bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A41: Complementary genomic approaches highlight the PI3K/mTOR pathway as a common vulnerability in osteosarcoma
Authors: Kiezun Adam , Perry Jennifer , Tonzi Peter , Allen Eliezer Van , Carter Scott L. , Baca Sylvan , Bhatt Ami , Lawrence Michael , Walensky Loren , Wagle Nikhil , Mora Jaume , deTorres Carmen , Lavarino Cinzia , Velasco-Hidalgo Liliana , Cardenas-Cardos Rocio , Aguiar Simone dos Santos , Yunes Jose A. , Mercado Gabriela , Melendez-Zajgla Jorge , Roberts Charles , Garraway Levi , Rodriguez-Galindo Carlos , Golub Todd , Orkin Stuart , Getz Gad , Janeway Katherine
Published: May 2015

Osteosarcoma is the most common primary bone tumor and yet there have been no substantial advances in treatment or survival in over 2 decades. We examined 59 tumor/normal pairs by whole-genome, whole-exome and RNA-Sequencing. Only TP53 was mutated at significant frequency across the 59 samples. The mean non-silent somatic mutation rate was 1.2 mutation per megabase and there were a median of 231 somatic rearrangements per tumor. Complex chains of rearrangements and localized hypermutation were detected in almost all cases. Given the inter-tumor heterogeneity, the extent of genomic instability and the difficulty in acquiring a large sample size in a rare tumor we used several methods to identify genomic events contributing to osteosarcoma proliferation and survival. Pathway analysis, a heuristic analytic algorithm, a comparative oncology approach and a genome-wide, pooled short hairpin RNA (shRNA) screen all point to the PI3K/mTOR pathway as a potential central vulnerability for therapeutic exploitation in osteosarcoma. Osteosarcoma cell lines are responsive to pharmacologic and genetic inhibition of the PI3K/mTOR pathway both in vitro and in vivo.

Citation Format: Adam Kiezun, Jennifer Perry, Peter Tonzi, Eliezer Van Allen, Scott L. Carter, Sylvan Baca, Ami Bhatt, Michael Lawrence, Loren Walensky, Nikhil Wagle, Jaume Mora, Carmen deTorres, Cinzia Lavarino, Liliana Velasco-Hidalgo, Rocio Cardenas-Cardos, Simone dos Santos Aguiar, Jose A. Yunes, Gabriela Mercado, Jorge Melendez-Zajgla, Charles Roberts, Levi Garraway, Carlos Rodriguez-Galindo, Todd Golub, Stuart Orkin, Gad Getz, Katherine Janeway. Complementary genomic approaches highlight the PI3K/mTOR pathway as a common vulnerability in osteosarcoma. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr A41.
Abstract A42: miR34a: A valuable indicator of differential outcome of Ewing sarcoma patients with complex functions
Authors: Scotlandi Katia , Marino Maria Teresa , Grilli Andrea , Picci Piero , Carè Alessandra , Tripodo Claudio , Ferrari Stefano
Published: May 2015

The identification of reliable indicators of prognosis, which may allow the stratification of patients according to different risk at diagnosis isan important aspect of translational research in Ewing sarcoma (ES). In this paper, we validated our previous evidence showing how expression of miR34a in ES tumor samples at diagnosis was signficantly associated with tumor progression (Nakatani F. J Pathol 2012). Here we analyzed a different series of speciments derived from very controlled and homogeneously treated non-metastatic ES patients, and we compared evaluation of miR34a by RT-PCR using frozen samples with that obtained by in situ hybridization on paraffin-embedded samples . The median follow-up of the 109 EWS patients was 90 months (range 9 to 241 months). 68 patients (63%) remained continuously free of disease and 41 (38%) relapsed. Expression of miR34a was evaluated by qRT-PCR using TaqMan miRNA assay kit and/or by in situ hybridization ISH optimization kit from Exiqon. High expression of miR34a was significantly related to better EFS and OVS : 5-year EFS was 74% for the 55 patients with high expression of miR34a and was 51% for the 54 patients with low expression (p = 0.004); 5-year OVS was 83% in high-expressors and 58% in low-expressors . By multivariate Cox regression analysis, the value of low miR-34a expression as well as of non-total necrosis and high LDH were all confirmed as independent risk factors associated with poor outcome. miR34a was also evaluated by ISH on TMA. miRNA expression by ISH correlates with that obtained by RT-PCR (r=0.59, p<0.0001, Spearman test). Although not significant, high expression of miR34a evalutated on tissue microarray still shows an association with better outcome (p=0.19). Expression of miR34a inversely correlated with expression of cyclin D1 mRNA, as well as with Ki-67 labelling. In contrast positive association was observed with YY1, a transcription factor that regulates a dazzling list of genes and whose role in malignancy is complex and has just started to emerge. The value of miR34a as predictor was higher than that of these specific targets, indicating a more complex relationship with tumor malignancy.

Citation Format: Katia Scotlandi, Maria Teresa Marino, Andrea Grilli, Piero Picci, Alessandra Carè, Claudio Tripodo, Stefano Ferrari. miR34a: A valuable indicator of differential outcome of Ewing sarcoma patients with complex functions. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr A42.
Abstract A46: HSP-90 inhibition in pediatric sarcomas
Authors: Arnaldez Fernanda I. , Terwilliger Toby , Yeung Choh , Neckers Len , Helman Lee
Published: May 2015

Hsp90 is a molecular chaperone that regulates post-translational folding, stability, and function of many client proteins, which play critical roles in key signal transduction pathways implicated in cell growth, differentiation, and survival. Several relevant oncogenic proteins are described as clients, such as insulin growth factor receptor 1, AKT/PKB, and src-family kinases. Signaling through these molecules is critical in the biology of rhabdomyosarcoma and Ewing's sarcoma, which are two of the most common pediatric sarcomas. Novel therapies for these tumors are clearly needed since patients with relapsed and metastatic disease continue to have poor outcomes and multimodality therapy, even when successful, is often accompanied by long-term morbidity.

Ganetespib (Synta Pharmaceuticals) is a small molecule Hsp90 inhibitor that binds to the ATP pocket in the N-terminus of Hsp90, leading to down-regulation of Hsp90 client protein levels. We sought to evaluate the preclinical activity of ganetespib in a panel of Ewing's Sarcoma and rhabdomyosarcoma cell lines. We evaluated in vitro activity of ganetespib in Ewing Sarcoma cell lines (TC71, TC32, EW8, RDES) and in rhabdomyosarcoma (RMS) cell lines (RD, RH30) using kinetic proliferation assays and MTS. In all cases, marked inhibition of cell growth was achieved in a dose-dependent manner with drug IC50s in the low nanomolar range (3-6 nM). We found that ganetespib exposure is associated with both induction of apoptosis and alterations in cell cycle progression. In addition to upregulation of Hsp70, which is considered a biomarker of Hsp90 inhibition, ganetespib treatment was associated with loss of expression of IGF1R-beta as well as downregulation of key signaling pathways including mammalian target of rapamycin (mTOR), pAKT, and Src-family kinases, particularly YES1, a kinase we previously identified as critical in rhabdomyosarcoma biology. Moreover, we observed a cooperative effect between Hsp90 inhibition and IGF1R blockade with R1507, a monoclonal antibody targeting this receptor (Hoffman-La Roche). Furthermore, synergy was seen when ganetespib was combined with the SFK inhibitor dasatinib. While in-vivo validation of these results is ongoing, we conclude that Hsp90 inhibition with ganetespib is an attractive strategy to explore for the therapy of pediatric sarcomas, possibly in combination with other targeted therapies.

Citation Format: Fernanda I. Arnaldez, Toby Terwilliger, Choh Yeung, Len Neckers, Lee Helman. HSP-90 inhibition in pediatric sarcomas. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr A46.
Abstract A51: The HoxD locus: Its contribution to osteogenic phenotype and malignancy of Ewing sarcoma
Authors: Richter Guenther HS , Heyking Kristina von , Roth Laura , Ertl Miriam , Burdach Stefan
Published: May 2015

Ewing sarcoma (ES), an osteogenic malignancy that mainly affects children and young adults, is characterized by early metastasis to lung and bone. Microarray analysis revealed genes of the HoxD locus to be clearly over-expressed in primary ES. Especially, genes such as HOXD10, HOXD11 and HOXD13 normally involved in bone formation and ossification pattern of bones are significantly over-expressed in ES. The expression of HOXD10, HOXD11 or HOXD13 seems not to be influenced via ES pathognomonic ews/ets translocations, since RNA interference of EWS-FLI1 or its over-expression in mesenchymal stem cells did not influence HOXD expression. However, RNA knock down of DKK2, a canonical WNT/β-catenin agonist and critical mediator of osteolytic tumor growth in ES resulted in a significant suppression of HOXD11 and HOXD13 expression. Subsequently, RNA interference of individual HoxD genes demonstrated HOXD11 and HOXD13 to be critical for in vitro proliferation and contact independent growth of ES. Similarly, in vitro invasiveness of ES lines was dependent on HOXD10, HOXD11 as well as HOXD13 and seemed mediated via MMP1, since down-regulation of individual HoxD genes similarly resulted in a suppression of MMP1 expression. But, HoxD genes only marginally influenced the expression of osteogenic genes in ES nor did they promote its chondrogenic or osteogenic differentiation. Whether HOXD10, HOXD11 or HOXD13 expression further metastasis or contribute to osteolytic tumor growth is currently investigated in a xenograft model using Rag2-/-gammaC-/- mice and data will be presented.

Citation Format: Guenther HS Richter, Kristina von Heyking, Laura Roth, Miriam Ertl, Stefan Burdach. The HoxD locus: Its contribution to osteogenic phenotype and malignancy of Ewing sarcoma. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr A51.
Abstract A61: Dissecting the molecular basis of Ewing's sarcoma metastasis
Authors: Choo Sun , Yang Jing
Published: May 2015

Ewing's sarcoma family of tumors is a group of poorly differentiated malignant pediatric cancers of bone and soft tissue. About 25% of patients present with clinically detectable metastases. Despite aggressive therapy, little improvement has been seen in patients with metastatic disease due to the lack of understanding of the molecular pathways that regulate its spread. There has been immunohistologic and gene expression profiling analyses indicating a striking similarity between Ewing's sarcoma and fetal and neuronal tissues. We hypothesize that a group of genes that regulate a specialized group of embryonic stem cells (neural crest cells) are reactivated to allow Ewing's sarcoma cells to metastasize.

We examined primary human Ewing's sarcoma samples to detect the expression of one of those genes, the Twist1 transcription factor. Twenty Ewing's sarcoma samples were strongly positive for Ewing's sarcoma marker CD99, confirming the correct tumor type. Interestingly 88% (8/11) of metastatic Ewing's sarcoma patients had strong nuclear staining of Twist1 by immunohistochemistry (IHC). In contrast, only 17% (1/6) of non-metastatic tumor samples showed positive Twist1 signals, thus indicating that expression of Twist1 is tightly associated with metastasis in Ewing's sarcoma (P <0.05). Notably Twist1 positivity is also an independent prognostic marker for poor survival in this group of patients. 7 out of the 8 (88%) Twist1 positive patients died from disease versus only 2 out of 8 (25%) in the Twist1 negative patients (p < 0.05). In addition we explored PDGFRα as a possible target for therapy given that PDGFRα is a direct transcription target of Twist1. Indeed PDGFRα expression was significantly associated with Twist1 and also tightly linked to survival (P<0.05) in these patients.

In summary, these results suggest that reactivation of the neural crest migration program through Twist1 plays a critical role in promoting metastasis in Ewing's sarcoma. Functional studies on the role of Twist1 and PDGFRα in Ewing's sarcoma metastasis are ongoing and may lead to targeted therapies against this unique developmental pathway to combat Ewing's sarcoma metastasis.

Citation Format: Sun Choo, Jing Yang. Dissecting the molecular basis of Ewing's sarcoma metastasis. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr A61.
Abstract A84: Stereotactic injections of primary medulloblastomas as a representative model of the different subgroups for preclinical drug screening
Authors: Krona Cecilia , Dyberg Cecilia , Sandén Emma , Darabi Anna , Wickström Malin , Northcott Paul , Johnsen John Inge , Siesjö Peter
Published: May 2015

Established tumor cell lines are extensively used for screening of novel therapeutic compounds. However, during long-term culturing cells adjust to the conditions and acquire additional genetic aberrations, which may cause them to differ significantly from the original tumor. In vitro conditions may also fail to recapitulate aspects of the tumor microenvironment that may have an impact on cell fate, for example, drug clearance by the circulation, which would lead to renewed cell cycling and the heterogeneity of the tumor cell population versus the homogenous population of cells in culture. Predisposed genetic mouse models more closely recapitulate most aspects of human disease but they usually require complex breeding schemes and may suffer from incomplete tumor penetrance and a variable age of tumor onset.

In order to establish a new medulloblastoma model for therapeutic studies, we have acquired primary cultures of medulloblastoma tumors representing the four different subtypes of medulloblastomas (Wnt, Shh, group 3 and group 4). Cells were grown as neurospheres and characterized regarding stem cell markers and immunological status. Early passages were collected and for each primary line, two NOD scid mice were orthotopically injected with 20.000 and 200.000 cells, respectively. Mice were closely monitored for symptoms of brain tumor burden (weight loss, hunched posture, uncoordinated movement, lethargy, poor balance and/or paralysis) during six months.

Mice injected with cells from the SHH subgroup and group 3 medulloblastomas developed symptoms of brain tumors with a latency of 13-25 weeks. A positive correlation was observed between tumor latency and number of injected cells. Brains were collected and processed for histopathological confirmation of tumor prevalence, whole genome sequencing and gene expression analysis. Neurosphere cultures were also re-established to create a reproducible model for pre-clinical therapeutic trials on human medulloblastoma by serial orthotopic transplantation.

Citation Format: Cecilia Krona, Cecilia Dyberg, Emma Sandén, Anna Darabi, Malin Wickström, Paul Northcott, John Inge Johnsen, Peter Siesjö. Stereotactic injections of primary medulloblastomas as a representative model of the different subgroups for preclinical drug screening. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr A84.
Abstract B38: Whole exome sequencing of 101 neuroblastomas with distinct genomic subgroups identified significantly mutated pathways in aggressive tumor subtypes
Authors: Ohira Miki , Li Yuanyuan , Zhou Yong , Li Xiangchun , Gao Zhibo , Tatsuno Kenji , Tsutsumi Shuichi , Yamamoto Shogo , Nakamura Yohko , Kamijo Takehiko , Aburatani Hiroyuki , Nakagawara Akira
Published: May 2015

Neuroblastoma is known to exhibit wide ranges of clinical behavior, from spontaneous regression to highly resistant to chemotherapy. Previously, we have established the risk classification system based on the copy number profiles of the tumor determined by array CGH analysis. The two most major subclasses with aggressive phenotype are P1a (with partial chromosomal gains/losses, MYCN amplification, 1p loss and 17q gain, but no 11q loss) and P3s (with partial chromosomal gains/losses, 11q loss and 17q gain, but no 1p loss nor MYCN amplification), whose 8-year survival rates were 33% and 31%, respectively, in our database. On the other hand, Ss subgroup, categorized as few chromosomal gains/losses, showed favorable prognosis (8-year survival rate was 82%). To determine and compare the spectrum of genetic alterations in each tumor subtype, we have so far conducted whole-exome sequencing of 101 cases (P1a:17, P3s:44, Ss:20, others including metastasized or relapsed:20). On average, P1a and P3s subgroups had approximately 14 and 19 somatic alterations in coding genes, respectively, while Ss had very few alterations with only 1.2. Few recurrent non-silent mutations were found in all subgroups, however, pathway analysis by David with KEGG database indicated that a part of these novel somatic mutations were concentrated in cancer-related signaling pathways, such as those of MAPK (14 genes, adjusted p<0.001) and Wnt (7 genes, p<0.001), significantly in P1a subtype. Ongoing efforts will validate mutation candidates in a larger scale sample set by independent analysis platforms as well as the correlations with prognosis of each tumor subset.

Citation Format: Miki Ohira, Yuanyuan Li, Yong Zhou, Xiangchun Li, Zhibo Gao, Kenji Tatsuno, Shuichi Tsutsumi, Shogo Yamamoto, Yohko Nakamura, Takehiko Kamijo, Hiroyuki Aburatani, Akira Nakagawara. Whole exome sequencing of 101 neuroblastomas with distinct genomic subgroups identified significantly mutated pathways in aggressive tumor subtypes. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr B38.
Abstract B40: MYCN/MYC protein expression in high-MKI (Mitosis-Karyorrhexis Index) neuroblastomas: A report from the Children's Oncology Group
Authors: Wang Larry L. , Teshiba Risa , He Lejian , Naranjo Arlene , London Wendy B. , Gastier-Foster Julie M. , Seeger Robert C. , Cohn Susan L. , Maris John M. , Park Julie R. , Hogarty Michael D. , Shimada Hiroyuki
Published: May 2015

Background: In neuroblastoma (NB), Mitosis-Karyorrhexis Index (MKI; low-L, <100/5,000 cells; intermediate-I, 100-200/5,000 cells; high-H, >200/5,000 cells) is one of the histologic indicators for predicting a patient's clinical outcome. Event-Free Survival (EFS) and Overall Survival (OS) are significantly worse as MKI increases (p<0.0001): 3-year EFS for L-MKI (81.2+1.0%), I-MKI (68.6+1.8%), H-MKI (51.0+2.2%); and 3-year OS for L-MKI (92.0+0.7%), I-MKI (81.0+1.6%), H-MKI (64.4+2.1%). MYCN amplification (MYCN-A) is significantly associated with H-MKI, which indicates markedly increased mitotic (cellular proliferation) and karyorrhectic (cellular death) cells. However, about one-third of H-MKI tumors do not have MYCN-A.

Study design: A total of 4,712 NB cases reviewed by the Children's Oncology Group (COG) Neuroblastoma Pathology Reference Laboratory (Children's Hospital Los Angeles) between 06/18/2001 and 06/06/2013 included 2,595 L-MKI (3% with MYCN-A), 1,197 I-MKI (16% with MYCN-A), and 920 H-MKI (70% with MYCN-A) tumors. In this study, immunohistochemical detection of MYCN and MYC (C-myc) protein was performed on 82 H-MKI tumors (53 with MYCN-A and 29 without MYCN-A).

Results: 50/53 (94%) of H-MKI tumors having MYCN-A were positive for MYCN protein (including one case positive for both MYCN and MYC proteins), and only 3 cases were negative for both proteins immunohistochemically. Among the H-MKI tumors without MYCN-A, 16 cases (55%) showed positive staining for MYC protein, 6 cases (21%) were positive for MYCN protein, 2 cases (7%) were positive for both proteins, and 5 cases (17%) were negative for both proteins.

Conclusions: MYCN-A and subsequent MYCN protein expression are considered as the starting point for leading NB tumors to H-MKI status. However, when MYCN is not amplified, high mitotic/karyorrhectic (M/K) activities in NB tumors are often associated with MYC protein expression. Even some MYCN non-amplified tumors can express MYCN protein, which is associated with H-MKI. There is still a small group of H-MKI tumors whose increased M/K activities are not related to MYCN/MYC protein expression.

Citation Format: Larry L. Wang, Risa Teshiba, Lejian He, Arlene Naranjo, Wendy B. London, Julie M. Gastier-Foster, Robert C. Seeger, Susan L. Cohn, John M. Maris, Julie R. Park, Michael D. Hogarty, Hiroyuki Shimada. MYCN/MYC protein expression in high-MKI (Mitosis-Karyorrhexis Index) neuroblastomas: A report from the Children's Oncology Group. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr B40.
Abstract B59: Wild-type ALK and both ALK-R1275Q and ALK-F1174L activating mutations display a strong oncogenic activity in vivo in murine neural crest progenitor cells via cooperation with c-myc
Authors: Mühlethaler-Mottet Annick , Montavon Gisèle , Flahaut Marjorie , Jauquier Nicolas , Joseph Jean-Marc , Delattre Olivier , Sommer Lukas , Janoueix-Lerosey Isabelle , Gross Nicole
Published: May 2015

Neuroblastoma (NB), a neural crest-derived embryonal tumor, is a heterogeneous childhood malignancy that often presents as an incurable disease. The anaplastic lymphoma receptor tyrosine kinase gene (ALK) was shown to be overexpressed, mutated or amplified in the majority of NB. The most common mutation, ALK-F1174L displayed an efficient transforming activity in vivo, and was shown in transgenic mouse models to drive NB formation and to cooperate with MYCN in the oncogenic process. In this project, we aimed at comparing the in vivo oncogenic potential of ALK-wt, with the two most frequent activating mutations ALK-F1174L (only present in sporadic NB), and ALK-R1275Q (present in familial and sporadic NB). Our strategy included the stable expression of ALK-wt and mutated variants into murine neural crest progenitor cells (JoMa1), which are the well-recognized NB progenitors.

In vitro, only ALK-F1174L and ALK-R1275Q conferred an oncogenic potential to JoMa1 cells as measured by clonogenic assays. In contrast, in vivo experiments showed that JoMa1 cells expressing ALK-wt, as well as activating mutations ALK-R1275Q and ALK-F1174L rapidly produced highly aggressive tumors after subcutaneous or orthotopic (adrenal gland) implantations in nude mice. JoMa1-ALK-F1174L cells induced the fastest tumor growth as compared to JoMa1-ALK-R1275Q and JoMa1-ALK-wt cells, revealing the tremendous tumorigenic potential of ALK-F1174L cells. Interestingly, as a result from ALK activation, orthotopic tumors or their derived cell lines strongly upregulated c-myc expression. Moreover, specific ALK inhibition using TAE684, or c-myc inhibition with 10058-F4, completely abrogated the in vitro clonogenic capacity of tumor-derived cell lines. Such observations suggest that the tumorigenic potential of neural crest progenitor cells is strongly dependent on both ALK and c-myc activity.

Our study demonstrates for the first time an oncogenic activity of ALK-R1275Q and ALK-wt when overexpressed in neural crest cells, and reveals the complex interactions between ALK and the myc oncogene family in neural crest cell-derived tumor formation.

Citation Format: Annick Mühlethaler-Mottet, Gisèle Montavon, Marjorie Flahaut, Nicolas Jauquier, Jean-Marc Joseph, Olivier Delattre, Lukas Sommer, Isabelle Janoueix-Lerosey, Nicole Gross. Wild-type ALK and both ALK-R1275Q and ALK-F1174L activating mutations display a strong oncogenic activity in vivo in murine neural crest progenitor cells via cooperation with c-myc. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr B59.
Abstract B70: Modification of hematopoietic stem cells with CD19-specific chimeric antigen receptors as a novel approach for cancer immunotherapy
Authors: Oliveira Satiro N. De , Ryan Christine , Wherley Jennifer , Tu Andy , Elashoff David , Cooper Laurence JN , Hollis Roger P. , Kohn Donald B.
Published: May 2015

Pediatric patients with recurrent B-lineage hematological malignancies have less than 50% of chance of cure, despite intensive therapy. Chimeric Antigen Receptors (CARs) redirect immune cells to tumor-associated antigens. CD19 is proposed as target because its B-lineage restriction and expression in the majority of hematological malignancies. Current clinical trials use CD19-specific CAR-modified T-cells, but the effector cells are only transiently present. The main hypothesis is that modification of hematopoietic stem cells (HSCs) with anti-CD19 CAR will generate persistent anti-leukemic activity through production of multilineage effectors. Gene transfer did not impair HSC differentiation and proliferation when transduced at 1-2 copies/cell. CAR-bearing myeloid and NK cells specifically lysed CD19-positive targets, with second-generation CAR including CD28 domains being more efficient in NK cells. CAR-modified human HSCs engrafted in NSG mice, producing functional cell progenies. Furthermore, ex vivo leukocytes presented antigen-specific target lysis, and animals engrafted with CAR-modified cells presented inhibition or elimination of CD19-positive tumors, and consequent survival advantage. First-generation CAR did not present tumor development inhibition or survival advantage when compared to non-modified HSCs, confirming that the addition of co-stimulatory moieties to the CAR construct is necessary for effectiveness. This approach is untested in cancer immunotherapy, implies the use of a patient's own cells, and can be applied to different cancers just by adjusting the target specificity. It bears the possibility of decreased morbidity and mortality, being desirable for vulnerable populations such as children, and offers alternative treatment for patients with no available HLA-matched sources for bone marrow transplantation, benefiting ethnic minorities.

Citation Format: Satiro N. De Oliveira, Christine Ryan, Jennifer Wherley, Andy Tu, David Elashoff, Laurence JN Cooper, Roger P. Hollis, Donald B. Kohn. Modification of hematopoietic stem cells with CD19-specific chimeric antigen receptors as a novel approach for cancer immunotherapy. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr B70.
Abstract B72: Upfront treatment of high-risk neuroblastoma with 131I-MIBG therapy and Topotecan. A phase II pilot window study (AMRO-NB-HR-2000/01)
Authors: Noesel Max M. van , Kraal Kathelijne CJM , Kraker Jan de , Eck-Smit Berthe LF van , Tytgat Godelieve AM , Caron Huib N.
Published: May 2015

Purpose: Patients with high-risk (HR) neuroblastoma (NBL) have a poor prognosis and new treatment strategies are needed. 131I- Meta-Iodobenzylguanidine (MIBG) therapy alone has a significant antitumor efficacy against NBL. Topotecan (TPT) is a radio-enhancer and can potentiate radiation-induced cytotoxicity and up-regulate the uptake of MIBG in vitro. We designed a clinical study with upfront 131I-MIBG therapy and Topotecan for HR-NBL. We evaluated short term clinical response rate and outcome. Clinical response was scored according to International Neuroblastoma response Criteria (INRC) and Curie score (MIBG) after 2 courses of MIBG/TPT and after induction chemotherapy and HD ASCT. Haematological toxicity and the effect on harvesting/ feasibility performing autologous stem cell transplantation (ASCT) was evaluated. Topoisomerase-1 activity (Topo-1) levels were measured.

Methods: Multi-centre, prospective (window phase II) study performed between 2000-2003 in HR NBL patients treated with 2 cycles of upfront 131I-MIBG therapy followed by the addition of TPT 0.7 mg/m2 for 5 days after each course. Thereafter, patients received 4 courses of VECI chemotherapy, followed by surgery and HD ASCT.

Results: Sixteen patients (10 male), median age 2, 8 yrs. NMYC amplified 8/14 (57%) and LOH1P in 7/15 (47%). Surgery performed in 12/16 (75%) patients. Clinical response after 2x MIBG/TPT 15/16 (94%, VGPR/ PR/ MR), 1 PD; after 4x VECI 11/16 (69%, CR/ VGPR/ PR/MR), 3 PD, 1 death and 1 unknown. More than 50% reduction in MIBG Curie score after 2x MIBG/ TPT and subsequent 4x VECI courses in most cases. Overall outcome 2/16 currently alive. Long term follow up was limited, possibly related to low intensity induction chemotherapy as used in this study. Harvesting of stem cells in 13/16 patients (79%), mean yield 2, 2 CD34 pos/ kg, 9/16 (56%) underwent HD ASCT. Haematological toxicity was limited, median platelet recovery after HD ASCT was 73 days. Topo-1 activity was measured in 10/16 tumors, increased compared to reference level.

Conclusion: Upfront treatment of HR-NBL with MIBG/TPT is feasible and highly effective after 2 courses. The toxicity is limited (haematological). Stem cell harvesting and HD ASCT are manageable.

Citation Format: Max M. van Noesel, Kathelijne CJM Kraal, Jan de Kraker, Berthe LF van Eck-Smit, Godelieve AM Tytgat, Huib N. Caron. Upfront treatment of high-risk neuroblastoma with 131I-MIBG therapy and Topotecan. A phase II pilot window study (AMRO-NB-HR-2000/01). [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr B72.
Abstract IA22: Targeting histone modifying enzymes in leukemia
Authors: Armstrong Scott A.
Published: May 2015

Leukemias harboring rearrangements of the MLL gene carry a poor prognosis. Recently, it has become increasingly clear that MLL-fusion proteins induce widespread epigenetic deregulation that may mediate much of their transforming activity. The histone methyltransferase DOT1L, which methylates histone 3 on lysine 79 (H3K79), has received particular attention. Several MLL-fusion proteins physically interact with DOT1L. Genome-wide H3K79 methylation profiles in MLL-rearranged leukemias are abnormal, and can serve to distinguish MLL-rearranged from other types of leukemias. Mechanistic studies have demonstrated that MLL-fusion proteins subvert a normal gene regulatory mechanism through aberrant hyperconversion of H3K79 methylation to higher methylated states at critical oncogenic targets including the HoxA cluster genes and Meis1. Remarkably, genetic inactivation or small molecule inhibition of DOT1L and thus H3K79 methylation affects expression of MLL-target loci and is detrimental to the leukemogenic activity of MLL-rearranged cells, thus demonstrating that transformation in these leukemias is driven by a DOT1L dependent, aberrant epigenetic program. Clinical trials of small molecule DOT1L inhibitors are in phase 1 clinical trials. Recent studies on the roles for DOT1L and H3K79 methylation in MLL-rearranged leukemias will be discussed.

Citation Format: Scott A. Armstrong. Targeting histone modifying enzymes in leukemia. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr IA22.
Abstract IA37: Clinical genomics
Authors: Janeway Katherine A.
Published: May 2015

The genomic features of pediatric malignancies and pediatric-specific issues in clinical investigation pose pediatric-specific challenges with respect to translating genomic discoveries to the clinic. However, through large scale molecular profiling of pediatric tumors, continued coordinated efforts to evaluate novel therapies in the pediatric population, thoughtful phase II and III trial design and continued drug development, molecularly based targeted therapies will become more common in the pediatric oncology clinic in the future. Consequently, it is essential to rigorously evaluate the clinical utility of advanced molecular diagnostics in pediatric oncology and the efficacy of a precision medicine approach to therapy selection. We are conducting a multi-institution clinical tumor profiling study, the iCat1 study evaluating the feasibility of identifying actionable alterations and making individualized cancer therapy recommendations using currently available clinically applicable tumor profiling technologies.

Citation Format: Katherine A. Janeway. Clinical genomics. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr IA37.
Abstract PR05: Clonal evolution enhances leukemia-propagating cell activity in T-cell acutelymphoblastic leukemia through AKT/mTORC1 pathway activation
Authors: Blackburn Jessica , Liu Sali , Martinez Sarah , Dobrinski Kimberly , Moore Finola , Lobbardi Riadh , Langenau David
Published: May 2015

Leukemia progression and relapse are driven by molecularly distinct and often-rare cancer cells called leukemia-propagating cells (LPCs). If LPCs are retained following treatment, they will ultimately initiate relapse disease. Despite the substantial number of genetic lesions that have been identified in relapse samples and the contention that these mutations likely modulate response to therapy, acquired mutations that increase the overall frequency of tumor propagating cells following continued clonal evolution have not been reported in any cancer to date. Here, we have developed a transgenic zebrafish model where single fluorescently-labeled T-cell acute lymphoblastic leukemia (T-ALL) cells are transplanted into genetically identical recipient fish and functionally assessed for differences in leukemia propagating cell frequency, growth, and dexamethasone resistance. While subclonal variation was observed within single cells from the same primary leukemia, a subset of clones continued to evolve genetic lesions and epigenetic modifications to enhance growth and overall LPC frequency. A majority of evolved clones acquired activated AKT signaling, which simultaneously increased the number of leukemia propagating cells through activating the mTORC1 pathway, enhanced growth by stabilizing Myc protein levels, and rendered T-ALL cells resistant to dexamethasone, which was reversed by combined treatment with an AKT inhibitor. These results were confirmed using large-scale transgenic epistasis experiments and limiting-dilution cell transplantation studies. In total, our data suggest that diagnosis clones can stochastically acquire mutations necessary to survive treatment and drive relapse even before a patient begins treatment, with acquired mutations being independently selected based on important cancer phenotypes including elevated growth rate and leukemia propagating potential. Moreover, our work also identifies combination therapies that utilize dexamethasone and AKT inhibitor can kill LPCs in a subset of refractory T-ALL. Finally, these are the first studies performed in any model to follow single cell evolution as it relates to relapse, utilizing in excess of 6,000 transplant recipient animals and opening new and exciting avenues of study to uncover genetic pathways that drive cancer malignancy.

This abstract is also presented as Poster B23.

Citation Format: Jessica Blackburn, Sali Liu, Sarah Martinez, Kimberly Dobrinski, Finola Moore, Riadh Lobbardi, David Langenau. Clonal evolution enhances leukemia-propagating cell activity in T-cell acutelymphoblastic leukemia through AKT/mTORC1 pathway activation. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr PR05.
Adulthood Weight Change and Risk of Colorectal Cancer in the Nurses' Health Study and Health Professionals Follow-up Study
Authors: Song Mingyang , Hu Frank B. , Spiegelman Donna , Chan Andrew T. , Wu Kana , Ogino Shuji , Fuchs Charles S. , Willett Walter C. , Giovannucci Edward L.
Published: May 2015

We investigated the association between adulthood weight change and colorectal cancer risk in a prospective study with 24 to 34 years of follow-up among 90,988 women and 46,679 men. The primary exposures included weight change from early adulthood (age = 18 years for women, 21 years for men) to baseline enrollment (median age = 43 years for women, 52 years for men), and from baseline to present. In the secondary analyses, we also assessed 4-year weight change during follow-up, and during premenopausal (from age 18 years to menopause) and postmenopausal (from menopause to present) periods in women. Compared to men maintaining their weight from age 21 to baseline, those who gained 20 kg or more were at a higher risk of colorectal cancer (relative risk [RR], 1.64; 95% confidence interval [CI], 1.15–2.35, Ptrend < 0.001), whereas those who lost 8 kg or more had a lower risk (RR, 0.61; 95% CI, 0.30–1.22, Ptrend = 0.003). Similar but weaker associations were found in women and the corresponding RRs were 1.38 (95% CI, 1.13–1.69, Ptrend < 0.001) and 0.80 (95% CI, 0.58–1.09, Ptrend = 0.21). Weight change from baseline to present was not associated with colorectal cancer risk. Four-year weight change during follow-up was positively associated with colorectal cancer risk in men (Ptrend = 0.03) but not in women (Ptrend = 0.42). In addition, in women, weight change before, but not after, menopause was associated with colorectal cancer risk. Our findings provide further scientific rationale for recommendations to maintain a healthy body weight during adulthood. A potential differential association according to sex and timing of weight change warrants further investigation. Cancer Prev Res; 8(7); 620–7. ©2015 AACR.
Impaired Development of Left Anterior Heart Field by Ectopic Retinoic Acid Causes Transposition of the Great Arteries
Authors: Narematsu Mayu , Kamimura Tatsuya , Yamagishi Toshiyuki , Fukui Mitsuru , Nakajima Yuji
Published: May 2015

Background

Transposition of the great arteries is one of the most commonly diagnosed conotruncal heart defects at birth, but its etiology is largely unknown. The anterior heart field (
AHF
) that resides in the anterior pharyngeal arches contributes to conotruncal development, during which heart progenitors that originated from the left and right
AHF
migrate to form distinct conotruncal regions. The aim of this study is to identify abnormal AHF development that causes the morphology of transposition of the great arteries.

Methods and Results

We placed a retinoic acid–soaked bead on the left or the right or on both sides of the
AHF
of stage 12 to 14 chick embryos and examined the conotruncal heart defect at stage 34. Transposition of the great arteries was diagnosed at high incidence in embryos for which a retinoic acid–soaked bead had been placed in the left
AHF
at stage 12. Fluorescent dye tracing showed that
AHF
exposed to retinoic acid failed to contribute to conotruncus development.
FGF
8 and Isl1 expression were downregulated in retinoic acid–exposed
AHF
, and differentiation and expansion of cardiomyocytes were suppressed in cultured
AHF
in medium supplemented with retinoic acid.

Conclusions

The left
AHF
at the early looped heart stage, corresponding to Carnegie stages 10 to 11 (28 to 29 days after fertilization) in human embryos, is the region of the impediment that causes the morphology of transposition of the great arteries.
Hold Back To Move Forward? Early Grade Retention And Student Misbehavior
Authors: Özek Umut
Published: May 2015

Test-based accountability has become the new norm in public education over the last decade. In many states and school districts nationwide, student performance on standardized tests plays an important role in high-stakes decisions, such as grade retention. This study examines the effects of grade retention on student misbehavior in Florida, which requires students with reading skills below grade level to be retained in the third grade. The regression discontinuity estimates suggest that grade retention increases the likelihood of disciplinary incidents and suspensions in the short run, yet these effects dissipate over time. The findings also suggest that these short-term adverse effects are concentrated among economically disadvantaged and male students.
School Districts and Student Achievement
Authors: Chingos Matthew M. , Whitehurst Grover J. , Gallaher Michael R.
Published: May 2015

School districts are a focus of education reform efforts in the United States, but there is very little existing research about how important they are to student achievement. We fill this gap in the literature using 10 years of student-level, statewide data on fourth- and fifth-grade students in Florida and North Carolina. A variance decomposition analysis based on hierarchical linear models indicates that districts account for only a small share (1 to 2 percent) of the total variation in student achievement. Nevertheless, the differences between lower- and higher-performing districts are large enough to be of practical and policy significance, with a one standard deviation difference in district effectiveness corresponding to about 0.11 standard deviations in student achievement (about nine weeks of schooling). District performance is generally stable over time, but there are examples of districts that have shown significant increases or decreases in performance.
Deconstructing Praise
Authors: Quiroga Puertas Alberto J.
Published: May 2015

The purpose of this paper is to analyze the ethical and moral portrait of the emperor Theodosius in Zosimus’ New History. It is my working hypothesis that the historian subverted the rhetorical topics usually deployed in the basilikòs lógos to accommodate the emperor’s ethical portrayal to his religious and historiographical programme. In order to do so, Zosimus emptied the concept of ἀνδρεία from its philosophical and moral connotations.
Sports-writing
Authors: Hadjimichael Theodora A.
Published: May 2015

The avowed purpose of the epinician genre is to praise the athletic victory and the victor. The athletic event, however, is not mentioned in the victory ode, and this absence would suggest that an athletic description had no role within the economy and rhetoric of the poem. Nevertheless, the absence is not total. It has long been observed that Bacchylides is more prone than Pindar to describe the athletic victory. In general, however, scholars have been satisfied to note the fact and simply enumerate the instances in Bacchylides in comparison to the Pindaric ‘descriptions’. The present study will look at the role of victory descriptions within the economy of Bacchylides’ victory odes. I would like to examine the narrative of the particular descriptions, their contribution to the commemoration and celebration of the event, and the rhetorical aim they serve within the poem.1
A Potential Role of Auditory Induced Modulations in Primary Visual Cortex
Authors: Azevedo Frederico A. C. , Azevedo Frederico A. C. , Ortiz-Rios Michael , Azevedo Frederico A. C. , Ortiz-Rios Michael , Li Qinglin , Azevedo Frederico A. C. , Ortiz-Rios Michael , Li Qinglin , Logothetis Nikos K. , Azevedo Frederico A. C. , Ortiz-Rios Michael , Li Qinglin , Logothetis Nikos K. , Keliris Georgios A.
Published: May 2015

A biologically relevant event is normally the source of multiple, typically correlated, sensory inputs. To optimize perception of the outer world, our brain combines the independent sensory measurements into a coherent estimate. However, if sensory information is not readily available for every pertinent sense, the brain tries to acquire additional information via covert/overt orienting behaviors or uses internal knowledge to modulate sensory sensitivity based on prior expectations. Cross-modal functional modulation of low-level auditory areas due to visual input has been often described; however, less is known about auditory modulations of primary visual cortex. Here, based on some recent evidence, we propose that an unexpected auditory signal could trigger a reflexive overt orienting response towards its source and concomitantly increase the primary visual cortex sensitivity at the locations where the object is expected to enter the visual field. To this end, we propose that three major functionally specific pathways are employed in parallel. A stream orchestrated by the superior colliculus is responsible for the overt orienting behavior, while direct and indirect (via higher-level areas) projections from A1 to V1 respectively enhance spatiotemporal sensitivity and facilitate object detectability.
A new species of Standleya (Rubiaceae, Coussareeae) with a new record for Bahia, Brazil
Authors: Jardim Jomar Gomes , COSTA CRISTINA BESTETTI
Published: May 2015

Standleya glomerulata, a new species and a first record for the semiarid region of Bahia, Brazil, is described and illustrated. It differs from all other known species of the genus by its prostrate decumbent and reptant habit, glomerulate sessile inflorescences, and a calyx with two unequal lobes. S. prostrata has a similar habit, but can be distinguished by the pedunculate inflorescences and a calyx with four equal lobes. The new species is known from only a few localities in two protected areas and must therefore be considered threatened.
Swedish Plectida (Nematoda). Part 9. The genus Leptolaimoides Vitiello, 1971
Authors: Holovachov Oleksandr
Published: May 2015

Three known and two new species of Leptolaimoides are described from bottom sediments collected in Skagerrak off the west coast of Sweden. The following known species are redescribed: Leptolaimoides haploopis Jensen, 1978, L. tubulosus Vitiello, 1971 and L. hexatubulosus Hoang Lai-Phu et al., 2009. Leptolaimoides filicaudatus sp. n. is characterised by the 431–543 µm long body; cephalic sensilla papilliform; amphid 23–26 µm long, located 9–10 µm from anterior end; first body pore located 35–37 µm from anterior end; lateral field simple along most of body, areolated on tail, arising 36–40 µm from anterior end; female without supplements, vagina without pars refringens, vulva midventral; male without tubular and without alveolar supplements; spicules arcuate and 16 µm long. Leptolaimoides leptomicron sp. n. is characterised by the 776–847 µm long body; cephalic sensilla papilliform; amphid 15–17 µm long, located 9–13 µm from anterior end; first body pore located 40–46 µm from anterior end; lateral field areolated, arising 26–28 µm from anterior end; female without supplements, vagina without pars refringens, vulva midventral; male with three tubular and without alveolar supplements, spicules arcuate and 28–29 µm long. The diagnosis of the genus Leptolaimoides is emended and a tabular compendium and dichotomous identification key to species of the genus Leptolaimoides are provided.