Regulation Of VEGF Expression Research Articles

Targeting ONECUT2 inhibits tumor angiogenesis via down-regulating ZKSCAN3/VEGFA

OC-2 plays a vital role in tumor growth, metastasis and angiogenesis, but molecular mechanism how OC-2 regulates angiogenic factors is unclear. We found that OC-2 was highly expressed in HepG2, COLO, MCF-7, SKOV3 cells and rectum carcinoma tissues, and angiogenic factors levels were positively related to OC-2. Then OC-2 KD inhibited the tumor growth, metastasis and angiogenesis process in vitro and vivo. ChIP-Seq showed that 228 target genes of OC-2 were identified and they were associated with tumor growth, metastasis, angiogenesis and signal transduction; OC-2 bound to ZKSCAN3 at promoter region. Luciferase assays showed that ZKSCAN3 was identified as target gene of OC-2 and VEGFA was identified as target gene of ZKSCAN3; OC-2 promoted VEGFA expression via activating ZKSCAN3 transcriptional program. Importantly, OC-2 KD down-regulated VEGFA secretion to suppress tumor angiogenesis of HUVECs. Besides VEGFA, OC-2 was positively correlated with other angiogenic factors HIF-1α, FGF2, EGFL6 and HGF. Meanwhile, ERK1/2 and Smad1 signaling pathways might be related to function of OC-2 driving tumor aggressiveness. We revealed that OC-2 might regulate tumor growth, metastasis, angiogenesis via ERK1/2, Smad1 signaling pathways and regulate VEGFA expression for tumor angiogenesis via activating ZKSCAN3 transcriptional program, indicating that OC-2 was a convincing target to develop novel anti-tumor drugs based on angiogenesis.

MALAT1 regulates network of microRNA-15a/16-VEGFA to promote tumorigenesis and angiogenesis in multiple myeloma.

MALAT1 is one of the most hopeful members implicated in angiogenesis in a variety of non-malignant diseases. In multiple myeloma (MM), MALAT1 is recognized as the most highly expressed long non-coding RNA. However, the functional roles of MALAT1 in angiogenesis and the responsible mechanisms have not yet been explored. Herein, we discovered a novel regulatory network dependent on MALAT1 in relation to MM tumorigenesis and angiogenesis. We observed that MALAT1 was upregulated in MM and significantly associated with poor overall survival. MALAT1 knockdown suppressed MM cell proliferation and promoted apoptosis, while restricting endothelial cells angiogenesis. Moreover, MALAT1 directly targeted microRNA-15a/16, and microRNA-15a/16 suppression partly reverted the effects of MALAT1 deletion on MM cells in vitro as well as tumor growth and angiogenesis in vivo. In addition, further study indicated that MALAT1 functioned as a competing endogenous RNA for microRNA-15a/16 to regulate vascular endothelial growth factor A (VEGFA) expression. Our results suggest that MALAT1 plays an important role in the regulatory axis of microRNA-15a/16-VEGFA to promote tumorigenicity and angiogenesis in MM. Consequently, MALAT1 could serve as a novel promising biomarker and a potential antiangiogenic target against MM.

Mitochondrial UQCC3 controls embryonic and tumor angiogenesis by regulating VEGF expression

Mitochondria play important roles in angiogenesis. However, the mechanisms remain elusive. In this study, we found that mitochondrial ubiquinol-cytochrome c reductase complex assembly factor 3 (UQCC3) is a key regulator of angiogenesis. TALEN-mediated knockout of Uqcc3 in mice caused embryonic lethality at 9.5-10.5days postcoitum, and vessel density was dramatically reduced. Similarly, knockout of uqcc3 in zebrafish induced lethality post-fertilization and impaired vascular development. Knockout of UQCC3 resulted in slower tumor growth and angiogenesis. Mechanistically, UQCC3 was upregulated under hypoxia, promoted reactive oxygen species (ROS) generation, enhanced HIF-1α stability and increased VEGF expression. Finally, higher expression of UQCC3 was associated with poor prognosis in multiple types tumors, implying a role for UQCC3 in tumor progression. In conclusion, our findings highlight the important contribution of UQCC3 to angiogenesis under both physiological and pathological conditions, indicating the potential of UQCC3 as a therapeutic target for cancer.

Folate receptor targeted NIR cleavable liposomal delivery system augment penetration and therapeutic efficacy in breast cancer

BackgroundLiposomes are predominantly used sorts of nanocarriers for active a targeted delivery through surface functionalization using targeting ligand. The folate receptors are overexpressed in various cancers including breast cancer and because of its binding aptitude specifically to folate receptors, folic acid became the attractive ligand. MethodsIn this research, we have developed a folate and Poly-l-Lysine conjugate and coated this conjugate onto the liposomes. The prepared liposomes were characterized using DLS, FTIR, NMR, SEM, TEM, XRD, AFM, stability and drug release studies. Furthermore, in vitro studies were carried out on FR overexpressed breast cancer cell line. ResultsThe FA-LUT-ABC-Lip have diameter of 183 ± 3.17 nm with positive surface charge +33.65 ± 3 mV and the drug release studies confirm the NIR responsive payload cleavage. The coated formulation (in presence of NIR light) effectively reduced the IC50 values and kills breast cancer cells through FR mediated internalization and accelerated drug release. Moreover, LUT Formulation shows anticancer effect due to significant inhibition of cell migration and proliferation by regulating VEGF expression and induced apoptosis through the caspase-3 up-regulation. ConclusionIt is evident from the in vitro studies that the formulation was found to be very effective and can be explored for triggered and targeted delivery of the substances through active targeting. General significanceCombining receptor mediated drug delivery with triggered release aid in more amounts of drug reaching the target site and achieving enhanced therapeutic activity.

LITESPARK-011: belzutifan plus lenvatinib vs cabozantinib in advanced renal cell carcinoma after anti-PD-1/PD-L1 therapy.

The first-in-class, small molecule HIF-2αinhibitor, belzutifan, has demonstrated promising antitumor activity in previously treated patients with clear cell renal cell carcinoma (RCC). HIF-2α also regulates VEGF expression and is involved in resistance to anti-VEGF therapy. This study describes the rationale and design for a randomized, phase III study evaluating efficacy and safety of belzutifan plus the tyrosine kinase inhibitor (TKI) lenvatinib versus the TKI cabozantinib in patients with advanced RCC progressing after anti-PD-1/PD-L1 therapy in the first- or second-line setting or as adjuvant therapy. Considering the unmet need for effective and tolerable treatment of advanced RCC following immune checkpoint inhibitors, belzutifan plus lenvatinib may have a positive benefit/risk profile. Clinical Trial Registration: NCT04586231 (ClinicalTrials.gov).

Targeting regulation of VEGF by BPTF in non-small cell lung cancer and its potential clinical significance

PurposeVEGF facilitates tumor angiogenesis, and bevacizumab targeting VEGF is used in anti-tumor therapy. It is meaningful to clarify the upstream regulatory mechanism of VEGF. BPTF is important in chromosomal remodeling, and promotes the progression of tumors. However, its role in promoting tumor angiogenesis by targeting VEGF has not been fully reported. This study aims to elucidate the expression regulation of VEGF by BPTF and its clinical significance in NSCLC.Methods1. BPTF siRNA and shRNA plasmids were used to reduce the expression of BPTF by transfection in vivo and in vitro. BPTF, VEGF and CD144 expressions were examined by immunofluorescence and Western Blot. 2. The expressions of BPTF, VEGF, CD144 and CD31 were detected in lung adenocarcinoma samples by immunofluorescence, Western blot and immunohistochemical staining. 3. 26 lung adenocarcinoma patients treated by bevacizumab were divided into 2 groups according to the treatment efficacy. BPTF and VEGF expressions were analyzed.Results1. BPTF knockdown inhibited the expression of VEGF and CD144 in vivo and in vitro. 2. Compared with para-cancer tissues, BPTF, VEGF, CD144 and CD31 were highly expressed in lung adenocarcinoma. 3. In 75 lung adenocarcinoma specimens, BPTF and VEGF overexpression was correlated with lymph node metastasis and clinical stage. The 5-year survival rate of patients with BPTF and VEGF low expression was higher, and BPTF expression was positively correlated with VEGF expression. 4. Among 26 patients treated with bevacizumab, the patients with BPTF overexpression are more sensitive to the treatment.ConclusionsBPTF positively regulates VEGF expression and its high expression predicts a better efficacy of bevacizumab treatment in NSCLC.

TBX3 regulates the transcription of VEGFA to promote osteoblasts proliferation and microvascular regeneration.

ObjectiveOsteochondral decellularization can promote local vascular regeneration, but the exact mechanism is unknown. The aim of this study is to study osteogenic microvascular regeneration in single cells.MethodsThe scRNA-seq dataset of human periosteal-derived cells (hPDCs) were analyzed by pySCENIC. To examine the role of TBX3 in osteogenesis and vascularization, cell transfection, qRT-PCR, western blot, and CCK-8 cell proliferation assays were performed.ResultsTCF7L2, TBX3, FLI1, NFKB2, and EZH2 were found to be transcription factors (TFs) most closely associated with corresponding cells. The regulatory network of these TFs was then visualized. Our study knocked down the expression of TBX3 in human osteoblast cell lines. In the TBX3 knockdown group, we observed decreased expression of VEGFA, VEGFB, and VEGFC. Moreover, Western blot analysis showed that downregulating TBX3 resulted in a reduction of VEGFA expression. And TBX3 stimulated osteoblast proliferation in CCK-8 assays.ConclusionTBX3 regulates VEGFA expression and promotes osteoblast proliferation in skeletal microvasculature formation. The findings provide a theoretical basis for investigating the role of TBX3 in promoting local vascular regeneration.

Nuclear microRNA-466c regulates Vegfa expression in response to hypoxia.

MicroRNAs are well characterized in their role in silencing gene expression by targeting 3´-UTR of mRNAs in cytoplasm. However, recent studies have shown that miRNAs have a role in the regulation of genes in the nucleus, where they are abundantly located. We show here that in mouse endothelial cell line (C166), nuclear microRNA miR-466c participates in the regulation of vascular endothelial growth factor a (Vegfa) gene expression in hypoxia. Upregulation of Vegfa expression in response to hypoxia was significantly compromised after removal of miR-466c with CRISPR-Cas9 genomic deletion. We identified a promoter-associated long non-coding RNA on mouse Vegfa promoter and show that miR-466c directly binds to this transcript to modulate Vegfa expression. Collectively, these observations suggest that miR-466c regulates Vegfa gene transcription in the nucleus by targeting the promoter, and expands on our understanding of the role of miRNAs well beyond their canonical role.

Bmal1 Downregulation Worsens Critical Limb Ischemia by Promoting Inflammation and Impairing Angiogenesis.

Critical limb ischemia (CLI) is the most advanced clinical stage of peripheral vascular disease with high mobility and mortality. CLI patients suffer from lower extremity rest pain, ulceration, and gangrene caused by insufficient blood and oxygen supply. Seeking for effective biomarkers and therapeutic targets is of great significance for improving the life quality of CLI patients. The circadian clock has been reported to be involved in the progression of kinds of cardiovascular diseases. Whether and how circadian genes play a role in CLI remains unknown. In this study, by collecting femoral artery and muscle specimens of CLI patients who underwent amputation, we confirmed that the circadian gene Bmal1 is downregulated in the CLI femoral artery and ischemic distal lower limb muscle. Furthermore, we verified that Bmal1 affects CLI by regulating lipid metabolism, inflammation, and angiogenesis. A hindlimb ischemia model performed in wild-type and Bmal1−/− mice confirmed that Bmal1 disruption would lead to impaired angiogenesis. In vitro experiments indicated that the decreased expression of Bmal1 would increase ox-LDL uptake and impair endothelial cell functions, including proliferation, migration, and tube formation. As for mechanisms, Bmal1 represses inflammation by inhibiting lipid uptake and by activating IL-10 transcription and promotes angiogenesis by transcriptionally regulating VEGF expression. In conclusion, we provide evidence that the circadian gene Bmal1 plays an important role in CLI by inhibiting inflammation and promoting angiogenesis. Thus, Bmal1 may be an effective biomarker and a potential therapeutic target in CLI.

Catechin Metabolites along with Curcumin Inhibit Proliferation and Induce Apoptosis in Cervical Cancer Cells by Regulating VEGF Expression In-Vitro

Cervical cancer is the fourth most common cancer and the second cause of cancer-related death among women. Over the past two decades, green tea catechins and curcumin have received much attention for their role in preventing carcinogenesis. In this study, we evaluated the effects of the catechin metabolites and curcumin on cervical cancer cell proliferation and apoptosis. For this aim, the Ca Ski cell line was treated with different doses of catechin metabolites and curcumin. MTT assay and Flow cytometry were employed to investigate the cytotoxic effects of catechin metabolites and curcumin on the Ca Ski cell line. Real-time PCR and western blot were performed to evaluate the VEGF expression. Also, Real-Time PCR was performed to determine the expression level of microRNAs. Results showed that catechin metabolites along with curcumin reduce the VEGF expression. Further, miR-210 and miR-21 as oncogenic microRNAs were down-regulated, while it was reverse for miR-126 as a tumor-suppressor microRNA. Besides, MTT and Flow cytometry results showed that after using catechin metabolites with curcumin, cell survival was reduced by inducing apoptosis. In conclusion, catechin metabolites produced by intestinal microbiota besides the curcumin could serve as a promising therapeutic approach for women with cervical cancer.

Knockdown of Malat1 alleviates high-glucose-induced angiogenesis through regulating miR-205-5p/VEGF-A axis

Diabetic retinopathy (DR), characterized by intraretinal vessel formation, is a major complication in diabetes. Neovascularization is an important characteristic of DR, but its formation mechanism remains unclear. In this research, Malat1, miR-205-5p, and VEGF-A levels in high glucose (HG) treat-human retinal microvascular endothelial cells (hRMECs) was detected with qRT-PCR. CCK-8 assay, transwell assay, and tube formation assay was applied to access hRMEC viability, migration, and angiogenesis. Expression level of endothelial-mesenchymal transition (EndMT) markers (VE-cadherin, FSP1, and α-SMA) was detected by western blotting assay. Interaction among Malat1, miR-205-5p, and VEGF-A was confirmed by dual-luciferase reporter assay. Furthermore, in vivo DR mouse model was induced, and the effect of Malat1 on DR and EndMT markers was confirmed through hematoxylin-eosin (HE) staining and western blotting. As a result, Malat1 and VEGF-A was upregulated while miR-205-5p was suppressed under HG conditions. Malat1 could sponge miR-205-5p to regulate VEGF-A expression. Malat1 knockdown inhibited hRMEC proliferation, migration, and tube formation by targeting miR-205-5p under HG conditions. Furthermore, inhibition of Malat1 prevented the HG-induced EndMT process. In summary, Malat1 knockdown diminished hRMEC dysfunctions by regulating miR-205-5p/VEGF-A, providing a useful insight for exploring new therapeutic target for DR.

LINC00941 Promotes Progression of Non-Small Cell Lung Cancer by Sponging miR-877-3p to Regulate VEGFA Expression

Long noncoding RNAs (lncRNAs) play critical roles in carcinoma occurrence and metastasis. LINC00941 has been found to mediate the development of gastric cancer, and LINC00941 was negatively associated with the longer overall survival of lung adenocarcinoma patients. Herein, our aim was to investigate the effects and mechanisms of LINC00941 in NSCLC progression. Microarray was used to identify the change lncRNAs in NSCLC, LINC00941 was found to increase in tumor tissues and patients’ plasma. Knockdown of LINC00941 didn’t modulate the proliferation of NSCLC cells, but inhibition of LINC00941 in NSCLC cells suppressed the angiogenesis ability of human umbilical vein endothelial cells (HUVECs). Moreover, LINC00941 promoted tumorigenesis in vivo, while si-LINC00941 inhibited tumor development of NSCLC. VEGFA was should to be significantly modulated by LINC00941 in NSCLC cells, then luciferase assay proved that LINC00941 regulated VEGFA expression via interacting with miR-877-3p. Followed functional experiments indicated that overexpression of LINC00941 accelerated angiogenesis and NSCLC tumor progression via miR-877-3p/VEGFA axis both in vitro and in vivo. In conclusion, our results clarified the LINC00941 function for the first time, and LINC00941 promoted the progression of NSCLC, which was mediated by miR-877-3p/VEGFA axis. This study might provide new understanding and targets for NSCLC diagnosis and treatment.

Activation of LncRNA FOXD2-AS1 by H3K27 acetylation regulates VEGF-A expression by sponging miR-205-5p in recurrent pterygium.

LncRNA FOXD2‐AS1 is abnormally expressed in many diseases. However, the molecular mechanisms whereby FOXD2‐AS1 is involved in recurrent pterygium remain unknown. Here, qRT‐PCR was performed to quantify FOXD2‐AS1 expression, while CCK‐8, flow cytometer and neoplasm xenograft assays were used to investigate its function. Dual‐luciferase reporter, RIP and RNA pull‐down assays were conducted to address the relationship between FOXD2‐AS1, miR‐205‐5p and VEGF‐A, while ChIP assays were used to detect H3K27 acetylation at the FOXD2‐AS1 promoter. FOXD2‐AS1 expression was up‐regulated in recurrent pterygium tissues. Moreover, a high FOXD2‐AS1 expression was associated with advanced stages, increased microvessel density and shorter recurrent‐free survival. In addition, ROC analysis showed that FOXD2‐AS1 is a valid predictor of recurrent pterygium. Furthermore, we show that FOXD2‐AS1 induced proliferation and inhibited apoptosis in a cell line derived from recurrent pterygia (HPF‐R) at least partially through the regulation of the miR‐205‐VEGF pathway. In addition, the up‐regulation of FOXD2‐AS1 was attributed to the H3K27 acetylation at the promoter region. In conclusion, FOXD2‐AS1 is activated via its H3K27 acetylation and regulates VEGF‐A expression by sponging miR‐205‐5p in recurrent pterygium. Our results may provide a basis for the development of new therapeutic targets and biomarkers for recurrent pterygium.

MicroRNA-15b Targets VEGF and Inhibits Angiogenesis in Proliferative Diabetic Retinopathy.

Vascular endothelial growth factor (VEGF)-induced angiogenesis is a critical compensatory response to microvascular rarefaction in the diabetic retina that contributes to proliferative diabetic retinopathy (PDR). In this study, we sought to determine the role of specific micro ribonucleic acids (RNAs) (miRs) associated with VEGF in patients with PDR pathology. RNA sequencing was employed to detect differentially circulating miR associated with VEGF in patients with diabetes mellitus (DM), nonproliferative diabetic retinopathy (NPDR) and PDR. Quantitative real-time polymerase chain reaction was performed to measure the concentration of miR-15b in the serum of patients with DM (n = 115), NPDR (n = 47), or PDR (n = 76). The effects of miR-15b on DR and regulation of VEGF and endothelial cell function were also characterized. We demonstrated that circulating miR-15b was directly associated with VEGF compared with other miRs in patients with PDR. We found a significant inverse relationship between low levels of miR-15b and high levels of VEGF in patients with PDR when compared with the DM or NPDR groups. We found that miR-15b regulates the expression of VEGF by targeting the 3'-untranslated regions to inhibit its transcription. Similarly, overexpression of miR-15b suppressed vascular abnormalities in vivo in diabetic GK rats, inhibiting endothelial tube formation and VEGF expression. Circulating miR-15b is associated with PDR and may be targeted to regulate VEGF expression and angiogenesis.

LINC00173.v1 promotes angiogenesis and progression of lung squamous cell carcinoma by sponging miR-511-5p to regulate VEGFA expression

BackgroundAnti-angiogenic therapy represents a promising strategy for non-small-cell lung cancer (NSCLC) but its application in lung squamous cell carcinoma (SQC) is limited due to the high-risk adverse effects. Accumulating evidence indicates that long noncoding RNAs (lncRNAs) mediate in tumor progression by participating in the regulation of VEGF in NSCLC, which might guide the development of new antiangiogenic strategies.MethodsDifferential lncRNA expression in SQC was analyzed in AE-meta and TCGA datasets, and further confirmed in lung cancer tissues and adjacent normal tissues with RT-qPCR and in-situ hybridization. Statistical analysis was performed to evaluate the clinical correlation between LINC00173.v1 expression and survival characteristics. A tube formation assay, chick embryo chorioallantoic membrane assay and animal experiments were conducted to detect the effect of LINC00173.v1 on the proliferation and migration of vascular endothelial cells and tumorigenesis of SQC in vivo. Bioinformatics analysis, RNA immunoprecipitation and luciferase reporter assays were performed to elucidate the downstream target of LINC00173.v1. The therapeutic efficacy of antisense oligonucleotide (ASO) against LINC00173.v1 was further investigated in vivo. Chromatin immunoprecipitation and high throughput data processing and visualization were performed to identify the cause of LINC00173.v1 overexpression in SQC.ResultsLINC00173.v1 was specifically upregulated in SQC tissues, which predicted poorer overall and progression-free survival in SQC patients. Overexpression of LINC00173.v1 promoted, while silencing LINC00173.v1 inhibited the proliferation and migration of vascular endothelial cells and the tumorigenesis of SQC cells in vitro and in vivo. Our results further revealed that LINC00173.v1 promoted the proliferation and migration of vascular endothelial cells and the tumorigenesis of SQC cells by upregulating VEGFA expression by sponging miR-511-5p. Importantly, inhibition of LINC00173.v1 via the ASO strategy reduced the tumor growth of SQC cells, and enhanced the therapeutic sensitivity of SQC cells to cisplatin in vivo. Moreover, our results showed that squamous cell carcinoma-specific factor ΔNp63α contributed to LINC00173.v1 overexpression in SQC.ConclusionOur findings clarify the underlying mechanism by which LINC00173.v1 promotes the proliferation and migration of vascular endothelial cells and the tumorigenesis of SQC, demonstrating that LINC00173.v1-targeted drug in combination with cisplatin may serve as a rational regimen against SQC.

MiR-125 inhibited cervical cancer progression by regulating VEGF and PI3K/AKT signaling pathway

BackgroundMiR-125 has been shown to be involved in a variety of cancers, including cervical cancer (CC). Here, our goal was to explore miR-125 functional role and molecular mechanism in cervical cancer development and progression.MethodsqRT-PCR was employ to detect miR-125 and VEGF mRNA expression. Western blot was applied for testing protein levels (VEGF, E-cadherin, N-cadherin, vimentin, AKT, p-AKT, PI3K, and p-PI3K). MTT and transwell assays were used for detecting cervical cancer cell progression, including cell viability, migration, and invasion.ResultsWe observed that miR-125 was downregulated, whereas VEGF was upregulated in cervical cancer tissues and cell lines (CaSki and SiHa). MiR-125 inhibited the proliferation, invasion, and migration by targeting VEGF in cervical cancer. Moreover, miR-125 negatively regulated VEGF expression in cervical cancer tissues. Finally, we demonstrated that miR-520d-5p inhibited the activation of PI3K/AKT signaling pathway.ConclusionIn conclusion, the findings demonstrated that miR-125 inhibited cervical cancer progression and development by suppression VEGF and PI3K/AKT signaling pathway.

LncRNA MEG3 promotes recovery of knee osteoarthritis in rats through regulating VEGF expression.

LncRNA MEG3 promotes recovery of knee osteoarthritis in rats through regulating VEGF expression.

Retracted Article: Panax notoginseng saponins regulate VEGF to suppress esophageal squamous cell carcinoma progression via DVL3-mediated Wnt/β-catenin signaling.

Panax notoginseng saponins (PNS) have recently attracted increasing attention for their anti-tumor activities. The aim of this study was to explore the functional role and underlying mechanisms of PNS on the progression of esophageal squamous cell carcinoma (ESCC). The mRNA levels of vascular endothelial growth factor (VEGF), β-catenin and dishevelled-3 (DVL3) were assessed using qRT-PCR. Western blot was performed to detect the expression levels of VEGF, β-catenin and DVL3. Cell viability and proliferation abilities were determined using MTT assay. Transwell assays were used to evaluate cell migration and invasion capacities. Our data revealed that PNS hampered the viability of ESCC cells. VEGF silencing weakened proliferation, migration and invasion in ESCC cells. Mechanistically, PNS time-dependently reduced VEGF expression and PNS hampered ESCC cell proliferation, migration and invasion through VEGF. Moreover, β-catenin and DVL3 were upregulated in ESCC tissues and cells and positively correlated with VEGF level in ESCC tissues. VEGF regulated DVL3 via the Wnt/β-catenin signaling pathway in ESCC cells. Furthermore, PNS repressed DVL3 expression through VEGF in ESCC cells. Our study suggested that PNS suppressed ESCC progression at least partly through repressing VEGF via the DVL3-mediated Wnt/β-catenin signaling pathway, indicating that PNS might be promising anti-tumor agents for ESCC treatment.

Circular RNA circ-RanGAP1 regulates VEGFA expression by targeting miR-877-3p to facilitate gastric cancer invasion and metastasis.

The biological functions of circular RNAs (circRNAs) in gastric cancer (GC) remain largely unexplored. Here, we identified that circ-RanGAP1 was significantly upregulated in both GC tissues and exosomes from the plasma of GC patients. High circ-RanGAP1 expression was closely associated with an advanced TNM stage, lymph node metastases, and worse survival. Inhibition of circ-RanGAP1 decreased GC cell invasion and migration in vitro. Overexpression of circ-RanGAP1 had the opposite effect. Additionally, circ-RanGAP1 silencing remarkably suppressed tumor growth and metastasis of GC in vivo. Mechanistically, circ-RanGAP1 sponged miR-877-3p to upregulate VEGFA expression. Overexpression of miR-877-3p reversed the biological functions mediated by circ-RanGAP1 in GC cells. Interestingly, we demonstrated that circ-RanGAP1 was upregulated in plasma exosomes from preoperative GC patients. More importantly, the plasma exosomes derived from these patients enhanced the migration and invasion potential of GC cells. Overall, the circ-RanGAP1-mediated miR-877-3p/VEGFA axis promotes GC progression. Our findings suggest that circ-RanGAP1 might act as a potential prognostic biomarker and therapeutic target for GC treatment.

Hypoxia and EGF Stimulation Regulate VEGF Expression in Human Glioblastoma Multiforme (GBM) Cells by Differential Regulation of the PI3K/Rho-GTPase and MAPK Pathways.

Glioblastoma multiforme (GBM) is one of the most common and deadly cancers of the central nervous system (CNS). It is characterized by the presence of hypoxic regions, especially in the core, leading to an increase in vascularity. This increased vascularization is driven by the expression of the major angiogenic inducer VEGF and the indirect angiogenic inducer Epidermal growth factor (EGF), which stimulates VEGF expression. In this study, we examine the regulation of VEGF by both hypoxia and the EGF signaling pathway. We also examine the involvement of pathways downstream from EGF signaling, including the mitogen-activated protein kinase/extracellular regulated kinase (MAPK/ERK) pathway and the Phosphatidylinositol-3-kinase/RhoA/C (PI3K/RhoA/C) pathway in this regulation. Our results show that VEGF expression and secretion levels increase following either hypoxia or EGF stimulation, with the two stimuli signaling in parallel. We also observed an increase in ERK and protein kinase B (Akt) phosphorylation, in response to EGF stimulation, with kinetics that correlated with the kinetics of the effect on VEGF. Using pharmacological inhibitors against ERK and PI3K and small interfering RNAs (siRNAs) against RhoA and RhoC, we found that both the ERK and the PI3K/RhoA/C pathways have to cooperate in order to lead to an increase in VEGF expression, downstream from EGF. In response to hypoxia, however, only ERK was involved in the regulation of VEGF. Hypoxia also led to a surprising decrease in the activation of PI3K and RhoA/C. Finally, the decrease in the activation of these Rho-GTPases was found to be mediated through a hypoxia-driven overexpression of the Rho-GTPase GTPase activating protein (GAP), StarD13. Therefore, while under normoxic conditions, EGF stimulates the activation of both the PI3K and the MAPK pathways and the induction of VEGF, in glioblastoma cells, hypoxic conditions lead to the suppression of the PI3K/RhoA/C pathway and an exclusive switch to the MAPK pathway.