GNA14 Somatic Mutation Causes Congenital and Sporadic Vascular Tumors by MAPK Activation

Hypermethylation of GNA14 and its tumor-suppressive role in hepatitis B virus-related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide, and its specific mechanism has not been fully elucidated. Inactivation of tumor suppressors may contribute to the occurrence, progression, and recurrence of HCC. DNA methylation is a crucial mechanism involved in regulating the occurrence of HCC. Herein, we aimed to identify the key methylation-related tumor suppressors as well as potential biomarkers and therapeutic targets in HCC.

Methods: Combined analysis of TCGA and GEO databases was performed to obtain potential methylation-related tumor suppressors in HCC. Methyl-target sequencing was performed to analyze the methylation level of the GNA14 promoter. The diagnostic value of GNA14 as a predictor of HCC was evaluated in HCC tumor samples and compared with normal tissues. The functional role of GNA14 and its upstream and downstream regulatory factors were investigated by gain-of-function and loss-of-function assays in vitro. Subcutaneous tumorigenesis, lung colonization, and orthotopic liver tumor model were performed to analyze the role of GNA14 in vivo.

Results: The expression of GNA14 was found to be downregulated in HCC and it was negatively correlated with hepatitis B virus (HBV) infection, vascular invasion, and prognosis of HCC. DNA methylation was demonstrated to be responsible for the altered expression of GNA14 and was regulated by HBV-encoded X protein (HBx). GNA14 regulated the RB pathway by promoting Notch1 cleavage to inhibit tumor proliferation, and might inhibit tumor metastasis by inhibiting the expression of JMJD6.

Conclusion: GNA14 could be regulated by HBx by modulating the methylation status of its promoter. We identified GNA14 as a potential biomarker and therapeutic target for HCC.

Functional characterization of uveal melanoma oncogenes

Uveal melanoma (UM) is a currently untreatable form of melanoma with a 50% mortality rate. Characterization of the essential signaling pathways driving this cancer is critical to develop target therapies. Activating mutations in the Gαq signaling pathway at the level of GNAQ, GNA11, or rarely CYSLTR2 or PLCβ4 are considered alterations driving proliferation in UM and several other neoplastic disorders. Here, we systematically examined the oncogenic signaling output of various mutations recurrently identified in human tumors. We demonstrate that CYSLTR2 → GNAQ/11 → PLCβ act in a linear signaling cascade that, via protein kinase C (PKC), activates in parallel the MAP-kinase and FAK/Yes-associated protein pathways. Using genetic ablation and pharmacological inhibition, we show that the PKC/RasGRP3/MAPK signaling branch is the essential component that drives the proliferation of UM. Only inhibition of the MAPK branch but not the FAK branch synergizes with inhibition of the proximal cascade, providing a blueprint for combination therapy. All oncogenic signaling could be extinguished by the novel GNAQ/11 inhibitor YM-254890, in all UM cells with driver mutation in the Gαq subunit or the upstream receptor. Our findings highlight the GNAQ/11 → PLCβ → PKC → MAPK pathway as the central signaling axis to be suppressed pharmacologically to treat for neoplastic disorders with Gαq pathway mutations.

Congenital hepatic hemangiomas: Clinical, histologic, and genetic correlation

BACKGROUND

The guide for monitoring and treatment of congenital hepatic hemangiomas (CHH) will depend on the subtype and the postnatal clinical behavior. Our aim is to present a series of CHH and characterize its clinical, histologic and genetic correlation, compared to cutaneous congenital hemangiomas (CCH).

MATERIAL AND METHODS

A retrospective review of CHH patients diagnosed between 1991 and 2018 was performed. Clinical, morphological and histological data were analyzed and deep high-throughput sequencing was performed.

MAIN RESULTS

Sixteen patients with CHH were included. Five patients were followed up with serial ultrasounds while pharmacological treatment (corticosteroids and propranolol) was decided in five. Surgical resection was performed in five owing to hemorrhage and suspicion of malignancy, and the last patient underwent embolization. Histologic analysis was available in 7 patients and confirmed CHH, showing two different histological patterns that could be associated with the presence of somatic pathogenic variants in GNAQ and/or PIK3CA detected in the genetic testing. Review of 7 samples of CCH revealed some histologic differences compared to CHH.

CONCLUSION

CHH resemble its cutaneous homonym with similar clinical behavior. Histologic analysis can differentiate two subgroups while genetic testing can confirm mutations in GNAQ and in PIK3CA in a subset of CHH.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

IV.

New and Emerging Targeted Therapies for Vascular Malformations

Vascular malformations are inborn errors of vascular morphogenesis and consist of localized networks of abnormal blood and/or lymphatic vessels with weak endothelial cell proliferation. They have historically been managed by surgery and sclerotherapy. Extensive insight into the genetic origin and molecular mechanism of development has been accumulated over the last 20 years. Since the discovery of the first somatic mutations in a vascular anomaly 10 years ago, it is now recognized that they are perhaps all caused by inherited or somatic mutations in genes that hyperactivate two major intracellular signaling pathways: the RAS/MAPK/ERK and/or the phosphatidylinositol 3 kinase (PIK3)/protein kinase B/mammalian target of rapamycin (mTOR) pathway. Several targeted molecular inhibitors of these pathways have been developed, mostly for the treatment of cancers that harbor mutations in the same pathways. The mTOR inhibitor sirolimus is the most studied compound for the treatment of venous, lymphatic, and complex malformations. Disease responses of vascular malformations to sirolimus have now been reported in several studies in terms of clinical changes, quality of life, functional and radiological outcomes, and safety. Other targeted treatment strategies, such as the PIK3CA inhibitor alpelisib for PIK3CA-mutated vascular malformations, are also emerging. Repurposing of cancer drugs has become a major focus in this rapidly evolving field.

Klippel-Trenaunay and Sturge-Weber Overlap Syndrome with KRAS and GNAQ mutations

Patients with combined phenotypes of Sturge-Weber syndrome and Klippel-Trenaunay syndrome have been reported, though the underlying genetic spectrum in these individuals remains to be elucidated. We reported the patient presenting with Klippel-Trenaunay and Sturge-Weber overlap syndrome in mainland China. Histopathologic study confirmed the hemangioma of vein and capillary. Co-existence of a novel somatic KRAS c.182_183 delins TC mutation and GNAQ c.548G>A mutation was identified in the affected skin tissue rather than paired peripheral blood. The somatic mutations of GNAQ and KRAS may affect MAPK-ERK signaling pathway, resulting in endothelial anomaly and blood vessel malformation.

Downregulation of GNA14 in hepatocellular carcinoma indicates an unfavorable prognosis

Guanine nucleotide-binding protein subunit α14 (GNA14) knockdown was demonstrated to inhibit the proliferation of endometrial carcinoma cells in a recent study; however, its role in hepatocellular carcinoma (HCC) is unknown. In the present study, the clinical significance of GNA14 in HCC was assessed using a dataset of patients with HCC from The Cancer Genome Atlas database. The Integrative Molecular Database of Hepatocellular Carcinoma and Oncomine databases were also used to identify the expression levels of GNA14 in HCC tissues. The association between GNA14 expression levels and clinicopathological features was assessed using the Wilcoxon signed-rank test and logistic regression analysis. Kaplan-Meier curves and Cox regression analysis were applied to evaluate the independent risk factors for clinical outcomes. The present study determined GNA14 DNA methylation levels and tumor-infiltrating immune cells, as well as used Gene Set Enrichment Analysis (GSEA) in HCC. GNA14 mRNA expression levels were lower in HCC compared with normal tissues. Downregulation of GNA14 in HCC was significantly associated with tumor grade, clinical stage and T stage. Furthermore, low expression of GNA14 was an independent predictor for survival outcomes. GNA14 expression levels were partially correlated with the infiltration of B cells and macrophages. Additionally, GSEA analysis revealed that the expression levels of GNA14 were associated with multiple signaling pathways, such as translation, DNA replication, and homologous recombination. In conclusion, low GNA14 expression may be a novel biomarker for diagnosis and prognosis prediction for patients with HCC.

The molecular pathophysiology of vascular anomalies: Genomic research

Vascular anomalies are congenital localized abnormalities that result from improper development and maintenance of the vasculature. The lesions of vascular anomalies vary in location, type, and clinical severity of the phenotype, and the current treatment options are often unsatisfactory. Most vascular anomalies are sporadic, but patterns of inheritance have been noted in some cases, making genetic analysis relevant. Developments in the field of genomics, including next-generation sequencing, have provided novel insights into the genetic and molecular pathophysiological mechanisms underlying vascular anomalies. These insights may pave the way for new approaches to molecular diagnosis and potential disease-specific therapies. This article provides an introduction to genetic testing for vascular anomalies and presents a brief summary of the etiology and genetics of vascular anomalies.

Diffuse bone and soft tissue angiomatosis with GNAQ mutation

We describe a unique case of skeletal and extraskeletal angiomatosis complicated by Kasabach-Merritt syndrome. The patient was a 3-year-old boy, who presented with involvement of both femurs and left tibia, as well as with soft tissue lesions of the left thigh. At birth, multiple hemangiomas of the soft tissues of the frontal and parietal scalp had been identified, together with a space-occupying lesion of the lung. Histologically, the skeletal and soft tissue lesions consisted of a proliferation of thin-walled, dilated blood vessels, with an endothelial lining devoid of atypia and exhibiting immunoreactivity for CD31 and CD34, while podoplanin and GLUT1 were negative. Whole exome sequencing performed on samples from the lesion of the femur, the tibia and the skin of the thigh, showed a GNAQ (c.286A>T:p.T96S) variant in all specimens, that was confirmed with digital droplet PCR. This case expands the clinical and pathologic spectrum of vascular proliferations showing similar molecular biology, characterized by GNAQ, GNA11 or GNA14 mutations.

Identification of Potential Biomarkers for Thyroid Cancer Using Bioinformatics Strategy: A Study Based on GEO Datasets

Background

The molecular mechanisms and genetic markers of thyroid cancer are unclear. In this study, we used bioinformatics to screen for key genes and pathways associated with thyroid cancer development and to reveal its potential molecular mechanisms.

Methods

The GSE3467, GSE3678, GSE33630, and GSE53157 expression profiles downloaded from the Gene Expression Omnibus database (GEO) contained a total of 164 tissue samples (64 normal thyroid tissue samples and 100 thyroid cancer samples). The four datasets were integrated and analyzed by the RobustRankAggreg (RRA) method to obtain differentially expressed genes (DEGs). Using these DEGs, we performed gene ontology (GO) functional annotation, pathway analysis, protein-protein interaction (PPI) analysis and survival analysis. Then, CMap was used to identify the candidate small molecules that might reverse thyroid cancer gene expression.

Results

By integrating the four datasets, 330 DEGs, including 154 upregulated and 176 downregulated genes, were identified. GO analysis showed that the upregulated genes were mainly involved in extracellular region, extracellular exosome, and heparin binding. The downregulated genes were mainly concentrated in thyroid hormone generation and proteinaceous extracellular matrix. Pathway analysis showed that the upregulated DEGs were mainly attached to ECM-receptor interaction, p53 signaling pathway, and TGF-beta signaling pathway. Downregulation of DEGs was mainly involved in tyrosine metabolism, mineral absorption, and thyroxine biosynthesis. Among the top 30 hub genes obtained in PPI network, the expression levels of FN1, NMU, CHRDL1, GNAI1, ITGA2, GNA14 and AVPR1A were associated with the prognosis of thyroid cancer. Finally, four small molecules that could reverse the gene expression induced by thyroid cancer, namely ikarugamycin, adrenosterone, hexamethonium bromide and clofazimine, were obtained in the CMap database.

Conclusion

The identification of the key genes and pathways enhances the understanding of the molecular mechanisms for thyroid cancer. In addition, these key genes may be potential therapeutic targets and biomarkers for the treatment of thyroid cancer.

Mosaicism in genodermatoses

Genodermatoses are inherited disorders presenting with cutaneous manifestations with or without the involvement of other systems. The majority of these disorders, particularly in cases that present with a cutaneous patterning, may be explained in the context of genetic mosaicism. Despite the barriers to the genetic analysis of mosaic disorders, next-generation sequencing has led to a substantial progress in understanding their pathogenesis, which has significant implications for the clinical management and genetic counseling. Advances in paired and deep sequencing technologies in particular have made the study of mosaic disorders more feasible. In this review, we provide an overview of genetic mosaicism as well as mosaic cutaneous disorders and the techniques required to study them.

Soft Tissue Special Issue: Perivascular and Vascular Tumors of the Head and Neck

Perivascular and vascular neoplasms of the head and neck are a rare group of tumors comprising a spectrum of clinical/biologic and histological features. They are frequently diagnostically challenging, due to their morphologic and immunohistochemical overlap. In this review, we summarize the pathology of these neoplasms, discussing morphology, immunohistochemistry, associated genetic findings, and the differential diagnoses.

Analysis of mTOR pathway expression in lymphatic malformation and related diseases

The mammalian target of rapamycin (mTOR) inhibitor sirolimus is an effective treatment for difficult-to-treat lymphatic anomalies. However, little is known about the expression of mTOR pathway components in lymphatic anomalies. Here we investigated the expression pattern of mTOR pathway components and their phosphorylated forms (mTOR, p-mTOR, 4EBP1, p-4EBP1, S6K1 and p-S6K1) in normal lymphatic vessels and lymphatic anomalies using immunohistochemistry. We studied 18 patients of lymphatic anomalies, including lymphatic malformation (LM, n = 14), Kaposiform lymphangiomatosis (KLA, n = 2) and Kaposiform hemangioendothelioma (KHE, n = 2). Normal lymphatic vessels expressed 4EBP1, S6K1 and p-S6K1, but not p-4EBP1, mTOR or p-mTOR. The mTOR was detected in all lymphatic anomalies, whereas its activation form p-mTOR was detected in half cases of KLA and KHE but not in LM. All lymphatic anomalies expressed S6K1 and its activated form p-S6K1. The expression of 4EBP1 was also found in all lymphatic anomalies, but its activation was detected in approximately half of them. The activation of mTOR was seen in tumor (KLA and KHE) but not in malformation (LM), whereas the activation of S6K1 and 4EBP1 was seen in all and half of lymphatic anomalies, respectively.

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

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

Kaposiform hemangioendothelioma: current knowledge and future perspectives

Kaposiform hemangioendothelioma (KHE) is a rare vascular neoplasm with high morbidity and mortality. The initiating mechanism during the pathogenesis of KHE has yet to be discovered. The main pathological features of KHE are abnormal angiogenesis and lymphangiogenesis. KHEs are clinically heterogeneous and may develop into a life-threatening thrombocytopenia and consumptive coagulopathy, known as the Kasabach-Merritt phenomenon (KMP). The heterogeneity and the highly frequent occurrence of disease-related comorbidities make the management of KHE challenging. Currently, there are no medications approved by the FDA for the treatment of KHE. Multiple treatment regimens have been used with varying success, and new clinical trials are in progress. In severe patients, multiple agents with variable adjuvant therapies are given in sequence or in combination. Recent studies have demonstrated a satisfactory efficacy of sirolimus, an inhibitor of mammalian target of rapamycin, in the treatment of KHE. Novel targeted treatments based on a better understanding of the pathogenesis of KHE are needed to maximize patient outcomes and quality of life. This review summarizes the epidemiology, etiology, pathophysiology, clinical features, diagnosis and treatments of KHE. Recent new concepts and future perspectives for KHE will also be discussed.

Cerebrofacial venous metameric syndrome-spectrum of imaging findings

Cerebrofacial venous metameric syndrome (CVMS) is a complex craniofacial vascular malformation disorder in which patients have a constellation of venous vascular malformations affecting soft tissues, bone, dura, and neural structures including the eye and brain. It is hypothesized that a somatic mutation responsible for the venous abnormalities occurred prior to migration of the neural crest cells, and because of this, facial, osseous, and cerebral involvement typically follows a segmental or "metameric" distribution. The most commonly recognized form of CVMS is Sturge-Weber syndrome. However, a wide spectrum of CVMS phenotypical presentations exist with various metameric distributions of slow-flow vascular lesions including facial venous vascular malformations, developmental venous anomalies, venous angiomas, cavernous malformations (cavernomas), dural sinus malformations, and maybe even vascular tumors such as cavernous hemangiomas. Awareness of the various manifestations as described herewith is important for treatment and screening purposes.

Kaposiform hemangioendothelioma and tufted angioma - (epi)genetic analysis including genome-wide methylation profiling

Kaposiform hemangioendothelioma (KHE) is a locally aggressive vascular condition of childhood and is clinicopathologically related to tufted angioma (TA), a benign skin lesion. Due to their rarity molecular data are scarce. We investigated 7 KHE and 3 TA by comprehensive mutational analysis and genome-wide methylation profiling and compared the clustering, also with vascular malformations. Lesions were from 7 females and 3 males. The age range was 2 months to 9 years with a median of 10 months. KHEs arose in the soft tissue of the thigh (n = 2), retroperitoneum (n = 1), thoracal/abdominal (n = 1), supraclavicular (n = 1) and neck (n = 1). One patient presented with multiple lesions without further information. Two patients developed a Kasabach-Merritt phenomenon. TAs originated in the skin of the shoulder (n = 2) and nose/forehead (n = 1). Of the 5 KHEs and 2 TAs investigated by DNA sequencing, one TA showed a hot spot mutation in NRAS, and one KHE a mutation in RAD50. Unsupervised hierarchical clustering analysis indicated a common methylation pattern of KHEs and TAs, which separated from the homogeneous methylation pattern of vascular malformations. In conclusion, methylation profiling provides further evidence for KHEs and TAs potentially forming a spectrum of one entity. Using next generation sequencing, heterogeneous mutations were found in a subset of cases (2/7) without the presence of GNA14 mutations, previously reported in KHE and TA.

High frequency of GNA14, GNAQ, and GNA11 mutations in cherry hemangioma: a histopathological and molecular study of 85 cases indicating GNA14 as the most commonly mutated gene in vascular neoplasms

Cherry hemangioma is the most common hemangioma in adult life. Neoplastic and non-neoplastic theories had both been proposed for its pathogenesis, but its nature is still poorly understood. We noted a significant subset of anastomosing hemangiomas and congenital hemangiomas harbored a population of small capillaries surrounded by a perivascular hyaline layer, reminiscent of the vessels seen in cherry hemangioma. Both anastomosing hemangioma and congenital hemangioma harbor recurrent mutations in exon 5 of GNAQ and its paralogues. In this study, we analyzed 68 cherry hemangiomas and 17 cherry hemangioma-like hemangiomas exhibiting additional non-classical features including markedly dilated, cavernous vessels, and/or a deep component extending to the deep dermis. By Sanger sequencing, GNAQ, GNA11, and GNA14 exon 5 mutations were identified in 12, 4, and 32 cherry hemangiomas, respectively, and 5, 3, and 3 cherry hemangioma-like hemangiomas, respectively. MassARRAY analysis detected mutations (including exon 2 GNAQ^G48V mutations) in additional 8 cherry hemangiomas and 3 cherry hemangioma-like hemangiomas. Overall, the cherry hemangiomas and cherry hemangioma-like hemangiomas had equal GNA mutation rates (82%), and GNA14 and GNAQ mutations were present in approximately half of cherry hemangiomas and cherry hemangioma-like hemangiomas, respectively. All mutations were mutually exclusive. KRAS^G12V mutation was also detected in one cherry hemangioma-like hemangioma without GNA mutations. In summary, our study demonstrated recurrent GNA14/GNAQ/GNA11 mutations were present in the majority of this very common hemangioma and established its neoplastic nature. Our results also expanded the morphological spectrum of GNA-mutated hemangiomas to include tumors composed of cavernous-like vessels and indicated GNA14 was the most commonly mutated gene in vascular tumors.

Tufted angioma with associated Kasabach-Merritt phenomenon caused by somatic mutation in GNA14

Tufted angioma (TA) is a rare vascular tumor characterized by histologic tufts of proliferating capillaries that occurs in infancy or early childhood, with a poorly understood pathogenesis. Though benign, TA can be associated with the Kasabach-Merritt phenomenon (KMP), a life-threatening consumptive coagulopathy and thrombocytopenia. Here, we explored the genetic mechanism underlying a case of TA associated with KMP via targeted sequencing of laser capture micro-dissected lesion and blood DNA, and identified a somatic, activating GNA14 mutation specific to the tumor. Our findings support aberrant GNA14 activation underlies the pathogenesis of TA associated with KMP.

Thrombotic Hemangioma With Organizing/Anastomosing Features: Expanding the Spectrum of GNA-mutated Hemangiomas With a Predilection for the Skin of the Lower Abdominal Regions

In this study, we aimed to present the clinicopathologic and molecular features of a distinct group of hemangioma with GNA mutations that exhibited prominent thrombosis and organization changes with florid intravascular endothelial cell proliferation that we provisionally termed "thrombotic hemangioma with organizing/anastomosing features." Twenty-six cases were included. No sex predilection was seen (male:female=13:13). Patients' age ranged from 17 to 89 years (median: 51 y). All but 1 occurred in the skin whereas the remaining tumor involved the neck soft tissue. Remarkably, the majority (18) occurred in the lower abdominal/inguinal regions. Histologically, thrombotic hemangioma with organizing/anastomosing features were circumscribed tumors composed of variably sized and congested thin-walled vessels. The most striking features were prominent thrombosis and organization with florid intravascular endothelial cell proliferation. The proliferating endothelial cells exhibit a streaming pattern with focal anastomosing-like feature resembling anastomosing hemangioma. The stroma was sclerotic or hyalinized but could also be myxoid/edematous. Other features included vessels with nuclear hobnailing and perivascular hyalinization, cherry hemangioma-like component, cavernous-like or sinusoidal hemangioma-like areas, Masson hemangioma-like feature, and spindle cell fascicular pattern. Mitotic activity was usually low and nuclei were bland but 2 tumors exhibited moderate nuclear atypia and higher mitotic activity. Extramedullary hematopoiesis and hyaline globules were not identified. Genetically, by Sanger sequencing and MassARRAY analysis, mutually exclusive GNAQ, GNA11, and GNA14 exon 5 mutations were identified in 15, 5, and 2 tumors, respectively, with a combined mutation rate of 85% (22/26). In conclusion, we described a distinct group of hemangioma and expanded the clinicopathologic features of GNA-mutated hemangiomas.

Frequent GNAQ and GNA14 Mutations in Hepatic Small Vessel Neoplasm

Hepatic small vessel neoplasm (HSVN) is a recently described infiltrative vascular neoplasm of the liver, composed of small vessels. Although the infiltrative nature can mimic angiosarcoma, HSVN are thought to be benign or low-grade neoplasms because they lack cytologic atypia and increased proliferation. To characterize the molecular pathogenesis of HSVN, we performed both targeted panel sequencing and exome sequencing on 18 benign or low-grade vascular neoplasms in the liver including 8 HSVN, 6 classic cavernous hemangioma (CH), and 4 variant lesions (VL) with overlapping features between HSVN and CH. All 18 lesions had simple genomes without copy number alterations. In total, 75% (6/8) of HSVN demonstrated known activating hotspot mutations in GNAQ (2/8, p.Q209H) or GNA14 (4/8, p.Q205L), and the remaining 2 had the same missense mutation in GNAQ, p.G48L, which has not been previously described. 25% (1/4) of VL had a hotspot GNAQ p.Q209H mutation and another VL had a GNAQ p.G48L mutation. Known pathogenic mutations were not identified in any of the 6 CH. These data suggest that HSVN share a similar molecular biology to several other vascular lesions (congenital hemangioma, tufted angioma, anastomosing hemangioma, lobular capillary hemangioma, and kaposiform hemangioendothelioma) recently reported to have GNAQ, GNA11, or GNA14 mutations.

Oral pyogenic granulomas show MAPK/ERK signaling pathway activation, which occurs independently of BRAF, KRAS, HRAS, NRAS, GNA11, and GNA14 mutations

BACKGROUND

Pyogenic granuloma (PG) is a benign nodular lesion with a prominent vascular component which may affect different sites. Recently, BRAF, KRAS, HRAS, NRAS, GNA11, and GNA14 mutations were reported on PGs of the skin. The present study assessed the role of the MAPK/ERK pathway in oral PG pathogenesis.

METHODS

Mutations in hotspot regions of genes involved in the MAPK/ERK pathway activation were investigated by Sanger sequencing. The expression of phospho-ERK1/2 was evaluated by immunohistochemistry.

RESULTS

Oral PGs did not show mutations in the sequenced regions of the genes BRAF, KRAS, HRAS, NRAS, GNA11, or GNA14. Our results also showed activation of the MAPK/ERK pathway demonstrated by phospho-ERK1/2 immunohistochemical positivity.

CONCLUSIONS

Although oral PG shows MAPK/ERK pathway activation, the driver molecular event remains to be elucidated.

GNAQ Q209R Mutations Are Highly Specific for Circumscribed Choroidal Hemangioma

Several tumors, including uveal melanoma, show somatic mutations of GNAQ/GNA11. Circumscribed choroidal hemangioma is a benign tumor that becomes symptomatic in adulthood. In some patients, morphologic examination of biopsies is required for differential diagnosis between amelanotic choroidal melanoma and circumscribed choroidal hemangioma. Here, we report the results of GNAQ/GNA11 mutation analysis in samples from circumscribed choroidal hemangioma. Deep amplicon sequencing (Illumina MiSeq, San Diego, CA, USA) of positions R183 and Q209 of GNAQ and GNA11 in tissue samples from 33 patients with histologically diagnosed circumscribed choroidal hemangioma. All patients underwent biopsy or enucleation at our clinic between 2008 and 2018. To enable detection of variant alleles at low fractions, read depth exceeded 15,000-fold. DNA for genetic analysis was prepared from either snap-frozen (n = 22) or FFPE (n = 11) tissue samples. Samples from 28/33 patients (85%) showed a somatic missense mutation of GNAQ (c.626 A > G) predicted to result in p.Q209R. Variant allele fraction was variable (range 2.3% to 28%). Variants of GNAQ resulting in p.Q209 are characteristic for circumscribed choroidal hemangiomas. It appears that the GNAQ mutation spectrum in this tumor is narrow, possibly restricted to p.Q209R. Moreover, the spectrum is distinct from that of uveal melanoma, in which alterations resulting in p.Q209R are very rare.

Cellular and molecular mechanisms of PIK3CA-related vascular anomalies

The phosphoinositide 3-kinase (PI3K) pathway is a major mediator of growth factor signaling, cell proliferation and metabolism. Somatic gain-of-function mutations in PIK3CA, the catalytic subunit of PI3K, have recently been discovered in a number of vascular anomalies. The timing and origin of these mutations remain unclear although they are believed to occur during embryogenesis. The cellular origin of these lesions likely involves endothelial cells or an early endothelial cell lineage. This review will cover the diseases and syndromes associated with PIK3CA mutations and discuss the cellular origin, pathways and mechanisms. Activating PIK3CA 'hot spot' mutations have long been associated with a multitude of cancers allowing the development of targeted pharmacological inhibitors that are FDA-approved or in clinical trials. Current and future therapeutic approaches for PIK3CA-related vascular anomalies are discussed.

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

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

Estimating genome-wide off-target effects for pyrrole-imidazole polyamide binding by a pathway-based expression profiling approach

In the search for new pharmaceutical leads, especially with DNA-binding molecules or genome editing methods, the issue of side and off-target effects have always been thorny in nature. A particular case is the investigation into the off-target effects of N-methylpyrrole-N-methylimidazole polyamides, a naturally inspired class of DNA binders with strong affinity to the minor-groove and sequence specificity, but at < 20 bases, their relatively short motifs also insinuate the possibility of non-unique genomic binding. Binding at non-intended loci potentially lead to the rise of off-target effects, issues that very few approaches are able to address to-date. We here report an analytical method to infer off-target binding, via expression profiling, based on probing the relative impact to various biochemical pathways; we also proposed an accompanying side effect prediction engine for the systematic screening of candidate polyamides. This method marks the first attempt in PI polyamide research to identify elements in biochemical pathways that are sensitive to the treatment of a candidate polyamide as an approach to infer possible off-target effects. Expression changes were then considered to assess possible outward phenotypic changes, manifested as side effects, should the same PI polyamide candidate be administered clinically. We validated some of these effects with a series of animal experiments, and found agreeable corroboration in certain side effects, such as changes in aspartate transaminase levels in ICR and nude mice post-administration.

Insights into genetics, human biology and disease gleaned from family based genomic studies

Identifying genes and variants contributing to rare disease phenotypes and Mendelian conditions informs biology and medicine, yet potential phenotypic consequences for variation of >75% of the ~20,000 annotated genes in the human genome are lacking. Technical advances to assess rare variation genome-wide, particularly exome sequencing (ES), enabled establishment in the United States of the National Institutes of Health (NIH)-supported Centers for Mendelian Genomics (CMGs) and have facilitated collaborative studies resulting in novel "disease gene" discoveries. Pedigree-based genomic studies and rare variant analyses in families with suspected Mendelian conditions have led to the elucidation of hundreds of novel disease genes and highlighted the impact of de novo mutational events, somatic variation underlying nononcologic traits, incompletely penetrant alleles, phenotypes with high locus heterogeneity, and multilocus pathogenic variation. Herein, we highlight CMG collaborative discoveries that have contributed to understanding both rare and common diseases and discuss opportunities for future discovery in single-locus Mendelian disorder genomics. Phenotypic annotation of all human genes; development of bioinformatic tools and analytic methods; exploration of non-Mendelian modes of inheritance including reduced penetrance, multilocus variation, and oligogenic inheritance; construction of allelic series at a locus; enhanced data sharing worldwide; and integration with clinical genomics are explored. Realizing the full contribution of rare disease research to functional annotation of the human genome, and further illuminating human biology and health, will lay the foundation for the Precision Medicine Initiative.

Asymmetric cavernous sinus enlargement: a novel finding in Sturge-Weber syndrome

PURPOSE

Enlargement of deep cerebral veins and choroid plexus engorgement are frequently reported in Sturge-Weber syndrome. We aim to describe cavernous sinus involvement in patients with this syndrome and to identify possible clinical-neuroimaging correlations.

METHODS

Sixty patients with Sturge-Weber syndrome (31 females, mean age 4.5 years) and 120 age/sex-matched controls were included in this retrospective study. We performed a visual analysis to identify patients with asymmetric cavernous sinus enlargement. Then, we measured on axial T2WI the left (A), right (B), and bilateral (LL) transverse diameters of the cavernous sinus. We calculated the module of the difference |A-B| and the cavernous sinus asymmetry index as the ratio |A-B|/LL. Differences among groups were assessed by Mann-Whitney U and Kruskal-Wallis tests. Clinicoradiological associations were evaluated by Fisher exact test.

RESULTS

We found seven subjects (11.6%) with asymmetric CS enlargement. The |A-B| and cavernous sinus asymmetry index were higher in patients with asymmetric CS enlargement compared with controls and patients without visible CS abnormalities (p_B < 0.05). Asymmetric CS enlargement was always ipsilateral to facial port-wine stains (7/7), and, when present, to leptomeningeal vascular malformations (4/7). It was significantly associated with ipsilateral bone marrow changes (p = 0.013) and dilated veins (p = 0.002). Together with brain atrophy and deep venous dilatation, this sign was associated with neurological deficits (p < 0.05).

CONCLUSIONS

We expanded the spectrum of venous abnormalities in SWS, showing the presence of asymmetric cavernous sinus enlargement in more than one tenth of patients, likely related to increased venous drainage.

Comprehensive molecular and clinicopathological analysis of vascular malformations: A study of 319 cases

Vascular malformations are part of overgrowth syndromes characterized by somatic mosaic mutations or rarely by germline mutations. Due to their similarities and diversity, clinicopathological classification can be challenging. A comprehensive targeted Next Generation Sequencing screen using Unique Molecular Identifiers with a technical sensitivity of 1% mutant alleles was performed for frequently mutated positions in ≥21 genes on 319 formalin‐fixed paraffin‐embedded samples. In 132 out of 319 cases pathogenic mosaic mutations were detected affecting genes previously linked to vascular malformations e.g. PIK3CA (n=80), TEK (TIE2) (n=11), AKT1 (n=1), GNAQ (n=7), GNA11 (n=4), IDH1 (n=3), KRAS (n=9), and NRAS (n=1). Six cases harbored a combination of mutations in PIK3CA and in GNA11 (n=2), GNAQ (n=2), or IDH1 (n=2). Aberrations in PTEN and RASA1 with a variant allele frequency approaching 50% suggestive of germline origin were identified in six out of 102 cases tested; four contained a potential second hit at a lower allele frequency. Ninety‐one of the total 142 pathogenic mutations were present at a variant allele frequency <10% illustrating the importance of sensitive molecular analysis. Clinicopathological characteristics showed a broad spectrum and overlap when correlated with molecular data. Sensitive screening of recurrently mutated genes in vascular malformations may help to confirm the diagnosis and reveals potential therapeutic options with a significant contribution of PIK3CA/mTOR and RAS‐MAPK pathway mutations. The co‐existence of two activating pathogenic mutations in parallel pathways illustrates potential treatment challenges and underlines the importance of multigene testing. Detected germline mutations have major clinical impact.

A somatic activating NRAS variant associated with kaposiform lymphangiomatosis

Purpose:

Kaposiform lymphangiomatosis (KLA) is a rare, frequently aggressive, systemic disorder of the lymphatic vasculature, occurring primarily in children. Even with multimodal treatments, KLA has a poor prognosis and high mortality rate secondary to coagulopathy, effusions and systemic involvement. We hypothesized that, as has recently been found for other vascular anomalies, KLA may be caused by somatic mosaic variants affecting vascular development.

Methods:

We performed exome sequencing of tumor samples from five individuals with KLA, along with samples from uninvolved control tissue in three of the five. We used digital PCR (dPCR) to validate the exome findings and to screen KLA samples from six other individuals.

Results:

We identified a somatic activating NRAS variant (c.182A>G, p.Q61R) in lesional tissue from 10/11 individuals, at levels ranging from 1–28%, that was absent from the tested control tissues.

Conclusion:

The activating NRAS p.Q61R variant is a known ‘hotspot’ variant, frequently identified in several types of human cancer, especially melanoma. KLA, therefore, joins a growing group of vascular malformations and tumors caused by somatic activating variants in the RAS/PI3K/mTOR signalling pathways. This discovery will expand treatment options for these high risk patients as there is potential for use of targeted RAS pathway inhibitors.

GNAQ Mutations in Diffuse and Solitary Choroidal Hemangiomas

PURPOSE

GNAQ mutations have been identified in port wine stains (both syndromic and nonsyndromic) and melanocytic ocular neoplasms. This study investigates the presence of GNAQ mutations in diffuse (those associated with Sturge-Weber syndrome [SWS]) and solitary choroidal hemangiomas.

PARTICIPANTS

Tissue from 11 patients with the following diagnoses: port wine stain (n = 3), diffuse choroidal hemangioma (n = 1), solitary choroidal hemangioma (n = 6), and choroidal nevus (n = 1).

METHODS

Ten specimens were interrogated with Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets, a hybridization capture-based next-generation sequencing assay for targeted deep sequencing of all exons and selected introns of 468 key cancer genes in formalin-fixed, paraffin-embedded tumors. Digital polymerase chain reaction was used to detect GNAQ Q209 mutation in 1 specimen.

MAIN OUTCOME MEASURES

Detection of GNAQ codon-specific mutation.

RESULTS

Activating somatic GNAQ mutations (c.547C > T; p.Arg183Cys) were found in 100% (3 of 3) of the port wine stain and in the diffuse choroidal hemangioma. Somatic GNAQ mutations (c.626A > T; p.Gln209Leu) were found in 100% (6 of 6) of the solitary choroidal hemangiomas and (c.626A > C; p.Gln209Pro) in the choroidal nevus.

CONCLUSIONS

GNAQ mutations occur in both diffuse and solitary hemangiomas, although at distinct codons. An R183 codon is mutant in diffuse choroidal hemangiomas, consistent with other Sturge-Weber vascular malformations. By contrast, solitary choroidal hemangiomas have mutations in the Q209 codon, similar to other intraocular melanocytic neoplasms.

Comparative gene array analyses of severe elastic fiber defects in late embryonic and newborn mouse aorta

Elastic fibers provide reversible elasticity to the large arteries and are assembled during development when hemodynamic forces are increasing. Mutations in elastic fiber genes are associated with cardiovascular disease. Mice lacking expression of the elastic fiber genes elastin ( Eln-/-), fibulin-4 ( Efemp2-/-), or lysyl oxidase ( Lox-/-) die at birth with severe cardiovascular malformations. All three genetic knockout models have elastic fiber defects, aortic wall thickening, and arterial tortuosity. However, Eln-/- mice develop arterial stenoses, while Efemp2-/- and Lox-/- mice develop ascending aortic aneurysms. We performed comparative gene array analyses of these three genetic models for two vascular locations and developmental stages to determine differentially expressed genes and pathways that may explain the common and divergent phenotypes. We first examined arterial morphology and wall structure in newborn mice to confirm that the lack of elastin, fibulin-4, or lysyl oxidase expression provided the expected phenotypes. We then compared gene expression levels for each genetic model by three-way ANOVA for genotype, vascular location, and developmental stage. We found three genes upregulated by genotype in all three models, Col8a1, Igfbp2, and Thbs1, indicative of a common response to severe elastic fiber defects in developing mouse aorta. Genes that are differentially regulated by vascular location or developmental stage in all three models suggest mechanisms for location or stage-specific disease pathology. Comparison of signaling pathways enriched in all three models shows upregulation of integrins and matrix proteins involved in early wound healing, but not of mature matrix molecules such as elastic fiber proteins or fibrillar collagens.

G Protein α Subunit 14 Mediates Fibroblast Growth Factor 2-Induced Cellular Responses in Human Endothelial Cells

During pregnancy, a tremendous increase in fetoplacental angiogenesis is associated with elevated blood flow. Aberrant fetoplacental vascular function may lead to pregnancy complications including pre-eclampsia. Fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor A (VEGFA) are crucial regulators of fetoplacental endothelial function. G protein α subunit 14 (GNA14), a member of Gαq/11 subfamily is involved in mediating hypertensive diseases and tumor vascularization. However, little is known about roles of GNA14 in mediating the FGF2- and VEGFA-induced fetoplacental endothelial function. Using human umbilical vein endothelial cells (HUVECs) cultured under physiological chronic low oxygen (3% O₂ ) as a cell model, we show that transfecting cells with adenovirus carrying GNA14 complementary DNA (cDNA; Ad-GNA14) increases (p < 0.05) protein expression of GNA14. GNA14 overexpression blocks (p < 0.05) FGF2-stimulated endothelial migration, whereas it enhances (p < 0.05) endothelial monolayer integrity (maximum increase of ~35% over the control at 24 hr) in response to FGF2. In contrast, GNA14 overexpression does not significantly alter VEGFA-stimulated cell migration, VEGFA-weakened cell monolayer integrity, and intracellular Ca⁺⁺ mobilization in response to adenosine triphosphate (ATP), FGF2, and VEGFA. GNA14 overexpression does not alter either FGF2- or VEGFA-induced phosphorylation of ERK1/2. However, GNA14 overexpression time-dependently elevates (p < 0.05) phosphorylation of phospholipase C-β3 (PLCβ3) at S1105 in response to FGF2, but not VEGFA. These data suggest that GNA14 distinctively mediates fetoplacental endothelial cell migration and permeability in response to FGF2 and VEGFA, possibly in part by altering activation of PLCβ3 under physiological chronic low oxygen.

Beyond endothelial cells: Vascular endothelial growth factors in heart, vascular anomalies and placenta

Vascular endothelial growth factors regulate vascular and lymphatic growth. Dysregulation of VEGF signaling is connected to many pathological states, including hemangiomas, arteriovenous malformations and placental abnormalities. In heart, VEGF gene transfer induces myocardial angiogenesis. Besides vascular and lymphatic endothelial cells, VEGFs affect multiple other cell types. Understanding VEGF biology and its paracrine signaling properties will offer new targets for novel treatments of several diseases.

Vascular Anomalies: From a Clinicohistologic to a Genetic Framework

BACKGROUND

Vascular anomalies currently are classified according to their clinical and histological characteristics. Recent advances in molecular genetics have enabled the identification of somatic mutations in most types of vascular anomalies. The purpose of this study was to collate information regarding the genetic basis of vascular anomalies.

METHODS

The PubMed literature was reviewed for all citations that identified a mutation in a vascular anomaly between 1994 and 2017. Search terms included "vascular anomaly," "mutation," "gene," "hemangioma," "pyogenic granuloma," "kaposiform hemangioendothelioma," "capillary malformation," "venous malformation," lymphatic malformation," "arteriovenous malformation," and "syndrome." Articles that identified both germline and somatic mutations in vascular anomalies were analyzed. Mutations were categorized by type (germline or somatic), gene, signaling pathway, and cell(s) enriched for the mutation.

RESULTS

The majority of vascular anomalies had associated mutations that commonly affected tyrosine kinase receptor signaling through the RAS or PIK3CA pathways. Mutations in PIK3CA and G-protein-coupled receptors were most frequently identified. Specific types of vascular anomalies usually were associated with a single gene. However, mutations in the same gene occasionally were found in different vascular lesions, and some anomalies had a mutation in more than one gene. Mutations were most commonly enriched in endothelial cells.

CONCLUSIONS

Identification of somatic mutations in vascular anomalies is changing the paradigm by which lesions are diagnosed and understood. Mutations and their pathways are providing potential targets for the development of novel pharmacotherapy. In the future, vascular anomalies will be managed based on clinical characteristics and molecular pathophysiology.

Genetic testing for vascular anomalies

Vascular anomalies (VAs) have phenotypic variability within the same entity, overlapping clinical features between different conditions, allelic and locus heterogeneity and the same disorder can be inherited in different ways. Most VAs are sporadic (paradominant inheritance or de novo somatic or germline mutations), but hereditary forms (autosomal dominant or recessive) have been described. This Utility Gene Test was developed on the basis of an analysis of the literature and existing diagnostic protocols. The genetic test is useful for confirming diagnosis, as well as for differential diagnosis, couple risk assessment and access to clinical trials.

GNA14 silencing suppresses the proliferation of endometrial carcinoma cells through inducing apoptosis and G2/M cell cycle arrest

Endometrial carcinoma is the most common gynecological malignancy. The pathological factors triggering this disease are largely unknown. Although the role of guanine nucleotide-binding protein subunit α (GNA) 11 (GNA11) in melanoma has been described, the involvement of GNA14 in endometrial carcinoma remains to be determined. Here, we found that GNA14 expression was increased in endometrial carcinoma tissues compared with simple hyperplasia tissues. Based on lentivirus-mediated knockdown assay, we showed that GNA14 silencing significantly suppressed the proliferation of both HEC-1-A and Ishikawa cells. The caspase 3/caspase 7 activity and apoptosis were enhanced by GNA14 knockdown. GNA14 depletion led to cell cycle arrest at the G₂/M phase. In addition, Apoptosis Array analysis revealed that caspase-3 and Fas were up-regulated by GNA14 knockdown. Our study suggests that GNA14 silencing blunts endometrial carcinoma cell proliferation. Targetting GNA14 may bring help for the patients of endometrial carcinoma.

Targeting nucleotide exchange to inhibit constitutively active G protein α subunits in cancer cells

Constitutively active G protein α subunits cause cancer, cholera, Sturge-Weber syndrome, and other disorders. Therapeutic intervention by targeted inhibition of constitutively active Gα subunits in these disorders has yet to be achieved. We found that constitutively active Gαq in uveal melanoma (UM) cells was inhibited by the cyclic depsipeptide FR900359 (FR). FR allosterically inhibited guanosine diphosphate-for-guanosine triphosphate (GDP/GTP) exchange to trap constitutively active Gαq in inactive, GDP-bound Gαβγ heterotrimers. Allosteric inhibition of other Gα subunits was achieved by the introduction of an FR-binding site. In UM cells driven by constitutively active Gαq, FR inhibited second messenger signaling, arrested cell proliferation, reinstated melanocytic differentiation, and stimulated apoptosis. In contrast, FR had no effect on BRAF-driven UM cells. FR promoted UM cell differentiation by reactivating polycomb repressive complex 2 (PRC2)-mediated gene silencing, a heretofore unrecognized effector system of constitutively active Gαq in UM. Constitutively active Gαq and PRC2 therefore provide therapeutic targets for UM. The development of FR analogs specific for other Gα subunit subtypes may provide novel therapeutic approaches for diseases driven by constitutively active Gα subunits or multiple G protein-coupled receptors (GPCRs) where targeting a single receptor is ineffective.

De novo MYH9 mutation in congenital scalp hemangioma

Congenital hemangiomas are tumor-like vascular malformations with poorly understood pathogenesis. We report the case of a neonate with a massive congenital scalp hemangioma that required urgent neurosurgical removal on the second day of life because of concern for high-flow arteriovenous shunting. Exome sequencing identified a rare damaging de novo germline mutation in MYH9 (c.5308C>T, p.[Arg1770Cys]), encoding the MYH9 nonmuscle myosin IIA. MYH9 has a probability of loss-of-function intolerance (pLI) score of >0.99 and is highly intolerant to missense variation (z score = 5.59). The p.(Arg1770Cys) mutation substitutes an evolutionarily conserved amino acid in the protein's critical myosin tail domain and is predicted to be highly deleterious by SIFT, PolyPhen-2, MetaSVM, and CADD. MYH9 is a known regulator of cytokinesis, VEGF-regulated angiogenesis, and p53-dependent tumorigenesis. These findings reveal a novel association of germline de novo MYH9 mutation with congenital hemangioma.

Mosaicism in Cutaneous Disorders

Genetic mosaicism arises when a zygote harbors two or more distinct genotypes, typically due to de novo, somatic mutation during embryogenesis. The clinical manifestations largely depend on the differentiation status of the mutated cell; earlier mutations target pluripotent cells and generate more widespread disease affecting multiple organ systems. If gonadal tissue is spared-as in somatic genomic mosaicism-the mutation and its effects are limited to the proband, whereas mosaicism also affecting the gametes, such as germline or gonosomal mosaicism, is transmissible. Mosaicism is easily appreciated in cutaneous disorders, as phenotypically distinct mutant cells often give rise to lesions in patterns determined by the affected cell type. Genetic investigation of cutaneous mosaic disorders has identified pathways central to disease pathogenesis, revealing novel therapeutic targets. In this review, we discuss examples of cutaneous mosaicism, approaches to gene discovery in these disorders, and insights into molecular pathobiology that have potential for clinical translation.

Whole-exome sequencing for variant discovery in blepharospasm

BACKGROUND

Blepharospasm (BSP) is a type of focal dystonia characterized by involuntary orbicularis oculi spasms that are usually bilateral, synchronous, and symmetrical. Despite strong evidence for genetic contributions to BSP, progress in the field has been constrained by small cohorts, incomplete penetrance, and late age of onset. Although several genetic etiologies for dystonia have been identified through whole-exome sequencing (WES), none of these are characteristically associated with BSP as a singular or predominant manifestation.

METHODS

We performed WES on 31 subjects from 21 independent pedigrees with BSP. The strongest candidate sequence variants derived from in silico analyses were confirmed with bidirectional Sanger sequencing and subjected to cosegregation analysis.

RESULTS

Cosegregating deleterious variants (GRCH37/hg19) in CACNA1A (NM_001127222.1: c.7261_7262delinsGT, p.Pro2421Val), REEP4 (NM_025232.3: c.109C>T, p.Arg37Trp), TOR2A (NM_130459.3: c.568C>T, p.Arg190Cys), and ATP2A3 (NM_005173.3: c.1966C>T, p.Arg656Cys) were identified in four independent multigenerational pedigrees. Deleterious variants in HS1BP3 (NM_022460.3: c.94C>A, p.Gly32Cys) and GNA14 (NM_004297.3: c.989_990del, p.Thr330ArgfsTer67) were identified in a father and son with segmental cranio-cervical dystonia first manifest as BSP. Deleterious variants in DNAH17, TRPV4, CAPN11, VPS13C, UNC13B, SPTBN4, MYOD1, and MRPL15 were found in two or more independent pedigrees. To our knowledge, none of these genes have previously been associated with isolated BSP, although other CACNA1A mutations have been associated with both positive and negative motor disorders including ataxia, episodic ataxia, hemiplegic migraine, and dystonia.

CONCLUSIONS

Our WES datasets provide a platform for future studies of BSP genetics which will demand careful consideration of incomplete penetrance, pleiotropy, population stratification, and oligogenic inheritance patterns.

Nonepithelial Tumors and Tumor-like Lesions of the Skin and Subcutis in Children

This overview of mesenchymal tumors presenting in the skin and/or subcutis in children brings together the range of neoplasms and hamartomas which are seen in this age-group. It is not surprising from the perspective of the pediatric or general surgical pathologist that vascular anomalies, including true neoplasms and vascular malformations, are the common phenotypic category. Since there is considerable morphologic overlap among these lesions, clinicopathologic correlation may be more important than for many of the other mesenchymal tumors. The skin and subcutis are the most common sites of clinical presentation for the infantile myofibroma which is the most common of fibrous mesenchymal tumors in children. Several of the other mesenchymal tumors are more common adults-like dermatofibrosarcoma protuberans, but nonetheless have an important presence in children, even as a congenital neoplasm. A lipomatous tumor in a young child should be considered as a possible manifestation of an overgrowth syndrome.

Clinical value and potential targets of miR-224-5p in hepatocellular carcinoma validated by a TCGA- and GEO- based study

OBJECTIVE

to explore clinical value and potential targets of MicroRNA-224-5p in the tumorigenesis and progression of hepatocellular carcinoma (HCC).

METHODS

We evaluated the clinical value of MicroRNA-224-5p from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). Meanwhile, target genes of MicroRNA-224-5p were predicted by bioinformatics method. The target genes of MicroRNA-224-5p were finally analyzed in Gene Ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation, and Protein-Protein Interaction (PPI) network annotation.

RESULTS

MicroRNA-224-5p expression level in HCC was higher than in non-tumor tissues (SMD=1.24; 95% CI, 0.68 to 1.81; P<0.0001) and MicroRNA-224-5p might represent a diagnostic marker (overall AUC=0.92; 95% CI, 0.90 to 0.94). 262 target genes were acquired by overlapping 4927 genes predicted by more than four computational prediction tools with 1,123 down-regulated DEGs in HCC. Furthermore, gene sets enrichment analysis of the 262 overlapping genes was implemented. The mostly significant GO terms within the overlapping target genes of MicroRNA-224-5p were cellular response to chemical stimulus, plasma membrane part and coenzyme binding. KEGG pathway annotation showed the overlapping genes mostly took part in metabolic pathways. In PPI analysis, one hub gene, GNA14, stood out cause for the significant negative correlation with MicroRNA-224.

CONCLUSION

MicroRNA-224-5p is upregulated in HCC and may be a prospective biomarker for diagnosis. Moreover, MicroRNA-224-5p might play an oncogenic role in HCC by targeting GNA14.