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Purpose: Free fluid in the absence of solid organ or bony injury on abdominal CT scans in adults following blunt trauma is suggestive of hollow organ injury and considered an indication for surgical exploration. We wished to determine if these guidelines are applicable to children with blunt abdominal trauma. Methods: We queried the trauma registry to identify all children with blunt abdominal trauma, 12 years of age and under, admitted to our institution between 1/1/94 and 11/1/98. A retrospective chart review was conducted. Data were evaluated with Chi-square analysis and considered significant at p [is less than] 0.05. Results: There were 814 pediatric admissions for blunt trauma, and 437 had abdominal CT scans. Thirty-four studies revealed free fluid in association with solid organ injuries, pneumoperitoneum, or spine or pelvic fractures and were excluded from analysis. Thirty-two children had free fluid without associated injuries and formed the basis for the study. Five of these children underwent laparotomy. The remaining 27 had serial abdominal examinations and required no surgical intervention. A laparotomy was considered therapeutic if the child had an injury that required repair. Only 1 of the 5 children with isolated free fluid had a therapeutic laparotomy (20%). In comparison, during the same period, 38 children underwent laparotomy after blunt injury based only upon physical examination findings (no CT scan) with a therapeutic laparotomy rate of 68%. The therapeutic laparotomy rate was significantly higher when the procedure was based solely upon clinical exam as compared to finding isolated free fluid on the abdominal CT (26/38 vs. 1/5, p[is less than]0.05). The positive predictive value of isolated free fluid on CT scan resulting in a therapeutic laparotomy in children after blunt abdominal trauma was only 3.0%. Conclusions: In contrast to adults, finding isolated free fluid on abdominal CT scans in children after blunt trauma does not dictate immediate surgical exploration. Most children with isolated free fluid may be safely observed with serial abdominal examinations., EA Beierle, MD, MK Chen, MD, TV Whalen, MD, FAAP, EJ Doolin, MD, FAAP; UMDNJ-Robert Wood Johnson Medical School, Camden, NJ [...]

Leptomeningeal dissemination (LMD) is the primary cause of treatment failure in children with Group 3 medulloblastoma (MB). Building on our previous work on protein phosphatase 2A (PP2A) activation in MB, here we present pre-clinical and molecular data on the effects of two novel classes of PP2A activators on disease processes of LMD in Group 3 MB. The PP2A activators employed in this study are ATUX-6156 and ATUX-6954 (diarylmethylcycloamine sulfonylureas), and ATUX-1215 and ATUX-5800 (diarylmethyl-4-aminotetrahydropyran-sulfonamides). Treatment with these compounds led to suppression of the endogenous PP2A inhibitor, cancerous inhibitor of PP2A (CIP2A), enhanced phosphatase activity (10-60%), and reduced MB viability, migration, and invasion, prerequisites for MB cells to access the cerebrospinal fluid, affecting the initiation stage of LMD. PP2A activator treatment of MB cells led to apoptosis mediated via caspase 9/PARP signaling due to decreased phosphorylation of Bad, impeding the dispersal stage of LMD. Cell proliferation and LMD-driving cellular traits and molecules pertinent to the third stage, colonization, were also affected. Treatment with ATUX-1215 or ATUX-5800 prevented LMD in an intraventricular murine model of MB, possibly mediated by disruption of the CCL2-CCR2 axis by altered NF-kB phosphorylation via disrupted AKT signaling. The present investigation offers proof-of-principle data for PP2A-based reactivation therapy for Group 3 MB and provides the first indications that PP2A reactivation may challenge the current paradigm in targeting the 3-stage process of MB LMD. Further investigations of PP2A activators are warranted as these compounds may prove beneficial as therapeutics for MB., Competing Interests: Conflict of interest Patent applications WO2023/023594 and WO2021/188949, inventor MO, are assigned to Atux Iskay LLC. The other authors declare that they have no conflict of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Burn injuries remain one of the leading causes of injury and death in children. Studies have demonstrated a higher mortality for pediatric burns associated with non-accidental injury. Using data from a burn registry, our study aimed to discern potential factors associated with non-accidental burn injuries., Methods: We utilized the American Burn Association database from 2016 to 2018, which collects data from over one hundred burn centers across the United States, to evaluate a large pediatric burn population. Patients aged ≤14 years were analyzed. The population was then divided into suspected non-accidental versus accidental burn injuries. A multivariable logistic regression model was utilized to evaluate for predictors of burn injuries. Additional models were used to assess the relationship between suspected non-accidental burn injury and mortality, intensive care unit (ICU) stay, and hospital length of stay., Results: 16,671 pediatric patients were included. Of those, 1228 (7.4%) patients suffered non-accidental burn injury. A majority of children who sustained non-accidental burn injury were younger, non-white, and sustained scald burns. The regression model demonstrated predictors for non-accidental burn injuries included younger age, Black race, chemical/corrosion burns, government insurance, and increased total body surface area (TBSA) burn. Overall mortality for the population was 0.5%., Conclusion: This evaluation of a national burn registry reveals differences in pediatric patients sustaining non-accidental burns compared to accidental burns. The findings in this study identify pediatric populations at risk for suspected non-accidental burn injuries which may assist in preparing the families for expectations after admission for a burn injury., Level of Evidence: III., Competing Interests: Conflicts of interest None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Neuroblastoma is the most common extracranial solid tumor in children and accounts for 15% of pediatric cancer related deaths. Targeting neuroblastoma with immunotherapies has proven challenging due to a paucity of immune cells in the tumor microenvironment and the release of immunosuppressive cytokines by neuroblastoma tumor cells. We hypothesized that combining an oncolytic Herpes Simplex Virus (oHSV) with natural killer (NK) cells might overcome these barriers and incite tumor cell death., Methods: We utilized MYCN amplified and non-amplified neuroblastoma cell lines, the IL-12 expressing oHSV, M002, and the human NK cell line, NK-92 MI. We assessed the cytotoxicity of NK cells against neuroblastoma with and without M002 infection, the effects of M002 on NK cell priming, and the impact of M002 and priming on the migratory capacity and CD107a expression of NK cells. To test clinical applicability, we then investigated the effects of M002 and NK cells on neuroblastoma in vivo., Results: NK cells were more attracted to neuroblastoma cells that were infected with M002. There was an increase in neuroblastoma cell death with the combination treatment of M002 and NK cells both in vitro and in vivo. Priming the NK cells enhanced their cytotoxicity, migratory capacity and CD107a expression., Conclusions: To the best of our knowledge, these investigations are the first to demonstrate the effects of an oncolytic virus combined with self-maintaining NK cells in neuroblastoma and the priming effect of neuroblastoma on NK cells. The current studies provide a deeper understanding of the relation between NK cells and neuroblastoma and these data suggest that oHSV increases NK cell cytotoxicity towards neuroblastoma., (© 2024. The Author(s).)

Background: Pediatric gastroenteropancreatic neuroendocrine tumors are exceedingly rare, resulting in most pediatric treatment recommendations being based on data derived from adults. Trametinib is a kinase inhibitor that targets MEK1/2 and has been employed in the treatment of cancers harboring mutations in the Ras pathway., Methods: We utilized an established human pediatric gastroenteropancreatic neuroendocrine-like tumor patient-derived xenograft (PDX) with a known NRAS mutation to study the effects of MEK inhibition. We evaluated the effects of trametinib on proliferation, motility, and tumor growth in vivo. We created an intraperitoneal metastatic model of this PDX, characterized both the phenotype and the genotype of the metastatic PDX and again, investigated the effects of MEK inhibition., Results: We found target engagement with decreased ERK1/2 phosphorylation with trametinib treatment. Trametinib led to decreased in vitro cell growth and motility, and decreased tumor growth and increased animal survival in a murine flank tumor model. Finally, we demonstrated that trametinib was able to significantly decrease gastroenteropancreatic neuroendocrine intraperitoneal tumor metastasis., Conclusions: The results of these studies support the further investigation of MEK inhibition in pediatric NRAS mutated solid tumors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Introduction: Burn injuries are among the top ten leading causes of unintentional death in pediatric patients and are encountered by pediatric surgeons in all practice settings. There is a lack of literature evaluating mortality in pediatric burn injuries in regard to nonaccidental burns and potential disparities. Our study aims to determine the risk factors associated with mortality in pediatric burn injuries and highlight the characteristics of this patient population., Methods: We utilized the Trauma Quality Improvement Program database from 2017 to 2019 to identify primary burn injuries in children ≤14 y old. Physical abuse descriptors were used to identify patients with suspected nonaccidental injuries. Further demographics, including age, race, ethnicity, and insurance type, were evaluated. Descriptive statistics were generated and a multivariable logistic regression analysis was utilized to evaluate risk factors for mortality., Results: 13,472 pediatric burn patients (≤14 y old) were identified. The overall mortality was low (<1%). Children with burns to multiple body regions had the highest independent risk of mortality in this cohort. All older age groups had an independent risk of mortality compared to the youngest patients, but those from ages 5 to <10 y old had the highest risk of mortality (OR = 11.40; 95% confidence interval: 4.41-29.43, P < 0.001). Black children had a significantly higher mortality compared to White children. Nonaccidental burns carried a mortality that was twice that of accidental burns. Government insurance type was the primary insurance type for a majority of patients who died., Conclusions: Risk factors for mortality in pediatric burn include Black race, multiple affected body regions, and nonaccidental burns. This study identified an increased mortality risk in the older age groups in contrast to previous studies that showed increased mortality in younger patients suffering from burn injuries., (Published by Elsevier Inc.)

Glioblastoma (GBM) is an immunologically cold tumor, but several immunotherapy-based strategies show promise, including the administration of ex vivo expanded and activated cytotoxic gamma delta T cells. Cytotoxicity is partially mediated through interactions with natural killer group 2D ligands (NKG2DL) on tumor cells. We sought to determine whether the addition of the blood-brain barrier penetrant PARP inhibitor niraparib to the standard of care DNA alkylator temozolomide (TMZ) could upregulate NKG2DL, thereby improving immune cell recognition. Changes in viability were consistent with prior publications as there was a growth inhibitory effect of the combination of TMZ and niraparib. However, decreases in viability did not always correlate with changes in NKG2DL mRNA. ULBP1 / Mult-1 mRNA was increased with the combination therapy in comparison to either drug alone in two of the three cell types tested, even though viability was consistently decreased. mRNA expression correlated with protein levels and ULBP1/MULT-1 cell surface protein was significantly increased with TMZ and niraparib treatment in four of the five cell types tested. Gamma delta T cell-mediated cytotoxicity at a 10:1 effector-to-target ratio was significantly increased upon pretreatment of cells derived from a GBM PDX with TMZ and niraparib in comparison to the control or either drug alone. Together, these data demonstrate that the combination of PARP inhibition, DNA alkylation, and gamma delta T cell therapy has the potential for the treatment of GBM.

Lymphadenopathy is a common reason for referral to a subspecialist, which may result in significant anxiety for parents. Understanding which patients require a subspecialty referral for lymphadenopathy is key to streamlining health care utilization for this common clinical entity. This is an IRB-approved retrospective study examining pediatric patients consecutively referred to pediatric hematology oncology, otolaryngology, or surgery for lymphadenopathy from 2012 to 2021 at a free-standing tertiary-care children's hospital. Logistic regression was fitted to examine the association between the maximum size of the lymph nodes (LN) and a diagnosis of malignancy. The odds ratio, area under the receiver operator curve, sensitivity, and specificity were estimated. We found a significant association between LN size and cancer diagnosis. For every centimeter increase in the maximal dimension of LN, there was an estimated 2.3 times increase in the odds of malignancy (OR=2.3, 95% CI: 1.65-3.11; P <0.0001). The estimated area under the curve (0.84, 95% CI: 0.78-0.90) indicated that LN size correlated well with cancer diagnosis. A LN cut-off size of 2 cm resulted in an estimated sensitivity of 1.0 (95% CI: 0.87-1.00) and specificity of 0.54 (95% CI: 0.46-0.61). Maximum LN size may be a predictor of malignancy among pediatric patients with lymphadenopathy., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Chemoresistance contributes to relapse in high-risk neuroblastoma. Cancer cells acquire resistance through multiple mechanisms, including drug efflux pumps. In neuroblastoma, multidrug resistance-associated protein-1 (MRP1/ABCC1) efflux pump expression correlates with worse outcomes. These pumps are regulated by PIM kinases, a family of serine-threonine kinases, overexpressed in neuroblastoma. We hypothesized PIM kinase inhibition would sensitize neuroblastoma cells by modulating MRP1., Methods: Kocak database query evaluated ABCC1, PIM1, PIM2, and PIM3 expression in neuroblastoma patients. SK-N-AS and SK-N-BE(2) cells were treated with doxorubicin or the pan-PIM kinase inhibitor, AZD1208. Flow cytometry assessed intracellular doxorubicin accumulation. AlamarBlue assay measured viability. The lethal dose 50% (LD 50 ) of each drug and combination indices (CI) were calculated and isobolograms constructed to determine synergy., Results: Kocak database query demonstrated positive correlation between PIM genes and ABCC1. PIM kinase inhibition increased intracellular doxorubicin accumulation in both cell lines, suggesting PIM kinase regulation of MRP1. Isobolograms showed synergy between AZD1208 and doxorubicin., Conclusions: The correlation between PIM and ABCC1 gene expression suggests PIM kinases may contribute to neuroblastoma chemotherapeutic resistance. PIM kinase inhibition increased intracellular doxorubicin accumulation. Combination treatment with AZD1208 and doxorubicin decreased neuroblastoma cell viability in a synergistic fashion. These findings support further investigations of PIM kinase inhibition in neuroblastoma., Type of Study: Basic Science Research., Level of Evidence: NA., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Sarcomas are a heterogenous collection of bone and soft tissue tumors. The heterogeneity of these tumors makes it difficult to standardize treatment. CDK 4/6 inhibitors are a family of targeted agents which limit cell cycle progression and have been shown to be upregulated in sarcomas. In the current preclinical study, we evaluated the effects of lerociclib, a CDK4/6 inhibitor, on pediatric sarcomas in vitro and in 3D bioprinted tumors., Methods: The effects of lerociclib on viability, proliferation, cell cycle, motility, and stemness were assessed in established sarcoma cell lines, U-2 OS and MG-63, as well as sarcoma patient-derived xenografts (PDXs). 3D printed biotumors of each of the U-2 OS, MG-63, and COA79 cells were utilized to study the effects of lerociclib on tumor growth ex vivo., Results: CDK 4/6, as well as the intermediaries retinoblastoma protein (Rb) and phosphorylated Rb were identified as targets in the four sarcoma cell lines. Lerociclib treatment induced cell cycle arrest, decreased proliferation, motility, and stemness of sarcoma cells. Treatment with lerociclib decreased sarcoma cell viability in both traditional 2D culture as well as 3D bioprinted microtumors., Conclusions: Inhibition of CDK 4/6 activity with lerociclib was efficacious in traditional 2D sarcoma cell culture as well as in 3D bioprints. Lerociclib holds promise and warrants further investigation as a novel therapeutic strategy for management of these heterogenous groups of tumors., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Hepatoblastoma is the most common primary pediatric liver tumor. Children with pulmonary metastases at diagnosis experience survival rates as low as 25%. We have shown PIM kinases play a role in hepatoblastoma tumorigenesis. In this study, we assessed the role of PIM kinases in metastatic hepatoblastoma. We employed the metastatic hepatoblastoma cell line, HLM&#95;2. PIM kinase inhibition was attained using PIM3 siRNA and the pan-PIM inhibitor, AZD1208. Effects of PIM inhibition on proliferation were evaluated via growth curve. Flow cytometry determined changes in cell cycle. AlamarBlue assay assessed effects of PIM kinase inhibition and cisplatin treatment on viability. The lethal dose 50% (LD 50 ) of each drug and combination indices (CI) were calculated and isobolograms constructed to determine synergy. PIM kinase inhibition resulted in decreased HLM&#95;2 proliferation, likely through cell cycle arrest mediated by p21. Combination therapy with AZD1208 and cisplatin resulted in synergy, potentially through downregulation of the ataxia-telangiectasia mutated (ATM) kinase DNA damage response pathway. When assessing the combined effects of pharmacologic PIM kinase inhibition with cisplatin on HLM&#95;2 cells, we found the agents to be synergistic, potentially through inhibition of the ATM pathway. These findings support further exploration of PIM kinase inhibition as a therapeutic strategy for metastatic hepatoblastoma.

Background: Neuroblastoma arises from aberrancies in neural stem cell differentiation. PIM kinases contribute to cancer formation, but their precise role in neuroblastoma tumorigenesis is poorly understood. In the current study, we evaluated the effects of PIM kinase inhibition on neuroblastoma differentiation., Methods: Versteeg database query assessed the correlation between PIM gene expression and the expression of neuronal stemness markers and relapse free survival. PIM kinases were inhibited with AZD1208. Viability, proliferation, motility were measured in established neuroblastoma cells lines and high-risk neuroblastoma patient-derived xenografts (PDXs). qPCR and flow cytometry detected changes in neuronal stemness marker expression after AZD1208 treatment., Results: Database query showed increased levels of PIM1, PIM2, or PIM3 gene expression were associated with higher risk of recurrent or progressive neuroblastoma. Increased levels of PIM1 were associated with lower relapse free survival rates. Higher levels of PIM1 correlated with lower levels of neuronal stemness markers OCT4, NANOG, and SOX2. Treatment with AZD1208 resulted in increased expression of neuronal stemness markers., Conclusions: Inhibition of PIM kinases differentiated neuroblastoma cancer cells toward a neuronal phenotype. Differentiation is a key component of preventing neuroblastoma relapse or recurrence and PIM kinase inhibition provides a potential new therapeutic strategy for this disease., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: The tumor suppressor, protein phosphatase 2A (PP2A), is downregulated in hepatoblastoma. We aimed to examine the effects of two novel compounds of the tricyclic sulfonamide class, ATUX-3364 (3364) and ATUX-8385 (8385), designed to activate PP2A without causing immunosuppression, on human hepatoblastoma., Methods: An established human hepatoblastoma cell line, HuH6, and a human hepatoblastoma patient-derived xenograft, COA67, were treated with increasing doses of 3364 or 8385, and viability, proliferation, cell cycle and motility were investigated. Cancer cell stemness was evaluated by real-time PCR and tumorsphere forming ability. Effects on tumor growth were examined using a murine model., Results: Treatment with 3364 or 8385 significantly decreased viability, proliferation, cell cycle progression and motility in HuH6 and COA67 cells. Both compounds significantly decreased stemness as demonstrated by decreased abundance of OCT4, NANOG, and SOX2 mRNA. The ability of COA67 to form tumorspheres, another sign of cancer cell stemness, was significantly diminished by 3364 and 8385. Treatment with 3364 resulted in decreased tumor growth in vivo., Conclusion: Novel PP2A activators, 3364 and 8385, decreased hepatoblastoma proliferation, viability, and cancer cell stemness in vitro. Animals treated with 3364 had decreased tumor growth. These data provide evidence for further investigation of PP2A activating compounds as hepatoblastoma therapeutics., Competing Interests: Conflicts of interest MO is the inventor of ATUX-3364 and ATUX-8385 and the CEO of Atux Iskay, LLC. The other authors declare no competing financial interests in relation to the work described., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Invasive aspergillosis is a known complication in patients with hematologic malignancies. Tracheopleural fistulas are very rare and reported in immunocompromised adults. We present a case of invasive pulmonary aspergillosis with tracheopleural fistula in a pediatric patient with a history of rhabdomyosarcoma and macrophage activation syndrome. This case highlights the importance of recognizing life-threatening fungal infections and coordinating surgical subspecialities for patient care.

The use of three-dimensional (3D) bioprinting has remained at the forefront of tissue engineering and has recently been employed for generating bioprinted solid tumors to be used as cancer models to test therapeutics. In pediatrics, neural crest-derived tumors are the most common type of extracranial solid tumors. There are only a few tumor-specific therapies that directly target these tumors, and the lack of new therapies remains detrimental to improving the outcomes for these patients. The absence of more efficacious therapies for pediatric solid tumors, in general, may be due to the inability of the currently employed preclinical models to recapitulate the solid tumor phenotype. In this study, we utilized 3D bioprinting to generate neural crest-derived solid tumors. The bioprinted tumors consisted of cells from established cell lines and patient-derived xenograft tumors mixed with a 6% gelatin/1% sodium alginate bioink. The viability and morphology of the bioprints were analyzed via bioluminescence and immunohisto chemistry, respectively. We compared the bioprints to traditional twodimensional (2D) cell culture under conditions such as hypoxia and therapeutics. We successfully produced viable neural crest-derived tumors that retained the histology and immunostaining characteristics of the original parent tumors. The bioprinted tumors propagated in culture and grew in orthotopic murine models. Furthermore, compared to cells grown in traditional 2D culture, the bioprinted tumors were resistant to hypoxia and chemotherapeutics, suggesting that the bioprints exhibited a phenotype that is consistent with that seen clinically in solid tumors, thus potentially making this model superior to traditional 2D culture for preclinical investigations. Future applications of this technology entail the potential to rapidly print pediatric solid tumors for use in high-throughput drug studies, expediting the identification of novel, individualized therapies., Competing Interests: The authors declare no conflict of interests., (Copyright: © 2023, Quinn CH, Beierle AM, Julson JR, et al.)

The aim of this study is to demonstrate the safety and advantages of a multidisciplinary approach to surgical resection of mediastinal masses in children. Eight patients underwent resection of a mediastinal mass by a team involving both a pediatric general surgeon and pediatric cardiothoracic surgeon. One patient required rapid initiation of cardiopulmonary bypass to complete the tumor resection and repair an aortic injury that occurred when removing adherent tumor from the structure. Perioperative outcomes were excellent for all patients. This series shows that a multidisciplinary surgical approach can be potentially life saving.

Purpose: Oncolytic virotherapy with herpes simplex virus-1 (HSV) has shown promise for the treatment of pediatric and adult brain tumors; however, completed and ongoing clinical trials have utilized intratumoral/peritumoral oncolytic HSV (oHSV) inoculation due to intraventricular/intrathecal toxicity concerns. Intratumoral delivery requires an invasive neurosurgical procedure, limits repeat injections, and precludes direct targeting of metastatic and leptomeningeal disease. To address these limitations, we determined causes of toxicity from intraventricular oHSV and established methods for mitigating toxicity to treat disseminated brain tumors in mice., Experimental Design: HSV-sensitive CBA/J mice received intraventricular vehicle, inactivated oHSV, or treatment doses (1×107 plaque-forming units) of oHSV, and toxicity was assessed by weight loss and IHC. Protective strategies to reduce oHSV toxicity, including intraventricular low-dose oHSV or interferon inducer polyinosinic-polycytidylic acid (poly I:C) prior to oHSV treatment dose, were evaluated and then utilized to assess intraventricular oHSV treatment of multiple models of disseminated CNS disease., Results: A standard treatment dose of intraventricular oHSV damaged ependymal cells via virus replication and induction of CD8+ T cells, whereas vehicle or inactivated virus resulted in no toxicity. Subsequent doses of intraventricular oHSV caused little additional toxicity. Interferon induction with phosphorylation of eukaryotic initiation factor-2α (eIF2α) via intraventricular pretreatment with low-dose oHSV or poly I:C mitigated ependyma toxicity. This approach enabled the safe delivery of multiple treatment doses of clinically relevant oHSV G207 and prolonged survival in disseminated brain tumor models., Conclusions: Toxicity from intraventricular oHSV can be mitigated, resulting in therapeutic benefit. These data support the clinical translation of intraventricular G207., (©2022 American Association for Cancer Research.)

Patients presenting with metastatic hepatoblastoma have limited treatment options and survival rates as low as 25%. We previously demonstrated that Proviral Integration site in Maloney murine leukemia virus 3 (PIM3) kinase promotes tumorigenesis and cancer cell stemness in hepatoblastoma. In this study, we assessed the role of PIM3 kinase in promoting hepatoblastoma metastasis. We utilized a tail vein injection model of metastasis to evaluate the effect of CRISPR/Cas9-mediated PIM3 knockout, stable overexpression of PIM3, and pharmacologic PIM inhibition on the formation of lung metastasis. In vivo studies revealed PIM3 knockout impaired the formation of lung metastasis: 5 out of 6 mice injected with wild type hepatoblastoma cells developed lung metastasis while none of the 7 mice injected with PIM3 knockout hepatoblastoma cells developed lung metastasis. PIM3 overexpression in hepatoblastoma increased the pulmonary metastatic burden in mice and mechanistically, upregulated the phosphorylation and cell surface expression of CXCR4, a key receptor in the progression of cancer cell metastasis. CXCR4 blockade with AMD3100 decreased the metastatic phenotype of PIM3 overexpressing cells, indicating that CXCR4 contributed to PIM3's promotion of hepatoblastoma metastasis. Clinically, PIM3 expression correlated positively with CXCR4 expression in primary hepatoblastoma tissues. In conclusion, we have shown PIM3 kinase promotes the metastatic phenotype of hepatoblastoma cells through upregulation of CXCR4 cell surface expression and these findings suggest that targeting PIM3 kinase may provide a novel therapeutic strategy for metastatic hepatoblastoma., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

One of the least-investigated areas of brain pathology research is glycosylation, which is a critical regulator of cell surface protein structure and function. β-Galactoside α2,6-sialyltransferase (ST6GAL1) is the primary enzyme that α2,6 sialylates N-glycosylated proteins destined for the plasma membrane or secretion, thereby modulating cell signaling and behavior. We demonstrate a potentially novel, protumorigenic role for α2,6 sialylation and ST6GAL1 in the deadly brain tumor glioblastoma (GBM). GBM cells with high α2,6 sialylation exhibited increased in vitro growth and self-renewal capacity and decreased mouse survival when orthotopically injected. α2,6 Sialylation was regulated by ST6GAL1 in GBM, and ST6GAL1 was elevated in brain tumor-initiating cells (BTICs). Knockdown of ST6GAL1 in BTICs decreased in vitro growth, self-renewal capacity, and tumorigenic potential. ST6GAL1 regulates levels of the known BTIC regulators PDGF Receptor β (PDGFRB), Activated Leukocyte Cell Adhesion Molecule, and Neuropilin, which were confirmed to bind to a lectin-recognizing α2,6 sialic acid. Loss of ST6GAL1 was confirmed to decrease PDGFRB α2,6 sialylation, total protein levels, and the induction of phosphorylation by PDGF-BB. Thus, ST6GAL1-mediated α2,6 sialylation of a select subset of cell surface receptors, including PDGFRB, increases GBM growth.

Malignant brain tumors constitute nearly one-third of cancer diagnoses in children and have recently surpassed hematologic malignancies as the most lethal neoplasm in the pediatric population. Outcomes for children with brain tumors are unacceptably poor and current standards of care-surgical resection, chemotherapy, and radiation-are associated with significant long-term morbidity. Oncolytic virotherapy has emerged as a promising immunotherapy for the treatment of brain tumors. While the majority of brain tumor clinical trials utilizing oncolytic virotherapy have been in adults, five viruses are being tested in pediatric brain tumor clinical trials: herpes simplex virus (G207), reovirus (pelareorep/Reolysin), measles virus (MV-NIS), poliovirus (PVSRIPO), and adenovirus (DNX-2401, AloCELYVIR). Herein, we review past and current pediatric immunovirotherapy brain tumor trials including the relevant preclinical and clinical research that contributed to their development. We describe mechanisms by which the viruses may overcome barriers in treating pediatric brain tumors, examine challenges associated with achieving effective, durable responses, highlight unique aspects and successes of the trials, and discuss future directions of immunovirotherapy research for the treatment of pediatric brain tumors., (Copyright © 2022. Published by Elsevier Inc.)

Cancer continues to be a significant cause of non-traumatic pediatric mortality. Diagnosis of pediatric solid tumors is paramount to prescribing the correct treatment regimen. Recent efforts have focused on non-invasive methods to obtain tumor tissues, but one of the challenges encountered is the ability to obtain an adequate amount of viable tissue. In this study, a wireless, inductor-capacitor (LC) sensor was employed to detect relative permittivity of pediatric tumor tissues. There is a comparison of resonant frequencies of tumor tissues between live versus dead tissues, the primary tumor tissue versus tissue from the organs of origin or metastasis, and treated versus untreated tumors. The results show significant shifts in resonant frequencies between the comparison groups. Dead tissues demonstrated a significant shift in resonant frequencies compared to alive tissues. There were significant differences between the resonant frequencies of normal tissues versus tumor tissues. Resonant frequencies were also significantly different between primary tumors compared to their respective metastases. These data indicate that there are potential clinical applications of LC technology in the detection and diagnosis of pediatric solid tumors., Competing Interests: The authors declare the following competing financial interest(s): Michael Ohlmeyer is the inventor of Atux-792 and is the founder of and vice president of chemistry at Atux-Iskay, LLC. The other authors have nothing to declare., (© 2022 The Authors. Published by American Chemical Society.)

PIM kinases have been identified as potential therapeutic targets in several malignancies. Here, we provide an in-depth review of PIM kinases, including their structure, expression, activity, regulation, and role in pediatric carcinogenesis. Also included is a brief summary of the currently available pharmaceutical agents targeting PIM kinases and existing clinical trials.

Background/purpose: Metastatic hepatoblastoma continues to pose a significant treatment challenge, primarily because the precise mechanisms involved in metastasis are not fully understood, making cell lines and preclinical models that depict the progression of disease and metastasis-related biology paramount. We aimed to generate and characterize a metastatic hepatoblastoma cell line to create a model for investigation of the molecular mechanisms associated with metastasis., Materials/methods: Using a murine model of serial tail vein injections of the human hepatoblastoma HuH6 cell line, non-invasive bioluminescence imaging, and dissociation of metastatic pulmonary lesions, we successfully established and characterized the metastatic human hepatoblastoma cell line, HLM&#95;3., Results: The HLM&#95;3 cells exhibited enhanced tumorigenicity and invasiveness, both in vitro and in vivo compared to the parent HuH6 cell line. Moreover, HLM&#95;3 metastatic hepatoblastoma cells exhibited a stem cell-like phenotype and were more resistant to the standard chemotherapeutic cisplatin., Conclusion: This newly described metastatic hepatoblastoma cell line offers a novel tool to study mechanisms of tumor metastasis and evaluate new therapeutic strategies for metastatic hepatoblastoma., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Serine-threonine kinase receptor associated protein (STRAP), a scaffolding protein, is upregulated in many solid tumors. As such, we hypothesized that STRAP may be overexpressed in neuroblastoma tumors and may play a role in neuroblastoma tumor progression., Methods: We examined two publicly available neuroblastoma patient databases, GSE49710 (n = 498) and GSE49711 (n = 498), to investigate STRAP expression in human specimens. SK-N-AS and SK-N-BE(2) human neuroblastoma cell lines were stably transfected with STRAP overexpression (OE) plasmid, and their resulting phenotype studied. PamChip® kinomic peptide microarray evaluated the effects of STRAP overexpression on kinase activation., Results: In human specimens, higher STRAP expression correlated with high-risk disease, unfavorable histology, and decreased overall neuroblastoma patient survival. STRAP OE in neuroblastoma cell lines led to increased proliferation, growth, supported a stem-like phenotype and activated downstream FAK targets. When FAK was targeted with the small molecule FAK inhibitor, PF-573,228, STRAP OE neuroblastoma cells had significantly decreased growth compared to control empty vector cells., Conclusion: Increased STRAP expression in neuroblastoma was associated with unfavorable tumor characteristics. STRAP OE resulted in increased kinomic activity of FAK. These findings suggest that the poorer outcomes in neuroblastoma tumors associated with STRAP overexpression may be secondary to FAK activation., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Hepatoblastoma remains one of the most difficult childhood tumors to treat and is alarmingly understudied. We previously demonstrated that Proviral Insertion site in Maloney murine leukemia virus (PIM) kinases, specifically PIM3, are overexpressed in human hepatoblastoma cells and function to promote tumorigenesis. We aimed to use CRISPR/Cas9 gene editing with dual gRNAs to introduce large inactivating deletions in the PIM3 gene and achieve stable PIM3 knockout in the human hepatoblastoma cell line, HuH6. PIM3 knockout of hepatoblastoma cells led to significantly decreased proliferation, viability, and motility, inhibited cell-cycle progression, decreased tumor growth in a xenograft murine model, and increased animal survival. Analysis of RNA sequencing data revealed that PIM3 knockout downregulated expression of pro-migratory and pro-invasive genes and upregulated expression of genes involved in apoptosis and differentiation. Furthermore, PIM3 knockout decreased hepatoblastoma cancer cell stemness as evidenced by decreased tumorsphere formation, decreased mRNA abundance of stemness markers, and decreased cell surface expression of CD133, a marker of hepatoblastoma stem cell-like cancer cells. Reintroduction of PIM3 into PIM3 knockout cells rescued the malignant phenotype. Successful CRISPR/Cas9 knockout of PIM3 kinase in human hepatoblastoma cells confirmed the role of PIM3 in promoting hepatoblastoma tumorigenesis and cancer cell stemness., (© 2021. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Background: Protein phosphatase 2A (PP2A) functions as an inhibitor of cancer cell proliferation, and its tumor suppressor function is attenuated in many cancers. Previous studies utilized FTY720, an immunomodulating compound known to activate PP2A, and demonstrated a decrease in the malignant phenotype in neuroblastoma. We wished to investigate the effects of two novel PP2A activators, ATUX-792 (792) and DBK-1154 (1154)., Methods: Long-term passage neuroblastoma cell lines and human neuroblastoma patient-derived xenograft (PDX) cells were used. Cells were treated with 792 or 1154, and viability, proliferation, and motility were examined. The effect on tumor growth was investigated using a murine flank tumor model., Results: Treatment with 792 or 1154 resulted in PP2A activation, decreased cell survival, proliferation, and motility in neuroblastoma cells. Immunoblotting revealed a decrease in MYCN protein expression with increasing concentrations of 792 and 1154. Treatment with 792 led to tumor necrosis and decreased tumor growth in vivo., Conclusions: PP2A activation with 792 or 1154 decreased survival, proliferation, and motility of neuroblastoma in vitro and tumor growth in vivo. Both compounds resulted in decreased expression of the oncogenic protein MYCN. These findings indicate a potential therapeutic role for these novel PP2A activators in neuroblastoma.

Extramedullary hematopoiesis occurs in the setting of hematologic disorders or malignancies when the activity of the bone marrow is insufficient to generate blood cells. We report a unique case of adrenal extramedullary hematopoiesis diagnosed in a 16 year old female with a history of anti-Diego antibody and congenital dyserythropoietic anemia. She presented with an enlarging adrenal mass and underwent surgical resection. Pathology revealed extramedullary hematopoiesis. On literature review, we identified only two prior existing cases of adrenal extramedullary hematopoiesis in pediatric patients, with no prior case reports of adrenal extramedullary hematopoiesis occurring in patients with anti-Diego antibody or in those with congenital dyserythropoietic anemia., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Janet Rae Julson reports financial support was provided by National Institute of Health. Janet Rae Julson reports a relationship with National Institute of Health that includes: funding grants.

Vascular anomalies comprise a spectrum of disorders characterized by the abnormal development or growth of blood and lymphatic vessels. These growths have unique features and diverse behaviors, mandating a multidisciplinary approach in their evaluation, diagnosis, and management. Here we describe the case of a male toddler presenting with an abdominal mass, originally treated as a metastatic retroperitoneal tumor, but subsequently felt to represent a vascular anomaly., (© 2021 Wiley Periodicals LLC.)

Cancer is the leading cause of death by disease in children, and over 15% of pediatric cancer-related mortalities are due to neuroblastoma. Current treatment options for neuroblastoma remain suboptimal as they often have significant toxicities, are associated with long-term side effects, and result in disease relapse in over half of children with high-risk disease. There is a dire need for new therapies, and oncolytic viruses may represent an effective solution. Oncolytic viruses attack tumor cells in two ways: direct infection of tumor cells leading to cytolysis, and production of a debris field that stimulates an anti-tumor immune response. Our group has previously shown that M002, an oncolytic herpes simplex virus (oHSV), genetically engineered to express murine interleukin-12 (mIL-12), was effective at targeting and killing long term passage tumor cell lines. In the current study, we investigated M002 in three neuroblastoma patient-derived xenografts (PDXs). PDXs better recapitulate the human condition, and these studies were designed to gather robust data for translation to a clinical trial. We found that all three PDXs expressed viral entry receptors, and that the virus actively replicated in the cells. M002 caused significant tumor cell death in 2D culture and 3D bioprinted tumor models. Finally, the PDXs displayed variable susceptibility to M002, with a more profound effect on high-risk neuroblastoma PDXs compared to low-risk PDX. These findings validate the importance of incorporating PDXs for preclinical testing of oncolytic viral therapeutics and showcase a novel technique, 3D bioprinting, to test therapies in PDXs. Collectively, our data indicate that oHSVs effectively target high-risk neuroblastoma, and support the advancement of this therapy to the clinical setting.

Purpose: Burn is one of the leading causes of injury and death in children. Currently, the Residency Review Committee does not require general surgery residents to rotate on a burn service. With many trainees no longer receiving burn training during residency, we sought to evaluate the exposure to burn management in pediatric surgery training programs., Material and Methods: An electronic survey was sent to program directors at accredited pediatric surgery training programs (56) during the 2020 academic year. Case log reviews were performed for 2005-2019. Descriptive statistical analysis was performed., Results: Thirty-six program directors participated in the survey (64%), and 56% reported having an inpatient and outpatient component for burn management. Nearly 20% of program directors reported having no burn management at their institution. Fifty-four percent of responding programs had fellow participation in burn management. Over a fifteen-year period, case logs identified a median of 0-2 burn cases logged each year for graduating fellows. Logistically, 65% of burn centers relied on general pediatric surgeons for management., Conclusion: Pediatric surgery trainee involvement in burn management varies with many programs offering no designated burn training. Increasing exposure to pediatric burn management during training is needed to provide improved care for this patient population., Level of Evidence: III, Retrospective Review., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Introduction: Coronavirus Disease-19 (COVID-19) was declared a pandemic in March 2020. States issued stay-at-home orders and hospitals cancelled non-emergent surgeries. During this time, we anecdotally noticed more admissions for perforated appendicitis. Therefore, we hypothesized that during the months following the COVID-19 pandemic declaration, more children were presenting with perforated appendicitis., Materials and Methods: This is a retrospective cohort study reviewing pediatric patients admitted at a single institution with acute and/or perforated appendicitis between October 2019 to May 2020. Interval appendectomies were excluded. COVID-19 months were designated as March, April, and May 2020. Additional analysis of March, April, and May 2019 was performed for comparison purposes. Analyzed data included demographics, symptoms, white blood cell count, imaging findings, procedures performed, and perforation status. Statistical analysis was performed., Results: During the study period, 285 patients were admitted with the diagnosis of acute appendicitis with 95 patients being perforated. We identified a significant increase in perforated appendicitis cases in the three COVID-19 months compared with the preceding five months (45.6% vs 26.4%; P <0.001). In addition, a similar significant increase was identified when comparing to the same months a year prior (P = 0.003). No significant difference in duration of pain was identified (P=0.926)., Conclusion: The COVID-19 pandemic and its associated stay-at-home orders have had downstream effects on healthcare. Our review has demonstrated a significant increase in the number of children presenting with perforated appendicitis following these stay-at-home ordinances. These results demonstrate that further investigations into the issues surrounding access to healthcare, especially during this pandemic, are warranted., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Purpose: Diversity in the physician workforce remains a priority in healthcare as it has been shown to improve outcomes. Decisions for choosing specific fields in medicine are partly influenced by mentors, which tend to be the same sex or ethnicity. Females are starting to outnumber males in medical school and minorities are targeted for recruitment. We hypothesized that diversity in pediatric surgery has increased over time., Methods: The recently published A Genealogy of North American Pediatric Surgery was utilized to identify graduating pediatric surgery fellows from 1981 to 2018. Organization websites were used to identify past and current leaders. A web-based analysis, including online facial recognition software, was performed. A year-to-year and decade-to-decade demographic comparison was completed., Results: 1217 pediatric surgery fellows graduated between 1981 and 2018. When comparing graduates from the first and last decades, an increase from 16.9% to 39.5% for female graduates was observed (p = 0.046). A significant increase in nonwhite graduates was seen for all races (p < 0.05). Representation in leadership was White and male dominant., Conclusion: There was a significant increase in diversity in pediatric surgery fellowship graduates. There were increasing trends in female graduates and all nonwhite racial groups. Focusing on enhancing the pipeline and mentoring underrepresented minorities will continue to enhance this trend for the field of pediatric surgery., Level of Evidence: III; Retrospective Review., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Patient-derived xenografts provide significant advantages over long-term passage cell lines when investigating efficacy of treatments for solid tumors. Our laboratory encountered a high-grade, metastatic, neuroendocrine-like tumor from a pediatric patient that presented with a unique genetic profile. In particular, mutations in TYRO3 and ALK were identified. We established a human patient-derived xenoline (PDX) of this tumor for use in the current study. We investigated the effect of crizotinib, a chemotherapeutic known to effectively target both TYRO3 and ALK mutations. Crizotinib effectively decreased viability, proliferation, growth, and the metastatic properties of the PDX tumor through downregulation of STAT3 signaling, but expression of PDGFRß was increased. Sunitinib is a small molecule inhibitor of PDGFRß and was studied in this PDX independently and in combination with crizotinib. Sunitinib alone decreased viability, proliferation, and growth in vitro and decreased tumor growth in vivo. In combination, sunitinib was able to overcome potential crizotinib-induced resistance through downregulation of ERK 1/2 activity and PDGFRß receptor expression; consequently, tumor growth was significantly decreased both in vitro and in vivo. Through the use of the PDX, it was possible to identify crizotinib as a less effective therapeutic for this tumor and suggest that targeting PDGFRß would be more effective. These findings may translate to other solid tumors that present with the same genetic mutations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier Inc.)

Background: Serine-threonine kinase receptor-associated protein (STRAP) plays an important role in neural development but also in tumor growth. Neuroblastoma, a tumor of neural crest origin, is the most common extracranial solid malignancy of childhood and it continues to carry a poor prognosis. The recent discovery of the role of STRAP in another pediatric solid tumor, osteosarcoma, and the known function of STRAP in neural development, led us to investigate the role of STRAP in neuroblastoma tumorigenesis. Methods: STRAP protein expression was abrogated in two human neuroblastoma cell lines, SK-N-AS and SK-N-BE(2), using transient knockdown with siRNA, stable knockdown with shRNA lentiviral transfection, and CRISPR-Cas9 genetic knockout. STRAP knockdown and knockout cells were examined for phenotypic alterations in vitro and tumor growth in vivo. Results: Cell proliferation, motility, and growth were significantly decreased in STRAP knockout compared to wild-type cells. Indicators of stemness, including mRNA abundance of common stem cell markers Oct4, Nanog, and Nestin, the percentage of cells expressing CD133 on their surface, and the ability to form tumorspheres were significantly decreased in the STRAP KO cells. In vivo, STRAP knockout cells formed tumors less readily than wild-type tumor cells. Conclusion: These novel findings demonstrated that STRAP plays a role in tumorigenesis and maintenance of neuroblastoma stemness.

Background: Novel therapies are needed for patients with hepatoblastoma because of an increasing incidence of disease and poor prognosis for advanced, refractory, and recurrent disease. PIM kinases promote tumorigenesis in hepatoblastoma. A novel PIM inhibitor, PIM447, has shown promise in inhibiting oncogenesis in hematologic and lymphoid malignancies. We hypothesized that PIM inhibition with PIM447 would result in decreased tumorigenesis in hepatoblastoma., Methods: The effects of PIM447 on hepatoblastoma viability, proliferation, motility, apoptosis, and tumor cell stemness were assessed in HuH6, a human hepatoblastoma cell line, and COA67, a human hepatoblastoma patient-derived xenograft., Results: PIM447 significantly decreased the viability, proliferation, and motility of HuH6 and COA67 cells. Apoptosis significantly increased following PIM447 treatment. PIM447 had a significant impact on tumor cell stemness as evidenced by decreased expression of CD133 and reduced ability of HuH6 and COA67 cells to form tumorspheres. Furthermore, combining PIM447 with cisplatin resulted in a significant decrease in cell viability compared to either treatment alone., Conclusion: We showed that PIM447 inhibits oncogenesis and potentiates the effects of cisplatin in hepatoblastoma and, therefore, warrants further investigation as a potential therapeutic agent for hepatoblastoma., (Copyright © 2021. Published by Elsevier Inc.)

Introduction: The poor therapeutic efficacy seen with current treatments for neuroblastoma may be attributed to stem cell-like cancer cells (SCLCCs), a subpopulation of cancer cells associated with poor prognosis and disease recurrence. Retinoic acid (RA) is a differentiating agent used as maintenance therapy for high-risk neuroblastoma but nearly half of children treated with RA relapse. We hypothesized that 6-Methyl-UAB30 (6-Me), a second-generation rexinoid recently developed with a favorable toxicity profile compared to RA, would reduce cancer cell stemness in human neuroblastoma patient-derived xenografts (PDXs)., Methods: Cells from three neuroblastoma PDXs were treated with 6-Me and proliferation, viability, motility, and cell-cycle progression were assessed. CD133 expression, sphere formation, and mRNA abundance of stemness and differentiation markers were evaluated using flow cytometry, in vitro extreme limiting dilution analysis, and real-time PCR, respectively., Results: Treatment with 6-Me decreased proliferation, viability, and motility, and induced cell-cycle arrest and differentiation in all three neuroblastoma PDXs. In addition, 6-Me treatment led to decreased CD133 expression, decreased sphere-forming ability, and decreased mRNA abundance of Oct4, Nanog, and Sox2, indicating decreased cancer cell stemness., Conclusions: 6-Me decreased oncogenicity and reduced cancer cell stemness of neuroblastoma PDXs, warranting further exploration of 6-Me as potential novel therapy for neuroblastoma., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this manuscript., (Copyright © 2021. Published by Elsevier Inc.)

In the quest to advance neuroblastoma therapeutics, there is a need to have a deeper understanding of the tumor microenvironment (TME). From extracellular matrix proteins to tumor associated macrophages, the TME is a robust and diverse network functioning in symbiosis with the solid tumor. Herein, we review the major components of the TME including the extracellular matrix, cytokines, immune cells, and vasculature that support a more aggressive neuroblastoma phenotype and encumber current therapeutic interventions. Contemporary treatments for neuroblastoma are the result of traditional two-dimensional culture studies and in vivo models that have been translated to clinical trials. These pre-clinical studies are costly, time consuming, and neglect the study of cofounding factors such as the contributions of the TME. Three-dimensional (3D) bioprinting has become a novel approach to studying adult cancers and is just now incorporating portions of the TME and advancing to study pediatric solid. We review the methods of 3D bioprinting, how researchers have included TME pieces into the prints, and highlight present studies using neuroblastoma. Ultimately, incorporating the elements of the TME that affect neuroblastoma responses to therapy will improve the development of innovative and novel treatments. The use of 3D bioprinting to achieve this aim will prove useful in developing optimal therapies for children with neuroblastoma.

Despite increasing incidence, treatment for hepatoblastoma has not changed significantly over the past 20 years. Chemotherapeutic strategies continue to rely on cisplatin, as it remains the most active single agent against hepatoblastoma. However, chemoresistance remains a significant challenge with 54-80% of patients developing resistance to chemotherapy after 4-5 cycles of treatment. Stem cell-like cancer cells (SCLCCs) are a subset of cells thought to play a role in chemoresistance and disease recurrence. We have previously demonstrated that Proviral Integration site for Moloney murine leukemia virus (PIM) kinases, specifically PIM3, play a role in hepatoblastoma cell proliferation and tumor growth and maintain the SCLCC phenotype. Here, we describe the development of a cisplatin-resistant hepatoblastoma xenograft model of the human HuH6 cell line and a patient-derived xenograft, COA67. We provide evidence that these cisplatin-resistant cells are enriched for SCLCCs and express PIM3 at higher levels than cisplatin-naïve cells. We demonstrate that PIM inhibition with AZD1208 sensitizes cisplatin-resistant hepatoblastoma cells to cisplatin, enhances cisplatin-mediated apoptosis, and decreases the SCLCC phenotype seen with cisplatin resistance. Together, these findings indicate that PIM inhibition may be a promising adjunct in the treatment of hepatoblastoma to effectively target SCLCCs and potentially decrease chemoresistance and subsequent disease relapse.

Investigation of the mechanisms responsible for aggressive neuroblastoma and its poor prognosis is critical to identify novel therapeutic targets and improve survival. Enhancer of Zeste Homolog 2 (EZH2) is known to play a key role in supporting the malignant phenotype in several cancer types and knockdown of EZH2 has been shown to decrease tumorigenesis in neuroblastoma cells. We hypothesized that the EZH2 inhibitor, GSK343, would affect cell proliferation and viability in human neuroblastoma. We utilized four long-term passage neuroblastoma cell lines and two patient-derived xenolines (PDX) to investigate the effects of the EZH2 inhibitor, GSK343, on viability, motility, stemness and in vivo tumor growth. Immunoblotting confirmed target knockdown. Treatment with GSK343 led to significantly decreased neuroblastoma cell viability, migration and invasion, and stemness. GSK343 treatment of mice bearing SK-N-BE(2) neuroblastoma tumors resulted in a significant decrease in tumor growth compared to vehicle-treated animals. GSK343 decreased viability, and motility in long-term passage neuroblastoma cell lines and decreased stemness in neuroblastoma PDX cells. These data demonstrate that further investigation into the mechanisms responsible for the anti-tumor effects seen with EZH2 inhibitors in neuroblastoma cells is warranted., Competing Interests: The authors have declared that no competing interests exist.

Background: Trauma is the leading cause of pediatric and adolescent morbidity and mortality. Firearm-related injuries and deaths contribute substantially to the overall disease burden. This study described the intent, location, demographics, and outcomes of a nationally representative pediatric population with firearm injuries. We hypothesized that younger patients would have a higher percentage of unintentional and self-inflicted injuries with associated higher mortality rates., Materials and Methods: The National Trauma Data Bank, maintained by the American College of Surgeons, from 2010 to 2016 was utilized. All pediatric patients (0-19 y) with firearm injuries who had complete data were analyzed for mechanism, location, demographics, and outcomes. Basic descriptive statistics were used to compare subgroups. Multivariable logistic regression analysis was applied to investigate risk factors for firearm injury-caused mortality., Results: In the study period, 46,039 pediatric patients sustained firearm injuries (median age = 17 y). Males, Blacks, ages 15-19, and the Southern region were the most common injured demographics. However, subgroup analysis showed the demographics differ for self-inflicted and unintentional firearm injuries, which had significantly higher White patients (66.6% and 47.9%, respectively; P < 0.001). Nearly 76% of injuries were related to assaults, 14% were unintentional, 5% were self-inflicted, and 5% were undetermined. The overall mortality was nearly 12%. The youngest population had higher proportion of unintentional injuries and highest mortality rate when compared with other classifications of intent (P < 0.001)., Conclusions: Pediatric firearm injuries have high mortality, especially in the youngest populations. Age-tailored prevention strategies, such as strict child access prevention laws and enforced gun storage violations, may help in reducing firearm injuries and improving health outcomes., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Retinoic acid (RA) therapy has been utilized as maintenance therapy for high-risk neuroblastoma, but over half of patients treated with RA relapse. Neuroblastoma stem cell-like cancer cells (SCLCCs) are a subpopulation of cells characterized by the expression of the cell surface marker CD133 and are hypothesized to contribute to drug resistance and disease relapse. A novel rexinoid compound, 9-cis-UAB30 (UAB30), was developed having the same anti-tumor effects as RA but a more favorable toxicity profile. In the current study, we investigated the efficacy of UAB30 in neuroblastoma patient-derived xenografts (PDX). Two PDXs, COA3 and COA6, were utilized and alterations in the malignant phenotype were assessed following treatment with RA or UAB30. UAB30 significantly decreased proliferation, viability, and motility of both PDXs. UAB30 induced cell-cycle arrest as demonstrated by the significant increase in percentage of cells in G1 (COA6: 33.7 ± 0.7 vs. 43.3 ± 0.7%, control vs. UAB30) and decrease in percentage of cells in S phase (COA6: 44.7 ± 1.2 vs. 38.6 ± 1%, control vs. UAB30). UAB30 led to differentiation of PDX cells, as evidenced by the increase in neurite outgrowth and mRNA abundance of differentiation markers. CD133 expression was decreased by 40% in COA6 cells after UAB30. The ability to form tumorspheres and mRNA abundance of known stemness markers were also significantly decreased following treatment with UAB30, further indicating decreased cancer cell stemness. These results provide evidence that UAB30 decreased tumorigenicity and cancer cell stemness in neuroblastoma PDXs, warranting further exploration as therapy for high-risk neuroblastoma., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Primary pulmonary malignancies are rare in childhood. The most common, pleuropulmonary blastoma (PPB), has an incidence of 25-50 cases per year in the United States (Knight and et al., 2019) [1]. The majority of children are diagnosed with PPB before the age of four years. PPB is divided into subtypes I, Ir (type I-regressed), II, and III, which correlates to the age of diagnosis and patient prognosis [2,3]. Here we report an unusual presentation of PPB in a teen-aged female who presented with a one month history of a non-productive cough., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.