Apoptosis In Neuroblastoma Cells Research Articles

SNHG16 Silencing Inhibits Neuroblastoma Progression by Downregulating HOXA7 via Sponging miR-128-3p.

Neuroblastoma (NB) is a common intracranial solid tumor with high mortality. Small nucleolar RNA host gene 16 (SNHG16), one of the long noncoding RNAs (lncRNAs), has been reported to be linked to the poor prognosis of NB. However, the mechanisms of SNHG16 in regulating NB progression remain poorly understood. The expression level of SNHG16 was measured by quantitative real time polymerase chain reaction (qRT-PCR). The starBase was employed to predict the interaction of miR-128-3p and SNHG16 or HOXA7, which was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Cell proliferation and apoptosis were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry, respectively. Transwell assay was used to detect cell invasion or migration. The mRNA and protein levels of homeobox protein A7 (HOXA7) were determined by qRT-PCR and western blot, respectively. The levels of SNHG16 and HOXA7 were conspicuously increased in NB tissues and cells, while the expression of miR-128-3p was obviously declined, compared with corresponding normal tissues and cells. SNHG16 silencing inhibited proliferation, migration and invasion and induced apoptosis of NB cells. We identified that SNHG16 directly interacted with miR-128-3p, and miR-128-3p could target the 3'UTR of HOXA7 in NB cells. Simultaneously, miR-128-3p expression was negatively associated with SNHG16 or HOXA7. Further studies indicated that SNHG16 overexpression rescued the effects of miR-128-3p-mediated on inhibiting proliferation, migration, invasion and promoting apoptosis of NB cells. Moreover, SNHG16 could modulate HOXA7 by sponging miR-128-3p in NB cells. Besides, SNHG16 silencing suppressed tumor growth in vivo. Knockdown of SNHG16 impeded proliferation, migration, invasion and induced apoptosis through the SNHG16/miR-128-3p/HOXA7 axis in NB cells.

The dual role of BI 2536, a small-molecule inhibitor that targets PLK1, in induction of apoptosis and attenuation of autophagy in neuroblastoma cells.

Neuroblastoma (NB) is the most common extra-cranial solid tumor in childhood with the overall 5 years' survival less than 40%. Polo-like kinase 1 (PLK1) is a serine/threonine-protein kinase expressed during mitosis and over expressed in multiple cancers, including neuroblastoma. We found that higher PLK1 expression related to poor outcome of NB patients. BI2536, a small molecule inhibitor against PLK1, significantly reduced cell viability in a panel of NB cell lines, with IC50 less than 100 nM. PLK1 inhibition by BI 2536 treatment induced cell cycle arrest at G2/M phase and cell apoptosis in NB cells. Realtime PCR array revealed the PLK1 inhibition related genes, such as BIRC7, TNFSF10, LGALS1 and DAD1 et al. Moreover, autophagy activity was investigated in the NB cells treated with BI 2536. BI 2536 treatment in NB cells increased LC3-II puncta formation and LC3-II expression. Formation of autophagosome induced by BI 2536 was observed by transmission electron microscopy. However, BI2536 abrogated the autophagic flux in NB cells by reducing SQSTM1/p62 expression and AMPKαT172 phosphorylation. These results provide new clues for the molecular mechanism of cell death induced by BI 2536 and suggest that BI 2536 may act as new candidate drug for neuroblastoma.

Perfusion-guided sonopermeation of neuroblastoma: a novel strategy for monitoring and predicting liposomal doxorubicin uptake in vivo.

Neuroblastoma (NB) is the most common extracranial solid tumor in infants and children, and imposes significant morbidity and mortality in this population. The aggressive chemoradiotherapy required to treat high-risk NB results in survival of less than 50%, yet is associated with significant long-term adverse effects in survivors. Boosting efficacy and reducing morbidity are therefore key goals of treatment for affected children. We hypothesize that these may be achieved by developing strategies that both focus and limit toxic therapies to the region of the tumor. One such strategy is the use of targeted image-guided drug delivery (IGDD), which is growing in popularity in personalized therapy to simultaneously improve on-target drug deposition and assess drug pharmacodynamics in individual patients. IGDD strategies can utilize a variety of imaging modalities and methods of actively targeting pharmaceutical drugs, however in vivo imaging in combination with focused ultrasound is one of the most promising approaches already being deployed for clinical applications. Over the last two decades, IGDD using focused ultrasound with “microbubble” ultrasound contrast agents (UCAs) has been increasingly explored as a method of targeting a wide variety of diseases, including cancer. This technique, known as sonopermeation, mechanically augments vascular permeability, enabling increased penetration of drugs into target tissue. However, to date, methods of monitoring the vascular bioeffects of sonopermeation in vivo are lacking. UCAs are excellent vascular probes in contrast-enhanced ultrasound (CEUS) imaging, and are thus uniquely suited for monitoring the effects of sonopermeation in tumors.Methods: To monitor the therapeutic efficacy of sonopermeation in vivo, we developed a novel system using 2D and 3D quantitative contrast-enhanced ultrasound imaging (qCEUS). 3D tumor volume and contrast enhancement was used to evaluate changes in blood volume during sonopermeation. 2D qCEUS-derived time-intensity curves (TICs) were used to assess reperfusion rates following sonopermeation therapy. Intratumoral doxorubicin (and liposome) uptake in NB was evalauted ex vivo along with associated vascular changes.Results: In this study, we demonstrate that combining focused ultrasound therapy with UCAs can significantly enhance chemotherapeutic payload to NB in an orthotopic xenograft model, by improving delivery and tumoral uptake of long-circulating liposomal doxorubicin (L-DOX) nanoparticles. qCEUS imaging suggests that changes in flow rates are highly sensitive to sonopermeation and could be used to monitor the efficacy of treatment in vivo. Additionally, initial tumor perfusion may be a good predictor of drug uptake during sonopermeation. Following sonopermeation treatment, vascular biomarkers show increased permeability due to reduced pericyte coverage and rapid onset of doxorubicin-induced apoptosis of NB cells but without damage to blood vessels.Conclusion: Our results suggest that significant L-DOX uptake can occur by increasing tumor vascular permeability with microbubble sonopermeation without otherwise damaging the vasculature, as confirmed by in vivo qCEUS imaging and ex vivo analysis. The use of qCEUS imaging to monitor sonopermeation efficiency and predict drug uptake could potentially provide real-time feedback to clinicians for determining treatment efficacy in tumors, leading to better and more efficient personalized therapies. Finally, we demonstrate how the IGDD strategy outlined in this study could be implemented in human patients using a single case study.

Dysregulated Long Non-coding RNAs in Parkinson's Disease Contribute to the Apoptosis of Human Neuroblastoma Cells.

The molecular mechanism underlying Parkinson’s disease (PD), an increasingly common neurodegenerative disease, remains unclear. Long non-coding RNA (lncRNA) plays essential roles in gene expression and human diseases. We hypothesize that lncRNAs are involved in neuronal degeneration of PD. Using microarray, we identified 122 differentially expressed (DE) lncRNAs and 48 DE mRNAs between the circulating leukocytes from PD patients and healthy controls. There were 714 significant correlations (r ≥ 0.8 or ≤−0.8, p < 0.05) among the DE lncRNAs and mRNAs. Gene function and pathway analysis of the 48 DE mRNAs revealed biological pathways related to PD pathogenesis, including immune response, inflammatory response, MAPK, and Jak-STAT pathway. In a cohort of 72 PD patients and 22 healthy controls, the upregulation of four lncRNAs (AC131056.3-001, HOTAIRM1, lnc-MOK-6:1, and RF01976.1-201) in circulating leukocytes of PD patients were further confirmed. These lncRNAs were also upregulated in THP-1 cells, a human monocytic cell line, after inflammatory stimulation. Interestingly, the conditioned culture medium of THP-1 cells or 6-OHDA significantly increased the expression of these lncRNAs in SH-SY5Y cells, a human neuroblastoma cell line expressing dopaminergic markers. Importantly, overexpression of AC131056.3-001 or HOTAIRM1 increased baseline and 6-OHDA-induced apoptosis of SH-SY5Y cells. Taken together, we identified distinct expression profiles of lncRNA and mRNA in circulating leukocytes between PD patients and healthy controls. Dysregulated lncRNAs such as HOTAIRM1 and AC131056.3-001 may contribute to PD pathogenesis by promoting the apoptosis of dopaminergic neuron.

MXD3 antisense oligonucleotide with superparamagnetic iron oxide nanoparticles: A new targeted approach for neuroblastoma

Neuroblastoma (NB) is the most common extracranial solid tumor in children. The outcomes for aggressive forms of NB remain poor. The aim of this study was to develop a new molecular-targeted therapy for NB using an antisense oligonucleotide (ASO) and superparamagnetic iron oxide (SPIO) nanoparticles (NPs), as a delivery vehicle, targeting the transcription regulator MAX dimerization protein 3 (MXD3). We previously discovered that MXD3 was highly expressed in high-risk NB, acting as an anti-apoptotic factor; therefore, it can be a good therapeutic target. In this study, we developed two ASO-NP complexes using electrostatic conjugation to polyethylenimine-coated SPIO NPs and chemical conjugation to amphiphilic polymers on amine-functionalized SPIO NPs. Both ASO-NP complexes demonstrated MXD3 knockdown, which resulted in apoptosis in NB cells. ASO chemically-conjugated NP complexes have the potential to be used in the clinic as they showed great efficacy with minimum NP-associated cytotoxicity.

GX15\u2013070 (Obatoclax), a Bcl-2 family proteins inhibitor engenders apoptosis and pro-survival autophagy and increases Chemosensitivity in neuroblastoma

BackgroundNeuroblastoma (NB) is a frequent pediatric tumor associated with poor prognosis. The disregulation of Bcl-2, an anti-apoptotic protein, is crucial for the tumoral development and chemoresistance. Autophagy is also implicated in tumor cell survival and chemoresistance. The aim of our study was to demonstrate therapeutic efficiency of GX 15–070, a pan-Bcl-2 family inhibitor, used alone and in combination with conventional drugs or with hydroxychloroquine (HCQ), an autophagy inhibitor.MethodsFive neuroblastoma cell lines were tested for the cytotoxic activity of GX 15–070 alone or in combination with cisplatin, doxorubicin, HCQ or Z-VAD-FMK a broad-spectrum caspase inhibitor. Apoptosis and autophagy levels were studied by western-blot and FACS. Orthotopic injections were performed on NOD/LtSz-scid/IL-2Rgamma null mice that were treated with either GX 15–070 alone or in combination with HCQ.ResultsSynergistic cytotoxicity was observed for the drug combination in all of the 5 neuroblastoma cell lines tested, including MYCN amplified lines and in cancer stem cells. GX 15–070 significantly increased apoptosis and autophagy in neuroblastoma cells as evidenced by increased levels of the autophagy marker, LC3-II. Inhibition of autophagy by HCQ, further increased the cytotoxicity of this combinatorial treatment, suggesting that autophagy induced by these agent plays a cytoprotective role. In vivo, GX 15–070 combined with HCQ significantly decreased the growth of the tumor and the number of distant metastases.ConclusionsBased on the synergistic effect of HCQ and GX 15–070 observed in this study, the combination of these two drugs may be utilized as a new therapeutic approach for neuroblastoma.

Effect of CHL1 gene on cell viability, invasiveness and apoptosis in neuroblastoma cells

Objective: To investigate the effect and mechanisms of CHL1 gene overexpression on cell viability, invasiveness and apoptosis in neuroblastoma cells. Methods: The empty plasmid (pcDNA3.1 group) and CHL1 recombinant plasmid (pcDNA3.1-CHL1 group) were transfected into SK-N-SH human neuroblastoma cells, and the untransfected cells were used as blank control. Forty-eight hours after transfection, the protein expressions of CHL1, PCNA, MMP-2, Bax, STAT3 and p-STAT3 were detected by western blot. Meanwhile, cell viability, invasion and apoptosis were detected by MTT, transwell and flow cytometry assays, respectively. Results: The expression level of CHL1 protein in pcDNA3.1-CHL1 group was 0.612±0.052, which was higher than that of pcDNA3.1 group 0.122±0.014 and blank control group 0.120±0.013, with statistically significant difference (P<0.05). After 24, 48 and 72 hours of transfection, the absorbance (A) values of SK-N-SH cells in the pcDNA3.1-CHL1 group were 0.328±0.035, 0.502±0.051 and 0.688±0.064, respectively, whereas those in the pcDNA3.1 group were 0.562±0.050, 0.796±0.065 and 0.973±0.077, respectively. The differences were statistically significant (P<0.05). The invaded cells in the pcDNA3.1-CHL1 group were 104.9±3.7, which were lower than that in the pcDNA3.1 group (175.6±4.6), with statistically significant difference (P<0.05). Additionally, the apoptotic rate of pcDNA3.1-CHL1 cells was (23.46±1.22)%, which was higher than that in pcDNA3.1 group (3.45±0.20)%(P<0.05). Furthermore, the levels of PCNA, MMP-2, Bax and p-STAT3 proteins in pcDNA3.1-CHL1 group were 0.156±0.018, 0.122±0.015, 0.285±0.032 and 0.023±0.004, respectively, whereas those in pcDNA3.1 group were 0.542±0.053, 0.196±0.021, 0.073±0.009 and 0.057±0.007, respectively. There were statistically significant differences between two groups (P<0.05). Conclusion: Overexpression of CHL1 inhibits the cell viability and invasion, as well as induces apoptosis of neuroblastoma cells, which is related to the inhibition of STAT3 signaling pathway.

Long noncoding RNA KCNQ1OT1 promotes apoptosis in neuroblastoma cells by regulating miR-296-5p/Bax axis.

Long noncoding RNAs (lncRNAs) are emerging as important regulators of multiple cellular processes such as cell invasion, growth, apoptosis and differentiation. LncRNAs can function as competing endogenous RNAs (ceRNAs) which sponge and sequester microRNA (miRNA) to regulate specific targets. Previously, we found that the target genes of several miRNAs, including FADD, Fas, Casp and Bax, are related to neuronal apoptosis and form a regulatory network. Among several factors, microRNA-296-5p expression was found to be negatively correlated with caspase activity and apoptosis. Here, we aimed to investigate the role of miR-296-5p in neuroblastoma (NB) cells. By performing quantitative real-time PCR (qRT-PCR), western blot and flow cytometry assays we analysed the expression of apoptotic markers in NB cells transfected with miR-296-5p mimics or inhibitor. Pathway-specific PCR array allowed us to identify the target genes of miR-296-5p. Using LncBase online tool, we predicted lncRNA KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) as an upstream regulator of miR-296-5p. The binding of KCNQ1OT1 and miR-296-5p was validated via RNA immunoprecipitation and Biotin pull-down assays. We also demonstrate that miR-296-5p suppresses apoptosis of NB cells invitro and invivo. Mechanistically, miR-296-5p directly bound the 3'UTR of Bax mRNA, thus repressing Bax at the mRNA and protein level. Moreover, through bioinformatic analysis and molecular experiments, we showed that KCNQ1OT1 sponged miR-296-5p and impaired its effect on NB cell apoptosis. In summary, KCNQ1OT1 is a potent promoting factor of cell apoptosis, which acts by sponging miR-296-5p and upregulating Bax. Our findings identify a regulatory axis of cell fate in NB cells.

Ginsenoside Compound K Induces Ros-Mediated Apoptosis and Autophagic Inhibition in Human Neuroblastoma Cells In Vitro and In Vivo

Autophagy can result in cellular adaptation, as well as cell survival or cell death. Modulation of autophagy is increasingly regarded as a promising cancer therapeutic approach. Ginsenoside compound K (CK), an active metabolite of ginsenosides isolated from Panax ginseng C.A. Meyer, has been identified to inhibit growth of cancer cell lines. However, the molecular mechanisms of CK effects on autophagy and neuroblastoma cell death have not yet been investigated. In the present study, CK inhibited neuroblastoma cell proliferation in vitro and in vivo. Treatment by CK also induced the accumulation of sub-G1 population, and caspase-dependent apoptosis in neuroblastoma cells. In addition, CK promotes autophagosome accumulation by inducing early-stage autophagy but inhibits autophagic flux by blocking of autophagosome and lysosome fusion, the step of late-stage autophagy. This effect of CK appears to be mediated through the induction of intracellular reactive oxygen species (ROS) and mitochondria membrane potential loss. Moreover, chloroquine, an autophagy flux inhibitor, further promoted CK-induced apoptosis, mitochondrial ROS induction, and mitochondria damage. Interestingly, those promoted phenomena were rescued by co-treatment with a ROS scavenging agent and an autophagy inducer. Taken together, our findings suggest that ginsenoside CK induced ROS-mediated apoptosis and autophagic flux inhibition, and the combination of CK with chloroquine, a pharmacological inhibitor of autophagy, may be a novel therapeutic potential for the treatment of neuroblastoma.

Co-Inhibition of the DNA Damage Response and CHK1 Enhances Apoptosis of Neuroblastoma Cells.

Checkpoint kinase 1 (CHK1) is a central mediator of the DNA damage response (DDR) at the S and G2/M cell cycle checkpoints, and plays a crucial role in preserving genomic integrity. CHK1 overexpression is thought to contribute to cancer aggressiveness, and several selective inhibitors of this kinase are in clinical development for various cancers, including neuroblastoma (NB). Here, we examined the sensitivity of MYCN-amplified NB cell lines to the CHK1 inhibitor PF-477736 and explored mechanisms to increase its efficacy. PF-477736 treatment of two sensitive NB cell lines, SMS-SAN and CHP134, increased the expression of two pro-apoptotic proteins, BAX and PUMA, providing a mechanism for the effect of the CHK1 inhibitor. In contrast, in NB-39-nu and SK-N-BE cell lines, PF-477736 induced DNA double-strand breaks and activated the ataxia telangiectasia mutated serine/threonine kinase (ATM)-p53-p21 axis of the DDR pathway, which rendered the cells relatively insensitive to the antiproliferative effects of the CHK1 inhibitor. Interestingly, combined treatment with PF-477736 and the ATM inhibitor Ku55933 overcame the insensitivity of NB-39-nu and SK-N-BE cells to CHK1 inhibition and induced mitotic cell death. Similarly, co-treatment with PF-477736 and NU7441, a pharmacological inhibitor of DNA-PK, which is also essential for the DDR pathway, rendered the cells sensitive to CHK1 inhibition. Taken together, our results suggest that synthetic lethality between inhibitors of CHK1 and the DDR drives G2/M checkpoint abrogation and could be a novel potential therapeutic strategy for NB.

Effects of miR-144 on proliferation, apoptosis and cisplatin resistance by targeting MYCN in pediatric neuroblastoma

Objective: To investigate the effects and mechanisms of miR-144 on proliferation, apoptosis and cisplatin (DDP) resistance of neuroblastoma cells. Methods: Real-time fluorescence quantitative PCR (RT-qPCR) was used to detect the mRNA expressions of miR-144 and MYCN in neuroblastoma cell lines, including SH-SY5Y and SK-N-SH, and human umbilical vein endothelial cells HUVEC. The miR-negative control, miR-144 mimics, si-negative control, si-MYCN, miR-144 mimics and pcDNA, miR-144 mimics and pcDNA-MYCN co-transfected SH-SY5Y cells were described as miR-NC, miR-144, si-NC, si-MYCN, miR-144+ pcDNA and miR-144+ pcDNA-MYCN group, respectively. The half maximal inhibitory concentration (IC(50)) and cell proliferation were detected by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) assay. The protein expressions of MYCN, p21, cyclin D1, Bax, Bcl-2 were analyzed by western blot. Cell apoptosis was detected by flow cytometry. The cell fluorescence activity was detected by double luciferase reporter gene assay. Results: Compared with HUVEC cells, the expressions of miR-144 in neuroblastoma cells SH-SY5Y and SK-N-SH significantly decreased, while the mRNA and protein expression of MYCN significantly increased. The IC(50) of DDP was 9.16 μg/ml in SH-SY5Y cells. The absorbance value in 490nm (A(490) value) of miR-144 group was 0.30±0.03, significantly lower than 0.46±0.03 of miR-NC group. The cell apoptotic rate of miR-144 group was 26.94%±2.01%, significantly higher than 9.68%±0.52% of miR-NC group. The IC(50) value of DDP in miR-144 group was 2.95±0.26, significantly lower than 9.23±0.61 of miR-NC group. The expressions of p21, cyclin D1, Bax, Bcl-2 in miR-NC and miR-144 group were 2.67±0.19, 0.41±0.04, 2.12±0.21, 0.18±0.01 and 1.01±0.07, 1.00±0.06, 1.00±0.05, 1.00±0.06, respectively, with statistical significance (all P<0.05). Knockdown of MYCN showed the similar effects with those of miR-144 overexpression in SH-SYSY cells. MiR-144 significantly inhibited the fluorescence activity of ectopic MYCN expressing cells and negatively regulated the expression of MYCN. Overexpression of MYCN can reverse the effects of miR-144 on proliferation inhibition, apoptosis promotion and sensitization of SH-SY5Y cells to DDP. Conclusion: MiR-144 inhibits proliferation, promotes apoptosis and enhances the sensitivity of neuroblastoma cells to DDP through targeting MYCN, which provides a potential treatment for neuroblastoma.

Perampanel Inhibits Neuroblastoma Cell Proliferation Through Down-regulation of AKT and ERK Pathways.

Activation of AKT serine/ threonine kinase (AKT) predicts poor outcome in neuroblastoma, which highlights the potential of the AKT pathway as a promising target for neuroblastoma treatment. Several studies reported that blockade of α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors (AMPARs) reduces proliferation in glioblastoma or lung cancer by inhibiting AKT and extracellular signal-related kinase (ERK) pathways. In this study, we examined the effect of the AMPAR antagonist perampanel on human neuroblastoma cells. Cell proliferation, caspase activity, and western blot assays were performed to determine the effect of perampanel on the KP-N-SI9s human neuroblastoma cell line. Perampanel inhibited cell proliferation without triggering apoptosis in neuroblastoma cells. Down-regulation of AKT protein levels, AKT phosphorylation, and ERK1/2 phosphorylation were also observed in neuroblastoma cells with perampanel treatment. Perampanel inhibits neuroblastoma cell proliferation through down-regulation of AKT and ERK pathways and has potential for the treatment of neuroblastoma.

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.

KHG21834 attenuates glutamate-induced mitochondrial damage, apoptosis, and NLRP3 inflammasome activation in SH-SY5Y human neuroblastoma cells

New compounds were screened to develop effective drugs against glutamate-induced toxicity. The present study assessed the effects of the novel thiazole derivative KHG21834 against glutamate-induced toxicity in human neuroblastoma SH-SY5Y cell cultures. Treatment of SH-SY5Y cells with KHG21834 significantly protected cells against glutamate-induced toxicity in a dose-dependent manner, with an optimum concentration of 50 μM. KHG21834 protected SH-SY5Y cells against glutamate toxicity by suppressing glutamate-induced oxidative stress by 50%. KHG21834 also attenuated glutamate-induced mitochondrial membrane potential, ATP level reductions, and intracellular Ca2+ influx. Furthermore, KHG21834 efficiently reduced glutamate-induced ER stress and NLRP3 inflammasome activation (59% and 65% of glutamate group, respectively). In addition, KHG21834 effectively attenuated glutamate-induced levels of Bax, Bcl-2, cleaved caspase-3, p-p38, p-JNK proteins, and TUNEL positive cells. To our knowledge, this is the first study showing that KHG21834 can effectively protect SH-SY5Y cells against glutamate toxicity, suggesting that this compound may be a valuable therapeutic agent for the treatment of glutamate toxicity.

FTY720 Inhibits MPP+-Induced Microglial Activation by Affecting NLRP3 Inflammasome Activation.

Parkinson's disease (PD) is characterized by the degeneration of dopaminergic neurons and excessive microglial activation in the substantia nigra pars compacta (SNpc). In the present study, we aimed to demonstrate the therapeutic effectiveness of the potent sphingosine-1-phosphate receptor antagonist fingolimod (FTY720) in an animal model of PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and to identify the potential mechanisms underlying these therapeutic effects. C57BL/6J mice were orally administered FTY720 before subcutaneous injection of MPTP. Open-field and rotarod tests were performed to determine the therapeutic effect of FTY720. The damage to dopaminergic neurons and the production of monoamine neurotransmitters were assessed using immunohistochemistry, high-performance liquid chromatography, and flow cytometry. Immunofluorescence (CD68- positive) and enzyme-linked immunosorbent assay were used to analyze the activation of microglia, and the levels of activated signaling molecules were measured using Western blotting. Our findings indicated that FTY720 significantly attenuated MPTP-induced behavioral deficits, reduced the loss of dopaminergic neurons, and increased dopamine release. FTY720 directly inhibited MPTP-induced microglial activation in the SNpc, suppressed the production of interleukin (IL)-6, IL-1β, and tumor necrosis factor-α in BV-2 microglial cells treated with 1-methyl-4-phenylpyridinium (MPP+), and subsequently decreased apoptosis in SH-SY5Y neuroblastoma cells. Moreover, in MPP+-treated BV-2 cells and primary microglia, FTY720 treatment significantly attenuated the increases in the phosphorylation of PI3K/AKT/GSK-3β, reduced ROS generation and p65 activation, and also inhibited the activation of NLRP3 inflammasome and caspase-1. In conclusion, FTY720 may reduce PD progression by inhibiting NLRP3 inflammasome activation via its effects on ROS generation and p65 activation in microglia. These findings provide novel insights into the mechanisms underlying the therapeutic effects of FTY720, suggesting its potential as a novel therapeutic strategy against PD. Graphical Abstract FTY720 may reduce ROS production by inhibiting the PI3K/AKT/GSK-3β signaling pathway, while at the same time reducing p65 phosphorylation, thus decreasing NLRP3 inflammasome activation through these two pathways, ultimately reducing microglia activation-induced neuronal damage.

Moringin from Moringa Oleifera Seeds Inhibits Growth, Arrests Cell-Cycle, and Induces Apoptosis of SH-SY5Y Human Neuroblastoma Cells through the Modulation of NF-κB and Apoptotic Related Factors.

In the last decades, glucosinolates (GLs), precursors of isothiocyanates (ITCs), have been studied mostly for their chemopreventive and chemotherapeutic properties. The aim of our research was to study the antiproliferative effect of 4-(α-L-rhamnopyranosyloxy) benzyl glucosinolate (glucomoringin; GMG) bioactivated by myrosinase enzyme to form the corresponding isothiocyanate 4-(α-L-rhamnopyranosyloxy) benzyl C (moringin) in SH-SY5Y human neuroblastoma cells. We found that moringin significantly reduced SH-SY5Y cell growth in a time and concentration-dependent (p < 0.05, 0.01, and 0.001 vs. ctrl, after treatment with 16.4 µM moringin for 24, 48, and 72 h, respectively) manner through a mechanism involving the activation of apoptotic machinery. In addition, it altered the normal progression of cells through the cell cycle, increasing the cell population in both G2 and S phases, as well as decreasing that in the G1 phase. Studying the drug mechanism of action, we found that moringin was able to increase the expression of p53, p21, and Bax at both the protein and transcriptional level. Moreover, exposure of SH-SY5Y cells to moringin significantly increased the gene expression of both caspase 3 and 9 and enhanced their cleavage, thereby initiating an intrinsic apoptotic cascade. Finally, moringin inhibited nuclear translocation of NF-κB. Our study demonstrates the ability of moringin to reduce the growth of SH-SY5Y cells and reveals its mechanism of action, suggesting its promising role as an anticancer drug.

Ginsenoside Rk1 Induces Apoptosis in Neuroblastoma Cells Through Loss of Mitochondrial Membrane Potential and Activation of Caspases.

Neuroblastoma (NB) is the most common childhood cancer, with a very poor prognosis. More than 60% of children with NB die within five years; therefore, a more effective therapy for NB is required. Although ginsenoside has been shown to significantly inhibit the growth of various cancers, the effect of ginsenoside Rk1 on neuroblastoma has not been known yet. Hence, we examined the anticancer effects of highly pure Rk1 on neuroblastoma cell lines. The apoptotic effects of Rk1 on neuroblastoma cells were examined using cell viability assay, flow cytometry and cell staining assay, and the change in gene expression levels were analysed using RT-PCR, western blots, and immunohistochemistry. The metastatic effect of Rk1 was monitored by wound healing assay, invasion and migration with Matrigels. Rk1 inhibited neuroblastoma cell viability dose-dependently. Rk1-induced apoptosis was investigated through nuclear condensation and mitochondrial membrane potential loss, and it showed that Rk1 can induce cell cycle arrest at the G0/G1 phase but also inhibit the metastatic ability of neuroblastoma cells. Moreover, Rk1 (30 mg/kg) injections markedly inhibited xenograft tumor growth. These findings demonstrate that Rk1 might be valuable in the development of anti-cancer agents for neuroblastoma treatment.

MiR-34a inhibits progression of neuroblastoma by targeting autophagy-related gene 5

Neuroblastoma (NB) is a common pediatric malignancy with high mortality in childhood. Although many attentions have been gained, novel biomarkers for NB diagnosis and prognosis are still needed. microRNAs (miRNAs) played important roles in NB progression and miR-34a is a tumor suppressor in NB. However, the mechanism that underlies miR-34a regulating proliferation, migration, invasion and autophagy in NB remains poorly understood. In this study, cell proliferation was investigated by MTT and colony assay. Cell apoptosis was measured by caspase 3 activity assay. Cell migration and invasion were detected by trans-well analysis. Autophagy was measured via GFP-LC3 puncta fluorescence assay and western blots (WB). The expression of miR-34a was examined by quantitative real-time PCR (qRT-PCR). The regulatory effect of miR-34a on autophagy-related gene 5 (ATG5) was detected by qRT-PCR and WB. The interaction between miR-34a and ATG5 was probed by luciferase activity and RNA immunoprecipitation (RIP) assay. Results showed that miR-34a expression was inhibited in NB tissues and cells with low survival rate. Addition of miR-34a suppressed cell proliferation, migration, invasion and autophagy but promoted apoptosis in NB cells, whereas miR-34a deficiency played opposite roles in NB progression. Intriguingly, ATG5 was directly targeted by miR-34a. Moreover, ATG5 restoration attenuated miR-34a-mediated inhibitory effect on proliferation, apoptosis, migration, invasion and autophagy. These results indicated miR-34a suppressed proliferation, apoptosis, migration, invasion and autophagy in NB cells by targeting ATG5, providing a novel therapeutic avenue for NB treatment.

Role of miRNA in the regulation of cannabidiol-mediated apoptosis in neuroblastoma cells

Neuroblastoma (NBL) is one of the most common childhood cancers that originate from the immature nerve cells of the sympathetic system. Studies with NBL cancers have also shown that miRNAs are dysregulated and may play a critical role in pathogenesis. Cannabidiol (CBD) is a non-psychoactive compound found in marijuana which has been previously shown by our laboratory and others to induce apoptosis in cancer cells. However, there are no studies reported to test if CBD mediates these effects through regulation of miRNA. In the current study, therefore, we investigated if CBD induces apoptosis in human NBL cell lines, SH SY5Y and IMR-32, and if it is regulated by miRNA. Our data demonstrated that CBD induces apoptosis in NBL cells through activation of serotonin and vanilloid receptors. We also found that caspase-2 and -3 played an important role in the induction of apoptosis. CBD also significantly reduced NBL cell migration and invasion in vitro. Furthermore, CBD blocked mitochondrial respiration and caused a shift in metabolism towards glycolysis. CBD altered the expression of miRNA specifically, down-regulating hsa-let-7a and upregulating hsa-mir-1972. Downregulation of let-7a increased expression of target caspase-3, and growth arrest specific-7 (GAS-7) genes. Upregulation of hsa-mir-1972 caused decreased expression of BCL2L1 and SIRT2 genes. Together, our studies suggest that CBD-mediated apoptosis in NBL cells is regulated by miRNA.

Honokiol Induces Autophagic Apoptosis in Neuroblastoma Cells through a P53-Dependent Pathway.

In children, neuroblastomas are the most common and deadly solid tumor. Our previous studies showed that honokiol can cross the blood-brain barrier and kill neuroblastoma cells. In this study, we further evaluated if exposure to honokiol for short periods could induce autophagy and subsequent apoptosis of neuroblastoma cells and possible mechanisms. Exposure of neuroblastoma neuro-2a cells to honokiol for 24 h induced morphological shrinkage and cell death. As to the mechanisms, honokiol consecutively induced cytochrome c release from mitochondria, caspase-3 activation, DNA fragmentation and cell apoptosis. Separately, honokiol time-dependently augmented the proportion of autophagic cells and the ratio of light chain 3 (LC3)-II/LC3-I. Pretreatment of neuro-2a cells with 3-methyladenine, an inhibitor of autophagy, attenuated honokiol-induced cell autophagy, caspase-3 activation, DNA damage and cell apoptosis. In contrast, stimulation of autophagy by rapamycin, an inducer of autophagy, significantly enhanced honokiol-induced cell apoptosis. Furthermore, honokiol-induced autophagic apoptosis was confirmed in neuroblastoma NB41A3 cells. Knocking down translation of p53 using RNA interference attenuated honokiol-induced autophagy and apoptosis in neuro-2a and NB41A3 cells. Taken together, this study showed that at early periods, honokiol can induce autophagic apoptosis of neuroblastoma cells through activating a p53-dependent mechanism. Consequently, honokiol has the potential to be a therapeutic option for neuroblastomas.