Embryonic Neural Crest Cells Research Articles

Insights into the molecular characteristics of embryonic cranial neural crest cells and their derived mesenchymal cell pools

Neural crest cells (NCCs) are central to vertebrate embryonic development, giving rise to diverse cell types with unique migratory and differentiation capacities. This study examines the molecular characteristics of cranial neural crest cell (CNCC)-derived mesenchymal cells, specifically those from teeth which in deer show continuous but limited growth, and antlers, which exhibit remarkable regenerative capabilities. Here, through single-cell RNA sequencing analysis, we uncover shared gene expression profiles between adult antlerogenic and dental mesenchymal cells, indicating common developmental pathways. We identify a striking resemblance in transcriptomic features between antlerogenic progenitor cells and dental pulp mesenchymal cells. Comparative analysis of CNCC-derived and non-CNCC-derived mesenchymal cell pools across species reveals core signature genes associated with CNCCs and their derivatives, delineating essential connections between CNCCs and CNCC-derived adult mesenchymal pools. Furthermore, whole-genome DNA methylation analysis unveils hypomethylation of CNCC derivate signature genes in regenerative antlerogenic periosteum, implying a role in maintaining multipotency. These findings offer crucial insights into the developmental biology and regenerative potential of CNCC-derived mesenchymal cells, laying a foundation for innovative therapeutic strategies in tissue regeneration.

High-Risk Neuroblastoma Challenges and Opportunities for Antibody-Based Cellular Immunotherapy.

Immunotherapy has emerged as an attractive option for patients with relapsed or refractory high-risk neuroblastoma (HRNB). Neuroblastoma (NB), a sympathetic nervous system cancer arising from an embryonic neural crest cell, is heterogeneous clinically, with outcomes ranging from an isolated abdominal mass that spontaneously regresses to a widely metastatic disease with cure rates of about 50% despite intensive multimodal treatment. Risk group stratification and stage-adapted therapy to achieve cure with minimal toxicities have accomplished major milestones. Targeted immunotherapeutic approaches including monoclonal antibodies, vaccines, adoptive cellular therapies, their combinations, and their integration into standard of care are attractive therapeutic options, although curative challenges and toxicity concerns remain. In this review, we provide an overview of immune approaches to NB and the tumor microenvironment (TME) within the clinical translational framework. We propose a novel T cell-based therapeutic approach that leverages the unique properties of tumor surface antigens such as ganglioside GD2, incorporating specific monoclonal antibodies and recent advancements in adoptive cell therapy.

Abstract LB233: Single-cell transcriptional analysis of embryonic melanoblasts pinpoints embryonic cell states that underlie targeted therapy and immune checkpoint blockade resistance

Abstract Melanoma is a malignant neoplasia of pigment-producing melanocytes notable for its ability to metastasize early during primary tumor growth. Melanomas display typically high mutation burden—a hallmark associated with immune checkpoint blockade therapy (ICBT) sensitivity—but can still evade ICBT. These melanoma phenotypes likely relate to embryonic neural crest cells, a population of cells from which melanocytes arise. For instance, BRAF inhibition-evading melanoma cells adopt neural crest-like states. However, the exact embryonic lineage underlying BRAFi resistance remains unknown as does its relationship with any neural crest-like states that underlie ICBT resistance. To discover such states, we used a mouse fluorescent reporter model of melanoblast development in which melanocyte-specific GFP is driven by the dopachrome tautomerase promoter (iDct-GFP). Embryonic day (E) 11.5 and 15.5 melanoblasts were isolated and sequenced using single-cell transcriptomics (scRNA-seq). These time-points enriched for cells migrating from the dermis to epidermis (at E11.5) or for cells colonizing the hair follicle (at E15.5). These characteristics could help metastatic progression, namely migration across the basement membrane in early invasive melanomas and colonization of metastatic sites. We classified these embryonic melanocytes and their precursors into multiple clusters which in turn were grouped into four key lineages: Neural Progenitor, Schwann Cell Progenitor (SCP), Mesencyhmal (Mes) and Melanocytes (Mel). To detect the presence of these states in tumors, we derived developmental gene modules (DGMs): sets of genes that were preferentially co-expressed in each embryonic cell state. DGMs stratified TCGA samples; SCP-high and Mes-high subtypes were associated with worse survival compared to Mel-high tumors. Moreover, SCP-high tumors had lower T cell infiltration, and were associated with higher NGFR expression, a known marker of ICBT resistance. High expression of SCP DGMs was associated with poor response to anti-PD1 ICBT. Targeting factors underlying the SCP state might therefore sensitize tumours to ICBT. Mes DGMs on the other hand were associated with targeted therapy resistance. Cross-referencing DGMs with published RNA-seq data from melanoma cell lines suggest that SCP and Mes DGMs are induced by pro-inflammatory cytokines secreted by immune cells in the tumor microenvironment. Together, these observations suggest that the SCP state is implicated in the phenomenon of inflammation-induced de-differentiation, a process by which melanomas are able to evade ICBT. Our identification of the SCP and Mes states, along with a deeper understanding of their transcriptional programs and signaling pathways, may reveal clinically actionable targets to disrupt immuno- or targeted-therapy resistance. Citation Format: Vishaka Gopalan, Chun Wai Wong, Chi-Ping Day, Eva Perez-Guijarro, Maxwell P. Lee, Yuhong Jiang, Howard H. Yang, Maira Alves-Constantino, Antonella Sassano, Cari Smith, Mark Simpson, Sung Chin, Jessica Ebersole, Charli Gruen, Emily Wu, Sridhar Hannenhalli, Adam Hurlstone, Glenn Merlino, Kerrie Marie. Single-cell transcriptional analysis of embryonic melanoblasts pinpoints embryonic cell states that underlie targeted therapy and immune checkpoint blockade resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB233.

Abstract 2865: Efficacy of MDM2 and epigenetic inhibitors treatments for neuroblastoma

Abstract Pediatric Neuroblastoma (NB) is one of the most prevalent solid tumors in children that arise from embryonic neural crest cells and poses a significant challenge in the field of oncology. There are about 700 to 800 new cases of neuroblastoma diagnosed each year in the United States, and accounts for approximately 15% of all childhood cancer mortalities. Since this malignancy predominantly affects infants and young children, it is imperative to decipher the underlying molecular factors driving its pathogenesis. The novel molecular therapeutic approach includes the use of epigenetic modifiers as drugs. This approach aims to reverse significant epigenetic events underlying cancer pathogenesis, particularly abnormalities in histone modifications and DNA methylation. The reduction of both DNA and histone methylation levels leads to the reactivation of tumor suppressor genes and inhibits cancer cell proliferation and cell growth. In this study, we used selective and reversible small molecule agents such as MDM2 inhibitor (RG7388) and epigenetic modifiers (CM272 and SAHA) to block cell proliferation by inducing cell cycle arrest via enforcing Epigenetic alterations. Our initial experiments were designed to understand the effects of RG7388, CM272, and SAHA treatments on NB and their impact on cell cycle progression. It was hypothesized that the decrease in DNA methylation and increase in histone modification- augment p21 expression via the use of MDM2 inhibitors and epigenetic modifiers. To test this hypothesis, the NB cells (SK-N-SK and IMR-32) were treated with RG7388, CM272, and SAHA for 24 hours. The extent of Cell death was determined for NB cells by using the Trypan Blue Dye Exclusion (TBDE) method, and CellTiter-Glo® Luminescent Cell Viability Assay. Induction of apoptosis was determined by using the Immunofluorescence staining method with DEVD-amc substrate. The results of our study suggested that RG7388, CM272, and SAHA were able to induce cell death in the SK-N-SH cells following 24-hour treatment. Furthermore, we analyzed the levels of Tumor suppressor (p53), cell cycle arrest (p21, p27, AurkB, CDC25A, CyclinD) cell death (Bax, Bcl2, LC3, Beclin, PARP, Cleaved PARP, RIP1, RIP3, MLKL, p-AKT), and Epigenetic biomarker (DNMT1, DNMT3A, DNMT3B, acetyl histoneH3, H4, and H2b) protein expression levels using western blot analysis. The results showed significant elevation of p53, p21, p27, and acetylation of histone family biomarkers after treatment when compared with the control group. In summary, our results indicate that RG7388, CM272, and SAHA treatments can effectively induce cellular responses and prevent cell growth and progression by enforcing epigenetic changes in the NB cells. (This research was supported by the National Pediatric Cancer Foundation, Tampa, Florida, and the Royal Dames of Cancer Research Inc. of Ft. Lauderdale, Florida) Citation Format: Tahani Momenah, Umamaheswari Natarajan, Shyam Jaganathan, Appu Rathinavelu. Efficacy of MDM2 and epigenetic inhibitors treatments for neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2865.

Neurogenin 2 and Neuronal Differentiation 1 Control Proper Development of the Chick Trigeminal Ganglion and Its Nerve Branches.

The trigeminal ganglion contains the cell bodies of sensory neurons comprising cranial nerve V, which relays information related to pain, touch, and temperature from the face and head to the brain. Like other cranial ganglia, the trigeminal ganglion is composed of neuronal derivatives of two critical embryonic cell types, neural crest and placode cells. Neurogenesis within the cranial ganglia is promoted by Neurogenin 2 (Neurog2), which is expressed in trigeminal placode cells and their neuronal derivatives, and transcriptionally activates neuronal differentiation genes such as Neuronal Differentiation 1 (NeuroD1). Little is known, however, about the role of Neurog2 and NeuroD1 during chick trigeminal gangliogenesis. To address this, we depleted Neurog2 and NeuroD1 from trigeminal placode cells with morpholinos and demonstrated that Neurog2 and NeuroD1 influence trigeminal ganglion development. While knockdown of both Neurog2 and NeuroD1 affected innervation of the eye, Neurog2 and NeuroD1 had opposite effects on ophthalmic nerve branch organization. Taken together, our results highlight, for the first time, functional roles for Neurog2 and NeuroD1 during chick trigeminal gangliogenesis. These studies shed new light on the molecular mechanisms underlying trigeminal ganglion formation and may also provide insight into general cranial gangliogenesis and diseases of the peripheral nervous system.

Wnt/BMP Mediated Metabolic Reprogramming Preserves Multipotency of Neural Crest-Like Stem Cells.

Neural crest-like stem cells resembling embryonic neural crest cells (NCs) can be derived from adult human tissues such as the epidermis. However, these cells lose their multipotency rapidly in culture limiting their expansion for clinical use. Here, we show that the multipotency of keratinocyte-derived NCs (KC-NCs) can be preserved by activating the Wnt and BMP signaling axis, promoting expression of key NC-specifier genes and ultimately enhancing their differentiation potential. We also show that transcriptional changes leading to multipotency are linked to metabolic reprogramming of KC-NCs to a highly glycolytic state. Specifically, KC-NCs treated with CHIR and BMP2 rely almost exclusively on glycolysis for their energy needs, as seen by increased lactate production, glucose uptake, and glycolytic enzyme activities. This was accompanied by mitochondrial depolarization and decreased mitochondrial ATP production. Interestingly, the glycolytic end-product lactate stabilized β-catenin and further augmented NC-gene expression. Taken together, our study shows that activation of the Wnt/BMP signaling coordinates the metabolic demands of neural crest-like stem cells governing decisions regarding multipotency and differentiation, with possible implications for regenerative medicine.

Targeting ARHGEF12 promotes neuroblastoma differentiation, MYCN degradation, and reduces tumorigenicity.

Neuroblastoma arises from developmental block of embryonic neural crest cells and is one of the most common and deadly pediatric tumors. However, the mechanism underlying this block is still unclear. Here, we show that targeting Rho guanine nucleotide exchange factor 12 (ARHGEF12, also named LARG) promotes MYCN degradation and neuroblastoma differentiation, leading to reduced neuroblastoma malignancy. The neuroblastoma TARGET dataset was downloaded to assess ARHGEF12 expression. Cell differentiation, proliferation, colony formation and cell migration analyses were performed to investigate the effects of ARHGEF12 knockdown on neuroblastoma cells. Western blotting and immunohistochemistry were employed to determine protein expression. Animal xenograft models were used to investigate antitumor effects after ARHGEF12 knockdown or treatment with the ARHGEF12 inhibitor Y16 in vivo. We found that the expression level of ARHGEF12 was higher in neuroblastoma than in better-differentiated ganglioneuroblastoma. Knockdown of ARHGEF12 promoted neuroblastoma differentiation, decreased stemness-related gene expression, and increased differentiation-related gene expression. ARHGEF12 knockdown reduced tumor growth, and the resulting tumors showed bigger tumor cells compared to those in control neuroblastoma xenografts. In addition, it was found that ARHGEF12 knockdown promoted MYCN ubiquitination and degradation in MYCN-amplified tumors through RhoA/ROCK/GSK3β signaling. Targeting ARHGEF12 with the small molecular inhibitor Y16 induced cell differentiation and attenuated neuroblastoma tumorigenicity. Our findings provide new insight into the mechanism by which ARHGEF12 regulates neuroblastoma tumorigenicity and suggest a translatable therapeutic approach by targeting ARHGEF12 with a small molecular inhibitor.

PMON88 A Rare Case of Composite Paraganglioma in the Bladder

Abstract Background Paragangliomas are neuroendocrine tumors that arise from embryonic neural crest cells; they are essentially extra-adrenal pheochromocytomas most frequently found in the head and neck. Composite tumors are rare and consist of the presence of two histologically distinct tissues within a single tumor. Additionally rare is the presence of a composite paraganglioma in the retroperitoneum and urinary bladder, of which there are few reported cases. Case Report We present a case of a 57 year old female who was found to have an incidental pelvic mass noted to progressively increase in size over the years on subsequent imaging. The patient had a cystoscopy and retrograde pyelogram that were both unremarkable. MRI Pelvis showed a 1.8×1.8×1.9 cm rounded, well-circumscribed lesion at the left posterior lateral bladder extending exophytically from the serosa at the ureterovesicular junction. As she had associated hypertension, palpitations, and anxiety, the patient was evaluated for pheochromocytoma.Laboratory workup showed elevated plasma levels of free Metanephrines at 130 (<57 pg/mL), free Normetanephrines at 247 (<148 pg/mL), and a free Total level at 377 (<205 pg/mL). 24-hour urine collection was consistent with mild elevation of Metanephrines at 330 (90-315 mcg/24 h), normal levels of Normetanephrines at 469 (122-676 mcg/24 h), and normal levels of Total urine Metanephrines of 799 (224-832 mcg/24 h). 24-hour urine free Catecholamines showed: Epinephrine of 6 (2-24 mcg/24 h), Norepinephrine of 77 (15-100 mcg/24 h), and a Total (Epi+NE) of 83 (26-121 mcg/24 h), with Dopamine of 220 (52-480 mcg/24 h).Due to mildly elevated metanephrine levels, the patient was started on the alpha-blocker doxazosin. She ultimately underwent a laparoscopic removal of the bladder mass, with pathology reports confirming presence of a composite paraganglioma with atypical features. Additionally, further immunohistochemistry was negative for the SDHB gene mutation in the tissue samples obtained. Conclusion Composite paragangliomas of the urinary bladder are very rare. Certain genetic pathologic variants carry an increased risk for malignancy and possible metastasis; therefore, these neuroendocrine tumors usually require targeted mutation testing. At this time, the pathogenesis of composite paragangliomas is still largely unknown, with little information available about treatment options and clinical outcomes. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

ODP552 Hypercalcemic Crisis Due to PTH Secretion From a Poorly Differentiated Esophageal Neuroendocrine Tumor

Abstract Background Paraneoplastic secretion of PTH is described in a number of solid organ tumors. Hypercalcemia occurs in up to 30% of patients with malignancy. The most common cause of this phenomenon is PTHrP production. We present a rare case of PTH mediated hypercalcemic crisis from a tumor of presumed esophageal lineage. Clinical Case A 54-year-old man presented with several days of fatigue, lethargy and polyuria. Initial calcium was markedly elevated at 18.4 (8.3-10.1mg/dL). Past medical history included Barrett's esophagus, history of gastric bypass, and prior alcohol abuse. He also had progressive dysphagia and 30lb weight loss over the prior month. On examination, he had tachycardia, cachexia, and encephalopathy. Laboratory testing revealed an elevated PTH of 281 (nl 18.4-80.1pg/mL), creatinine 1.34mg/dL, and low phosphorus at 2.8 (nl 2.7-4.5mg/mL). Hypercalcemia was treated with IV fluids, calcitonin, and pamidronate. The calcium normalized but PTH remained 210pg/mL. Subsequent PTHrP and 1,25 di-hydroxy vitamin D levels were normal. Esophagogastroduodenoscopy (EGD) revealed a friable esophageal mass and biopsy identified a poorly differentiated carcinoma with neuroendocrine features, immunoreactive to synaptophysin and high Ki-67 index of 90%. Immunostains for chromogranin and PTH were negative. A CT of the chest, abdomen, and pelvis revealed diffuse metastases in the liver, lungs, and enlarged mediastinal lymph nodes. The source of primary tumor could not be fully identified from pathology but suspected to be esophageal. Parathyroid scan showed a subtle persistent uptake posterior to right side of trachea suspicious for a parathyroid adenoma, but that could not account for the severity of PTH elevation. He was readmitted in 1 month with recurrent symptomatic severe hypercalcemia to 18mg/dL and PTH to 619.4pg/mL. Again, he received IV fluids, calcitonin, and zoledronic acid. He received 3 cycles of platinum and etoposide based chemotherapy. After chemotherapy, PTH decreased to 123pg/mL and calcium to 9.7mg/dL but he continued to have rapid disease progression including jaundice, pathological bone fractures and orbital metastases. He elected hospice care and passed away in about 4 months from initial diagnosis. Final PTH was 916.8pg/mL. Conclusion PTH is a normally secreted by parathyroid gland chief cells, which are part of the embryonic neural crest cells found in various neuroendocrine tissues. It is plausible that malignancies with neuroendocrine features may secrete neuropeptides including PTHrP and PTH. Few case reports exist describing PTH secretion by neuroendocrine tumors, though most common are tumors of gastroenteropancreatic origin. PTH stain and focal chromogranin tends to be negative with poorly differentiated neuroendocrine tumors. PTH gene is usually intact and upregulation of the regulator sequence of PTH gene promotor is suspected to be the mechanism of elevated PTH levels and hypercalcemia. This case demonstrates the potential for poorly differentiated neuroendocrine malignancies to cause hypercalcemic crises from paraneoplastic secretion of PTH. Presentation: No date and time listed

Inhibition of Wnt/β‐catenin Signaling Pathway on Melanogenesis‐ Insights from Zebrafish (Danio rerio)

IntroductionVertebrate color patterns are composed of specialized pigment‐producing cells, the chromatophores. Melanin is the main pigment type that colors the skin and skin appendages in mammals. Melanin is produced by specialized cells called melanocytes. Melanocytes have embryonic neural crest cells origin and their development and functions are ubiquitous across vertebrates, residing in dermal and epidermal skin layers. Studies of melanogenesis have provided experimentalists with a valuable system for understanding pattern formation in the developing embryo. In addition, studying these mechanisms may have important consequences for the clinical sciences. Alcohol is a widely abused teratogenic substance. Fetal alcohol spectrum disorder (FASD) is described as birth defects associated with prenatal alcohol exposure (PAE). PAE is likely one of the leading causes of birth defects but pathophysiology of FASD associated body pigmentation disorders are needed to be investigated further. Zebrafish (Danio rerio) (ZF) is identified as a good model to study FASD and melanocyte biology. Wnt signaling pathway is a conserved signal transduction pathway which is important in embryonic development and it regulates many aspects of melanogenesis. The current study was designed to investigate the effect of Alcohol‐Wnt signaling pathway activity on ZF melanogenesis.Materials and MethodsWild‐type (WT) ZF embryos were treated with Wnt pathway inhibitor (LiCl) and combined chemical treatment (LiCl and 1% alcohol) at 10 hours post fertilization (hpf). The differential effects of above substances on early development, differentiation, patterning of melanocytes were investigated using cell biology and imaging techniques.ResultsMelanocytes of LiCl exposed samples showed defects in migration, arrangement and survival. Ectopic melanocytes and developmental aberrations of eye pigmentation were noticed in both chemical treatments. Significant variation of the melanocyte cell size, shape and body pigmentation patterning was observed among the LiCl and combined treated samples compared to the control.ConclusionEmbryonic LiCl and alcohol exposures affect the development and patterning of the melanocytes in ZF. The molecular mechanisms underlying the above phenotypes will be investigated further to understand the FASD associated pigmentation defects.

Absent Red Reflexes and Cloudy Corneas.

Absent Red Reflexes and Cloudy Corneas.

Dexamethasone Suppresses Palatal Cell Proliferation through miR-130a-3p

Cleft lip with or without cleft palate (CL/P) is one of the most common congenital birth defects. This study aims to identify novel pathogenic microRNAs associated with cleft palate (CP). Through data analyses of miRNA-sequencing for developing palatal shelves of C57BL/6J mice, we found that miR-449a-3p, miR-449a-5p, miR-449b, miR-449c-3p, and miR-449c-5p were significantly upregulated, and that miR-19a-3p, miR-130a-3p, miR-301a-3p, and miR-486b-5p were significantly downregulated, at embryonic day E14.5 compared to E13.5. Among them, overexpression of the miR-449 family (miR-449a-3p, miR-449a-5p, miR-449b, miR-449c-3p, and miR-449c-5p) and miR-486b-5p resulted in reduced cell proliferation in primary mouse embryonic palatal mesenchymal (MEPM) cells and mouse cranial neural crest cell line O9-1. On the other hand, inhibitors of miR-130a-3p and miR-301a-3p significantly reduced cell proliferation in MEPM and O9-1 cells. Notably, we found that treatment with dexamethasone, a glucocorticoid known to induce CP in mice, suppressed miR-130a-3p expression in both MEPM and O9-1 cells. Moreover, a miR-130a-3p mimic could ameliorate the cell proliferation defect induced by dexamethasone through normalization of Slc24a2 expression. Taken together, our results suggest that miR-130-3p plays a crucial role in dexamethasone-induced CP in mice.

Stem-like cells drive NF1-associated MPNST functional heterogeneity and tumor progression.

NF1-associated malignant peripheral nerve sheath tumors (MPNSTs) are the major cause of mortality in neurofibromatosis. MPNSTs arise from benign peripheral nerve plexiform neurofibromas that originate in the embryonic neural crest cell lineage. Using reporter transgenes that label early neural crest lineage cells in multiple NF1 MPNST mouse models, we discover and characterize a rare MPNST cell population with stem-cell-like properties, including quiescence, that is essential for tumor initiation and relapse. Following isolation of these cells, we derive a cancer-stem-cell-specific gene expression signature that includes consensus embryonic neural crest genes and identify Nestin as a marker for the MPNST cell of origin. Combined targeting of cancer stem cells along with antimitotic chemotherapy yields effective tumor inhibition and prolongs survival. Enrichment of the cancer stem cell signature in cognate human tumors supports the generality and relevance of cancer stem cells to MPNST therapy development.

Isolation and primary culture of chick embryonic neural crest cells

هدف: هدف از این مطالعه ارائه یک روش ساده و کارآمد جهت جداسازی و تعیین خصوصیت سلول‏های ستیغ عصبی از بافت لوله عصبی می‏باشد.مواد و روش‏ها: تخم مرغ‏های نطفه‏دار حدود 35 ساعت در دمای 38 درجه سانتی‏گراد و رطوبت نسبی 55 تا 60 درصد در داخل انکوباتور قرار داده شدند تا جنین‏ها به‏مراحل 10-12 طبق جدول تکاملی هامبورگر-هامیلتون رسیدند. سپس جنین‏ها از روی سطح زرده تخم مرغ جداسازی شده و لوله عصبی از جنین جوجه جدا و به‏مدت 24 ساعت در ظروف کشت سلولی، کشت داده شد تا سلول‏های ستیغ عصبی از آن جدا شوند. آن‏گاه لوله عصبی از کف ظروف کشت جدا و خارج شد و به سلول‏ها به‏مدت 5 روز اجازه تکثیر و ازدیاد داده شد. در نهایت این سلول‏ها جمع‏آوری شدند و جهت ارزیابی پروفایل بیان ژن، PCR صورت گرفت.نتایج: سلول‏های ستیغ عصبی از لوله عصبی جدا شده و در شرایط کشت گسترش یافتند. این سلول‏ها هم‏چنین نشانگرهای Slug، Sox9 و Sox10 را به‏روش RT-PCR بیان کردند.نتیجه‏گیری: سلول‏های ستیغ عصبی می‏توانند در محیط آزمایشگاهی از لوله عصبی رها شده و در شرایط کشت مناسب و ساده تکثیر و گسترش یابند.

Puma- and Caspase9-mediated apoptosis is dispensable for p53-driven neural crest-based developmental defects.

Inappropriate activation of the p53 transcription factor is thought to contribute to the developmental phenotypes in a range of genetic syndromes. Whether p53 activation drives these developmental phenotypes by triggering apoptosis, cell cycle arrest, or other p53 cellular responses, however, has remained elusive. As p53 hyperactivation in embryonic neural crest cells (NCCs) drives a number of phenotypes, including abnormal craniofacial and neuronal development, we investigate the basis for p53 action in this context. We show that p53-driven developmental defects are associated with the induction of a robust pro-apoptotic transcriptional signature. Intriguingly, however, deleting Puma or Caspase9, which encode key components of the intrinsic apoptotic pathway, does not rescue craniofacial, neuronal or pigmentation defects triggered by p53 hyperactivation in NCCs. Immunostaining analyses for two key apoptosis markers confirm that deleting Puma or Caspase9 does indeed impair p53-hyperactivation-induced apoptosis in NCCs. Furthermore, we demonstrate that p53 hyperactivation does not trigger a compensatory dampening of cell cycle progression in NCCs upon inactivation of apoptotic pathways. Together, our results indicate that p53-driven craniofacial, neuronal and pigmentation defects can arise in the absence of apoptosis and cell cycle arrest, suggesting that p53 hyperactivation can act via alternative pathways to trigger developmental phenotypes.

COMPUTER TOMOGRAPHY AND X-RAY DIAGNOSTICS OF PERIPHERAL PRIMITIVE NEUROEECTODERMAL TUMORS (PNET) IN CHILDREN

Relevance: Peripheral primitive neuroectodermal tumor (PNET) belongs to the group of malignant tumors that develop from migrating embryonic neural crest cells. PNET includes a number of nosological forms: Askin's tumor, esthesioneuroblastoma, the very peripheral primitive neuroectodermal tumor, Ewing's sarcoma . PNET accounts for 3–9% of all soft tissue tumors in children and 19% of all soft tissue sarcomas. In European countries and the United States, the frequency of their occurrence is 3.4 cases per year per 1 million children under 15 years of age, in Kazakhstan - 0.6-1.2 cases per 1 million child population. Rapid tumor growth, malignancy and early metastasis to other organs and systems predetermines its special role in oncology. Objective of the study: to improve the quality and availability of early diagnosis of sarcomas in children in medical institutions of the general medical network. Results of the study: 35 cases of peripheral PNET in children were analyzed. The age of the patients is from 1.5 to 17 years. The average age is 9.3 years. There were 1.3 times more boys among patients than girls. Extra-skeletal localization was found in one patient (3.6%). Radiographically, it is often almost impossible to make a differential diagnosis between the manifestations of Ewing's sarcoma and primary chronic or "healed" (antibiotic) forms of acute hematogenous osteomyelitis in the initial phase of the process, before the formation of the extraosseous soft tissue component. The process of bone damage is more often localized in its diaphysis and subsequently spreads to the metaphyses of the bone.

Genetic Events and Signaling Mechanisms Underlying Schwann Cell Fate in Development and Cancer.

In this review, we describe Schwann cell development from embryonic neural crest cells to terminally differentiated myelinated and nonmyelinated mature Schwann cells. We focus on the genetic drivers and signaling mechanisms mediating decisions to proliferate versus differentiate during Schwann cell development, highlighting pathways that overlap with Schwann cell development and are dysregulated in tumorigenesis. We conclude by considering how our knowledge of the events underlying Schwann cell development and mouse models of schwannoma, neurofibroma, and malignant peripheral nerve sheath tumor can inform novel therapeutic strategies for patients with cancers derived from Schwann cell lineages.

Radiation diagnosis of peripheral
 primitive neuroectodermal tumors
 (PNET) in children under
 the conditions of the scientific center of
 pediatrics and pediatric surgery
 (Almaty, Kazakhstan)

Relevance: Peripheral primitive neuroectodermal tumor (PNET) belongs to the group of malignant tumors that
 develop from migrating embryonic neural crest cells. PNET
 includes several nosological forms: Askin’s tumor, esthesioneuroblastoma, the very peripheral primitive neuroectodermal tumor, and Ewing’s sarcoma [1]. PNET accounts
 for 3–9% of all soft tissue tumors and 19% of all soft tissue
 sarcomas in children [2, 3]. In Europe and the US, PNETs account for 3.4 cases per year per 1 million children below 15
 years; in Kazakhstan – 0.6-1.2 cases per 1 million child population. Rapid tumor growth, malignancy, and early metastasis to other organs and systems predetermine the PNET’s
 specific role in oncology [4].
 The purpose was to improve the quality and availability of early sarcoma diagnostics in children in medical institutions of the general medical network.
 Results: 35 cases of peripheral PNET in children were analyzed. The age of the patients was 1.5 to 17 years, the average age – 9.3 years. Boys were 1.3 times more than girls. One
 patient (3.6%) had extra-skeletal tumor localization. Children with stage IIB prevailed – 46.4% of cases (13 children).
 Radiographical differentiation between Ewing’s sarcoma and primary chronic or “healed” (antibiotic) acute
 hematogenous osteomyelitis in the initial phase of the process is almost impossible before the extraosseous soft tissue
 component is formed. The bone damage process is more
 often localized in the bone diaphysis and subsequently
 spreads to its metaphyses.
 Conclusion: PNET originates most often from the chest
 wall, so it is advisable to start the X-ray examination from
 the chest. In terms of radiation semiotics, PNET is similar to
 Ewing’s sarcoma and Askin’s tumor; therefore, an additional
 immunohistochemical study of the tumor tissue is required.
 An important indirect diagnostic criterion in Ewing’s sarcoma
 is the predominance of the soft tissue component over the
 bone manifestations. Extended CT and MRI studies with contrast enhancement (chest, abdominal cavity, pelvis, and the
 primary lesion area) and skeletal scintigraphy are required to
 clarify the extent of changes, stage the tumor accurately, and
 assess the tumor dynamics after treatment. The above conclusions generally coincide with the available literature data.

Radiation diagnostics of peripheral primitive
 neuroectodermal tumors (PNET)
 in children at the Scientific Center
 of Pediatrics and Pediatric Surgery
 (Almaty, Kazakhstan)

Relevance: Peripheral primitive neuroectodermal tumor (primitive neuroectodermal tumor – PNET) belongs to the group
 of malignant tumors that develop from migrating embryonic neural crest cells. PNET includes several nosological forms: Askin’s
 tumor, esthesioneuroblastoma, the very peripheral primitive neuroectodermal tumor, and Ewing’s sarcoma. PNET accounts for
 3–9% of all soft tissue tumors and 19% of all soft tissue sarcomas in children. In Europe and the US, PNETs account for 3.4 cases
 per year per 1 million children below 15 years; in Kazakhstan – 0.6-1.2 cases per 1 million child population. Rapid tumor growth,
 malignancy, and early metastasis to other organs and systems predetermine the PNET’s specific role in oncology.
 The purpose of the study was to improve the quality and availability of early sarcoma diagnostics in children at medical
 institutions of the general medical network.
 Results: 35 cases of peripheral PNET in children were analyzed. The age of the patients was 1.5 to 17 years, the average age –
 9.3 years. Boys were 1.3 times more than girls. One patient (3.6%) had extra-skeletal tumor localization. Children with stage IIB
 prevailed – 46.4% of cases (13 children).
 Radiographical differentiation between Ewing’s sarcoma and primary chronic or “healed” (antibiotic) acute hematogenous
 osteomyelitis in the initial phase of the process is almost impossible before the extraosseous soft tissue component is formed.
 The bone damage process is more often localized in the bone diaphysis and subsequently spreads to its metaphyses.
 Conclusion: PNET is more likely to come from the chest wall, so it is advisable to start the X-ray examination from the chest.
 In terms of radiation semiotics, PNET is similar to Ewing’s sarcoma and Askin’s tumor; therefore, an additional immunohistochemical study of the tumor tissue is required. An important indirect diagnostic criterion in Ewing’s sarcoma is the predominance of the soft tissue component over the bone manifestations. Extended CT and MRI studies with contrast enhancement
 (chest, abdominal cavity, pelvis, and the primary lesion area) and skeletal scintigraphy are required to clarify the extent of
 changes, stage the tumor accurately, and assess the tumor dynamics after treatment. The above conclusions generally confirm
 the available literature data.

Live Imaging of Cytoskeletal Dynamics in Embryonic Xenopus laevis Growth Cones and Neural Crest Cells.

The cytoskeleton is a dynamic, fundamental network that not only provides mechanical strength to maintain a cell's shape but also controls critical events like cell division, polarity, and movement. Thus, how the cytoskeleton is organized and dynamically regulated is critical to our understanding of countless processes. Live imaging of fluorophore-tagged cytoskeletal proteins allows us to monitor the dynamic nature of cytoskeleton components in embryonic cells. Here, we describe a protocol to monitor and analyze cytoskeletal dynamics in primary embryonic neuronal growth cones and neural crest cells obtained from Xenopus laevis embryos.