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.

Silencing microRNA-210 in Hypoxia-Induced HUVEC-Derived Extracellular Vesicles Inhibits Hemangioma.

BACKGROUND: Hemangioma (Hem) is a benign tumor commonly seen in infancy with a relative high morbidity. Human umbilical vein endothelial cell (HUVEC)-derived extracellular vesicles (EVs) are actively participated in Hem. Therefore, this study is designed to figure out the underlying mechanism of HUVEC-derived EVs in Hem. METHODS: Initially, EVs were separated from HUVECs and identified. HUVEC-derived EVs in normoxia or hypoxia were then cultivated with Hem endothelial cells (HemECs) to test the proliferation, apoptosis, and migration of HemECs. Microarray analysis was performed to select microRNAs (miRs) with differential expression. miR-210 in hypoxia-induced HUVECs was silenced, and the relevant EVs were extracted and then co-cultured with HemECs to perform biological effect experiments. Then, the target relation between miR-210 and homeobox A9 (HOXA9) was identified by the dual luciferase reporter gene assay and RNA immunoprecipitation assay. Moreover, xenograft transplantation was also applied to confirm the in vitro experiments. RESULTS: Hypoxia-induced HUVECs promoted release of EVs, which were absorbed by HemECs. Hypoxia-induced HUVEC-EVs promoted HemEC proliferation and migration and inhibited apoptosis. miR-210 from the hypoxia-induced HUVEC-EVs was highly expressed and promoted HemEC growth. Silencing miR-210 expression in the hypoxia-induced HUVEC-EVs suppresses Hem development in vivo. In addition, miR-210 targeted HOXA9. CONCLUSION: Silencing miR-210 in HUVEC-derived EVs could suppress Hem by targeting HOXA9. This investigation may provide novel insights for Hem treatment.

The ester derivatives obtained by C-ring modification of podophyllotoxin-induced apoptosis and inhibited proliferation in Hemangioma Endothelial Cells via downregulation of PI3K/Akt signaling pathway.

Infantile hemangioma (IH) is a common benign endothelial cell tumor in infants and young children, sometimes accompanied by potential complications, and may develop into malignant tumors. Hemangioma endothelial cells (HemECs) are one of the main components of IH. Podophyllotoxin (PPT) has been reported to have many pharmacological activities, especially anti-tumor, but its high toxicity, poor water solubility, and serious gastrointestinal side effects limit its clinical application. In this study, we have designed and synthesized 20 ester derivatives by introducing Boc-amino acids or organic acids at the C-4 position of podophyllotoxin through esterification reactions. The cytotoxicity of these compounds was evaluated on HemECs. Changes in cell proliferation and apoptotic signaling pathways were studied by DAPI staining, colony formation assay, migration assay, measurement of reactive oxygen species (ROS) levels flow cytometry, and Western blot analysis. We found that eight of the compounds were more potent than PPT. Of these, compound V-31 was the most active (IC50  = 0.079 ± 0.0049 µM). Further research indicated that compound V-31 inhibited its proliferation and migration, increased the level of ROS in cells, and induced apoptosis by downregulating p-PI3K, p-Akt, and Bcl-2, and upregulating cleaved caspase-3 and Bax. Our research provides the first insight into the application of PPT derivatives in HemECs, may provide an effective medicine for IH treatment.

MiR-206 promotes extracellular matrix accumulation and relieves infantile hemangioma through targeted inhibition of DNMT3A.

MiR-206 is abnormally expressed in infant hemangioma endothelial cells (HemECs), but the mechanism is not clear. We explored the intervention of miR-206 in HemECs in relation to extracellular matrix (ECM) metabolism. We selected 48 cases of infantile hemangioma (IH) from volunteer organizations. After the isolated and extracted HemECs were interfered with overexpressed or silenced miR-206, the effects of miR-206 on the proliferation, migration and invasion of HemECs were examined through basic cell function experiments. The expression differences of miR-206, DNA Methyltransferase 3A (DNMT3A) and ECM-related genes were analyzed as needed by qRT-PCR or Western blot. TargetScan and dual-luciferase experiments were applied to predict and confirm the binding relationship between miR-206 and DNMT3A. The correlation between miR-206 and DNMT3A was analyzed in IH tissues by Pearson correlation coefficient, and further confirmed in HemECs by conducting rescue experiments. A nude mouse model of xenograft tumor was constructed to verify the results of in vitro experiments. MiR-206, which was downregulated in proliferative hemangioma, suppressed the malignant development of HemECs by regulating ECM-related genes. As the target gene of miR-206, DNMT3A was high-expressed in IH tissues and was negatively correlated with miR-206. Overexpressed DNMT3A counteracted the inhibitory effect of miR-206 mimic on HemECs and its regulatory effect on ECM. The results of in vivo experiments were consistent with those from cell experiments. Thus, miR-206 could promote ECM accumulation through targeted inhibition of DNMT3A, further inhibiting the malignant development of HemECs and relieving IH.

LncRNA OIP5-AS1 Promotes the Proliferation of Hemangioma Vascular Endothelial Cells via Regulating miR-195-5p/NOB1 Axis.

Background: Hemangioma, which is a benign vascular neoplasm, has been demonstrated to be the most common tumor of infancy, resulting from aberrant proliferation of endothelial cells and pericytes. Objective: The aim of this study was to determine the role of lncRNA OIP5-AS1 on the proliferation and metastasis of human hemangioma endothelial cells (HemECs). Methods: In this study, we examined the expression of OIP5-AS1 and miR-195-5p in hemangiomas patients. The effects of knockdown or ectopic expression of OIP5-AS1 on the viability, proliferation and apoptosis of HemECs were explored. Rescue assays were performed to explore the effects of OIP5-AS1/miR-195-5p/NOB1 axis on biological behaviors in the HemECs. Results: It was found that OIP5-AS1 was overexpressed in both hemangioma tissues and HemECs cells. OIP5-AS1 knockdown suppressed the proliferation, migration, and invasion of HemECs cell, while overexpression of OIP5-AS1 had opposite effects LncRNA OIP5-AS1 acted as a ceRNA through binding with miR-195-5p to upregulate NOB1 in HemECs. Conclusion: Taken together, lncRNA OIP5-AS1 acted as a ceRNA to drive proliferation, migration and invasion of HemECs through regulating miR-195-5p/NOB1 axis.

Sildenafil suppresses the proliferation and enhances the apoptosis of hemangioma endothelial cells.

Treatment of infantile hemangiomas (IH) with propranolol was first reported in 2008. Regressions of lymphatic malformations combined with pulmonary hypertension was first reported in 2012 after three children received treatment with oral sildenafil, which serves as an antagonist of phosphodiesterase isoform-5 (PDE-5). A marked expression of endothelial cells in the cytoplasm of IH tissues was obtained in our previous study. Therefore, the present study hypothesized that the antagonist of PDE-5, sildenafil, may lead to the regression of hemangiomas. To assess this hypothesis, the proliferation and apoptosis of specimen-derived hemangioma endothelial cells (HemECs) was determined in vitro by an MTT assay and flow cytometry, respectively, following treatment with sildenafil. The potential mechanisms underlying the mRNA and protein expression levels of inhibitor of differentiation 1 (Id-1) were determined by reverse transcription-quantitative polymerase chain reaction and western blotting. The results demonstrated that 5 µM sildenafil suppressed the proliferation of HemECs and significantly enhanced the rate of apoptosis after 24 h. Additionally, the mRNA and protein expression levels of Id-1 were downregulated following treatment with sildenafil. Therefore, the present study concluded that PDE-5 may be a potential therapeutic target for hemangiomas and Id-1 may serve a vital role in the associated signaling transduction pathways.