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

β-Klotho as novel therapeutic target in Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): A narrative review

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) represents the most frequent cause of hepatic disorder, and its progressive form defined as Metabolic Dysfunction-Associated Steatohepatitis (MASH) contributes to the development of fibrosis/cirrhosis and hepatocellular carcinoma (HCC). Today effective therapeutic strategies addressing MASH-related comorbidities, inflammation, and fibrosis are needed. The fibroblast growth factor (FGF) 19 and 21 and their fibroblast growth factor receptor/β-Klotho (KLB) complexes have recently emerged as promising druggable targets for MASLD. However, less is known regarding the causative association between KLB activity and advanced stages of liver disease. In the present narrative review, we aimed to provide an up-to-date picture of the role of the KLB co-receptor in MASLD development and progression. We performed a detailed analysis of recently published preclinical and clinical data to decipher the molecular mechanisms underlying KLB function and to correlate the presence of inherited or acquired KLB aberrancies with the predisposition towards MASLD. Moreover, we described ongoing clinical trials evaluating the therapeutic approaches targeting FGF19-21/FGFR/KLB in patients with MASLD and discussed the challenges related to their use. We furtherly described that KLB exhibits protective effects against metabolic disorders by acting in an FGF-dependent and independent manner thus triggering the hypothesis that KLB soluble forms may play a critical role in preserving liver health. Therefore, targeting KLB may provide promising strategies for treating MASLD, as supported by experimental evidence and ongoing clinical trials.

Exploring endocrine FGFs - structures, functions and biomedical applications

The family of fibroblast growth factors (FGFs) consists of 22 members with diverse biological functions in cells, from cellular development to metabolism. The family can be further categorized into three subgroups based on their three modes of action. FGF19, FGF21, and FGF23 are endocrine FGFs that act in a hormone-like/endocrine manner to regulate various metabolic activities. However, all three members of the endocrine family require both FGF receptors (FGFRs) and klotho co-receptors to elicit their functions. α-klotho and β-klotho act as scaffolds to bring endocrine FGFs closer to their receptors (FGFRs) to form active complexes. Numerous novel studies about metabolic FGFs' structures, mechanisms, and physiological insights have been published to further understand the complex molecular interactions and physiological activities of endocrine FGFs. Herein, we aim to review the structures, physiological functions, binding mechanisms to cognate receptors, and novel biomedical applications of endocrine FGFs in recent years.

PAX fusion proteins deregulate gene networks controlling mitochondrial translation in pediatric rhabdomyosarcoma

Alveolar rhabdomyosarcoma (ARMS) patients harboring PAX3-FOXO1 and PAX7-FOXO1 fusion proteins exhibit a greater incidence of tumor relapse, metastasis, and poor survival outcome, thereby underscoring the urgent need to develop effective therapies to treat this subtype of childhood cancer. To uncover mechanisms that contribute to tumor initiation, we developed a novel muscle progenitor model and used epigenomic approaches to unravel genome re-wiring events mediated by PAX3/7 fusion proteins. Importantly, these regulatory mechanisms are conserved across established ARMS cell lines, primary tumors, and orthotopic-patient derived xenografts. Among the key targets of PAX3- and PAX7-fusion proteins, we identified a cohort of oncogenes, FGF receptors, and genes essential for mitochondrial metabolism and protein translation, which we successfully targeted in preclinical trials. Our data suggest an explanation for the relative paucity of recurring mutations in this tumor, provide a compelling list of actionable targets, and suggest promising new strategies to treat this tumor.

FGFR4-driven plasticity in breast cancer progression and resistance to therapy

Breast cancer (BCa) is a complex and heterogeneous disease, with different intrinsic molecular subtypes that have distinct clinical outcomes and responses to therapy. Although intrinsic subtyping provides guidance for treatment decisions, it is now widely recognised that, in some cases, the switch of the BCa intrinsic subtype (which embodies cellular plasticity), may be responsible for therapy failure and disease progression. Aberrant FGFR4 signalling has been implicated in various cancers, including BCa, where it had been shown to be associated with aggressive subtypes, such as HER2-enriched BCa, and poor prognosis. More importantly, FGFR4 is also emerging as a potential driver of BCa intrinsic subtype switching, and an essential promoter of brain metastases, particularly in the HER2-positive BCa. Although the available data are still limited, the findings may have far-reaching clinical implications. Here, we provide an updated summary of the existing both pre- and clinical studies of the role of FGFR4 in BCa, with a special focus on its contribution to subtype switching during metastatic spread and/or induced by therapy. We also discuss a potential clinical benefit of targeting FGFR4 in the development of new treatment strategies.

The endocrine FGFs axis: A systemic anti-fibrotic response that could prevent pulmonary fibrogenesis?

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal disease for which therapeutic options are limited, with an unmet need to identify new therapeutic targets. IPF is thought to be the consequence of repeated microlesions of the alveolar epithelium, leading to aberrant epithelial-mesenchymal communication and the accumulation of extracellular matrix proteins. The reactivation of developmental pathways, such as Fibroblast Growth Factors (FGFs), is a well-described mechanism during lung fibrogenesis. Secreted FGFs with local paracrine effects can either exert an anti-fibrotic or a pro-fibrotic action during this pathological process through their FGF receptors (FGFRs) and heparan sulfate residues as co-receptors. Among FGFs, endocrine FGFs (FGF29, FGF21, and FGF23) play a central role in the control of metabolism and tissue homeostasis. They are characterized by a low affinity for heparan sulfate, present in the cell vicinity, allowing them to have endocrine activity. Nevertheless, their interaction with FGFRs requires the presence of mandatory co-receptors, alpha and beta Klotho proteins (KLA and KLB). Endocrine FGFs are of growing interest for their anti-fibrotic action during liver, kidney, or myocardial fibrosis. Innovative therapies based on FGF19 or FGF21 analogs are currently being studied in humans during liver fibrosis. Recent data report a similar anti-fibrotic action of endocrine FGFs in the lung, suggesting a systemic regulation of the pulmonary fibrotic process. In this review, we summarize the current knowledge on the protective effect of endocrine FGFs during the fibrotic processes, with a focus on pulmonary fibrosis.

Role of serum endotoxin, FGF19, TLR2, TNF-α, IL-12 and IL-10 in NAFLD-associated T2DM pathogenesis: Insights into Th1 bias and protective mechanisms

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) in non-obese patients is pathophysiologically distinct, exhibiting common immunological link with type-2 diabetes mellitus (T2DM). This study aims to delineate the role of Toll-like receptor 2 (TLR2)-mediated immuno-modulation along with its association with fibroblast growth factor receptor 4 (FGFR4) and its ligand fibroblast growth factor 19 (FGF19) in the pathogenesis of NAFLD without or with T2DM.

METHODOLOGY

Blood samples were collected from patients with NAFLD (n = 90), NAFLD with T2DM (n = 90) and healthy cohorts (n = 90) with consent and clinical records. Real-time polymerase chain reaction (PCR), enzyme-linked immunoassay (ELIZA) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) were used to analyze messenger ribonucleic acid (mRNA), protein expression and gene polymorphism.

RESULTS

The molecular genetic analysis revealed the prevalence of variant allele(A) in FGFR4 gene in both cases compared to controls. The mRNA expression of FGF19 and TLR2 exhibited significant upregulation in NAFLD without T2DM compared to NAFLD with T2DM. Tumor necrosis factor-α (TNF-α) and interleukin-12 (IL-12) showed upregulation in both disease cohorts compared to control while IL-10 showed significant downregulation in NAFLD with T2DM compared to the other two cohorts. Correlation analysis between FGF19 and TLR2 revealed significant positive association in both NAFLD with and without T2DM. The Th1:Th2 ratio showed significant upregulation in NAFLD with T2DM compared to NAFLD without T2DM.

CONCLUSION

In conclusion, elevated serum endotoxin levels appear to contribute to NAFLD and T2DM development. Upregulated FGF19 seems to be protective against developing T2DM in NAFLD patients. Higher TLR2, TNF-α and IL-12 expression in NAFLD without T2DM suggests a Th1 bias in its pathogenesis, while reduced IL-10 in NAFLD with T2DM implies a more skewed Th1 state in this condition.

Engineering an fgfr4 knockout zebrafish to study its role in development and disease

Fibroblast growth factor receptor 4 (FGFR4) has a role in many biological processes, including lipid metabolism, tissue repair, and vertebrate development. In recent years, FGFR4 overexpression and activating mutations have been associated with numerous adult and pediatric cancers. As such, FGFR4 presents an opportunity for therapeutic targeting which is being pursued in clinical trials. To understand the role of FGFR4 signaling in disease and development, we generated and characterized three alleles of fgfr4 knockout zebrafish strains using CRISPR/Cas9. To generate fgfr4 knockout crispants, we injected single-cell wildtype zebrafish embryos with fgfr4 targeting guide RNA and Cas9 proteins, identified adult founders, and outcrossed to wildtype zebrafish to create an F1 generation. The generated mutations introduce a stop codon within the second Ig-like domain of Fgfr4, resulting in a truncated 215, 223, or 228 amino acid Fgfr4 protein compared to 922 amino acids in the full-length protein. All mutant strains exhibited significantly decreased fgfr4 mRNA expression during development, providing evidence for successful knockout of fgfr4 in mutant zebrafish. We found that, consistent with other Fgfr4 knockout animal models, the fgfr4 mutant fish developed normally; however, homozygous fgfr4 mutant zebrafish were significantly smaller than wildtype fish at three months post fertilization. These fgfr4 knockout zebrafish lines are a valuable tool to study the role of FGFR4 in vertebrate development and its viability as a potential therapeutic target in pediatric and adult cancers, as well as other diseases.

Bile acid metabolism and signaling in health and disease: molecular mechanisms and therapeutic targets

Bile acids, once considered mere dietary surfactants, now emerge as critical modulators of macronutrient (lipid, carbohydrate, protein) metabolism and the systemic pro-inflammatory/anti-inflammatory balance. Bile acid metabolism and signaling pathways play a crucial role in protecting against, or if aberrant, inducing cardiometabolic, inflammatory, and neoplastic conditions, strongly influencing health and disease. No curative treatment exists for any bile acid influenced disease, while the most promising and well-developed bile acid therapeutic was recently rejected by the FDA. Here, we provide a bottom-up approach on bile acids, mechanistically explaining their biochemistry, physiology, and pharmacology at canonical and non-canonical receptors. Using this mechanistic model of bile acids, we explain how abnormal bile acid physiology drives disease pathogenesis, emphasizing how ceramide synthesis may serve as a unifying pathogenic feature for cardiometabolic diseases. We provide an in-depth summary on pre-existing bile acid receptor modulators, explain their shortcomings, and propose solutions for how they may be remedied. Lastly, we rationalize novel targets for further translational drug discovery and provide future perspectives. Rather than dismissing bile acid therapeutics due to recent setbacks, we believe that there is immense clinical potential and a high likelihood for the future success of bile acid therapeutics.

FGF19-Based Mini Probe Targeting FGFR4 for Diagnosis and Surgical Navigation of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a frequent malignancy that has a high death rate and a high rate of recurrence following surgery, owing to insufficient surgical resection. Furthermore, HCC is prone to peritoneal metastasis (HCC-PM), resulting in a significant number of tiny cancer lesions, making surgical removal more challenging. As a potential imaging target, FGFR4 is highly expressed in tumors, especially in HCC, but is less expressed in the normal liver. In this study, we used computational simulation approaches to develop peptide I0 derived from FGF19, a particular ligand of FGFR4, and labeled it with the NIRF dye, MPA, for HCC detection. In surgical navigation, the TBR was 9.31 ± 1.36 and 8.57 ± 1.15 in HepG2 in situ tumor and HCC-PM models, respectively, indicating considerable tumor uptake. As a result, peptide I0 is an excellent clinical diagnostic reagent for HCC, as well as a tool for surgically resecting HCC peritoneal metastases.

Fibroblast growth factor receptor-4 mediates activation of Nuclear Factor Erythroid 2-Related Factor-2 in gastric tumorigenesis

Helicobacter pylori (H. pylori) is the leading risk factor for gastric carcinogenesis. Fibroblast growth factor receptor 4 (FGFR4) is a member of transmembrane tyrosine kinase receptors that are activated in cancer. We investigated the role of FGFR4 in regulating the cellular response to H. pylori infection in gastric cancer. High levels of oxidative stress signature and FGFR4 expression were detected in gastric cancer samples. Gene set enrichment analysis (GSEA) demonstrated enrichment of NRF2 signature in samples with high FGFR4 levels. H. pylori infection induced reactive oxygen species (ROS) with a cellular response manifested by an increase in FGFR4 with accumulation and nuclear localization NRF2. Knocking down FGFR4 significantly reduced NRF2 protein and transcription activity levels, leading to higher levels of ROS and DNA damage following H. pylori infection. We confirmed the induction of FGFR4 and NRF2 levels using mouse models following infection with a mouse-adapted H. pyloristrain. Pharmacologic inhibition of FGFR4 using H3B-6527, or its knockdown, remarkably reduced the level of NRF2 with a reduction in the size and number of gastric cancer spheroids. Mechanistically, we detected binding between FGFR4 and P62 proteins, competing with NRF2-KEAP1 interaction, allowing NRF2 to escape KEAP1-dependent degradation with subsequent accumulation and translocation to the nucleus. These findings demonstrate a novel functional role of FGFR4 in cellular homeostasis via regulating the NRF2 levels in response to H. pylori infection in gastric carcinogenesis, calling for testing the therapeutic efficacy of FGFR4 inhibitors in gastric cancer models.

Insight into the design of FGFR4 selective inhibitors in cancer therapy: Prospects and challenges

Recently, FGFR4 has become a hot target for the treatment of cancer owing to its important role in cellular physiological processes. FGFR4 has been validated to be closely related to the occurrence of cancers, such as hepatocellular carcinoma, rhabdomyosarcoma, breast cancer and colorectal cancer. Hence, the development of FGFR4 small-molecule inhibitors is essential to further understanding the functions of FGFR4 in cancer and the treatment of FGFR4-dependent diseases. Given the particular structures of FGFR1-4, the development of FGFR4 selective inhibitors presents significant challenges. The non-conserved Cys552 in the hinge region of the FGFR4 complex becomes the key to the selectivity of FGFR4 and FGFR1/2/3 inhibitors. In this review, we systematically introduce the close relationship between FGFR4 and cancer, and conduct an in-depth analysis of the developing methodology, binding mechanism, kinase selectivity, pharmacokinetic characteristics of FGFR4 selectivity inhibitors, and their application in clinical research.

Intestinal transit-amplifying cells require METTL3 for growth factor signaling and cell survival

Intestinal epithelial transit-amplifying cells are essential stem progenitors required for intestinal homeostasis, but their rapid proliferation renders them vulnerable to DNA damage from radiation and chemotherapy. Despite these cells' critical roles in intestinal homeostasis and disease, few studies have described genes that are essential to transit-amplifying cell function. We report that RNA methyltransferase-like 3 (METTL3) is required for survival of transit-amplifying cells in the murine small intestine. Transit-amplifying cell death after METTL3 deletion was associated with crypt and villus atrophy, loss of absorptive enterocytes, and uniform wasting and death in METTL3-depleted mice. Sequencing of polysome-bound and methylated RNAs in enteroids and in vivo demonstrated decreased translation of hundreds of methylated transcripts after METTL3 deletion, particularly transcripts involved in growth factor signal transduction such as Kras. Further investigation verified a relationship between METTL3 and Kras methylation and protein levels in vivo. Our study identifies METTL3 as an essential factor supporting the homeostasis of small intestinal tissue via direct maintenance of transit-amplifying cell survival. We highlight the crucial role of RNA modifications in regulating growth factor signaling in the intestine with important implications for both homeostatic tissue renewal and epithelial regeneration.

Whole-exome sequencing reveals candidate high-risk susceptibility genes for endometriosis

BACKGROUND

Endometriosis is a common, chronic disease among fertile-aged women. Disease course may be highly invasive, requiring extensive surgery. The etiology of endometriosis remains elusive, though a high level of heritability is well established. Several low-penetrance predisposing loci have been identified, but high-risk susceptibility remains undetermined. Endometriosis is known to increase the risk of epithelial ovarian cancers, especially of endometrioid and clear cell types. Here, we have analyzed a Finnish family where four women have been diagnosed with surgically verified, severely symptomatic endometriosis and two of the patients also with high-grade serous carcinoma.

RESULTS

Whole-exome sequencing revealed three rare candidate predisposing variants segregating with endometriosis. The variants were c.1238C>T, p.(Pro413Leu) in FGFR4, c.5065C>T, p.(Arg1689Trp) in NALCN, and c.2086G>A, p.(Val696Met) in NAV2. The only variant predicted deleterious by in silico tools was the one in FGFR4. Further screening of the variants in 92 Finnish endometriosis and in 19 endometriosis-ovarian cancer patients did not reveal additional carriers. Histopathology, positive p53 immunostaining, and genetic analysis supported the high-grade serous subtype of the two tumors in the family.

CONCLUSIONS

Here, we provide FGFR4, NALCN, and NAV2 as novel high-risk candidate genes for familial endometriosis. Our results also support the association of endometriosis with high-grade serous carcinoma. Further studies are required to validate the findings and to reveal the exact pathogenesis mechanisms of endometriosis. Elucidating the genetic background of endometriosis defines the etiology of the disease and provides opportunities for expedited diagnostics and personalized treatments.

FXR and NASH: an avenue for tissue-specific regulation

NASH is within the spectrum of NAFLD, a liver condition encompassing liver steatosis, inflammation, hepatocyte injury, and fibrosis. The prevalence of NASH-induced cirrhosis is rapidly rising and has become the leading indicator for liver transplantation in the US. There is no Food and Drug Administration (FDA)-approved pharmacological intervention for NASH. The farnesoid X receptor (FXR) is essential in regulating bile acid homeostasis, and dysregulation of bile acids has been implicated in the pathogenesis of NASH. As a result, modulators of FXR that show desirable effects in mitigating key characteristics of NASH have been developed as promising therapeutic approaches. However, global FXR activation causes adverse effects such as cholesterol homeostasis imbalance and pruritus. The development of targeted FXR modulation is necessary for ideal NASH therapeutics, but information regarding tissue-specific and cell-specific FXR functionality is limited. In this review, we highlight FXR activation in the regulation of bile acid homeostasis and NASH development, examine the current literature on tissue-specific regulation of nuclear receptors, and speculate on how FXR regulation will be beneficial in the treatment of NASH.

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.

Multiomics of Colorectal Cancer Organoids Reveals Putative Mediators of Cancer Progression Resulting from SMAD4 Inactivation

The development of metastasis severely reduces the life expectancy of patients with colorectal cancer (CRC). Although loss of SMAD4 is a key event in CRC progression, the resulting changes in biological processes in advanced disease and metastasis are not fully understood. Here, we applied a multiomics approach to a CRC organoid model that faithfully reflects the metastasis-supporting effects of SMAD4 inactivation. We show that loss of SMAD4 results in decreased differentiation and activation of pro-migratory and cell proliferation processes, which is accompanied by the disruption of several key oncogenic pathways, including the TGFβ, WNT, and VEGF pathways. In addition, SMAD4 inactivation leads to increased secretion of proteins that are known to be involved in a variety of pro-metastatic processes. Finally, we show that one of the factors that is specifically secreted by SMAD4-mutant organoids─DKK3─reduces the antitumor effects of natural killer cells (NK cells). Altogether, our data provide new insights into the role of SMAD4 perturbation in advanced CRC.

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.

Investigation of the Proliferative Potential of FGF21 or FGF19 in Liver-Specific FGFR4-Deficient Mice

Fibroblast growth factor 21 (FGF21) and FGF15/FGF19 belong to the same subgroup of FGFs and are believed to have therapeutic potential in the treatment of type 2 diabetes and associated metabolic dysfunctionalities and pathological conditions. FGF19 has been proposed to induce hyperplasia and liver tumors in FVB mice (named after its susceptibility to Friend leukemia virus B), mediated by the FGF receptor 4 (FGFR4). The goal of this work was to investigate whether FGF21 might also have a potential proliferative effect mediated via FGFR4 using liver-specific Fgfr4 knockout (KO) mice. We conducted a mechanistic 7-day study involving female Fgfr4 fl/fl and Fgfr4 KO mice with a treatment regimen of twice daily or daily subcutaneous injections of FGF21 or FGF19 (positive control), respectively. The Ki-67 liver labeling index (LI) was evaluated by a semi-automated bioimaging analysis. The results showed a statistically significant increase in FGF21- and FGF19-treated Fgfr4 fl/fl mice. Interestingly, in Fgfr4 KO mice, this effect was absent following both treatments of FGF19 and FGF21, indicating that not only the FGFR4 receptor is pivotal for the mediation of hepatocellular proliferation by FGF19 leading finally to liver tumors but it seems also that FGFR4/FGF21 signaling has an impact on the hepatocellular proliferative activity, which does not promote the formation of hepatocellular liver tumors based on the current knowledge.

Melatonin: Emerging Player in the Management of Oral Cancer

Oral cancer (OC) has emerged as a major medical and social issue in many industrialized nations due to the high death rate. It is becoming increasingly common in people under the age of 45, although the underlying causes and mechanisms of this increase remain unclear. Melatonin, as a pleiotropic hormone, plays a pivotal role in a wide variety of cellular and physiological functions. Mounting evidence supports melatonin's ability to modify/influence oral carcinogenesis, help in the reduction of the incidence of OC, and increase chemo- and radiosensitivity. Despite its potential anti-carcinogenic effects, the precise function of melatonin in the management of OC is not well understood. This review summarizes the current knowledge regarding melatonin function in anti-carcinogenesis mechanisms for OC. In addition, clinical assessment and the potential therapeutic utility of melatonin in OC are discussed. This review will provide a basis for researchers to create new melatonin-based personalized medicines for treating and preventing OC.

Identification of metabolism-related genes for predicting peritoneal metastasis in patients with gastric cancer

OBJECTIVE

The reprogramming of metabolism is an important factor in the metastatic process of cancer. In our study, we intended to investigate the predictive value of metabolism-related genes (MRGs) in recurrent gastric cancer (GC) patients with peritoneal metastasis.

METHODS

The sequencing data of mRNA of GC patients were obtained from Asian Cancer Research Group (ACRG) and the GEO databases (GSE53276). The differentially expressed MRGs (DE-MRGs) between a cell line without peritoneal metastasis (HSC60) and one with peritoneal metastasis (60As6) were analyzed with the Limma package. According to the LASSO regression, eight MRGs were identified as crucially related to peritoneal seeding recurrence in patients. Then, disease free survival related genes were screened using Cox regression, and a promising prognostic model was constructed based on 8 MRGs. We trained and verified it in two independent cohort.

RESULTS

We confirmed 713 DE-MRGs and the enriched pathways. Pathway analysis found that the MRG-related pathways were related to tumor metabolism development. With the help of Kaplan-Meier analysis, we found that the group with higher risk scores had worse rates of peritoneal seeding recurrence than the group with lower scores in the cohorts.

CONCLUSIONS

This study developed an eight-gene signature correlated with metabolism that could predict peritoneal seeding recurrence for GC patients. This signature could be a promising prognostic model, providing better strategy in treatment.

Evolving therapeutic landscape of advanced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common solid malignancies worldwide. A large proportion of patients with HCC are diagnosed at advanced stages and are only amenable to systemic therapies. We have witnessed the evolution of systemic therapies from single-agent targeted therapy (sorafenib and lenvatinib) to the combination of a checkpoint inhibitor plus targeted therapy (atezolizumab plus bevacizumab therapy). Despite remarkable advances, only a small subset of patients can obtain durable clinical benefit, and therefore substantial therapeutic challenges remain. In the past few years, emerging systemic therapies, including new molecular-targeted monotherapies (for example, donafenib), new immuno-oncology monotherapies (for example, durvalumab) and new combination therapies (for example, durvalumab plus tremelimumab), have shown encouraging results in clinical trials. In addition, many novel therapeutic approaches with the potential to offer improved treatment effects in patients with advanced HCC, such as sequential combination targeted therapy and next-generation adoptive cell therapy, have also been proposed and developed. In this Review, we summarize the latest clinical advances in the treatment of advanced HCC and discuss future perspectives that might inform the development of more effective therapeutics for advanced HCC.

Variant Enrichment Analysis to Explore Pathways Disruption in a Necropsy Series of Asbestos-Exposed Shipyard Workers

The variant enrichment analysis (VEA), a recently developed bioinformatic workflow, has been shown to be a valuable tool for whole-exome sequencing data analysis, allowing finding differences between the number of genetic variants in a given pathway compared to a reference dataset. In a previous study, using VEA, we identified different pathway signatures associated with the development of pulmonary toxicities in mesothelioma patients treated with radical hemithoracic radiation therapy. Here, we used VEA to discover novel pathways altered in individuals exposed to asbestos who developed or not asbestos-related diseases (lung cancer or mesothelioma). A population-based autopsy study was designed in which asbestos exposure was evaluated and quantitated by investigating objective signs of exposure. We selected patients with similar exposure to asbestos. Formalin-fixed paraffin-embedded (FFPE) tissues were used as a source of DNA and whole-exome sequencing analysis was performed, running VEA to identify potentially disrupted pathways in individuals who developed thoracic cancers induced by asbestos exposure. By using VEA analysis, we confirmed the involvement of pathways considered as the main culprits for asbestos-induced carcinogenesis: oxidative stress and chromosome instability. Furthermore, we identified protective genetic assets preserving genome stability and susceptibility assets predisposing to a worst outcome.

Hydroxysteroid Dehydrogenase Like 2 Promotes the Invasion and Migration of Osteosarcoma by Regulating Fibroblast Growth Factor Receptor 4

We aimed to explore the expression characteristics of HSDL2 in osteosarcoma (OS) as well as the underlying mechanism. A total of 42 OS patients’ tissue samples were collected. HSDL2 level was markedly higher in OS tissues as well as OS cell lines. Besides, patients with high HSDL2 expression had a higher incidence of distant metastasis and a lower overall survival rate. Furthermore, the ability of OS cells to proliferate, invade and metastasize was markedly reduced after HSDL2 knockdown; however, the overexpression of HSDL2 could markedly increase the proliferative, invasive and metastasis ability of OS cells. In addition, HSDL2 can target FGFR4. Furthermore, FGFR4 expression was markedly decreased after HSDL2 knockdown, besides, HSDL2 and FGFR4 expressions were positively correlated in OS tissues. In addition, the recovery experiments suggested that HSDL2 and FGFR4 had a mutual regulation, thereby jointly promoting the invasive and migration ability of OS. HSDL2 expression was markedly increased in OS tissues as well as OS cell lines, which was markedly related to distant metastasis along with poor prognosis of OS patients. Besides, HSDL2 may promote OS progression by increasing the FGFR4 expression.

Molecular Profiling of Kenyan Acute Myeloid Leukemia Patients

Acute myeloid leukemia (AML) is an infrequent disease, and it is associated with high morbidity and mortality. It harbors a unique configuration of cytogenetic abnormalities and molecular mutations that can be detected using microscopic and molecular methods respectively. These genetic tests are core elements of diagnosis and prognostication in high-income countries. They are routinely incorporated in clinical decision making, allowing for the individualization of therapy. However, these tests are largely inaccessible to most patients in Kenya and therefore no data has been reported on this group of patients. The main purpose of this study is to describe the cytogenetic and molecular abnormalities of acute myeloid leukemia patients seen at the hemato-oncology unit of Kenyatta National Hospital. A cross-sectional descriptive study was carried out over a 3-month period on ten patients with a diagnosis of AML. Social demographics and clinical data were collected through a study proforma. A peripheral blood sample was collected for conventional metaphase G-banding technique and next generation sequencing. Particularly, targeted DNA sequencing (Illumina myeloid panel) and whole exome sequencing (WES) were performed. Cytogenetic analysis failed in 10/10 cases. Targeted sequencing was successfully obtained in 8 cases, whereas WES in 7. Cytogenetic studies yielded no results. There were 20 mutations detected across 10 commonly mutated genes. All patients had at least one clinically relevant mutation. Based on ELN criteria, NGS identified three patients with high-risk mutations, affecting TP53 (n = 2) and RUNX1 (n = 1). One patient was classified as favorable (PML-RARA) while 4 were standard risk. However, WT1 mutations associated with unfavorable prognosis were recorded in additional 2 cases. WES showed concordant results with targeted sequencing while unveiling more mutations that warrant further attention. In conclusion, we provide the first molecular profiling study of AML patients in Kenya including application of advanced next generation sequencing technologies, highlighting current limitations of AML diagnostics and treatment while confirming the relevance of NGS in AML characterization.

The novel FGFR inhibitor F1-7 induces DNA damage and cell death in colon cells

BACKGROUND

Fibroblast growth factor receptor (FGFR) signaling influenced tumour occurrence and development. Overexpression of FGFR had been observed in many types of cancers, including colon cancer. FGFR inhibitor is considered to be effective in treating colon cancer patients.

METHODS

First, the kinase inhibition rate was determined. MTT, western blotting, colony formation, EdU and comet assays were performed to evaluate the anti-tumour effects of F1-7 in vitro. RNA-seq and bioinformatics analysis were used for further verification. Additionally, a xenograft model was generated to investigate the anti-tumour effect of F1-7.

RESULTS

F1-7 can inhibit the proliferation of colon cancer cells in vitro. It could significantly inhibit FGFR phosphorylation and its downstream signaling pathway. Whole-genome RNA-seq analysis found that the changed genes were not only functionally focused on MAPK signaling pathway but also related to cell apoptosis and ferroptosis. Experimental evidence demonstrated that F1-7 can directly increase the level of cellular DNA damage. The occurrence of DNA damage led to cell cycle arrest and inhibition of cell metastasis and cell apoptosis. Mouse model experiments also confirmed that F1-7 could inhibit tumour growth by inhibiting the FGFR pathway.

CONCLUSIONS

F1-7 exhibits anti-tumour activity by inhibiting the FGFR pathway. It could be a novel therapeutic agent for targeting colon cancer cells.

FGF19 Is Coamplified With CCND1 to Promote Proliferation in Lung Squamous Cell Carcinoma and Their Combined Inhibition Shows Improved Efficacy

Lung squamous cell carcinoma (LUSC) remains as a major cause of cancer-associated mortality with few therapeutic options. Continued research on new driver genes is particularly important. FGF19, a fibroblast growth factor, is frequently observed as amplified in human LUSC, which is also associated with multiple genomic gains and losses. However, the importance of these associated changes is largely unknown. In this study, we aimed to clarify a novel mechanism that link neighboring oncogene co-amplification in the development of LUSC. We found that FGF19 was co-amplified and co-expressed with its neighboring gene CCND1 in a subset of LUSC patients and associated with poor prognosis. Moreover, FGF19 combined with CCND1 promoted the cell cycle progression of LUSC cells. Mechanistically, FGF19 also enhanced CCND1 expression by activating FGFR4-ERK1/2 signaling and strengthening CCND1-induced phosphorylation and inactivation of retinoblastoma (RB). In a murine model of lung orthotopic cancer, knockdown of CCND1 was found to prolong survival by attenuating FGF19-induced cell proliferation. Furthermore, the combination treatment of the FGFR4 inhibitor BLU9931 and the CDK4/6 inhibitor palbociclib potentiated the growth inhibition and arrested cells in G1 phase. In vivo, co-targeting FGFR4 and CDK4/6 also showed marked inhibition of tumor growth than single agent treatment. These findings further elucidate the oncogenic role of FGF19 in LUSC and provide insights into how the co-amplification of neighboring genes synergistically function to promote cancer growth, and combined inhibition against both FGF19 and CCND1 is more effective.

Identification of Pyridinyltriazine Derivatives as Potent panFGFR Inhibitors against Gatekeeper Mutants for Overcoming Drug Resistance

Although FGFR inhibitors hold promise in treating various cancers, resistance to the FGFR inhibitors caused by acquired secondary mutations has emerged. To discover novel FGFR inhibitors capable of inhibiting FGFR mutations, including gatekeeper mutations, we designed and synthesized several new pyridinyltriazine derivatives. A structure-activity relationship (SAR) study led to the identification of 17a as a highly potent panFGFR inhibitor against wild-type and mutant FGFRs. Notably, 17a is superior to infigratinib in terms of kinase-inhibitory and cellular activities, especially against V555M-FGFR3. Molecular dynamics simulations provide a clear understanding of why pyridinyltraizine derivative 17a possesses activity against V555M-FGFR3. Moreover, 17a significantly suppresses proliferation of cancer cells harboring FGFR mutations via FGFR signaling blockade, cell cycle arrest, and apoptosis. Furthermore, 17a and 17b exhibited remarkable efficacies in TEL-V555M-FGFR3 Ba/F3 xenograft mouse model and 17a is more efficacious than infigratinib. This study provides new insight into the design of novel FGFR inhibitors that are active against FGFR mutants.

Effects of Overexpression of Fibroblast Growth Factor 15/19 on Hepatic Drug Metabolizing Enzymes

Fibroblast growth factors 15 (FGF15) and 19 (FGF19) are endocrine growth factors that play an important role in maintaining bile acid homeostasis. FGF15/19-based therapies are currently being tested in clinical trials for the treatment of nonalcoholic steatohepatitis and cholestatic liver diseases. To determine the physiologic impact of long-term elevations of FGF15/19, a transgenic mouse model with overexpression of Fgf15 (Fgf15 Tg) was used in the current study. The RNA sequencing (RNA-seq) analysis revealed elevations of the expression of several genes encoding phase I drug metabolizing enzymes (DMEs), including Cyp2b10 and Cyp3a11, in Fgf15 Tg mice. We found that the induction of several Cyp2b isoforms resulted in increased function of CYP2B in microsomal metabolism and pharmacokinetics studies. Because the CYP2B family is known to be induced by constitutive androstane receptor (CAR), to determine the role of CAR in the observed inductions, we crossed Fgf15 Tg mice with CAR knockout mice and found that CAR played a minor role in the observed alterations in DME expression. Interestingly, we found that the overexpression of Fgf15 in male mice resulted in a phenotypical switch from the male hepatic expression pattern of DMEs to that of female mice. Differences in secretion of growth hormone (GH) between male and female mice are known to drive sexually dimorphic, STAT5b-dependent expression patterns of hepatic genes. We found that male Fgf15 Tg mice presented with many features similar to GH deficiency, including lowered body length and weight, Igf-1 and Igfals expression, and STAT5 signaling. SIGNIFICANCE STATEMENT: The overexpression of Fgf15 in mice causes an alteration in DMEs at the mRNA, protein, and functional levels, which is not entirely due to CAR activation but associated with lower GH signaling.

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.

Novel Bile Acid-Dependent Mechanisms of Hepatotoxicity Associated with Tyrosine Kinase Inhibitors

Drug-induced liver injury (DILI) is the leading cause of acute liver failure and a major concern in drug development. Altered bile acid homeostasis via inhibition of the bile salt export pump (BSEP) is one mechanism of DILI. Dasatinib, pazopanib, and sorafenib are tyrosine kinase inhibitors (TKIs) that competitively inhibit BSEP and increase serum biomarkers for hepatotoxicity in ∼25-50% of patients. However, the mechanism(s) of hepatotoxicity beyond competitive inhibition of BSEP are poorly understood. This study examined mechanisms of TKI-mediated hepatotoxicity associated with altered bile acid homeostasis. Dasatinib, pazopanib, and sorafenib showed bile acid-dependent toxicity at clinically relevant concentrations, based on the C-DILI assay using sandwich-cultured human hepatocytes (SCHH). Among several bile acid-relevant genes, cytochrome P450 (CYP) 7A1 mRNA was specifically upregulated by 6.2- to 7.8-fold (dasatinib) and 5.7- to 9.3-fold (pazopanib), compared with control, within 8 hours. This was consistent with increased total bile acid concentrations in culture medium up to 2.3-fold, and in SCHH up to 1.4-fold, compared with control, within 24 hours. Additionally, protein abundance of sodium taurocholate co-transporting polypeptide (NTCP) was increased up to 2.0-fold by these three TKIs. The increase in NTCP protein abundance correlated with increased function; dasatinib and pazopanib increased hepatocyte uptake clearance (CL_uptake) of taurocholic acid, a probe bile acid substrate, up to 1.4-fold. In conclusion, upregulation of CYP7A1 and NTCP in SCHH constitute novel mechanisms of TKI-associated hepatotoxicity. SIGNIFICANCE STATEMENT: Understanding the mechanisms of hepatotoxicity associated with tyrosine kinase inhibitors (TKIs) is fundamental to development of effective and safe intervention therapies for various cancers. Data generated in sandwich-cultured human hepatocytes, an in vitro model of drug-induced hepatotoxicity, revealed that TKIs upregulate bile acid synthesis and alter bile acid uptake and excretion. These findings provide novel insights into additional mechanisms of bile acid-mediated drug-induced liver injury, an adverse effect that limits the use and effectiveness of TKI treatment in some cancer patients.

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.

The ponatinib/gossypol novel combination provides enhanced anticancer activity against murine solid Ehrlich carcinoma via triggering apoptosis and inhibiting proliferation/angiogenesis

The search for new antitumor agents or combinations that are more effective and, hopefully, provide fewer health hazards is ongoing. Therefore, this study investigated the efficacy of a novel combination of ponatinib, a multi-targeted tyrosine kinase inhibitor, and the natural phytochemical gossypol against murine solid Ehrlich carcinoma. Six groups of ten mice each received vehicle (I), ponatinib in doses of 10 and 15 mg/kg (II, III) respectively, gossypol in a dose of 4 mg/kg (IV), and ponatinib (10 or 15 mg/kg) in combination with gossypol (4 mg/kg; V, VI). All treatments started on the 12th post-Ehrlich ascites carcinoma (EAC) implantation day and were administered intraperitoneally in daily doses for 3 weeks. Treatment of EAC-bearing mice with ponatinib/gossypol combination improved anticancer efficacy over either drug alone, as demonstrated by greater decreases in tumor weight and volume, and ponatinib (10 mg/kg)/gossypol combination was more efficient than ponatinib (15 mg/kg). Mechanistically, the ponatinib/gossypol combination significantly increased apoptotic markers p53, Bax, and caspase-9 while decreasing anti-apoptotic marker Bcl-2. Furthermore, it greatly decreased proliferative and angiogenic markers, FGFR4 and VEGF, respectively. Histopathology revealed a significant decline in neoplastic cells, the majority of which have necrotic changes and numerous apoptotic bodies, as well as a decrease in mitotic figures and tumor giant cells, indicating the capacity to suppress cancer proliferation/persistence. Overall, gossypol could be used as an adjuvant medication for ponatinib in cancer treatment, possibly leading to successful dose reductions and fewer side effects; however, further research is needed before a clinical application could be feasible.

The Role of Fibroblast Growth Factor (FGF) Signaling in Tissue Repair and Regeneration

Fibroblast growth factors (FGFs) are a large family of secretory molecules that act through tyrosine kinase receptors known as FGF receptors. They play crucial roles in a wide variety of cellular functions, including cell proliferation, survival, metabolism, morphogenesis, and differentiation, as well as in tissue repair and regeneration. The signaling pathways regulated by FGFs include RAS/mitogen-activated protein kinase (MAPK), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)–protein kinase B (AKT), phospholipase C gamma (PLCγ), and signal transducer and activator of transcription (STAT). To date, 22 FGFs have been discovered, involved in different functions in the body. Several FGFs directly or indirectly interfere with repair during tissue regeneration, in addition to their critical functions in the maintenance of pluripotency and dedifferentiation of stem cells. In this review, we summarize the roles of FGFs in diverse cellular processes and shed light on the importance of FGF signaling in mechanisms of tissue repair and regeneration.

Melatonin Suppresses Oral Squamous Cell Carcinomas Migration and Invasion through Blocking FGF19/FGFR 4 Signaling Pathway

Oral squamous cell carcinomas (OSCCs) are one of the most prevalent malignancies, with a low five-year survival rate, thus warranting more effective drugs or therapy to improve treatment outcomes. Melatonin has been demonstrated to exhibit oncostatic effects. In this study, we explored the anti-cancer effects of melatonin on OSCCs and the underlying mechanisms. A human tongue squamous cell carcinoma cell line (SCC-15) was treated with 2 mM melatonin, followed by transwell migration and invasion assays. Relative expression levels of Fibroblast Growth Factor 19 (FGF19) was identified by Cytokine Array and further verified by qPCR and Western blot. Overexpression and downregulation of FGF19 were obtained by adding exogenous hFGF19 and FGF19 shRNA lentivirus, respectively. Invasion and migration abilities of SCC-15 cells were suppressed by melatonin, in parallel with the decreased FGF19/FGFR4 expression level. Exogenous hFGF19 eliminated the inhibitory effects of melatonin on SCC-15 cells invasion and migration, while FGF19 knocking-down showed similar inhibitory activities with melatonin. This study proves that melatonin suppresses SCC-15 cells invasion and migration through blocking the FGF19/FGFR4 pathway, which enriches our knowledge on the anticancer effects of melatonin. Blocking the FGF19/FGFR4 pathway by melatonin could be a promising alternative for OSCCs prevention and management, which would facilitate further development of novel strategies to combat OSCCs.

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.

Impact of FGFR4 Gene Polymorphism on the Progression of Colorectal Cancer

Colorectal cancer (CRC) is a multifactorial malignancy, and its high incidence and mortality rate remain a global public health burden. Fibroblast growth factor receptor 4 (FGFR4) is a receptor tyrosine kinase that has been shown to play a key role in cancer development and prognosis via the activation of its downstream oncogenic signaling pathways. The present study aimed to explore the impact of FGFR4 gene polymorphisms on the risk and progression of CRC. Three FGFR4 single-nucleotide polymorphisms (SNPs), including rs1966265, rs351855, and rs7708357, were evaluated in 413 CRC cases and 413 gender- and age-matched cancer-free controls. We did not observe any significant association of three individual SNPs with the risk of CRC between the case and control group. However, while assessing the clinicopathological parameters, patients of rectal cancer possessing at least one minor allele of rs1966265 (AG and GG; AOR, 0.236; p = 0.046) or rs351855 (GA and AA; AOR, 0.191; p = 0.022) were found to develop less metastasis as compared to those who are homozygous for the major allele. Further analyses using the datasets from the Genotype-Tissue Expression (GTEx) Portal and The Cancer Genome Atlas (TCGA) revealed that rs351855 regulated FGFR4 expression in many human tissues, and increased FGFR4 levels were associated with the occurrence, advanced stage, and distal metastasis of colon adenocarcinoma. These data suggest that the amino acid change in combination with altered expression levels of FGFR4 due to genetic polymorphisms may affect CRC progression.

GWAS of allometric body-shape indices in UK Biobank identifies loci suggesting associations with morphogenesis, organogenesis, adrenal cell renewal and cancer

Genetic studies have examined body-shape measures adjusted for body mass index (BMI), while allometric indices are additionally adjusted for height. We performed the first genome-wide association study of A Body Shape Index (ABSI), Hip Index (HI) and the new Waist-to-Hip Index and compared these with traditional indices, using data from the UK Biobank Resource for 219,872 women and 186,825 men with white British ancestry and Bayesian linear mixed-models (BOLT-LMM). One to two thirds of the loci identified for allometric body-shape indices were novel. Most prominent was rs72959041 variant in RSPO3 gene, expressed in visceral adipose tissue and regulating adrenal cell renewal. Highly ranked were genes related to morphogenesis and organogenesis, previously additionally linked to cancer development and progression. Genetic associations were fewer in men compared to women. Prominent region-specific associations showed variants in loci VEGFA and HMGA1 for ABSI and KLF14 for HI in women, and C5orf67 and HOXC4/5 for ABSI and RSPO3, VEGFA and SLC30A10 for HI in men. Although more variants were associated with waist and hip circumference adjusted for BMI compared to ABSI and HI, associations with height had previously been reported for many of the additional variants, illustrating the importance of adjusting correctly for height.

The Role of Fibroblast Growth Factor 19 in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common type of cancer and the third leading cause of cancer-related deaths worldwide. Liver resection or liver transplantation is the most effective therapy for HCC because drugs approved by the US Food and Drug Administration to treat patients with unresectable HCC have an unfavorable overall survival rate. Therefore, the development of biomarkers for early diagnosis and effective therapy strategies are still necessary to improve patient outcomes. Fibroblast growth factor (FGF) 19 was amplified in patients with HCC from various studies, including patients from The Cancer Genome Atlas. FGF19 plays a syngeneic function with other signaling pathways in primary liver cancer development, such as epidermal growth factor receptor, Wnt/β-catenin, the endoplasmic reticulum-related signaling pathway, STAT3/IL-6, RAS, and extracellular signal-regulated protein kinase, among others. The current review presents a comprehensive description of the FGF19 signaling pathway involved in liver cancer development. The use of big data and bioinformatic analysis can provide useful clues for further studies of the FGF19 pathway in HCC, including its application as a biomarker, targeted therapy, and combination therapy strategies.

Efficacy of niclosamide on the intra-abdominal inflammatory environment in endometriosis

Endometriosis, a common gynecological disease, causes chronic pelvic pain and infertility in women of reproductive age. Due to the limited efficacy of current therapies, a critical need exists to develop new treatments for endometriosis. Inflammatory dysfunction, instigated by abnormal macrophage (MΦ) function, contributes to disease development and progression. However, the fundamental role of the heterogeneous population of peritoneal MΦ and their potential druggable functions is uncertain. Here we report that GATA6-expressing large peritoneal MΦ (LPM) were increased in the peritoneal cavity following lesion induction. This was associated with increased cytokine and chemokine secretion in the peritoneal fluid (PF), as well as MΦ infiltration, vascularization and innervation in endometriosis-like lesions (ELL). Niclosamide, an FDA-approved anti-helminthic drug, was effective in reducing LPM number, but not small peritoneal MΦ (SPM), in the PF. Niclosamide also inhibits aberrant inflammation in the PF, ELL, pelvic organs (uterus and vagina) and dorsal root ganglion (DRG), as well as MΦ infiltration, vascularization and innervation in the ELL. PF from ELL mice stimulated DRG outgrowth in vitro, whereas the PF from niclosamide-treated ELL mice lacked the strong stimulatory nerve growth response. These results suggest LPM induce aberrant inflammation in endometriosis promoting lesion progression and establishment of the inflammatory environment that sensitizes peripheral nociceptors in the lesions and other pelvic organs, leading to increased hyperalgesia. Our findings provide the rationale for targeting LPM and their functions with niclosamide and its efficacy in endometriosis as a new non-hormonal therapy to reduce aberrant inflammation which may ultimately diminish associated pain.

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.

Src is essential for the endosomal delivery of the FGFR4 signaling complex in hepatocellular carcinoma

Background

Hepatocytes usually express fibroblast growth factor receptor 4 (FGFR4), but not its ligand, fibroblast growth factor 19 (FGF19). A subtype of hepatocellular carcinoma (HCC) expresses FGF19, which activates the FGFR4 signaling pathway that induces cell proliferation. FGFR4 inhibitors that target this mechanism are under clinical development for the treatment of HCCs with FGF19 amplification or FGFR4 overexpression. Src plays an essential role in the FGFR1 and FGFR2 signaling pathways. However, it is yet to be understood whether Src has any role in the FGF19-FGFR4 pathway in HCCs. In this study, we aimed to elucidate the role of Src in the FGF19-FGFR4 axis in HCC.

Methods

3 HCC cell lines expressing both FGF19 and FGFR4 were selected. The expression of each protein was suppressed by siRNA treatment, and the activity-regulating relationship between FGFR4 and Src was investigated by westernblot. Co-immunoprecipitation was performed using the FGFR4 antibody to identify the endosomal complex formation and receptor endocytosis. The intracellular migration pathways of the endosomal complex were observed by immuno-fluorescence and nuclear co-immunoprecipitation. Dasatinib and BLU9931 were used for cytotoxicity comparison.

Results

FGFR4 modulates the activity of Src and Src modulates the expression of FGFR4, showing a mutual regulatory relationship. FGFR4 activated by FGF19 formed an endosomal complex with Src and STAT3 and moved to the nucleus. However, when Src was suppressed, the formation of the endosomal complex was not observed. FGFR4 was released from the complex transferred into the nucleus and the binding of Src and STAT3 was maintained. Dasatinib showed cytotoxic results comparable to BLU9931. The results of our study demonstrated that Src is essential for the nuclear transport of STAT3, as it induces the endosomal delivery of FGFR4 in FGF19-expressing HCC cell lines.

Conclusions

We found that Src is essential for the endosomal delivery of the FGFR4 signaling complex in HCC. Our findings provide a scientific rationale for repurposing Src inhibitors for the treatment of HCCs in which the FGFR4 pathway is activated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02807-4.

Enhanced expression of FGF19 predicts poor prognosis in patients with non-small cell lung cancer

Background

Lung cancer is one of the most common cancers and a leading cause of cancer-related death worldwide. Although many treatment options exist for lung cancer, some patients still suffer postoperative recurrence, and a consequent reduction of overall survival (OS). Our study aimed to investigate the correlation of FGF19 expression with the clinicopathological features and survival outcomes of non-small cell lung cancer (NSCLC) patients.

Methods

Bioinformatics analysis was conducted using the data from The Cancer Genome Atlas (TCGA) database to distinguish between the FGF19 levels of tumor and normal tissue and to determine their correlation with the OS. A total of 187 NSCLC patients who underwent radical resection of lung cancer were enrolled, and tissues were collected to determine FGF19 expression by immunohistochemistry (IHC) assay. Clinicopathological features including the survival date were collected for detailed research.

Results

According to the analysis based on the TCGA database, we found that the NSCLC tissues exhibited enhanced FGF19 messenger RNA (mRNA) expression and that the FGF19 mRNA levels correlated with shorter OS in NSCLC patients. IHC staining indicated that 88 (47.1%) patients had high FGF19 expression and 99 (52.9%) patients had low FGF19 expression. Meanwhile, survival data showed that high FGF19 expression was correlated with reduced OS (P<0.001). Moreover, both the univariate analysis and the forward stepwise multivariate Cox regression revealed that high FGF19 expression was an independent prognostic factor for decreased OS (P=0.001).

Conclusions

The expression of FGF19 is significantly upregulated in NSCLC, and the overexpression of FGF19 is correlated with poor OS, especially in lung adenocarcinoma (LUAD) cases. FGF19 might serve as a potential biomarker for predicting poor OS in NSCLC patients.

Design, synthesis, and biological evaluation of indazole derivatives as selective and potent FGFR4 inhibitors for the treatment of FGF19-driven hepatocellular cancer

Fibroblast growth factor receptor 4 (FGFR4) is a member of the fibroblast growth factor receptor family, which is closely related to the occurrence and development of hepatocellular carcinoma (HCC). In this article, a series of indazole derivatives were designed and synthesized by using computer-aided drug design (CADD) and structure-based design strategies, and then they were evaluated for their inhibition of FGFR4 kinase and antitumor activity. F-30 was subtly selective for FGFR4 compared to FGFR1; it affected cell growth and migration by inhibiting FGFR4 pathways in HCC cell lines in a dose-dependent manner.

S100A16 promotes metastasis and progression of pancreatic cancer through FGF19-mediated AKT and ERK1/2 pathways

The S100 protein family genes play a crucial role in multiple stages of tumorigenesis and progression. Most of S100 genes are located at chromosome locus 1q21, which is a region frequently rearranged in cancers. Here, we examined the expression of the S100 family genes in paired pancreatic ductal adenocarcinoma (PDAC) samples and further validated the expression of S100A16 by immunohistochemistry staining. We found that S100A16 is significantly upregulated in clinical PDAC samples. However, its roles in PDAC are still unclear. We next demonstrated that S100A16 promotes PDAC cell proliferation, migration, invasion, and metastasis both in vitro and in vivo. Knockdown of S100A16 induces PDAC cell cycle arrest in the G2/M phase and apoptosis. Furthermore, we also demonstrated that S100A16 promotes PDAC cell proliferation, migration, and invasion via AKT and ERK1/2 signaling in a fibroblast growth factor 19 (FGF19)-dependent manner. Taken together, our results reveal that S100A16 is overexpressed in PDAC and promotes PDAC progression through FGF19-mediated AKT and ERK1/2 signaling, suggesting that S100A16 may be a promising therapeutic target for PDAC. S100A16 was upregulated in PDAC and associated with prognosis of PDAC patients. S100A16 regulates apoptosis and the cell cycle of pancreatic cancer cells. S100A16 promotes the progression of pancreatic cancer by AKT-ERK1/2 signaling. S100A16 may be a promising therapeutic target for PDAC.

MicroRNA-9-3p Aggravates Cerebral Ischemia/Reperfusion Injury by Targeting Fibroblast Growth Factor 19 (FGF19) to Inactivate GSK-3β/Nrf2/ARE Signaling

PURPOSE

MicroRNAs (miRNAs) are emerging as essential regulators in the development of cerebral ischemia/reperfusion (I/R) injury. This study aimed to explore the regulation of miR-9-3p on FGF19-GSK-3β/Nrf2/ARE signaling in cerebral I/R injury.

MATERIALS AND METHODS

A mouse model with I/R injury was constructed by middle cerebral artery occlusion (MCAO) and an HT22 cell model was established by oxygen-glucose deprivation/reperfusion (OGD/R). The expression of miR-9-3p was detected by RT-qPCR. Protein expression of fibroblast growth factor 19 (FGF19), cleaved caspase-3, and GSK-3β signaling-related proteins (p-GSK-3β and Nrf2) were detected by Western blot. Cell viability was assessed by MTT assay. Oxidative stress was detected by commercial kits. The target of miR-9-3p was predicted by TargetScan and confirmed by luciferase reporter assay. The effects of miR-9-3p on GSK-3β/Nrf2/ARE signaling were assessed by rescue experiments.

RESULTS

MiR-9-3p was significantly upregulated in brain tissues of MCAO/R-treated mice and OGD/R-treated HT22 cells. Downregulation of miR-9-3p attenuated infarct volume and neurological outcomes of MCAO/R-treated mice in vivo and OGD/R-induced cell injury and oxidative stress in vitro, while overexpression of miR-9-3p showed the opposite effects. MiR-9-3p directly bound to the 3'-untranslated region of FGF19 and negatively regulated its expression. Inhibition of miR-9-3p enhanced GSK-3β/Nrf2/ARE signaling-mediated antioxidant response, while this effect was partially eliminated by FGF19 or Nrf2 silencing.

CONCLUSION

Our study suggests that inhibition of miR-9-3p protects against cerebral I/R injury through activating GSK-3β/Nrf2/ARE signaling-mediated antioxidant responses by targeting FGF19, providing a potential therapeutic target for ischemic stroke.

Gracillin shows potent efficacy against colorectal cancer through inhibiting the STAT3 pathway

Colorectal cancer (CRC) accounts for about 10% of all annually diagnosed cancers and cancer-related deaths worldwide. STAT3 plays a vital role in the occurrence and development of tumours. Gracillin has shown a significant antitumour activity in tumours, but its mechanism remains unknown. The human CRC cell lines HCT116, RKO, and SW480 and immunodeficient mice were used as models to study the effects of gracillin on cell proliferation, migration and apoptosis. These were evaluated by cell viability, colony formation, wound-healing migration and cell apoptosis assays. Luciferase reporter assay, and immunostaining and western blot analyses were used to explore the specific mechanism through which gracillin exerts its effects. Gracillin significantly reduces viability and migration and stimulates apoptosis in human CRC cells. It also significantly inhibits tumour growth with no apparent physiological toxicity in animal model experiments. Moreover, gracillin is found to inhibit STAT3 phosphorylation and STAT3 target gene products. In addition, gracillin inhibits IL6-induced nuclear translocation of P-STAT3. Gracillin shows potent efficacy against CRC by inhibiting the STAT3 pathway. It should be further explored as a unique STAT3 inhibitor for the treatment of CRC.