A possible hypoxia-induced endothelial proliferation in the pathogenesis of epithelioid hemangioma

HIF-1α contributes to tube malformation of human lymphatic endothelial cells by upregulating VEGFR-3

Hypoxia-inducible factor-1α (HIF-1α) is upregulated in various tumors and associated with lymphangiogenesis and angiogenesis during tumor development and metastasis. However, the role of HIF-1α in cystic lymphatic malformations (cLM) remains unclear. In the present study, expression of HIF-1α and vascular endothelial growth factor receptor 3 (VEGFR-3) was evaluated in 20 pairs of cLM specimens from patients who accepted curative surgery at Children’s Hospital of Nanjing Medical University (Nanjing, China). Additionally, a stable HIF-1α-overexpressing human lymphatic endothelial cell (HLEC) line was established. Overexpression and silencing of HIF-1α were used to investigate the biological role in colony formation, migration and lymphatic tube formation. HIF-1α and VEGFR-3 were upregulated in cLM specimens compared with adjacent normal tissues. In addition, HIF-1α effectively induced HLEC colony formation and migration. Furthermore, lymphatic malformation of HLECs was promoted in vitro by overexpression of HIF-1α. HIF-1α overexpression upregulated VEGFR-3 during lymphangiogenesis. Additionally, expression of lymphatic endothelial markers prospero homeobox protein 1 and lymphatic vessel endothelial hyaluronan receptor 1 increased significantly during lymphatic tube malformation. The presented data demonstrated that HIF-1α overexpression in HLECs promoted colony formation, migration and tube malformation via upregulation of VEGFR-3. These findings may assist in the development of HIF-1α-targeted cLM therapeutics in the future.

Vascular Anomalies Classification: Recommendations From the International Society for the Study of Vascular Anomalies

Vascular anomalies represent a spectrum of disorders from a simple "birthmark" to life- threatening entities. Incorrect nomenclature and misdiagnoses are commonly experienced by patients with these anomalies. Accurate diagnosis is crucial for appropriate evaluation and management, often requiring multidisciplinary specialists. Classification schemes provide a consistent terminology and serve as a guide for pathologists, clinicians, and researchers. One of the goals of the International Society for the Study of Vascular Anomalies (ISSVA) is to achieve a uniform classification. The last classification (1997) stratified vascular lesions into vascular malformations and proliferative vascular lesions (tumors). However, additional disease entities have since been identified that are complex and less easily classified by generic headings, such as capillary malformation, venous malformation, lymphatic malformation, etc. We hereby present the updated official ISSVA classification of vascular anomalies. The general biological scheme of the classification is retained. The section on tumors has been expanded and lists the main recognized vascular tumors, classified as benign, locally aggressive or borderline, and malignant. A list of well-defined diseases is included under each generic heading in the "Simple Vascular Malformations" section. A short definition is added for eponyms. Two new sections were created: one dealing with the malformations of individually named vessels (previously referred to as "truncular" malformations); the second groups lesions of uncertain or debated nature (tumor versus malformation). The known genetic defects underlying vascular anomalies are included in an appendix. This classification is meant to be a framework, acknowledging that it will require modification as new scientific information becomes available.

Oxymatrine suppresses proliferation and induces apoptosis of hemangioma cells through inhibition of HIF-1a signaling

Oxymatrine (OMT), a natural quinolizidine alkaloid, has been known to have anti-inflammation, anti-anaphylaxis, and chemopreventive effects on various cancer cells. To clarify the underlying role and molecular mechanisms of OMT in human hemangioma (HA), in the present study, we examined the expression of hypoxia-inducible factor-1a (HIF-1a) and vascular endothelial growth factor (VEGF) in different phases of human HA. After HA derived endothelial cells (HDEC) were pretreated with different concentrations of OMT, cell proliferation, apoptosis, and cycle distribution were evaluated by MTT assay and flow cytometry analysis, respectively. The effects of OMT on expression of HIF-1a signaling were determined by real-time PCR and western blot assays. Our results showed that, the expression of HIF-1a and VEGF was significantly increased in proliferating phase HA, but decreased in involuting phase HA. Moreover, OMT in vitro inhibited proliferative activities and induced cell apoptosis and cycle arrest in G0/G1 phase in HA cells with decreased expression of HIF-1a, VEGF, Bcl-2, and CyclinD1, and increased expression of p53. Taken together, our findings suggest that, the expression of HIF-1a and VEGF is increased in proliferating phase HA, and OMT suppresses cell proliferation and induces cell apoptosis and cycle arrest in proliferative phase HA through inhibition of the HIF-1a signaling pathway, suggesting OMT may provide a novel therapeutic strategy for the treatment of HA.

Epithelioid hemangioma of the internal carotid artery: a case report supporting the reactive pathogenesis hypothesis of this vascular tumor

The pathogenesis of epithelioid hemangioma is intriguing and has remained a controversial topic in the medical literature. Whether its etiology follows a neoplastic or reactive process is unclear, but a history of traumatic insult to the involved region is common. We report a case of epithelioid hemangioma of the internal carotid artery in a child who had undergone cannulization of the internal jugular vein as an infant to receive extracorporeal membrane oxygenation.