Circ_0004851 regulates the molecular mechanism of miR-296-3p/FGF11 in the influence of high iodine on PTC.

The prevalence of papillary thyroid cancer (PTC) has been rising in recent years. Despite its relatively low mortality, PTC frequently metastasizes to lymph nodes and often recurs, posing significant health and economic burdens. The role of iodine in the pathogenesis and advancement of thyroid cancer remains poorly understood. Circular RNAs (circRNAs) are recognized to function as competing endogenous RNAs (ceRNAs) that modulate gene expression and play a role in various cancer stages. Consequently, this research aimed to elucidate the mechanism by which circRNA influences the impact of iodine on PTC. Our research indicates that high iodine levels can exacerbate the malignancy of PTC via the circ_0004851/miR-296-3p/FGF11 axis. These insights into iodine's biological role in PTC and the association of circRNA with the disease could pave the way for novel biomarkers and potentially effective therapeutic strategies to mitigate PTC progression.

Fibroblast Growth Factor 11 Inhibits Hepatitis B Virus Gene Expression Through FXRα Suppression.

Fibroblast growth factor 11 (FGF11) is a member of the intracellular FGF family, which shows different signal transmission compared with other FGF superfamily members. The molecular function of FGF11 is not clearly understood. In this study, we identified the inhibitory effect of FGF11 on hepatitis B virus (HBV) gene expression through transcriptional suppression. FGF11 decreased the mRNA and protein expression of HBV genes in liver cells. While the nuclear receptor FXRα1 increased HBV promoter transactivation, FGF11 decreased the FXRα-mediated gene induction of the HBV promoter by the FXRα agonist. Reduced endogenous levels of FXRα by siRNA and the dominant negative mutant protein (aa 1-187 without ligand binding domain) of FXRα expression indicated that HBV gene suppression by FGF11 is dependent on FXRα inhibition. In addition, FGF11 interacts with FXRα protein and reduces FXRα protein stability. These results indicate that FGF11 inhibits HBV replicative expression through the liver cell-specific transcription factor, FXRα, and suppresses HBV promoter activity. Our findings may contribute to the establishment of better regimens for the treatment of chronic HBV infections by including FGF11 to alter the bile acid mediated FXR pathway.

Fibroblast Growth Factor 11 (FGF11) Promotes Progression and Cisplatin Resistance Through the HIF-1α/FGF11 Signaling Axis in Ovarian Clear Cell Carcinoma.

Background: A poor prognosis is often associated with ovarian clear cell carcinoma (OCCC) due to its relative resistance to platinum-based chemotherapy. Although several studies have been launched to explore the pathogenesis of OCCC, the mechanism of chemoresistance has yet to be uncovered. Methods: Nanostring nCounter PanCancer Pathways Panel was performed to explore the expression profiles of OCCC tissues from patients showing different platinum sensitivity. Bioinformatic analysis was performed to select genes associated with chemoresistance and cell function assays, including colony formation, wound healing, transwell and flow cytometric analysis, were used to explore the role of the target gene in the progression of OCCC and resistance to cisplatin (DDP). Results: Gene expression profiles and bioinformatic analysis verified that the expression of fibroblast growth factor 11 (FGF11) was significantly increased in platinum-resistant OCCC tissues and increased FGF11 expression was related to poorer survival. Downregulation of FGF11 inhibited the proliferation, migration, and invasion, reversing the DDP resistance of OCCC cells. Mechanically, FGF11 was regulated by hypoxia-inducible factor-1α (HIF-1α) to modulate the DDP sensitivity. Conclusion: FGF11 was highly expressed in platinum-resistant OCCC tissues, promoting progression and resistance to DDP through the HIF-1α/FGF11 signaling axis.

Transcriptomic Analysis Reveals Fibroblast Growth Factor 11 (FGF11) Role in Brown Adipocytes in Thermogenic Regulation of Goats.

Brown adipose tissue (BAT) is the main site of adaptive thermogenesis, generates heat to maintain body temperature upon cold exposure, and protects against obesity by promoting energy expenditure. RNA-seq analysis revealed that FGF11 is enriched in BAT. However, the functions and regulatory mechanisms of FGF11 in BAT thermogenesis are still limited. In this study, we found that FGF11 was significantly enriched in goat BAT compared with white adipose tissue (WAT). Gain- and loss-of-function experiments revealed that FGF11 promoted differentiation and thermogenesis in brown adipocytes. However, FGF11 had no effect on white adipocyte differentiation. Furthermore, FGF11 promoted the expression of the UCP1 protein and an EBF2 element was responsible for UCP1 promoter activity. Additionally, FGF11 induced UCP1 gene expression through promoting EBF2 binding to the UCP1 promoter. These results revealed that FGF11 promotes differentiation and thermogenesis in brown adipocytes but not in white adipocytes of goats. These findings provide evidence for FGF11 and transcription factor regulatory functions in controlling brown adipose thermogenesis of goats.

FGF homologous factors are secreted from cells to induce FGFR-mediated anti-apoptotic response.

FGF homologous factors (FHFs) are the least described group of fibroblast growth factors (FGFs). The FHF subfamily consists of four proteins: FGF11, FGF12, FGF13, and FGF14. Until recently, FHFs were thought to be intracellular, non-signaling molecules, despite sharing structural and sequence similarities with other members of FGF family that can be secreted and activate cell signaling by interacting with surface receptors. Here, we show that despite lacking a canonical signal peptide for secretion, FHFs are exported to the extracellular space. Furthermore, we propose that their secretion mechanism is similar to the unconventional secretion of FGF2. The secreted FHFs are biologically active and trigger signaling in cells expressing FGF receptors (FGFRs). Using recombinant proteins, we demonstrated their direct binding to FGFR1, resulting in the activation of downstream signaling and the internalization of the FHF-FGFR1 complex. The effect of receptor activation by FHF proteins is an anti-apoptotic response of the cell.

High Levels of FGF11 Correlate with Poor Survival in Patients with Human Papillomavirus (HPV)-Positive Oropharyngeal Squamous Cell Carcinoma.

Human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) is associated with a favourable prognosis. It has therefore been suggested that treatment should be individualized and separated by HPV status. However, additional prognostic markers are still needed before treatment can be individualized for this patient group. For this purpose, all patients diagnosed with HPV and p16-positive OPSCC in Stockholm 2000-2009, identified as having a partial/nonresponse to treatment and having viable tumour cells in their neck specimen with material available were categorized as cases. These were matched to controls (complete responders), and the differences in the gene expression were analysed. Two separate verification cohorts were identified including patients with HPV- and p16-positive OPSCC, and the data from the case-control study were verified by qPCR and immunohistochemistry (IHC) in the respective cohorts. A separation of gene expression in correlation with survival was observed in the case-control study, and FGF11 expression was identified as significantly differently expressed between the two groups. The prognostic role of FGF11 was validated in the two cohorts on the RNA and protein levels, respectively. Taken together, our findings suggest that FGF11 may indicate a poor prognosis in HPV-positive OPSCC and may serve as a prognostic biomarker.

Expression and purification of intracrine human FGF 11 and study of its FGFR-dependent biological activity.

Fibroblast growth factor 11 (FGF11) is one of intracrine FGFs (iFGFs), which function within cells. Unlike canonical FGFs, FGF11 remains intracellularly and plays biological roles in FGF receptor (FGFR)-independent manner. Here, we established an expression system of recombinant FGF11 proteins in E. coli and investigated whether the extracellular administration of FGF11 can activate cellular signaling. Human FGF11 has two isoforms, FGF11a and FGF11b, depending on the presence of nuclear localization sequences (NLSs) in the N-terminus. Because these two isoforms are unstable, we prepared an FGF11a-Mut by substituting three cysteine residues in the NLS with serine and FGF11b-ΔC with C-terminal truncation. The introduction of mutation in the NLS improved the solubility of FGF11 prepared from E. coli. Exogenous addition of FGF11b and FGF11b-ΔC to BALB3T3 increased cell proliferation, while FGF11a-Mut exerted no effect. FGF11b-ΔC showed higher cell proliferation activity and FGFR signaling than FGF11b. The cell-proliferating activities of FGF11b and FGF11b-ΔC were blocked by an FGFR1 inhibitor or a recombinant FGFR1, confirming the FGFR1-dependent extracellular activity of FGF11b. The analysis of circular dichroism suggested that the C-terminus of FGF11 has an α-helical structure, which may affect its interaction with FGFR1. These results suggest that the N-and C-terminus of recombinant FGF11 are involved in the activation of FGFR1. The above results provide novel insights into the function and mechanism of FGF11 that may aid the development of useful ligands for FGFR regulation.

Hypoxia promotes thyroid cancer progression through HIF1α/FGF11 feedback loop.

Hypoxia is an important cause of cervical lymph nodes metastasis and recurrence of thyroid cancer, but its specific mechanism remains unclear. In the present study, we constructed a hypoxia model of thyroid cancer cells and explored the potential targets of hypoxia response through sequencing. The function and mechanism of the target protein were investigated in an in vitro cell model. We found that fibroblast growth factor 11 (FGF11), a member of the FGFs family, was upregulated in hypoxic thyroid cancer cells and thyroid cancer tissues. The knockdown of FGF11 blocked the promotion of hypoxia on the proliferation, migration and invasion of tumor cells. Importantly, FGF11 enhanced the stability of HIF1α through inhibiting its degradation in TPC-1 cells. under hypoxic condition, FGF11 formed a positive feedback loop with HIF1α to promote the growth and metastasis of thyroid cancer.

Fibroblast growth factor 11 (FGF11) promotes non-small cell lung cancer (NSCLC) progression by regulating hypoxia signaling pathway.

BACKGROUND: Accumulating evidence highlights the critical roles of fibroblast growth factors (FGFs) in regulating the progression of multiple human cancers, including non-small cell lung cancer (NSCLC). In this study, we investigated the role of FGF11 in the progression of NSCLC. METHODS: Previously published transcriptomic data (GSE75037 and GSE81089) were used to compare FGF11 expression level between NSCLC tumor tissues and adjacent normal tissues. 100 cases of NSCLC tumor tissues and 30 cases of matched adjacent normal tissues were used to validate FGF11 expression at mRNA and protein level by qPCR and immunohistochemistry. Bioinformatics analysis and dual luciferase reporter analysis were performed to confirm the regulatory effect of miR-525-5p on FGF11 expression. CCK-8 assay and transwell migration assay were employed to examine cellular proliferation, migration and invasion. Gene set enrichment analysis (GSEA) was performed to identify the signaling pathway associated with FGF11 expression. Finally, the functional role of FGF11 in NSCLC tumor growth was evaluated by in vivo study. RESULTS: FGF11 was upregulated in NSCLC tumor tissues and tumor cell lines. High FGF11 expression was associated with a poor prognosis in NSCLC patients. In vitro loss- and gain-of function experiments demonstrated that FGF11 knockdown inhibited, whereas FGF11 overexpression promoted the proliferation, migration and invasion of NSCLC cells. Dual luciferase reporter assay confirmed that FGF11 was downregulated by miR-525-5p, and the effect of FGF11 on cell proliferation, migration and invasion could be interfered by miR-525-5p. GSEA analysis further revealed that FGF11 expression was enriched with genes in hypoxia signaling pathway and the oncogenic function of FGF11 could be suppressed by knocking down HIF-1α in NSCLC cells. Moreover, FGF11 knockdown suppressed NSCLC tumor growth whereas FGF11 overexpression promoted tumor growth in vivo. CONCLUSIONS: Our study showed that FGF11 functions as an oncogene in tumor NSCLC progression. miR-525-5p seems to negatively regulate FGF11 and the oncogenic role of FGF11 is dependent on the upregulation of HIF-1α. Our study suggests that targeting FGF11 and HIF-1α may serve as novel strategies for the treatment of NSCLC.

Circ_0080425 inhibits cell proliferation and fibrosis in diabetic nephropathy via sponging miR-24-3p and targeting fibroblast growth factor 11.

Diabetic nephropathy (DN) is a severe end-stage kidney disease developed from diabetes mellitus. The involvement of circular RNAs (circRNAs) in modulating DN pathogenesis has been implied, but underlying mechanism is still lacking. In this study, we demonstrated that the expression of circ_0080425 correlated with the DN progression, and exerted positive effect on cell proliferation and fibrosis in mesangial cells. Further assessment suggested that circ_0080425 function as sponge harboring miR-24-3p. Moreover, miR-24-3p negatively correlated with the DN progression, and showed an antagonistic effect to circ_0080425on regulating MCs cell proliferation and fibrosis. Bioinformatics analysis predicted fibroblast growth factor 11 (FGF11) acting as direct downstream target of miR-24-3p. Indeed, the expression of FGF11 was significantly activated by circ_0080425 while suppressed by miR-24-3p. Knockdown of FGF11 resulted in a significant reduced cell proliferation rate and fibrosis. In addition, miR-24-3p inhibitor rescued the suppression of si-circ_0080425 on FGF11, suggesting that circ_0080425 competitive binding to miR-24-3p could release FGF11 from miR-24-3p suppression, which subsequently promoted DN progression.In conclusion, we have reported a novel circ_0080425-miR-24-3p-FGF11 axis, and explored the underlying mechanism in regulating DN pathogenesis.

T2DM inhibition of endothelial miR-342-3p facilitates angiogenic dysfunction via repression of FGF11 signaling.

Understanding the function and molecular relevance of distinct miRNAs in endothelial cells (ECs) paves avenues for possible therapeutic intervention by targeting epigenetic mechanisms in vascular endothelial dysfunction, one of the major complications of type 2 diabetes mellitus (T2DM). MiR-342-3p, an obesity-associated miRNA, has recently been shown to be significantly upregulated in human angiosarcoma compared to benign hemangioma, indicating its potential involvement as a proangiogenic factor. Herein, we show that endothelial miR-342-3p expression was significantly compromised in T2DM organisms and this inhibition powerfully blocked vasculogenesis in vivo by repressing endothelial proliferation and migration. From a mechanistic standpoint, miR-342-3p promoted the transactivation of fibroblast growth factor 11 (FGF11) by directly targeting its 3' untranslated regions (3'UTRs). Functionally, overexpression of exogenous FGF11 successfully rescued miR-342-3p deficiency-impaired endothelial proliferation and migration. Thus, perturbation of miR-342-3p/FGF11 cascade by hyperinsulinemia plays a causative role in the induction of vascular dysfunction in T2DM. Overall, the current study underscore an endothelial facet of miR-342-3p, which may operate as a novel epigenetic integrator linking adipogenic homeostasis and angiogenesis.

FGF11 induced by hypoxia interacts with HIF-1α and enhances its stability.

Fibroblast growth factor 11 (FGF11) is an intracellular FGF. Although induction of FGF11 by hypoxia has been observed in several cell types, the molecular function of FGF11 is not clearly understood yet. Here, we investigated the role of FGF11 under hypoxia. We identified hypoxia-inducible factor-1α (HIF-1α) as an interacting protein of FGF11 using immunoprecipitation and mass spectrometry. FGF11 knockdown decreased HIF-1α protein, while FGF11 overexpression increased it, without affecting HIF-1α mRNA. Protein stability test and ubiquitination assay showed that FGF11 increased HIF-1α stability by acting upstream of proteasomal degradation. Altogether, these results suggest a cross-regulation between HIF-1α and FGF11, through which hypoxia-induced FGF11 reinforces hypoxia responses by enhancing the stability of HIF-1α.