bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4192: Identification of novel genetic drivers of vulvar carcinoma in a Sleeping Beauty model of spontaneous cancer
Authors: Guimaraes-Young Amy , Neff Traci , Meyerholz David K. , Dupuy Adam J. , Goodheart Michael J.
Published: August 2015

Introduction:

The purpose of this study was to develop a Sleeping Beauty (SB)-induced mouse model of metastatic vulvar carcinoma with which we could identify novel tumor-driving mutations.

Experimental Procedures:

An existing transgenic mouse model known to induce development of benign vaginal papillomas, (PrCre/+;KrasG12D), was bred to mice containing the components of the SB system to render (PrCre/+;KrasG12D;SB) mice. The SB system consists of a transposable element (transposon) and an activating enzyme (transposase) that induces excision of the transposon from one site to another in the host cell genome. Insertional mutations that enhance cell survival and proliferation are selected for, resulting in the development of cancer. We utilize the SB system to identify candidate driver mutations since the transposon is not only the mutagen but also serves as a sequence tag for localization of mutations. Mice were aged and monitored for phenotypic signs of disease. Upon necropsy, gynecologic and other grossly abnormal organs were harvested. Genomic DNA was extracted from each sample, prepared for genetic analysis, and sequenced using the Illumina platform. Candidate genes were identified using an unbiased Monte-Carlo approach in conjunction with a gene-centric Chi-Squared analysis. Paraffin-embedded human tumor samples were obtained from the University of Iowa Hospitals and Clinics for immunohistochemical labeling of protein expression for selected genes.

Results:

Vulvar carcinoma developed in 29 of 29 PrCre/+;KrasG12D;SB female mice with metastases by seven months of age confirmed in 13 animals. Organs within the abdominal cavity including the uterus and ovaries contained metastatic lesions in some mice. In one mouse, a distant metastasis within the subcutaneous tissue of the thoracic back was observed. Illumina sequencing of primary lesions from all mice revealed 77 candidate tumor drivers.

Conclusions:

To our knowledge, the PrCre/+;KrasG12D;SB mouse is the first reported metastatic model of vulvar carcinoma. Protein expression of candidate genes identified by our SB screen are being assessed in human tissue samples. Patient clinical data will be incorporated into analyses to determine whether candidate genes are correlated to patient outcomes. This work will permit insights into the pathophysiology and future treatment of vulvar cancer.

Note: This abstract was not presented at the meeting.

Citation Format: Amy Guimaraes-Young, Traci Neff, David K. Meyerholz, Adam J. Dupuy, Michael J. Goodheart. Identification of novel genetic drivers of vulvar carcinoma in a Sleeping Beauty model of spontaneous cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4192. doi:10.1158/1538-7445.AM2015-4192
Abstract 4195: GNASR201H and KrasG12D cooperate to promote murine pancreatic tumorigenesis recapitulating human intraductal papillary mucinous neoplasm
Authors: Furukawa Toru , Tanji Etsuko , Ohmuraya Masaki , Taki Katsunobu , Araki Kimi
Published: August 2015

Intraductal papillary mucinous neoplasm (IPMN) is the most common pancreatic cystic neoplasm, which is a precursor of the invasive ductal adenocarcinoma. IPMNs recurrently harbor activating somatic mutations in GNAS and KRAS, mostly GNASR201H and KRASG12D. GNAS encodes the stimulatory G-protein α subunit (Gsα) that mediates a stimulatory signal to adenylyl cyclase to produce cyclic AMP (cAMP), a second messenger activating cAMP dependent protein kinase (PKA). The GNASR201H mutation is known to result in constitutive activation of Gsα and its downstream signaling molecules, which induces expression of various genes including mucin genes. To study a role of GNAS in pancreatic tumourigenesis in vivo, we generated transgenic mice lines of which transgene is consisted of Lox-STOP-Lox (LSL)- GNASR201H under the control of the CAG promoter (Tg(CAG-LSL-GNAS)). The transgene contains genetic elements that inhibit transcription and translation of GNASR201H flanked by functional LoxP sites. These mice lines were crossed to pancreatic transcription factor 1 a (Ptf1a)-cre mice, and generated Tg(CAG-LSL-GNAS);Ptf1a-cre mice. This mouse line showed elevated cAMP levels and a compensatory upregulation of PKA in the pancreas. GNASR201H alone was not sufficient to induce tumourigenesis by 2 months of age, but small dilated tubular complex formation, loss of acinar cells, and fibrosis, which could be a very early phenotype of IPMN. To know a cooperative effect of GNASR201H and KRASG12D in pancreatic tumorigenesis, we crossed Tg(CAG-LSL-GNAS);Ptf1a-cre mice with LSL-KrasG12D mice. Tg(CAG-LSL-GNAS);LSL-KrasG12D;Ptf1a-cre mice developed multiple cysts consisting of marked dilated ducts lined with papillary dysplastic epithelia in the pancreas within 5 weeks, which recapitulated human IPMNs. Our data strongly suggest that mutated GNAS cooperating with mutated KRAS may sufficiently cause to develop IPMN.

Citation Format: Toru Furukawa, Etsuko Tanji, Masaki Ohmuraya, Katsunobu Taki, Kimi Araki. GNASR201H and KrasG12D cooperate to promote murine pancreatic tumorigenesis recapitulating human intraductal papillary mucinous neoplasm. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4195. doi:10.1158/1538-7445.AM2015-4195
Abstract 4196: Neuregulin signaling in development and transformation of the luminal breast epithelium
Authors: Vaught David B. , Hicks Donna , Sanchez Violeta , Cook Rebecca
Published: August 2015

ErbB3 and ErbB4 are members of the ErbB family of receptor tyrosine kinases (RTK) that can be activated by neuregulins (NRGs) and as a result are often referred to as the neuregulin receptors. The neuregulin receptors are required for growth and survival of the ductal and alveolar luminal epithelium. We have recently shown that ErbB3 is required for survival and growth of the ductal luminal epithelium and to maintain the balance of differentiated epithelial cell types in the mammary gland, which is consistent with the fact the ErbB3 expression is highest in the ductal luminal epithelium and in luminal progenitor populations of the mouse and human mammary glands. ErbB4, is also required for growth in the luminal mammary epithelium, but not within the ductal luminal population, rather in the alveolar luminal population. In addition to neuregulin receptor signaling in development, ErbB3 and ErbB4 expression has been found to be at the highest levels in luminal breast cancers compared to other molecular breast cancer subtypes. Furthermore, human luminal breast cancer cell lines also express higher levels of ErbB3 and ErbB4 than cell lines derived from other molecular breast cancer subtypes. Since both ErbB3 and ErbB4 are capable of binding to neuregulin ligands and heterodimerizing with other ErbB family members, there is evidence that ErbB4 may compensate for loss of ErbB3, and vice versa. Thus, our goal is to understand how combined loss of ErbB3 and ErbB4 impact the normal luminal cell populations and the transformed cell populations of the breast epithelium. We hypothesize that loss of ErbB3 and ErbB4 will decrease cellular growth and survival during development and in our mouse models of breast cancer. Early studies demonstrate conditional loss of ErbB3fl/fl and ErbB4fl/fl independently and in combination decrease pup weights compared to control mice and demonstrate reduced epithelium/alveolar cell expansion in whole mount and histology analysis. In addition, early analysis of ErbB3fl/fl, ErbB4fl/fl ErbB3fl/fl/ErbB4fl/fl crossed to the p110 inducible mouse model of breast cancer are trending to a delay in tumor onset. Molecular analysis demonstrates a reduction in Pi3K/Akt signaling and Jak/Stat signaling in ErbB3fl/fl and ErbB4fl/fl respectively, with ongoing studies currently underway to analyze signaling in ErbB3fl/fl/ErbB4fl/fl mice in development.

Citation Format: David B. Vaught, Donna Hicks, Violeta Sanchez, Rebecca Cook. Neuregulin signaling in development and transformation of the luminal breast epithelium. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4196. doi:10.1158/1538-7445.AM2015-4196
Abstract 4199: Developing therapies for rare tumors: Using mouse models of malignant peripheral nerve sheath tumors to complement rare human samples in drug screens
Authors: Reilly Karlyne M. , Tuskan Robert G. , Widemann Brigitte C.
Published: August 2015

Rare cancers are defined by the US Orphan Drug Act as affecting <200,000 patients in the US. For patients with these cancers, there may be an urgent need for new therapies; however, these rare cancers present challenges to drug development. Because of the small number of patients, the cancers are not well characterized, the molecular mechanisms may not be well-understood, and there may not be adequate model systems available for research and drug development.

The Rare Tumors Initiative in the Intramural Research Program at the National Cancer Institute is focusing on overcoming hurdles in rare tumor research by developing new approaches to treat malignant peripheral nerve sheath tumors (MPNST). MPNSTs occur in younger adults with an incidence of 1 in 100,000, with a higher incidence in patients with Neurofibromatosis type 1. Due to a limited number of high quality human MPNST tumor lines, drug testing has been challenging both in vitro and in vivo. A genetically engineered mouse model carrying mutations in Nf1 and Trp53 develops MPNST spontaneously starting around 3 months of age. We have generated tumor lines from over 30 independent mouse MPNSTs, from different sexes and genetic backgrounds that we are using to test drugs in combination with available human MPNST lines. We find good concordance between the mouse and human MPNST lines in response to drugs. Furthermore, although the MPNST lines show good dose response and high maximum response to many targeted compounds, the concentrations of drug required to achieve inhibition is often high, suggesting that one of the difficulties in developing MPNST therapy is the inherent resistance of MPNST cells to drug inhibition.

We will present results of ongoing drug screens in panels of mouse and human MPNST cell lines, using drugs that are in different phases of clinical trials or approved for other diseases.

Citation Format: Karlyne M. Reilly, Robert G. Tuskan, Brigitte C. Widemann. Developing therapies for rare tumors: Using mouse models of malignant peripheral nerve sheath tumors to complement rare human samples in drug screens. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4199. doi:10.1158/1538-7445.AM2015-4199
Abstract 4227: PARP inhibitors sensitize glioblastoma stem cells to oncolytic herpes simplex virus therapy
Authors: Ning Jianfang , Wakimoto Hiroaki , Martuza Robert , Rabkin Samuel
Published: August 2015

Glioblastoma (GBM) is an invariably fatal brain tumor in adults and remains a great challenge for preclinical and clinical research. PARP inhibitors (PARPi) have been used alone or in combination with genotoxic agents for the treatment of cancers with homologous recombination (HR) repair deficiencies. Oncolytic herpes simplex viruses (oHSVs) are genetically-engineered to selectively replicate in cancer cells, and previous studies have shown that oHSV infection of glioblastoma stem cells (GSC) induces DNA damage and compromises HR DNA repair. Therefore, we hypothesized that PARPi and oHSV would synergistically kill GSCs through inducing lethal DNA damage.

Here, we show that PARPi consistently inhibited PARylation in a panel of patient-derived GSC lines. Surprisingly, half of GSCs (4 of 8) were sensitive to PARPi killing, with the other half being resistant. When combined with 2 different oHSVs, MG18L and G47Δ, PARPi olaparib and oHSV synergistically killed olaparib-sensitive GSCs in vitro. Moreover, olaparib sensitized PARPi-resistant GSCs to the cytotoxic effects of MG18L or G47Δ, leading to increased DNA damage and cell death. While monotherapy with systemic olaparib or intratumoral injection of MG18L increased survival in an orthotopic xenograft model generated with olaparib-sensitive GSCs, combination treatment greatly extended survival over either monotherapy alone, with concomitant induction of robust DNA damage and apoptosis in the tumors. Furthermore, in an orthotopic model with olaparib-resistant GSCs, in which olaparib monotherapy was not effective, combinatorial therapy of olaparib and MG18L was significantly more efficacious than MG18L alone in prolonging lifespan. Our studies demonstrate that PARPi have anti-GSC activity in about half of GBMs tested, and combining PARPi with oHSV targets DNA damage responses and induces a synthetic lethal effect in vitro and in vivo against both PARPi-sensitive and -resistant GSCs. This report describes a new therapeutic strategy for GBM and supports investigations of this combination in the clinic.

Citation Format: Jianfang Ning, Hiroaki Wakimoto, Robert Martuza, Samuel Rabkin. PARP inhibitors sensitize glioblastoma stem cells to oncolytic herpes simplex virus therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4227. doi:10.1158/1538-7445.AM2015-4227
Abstract 4234: Targeting cancer stem cell to enhance therapeutic efficacy of prostate cancer
Authors: Yun Eun-Jin , Hernandez Elizabeth , Hsieh Jer-Tsong
Published: August 2015

Increasing evidence has indicated the role of cancer stem cell (CSC) in the progression toward to more aggressive cancer. CSC is defined as a tumor initiating population that are capable of self-renewal and also regenerate fast-proliferative tumor cell progeny. Especially, CSCs appear to be more resistant than highly proliferative tumor cells to conventional therapies, which could explain therapeutic failure. Thus, CSCs have been recognized as important candidate targets to cure the patient. In prostate cancer (PCa), castration resistance prostate cancer (CRPC) is an end-stage, incurable disease and associated with the majority of mortality. CRPCa is characterized to be androgen-independent and express many specific genes from basal cells that contain stem cell population. Also, some evidence suggests CRPC possessing CSC phenotypes. In this study, we employed several non-tumorigenic, immortalized normal human prostate epithelial cells derived from basal cell population as a model to study the relationship of CSC with CRPC. These cells express unique stem cell markers (CD44high/CD24low) from profiling stem cell gene expression, acquire stem cell phenotypes based on prostatesphere and side population assays after knocking down a novel tumor suppressor gene-DAB2IP that is involved in cell trans-differentiation such as epithelial-to-mesenchymal transition (EMT). These cells become highly tumorigenic with very low cell number using in vitro colony formation and anchorage-independent assays and in vivo xenograft model. Also, these cells are highly resistant to chemotherapeutic agent or radiotherapy. From a tissue microarray study, we observed a significant correlation of CD44 expression determined by immunohistochemical staining with advanced stage of PCa specimens. CD44 is not only a stem cell marker but also plays a key role in CSC formation. Mechanistically, CD44 expression is regulated by Wnt signaling in which DAB2IP functions as a potent scaffold protein to recruit PP2A and GSK3β inhibit β-catenin activation. Thus, by targeting this pathway using Wnt-specific small molecular inhibitors can reduce CSC population and synergistically enhances the drug effect of conventional chemotherapy. Furthermore, using in vivo CSC model, combination therapy exhibited a synergistic effect on tumor growth. Taken together, this study provides a strong evidence of the relationship of CSC with CRPC. It also offers a new and promising therapeutic strategy targeting CSC as well as proliferative non-CSC cell population in hope to eradicate tumor initiating cell and its progeny population simultaneously.

Citation Format: Eun-Jin Yun, Elizabeth Hernandez, Jer-Tsong Hsieh. Targeting cancer stem cell to enhance therapeutic efficacy of prostate cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4234. doi:10.1158/1538-7445.AM2015-4234
Abstract 4244: Comparison of different ALK tests in non-small cell lung cancer (NSCLC) patients treated with crizotinib and their clinical outcome
Authors: van der Wekken Anthonie J. , Hiltermann Thijo JN , Timens Wim , Schuuring Ed , Groen Harry JM
Published: August 2015

Background:

The screening algorithm for detection of ALK-rearranged NSCLC is still under investigation. The Break-Apart ALK FISH is the standard diagnostic test for the treatment with crizotinib. However, immunohistochemistry (IHC) with different antibodies shows excellent results when compared to ALK FISH. The efficacy of crizotinib is studied in relation to ALK FISH. We compared IHC outcome and the number of ALK breaks estimated with FISH with clinical outcome.

Methods:

Patients treated with crizotinib who had biopsies with sufficient tumor tissue were selected. Tumour response was assessed by CT using RECIST. Fluorescence in situ hybridization (FISH) was performed with Vysis LSI ALK Break Apart FISH Probe KIT (Abbott Molecular) and immunohistochemistry with Ventana ALK IHC Kit using D5F3 antibody.

Results:

Twenty one patients with NSCLC were selected, median (range) age 54 yrs (21-75); 19 had adenocarcinoma, 2 had large-cell carcinoma. We confirmed the presence of EML4-ALK fusions in all samples either by FISH or IHC. Median percentage of ALK breaks was 47% (6-76). Tumour response occurred in 12 pts having a median of 51 (6-76) breaks and 9 non-responders having a median of 27 (15-64) breaks. Of the 12 responders, 8 pts had positive IHC (67%), 3 were negative and 1 was not done; the FISH negative, IHC positive patient was one of the responders. Of the 9 non-responders 2 had positive IHC (22%), 3 negative (33%), and 1 was equivocal and 3 not done. Median PFS for positive IHC is 7.9 mo (95% CI., 5.5 - 10.3) and for negative IHC 1.6 mo (1.3 - 1.8), n = 17, p<0.0001. OS survival data are 6.5 mo (95% CI., 0 - 17.8) and 18.3 mo (95% CI., 11.1 - 25.6) respectively, n = 17 p = 0.052.

PFS above 30% number of breaks was 7.0 mo (95% CI., 1.8 - 12.2) versus PFS below is 1.8 mo (95% CI., 0.7 - 2.9), n = 21, p = 0.05. OS survival data are 4.1 mo (95% CI., 0 - 9.3) and 16.1 mo (95% CI., 9.0 - 23.2) respectively, n = 21 p = 0.003. Therefore PFS and OS is more prolonged in those tumors who have ALK breaks above 30%. IHC difference are only significant for PFS.

Conclusions:

Both ALK FISH and IHC identify NSCLC patients who benefit from crizotinib treatment. Patients with ALK breaks above 30% have a better PFS and OS. IHC only differentiates for PFS.

Citation Format: Anthonie J. van der Wekken, Thijo JN Hiltermann, Wim Timens, Ed Schuuring, Harry JM Groen. Comparison of different ALK tests in non-small cell lung cancer (NSCLC) patients treated with crizotinib and their clinical outcome. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4244. doi:10.1158/1538-7445.AM2015-4244
Abstract 4262: PRAME as a biomarker for a new molecular subclass of uveal melanoma
Authors: Field Matthew G. , Decatur Christina L. , Harbour J. William
Published: August 2015

Introduction: Uveal melanoma is the most common primary intraocular tumor of the eye and has a propensity for fatal hematogenous metastasis. Gene expression profiling is routinely used in clinic to classify uveal melanoma into prognostic subgroups: Class 1 (low metastatic risk) and Class 2 (high metastatic risk). Approximately 40% of Class 2 patients metastasize, which accounts for 85% of metastasis. The remaining 15% of patients that metastasize are Class 1 based on gene expression profiling, however this study demonstrates that the Class 1 patients that metastasize (Class1met+) can be defined as a new molecular subclass, distinct from Class 1 patients that do not metastasize (Class1met-) and Class 2 patients.

Methods: Tumor samples from Class1met+ and Class1met- patients with at least 1 year of follow-up underwent histopathologic, cytogenetic and transcriptomic analyses.

Results: In a comparison of Class1met+ and Class1met- tumors, the only significant difference was a larger mean basal tumor diameter in Class1met+ tumors. Cytogenetic analyses revealed more extensive copy number gains and losses in Class1met+ tumors. The most significant differentiating features in Class1met+ tumors included 1q gain, 6p gain, 6q loss, and 8q gain. Using principal component analysis, the Class1met+ tumors clustered separately from the Class1met- tumors, indicating the existence of significant transcriptomic differences between the two subgroups. Strikingly, the most highly differentially expressed gene in Class1met+ tumors was preferentially expressed antigen in melanoma (PRAME); mean mRNA expression of PRAME in Class1met+ tumors was 61-fold higher than in Class1met- tumors.

Discussion: We define a new subtype of uveal melanoma and demonstrate that gene expression of PRAME can distinguish between Class1met+ patients and Class1met- patients.

Citation Format: Matthew G. Field, Christina L. Decatur, J. William Harbour. PRAME as a biomarker for a new molecular subclass of uveal melanoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4262. doi:10.1158/1538-7445.AM2015-4262
Abstract 4263: Concurrent aberrations in the Wnt, MAPK and PI3K pathways identified through next generation sequencing of relapsed refractory colorectal adenocarcinoma (CRC): Implications for future therapeutic trials
Authors: Subbiah Ishwaria M. , Janku Filip , Tsimberidou Apostolia M. , Naing Aung , Subbiah Vivek , Wheler Jennifer J. , Zinner Ralph , Eng Cathy , Overman Michael J. , Kopetz Scott , Hong David S.
Published: August 2015

Background: Relapsed refractory colorectal adenocarcinoma (CRC) is evolving as a disease with distinct molecular subsets rather than a singular histology. Given the varied outcomes of CRC patients treated on clinical trials particularly with targeted therapies, we aimed to identify a molecular phenotype for future therapeutic targeting.

Methods: We identified CRC patients referred to our Phase I clinic with adequate tissue for next generation sequencing (NGS) on a commercially available platform (FoundationOne, Boston, MA). Over 2000 exons of 186 cancer-related genes plus over 30 introns from 14 genes often rearranged in cancer were fully sequenced for point mutations, insertions/deletions, copy number alterations (CNAs) and select gene fusions.

Results: Overall, 60 relapsed CRC patients (31 male, 29 female; median age 55 years; 56 colon primary, 4 rectum primary). 48 (80%) patients had a mutation linked to aberrant Wnt pathway signaling (most commonly, APC 43 pts, 90%). Of these 48 patients, over half (n = 26, 54%) demonstrated a concurrent mutation affecting the PI3K cascade (PIK3CA in 12 patients [4 E545K, 3 Q546K, 2 E542K, 1 H1047Y, 1 E453K, 1 R38C]). Of these 26 pts with concurrent aberrant Wnt and PI3K pathways, 22 also demonstrated a concomitant MAPK pathway mutation (17 KRAS and 3 BRAF). Of the 60 CRC pts overall, 22 (37%) patients had coexisting aberrations linked to in all three (Wnt, PI3K, and MAPK) cascades.

Conclusions: Concomitant mutations in three pathways (Wnt, MAPK, PI3K) implicated in cancer occur frequently in patients with advanced CRC, emphasizing the need for a combinatorial therapeutic strategy ideally targeting all three cascades.

Note: This abstract was not presented at the meeting.

Citation Format: Ishwaria M. Subbiah, Filip Janku, Apostolia M. Tsimberidou, Aung Naing, Vivek Subbiah, Jennifer J. Wheler, Ralph Zinner, Cathy Eng, Michael J. Overman, Scott Kopetz, David S. Hong. Concurrent aberrations in the Wnt, MAPK and PI3K pathways identified through next generation sequencing of relapsed refractory colorectal adenocarcinoma (CRC): Implications for future therapeutic trials. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4263. doi:10.1158/1538-7445.AM2015-4263
Abstract 427: Host and tumoral CXCR2 signaling contributes to tumor growth
Authors: Carroll Danielle , Harper James , McDaid Karen , Franks Ruth , Eberline Catherine , Kendrew Jane , Sainson Richard , Anderton Judith , Rossant Chris , Coffman Karen , Leow Ching Ching , Inigo Ivan , Reville Mitchell , Shenton Jacintha , Young Lesley , Barry Simon
Published: August 2015

Chemokines are essential mediators of leukocyte migration and inflammation. Additionally they play an important role in tumour growth. The G-protein coupled receptor, CXCR2, and its ligands (CXCL 1,2,3,5,6,7 and IL8) have been shown to promote tumour initiation and growth, chemo-resistance, angiogenesis and immune cell infiltration (neutrophil, myeloid derived suppressor cells (MDSCs) and macrophages) into the tumour microenvironment. However the contribution of host and tumour CXCR2 has not been elucidated.

We have developed both murine and human specific anti-CXCR2 antibodies alongside a humanised CXCR2 transgenic mouse to address the contribution of host and tumour CXCR2 signalling to tumour growth and maintenance. In pre-clinical tumours, granulocytic cells (neutrophils and MDSCs) within the tumour increase with size, in parallel with alteration in cell numbers observed within the spleen, peripheral blood and bone marrow.

Inhibition of host CXCR2 has a dramatic impact on peripheral neutrophil levels, as well as their ability to become activated.

In pre-clinical tumour models, inhibition of CXCR2 results in tumour growth inhibition. Contribution of host or tumour cells to the effect of CXCR2 blockade was model dependent. In the EL4 murine lymphoma model, only inhibition of host/peripheral CXCR2 was able to impact tumour growth. Whereas, in other murine syngeneic models (CT26 and B16), both host and tumour CXCR2 play a role in tumour growth. This was further demonstrated in an NSCLC patient derived xenograft, where the contribution of tumour CXCR2 was stronger than the host.

Collectively our data show that CXCR2 inhibition (alone or in combination) has potential to influence growth of a number of tumour types. Future work is focused on understanding the mechanisms underlying the effects of CXCR2 inhibition, which remain key to developing it as an effective anti-cancer therapeutic.

Citation Format: Danielle Carroll, James Harper, Karen McDaid, Ruth Franks, Catherine Eberline, Jane Kendrew, Richard Sainson, Judith Anderton, Chris Rossant, Karen Coffman, Ching Ching Leow, Ivan Inigo, Mitchell Reville, Jacintha Shenton, Lesley Young, Simon Barry. Host and tumoral CXCR2 signaling contributes to tumor growth. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 427. doi:10.1158/1538-7445.AM2015-427
Abstract 4283: Anticancer effects obtained against A20 lymphomas following treatment with LTX-315 (Oncopore®) in combination with low-dose cyclophosphamide
Authors: Camilio Ketil André , Eike Liv-Marie , Rekdal Øystein , Sveinbjornsson Baldur
Published: August 2015

Background: Host defense peptides (HDPs) are naturally occurring molecules found in most eukaryotic species, where they play a significant role in the first line of defense against pathogens. Several HDPs have been shown to possess anticancer activity. Structure-activity relationship studies on the HDP bovine lactoferricin has resulted in the design of LTX-315, a short chemically modified peptide that induces immunogenic dell death. Previous animal studies have demonstrated that intratumoral (i.t.) treatment of syngeneic murine A20 B-cell lymphomas, CT26WT colon carcinomas and B16F1 melanomas with LTX-315 resulted in complete tumor regression and tumor specific immune responses. In the present study, we investigated the antitumor effects of LTX-315 in combination with low-dose cyclophosphamide (CY) against A20 lymphomas. Methods: A20 lymphoma cells (5 × 106) were intradermally inoculated into the abdomen of syngeneic Balb/c mice. Established tumors were treated i.t. with LTX-315 in combination with low-dose CY. Results: Intratumoral (i.t.) administration of LTX-315 in a suboptimal setting resulted in a synergistic antitumor effect when combined with low-dose CY, compared to CY and LTX-315 alone. In the combination therapy group the treatment induced a complete regression of the tumor in the majority of the animals (6 out of 9 animals), compared to LTX-315 alone (1 out of 8 animals) and no regression in the two control groups (CY alone and vehicle). Conclusions: Our results demonstrate that treatment with LTX-315 in combination with low-dose CY results in a synergistic antitumor effect in vivo. Thus, local treatment with the immunogenic cell death inducer LTX-315 combined with systemic chemotherapy may represent a promising combination strategy in future cancer therapy.

Citation Format: Ketil André Camilio, Liv-Marie Eike, Øystein Rekdal, Baldur Sveinbjornsson. Anticancer effects obtained against A20 lymphomas following treatment with LTX-315 (Oncopore®) in combination with low-dose cyclophosphamide. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4283. doi:10.1158/1538-7445.AM2015-4283
Abstract 4285: Immunomodulatory activity of aza-podophyllotoxin derivatives
Authors: Kumar Ajay , Valentin Eric Miranda , Otero Miguel
Published: August 2015

Derivatives of podophyllotoxin, namely etoposide (2), etopophos (3) and teniposide (4) have been developed and are currently used in clinic for the treatment of a variety of malignancies. Due to structural complexity of podophyllotoxin, commercial synthesis, further derivative synthesis and structural modifications of podophyllotoxin are limited. We have developed some heterocyclic analogues of podophyllotoxin i.e. N-hydroxyethyl-4-aza-podophyllotoxin derivatives (AZPs). Advantage of these compounds is their easy and fast synthesis as compared to the parent natural lignin i.e. podophyllotoxin. Owing to their promising activity against 60 cell lines at NCI, we further expanded the library of AZPs substituted at ring A and E. This was followed by a screen of in vivo activity using a panel of tumor hollow-grafts implanted in mice consisting of breast (MDA-MB-231), non-small lung (NCI-H23 and NCI-H522), colon (SW-620 and COLO 205), melanoma (UACC-62, MDA-MB-435 and LOXIMVI), ovarian (OVCAR-5 and OVCAR-3) and CNS (U251 and SF-295) cell lines. These new compounds shows comparatively excellent activity against several human cancer cell lines at NCI. We recently reported activity of AZPs in MTA resistant Cancer Cells.

We are now reporting immunomodulatory effect of our AZPs for the first time, assessed by in-vitro stimulation of mouse lymphocytes for five days. Specifically, our preliminary data shows AP-102, AP-103, AP-104, and AP-205 to induce 2208, 2575, 2071, and 7166 pg/mL of G-CSF, respectively, and the AP-311, AP-312, AP-102, AP-103, AP-104, and AP-205 induced 551, 810, 772, 1125, 782, and 4351 pg/mL of IL-6, respectively. These data demonstrate the immunostimulatory ability of our AP compounds. Further experiments need to be performed to study the impact of these compounds in the modulation of the immune system.

Citation Format: Ajay Kumar, Eric Miranda Valentin, Miguel Otero. Immunomodulatory activity of aza-podophyllotoxin derivatives. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4285. doi:10.1158/1538-7445.AM2015-4285
Abstract 4287: Talimogene laherparepvec activates systemic T-cell-mediated anti-tumor immunity
Authors: Piasecki Julia , Rottman Jim , Le Tiep , Ponce Rafael , Beers Courtney
Published: August 2015

Talimogene laherparepvec is an investigational oncolytic immunotherapy based on a modified herpes simplex virus type-1 (HSV-1) immunotherapy designed to selectively replicate in tumors and to initiate an anti-tumor immune response. Intralesional administration of talimogene laherparepvec is intended to result in oncolysis within injected tumors. Iterative replication of virus within permissive tumor tissue results in lytic cell destruction and local release of progeny virus and tumor derived antigens. GM-CSF, a product of the viral transgene, is also produced locally such that it can recruit and stimulate antigen presenting cells which, in addition to relevant tumor-derived antigens, are required for the initiation of a systemic antitumor immune response.

The talimogene laherparepvec-induced immune mediated mechanism of action in both the virus-injected and distant tumors have yet to be fully understood therefore, we evaluated viral replication, tumor cell lysis, and the changes in immune cell populations in both the injected and distant tumors using syngeneic contralateral tumor models. Animals received a single intratumoral dose of the murine surrogate of talimogene laherparepvec (OncoVEXmuGM-CSF), which induced regression in the majority of virus-injected tumors and tumor growth inhibition/regression in the contralateral (uninjected) tumors. HSV-1 antigen was only detected by IHC in the virus-injected tumor and not the contralateral tumor (and no other tissues). Virally-mediated tumor destruction (oncolysis) was also localized to only the virus-injected tumor. In preliminary experiments, morphometric analysis of the tumor tissue revealed that the percent area of CD3+ and CD8+ lymphocytes were significantly increased in both the virus-injected and contralateral tumors compared to the formulation control mice. In addition, the percent area occupied by CD103+ cells (a marker found on potent cytotoxic T cell stimulating dendritic cells) was increased in the virus-injected tumor compared to the contralateral tumor and the tumors in the control animals. Although cellular infiltration was increased in both virus-injected and contralateral tumors and was inversely correlated with tumor volume, the decreased volume of injected tumors was attributed to viral oncolysis. Taken together these data supports that talimogene laheparepvec activates a systemic T cell mediated anti-tumor immune response.

Citation Format: Julia Piasecki, Jim Rottman, Tiep Le, Rafael Ponce, Courtney Beers. Talimogene laherparepvec activates systemic T-cell-mediated anti-tumor immunity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4287. doi:10.1158/1538-7445.AM2015-4287
Abstract 4295: INT230-6, a novel intratumoral anticancer agent, is able to eradicate large established tumors and stimulate potent anti tumor immunity
Authors: Walters Ian B. , Bender Lewis H. , Terabe Masaki , Berzofsky Jay A.
Published: August 2015

Historically, intratumoral (IT) administered chemotherapy has not been shown to provide better efficacy than the same drugs delivered intravenously. This is postulated to be due to poor drug diffusion and dispersion throughout the tumor. Intensity has developed a novel formulation of cytotoxic chemotherapy plus a penetration enhancer which improves drug diffusion and uptake into the cancer cell. INT230-6 is a combination of low dose cisplatin, vinblastine and a cell penetration excipient. This technology enables more rapid and improved penetration throughout the tumor including hypoxic and un-vascularized areas. Cohorts of 10 BALB/c mice were inoculated with 1×106 CT26 cells subcutaneously (SC). Tumors were grown to a mean of 325mm3 and then treatment with INT230-6 was administered IT daily for a single cycle of 5 days. Control arms using comparable size tumors pre-dose included no treatment, IV cisplatin and vinblastine, and IT injection of these drugs without the enhancer. INT230-6 treatment resulted in regression from baseline in all animals with a complete regression of the large tumors in 20%. Many tumors continued to shrink in size well beyond multiple half-lives of the chemotherapy and excipient implying an anti-tumor effect not due to direct cytotoxicity from the drugs. INT230-6 administration resulted in a significant extension of overall survival compared to all controls. Notably complete responders with this treatment were resistant to 3 separate attempts at re-inoculation with 1×106 CT26 cells by SC or IV administration without retreatment of drug, while control animals rapidly developed metastatic tumors and died. This apparent tumor immunity persisted for > 440 days suggesting permanent immunity. In a follow-on study, tumors of some animals receiving INT230-6 were shown to be 75% necrotic on day 3 of treatment with an observed increase in the density of CD4 positive cells and CD11c positive cells in the treated tumors on day 10 versus controls. These changes might be involved in the induction of immunity. These results suggest that intratumoral administration of INT230-6 creates the proper tumor cell apoptosis kinetics and antigen presentation to enable a personalized adaptive immune response to develop. Further work is being done to look at repeat dosing and combinations with other immunomodulating agents.

Citation Format: Ian B. Walters, Lewis H. Bender, Masaki Terabe, Jay A. Berzofsky. INT230-6, a novel intratumoral anticancer agent, is able to eradicate large established tumors and stimulate potent anti tumor immunity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4295. doi:10.1158/1538-7445.AM2015-4295
Abstract 4296: Dextran sodium sulfate-induced colitis in dendritic cell deletion mice
Authors: Masuda Junko , Kitani Atsuhi , Fuss Ivan , Seno Masaharu , Strober Warren
Published: August 2015

Dendritic cells (DC) located in lamina propria are critical for converting to CD4+Foxp3+ regulatory T (Treg) cells from CD4+Foxp3- in the presence of retinoic acid and TGF-beta. However, role of DC and Treg in immunological tolerance with commensal bacteria is still controversial. To address this question, we bred constitutively CD11c+ DC-depleted mice on C57BL/6 background. Although CD4+ T cells isolated from splenocytes showed normal in vitro differentiation into Th1 and Th17 cells, these DC-depleted mice were more protective than that of control against dextran sodium sulfate (DSS) -induced colitis. Treg expression level of DC-depleted mice was lower than that of control and not changed even after colitis. These results suggest that other cell populations regulate gastrointestinal system in both static and chronic inflammatory state in DC-depleted mice.

Citation Format: Junko Masuda, Atsuhi Kitani, Ivan Fuss, Masaharu Seno, Warren Strober. Dextran sodium sulfate-induced colitis in dendritic cell deletion mice. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4296. doi:10.1158/1538-7445.AM2015-4296
Abstract 4309: Description of a scientific treatment approach of mast cell leukemia, an aggressive orphan hematologic disorder: strategy based on next-generation sequencing data
Authors: Youk Jeonghwan , Koh Youngil , Kim Ji-Won , Kim Dae-Yoon , Jung Woo June , Ahn Kwang-Sung , Yoon Sung-Soo , Jung Hye Lim
Published: August 2015

Background

Mast cell leukemia (MCL) is the most aggressive form of disorder among systemic mastocytosis. Due to its rarity, neither pathogenesis nor standard treatment is not established for this orphan disease. Hence, we tried to treat a patient with MCL based on the exome and transcriptome sequencing result of the patient's own DNA and RNA.

Brief Case History and Results

In October 2013, an 18-year-old Korean female were diagnosed as MCL after visiting our hospital due to left knee, ankle pain and inguinal lymphadenopathy. C-KIT overexpression was observed by immunohistochemistry. Whole exome sequencing result failed to demonstrate either noticeable single nucleotide variant (SNV) or copy number change. Interestingly, whole transcriptome sequencing (WTS) revealed mutation of KIT S476I, functionality of which is not known. Fusion analysis was performed using WTS data, possibility of RARα-B2M fusion has been arised. However, it was not validated by PCR sequencing. When RNA expression analysis was performed using WTS data, upregulation of PIK3/AKT pathway, which is a downstream of KIT (BAD phosphorylation) and mTOR has been observed.

For the treatment perspective, she failed to achieve complete remission after cytarabine and idarubicin chemotherapy. Based on our WES and WTS result, we first tried all-trans retinoic acid targeting RARα, which failed to demonstrate efficacy. Then, she received dasatinib targeting KIT, which showed transient response for 2 weeks. Now she is under everolimus targeting mTOR pathway and, further treatment with PI3K inhibitor is planned in case of disease progression.

Conclusions

We are demonstrating a case of orphan disease, where we used targeted approach using WES and WTS data of the patient. Final results of our treatment outcome will be uncovered shortly, and utility of this kind of approach is to be validated.

Citation Format: Jeonghwan Youk, Youngil Koh, Ji-Won Kim, Dae-Yoon Kim, Woo June Jung, Kwang-Sung Ahn, Sung-Soo Yoon, Hye Lim Jung. Description of a scientific treatment approach of mast cell leukemia, an aggressive orphan hematologic disorder: strategy based on next-generation sequencing data. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4309. doi:10.1158/1538-7445.AM2015-4309
Abstract 4322: Kinase activity profiles distinguish papillary thyroid cancers with and without BRAF V600E mutations
Authors: Hilhorst Maria H. , van den Berg Adrienne , van Wezel Tom , Kievits Tim , Boender Piet J. , de Wijn Rik , Ruijtenbeek Rob , Corver Wim , Morreau Hans
Published: August 2015

Background: Most differentiated non medullary thyroid cancers (DTC) are curatively treated by surgery and radio-active iodine ablation therapy. A subset of patients shows recurrence due to a loss of iodine transport. Two main subgroups of recurrent DTC are seen: papillary thyroid cancers (PTC) with somatic BRAF mutations (V600E) and oncocytic follicular cancer. Recurrent DTC are clinically treated by multi-kinase inhibitors such as sorafenib, with a low affinity for BRAF V600E. Vemurafenib and dabrafenib were specifically designed against this mutant.

The aim of this study was twofold:

- Can benign and malign DTC be classified based on kinase activity profiles?

- Do sorafenib (and regorafenib) show different inhibition profiles than dabrafenib?

Methods: Tissue cryosections from fresh frozen thyroid tumors were lysed. All tumor specimens were analyzed for BRAF mutations. Serine/threonine kinase (STK) activity profiles of the lysates (0.5 μg protein per array) were generated on PamChip® peptide microarrays, comprising peptide sequences from known human phosphorylation sites. The ex vivo effect of BRAF inhibitors sorafenib, regorafenib and dabrafenib on kinase activity profiles of 14 PTC's was determined as well. Data were analysed with Bionavigator software.

Results: A classifier built on the STK kinase activity profiles of 57 thyroid cancer samples was able to classify malignant and benign tumors with a limited error rate. Leave One Out Cross Validation classified 26/35 of malignant and 17/22 of benign samples correctly. Kinase inhibition profiles of PTC's with sorafenib and regorafenib did not discrimate V600E mutants from wild type tumors whereas with dabrafenib 34/144 peptides were identified that potentially differentiated the groups.

Conclusions: Serine/threonine kinase activity profiling appears to be able to differentiate benign and malignant thyroid tumors. Ex vivo spiking in of kinase inhibitors shows differential inhibition in tumors with a somatic BRAF mutation. Potentially, an industrial prediction platform can be envisioned for testing of novel drugs in tumor tissue. Whether individual patient responses against registered kinase inhibitors can be predicted must be investigated.

Citation Format: Maria H. Hilhorst, Adrienne van den Berg, Tom van Wezel, Tim Kievits, Piet J. Boender, Rik de Wijn, Rob Ruijtenbeek, Wim Corver, Hans Morreau. Kinase activity profiles distinguish papillary thyroid cancers with and without BRAF V600E mutations. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4322. doi:10.1158/1538-7445.AM2015-4322