bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract B28: Genomic analysis of osteosarcoma for identification of targeted therapies
Authors: Sayles Leanne , Breese Marcus , Sweet-Cordero E. Alejandro
Published: May 2016

Osteosarcoma (OS) is an aggressive pediatric bone malignancy that affects 400 children per year in the United States. OS is characterized by genomic instability and numerous copy number alterations (CNA). We hypothesized that CNA may be drivers of OS and that targeting cancer genes with CNAs may be a novel approach for treatment of OS. We have established a robust approach for generation of patient-derived xenografts (PDX) from patients with OS. To date, 15 PDX have been established from OS patients. Using whole-genome sequencing (WGS), we have identified possible target CNAs for individual patients and are currently testing them in their corresponding PDX. In two patients, an amplification in c-myc suggested possible susceptibility to the BRD4 inhibitor JQ1 or the CDK9 inhibitor AT7519. In a third patient sample, amplification of Cyclin D and Cyclin E in the setting of wild-type Rb suggested responsiveness to a CDK inhibitor. A fourth patient had a FOXM1 amplification which suggests a vulnerability to Palbociclib, a CDK4/6 specific inhibitor. This patient sample also had an Aurora kinase B amplification, suggesting susceptibility to inhibition of this kinase as a therapeutic approach. We treated the corresponding PDX with the drug predicted to target the patient sample based on CNA. In all cases, treatment of the PDX with the drugs predicted show a significant reduction in tumor growth compared to vehicle alone or to the drugs predicted for the other patient CNAs. As a follow up we are currently submitting several more patient samples and paired PDX for WGS as well as RNAseq to determine other potential targeted therapeutics based on CNA. In summary, our work suggests that WGS can be used to identify potential novel therapies for patients with OS. Further work will be needed to determine whether response in PDX models correlates with clinical response in patients.

Citation Format: Leanne Sayles, Marcus Breese, E. Alejandro Sweet-Cordero. Genomic analysis of osteosarcoma for identification of targeted therapies. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B28.
Abstract B29: MDM4 is a major p53 regulator in hepatoblastoma
Authors: Shi Yan , Patel Roma , Hollingsworth Emporia , Sarabia Stephen , Jin Jingling , Lopez-Terrada Dolores , Vasudevan Sanjeev
Published: May 2016

Purpose: Unresectable or metastatic hepatoblastoma generally confers a poor survival. MDM4 and MDM2 are the major negative regulators of p53, which has a predominantly wild type status in hepatoblastoma. Having previously shown that MDM4 has copy gain/amplification associated with the 1q32.1 amplicon in hepatoblastoma, we hypothesize that MDM4 is the predominant negative regulator of p53 function in hepatoblastoma and that blocking MDM4 will cause tumor cell death due to uninhibited p53 tumor suppressor activity.

Methods: An MTT assay was used to measure NSC207895 (MDM4 inhibitor) and Nutlin-3a (MDM2 inhibitor) cytotoxicity on hepatoblastoma cell lines (HepG2, HepT1, and Huh-6) as well as a patient-derived hepatoblastoma cell line (PDCL-1). CCK-8 was used to assess effects of low dose NSC207895 on HB cell line proliferation. Soft agar was used to assess the effect of NSC207895 on hepatoblastoma colony formation. Immunoblotting and quantitative RT-PCR was used to measure expression of p53 downstream targets in hepatoblastoma after treatment with NSC207895. P53 knockdowns were created to assess the effect of NSC207895 in hepatoblastoma in the absence of p53. Cell cycle analysis was performed using BRDU.

Results: Huh-6, HepG2, and HepT1 were all tested with Nutlin-3a and did not show significant cell death (IC50 >10μΜ) inhibition with NSC207895 caused significant cell death in Huh-6 (IC50=1.27μΜ), HepG2 (1.62μΜ), and HepT1 (2.05μΜ). A decrease in cell proliferation was noted with concentrations of NSC207895 as low as 0.05μΜ, 0.1μΜ and 0.3μΜ in HepG2, HepT1, and Huh-6 respectively. An increase in IC50 was seen in the p53 knockdowns compared to each respective control (HepG2: 12.6μΜ vs 3.38μΜ; HepT1: >50μΜ vs 1.45μΜ; Huh-6: 20.2μΜ vs 7.52μΜ). Increased PARP cleavage products and decreased MDM4 expression were seen on immunoblotting after treatment with NSC207895. By both immunoblotting and qPCR, the p53 downstream transcriptional targets, p21, BAX and PUMA, were increased after exposure to NSC207895 in all three cell lines. Cell cycle analysis showed an increased percentage of cells in G1/G0-phase and decreased percentage of actively replicating S-phase cells in HepG2 with NSC207895 treatment.

Conclusion: Our data supports the hypothesis that in hepatoblastoma, MDM4 may be a dominant inhibitor of p53 and inhibition of MDM4 causes p53-mediated cell death and growth inhibition. Therefore, inhibition of MDM4 may be a viable drug target for treating hepatoblastoma.

Citation Format: Yan Shi, Roma Patel, Emporia Hollingsworth, Stephen Sarabia, Jingling Jin, Dolores Lopez-Terrada, Sanjeev Vasudevan. MDM4 is a major p53 regulator in hepatoblastoma. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B29.
Abstract B35: Enhanced antitumor efficacy by combining oncolytic herpes simplex virus and Aurora A kinase inhibition in models of neuroblastoma and malignant peripheral nerve sheath tumor
Authors: Currier Mark , Rizvi Tilat , Nartker Brooke , Chen Duo , Chen Chun-Yu , Wang Pin-Yi , Sprague Les , Franczek Meghan , Patel Ami , Chaney Katherine , Streby Keri , Ecsedy Jeff , Conner Joe , Ratner Nancy , Cripe Timothy
Published: May 2016

We previously reported xenograft models of neuroblastoma and malignant peripheral nerve sheath tumor (MPNST) are responsive to direct intratumoral injection of oncolytic Herpes Simplex Viruses (Parikh et al., Ped Blood Can 44:469, 2005; Mahller et al., Ped Blood Can 46:745, 2006; Mahller et al., Can Res 68:1170, 2008). We have confirmed these findings using an oncolytic HSV, Seprehvir (HSV1716), which is in clinical trials that include pediatric patients (NCT00931931, NCT02031965). The models showed wide variability, however, with some models having maintained complete responses and others showing only delayed growth. Because DNA viruses are highly dependent on normal nuclear machinery for DNA synthesis/replication and virus packaging/assembly, we postulated that increased transit time in mitosis may be beneficial to an oncolytic DNA virus. Aurora A Kinase is an enzyme critical for formation of centrioles and mitotic spindles during mitosis and is often dysregulated in cancer. The selective AAK inhibitor, Alisertib (MLN8237), arrests cells in G2/M and has significant activity in models of neuroblastoma (data from the Pediatric Preclinical Testing Program) and in MPNST (data from our prior study: Patel et al., Clin Can Res 18:5020, 2012). We found tumor responses in xenograft models using the combination of Seprehvir and Alisertib was more than additive. Immunohistochemical staining for HSV antigens revealed a marked difference in the extent and spread of virus as early as 24 hrs after virus injection. Our preliminary data assessing kinetics of virus infection suggest that Alisertib pretreatment enhances virus uptake and spread, accounting for the combinatorial effects. These data strongly suggest alisertib pretreatment “primes” tumor cells, making them highly susceptible to virus infection and spread and greatly accelerates the virolytic effects. Overall, our findings support clinical testing of Alisertib combined with Seprehvir in patients with refractory neurogenic tumors such as neuroblastoma and MPNST.

Citation Format: Mark Currier, Tilat Rizvi, Brooke Nartker, Duo Chen, Chun-Yu Chen, Pin-Yi Wang, Les Sprague, Meghan Franczek, Ami Patel, Katherine Chaney, Keri Streby, Jeff Ecsedy, Joe Conner, Nancy Ratner, Timothy Cripe. Enhanced antitumor efficacy by combining oncolytic herpes simplex virus and Aurora A kinase inhibition in models of neuroblastoma and malignant peripheral nerve sheath tumor. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B35.
Abstract B39: NQO1 as a therapeutic target for atypical teratoid/ rhabdoid tumor
Authors: Meade Julia C. , Moore Zachary R. , Stuart Sarai H. , Cholka Agnieszka , Boriack Richard L. , Xu Jingying , Erdreich-Epstein Anat , Rakheja Dinesh , Boothman David A. , Amatruda James F. , Laetsch Theodore W.
Published: May 2016

Atypical Teratoid/ Rhabdoid Tumor (ATRT) is an aggressive cancer that accounts for up to 20% of infant brain tumors. Even with intense chemotherapy and radiation, approximately 75% of children die from their disease at a median of 10 months after diagnosis. We found that the pathognomonic genetic lesion of ATRTs and related malignant rhabdoid tumors (MRTs), loss of the SWI/SNF chromatin remodeling complex member INI1/hSNF5/SMARCB1, is associated with high expression of NAD(P)H:quinone oxidoreductase 1 (NQO1), a two-electron oxidoreductase. Thus, we hypothesized that ATRTs will be vulnerable to drugs such as ß-lapachone (ß-lap, ARQ761 in clinical form) that selectively kill NQO1-expressing cells via mu-calpain mediated cell necrosis.

A panel of ATRT cell lines exhibited overall high NQO1 expression and sensitivity to ß-lap (IC50 1.6-4 uM). A two-hour pulse with ß-lap caused a burst of ROS-mediated DNA damage and PARP1 hyperactivation, resulting in NAD+ and ATP depletion. Lack of NQO1 expression or inhibition of NQO1 with dicoumarol abrogated sensitivity to ß-lap. Low expression of NQO1 in normal brain and other pediatric tissues suggests a wide therapeutic window for ß-lap, and a survival advantage was observed after treatment in a heterotopic mouse xenograft model with several mice achieving apparent cures. Furthermore, the mechanism of ß-lap results in synergy with standard of care agents such as ionizing radiation, increasing its potential for clinical applications.

Citation Format: Julia C. Meade, Zachary R. Moore, Sarai H. Stuart, Agnieszka Cholka, Richard L. Boriack, Jingying Xu, Anat Erdreich-Epstein, Dinesh Rakheja, David A. Boothman, James F. Amatruda, Theodore W. Laetsch. NQO1 as a therapeutic target for atypical teratoid/ rhabdoid tumor. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B39.
Abstract B42: Hope for a future: Conditional survival estimates for childhood cancer in Australia, 2002-2011
Authors: Youlden Danny , Baade Peter , Hallahan Andrew , Valery Patricia , Green Adele , Aitken Joanne
Published: May 2016

Purpose: Conditional survival rates provide a more realistic assessment of long-term prognosis than survival rates calculated from the date of diagnosis because they take into account the time that a patient has already remained alive following diagnosis. However, estimates of conditional survival are scarce for childhood cancer. Here we provide results from a national population-based childhood cancer registry by diagnostic group, age at diagnosis and stage of cancer.

Methods: De-identified population-based data were obtained from the Australian Paediatric Cancer Registry for children aged 0-14 years diagnosed with cancer between 1983 and 2010. Mortality status was followed up to the end of 2011. The hybrid period method was used to calculate relative survival estimates for those who were at risk during the period 2002 to 2011. Conditional survival was then obtained from the ratio of the relative survival estimates at different time points.

Results: A total of 13,537 children were eligible for inclusion in the study. Five-year survival for all childhood cancers combined improved from 82% at diagnosis (95% confidence interval = 81%-83%) to 89% (88%-90%), 95% (94%-96%) and 97% (97%-98%) conditional on surviving 1, 3 and 5 years after diagnosis, respectively. Conditional survival reached 95% within five years of diagnosis for nearly all types of cancer, regardless of age or stage at diagnosis.

Conclusions: Most children diagnosed with cancer who are alive five years after diagnosis can anticipate a similar chance of survival to children in the general population. For childhood cancer patients and their families, this information provides a more accurate and optimistic picture of long-term prognosis than has been available until now.

Citation Format: Danny Youlden, Peter Baade, Andrew Hallahan, Patricia Valery, Adele Green, Joanne Aitken. Hope for a future: Conditional survival estimates for childhood cancer in Australia, 2002-2011. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B42.
Abstract B48: The synthetic retinoid ST1926 as a novel therapeutic agent in rhabdomyosarcoma
Authors: Basma Hussein , Ghayad Sandra , Mancinelli Angelo , Pisano Claudio , Darwiche Nadine , Saab Raya
Published: May 2016

Rhabdomyosarcoma (RMS) is the most frequent soft tissue sarcoma in children. Despite multiple attempts at intensifying chemotherapeutic approaches to treatment, only moderate improvements in survival have been made for patients with advanced disease. Retinoic acid is a differentiation agent that has shown some anti-tumor efficacy in RMS cells in vitro, however the effects are of low magnitude. E-3-(4'-hydroxyl-3'-adamantylbiphenyl-4-yl) acrylic acid (known as ST1926) is a novel orally available synthetic atypical retinoid, shown to have more potent activity than retinoic acid in several types of cancer cells. We used in vitro and in vivo models of RMS to explore the efficacy of ST1926 as a possible therapeutic agent in this sarcoma. We found that ST1926 reduced RMS cell viability in all tested alveolar (ARMS) and embryonal (ERMS) RMS cell lines, at readily achievable in vivo micromolar concentrations. ST1926 induced an early DNA damage response, which led to increase in apoptosis, in addition to S-phase cell cycle arrest and a reduction in protein levels of the cell cycle kinase CDK1. Effects were irrespective of TP53 mutational status. Interestingly, in ARMS cells, ST1926 treatment decreased PAX3-FOXO1 fusion protein levels, and this suppression occurred at a post-transcriptional level. In vivo, ST1926 was effective in retarding the growth of ARMS and ERMS xenografts, and induced a prominent DNA damage response. We conclude that ST1926 has preclinical efficacy against RMS, and should be considered further investigated in clinical trials, possibly in combination therapy.

Citation Format: Hussein Basma, Sandra Ghayad, Angelo Mancinelli, Claudio Pisano, Nadine Darwiche, Raya Saab. The synthetic retinoid ST1926 as a novel therapeutic agent in rhabdomyosarcoma. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B48.
Abstract IA04: Using genome editing to model MLL rearranged leukemias
Authors: Breese Erin , Buechele Corina , Cleary Michael , Porteus Matthew
Published: May 2016

MLL rearranged leukemias, particularly those associated with infant acute lymphoblastic leukemias, continue to have a generally poorer prognosis than other childhood leukemias. Improved understanding of these leukemias has been gained by using transgenic mouse models and retroviral transduction of human cells but each of these approaches has well recognized limitations. With the recent development of an expanded genome editing toolbox, it is now possible to use genome editing in primary human hematopoietic stem and progenitor cells (HSPCs) to directly re-create genomic rearrangements, including those involving the MLL gene. Using these tools we have generated MLL-AF4 and MLL-AF9 translocations in HSPCs and studied the biologic properties of these cells. Moreover, we have further used genome editing of HSPCs to knock-in the AF9 fusion partner into the MLL locus to create the MLL-AF9 fusion. When the modified HSPCs were transplanted into immunodeficient mice (NSG), these modified cells gave rise to ALL, mixed phenotype leukemias, and AML. These results now give a powerful new way to study the developmental biology and pathogenesis of MLL rearranged leukemias and provide a proof-of-concept of how genome editing of human HSPCs can be used to study a wide variety of hematologic disorders.

Citation Format: Erin Breese, Corina Buechele, Michael Cleary, Matthew Porteus. Using genome editing to model MLL rearranged leukemias. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr IA04.
Abstract IA05: Oncogenic signaling pathways and resistance to therapy in T-ALL
Authors: Ferrando Adolfo
Published: May 2016

Aberrant NOTCH1 signaling plays a major role in the pathogenesis of over 60% of T-ALLs harboring activating mutations in the NOTCH1 gene. Most notably, oncogenic NOTCH1 has been proposed as a therapeutic target in NOTCH1-mutant leukemias and small molecule γ-secretase inhibitors (GSIs), which effectively block NOTCH activation via inhibition of a critical intramembrane proteolytic cleavage required for NOTCH signaling. However, the clinical development of anti-NOTCH1 therapies in T-ALL has been hampered by the limited and delayed therapeutic response to these drugs, making the identification of highly effective and synergistic drug combinations capable of delivering strong antileukemic responses a top priority in the field. Here we identify glutaminolysis as a critical pathway for leukemia cell growth downstream of NOTCH1 and a key determinant of clinical response to anti-NOTCH1 therapies. Mechanistically, inhibition of NOTCH1 signaling in T-ALL induces a metabolic shutdown with prominent inhibition of glutaminolysis and triggers autophagy as a salvage pathway supporting leukemia cell metabolism. Consequently, both inhibition of glutaminolysis and inhibition of autophagy strongly and synergistically enhance the antileukemic effects of anti-NOTCH1 therapies. Moreover, Pten loss and consequent activation of the PI3K pathway induces increased glycolysis and consequently rescues leukemic cell metabolism abrogating the antileukemic effects of NOTCH1 inhibition. Overall, these results identify glutaminolysis as a major node in cancer metabolism controlled by NOTCH1 and as therapeutic target for the treatment of T-ALL. These results highlight the fundamental importance of NOTCH1 signaling in the control of leukemia cell metabolism, extend our understanding of the prominent role of PTEN and the PI3K pathway in the control of oncogenic cell growth and provide the basis for the design of new therapeutic strategies targeting cell metabolism for the treatment of T-ALL.

Citation Format: Adolfo Ferrando. Oncogenic signaling pathways and resistance to therapy in T-ALL. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr IA05.
Abstract IA18: Children, adolescents, and young adult ALL: Translating novel discoveries into therapeutic opportunities
Authors: Loh Mignon L.
Published: May 2016

Acute lymphoblastic leukemia (ALL) is a genetically complex disease that remains a major cause of childhood cancer-related mortality. Some subsets of ALL can be successfully treated with traditional cytotoxic chemotherapy while others remain at high risk of relapse. Specifically, adolescents and young adults have higher relapse rates than younger children and also experience increased toxicity with cytotoxics. Major advances in genomic profiling through the application of next generation sequencing technologies in these high risk patients have uncovered recurrent mutations in key pathways that may be targeted with the addition of signal transduction inhibitors to chemotherapy. Such therapeutic approaches will mandate genetically precise risk stratification of patients. The Children's Oncology Group (COG) is poised to act in real time to identify these high risk subsets and will be introducing relevant signal transduction inhibitors in clinical trials shortly. Relapsed ALL remains a significant therapeutic challenge additional genomic analyses have shed light on new events that occur at relapse, but these may be difficult to individually target. Indeed, immunotherapeutic approaches are being harnessed to focus on eradicating the malignant B-cell without regard to genetic lesions, which may be useful in relapsed ALL. This discussion will review genomic data generated through large scale collaborations with the COG ALL committee and also present an overview of the clinical trials that will capitalize on these recent discoveries.

Citation Format: Mignon L. Loh. Children, adolescents, and young adult ALL: Translating novel discoveries into therapeutic opportunities. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr IA18.
Abstract IA19: Genome-epigenome interplay in medulloblastoma
Authors: Northcott Paul
Published: May 2016

The recent application of genomics to large series of primary human medulloblastomas has dramatically improved our perspective of the genes, pathways, and molecular processes underpinning this highly malignant pediatric brain tumor. Transcriptionally defined molecular subgroups have emerged, changing the fundamental definition of medulloblastoma from a single histologically recognized entity, to four distinct subtypes: WNT, SHH, Group3, and Group4. These subgroups exhibit highly discriminatory genomic landscapes, patient demographics, and clinical phenotypes. Next-generation sequencing has identified and implicated recurrently altered somatic drivers, many of which are affected in a subgroup-restricted manner. In contrast, somatic variants affecting chromatin-modifying genes, including histone writers, erasers, and readers are prevalent in medulloblastoma and occur across subgroups, suggesting that deregulation of the epigenome is an essential step during medulloblastoma development. Integrative omics-based strategies have begun to dissect the fascinating genome-epigenome interplay underlying medulloblastoma, revealing previously undisclosed oncogenic mechanisms and drivers of disease. Furthermore, new insights into the biology and putative origins of the poorly understood Group3 and Group4 medulloblastomas have likewise been revealed. This talk will summarize these recent discoveries afforded through genomics and discuss their potential implications, both in the lab and in the clinic, going forward.

Citation Format: Paul Northcott. Genome-epigenome interplay in medulloblastoma. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr IA19.
Abstract PR10: The chromatin remodeler CHD4 as a potential specific target for alveolar rhabdomyosarcoma therapy
Authors: Marques Joana , Boehm Maria , Wachtel Marco , Schaefer Beat
Published: May 2016

Fusion-positive alveolar rhabdomyosarcoma (FP-RMS) is a paediatric tumour driven by an oncogenic fusion transcription factor, PAX3-FOXO1. Conventional chemotherapy is only effective for low risk patients which carry no metastasis, achieving a 5-year overall survival of 65%. The unique presence of this fusion protein in FP-RMS as well as the tumour cell survival dependency on PAX3-FOXO1 make this transcription factor a promising target for therapy. However, due to the difficulties associated with drug development targeting transcription factors, we performed a combined proteomic and genetic screen to identify new druggable co-regulators of PAX3-FOXO1 transcriptional activity.

Interactor candidates were defined by mass spectrometry analysis of proteins co-purified with the fusion protein and individually validated for their relevance for PAX3-FOXO1 activity through siRNA silencing. The chromodomain-DNA-binding protein 4 (CHD4), a nucleosome remodeler and core member of the NuRD complex (Nucleosome Remodelling and Deacetylase), was identified as an essential positive co-regulator of PAX3-FOXO1 transcriptional activity. ChIP-qPCR experiments demonstrated that CHD4 not only co-localizes with PAX3-FOXO1 in the FP-RMS genome but also it is necessary for the binding of the fusion protein to cis-regulatory sites for a subset of its target genes. Consequently, CHD4 silencing affected the expression of more than 50% of PAX3-FOXO1 regulated target genes. Additionally, depletion of CHD4 impaired FP-RMS cell proliferation and caused a complete regression of xenograft tumours in mice. Moreover, CHD4 silencing had no effect in cell proliferation of human myoblasts or fibroblasts, suggesting a unique tumour dependency on this chromatin remodeler.

In summary, our data propose that CHD4 has a crucial role as a co-regulator of PAX3-FOXO1 driven gene expression whose presence is required for FP-RMS cell viability. To our knowledge, CHD4 is the first identified chromatin remodeler associated with PAX3-FOXO1 transcriptional activity, thus highlighting the relevance of epigenetic regulation in FP-RMS tumour development. Collectively, our findings suggest CHD4 as a potential novel therapeutic target in this childhood malignancy, and are motivating ongoing work aimed at finding first-in-class small molecules to inhibit CHD4.

This abstract is also presented as Poster A20.

Citation Format: Joana Marques, Maria Boehm, Marco Wachtel, Beat Schaefer. The chromatin remodeler CHD4 as a potential specific target for alveolar rhabdomyosarcoma therapy. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr PR10.
Abstract BS3-1: Dominance of mitochondria in determining the malignant phenotype
Authors: Kaipparettu BA
Published: May 2016

Mitochondria are semiautonomous organelles within cells that play an important role in cellular energy metabolism, free radical generation, and apoptosis. Mitochondria contain their own genome (mtDNA), which encodes a number of proteins critical for energy metabolism, particularly in oxidative phosphorylation. They are also the major source of generating reactive oxygen species (ROS) in the cell. Advances in cancer metabolism research over the last decade have enhanced and modified our understanding on Warburg effect. It is now known that mitochondria in tumors are not always defective in their ability to carry out oxidative phosphorylation. Instead, in proliferating cells, mitochondrial energy pathways are reprogrammed to meet the challenges of macromolecular synthesis and to escape from apoptosis. Mitochondrial retrograde regulation (MRR) is a bidirectional communication between mitochondria and nucleus. MRR is triggered by mitochondrial functional demands and it responds in a continuous manner to the changing metabolic needs of the cell. At present, it is not clear whether mitochondrial genomic status or metabolomic reprogramming affect nuclear genome stability. Also, limited evidence is available on the significance of proteins involved in the inter-genomic cross talk in the regulation of tumorigenesis. Transmitochondrial cybrids (cybrids) are a great utility for the study of the functional effects of mitochondria in a defined nuclear background. Cybrids are constructed by fusing enucleated cells harboring mitochondria of interest with ρ0 cells (mtDNA-depleted cells). Our approach of discovering mitochondria regulated pathways using cybrid models and their in vitro and in vivo validation in different breast cancer cell lines and patient derived xenograft models suggest that mitochondrial metabolic character and retrograde signaling are playing important roles in oncogenic transformation and metastasis. Importantly, mitochondria-nuclear crosstalk is critical in the regulation of some of the major cancer pathways. Compared to hormone regulated/responsive breast cancers, triple negative breast cancer patients suffer from worse overall survival, significantly shorter disease-free and post-recurrence survival. Due to the lack of known oncogenic drivers for triple negative breast cancer, clinical benefit from currently available targeted therapies is limited, and new therapeutic strategies are urgently needed. Thus, understanding MRR and mitochondria mediated oncogenic signature is critical in understanding the currently limited known etiology and treatment resistance of certain subgroups of cancers like the triple negative breast cancer.

Citation Format: Kaipparettu BA. Dominance of mitochondria in determining the malignant phenotype. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr BS3-1.
Abstract ES2-3: Metabolic asymmetry in breast cancer: Implications for personlised medicine
Authors: Lisanti MP
Published: May 2016

Over the last decade, strong evidence has accumulated that the tumor micro-environment plays a key role in recurrence, metastasis and poor clinical outcome in breast cancer patients. In this context, more recent discoveries indicate that catabolic cancer-associated fibroblasts (CAFs) produce nutrients (lactate, ketone bodies and glutamine) to fuel anabolic mitochondrial metabolism in cancer cells. This new paradigm is known as metabolic-symbiosis or metabolic asymmetry and reflects the co-existence of multiple metabolic compartments in a given tumor. This type of metabolic co-operation in the tumor ecosystem underlies the metabolic heterogeneity found in human breast cancers, and can be used to more effectively predict tumor recurrence, metastasis, drug-resistance and poor clinical outcome, in breast cancer patients.

In my talk, I will highlight how this metabolic-symbiosis phenotype could be targeted from a therapeutic point of view, bringing us closer to the goal of personalized medicine.

For further information on this topic, please see the following references:

Caveolae and signalling in cancer.

Martinez-Outschoorn UE, Sotgia F, Lisanti MP.

Nat Rev Cancer. 2015 Apr;15(4):225-37.

Metabolic asymmetry in cancer: A balancing act that promotes tumor growth.

Martinez-Outschoorn UE, Sotgia F, Lisanti MP.

Cancer Cell. 2014 Jul 14;26(1):5-7.

Power surge: Supporting cells fuel cancer cell mitochondria.

Martinez-Outschoorn UE, Sotgia F, Lisanti MP.

Cell Metab. 2012 Jan 4;15(1):4-5.

Citation Format: Lisanti MP. Metabolic asymmetry in breast cancer: Implications for personlised medicine. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr ES2-3.
Abstract ES4-1: Longitudinal strategies in ER+ disease
Authors: Dickler M
Published: May 2016

Endocrine therapy is a relatively well-tolerated treatment for hormone receptor-positive (HR+) breast cancer. This therapy can be offered as first-line treatment before initiation of chemotherapy in patients with manageable symptoms from their disease and no evidence of clinically significant compromise of visceral organ function. Targeting the estrogen receptor pathway with agents such as the aromatase inhibitors, tamoxifen and fulvestrant can provide effective therapy with a durable response to treatment for some patients. This presentation will review clinical trial data to guide choice of endocrine therapy and the sequential use of these agents in patients with endocrine-responsive disease. Within HR+ breast cancer, there is molecular diversity that can influence responsiveness to endocrine therapy. In addition, recent insight into the complex interactions between the estrogen receptor and cell cycle survival and/or growth factor signalling pathways have uncovered potential mechanisms of endocrine therapy resistance in HR+ breast cancer. This improved understanding has led to new options for treatment. We will review the clinical trial evidence that supports the addition of a cell cycle inhibitor, palbociclib, to first-line letrozole and second-line fulvestrant. We will also review evidence supporting the combination of an mTOR inhibitor, everolimus, to second- or third-line exemestane. These targeted agents increase progression-free survival when added to endocrine therapy, however at the present time, there is no benefit in overall survival. With this limitation in mind, we will review the side effects of these agents, weigh the toxicity and potential benefits, and examine if patient and/or tumor-based factors may help to determine which patients are best suited for these agents. Lastly, we will discuss the subset of patients with bone-only HR+ disease, and the complexities of assessing imaging and their response to therapy.

Citation Format: Dickler M. Longitudinal strategies in ER+ disease. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr ES4-1.
Abstract ES5-2: Circulating tumor DNA analysis for liquid biopsies: Current status and future opportunities
Authors: Diehn M
Published: May 2016

Circulating tumor DNA (ctDNA) represents a promising biomarker for sensitive, specific, and dynamic detection of disease burden in cancer patients. Additionally, ctDNA analysis allows non-invasive access to cancer genomes and therefore can be used for non-invasive tumor genotyping and monitoring of resistance mutations. In this presentation I will describe technical aspects of ctDNA detection and emerging clinical results from recent studies employing ctDNA analysis.

Citation Format: Diehn M. Circulating tumor DNA analysis for liquid biopsies: Current status and future opportunities. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr ES5-2.
Abstract OT1-03-09: FAIRLANE: A phase II randomized, double-blind, study of the Akt inhibitor ipatasertib (Ipat, GDC-0068) in combination with paclitaxel (Pac) as neoadjuvant treatment for early stage triple-negative breast cancer (TNBC)
Authors: Saura C , Isakoff SJ , Calvo I , Patt D , Andersen J , Gonzalez-Martin A , Fisher J , Ciruelos E , Gil-Gil M , De la Peña L , Choi Y , Jia S , Singel S , Patel PH , Baselga J , Oliveira M
Published: May 2016

Background: TNBC often exhibits activation of PI3K/Akt signaling, associated with loss of PTEN expression, low INPP4B expression, and/or increased AKT3 amplification. Inhibition of the PI3K/Akt pathway in diverse cancers leads to radiosensitization and/or chemosensitization. Ipat is an oral, potent ATP-competitive small molecule inhibitor of all three isoforms of Akt. The combination of ipat with taxanes in preclinical models resulted in enhanced efficacy relative to either ipat or chemotherapy alone. In a Phase Ib clinical study, the combination of ipat with diverse chemotherapy regimens was well-tolerated and resulted in RECIST responses, particularly pts with tumors having PI3K/Akt activation.

Methods: FAIRLANE is a randomized, double-blind, placebo controlled, multicenter, neoadjuvant Phase II study designed to estimate the efficacy of ipat combined with pac versus placebo combined with pac in women with Stage Ia  IIIa TNBC. Approximately 150 pts (Pts) will be enrolled, randomized in a 1:1 ratio, and stratified by PTEN status, node involvement, and tumor size. Pts will receive 3 cycles of ipat 400 mg or placebo orally once daily on Days 1 to 21 of each 28-day cycle, along with pac 80 mg/m2 every 7 days for a total of 12 doses. All pts will undergo pretreatment and Day 8 tumor tissue acquisition to evaluate pathway biomarkers. Following three cycles of treatment, pts will undergo surgery. The primary efficacy endpoint, pCR within the breast and axilla (ypT0/Tis ypN0) in all pts and in pts with PTEN low tumors, will be assessed by local pathology evaluation following completion of neoadjuvant therapy and surgery. Additional endpoints include objective response rate, safety, BCS rate, pharmacokinetics, and pathway biomarkers. Following surgical resection of primary tumor, pts are expected to continue post-operative treatment with a standard adjuvant chemotherapy regimen at physician's discretion. The study is open for accrual. Clinical trial information: NCT02301988.

Citation Format: Saura C, Isakoff SJ, Calvo I, Patt D, Andersen J, Gonzalez-Martin A, Fisher J, Ciruelos E, Gil-Gil M, De la Peña L, Choi Y, Jia S, Singel S, Patel PH, Baselga J, Oliveira M. FAIRLANE: A phase II randomized, double-blind, study of the Akt inhibitor ipatasertib (Ipat, GDC-0068) in combination with paclitaxel (Pac) as neoadjuvant treatment for early stage triple-negative breast cancer (TNBC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT1-03-09.
Abstract OT3-02-01: Randomized phase II study of Hangeshashinto (TJ-14) for chemotherapy induced oral mucositis in patients with breast cancer (Hangesha-B study)
Authors: Iwamoto M , Umezaki N , Matsuda J , Kawaguchi K , Terasawa R , Sato N , Fyjioka H , Kimura K , Tanaka S , Uchiyama K
Published: May 2016

Background: Oral mucositis is a common complication of systemic chemotherapy for cancer, and is associated with higher risk of infection, pain, chemotherapy dose reduction. Severe mucositis impairs oral function and seriously affects nutrition and quality of life of the patients.

Hangeshashinto (TJ-14) is a traditional Japanese herbal (Kampo) medicine reduces the level of prostaglandin E2 and affects the cyclooxygenase activity, and alleviates chemotherapy induced oral mucositis. We conducted a randomized phase II trial to investigate whether Hangeshashinto (TJ-14) prevents or controls chemotherapy induced oral mucositis.

Patients and Methods: Patients who develop moderate to severe chemotherapy induced oral mucositis (WHO grade>1) during any cycle of chemotherapy are randomly assigned to receive either Hangeshashinto (TJ-14) (n=25) or placebo (n=25). Patients receive the administration of Hangeshashinto (TJ-14) or placebo for 3 weeks at the beginning of the next course of chemotherapy. The patients are advised to dissolve 2.5g of Hangeshashinto (TJ-14) or placebo in 50ml drinking water, and divide it into twice or three times in an oral cavity. Patients rinse their oral cavity with it three times daily. The signs of oral mucositis is assessed by the investigator during the screening cycle. The CTCAE v4.0 grading is used to assess the severity of oral mucositis. The primary endpoint is duration time of oral mucositis, and secondary endpoints include incidence of oral mucositis, incidence of diarrhea, blood levels of CRP, The change of body weight, and blood levels of albumin.

Accrual: This study began in June 2015. The expected end of accrual of 50 patients will be the last quarter 2017.

Citation Format: Iwamoto M, Umezaki N, Matsuda J, Kawaguchi K, Terasawa R, Sato N, Fyjioka H, Kimura K, Tanaka S, Uchiyama K. Randomized phase II study of Hangeshashinto (TJ-14) for chemotherapy induced oral mucositis in patients with breast cancer (Hangesha-B study). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT3-02-01.
Abstract P1-03-06: Leptin as a mediator of tumor-stromal interactions promotes breast cancer stem cell activity
Authors: Giordano C , Panza S , Chemi F , Barone I , Bonofiglio D , Cordella A , Hashim A , Györffy B , Simões BM , Clarke RB , Weisz A , Catalano S , Andò S
Published: May 2016

Breast cancer stem cells (BCSCs) play crucial roles in tumor initiation, metastasis and resistance to anticancer therapies. These cells rely for their properties on complex interactions with the tumor microenvironment through networks of cytokines and growth factors. In this study, we investigated how leptin, as a mediator of tumor-stromal interactions, may affect BCSC activity using breast cancer cell lines and patient-derived samples. We found that conditioned media (CM) from cancer associated fibroblasts and breast adipocytes significantly increase mammosphere formation in breast cancer cells. Depletion of leptin from stromal cell-CM as well as inhibition of leptin signaling by using a full leptin receptor antagonist peptide LDFI completely abrogated this effect. Accordingly, mammosphere cultures exhibited increased leptin receptor expression and leptin exposure enhanced mammosphere formation. Microarray analyses revealed a similar expression profile of genes involved in stem cell biology in mammosphere cells treated with stromal cell-CM and leptin. Interestingly, leptin is able to increase the mammosphere formation in metastatic breast cancer cells isolated from patients (n = 10) and this can be blocked by using peptide LDFI. In addition, leptin receptor (OBR) mRNA expression, analyzed in cells from metastatic fluids, directly correlated with mammosphere formation activity ex vivo (r=0.68, p= 0.05; n = 8). Finally, Kaplan–Meier survival curves indicated that OBR expression correlated with reduced overall survival in breast carcinomas (HR=1.9, p=0.022). Together, our results suggest that leptin/leptin receptor may represent a potential therapeutic target that can block the stromal-tumor interactions that drive BCSC-mediated disease progression.

Citation Format: Giordano C, Panza S, Chemi F, Barone I, Bonofiglio D, Cordella A, Hashim A, Györffy B, Simões BM, Clarke RB, Weisz A, Catalano S, Andò S. Leptin as a mediator of tumor-stromal interactions promotes breast cancer stem cell activity. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-03-06.
Abstract P1-03-08: Tartrate-resistant acid phosphatase (TRAcP) dependent polarization of breast cancer-promoting macrophages
Authors: Dai M-S , Janckila A , Lo H-C , Wu C-C , Chao T-Y , Yu J-C
Published: May 2016

Background:

Breast cancer associated macrophages often promote tumor growth and metastasis by conditioning the tumor microenvironment and suppressing adaptive immune responses. Tartrate-resistant acid phosphatase (TRACP) is a novel serum biomarker associated with systemic macrophage burden in a variety of chronic inflammatory diseases and is strongly expressed by tumor-associated macrophages. We tested the hypothesis that TRACP is required for M2 macrophage polarization.

Methods:

Macrophage cell lines were polarized in vitro and tested for TRACP, iNOS and Arg-1 expression and their ability to promote or repress breast cancer cell growth and invasion in vitro and in vivo. A novel TRACP deficient, Acp5 mutant mouse was used as a macrophage source and as a breast cancer host to confirm a role for TRACP for macrophages to support cancer growth.

Results:

TRACP was up-regulated in concert with M2 polarization and down-regulated in M1 polarized cells. TRACP expression correlated with macrophage promotion of tumor growth and invasion in vitro. Although TRACP-deficient macrophages could be induced to express Arg-1 when stimulated with IL-4 plus IL-13 (M2 phenotype), the TRACP deficient macrophages behaved like M1 cells suppressing tumor growth and invasion compared to than WT cells. Tumor xenografts grew slower in primary subcutaneous grafts and metastasized less extensively in intravenous grafts in TRACP deficient mice compared to WT. Furthermore, the tumor metastatic patterns could be reversed in WT animals by co-grafting TRACP-deficient macrophages and in TRACP deficient hosts by co-grafting WT macrophages.

Conclusions:

TRACP expression is normally a phenotypic marker for alternatively activated macrophages, but not necessary for expression of Arg-1. In a host environment of TRACP deficiency, Arg-1 positive macrophages can be generated by cytokine stimulation in vitro and by tumor in vivo, however, TRACP deficiency still conveyed a tumor suppressive phenotype in cell based studies and in intact animals. TRACP plays a role in functional polarization of M2 macrophages and their ability to promote breast cancer growth and metastasis.

Citation Format: Dai M-S, Janckila A, Lo H-C, Wu C-C, Chao T-Y, Yu J-C. Tartrate-resistant acid phosphatase (TRAcP) dependent polarization of breast cancer-promoting macrophages. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-03-08.