Neuroblastoma Cell Line IMR-32 Research Articles

Temporal Quantitative Proteomic and Phosphoproteomic Profiling of SH-SY5Y and IMR-32 Neuroblastoma Cells during All-Trans-Retinoic Acid-Induced Neuronal Differentiation.

The human neuroblastoma cell lines SH-SY5Y and IMR-32 can be differentiated into neuron-like phenotypes through treatment with all-trans-retinoic acid (ATRA). After differentiation, these cell lines are extensively utilized as in vitro models to study various aspects of neuronal cell biology. However, temporal and quantitative profiling of the proteome and phosphoproteome of SH-SY5Y and IMR-32 cells throughout ATRA-induced differentiation has been limited. Here, we performed relative quantification of the proteomes and phosphoproteomes of SH-SY5Y and IMR-32 cells at multiple time points during ATRA-induced differentiation. Relative quantification of proteins and phosphopeptides with subsequent gene ontology analysis revealed that several biological processes, including cytoskeleton organization, cell division, chaperone function and protein folding, and one-carbon metabolism, were associated with ATRA-induced differentiation in both cell lines. Furthermore, kinase-substrate enrichment analysis predicted altered activities of several kinases during differentiation. Among these, CDK5 exhibited increased activity, while CDK2 displayed reduced activity. The data presented serve as a valuable resource for investigating temporal protein and phosphoprotein abundance changes in SH-SY5Y and IMR-32 cells during ATRA-induced differentiation.

Polyphyllin D induces necroptosis in neuroblastoma cells (IMR-32 and LA-N-2) in mice.

We previously reported that polyphyllin D, the main component of the traditional herbal medicinal Paris polyphylla, exhibited anticancer effects in vitro against human neuroblastoma cells. The aim of this investigation was to examine in vivo antitumor effects of polyphyllin D. Subcutaneous tumors were established in immune-deficient BALB/c nude mice using human neuroblastoma cell lines IMR-32 and LA-N-2. To evaluate the polyphyllin D activity, we used a mouse model of IMR-32 or LA-N-2 cell lines and analyzed subcutaneous tumors. Subcutaneous tumor models were successfully established in mice using two human neuroblastoma cell lines. In the subcutaneous tumor model, porphyrin D was found to suppress tumor volume. We found that polyphyllin D suppressed the number of foci by Ki-67 staining (IMR-32 and LA-N-2; p < 0.01, 0.02, respectively). We found that polyphyllin D induces the RIPK3 expression, while polyphyllin D phosphorylates Ser358 in IMR-32 and Ser358 and Tyr376 in LA-N-2. We developed a mouse model of subcutaneous tumors of neuroblastoma and demonstrated for the first time that polyphyllin D has an antitumor effect on neuroblastoma. Polyphyllin D can cause necroptosis depending on the cell type. The new drug can be expected by investigating a method to selectively induce cell death through the analysis of necroptosis.

Apo-form of recombinant human lactoferrin changes the genome-wide DNA methylation level and the chromatin compaction degree in neuroblastoma cell line IMR-32

BACKGROUND: Neuroblastoma is one of the most common extracranial solid tumors in childhood. At present, epigenetic disorders play a significant role in neoplasms development. Since epigenetic changes in the cell are quite dynamic and reversible, epigenome-modulating exogenous agents can be used in epigenetic targeted therapy for various types of tumors. Therefore, the identification of these agents is still significant. Lactoferrin is one such potential molecule from the transferrin family. Currently, the anti-tumor properties of lactoferrin have been identified, but its effect on the epigenome of cells of various tumors types, particularly on neuroblastomas, is practically unknown.&#x0D; AIM: To study the effect of the exogenous recombinant human apolactoferrin on the viability and epigenomic status of IMR-32 neuroblastoma cells.&#x0D; MATERIALS AND METHODS: We studied human IMR-32 neuroblastoma cells after 72 hours of exposure to 8 doses of recombinant human apolactoferrin: 0.1, 0.5, 1, 5, 10, 50, 100 and 500 g/ml. The level of genome-wide DNA methylation and the degree of chromatin compaction in IMR-32 cells were quantified using commercial kits 5-mC DNA ELISA Kit, Global DNA Methylation LINE-1 Kit, as well as enzymatic hydrolysis of MspI / HpaII and DNaseI.&#x0D; RESULTS: The recombinant apolactoferrin reduces the viability of IMR-32 and, depending on the dose, differentially affects the level of genome-wide DNA methylation (СpG dinucleotides, CCGG sites, LINE-1 repeats) and the degree of chromatin compaction. At the same time, a complex picture of the epigenomic cellular response to the effect of apo-lactoferrin was observed (nonlinear nonmonotonic dose-effect relationship).&#x0D; CONCLUSIONS: We assumed that apolactoferrin modulates gene activity through epigenetic mechanisms, in particular, by changing the DNA methylation pattern and affecting the chromatin structure, which may be one of the molecular mechanisms of its anti-tumor effect.

HES1 promoter activation dynamics reveal the plasticity, stemness and heterogeneity in neuroblastoma cancer stem cells.

Notch signaling and its downstream gene target HES1 play a critical role in regulating and maintaining cancer stem cells (CSCs), similar to as they do during embryonic development. Here, we report a unique subclass of Notch-independent Hes-1 (NIHes-1)-expressing CSCs in neuroblastoma. These CSCs maintain sustained HES1 expression by activation of HES1 promoter region upstream of classical CBF-1 binding sites, thereby completely bypassing Notch receptor-mediated activation. These stem cells have self-renewal ability and potential to generate tumors. Interestingly, we observed that NIHes-1 CSCs could transition to Notch-dependent Hes-1-expressing (NDHes-1) CSCs where HES1 is expressed by Notch receptor-mediated promoter activation. We observed that NDHes-1-expressing CSCs also had the potential to transition to NIHes-1 CSCs and during this coordinated bidirectional transition, both CSCs gave rise to the majority of the bulk cancer cells, which had an inactive HES1 promoter (PIHes-1). A few of these PIHes-1 cells were capable of reverting into a CSC state. These findings explain the existence of a heterogenic mode of HES1 promoter activation within the IMR-32 neuroblastoma cell line and the potential to switch between them. This article has an associated First Person interview with the first authors of the paper.

Apoptosis is responsible for the cytotoxic effects of anti-GD2 ganglioside antibodies and aurora A kinase inhibitors on human neuroblastoma cells

In recent years, immunotherapy has been identified as an effective treatment method for high-risk neuroblastoma. A previous study demonstrated that an anti-GD2 ganglioside (GD2) mouse 14G2a monoclonal antibody (mAb) combined with a small molecule, i.e., an aurora A kinase inhibitor (MK-5108), significantly increased cytotoxicity against human neuroblastoma cells, as compared to monotherapy. This study aimed to demonstrate the mechanism of neuroblastoma cell death in vitro following the addition of an anti-GD2 human-mouse chimeric ch14.18/CHO mAb (presently used in clinics) and two aurora A inhibitors (MK-5108 and MK-8745). The effects of the aforementioned agents on neuroblastoma cells were determined by measuring the level of ATP, the level of apoptotic and necroptotic markers, and the activity of caspase 3/7. The results revealed that the ch14.18/CHO mAb decreased cellular ATP levels in the IMR-32 and CHP-134 neuroblastoma cell lines, similarly to the 14G2a mAb. Regarding ch14.18/CHO mAb treated IMR-32 cells, the observed cytotoxic effect was concomitant with induced caspase 3 cleavage, which indicated the induction of apoptosis in IMR-32 cells, but not in CHP-134 cells. Furthermore, the MK-5108 inhibitor induced apoptosis, as indicated by the increased cleavage of caspase 3 and increased activity of caspase 3/7. However, the presence of necroptosis was ruled out in MK-5108-treated IMR-32 and CHP-134 cells. In summary, the effects of the combination of ch14.18/CHO mAb and aurora A kinase inhibitors (MK-5108 and MK-8745) were shown to enhance apoptosis in IMR-32 cells compared to when used individually.

Apoptosis is responsible for the cytotoxic effects of anti-GD2 ganglioside antibodies and aurora A kinase inhibitors on human neuroblastoma cells.

In recent years, immunotherapy has been identified as an effective treatment method for high-risk neuroblastoma. A previous study demonstrated that an anti-GD2 ganglioside (GD2) mouse 14G2a monoclonal antibody (mAb) combined with a small molecule, i.e., an aurora A kinase inhibitor (MK-5108), significantly increased cytotoxicity against human neuroblastoma cells, as compared to monotherapy. This study aimed to demonstrate the mechanism of neuroblastoma cell death in vitro following the addition of an anti-GD2 human-mouse chimeric ch14.18/CHO mAb (presently used in clinics) and two aurora A inhibitors (MK-5108 and MK-8745). The effects of the aforementioned agents on neuroblastoma cells were determined by measuring the level of ATP, the level of apoptotic and necroptotic markers, and the activity of caspase 3/7. The results revealed that the ch14.18/CHO mAb decreased cellular ATP levels in the IMR-32 and CHP-134 neuroblastoma cell lines, similarly to the 14G2a mAb. Regarding ch14.18/CHO mAb treated IMR-32 cells, the observed cytotoxic effect was concomitant with induced caspase 3 cleavage, which indicated the induction of apoptosis in IMR-32 cells, but not in CHP-134 cells. Furthermore, the MK-5108 inhibitor induced apoptosis, as indicated by the increased cleavage of caspase 3 and increased activity of caspase 3/7. However, the presence of necroptosis was ruled out in MK-5108-treated IMR-32 and CHP-134 cells. In summary, the effects of the combination of ch14.18/CHO mAb and aurora A kinase inhibitors (MK-5108 and MK-8745) were shown to enhance apoptosis in IMR-32 cells compared to when used individually.

Antitumor effect of polyphyllin D on liver metastases of neuroblastoma.

We previously reported that polyphyllin D, a main component of the traditional Chinese medicinal herb Paris polyphylla, exhibited anticancer effects in vitro against human neuroblastoma cells. The aims of this investigation was to examine the presence or absence of in vivo anti-metastasis effects of polyphyllin D were to establish a liver metastasis model of neuroblastoma and to evaluate the anti-metastasis effects of polyphyllin D. Subcutaneous and intraperitoneal tumors, and metastasis models were established in immune-deficient BALB/c nude and BALB/c Rag-2/Jak3 double-deficient (BRJ) mice using the human neuroblastoma cell lines IMR-32, LA-N-2, or NB-69. For evaluating polyphyllin D activity, we used a mouse model of liver metastasis with the IMR-32 cells line injected through the tail vein. We analyzed the livers number and area of liver tumors in of the phosphate buffer solution- and polyphyllin D-treated groups. Liver metastasis and intraperitoneal dissemination models were successfully established in immune-deficient BRJ mice using the three human neuroblastoma cell lines. In the liver metastasis, the model of IMR-32 cells, we found that polyphyllin D suppressed both the number and total area of metastatic foci the average number of metastatic foci, average focus areas, and number of cleaved caspase-3-positive cells were significantly lower in the polyphyllin D group (p = 0.016, 0.020, 0.043, respectively). We developed a mouse models of neuroblastoma metastasis and demonstrated for the first time that polyphyllin D has an antitumor effect on neuroblastoma liver metastases.

Markers to sensibility and relapse on IMR-32 neuroblastoma cell line cultured in monolayer (2D) and neurosphere (3D) models cisplatin-treated

The complexity of different components of tumor stroma poses huge challenges for therapies targeting the neuroblastoma (NB) microenvironment. The present study aimed to evaluate platinum-based response in IMR-32 neuroblastoma cell line cultured in monolayer (2D) and neurosphere (3D) models. For this, we evaluated mRNA expression of heat shock proteins HSPA1A, HSPB1, TRAP1, HSPA1AL, HSPD1, and DNA damage repair gene ERCC1. After treatment, residual cells were grafted on CAM (chicken chorioallantoic membrane) to evaluate the growth capability and histological paraffin sections were made to assess Ki-67 and HER-2 proteins by immunofluorescence. Our results showed that cisplatin induces mRNA downregulation of Heat Shock Proteins and ERCC1 in IMR-32 cells cultured in 2D or 3D models. In addition, the cisplatin-treatment approach increased HER-2 expression in residual IMR-32 cells grafted on the CAM. Therefore, these insights provide many advances in neuroendocrine tumor biology and knowledge about cisplatin-response in neuroblastoma.

Abstract P209: Collaborative crosstalk between two apoptosis pathways drives synergy of dual inhibition of BCL-2/MDM2 in preclinical models of neuroblastoma

Abstract Introduction: The prognosis of patients with neuroblastoma is poor, and novel therapeutic strategies are needed to improve clinical outcomes. Neuroblastoma often exhibits a low TP53 mutation rate and overexpresses MDM2 and BCL-2 genes. Dual targeting of the MDM2-P53 and BCL-2 apoptotic pathways is an attractive treatment strategy (Vernooij et al, Mol Cancer Ther 2021; Dalton et al, Mol Cancer Ther 2021) and is under clinical development using idasanutlin and venetoclax. However, the mechanisms of action (MOAs) of this combination in neuroblastoma are not fully understood. Alrizomadlin (APG-115) is a potent, orally bioactive MDM2 inhibitor. Lisaftoclax (APG-2575) is a novel BCL-2 selective inhibitor. Both agents have shown clinical activity in solid and hematologic malignancies (Tolcher et al, J Clin Oncol 2021:2506; Ailawadhi et al, J Clin Oncol 2021:7502). We investigated the effects of combined alrizomadlin and lisaftoclax treatment in preclinical models of neuroblastoma and examined novel MOAs associated with this combination. Materials and Methods: Antiproliferative activity was measured by CellTiter-Glo luminescent cell viability assay. Apoptosis was evaluated by annexin V/propidium iodide staining and flow cytometry. Meso-Scale Discovery ELISA and western blot analyses characterized the mechanisms of this combination’s synergistic effects. In animal studies, clinically relevant doses of lisaftoclax were employed. A pulsed high-dose regimen of alrizomadlin was used to achieve best efficacy and manage on-target toxicity. Results: In TP53WT neuroblastoma cell lines IMR-32 and SH-SY5Y, the combination of lisaftoclax and alrizomadlin synergistically inhibited proliferation and induced apoptosis, as evidenced by elevations in caspase-3/7, cleaved PARP, and annexin V+ subpopulations. Tumor growth was synergistically inhibited in 3 distinct subcutaneous mouse xenograft tumor models derived from neuroblastoma cell lines or patient tumors. In the cell lines, alrizomadlin treatment upregulated proapoptotic BCL-2 family member expression (NOXA, BAX, and PUMA) and downregulated antiapoptotic BCL-2 family member MCL-1, likely sensitizing cancer cells to lisaftoclax-induced apoptosis. Treatment of these cells with lisaftoclax and alrizomadlin reduced all 3 major BIM-related complexes, thereby increasing free BIM and triggering cellular apoptosis. Lisaftoclax and alrizomadlin downregulated NMYC and its transcription target MDM2, preventing the development of alrizomadlin resistance mediated by a feedback upregulation of MDM2, and inhibition of the MDM2-P53 apoptotic pathway by alrizomadlin primed cancer cells to BCL-2 inhibition. Conclusions: Alrizomadlin synergizes with lisaftoclax to achieve synthetic lethality through a regulated interaction at multiple molecular nodules, and inhibition of BCL-2 apoptotic pathway by lisaftoclax may prevent cancer cells from developing resistance to MDM2-P53 inhibition. These data warrant clinical development of combined alrizomadlin and lisaftoclax treatment in patients with neuroblastoma. Citation Format: Douglas D. Fang, Qiuqiong Tang, Qixin Wang, Yanhui Kong, Na Li, Feng Zhou, Ran Tao, Dajun Yang, Yifan Zhai. Collaborative crosstalk between two apoptosis pathways drives synergy of dual inhibition of BCL-2/MDM2 in preclinical models of neuroblastoma [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P209.

Evaluation of commercially available antibodies and fluorescent conotoxins for the detection of surface ganglionic acetylcholine receptor on the neuroblastoma cell line, IMR-32 by flow cytometry

Commercially available antibodies that bind to the human muscle acetylcholine receptor (ACHR) have been validated previously for flow cytometric use (Keefe et al., 2009; Leite et al., 2008; Lozier et al., 2015). Despite a multitude of commercially available antibodies to other nicotinic ACHRs, validation in a wide variety of immunoassay formats is lacking; when studied, a large proportion of these antibodies have been deemed not fit for most research purposes (Garg and Loring, 2017).We have recently described a flow cytometric immunomodulation assay for the diagnosis of Autoimmune Autonomic Ganglionopathy (AAG) (Urriola et al., 2021) that utilises the monoclonal antibody mab35(Urriola et al., 2021) which is specific for ganglionic ACHR (gnACHR) that contain α3 subunits (Vernino et al., 1998). Other fluorescent ligands for α3-gnACHR have not been validated for flow cytometric use.We investigated 7 commercially sourced antibodies and 3 synthetic fluorescent novel conotoxins purported to specifically bind to the extracellular domains of the gnACHR, and compared the results to staining by mab35, using flow cytometry with the neuroblastoma cell line IMR-32. We also evaluated the degree of non-specific binding by depleting the cell membrane of the relevant acetylcholine receptor with a pre-incubation step involving the serum from a patient with Autoimmune Autonomic Ganglionopathy containing pathogenic antibodies to the ganglionic acetylcholine receptor. None of the assessed conotoxins, and only one antibody (mab35) was found to perform adequately in flow cytometric staining of the native ganglionic acetylcholine receptor.

Differentiation of IMR32 Neuroblastoma Is Accompanied by a Global Change in the Transcriptome.

Neuroblastoma is one of the most common cancers in infants and is often multidrug-resistant. One of the methods of treating neuroblastomas is to create conditions for their differentiation. In this work, we performed a full-transcriptome analysis of gene expression in an undifferentiated and differentiated in vitro human neuroblastoma cell line IMR-32 and identified the signaling pathways and biological processes that undergo the greatest changes during differentiation. The results obtained show that a complex heterogeneous population of nerve cells is formed at different stages of differentiation. In the cell population of differentiating neuroblastoma, the expression of genes in which cortical neuronal progenitor cells are enriched increases; at the same time, there are cells expressing markers of early postmitotic neurons. Cells differentiate in several different directions according to the type of synaptic mediator. At the same time, the differentiation of IMR-32 cells is accompanied by an increase in the transcription of genes that suppress the differentiation of nerve cells, Sox2 and PROM1, the expression of which is normally suppressed during in vivo differentiation.

Neuroprotective Activity of Beetroot (Beta vulgaris) Extract on H2O2-Induced Damage in IMR32 and SHSY5Y Cell Lines

In several ailments, oxidative stress intercedes cell damage, including neuro-degenerative conditions. This study aims to ascertain the protective ability of methanol extract of beetroot (Beta vulgaris) as a neuroprotective agent, through the biochemical perspective of neuroprotection. Oxidative stress was induced using hydrogen peroxide (H2O2) in neuroblastoma IMR32 and SHSY5Y cell line. MTT assay was performed to assess cell viability. IMR32 and SHSY5Y cell-line were pre and post-treated with four doses of beetroot extract. It was observed that cells recovered in a dose-dependent manner. This indicated that beetroot treatment facilitate the cells to recover from hydrogen peroxide insult. The result for LDH indicated that with increase in time at higher concentration SHSY5Y cell gets stressed and releases the LDH. Catalase activity in IMR32 and SHSY5Y cells decreases at higher concentrations and increases with a decrease in concentration. IMR32 and SHSY5Y cell lysate showed no activity of acetylcholinesterase. However, the media in which the cells were grown showed the activity of acetylcholinesterase. The biochemical assay showed that beetroot extract mitigates the cells from oxidative insult. Our study suggests that beetroot extract helps in the proliferation and neuroprotection of IMR 32 and SHSY5Y cells. IMR32 and SHSY5Y neuroblastoma cell lines were used to assess neuroprotective efficacy of beetroot extract when the cells were subjected to oxidative insult. In the current study, MTT assay was used to determine the cell viability after the treatments. Biochemical assays viz. LDH, Catalase and specific activity acetylcholine esterase were performed to define neuroprotective property of beetroot extract. Results from cell viability assay confirmed the ability of beetroot extract to enable cell proliferation. Biochemical assays also showed a striking result that beetroot extract protected the cells from oxidative insult.

Aflatoxin B1 Induces Neurotoxicity through Reactive Oxygen Species Generation, DNA Damage, Apoptosis, and S-Phase Cell Cycle Arrest.

Aflatoxin B1 (AFB1) is a mycotoxin widely distributed in a variety of food commodities and exhibits strong toxicity toward multiple tissues and organs. However, little is known about its neurotoxicity and the associated mechanism. In this study, we observed that brain integrity was markedly damaged in mice after intragastric administration of AFB1 (300 μg/kg/day for 30 days). The toxicity of AFB1 on neuronal cells and the underlying mechanisms were then investigated in the neuroblastoma cell line IMR-32. A cell viability assay showed that the IC50 values of AFB1 on IMR-32 cells were 6.18 μg/mL and 5.87 μg/mL after treatment for 24 h and 48 h, respectively. ROS levels in IMR-32 cells increased significantly in a time- and AFB1 concentration-dependent manner, which was associated with the upregulation of NOX2, and downregulation of OXR1, SOD1, and SOD2. Substantial DNA damage associated with the downregulation of PARP1, BRCA2, and RAD51 was also observed. Furthermore, AFB1 significantly induced S-phase arrest, which is associated with the upregulation of CDKN1A, CDKN2C, and CDKN2D. Finally, AFB1 induced apoptosis involving CASP3 and BAX. Taken together, AFB1 manifests a wide range of cytotoxicity on neuronal cells including ROS accumulation, DNA damage, S-phase arrest, and apoptosis—all of which are key factors for understanding the neurotoxicology of AFB1.

Silencing of AURKA augments the antitumor efficacy of the AURKA inhibitor MLN8237 on neuroblastoma cells

BackgroundAurora kinase A (AURKA) has been implicated in the regulation of cell cycle progression, mitosis and a key number of oncogenic signaling pathways in various malignancies including neuroblastoma. Small molecule inhibitors of AURKA have shown potential, but still not as good as expected effects in clinical trials. Little is known about this underlying mechanism. Here, we evaluated the inhibitory effects of AURKA inhibitor MLN8237 on neuroblastoma cells to understand the potential mechanisms responsible for tumor therapy.MethodsMLN8237 treatment on neuroblastoma cell line IMR32 was done and in vivo inhibitory effects were investigated using tumor xenograft model. Cellular senescence was evaluated by senescence-associated β-gal Staining assay. Flow cytometry was used to tested cell cycle arrest and cell apoptosis. Senescence-associated signal pathways were detected by western blot. CD133 microbeads and microsphere formation were used to separate and enrich CD133+ cells. AURKA small interfering RNA transfection was carried to downregulate AURKA level. Finally, the combination of MLN8237 treatment with AURKA small interfering RNA transfection were adopted to evaluate the inhibitory effect on neuroblastoma cells.ResultsWe demonstrate that MLN8237, an inhibitor of AURKA, induces the neuroblastoma cell line IMR32 into cellular senescence and G2/M cell phase arrest. Inactivation of AURKA results in MYCN destabilization and inhibits cell growth in vitro and in a mouse model. Although MLN8237 inhibits AURKA kinase activity, it has almost no inhibitory effect on the AURKA protein level. By contrast, MLN8237 treatment leads to abnormal high expression of AURKA in vitro and in vivo. Knockdown of AURKA reduces cell survival. The combination of MLN8237 with AURKA small interfering RNA results in more profound inhibitory effects on neuroblastoma cell growth. Moreover, MLN8237 treatment followed by AURKA siRNA forces senescent cells into apoptosis via suppression of the Akt/Stat3 pathway.ConclusionsThe effect of AURKA-targeted inhibition of tumor growth plays roles in both the inactivation of AURKA activity and the decrease in the AURKA protein expression level.

Differentiation of human neuroblastoma cell line IMR-32 by sildenafil and its newly discovered analogue IS00384

Sildenafil, a phosphodiesterase-5 inhibitor is FDA approved drug against erectile dysfunction. It is currently undergoing many clinical trials, alone or in combinations against different diseases. Treatment of neural progenitor cells with sildenafil is known to regulate their basal cGMP levels and enhance neurogenesis and differentiation. cGMP as well as cAMP are known to play a central role in the maintenance, repair and remodelling of the nervous system. In the present study, we report the neurodifferentiation property of sildenafil in neuroblastoma cancer cell line IMR-32. Sildenafil was found to induce the formation of neurite outgrowths that were found expressing neuronal markers, such as NeuN, NF-H and βIII tubulin. IS00384, a recently discovered PDE5 inhibitor by our laboratory, was also found to induce neurodifferentiation of IMR-32 cells. The effect of IS00384 on differentiation was even more profound than sildenafil. Both the compounds were found to elevate and activate the Guanine nucleotide exchange factor C3G, which is a regulator of differentiation in IMR-32 cells. They were also found to elevate the levels of cGMP and activate the AMPK-ACC and PI3K-Akt signalling pathways. These pathways are known to play important role in cytoskeletal rearrangements necessary for differentiation. This study highlights the role of phosphodiesterases-5 in neurodifferentiation and use of sildenafil and IS00384 as small molecule tools to study the process of cellular differentiation.

Abstract 5262: Lipidomic profiling of neuroblastoma cells after treatment with novel withalongolide A 4, 19, 27-triacetate (WGA-TA)

Abstract Introduction: Neuroblastoma (NB) is a pediatric solid tumor that affects approximately 700 children every year in the United States. Despite advances in treatment, the cure rate for high risk advanced NB having N-myc amplification has a poor response of 40-50%. Standard of care treatment for high risk NB patient consists of surgery, intensive chemotherapy and radiotherapy. Recently, we and others have shown that withanolide treatment of NB induce apoptosis of NB cells, through several mechanism including lipid oxidation, down regulation of N-myc and suppression of Akt/mTOR/NF-κB activation. Therefore, we hypothesized that mass spectrometric analysis of untargeted lipidomic profiling after treatment of NB cells with withanolide WGA-TA will identify novel prognostic and diagnostic biomarkers of NB. Methods: Validated neuroblastoma cell lines IMR32 (N-myc amplified) and SH-EP (N-myc non-amplified) were grown in 2D culture in appropriate growth medium. Lipids were extracted from cells using modified Bligh and Dyer method. Lipidomic profiling was carried out using LC MS/MS. Principal component analysis (PCA) was used to identify differentially regulated metabolites. Results: Principal component analysis of NB cell lines and WGA-TA treatment showed complete separation of samples as well as internal controls. Initial analysis of lipid profiling of IMR32 and SH-EP cells showed differential regulation of several lipids. N-myc non-amplified SH-EP cells have upregulation of phospholipids such as phosphocholine (PC), phosphor ethanol amine (PE), sphingomyelin (SM) and free fatty acid, whereas glycerol lipid diacyl glycerol (DG) is down regulated in SH-EP cells compared to IMR32 cells. Treatment of IMR32 cells with WGA-TA led to up regulation of phospho lipids such as PC, phosphoserine (PS), SM, Lyso PE, free fatty acids just like N-myc non-amplified cells. But, triglycerides (TG) were up regulated after treatment with WGA-TA in both IMR32 and SH-EP cells. Conclusions: WGA-TA treatment of N-myc amplified cells led to upregulation of phospholipids similar to that of N-myc non-amplified cells indicating that CDP-Choline pathway lipids might play an important role in NB. Further analysis is needed to unravel the link between N-myc and lipid metabolism in NB. Citation Format: Chitra Subramanian, Rajendiran Thekkelnaycke, Tanu Soni, Valerie P. Opipari, Barbara N. Timmermann, Mark S. Cohen. Lipidomic profiling of neuroblastoma cells after treatment with novel withalongolide A 4, 19, 27-triacetate (WGA-TA) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5262.

The formyl peptide receptor agonist FPRa14 induces differentiation of Neuro2a mouse neuroblastoma cells into multiple distinct morphologies which can be specifically inhibited with FPR antagonists and FPR knockdown using siRNA.

The N-formyl peptide receptors (FPRs) have been identified within neuronal tissues and may serve as yet undetermined functions within the nervous system. The FPRs have been implicated in the progression and invasiveness of neuroblastoma and other cancers. In this study the effects of the synthetic FPR agonist FPRa14, FPR antagonists and FPR knockdown using siRNA on mouse neuroblastoma neuro2a (N2a) cell differentiation plus toxicity were examined. The FPRa14 (1–10μM) was found to induce a significant dose-dependent differentiation response in mouse neuroblastoma N2a cells. Interestingly, three distinct differentiated morphologies were observed, with two non-archetypal forms observed at the higher FPRa14 concentrations. These three forms were also observed in the human neuroblastoma cell-lines IMR-32 and SH-SY5Y when exposed to 100μM FPRa14. In N2a cells combined knockdown of FPR1 and FPR2 using siRNA inhibited the differentiation response to FPRa14, suggesting involvement of both receptor subtypes. Pre-incubating N2a cultures with the FPR1 antagonists Boc-MLF and cyclosporin H significantly reduced FPRa14-induced differentiation to near baseline levels. Meanwhile, the FPR2 antagonist WRW4 had no significant effect on FPRa14-induced N2a differentiation. These results suggest that the N2a differentiation response observed has an FPR1-dependent component. Toxicity of FPRa14 was only observed at higher concentrations. All three antagonists used blocked FPRa14-induced toxicity, whilst only siRNA knockdown of FPR2 reduced toxicity. This suggests that the toxicity and differentiation involve different mechanisms. The demonstration of neuronal differentiation mediated via FPRs in this study represents a significant finding and suggests a role for FPRs in the CNS. This finding could potentially lead to novel therapies for a range of neurological conditions including neuroblastoma, Alzheimer’s disease, Parkinson’s disease and neuropathic pain. Furthermore, this could represent a potential avenue for neuronal regeneration therapies.

&lt;p&gt;IGF1R facilitates epithelial-mesenchymal transition and cancer stem cell properties in neuroblastoma via the STAT3/AKT axis&lt;/p&gt;

BackgroundNeuroblastoma (NB) displays the most heterogeneity in clinical manifestation. The insulin-like growth factor 1 receptor (IGF1R) has long been recognized for its role in tumourigenesis and growth. The IGF/IGF1R pathway is important in maintaining cell survival. It is reported that IGF1R participates in the occurrence of NB, but the mechanism is still unclear.MethodsHuman NB cell lines IMR-32 and SH-SY5Y were recruited in this study. IGF1R was knocked down by transfection with short hairpin RNA. Signal transducer and activator of transcription 3 (STAT3) expression was inhibited by Cryptotanshinone treatment. Cell proliferation, migration, and invasion were determined by MTT assay, wound healing assay, and cell invasion assay, respectively. The cancer stem cell properties were characterized by tumour sphere formation assay and colony formation assay. The mRNA and protein expression levels of related proteins were detected by RT-PCR and Western blot, respectively.ResultsThe knockdown of IGF1R inhibits NB cell tumourigenesis and the epithelial-mesenchymal transition (EMT) of NB cells. Additionally, IGF1R was found to stimulate cancer stem cell-like properties in NPC cells. The knockdown of IGF1R significantly reduced the phosphorylation of AKT, and STAT3, indicating that the activation of the AKT and STAT3 pathways was inhibited by IGF1R knockdown. Furthermore, IGF1R was demonstrated to stimulate cancer stem cell-like properties in NB cells via the regulation of the STAT3/AKT axis.ConclusionIGF1R promotes cancer stem cell properties to facilitate EMT in neuroblastoma via the STAT3/AKT axis.

Activation of cell migration via morphological changes in focal adhesions depends on shear stress in MYCN-amplified neuroblastoma cells

Neuroblastoma is the most common solid tumour of childhood, and it metastasizes to distant organs. However, the mechanism of metastasis, which generally depends on the cell motility of the neuroblastoma, remains unclear. In many solid tumours, it has been reported that shear stress promotes metastasis. Here, we investigated the relationship between shear stress and cell motility in the MYCN-amplified human neuroblastoma cell line IMR32, using a microfluidic device. We confirmed that most of the cells migrated downstream, and cell motility increased dramatically when the cells were exposed to a shear stress of 0.4 Pa, equivalent to that expected in vivo. We observed that the morphological features of focal adhesion were changed under a shear stress of 0.4 Pa. We also investigated the relationship between malignancy and the motility of IMR32 cells under shear stress. Decreasing the expression of MYCN in IMR32 cells via siRNA transfection inhibited cell motility by a shear stress of 0.4 Pa. These results suggest that MYCN-amplified neuroblastoma cells under high shear stress migrate to distant organs due to high cell motility, allowing cell migration to lymphatic vessels and venules.

Anti-brain cancer activity of chloroform and hexane extracts of Tinospora cordifolia Miers: an in vitro perspective

Plants have been suggested as safest source of therapeutic agents, with multi targeted mode of action and least side effects. Tinospora cordifolia, commonly known as Guduchi in India, is one of the most highly valued herbs in Ayurvedic medicine. It possesses potential anti-cancer, anti-inflammatory, hepatoprotective, anti-diabetic, immune-stimulatory and various other beneficial activities. The present study was aimed to investigate the differentiation inducing potential of chloroform and hexane extracts of T. cordifolia using U87MG glioblastoma and IMR-32 neuroblastoma cell lines as model system. Chloroform (Chl-TCE) and hexane (Hex-TCE) extracts significantly reduced the rate of proliferation and induced cell differentiation as evidenced by MTT assay and immunostaining for GFAP and MAP-2 in glioblastoma and neuroblastoma, respectively. Further these extracts increased the expression of stress markers HSP70 and Mortalin and induced senescence. Chloroform and hexane extracts also inhibited the migration of U87MG glioblastoma and IMR-32 neuroblastoma as indicated by wound scratch assay and supported by reduced expression of NCAM. Furthermore these extracts are not toxic to normal cells as they showed no inhibitory effects on primary astrocytic and neuronal cultures. The present study suggests that chloroform and hexane extracts of T. cordifolia retard the rate of proliferation, induce differentiation and inhibit migration of human glioblastomas and neuroblastomas, thus may act as potential phytotherapeutic intervention in treatment of neural cancers.