Despite being the most common liver cancer in children, hepatoblastoma (HB) is a rare neoplasm. Consequently, few pretreatment tumors have been molecularly profiled, and there are no validated prognostic or therapeutic biomarkers for HB patients. We report on the first large-scale effort to profile pretreatment HBs at diagnosis. Our analysis of 88 clinically annotated HBs revealed three risk-stratifying molecular subtypes that are characterized by differential activation of hepatic progenitor cell markers and metabolic pathways: high-risk tumors were characterized by up-regulated nuclear factor, erythroid 2-like 2 activity; high lin-28 homolog B, high mobility group AT-hook 2, spalt-like transcription factor 4, and alpha-fetoprotein expression; and high coordinated expression of oncofetal proteins and stem-cell markers, while low-risk tumors had low lin-28 homolog B and lethal-7 expression and high hepatic nuclear factor 1 alpha activity. Conclusion: Analysis of immunohistochemical assays using antibodies targeting these genes in a prospective study of 35 HBs suggested that these candidate biomarkers have the potential to improve risk stratification and guide treatment decisions for HB patients at diagnosis; our results pave the way for clinical collaborative studies to validate candidate biomarkers and test their potential to improve outcome for HB patients. (HEPATOLOGY 2017;65:104-121).H epatoblastoma (HB) is the most common pediatric liver tumor. It has an annual incidence rate of approximately 1.8 diagnosed cases per million in the United States, and this rate is increasing at more than 4.3% annually.(1) HBs are embryonal neoplasms that are most commonly diagnosed during the first 3 years of life. They are believed to arise from hepatic cell precursors and are characterized by heterogeneous histological patterns reminiscent of liver developmental stages.(2) Therapeutic strategies combining surgical resection and chemotherapy have improved outcomes for children with HB, but the prognosis for patients with advanced or chemotherapy-refractory disease remains poor.(1) In addition, the most effective platinum-based agents for treatment of HB often lead to serious long-term adverse effects, including ototoxicity and nephrotoxicity.(1)We describe the results of a comprehensive genomic analysis of the largest set of clinically annotated HBs reported to date. Such efforts have previously identified

We are developing a novel treatment for high-grade gliomas using near infrared-absorbing silica–gold nanoshells that are thermally activated upon exposure to a near infrared laser, thereby irreversibly damaging cancerous cells. The goal of this work was to determine the efficacy of nanoshell-mediated photothermal therapy in vivo in murine xenograft models. Tumors were induced in male Icr-Tac:ICR-PrkdcSCID mice by subcutaneous implantation of Firefly Luciferase-labeled U373 human glioma cells and biodistribution and survival studies were performed. To evaluate nanoparticle biodistribution, nanoshells were delivered intravenously to tumor-bearing mice and after 6, 24, or 48 h the tumor, liver, spleen, brain, muscle, and blood were assessed for gold content by inductively coupled plasma-mass spectrometry (ICP-MS) and histology. Nanoshell concentrations in the tumor increased for the first 24 h and stabilized thereafter. Treatment efficacy was evaluated by delivering saline or nanoshells intravenously and externally irradiating tumors with a near infrared laser 24 h post-injection. Success of treatment was assessed by monitoring tumor size, tumor luminescence, and survival time of the mice following laser irradiation. There was a significant improvement in survival for the nanoshell treatment group versus the control (P < 0.02) and 57% of the mice in the nanoshell treatment group remained tumor free at the end of the 90-day study period. By comparison, none of the mice in the control group survived beyond 24 days and mean survival was only 13.3 days. The results of these studies suggest that nanoshell-mediated photothermal therapy represents a promising novel treatment strategy for malignant glioma.

Purpose: A phase1study to determine the maximum-tolerated dose, dose-limiting toxicity, pharmacokinetics, and biological effects of bortezomib in children with recurrent/refractory leukemia. Experimental Design: Bortezomib was administered twice weekly for 2 consecutive weeks at either 1.3 or 1.7 mg/m 2 dose followed by a 1-week rest. Bortezomib pharmacokinetics and nuclear factor nB (NF-nB) binding activity were evaluated during the first treatment cycle. Results:Twelve patients (nine with acute lymphoblastic leukemia, three with acute myelogenous leukemia), median age 11years (range, 1-18 years), were enrolled between May 2004 and November 2005, of whom seven were not fully evaluable for toxicity due to rapidly progressive disease or uncontrolled infection. Dose-limiting toxicities occurred in two patients at the 1.7 mg/m 2 dose level. One patient experienced grade 3 confusion and the other patient had grade 4 febrile neutropenia associated with grade 4 hypotension and grade 3 creatinine. Pharmacokinetic analysis at 1.3 mg/m 2 revealed a clearance of 11 mL/h/m 2 , a central volume of distribution of 6.7 L/m 2 , and a terminal half-life of 12.6 h. NF-nB activity was examined in five patients and was noted to transiently increase and then decrease 4-to 6-fold by 24 h following bortezomib in two patients. There were no objective clinical responses. Conclusions: For children with leukemia, the recommended phase 2 dose of bortezomib, administered twice weekly for 2 weeks followed by a 1-week rest, is 1.3 mg/m 2

We are developing a novel approach to specifically target malignant brain tumor cells for photothermal ablation using antibody-tagged, near infrared-absorbing gold-silica nanoshells, referred to as immunonanoshells. Once localized to tumor cells, these nanoshells are extremely efficient at absorbing near-infrared light and can generate sufficient heat to kill cancer cells upon exposure to laser light. In this study, we evaluated the efficacy of immunonanoshells in vitro against both medulloblastoma and high-grade glioma cell lines. We used an antibody against HER2 to target gold-silica nanoshells to medulloblastoma cells, since HER2 is frequently overexpressed in medulloblastoma. We show that treatment with HER2-targeted nanoshells, but not non-targeted nanoshells, followed by exposure to laser light, can induce cell death in the HER2-overexpressing medulloblastoma cell line Daoy.2, as well as the parental Daoy cell line, which expresses HER2 at a moderate level, but not in dermal fibroblasts that do not express HER2. In an analogous set of experiments, we conjugated gold-silica nanoshells to an antibody against interleukin-13 receptor-alpha 2 (IL13Ralpha2), an antigen that is frequently overexpressed in gliomas. We demonstrate that these immunonanoshells are capable of inducing cell death in two high-grade glioma cell lines that express IL13Ralpha2, U373 and U87, but not in A431 epidermoid carcinoma cells that do not express significant levels of IL13Ralpha2. We believe that the use of antibody-tagged gold-silica nanoshells to selectively target cancer cells presents a promising new strategy for the treatment of central nervous system tumors that will minimize the damage and resulting toxicity to the surrounding normal brain.

Doxorubicinol clearance is decreased in children with >30% body fat. This finding is potentially important clinically, because doxorubicinol may contribute significantly to cardiac toxicity after doxorubicin administration. Further study of the body composition on doxorubicin and doxorubicinol pharmacokinetics and on clinical outcomes is warranted.

Aim To develop nanoshells for vascular-targeted photothermal therapy of glioma. Materials & methods The ability of nanoshells conjugated to VEGF and/or poly(ethylene glycol) (PEG) to thermally ablate VEGF receptor-2 positive endothelial cells upon near-infrared laser irradiation was evaluated in vitro. Subsequent in vivo studies evaluated therapy in mice bearing intracerebral glioma tumors by exposing tumors to near-infrared light after systemically delivering saline, PEG-coated nanoshells, or VEGF-coated nanoshells. The treatment effect was monitored with intravital microscopy and histology. Results VEGF-coated but not PEG-coated nanoshells bound VEGF receptor-2 positive cells in vitro to enable targeted photothermal ablation. In vivo, VEGF targeting doubled the proportion of nanoshells bound to tumor vessels and vasculature was disrupted following laser exposure. Vessels were not disrupted in mice that received saline. The normal brain was unharmed in all treatment and control mice. Conclusion Nanoshell therapy can induce vascular disruption in glioma.

Background & Aims Pediatric liver cancer is a rare but serious disease whose incidence is rising, and for which the therapeutic options are limited. Development of more targeted, less toxic therapies is hindered by the lack of an experimental animal model that captures the heterogeneity and metastatic capability of these tumors. Methods Here we established an orthotopic engraftment technique to model a series of patient-derived tumor xenograft (PDTX) from pediatric liver cancers of all major histologic subtypes: hepatoblastoma, hepatocellular cancer and hepatocellular malignant neoplasm. We utilized standard (immuno) staining methods for histological characterization, RNA sequencing for gene expression profiling and genome sequencing for identification of druggable targets. We also adapted stem cell culturing techniques to derive two new pediatric cancer cell lines from the xenografted mice. Results The patient-derived tumor xenografts recapitulated the histologic, genetic, and biological characteristics—including the metastatic behavior—of the corresponding primary tumors. Furthermore, the gene expression profiles of the two new liver cancer cell lines closely resemble those of the primary tumors. Targeted therapy of PDTX from an aggressive hepatocellular malignant neoplasm with the MEK1 inhibitor trametinib and pan-class I PI3 kinase inhibitor NVP-BKM120 resulted in significant growth inhibition, thus confirming this PDTX model as a valuable tool to study tumor biology and patient-specific therapeutic responses. Conclusions The novel metastatic xenograft model and the isogenic xenograft-derived cell lines described in this study provide reliable tools for developing mutation- and patient-specific therapies for pediatric liver cancer. Lay summary Pediatric liver cancer is a rare but serious disease and no experimental animalmodel currently captures the complexity and metastatic capability of these tumors. We have established a novel animal model using human tumor tissue that recapitulates the genetic and biological characteristics of this cancer. We demonstrate that our patient-derived animal model, as well as two new cell lines, are useful tools for experimental therapies.

A four-compartment NONMEM(®) model for doxorubicin and doxorubicinol adequately described the plasma concentrations in adults and children (>3 years). No pronounced effects of age on the clearance of doxorubicin or doxorubicinol were found, and the analysis did not support the modification of the dosing strategies presently used in children and adults.