Evaluation of Effect of Propranolol on Serum Vascular Endothelial Growth Factor and Tissue Inhibitor of Metalloproteinase-2 Levels in Infantile Hemangioma

Molecular Mechanisms of Carcinogenesis in Pediatric Airways Tumors

Primary tumors of the airways in the pediatric population are very rare entities. For this reason, little is known about the pathogenesis of these neoplasms. Understanding the biology has different practical implications: for example, it could help in the differential diagnosis, have a prognostic significance, or may lead to the development of a targeted therapy. The aim of this article is to present the current knowledge about pediatric airways tumors, focusing on the molecular mechanisms that cause the onset and progression of these neoplasms. After a brief introduction of epidemiology and clinical presentation, the tumorigenesis of the most frequent pediatric airways tumors will be described: Juvenile-onset recurrent respiratory papillomatosis (JORRP), Subglottic Hemangiona (SH), Rhabdomyosarcoma (RMS), and Mucoepidermoid carcinoma (MEC).

VEGF Pathway Gene Expression Profile of Proliferating versus Involuting Infantile Hemangiomas: Preliminary Evidence and Review of the Literature

Background. Infantile hemangiomas may have unexpected behavior. Initial regression (spontaneously or drug-induced) may be followed by unexplained recurrences. At this moment, there are no well-established criteria to predict infantile hemangioma reccurrences. Methods. We compared the VEGF pathway gene expression profile for one case of involuting infantile hemangioma versus one case of recurrent proliferative infantile hemangioma using TaqMan Array. Results. We found ten genes upregulated for both involuting and recurrent proliferative hemangiomas: ACTB, KRAS, MAP2K1, HRAS, NOS3, BAD, HSPB1, HPRT1, GUSB, and CASP9. Thirteen genes were downregulated for both involuting and proliferative hemangiomas: FIGF, ACTG1, GRB2, MAPKAPK2, ACTG2, MAP2K2, MAPK3, HSP90AA1, MAP2K6, NRAS, ACTA1, KDR, and MAPK1. Three genes showed divergent expression between proliferating and involuting hemangiomas. Proliferating hemangioma had MAPK14 and AKT1 gene upregulation and ACTA2 downregulation. Involuting infantile hemangioma was characterized by ACTA2 upregulation and AKT1 and MAPK14 downregulation. Conclusions. Three genes, AKT1, p38/MAPK14, and ACTA2, were found to have divergent expression in proliferating and involuting infantile hemangiomas. Excepting AKT1, which was mentioned in the last ISSVA classification (strictly related to Proteus Syndrome), none of the other genes were reported. An accurate gene expression profile mapping of infantile hemangiomas together with a gene expression-based hemangioma classification is stringently needed.

Propranolol in the Treatment of Infantile Hemangiomas

Propranolol, as the first generation of β-blocker family, was initially introduced in the clinical application for tachycardia and hypertension in the 1960s. However, the occasional discovery of propranolol in the involution of infantile hemangiomas (IHs) brought us a new perspective. IHs are the most common infantile tumor, affecting 4–10% newborns. So far, oral propranolol is the first-line medication for IHs treatment. At the same time, local injection and topical propranolol are developing. Despite the worldwide application, the precise mechanism of propranolol of IHs has not been completely studied. In this article, we reviewed and summarized the current information on pharmacology, mechanism, efficacy, and adverse effects of propranolol. Novel design of biomaterials and bioactive molecules are needed for new treatment and ideal pathway to attain the minimal effective treatment concentration and eliminate the adverse effects.

Ocular Versus Oral Propranolol for Prevention and/or Treatment of Oxygen-Induced Retinopathy in a Rat Model

Purpose: Propranolol, a nonselective B1/B2 adrenoceptor antagonist, promotes the regression of infantile hemangiomas likely through suppression of vascular endothelial growth factor (VEGF), which prompted its use for the prevention of retinopathy of prematurity. We tested the hypothesis that topical ocular propranolol is safe and effective for reducing the severity of oxygen-induced retinopathy (OIR) in the neonatal rat intermittent hypoxia (IH) model. Methods: At birth (P0), rat pups were randomly assigned to room air or neonatal intermittent hypoxia (IH) consisting of 50% O₂ with brief episodes of hypoxia (12% O₂) from P0 to P14, during which they received a single daily dose of oral propranolol (1 mg/kg/day in 50 μL in sterile normal saline) or topical ocular propranolol (0.2% in 10 μL in normal saline) from P5 to P14. Placebo-controlled littermates received 50 μL oral or 10 μL topical ocular sterile normal saline. Retinal vascular and astrocyte integrity; retinal histopathology and morphometry; and angiogenesis biomarkers were determined. Results: Topical ocular propranolol improved retinal vascular damage and preserved the astrocytic template, but did not completely prevent OIR. The beneficial effects of propranolol were associated with reduced ocular VEGF and increased endogenous soluble inhibitor, sVEGFR-1, when administered topically. Conclusions: Propranolol failed to completely prevent severe OIR, however, it prevented astrocyte degeneration resulting from neonatal IH-induced damage. We conclude that the mechanisms of propranolol's beneficial effects in neonatal IH may involve in part, astrocyte preservation.