FGF18, a prominent player in FGF signaling, promotes gastric tumorigenesis through autocrine manner and is negatively regulated by miR-590-5p

High FGF18 expression levels predict poor prognosis in endometrial carcinoma patients and promote tumor growth and metastasis

OBJECTIVE

To investigate if fibroblast growth factor 18 (FGF18) expression plays an important role in endometrial carcinoma (EC).

METHODS

The clinicopathological associations and prognostic value of FGF18 expression were retrospectively analyzed in 190 patients with EC. FGF18 expression was stably knocked down in EC cell lines. Changes in cell proliferation, migration, and invasion rates were examined via cell behavior experiments. Tumor growth was investigated using a xenograft mouse model. RNA sequencing (RNA-seq) was performed to identify differentially expressed genes (DEGs) in HEC-1-B cells after FGF18 knockdown, followed by pathway enrichment analysis of the DEGs.

RESULTS

High FGF18 expression levels were closely correlated with EC clinicopathological features, such as histological subtype, FIGO stage, depth of myometrial invasion, and tumor size. Moreover, EC patients with high FGF18 expression levels had poorer overall survival. FGF18 knockdown in EC cells revealed its role in promoting tumor cell proliferation, migration, and invasion in vitro, as well as tumor growth in vivo. RNA-seq of HEC-1-B cells revealed that the DEGs were enriched in signaling pathways related to cell proliferation and migration.

CONCLUSIONS

Overexpression of FGF18 may serve as a prognostic biomarker for EC patients and is a potential therapeutic target for treating this disease.

WYC-209 suppresses gastric cancer by down-regulating FGF18 via inactivating the STAT3 signaling pathway

BACKGROUND

Gastric cancer (GC) is regarded as a major health burden all over the world. WYC-209 inhibits the growth and metastasis of tumor-repopulating cells (TRCs). However, its effectiveness on GC was unexplored. Herein, this study aims to investigate the effect of WYC-209 on GC and elucidate its underlying mechanism.

METHODS

We examined the effects of WYC-209 on cell survival, migration, invasion, and colony-forming capacities of two GC cell lines (AGS and HGC-27). Subsequently, RNA-seq and enrichment analyses were performed to screen the differentially expressed genes (DEGs) and the enriched signaling pathways. To further explore the underlying mechanism, loss- and gain-function experiments, Chromatin immunoprecipitation, and luciferase reporter were conducted. Finally, xenograft models were constructed to examine the effects of WYC-209 in vivo.

RESULTS

WYC-209 significantly inhibited cell motility in vitro and tumor growth in vivo. RNA-seq performed in AGS cells after WYC-209 treatment revealed that the inhibition effect of WYC-209 on GCs may be associated with the down-regulation of fibroblast growth factor-18 (FGF18), and pleasantly, FGF18 overexpression abrogated the suppression effect of the drug. In addition, we found that WYC-209 attenuated the activation of the Signal Transducer and Activator of Transcription 3 (STAT3) signaling pathway, and impeded the FGF18 levels expressed in GCs. Importantly, the WYC-209 treatment circumvented the binding of STAT3 to the FGF18 promoter, suggested that WYC-209 down-regulated FGF18 expression via the STAT3 signaling pathway.

CONCLUSION

Together, our findings presented the promise of WYC-209 in suppressing GC by down-regulating FGF18 expression through inactivating the STAT3 signaling pathway.

Exploring the diagnostic potential of miRNA signatures in the Fabry disease serum: A comparative study of automated and manual sample isolations

Fabry disease, an X-linked lysosomal storage disorder caused by galactosidase α (GLA) gene mutations, exhibits diverse clinical manifestations, and poses significant diagnostic challenges. Early diagnosis and treatment are crucial for improved patient outcomes, pressing the need for reliable biomarkers. In this study, we aimed to identify miRNA candidates as potential biomarkers for Fabry disease using the KingFisher™ automated isolation method and NanoString nCounter® miRNA detection assay. Clinical serum samples were collected from both healthy subjects and Fabry disease patients. RNA extraction from the samples was performed using the KingFisher™ automated isolation method with the MagMAX mirVanaTM kit or manually using the Qiagen miRNeasy kit. The subsequent NanoString nCounter® miRNA detection assay showed consistent performance and no correlation between RNA input concentration and raw count, ensuring reliable and reproducible results. Interestingly, the detection range and highly differential miRNA between the control and disease groups were found to be distinct depending on the isolation method employed. Nevertheless, enrichment analysis of miRNA-targeting genes consistently revealed significant associations with angiogenesis pathways in both isolation methods. Additionally, our investigation into the impact of enzyme replacement therapy on miRNA expression indicated that some differential miRNAs may be sensitive to treatment. Our study provides valuable insights to identify miRNA biomarkers for Fabry disease. While different isolation methods yielded various detection ranges and highly differential miRNAs, the consistent association with angiogenesis pathways suggests their significance in disease progression. These findings lay the groundwork for further investigations and validation studies, ultimately leading to the development of non-invasive and reliable biomarkers to aid in early diagnosis and treatment monitoring for Fabry disease.

BUB1 potentiates gastric cancer proliferation and metastasis by activating TRAF6/NF-κB/FGF18 through m6A modification

AIMS

Gastric cancer (GC) is one of the most common malignant tumors of the digestive system. High expression of the mitotic kinase BUB1 has been shown to be associated with the development of many cancers, but the role of BUB1 in GC is still unclear. The current study aimed to investigate the role of BUB1 in GC.

MATERIALS AND METHODS

BUB1 inhibitor, siRNA or BUB1 overexpression plasmid-mediated functional studies were performed in vitro and in vivo to explore the oncogenic role of BUB1 in GC. The expression of BUB1 and FGF18 in GC tumor samples was determined by IHC staining. RNA-seq, Western blot, MeRIP-qPCR and Co-IP assays were used to investigate the molecular mechanisms by which BUB1 regulates GC progression.

KEY FINDINGS

Knockdown of BUB1 significantly inhibited the proliferation and metastasis of GC cells in vitro and in vivo. Moreover, overexpression of BUB1 significantly promoted the proliferation, migration and invasion of GC cells. High expression of BUB1 and FGF18 in GC tissues predicted poor prognosis in GC patients. Mechanistically, BUB1 interacted with METTL3 and induced m6A modification of TRAF6 mRNA, further activating the NF-κB/FGF18 axis in GC cells.

SIGNIFICANCE

Our results confirmed that BUB1 acts as a positive regulator of GC cell proliferation and metastasis by activating the TRAF6/NF-κB/FGF18 pathway through METTL3-mediated m6A methylation. Targeting the BUB1/METTL3/TRAF6/NF-κB/FGF18 axis might be a novel diagnostic and therapeutic strategy in GC.

FGF18 impairs blastocyst viability, DNA double-strand breaks and maternal recognition of pregnancy genes

Embryonic mortality in cattle is high, reaching 10-40 % in vivo and 60-70 % in vitro. Death of embryos involves reduced expression of genes related to embryonic viability, inhibition of DNA repair and increased DNA damage. In follicular granulosa cells, FGF18 from the theca layer increases apoptosis and DNA damage, so we hypothesized that FGF18 may also affect the oocyte and contribute to early embryonic death. The aims of this study were to identify the effects of FGF18 on cumulus expansion, oocyte maturation and embryo development from cleavage to blastocyst stage using a conventional bovine in vitro embryo production system using ovaries of abattoir origin. Addition of FGF18 during in-vitro maturation did not affect FSH-induced cumulus expansion or rates of nuclear maturation. When FGF18 was present in the culture system, rates of cleavage were not affected however, blastocyst and expanded blastocyst development was substantially inhibited (P < 0.05), indicating a delay of blastulation. The number of phosphorylated histone H2AFX foci per nucleus, a marker of DNA damage, was higher in cleavage-stage embryos cultured with FGF18 than in those from control group (P < 0.05). Furthermore, FGF18 decreased accumulation of PTGS2 and IFNT2 mRNA in blastocysts. In conclusion, these novel findings suggest that FGF18 plays a role in the regulation of embryonic death during the early stages of development by impairing DNA double-strand break repair and expression of genes associated with embryo viability and maternal recognition of pregnancy during the progression from oocyte to expanded blastocysts.

Roles of fibroblast growth factors in the treatment of diabetes

Diabetes affects about 422 million people worldwide, causing 1.5 million deaths each year. However, the incidence of diabetes is increasing, including several types of diabetes. Type 1 diabetes (5%-10% of diabetic cases) and type 2 diabetes (90%-95% of diabetic cases) are the main types of diabetes in the clinic. Accumulating evidence shows that the fibroblast growth factor (FGF) family plays important roles in many metabolic disorders, including type 1 and type 2 diabetes. FGF consists of 23 family members (FGF-1-23) in humans. Here, we review current findings of FGFs in the treatment of diabetes and management of diabetic complications. Some FGFs (e.g., FGF-15, FGF-19, and FGF-21) have been broadly investigated in preclinical studies for the diagnosis and treatment of diabetes, and their therapeutic roles in diabetes are currently under investigation in clinical trials. Overall, the roles of FGFs in diabetes and diabetic complications are involved in numerous processes. First, FGF intervention can prevent high-fat diet-induced obesity and insulin resistance and reduce the levels of fasting blood glucose and triglycerides by regulating lipolysis in adipose tissues and hepatic glucose production. Second, modulation of FGF expression can inhibit renal and cardiac fibrosis by regulating the expression of extracellular matrix components, promote diabetic wound healing process and bone repair, and inhibit cancer cell proliferation and migration. Finally, FGFs can regulate the activation of glucose-excited neurons and the expression of thermogenic genes.

miR-590-5p/Tiam1-mediated glucose metabolism promotes malignant evolution of pancreatic cancer by regulating SLC2A3 stability

BACKGROUND

T lymphoma invasion and metastasis 1 (Tiam1) is a tumor related gene that specifically activates Rho-like GTPases Rac1 and plays a critical role in the progression of various malignancies. Glycolysis plays an important role in cancer progression, it is crucial for supplying energy and producing metabolic end products, which can maintain the survival of tumor cells. As yet, however, the mechanism of Tiam1 in glycolysis reprogramming of pancreatic cancer (PC) remains to be clarified. Here, we investigated the functional role of Tiam1 in PC cell proliferation, metastasis and glycolysis reprogramming. It is expected to provide a new direction for clinical treatment.

METHODS

The clinical relevance of Tiam1 was evaluated in 66 patients with PC, the effect of Tiam1 on cell proliferation was detected via 5-Ethynyl-2'-deoxyuridine (EdU) and colony formation. The ability of cell migration was detected by the wound healing and Transwell. Quantitative real time polymerase chain reaction (qRT-PCR) and luciferase reporter gene experiments clarify the regulatory relationship of miR-590-5p inhibiting Tiam1. Detection of the molecular mechanism of Tiam1 regulating glucose metabolism reprogramming in PC by glucose metabolism kit. RNA sequencing and Co-Immunoprecipitation (CoIP) have identified glucose transporter protein 3 (SLC2A3) as a key downstream target gene for miR-590-5p/Tiam1.

RESULTS

We found that Tiam1 expression increased in PC tissues and was associated with lymph node metastasis. The silencing or exogenous overexpression of Tiam1 significantly altered the proliferation, invasion, and angiogenesis of PC cells through glucose metabolism pathway. In addition, Tiam1 could interact with the crucial SLC2A3 and promote the evolution of PC in a SLC2A3-dependent manner. Moreover, miR-590-5p was found to exacerbate the PC cell proliferation, migration and invasion by targeting Tiam1. Furthermore, the reversing effects on proliferation, migration and invasion were found in PC cells with miR-590-5p/Tiam1 overexpression after applying glucose metabolism inhibition.

CONCLUSIONS

Our findings demonstrate the critical role of Tiam1 in PC development and the miR-590-5p/Tiam1/SLC2A3 signaling pathway may serve as a target for new PC therapeutic strategies.

Gastric Cancer: Molecular Mechanisms, Novel Targets, and Immunotherapies: From Bench to Clinical Therapeutics

Gastric cancer is a global health concern, ranking fifth in cancer diagnoses and fourth in cancer-related deaths worldwide. Despite recent advancements in diagnosis, most cases are detected at advanced stages, resulting in poor outcomes. However, recent breakthroughs in genome analysis have identified biomarkers that hold positive clinical significance for GC treatment. These biomarkers and classifications offer the potential for more precise diagnostic and therapeutic approaches for GC patients. In this review, we explore the classification and molecular pathways in this disease, highlighting potential biomarkers that have emerged in recent studies including targeted therapies and immunotherapies. These advancements provide a promising direction for improving the management of GC.

Fibroblast growth factor 18 stimulates the proliferation of hepatic stellate cells, thereby inducing liver fibrosis

Liver fibrosis results from chronic liver injury triggered by factors such as viral infection, excess alcohol intake, and lipid accumulation. However, the mechanisms underlying liver fibrosis are not fully understood. Here, we demonstrate that the expression of fibroblast growth factor 18 (Fgf18) is elevated in mouse livers following the induction of chronic liver fibrosis models. Deletion of Fgf18 in hepatocytes attenuates liver fibrosis; conversely, overexpression of Fgf18 promotes liver fibrosis. Single-cell RNA sequencing reveals that overexpression of Fgf18 in hepatocytes results in an increase in the number of Lrat+ hepatic stellate cells (HSCs), thereby inducing fibrosis. Mechanistically, FGF18 stimulates the proliferation of HSCs by inducing the expression of Ccnd1. Moreover, the expression of FGF18 is correlated with the expression of profibrotic genes, such as COL1A1 and ACTA2, in human liver biopsy samples. Thus, FGF18 promotes liver fibrosis and could serve as a therapeutic target to treat liver fibrosis.

Circulating FGF18 is decreased in pleural mesothelioma but not correlated with disease prognosis

BACKGROUND

Pleural mesothelioma (PM) is a relatively rare malignancy with limited treatment options and dismal prognosis. We have previously found elevated FGF18 expression in PM tissue specimens compared with normal mesothelium. The objective of the current study was to further explore the role of FGF18 in PM and evaluate its suitability as a circulating biomarker.

METHODS

FGF18 mRNA expression was analyzed by real-time PCR in cell lines and in silico in datasets from the Cancer Genome Atlas (TCGA). Cell lines overexpressing FGF18 were generated by retroviral transduction and cell behavior was investigated by clonogenic growth and transwell assays. Plasma was collected from 40 PM patients, six patients with pleural fibrosis, and 40 healthy controls. Circulating FGF18 was measured by ELISA and correlated to clinicopathological parameters.

RESULTS

FGF18 showed high mRNA expression in PM and PM-derived cell lines. PM patients with high FGF18 mRNA expression showed a trend toward longer overall survival (OS) in the TCGA dataset. In PM cells with low endogenous FGF18 expression, forced overexpression of FGF18 resulted in reduced growth but increased migration. Surprisingly, despite the high FGF18 mRNA levels observed in PM, circulating FGF18 protein was significantly lower in PM patients and patients with pleural fibrosis than in healthy controls. No significant association of circulating FGF18 with OS or other disease parameters of PM patients was observed.

CONCLUSIONS

FGF18 is not a prognostic biomarker in PM. Its role in PM tumor biology and the clinical significance of decreased plasma FGF18 in PM patients warrant further investigation.

The role of fibroblast growth factor 18 in cancers: functions and signaling pathways

Fibroblast growth factor 18(FGF18) is a member of the fibroblast growth factor family (FGFs). FGF18 is a class of bioactive substances that can conduct biological signals, regulate cell growth, participate in tissue repair and other functions, and can promote the occurrence and development of different types of malignant tumors through various mechanisms. In this review, we focus on recent studies of FGF18 in the diagnosis, treatment, and prognosis of tumors in digestive, reproductive, urinary, respiratory, motor, and pediatric systems. These findings suggest that FGF18 may play an increasingly important role in the clinical evaluation of these malignancies. Overall, FGF18 can function as an important oncogene at different gene and protein levels, and can be used as a potential new therapeutic target and prognostic biomarker for these tumors.

Biological and clinical implications of FGFR aberrations in paediatric and young adult cancers

Rare but recurrent mutations in the fibroblast growth factor receptor (FGFR) pathways, most commonly in one of the four FGFR receptor tyrosine kinase genes, can potentially be targeted with broad-spectrum multi-kinase or FGFR selective inhibitors. The complete spectrum of these mutations in paediatric cancers is emerging as precision medicine programs perform comprehensive sequencing of individual tumours. Identification of patients most likely to benefit from FGFR inhibition currently rests on identifying activating FGFR mutations, gene fusions, or gene amplification events. However, the expanding use of transcriptome sequencing (RNAseq) has identified that many tumours overexpress FGFRs, in the absence of any genomic aberration. The challenge now presented is to determine when this indicates true FGFR oncogenic activity. Under-appreciated mechanisms of FGFR pathway activation, including alternate FGFR transcript expression and concomitant FGFR and FGF ligand expression, may mark those tumours where FGFR overexpression is indicative of a dependence on FGFR signalling. In this review, we provide a comprehensive and mechanistic overview of FGFR pathway aberrations and their functional consequences in paediatric cancer. We explore how FGFR over expression might be associated with true receptor activation. Further, we discuss the therapeutic implications of these aberrations in the paediatric setting and outline current and emerging therapeutic strategies to treat paediatric patients with FGFR-driven cancers.

Exploring the Structural and Functional Diversity among FGF Signals: A Comparative Study of Human, Mouse, and Xenopus FGF Ligands in Embryonic Development and Cancer Pathogenesis

Fibroblast growth factors (FGFs) encode a large family of growth factor proteins that activate several intracellular signaling pathways to control diverse physiological functions. The human genome encodes 22 FGFs that share a high sequence and structural homology with those of other vertebrates. FGFs orchestrate diverse biological functions by regulating cellular differentiation, proliferation, and migration. Dysregulated FGF signaling may contribute to several pathological conditions, including cancer. Notably, FGFs exhibit wide functional diversity among different vertebrates spatiotemporally. A comparative study of FGF receptor ligands and their diverse roles in vertebrates ranging from embryonic development to pathological conditions may expand our understanding of FGF. Moreover, targeting diverse FGF signals requires knowledge regarding their structural and functional heterogeneity among vertebrates. This study summarizes the current understanding of human FGF signals and correlates them with those in mouse and Xenopus models, thereby facilitating the identification of therapeutic targets for various human disorders.

Signaling pathways and therapeutic interventions in gastric cancer

Gastric cancer (GC) ranks fifth in global cancer diagnosis and fourth in cancer-related death. Despite tremendous progress in diagnosis and therapeutic strategies and significant improvements in patient survival, the low malignancy stage is relatively asymptomatic and many GC cases are diagnosed at advanced stages, which leads to unsatisfactory prognosis and high recurrence rates. With the recent advances in genome analysis, biomarkers have been identified that have clinical importance for GC diagnosis, treatment, and prognosis. Modern molecular classifications have uncovered the vital roles that signaling pathways, including EGFR/HER2, p53, PI3K, immune checkpoint pathways, and cell adhesion signaling molecules, play in GC tumorigenesis, progression, metastasis, and therapeutic responsiveness. These biomarkers and molecular classifications open the way for more precise diagnoses and treatments for GC patients. Nevertheless, the relative significance, temporal activation, interaction with GC risk factors, and crosstalk between these signaling pathways in GC are not well understood. Here, we review the regulatory roles of signaling pathways in GC potential biomarkers, and therapeutic targets with an emphasis on recent discoveries. Current therapies, including signaling-based and immunotherapies exploited in the past decade, and the development of treatment for GC, particularly the challenges in developing precision medications, are discussed. These advances provide a direction for the integration of clinical, molecular, and genomic profiles to improve GC diagnosis and treatments.

Small RNA-Seq Reveals Similar miRNA Transcriptome in Children and Young Adults with T-ALL and Indicates miR-143-3p as Novel Candidate Tumor Suppressor in This Leukemia

We aimed to identify miRNAs and pathways specifically deregulated in adolescent and young adult (AYA) T-ALL patients. Small RNA-seq showed no major differences between AYA and pediatric T-ALL, but it revealed downregulation of miR-143-3p in T-ALL patients. Prediction algorithms identified several known and putative oncogenes targeted by this miRNA, including KRAS, FGF1, and FGF9. Pathway analysis indicated signaling pathways related to cell growth and proliferation, including FGFR signaling and PI3K-AKT signaling, with the majority of genes overrepresented in these pathways being predicted targets of hsa-miR-143-3p. By luciferase reporter assays, we validated direct interactions of this miRNA with KRAS, FGF1 and FGF9. In cell proliferation assays, we showed reduction of cell growth upon miR-143-3p overexpression in two T-ALL cell lines. Our study is the first description of the miRNA transcriptome in AYA T-ALL patients and the first report on tumor suppressor potential of miR-143-3p in T-ALL. Downregulation of this miRNA in T-ALL patients might contribute to enhanced growth and viability of leukemic cells. We also discuss the potential role of miR-143-3p in FGFR signaling. Although this requires more extensive validation, it might be an interesting direction, since FGFR inhibition proved promising in preclinical studies in various cancers.

Identification of an immune-related gene prognostic index for predicting survival and immunotherapy efficacy in papillary renal cell carcinoma

Despite considerable progress has been made in the understanding of the genetics and molecular biology of renal cell carcinoma (RCC), therapeutic options of patients with papillary renal cell carcinoma (PRCC) are limited. Immunotherapy based on immune checkpoint inhibitors (ICIs) has become a hot point in researching new drug for tumor and been tested in a number of human clinical trials. In this study, an immune-related gene prognostic index (IRGPI) was developed and provided a comprehensive and systematic analysis of distinct phenotypic and molecular portraits in the recognition, surveillance, and prognosis of PRCC. The reliability of the IRGPI was evaluated using independent datasets from GEO database and the expression levels of the genes in the IRGPI detected by real-time PCR. Collectively, the currently established IRGPI could be used as a potential biomarker to evaluate the response and efficacy of immunotherapy in PRCC.

Immunoreactivity against fibroblast growth factor 8 in alveolar rhabdomyosarcoma patients and its involvement in tumor aggressiveness

Rhabdomyosarcoma (RMS) is an aggressive pediatric soft tissue sarcoma characterized by a very poor prognosis when relapses occur after front-line therapy. Therefore, a major challenge for patients’ management remains the identification of markers associated with refractory and progressive disease. In this context, cancer autoantibodies are natural markers of disease onset and progression, useful to unveil novel therapeutic targets. Herein, we matched autoantibody profiling of alveolar RMS (ARMS) patients with genes under regulatory control of PAX3-FOXO1 transcription factor and revealed fibroblast growth factor 8 (FGF8) as a novel ARMS tumor antigen of diagnostic, prognostic, and therapeutic potential. We demonstrated that high levels of FGF8 autoantibodies distinguished ARMS patients from healthy subjects and represented an independent prognostic factor of better event-free survival. FGF8 was overexpressed in ARMS tumors compared to other types of pediatric soft tissue sarcomas, acting as a positive regulator of cell signaling. Indeed, FGF8 was capable of stimulating ARMS cells migration and expression of pro-angiogenic and metastasis-related factors, throughout MAPK signaling activation. Of note, FGF8 was found to increase in recurrent tumors, independently of PAX3-FOXO1 expression dynamics. Risk of recurrence correlated positively with FGF8 expression levels at diagnosis and reduced FGF8 autoantibodies titer, almost as if to suggest a failure of the immune response to control tumor growth in recurring patients. This study provides evidence about the crucial role of FGF8 in ARMS and the protective function of natural autoantibodies, giving new insights into ARMS biology and laying the foundations for the development of new therapeutic strategies.

New developments in the biology of fibroblast growth factors

The fibroblast growth factor (FGF) family is composed of 18 secreted signaling proteins consisting of canonical FGFs and endocrine FGFs that activate four receptor tyrosine kinases (FGFRs 1-4) and four intracellular proteins (intracellular FGFs or iFGFs) that primarily function to regulate the activity of voltage-gated sodium channels and other molecules. The canonical FGFs, endocrine FGFs, and iFGFs have been reviewed extensively by us and others. In this review, we briefly summarize past reviews and then focus on new developments in the FGF field since our last review in 2015. Some of the highlights in the past 6 years include the use of optogenetic tools, viral vectors, and inducible transgenes to experimentally modulate FGF signaling, the clinical use of small molecule FGFR inhibitors, an expanded understanding of endocrine FGF signaling, functions for FGF signaling in stem cell pluripotency and differentiation, roles for FGF signaling in tissue homeostasis and regeneration, a continuing elaboration of mechanisms of FGF signaling in development, and an expanding appreciation of roles for FGF signaling in neuropsychiatric diseases. This article is categorized under: Cardiovascular Diseases > Molecular and Cellular Physiology Neurological Diseases > Molecular and Cellular Physiology Congenital Diseases > Stem Cells and Development Cancer > Stem Cells and Development.

HSP90-CDC37 functions as a chaperone for the oncogenic FGFR3-TACC3 fusion

The FGFR3-TACC3 (F3-T3) fusion gene was discovered as an oncogenic molecule in glioblastoma and bladder cancers, and has subsequently been found in many cancer types. Notably, F3-T3 was found to be highly expressed in both untreated and matched recurrence glioblastoma under the concurrent radiotherapy and temozolomide (TMZ) treatment, suggesting that targeting F3-T3 is a valid strategy for treatment. Here, we show that the F3-T3 protein is a client of heat shock protein 90 (HSP90), forming a ternary complex with the cell division cycle 37 (CDC37). Deprivation of HSP90 or CDC37 disrupts the formation of the ternary complex, which destabilizes glycosylated F3-T3, and thereby suppresses F3-T3 oncogenic activity. Gliomas harboring F3-T3 are resistant to TMZ chemotherapy. HSP90 inhibitors sensitized F3-T3 glioma cells to TMZ via the inhibition of F3-T3 activation and potentiated TMZ-induced DNA damage. These results demonstrate that F3-T3 oncogenic function is dependent on the HSP90 chaperone system and suggests a new clinical option for targeting this genetic aberration in cancer.

HDAC7 promotes NSCLC proliferation and metastasis via stabilization by deubiquitinase USP10 and activation of β-catenin-FGF18 pathway

Background

Histone deacetylases (HDACs) play crucial roles in cancers, but the role and mechanism of HDAC7 in NSCLC have not been fully understood.

Methods

A total of 319 patients with non-small cell lung cancer (NSCLC) who underwent surgery were enrolled in this study. Immunohistochemistry and Kaplan–Meier survival analysis were performed to investigate the relationship between HDAC7, fibroblast growth factor 18 (FGF18) expression, and clinicopathologic characteristics. Cell functional experiments were implemented both in vivo and in vitro to investigate the effects on NSCLC cell proliferation and metastasis. Recombinant lentivirus–meditated in vivo gene overexpression or knockdown, real-time polymerase chain reaction (PCR), western blotting, and coimmunoprecipitation assays were applied to clarify the underlying molecular mechanism of HDAC7 in promoting NSCLC progression.

Results

The elevated expression of HDAC7 or FGF18 was positively correlated with poor prognosis, tumor–node–metastasis (TNM) stage, and tumor differentiation of NSCLC patients. NSCLC patients with co-expressed HDAC7 and FGF18 suffered the worst prognosis. HDAC7 overexpression promoted NSCLC proliferation and metastasis by upregulating FGF18. Conversely, overexpression of FGF18 reversed the attenuated ability in tumor growth and metastasis mediated by downregulating HDAC7. In terms of mechanism, our results suggested that the interaction of HDAC7 with β-catenin caused decreased β-catenin acetylation level at Lys49 and decreased phosphorylation level at Ser45. As a consequence, the HDAC7-mediated posttranslational modification of β-catenin facilitated nuclear transfer and activated FGF18 expression via binding to TCF4. Furthermore, deubiquitinase USP10 interacted with and stabilized HDAC7. The suppression of USP10 significantly accelerated the degradation of HDAC7 and weakened NSCLC growth and migration.

Conclusions

Our findings reveal that HDAC7 promotes NSCLC progression through being stabilized by USP10 and activating the β-catenin-FGF18 pathway. Targeting this novel pathway may be a promising strategy for further developments in NSCLC therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02266-9.

The beginning of the era of precision medicine for gastric cancer with fibroblast growth factor receptor 2 aberration

Despite recent advances in the systemic treatment of metastatic gastric cancer (GC), prognostic outcomes remain poor. Considerable research effort has been invested in characterizing the genomic landscape of GC and identifying potential therapeutic targets. FGFR2 is one of the most attractive targets because aberrations in this gene are frequently associated with GC, particularly the diffuse type in Lauren's classification, which confers an unfavorable prognosis. Based on the preclinical data, the FGFR2 signaling pathway plays a key role in the development and progression of GC, and several FGFR inhibitors have been clinically assessed. However, the lack of robust treatment efficacy has hampered precision medicine for patients with FGFR2-aberrant GC. Recently, the clinical benefits of the FGFR2-IIIb-selective monoclonal antibody bemarituzumab for FGFR2b-positive GC patients were shown in a randomized phase II FIGHT trial of bemarituzumab combined with the first-line chemotherapy. This trial demonstrates proof of concept, suggesting that FGFR2 is a relevant therapeutic target for patients with FGFR2b-positive GC and that bemarituzumab brings new hope for diffuse-type GC patients. In this review, we summarize the oncogenic roles of FGFR2 signaling and highlight the most recent advances in FGFR inhibitors based on the findings of pivotal clinical trials for patients with FGFR2-aberrant GC. Thus, the era of precision medicine for patients with FGFR2-aberrant GC will be opened.

miR-590-5p affects chondrocyte proliferation, apoptosis, and inflammation by targeting FGF18 in osteoarthritis

OBJECTIVE

To investigate the potential miRNA targeting FGF18, and its role in regulating the proliferation, apoptosis and inflammation in human primary chondrocytes.

METHODS

The normal human chondrocytes were induced by IL-1β to mimic OA in vitro. qPCR and Western blotting were performed to evaluate the expression of FGF18. Target Scan analysis was performed to predict the miRNA targeting FGF18. Then, the expression of miR-590-5p was quantified by qPCR in IL-1β-induced chondrocytes. After transfection of miR-590-5p mimics or inhibitors, CCK-8 assay was conducted to determine the cell viability and apoptosis-related proteins, and cartilage degeneration related biomarkers were assayed by qPCR and Western blotting. The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-8 were determined by ELISA. The targeting relationship between miR-590-5p and FGF18 was assayed by luciferase reporter assay in IL-1β-induced chondrocytes.

RESULTS

Target Scan analysis predicted that FGF18 is directly targeted by miR-590-5p. miR-590-5p was up-regulated, whereas FGF18 expression was inhibited in IL-1β-induced chondrocytes. miR-590-5p mimics reduced the expression of FGF18 protein, inhibited the cell viability of chondrocytes, and promoted secretion of inflammatory factors in chondrocytes, while miR-590-5p inhibitors increased FGF18 levels in IL-1β-treated chondrocytes. Furthermore, expression of inflammatory factors in chondrocytes was reduced by miR-590-5p inhibitors. The luciferase reporter assay showed that miR-590-5p could target FGF18.

CONCLUSIONS

miR-590-5p promotes OA progression by targeting FGF18, which serves as a potential therapeutic target for OA.

Gastric Cancer: Identification of microRNAs Inhibiting Druggable Targets and Mediating Efficacy in Preclinical In Vivo Models

In addition to chemotherapy, targeted therapies have been approved for treatment of locally advanced and metastatic gastric cancer. The therapeutic benefit is significant but more durable responses and improvement of survival should be achieved. Therefore, the identification of new targets and new approaches for clinical treatment are of paramount importance. In this review, we searched the literature for down-regulated microRNAs which interfere with druggable targets and exhibit efficacy in preclinical in vivo efficacy models. As druggable targets, we selected transmembrane receptors, secreted factors and enzymes. We identified 38 microRNAs corresponding to the criteria as outlined. A total of 13 miRs target transmembrane receptors, nine inhibit secreted proteins and 16 attenuate enzymes. These microRNAs are targets for reconstitution therapy of gastric cancer. Further target validation experiments are mandatory for all of the identified microRNAs.

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

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

Role of FGF System in Neuroendocrine Neoplasms: Potential Therapeutic Applications

Neuroendocrine neoplasms (NENs) are a heterogeneous group of tumors originating from neuroendocrine cells dispersed in different organs. Receptor tyrosine kinases are a subclass of tyrosine kinases with a relevant role in several cellular processes including proliferation, differentiation, motility and metabolism. Dysregulation of these receptors is involved in neoplastic development and progression for several tumors, including NENs. In this review, we provide an overview concerning the role of the fibroblast growth factor (FGF)/fibroblast growth factor receptor (FGFR) system in the development and progression of NENs, the occurrence of fibrotic complications and the onset of drug-resistance. Although no specific FGFR kinase inhibitors have been evaluated in NENs, several clinical trials on multitarget tyrosine kinase inhibitors, acting also on FGF system, showed promising anti-tumor activity with an acceptable and manageable safety profile in patients with advanced NENs. Future studies will need to confirm these issues, particularly with the development of new tyrosine kinase inhibitors highly selective for FGFR.

FGF/FGFR Signaling in Hepatocellular Carcinoma: From Carcinogenesis to Recent Therapeutic Intervention

Simple Summary

As the most common primary liver cancer, HCC is a tricky cancer resistant to systemic therapies. The fibroblast growth factor family and its receptors are gaining more and more attention in various cancers. Noticing an explosion in the number of studies about aberrant FGF/FGFR signaling in HCC being studied, we were encouraged to summarize them. This review discusses how FGF/FGFR signaling influences HCC development and its implications in HCC prediction and target treatment, and combination treatment.

Abstract

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, ranking third in cancer deaths worldwide. Over the last decade, several studies have emphasized the development of tyrosine kinase inhibitors (TKIs) to target the aberrant pathways in HCC. However, the outcomes are far from satisfactory due to the increasing resistance and adverse effects. The family of fibroblast growth factor (FGF) and its receptors (FGFR) are involved in various biological processes, including embryogenesis, morphogenesis, wound repair, and cell growth. The aberrant FGF/FGFR signaling is also observed in multiple cancers, including HCC. Anti-FGF/FGFR provides delightful benefits for cancer patients, especially those with FGF signaling alteration. More and more multi-kinase inhibitors targeting FGF signaling, pan-FGFR inhibitors, and selective FGFR inhibitors are now under preclinical and clinical investigation. This review summarizes the aberrant FGF/FGFR signaling in HCC initiating, development and treatment status, and provide new insights into the treatment of HCC.

Dysregulation of miR-638 in the progression of cancers

MicroRNA (miRNA) is a form of short, single-stranded and non-coding RNA that is important in regulating the post-transcriptional modification of multiple downstream targets. Many miRNAs have been reported to involve in controlling the progression of human diseases, and one of them is miR-638, which play essential roles in regulating the development of human cancer. By targeting the 3'-ends of its targets, miR-638 can regulate cellular processes including proliferation, invasion, metastases, angiogenesis, apoptosis and inflammation. This review was aimed to summarize current findings on the roles of miR-638 in different human cancers based on the results from various in vitro, in vivo and clinical studies. The biogenesis process and tissue expression, followed by the roles of miR-638 in regulating the development of various human cancers by targeting different downstream targets were covered in this review. The potential applications and challenges of employing miR-638 as cancer biomarker and therapeutic agent were also discussed.

Crosstalk Between Cancer Associated Fibroblasts and Cancer Cells in Scirrhous Type Gastric Cancer

Gastric cancer (GC) is the third leading cause among all cancer deaths globally. Although the treatment outcome of GC has improved, the survival of patients with GC at stages III and IV remains unsatisfactory. Among several types of GC, scirrhous type GC (SGC) shows highly aggressive growth and invasive activity, leading to frequent peritoneal metastasis. SGC is well known to accompany abundant stromal cells that compose the tumor microenvironment (TME) along with the produced extracellular matrix (ECM) and secreted factors. One of the main stromal components is cancer associated fibroblast (CAF). In the SGC microenvironment, CAFs are a source of various secreted factors, including fibroblast growth factors (FGFs), which mediate prominent tumor-stimulating activity. In turn, cancer cells also secrete numerous factors, which can activate and educate CAFs. Current findings suggest that cancer cells and stromal cells communicate interactively via the soluble factors, the ECM, and likely also by exosomes. In this review, we focus on the soluble factors mediating communication between cancer cells and CAFs in SGC, and consider how they are related to the modulation of TME and the high rate of peritoneal metastasis. At last, we discuss the perspectives on targeting these communication pathways for improved future treatment.

Fibroblast growth factor 8 overexpression is predictive of poor prognosis in pancreatic ductal adenocarcinoma

Background

Despite distinctive advances in the field of pancreatic cancer therapy over the past few years, patient survival remains poor. Fibroblast growth factors 8 (FGF8) and 18 (FGF18) both play a role in modulating the activity of malignant cells and have been identified as promising biomarkers in a number of cancers. However, no data exist on the expression of FGF8 and FGF18 in pancreatic ductal adenocarcinoma (PDAC).

Methods

Protein expression levels of FGF8 and FGF18 in postoperative specimens of neoadjuvantly treated and primarily resected patients were investigated using immunohistochemistry. Immunostaining scores were calculated as the products of the staining intensity and the staining rate. Scores exceeding the median score were considered as high expression.

Results

Specimens from 78 patients with PDAC were available and met the eligibility criteria for analysis of protein expression using immunohistochemistry. 15 (19.2%) patients had received neoadjuvant chemotherapy. High protein levels of FGF8 and FGF18 were detected in 40 (51.8%) and 33 (42.3%) patients, respectively. Kaplan–Meier analysis demonstrated significantly shorter overall survival in patients with high expression of FGF8 (p = 0.04). Multivariable Cox proportional hazard regression models revealed that high expression of FGF8 (Hazard ratio [HR] 0.53, 95% Confidence interval [CI] 0.32–0.89, p = 0.016) was an independent prognostic factor for diminished overall survival in patients with PDAC. By contrast, no statistical significance was found for FGF18 overexpression. In addition, the FGF8 protein level correlated with the factor resection margin (p = 0.042).

Conclusion

FGF8 is a promising target for new anticancer therapies using FGF inhibitors in pancreatic ductal adenocarcinomas.

FGF18 Inhibits Clear Cell Renal Cell Carcinoma Proliferation and Invasion via Regulating Epithelial-Mesenchymal Transition

Fibroblast growth factor 18 (FGF18) is a member of the FGF family and contributes to a broad range of biological events. The important role of the overexpression of FGF18 has been identified in the progression of several types of cancers. However, there is still little information on the biological role of FGF18 on clear cell renal cell carcinoma (ccRCC), which is of interest in investigating the biological functions of FGF18 in ccRCC. Our results showed that FGF18 was lowly expressed in ccRCC tissues compared to paired normal renal tissue from the TCGA database and clinical cohort of Huashan Hospital and that high expression of FGF18 correlated with a good prognosis in ccRCC patients. In addition, overexpression of FGF18 significantly inhibited the proliferation ability of ccRCC cell lines in vitro and in vivo. Gene set enrichment analysis (GSEA) identified epithelial-mesenchymal transition (EMT) involved in a high FGF18 expression group of ccRCC patients in the TCGA cohort, which was further validated with EMT related markers in FGF18 overexpressed ccRCC cell lines. Furthermore, FGF18 overexpression significantly inhibited the PI3K/Akt pathway in ccRCC cells. Taken together, this study concludes that FGF18 is of potential value as a target for ccRCC.

FGF18-FGFR2 signaling triggers the activation of c-Jun-YAP1 axis to promote carcinogenesis in a subgroup of gastric cancer patients and indicates translational potential

Fibroblast growth factor receptor type 2 (FGFR2) has emerged as a key oncogenic factor that regulates gastric cancer (GC) progression, but the underlying mechanism of FGF–FGFR2 signaling pathway remains largely unknown. To identify the potential molecular mechanisms of the oncogenic FGFR2 in gastric carcinogenesis and convey a novel therapeutic strategy, we profiled the FGFR alterations and analyzed their clinical associations in TCGA and Hong Kong GC cohorts. We found that FGFR2 overexpression in GC cell lines and primary tumors predicted poor survival and was associated with advanced stages of GC. Functionally, growth abilities and cell cycle progression of GC were inhibited by inactivation of ERK–MAPK signal transduction after FGFR2 knockdown, while apoptosis was promoted. Meanwhile, the first-line anti-cancer drug sensitivity was enhanced. RNA-seq analysis further revealed that YAP1 signaling serves as a significant downstream modulator and mediates the oncogenic signaling of FGFR2. When stimulating FGFR2 by rhFGF18, we observed intensified F-actin, nuclear accumulation of YAP1, and overexpression of YAP1 targets, but these effects were attenuated by either FGFR2 depletion or AZD4547 administration. Additionally, the FGF18–FGFR2 signaling upregulated YAP1 expression through activating c-Jun, an effector of MAPK signaling. In our cohort, 28.94% of GC cases were characterized as FGFR2, c-Jun, and YAP1 co-positive and demonstrated worse clinical outcomes. Remarkably, we also found that co-targeting FGFR2 and YAP1 by AZD4547 and Verteporfin synergistically enhanced the antitumor effects in vitro and in vivo. In conclusion, we have identified the oncogenic FGF–FGFR2 regulates YAP1 signaling in GC. The findings also highlight the translational potential of FGFR2–c-Jun–YAP1 axis, which may serve as a prognostic biomarker and therapeutic target for GC.

Circular RNA circPDE4D Protects against Osteoarthritis by Binding to miR-103a-3p and Regulating FGF18

Osteoarthritis (OA) is a common, age-related, and painful disease characterized by cartilage destruction, osteophyte formation, and synovial hyperplasia. This study revealed that circPDE4D, a circular RNA derived from human linear PDE4D, plays a critical role in maintaining the extracellular cellular matrix (ECM) during OA progression. circPDE4D was significantly downregulated in OA cartilage tissues and during stimulation with inflammatory cytokines. The knockdown of circPDE4D predominantly contributed to Aggrecan loss and the upregulation of matrix catabolic enzymes, including MMP3, MMP13, ADAMTS4, and ADAMTS5, but not proliferation or apoptosis. In a murine model of destabilization of the medial meniscus (DMM), the intraarticular injection of circPDE4D alleviated DMM-induced cartilage impairments. Mechanistically, we found that circPDE4D exerted its effect by acting as a sponge for miR-103a-3p and thereby regulated FGF18 expression, which is a direct target of miR-103a-3p. In conclusion, our findings highlight a novel protective role of circPDE4D in OA pathogenesis and indicate that the targeting of the circPDE4D-miR-103a-3p-FGF18 axis might provide a potential and promising approach for OA therapy.

FGF/FGFR signaling in health and disease

Growing evidences suggest that the fibroblast growth factor/FGF receptor (FGF/FGFR) signaling has crucial roles in a multitude of processes during embryonic development and adult homeostasis by regulating cellular lineage commitment, differentiation, proliferation, and apoptosis of various types of cells. In this review, we provide a comprehensive overview of the current understanding of FGF signaling and its roles in organ development, injury repair, and the pathophysiology of spectrum of diseases, which is a consequence of FGF signaling dysregulation, including cancers and chronic kidney disease (CKD). In this context, the agonists and antagonists for FGF-FGFRs might have therapeutic benefits in multiple systems.

Estrogen-Induced Stromal FGF18 Promotes Proliferation and Invasion of Endometrial Carcinoma Cells Through ERK and Akt Signaling

Objective

The aim of this study was to evaluate whether estrogen promoted the proliferation and invasion of endometrial carcinoma (EC) cells through paracrine FGFs in endometrial stromal cells (ESCs).

Patients and Methods

We screened gene alterations in a primary ESC culture after 10 nM estrogen treatment using an Agilent mRNA microarray. We knocked down stromal FGF18 expression in a co-culture system and aimed to explore the contribution of E2-induced stromal FGF18 to the proliferation and invasion of EC cells. To determine the effective receptors and detailed downstream signaling of FGF18, we co-cultured estrogen-treated hESCs with FGFR1-, FGFR2-, FGFR3- or FGFR4-knockdown Ishikawa cells. Finally, we detected FGF18 expression in clinical samples, including several primary cultures of different ESCs and a series of tissue microarrays (TMAs) of 90 patients with EC.

Results

A few genes altered significantly in estrogen-treated primary ESCs, but only FGF18 was noticeably enhanced among the FGF family genes. Knockdown of FGF18 expression in hESCs inhibited the promoting effect of FGF18 on the proliferation and invasion of EC cells. FGF18 bound FGFR2 and FGFR3 in Ishikawa cells to activate downstream ERK and Akt pathways and to promote the viability of EC cells. The FGF18-FGFR2 and FGF18-FGFR3 pathways had close correlations with Survivin and CD44V6 expression but not with P53. Primary ESCs of endometrioid EC (EEC, type I EC) had higher FGF18 expression than ESCs of normal endometrium (NE), endometrial atypical hyperplasia (EAH) and type II EC.

Conclusion

Estrogen induced FGF18 in ESCs to promote the proliferation and invasion of EC cells, and FGFR inhibitors should be considered as promising candidate targets for EC treatment.

Long noncoding RNA DUXAP8 regulates proliferation and apoptosis of ovarian cancer cells via targeting miR-590-5p

The aim of this study is to investigate the effect of lncRNA DUXAP8 on proliferation and apoptosis of ovarian cancer cells, and to explore its potential mechanism. DUXAP8 interfering and overexpressing cell lines were constructed and the cell proliferation and apoptosis were tested. Hematoxylin-eosin, TdT-mediated dUTP nick end labeling, and immunohistochemistry were used to detect the effect of DUXAP8 on the ability of tumor formation. Quantitative real-time polymerase chain reaction and western blot were used to detect the mRNA and protein expression of miR-590-5p and YAP1, respectively. Dual luciferase assay was used to determine the target relationship between DUXAP8, miR-590-5p, and YAP1. DUXAP8 interference and miR-590-5p down-regulated cell lines were further constructed. Compared with normal ovarian cells, the expression of DUXAP8 in ovarian cancer cells was significantly increased, while the expression of miR-590-5p was decreased (p < 0.05). After DUXAP8 interference, cell proliferation and colony formation were decreased, and apoptosis was increased. The results of in vivo experiment are consistent with the in vitro experiments. The expression of miR-590-5p was up-regulated and the expression of YAP1 was decreased after DUXAP8 interference. Moreover, miR590-5p inhibitor can attenuate the effect of DUXAP8 interference on ovarian cancer cells. Taken together, lncRNA DUXAP8 can regulate the proliferation and apoptosis of ovarian cancer cells, and its mechanism may be related to the regulation of YAP1 gene by targeting miR-590-5p.

The Emerging Role of the FGF/FGFR Pathway in Gastrointestinal Stromal Tumor

Gastrointestinal stromal tumors (GIST) are rare neoplasms of mesenchymal origin arising in the gastrointestinal tract. The vast majority are characterized by mutually exclusive activating mutations in KIT or Platelet-derived growth factor alpha (PDGFRA) receptors, or less frequently by succinate dehydrogenase complex (SDH) or NF1 inactivation, with very rare cases harboring mutant BRAF or RAS alleles. Approximately 5% of GISTs lack any of such mutations and are called quadruple wild-type (WT) GISTs. Recently, deregulated Fibroblast Growth Factor (FGF)/FGF-receptor (FGFR) signaling emerged as a relevant pathway driving oncogenic activity in different molecular subgroups of GISTs. This review summarizes all the current evidences supporting the key role of the FGF/FGFR pathway activation in GISTs, whereby either activating mutations, oncogenic gene fusions, or autocrine/paracrine signaling have been detected in quadruple WT, SDH-deficient, or KIT-mutant GISTs.

The Complex Network between MYC Oncogene and microRNAs in Gastric Cancer: An Overview

Despite the advancements in cancer treatments, gastric cancer is still one of the leading causes of death worldwide. In this context, it is of great interest to discover new and more effective ways of treating this disease. Accumulated evidences have demonstrated the amplification of 8q24.21 region in gastric tumors. Furthermore, this is the region where the widely known MYC oncogene and different microRNAs are located. MYC deregulation is key in tumorigenesis in various types of tissues, once it is associated with cell proliferation, survival, and drug resistance. microRNAs are a class of noncoding RNAs that negatively regulate the protein translation, and which deregulation is related with gastric cancer development. However, little is understood about the interactions between microRNAs and MYC. Here, we overview the MYC role and its relationship with the microRNAs network in gastric cancer aiming to identify potential targets useful to be used in clinic, not only as biomarkers, but also as molecules for development of promising therapies.

CFIm25-regulated lncRNA acv3UTR promotes gastric tumorigenesis via miR-590-5p/YAP1 axis

Accumulating evidences indicate that 3ʹUTR of the coding gene can act as crucial regulators in gastric cancer (GC). However, the detailed mechanisms and responsive targets are not well established. Here, we found that acvr1b gene 3ʹUTR (acv3UTR) was elevated in GC tissue, the expression of which was significantly correlated with advanced pTNM-stage and poor outcome in clinical patients. Forced expression of acv3UTR promoted GC cells growth in vitro and in vivo. Mechanistically, our results suggested that acv3UTR functioned as an oncogenic competing endogenous RNA via sponging miR-590-5p and enhancing YAP1 level. Tumor suppressor miR-590-5p was a molecular module in acv3UTR regulatory axis, the forced expression of which led to impairing of oncogenic potential of acv3UTR. The positive correlation of acv3UTR and YAP1 expression, and the negative correlation of acv3UTR and miR-590-5p expression, were verified in GC patients. Moreover, CFIm25 was identified as a key regulator contributing to acv3UTR aberrant expression in GC binding to UGUA-264 motif. Overall, our finding defines a mechanism for understanding the potential role of acv3UTR transcription in GC tumorigenesis, and indicates a correlation between 3ʹUTR trans-regulatory effect and GC development.

Circulating microRNA-590-5p functions as a liquid biopsy marker in non-small cell lung cancer

Despite the availability of various diagnostic procedures, a tissue biopsy is still indispensable for the routine diagnosis of lung cancer. However, inaccurate diagnoses can occur, leading to inefficient cancer management. In this context, use of circulating microRNAs (miRNAs) may serve as diagnostic tools as liquid biopsies, and as biomarkers to better understand the molecular mechanisms involved in the progression of cancer. We identified miR‐590‐5p as a potential prognostic marker in the progression of non‐small cell lung cancer (NSCLC). We were able to detect this miRNA in blood plasma samples of NSCLC patients through quantitative real‐time PCR. Our data showed an ~7.5‐fold downregulation of miR‐590‐5p in NSCLC patients compared to healthy controls, which correlated with several clinicopathological features. Further, overexpression of miR‐590‐5p led to decreased cell viability, proliferation, colony formation, migration, and invasion potential of lung cancer cells, whereas its knockdown showed the opposite effect. In addition, the levels of several proteins involved in the epithelial‐to‐mesenchymal transition negatively correlated with miR‐590‐5p levels in lung adenocarcinoma cells and tumors of NSCLC patients. Further, dual‐luciferase reporter assays identified STAT3 as a direct target of miR‐590‐5p, which negatively regulated STAT3 activation and its downstream signaling molecules (eg, Cyclin D1, c‐Myc, Vimentin, and β‐catenin) involved in tumorigenesis. Taken together, our study suggests that miR‐590‐5p functions as a tumor suppressor in NSCLC through regulating the STAT3 pathway, and may serve as a useful biomarker for the diagnosis/prognosis of NSCLC, and as a potential therapeutic target for the treatment of NSCLC.

Expression of FGF8, FGF18, and FGFR4 in Gastroesophageal Adenocarcinomas

Even though distinctive advances in the field of esophageal cancer therapy have occurred over the last few years, patients' survival rates remain poor. FGF8, FGF18, and FGFR4 have been identified as promising biomarkers in a number of cancers; however no data exist on expression of FGF8, FGF18, and FGFR4 in adenocarcinomas of the esophago-gastric junction (AEG). A preliminary analysis of the Cancer Genome Atlas (TCGA) database on FGF8, FGF18, and FGFR4 mRNA expression data of patients with AEG was performed. Furthermore, protein levels of FGF8, FGF18, and FGFR4 in diagnostic biopsies and post-operative specimens in neoadjuvantly treated and primarily resected patients using immunohistochemistry were investigated. A total of 242 patients was analyzed in this study: 87 patients were investigated in the TCGA data set analysis and 155 patients in the analysis of protein expression using immunohistochemistry. High protein levels of FGF8, FGF18, and FGFR4 were detected in 94 (60.7%), 49 (31.6%) and 84 (54.2%) patients, respectively. Multivariable Cox proportional hazard regression models revealed that high expression of FGF8 was an independent prognostic factor for diminished overall survival for all patients and for neoadjuvantly treated patients. By contrast, FGF18 overexpression was significantly associated with longer survival rates in neoadjuvantly treated patients. In addition, FGF8 protein level correlated with Mandard regression due to neoadjuvant therapy, indicating potential as a predictive marker. In summary, FGF8 and FGF18 are promising candidates for prognostic factors in adenocarcinomas of the esophago-gastric junction and new potential targets for new anti-cancer therapies.

Targeting the Oncogenic FGF-FGFR Axis in Gastric Carcinogenesis

Gastric cancer (GC) is one of the most wide-spread malignancies in the world. The oncogenic role of signaling of fibroblast growing factors (FGFs) and their receptors (FGFRs) in gastric tumorigenesis has been gradually elucidated by recent studies. The expression pattern and clinical correlations of FGF and FGFR family members have been comprehensively delineated. Among them, FGF18 and FGFR2 demonstrate the most prominent driving role in gastric tumorigenesis with gene amplification or somatic mutations and serve as prognostic biomarkers. FGF-FGFR promotes tumor progression by crosstalking with multiple oncogenic pathways and this provides a rational therapeutic strategy by co-targeting the crosstalks to achieve synergistic effects. In this review, we comprehensively summarize the pathogenic mechanisms of FGF-FGFR signaling in gastric adenocarcinoma together with the current targeted strategies in aberrant FGF-FGFR activated GC cases.

The expression profiling of circulating miR-204, miR-182, and lncRNA H19 as novel potential biomarkers for the progression of peptic ulcer to gastric cancer

Deregulation of noncoding RNAs, microRNAs (miRNAs) and long noncoding RNA (lncRNA), are implicated in the initiation and progression of gastric cancer (GC). This study is a pilot case-control study carried out on 75 subjects, 40 of them were Helicobacter pylori-gastric ulcer patients and 35 were GC patients recruited from the Gastrointestinal Endoscopy Unit in Al-Kasr Al-Aini Hospital, Cairo University in Egypt. Real-time PCR was performed to evaluate the expression level of serum miR-204, miR-182, and lncRNA H19 in patients with peptic ulcer-progressed GC vs nonprogressed peptic ulcer patients. Fibroblast growth factor 18 (FGF-18)/FGF receptor 2 (FGFR2) expression and their downstream immunological and inflammatory signaling markers were assessed and their association with the addressed noncoding RNAs investigated. As regards miR-204 and miR-182, they were significantly increased (12.5 and 2.6 folds, respectively) in GU samples, compared with those of healthy control levels. The elevated levels of these miRNAs were significantly de-escalated in GC samples compared with GU and the fold decrease valued 2.2 fold for miR-204 and 1.8 folds for miR-182. On the other hand, the significant escalation in the level of lnRNA H19 in GU recorded a 16.6 fold increase and further elevation in its levels was evident in GC samples. The herein assessed miRNAs are correlated with disease duration and FGFR2 with miR-182 being significantly correlated with all inflammatory markers, TAC, INF-γ, matrix metallopeptidase 9, and FGF-18. In terms of diagnostic accuracy of assessed miRNAs (stages III to IV), the receiver operating characteristic analysis indicated that serum lncRNA H19 showed the highest diagnostic accuracy (95.5%), specificity (100%), and sensitivity (90.9%), compared with miR-204 and miR-182, which showed the same specificity (60%), sensitivity (72.7%), and diagnostic accuracy (68.8%). Our findings conclude that lnRNA H19, miR-204, and miR-182 may function as novel prospective plasma biomarkers to detect GC and its progression from H. pylori-peptic ulcer, which would be helpful to improve the theranostics of GC.

Mechanotransduction and Cytoskeleton Remodeling Shaping YAP1 in Gastric Tumorigenesis

The essential role of Hippo signaling pathway in cancer development has been elucidated by recent studies. In the gastrointestinal tissues, deregulation of the Hippo pathway is one of the most important driving events for tumorigenesis. It is widely known that Yes-associated protein 1 (YAP1) and WW domain that contain transcription regulator 1 (TAZ), two transcriptional co-activators with a PDZ-binding motif, function as critical effectors negatively regulated by the Hippo pathway. Previous studies indicate the involvement of YAP1/TAZ in mechanotransduction by crosstalking with the extracellular matrix (ECM) and the F-actin cytoskeleton associated signaling network. In gastric cancer (GC), YAP1/TAZ functions as an oncogene and transcriptionally promotes tumor formation by cooperating with TEAD transcription factors. Apart from the classic role of Hippo-YAP1 cascade, in this review, we summarize the current investigations to highlight the prominent role of YAP1/TAZ as a mechanical sensor and responder under mechanical stress and address its potential prognostic and therapeutic value in GC.