Interleukin-6 (IL-6) triggers the malignancy of hemangioma cells via activation of HIF-1α/VEGFA signals

The influence of redox modulation on hypoxic endothelial cell metabolic and proteomic profiles through a small thiol-based compound tuning glutathione and thioredoxin systems

Reduction in oxygen levels is a key feature in the physiology of the bone marrow (BM) niche where hematopoiesis occurs. The BM niche is a highly vascularized tissue and endothelial cells (ECs) support and regulate blood cell formation from hematopoietic stem cells (HSCs). While in vivo studies are limited, ECs when cultured in vitro at low O2 (<5%), fail to support functional HSC maintenance due to oxidative environment. Therefore, changes in EC redox status induced by antioxidant molecules may lead to alterations in the cellular response to hypoxia likely favoring HSC self-renewal. To evaluate the impact of redox regulation, HUVEC, exposed for 1, 6, and 24 h to 3% O2 were treated with N-(N-acetyl-l-cysteinyl)-S-acetylcysteamine (I-152). Metabolomic analyses revealed that I-152 increased glutathione levels and influenced the metabolic profiles interconnected with the glutathione system and the redox couples NAD(P)+/NAD(P)H. mRNA analysis showed a lowered gene expression of HIF-1α and VEGF following I-152 treatment whereas TRX1 and 2 were stimulated. Accordingly, the proteomic study revealed the redox-dependent upregulation of thioredoxin and peroxiredoxins that, together with the glutathione system, are the main regulators of intracellular ROS. Indeed, a time-dependent ROS production under hypoxia and a quenching effect of the molecule were evidenced. At the secretome level, the molecule downregulated IL-6, MCP-1, and PDGF-bb. These results suggest that redox modulation by I-152 reduces oxidative stress and ROS level in hypoxic ECs and may be a strategy to fine-tune the environment of an in vitro BM niche able to support functional HSC maintenance.

Mechanism of the HIF-1α/VEGF/VEGFR-2 pathway in the proliferation and apoptosis of human haemangioma endothelial cells

Haemangiomas (HAs) are prevalent vascular endothelial cell tumours. With respect to the possible involvement of HIF-1α in HAs, we have explored its role in haemangioma endothelial cell (HemEC) proliferation and apoptosis. shRNA HIF-1α and pcDNA3.1 HIF-α were manipulated into HemECs. HIF-α, VEGF, and VEGFR-2 mRNA and protein levels were assessed by qRT-PCR and Western blotting. Cell proliferation and viability, cell cycle and apoptosis, migration and invasion, and ability to form tubular structures were assessed by colony formation assay, CCK-8, flow cytometry, Transwell assay, and tube formation assay. Cell cycle-related protein levels, and VEGF and VEGFR-2 protein interaction were detected by Western blot and immunoprecipitation assays. An Haemangioma nude mouse model was established by subcutaneous injection of HemECs. Ki67 expression was determined by immunohistochemical staining. HIF-1α silencing suppressed HemEC neoplastic behaviour and promoted apoptosis. HIF-1α facilitated VEGF/VEGFR-2 expression and the VEGF had interacted with VEGFR-2 at protein - protein level. HIF-1α silencing arrested HemECs at G0/G1 phase, diminished Cyclin D1 protein level, and elevated p53 protein level. VEGF overexpression partially abrogated the effects of HIF-1α knockdown on inhibiting HemEC malignant behaviours. Inhibiting HIF-1α in nude mice with HAs repressed tumour growth and Ki67-positive cells. Briefly, HIF-1α regulated HemEC cell cycle through VEGF/VEGFR-2, thus promoting cell proliferation and inhibiting apoptosis.

Inhibiting Interleukin-6/Signal Transducers and Activators of Transduction-3/Hypoxia-Inducible Factor-1α Signaling Pathway Suppressed the Growth of Infantile Hemangioma

OBJECTIVE

 This study aims to evaluate the expression of interleukin 6 (IL-6) in patients with infantile hemangioma (IH) and investigate the role of the IL-6/signal transducers and activators of transduction-3 (STAT3)/hypoxia-inducible factor-1α (HIF-1α) pathways in the progression of IH.

METHODS

 Serum samples were obtained from the patients with IH and normal infants to measure IL-6 expression. Hemangioma-derived stem cells (HemSCs) were transfected with small interfering RNA (siRNA) targeting IL-6, HIF-1α, or STAT3. Then, cell viability and wound healing assays were conducted. After that, the HemSC tumor mouse model was established. The in vivo anticancer effect of the IL-6 inhibitor was investigated.

RESULTS

 The patients with IH had much higher IL-6 levels compared with the healthy controls (p = 0.005). HemSCs transfected with IL-6 siRNA had significantly lower viability and migration rates than normal HemSCs. HemSCs transfected with STAT3 siRNA or HIF-1α siRNA had similar tendencies. On tumor-bearing mice, the IL-6 inhibitor treatment significantly delayed tumor growth. Compared with the control group, caspase-3 was significantly increased in the IL-6 inhibitor group (p < 0.05), whereas Ki-67 was decreased in the IL-6 inhibitor group (p < 0.05). In the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, the IL-6 inhibitor group had much higher apoptosis rates than the controls (p < 0.05).

CONCLUSION

 Our findings indicate that inhibiting the IL-6/STAT3/HIF-1α signaling pathways could suppress IH growth.

Overcoming cancer-associated fibroblast-induced immunosuppression by anti-interleukin-6 receptor antibody

Cancer-associated fibroblasts (CAFs) are a critical component of the tumor microenvironment and play a central role in tumor progression. Previously, we reported that CAFs might induce tumor immunosuppression via interleukin-6 (IL-6) and promote tumor progression by blocking local IL-6 in the tumor microenvironment with neutralizing antibody. Here, we explore whether an anti-IL-6 receptor antibody could be used as systemic therapy to treat cancer, and further investigate the mechanisms by which IL-6 induces tumor immunosuppression. In clinical samples, IL-6 expression was significantly correlated with α-smooth muscle actin expression, and high IL-6 cases showed tumor immunosuppression. Multivariate analysis showed that IL-6 expression was an independent prognostic factor. In vitro, IL-6 contributed to cell proliferation and differentiation into CAFs. Moreover, IL-6 increased hypoxia-inducible factor 1α (HIF1α) expression and induced tumor immunosuppression by enhancing glucose uptake by cancer cells and competing for glucose with immune cells. MR16-1, a rodent analog of anti-IL-6 receptor antibody, overcame CAF-induced immunosuppression and suppressed tumor progression in immunocompetent murine cancer models by regulating HIF1α activation in vivo. The anti-IL-6 receptor antibody could be systemically employed to overcome tumor immunosuppression and improve patient survival with various cancers. Furthermore, the tumor immunosuppression was suggested to be induced by IL-6 via HIF1α activation.

Monocyte Metabolism and Function in Patients Undergoing Cardiac Surgery

Objective

Cardiopulmonary bypass (CPB) can lead to systemic inflammation, which is associated with higher morbidity. Therefore, we investigated the metabolism of isolated blood monocytes before and after CPB compared to healthy controls.

Methods

In this prospective, monocentric, observational study, we included 30 patients undergoing CPB and 20 controls. We isolated monocytes from heparinized blood and investigated their metabolism by using Seahorse technology before (t0), 4 h (t4), and 24 h (t24) after the start of the CPB. We also examined programmed cell death 1 ligand (PD-L1), PD-L2, V-domain Ig suppressor of T cell activation (VISTA), and human leukocyte antigen-DR isotype (HLA-DR) using fluorescence-activated cell sorting analysis. Additionally, we investigated plasma cytokine levels in patients without and after ex vivo stimulation.

Results

CPB-induced inflammatory responses are shown by significantly elevated plasma interleukin-6 levels in the CPB group compared to baseline and controls [t0: 0 ng/ml (95%CI 0-0 ng/ml); t4: 0.16 ng/ml (95%CI 0.1-0.197 ng/ml), p < 0.0001; t24: 0.11 ng/ml (95% CI 0.1-0.16 ng/ml), p < 0.0001, and controls: 0 ng/ml (95% CI 0-0 ng/ml)]. The cytokine release in the ex vivo stimulation is reduced for lipopolysaccharide stimulation at t4 [t0: 35.68 ng/ml (95% CI 22.17-46.57 ng/ml) vs. t4: 15.02 (95% CI 10.25-24.78 ng/ml), p < 0.0001]. Intracellular metabolism of monocytes after CPB showed a protracted shift to aerobic glycolysis [t0: 179.2 pmol/min (95% CI 138.0-205.1 pmol/min) vs. t24: 250.1 pmol/min (95% CI 94.8-300.2 pmol/min), p < 0.0001]. Additionally, we observed an altered metabolism in monocytes in patients undergoing cardiac surgery compared to controls even before any surgical procedure [t0: 179.2 pmol/min (95% CI 138.0-205.1) vs. controls 97.4 (95% CI 59.13-144.6 pmol/min), p = 0.0031].

Conclusion

After CPB, patients' monocytes show a shift in metabolism from oxidative phosphorylation to aerobic glycolysis, which is associated with energy-demanding and proinflammatory processes. This is the first study to show changes in monocyte immunometabolism in cardiac surgery. Monocytes of patients undergoing cardiac surgery were leaning toward aerobic glycolysis even before any surgical procedure was conducted. Leaving the question of the pathophysiological mechanisms for future studies to be investigated and paving the way for potential therapy approaches preventing inflammatory effects of CPB.

Hemangioma Endothelial Cells and Hemangioma Stem Cells in Infantile Hemangioma

BACKGROUND

Hemangioma is one of the most common benign tumors in infants and young children. The 2 most important cells in the course of infantile hemangioma (IH) are hemangioma stem cells (HemSCs) and hemangioma endothelial cells (HemECs). Infantile hemangioma is characterized by massive proliferation of HemECs, but current studies indicate that HemSCs play an important role in pathogenesis of IH.

OBJECTIVE

This review aimed to identify molecules that influence HemSC differentiation and HemEC proliferation and apoptosis to help clarify the pathogenesis of IH and provide novel drug targets for the treatment of IH.

METHODS

Relevant basic science studies related to IH were identified by searching Google Scholar, Embase, PubMed, MEDLINE, and peer-reviewed journal articles.

RESULT

Hemangioma stem cells can differentiate into HemECs, pericytes, and adipocytes. In the proliferating phase of IH, HemSCs mainly differentiate into HemECs and pericytes to promote angiogenesis. In the regressive phase, they mainly differentiate into adipocytes. Therefore, increasing the proportion of HemSCs differentiating into adipocytes, inhibiting the proliferation of HemECs, and promoting the apoptosis of HemECs can facilitate the regression of IH.

Exosomal linc-ROR mediates crosstalk between cancer cells and adipocytes to promote tumor growth in pancreatic cancer

Exosomes are emerging as important mediators of the crosstalk between tumor cells and stromal cells in the microenvironment. However, the underlying molecular mechanism of pancreatic cancer (PC)-derived exosomes in the progression of the tumor microenvironment (TME) and crosstalk with adipocytes has not been elucidated. Exosomes isolated from PC cell culture supernatant through ultracentrifugation were rich in long intergenic non-coding ROR (linc-ROR). After constructing PC cell lines with stable linc-ROR knockdown or overexpression via the transfection of short hairpin RNA (shRNA) and pLent-U6-GFP-Puro, direct and indirect coculture systems were established to simulate the interaction between adipocytes and PC cells. Next, the effects of conditioned medium collected from dedifferentiated adipocytes on PC cell proliferation, motility, metastasis, and epithelial-mesenchymal transition (EMT) were evaluated by western blot analysis, colony forming, real-time cell analysis (RTCA), 5-ethynyl-2'-deoxyuridine (EdU), immunofluorescence (IF), Transwell, and wound-healing assays in vitro. Xenograft models were employed to identify whether conditioned medium loaded with interleukin-1β (IL-1β) promoted PC cell growth in vivo. Our results demonstrate that linc-ROR delivery via exosomes represents a brand-new perspective of dedifferentiating adipocytes in the TME of PC, which further induce PC cell EMT via the hypoxia inducible factor 1α (HIF1α)-ZEB1 axis. Moreover, exosomal linc-ROR may become a novel diagnostic marker for PC patients.

Qinzhuliangxue mixture alleviates psoriasis-like skin lesions via inhibiting the IL6/STAT3 axis

ETHNOPHARMACOLOGICAL RELEVANCE

Psoriasis is a chronic inflammatory skin disease mediated by immunity. Our pre-clinical studies have proved that QZLX mixture can improve patients' clinical symptoms with psoriasis without noticeable adverse reactions. In a psoriasis-like mouse model induced by imiquimod, QZLX mixture has been shown to alleviate epidermal inflammation and inhibit the hyperproliferation of keratinocytes. However, its related molecular mechanism remains to be elucidated.

AIM OF THE STUDY

To assess the mechanism of QZLX mixture against psoriasis.

MATERIALS AND METHODS

This study combines network pharmacology and experiments to study the mechanism of QZLX against psoriasis. First, construct the active compound-target network and PPI network. Secondly, determine possible drug targets through Molecular docking and KEGG. Thirdly, high-performance liquid chromatography (HPLC) was used for the quality control of QZLX. Finally, use a mouse model of psoriasis to further confirm the role of QZLX.

RESULTS

(1) Network pharmacology analysis shows that QZLX alleviates psoriasis's epidermal inflammation, and neovascularization may be achieved by inhibiting the IL6/STAT3 signaling pathway. (2) QZLX improves the pathological characteristics of IMQ-induced skin damage in psoriasis-like mice. (3) QZLX inhibits the IL6/STAT3 signaling pathway and reduces the expression of IL-17, IL-23, and TNF-α related to inflammation in peripheral blood, as well as the expression of S100A7 in the lesion area. QZLX is better than MTX in inhibiting neovascularization by down-regulating the expression of HIF-1 and CD31 in the lesion area. Finally, inhibition of Ki67 alleviates the excessive proliferation of keratinocytes.

CONCLUSION

In sum, this study clarifies the mechanism of QZLX against psoriasis and provides evidence to support its clinical use.

Alginic acid inhibits non-small cell lung cancer-induced angiogenesis via activating miR-506 expression

Angiogenesis is a key event in non-small cell lung cancer progression. Alginic acid (AA), a kind of naturally occurring polyuronic acid, is generally enriched in edible brown algae. Recent studies have uncovered its anti-anaphylactic and anti-inflammatory properties. However, the effects of AA on human malignancies remain unknown. Herein, efficient inhibition of AA on NSCLC-induced angiogenesis was observed with tube formation and xenograft models. Subsequent results indicated that AA downregulated the expression of VEGF-A, a key angiogenesis-inducing cytokine. In addition, AA downregulated STAT3, a transcriptional inducer of VEGF-A and increased non-coding RNA miR-506 expression, respectively. Furthermore, miR-506 directly modulated STAT3 relying on base pairing the 3'-UTR in STAT3 mRNA. We also found that abrogation of miR-506 abolished the inhibitory effect of AA on VEGF-A expression and NSCLC-induced angiogenesis. Finally, xenografts experiments also showed that oral administration of AA could significantly attenuate NSCLC angiogenesis, indicated by decreased micro-vessel density (MVD) and the MVD marker CD31 expression in xenografts tissues. Correspondingly, AA treatment also downregulated VEGF-A, STAT3 and increased miR-506 expression in xenografts samples, respectively. Taken together, these results suggested that AA could suppress NSCLC-induced angiogenesis via miR-506/STAT3/VEGF-A axis. .

Proanthocyanidins as a Potential Novel Way for the Treatment of Hemangioma

Hemangioma, the most common benign vascular tumor, not only affects the appearance and psychology but also has a life-threatening potential. It is considered that clonal vascular endothelial cell proliferation and excessive angiogenesis are responsible for hemangioma pathogenesis, in which abnormal cytokines/pathways are closely implicated, primarily including high expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) as well as their downstream pathways, especially phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt). These further stimulate the migration and proliferation of vascular endothelial cells and promote the formation of new vessels, ultimately leading to the occurrence and development of hemangioma. Proanthocyanidins are naturally active substance from plants and fruits. They possess multiple functions like antiproliferation, antiangiogenesis, and antitumor. It has been demonstrated that proanthocyanidins effectively work in various diseases via inhibiting the expression of various factors, e.g., HIF-1α, VEGF, PI3K, and Akt. Considering the pathogenesis of hemangioma and the effect of proanthocyanidins, we hold a hypothesis that proanthocyanidins would be applied in hemangioma via downregulating cytokine/pathway expression, suppressing vascular cell proliferation and arrest abnormal angiogenesis. Taken together, proanthocyanidins may be a potential novel way for the treatment of hemangioma.

IL-10 regulates the malignancy of hemangioma-derived endothelial cells via regulation of PCNA

Hemangioma (HA) is the most common benign tumor and formed by the proliferating endothelial cells of blood vessels. Interleukins (ILs) have been reported to be critical for HA progression. Our present study found that the expression of IL-10 was decreased in HA cells and tissues as compared to their corresponding controls. Treatment with recombinant IL-10 (rIL-10) can suppress the proliferation of HA cells via suppression of proliferating cell nuclear antigen (PCNA), while over expression of PCNA can attenuate rIL-10-inhibited cell proliferation. Further, rIL-10 can decrease the promoter activity and mRNA stability of PCNA in HA cells. Mechanistically, rIL-10 can increase expression of miR-27b-3p to decrease mRNA stability of PCNA, while down regulation of YY1 is involved in rIL-10 suppressed transcription of PCNA. Collectively, IL-10 can suppress the expression of PCNA via miR-27b-3p mediated suppression of mRNA stability and YY1 mediated down regulation of transcription. It suggested that rIL-10 might be a potential therapeutic approach for HA development and progression.

Resveratrol Suppresses Tumor Progression via Inhibiting STAT3/HIF-1α/VEGF Pathway in an Orthotopic Rat Model of Non-Small-Cell Lung Cancer (NSCLC)

Background

The STAT3/HIF-1α/VEGF pathway is associated with the development and progress of various tumors including NSCLC. The aim of the present study was to investigate whether resveratrol (RES) could suppress NSCLC progression via inhibiting the expressions of STAT3, HIF-1α, and VEGF in a nude rat model.

Methods

Twenty-four nude rats were randomly divided into control, NSCLC, and NSCLC+RES groups. An orthotopic rat model of NSCLC was established. The animals in the NSCLC+RES group received the same operation as the NSCLC group and were intragastrically administered RES at 250 mg/kg/day for 12 weeks. Lung tissue samples were harvested for gross tumor burden measurement, histological examinations, RT-PCR, and Western blot assays.

Results

In the NSCLC+RES group, significant decreases in lung weight index, lung tumor burden, STAT3/HIF-1α/VEGF mRNA, and protein levels were observed when compared with the NSCLC group (all P<0.05). The structural integrity of the lung was less affected and the apoptotic index was significantly higher in the NSCLC+RES group, when compared to the NSCLC group (P<0.05).

Conclusion

RES suppresses NSCLC partly through inhibiting the expressions of STAT3, HIF-1α, and VEGF. The STAT3/HIF-1α/VEGF pathway might be a candidate drug target for developing new chemotherapy agents derived from RES for the treatment of NSCLC.

Oxygen homeostasis and cardiovascular disease: A role for HIF?

Hypoxia, the decline of tissue oxygen stress, plays a role in mediating cellular processes. Cardiovascular disease, relatively widespread with increased mortality, is closely correlated with oxygen homeostasis regulation. Besides, hypoxia-inducible factor-1(HIF-1) is reported to be a crucial component in regulating systemic hypoxia-induced physiological and pathological modifications like oxidative stress, damage, angiogenesis, vascular remodeling, inflammatory reaction, and metabolic remodeling. In addition, HIF1 controls the movement, proliferation, apoptosis, differentiation and activity of numerous core cells, such as cardiomyocytes, endothelial cells (ECs), smooth muscle cells (SMCs), and macrophages. Here we review the molecular regulation of HIF-1 in cardiovascular diseases, intended to improve therapeutic approaches for clinical diagnoses. Better knowledge of the oxygen balance control and the signal mechanisms involved is important to advance the development of hypoxia-related diseases.

miR-4458 directly targets IGF1R to inhibit cell proliferation and promote apoptosis in hemangioma

Hemangiomas (HAs) are benign neoplasms of the vasculature. MicroRNA-4458 (miR-4458) has been reported to function as a tumor suppressor in multiple malignancies, but its biological function in HAs remains unknown. In the present study, the potential role of miR-4458 in HA-derived endothelial cells (HDECs) was investigated. Firstly, reverse-transcription-quantitative PCR analysis was used to confirm the expression of miR-4458 in HDECs following transfection with miR-4458 mimics or inhibitor. Subsequently, MTT and EdU assays were performed and subsequently determined that miR-4458 overexpression significantly inhibited proliferation, and knockdown promoted cell proliferation in HDECs. Flow cytometry analysis revealed that miR-4458 overexpression induced cell cycle arrest, whereas knockdown reversed G0/G1 phase arrest and apoptosis. Furthermore, insulin-like growth factor 1 receptor (IGF1R) was identified as a target of miR-4458. IGF1R knockdown enhanced the effects of miR-4458 on cell proliferation, cell cycle G0/G1 phase arrest and apoptosis in HDECs. Taken together, the results revealed that miR-4458 targeting of IGF1R may serve as a novel therapeutic strategy for treating patients with HAs.

Tanshinone IIA reduces secretion of pro‑angiogenic factors and inhibits angiogenesis in human colorectal cancer

Tumor angiogenesis is an important factor which precipitates recurrence and metastasis of colorectal cancer (CRC). Angiogenesis is also a significant feature which accompanies invasion and metastasis of CRC. Tumor hypoxia activates hypoxia inducible factor (HIF), which promotes angiogenesis in CRC. HIF significantly promotes cell proliferation and angiogenesis in CRC, facilitating invasion and metastasis. Tanshinone IIA (Tan IIA) has been revealed to effectively inhibit angiogenesis in CRC, although the underlying mechanism remains to be determined. The aim of the present study was to determine the effects of HIF-1α on hypoxia induced angiogenesis in CRC cells, the effects of Tan IIA on the expression of pro-angiogenic factors in CRC cells, and on human umbilical vein endothelial cell (HUVEC) tube formation in normal and hypoxic conditions. The results of the present study revealed that Tan IIA not only decreased HIF-1α expression and inhibited the secretion level of vascular endothelial growth factor and basic fibroblast growth factor, but also efficiently decreased proliferation, tube formation and metastasis of HUVECs. The results highlight the potential of Tan IIA-mediated targeting of HIF-1α as a potential therapeutic option for treatment of patients with CRC.

Comprehensive investigation of p53, p21, nm23, and VEGF expression in hepatitis B virus-related hepatocellular carcinoma overall survival after hepatectomy

Objective: The goal of our current study is to assess the immunohistochemical of p53, p21, nm23, and VEGF expression in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) prognosis after hepatectomy, as well as the prospective molecular mechanisms of prognostic indicator. Methods: There were 419 HBV-related HCC patients who were from southern China of Guangxi province and were used to evaluate the immunohistochemical expression for these biomarkers in prognosis. A genome-wide expression microarray dataset of HBV-related HCC were obtained from GSE14520. Results: In our study, the expression of p53, p21, and nm23 in cancer tissues of patients with hepatitis B-related hepatocellular carcinoma did not affected the clinical outcome of 2 years, 5 years or overall. Patients with high expression of VEGF had a worse overall survival after 2 years of surgery than patients with low expression (adjusted P=0.040, adjusted HR = 1.652, 95% CI = 1.024-2.665). Survival analysis of VEGF in GSE14520 cohort also demonstrated that VEGF mRNA expression also significantly associated with HBV-related HCC OS (adjusted P=0.035, adjusted HR =1.651, 95% CI =1.035-2.634). The prospective molecular mechanisms by co-expression analysis suggested that VEGF might be correlated to regulation of cell proliferation, cell growth and apoptotic process, Rap1 signaling pathway, HIF-1 signaling pathway, PPAR signaling pathway, cell cycle. Whereas the GSEA suggested that VEGF might involve in the regulation of HIF and HIF1A pathway, and TP53 regulation pathway. Conclusion: Our findings suggested that VEGF might be a prognostic indicator of HBV-related HCC, and we also identified the VEGF prospective molecular mechanisms through the whole genome co-expression and GSEA approaches.

HIF-1α Promotes the Metastasis of Esophageal Squamous Cell Carcinoma by Targeting SP1

Background: In microenvironment of malignant tumors, Hypoxia-Inducible Factors (HIF), most importantly HIF-1α, play an important role in regulation of adaptive biological response to hypoxia, promoting angiogenesis and metastasis. However, the underlying mechanism that HIF-1α regulates metastasis needs to be further clarified. Methods: The expressions of HIF-1α and SP1 were detected in 182 samples of esophageal squamous cell carcinoma (ESCC) and adjacent normal tissues by immunohistochemistry (IHC), and the correlation between the expression levels of HIF-1α and SP1 was analyzed. The expression of HIF-1α in ESCC cell lines TE1 and KYSE30 was then detected using qRT-PCR and western blot. The potential binding sites of HIF-1α on the SP1 promoter were analyzed using UCSC and JASPAR databases, verified by chromosomal immunoprecipitation (ChIP) assay and qRT-PCR. The effects of HIF-1α and SP1 on ESCC cell migration and invasion were then tested with Transwell and Matrigel experiments. Results: The expression of HIF-1α in cancer tissues is higher than adjacent normal tissues, and is correlated with metastasis, recurrence and poor prognosis. Upon silencing HIF-1α by siRNA, the invasion and migration ability of ESCC cells were significantly inhibited, which could be restored by the overexpression of SP1. Hypoxic conditions significantly increased the expression of HIF-1α and SP1 at both protein and mRNA levels in ESCC cells. HIF-1α enhanced SP1 transcription through binding to the promoter region. The expression of protein and mRNA levels of SP1 was decreased by silencing HIF-1α in cells. In contrast, overexpression of HIF-1α significantly increased the mRNA and protein levels of SP1. The expression of SP1 in ESCC was positively correlated with the protein expression of HIF-1α and poor prognosis. Conclusion: The results of our study indicate that HIF-1α promotes metastasis of ESCC by targeting SP1 in a hypoxic microenvironment. Further study on this mechanism may elucidate the possibility of HIF-1α and SP1 as new targets for the treatment of ESCC.

Key Regulatory Effect of Activated HIF-1α/VEGFA Signaling Pathway in Systemic Capillary Leak Syndrome Confirmed by Bioinformatics Analysis

Systemic capillary leak syndrome (SCLS) is a rare disorder characterized by capillary leakage of plasma fluids throughout the endothelium. The mechanism of SCLS is still unknown. Vascular endothelial growth factor (VEGF), an inducer or barrier disruption, is markedly upregulated in SCLS. This study was to investigate the molecular mechanisms involving SCLS-related inflammation and neuron damage in SCLS remain unclear. Data files of GSE97287 dataset were extracted and processed for identification of differentially expressed genes (DEGs), including upregulated adrenomedullin (ADM) gene, hypoxia-inducible factor-1α (HIF-1α) and VEGFA; and downregulated aldehyde dehydrogenase 1A1 (ALDH1A1) gene and interleukin (IL)-2 receptor β (IL-2RB) gene. Weighted gene coexpression network analysis (WGCNA) was performed for DEGs and four significant modules were identified and were enriched Gene Ontology (GO) biological processes and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways related to immune response, angiogenesis, neuroblast proliferation, HIF-1 signaling pathway, and Parkinson's disease. The activated HIF-1α/VEGFA signaling in SCLS patients might well be responsible for the impaired inflammatory, nervous, and immune systems.