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.

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.

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.

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.

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.

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.

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.

A Rare Case of Primary Epithelioid Hemangioma of Bone with WWTR1::FOSB Fusion: A Benign Lesion with the Potential to Mimic Malignancy.

Epithelioid hemangioma of bone is a rare benign, locally aggressive vascular tumor that can be particularly challenging to diagnose given its frequent multifocality, non-specific imaging findings, and wide range of morphologic appearances. Additionally, some epithelioid hemangiomas demonstrate atypical histologic features including increased cellularity, necrosis, and moderate cytologic atypia - characteristics that may raise concern for malignancy. Molecular studies can serve as a powerful, objective tool in the differential diagnosis of diagnostically challenging epithelioid vascular tumors. Importantly, FOS and FOSB gene rearrangements have been identified as the genetic hallmarks of osseous epithelioid hemangioma, present in greater than 70% of cases. FOSB-fusion-positive epithelioid hemangioma, in particular, may display atypical histologic features. While ZFP36 is the typical FOSB fusion partner in epithelioid hemangioma, we herein present a case of epithelioid hemangioma of bone with a rare WWTR1::FOSB fusion. This case demonstrates the diagnostic challenges associated with epithelioid hemangioma, especially in the setting of FOSB gene rearrangements, and the importance of genomic studies in the work up of these vascular tumors.

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.

Expression of TGFBI in infantile hemangioma tissues and its effect on the biological characteristics of hemangioma endothelial cells.

OBJECTIVES: This study aimed to investigate the expression of TGFBI in infantile hemangioma (IH) of proliferative stage or involuting stage and detect the effects of TGFBI overexpression or knockdown on the biological beha-vior of hemangioma endothelial cells (HemECs) from proliferative IH by using plasmid and siRNA. METHODS: TGFBI expression levels in proliferative IH and involuting IH were detected by immunofluorescence. TGFBI overexpression plasmid and negative control plasmid were constructed and transfected into HemECs. siRNA for TGFBI and its negative control siRNA were constructed and transfected into HemECs. Western blot was used to detect the expression of TGFBI in the TGFI overexpression group (OE group) and its negative control (NC group), as well as TGFBI knockdown group (si-TGFBI group) and its negative control (si-NC group), to confirm the efficiency of transfection. CCK-8 assays were performed to assess the viability of HemECs. EdU assays were conducted to investigate the proliferation ability of HemECs. Transwell assays were used to detect the migration ability of HemECs. Tube formation assays were carried out to assess the angiogenic capacity of HemECs. Extracellular acidification rate (ECAR) assays were performed to investigate the glycolysis level of HemECs. RESULTS: The results of immunofluorescence showed that TGFBI expression was significantly elevated in proliferative IH compared with that in involuting IH. Western blot showed that TGFBI expression in the OE group was upregulated compared with that in the NC group, and TGFBI expression in si-TGFBI was downregulated compared with that in the si-NC group. The viability, cell proliferation, migration ability, and angiogenic capacity of HemECs were promoted in the OE group compared with those in the NC group, whereas these biological behaviors were inhibited in the si-TGFBI group compared with those in the si-NC group. In ECAR assays, the glycolysis level of HemECs in the OE group was enhanced compared with that in the NC group. CONCLUSIONS: TGFBI is upregulated in proliferative IH. TGFBI overexpression enhanced the viability, cell proliferation, migration ability, and angiogenic capacity of HemECs, which indicated that TGFBI might play a key role in IH progression by accelerating glycolysis. Thus, targeting TGFBI might be an effective therapeutic strategy for IH.

Long Noncoding RNA DSCAM-AS1 Facilitates Proliferation and Migration of Hemangioma Endothelial Cells by Targeting miR-411-5p/TPD52 Axis.

Background: Diagnosed as a kind of vascular neoplasm of infancy, hemangioma (HA) occurs mainly due to the aberrant proliferation of endothelial cells. Existing evidence has manifested the close relationship of long noncoding RNAs (lncRNAs) with the pathogenesis of HA. Although lncRNA DSCAM antisense RNA 1 (DSCAM-AS1) has been revealed to be implicated in the progression of human diseases, the underlying mechanism DSCAM-AS1 exerts in HA formation is unclear. Aims: To figure out how DSCAM-AS1 may regulate the progression of human hemangioma endothelial cells (HemECs). Methods: DSCAM-AS1 expression was verified through RT-qPCR detection. Functional assays including EdU assay, colony formation assay, flow cytometry analysis, TUNEL assay, and transwell assay were applied to evaluate cell proliferation, apoptosis, and migration upon DSCAM-AS1 knockdown. Moreover, RNA pull-down assay, luciferase reporter assay, RIP assay, and other mechanism experiments were utilized for evaluating the correlation of DSCAM-AS1 and RNAs in HemECs. Results: DSCAM-AS1 knockdown inhibited proliferative capability and migratory capability of HemECs whereas expedited apoptosis. Molecular mechanism results testified DSCAM-AS1 could function as a ceRNA to bind miR-411-5p in HemECs. Besides, it was confirmed that tumor protein D52 (TPD52) served as a downstream target of miR-411-5p in HemECs. More importantly, related rescue assays uncovered that elevated expression of TPD52 or inhibited expression of miR-411-5p reversed the repressive progression of HemECs mediated by DSCAM-AS1 depletion. Conclusion: DSCAM-AS1 expedited HA progression via miR-411-5p/TPD52 pathway, which provided a novel therapeutic option for HA treatment.

Hemangioma Genetics and Associated Syndromes.

This article explores what is known regarding infantile hemangioma (IH) genetics. Despite a great deal of research on this topic, the relationship between IH genetics and pathogenesis has yet to be understood. This article also outlines the appropriate work-up and management of syndromes associated with specific presentations of IH.

Identification of a functional circRNA-miRNA-mRNA regulatory network in infantile hemangioma by bioinformatics analysis.

Several circRNA have been reported to serve critical roles in various biological processes of human body. The present study aimed to build a circRNA-based competing endogenous RNA (ceRNA) network and explore the regulatory mechanisms of circRNA in infantile hemangiomas (IH). Differentially expressed circRNA, miRNA, and mRNA were downloaded from the gene expression synthesis (GEO) microarray database (GSE98795, GSE69136, and GSE127487). Cancer-specific circRNA database (CSCD), miRDB and Targetscan were employed to predict the targets of RNA. A total of 855 DEcircRNAs, 69 differentially expressed miRNAs (DEmiRNAs), and 3233 differentially expressed mRNAs (DEmRNAs) appeared as genes that were aberrantly expressed in IH. The circRNA-miRNA-mRNA network was constructed based on 108 circRNAs, 7 miRNAs, 274 mRNAs in IH. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis indicated hypoxia-inducible factors (HIF)-1 signaling pathway and Notch signaling pathway were significantly enriched in IH with being constructed a ceRNA regulatory network. Furthermore, protein-protein interaction (PPI) network and Cytoscape showed the top 10 hub genes that regulate angiogenesis, namely FBXW7, CBLB, HECW2, FBXO32, FBXL7, KLHL5, EP300, MAPK1, MEF2C, and PLCG1. Our findings provide a deeper understanding the circRNA-related ceRNA regulatory mechanism in IH. This study further perfected the circRNA-miRNA-mRNA regulatory network related to IH and explored the potential function of mRNA in this network. It provides more understanding for the circRNA-related ceRNA regulation mechanism in the pathogenesis of IH.

Circular RNA hsa_circ_0000915 promotes propranolol resistance of hemangioma stem cells in infantile haemangiomas.

BACKGROUND: Propranolol is a first-line clinical drug for infantile haemangiomas (IH) therapy. Nevertheless, resistance to propranolol is observed in some patients with IH. Circular RNAs (circRNAs) has been increasingly reported to act as a pivotal regulator in tumor progression. However, the underlying mechanism of circRNAs in IH remains unclear. METHODS: Quantitative real-time polymerase chain reaction was performed to detect Circ_0000915, miR-890 and RNF187 expression. Protein levels were determined using western blot. CCK-8 assay was used to measure cell proliferation. Caspase-3 activity assay and flow cytometry were conducted to determine cell apoptosis. Luciferase reporter assay was carried out to assess the interaction between miR-890 and Circ_0000915 or RNF187. Chromatin immunoprecipitation assay was performed to detect the interaction between STAT3 and Circ_0000915 promoter. Biotin pull-down assay was used to detect the direct interaction between miR-890 and Circ_0000915. In vivo experiments were performed to measure tumor formation. RESULTS: Here, we discovered depletion of Circ_0000915 increased propranolol sensitivity of haemangioma derived stem cells (HemSCs) both in vitro and in vivo, whereas forced expression of Circ_0000915 exhibited opposite effects. Mechanistically, Circ_0000915, transcriptionally induced by IL-6/STAT3 pathway, competed with RNF187 for the biding site in miR-890, led to upregulation of RNF187 by acting as a miR-890 "sponge". Furthermore, silence of miR-890 reversed increased propranolol sensitivity of HemSCs due to Circ_0000915 ablation. Moreover, increased Circ_0000915 and RNF187 levels were observed in IH tissues and positively associated with propranolol resistance, miR-890 exhibited an inverse expression pattern. CONCLUSION: We thereby uncover the activation of IL-6/STAT3/Circ_0000915/miR-890/RNF187 axis in propranolol resistance of IH, and provide therapeutic implications for patients of IH with propranolol resistance.