The embryo-placental CD15-positive "vasculogenic zones" as a source of propranolol-sensitive pediatric vascular tumors.

Abstract Objective Propranolol-induced involution is a unique biological feature of some pediatric vascular tumors, for instance infantile hemangioma (IH), cerebral cavernoma or chorioangioma. Currently, the cellular origin of these distinct tumors is unclear. In this study, we tested the hypothesis that propranolol-responsive vascular tumors are derived from common vessel-forming CD15 + progenitor cells which occur in early gestation. The aim of this study was to identify the tumor-relevant CD15 + progenitors at the early stages of embryo-placental development. Materials and methods Human embryo-placental units of 4–8 weeks gestation and pediatric vascular tumors were tested for expression…

Sex-specific windows for high mRNA expression of DNA methyltransferases 1 and 3A and methyl-CpG-binding domain proteins 2 and 4 in human fetal gonads

DNA methyltransferases (DNMTs) and 5-methyl-CpG-binding domain proteins (MBDs) are involved in the acquisition of parent-specific epigenetic modifications in human male and female germ cells. Reverse Northern blot analyses demonstrated sex-specific differences in mRNA expression for the maintenance DNMT1 and the de novo DNMT3A in developing testis and ovary. In fetal testis DNMT1 and DNMT3A expression peaked in mitotically arrested spermatogonia around 21 weeks gestation. In fetal ovary transcriptional upregulation of DNMT1 and DNMT3A occurred during a very brief period at 16 weeks gestation, when the oocytes proceeded through meiotic prophase. Fetal gonads showed several fold higher DNMT3A…

Tumor Lipids of Pediatric Papillary Renal Cell Carcinoma Stimulate Unconventional T Cells

Papillary renal cell carcinoma (PRCC) is a rare entity in children with no established therapy protocols for advanced diseases. Immunotherapy is emerging as an important therapeutic tool for childhood cancer. Tumor cells can be recognized and killed by conventional and unconventional T cells. Unconventional T cells are able to recognize lipid antigens presented via CD1 molecules independently from major histocompatibility complex, which offers new alternatives for cancer immunotherapies. The nature of those lipids is largely unknown and α-galactosylceramide is currently used as a synthetic model antigen. In this work, we analyzed infiltrating lymphocytes of two pediatric PRCCs using flow cy…

Extreme Methylation Values of Imprinted Genes in Human Abortions and Stillbirths

Imprinted genes play an important role in fetal and placental development. Using quantitative bisulfite pyrosequencing assays, we determined the DNA methylation levels at two paternally methylated (H19 and MEG3) and four maternally methylated (LIT1, NESP55, PEG3, and SNRPN) imprinted regions in fetal muscle samples from abortions and stillbirths. Two of 55 (4%) spontaneous abortions and 10 of 57 (18%) stillbirths displayed hypermethylation in multiple genes. Interestingly, none of 34 induced abortions had extreme methylation values in multiple genes. All but two abortions/stillbirths with multiple methylation abnormalities were male, indicating that the male embryo may be more susceptible t…

Transient CD15-positive endothelial phenotype in the human placenta correlates with physiological and pathological fetoplacental immaturity

Abstract Objective Placental growth and villous maturation are critical parameters of placental function at the end of pregnancy. A failure in these processes leads to the development of placental dysfunction, as well as fetal and neonatal mortality and morbidity. The aim of the study was to determine the relevant diagnostic markers associated with pathological placental development. Study design Forty tissue samples from normal placentas of different gestational age and 68 pathological term placentas with defective villous maturation (GDM, idiopathic IUFD, preeclamsia, HELLP syndrome) comprised the comparative immunohistochemical study (CD15, CD45 and CD34). Positive immunohistochemical re…

49P Targeting IGF1R in osteosarcoma

CD15 – A new marker of pathological villous immaturity of the term placenta

Abstract Introduction Idiopathic immaturity is one of the main reasons for latent placental insufficiency and antenatal hypoxia. Postnatal identification of the immature placental phenotype may help early stratification of a heterogeneous population of newborns and individually identify risk of disease in the immediate postnatal life. The aim of the study was to determine the relevant diagnostic markers associated with pathological placental immaturity. Methods 111 tissue samples from normal and pathological term placentas with persisting villous immaturity comprised the comparative immunohistochemical study (CD15, CD34). Positive immunohistochemical reactions were quantitatively assessed i…

Identification of an Immunogenic Medulloblastoma-Specific Fusion Involving EPC2 and GULP1

Medulloblastoma is the most common malignant brain tumor in children. Immunotherapy is yet to demonstrate dramatic results in medulloblastoma, one reason being the low rate of mutations creating new antigens in this entity. In tumors with low mutational burden, gene fusions may represent a source of tumor-specific neoantigens. Here, we reviewed the landscape of fusions in medulloblastoma and analyzed their predicted immunogenicity. Furthermore, we described a new in-frame fusion protein identified by RNA-Seq. The fusion involved two genes on chromosome 2 coding for the enhancer of polycomb homolog 2 (EPC2) and GULP PTB domain containing engulfment adaptor 1 (GULP1) respectively. By qRT-PCR …

TRTH-08. HIGH GRADE NEUROEPITHELIAL TUMOR OF THE CENTRAL NERVOUS SYSTEM WITH BCOR ALTERATION IS SENSITIVE TO IGF1R INHIBITION

High grade neuroepithelial tumor of the central nervous system with BCOR alteration (CNS HGNET-BCOR) is a recently described new tumor entity which was formerly diagnosed with diverse histological diagnoses, for example as ependymoma. This tumor predominantly affects children and has a dismal prognosis. No standard therapies for this entity exist so far. Recently we described the activation of the Sonic hedgehog (SHH) and the WNT signaling pathway in this tumor and described a primary cell culture (PhKh1) isolated from a skull metastasis of a seven years old patient. We also detected a high expression of IGF2, which is known to be required for SHH signaling in medulloblastoma. IGF2 signals …

Quantitative methylation analysis of developmentally important genes in human pregnancy losses after ART and spontaneous conception.

To study possible effects of assisted reproductive technologies (ART) on epigenetic reprogramming, we have analyzed the DNA methylation levels of differentially methylated regions (DMRs) of seven imprinted genes (H19, MEG3, LIT1, MEST, NESP55, PEG3 and SNRPN) as well as the promoter regions of the pluripotency gene NANOG and the tumor suppressor gene APC in chorionic villus samples (CVS) of 42 spontaneous miscarriages and stillbirths after ART and 29 abortions/stillbirths after spontaneous conception. We did not find an increased rate of faulty methylation patterns after ART, but significant and trend differences (ROC curve analysis, Wilcoxon test) in the methylation levels of LIT1 (P = 0.0…

A familial disorder of altered DNA-methylation

BackgroundIn a subset of imprinting disorders caused by epimutations, multiple imprinted loci are affected. Familial occurrence of multilocus imprinting disorders is rare.Purpose/objectiveWe have investigated the clinical and molecular features of a familial DNA-methylation disorder.MethodsTissues of affected individuals and blood samples of family members were investigated by conventional and molecular karyotyping. Sanger sequencing and RT-PCR of imprinting-associated genes (NLRP2, NLRP7, ZFP57, KHDC3L, DNMT1o), exome sequencing and locus-specific, array-based and genome-wide technologies to determine DNA-methylation were performed.ResultsIn three offspring of a healthy couple, we observed…

Exploiting Gangliosides for the Therapy of Ewing’s Sarcoma and H3K27M-Mutant Diffuse Midline Glioma

Simple Summary Osteosarcoma, Ewing’s sarcoma, and H3K27M-mutant diffuse midline glioma are rare but aggressive malignancies occurring mainly in children. Due to their rareness and often fatal course, drug development is challenging. Here, we repurposed the existing drugs dinutuximab and eliglustat and investigated their potential to directly target or indirectly modulate the tumor cell-specific ganglioside GD2. Our data suggest that targeting and/or modulating tumor cell-specific GD2 may offer a new therapeutic strategy for the above mentioned tumor entities. Abstract The ganglioside GD2 is an important target in childhood cancer. Nevertheless, the only therapy targeting GD2 that is approve…

PNR-35CNS HGNET-BCOR - MOLECULAR CHARACTERIZATION AND IDENTIFICATION OF POSSIBLE THERAPEUTIC TARGETS OF A NEW BRAIN TUMOR ENTITY

16P Molecular analysis for precision oncology of children: Beyond genomics

Epigenetic dysregulation in the developing Down syndrome cortex

Using Illumina 450K arrays, 1.85% of all analyzed CpG sites were significantly hypermethylated and 0.31% hypomethylated in fetal Down syndrome (DS) cortex throughout the genome. The methylation changes on chromosome 21 appeared to be balanced between hypo- and hyper-methylation, whereas, consistent with prior reports, all other chromosomes showed 3–11 times more hyper- than hypo-methylated sites. Reduced NRSF/REST expression due to upregulation of DYRK1A (on chromosome 21q22.13) and methylation of REST binding sites during early developmental stages may contribute to this genome-wide excess of hypermethylated sites. Upregulation of DNMT3L (on chromosome 21q22.4) could lead to de novo methyl…

Imbalance of expression of bFGF and PK1 is associated with defective maturation and antenatal placental insufficiency.

Abstract Objective Defective placental maturation is associated with restricted functional capacity and adverse perinatal fetal outcomes. The aim of the study was a comparative analysis of the role of mRNA expression of various angiogenic factors in placental maturation defects. Study design We examined the mRNA expression patterns of prokineticin 1 (PK1), its receptors (PKRs), basic-fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) in tissue from third-trimester placentae that exhibited delayed or accelerated villous maturation. Results The expression of PK1 and PKR2 was elevated in placental tissue exhibiting accelerated maturati…

Immaturity for gestational age of microvasculature and placental barrier in term placentas with high weight

Abstract Objective Villous immaturity for gestational age is a multifactorial developmental deviation associated with unexpected placental insufficiency, fetal hypoxia and term fetal death. In our previous work we have shown that immature CD15+/CD31+/CD34+ endothelial cells were an important indicator of placental villous immaturity and chronic insufficiency. The aim of this study was to perform a comparative analysis of CD15-marked immaturity in the vessel walls between normal and pathological term placentas of clinically and structurally heterogenous groups with normal, low and high weight. Study design 165 clinically normal and pathological placentas of gestational age 39–42 with normal …

CD15 immunostaining improves placental diagnosis of fetal hypoxia

Fetal hypoxic events with unclear predictive value are a common indication for placenta examination. We evaluated whether the use of CD15 immunostaining can improve the assessment of severity and duration of fetal hypoxia.We compared placentas (37-42 gestational weeks) from stillborns/newborns with birth asphyxia (BA) and non-hypoxic newborns. Placental findings were studied in following groups: (1) acute BA (n = 11) due to placental abruption, (2) non-acute BA (n = 121) due to non-acute conditions, (3) non-BA (n = 46) in pregnancies with preeclampsia and gestational diabetes, and (4) controls (n = 30).A high expression of CD15 in feto-placental resistance vessels (FRVs) was present in non-…