scholarly journals Exosomal excretion of miR-3 7 5 promotes glioma progression by activating the CTGF-EGF R  pathway

2020 ◽  
Author(s):  
Xiangdong Xu ◽  
Yang Liu ◽  
Yan Li ◽  
Huajian Chen ◽  
Yuxuan Zhang ◽  
...  
Keyword(s):  
Growth Factor ◽  
Human Peripheral Blood ◽  
Biological Significance ◽  
Xenograft Model ◽  
Growth Factor Receptor ◽  
Glioma Cells ◽  
Tissue Growth ◽  
Migration And Invasion ◽  
Functional Link ◽  
Qrt Pcr

Abstract Background: Exosomes are membrane-bound extracellular vesicles of 40–150 nm produced by many cell types, and playing an important role in the maintenance of cellular homeostasis. Exosome secretion allows for the selective removal of harmful substances from cells. Whether this process also takes place in glioma cells is unknown. Methods: The role of the tumour suppressor miR-375 was explored in human glioma cell lines. Immunoblotting and qRT-PCR experiments demonstrated a functional link between miR-375 and its target, connective tissue growth factor (CTGF), and led to identify the involved molecular pathways. The exosomes secreted by glioma cells were extracted by ultracentrifugation and examined by transmission electron microscopy. The exosomal expression of miR-375 was analyzed by qRT-PCR. The exosome secretion inhibitor, GW4869, was used to study the biological significance of miR-375 release. Moreover, the dynamics of miR-375 release by glioma cells was investigated by using fluorescently labelled exosomes. Finally, exosomal miR-375 release was studied in an orthotopic xenograft model in nude mice. Results: MiR-375 expression was downregulated in gliomas. MiR-375 suppressed glioma proliferation, migration, and invasion by inhibiting the CTGF-epidermal growth factor receptor (EGFR) signalling pathway. MiR-375-containing exosomes were also found in human peripheral blood samples from glioma patients, and their level was correlated with the status of disease progression. Exosomal miR-375 secretion had an impact on the activity of the CTGF-EGFR pathway. Once secreted, exosomal miR-375 was not reuptaken by glioma cells. Conclusions: Exosomal miR-375 secretion allowed for sustained activation of the CTGF-EGFR oncogenic pathway, promoting the proliferation and invasion of glioma cells. These findings enhance our understanding of exosome biology, and may inspire the development of new therapies for glioma.

scholarly journals Selective exosome exclusion of miR-375 by glioma cells promotes glioma progression by activating the CTGF-EGFR pathway

2020 ◽  
Author(s):  
Xiangdong Xu ◽  
Yang Liu ◽  
Yan Li ◽  
Huajian Chen ◽  
Yuxuan Zhang ◽  
...  
Keyword(s):  
Growth Factor ◽  
Human Peripheral Blood ◽  
Biological Significance ◽  
Xenograft Model ◽  
Growth Factor Receptor ◽  
Glioma Cells ◽  
Tissue Growth ◽  
Migration And Invasion ◽  
Functional Link ◽  
Qrt Pcr

Abstract Background: Exosomes are membrane-bound extracellular vesicles of 40–150 nm in size, that are produced by many cell types, and play an important role in the maintenance of cellular homeostasis. Exosome secretion allows for the selective removal of harmful substances from cells. However, it remains unclear whether this process also takes place in glioma cells.Methods: Herein, the role of the tumour-suppressor miR-375 was explored in human glioma cells. Immunoblotting and qRT-PCR experiments demonstrated a functional link between miR-375 and its target, connective tissue growth factor (CTGF), which led to the identification of the underlying molecular pathways. The exosomes secreted by glioma cells were extracted by ultracentrifugation and examined by transmission electron microscopy. Exosomal expression of miR-375 was then analysed by qRT-PCR; while the exosome secretion inhibitor, GW4869, was used to examine the biological significance of miR-375 release. Moreover, the dynamics of miR-375 release by glioma cells was investigated using fluorescently labelled exosomes. Finally, exosomal miR-375 release was examined in an orthotopic xenograft model in nude mice.Results: MiR-375 expression was downregulated in gliomas. MiR-375 suppressed glioma proliferation, migration, and invasion by inhibiting the CTGF-epidermal growth factor receptor (EGFR) signalling pathway. MiR-375-containing exosomes were also identified in human peripheral blood samples from glioma patients, and their level correlated with disease progression status. Exosomal miR-375 secretion impacted the CTGF-EGFR pathway activity. Once secreted, exosomal miR-375 was not taken back up by glioma cells.Conclusions: Exosomal miR-375 secretion allowed for sustained activation of the CTGF-EGFR oncogenic pathway, promoting the proliferation and invasion of glioma cells. These findings enhance our understanding of exosome biology and may inspire development of new glioma therapies.

scholarly journals Selective exosome exclusion of miR-375 by glioma cells promotes glioma progression by activating the CTGF-EGFR pathway

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Xiangdong Xu ◽  
Yang Liu ◽  
Yan Li ◽  
Huajian Chen ◽  
Yuxuan Zhang ◽  
...  
Keyword(s):  
Human Peripheral Blood ◽  
Biological Significance ◽  
Xenograft Model ◽  
Glioma Cells ◽  
Cell Types ◽  
Migration And Invasion ◽  
Functional Link ◽  
Qrt Pcr ◽  
Orthotopic Xenograft Model ◽  
Transmission Electron

Abstract Background Exosomes are membrane-bound extracellular vesicles of 40–150 nm in size, that are produced by many cell types, and play an important role in the maintenance of cellular homeostasis. Exosome secretion allows for the selective removal of harmful substances from cells. However, it remains unclear whether this process also takes place in glioma cells. Methods Herein, the role of the tumour-suppressor miR-375 was explored in human glioma cells. Immunoblotting and qRT-PCR experiments demonstrated a functional link between miR-375 and its target, connectivetissuegrowthfactor (CTGF), which led to the identification of the underlying molecular pathways. The exosomes secreted by glioma cells were extracted by ultracentrifugation and examined by transmission electron microscopy. Exosomal expression of miR-375 was then analysed by qRT-PCR; while the exosome secretion inhibitor, GW4869, was used to examine the biological significance of miR-375 release. Moreover, the dynamics of miR-375 release by glioma cells was investigated using fluorescently labelled exosomes. Finally, exosomal miR-375 release was examined in an orthotopic xenograft model in nude mice. Results MiR-375 expression was downregulated in gliomas. MiR-375 suppressed glioma proliferation, migration, and invasion by inhibiting the CTGF-epidermalgrowthfactorreceptor (EGFR) signalling pathway. MiR-375-containing exosomes were also identified in human peripheral blood samples from glioma patients, and their level correlated with disease progression status. Exosomal miR-375 secretion impacted the CTGF-EGFR pathway activity. Once secreted, exosomal miR-375 was not taken back up by glioma cells. Conclusions Exosomal miR-375 secretion allowed for sustained activation of the CTGF-EGFR oncogenic pathway, promoting the proliferation and invasion of glioma cells. These findings enhance our understanding of exosome biology and may inspire development of new glioma therapies.

Μοριακή μελέτη των γονιδίων του αυξητικού επιδερμικού παράγοντα {epidermal growth factor receptor EGFR} και του C-KIT/CD117 σε καρκινώματα αγνώστου πρωτοπαθούς εστίας {ΚΑΠΕ}

2007 ◽  
Author(s):  
Λευκοθέα Ντόβα
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
Qrt Pcr ◽  
Epidermal Growth

Τα καρκινώματα αγνώστου πρωτοπαθούς εστίας (ΚΑΠΕ) αντιπροσωπεύουν μια ετερογενή ομάδα μεταστατικών όγκων για τους οποίους η πρωτοπαθής εστία δεν μπορεί να διαπιστωθεί τη στιγμή της διάγνωσης. Σε μια προσπάθεια διερεύνησης του γενετικού και μεταφραστικού προφίλ των ΚΑΠΕ, η παρούσα εργασία εστιάστηκε στην ανάλυση μεταλλάξεων και γονιδιακής έκφρασης των γονιδίων EGFR και C-KIT/CD117 χρησιμοποιώντας μοριακές τεχνικές που επιτρέπουν την ανίχνευση γενωμικών και πρωτεϊνικών διαταραχών. Συγκεκριμένα πραγματοποιήθηκε ανάλυση με PCR, SSCP, Sequencing, QRT-PCR και ανοσοιστοχημεία. Το 74% των δειγμάτων ΚΑΠΕ εξέφραζε την EGFR πρωτεΐνη ενώ το C-KIT εμφάνισε έκφραση στο 81%. Δεν ανιχνεύθηκαν ενεργοποιητικές μεταλλάξεις ούτε γονιδιακή ενίσχυση, ενώ συνολικά εκτιμάται απουσία δεικτών ενεργού EGFR και C-KIT σηματοδότησης σε ασθενείς με ΚΑΠΕ. Τα αποτελέσματα συνηγορούν υπέρ της έλλειψης κλινικού οφέλους από στοχευμένη θεραπεία μέσω αναστολέων των ως άνω υποδοχέων στα ΚΑΠΕ.

scholarly journals The MEK/ERK/miR-21 Signaling Is Critical in Osimertinib Resistance in EGFR-Mutant Non-Small Cell Lung Cancer Cells

Cancers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 6005
Author(s):  
Wen-Chien Huang ◽  
Vijesh Kumar Yadav ◽  
Wei-Hong Cheng ◽  
Chun-Hua Wang ◽  
Ming-Shou Hsieh ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Growth Factor ◽  
Tumor Suppressor ◽  
Growth Inhibition ◽  
Xenograft Model ◽  
Growth Factor Receptor ◽  
Mek Inhibitor ◽  
Small Cell ◽  
Erk Signaling ◽  
Small Cell Lung

Background: The third-generation epidermal growth factor receptor (EGFR) inhibitor, Osimertinib, is used to treat non-small cell lung cancer (NSCLC) patients with tyrosine kinase inhibitor (TKI) resistance caused by acquired EGFR T790M mutation. However, patients eventually develop resistance against Osimertinib with mechanisms not yet fully clarified. Activated alternative survival pathways within the tumor cells and cancer-associated fibroblasts (CAFs) have been proposed to contribute to Osimertinib resistance. MET and MEK inhibitors may overcome EGFR-independent resistance. Another acquired resistance mechanism of EGFR-TKI is the up-regulation of the RAS/RAF/MEK/ERK signaling pathway, which is the key to cell survival and proliferation; this may occur downstream of various other signaling pathways. In this report, we reveal the possible regulatory mechanism and inhibitory effect of the MEK inhibitor trametinib applied to MEK/ERK/miR-21 axis and PDCD4 in Osimertinib resistance. We found a possible regulatory role of PDCD4 in ERK signaling. PDCD4 is a new type of tumor suppressor that has multiple functions of inhibiting cell growth, tumor invasion, metastasis, and inducing apoptosis. Previous bioinformatics analysis has confirmed that PDCD4 contains the binding site of miR-21 and acts as a tumor suppressor in the regulation of various processes associated with the development of cancer, including cell proliferation, invasion, metastasis, and neoplastic transformation. Based on the above analysis, we hypothesized that the tumor suppressor PDCD4 is one of the effective inhibitory targets of miR-21-5p. Methods: The expression between EGFR and ERK2 in lung adenocarcinoma was evaluated from the TCGA database. Osimertinib-sensitive and resistant NSCLC cells obtained from patients were used to co-culture with human lung fibroblasts (HLFs) to generate CAF cells (termed CAF_R1 and CAF_S1), and the functional roles of these CAF cells plus the regulatory mechanisms were further explored. Then, MEK inhibitor Trametinib with or without Osimertinib was applied in xenograft model derived from patients to validate the effects on growth inhibition of Osimertinib-resistant NSCLC tumors. Result: ERK2 expression correlated with EGFR expression and higher ERK2 level was associated with worse prognosis of patients and Osimertinib resistance. CAFs derived from Osimertinib-resistant cells secreted more IL-6, IL-8, and hepatocyte growth factor (HGF), expressed stronger CAF markers including α-smooth muscle actin (α-SMA), fibroblast activation protein (FAP) plus platelet-derived growth factor receptor (PDGFR), and enhanced stemness and Osimertinib resistance in NSCLC cells. Meanwhile, increased MEK/ERK/miR-21 expressions were found in both CAFs and NSCLC cells. MEK inhibitor Trametinib significantly abrogated the abovementioned effects by modulating β-catenin, STAT3, and ERK. The xenograft model showed combining Osimertinib and Trametinib resulted in the most prominent growth inhibition of Osimertinib-resistant NSCLC tumors. Conclusions: Our results suggested that MEK/ERK/miR-21 signaling is critical in Osimertinib resistance and CAF transformation of NSCLC cells, and MEK inhibitor Trametinib significantly suppressed Osimertinib-resistant NSCLC tumor growth by abolishing both processes.

scholarly journals miR-7-5p Promotes Hepatic Stellate Cell Activation by Targeting Fibroblast Growth Factor Receptor 4

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Shuxia Tian ◽  
Min Chen ◽  
Bing Wang ◽  
Yonglong Han ◽  
Haonan Shang ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Hepatic Stellate Cell ◽  
Fibroblast Growth Factor Receptor ◽  
Stellate Cell ◽  
Growth Factor Receptor ◽  
Fibroblast Growth ◽  
Qrt Pcr ◽  
Immunoblotting Assay ◽  
Liver Tissues

Aims. Fibroblast growth factor receptor 4 (FGFR4) is a key mediator that protects the liver from chronic injury. MicroRNA-7 (miR-7) is a tumor suppressor and associated with lipid homeostasis in the liver. This study was designed to examine the role of the miR-7-5p/FGFR4 axis in liver fibrogenesis. Methods. TargetScan was employed to predict microRNAs that targeted FGFR4 on the 3′-untranslated region (3′-UTR). miR-7-5p and FGFR4 expression in pathological liver tissues and LX-2 cells was determined using qRT-PCR and an immunoblotting assay. A dual-luciferase assay was conducted to validate the target prediction. A Cell Counting Lit-8 assay was performed to assess the proliferation ability of LX-2 cells. Hydroxyproline content in LX-2 cells was measured using a hydroxyproline assay. The expression of hepatic stellate cell (HSC) activation markers was examined using qRT-PCR and an immunoblotting assay. Results. FGFR4 was a putative target of miR-7-5p. In LX-2 cells, miR-7-5p targeted FGFR4 by binding to 3′-UTR. FGFR4 was downregulated, but miR-7-5p was markedly enhanced in the liver samples as the degree of liver fibrosis rose. miR-7-5p was negatively associated with FGFR4 expression in liver tissues. The miR-7-5p inhibitor blocked the lipopolysaccharide-induced proliferation and activation of LX-2 cells, and FGFR4 overexpression inhibited LX-2 cell proliferation and activation triggered by miR-7-5p. Conclusion. miR-7-5p promotes HSC proliferation and activation by downregulating FGFR4.

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