Single-cell transcriptomics of human embryos identifies multiple sympathoblast lineages with potential implications for neuroblastoma origin

Characterization of the progression of cellular states during human embryogenesis can provide insights into the origin of pediatric diseases. We examined the transcriptional states of neural crest- and mesoderm-derived lineages differentiating into adrenal glands, kidneys, endothelium and hematopoietic tissue between post-conception weeks 6 and 14 of human development. Our results reveal transitions connecting the intermediate mesoderm and progenitors of organ primordia, the hematopoietic system and endothelial subtypes. Unexpectedly, by using a combination of single-cell transcriptomics and lineage tracing, we found that intra-adrenal sympathoblasts at that stage are directly derived from nerve-associated Schwann cell precursors, similarly to local chromaffin cells, whereas the majority of extra-adrenal sympathoblasts arise from the migratory neural crest. In humans, this process persists during several weeks of development within the large intra-adrenal ganglia-like structures, which may also serve as reservoirs of originating cells in neuroblastoma.

Metastatic neuroblastoma diagnosed on prenatal sonographic examination performed for decreased fetal movement

We report a case of fetal neuroblastoma presenting with massive liver metastasis diagnosed during the biophysical profile sonographic examination performed for decreased fetal movement. The patient presented at 37 weeks' gestation with limited fetal movement over 24 hours. Biophysical profile showed marked polyhydramnios and an enlarged abdomen filled with a homogeneous mass lesion suspicious for liver metastasis. Primary urgent cesarean section was performed revealing a cachectic neonate with a rigid and grossly distended abdomen. Neonatal evaluation confirmed the etiology of the abdominal mass to be liver metastasis from neuroblastoma. The child died on the 46th day. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:502-506, 2017.

Cyclin D1 in human neuroblastic tumors recapitulates its developmental expression: An immunohistochemical study

The protein cyclin D1 (CD1), which belongs to a family of proteins functioning as regulators of CDKs (cyclin-dependent kinases) throughout the cell cycle, has been immunohistochemically detected in a wide variety of human malignant tumors. The aim of the present study was to investigate immunohistochemically the expression and distribution of CD1 in the developing human peripheral sympathetic nervous system (PSNS) and in childhood peripheral neuroblastic tumors (neuroblastomas, ganglioneuroblastomas, and ganglioneuromas). The above mentioned fetal and neoplastic tissues represent an in vivo model in which undifferentiated neuroblastic cells undergo ganglion cell differentiation. During development, a strong nuclear expression of CD1 was restricted to neuroblasts, disappearing progressively from the maturing ganglion cells with increasing gestational age. In neoplastic tissues, CD1 immunoreactivity was restricted to neuroblastic cell component of all neuroblastomas and ganglioneuroblastomas, whereas it was absent or only focally detectable in maturing/mature ganglion cell component of differentiating neuroblastomas, ganglioneuroblastomas, and ganglioneuromas. We conclude that CD1 is a reliable marker, which can be used routinely to stain neuroblastic cells in both developing and neoplastic tissues. Furthermore, our results indicate that CD1 expression in childhood peripheral neuroblastic tumors recapitulates the changes during normal development of PSNS, as previously reported for Bcl-2 oncoprotein, c-ErbB2, insulin-like growth factor 2, β-2-microglobulin, and cathepsin D. This is consistent with the current view that childhood peripheral neuroblastic tumors exhibit gene expression profiles mirroring those occurring during PSNS development.

[Prenatal diagnosis of retroperitoneal neuroblastoma. Case report]

Neuroblastoma is the foremost malignant neoplasm of the fetus and neonate. It is a tumor of the sympathetic nervous system that originates from the neural crest which etiology is largely unknown. Due to its general variability in outcome, neuroblastoma has long been considered one of the most enigmatic of cancers. Although technological advances in ultrasonography have possible intrauterine detection, prenatal diagnosis is still a rare event. This kind of tumor has a high morbidity and mortality rate due to the metastatic risk. Early detection of the tumor is critical to improve outcome. We report a case of retroperitoneal neuroblastoma diagnosed at 32 week of gestation.

Motoneuronal cell death is not correlated with aggregate formation of androgen receptors containing an elongated polyglutamine tract

Spinal and bulbar muscular atrophy (SBMA) is associated with an abnormal expansion of the (CAG)(n)repeat in the androgen receptor (AR) gene. Similar mutations have been reported in other proteins that cause neurodegenerative disorders. The CAG-coded elongated polyglutamine (polyGln) tracts induce the formation of neuronal intracellular aggregates. We have produced a model to study the effects of potentially 'neurotoxic' aggregates in SBMA using immortalized motoneuronal cells (NSC34) transfected with AR containing polyGln repeats of different sizes [(AR.Q(n = 0, 23 or 46)]. Using chimeras of AR.Q(n) and the green fluorescent protein (GFP), we have shown that aggregate formation occurs when the polyGln tract is elongated and AR is activated by androgens. In NSC34 cells co-expressing the AR with the polyGln of pathological length (AR.Q46) and the GFP we have noted the presence of several dystrophic neurites. Cell viability analyses have shown a reduced growth/survival rate in NSC34 expressing the AR.Q46, whereas testosterone treatment partially counteracted both cell death and the formation of dystrophic neurites. These observations indicate the lack of correlation between aggregate formation and cell survival, and suggest that neuronal degeneration in SBMA might be secondary to axonal/dendritic insults.

In vivo spontaneous neuronal to neuroendocrine lineage conversion in a subset of neuroblastomas

Neuroblastoma is an embryonal tumor derived from the sympathetic nervous system. Although all neuroblastomas have a neuronal character, a subset of tumors also show evidence of extra-adrenal neuroendocrine differentiation in discrete cell layers. A characterization of the cells of the developing human sympathetic nervous system was performed, identifying growth-associated protein-43, neuropeptide tyrosine, and Bcl-2 as marker genes for sympathetic neurons. Whereas all neuroblastomas express growth-associated protein-43, neuropeptide tyrosine, and Bcl-2, tumors with differentiating cells with neuroendocrine features expressed these genes only in the morphologically immature, proliferating cells. Thus, with neuroendocrine tumor cell differentiation, neuronal marker gene expression vanished and proliferation ceased and was succeeded by expression of chromogranin A/B and insulin-like growth factor-2, markers of neuroendocrine chromaffin differentiation. These tumors appear to provide examples of spontaneous lineage conversion from a neuronal to a neuroendocrine phenotype.

A developmental model of neuroblastoma: differentiating stroma-poor tumors' progress along an extra-adrenal chromaffin lineage

The prognosis of children with neuroblastoma (NB) is dependent upon the patient's age at diagnosis, the location of the primary tumor, and histologic tumor cell differentiation. These characteristics, as well as the presumption that NB results from clonal expansion of primitive cells involved in sympathetic nervous system (SNS) development, predict that a model of tumorigenesis based upon normal fetal SNS histogenesis might indicate tumor progenitor status and define biologic and clinical behavior. Immunohistochemistry and in situ hybridization were used to examine a panel of marker gene products predicted or shown to be expressed during SNS development in the normal human fetal SNS from 8 to 24 weeks' gestational age. A similar analysis was performed in a selection of clinical NB tumors, and the results were compared. In a subset of differentiating, often extra-adrenal NB tumors in patients who frequently had a favorable outcome; advancing morphologic tumor cell differentiation spatially paralleled an advancing fetal extra-adrenal chromaffin marker gene expression phenotype (ie, increasing TrkA, TrkC, TH, IGF-2, and neuron-specific enolase expression but a lack of phenylethanolamine N-methyltransferase expression). In these tumors, expression of gene products associated with normal fetal sympathetic ganglionic differentiation (ie, Bcl-2, HNK-1, and neuropeptide Y) was lost with morphologic tumor cell differentiation. In contrast, undifferentiated tumors, the majority of which were high stage, adrenal in origin, and prognostically unfavorable, displayed marker expression characteristics mirroring that of an early fetal ganglionic lineage. Thus, we show that morphologic differentiation in stroma-poor NB tumors, long held as an important prognostic feature in tumor grading systems, often corresponds to an extra-adrenal chromaffin rather than a ganglion cell or adrenal medullary chromaffin phenotype. Understanding the biology of extra-adrenal chromaffin tissues may provide an explanation for the clinically less aggressive nature of differentiating NB tumors and suggest potential mechanisms for spontaneous regression and/or treatment response.

Microscopic neuroblastoma in a fetus with a de novo unbalanced translocation 3;10

We report on a fetus with a de novo unbalanced translocation 3;10 and a microscopic neuroblastoma. The fetus had the karyotypic and phenotypic manifestations of partial dup (3q). The finding of a constitutional chromosomal abnormality and a microscopic neuroblastoma, although possibly coincidental, supports Knudson's two hit hypothesis for development of neuroblastomas and other embryonal tumors. In this case the first mutation is represented by the constitutional abnormality, possibly resulting in the microscopic neuroblastoma. A second mutation affecting the abnormal cells, which may be more prone to mutagenesis, may trigger a neuroblastoma.

Pathology of neuroblastic tumors

Histogenesis, basic histologic features, nomenclature, and criteria for diagnosis and prognostic classifications based on morphological features of neuroblastic tumors (NTs) are described. NTs that arise from neuroectodermal cells of the adrenal medulla and sympathetic ganglia recapitulate the development of sympathetic ganglion. The following three basic types of NTs are recognized: neuroblastoma (NBs) and ganglioneuroblastomas (GNBs) and ganglioneuromas (GNs). NBs can be undifferentiated, poorly differentiated or differentiating; GNBs have the following three subtypes. (1) nodular, (2) intermixed, and (3) borderline. The conventional and recommended terminology and Shimada terminology of NTs are described (Tables 1 and 2). There are three basic pathologic components of NTs, neuroblastomatous, ganglioneuromatous, and intermediate components (Figs 3, 5, and 7). There are two major prognostic classifications based on morphological features of NTs, Shimada classification and histologic grading (Tables 3 and 4).

Disordered differentiation as a target for novel approaches to the treatment of neuroblastoma

Some childhood malignant neoplasms are thought to arise in embryonic tissues. These tumors present unique opportunities for studying the maturation of specific cellular lineages and examining the possible role of alterations in the regulation of differentiation in tumor development. Several features of neuroblastoma, a tumor thought to arise in cells originating in the embryonic neural crest, suggest that it may be particularly useful in this regard. The identification of a series of markers that characterize the various cell types of the peripheral nervous system that are detectable in neuroblastoma tumor tissues has made it possible to recognize that the cells of neuroblastoma tumor cell lines and tissues correspond to specific stages of adrenal gland development. Experiments directed at understanding the cellular signals by which neural crest cell maturation is mediated may provide insights of therapeutic import because neuroblastoma tumors corresponding to some stages of differentiation respond very differently to nonspecific cytotoxic therapies than tumors corresponding to other stages.

Neuroblastoma: epidemiology and pattern of regression. Problems in interpreting results of mass screening

Neuroblastomas are malignant, embryonic tumors, and most are probably congenital in origin. Neuroblastoma is a heterogeneous neoplastic disease with respect to response to treatment and prognosis. Some of its clinical behavior is ascribed to the ability of the tumor to regress spontaneously. Spontaneous regression of neuroblastoma is occasionally observed in young infants, but occurs extremely rarely in older children. This feature is in accordance with the concept that tumors develop by a series of changes, progressing from a dependent state to an autonomous state. Spontaneous regression was documented in less than 2% of Danish neuroblastoma patients. However, the "true" incidence of regression may be higher. Epidemiological data suggest that, in recent decades, borderline lesions may be included among truly malignant neuroblastomas. The recent birth cohorts compiled in Denmark show that 1 in 7,000 live births will develop neuroblastoma before 15 years of age. If 65% of all childhood neuroblastomas could be detected at or before the age of 6 months, then the expected prevalence by screening would be 1/11,000. One can speculate that 1/18,000 live births might possibly benefit from screening at age 6 months, since 59% of these children had tumors in stages III and IV diagnosed after the age of 6 months. However, the proof that screening can only detect lesions that would have progressed to become malignant tumors depends on observing an appropriate fall in the incidence of the malignant tumors in older children and a decline in mortality. Therefore, it is of some concern that the incidence of neuroblastomas appears to actually increase with screening while mortality has been little effected.(ABSTRACT TRUNCATED AT 250 WORDS)

Beta 2-microglobulin expression in human embryonal neuroblastoma reflects its developmental regulation

Class I major histocompatibility complex (MHC) antigen expression in neuroblastoma may play a role in the oncogenicity of this embryonal tumor of childhood. Since N-myc amplification in neuroblastoma tumors is associated with rapid tumor progression (33) and N-myc decreases Class I MHC antigen expression in rat neuroblastoma cells (21), we quantitated levels of N-myc mRNA and Class I MHC cell surface antigens in a panel of 24 human neuroblastoma cell lines. We found that N-myc expression is not invariably associated with low levels of beta 2-microglobulin (B2M) and Class I MHC antigen expression. As we considered that Class I MHC antigens may be regulated in association with the differentiation stage of the neuroblastoma tumor, we examined the expression of B2M during development of the human adrenal medulla, the tissue of origin of most neuroblastomas. We found that B2M is a marker of differentiated adrenal medullary cells, expressed late during the third trimester of development. Moreover, using morphological and immunological criteria, we found that B2M is expressed in differentiated tumor cells. These data suggest that the expression of B2M in neuroblastoma is associated with the stage of differentiation of the tumor cell and not N-myc expression. Furthermore, these findings suggest that neuroblastomas may correspond to the arrested differentiation of adrenal neuroblasts at different stages of development.

The association of congenital neuroblastoma and congenital heart disease. Is there a common embryologic basis?

Several authors have reported an association between neuroblastoma and congenital heart disease; others contend that, unlike specific well-known associations between malignancy and congenital defects (Wilm's tumor and aniridia, leukemia and Down's syndrome), no real relationship exists. We present three cases of cyanotic congenital heart disease in which subclinical neuroblastoma was found. We speculate that abnormal neural crest cell migration and development may be a common link between cardiac malformations and congenital neuroblastoma.

Peripheral and central primitive neuroectodermal tumors. A nosologic concept seeking a consensus

The term primitive neuroectodermal tumor is widely used in the literature for a group of small, round-cell tumors in the central and sympathetic nervous systems and soft tissues as well as a specific diagnostic term for individual neoplasms; however, the contention that these various clinicopathologic entities (neuroblastoma, medulloblastoma, and peripheral neuroepithelioma) are histogenetically related is an unproved hypothesis. Morphologic, cytogenetic, immunohistochemical, biochemical, and in vitro studies have established phenotypic similarities among these putatively related neoplasms whether they originate in the brain, adrenal gland, or soft tissues. Because one tumor resembles another in terms of its phenotypic expression, that does not necessarily imply a common histogenesis. This point has been made by previous investigators. The purpose of this review is to evaluate and discuss the present status of our understanding and some of the controversial aspects of this enigmatic category of neoplasms, mainly occurring in children, known as the primitive neuroectodermal tumors.

Present concepts in the treatment of neuroblastoma

The outlook for the child with neuroblastoma remains dismal. The tumor has been known to undergo spontaneous resolution, and this phenomenon has led to increased interest and research in possible immune mechanisms that may be involved. Treatment often involves the use of surgery, radiation, and chemotherapy, frequently producing a short-term response, but a cure of the disease in an advanced stage can rarely be attributed to any of these treatment modalities. The present staging and treatment method used by the authors is that of the Pediatric Oncology Group (POG) #8104. As far as the immunological therapeutic approach is concerned, promising results have been obtained in animal studies with monoclonal antibodies and immunocellular components. Cumulative data from various pediatric centers have showed that the patient's age strongly influences the prognosis in all stages of the disease.

Diagnosis of neural crest tumors by reversed-phase high-performance liquid chromatographic determination of urinary catecholamine metabolites

Aberrations in the metabolic pathways of catecholamines in patients with neural crest tumors result in characteristic urinary excretion patterns of their catabolites. Tumors such as pheochromocytoma, neuroblastoma and ganglioneuroma usually defy clinical diagnosis because of their rarity, small size, intraabdominal position and clinical symptoms similar to those of essential hypertension. Quantitative determination of catecholamine metabolites such as vanillylmandelic acid (VMA) and 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) offers possibilities for reliable confirmation of diagnosis. However, previous techniques for the assessment of catabolite levels suffered from inadequate sensitivity, reproducibility or specificity, which seriously diminished their usefulness as biochemical determinants in the prognosis of these life-threatening tumors. Reported in this paper is the analysis of urinary levels of VMA and MHPG using reversed-phase high-performance liquid chromatography with electrochemical and sectrophotometric detection. We present the excretion patterns showing these metabolites in 15 control subjects, 15 patients with pheochromocytoma and 5 patients with neuroblastoma.

Spontaneous regression of neuroblastoma

Case of spontaneous regression of neuroblastoma continue to occur in the present multimodal therapy era at institutions where physicians are prepared to withhold treatment on certain patients with residual primary or metastatic disease. From a survey of the 22 member institutions of Children's Cancer Study Group, seven hospitals submitted data on 24 neuroblastoma patients whose disease underwent regression after minimal, unusual, or no treatment. An analysis of these patients and of 33 patients form two large series in the literature shows that the majority of patients are infants with Stage II or Stage IVS disease. The spontaneous regression usually consists of complete disappearance of the disease, but in some neuroblastomas, maturation to ganglioneuroma takes place. The various factors that may influence regression are discussed.