Identification of Potential Therapeutics for Infantile Hemangioma via in silico Investigation and in vitro Validation.

Introduction: Infantile Hemangioma (IH) is a prevalent benign vascular tumor affecting approximately 5-10% of infants. Its underlying pathogenesis remains enigmatic, and current therapeutic approaches show limited effectiveness. Our study aimed to discover potential IH-associated therapeutics through a transcriptomic, computational drug repurposing methodology. Methods: Utilizing the IH-specific dataset GSE127487 from the Gene Expression Omnibus, we identified differentially expressed genes (DEGs) and conducted weighted gene coexpression network analysis (WGCNA). Subsequently, a protein-protein interaction (PPI) network was constructed to obtain the top 100 hub genes. Drug candidates were sourced from the Connectivity Map (CMap) and Comparative Toxicogenomics Database (CTD). Results: Our analysis revealed 1203 DEGs and a significant module of 1780 mRNAs strongly correlated with IH. These genes were primarily enriched in the PI3K/AKT/MTOR, RAS/MAPK, and CGMP/PKG signaling pathway. After creating a PPI network of overlapping genes, we filtered out the top 100 hub genes. Ultimately, 44 non-toxic drugs were identified through the CMap and CTD databases. Twelve molecular-targeting agents (belinostat, chir 99021, dasatinib, entinostat, panobinostat, sirolimus, sorafenib, sunitinib, thalidomide, U 0126, vorinostat, and wortmannin) may be potential candidates for IH therapy. Moreover, in vitro experiments demonstrated that entinostat, sorafenib, dasatinib, and sirolimus restricted the proliferation and migration and initiated apoptosis in HemEC cells, thereby underscoring their potential therapeutic value. Conclusion: Our investigation revealed that the pathogenic mechanism underlying IH might be closely associated with the PI3K/AKT/MTOR, RAS/MAPK, and CGMP/PKG signaling pathways. Furthermore, we identified twelve molecular-targeting agents among the predicted drugs that show promise as therapeutic candidates for IH.

Transcriptomic analysis used to discover potential therapeutics for Infantile Hemangioma (IH). Key IH-related pathways: PI3K/AKT/MTOR, RAS/MAPK, and CGMP/PKG signaling identified. Identified 44 non-toxic drugs as potential IH therapies via CMap and CTD. Twelve molecular agents show potential as IH therapy candidates. In vitro studies confirmed entinostat, sorafenib, dasatinib, and sirolimus inhibit HemEC cell proliferation and induce apoptosis.

IL13RA2 promotes progression of infantile haemangioma by activating glycolysis and the Wnt/ß-catenin signaling pathway.

Background: Interleukin 13 receptor subunit alpha 2 (IL13RA2) plays an essential role in the progression of many cancers. However, the role of IL13RA2 in infantile haemangioma (IH) is still unknown. Materials and Methods: IL13RA2 expression in IH tissues was analyzed using western blot, qRT-PCR, and immunofluorescence. The role of IL13RA2 in haemangioma-derived endothelial cells (HemECs) was determined following knockdown or overexpression of IL13RA2 using CCK-8, colony formation, apoptosis, wound healing, tubule formation, Transwell, and western blot. Results: IL13RA2 expression was upregulated in IH tissues. IL13RA2 overexpression promoted proliferation, migration, and invasion of HemECs and induced glycolysis, which was confirmed with a glycolysis inhibitor. Specifically, IL13RA2 interacted with ß-catenin and activated the Wnt/ß-catenin pathway in HemECs, which were involved in the above-mentioned effects of IL13RA2. Conclusions: These findings revealed that targeting IL13RA2 is a potential therapeutic approach for IH.

[Genetic analysis of a child with Hereditary hemorrhagic telangiectasia type I in conjunct with Splenic sinus shore cell hemangioma].

OBJECTIVE: To explore the genetic basis and pathogenesis for a child with type I Hereditary hemorrhagic telangiectasia (HHTⅠ) and Splenic sinus shore cell hemangioma (LCA). METHODS: A child with HHT complicated with LCA diagnosed at the First Affiliated Hospital of Dali University in April 2022 was selected as the study subject. Clinical data of the child and her relatives were collected, and pathogenic variants were screened by whole exome sequencing. Candidate variant was verified by Sanger sequencing and bioinformatic analysis. RESULTS: The patient, a 16-year-old female, had recurrent epitaxis since childhood, which sometimes necessitated hemostasis treatment. She also had splenectomy due to splenic rupture and was diagnosed with LCA. Her father and grandmother also had a history of recurrent epitaxis. Her father had deceased due to cerebral vascular rupture. The child was found to harbor a c.360+1G>A variant in the ENG gene. The same variant was not found in her asymptomatic mother and brother. CONCLUSION: The c.360+1G>A variant of the ENG gene probably underlay the pathogenesis in this child.

[Circumscribed choroidal hemangioma and non-pigmented choroidal melanoma: clinical, instrumental and molecular genetic features]. / Otgranichennaya gemangioma i bespigmentnaya melanoma khorioidei: kliniko-instrumental'nye i molekulyarno-geneticheskie osobennosti.

Circumscribed choroidal hemangioma (CCH) and early non-pigmented choroidal melanoma (CM) have similar clinical, ultrasound and morphometric features, which in some cases makes their differential diagnosis difficult. There are few studies in the literature devoted to a comparative analysis of the molecular genetic features of CCH and non-pigmented CM, and the results of those studies are contradictory. PURPOSE: This study attempts to develop a method of non-invasive molecular genetic differential diagnostics of CCH and non-pigmented CM. MATERIAL AND METHODS: Based on the results of clinical and instrumental examination methods, 60 patients (60 eyes) with CCH (n=30) and non-pigmented CM (n=30) were included in this prospective study. The control group consisted of 30 individuals without intraocular tumors. Mutations in the GNAQ/GNA11 genes were determined by real-time PCR using the analysis of genomic circulating tumor DNA isolated from peripheral blood plasma. The average follow-up period was 12.1±1.8 months. RESULTS: The study revealed a significant association of mutations in exons 4 and 5 of the GNAQ/GNA11 genes with the presence of non-pigmented CM (27/30; 90%). These mutations were not detected in the group of patients with CCH. Mutations in exons 4 and 5 of the GNAQ/GNA11 genes were also not detected in the control group of healthy individuals. CONCLUSION: This study proposes a method of non-invasive and low-cost differential diagnostics based on molecular genetic analysis and detection of mutations in exons 4 and 5 of the GNAQ and GNA11 genes, which are specific for CM (90%).

CCL2 regulated by the CTBP1-AS2/miR-335-5p axis promotes hemangioma progression and angiogenesis.

CONTEXT: Hemangioma (HA) is a benign vascular neoplasm that can lead to permanent scarring. C-C motif chemokine ligand 2 (CCL2) plays a crucial role in facilitating growth and angiogenesis during HA progression. However, the mechanism regulating CCL2 in HA remains poorly elucidated. OBJECTIVE: To elucidate the mechanism regulating CCL2 in HA. METHODS: Quantitative real-time polymerase chain reaction (RT-qPCR) was employed to determine the expression levels of CCL2, long noncoding RNA (lncRNA) CTBP1 divergent transcript (CTBP1-AS2), and microRNAs (miRNAs). Proliferation, migration, invasion, and angiogenic abilities of human HA endothelial cells (HemECs) were assessed using cell counting kit-8 (CCK-8), colony formation, flow cytometry, transwell, and tube formation assays. Bioinformatics analysis, RNA pull-down, and luciferase reporter assays were conducted to investigate whether CCL2 targets miR-335-5p. Additionally, rescue experiments were performed in this study. RESULTS: CCL2 expression was markedly upregulated in HemECs. CCL2 promoted HA cell proliferation, migration, invasion, and angiogenesis while inhibiting apoptosis. CCL2 was directly targeted by miR-335-5p. Additionally, we found that CTBP1-AS2 could function as a competing endogenous RNA (ceRNA) to sponge miR-335-5p, thereby upregulating CCL2. CONCLUSION: Our findings suggest that targeting the CTBP1-AS2/miR-335-5p/CCL2 axis may hold promise as a therapeutic strategy for HA.

Whole exome sequencing of placental chorangioma.

INTRODUCTION: Placental chorangioma is a benign non-trophoblastic vascular proliferation of the placental chorion favored to represent hamartoma-like or hyperplastic capillary lesions. As the exact pathophysiology has not been established, we investigated the molecular characteristics of placental chorangiomas using exploratory whole exome sequencing. METHODS: Three cases were retrospectively selected and whole exome sequencing was performed on macrodissected lesions. DNA extraction, DNA quantification, library preparation and sequencing were performed with IDT xGen™ Exome Hybridization Panel v2 for library capture. Sequencing data was analyzed with an in-house bioinformatics pipeline for single-nucleotide variants and insertions/deletions. RESULTS: All neonates were delivered at term and had birth weights ranging from 11th-35th percentile for gestational age. All mothers presented with hypertensive disorder during pregnancy. Chorangiomas ranged from 0.7 cm to 5.1 cm and were well-circumscribed near the fetal surface. Case 1 showed a background of chorangiosis and acute subchorionitis, while case 2 had foci of chronic lymphocytic villitis. Whole exome sequencing did not reveal any significant pathologic variants. DISCUSSIONS: The absence of molecular alteration in placental chorangioma is likely indicative of the reactive/non-neoplastic nature of this lesion. The presence of compromised blood flow in the form of hypertensive disorders in our cases may be one of its underlying pathophysiologic mechanisms.

LUMBAR syndrome-OEIS complex overlap: A case series and review.

We present three new and six published infants with overlapping features of LUMBAR syndrome (lower body hemangioma, urogenital anomalies, spinal cord malformations, bony deformities, anorectal/arterial anomalies and renal anomalies) and OEIS complex (omphalocele, exstrophy, imperforate anus, and spinal defects), also known as cloacal exstrophy. OEIS is included under the recently proposed umbrella coined recurrent constellations of embryonic malformations (RCEMs). The RCEMs represent a phenotypically overlapping spectrum of rare disorders of caudal dysgenesis with unknown cause but likely shared pathogenesis. It has recently been proposed that LUMBAR be considered an RCEM. This report of infants with combined features of OEIS and LUMBAR is the first to demonstrate an overlap between LUMBAR and another RCEM, which supports LUMBAR's inclusion within the RCEM spectrum.

KLF2 Orchestrates Pathological Progression of Infantile Hemangioma through Hemangioma Stem Cell Fate Decisions.

Infantile hemangioma (IH) is the most prevalent vascular tumor during infancy, characterized by a rapid proliferation phase of disorganized blood vessels and spontaneous involution. IH possibly arises from a special type of multipotent stem cells called hemangioma stem cells (HemSCs), which could differentiate into endothelial cells, pericytes, and adipocytes. However, the underlying mechanisms that regulate the cell fate determination of HemSCs remain elusive. In this study, we unveil KLF2 as a candidate transcription factor involved in the control of HemSCs differentiation. KLF2 exhibits high expression in endothelial cells in proliferating IH but diminishes in adipocytes in involuting IH. Using a combination of in vitro culture of patient-derived HemSCs and HemSCs implantation mouse models, we show that KLF2 governs the proliferation, apoptosis, and cell cycle progression of HemSCs. Importantly, KLF2 acts as a crucial determinant of HemSC fate, directing their differentiation toward endothelial cells while inhibiting adipogenesis. Knockdown of KLF2 induces a proadipogenic transcriptome in HemSCs, leading to impaired blood vessel formation and accelerated adipocyte differentiation. Collectively, our findings highlight KLF2 as a critical regulator controlling the progression and involution of IH by modulating HemSC fate decisions.

Circulating Mesenchymal Stromal Cells in Patients with Infantile Hemangioma: Evaluation of Their Functional Capacity and Gene Expression Profile.

We previously published that in patients with infantile hemangioma (IH) at the onset (T0) colony forming unit-fibroblasts (CFU-Fs) are present in in vitro cultures from PB. Herein, we characterize these CFU-Fs and investigate their potential role in IH pathogenesis, before and after propranolol therapy. The CFU-F phenotype (by flow cytometry), their differentiation capacity and ability to support angiogenesis (by in vitro cultures) and their gene expression (by RT-PCR) were evaluated. We found that CFU-Fs are actual circulating MSCs (cMSCs). In patients at T0, cMSCs had reduced adipogenic potential, supported the formation of tube-like structures in vitro and showed either inflammatory (IL1ß and ESM1) or angiogenic (F3) gene expression higher than that of cMSCs from CTRLs. In patients receiving one-year propranolol therapy, the cMSC differentiation in adipocytes improved, while their support in in vitro tube-like formation was lost; no difference was found between patient and CTRL cMSC gene expressions. In conclusion, in patients with IH at T0 the cMSC reduced adipogenic potential, their support in angiogenic activity and the inflammatory/angiogenic gene expression may fuel the tumor growth. One-year propranolol therapy modifies this picture, suggesting cMSCs as one of the drug targets.

Revealing the mechanism of 755-nm long-pulsed alexandrite laser in inhibiting infantile hemangioma endothelial cells through transcriptome sequencing.

Laser therapy has shown promising outcomes in treating infantile hemangiomas. However, the molecular mechanisms underlying laser treatment for IH remain incompletely elucidated. This study aimed to unravel the molecular mechanisms of laser therapy in IH treatment. We evaluated the inhibitory effects of laser treatment on the proliferation and promotion of apoptosis in human hemangioma endothelial cells (HemECs) through cell counting kit-8 (CCK-8) assay, Hoechst 33342 staining, and flow cytometric analysis. Transcriptome sequencing analysis of HemECs following laser treatment revealed a significant decrease in the expression level of the GSTM5 gene. The qRT-PCR and western blot analysis also showed that GSTM5 expression in HemECs was downregulated compared to human umbilical vein endothelial cells (HUVECs), and concomitantly, the p62-Nrf2 pathway was suppressed. Using siRNA to downregulate GSTM5 expression, we observed that inhibiting GSTM5 expression could restrain cell proliferation, elevate intracellular ROS levels, and induce apoptosis in HemECs. Furthermore, upon inhibition of the p62-Nrf2 pathway using p62-specific siRNA, a significant decrease in GSTM5 expression and an elevation in intracellular ROS levels were noted in laser-treated HemECs. These findings suggested that laser treatment may operate by inhibiting the p62-Nrf2 pathway, thereby downregulating GSTM5 expression, elevating ROS levels, and consequently inducing apoptosis in HemECs.

Beckwith-Wiedemann syndrome with multiple hepatic and cutaneous hemangiomas in a female patient of Albanian origin: Diagnostic and therapeutic considerations.

We describe a 2-month-old female infant with macroglossia, macrosomia, omphalocele, neonatal hypoglycemia, earlobe creases, low nasal bridge, midface retrusion, syndromic facies and multiple cutaneous and hepatic hemangiomas (HH). Genetic evaluation confirmed the diagnosis of Beckwith-Wiedemann Syndrome (BWS) with mosaic uniparental disomy 11 as the underlying genetic mechanism suggested by partial hypermethylation of H19/IGF2:IG-DMR and partial hypomethylation of KCNQ1OT1:TSS-DMR on chromosome 11p15.5. Pediatric endocrinology and cardiology assessments were normal. No malignant liver or renal tumors were detected during the follow-up period. Treatment with propranolol was started for the multiple HH, according to international recommendations. At 3-, 6-, and 9-month follow up, a gradual decrease in the size of the hemangiomas and AFP levels was observed, without side effects. This is the fifth case in the literature combining HH and BWS, and among these, the third case with this specific genetic defect suggesting a possible association between HH and BWS caused by 11 paternal uniparental disomy [upd(11)pat]. The case also highlights that if treatment is warranted, then oral propranolol can be used for the management of infantile HH in BWS patients similarly to non-BWS patients.

Apolipoprotein A-I Binding Protein Inhibits the Formation of Infantile Hemangioma through Cholesterol-Regulated Hypoxia-Inducible Factor 1α Activation.

Infantile hemangioma (IH) is the most frequent vascular tumor of infancy with unclear pathogenesis; disordered angiogenesis is considered to be involved in its formation. Apolipoprotein A-I binding protein (AIBP)-also known as NAXE (NAD [P]HX epimerase)-a regulator of cholesterol metabolism, plays a critical role in the pathological angiogenesis of mammals. In this study, we found that AIBP had much lower expression levels in both tissues from patients with IH and hemangioma endothelial cells (HemECs) than in adjacent normal tissues and human dermal vascular endothelial cells, respectively. Knockout of NAXE by CRISPR-Cas9 in HemECs enhanced tube formation and migration, and NAXE overexpression impaired tube formation and migration of HemECs. Interestingly, AIBP suppressed the proliferation of HemECs in hypoxia. We then found that reduced expression of AIBP correlated with increased hypoxia-inducible factor 1α levels in tissues from patients with IH and HemECs. Further mechanistic investigation demonstrated that AIBP disrupted hypoxia-inducible factor 1α signaling through cholesterol metabolism under hypoxia. Notably, AIBP significantly inhibited the development of IH in immunodeficient mice. Furthermore, using the validated mouse endothelial cell (ie, EOMA cells) and Naxe-/- mouse models, we demonstrated that both endogenous AIBP from tumors and AIBP in the tumor microenvironment limit the formation of hemangioma. These findings suggested that AIBP was a player in the pathogenesis of IH and could be a potential pharmacological target for treating IH.

Papillary Hemangioma Harbors Somatic GNA11 and GNAQ Mutations.

Papillary hemangioma (PH) is a small, primarily dermal lesion occurring predominantly in the head and neck in both children and adults. Its signature characteristics are dilated thin-walled channels containing papillary clusters of mainly capillary-sized vessels and endothelial cytoplasmic eosinophilic inclusions. Given certain histopathologic similarities to congenital hemangioma which harbor mutations in GNAQ and GNA11 , we investigated whether similar mutations are present in PH. Seven PH specimens were studied. All presented in the first 4 years of life, with one being noted at birth. With the exception of one lesion, all were in the head and neck. Lesions were bluish and ranged in size from 0.5 to 2.8 cm. Four samples had GNA11 p.Q209L and 3 had GNAQ p.Q209L missense mutations. Mutations in GNA11 and GNAQ are associated with other types of somatic vascular lesions including capillary malformation, congenital hemangioma, anastomosing hemangioma, thrombotic anastomosing hemangioma, and hepatic small cell neoplasm. Shared mutations in GNA11 and GNAQ may account for some overlapping clinical and pathologic features in these entities, perhaps explicable by the timing of the mutation or influence of the germline phenotype.

Anastomosing haemangioma of the mediastinum: Clinicopathological series with radiological and genetic characterisation.

AIMS: Anastomosing haemangiomas are benign tumours with anastomosing vascular channels that may mimic angiosarcoma. While anastomosing haemangiomas have been described in diverse locations, particularly the abdominal/paraspinal region, data on anastomosing haemangiomas in the mediastinum remain limited. We report the clinicopathological, radiological and molecular characteristics of the largest single-institutional series of mediastinal anastomosing haemangiomas. METHODS AND RESULTS: In our pathology archives in 2011-23, we reviewed all vascular lesions involving the mediastinum and identified seven anastomosing haemangiomas. Clinical information was abstracted from medical charts; available radiological imaging was reviewed. Targeted DNA-based next-generation sequencing (447 genes, including GNAQ and GNA11) was performed on five cases. The seven patients included five women and two men, with an age range of 55-77 (median = 72) years. Of the six tumours with available radiology, two each were in the prevascular, visceral and paravertebral mediastinum, with lobulated peripheral enhancement in all tumours examined with contrast enhancement. Six patients underwent tumour resection; one patient received proton radiotherapy. Microscopically, each tumour was solitary and characterised by anastomosing capillary-sized vessels lined by hobnail endothelial cells. Fibrin microthrombi, hyaline globules and extramedullary haematopoiesis were common. In the five tumours analysed by next-generation sequencing, GNAQ p.Q209P was identified in one tumour; no additional reportable alterations were identified in the remaining cases. No recurrence was noted in the four patients with available follow-up of 3-58 (median = 9.5) months after resection. CONCLUSION: While mediastinal anastomosing haemangiomas can microscopically mimic angiosarcoma, awareness of this entity and radiological correlation may help to circumvent this diagnostic pitfall.

M2 Macrophage-Derived Exosomal lncRNA MIR4435-2HG Promotes Progression of Infantile Hemangiomas by Targeting HNRNPA1.

Purpose: Infantile hemangiomas (IHs) are commonly observed benign tumors that can cause serious complications. M2-polarized macrophages in IHs promote disease progression. In this study, we investigated the role of M2 macrophage-derived exosomal lncRNA MIR4435-2HG in IHs. Patients and Methods: Exosomes derived from M2 polarized macrophages were extracted. Next, using cell co-culture or transfection, we investigated whether M2 polarized macrophage-derived exosomes (M2-exos) can transport MIR4435-2HG to regulate the proliferation, migration, invasion, and angiogenesis of hemangioma-derived endothelial cells (HemECs). RNA-seq and RNA pull-down assays were performed to identify targets and regulatory pathways of MIR4435-2HG. We explored the possible mechanisms through which MIR4435-2HG regulates the biological function of HemECs. Results: M2-exos significantly enhanced the proliferation, migration, invasion, and angiogenesis of HemECs. Thus, HemECs uptake M2-exos and promote biological functions through the inclusion of MIR4435-2HG. RNA-seq and RNA pull-down experiments confirmed that MIR4435-2HG regulates of HNRNPA1 expression and directly binds to HNRNPA1, consequently affecting the NF-κB signal pathway. Conclusion: MIR4435-2HG of M2-exos promotes the progression of IHs and enhances the proliferation, migration, invasion, and angiogenesis of HemECs by directly binding to HNRNPA1. This study not only reveals the mechanism of interaction between M2 macrophages and HemECs, but also provides a promising therapeutic target for IHs.

Somatic mutation spectrum of a Chinese cohort of pediatrics with vascular malformations.

BACKGROUND: Somatic mutations of cancer driver genes are found to be responsible for vascular malformations with clinical manifestations ranging from cutaneous birthmarks to life-threatening systemic anomalies. Till now, only a limited number of cases and mutations were reported in Chinese population. The purpose of this study was to describe the somatic mutation spectrum of a cohort of Chinese pediatrics with vascular malformations. METHODS: Pediatrics diagnosed with various vascular malformations were collected between May 2019 and October 2020 from Beijing Children's Hospital. Genomic DNA of skin lesion of each patient was extracted and sequenced by whole-exome sequencing to identify pathogenic somatic mutations. Mutations with variant allele frequency less than 5% were validated by ultra-deep sequencing. RESULTS: A total of 67 pediatrics (33 males, 34 females, age range: 0.1-14.8 years) were analyzed. Exome sequencing identified somatic mutations of corresponding genes in 53 patients, yielding a molecular diagnosis rate of 79.1%. Among 29 PIK3CA mutations, 17 were well-known hotspot p.E542K, p.E545K and p.H1047R/L. Non-hotspot mutations were prevalent in patients with PIK3CA-related overgrowth spectrum, accounting for 50.0% (11/22) of detected mutations. The hotspot GNAQ p.R183Q and TEK p.L914F mutations were responsible for the majority of port-wine stain/Sturge-Weber syndrome and venous malformation, respectively. In addition, we identified a novel AKT1 p.Q79K mutation in Proteus syndrome and MAP3K3 p.E387D mutation in verrucous venous malformation. CONCLUSIONS: The somatic mutation spectrum of vascular malformations in Chinese population is similar to that reported in other populations, but non-hotspot PIK3CA mutations may also be prevalent. Molecular diagnosis may help the clinical diagnosis, treatment and management of these pediatric patients with vascular malformations.

The effects of propranolol on the biology and Notch signaling pathway of human umbilical vein endothelial cells.

BACKGROUND: Propranolol is the first choice for treating infantile hemangioma (IH). How propranolol works in IH remains unclear. Infantile hemangioma endothelial cells (HemECs) express Notch1, Jagged, Hey1, and other molecules in the Notch pathway, suggesting that Notch pathway-related molecules play an important role in affecting vascular endothelial cell proliferation. Whether propranolol can affect the Notch signaling pathway in IH treatment is unclear. METHODS: We performed this study to observe the effect of propranolol on the expression of Notch signaling pathway molecules in human umbilical vein endothelial cells (HUVECs) and to explore the therapeutic mechanism of propranolol on IH. HUVECs cultured in vitro were exposed to 60, 120, 240, 360, or 480 µM propranolol. The morphological changes of the HUVECs were observed under an inverted microscope. HUVECs proliferation was detected with Cell Counting Kit-8 (CCK-8). The effects of propranolol on HUVECs apoptosis were detected by flow cytometry. The role of Notch in propranolol inhibition of HUVEC proliferation was analyzed with real-time polymerase chain reaction (PCR) and western blotting. RESULTS: Propranolol reduced HUVECs numbers and altered their morphology. The inhibitory effect of propranolol on cell proliferation was dependent on the reaction time and drug concentration. Propranolol upregulated Jagged1, Notch1, and Hey1 expression and downregulated delta-like ligand4 (DLL4) expression. CONCLUSIONS: Propranolol may play a role in IH treatment by increasing Jagged1 expression in endothelial cells, activating the Notch pathway and inducing the upregulation of the downstream target gene HEY1.

Mutation of the TP53 Gene in Placental Chorangiomatosis.

Objective: We explored the frequency of TP53 gene mutations in chorangiomas (CA) and chorangiomatosis (CM). Materials and -methods: By Sanger sequencing, we evaluated mutations in exons 4-6 of the TP53 gene in CM and CA regions of placentas. Results: In total, 7/11(63.6%) CAs and 24/26 (92.3%) CMs had TP53 mutations, with a significantly higher frequency in the latter. Mutations in both groups predominately involved exon 4, most commonly at the 119th C. The mutation types at the 119th C were C/G and G/G. Among the patients with exon 4 mutations at the 119th C, C/G mutations, the most common type, were observed more frequently in the CM group (63.16%, 12/19) than in the CA group (14.29%, 1/7), and the difference was significant. Conclusion: It is suggested that both CM and CA are tumors rather than tumor-like lesions. Although they are histologically similar, they have a different TP53 profile.

Epithelioid and Spindle Cell Hemangioma: Clinicopathologic Analysis of 18 Primary Bone and Soft Tissue Tumors Highlighting a Predilection for the Hands and Feet, Frequent Multicentricity, and Benign Behavior.

Epithelioid and spindle cell hemangioma was initially described in 1999 in a series of primary bone tumors and was subsequently suggested by some to represent a variant of epithelioid hemangioma. Here, we studied 18 epithelioid and spindle cell hemangiomas. Nine patients (50%) were male. Age at presentation ranged from 12 to 78 years (median: 38.5 y). Nine patients (50%) had tumor(s) limited to bone, 5 (28%) had tumor(s) limited to soft tissue, and 4 (22%) had tumor(s) involving bone and soft tissue. Nine patients (50%) had multiple tumors, all in a unilateral anatomic region involving the wrist, hand, ankle, or foot. Seventeen tumors (94%) occurred in an extremity, including 12 (67%) in the hands and feet, and 1 occurred in a vertebra. In imaging studies, primary bone tumors were lobulated, expansile, and lytic, and 7 bone tumors with available imaging (58%) showed cortical breakthrough. Tumor sizes were 0.8 to 7.2 cm (median: 2.2 cm). Epithelioid and spindle cell hemangioma is composed of lobules of epithelioid and spindled endothelial cells with bland, vesicular nuclei. Neoplastic cells show orderly vasoformative growth, with hemorrhagic stroma and no endothelial atypia or multilayering. Immunohistochemistry demonstrated uniform positivity for CD31 and ERG. Where positive, SMA highlighted pericytes (11/13 tumors). FOSB was strongly positive in 4 of 16 tumors (25%), and FOS was strongly positive in 5 of 10 stained tumors (50%). Break-apart fluorescence in situ hybridization confirmed the presence of FOS split signals in 4 tumors positive for FOS by immunohistochemistry and FOSB split signals in 2 FOSB-positive tumors. DNA sequencing demonstrated a GATA6 :: FOXO1 fusion in 1 of 3 sequenced tumors. Clinical follow-up was available for 15 patients (83%; range: 5 mo to 11 y; median: 3.5 y). Seven patients (47%) had no evidence of disease at most recent follow-up. Seven of 13 patients (54%) who underwent surgery experienced local recurrence at the primary tumor site: 5 patients within a year, 1 at 2.4 years, and 1 thrice at 2, 3, and 5 years. Six patients were alive with multifocal disease (median: 3.5 y; range: 5 mo to 6 y). No tumors gave rise to distant metastases. The clinicopathologic and genetic findings in this study support the notion that epithelioid and spindle cell hemangioma is a morphologic variant of epithelioid hemangioma that can occur in soft tissue as well as bone and that shows a striking predilection for the extremities. Given that most recurrences and primary tumors behaved indolently, watchful waiting would be reasonable for patients with multicentric disease that is not readily amenable to surgery.

KIAA1429 promotes infantile hemangioma regression by facilitating the stemness of hemangioma endothelial cells.

Infantile hemangiomas are common vascular tumors with a specific natural history. The proliferation and regression mechanism of infantile hemangiomas may be related to the multilineage differentiation ability of hemangioma stem cells, but the specific mechanism is not well elucidated. KIAA1429 is an N6 -methyladenosine methylation-related protein that can also exert its role in a methylation-independent manner. This study aims to explore the function of KIAA1429 in infantile hemangiomas. qRT-PCR, western blotting, and immunostaining were performed to verify the expression of KIAA1429. The endothelial and fibroblast-like phenotypes of hemangioma endothelial cells were detected after KIAA1429 knockdown and overexpression. The stemness properties of hemangioma endothelial cells and the underlying mechanism of KIAA1429 in hemangiomas were also investigated. Nude mouse models of infantile hemangiomas were conducted to ascertain the effects of KIAA1429 in vivo. The results showed that KIAA1429 was highly expressed in infantile hemangiomas, particularly in involuting hemangiomas. In vitro experiments confirmed that KIAA1429 inhibited the endothelial phenotype, enhanced the differentiation ability, and promoted the fibroblast-like phenotype of hemangioma endothelial cells by inducing endothelial cell transition to facultative stem cells. However, the effect of KIAA1429 on the potential target was shown to be independent of N6 -methyladenosine methylation modification. Mouse models further revealed that KIAA1429 could inhibit the proliferation and promote the regression of hemangiomas. In conclusion, this study found that KIAA1429 played an important role in the regression of infantile hemangiomas by enhancing the stemness of hemangioma endothelial cells and could be a potential treatment target for infantile hemangiomas.