Blockage of store-operated Ca²⁺ entry antagonizes Epstein–Barr virus-promoted angiogenesis by inhibiting Ca²⁺ signaling-regulated VEGF production in nasopharyngeal carcinoma

Abstract

BackgroundEpstein–Barr virus (EBV) actively contributes to the pathological process of nasopharyngeal carcinoma (NPC) by enabling NPC cells to acquire various capacities required for their malignant biological actions. Our earlier works demonstrated that EBV-encoded latent membrane protein 1 (LMP1) enhanced vascular endothelial growth factor (VEGF)-mediated angiogenesis by boosting store-operated Ca2+ entry (SOCE) upon extracellular epidermal growth factor (EGF) stimulation. However, the antagonistic effects of SOCE blockage on EBV-promoted angiogenesis must be appropriately evaluated in vivo, and the global effect of EBV infection on the EGF-elicited cytosolic Ca2+ signaling, which regulates VEGF-mediated angiogenesis remains to be further clarified.Materials and methodsTwo EBV-infected NPC cell lines, CNE2-EBV and HK1-EBV, along with their parental cell lines were employed in the present study. Dynamic cytosolic Ca2+ changes were measured in individual fluorescent Ca2+ indicator-loaded cells. Amounts of VEGF production were determined by enzyme-linked immunosorbent assay (ELISA). Human umbilical vein endothelial cells (HUVECs)-formed tube networks were quantitatively evaluated as an in vitro angiogenesis assay. A mouse model concurrently bearing EBV-positive/negative xenografts was utilized to evaluate the tumor growth and angiogenesis in vivo.ResultsEBV infection reliably promoted transplanted tumor growth while enhancing angiogenesis. Introduction of EBV into EBV-negative NPC cells increased the EGF-stimulated VEGF production while amplifying the EGF-evoked Ca2+ responses. Inhibition of the EBV-boosted Ca2+ signaling using 2-aminoethyl diphenylborinate (2-APB), a specific SOCE inhibitor, effectively antagonized the EBV-promoted VEGF production and endothelial tube formation in vitro. Pharmacological blockage of SOCE exhibited anti-angiogenic effect in the EBV-positive xenografts.ConclusionSOCE can serve as a candidate pharmacological target for treating NPC, as blockage of the Ca2+ signaling via SOCE is a feasible strategy to suppress the EBV-driven malignant profiles in NPC cells.

The Effect and Mechanism of TRPC1, 3, and 6 on the Proliferation, Migration, and Lumen Formation of Retinal Vascular Endothelial Cells Induced by High Glucose

“…TRPC1 is a Ca2+-through pathway found in key metabolic organs and tissues, including hypothalamus, adipose tissue, and skeletal muscle. Deletion of TRPC1 may alter the regulation of cellular energy metabolism [36][37][38]. The TRPC1 promoter has 3 putative NF-κB binding sites.…”

Modulation of Angiogenic Processes by the Human Gammaherpesviruses, Epstein–Barr Virus and Kaposi’s Sarcoma-Associated Herpesvirus

“…Further evidence has demonstrated that EBV-positive NPC cells are more tumorigenic and angiogenic in vivo than EBV-negative NPC cells (Ye et al, 2018). EBV is associated with high levels of VEGF and reduced survival of Hodgkin’s lymphoma patients (Koh et al, 2018).…”

“…In addition to NF-κB, STAT-3, and protein kinase C gamma (PKCγ) are essential for the LMP1-CTAR1-induced augmentation of EGFR activation (Kung and Raab-Traub, 2008). It is possible that through the activation of EGFR in NPC cells, EBV enhances calcium signaling that promotes VEGF expression (Ye et al, 2018). Together, these studies suggest that induction of both FGFR and EGFR contributes to LMP1-mediated angiogenesis.…”

“…The models to study EBV-induced angiogenesis in vivo have not been developed to the same extent as with KSHV. Most of these models consist of the injection of EBV-positive NPC cells or EBV-transformed LCLs into immunocompromised mice (Hong et al, 2005b; Smith et al, 2011; Yang et al, 2015; Ma et al, 2018; Ye et al, 2018). Although these models have not been extensively used for angiogenic studies, they have provided vital knowledge with regards to pro-tumorigenic viral factors.…”

Expression significance and potential mechanism of hypoxia‐inducible factor 1 alpha in patients with myelodysplastic syndromes

“…Currently, researchers are not very knowledgeable about the complex pathogenesis of MDS. However, angiogenesis has been regarded as a vital pathophysiological process in solid tumors for tumor growth, proliferation, and metastasis . In addition, recent studies showed that angiogenesis and angiogenesis factors play a vital role in the onset and development of MDS and AML .…”