Apoptotic cell death in neuroblastoma

Joint CB1 and NGF Receptor Activation Suppresses TRPM8 Activation in Etoposide-Resistant Retinoblastoma Cells

In childhood, retinoblastoma (RB) is the most common primary tumor in the eye. Long term therapeutic management with etoposide of this life-threatening condition may have diminishing effectiveness since RB cells can develop cytostatic resistance to this drug. To determine whether changes in receptor-mediated control of Ca2+ signaling are associated with resistance development, fluorescence calcium imaging, semi-quantitative RT-qPCR analyses, and trypan blue dye exclusion staining patterns are compared in WERI-ETOR (etoposide-insensitive) and WERI-Rb1 (etoposide-sensitive) cells. The cannabinoid receptor agonist 1 (CNR1) WIN55,212-2 (40 µM), or the transient receptor potential melastatin 8 (TRPM8) agonist icilin (40 µM) elicit similar large Ca2+ transients in both cell line types. On the other hand, NGF (100 ng/mL) induces larger rises in WERI-ETOR cells than in WERI-Rb1 cells, and its lethality is larger in WERI-Rb1 cells than in WERI-ETOR cells. NGF and WIN55,212-2 induced additive Ca2+ transients in both cell types. However, following pretreatment with both NGF and WIN55,212-2, TRPM8 gene expression declines and icilin-induced Ca2+ transients are completely blocked only in WERI-ETOR cells. Furthermore, CNR1 gene expression levels are larger in WERI-ETOR cells than those in WERI-Rb1 cells. Therefore, the development of etoposide insensitivity may be associated with rises in CNR1 gene expression, which in turn suppress TRPM8 gene expression through crosstalk.

Integrating bulk-seq and single-cell-seq reveals disulfidptosis potential index associating with neuroblastoma prognosis and immune infiltration

PURPOSE

Neuroblastoma is a challenging pediatric tumor with a need for improved treatment strategies. This study explores the role of disulfidptosis, a form of cell death induced by intracellular disulfide accumulation, in neuroblastoma and its implications for prognosis and immune infiltration.

METHODS

We subgrouped neuroblastoma samples based on disulfidptosis-related gene expression and constructed a disulfidptosis potential index (DPI) to quantify disulfidptosis levels in neurobalstoma. The correlation between DPI, outcome, immune infiltration, and drug sensitivity were explored.

RESULTS

Combing RNA-seq and single-cell dataset, we found that higher disulfidptosis potential index (DPI) is associated with poorer outcomes in neuroblastoma patients, indicating the detrimental impact of enhanced disulfide stress and cellular dysfunction. Furthermore, we found that higher DPI is correlated with reduced immune infiltration within the tumor microenvironment, highlighting an immunosuppressive milieu in high DPI neuroblastomas. The DPI-high neuroblastoma may benefit from the estrogen pathway related drug fulvestrant.

CONCLUSION

Overall, this study highlights the significance of disulfidptosis as a potential therapeutic target and underscores the importance of integrating immune modulation strategies, offering new avenues for improved management of neuroblastoma.

Anticancer and apoptotic activity in neuroblastoma SK-N-SH using phospholipid extract from bone of Scomberomorus niphonius

Among various types children's health challenges, neuroblastoma is the most serious solid neoplasm forming outside the cranium. Scomberomorus niphonius is a valuable edible fish that has been widely used for a meal. In this study, we obtained phospholipid extract from the bone of S. niphonius with the supercritical CO2 extraction method and tested anticancer activity with a cell viability assay. The phospholipid showed anticancer activity on neuroblastoma SK-N-SH cells, and the anticancer activity was presented with an IC50 of 710.25 ± 28.31 μg/ml, but did not show a significant toxicity on HUVEC cell lines. Western blot was used to detect signaling proteins; Bak, caspase-9, caspase-8, caspase-3, Bax, and IκBα were increased, whereas IKKβ and NFκB were downregulated in experimental groups compared to untreated groups. Gene expression was revealed by RT-qPCR, and the fold ratio of Apaf-1, cytochrome-c, caspase-9, caspase-3, and Bax genes' expression was raised in treated groups, implying apoptosis. Gel electrophoresis revealed that the experimental groups had more fragmented DNA than the control group. The study shows that a phospholipid extract from S. niphonius' bone could be used as a biological origin of anticancer activity in neuroblastoma SK-N-SH cells.

Schwann cell plasticity regulates neuroblastic tumor cell differentiation via epidermal growth factor-like protein 8

Adult Schwann cells (SCs) possess an inherent plastic potential. This plasticity allows SCs to acquire repair-specific functions essential for peripheral nerve regeneration. Here, we investigate whether stromal SCs in benign-behaving peripheral neuroblastic tumors adopt a similar cellular state. We profile ganglioneuromas and neuroblastomas, rich and poor in SC stroma, respectively, and peripheral nerves after injury, rich in repair SCs. Indeed, stromal SCs in ganglioneuromas and repair SCs share the expression of nerve repair-associated genes. Neuroblastoma cells, derived from aggressive tumors, respond to primary repair-related SCs and their secretome with increased neuronal differentiation and reduced proliferation. Within the pool of secreted stromal and repair SC factors, we identify EGFL8, a matricellular protein with so far undescribed function, to act as neuritogen and to rewire cellular signaling by activating kinases involved in neurogenesis. In summary, we report that human SCs undergo a similar adaptive response in two patho-physiologically distinct situations, peripheral nerve injury and tumor development.

Neuroblastoma Cell Lines Are Refractory to Genotoxic Drug-Mediated Induction of Ligands for NK Cell-Activating Receptors

Neuroblastoma (NB), the most common extracranial solid tumor of childhood, causes death in almost 15% of children affected by cancer. Treatment of neuroblastoma is based on the combination of chemotherapy with other therapeutic interventions such as surgery, radiotherapy, use of differentiating agents, and immunotherapy. In particular, adoptive NK cell transfer is a new immune-therapeutic approach whose efficacy may be boosted by several anticancer agents able to induce the expression of ligands for NK cell-activating receptors, thus rendering cancer cells more susceptible to NK cell-mediated lysis. Here, we show that chemotherapeutic drugs commonly used for the treatment of NB such as cisplatin, topotecan, irinotecan, and etoposide are unable to induce the expression of activating ligands in a panel of NB cell lines. Consistently, cisplatin-treated NB cell lines were not more susceptible to NK cells than untreated cells. The refractoriness of NB cell lines to these drugs has been partially associated with the abnormal status of genes for ATM, ATR, Chk1, and Chk2, the major transducers of the DNA damage response (DDR), triggered by several anticancer agents and promoting different antitumor mechanisms including the expression of ligands for NK cell-activating receptors. Moreover, both the impaired production of reactive oxygen species (ROS) in some NB cell lines and the transient p53 stabilization in response to our genotoxic drugs under our experimental conditions could contribute to inefficient induction of activating ligands. These data suggest that further investigations, exploiting molecular strategies aimed to potentiate the NK cell-mediated immunotherapy of NB, are warranted.

The Netrin-4/ Neogenin-1 axis promotes neuroblastoma cell survival and migration

Neogenin-1 (NEO1) is a transmembrane receptor involved in axonal guidance, angiogenesis, neuronal cell migration and cell death, during both embryonic development and adult homeostasis. It has been described as a dependence receptor, because it promotes cell death in the absence of its ligands (Netrin and Repulsive Guidance Molecule (RGM) families) and cell survival when they are present. Although NEO1 and its ligands are involved in tumor progression, their precise role in tumor cell survival and migration remain unclear. Public databases contain extensive information regarding the expression of NEO1 and its ligands Netrin-1 (NTN1) and Netrin-4 (NTN4) in primary neuroblastoma (NB) tumors. Analysis of this data revealed that patients with high expression levels of both NEO1 and NTN4 have a poor survival rate. Accordingly, our analyses in NB cell lines with different genetic backgrounds revealed that knocking-down NEO1 reduces cell migration, whereas silencing of endogenous NTN4 induced cell death. Conversely, overexpression of NEO1 resulted in higher cell migration in the presence of NTN4, and increased apoptosis in the absence of ligand. Increased apoptosis was prevented when utilizing physiological concentrations of exogenous Netrin-4. Likewise, cell death induced after NTN4 knock-down was rescued when NEO1 was transiently silenced, thus revealing an important role for NEO1 in NB cell survival. In vivo analysis, using the chicken embryo chorioallantoic membrane (CAM) model, showed that NEO1 and endogenous NTN4 are involved in tumor extravasation and metastasis. Our data collectively demonstrate that endogenous NTN4/NEO1 maintain NB growth via both pro-survival and pro-migratory molecular signaling.

Moringa isothiocyanate complexed with α-cyclodextrin: a new perspective in neuroblastoma treatment

BACKGROUND

Several lines of evidence suggest the consume of natural products for cancer prevention or treatment. In particular, isothiocyanates (ITCs) exerting anti-cancer properties, have received great interest as potential chemotherapeutic agents. This study was designed to assess the anti-proliferative activities of a new preparation of Moringa oleifera-derived 4-(α-L-rhamnopyranosyloxy)benzyl ITC (moringin) complexed with alpha-cyclodextrin (moringin + α-CD; MAC) on SH-SY5Y human neuroblastoma cells. This new formulation arises in the attempt to overcome the poor solubility and stability of moringin alone in aqueous media.

METHODS

SH-SY5Y cells were cultured and exposed to increasing concentrations of MAC (1.0, 2.5 and 5.0 μg). Cell proliferation was examined by MTT and cell count assays. The cytotoxic activity of the MAC complex was assessed by lactate dehydrogenase (LDH) assay and trypan blue exclusion test. In addition, western blotting analyses for the main apoptosis-related proteins were performed.

RESULTS

Treatment of SH-SY5Y cells with the MAC complex reduced cell growth in concentration dependent manner. Specifically, MAC exhibited a potent action in inhibiting the PI3K/Akt/mTOR pathway, whose aberrant activation was found in many types of cancer. MAC was also found to induce the nuclear factor-κB (NF-κB) p65 activation by phosphorylation and its translocation into the nucleus. Moreover, treatment with MAC was able to down-regulate MAPK pathway (results focused on JNK and p38 expression). Finally, MAC was found to trigger apoptotic death pathway (based on expression levels of cleaved-caspase 3, Bax/Bcl-2 balance, p53 and p21).

CONCLUSION

These findings suggest that use of MAC complex may open novel perspectives to improve the poor prognosis of patients with neuroblastoma.

Genomic analysis-integrated whole-exome sequencing of neuroblastomas identifies genetic mutations in axon guidance pathway

Neuroblastoma (NB) is a childhood solid malignant tumor originating from precursor cells of the peripheral nervous system. We have previously established a risk classification system based on DNA copy number profiles. To further explore the pathogenesis of NBs in distinct risk groups, we performed whole-exome sequencing analysis of 57 primary and 7 recurrent/metastatic tumors with unique chromosomal aberration profiles as categorized by our genomic sub-grouping system. Overall, a low frequency of somatic mutations was found. Besides ALK (4/64, 6.3%), SEMA6C, SLIT1 and NRAS, genes involved in the axon guidance pathway, were identified as recurrently mutated in 6 of 64 tumors (9.4%). Pathway enrichment analysis revealed enrichment of 25 mutated genes in the mitogen-activated protein kinase (MAPK) pathway, 13 genes in the Wnt pathway, and 12 genes in the axon guidance pathway. Genomic analyses demonstrated that primary and matched recurrent or metastatic tumors obtained from sporadic and monozygotic twin NBs were clonally related with variable extents of genetic heterogeneity. Monozygotic twin NBs displayed different evolutionary trajectories. These results indicate the involvement of the axon guidance, MAPK and Wnt pathways in NB and demonstrate genomic diversity with NB progression.

Evaluation of Cytotoxicity and Cell Death Induced In Vitro by Saxitoxin in Mammalian Cells

Since the cyanotoxin saxitoxin (STX) is a neurotoxin and induces ecological changes in aquatic environments, a potential risk to public and environmental health exists. However, data on STX-mediated cytotoxic and genotoxic effects are still scare. In order to gain a better understanding of the effects of this toxin, the cytotoxic and genotoxic potential of STX was examined in two mammalian cell lines. Neuro 2A (N2A), a neuroblastoma mouse cell line, and Vero cell line, derived from Vero green monkey kidney cells, were exposed to several concentrations of STX ranging from 0.5 to 64 nM to determine cell viability, induction of apoptosis (DNA fragmentation assay), and formation of micronuclei (MN) (cytokinesis-block micronucleus assay; CBMN) following 24 h of incubation. The half maximal effective concentration (EC50) values for STX calculated in cell viability tests were 1.01 nM for N2A and 0.82 nM for Vero cells. With increasing STX concentration there was evidence of DNA fragmentation indicating apoptosis induction in Vero cells with a 50% increase in DNA fragmentation compared to control at the highest STX concentration tested (3 nM). The results demonstrated no significant changes in the frequency of micronucleated binucleated cells in N2A and Vero cells exposed to STX, indicating the absence of genotoxicity under these test conditions. There was no apparent cellular necrosis as evidenced by a lack of formation of multinucleated cells. In conclusion, data reported herein demonstrate that STX produced death of both cell types tested through an apoptotic process.

The role of intracellular calcium for the development and treatment of neuroblastoma

Neuroblastoma is the second most common paediatric cancer. It developsfrom undifferentiated simpatico-adrenal lineage cells and is mostly sporadic; however, theaetiology behind the development of neuroblastoma is still not fully understood. Intracellularcalcium ([Ca2+]i) is a secondary messenger which regulates numerous cellular processesand, therefore, its concentration is tightly regulated. This review focuses on the role of[Ca2+]i in differentiation, apoptosis and proliferation in neuroblastoma. It describes themechanisms by which [Ca2+]i is regulated and how it modulates intracellular pathways.Furthermore, the importance of [Ca2+]i for the function of anti-cancer drugs is illuminatedin this review as [Ca2+]i could be a target to improve the outcome of anti-cancer treatmentin neuroblastoma. Overall, modulations of [Ca2+]i could be a key target to induce apoptosisin cancer cells leading to a more efficient and effective treatment of neuroblastoma.