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Increased apoptosis and secretion of tryptase by mast cells in infantile haemangioma treated with propranolol. Pathology 2014; 46:496-500. [PMID: 25158819 DOI: 10.1097/pat.0000000000000143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Propranolol is increasingly used to treat problematic infantile haemangioma (IH), although its molecular mechanisms remain unclear. A key feature of propranolol therapy is the decreased deposition of fibrofatty residuum compared with spontaneously involuting IH. This study investigated the molecular consequences of propranolol treatment for IH in vivo.Immunohistochemical and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining was performed on five age matched patients with proliferative IH. Two patients (A and B) were undergoing propranolol treatment at the time of surgical resection.Propranolol treatment increased apoptosis, and induced mast cells to degranulate and secrete tryptase into the interstitium. The microvessels of patient A were immature [weak von Willibrand Factor (vWF), and strong osteoprotegerin (OPG) staining], comparable to untreated proliferative IH, while those of patient B were mature (strong vWF staining, and no OPG staining). The perivascular CD90 mesenchymal stem cell population was preserved in both propranolol treated patients.Using rarely obtained biopsies from IH patients treated with propranolol, we show increased apoptosis by propranolol for the first time in vivo. We also suggest that mast cells, through secreted proteases, may contribute to the decreased fibrofatty residuum seen with propranolol treatment.
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Lee D, Boscolo E, Durham JT, Mulliken JB, Herman IM, Bischoff J. Propranolol targets the contractility of infantile haemangioma-derived pericytes. Br J Dermatol 2014; 171:1129-37. [PMID: 24720697 DOI: 10.1111/bjd.13048] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/06/2014] [Indexed: 12/25/2022]
Abstract
BACKGROUND Propranolol, a β-adrenergic receptor (AR) antagonist, is an effective treatment for endangering infantile haemangioma (IH). Dramatic fading of cutaneous colour is often seen a short time after initiating propranolol therapy, with accelerated regression of IH blood vessels discerned after weeks to months. OBJECTIVES To assess a possible role for haemangioma-derived pericytes (HemPericytes) isolated from proliferating and involuting phase tumours in apparent propranolol-induced vasoconstriction. METHODS HemPericytes were assayed for contractility on a deformable silicone substrate: propranolol (10 μmol L(-1)) restored basal contractile levels in HemPericytes that were relaxed with the AR agonist epinephrine. Small interfering RNA knockdown of β2-AR blunted this response. HemPericytes and haemangioma-derived endothelial cells were co-implanted subcutaneously in nude mice to form blood vessels; at day 7 after injection, mice were randomized into vehicle and propranolol-treated groups. RESULTS HemPericytes expressed high levels of β2-AR mRNA compared with positive control bladder smooth muscle cells. In addition, β2-AR mRNA levels were relatively high in IH specimens (n = 15) compared with β1-AR, β3-AR and α1b-AR. Normal human retinal and placental pericytes were not affected by epinephrine or propranolol in this assay. Propranolol (10 μmol L(-1)) inhibited the proliferation of HemPericytes in vitro, as well as normal pericytes, indicating a nonselective effect in this assay. Contrast-enhanced microultrasonography of the implants after 7 days of treatment showed significantly decreased vascular volume in propranolol-treated animals, but no reduction in vehicle-treated animals. CONCLUSIONS These findings suggest that the mechanism of propranolol's effect on proliferating IH involves increased pericytic contractility.
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Affiliation(s)
- D Lee
- Vascular Biology Program and Department of Surgery, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, U.S.A
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Phillips RJ, Lokmic Z, Crock CM, Penington A. Infantile haemangiomas that failed treatment with propranolol: clinical and histopathological features. J Paediatr Child Health 2014; 50:619-25. [PMID: 24905852 DOI: 10.1111/jpc.12600] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/05/2014] [Indexed: 12/28/2022]
Abstract
AIM To describe the clinical and histopathological characteristics of infantile haemangiomas that failed treatment with oral propranolol . DESIGN This study is a case series from the vascular birthmarks clinic at Royal Children's Hospital, Melbourne. PATIENTS The patients for this study were infants who commenced treatment with oral propranolol before 6 months of age and who were treated for at least 4 months without a satisfactory result. For histology and immunohistochemistry, tissue from the four non-responding patients who subsequently underwent surgical excision was matched with four historical controls. OUTCOME MEASURES Based on medical record review and photographic assessments, infants were defined as having failed treatment with oral propranolol if the infantile haemangioma either continued to grow or showed 20% improvement or less. Tissue sections were examined for tissue structure, mast cells, sympathetic innervations and beta-2 adrenergic receptor expression, and the number of mast cells and beta-2 adrenergic positive cells. RESULTS From a group of 135 infants who met the inclusion criteria, 14 infants failed propranolol treatment. Eleven of these infants had focal facial haemangiomas. No difference was seen in tissue morphology, tissue innervations, beta-2 adrenergic receptor expression, cell number or mast cell distribution, and number between non-responding and control haemangiomas. CONCLUSION We report a treatment failure rate of 10%, which is higher than previously reported. Focal facial lesions failed to respond twice as frequently as other types of haemangioma. No histopathological reason was identified to indicate why some haemangiomas failed to respond.
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Affiliation(s)
- Roderic J Phillips
- Vascular Biology, Murdoch Children's Research Institute, Melbourne, Victoria, Australia; Paediatrics, Monash University, Melbourne, Victoria, Australia
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Simavli H, Erdurmus M, Terzi EH, Bucak YY, Önder Hİ, Kükner AŞ. The effect of β receptor blockade through propranolol on corneal neovascularization. J Ocul Pharmacol Ther 2014; 30:650-6. [PMID: 24983781 DOI: 10.1089/jop.2013.0238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
PURPOSE To evaluate the inhibitory effects of propranolol, a nonselective and lipophilic β-adrenergic receptor blocker, on alkali-induced corneal neovascularization (NV). METHODS Corneal NV was induced in 24 eyes of 24 Wistar rats using NaOH. Following alkali burn, animals were randomized into 4 groups according to topical treatment. Group I received 0.9% NaCl, Group II received preservative-free dexamethasone sodium phosphate 1 mg/mL, Group III received propranolol hydrochloride 1 mg/mL, and Group IV received 0.5 mg/mL propranolol hydrochloride drops twice a day for 7 days. The inhibitory effects of the drugs were compared as the percent areas of cornea covered by NV. Anti-vascular endothelial growth factor (VEGF) and anti-active caspase-3 immunostainings were also performed in corneal sections. RESULTS The median percent area of corneal NV was 59% (40.3-65.6) in Group I, 25.5% (20.9-43.4) in Group II, 68.9% (36.7-78.0) in Group III, and 50.4% (42.2-63.3) in Group IV. Group III and IV did not show any difference in comparison to Group I. Group II showed a statistically significant smaller area of corneal NV compared with Group I, III, and IV (P=0.004 for each comparison). Anti-VEGF immunostaining was significantly less in Group II compared with the other groups. Anti-active caspase-3 immunostaining was not different among the treatment groups. CONCLUSIONS Topical propranolol 1 or 0.5 mg/mL does not have a significant inhibitory effect on alkali-induced corneal NV in rats.
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Affiliation(s)
- Hüseyin Simavli
- 1 Ophthalmology Clinic, Izzet Baysal State Hospital , Bolu, Turkey
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Ma X, Zhao T, Ouyang T, Xin S, Ma Y, Chang M. Propranolol enhanced adipogenesis instead of induction of apoptosis of hemangiomas stem cells. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2014; 7:3809-3817. [PMID: 25120757 PMCID: PMC4128992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Accepted: 06/23/2014] [Indexed: 06/03/2023]
Abstract
Propranolol has been widely used in treating infantile hemangiomas (IHs). But recurrence of IHs was found in some cases on cessation of propranolol treatment. The other is that Chinese individuals reacted to propranolol differently from American Whites. Whether the difference of sensitivity is due to the β adrenoceptor (β-AR) expression pattern of hemangioma initiating cells remains unclear. In the present study, we isolated hemangioma-derived stem cells (hemSCs) from proliferative IHs and analyzed the biological characteristics and β-AR expression pattern of hemSCs by immunostaining, Western blotting and multilineage differentiation assay as well. We also tested the effects of propranolol on hemSCs by evaluating VEGF expression, proliferation and apoptosis related parameters. Our results indicated that CD133(+) hemSCs located pre-vascular in proiferative IH tissues. Both β1 and β2-AR were expressed, while β2-AR was dominant on hemSCs. Propranolol at 100-150 μM inhibited proliferation of hemSCs, not did 50 μM. Propranolol down-regulated VEGF expression of hemSCs, instead of inducing apoptosis. The adipogenic potential was enhanced by propranolol. Therefore, our current results suggested propranolol could not induce apoptosis of hemSCs, but played a curative role though suppressing VEGF synthesis and enhancement of adipogenesis of hemSCs. Our results might partially provide the insight of mechanism of relapse in some cases on cessation of propranolol treatment.
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Affiliation(s)
- Xiaorong Ma
- Department of Plastic and Reconstructive Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China
| | - Tinghui Zhao
- Department of Plastic and Reconstructive Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China
| | - Tianxiang Ouyang
- Department of Plastic and Reconstructive Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China
| | - Shujia Xin
- Department of Nursing, Huadong Hospital, Shanghai Fudan UniversityShanghai, China
| | - Yueting Ma
- Department of Plastic and Reconstructive Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China
| | - Mengling Chang
- Department of Plastic and Reconstructive Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China
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Ou JM, Yu ZY, Qiu MK, Dai YX, Dong Q, Shen J, Wang XF, Liu YB, Quan ZW, Fei ZW. Knockdown of VEGFR2 inhibits proliferation and induces apoptosis in hemangioma-derived endothelial cells. Eur J Histochem 2014; 58:2263. [PMID: 24704994 PMCID: PMC3980207 DOI: 10.4081/ejh.2014.2263] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 01/29/2014] [Accepted: 02/03/2014] [Indexed: 01/14/2023] Open
Abstract
Angiogenesis is a process of development and growth of new capillary blood vessels from pre-existing vessels. Angiogenic growth factors play important roles in the development and maintenance of some malignancies, of which vascular endothelial growth factor (VEGF)/VEGFR2 interactions are involved in proliferation, migration, and survival of many cancer cells. The aim of this study was to investigate the function of VEGFR2 in human hemangiomas (HAs). Using immunohistochemistry assay, we examined the expression levels of VEGF, VEGFR2, Ki-67, glucose transporter-1 (Glut-1), phosphorylated protein kinase B (p-AKT) and p-ERK in different phases of human HAs. Positive expression of VEGF, VEGFR2, Ki-67, Glut-1, p-AKT and p-ERK was significantly increased in proliferating phase HAs, while decreased in involuting phase HAs (P=0.001; P=0.003). In contrast, cell apoptotic indexes were decreased in proliferating phase HAs, but increased in involuting phase HAs (P<0.01). Furthermore, we used small hairpin RNA (shRNA)-mediated VEGFR2 knockdown in primary HA-derived endothelial cells (HemECs) to understand the role of VEGF/VEGFR2 signaling. Knockdown of VEGFR2 by Lv-shVEGFR2 inhibited cell viability and induced apoptosis in primary HemECs companied with decreased expression of p-AKT, p-ERK, p-p38MAPK and Ki-67 and increased expression of caspase-3 (CAS-3). Overexpression of VEGFR2 promoted cell viability and blocked apoptosis in Lv-VEGFR2-transfected HemECs. Taken together, our findings demonstrate that, increased expression of VEGFR2 is involved in the development of primary HemECs possibly through regulation of the AKT and ERK pathways, suggesting that VEGFR2 may be a potential therapeutic target for HAs.
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Propranolol inhibits growth of hemangioma-initiating cells but does not induce apoptosis. Pediatr Res 2014; 75:381-8. [PMID: 24296797 PMCID: PMC3951485 DOI: 10.1038/pr.2013.231] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 07/26/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND Infantile hemangioma (IH) is the most common tumor of infancy. The first-line therapy for IH is propranolol, a nonselective β-adrenergic receptor antagonist. However, mechanisms for the therapeutic effect of propranolol and regrowth of IH following cessation of treatment in some cases are not clear. We have recently shown that IH arises from multipotent stem cells. Whether IH stem cells are responsive to propranolol and are selectively targeted is unknown, and this is the focus of this study. METHODS IH stem cells were exposed to propranolol and were assayed for cellular and molecular alterations. We used endothelial cells (ECs) as controls and bone marrow-derived mesenchymal progenitor cells (bm-MPCs) as normal stem/progenitor counterparts to determine selectivity. RESULTS Our results show that propranolol significantly reduced IH stem cell growth but failed to induce caspase-3 activation. Normal bm-MPCs and mature ECs showed maintained or increased caspase-3 activation and significantly reduced cyclin-D1 levels. We further show that IH stem cells may escape apoptosis by inducing antiapoptotic pathways. CONCLUSION This study reveals that propranolol does not induce apoptosis in IH stem cells, which is in contrast with the result for ECs. Escape from apoptosis in IH stem cells may involve induction of antiapoptotic pathways.
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Reply to letter: "propranolol: a novel antihemangioma agent with multiple potential mechanisms of action". Ann Surg 2014; 261:e53. [PMID: 24374536 DOI: 10.1097/sla.0000000000000453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Shehata N, Powell J, Dubois J, Hatami A, Rousseau E, Ondrejchak S, McCuaig C. Late rebound of infantile hemangioma after cessation of oral propranolol. Pediatr Dermatol 2013; 30:587-91. [PMID: 24016283 DOI: 10.1111/pde.12190] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Propranolol has become the first line of treatment for infantile hemangiomas (IHs), with a high response rate, but rebound growth after cessation of propranolol has been reported, primarily in the first year of life. We sought to determine the frequency and associated factors leading to late regrowth after successful treatment at an age when the proliferative phase has usually ceased. We retrospectively reviewed the clinical charts, serial photographs, and radiologic images of children with rebound IH occurring after the age of 15 months after a successful course of oral propranolol averaging 2.6 mg/kg/day (range 2-3 mg/kg/day). Thirteen (10 female, 3 male) of 212 patients (6%) treated with oral propranolol since 2008 were evaluated. The mean age at the start of treatment was 5.3 months (range 1.8-13 months), and an average of 10.3 months (range 4.5-16 months) of treatment was given. It took an average of 5.3 months (range 1-13.8 months) for a significant rebound to appear. Late rebound after successful propranolol indicates a prolonged proliferation phase of IH even after 15 months of age. This is compared with previous reports of rebound, which occurred primarily in infants younger than 1 year old. Late proliferation can occur in localized, small, mixed, and deep IH, even after several months of a positive response to propranolol. A second course of propranolol readily controlled the recurrence.
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Affiliation(s)
- Nancy Shehata
- Division of Dermatology, Department of Pediatrics, CHU Sainte-Justine, University of Montreal, Quebec, Canada
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Hong P, Tammareddi N, Walvekar R, Chiu ES, Poole JC, Kluka EA, Simon LM. Successful discontinuation of propranolol for infantile hemangiomas of the head and neck at 12 months of age. Int J Pediatr Otorhinolaryngol 2013; 77:1194-7. [PMID: 23706952 DOI: 10.1016/j.ijporl.2013.04.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 04/09/2013] [Accepted: 04/29/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND Although propranolol can be an effective primary medical therapy for infantile hemangiomas of the head and neck, the duration of treatment and time to discontinue propranolol is unclear. OBJECTIVE The objective of this study is to determine the duration of treatment and age at which propranolol may be successfully discontinued in children with infantile hemangiomas of the head and neck. METHODS A review of all patients presenting to a pediatric vascular anomalies clinic from January 2008 to December 2011 was performed. Those with head and neck infantile hemangiomas who completed propranolol therapy were included. Each patient's records were reviewed for demographics, clinical response to propranolol, age at discontinuation of propranolol, and adverse events. RESULTS Forty-five patients were included for review (mean age at presentation, 3.5 months) with all demonstrating positive responses. The mean age at discontinuation of propranolol was 11.8 months of age (range, 8-15 months) with a mean treatment duration of 6.5 months (range, 3-11 months). No recurrences were noted over a mean follow-up period of 19.9 months (range, 10-28 months). CONCLUSION Discontinuation of propranolol at approximately 12 months of age was found to be appropriate in our study population.
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Affiliation(s)
- Paul Hong
- IWK Health Centre, Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, Dalhousie University, Halifax, NS, Canada.
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Stiles JM, Amaya C, Rains S, Diaz D, Pham R, Battiste J, Modiano JF, Kokta V, Boucheron LE, Mitchell DC, Bryan BA. Targeting of beta adrenergic receptors results in therapeutic efficacy against models of hemangioendothelioma and angiosarcoma. PLoS One 2013; 8:e60021. [PMID: 23555867 PMCID: PMC3610939 DOI: 10.1371/journal.pone.0060021] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 02/21/2013] [Indexed: 12/14/2022] Open
Abstract
Therapeutic targeting of the beta-adrenergic receptors has recently shown remarkable efficacy in the treatment of benign vascular tumors such as infantile hemangiomas. As infantile hemangiomas are reported to express high levels of beta adrenergic receptors, we examined the expression of these receptors on more aggressive vascular tumors such as hemangioendotheliomas and angiosarcomas, revealing beta 1, 2, and 3 receptors were indeed present and therefore aggressive vascular tumors may similarly show increased susceptibility to the inhibitory effects of beta blockade. Using a panel of hemangioendothelioma and angiosarcoma cell lines, we demonstrate that beta adrenergic inhibition blocks cell proliferation and induces apoptosis in a dose dependent manner. Beta blockade is selective for vascular tumor cells over normal endothelial cells and synergistically effective when combined with standard chemotherapeutic or cytotoxic agents. We demonstrate that inhibition of beta adrenergic signaling induces large scale changes in the global gene expression patterns of vascular tumors, including alterations in the expression of established cell cycle and apoptotic regulators. Using in vivo tumor models we demonstrate that beta blockade shows remarkable efficacy as a single agent in reducing the growth of angiosarcoma tumors. In summary, these experiments demonstrate the selective cytotoxicity and tumor suppressive ability of beta adrenergic inhibition on malignant vascular tumors and have laid the groundwork for a promising treatment of angiosarcomas in humans.
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Affiliation(s)
- Jessica M. Stiles
- Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas, United States of America
| | - Clarissa Amaya
- Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas, United States of America
| | - Steven Rains
- Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas, United States of America
| | - Dolores Diaz
- Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas, United States of America
| | - Robert Pham
- Klipsch School of Electrical and Computer Engineering, New Mexico State University, Las Cruces, New Mexico, United States of America
| | - James Battiste
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Jaime F. Modiano
- Masonic Cancer Center, Department of Veterinary Clinical Sciences, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Victor Kokta
- Department of Pathology, CHU Sainte-Justine, University of Montreal, Montreal, Quebec, Canada
| | - Laura E. Boucheron
- Klipsch School of Electrical and Computer Engineering, New Mexico State University, Las Cruces, New Mexico, United States of America
| | - Dianne C. Mitchell
- Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas, United States of America
| | - Brad A. Bryan
- Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas, United States of America
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Stiles JM, Rowntree RK, Amaya C, Diaz D, Kokta V, Mitchell DC, Bryan BA. Gene expression analysis reveals marked differences in the transcriptome of infantile hemangioma endothelial cells compared to normal dermal microvascular endothelial cells. Vasc Cell 2013; 5:6. [PMID: 23531100 PMCID: PMC3655845 DOI: 10.1186/2045-824x-5-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 03/13/2013] [Indexed: 01/11/2023] Open
Abstract
Background Infantile hemangiomas are benign vascular tumors primarily found on the skin in 10% of the pediatric population. The etiology of this disease is largely unknown and while large scale genomic studies have examined the transcriptomes of infantile hemangioma tumors as a whole, no study to date has compared the global gene expression profiles of pure infantile hemangioma endothelial cells (HEMECs) to that of normal human dermal microvascular endothelial cells (HDMVECs). Methods To shed light on the molecular differences between these normal and aberrant dermal endothelial cell types, we performed whole genome microarray analysis on purified cultures of HEMECs and HDMVECs. We then utilized qPCR and immunohistochemistry to confirm our microarray results. Results Our array analysis identified 125 genes whose expression was upregulated and 104 genes whose expression was downregulated by greater than two fold in HEMECs compared to HDMVECs. Bioinformatics analysis revealed three major classifications of gene functions that were altered in HEMECs including cell adhesion, cell cycle, and arachidonic acid production. Several of these genes have been reported to be critical regulators and/or mutated in cancer, vascular tumors, and vascular malformations. We confirmed the expression of a subset of these differentially expressed genes (ANGPT2, ANTXR1, SMARCE1, RGS5, CTAG2, LTBP2, CLDN11, and KISS1) using qPCR and utilized immunohistochemistry on a panel of paraffin embedded infantile hemangioma tumor tissues to demonstrate that the cancer/testis antigen CTAG2 is highly abundant in vessel-dense proliferating infantile hemangiomas and with significantly reduced levels during tumor involution as vascular density decreases. Conclusion Our data reveal that the transcriptome of HEMECs is reflective of a pro-proliferative cell type with altered adhesive characteristics. Moveover, HEMECs show altered expression of many genes that are important in the progression and prognosis of metastatic cancers.
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Affiliation(s)
- Jessica M Stiles
- Department of Biomedical Sciences, Paul L, Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX, USA.
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