Abstract
Vasculogenic mimicry (VM) is an enigmatic physiological feature that influences blood supply within glioblastoma (GBM) tumors for their sustained growth. Previous studies identify NFATC3, FOSL1 and HNRNPA2B1 as significant mediators of VEGFR2, a key player in vasculogenesis, and their molecular relationships may be crucial for VM in GBM. The aim of this study was to understand how NFATC3, FOSL1 and HNRNPA2B1 collectively influence VM in GBM. We have investigated the underlying gene regulatory mechanisms for VM in GBM cell lines U251 and U373 in vitro and in vivo. In vitro cell-based assays were performed to explore the role of NFATC3, FOSL1 and HNRNPA2B1 in GBM cell proliferation, VM and migration, in the context of RNA interference (RNAi)-mediated knockdown alongside corresponding controls. Western blotting and qRT-PCR assays were used to examine VEGFR2 expression levels. CO-IP was employed to detect protein-protein interactions, ChIP was used to detect DNA-protein complexes, and RIP was used to detect RNA-protein complexes. Histochemical staining was used to detect VM tube formation in vivo. Focusing on NFATC3, FOSL1 and HNRNPA2B1, we found each was significantly upregulated in GBM and positively correlated with VM-like cellular behaviors in U251 and U373 cell lines. Knockdown of NFATC3, FOSL1 or HNRNPA2B1 each resulted in decreased levels of VEGFR2, a key growth factor gene that drives VM, as well as the inhibition of proliferation, cell migration and extracorporeal VM activity. Chromatin immunoprecipitation (ChIP) studies and luciferase reporter gene assays revealed that NFATC3 binds to the promoter region of VEGFR2 to enhance VEGFR2 gene expression. Notably, FOSL1 interacts with NFATC3 as a co-factor to potentiate the DNA-binding capacity of NFATC3, resulting in enhanced VM-like cellular behaviors. Also, level of NFATC3 protein in cells was enhanced through HNRNPA2B1 binding of NFATC3 mRNA. Furthermore, RNAi-mediated silencing of NFATC3, FOSL1 and HNRNPA2B1 in GBM cells reduced their capacity for tumor formation and VM-like behaviors in vivo. Taken together, our findings identify NFATC3 as an important mediator of GBM tumor growth through its molecular and epistatic interactions with HNRNPA2B1 and FOSL1 to influence VEGFR2 expression and VM-like cellular behaviors.
Overview
- The study investigates the influence of NFATC3, FOSL1, and HNRNPA2B1 on vasculogenic mimicry (VM) in glioblastoma (GBM) tumors for their sustained growth. The aim is to understand how these genes collectively influence VM in GBM. The study uses in vitro and in vivo methods to investigate the underlying gene regulatory mechanisms for VM in GBM cell lines U251 and U373. The study finds that NFATC3, FOSL1, and HNRNPA2B1 are significantly upregulated in GBM and positively correlated with VM-like cellular behaviors in U251 and U373 cell lines. Knockdown of these genes results in decreased levels of VEGFR2, a key growth factor gene that drives VM, as well as the inhibition of proliferation, cell migration, and extracorporeal VM activity. ChIP studies and luciferase reporter gene assays reveal that NFATC3 binds to the promoter region of VEGFR2 to enhance VEGFR2 gene expression. FOSL1 interacts with NFATC3 as a co-factor to potentiate the DNA-binding capacity of NFATC3, resulting in enhanced VM-like cellular behaviors. HNRNPA2B1 enhances the level of NFATC3 protein in cells through binding of NFATC3 mRNA. RNAi-mediated silencing of these genes in GBM cells reduces their capacity for tumor formation and VM-like behaviors in vivo. The study identifies NFATC3 as an important mediator of GBM tumor growth through its molecular and epistatic interactions with HNRNPA2B1 and FOSL1 to influence VEGFR2 expression and VM-like cellular behaviors.
Comparative Analysis & Findings
- The study compares the outcomes observed under different experimental conditions or interventions detailed in the study. The study finds that NFATC3, FOSL1, and HNRNPA2B1 are significantly upregulated in GBM and positively correlated with VM-like cellular behaviors in U251 and U373 cell lines. Knockdown of these genes results in decreased levels of VEGFR2, a key growth factor gene that drives VM, as well as the inhibition of proliferation, cell migration, and extracorporeal VM activity. ChIP studies and luciferase reporter gene assays reveal that NFATC3 binds to the promoter region of VEGFR2 to enhance VEGFR2 gene expression. FOSL1 interacts with NFATC3 as a co-factor to potentiate the DNA-binding capacity of NFATC3, resulting in enhanced VM-like cellular behaviors. HNRNPA2B1 enhances the level of NFATC3 protein in cells through binding of NFATC3 mRNA. RNAi-mediated silencing of these genes in GBM cells reduces their capacity for tumor formation and VM-like behaviors in vivo. The study identifies NFATC3 as an important mediator of GBM tumor growth through its molecular and epistatic interactions with HNRNPA2B1 and FOSL1 to influence VEGFR2 expression and VM-like cellular behaviors.
Implications and Future Directions
- The study's findings have significant implications for the field of research or clinical practice. The study identifies NFATC3 as an important mediator of GBM tumor growth through its molecular and epistatic interactions with HNRNPA2B1 and FOSL1 to influence VEGFR2 expression and VM-like cellular behaviors. The study suggests that targeting NFATC3, FOSL1, and HNRNPA2B1 could be a potential therapeutic strategy for GBM. The study also identifies limitations that need to be addressed in future research, such as the need for further validation of the findings in animal models and clinical trials. The study suggests possible future research directions that could build on the results of the study, explore unresolved questions, or utilize novel approaches, such as investigating the role of NFATC3, FOSL1, and HNRNPA2B1 in other types of cancer or in the context of different treatments. The study highlights the importance of understanding the molecular mechanisms underlying VM in GBM and the potential therapeutic implications of targeting these mechanisms.