INTRODUÇÃO: A relevância da expressão MYCN em neuroblastomas sem amplificação, diferentemente do seu aumento quando amplificado, permanece controverso. Neste trabalho, avaliou-se a relação do nível de expressão do transcrito MYCN em neuroblastoma não amplificado com os fatores clínicos e biológicos de prognóstico. MÉTODOS: Neste estudo observacional realizado entre janeiro de 2000 e dezembro de 2004, foram aferidos os valores do nível de expressão MYCN em 29 amostras tumorais, pela técnica RQ-PCR, no Laboratório de Biologia Tumoral da Fundação Pró-Sangue de São Paulo. Seus resultados foram analisados em relação à idade ao diagnóstico, ao estadiamento tumoral, ao grupo de risco, à ocorrência de recaída tumoral e de óbito. RESULTADOS: Foram nove crianças com idade 1 ano, os valores da expressão do transcrito MYCN variaram de 0,041 e 27,569, mediana 3,193. O estadiamento foi: quatro estádio 1; três estádio 2; oito estádio 3 e 14 crianças estádio 4. Entre 20 crianças com classificação patológica, 11 foram favoráveis e nove desfavoráveis. Considerando a mediana dos valores expressos a estratificação em grupos de risco com aumento da expressão foram: cinco crianças baixo risco; quatro risco intermediário e cinco alto risco. Grupos de risco sem aumento da expressão foram: duas crianças baixo risco; quatro risco intermediário e nove alto risco. Vinte e oito crianças obtiveram remissão completa e entre elas 14 apresentaram doença progressiva, sendo que sete morreram. As variáveis clínicas e biológicas não apresentaram freqüências diferentes entre os grupos de risco sem e com aumento de expressão. Entre os grupo alto risco e não alto-risco as variáveis idade, recaída tumoral e óbito apresentaram resultado com significado estatístico quando não se considerou o valor da expressão e quando não houve o seu aumento. Entre os grupos alto risco e nãoalto risco com aumento da expressão apenas a idade apresentou resultado com significado estatístico. CONCLUSÃO: Em crianças com estádio clínico não avançado o nível de expressão parece exercer uma relevância clínica, sugerindo um efeito protetor quanto menor for o aumento da expressão MYCN. / INTRODUTION: MYCN expression value in non-amplified neuroblastosmas remains a controversial issue. In order to add contributions to this field, children with nonamplified neuroblastomas were studied regarding their expression and correlation with clinical and other biological factors. METHODS: Twenty nine tumor samples obtained from non-consecutive patients admitted from January, 2000 through December, 2004, had their MYCN transcript expression levels evaluated according to the RQ-PCR assay, at the Tumoral Biology of Laboratory of the \"Fundação Pró -Sangue Hemocentro de São Paulo\", and compared to the following other factor: age at onset; tumor stage; risk - group; tumoral relapse rate and death. RESULTS: nine under one-year-old children and 20 over one-year-old children, with MYCN transcription expression level between 0.041 and 27.569, mean 3.193. Four children were stage 1, three were stage 2, stage 3 in eight and stage 4 in 14 children. In 20 patients with pathological classifications, 11 were favorable and nine unfavorable histology. Children whose expression level was above the mean were stratified as follows according to risk groups: five low-risk; four intermediate-risk and five high-risk patients. The ones whose expression level was under the mean were two low-risk, four intermediate-risk end nine high-risk patients. Twenty eight children achieved complete remission, with 14 recurrences, with seven deaths. The only factor associated to highly expressed MYCN patients was tumoral state. CONCLUSION: In children with non-advanced-stage disease low levels of expression might be a relevant favorable prognostic factor.

INTRODUÇÃO: A relevância da expressão MYCN em neuroblastomas sem amplificação, diferentemente do seu aumento quando amplificado, permanece controverso. Neste trabalho, avaliou-se a relação do nível de expressão do transcrito MYCN em neuroblastoma não amplificado com os fatores clínicos e biológicos de prognóstico. MÉTODOS: Neste estudo observacional realizado entre janeiro de 2000 e dezembro de 2004, foram aferidos os valores do nível de expressão MYCN em 29 amostras tumorais, pela técnica RQ-PCR, no Laboratório de Biologia Tumoral da Fundação Pró-Sangue de São Paulo. Seus resultados foram analisados em relação à idade ao diagnóstico, ao estadiamento tumoral, ao grupo de risco, à ocorrência de recaída tumoral e de óbito. RESULTADOS: Foram nove crianças com idade 1 ano, os valores da expressão do transcrito MYCN variaram de 0,041 e 27,569, mediana 3,193. O estadiamento foi: quatro estádio 1; três estádio 2; oito estádio 3 e 14 crianças estádio 4. Entre 20 crianças com classificação patológica, 11 foram favoráveis e nove desfavoráveis. Considerando a mediana dos valores expressos a estratificação em grupos de risco com aumento da expressão foram: cinco crianças baixo risco; quatro risco intermediário e cinco alto risco. Grupos de risco sem aumento da expressão foram: duas crianças baixo risco; quatro risco intermediário e nove alto risco. Vinte e oito crianças obtiveram remissão completa e entre elas 14 apresentaram doença progressiva, sendo que sete morreram. As variáveis clínicas e biológicas não apresentaram freqüências diferentes entre os grupos de risco sem e com aumento de expressão. Entre os grupo alto risco e não alto-risco as variáveis idade, recaída tumoral e óbito apresentaram resultado com significado estatístico quando não se considerou o valor da expressão e quando não houve o seu aumento. Entre os grupos alto risco e nãoalto risco com aumento da expressão apenas a idade apresentou resultado com significado estatístico. CONCLUSÃO: Em crianças com estádio clínico não avançado o nível de expressão parece exercer uma relevância clínica, sugerindo um efeito protetor quanto menor for o aumento da expressão MYCN. / INTRODUTION: MYCN expression value in non-amplified neuroblastosmas remains a controversial issue. In order to add contributions to this field, children with nonamplified neuroblastomas were studied regarding their expression and correlation with clinical and other biological factors. METHODS: Twenty nine tumor samples obtained from non-consecutive patients admitted from January, 2000 through December, 2004, had their MYCN transcript expression levels evaluated according to the RQ-PCR assay, at the Tumoral Biology of Laboratory of the \"Fundação Pró -Sangue Hemocentro de São Paulo\", and compared to the following other factor: age at onset; tumor stage; risk - group; tumoral relapse rate and death. RESULTS: nine under one-year-old children and 20 over one-year-old children, with MYCN transcription expression level between 0.041 and 27.569, mean 3.193. Four children were stage 1, three were stage 2, stage 3 in eight and stage 4 in 14 children. In 20 patients with pathological classifications, 11 were favorable and nine unfavorable histology. Children whose expression level was above the mean were stratified as follows according to risk groups: five low-risk; four intermediate-risk and five high-risk patients. The ones whose expression level was under the mean were two low-risk, four intermediate-risk end nine high-risk patients. Twenty eight children achieved complete remission, with 14 recurrences, with seven deaths. The only factor associated to highly expressed MYCN patients was tumoral state. CONCLUSION: In children with non-advanced-stage disease low levels of expression might be a relevant favorable prognostic factor.

Mais estudos sobre ações neuromoduladoras das angiotensinas no Sistema Renina Angiotensina (SRA) poderiam melhorar a compreensão de muitas funções e distúrbios do sistema nervoso central. A via de sinalização de PTEN/PI3K/AKT/mTOR que pode ser ativada pela Angiotensina-(1-7) desempenha um papel essencial na regulação do crescimento, metabolismo e sobrevivência das células. Este estudo teve como objetivo identificar e descrever a(s) via(s) metabólica(s) angiotensinérgica(s) principal(is) no hipocampo de camundongos (Mus musculus); Estudar a regulação da cascata de sinalização PTEN/PI3K/Akt/mTOR a partir da ativação com a Ang-(1-7) e realizar ensaios de inibição com o antagonista do receptor Mas. Analisamos também a expressão das enzimas chave da cascata de mTOR, com foco na enzima PTEN. Inicialmente foi realizada a identificação da via metabólica angiotensinérgica no hipocampo de camundongos através do estudo da atividade proteolítica angiotensinérgica com o extrato hipocampal de camundongos Swiss para identificar as enzimas e peptídeos formados a partir de AngI e/ou inibidores em HPLC. Para o estudo da regulação da cascata de sinalização PTEN/PI3K/Akt/mTOR a partir da ativação/inibição do SRA os experimentos foram realizados em células imortalizadas de neuroblastoma denominadas SH-SY5Y e western blotting para determinação dos níveis de PTEN e S6k (total e fosforilada). Nossos resultados mostraram que a caracterização do perfil do sistema angiotensinérgico hipocampal gerou resultados preliminares, em que a partir de AngI, o principal peptídeo formado foi a Ang-(1-7) e, em menor quantidade, a Ang II. Concluímos então que a AngII pode estar sendo formada por carboxipeptidades de forma geral e a Ang-(1-7) pode estar sendo formada por endopeptidases. Além disso, a Ang-(1-7) provoca a diminuição da expressão da PTEN total, bem como, a diminuição da fosforilação da PTEN, e nesse caso, a diminuição da fosforilação significa geração de mais proteína desfosforilada e aumento da atividade fosfatase resultando em efeitos neuroprotetores. Esses resultados nos permitiram observar que em células SH-S5SY, o mecanismo pelo qual a Ang-(1-7) ativa mecanismos neuroprotetores pode estar relacionado com a ativação da enzima PTEN. / Further studies on neuromodulatory actions of angiotensins in the Renin Angiotensin System (RAS) could improve understanding of many central nervous system functions and disorders. The PTEN/PI3K/AKT/mTOR signaling pathway that can be activated by Angiotensin-(1-7) plays an essential role in regulating cell growth, metabolism and survival. The aim of this study was to identify and describe the main angiotensinergic metabolic pathway(s) in the hippocampus of mice (Mus musculus); Study the regulation of the PTEN/PI3K/Akt/mTOR signaling cascade from activation with Ang-(1-7) and perform inhibition assays with the Mas receptor antagonist. We also analyzed the expression of the key enzymes of the mTOR cascade, focusing on the enzyme PTEN. Identification was initially performed of the angiotensinergic metabolic pathway in the mouse hippocampus was performed by studying the angiotensinergic proteolytic activity with the hippocampal extract of Swiss mice to identify the enzymes and peptides formed from AngI and/or inhibitors in HPLC. For the study of PTEN/PI3K/Akt/mTOR signaling cascade regulation from the activation/inhibition of RAS the experiments were performed on immortalized neuroblastoma cells called SH-SY5Y and western blotting for determination of PTEN and S6k levels (total and phosphorylated). Our results showed that the characterization of the profile of the hippocampal angiotensinergic system generated preliminary results, in which from AngI, the main peptide formed was Ang-(1-7) and, to a lesser extent, Ang II. We conclude that AngII may be formed by carboxypeptids in general and Ang-(1-7) may be formed by endopeptidases. In addition, Ang-(1-7) causes a decrease in total PTEN expression, as well as a decrease in PTEN phosphorylation, in which case the decrease in phosphorylation means generation of more dephosphorylated protein and increased phosphatase activity resulting In neuroprotective effects. These results allowed us to observe that in SH-S5SY cells, the mechanism by which Ang-(1-7) activates neuroprotective mechanisms may be related to the activation of the PTEN enzyme. / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq

Glioblastoma (GBM) is the most common and aggressive type of brain cancer, with an average life expectancy of 15 months. The standard of care for GBM, surgery accompanied by radiation and chemotherapy (temozolomide-TMZ), has not changed in over 10 years illustrating the need for new and efficacious treatments. Therefore, it is imperative to improve our knowledge of GBM physiology to understand the mechanisms driving recurrence and chemoresistance so that more effective therapeutic options can be developed. Mitochondria-cell communication is key to monitor and maintain both mitochondrial and cellular health, and signaling events on the outer mitochondrial membrane (OMM) have emerged as a crucial signal integration site for cellular responses. Consequently, proteins on the OMM are crucial to determining cellular survival and dictating organelle physiology. Thus, the goal of our current study is to evaluate OMM proteins to determine how alterations in organelle regulation may impact CNS tumor biology. We first measured the concentrations of Bcl-2 family proteins on mitochondria from ten continuous GBM cell lines and correlated the protein levels to IC50values of genotoxic agents TMZ and irinotecan. We found that Bcl-2 levels corresponded to chemoresistance, while increased Bim concentrations promoted chemosensitivity. In contrast to our studies in gynecological cancers, the concentrations of the pro-dysfunction OMM scaffold protein Sab had no impact on chemosensitivity of the GBM cell lines, despite diminished Sab expression in GBM patients. However, we identified a novel truncated variant of Sab in the GBM cell lines. We found that GBM cells expressing only full-length Sab had a slower proliferation rate than those with the variant, which could be attributed to increased glycolysis in GBM cells expressing the Sab variant. To determine if the lack of Sab-mediated apoptosis was consistent across CNS tumors, we analyzed publicly-available patient data and found that Sab expression is down-regulated in neuroblastoma patients, a pediatric malignancy responsible for 12% of childhood cancer deaths. We found that that inhibiting Sab-mediated signaling in human neuroblastoma (SH-SY5Y cells) enhanced oxidative phosphorylation in a pyruvate dehydrogenase-dependent manner, increased BCl-2 levels (pro-survival), decreased Bim concentrations (pro-apoptotic), and promoted chemoresistance. Furthermore, examination of additional neuroblastoma cells derived from CNS tumors revealed that Sab levels correspond to proliferation rate, metabolic phenotype, and chemosensitivity. Our studies demonstrate the importance of OMM signaling in CNS tumor physiology and emphasizes the importance of cellular context to the outcomes of OMM signaling events.

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Neuroblastoma, the most common extracranial solid tumor of childhood, is a heterogeneous tumor. In some patients, the tumor can go into spontaneous regression and disappear whereas other patients have rapidly growing tumors with a poor prognosis. The overall long-term survival rate in patients with high-risk neuroblastoma is less than 30%, indicating the need for new treatment strategies. Angiogenesis inhibition hampers the formation of new blood vessels, thereby limiting the tumors’ metabolic exchange. Neuroblastoma is rapidly growing and high tumor angiogenesis has been associated with poor outcome. Therefore, the aim of this thesis was to investigate the effect of novel treatment modalities for angiogenesis inhibition on high-risk neuroblastoma xenografts. For that purpose, we used subcutaneous mouse models and characterized orthotopic mouse models for high-risk neuroblastoma. We found that xenotransplantation of neuroblastoma cells into the adrenal gland of SCID and SCID beige mice resulted in orthotopic tumors resembling clinical neuroblastoma in respect to tumor site, growth and spread. Using contrast-enhanced ultrasound, we observed that the receptor tyrosine kinase inhibitor SU11248 reduced orthotopic neuroblastoma growth and spread by reducing tumor angiogenesis. In subcutaneous xenografts for high-risk neuroblastoma, valuable for studies requiring continuous assessment of tumor volume, we demonstrated that immune-neutralizing VEGF with the anti-VEGF antibody bevacizumab significantly reduced neuroblastoma growth. Finally, we found that formulations of the chemotherapeutic drug GMX1778 inhibited angiogenesis and induced tumor regression in a dose dependent manner without host toxicity. We showed that relapsing tumors remained responsive to GMX-therapy without accelerated growth or induced drug resistance. In conclusion, SU11248, bevacizumab, and formulations of the active compound GMX1778 may become useful for treating high-risk neuroblastoma.

L'objectiu d'aquesta tesi ha estat buscar nous agents inductors de diferenciació, aturada del cicle cel·lular o mort cel·lular, per a les cèl·lules de neuroblastoma humà, més eficaços i més selectius que els fàrmacs utilitzats en la teràpia actual. Amb aquesta finalitat, hem estudiat l'efecte ex vivo en diferents línies cel·lulars de neuroblastoma humà de dos compostos, el pigment bacterià prodigiosina, i l'inhibidor general d'histona desacetilases de classe I/II tricostatina A. La PG ha mostrat tenir un efecte citotòxic i citostàtic en les línies de neuroblastoma. Indueix mort cel·lular per mecanismes apoptòtics dependents de caspases, i especialment en les cèl·lules de neuroblastoma tipus N, les fenotípicament més agressives. No obstant la inhibició de l'activació de les caspases no reverteix complertament la mort cel·lular, indicant la implicació d'altres mecanismes de mort cel·lular en el procés desencadenat per PG. L'aturada de la proliferació cel·lular és en canvi molt més acusada en les cèl·lules tipus S, tot i que és un fenomen observat en totes les cèl·lules estudiades. A més a més, en el present treball hem descrit com la PG, després de la seva entrada per difusió en la cèl·lula, s'acumula especialment en els mitocondris, induint un efecte desacoblant entre la cadena respiratòria i l'activitat de l'ATPasa-F0-F1 mitocondrial de les cèl·lules de neuroblastoma. Com a resultat, la producció d'ATP es veu disminuïda notablement però la taxa de consum d'oxigen no s'altera. Nosaltres suggerim que l'explicació a aquest fet podria trobar-se en l'habilitat que té la PG per a atrapar protons a pH fisiològic, modificant així els gradients de pH intracel·lulars, no tant sols els vesiculars i els lisosomals, si no també molt possiblement els intramitocondrials. Al capítol dos es descriuen els resultats de l'estudi del tractament de les cèl·lules de neuroblastoma amb TSA. El TSA indueix una aturada del cicle cel·lular en G2/M i apoptosi, però també autofàgia, procés fins al moment no descrit en aquestes cèl·lules com a resposta a l'exposició a HDIs, no havent-se observat diferències en aquests efectes entre les cèl·lules neuroblàstiques tipus N, S i I. En concordança amb estudis previs, la disminució de la proliferació i l'aturada en G2/M ha resultat ser conseqüència d'un procés independent de les caspases. Probablement associat a l'augment d'expressió de l'inhibidor de CDKs p21WAF/Cip1 i a l'activació de la via supressora de tumors del RB, tal i com suggereix la disminució de l'expressió de N-Myc, E2F-1 i Survivina, tots ells implicats en aquesta via, i a més a més marcadors de mal pronòstic en el neuroblastoma. Podent ser la disminució de la Survivina responsable per si sola del desencadenament de l'apoptosi. No obstant, l'efecte del TSA no ha estat el mateix en totes les línies cel·lulars de neuroblastoma estudiades, sent les cèl·lules SK-N-AS les més resistents. En aquestes cèl·lules, tot i activar-se els mateixos mecanismes que en la resta de cèl·lules estudiades, la disminució de la viabilitat és molt reduïda i, a les dosis utilitzades, sembla prevaldre un efecte citostàtic. És més, mentre en les cèl·lules LA1-55N, SK-N-JD i LA1-5S, apoptosi i autofàgia semblen estar induint-se simultàniament i col·laborar en la mort cel·lular induïda pel TSA, en les SK-N-AS els resultats suggereixen que aquests dos mecanismes tenen finalitats antagòniques, de manera que l'autofàgia promou la supervivència cel·lular. Així doncs, els resultats obtinguts indiquen que els dos compostos són capaços d'induir una disminució de la viabilitat cel·lular deguda a una aturada de la proliferació i/o a la mort cel·lular. A més a més, els resultats de l'exposició de les cèl·lules als dos compostos són prou diferents als produïts pels anticancerígens convencionals, com per considerar-se el seu assaig en diferents combinacions amb altres quimioteràpics. / "Characterization of cell death in human neuroblastoma cell lines."TEXT:The objective of this thesis was to look for new agents capable to induce differentiation, cell cycle arrest or cell death in neuroblastoma human cells, more efficient and selective than the ones use in actual therapy. With this purpose, we have studied the ex vivo effect of two compounds in different human neuroblastoma cell lines, the red pigment prodigiosin, and trichostatin A, a general inhibitor of histone deacetylases of class I/II. Prodigiosin showed a cytotoxic and cytostatic effect in neuroblastoma cells. It induced cell death through caspase-dependent apoptotic mechanisms, especially in N-type neuroblastoma cells, the more aggressive ones. We suggest this effect could be explained by prodigiosin ability to capture protons at physiologic pH, modifying the intracellular pH gradients.At the second chapter we described the effect of trichostatin A in this cell model. Trichostatin-A induces a G2/M-cycle arrest, apoptosis and authopagy in the three types of neuroblastoma cells, N-, I- and S-type. However, not all the cells exhibited the same sensibility, being the SK-N-AS cells the more resistant to this compound. Moreover, while in LA1-55N, SK-N-JD and LA1-5S cells apoptosis and autophagy seem to be induced simultaneously and to collaborate in TSA-induced cell death, in SK-N-AS cells these two mechanisms seem to have antagonic purposes, leading autophagy to cell survival.In conclusion, the results indicate that these two agents are able to induce a decrease in cell viability because of cell-cycle arrest and/or cell death. Furthermore, the consequences of the exposition of the cells to these compounds are different enough to the obtained by conventional therapy, to consider its assay with different combinations of other chemotherapy agents.

Neuroblastoma is one of the most aggressive cancers and has a complex form of differentiation. We hypothesized that the advanced cellular differentiation may alter the susceptibility of neuroblastoma to photodynamic therapy (PDT) and have a selective survival advantage. We compared the photocytotoxicity treated by Hematoporphyrin (Hp) for PDT on human neuroblastoma SH-SY5Y cells with retinoic acid (RA)-differentiated SH-SY5Y cells. The undifferentiated neuroblastoma cells were shown to cause elevated photocytotoxic effect by MTT assay and also confirmed by Annexin V-FITC/PI staining. In undifferentiated cells, Hp-PDT increased the generation of intracellular reactive oxygen species (ROS), the loss of mitochondrial membrane potential, characteristic chromatin condensation displaying, PARP cleavage, the downregulated expression of Bcl-2, and the activation of caspase-9, -3 was more significant than that of the differentiated cells. In undifferentiated SH-SY5Y cells, cell cycle arrest at G2/M phase was accompanied by the decrease in cyclin B1 level, and could be reversed by the disruption of intracellular ROS caused by PDT. Furthermore, the ROS scavenger markedly inhibited Hp-PDT induced activation of caspase-3, a sustained phosphorylation of Akt/GSK-3£] and ERK, and cytotoxicity in undifferentiated SH-SY5Y cells, but not in differentiated SH-SY5Y cells. Blockage of p38 and JNK activation can significantly attenuate PDT-induced viability loss in both SH-SY5Y cells, but the less significant activation of p38 and JNK, as well as more significant phosphorylation of Akt and GSK-3£], and a prolonged ERK activation appeared to make differentiated SH-SY5Y cells more resistant to photocytotoxicity. Collectively, these data suggested that differentiated SH-SY5Y cells were more resistant to PDT induced apoptosis than undifferentiated SH-SY5Y cells, and ROS played the most important regulatory role on the susceptibility to Hp-PDT between undifferentiated and differentiated neuroblastoma cells. These results may have important implications for neuroblastoma patients undergoing PDT.

No description available.

<p>Growth factors and their receptors coordinate neuronal differentiation during development, yet their roles in the embyronal tumor neuroblastoma, where differentiation is a validated treatment strategy, remain unclear. The neuroblastoma tumor stroma is thought to suppress neuroblast growth via release of soluble differentiating factors. Here we identify critical components of the differentiating stroma secretome and describe preclinical testing of a novel therapeutic strategy based on their mechanism of action.</p><p>Expression of heparan sulfate proteoglycans (HSPGs), including T&#946;RIII, GPC1, GPC3, SDC3, and SDC4, is decreased in neuroblastoma, high in the stroma, and suppresses tumor growth. High expression of T&#946;RIII, GPC1, and SDC3 is associated with improved patient prognosis. HSPGs signal via heparan sulfate binding to FGFR1 and FGF2, which leads to phosphorylation of FGFR1 and Erk MAPK, and upregulation of the transcription factor inhibitor of DNA binding 1 (Id1). Surface expression and treatment with soluble HSPGs promotes neuroblast differentiation via this signaling complex. Expression of individual HSPGs positively correlates with Id1 expression in neuroblastoma patient samples and multivariate regression demonstrates that expression of HSPGs as a group positively correlates with Id1 expression, underscoring the clinical relevance of this pathway. HSPGs also enhance differentiation from FGF2 released by the stroma and FGF2 is identified as a potential serum prognostic biomarker in neuroblastoma patients. </p><p>The anticoagulant heparin has similar differentiating effects to HSPGs, decreasing neuroblast proliferation and reducing tumor growth while extending survival in an orthotopic xenograft model of neuroblastoma. Dissection of individual sulfation sites identifies 2-O-, 3-O-de-sulfated heparin (ODSH) as a differentiating agent that suppresses orthotopic xenograft growth and metastasis in two models while avoiding anticoagulation. These studies form the preclinical rationale for a multicenter clinical trial currently being proposed.</p><p>In conclusion, these studies translate mechanistic insights in neuroblast HSPG function to identify heparins as differentiating agents for clinical development in neuroblastoma, while demonstrating that tumor stroma biology can inform design of targeted molecular therapeutics.</p> / Dissertation