Growth Of Neuroblastoma Cells Research Articles

FABP4 deactivates NF-κB-IL1α pathway by ubiquitinating ATPB in tumor-associated macrophages and promotes neuroblastoma progression.

Neuroblastoma (NB) is the most common and deadliest pediatric solid tumor. Targeting and reactivating tumor‐associated macrophages (TAMs) is necessary for reversing immune suppressive state and stimulating immune defense to exert tumoricidal function. However, studies on the function and regulation of TAMs in NB progression are still limited. Fatty acid binding protein 4 (FABP4) in TAMs was correlated with advanced clinical stages and unfavorable histology of NB. FABP4‐mediated macrophages increased migration, invasion, and tumor growth of NB cells. Mechanically, FABP4 could directly bind to ATPB to accelerate ATPB ubiquitination in macrophages. The consequently decreased ATP levels could deactivate NF‐κB/RelA‐IL1α pathway, which subsequently results in macrophages reprogrammed to an anti‐inflammatory phenotype. We also demonstrated that FABP4‐enhanced migration and invasion were significantly suppressed by IL1α blocking antibody. Furthermore, circulating FABP4 was also associated with the clinical stages of NB. Our findings suggest that FABP4‐mediated macrophages may promote proliferation and migration phenotypes in NB cells through deactivating NF‐κB‐IL1α pathway by ubiquitinating ATPB. This study reveals the pathologic and biologic role of FABP4‐mediated macrophages in NB development and exhibits a novel application of targeting FABP4 in macrophages for NB treatment.

Inhibition of the mRNA-Binding Protein IGF2BP1 Suppresses Proliferation and Sensitizes Neuroblastoma Cells to Chemotherapeutic Agents.

Gain at chromosome 17q21 in neuroblastoma is associated with a poor prognosis, independent of MYCN amplification status. Several potential proto-oncogenes have been identified in this region, one of them—insulin-like growth-factor-2 mRNA binding protein (IGF2BP1)—is expressed at high levels in stage 4 tumors, and associated with overall lower patient survival. Here, we demonstrate that down-regulation of IGF2BP1 activity, either by transcript silencing or chemical inhibition, suppresses neuroblastoma cell growth. Furthermore, the combination of IGF2BP1 inhibition along with commonly used chemotherapeutics that broadly affect DNA synthesis, or cyclin-dependent kinase (CDK) inhibitors that disrupt signal transduction, have a synergistic effect on the suppression of neuroblastoma cell proliferation.

MiR-338-3p inhibits cell growth, invasion, and EMT process in neuroblastoma through targeting MMP-2.

This study aimed to explore the regulatory mechanisms of miR-338-3p and matrix metalloproteinase-2 (MMP-2) in neuroblastoma. Putative target interaction regions of miR-338-3p on MMP-2 were predicted by miRcode and miRbase bioinformatics tools. Relative expression of miRNA-338-3p and MMP-2 in neuroblastoma tissues and GI-LI-N and SK-N-SH cells was determined by reverse transcription polymerase chain reaction experiment. Furthermore, the cell proliferation was determined by Cell Counting Kit-8 assay, the cell apoptosis rate was analyzed by flow cytometry assay, and the cell invasion was evaluated by transwell assay. miR-338-3p expression was downregulated, whereas MMP-2 expression was upregulated in metastasis tissue site compared to that in primary tissue site in total. Furthermore, miR-338-3p overexpression suppressed proliferation, invasion, and epithelial–mesenchymal transition (EMT) of neuroblastoma cells but promoted apoptosis, and the knockdown of MMP-2 triggered similar effects. Furthermore, MMP-2 was directly targeted by miR-338-3p, and overexpression of MMP-2 rescued the inhibitory effects of miR-338-3p on human neuroblastoma cell progression. Collectively, these data demonstrated that miR-338-3p could suppress cell growth, invasion, and EMT pathway and induce apoptosis in neuroblastoma cells by targeting MMP-2. MiR-338-3p sponged MMP-2 to regulate the PI3K/AKT pathway in human neuroblastoma cells.

Formulation of magnetic nanocomposites for intracellular delivery of micro-RNA for MYCN inhibition in neuroblastoma

Neuroblastoma, which accounts for almost 6% of all cancers in infants, originates from the sympathoadrenal progenitor cells within the neural crest. Approximately 25 % of neuroblastoma cases result from the amplification of the MYC-related oncogene MYCN, thus leading to high disease risk and poor prognosis; hence, studies focusing on the inhibition of MYCN are indispensable. Interestingly, microRNA-34 (miR-34) is a prospective candidate for cancer therapy because of its oncogenic and tumor-suppressing ability. This study presents the synthesis, characterization, and application of cationic magnetic nanocomposites (MNCs) comprising branched polyethylenimine (PEI)-coated iron oxide nanoparticles (IONPs). These positively charged MNCs possess the ability to penetrate the negatively charged cell wall for the delivery of miR-34a molecules into cancerous cells. The characteristic peaks at 3380, 1620, 2900, and 2840 cm−1 corresponding to −NH− and −CH2− groups suggest successful coating of PEI on the surface of IONPs. The X-ray powder diffraction (XRPD) peak of the prepared MNCs at 2θ = 35.44° resembled that of magnetite (Fe3O4, (311)). The transfection efficiency was enhanced through a magnetic field that enabled a very rapid concentration of the completely delivered vector dose onto cells. Additionally, the results of small-angle neutron scattering (SANS) revealed that core heat was generated and subsequently led to shell softening, which was activated by an alternative magnetic field (AMF). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that MNCs did not exhibit any significant toxicity against the tested cells. The increased amplification of miR-34a led to the suppression of the MYCN protein, which consequently inhibited the growth of neuroblastoma cells.

The Growth Response to Beta-Hydroxybutyrate in SH-SY5Y Neuroblastoma Cells is Suppressed by Glucose and Pyruvate Supplementation.

Neuroblastoma (NB) is a childhood malignancy of the sympathetic nervous system and is commonly studied using the SH-SY5Y cell line. Its neoplastic and neurodevelopmental manifestations are characterised by a high glucose demand which maintains its high proliferative capacity. This metabolic phenotype may be utilised in dietary therapies such as the ketone diet which alter substrate availability and thus starve NB cells of their preferred biosynthetic requirements. However, the effects of ketone metabolism on cancer growth remain poorly understood due to the involvement of other metabolic substrates in experimental paradigms and complexities underlying the Warburg effect. We investigated how the primary ketone body beta-hydroxybutyrate (βOHB) affects the growth of SH-SY5Y NB cells in the presence or absence of culture metabolic substrates. We demonstrated that while glucose deprivation reduced the growth and viability of SH-SY5Y cells, they proliferated and were initially unaffected by the addition of βOHB. However, a growth response to βOHB was subsequently revealed in media containing low levels of glucose, as well as in glucose and pyruvate deprived conditions. These data shed light on the roles of metabolic substrate availability as key determinants of the responses of SH-SY5Y NB cellsto ketone supplementation.

A 3D printed in vitro bone model for the assessment of molecular and cellular cues in metastatic neuroblastoma.

Metastasis is a complex and multifactorial process highly dependent on the interaction between disseminated tumor cells and the pre-metastatic niche. The metastatic sites detected in the bone of patients affected by neuroblastoma (NB), a malignancy of the developing sympathetic nervous system, are particularly aggressive. To improve our current knowledge of metastatic tumor cell biology and improve treatment success, appropriate in vitro and in vivo models that more closely resemble the native metastatic niche are needed. In this study, the impact of the geometry of synthetic β-tricalcium-phosphate (β-TCP) structures on the interaction of NB tumor cells with the stromal component has been examined. The tumor microenvironment is dynamically shaped by the stroma, which sustains the growth of NB cells inside the metastatic niche. The 3D growth conditions are a determining factor for the cell proliferation rate in β-TCP. With respect to planar counterparts, channeled 3D β-TCP structures stimulate more interleukin-6 and Fibronectin production and define Connexin 43 distribution inside the cells. Together, these results highlight how the biomechanical properties of the 3D microenvironment enable tumor cells to form spheroid-shaped arrangements. This, in turn, facilitates their pro-migratory and pro-invasive patterns and mimics the in vivo situation by translating realistic mechanobiological cues to the metastatic NB.

Characterising the Role of Hyaluronic Acid Receptor ‘HMMR’ in Regulating Neuroblastoma Cell Growth and Survival

Recent work conducted by the Stoker team at the GOSH Institute of Child Health has highlighted a gene of interest, HMMR, whose overexpression has been linked to poorer prognosis in neuroblastoma – a condition which remains a complex oncological challenge in young children. The Hyaluronic Acid-Mediated Motility Receptor (HMMR) is strongly implicated in driving tumourigenesis through its interactions with two key signalling molecules - Hyaluronic Acid (HA) and Aurora Kinase A (AURKA) - however its role in promoting disease progression in neuroblastoma has received little attention to date. This project aims to characterise, for the first time, the role that HMMR plays in regulating neuroblastoma cell growth and survival through Hyaluronic Acid and Aurora Kinase A.

Environment-Sensitive Polymeric Micelles Encapsulating SN-38 Potently Suppress Growth of Neuroblastoma Cells Exhibiting Intrinsic and Acquired Drug Resistance.

Conventional treatment approaches fail to provide durable control over aggressive malignancies due to intrinsic or acquired drug resistance characteristic of high-risk disease. SN-38, a potent camptothecin analog specifically targeting DNA topoisomerase I cleavage complexes, has shown promise in preclinical studies against aggressive solid tumors. However, its clinical utility is limited by inadequate solubility in pharmaceutically acceptable vehicles and by poor chemical and metabolic stability. Micelles formulated from amphiphilic invertible polymers (AIPs) can address these issues by concomitantly enabling solubilization of water-insoluble molecular cargoes and by protecting chemically labile agents from inactivation. Furthermore, the inversion of the AIP and disruption of the carrier-drug complexes triggered by contact with cell membranes makes it possible to deliver the therapeutic payload into the cell interior without compromising its biological activity. In the present study, we characterized a novel AIP-based micellar formulation of SN-38 and evaluated its growth inhibitory effect on neuroblastoma (NB) cells derived either at diagnosis or at relapse after intensive chemoradiotherapy. Colloidally stable, drug-loaded micellar assemblies with a uniform <100 nm size were prepared using an AIP consisting of alternating blocks of poly(ethylene glycol) and polytetrahydrofuran (PEG600-PTHF650). The micellar drug applied in a low nanomolar range (10-50 nM) completely suppressed the growth of chemo-naïve NB cells even after a brief (10 min) exposure. Furthermore, extending the exposure to 24 h resulted in a profound and lasting inhibitory effect of the micellar formulation on the growth of NB cells exhibiting an acquired loss of p53 function. These results suggest that micelle-mediated delivery of SN-38 can potentially offer a new and effective strategy for treating different phases of high-risk disease, including those showing poor response to conventional therapies.

CEP131 Abrogates CHK1 Inhibitor-Induced Replication Defects and Is Associated with Unfavorable Outcome in Neuroblastoma.

Checkpoint kinase 1 (CHK1) plays a key role in genome surveillance and integrity throughout the cell cycle. Selective inhibitors of CHK1 (CHK1i) are undergoing clinical evaluation for various human malignancies, including neuroblastoma. Recently, we reported that CHK1i, PF-477736, induced a p53-mediated DNA damage response. As a result, the cancer cells were able to repair DNA damage and became less sensitive to CHK1i. In this study, we discovered that PF-477736 increased expression of MDM2 oncogene along with CHK1i-induced replication defects in neuroblastoma NB-39-nu cells. A mass spectrometry analysis of protein binding to MDM2 in the presence of CHK1i identified the centrosome-associated family protein 131 (CEP131), which was correlated with unfavorable prognosis of neuroblastoma patients. We revealed that MDM2 was associated with CEP131 protein degradation, whereas overexpression of CEP131 accelerated neuroblastoma cell growth and exhibited resistance to CHK1i-induced replication defects. Thus, these findings may provide a future therapeutic strategy against centrosome-associated oncogenes involving CEP131 as a target in neuroblastoma.

Suppression of ABCE1-Mediated mRNA Translation Limits N-MYC-Driven Cancer Progression.

The ability of the N-MYC transcription factor to drive cancer progression is well demonstrated in neuroblastoma, the most common extracranial pediatric solid tumor, where MYCN amplification heralds a poor prognosis, with only 11% of high-risk patients surviving past 5 years. However, decades of attempts of direct inhibition of N-MYC or its paralogues has led to the conclusion that this protein is "undruggable." Therefore, targeting pathways upregulated by N-MYC signaling presents an alternative therapeutic approach. Here, we show that MYCN-amplified neuroblastomas are characterized by elevated rates of protein synthesis and that high expression of ABCE1, a translation factor directly upregulated by N-MYC, is itself a strong predictor of poor clinical outcome. Despite the potent ability of N-MYC in heightening protein synthesis and malignant characteristics in cancer cells, suppression of ABCE1 alone selectively negated this effect, returning the rate of translation to baseline levels and significantly reducing the growth, motility, and invasiveness of MYCN-amplified neuroblastoma cells and patient-derived xenograft tumors in vivo. The growth of nonmalignant cells or MYCN-nonamplified neuroblastoma cells remained unaffected by reduced ABCE1, supporting a therapeutic window associated with targeting ABCE1. Neuroblastoma cells with c-MYC overexpression also required ABCE1 to maintain cell proliferation and translation. Taken together, ABCE1-mediated translation constitutes a critical process in the progression of N-MYC-driven and c-MYC-driven cancers that warrants investigations into methods of its therapeutic inhibition. SIGNIFICANCE: These findings demonstrate that N-MYC-driven cancers are reliant on elevated rates of protein synthesis driven by heightened expression of ABCE1, a vulnerability that can be exploited through suppression of ABCE1.

MCPIP1 ribonuclease can bind and cleave AURKA mRNA in MYCN-amplified neuroblastoma cells

ABSTRACT The role of the inflammation-silencing ribonuclease, MCPIP1 (monocyte chemoattractant protein-induced protein 1), in neoplasia continuous to emerge. The ribonuclease can cleave not only inflammation-related transcripts but also some microRNAs (miRNAs) and viral RNAs. The suppressive effect of the protein has been hitherto suggested in breast cancer, clear cell renal cell carcinoma, osteosarcoma, and neuroblastoma. Our previous results have demonstrated a reduced levels of several oncogenes, as well as inhibited growth of neuroblastoma cells upon MCPIP1 overexpression. Here, we investigate the mechanisms underlying the suppression of MYCN proto-oncogene, bHLH transcription factor (MYCN)-amplified neuroblastoma cells overexpressing the MCPIP1 protein. We showed that the levels of several transcripts involved in cell cycle progression decreased in BE(2)-C and KELLY cells overexpressing MCPIP1 in a ribonucleolytic activity-dependent manner. However, RNA immunoprecipitation indicated that only AURKA mRNA (encoding for Aurora A kinase) interacts with the ribonuclease. Furthermore, the application of a luciferase assay suggested MCPIP1-dependent destabilization of the transcript. Further analyses demonstrated that the entire conserved region of AURKA seems to be indispensable for the interaction with the MCPIP1 protein. Additionally, we examined the effect of the ribonuclease overexpression on the miRNA expression profile in MYCN-amplified neuroblastoma cells. However, no significant alterations were observed. Our data indicate a key role of the binding and cleavage of the AURKA transcript in an MCPIP1-dependent suppressive effect on neuroblastoma cells.

NRAS Status Determines Sensitivity to SHP2 Inhibitor Combination Therapies Targeting the RAS-MAPK Pathway in Neuroblastoma.

Survival for high-risk neuroblastoma remains poor and treatment for relapsed disease rarely leads to long-term cures. Large sequencing studies of neuroblastoma tumors from diagnosis have not identified common targetable driver mutations other than the 10% of tumors that harbor mutations in the anaplastic lymphoma kinase (ALK) gene. However, at neuroblastoma recurrence, more frequent mutations in genes in the RAS-MAPK pathway have been detected. The PTPN11-encoded tyrosine phosphatase SHP2 is an activator of the RAS pathway, and we and others have shown that pharmacologic inhibition of SHP2 suppresses the growth of various tumor types harboring KRAS mutations such as pancreatic and lung cancers. Here we report inhibition of growth and downstream RAS-MAPK signaling in neuroblastoma cells in response to treatment with the SHP2 inhibitors SHP099, II-B08, and RMC-4550. However, neuroblastoma cell lines harboring endogenous NRAS Q61K mutation (which is commonly detected at relapse) or isogenic neuroblastoma cells engineered to overexpress NRASQ61K were distinctly resistant to SHP2 inhibitors. Combinations of SHP2 inhibitors with other RAS pathway inhibitors such as trametinib, vemurafenib, and ulixertinib were synergistic and reversed resistance to SHP2 inhibition in neuroblastoma in vitro and in vivo. These results suggest for the first time that combination therapies targeting SHP2 and other components of the RAS-MAPK pathway may be effective against conventional therapy-resistant relapsed neuroblastoma, including those that have acquired NRAS mutations. SIGNIFICANCE: These findings suggest that conventional therapy-resistant, relapsed neuroblastoma may be effectively treated via combined inhibition of SHP2 and MEK or ERK of the RAS-MAPK pathway.

Polyethylene glycol derivative 9bw suppresses growth of neuroblastoma cells by inhibiting oxidative phosphorylation.

Neuroblastoma (NB) is a childhood malignancy originating from the sympathetic nervous system, and accounts for approximately 15% of all pediatric cancer‐related deaths. As the 5‐y survival rate of patients with high‐risk NB is <50%, novel therapeutic strategies for NB patients are urgently required. Nonaethylene glycol mono(′4‐iodo‐4‐biphenyl)ester (9bw) is a polyethylene glycol derivative, synthesized by modifying a compound originally extracted from filamentous bacteria. Although 9bw shows remarkable inhibition of tumor cell growth, the underlying mechanisms remain unclear. Here, we examined the efficacy of 9bw on human NB‐derived cells, and investigated the molecular mechanisms underlying the cytotoxic effects of 9bw on these cells. Our results indicated that 9bw induced cell death in NB cells by decreasing the production of ATP. Metabolome analysis and measurement of oxygen consumption indicated that 9bw markedly suppressed oxidative phosphorylation (OXPHOS). Further analyses indicated that 9bw inhibited the activity of mitochondrial respiratory complex I. Moreover, we showed that 9bw inhibited growth of NB in vivo. Based on the results of the present study, 9bw is a good candidate as a novel agent for treatment of NB.

PRMT1 promotes neuroblastoma cell survival through ATF5

Aberrant expression of protein arginine methyltransferases (PRMTs) has been implicated in a number of cancers, making PRMTs potential therapeutic targets. But it remains not well understood how PRMTs impact specific oncogenic pathways. We previously identified PRMTs as important regulators of cell growth in neuroblastoma, a deadly childhood tumor of the sympathetic nervous system. Here, we demonstrate a critical role for PRMT1 in neuroblastoma cell survival. PRMT1 depletion decreased the ability of murine neuroblastoma sphere cells to grow and form spheres, and suppressed proliferation and induced apoptosis of human neuroblastoma cells. Mechanistic studies reveal the prosurvival factor, activating transcription factor 5 (ATF5) as a downstream effector of PRMT1-mediated survival signaling. Furthermore, a diamidine class of PRMT1 inhibitors exhibited anti-neuroblastoma efficacy both in vitro and in vivo. Importantly, overexpression of ATF5 rescued cell apoptosis triggered by PRMT1 inhibition genetically or pharmacologically. Taken together, our findings shed new insights into PRMT1 signaling pathway, and provide evidence for PRMT1 as an actionable therapeutic target in neuroblastoma.

MicroRNA-146b promotes neuroblastoma cell growth through targeting NUMB.

Accumulating evidence has demonstrated that the abnormal expression of microRNA (miRNA/miR) serves a crucial role in the development of numerous types of human cancer, including neuroblastoma (NB). The present study aimed to investigate the expression levels and biological roles of miR-146b in NB. miR-146b expression levels in NB cell lines and human umbilical vein endothelial cells (HUVECs) were analyzed using reverse transcription-quantitative PCR, and the regulatory effects of miR-146b on NB cell proliferation, invasion and apoptosis in vitro were investigated using CCK-8 assay, transwell invasion assay and flow cytometry. In addition, bioinformatics analysis, western blotting and dual-luciferase reporter assays were used to determine whether NUMB was a target gene of miR-146b. miR-146b expression levels were increased in NB cell lines compared with HUVECs. The knockdown of miR-146b using a miR-146b inhibitor significantly inhibited NB cell proliferation and invasion, but promoted cell apoptosis in vitro. Furthermore, it was revealed that miR-146b promoted NB cell proliferation through targeting NUMB. In conclusion, miR-146b was suggested to serve as an oncogene, at least in part, through directly targeting NUMB, which indicated that miR-146b may be a potential therapeutic target for NB treatment.

Long Noncoding RNA NHEG1 Drives β-Catenin Transactivation and Neuroblastoma Progression through Interacting with DDX5

Recent studies suggest that long noncoding RNAs (lncRNAs) play essential roles in tumor progression. However, the functional roles and underlying mechanisms of lncRNAs in neuroblastoma (NB), the most common malignant solid tumor in pediatric population, still remain elusive. Herein, through integrating analysis of a public RNA sequencing dataset, neuroblastoma highly expressed 1 (NHEG1) was identified as a risk-associated lncRNA, contributing to an unfavorable outcome of NB. Depletion of NHEG1 led to facilitated differentiation and decreased growth and aggressiveness of NB cells. Mechanistically, NHEG1 bound to and stabilized DEAD-box helicase 5 (DDX5) protein through repressing proteasome-mediated degradation, resulting in β-catenin transactivation that altered target gene expression associated with NB progression. We further determined a lymphoid enhancer binding factor 1 (LEF1)/transcription factor 7-like 2 (TCF7L2)/NHEG1/DDX5/β-catenin axis with a positive feedback loop and demonstrated that NHEG1 harbored oncogenic properties via its interplay with DDX5. Administration of small interfering RNAs against NHEG1 or DDX5 reduced tumor growth and prolonged survival of nude mice bearing xenografts. High NHEG1 or DDX5 expression was associated with poor survival of NB patients. These results indicate that lncRNA NHEG1 exhibits oncogenic activity that affects NB progression via stabilizing the DDX5 protein, which might serve as a potential therapeutic target for NB.

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.

Inhibition of Non-Receptor Tyrosine Kinase JAK2 Reduces Neuroblastoma Cell Growth and Enhances the Action of Doxorubicin

Novel treatments for various types of malignant diseases are warranted. In this study, we evaluated JAK2 inhibitors (Janus kinase 2) for suppressing the growth of malignant neuroblastoma and glioblastoma cells as well as breast and non-small cell lung cancers. Neuroblastoma and glioblastoma cells are the most sensitive to the JAK2 inhibitor AG490. A study of the relative expression of receptors that can activate JAK2 suggests that cell line sensitivity to AG490 may be mediated by IL6-R, IL11-R and/or CSF1-R. AG490 enhances the effect of doxorubicin on neuroblastoma cells. Our findings suggest the possible relevance of JAK2 inhibitors for neuroblastoma therapy, especially in combination with doxorubicin.

Conjugation of new DNA vaccine with polyethylenimine induces cellular immune response and tumor regression in neuroblastoma mouse model.

To estimate immunogenicity and antitumor effect of new DNA vaccine against neuroblastoma using tyrosine hydroxylase as an antigen and linear polyethylenimine (PEI) 20kDa as a synthetic DNA carrier in syngeneic mouse tumor model. DNA vaccine was made by cloning the tyrosine hydroxylase minigene fused to the potato virus X coat protein gene into the expression vector. The A/J mice were vaccinated by three intramuscular injections. For immunogenicity study, immune response was estimated by target cells cytotoxicity assay, interferon-gamma production in enzyme-linked immunospot assay and antigen-specific antibodies in 14days after the final vaccination. Antitumor effect was assessed by measurement of tumor volume and event-free survival rate in mice with engrafted NB41A3murine neuroblastoma cells following three intramuscular injections of the vaccine: 7days before, 5and 10days after tumor engraftment. The immune response was also assessed on the 30th day after tumor engraftment. The immunogenicity and antitumor effect of the vaccine in the form of aqueous solution of DNA and DNA-PEI conjugate were compared. Splenocytes cytotoxicity was the highest in the group of DNA-PEI vaccines (37.3 ± 6.9% lysis of target cells) compared with the unconjugated DNA vaccine (26.2 ± 4.0%) and placebo control (21.9 ± 3.7%). The production of interferon-gamma in the enzyme-linked immunospot assay was about ten times higher in the DNA-PEI group than in the other groups. The vaccine slowed or prevented the growth of the tumor. Mice vaccinated with the DNA-PEI vaccine had significantly better survival compared to control group (p < 0.0003). DNA vaccine against tyrosine hydroxylase, administered as a DNA-PEI 20kDa conjugate, slows down the growth of neuroblastoma cells engrafted to mice.

MicroRNA-145 overexpression inhibits neuroblastoma tumorigenesis in vitro and in vivo

ABSTRACT Neuroblastoma (NB) is responsible for 15% of all childhood cancer deaths. Despite advances in treatment and disease management, the overall 5-year survival rates remain poor in high-risk disease (25–40%). It is well known that miR-145 functions as a tumor suppressor in several types of cancer. However, the impact of miR-145 on NB is still ambiguous. Our aim was to investigate the potential tumor suppressive role and mechanisms of miR-145 in high-risk neuroblastoma. Expression levels of miR-145 in tissues and cells were determined using RT-qPCR. The effect of miR-145 on cell viability was evaluated using MTT assays, apoptosis levels were determined using TUNEL staining, and the MTDH protein expression was determined using western blot and RT-PCR. Luciferase reporter plasmids were constructed to confirm direct targeting for MTDH. The results showed that miR-145 expression was significantly lower in high-risk MYCN amplified (MNA) tumors and low miR-145 expression was associated with worse EFS and OS in our cohort. Over-expression of miR-145 reduced cell viability and increased apoptosis in SH-SY-5Y cells. We identified MTDH as a direct target for miR-145 in SH-SY-5Y cells. Targeting MTDH has the similar results as miR-145 overexpression. Our findings suggest that low miR-145 expression was associated with poor prognosis in patients with NB, and the overexpression of miR-145 inhibited NB cells growth by down-regulating MTDH, thus providing a potential target for the development of microRNA-based approach for NB therapy.