Serum metabolomic analysis can distinguish several characteristics of NB. A larger analysis of COG banked sera is warranted.

N-myc oncogene amplification is associated but not present in all cases of high-risk neuroblastoma (NB). Since oncogene expression could often modulate sensitivity to oncolytic viruses, we wanted to examine if N-myc expression status would determine virotherapy efficacy to high-risk NB. We showed that induction of exogenous N-myc in a non-N-myc-amplified cell line background (TET-21N) increased susceptibility to oncolytic vesicular stomatitis virus (mutant VSVΔM51) and alleviated the type I IFN-induced antiviral state. Cells with basal N-myc, on the other hand, were less susceptible to virus-induced oncolysis and established a robust IFN-mediated antiviral state. The same effects were also observed in NB cell lines with and without N-myc amplification. Microarray analysis showed that N-myc overexpression in TET-21N cells downregulated IFN-stimulated genes (ISGs) with known antiviral functions. Furthermore, virus infection caused significant changes in global gene expression in TET-21N cells overexpressing N-myc. Such changes involved ISGs with various functions. Therefore, the present study showed that augmented susceptibility to VSVΔM51 by N-myc at least involves downregulation of ISGs with antiviral functions and alleviation of the IFN-stimulated antiviral state. Our studies suggest the potential utility of N-myc amplification/overexpression as a predictive biomarker of virotherapy response for high-risk NB using IFN-sensitive oncolytic viruses.

SignificanceInflammatory bowel disease (IBD) encompasses a group of disorders that involve an exaggerated immune response to intestinal microbes. Maintenance of intestinal epithelial barrier function is highly dependent on normal mitochondrial networks. When the barrier is compromised, excessive pathological fission ensues via the enzyme dynamin related protein‐1 (DRP1) and its interaction with the receptor fission protein‐1 (Fis1), creating fragmented networks of mitochondria. Fragmented mitochondrial networks have impaired respiratory capacity, generate elevated reactive oxygen species and exacerbate inflammationObjectiveTo determine whether a novel peptide, P110, can mitigate dextran sodium sulfate (DSS) and dinitrobenzene sulfonic acid (DNBS) induced colitis by inhibiting DRP1 and Fis1 mediated fission in murine models.DesignHypothesising that elevated mitochondrial fission occurs in DSS and DNBS colitis, male Balb/c mice were split into control (n=15), P110 (3 mg/kg/d, intraperitoneally)(n=8), DSS (5% (w/v), 5 days + 3 days water)(n=16) and DSS+P110 (n=16). For the DNBS protocol, male Balb/c mice were divided into control (n=8), DNBS (3 mg/kg/d, intraperitoneally)(n=11) and DNBS+P110 (3 mg/kg/d, intraperitoneally)(n=8). Experimental measures included: body mass, colon length, macroscopic disease score, cross‐sectional histopathology and colonic motility.ResultsUpon necropsy DSS and DNBS treated mice displayed the characteristic signs of colitis associated with these models. Disease was substantially less in both DSS+P110 and DNBS+P110 treated mice as gauged by: (i) percent weight loss (ii) macroscopic disease score and (iii) colon shortening (p<0.05). Functional improvements in colonic motility were seen in P110 treated mice when compared to DSS alone (p<0.05). Analysis of histopathology on H&E stained sections of mid‐colon revealed significant improvement in DNBS mice with P110 (p<0.05). P110 was also found to improve survival rate of mice, compared to DNBS alone.ConclusionsSystemic administration of a selective inhibitor of mitochondrial fission (P110) reduced the severity of disease in two different, commonly used murine models of colitis. Future studies are required to define the mechanism of P110's action in terms of the target cell in IBD (e.g. epithelium, nerve, macrophage). We conclude that inhibition of DRP1 and Fis1 interaction provides a novel approach to mitigating gut barrier deterioration in IBDSupport or Funding InformationCrohn's and Colitis Canada. The authors wish to thank Daria Mochly‐Rosen for donating P110.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

SignificanceRecent evidence has shown that mitochondrial dynamics and more specifically, mitochondrial fission, play an important role in numerous disease of energy intensive tissues. In particular, mitochondrial fission mediated by the enzyme dynamin related protein‐1 (DRP1) and the receptor fission protein‐1 (Fis1) is associated with reduced ATP production, ROS generation and inflammation. Examination of this interaction and corresponding pathological mitochondrial fission has yet to be examined in the colon in the context of inflammatory bowel disease.ObjectiveTo identify if a common murine colitis agent, dextran sodium sulfate (DSS), induces mitochondrial respiration dysfunction and if the novel peptide (P110), can restore these deficiencies by inhibiting DRP1 and Fis1 mediated fission.DesignThe murine intestinal epithelial cell line, IEC4.1, was separated into control, P110, DSS and DSS + P110. Cell were seeded and allowed to incubate for 24 hrs before receiving their respective treatments and further incubation for another 24hrs.MethodsOptimization of both DSS (1–2w./v.%) and P110 (0.5–1.5 uM) dosage and exposure time was performed with the AlamarBlue cell proliferation assay. Basal, mitochondrial complex and maximal respiratory activity were assessed using the Oxygraph‐2k (OROBOROS Instruments, Austria). Respiratory function of cells under various substrate pathways was also examined.ResultsDSS (2%) significantly reduced cell proliferation compared to control and P110 groups (p<0.05). Administration of P110 in 2% DSS cells dose dependently increased cell proliferation, with 1.5 uM P110 exhibiting cell proliferation similar to control. Analysis of mitochondrial complexes revealed that DSS reduced basal, complex I, II, IV and maximal activity (p<0.05). P110 was found to restore DSS associated respiratory deficiencies in complex I, II and IV (p<0.05).ConclusionThis study highlights novel findings regarding the role of mitochondrial fission in a model system of epithelial dysfunction. Importantly, we show i) evidence that DRP1 and Fis1 mediated fission hold potential; pathological consequences in energetically demanding tissues like the colon and ii) P110 treatment reduces DSS induced damage and its associated respiratory deficiencies. These results suggest mitochondrial dysfunction could be intricately involved in gut barrier deterioration seen in inflammatory bowel disease.Support or Funding InformationCrohn's and Colitis Canada. The authors wish to thank Daria Mochly‐Rosen for donating P110.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Background: Neuroblastoma (NB), a tumour of neurocrest progenitor cells of the sympathetic nervous system, is the most common extracranial pediatric tumour and accounts for approximately 15 percent of childhood cancer mortality. Even with surgery, radiation therapy, aggressive cytotoxic chemotherapy including autologous stem cell transplantation and more recently immunotherapy, high risk neuroblastoma has only a 30 percent predicted survival rate. Reovirus, a double-stranded RNA virus, has been shown to be effective against a myriad of cancers through its ability to preferentially lyse cancer cells with aberrant Ras pathway signaling. In this study, we investigate the potential of reovirus (serotype 3, strain Dearing) as a novel treatment for neuroblastoma and neuroblastoma tumour initiating cells (nbTIC). Experimental Design/Results: Reovirus induces dramatic cytotoxic effects at a multiplicity of infection (MOI) of 40 within 48h as assessed by WST-1 viability assays for the IMR-32, IMR-5, SK-N-AS, SK-N-SH, LAN-1, LAN-5, and SHEP human neuroblastoma cell lines in vitro. Interestingly the human neuroblastoma tumor-initiating cell lines, NB-12, NB88 and NB122 (kind gift from Dr David Kaplan) were also found to be very sensitive to reovirus-induced cytotoxicity, suggesting a role for reovirus treatment of refractory neuroblastoma. In order to further study reovirus, immunotherapy and neuroblastoma, a syngeneic, immunocompetent murine model (Neuro2a, A/J neuroblastoma model) was utilized to test reovirus-induced cytotoxicity and RV-directed immunotherapy of Neuro2A in vitro and in vivo. Preliminary data suggest that the Neuro2a cells are exquisitely sensitive to reovirus in vitro. Updated results will be presented. Conclusion: These preclinical results suggest that reovirus holds promise as a novel therapeutic for neuroblastoma and that it warrants further investigation in early phase clinical trials. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4336. doi:10.1158/1538-7445.AM2011-4336