Hypoxia, hormones, and endothelial progenitor cells in hemangioma

First report of a gallbladder hemangioma coexisting with gallstones: a case report and literature review of a rare finding

Background

Gallbladder hemangioma is an exceptionally rare entity, with only ten cases reported in literature hitherto. The here described case is the first report of a gallbladder hemangioma coexisting with gallstones.

Case presentation

A 76-year-old male was hospitalized following repeated episodes of epigastric pain. Patient’s medical history included primary hypertension, type 2 diabetes mellitus, dyslipidemia, obesity and hyperuricemia. Physical examination revealed marked pain in the right hypochondriac region, and laboratory workup was notable for mildly elevated glycemia (125 mg/dL) and pancreatic amylase (60 IU/L). Abdominal ultrasound showed multiple gallstones, a thickened gallbladder wall and mild edema of the perivisceral adipose tissue as well as a hepatic angioma. During surgery, an incidental subserosal nodule of about 1 cm was detected within the gallbladder fundus. After surgery, the clinical course was uneventful and the patient was discharged. Histopathological examination of the subserosal nodule showed multiple dilated vascular channels within a sclerosing matrix, a finding consistent with a cavernous hemangioma. Diffuse chronic cholecystitis was also present.

Conclusions

Gallbladder hemangiomas represent a rare, likely underdiagnosed condition which can be undetected during the preoperative workup.

Role of Tumor Microenvironment in Cancer Stem Cells Resistance to Radiotherapy

Cancer is a chronic disorder that involves several elements of both the tumor and the host stromal cells. At present, the complex relationship between the various factors presents in the tumor microenvironment (TME) and tumor cells, as well as immune cells located within the TME, is still poorly known. Within the TME, the crosstalk of these factors and immune cells essentially determines how a tumor reacts to the treatment and how the tumor can ultimately be destroyed, remain dormant, or develop and metastasize. Also, in TME, reciprocal crosstalk between cancer-associated fibroblasts (CAFs), extracellular matrix (ECM), hypoxia-inducible factor (HIF) intensifies the proliferation capacity of cancer stem cells (CSCs). CSCs are subpopulation of cells that reside within the tumor bulk and have the capacity to self-renew, differentiate, and repair DNA damage. These characteristics make CSCs develop resistance to a variety of treatments, such as radiotherapy (RT). RT is a frequent and often curative treatment for local cancer which mediates tumor elimination by cytotoxic actions. Also, cytokines and growth factors that are released into TME, have been involved in the activation of tumor radioresistance and the induction of different immune cells, altering local immune responses. In this review, we discuss the pivotal role of TME in resistance of CSCs to RT.

Oxygen in Metabolic Dysfunction and Its Therapeutic Relevance

Significance: In recent years, a number of studies have shown altered oxygen partial pressure at a tissue level in metabolic disorders, and some researchers have considered oxygen to be a (macro) nutrient. Oxygen availability may be compromised in obesity and several other metabolism-related pathological conditions, including sleep apnea-hypopnea syndrome, the metabolic syndrome (which is a set of conditions), type 2 diabetes, cardiovascular disease, and cancer. Recent Advances: Strategies designed to reduce adiposity and its accompanying disorders have been mainly centered on nutritional interventions and physical activity programs. However, novel therapies are needed since these approaches have not been sufficient to counteract the worldwide increasing rates of metabolic disorders. In this regard, intermittent hypoxia training and hyperoxia could be potential treatments through oxygen-related adaptations. Moreover, living at a high altitude may have a protective effect against the development of abnormal metabolic conditions. In addition, oxygen delivery systems may be of therapeutic value for supplying the tissue-specific oxygen requirements. Critical Issues: Precise in vivo methods to measure oxygenation are vital to disentangle some of the controversies related to this research area. Further, it is evident that there is a growing need for novel in vitro models to study the potential pathways involved in metabolic dysfunction to find appropriate therapeutic targets. Future Directions: Based on the existing evidence, it is suggested that oxygen availability has a key role in obesity and its related comorbidities. Oxygen should be considered in relation to potential therapeutic strategies in the treatment and prevention of metabolic disorders. Antioxid. Redox Signal. 35, 642-687.

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.

Diagnosis of Klippel-Trenaunay syndrome and extensive heterotopic ossification in a patient with a femoral fracture: a case report and literature review

Background

Klippel-Trenaunay syndrome (KTS) is a rare complex vessel malformation syndrome characterized by venous varicosities, capillary malformations, and limb hypertrophy. However, extensive heterotopic ossification (HO) secondary to this syndrome is extremely rare.

Case presentation

We report the case of a patient with previously undiagnosed KTS and extensive HO who presented with a femoral fracture secondary to a motor vehicle accident. Extensive ossification, which leads to compulsive contracture deformity and dysfunction of the leg, was distributed on the flexor muscle side, as revealed by the radiograph. The diagnosis was finally established by combining imaging and histological analysis with classical clinical symptoms. Amputation was performed at the fracture site proximal to the infected necrotic foci. Open management of the fracture was challenging owning to the pervasive ossification and tendency for excessive bleeding. Gene sequencing analysis showed homozygous mutation of FoxO1 gene.

Conclusions

Definitive diagnosis of a combination of KTS and extensive HO requires detailed imaging analysis and pathologic evidence. Mutation of the FoxO1 gene, which regulates bone formation by resistance to oxidative stress in osteoblasts, is a potential factor in the microenvironment of malformed vessels caused by KTS.

Neurosurgery in paediatric strokes

Paediatric strokes are a different entity owing to the difference in pathological entity causing the stroke as well as difficulty in treatment and management due to the presence of a growing brain and small vascular volume making surgery and endovascular intervention dangerous. Yet, the high neuronal plasticity coupled with unique surgical and endovascular procedures makes surgery in these conditions rewarding with improving morbidity and mortality statistics. The field is young and dynamic leading to constant change and updating. We attempt to review the current recommendations with our own experience in paediatric neurosurgery for paediatric strokes and present an overview of common conditions causing paediatric strokes. A brief review of the literature is also supplied for reference.

Exosomes in Angiogenesis and Anti-angiogenic Therapy in Cancers

Angiogenesis is the process through which new blood vessels are formed from pre-existing ones. Exosomes are involved in angiogenesis in cancer progression by transporting numerous pro-angiogenic biomolecules like vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMPs), and microRNAs. Exosomes promote angiogenesis by suppressing expression of factor-inhibiting hypoxia-inducible factor 1 (HIF-1). Uptake of tumor-derived exosomes (TEX) by normal endothelial cells activates angiogenic signaling pathways in endothelial cells and stimulates new vessel formation. TEX-driven cross-talk of mesenchymal stem cells (MSCs) with immune cells blocks their anti-tumor activity. Effective inhibition of tumor angiogenesis may arrest tumor progression. Bevacizumab, a VEGF-specific antibody, was the first antiangiogenic agent to enter the clinic. The most important clinical problem associated with cancer therapy using VEGF- or VEFGR-targeting agents is drug resistance. Combined strategies based on angiogenesis inhibitors and immunotherapy effectively enhances therapies in various cancers, but effective treatment requires further research.

Risk factors for infantile hemangioma: a meta-analysis

BACKGROUND

Infantile hemangioma (IH) is one of the most common tumors in infants. Its pathogenesis is complex and poorly understood. The risk factors of IH have been extensively studied from clinical and epidemiological perspectives in recent years, but the conclusions in the literature reports are inconsistent. To provide a reference for the prevention of hemangioma, we conducted a meta-analysis of the published studies of potential risk factors for IH.

METHODS

The Cochrane Library, Ovid, PubMed, and Web of Science databases were searched systematically. Log odds ratios (log ORs), logistic regression standard errors and 95% confidence intervals (CIs) were used to compare the correlation between IH and potential risk factors. Review Manager 5.3.3 was used for the statistical analysis.

RESULTS

Six studies were included and 17 potential risk factors were eventually evaluated. P values < 0.05 were found for female gender (P < 0.01, OR 2.04, 95% CI 1.65-2.51), low birth weight (P < 0.01, OR 4.39, 95% CI 3.05-6.31), multiple gestation (P = 0.01, OR 2.39, 95% CI 1.21-4.71), preterm birth (P = 0.03, OR 2.37, 95% CI 1.07-5.23), progesterone therapy (P < 0.01, OR 2.73, 95% CI 2.12-3.51), and family history (P = 0.01, OR 1.98, 95% CI 1.16-3.38).

CONCLUSIONS

This meta-analysis revealed that risk factors, including female gender, low birth weight, multiple gestation, preterm birth, progesterone therapy, and family history may affect the occurrence of IH.

Identification of putative biomarkers for Infantile Hemangiomas and Propranolol treatment via data integration

Infantile hemangiomas (IHs) are the most common benign tumors in early childhood. They show a distinctive mechanism of tumor growth in which a rapid proliferative phase is followed by a regression phase (involution). Propranolol is an approved treatment for IHs, but its mechanism of action remains unclear. We integrated and harmonized microRNA and mRNA transcriptome data from newly generated microarray data on IHs with publicly available data on toxicological transcriptomics from propranolol exposure, and with microRNA data from IHs and propranolol exposure. We identified subsets of putative biomarkers for proliferation and involution as well as a small set of putative biomarkers for propranolol's mechanism of action for IHs, namely EPAS1, LASP1, SLC25A23, MYO1B, and ALDH1A1. Based on our integrative data approach and confirmatory experiments, we concluded that hypoxia in IHs is regulated by EPAS1 (HIF-2α) instead of HIF-1α, and also that propranolol-induced apoptosis in endothelial cells may occur via mitochondrial stress.

Vascular lesions of the head and neck: an update on classification and imaging review

Vascular lesions have a varied appearance and can commonly occur in the head and neck. A majority of these lesions are cutaneous and congenital; however, some may be acquired and malignant. The presentation and clinical history of patients presenting with head and neck lesions can be used to guide further imaging, which can provide important diagnostic and therapeutic considerations. This review discusses the revised International Society for the Study of Vascular Anomalies (ISSVA) classification system for vascular tumors and malformations, as well as explores the most common vascular anomalies including their clinical presentations and imaging findings.

Tumor angiogenesis: causes, consequences, challenges and opportunities

Tumor vascularization occurs through several distinct biological processes, which not only vary between tumor type and anatomic location, but also occur simultaneously within the same cancer tissue. These processes are orchestrated by a range of secreted factors and signaling pathways and can involve participation of non-endothelial cells, such as progenitors or cancer stem cells. Anti-angiogenic therapies using either antibodies or tyrosine kinase inhibitors have been approved to treat several types of cancer. However, the benefit of treatment has so far been modest, some patients not responding at all and others acquiring resistance. It is becoming increasingly clear that blocking tumors from accessing the circulation is not an easy task to accomplish. Tumor vessel functionality and gene expression often differ vastly when comparing different cancer subtypes, and vessel phenotype can be markedly heterogeneous within a single tumor. Here, we summarize the current understanding of cellular and molecular mechanisms involved in tumor angiogenesis and discuss challenges and opportunities associated with vascular targeting.

Genetic investigation of childhood vascular tumor biology reveals pathways for therapeutic intervention

Vascular tumors are neoplasms of endothelial cells, a significant number of which present in childhood. Recent studies have examined the mutational landscape of many subtypes of vascular tumors, identifying mutations primarily within the Ras–mitogen-activated protein kinase (MAPK) pathway and providing a unique opportunity to consider targeted therapeutics. This review will summarize the current understanding of childhood vascular tumor pathobiology.

Propranolol inhibits the activity of PI3K, AKT, and HIF-1α in infantile hemangiomas

PURPOSE

We sought to evaluate effect of propranolol in the treatment of infantile hemangiomas by quantifying the amount of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), and hypoxia-inducible factor-1α (HIF-1α).

METHODS

Hemangioma tissue was isolated from an infant patient and implanted into nude mice to establish a hemangioma model. Twenty-four hemangioma-model nude mice were divided into two groups including a control group (saline, by gastrogavage) and an experimental group (propranolol, by gastrogavage). The hemangioma-model nude mice were euthanized and tumors were removed at 30 and 50 days (before and after treatment). HE staining was used to observe the histopathological changes, and western blot and quantitative real-time PCR were used to describe levels of protein and mRNA expression of PI3K, AKT, and HIF-1α.

RESULTS

Propranolol treatment decreased tumor size as compared to the control group. Protein and mRNA expression levels of PI3K, AKT, and HIF-1α were lower in the experimental group at day 50 compared to the control group at day 50 and the experimental group at day 30 (p < 0.05).

CONCLUSION

Propranolol can promote regression of infantile hemangiomas, which may be related to the inhibition of PI3K, AKT, and HIF-1α activity.

Infantile hemangioma with minimal or arrested growth as the skin manifestation of PHACE syndrome

BACKGROUND

Infantile hemangiomas with minimal or arrested growth are vascular tumors with a proliferative component involving < 25% of their total surface area. They are commonly described as localized lesions and are mainly located on the lower body. Little has been described about segmental forms on the face and their associations with PHACE syndrome.

METHODS

We carried out a multicenter, retrospective, case-series study involving 5 hospitals in Spain. Information was collected on cases of PHACE syndrome featuring infantile hemangiomas with minimal or arrested growth.

RESULTS

The frontotemporal and maxillary areas were the most frequently involved sites in our series. The upper eyelid and upper lip were the 2 locations most frequently associated with proliferation and ulceration. Four patients experienced spontaneous resolution, and the rest had a very good cosmetic outcome with oral treatment. Cerebral and cervical arterial anomalies were the most frequent extracutaneous findings associated with PHACE, followed by cerebral and ocular anomalies. Some unique associated disorders were fructose intolerance and retinoblastoma.

CONCLUSION

We present the largest case series of segmental facial infantile hemangiomas with minimal or arrested growth in PHACE syndrome and emphasize the importance of recognizing these lesions in early infancy, because they can indicate PHACE syndrome. The data presented suggest that infantile hemangiomas with minimal or arrested growth-associated PHACE syndrome does not seem to differ significantly from PHACE syndrome with classic infantile hemangiomas, and thus the same recommendations for diagnosis, management, and therapy should be followed. Future studies with more patients could contribute to enlighten this specific subset.

Combined oral propranolol with intralesional injection of triamcinolone acetonide in treatment of infantile periocular hemangiomas

Aim

To evaluate the clinical effectiveness of combined oral propranolol with intralesional injection of triamcinolone acetonide in the treatment of infantile periorbital capillary hemangioma.

Patients and Methods

This prospective interventional study included children diagnosed with periocular infantile hemangiomas in the proliferative phase with vision-threatening lesions. The children presented to the oculoplastic unit in Sohag University Hospital in the period between January 2016 and February 2017 and were treated with a combined intralesional injection of triamcinolone acetonide with oral propranolol, with a follow-up period of 6 months. Treatment response was evaluated according to the size of the tumor (horizontal diameter); additionally, complications of both treatment methods were recorded.

Results

This study included 33 infants: 21 females (64%) and 12 males (36%). The mean age at the time of injection was 4.9±2.6 months. The study included three modes of treatment response: regression of the tumor, 28 patients (85%); stabilization, three patients (9%); and failure, two patients (6%), which necessitated repeated intralesional injection of triamcinolone but with minimal response. Regarding complications, only one patient reported with subconjunctival hemorrhage during intralesional injection of steroids; there were no recorded cases of hypotension, bradycardia, or hypoglycemia during the course of oral propranolol treatment. After the end of the follow-up period, there were no reported cases of recurrent increase in the size of the regressed group of infantile hemangiomas with stable tumor size.

Conclusion

Combined oral propranolol with intralesional injection of triamcinolone acetonide is the effective method of treatment for infantile periorbital capillary hemangioma with minimal adverse effects.

Propranolol inhibits the proliferation, migration and tube formation of hemangioma cells through HIF-1α dependent mechanisms

The aim of this study was to investigate the mechanism of propranolol on the regression of hemangiomas. Propranolol-treated hemangioma tissues were collected and the expression of hypoxia inducible factor-1α (HIF-1α) was examined. We also established HIF-1α overexpression and knockdown hemangioma cells, and determined the effects of HIF-1α on the hemangioma cells proliferation, apoptosis, migration and tube formation. Significantly increased HIF-1α level was found in the hemangioma tissues compared to that in normal vascular tissues, whereas propranolol treatment decreased the HIF-1α level in hemangioma tissues in a time- and dose-dependent manner. Moreover, propranolol treatment significantly decreased cell proliferation, migration and tube formation as well as promoted cell apoptosis in HIF-1α overexpression and knockdown hemangioma cells. Propranolol suppressed the cells proliferation, migration and tube formation of hemangioma cells through HIF-1α dependent mechanisms. HIF-1α could serve as a novel target in the treatment of hemangiomas.

Arrested Development: Infantile Hemangioma and the Stem Cell Teratogenic Hypothesis

BACKGROUND

Early-life programming is defined by the adaptive changes made by the fetus in response to an adverse in utero environment. Infantile hemangioma (IH), a vascular anomaly, is the most common tumor of infancy. Here we take IH as the tumor model to propose the stem cell teratogenic hypothesis of tumorigenesis and the potential involvement of the immune system.

OBJECTIVES

Teratogenic agents include chemicals, heavy metals, pathogens, and ionizing radiation. To investigate the etiology and pathogenesis of IH, we hypothesized that they result from a teratogenic mechanism. Immature, incompletely differentiated, dysregulated progenitor cells (multipotential stem cells) are arrested in development with vasculogenic, angiogenic, and tumorigenic potential due to exposure to teratogenic agents such as extrinsic factors that disrupt intrinsic factors via molecular mimicry. During the critical period of immunological tolerance, environmental exposure to immunotoxic agents may harness the teratogenic potential in the developing embryo or fetus and modify the early-life programming algorithm by altering normal fetal development, causing malformations, and inducing tumorigenesis. Specifically, exposure to environmental agents may interfere with physiological signaling pathways and contribute to the generation of IH, by several mechanisms.

DISCUSSION

An adverse in utero environment no longer serves as a sustainable environment for proper embryogenesis and normal development. Targeted disruption of stem cells by extrinsic factors can alter the genetic program.

CONCLUSIONS

This article offers new perspectives to stimulate discussion, explore novel experimental approaches (such as immunotoxicity/vasculotoxicity assays and novel isogenic models), and to address the questions raised to convert the hypotheses into nontoxic, noninvasive treatments.

Infantile Hemangioma with Minimal or Arrested Growth: Further Observations on Clinical and Histopathologic Findings of this Unique but Underrecognized Entity

BACKGROUND

Infantile hemangioma (IH) with minimal or arrested growth (IH-MAG) is becoming increasingly recognized in the literature. It is important to be aware of their existence, because the correct diagnosis is essential for prognostication and treatment and, in the case of facial segmental lesions, the direction of further investigations if PHACE (posterior fossa abnormalities and other structural brain abnormalities; hemangioma(s) of the cervical facial region; arterial cerebrovascular anomalies; cardiac defects, aortic coarctation, and other aortic abnormalities; eye anomalies) syndrome or Sturge-Weber syndrome is suspected. Although the clinical and histologic characteristics of IH-MAG resemble capillary malformations, positive GLUT-1 status is a delineating feature.

METHODS

We reviewed nine cases of infants who presented after 2000 with birthmarks showing unique clinical features suggestive of a special variant of IHs. All patients had serial photographs taken demonstrating resolution of the birthmark over time. Five of these cases had skin biopsy performed, all of which confirmed GLUT-1 positivity.

RESULTS

This photographic series of IH-MAG demonstrates their unique clinical, histologic, and immunochemistry features. They were nearly fully formed at birth, and their common clinical features included telangiectasia, venules, and matte erythema with light and dark areas. Spontaneous resolution over time without cosmetic disfigurement was the observed natural history in the majority of cases.

CONCLUSION

IH-MAG is a unique clinical subset of hemangioma for which close observation is the preferred treatment. When in doubt, a biopsy for histology and GLUT-1 status may be needed to confirm the diagnosis before embarking on unnecessary laser treatment or medical interventions.

Serum Basic Fibroblastic Growth Factor Levels in Children with Infantile Hemangioma

OBJECTIVES

To determine serum levels of basic fibroblastic growth factor (b-FGF) in hemangioma patients under 2 y of age.

METHODS

The study group consisted of 43 children with infantile hemangioma and b-FGF levels were analyzed using ELISA.

RESULTS

The serum b-FGF levels were higher in hemangioma patients than in healthy control individuals (p 0.01). There were no differences between the lesion size, number of lesions, patient age and serum b-FGF levels.

CONCLUSIONS

Thus, b-FGF is an important growth factor that plays a central role in hemangioma, but determining b-FGF serum levels was not helpful in distinguishing between patients who require treatment and those who do not.

Endothelial progenitor cells promote tumor growth and progression by enhancing new vessel formation

Tumor growth and progression require new blood vessel formation to deliver nutrients and oxygen for further cell proliferation and to create a neovascular network exit for tumor cell metastasis. Endothelial progenitor cells (EPCs) are a bone marrow (BM)-derived stem cell population that circulates in the peripheral circulation and homes to the tumor bed to participate in new blood vessel formation. In addition to structural support to nascent vessels, these cells can also regulate the angiogenic process by paracrine secretion of a number of proangiogenic growth factors and cytokines, thus playing a crucial role in tumor neovascularization and development. Inhibition of EPC-mediated new vessel formation may be a promising therapeutic strategy in tumor treatment. EPC-mediated neovascularization is a complex process that includes multiple steps and requires a series of cytokines and modulators, thus understanding the underlying mechanisms may provide anti-neovasculogenesis targets that may be blocked for the prevention of tumor development. The present review stresses the process and contribution of EPCs to the formation of new blood vessels in solid tumors, in an attempt to gain an improved understanding of the underlying cellular and molecular mechanisms involved, and to provide a potential effective therapeutic target for cancer treatment.

Propranolol for infantile hemangioma: Current state of affairs

Infantile hemangioma (IH) is the most common benign tumor seen in infancy. This review provides up-to-date information on the pathophysiology, variations in clinical presentation, and natural history of IH, elaborating on associated anomalies, such as PHACE(S) syndrome and LUMBAR syndrome. Because of the benign and self-limiting characteristics seen in more than 90% of cases of IH, a conservative approach is usually chosen. However, some circumstances, such as ulceration, vision loss, breathing difficulties, or potential disfigurement, will require treatment during the proliferative phase. For decades, treatment of IH has primarily consisted of corticosteroids or surgery. Since 2008, propranolol has become the treatment of first choice. In this article, we bring to light the crucial changes in the treatment of IH over the past years. To date, there is still a lack of data on the possible long-term effects of propranolol treatment in young infants. A theoretical probability of the central nervous system being affected (that is, impairment of short- and long-term memory, psychomotor function, sleep quality, and mood) has recently been suggested. This review highlights research topics concerning these long-term adverse effects. Finally, information is provided on the potential instruments to measure IH severity and activity in clinical trials and/or in clinical practice and the recently developed and first-validated IH-specific quality-of-life questionnaire.

A hydrogel-endothelial cell implant mimics infantile hemangioma: modulation by survivin and the Hippo pathway

Microvascular endothelial cells cultured in three-dimensional hydrogel scaffolds form a network of microvessel structures when implanted subcutaneously in mice, inosculate with host vessels, and over time remodel into large ectatic vascular structures resembling hemangiomas. When compared with infantile hemangiomas, similarities were noted, including a temporal progression from a morphological appearance of a proliferative phase to the appearance of an involuted phase, mimicking the proliferative and involutional phases of infantile hemangioma. Consistent with the progression of a proliferative phase to an involuted phase, both the murine implants and human biopsy tissue exhibit reduced expression of Ajuba, YAP, and Survivin labeling as they progressed over time. Significant numbers of CD45+, CD11b+, Mac3+ mononuclear cells were found at the 2-week time point in our implant model that correlated with the presence of CD45+, CD68+ mononuclear cells observed in biopsies of human proliferative-phase hemangiomas. At the 4-week time point in our implant model, only small numbers of CD45+ cells were detected, which again correlated with our findings of significantly diminished CD45+, CD68+ mononuclear cells in human involutional-phase hemangiomas. The demonstration of mononuclear cell infiltration transiently in the proliferative phase of these lesions suggests that the vascular proliferation and/or regression may be driven in part by an immune response. Gross and microscopic morphological appearances of human proliferative and involutional hemangiomas and our implant model correlate well with each other as do the expression levels of Hippo pathway components (Ajuba and YAP) and Survivin and correlate with proliferation in these entities. Inhibitors of Survivin and Ajuba (which we have demonstrated to inhibit proliferation and increase apoptosis in murine hemangioendothelioma cell tissue culture) may have potential as other beneficial treatments for proliferating infantile hemangiomas. This implant model may have potential as a modest through-put screen for testing and development of therapeutics targeted at the proliferative phase of infantile hemangiomas, reducing the subsequent postinvolutional scarring or deformities sometimes associated with these lesions.

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.

Ventral midline blanching in the setting of segmental infantile hemangiomas: clinical observations and pathogenetic implications

Areas of blanched skin in children may be seen as an independent finding or in association with vascular birthmarks. We performed a retrospective chart review to identify and describe infants with areas of ventral midline blanching in the presence of segmental infantile hemangiomas. We identified nine full-term infants with partial or full segmental hemangiomas and areas of midline ventral blanching. Additional ventral wall defects were seen in five patients. Six had cardiac anomalies and six had intracranial anomalies. Five were diagnosed with definite PHACE (posterior fossa, hemangioma, arterial, cardiac, and eye abnormalities) syndrome and three had possible PHACE syndrome. Eight were complicated by ulceration. Treatment varied according to the case. Ventral blanching, even in the absence of overt midline defects, can be seen in infants with segmental hemangiomas at risk for PHACE syndrome. We hypothesize that midline blanching may represent a minor manifestation of a developmental ventral defect.

Educational paper: Pathogenesis of infantile haemangioma, an update 2014 (part I)

Infantile haemangioma (IH) is the most frequent childhood tumour. Although it is benign and self-limiting, severe complications can arise due to localisation and fast tumour growth. Management and therapy of IH has changed greatly after 2008 with propranolol. However, the pathogenesis remains elusive. This update provides an overview of all possible mechanisms currently considered. We discuss the possibility that several mechanisms act together, although local hypoxia seems to be important. Clinically, in about half of the cases, an IH is preceded by an anaemic macula (local ischaemia) or a so-called precursor lesion. Laboratory findings indicate stabilisation and an increased transcription activity of hypoxia-inducible factor 1 alpha (HIF1α), leading to up-regulation of its downstream target genes (such as vascular endothelial growth factor (VEGF)), which normally occurs in cases of hypoxia.

CONCLUSION

Three main hypotheses have been proposed, namely (1) the theory of tissue hypoxia, (2) the theory of embolization of placental endothelial cells and (3) the theory of increased angiogenic and vasculogenic activity.

Support for the hypoxia theory in the pathogenesis of infantile haemangioma

BACKGROUND

The pathogenesis of infantile haemangioma (IH) is unknown. Several mechanisms have been proposed, including hypoxia, which triggers upregulation and stabilization of hypoxia-inducible factor (HIF)1α. HIF1α stimulates downstream transcription of target genes that enhance angiogenesis.

AIM

To identify possible involvement of hypoxia in the pathogenesis of IH, as hypoxia signalling constitutes a potential therapeutic target.

METHODS

IH tissue samples collected during the period 1991-2011 (preserved in paraffin wax) were immunohistochemically analysed for HIF1α and the known HIF1α targets: BCL2/adenovirus E1B kD-interacting protein family member 3 (BNIP3), carbon anhydrase (CA)-IX, glucose transporter (GLUT)-1, phosphorylated protein kinase B (pAKT), phosphorylated S6 protein (pS6) and vascular endothelial growth factor (VEGF). Four observers independently assessed the findings.

RESULTS

Of the 10 IH samples, 2 appeared to be in the growth phase. In all samples, GLUT-1, BNIP3, pAKT and VEGF were positive, CA-IX was weakly positive, and HIF1α was negative. pS6 was positive in 9/10 cases and negative in 1/10.

CONCLUSIONS

Several factors implicated in hypoxia-induced angiogenesis may be involved in IH development. However, the small sample size and retrospective approach of the study preclude definitive conclusions. Prospective studies are needed to conclusively determine which of the factors involved in the (hypoxia) cascade are required for an IH to grow, and could thus be a possible target of drugs for IH treatment.

Infantile hemangioma-like vascular lesion in a 26-year-old woman after abortion

A 26-year-old woman (G2P1A1) presented with a 5-week history of multiple red marks on her body after a therapeutic abortion. A physical examination found 15 palpable red marks on her head, neck, chest, arms and legs. Proliferating endothelial cells, which expressed CD31, CD34, von Willebrand factor, but not Glut-1 and merosin, were observed in the lesional area by histopathological analyses. Histocompatibility antigen typing of 2 lesions was identical to a sample from peripheral blood. Accelerated regression was observed in 2 lesions treated by intralesional injection of betamethasone, while spontaneous regression was observed within 9 months in the remaining lesions without any treatment. Rapid growth, spontaneous regression and histological analyses in this case support the diagnosis of 'infantile hemangioma-like vascular lesion'.

A novel oxygen carrier "YQ23" suppresses the liver tumor metastasis by decreasing circulating endothelial progenitor cells and regulatory T cells

Background

Surgical therapies are the first-line treatments for hepatocellular carcinoma (HCC) patients. However, the high incidence of tumor metastasis after liver surgery remains a severe problem. We aim to investigate the roles and the underlying mechanism of YQ23, stabilized non-polymeric diaspirin cross-linked tetrameric hemoglobin, in liver tumor metastasis after major hepatectomy and partial hepatic ischemia reperfusion (I/R) injury.

Methods

An orthotopic liver tumor model in Buffalo rat was established using the hepatocellular carcinoma cell line McA-RH7777. Major hepatectomy for tumor-bearing lobe and partial hepatic I/R injury were performed at two weeks after orthotopic liver tumor implantation. YQ23 (0.2 g/kg) was administered at 1 hour before ischemia and immediately after reperfusion. Blood samples were collected at day 0, 1, 7, 14, 21 and 28 for detection of circulating endothelial progenitor cells (EPCs) and regulatory T cells (Tregs).

Results

Our results showed that YQ23 treatment effectively inhibited intrahepatic and lung metastases together with less tumor angiogenesis at 4 weeks after major hepatectomy and partial hepatic I/R injury. The levels of circulating EPCs and Tregs were significantly decreased in YQ23 treatment group. Furthermore, YQ23 treatment also increased liver tissue oxygenation during hepatic I/R injury. Up-regulation of HO1 and down-regulation of CXCR3, TNF-α and IL6 were detected after YQ23 treatment.

Conclusions

YQ23 treatment suppressed liver tumor metastasis after major hepatectomy and partial hepatic I/R injury in a rat liver tumor model through increasing liver oxygen and reducing the populations of circulating EPCs and Tregs.

Current classification and terminology of pediatric vascular anomalies

OBJECTIVE

The purpose of this article is to review new terminology to diagnose, classify, and refer patients with vascular anomalies for additional imaging, intervention, and treatment.

CONCLUSION

In recent decades, much has been learned regarding the histopathology, cause, and treatment of vascular anomalies. As information has been gleaned, a new classification system has emerged that divides vascular anomalies into neoplasms and malformations. Its utility is based on accurate initial diagnosis that correlates consistently with clinical presentation, disease course, and treatment.

Age-related changes in brain support cells: Implications for stroke severity

Stroke is one of the leading causes of adult disability and the fourth leading cause of mortality in the US. Stroke disproportionately occurs among the elderly, where the disease is more likely to be fatal or lead to long-term supportive care. Animal models, where the ischemic insult can be controlled more precisely, also confirm that aged animals sustain more severe strokes as compared to young animals. Furthermore, the neuroprotection usually seen in younger females when compared to young males is not observed in older females. The preclinical literature thus provides a valuable resource for understanding why the aging brain is more susceptible to severe infarction. In this review, we discuss the hypothesis that stroke severity in the aging brain may be associated with reduced functional capacity of critical support cells. Specifically, we focus on astrocytes, that are critical for detoxification of the brain microenvironment and endothelial cells, which play a crucial role in maintaining the blood brain barrier. In view of the sex difference in stroke severity, this review also discusses studies of middle-aged acyclic females as well as the effects of the estrogen on astrocytes and endothelial cells.

Treatment of superficial infantile hemangiomas with timolol: Evaluation of short-term efficacy and safety in infants

Timolol has been demonstrated to be efficacious in the topical treatment of superficial infantile hemangiomas (IHs). We conducted a prospective study to evaluate the short-term efficacy and safety of timolol in the treatment of superficial IH in Chinese infants. From March to November 2012, 124 patients with superficial IHs were included in the prospective study. The patients were divided into two groups: treatment (101 patients, the timolol drops were administered on the surface of the lesions three times daily, and erythromycin ointment was applied around the lesions) and observation (23 patients, without treatment). The results were categorized into three grades: class 1 (ineffective), class 2 (controlled growth) and class 3 (promoted regression). Within one week of the initiation of timolol treatment, a number of the lesions became softer and lighter in color. Four months following the initiation of timolol treatment, the overall response was class 1 in eight patients (7.9%), class 2 in 36 patients (35.6%) and class 3 in 57 patients (56.4%). Complete tumor regression was observed in 12 patients. No adverse effects were recorded during the treatment period. Among the patients in the observation group, there were 15 class 1 patients (65.2%), seven class 2 patients (30.4%) and only one class 3 patient (4.3%). In conclusion, timolol is an effective and safe treatment for superficial IH. In addition, it may be used in the treatment of proliferative superficial IH, particularly in infants within 6 months of age.

Hypoxia-induced autophagy in endothelial cells: a double-edged sword in the progression of infantile haemangioma?

AIMS

The aim of this study was to investigate the precise role of hypoxia-induced autophagy in endothelial cells, and whether it contributes to the distinctive progression of infantile haemangioma (IH).

METHODS AND RESULTS

The endothelial cells (EOMA and HUVECs) were cultured under hypoxic conditions for indicated times (0-72 h). The results showed that short exposure of the endothelial cells to hypoxia resulted in increased cell survival and proliferation, accompanied by occurrence of autophagy. Prolonged hypoxia-induced autophagy, correlating with increased cell death, was also detected afterwards. Correspondingly, autophagy inhibition prevented the enhanced cell survival and proliferation capacity, advanced the occurrence of cell-death in early hypoxic stage, and meanwhile attenuated the ability of prolonged hypoxia in cell-death induction. Moreover, our data demonstrated that the functional transformation of hypoxia-induced autophagy, pro-survival to pro-death, was rigorously regulated by the switch between hypoxia-inducible factor-1α (HIF-1α) and mammalian target of rapamycin (mTOR) pathways. Importantly, we also revealed the activation levels of HIF-1α and mTOR, as well as the autophagy status during the progression of IH.

CONCLUSION

This study unmasks the functional switch between HIF-1α and mTOR in regulating hypoxia-induced autophagy in endothelial cells and, more importantly, indicates its potential role in the progression of IH.

Propranolol induces regression of hemangioma cells through HIF-1α-mediated inhibition of VEGF-A

OBJECTIVE

To investigate the mechanism of propranolol on regression of infantile hemangiomas.

BACKGROUND

Propranolol has been found to be effective in treatment of severe hemangiomas of infancy. However, its mechanism of action is as yet unknown.

METHODS

Cultured proliferating and involuting hemangioma endothelial cells were treated with varying concentrations of propranolol for up to 4 days. Analysis was performed using cell viability, migration, and tubulogenesis assays, as well as quantitative RT-PCR and flow cytometry. Western blots and ELISA assays were used to assess protein expression.

RESULTS

Treatment with propranolol led to a dose dependent cytotoxic effect in hemangioma endothelial cells with decreased cell viability, migration, and tubulogenesis. This cytotoxic effect was VEGF (vascular endothelial growth factor) dependent, as demonstrated by decreased VEGF, VEGF-R1, and VEGF-R2 production. Decreased signaling through the VEGF pathway resulted in downregulation of PI3/Akt and p38/MAPK activity. Decreased VEGF activity was mediated through the hypoxia inducible factor (HIF)-1α pathway but not through NF-κβ signaling.

CONCLUSIONS

Collectively, these data suggest that propranolol exerts its suppressive effects on hemangiomas through the HIF-1α-VEGF-A angiogenesis axis, with effects mediated through the PI3/Akt and p38/MAPK pathways. These findings provide a plausible mechanism of action of propranolol on regression of infantile hemangiomas.

Pathogenesis of infantile hemangiomas

1.Review the key features of the life cycle of infantile hemangiomas.2.Highlight cellular and molecular pathways involved in hemangioma-genesis.3.Discuss theories that may account for hemangioma-genesis.In the past, it was believed that a mother's visual impressions or behavior during pregnancy caused the growth of infantile hemangioma in her unborn child. She might have had an excessive craving for strawberries, witnessed the slaughter of an animal, directly contacted human or animal blood, or mocked a child with a similar birthmark.1 This folklore began to slowly fade once hemangiomas were examined through the light microscope. In 1863, Virchow2 suggested that hemangiomas are composed of proliferating new blood vessels resulting from progressive irritation of tissue. In 1933, Laidlow and Murray3 proposed a phylogenetic origin for hemangiomas and hypothesized that hemangiomas are remnants of vascular tufts functioning as accessory lungs for primitive amphibia. Pack and Miller4 (1950) hypothesized that hemangiomas develop from embryonic islands of angioblastic cells that were isolated from the systemic vasculature during fetal development.

Evaluation of intra-lesional corticosteroids in the treatment of peri-ocular haemangioma of infancy: still an alternative besides propranolol

PURPOSE

Haemangioma of infancy (HOI) is the most frequently occurring benign tumour of infancy. Alarming HOI require treatment. Current therapy is empirically based; corticosteroids are often administered but in recent publications propranolol was reported to be more effective. Peri-ocular HOI are highly sensitive to corticosteroids. Our goal was to evaluate the effectiveness of intra-lesional corticosteroids in the treatment of peri-ocular HOI.

METHODS

We selected all patients with peri-ocular HOI who had only been treated with intra-lesional corticosteroids at our hospital from 1993 until 2009. Treatment was standardized according to a prospective protocol.

RESULTS

A total of n = 34 patients were included. There were no complications at all after therapy. A second intra-lesional injection was necessary in five patients. At follow-up after 6 and 12 months after injection, 94 and 91% of the patients, respectively, had regression of the HOI. Astigmatism, Haemangioma Activity Score and global assessments all had improved after therapy.

CONCLUSIONS

This study shows that intra-lesional therapy with corticosteroids is very safe in the treatment of peri-ocular HOI. It remains a good and safe alternative besides propranolol or when propranolol therapy is not possible (e.g. asthma, PHACE syndrome, and certain cardiac diseases).

Refractive and structural changes in infantile periocular capillary haemangioma treated with propranolol

PURPOSE

To evaluate the optical and anatomical effects of oral propranolol treatment for infantile periocular capillary haemangioma.

METHODS

All children diagnosed with infantile capillary haemangioma in 2008-2010 at a tertiary paediatric medical centre underwent comprehensive evaluation, including imaging, by a multidisciplinary team followed by oral propranolol treatment. Clinical follow-up was performed regularly until the lesions disappeared. Main outcome measures included changes in anatomical extraocular extension, refractive sphere and cylindrical power, and spherical equivalent in the involved eye before and after treatment and between the two eyes.

RESULTS

A total of 30 patients (8 male; mean age at diagnosis, 1.6±2.8 months) participated. The lesions affected the left eye in 53.3% and were located preseptally in 83.3%. Four patients (13.3%) received steroids before propranolol. A treatment dosage of 2 mg/kg per day was started at mean age 5.0±4.5 months, 3.3±4.3 months from disease onset. Side effects occurred in 11 patients and warranted a dose reduction (to 1 mg/kg per day) in 3 and treatment termination in 1. Findings were significant for mean reduction in involved extraocular area (P<0.0001), post-treatment reduction in mean cylindrical power in involved eyes (P=0.02), pre- and post-treatment differences in mean cylindrical power between involved and uninvolved eyes (P=0.02 and P=0.01, respectively), and post-treatment change in absolute values of mean spherical power between involved and uninvolved eyes (P=0.025).

CONCLUSIONS

Early diagnosis of infantile periocular capillary haemangioma and prompt treatment with propranolol lead to a significant reduction in the involved ocular area, in astigmatism, and prevent ocular/facial disfiguration/deformation, without rebound. Propranolol is recommended as the preferred treatment compared with other accepted therapies.

Infantile haemangioma: part I. Pathophysiology, epidemiology, clinical features, life cycle and associated structural abnormalities

Infantile haemangioma (IH) is the most common tumour of infancy. Its typical natural history is characterized by an early rapid growth following birth and a slow spontaneous regression phase within a period of 3 to 7 years. The exact aetiopathogeny underlying IH is still to be fully understood, but the role of fetal hypoxic stress is strongly suggested as a triggering signal in epidemiological studies. IH are composed of a complex mixture of cells including multipotent stem cells, a majority of immature endothelial cells, pericytes, dendritic cells and in the late stage, adipocytes. Most of IH are nodular and are not associated with malformations. However, in some cases, IH referred to as segmental may be associated with developmental abnormalities such as PHACES and PELVIS/SACRAL syndromes.

Successful treatment of infantile haemangiomas of the orbit with propranolol

BACKGROUND

Propranolol is a novel therapeutic agent in the treatment of cutaneous infantile haemangiomas. We assessed the effect of propranolol therapy in infantile haemangiomas of the orbit.

METHODS

A case series of four patients with orbital infantile haemangiomas were referred for management in our tertiary referral hospitals. Two of the patients had inadequate responses to prior corticosteroid therapy. One of the patients was commenced on propranolol at 2.5 years of age when the lesion was not in the proliferative phase. This represented the first case report of propranolol treatment for infantile haemangioma outside infancy. The other three children were in their infancy when propranolol was commenced. The patients were treated with oral propranolol.

RESULTS

All patients had significant improvement in their physical appearance, ocular examination findings and size of their lesions on radiological evaluation. No side-effects of propranolol treatment were observed.

CONCLUSIONS

Propranolol is a promising treatment against infantile haemangiomas in the orbit, not only in infants but also in an older child with a stable lesion.