISD2 knockdown was related to Beclin1. When CISD2 and Beclin1 were inhibited, the effect on ferroptosis was correspondingly weakened.

Conclusion

Inhibition of CISD2 promoted sorafenib-induced ferroptosis in resistant cells, and this process promoted excessive iron ion accumulation through autophagy, leading to ferroptosis. The combination of CISD2 inhibition and sorafenib treatment is an effective therapeutic strategy for resistant HCC.

Evolution of systemic treatment for advanced hepatocellular carcinoma

Advanced hepatocellular carcinoma (HCC) was considered an inherently refractory tumor in the chemotherapy era (1950-2000). However, systemic therapy has evolved to molecular targeted therapy and immunotherapy, and nine treatment regimens have been approved worldwide during the past 20 years. The approved regimens target tumor angiogenesis or tumor immunity, the two cancer hallmarks. Recently, the combination of atezolizumab (antiprogrammed cell death ligand 1) and bevacizumab (anti-vascular endothelial growth factor) has improved the efficacy of systemic therapy in treating advanced HCC without excessive toxicities or deterioration of quality of life. This review summarizes the major advances in systemic therapy and provides future perspectives on the next-generation systemic therapy for advanced HCC.

Ginsenoside Rg3 in combination with artesunate overcomes sorafenib resistance in hepatoma cell and mouse models

Background

Sorafenib is effective in treating hepatoma, but most patients develop resistance to it. STAT3 signaling has been implicated in sorafenib resistance. Artesunate (ART) and 20(R)-ginsenoside Rg3 (Rg3) have anti-hepatoma effects and can inhibit STAT3 signaling in cancer cells. This study aimed to evaluate the effects of Rg3 in combination with ART (Rg3-plus-ART) in overcoming sorafenib resistance, and to examine the involvement of STAT3 signaling in these effects.

Methods

Sorafenib-resistant HepG2 cells (HepG2-SR) were used to evaluate the in vitro anti-hepatoma effects of Rg3-plus-ART. A HepG2-SR hepatoma-bearing BALB/c-nu/nu mouse model was used to assess the in vivo anti-hepatoma effects of Rg3-plus-ART. CCK-8 assays and Annexin V-FITC/PI double staining were used to examine cell proliferation and apoptosis, respectively. Immunoblotting was employed to examine protein levels. ROS generation was examined by measuring DCF-DA fluorescence.

Results

Rg3-plus-ART synergistically reduced viability of, and evoked apoptosis in HepG2-SR cells, and suppressed HepG2-SR tumor growth in mice. Mechanistic studies revealed that Rg3-plus-ART inhibited activation/phosphorylation of Src and STAT3 in HepG2-SR cultures and tumors. The combination also decreased the STAT3 nuclear level and induced ROS production in HepG2-SR cultures. Furthermore, over-activation of STAT3 or removal of ROS diminished the anti-proliferative effects of Rg3-plus-ART, and removal of ROS diminished Rg3-plus-ART's inhibitory effects on STAT3 activation in HepG2-SR cells.

Conclusions

Rg3-plus-ART overcomes sorafenib resistance in experimental models, and inhibition of Src/STAT3 signaling and modulation of ROS/STAT3 signaling contribute to the underlying mechanisms. This study provides a pharmacological basis for developing Rg3-plus-ART into a novel modality for treating sorafenib-resistant hepatoma.

Upregulation of the ErbB family by EZH2 in hepatocellular carcinoma confers resistance to FGFR inhibitor

PURPOSE

Hepatocellular carcinoma (HCC), the most common manifestation of liver cancer, is one of the leading causes of cancer-related mortality worldwide with limited treatment options. Infigratinib, a pan-FGFR inhibitor, has shown a potent antitumour effect in HCC. However, drug resistance is often observed in long-term treatment. In this study, we examined the potential feedback mechanism(s) leading to infigratinib and explored a combination therapy to overcome resistance in HCC.

METHODS

Patient-derived xenograft (PDX) tumours were subcutaneously implanted into SCID mice and were subsequently treated with infigratinib. Tumour growth was monitored over time, and tumour samples were subjected to immunohistochemistry and Western blotting. For drug combination studies, mice were treated with infigratinib and/or varlitinib. Gene overexpression and knockdown studies were conducted to investigate the relationship between EZH2 and ErbB activity in infigratinib resistance.

RESULTS

Infigratinib-resistant tumours exhibited higher levels of p-ErbB2 and p-ErbB3, concomitant with an increase in EZH2 expression. Gene overexpression and knockdown studies revealed that EZH2 directly regulates the levels of p-ErbB2 and p-ErbB3 in acquired resistance to infigratinib. The addition of varlitinib effectively overcame infigratinib resistance and prolonged the antitumour response, with minimal toxicity.

CONCLUSION

The upregulation of the ErbB family by EZH2 appears to contribute to infigratinib resistance. The combination of infigratinib and varlitinib showed a potent antitumour effect and did not result in additional toxicity, warranting further clinical investigation.

Microarray-based identification of differentially expressed genes associated with andrographolide derivatives-induced resistance in colon and prostate cancer cell lines

Chemoresistance poses a major hurdle to cancer treatments. Andrographolide-derived SRJ09 and SRJ23 were reported to exhibit potent, selective inhibitory activities against colon and prostate cancer cells, respectively. In this study, previously developed resistant colon (HCT-116^rst09) and prostate (PC-3^rst23) cancer cell lines were used to elucidate the molecular mechanisms contributing to chemoresistance. Cytotoxic effects of SRJ09 and SRJ23 on both parental and resistant cells were investigated. Cell cycle distributions in HCT-116^rst09 cells following SRJ09 treatment were analysed using flow cytometry. Whole-genome microarray analysis was performed on both parental and resistant cells to obtain differential gene expression profiles. Microarray data were subjected to protein-protein interaction network, functional enrichment, and pathway analyses. Reverse transcription-polymerase chain reaction (RT-PCR) was used to validate the changes in expression levels of selected genes. Besides morphological changes, HCT-116^rst09 cells showed 7.0-fold resistance to SRJ09 while PC-3^rst23 cells displayed a 5.5-fold resistance to SRJ23, as compared with their respective parental cells. G₀/G₁-phase cell cycle arrest was observed in HCT-116^rst09 cells upon SRJ09 treatment. Collectively, 77 and 21 genes were found differentially modulated in HCT-116^rst09 and PC-3^rst23 cells, respectively. Subsequent bioinformatics analysis revealed several genes associated with FGFR4 and PI3K pathways, and cancer stemness, were chemoresistance mediators in HCT-116^rst09 cells. RT-PCR confirmed the HMOX1 upregulation and ATG12 downregulation protected the PC-3^rst23 cells from SRJ23 cytotoxicity. In conclusion, acquired chemoresistance to SRJ09 and SRJ23 in colon and prostate cancer cells, respectively, could be attributed to the alterations in the expression of genes such as those related to PI3K and autophagy pathways.

Combination of molecularly targeted therapies and immune checkpoint inhibitors in the new era of unresectable hepatocellular carcinoma treatment

Multikinase inhibitors (MKIs) have been the only first-line treatment for advanced hepatocellular carcinoma (HCC) for more than a decade, until the approval of immune checkpoint inhibitors (ICIs). Moreover, the combination regimen of atezolizumab (anti-programmed cell death protein ligand 1 antibody) plus bevacizumab (anti-vascular endothelial growth factor monoclonal antibody) has recently been demonstrated to have superior efficacy when compared with sorafenib monotherapy. The remarkable efficacy has made this combination therapy the new standard treatment for advanced HCC. In addition to MKIs, many other molecularly targeted therapies are under investigation, some of which have shown promising results. Therefore, in the era of immuno-oncology, there is a significant rationale for testing the combinations of molecularly targeted therapies and ICIs. Indeed, numerous preclinical and clinical studies have shown the synergic antitumor efficacy of such combinations. In this review, we aim to summarize the current knowledge on the combination of molecularly targeted therapies and immune checkpoint therapies for HCC from both preclinical and clinical perspectives.

Maprotiline Suppresses Cholesterol Biosynthesis and Hepatocellular Carcinoma Progression Through Direct Targeting of CRABP1

Hepatocellular carcinoma (HCC) remains one of the leading causes of cancer-related death and has a poor prognosis worldwide, thus, more effective drugs are urgently needed. In this article, a small molecule drug library composed of 1,056 approved medicines from the FDA was used to screen for anticancer drugs. The tetracyclic compound maprotiline, a highly selective noradrenergic reuptake blocker, has strong antidepressant efficacy. However, the anticancer effect of maprotiline remains unclear. Here, we investigated the anticancer potential of maprotiline in the HCC cell lines Huh7 and HepG2. We found that maprotiline not only significantly restrained cell proliferation, colony formation and metastasis in vitro but also exerted antitumor effects in vivo. In addition to the antitumor effect alone, maprotiline could also enhance the sensitivity of HCC cells to sorafenib. The depth studies revealed that maprotiline substantially decreased the phosphorylation of sterol regulatory element-binding protein 2 (SREBP2) through the ERK signaling pathway, which resulted in decreased cholesterol biosynthesis and eventually impeded HCC cell growth. Furthermore, we identified cellular retinoic acid binding protein 1 (CRABP1) as a direct target of maprotiline. In conclusion, our study provided the first evidence showing that maprotiline could attenuate cholesterol biosynthesis to inhibit the proliferation and metastasis of HCC cells through the ERK-SREBP2 signaling pathway by directly binding to CRABP1, which supports the strategy of repurposing maprotiline in the treatment of HCC.

βKlotho, a direct target of miR-206, contributes to the growth of hepatoblastoma through augmenting PI3K/Akt/mTOR signaling

Hepatoblastoma (HB) is the most frequent pediatric liver malignancy. However, the treatment outcome for patients with advanced-stage HB remains unsatisfactory. Accumulating evidence indicates that βKlotho (KLB) acts as an oncogene or a tumor-suppressor gene in a context-dependent manner. Despite this, the expression profile and effects of KLB on the growth of HB are still elusive. This study aimed to explore the effect of miR-206/KLB axis on HB growth. The expression of KLB was explored in HB cells (HepG2 and HuH6) and tissues using quantitative polymerase chain reaction (qPCR), Western blot analysis, and immunohistochemistry. Besides, miR-206 expression was determined in HB cells and tissues using qPCR and fluorescence in situ hybridization. The prognostic value of KLB or miR-206 in our patients with HB was investigated using the Kaplan-Meier method. The biological effects of KLB or miR-206 on HB cells were identified in vitro. The proliferative effects of KLB on HuH6 cells were also investigated in vivo. Moreover, the mechanical signaling of KLB in HB was determined through bioinformatics analysis followed by experimental validation. The results showed a significant upregulation of KLB in HB tissues and cells. Elevated level of KLB was found to be significantly correlated with the aggressive phenotype and poor overall survival for children with HB. The in vitro function assay demonstrated that KLB knockdown promoted apoptosis and suppressed the proliferation, migration, and invasion of HB cells. Besides, KLB knockdown inhibited the proliferation of HuH6 cells in vivo, while KLB overexpression had the opposite effect. Furthermore, KLB was proved to be the direct target of miR-206. Low level of miR-206 served as an independent risk factor for poor prognosis in children with HB. The overexpression of miR-206 negatively regulated the aggressive biological behaviors of HB cells, which was partially rescued by KLB overexpression. Mechanically, the miR-206/KLB axis played a vital role in HB growth through augmenting the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling. In conclusion, the data demonstrated that the miR-206/KLB axis might serve as an important biomarker/therapeutic target for HB.