bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4102: Surgical imaging of pancreatic cancer using near infrared fluorescent hyaluronic acid nanomaterials
Authors: Qi Bowen , Crawford Ayrianne , Cohen Samuel , Hollingsworth Michael , Mohs Aaron M.
Published: August 2018

Purpose: Pancreatic ductal adenocarcinoma (PDAC) has an overall 5-year survival rate for all patients of approximately 7.1%. Surgery only increases the long-term survival rate of PDAC to 12.1%. Survival could potentially be increased with better detection of pancreatic cancer during surgical resection by improved margin detection, more effective debulking of disseminated disease, and earlier detection. In this work, we utilized nanoparticle formulations of the near infrared fluorophore indocyanine green (ICG) to provide optical detection of pancreatic tumors in an orthotopic, syngeneic mouse model of PDAC.

Methods: ICG was physico-chemically entrapped nanoparticles derived from amphiphilic hyaluronic acid, termed NanoICG and compared to ICG alone. Cytotoxicity and immunotoxicity of the imaging agents were determined by in vitro methods, while blood biochemistry, cell counts, and toxicological pathology, were examined in vivo. The ability to detect PDAC was determined in PDAC cells originating from KPC mice that were implanted orthotopically into syngeneic C57 mice. Contrast enhancement was determined using a combination of image-guided surgery systems and whole animal imaging systems.

Results: Neither Empty NP of NanoICG affected metabolic activity toward healthy pancreatic epithelial or pancreatic adenocarcinoma cells and NanoICG displayed did not have capacity to act as a chemoattractant. In vivo, NanoICG (normalized to maximum allowed ICG dose) did not alter blood biochemical markers including HGB, ALB, ALP, ALT, AMY, BUN, GLOB, and TP or cell counts including, WBC, RBC, PLT, or HCT. Histological examination showed no toxicity related to the administration of contrast agents in liver, lung, spleen, or kidneys. In the syngeneic, orthotopic PDAC model, NanoICG accumulated significantly within the pancreas and had a 2.1-fold stronger signal compared to ICG alone. Considering contrast within PDAC compared to uninvolved healthy pancreas, NanoICG was 2.34-fold stronger (P<0.05), while contrast between PDAC and healthy pancreas with ICG was minimally detectable. Using near infrared fluorescence microscopy, area strong signal from NanoICG localized to areas of PDAC.

Conclusions: NanoICG exhibited improved efficacy at detecting pancreatic tumors in an orthotopic pancreatic cancer model with negligible NP-derived toxicity, which shows NanoICG as a promising agent in pancreatic tumor diagnosis and surgical resection. Further research is being performed to minimize clearance organ uptake.

Citation Format: Bowen Qi, Ayrianne Crawford, Samuel Cohen, Michael Hollingsworth, Aaron M. Mohs. Surgical imaging of pancreatic cancer using near infrared fluorescent hyaluronic acid nanomaterials [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4102.
Abstract 4114: Development and application of 18F-labeled Tenascin-C aptamer for cancer imaging
Authors: Park Jun Young , Cho Ye Lim , Chae Ju Ri , Chu Ga Eul , Cho Won Gil , Kim Sang Wun , Kang Won Jun
Published: August 2018

Aptamers are synthetic single-stranded DNA or RNA that can be held together with complementary sequences by base-pairing. Tenascin-C is an extracellular matrix protein that is overexpressed in cancer tissues. Herein, we investigate the biological characteristics of Tenascin-C aptamer as potential tumor imaging agents. Cy5 or F-18 labeled Tenascin-C aptamers were prepared through hybridization-based labeling method using complementary oligonucleotide platform. Immunoblot analysis was performed on U-251 MG, U-87 MG, C6 and NCI-H460 cell lines to confirm the expression of tenascin-C. In vitro binding specificity of Tenascin-C aptamers was evaluated using confocal microscopy. In vivo biodistribution properties and PET Imaging of the 18F-labeled Tenascin-C were determined in C6 tumor-bearing nude mice. High levels of tenascin-C protein were detected in C6, U-251 MG. and U-87 MG cell lines. However, tenascin-C protein levels were undetectable in NCI-H460 cells. Confocal fluorescence microscopy images showed that Cy5-labeled Tenascin-C aptamer bound specifically to tenascin-C protein expressing cell lines including C6, U-251 MG and U-87 MG, however, not bound to NCI-H460 cells. Tumor uptake of 18F-labeled Tenascin-C aptamer was 1.64 ± 0.36 at 30 min after injection in C6 tumor xenografts. C6 tumors were clearly visualized by microPET imaging in a tumor-bearing mouse at 60 after injection. Tenascin-C aptamer was successfully labeled with F-18 labeled complementary oligonucleotide by base-pair hybridization. In vitro data showed that the cODN platform-hybridized Tenascin-C aptamer was selectively bound to target tumor cells. In addition, C6 tumor xenografts in mice were clearly visualized on microPET imaging. Our study demonstrated that Tenascin-C may be a useful target molecule for the imaging of malignant gliomas.

Citation Format: Jun Young Park, Ye Lim Cho, Ju Ri Chae, Ga Eul Chu, Won Gil Cho, Sang Wun Kim, Won Jun Kang. Development and application of 18F-labeled Tenascin-C aptamer for cancer imaging [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4114.
Abstract 4116: Rapid imaging of tumor cell death in vivo using C2Am
Authors: Neves Andre A. , Brindle Kevin M.
Published: August 2018

Cell death is an important target for imaging the early response of tumors to treatment. We describe here the validation of C2Am, a phosphatidylserine-binding agent based on the C2A domain of synaptotagmin-I, for detecting tumor cell death in vivo.

Methods: The capability of (99m)Technetium-, (111)Indium-labelled or near- infrared fluorophore-labelled derivatives of C2Am for imaging tumor cell death was evaluated in implanted and genetically engineered [Fig.1] mouse models of lymphoma and in a human colorectal xenograft, using single photon CT (SPECT) and planar near-infrared fluorescence imaging, respectively [1,2].

Results: (99m)Tc-C2Am and (111)In-C2Am showed favorable biodistribution profiles, with predominantly renal clearance and low nonspecific retention in the spleen and liver at 24 h after probe administration. (99m)Tc-C2Am and (111In)-C2Am generated tumor-to-muscle ratios in drug-treated tumors of 4.3× and 2.2×, respectively, at 2 h and 7.3× and 4.1×, respectively, at 24 h after administration. A fluorophore-labelled C2Am derivative also showed predominantly renal clearance and high specificity and sensitivity for detecting low levels of tumor cell death (<5%). There was a significant correlation (R=0.9) between fluorescently labelled C2Am binding and histologic markers of cell death (cleaved caspase-3); no such correlation was observed with a site-directed mutant of C2Am that does not bind phosphatidylserine (iC2Am).

Conclusions: Given the favorable biodistribution profile of radiolabelled C2Am derivatives, and their ability to produce rapid and cell death-specific image contrast, these agents have potential for clinical translation, particularly as PET tracers. We have initiated GMP manufacture and toxicology studies required for a Phase 1 trial.

References:

[1] Neves AA, Xie B, Fawcett S, Alam IS, Witney TH, de Backer MM, Summers J, Hughes W, McGuire S, Soloviev D, Miller J, Howat WJ, Hu DE, Rodrigues TB, Lewis DY, Brindle KM. Rapid Imaging of Tumor Cell Death In Vivo Using the C2A Domain of Synaptotagmin-I. (2017) J Nucl Med. 58:881-887.

[2] Xie B, Tomaszewski MR, Neves AA, Ros S, Hu DE, McGuire S, Mullins SR, Tice D, Sainson RCA, Bohndiek SE, Wilkinson RW, Brindle KM. Optoacoustic Detection of Early Therapy-Induced Tumor Cell Death Using a Targeted Imaging Agent. (2017) Clin Cancer Res. 23:6893-6903.

Citation Format: Andre A. Neves, Kevin M. Brindle. Rapid imaging of tumor cell death in vivo using C2Am [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4116.
Abstract 412: 8p12 amplification pattern dictates FGFR1 dependency in squamous cell lung cancer
Authors: Malchers Florian , Attekum Martijn Henricus van , Peifer Martin , Thomas Roman Kurt
Published: August 2018

Squamous cell lung cancer (SQLC) is the second most common lung cancer subtype after adenocarcinoma and accounts for 30% of all lung cancer cases. However, in contrast to adenocarcinoma, SQLC lacks therapeutic targets like activating EGFR mutations, ALK or ROS translocations. Besides immune-checkpoint-inhibition a promising treatment option in SQLC is the recurrent amplification of the tyrosine kinase fibroblast growth factor receptor 1 (FGFR1) within the 8p12-p11 region. Thus, small molecules inhibiting FGFRs have been employed to treat FGFR1-amplified SQLC. However, only about 10% of such FGFR1-amplified tumors respond to single agent inhibitor therapy. To investigate the mechanism of FGFR inhibitor resistance in 8p12-p11 amplified SQLC we performed deep genomic and transcriptome sequencing on 53 FGFR1 amplified samples including primary tumors (n=33), patient derived xenografts (n=13) and cell lines (n=7). For 22 of these samples the response to FGFR inhibition was known. We detected frequent breaks within NSD3 (n=3), also known as WHSC1L1, favoring the expression of NSD3-short, which is known to enhance MYC expression. Furthermore, the amplification pattern for all samples was compatible with a breakage-fusion-bridge (BFB) mechanism, showing chromosomal telomeric losses, copy number, and frequent intrachromosomal head to head and tail to tail breaks. Genomic reconstruction of one sample suggests a tandem duplication followed by a BFB mechanism, implying that the BFB mechanism is a later event in tumor genesis. Intrachromosomal tail to tail fusions within a 400kb region close to the FGFR1 open reading frame, have been detected in 75% of patients with a partial response to FGFR inhibitor therapy (3 of 4 patients). A similar break was detected in the FGFR inhibitor sensitive cell line H1581. All samples, which responded to FGFR inhibition (n=9), demonstrated a centered amplification pattern on NSD3 / FGFR1 and excluded amplification of the adjacent disintigrin and metalloproteinase family members (ADAM) genes. In contrast, the main amplification peak of the non-responding samples (n = 13) was centered on ADAM family members, corresponding to an increase in ADAM expression. These data suggest strong relevance of these genes for tumor development and growth, and warrant further investigation.

Citation Format: Florian Malchers, Martijn Henricus van Attekum, Martin Peifer, Roman Kurt Thomas. 8p12 amplification pattern dictates FGFR1 dependency in squamous cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 412.
Abstract 4120: A novel HDAC-targeted probe for triple-negative breast tumor imaging
Authors: Tang Chu , Du Yang , Tian Jie
Published: August 2018

Purpose: Due to lack of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER-2), there was no specific imaging probes can be applied to detect triple-negative breast cancers (TNBCs). Currently, several lines of evidences support that overexpression of histone deacetylases (HDACs) has been associated with TNBC. Here, we sought to develop HDAC-targeted probe for TNBC imaging.

Experimental Design: The pan-HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) was chosen as the targeting ligand, and was labeled with a near-infrared dye IRDye800CW for the development of HDAC-targeted probe IRDye800CW-SAHA. Subsequently, HDAC binding affinity and specificity of probe IRDye800CW-SelSA to TNBC MDA-MB-231 cells was evaluated by HDAC inhibition assay, flow cytometry and confocal laser microscope experiments. Moreover, the in vivo fluorescence molecular imaging (FMI) was performed to monitor the biodistribution and tumor targeting effects of the probe in MDA-MB-231 tumor xenografts.

Results: The fluorescence probe IRDye800CW-SAHA was successfully developed, and conjugating IRDye800CW to SAHA did not alter the HDAC binding affinity. The cellular uptake and the fluorescence intensity of probe on MDA-MB-231 cells were significantly higher compared to normal MCF-10A cells (P < 0.05). Meanwhile, the cellular uptake of probe can be effectively blocked by co-incubation with SAHA. The in vivo imaging results showed that IRDye800CW-SelSA was able to target tumor rapidly, and the tumor to normal tissue (T/N) fluorescence intensity ratio reached the peak around 12 h (T/N = 3.4).

Conclusions: Our study demonstrated that IRDye800CW-SAHA is an efficient probe for the targeted imaging of TNBC and may possess clinical translation in the future.

CT and YD contributed equally to this work

Citation Format: Chu Tang, Yang Du, Jie Tian. A novel HDAC-targeted probe for triple-negative breast tumor imaging [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4120.
Abstract 4124: YAP1 fusion proteins mediate oncogenic activity in ependymoma via interaction with TEAD transcription factors
Authors: Pajtler Kristian W. , Okonechnikov Konstantin , Vouri Mikaella , Brabetz Sebastian , Jones David T. , Korshunov Andrey , Capper David , Chavez Lukas , Pfister Stefan M. , Kool Marcel , Kawauchi Daisuke
Published: August 2018

Ependymomas are neuroepithelial tumors of the central nervous system (CNS), presenting in both adults and children but accounting for almost 10% of all pediatric CNS tumors and up to 30% of those in children under 3 years. In a previous study we identified two molecular groups of supratentorial (ST) ependymoma in pediatric patients driven by distinct gene fusions involving either the NF-κB effector RELA or the HIPPO signaling regulator YAP1, designated ST-EPN-RELA and ST-EPN-YAP1, respectively. The lack of adequate models for ST-EPN-YAP1, which predominantly occurs in very young children, has so far hindered the development of effective targeted therapies for these tumors. In an attempt to model this group, the most frequent fusion type, YAP1-MAMLD1, was cloned into a Luciferase-carrying transposable vector. Oncogenicity was subsequently tested using an electroporation-based in vivo gene transfer following injection of the vector into the lateral ventricle of E13.5 wildtype mouse embryos. After birth, YAP1-MAMLD1-expressing tumors, monitored using luciferase-based in vivo bioluminescence imaging, developed rapidly with 100% penetrance, indicating that the fusion alone is sufficient to initiate tumors. To further investigate the role of this fusion in human EPNs, we performed YAP1 ChIP-seq analyses on human ST-EPN-YAP1 and ST-EPN-RELA primary tumors. Despite similar gene expression levels of YAP1 in both molecular groups, our comparative analyses found that putative binding sites of TEADs, transcriptional factors interacting with YAP1, were significantly enriched in identified YAP1 peaks in ST-EPN-YAP1. In vivo validation further confirmed that interaction between YAP1-MAMLD1 and TEADs is crucial for oncogenicity of the fusion, since prevention of YAP1-TEAD binding did not result in tumor formation. Thus, targeting the YAP1-TEAD interaction might represent a promising therapeutic approach for this devastating infant disease.

Citation Format: Kristian W. Pajtler, Konstantin Okonechnikov, Mikaella Vouri, Sebastian Brabetz, David T. Jones, Andrey Korshunov, David Capper, Lukas Chavez, Stefan M. Pfister, Marcel Kool, Daisuke Kawauchi. YAP1 fusion proteins mediate oncogenic activity in ependymoma via interaction with TEAD transcription factors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4124.
Abstract 4127: A tumor evolution screen in zebrafish identifies PlexinA1 as a driver of metastasis and growth in human rhabdomyosarcoma
Authors: Welker Alessandra M. , Hayes Madeline N. , Tang Qin , Langenau David M.
Published: August 2018

Relapse and metastasis are major clinical problems facing patients with rhabdomyosarcoma (RMS), a devastating pediatric malignancy of the muscle. Alveolar Rhabdomyosarcoma (ARMS) is characterized by genetic translocations while Embryonal Rhabdomyosarcoma (ERMS) is characterized by Ras pathway activation. Treatment for either RMS subtype requires surgical resection, chemotherapy, and radiation with overall poor prognosis for patients with high-risk features including metastasis and relapse. Thus, there is great interest in elucidating key molecular pathways and genetic factors that are involved in continued RMS growth and tumor maintenance. In the Langenau lab, we utilize a powerful transgenic zebrafish model of kRASG12D- induced ERMS and have recently developed a p53-/- (null) zebrafish model. p53 is one of the most common tumor suppressor genes, and upwards of 1/3 of RMS patients have mutations or Loss-of-Heterozygosity (LOH) of this locus. This model accurately mimics the molecular underpinnings and histopathology of human ERMS and has been used to discover molecular pathways that drive relapse. Using our tp53-/- (null) zebrafish along with large-scale cell transplantation assays, we have assessed metastatic potential of our ERMS tumors following serial passaging and acquisition of new driver mutations. Specifically, we performed a tumor evolution screen using serial engraftment of ERMS into recipient fish followed by RNA sequencing to discover novel pathways that are associated with elevated tumor growth and metastasis. Plexin A1 was one of our top hits in this screen, being expressed at >8 fold in metastatic lesions of the zebrafish and expressed in >80% of human RMS. Plexins are a large family of receptors for transmembrane, secreted and GPI-anchored semaphorins. Knockdown of PLXNA1 decreased human ERMS cell proliferation, increased differentiation and impaired anchorage-independent growth and migration. Collectively, our data supports the hypothesis that PLXNA1 is an important moderator of tumor growth in a large fraction of human RMS and likely regulates local invasion and metastasis. This work will provide much needed data for discovery of novel therapeutically-actionable pathways for relapsed ERMS and likely inform future treatment for high-risk patients.

Citation Format: Alessandra M. Welker, Madeline N. Hayes, Qin Tang, David M. Langenau. A tumor evolution screen in zebrafish identifies PlexinA1 as a driver of metastasis and growth in human rhabdomyosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4127.
Abstract 4133: Increased I2PP2A compromises TP53 function by stabilizing MDM2 in Shh medulloblastoma
Authors: Wei Yun , Maximov Victor , Kenney Anna
Published: August 2018

Medulloblastoma is the most common malignant pediatric brain tumor. Currently, the standard therapy comprising radiation, surgery and chemotherapy “cures” about 70% of medulloblastoma patients. However, these aggressive and non-differential treatment modalities cause lifelong side effects in patients. Medulloblastoma patients are classified into four different subgroups based on transcriptional and molecular profiles, namely WNT, SHH, Group 3, and Group 4. The SHH subgroup accounts for approximately 30% of all medulloblastoma cases and is further subcategorized into TP53 wild type and TP53 deficient subtypes. The importance of TP53 status in SHH medulloblastoma patients has been recently recognized by the association between TP53 mutation and poor prognosis for these patients. However, research findings illustrating TP53 signaling in preclinical models of SHH medulloblastoma are quite limited. Apart from the fact that TP53 mutation is associated with poor survival, 80% of medulloblastoma cases are TP53 wild type. TP53 protein is a tumor suppressor which acts as a checkpoint protein for all types of cells. Cancer cells either mutate TP53 gene or employ other mechanisms such as overexpressing MDM2 to compromise TP53 protein function. Therefore we hypothesize that TP53 function is compromised by highly active MDM2 in TP53 wild type Shh medulloblastoma.

Using the SmoA1 mouse model, which closely recapitulates human SHH medulloblastoma, we aim to investigate whether TP53 signaling has been disrupted in Shh medulloblastoma. Surprisingly, we observed relatively higher TP53 protein levels in tumor tissue lysates as compared to that in neighboring normal cerebellum using SmoA1 mice. However, MDM2, the major suppressor of TP53, showed higher phosphorylation at Ser166, which would stabilize MDM2, resulting in degradation of newly-produced TP53 protein. We also found significantly increased protein levels of I2PP2A, an endogenous inhibitor of phosphatase 2A, which can dephosphorylate MDM2 at Ser166. Using COG112, a small molecule inhibitor of I2PP2A, we showed the reactivation of PP2A, concurrent with a decrease of p-MDM2 and an increase of TP53 in a time-dependent manner. From these experiments, we conclude that 1) TP53 pathway is functional in our SmoA1 mouse model; 2) I2PP2A upregulation could be the reason for rapid degradation of TP53 protein in SmoA1 mice. These findings have translational implications as they suggest that targeting I2PP2A in TP53 wild type SHH medulloblastoma patients could be a method of driving tumor cell death, thus resulting in better clinical outcomes for these patients.

Citation Format: Yun Wei, Victor Maximov, Anna Kenney. Increased I2PP2A compromises TP53 function by stabilizing MDM2 in Shh medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4133.
Abstract 4135: c-MYC drives a subset of high-risk pediatric neuroblastoma and is activated through mechanisms including enhancer hijacking and focal enhancer amplification
Authors: Zimmerman Mark W. , Liu Yu , He Shuning , Durbin Adam D. , Abraham Brian J. , Easton John , Shao Ying , Beisi Xu , Zhu Shizhen , Zhang Xiaoling , Li Zhaodong , Weichert-Leahey Nina , Young Richard A. , Zhang Jinghui , Look A. Thomas
Published: August 2018

The amplified MYCN gene serves as an oncogenic driver in approximately 20% of high-risk pediatric neuroblastomas. Here we show that c-MYC itself is a potent transforming gene in a separate subset of high-risk neuroblastoma cases (~10%), based on (i) its upregulation by focal enhancer amplification or genomic rearrangements leading to enhancer hijacking, and (ii) its ability to transform neuroblastoma precursor cells in a transgenic animal model. The aberrant regulatory elements associated with oncogenic c-MYC activation include focally amplified distal enhancers or translocation of highly active enhancers from other genes to within topologically associating domains containing the c-MYC gene locus. The clinical outcome for patients with high levels of c-MYC expression is virtually identical to that of patients with amplification of the MYCN gene, a known high-risk feature of this disease. Together, these findings establish c-MYC as a bona fide oncogene in a clinically significant group of high risk childhood neuroblastomas.

Citation Format: Mark W. Zimmerman, Yu Liu, Shuning He, Adam D. Durbin, Brian J. Abraham, John Easton, Ying Shao, Xu Beisi, Shizhen Zhu, Xiaoling Zhang, Zhaodong Li, Nina Weichert-Leahey, Richard A. Young, Jinghui Zhang, A. Thomas Look. c-MYC drives a subset of high-risk pediatric neuroblastoma and is activated through mechanisms including enhancer hijacking and focal enhancer amplification [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4135.
Abstract 4136: Marked decrease of BIRC5/Survivin by haploinsufficiency does not inhibit neuroblastoma in transgenic mice: Implications for survivin as a therapeutic target in neuroblastoma
Authors: Dorneburg Carmen , Rasche Volker , Lechel Andre , Katz Sarah-Fee , Debatin Klaus-Michael , Beltinger Christian
Published: August 2018

Overexpression of survivin, a crucial regulator of the mitotic spindle checkpoint with additional antiapoptotic effects, is associated with poor prognosis in neuroblastoma (NB) and other cancers. Thus, survivin is a promising therapeutic target in NB. Transcriptional inhibitors of survivin show preclinical efficacy and have been tested in clinical trials. The results of these trials, however, have been disappointing, due to modest efficacy and unexpected off-target effects. We thus investigated the consequences of marked, yet incomplete decrease of survivin on NB in a novel transgenic mouse model.

To this end, we crossed mice haploinsufficient for survivin with TH-MYCN mice to generate BIRC5+/- MYCN tg/+ mice. These mice developed NB with markedly decreased mRNA and protein expression of survivin. Surprisingly, incidence and latency of the NB that developed in the BIRC5+/- MYCN tg/+ mice were not different from those in the TH-MYCN mice. Growth of tumors was not decreased in BIRC5+/- MYCN tg/+ mice, as assessed by serial MRI imaging, and survival of the mice was not increased. Immunohistochemistry of the NB did not show decreased proliferation (Ki67), increased apoptosis (activated caspase 3) or a change in vascularity (CD31). No difference in copy number variations between the two NB mouse models was discernible using CGH arrays. To determine whether dysfunctional T cells described in mice haploinsufficient for survivin could have masked any loss of aggressiveness of NB cells haploinsufficient for survivin, NB of BIRC5+/- MYCN tg/+ mice were retransplanted into survivin sufficient mice. No difference in tumor incidence, latency and growth was detected.

Taken together, despite a marked decrease in the expression of BIRC5/survivin by haploinsufficiency development and growth of NB were not inhibited. While a further decrease of survivin beyond that seen in haploinsufficiency will inhibit NB, it most likely will also elicit marked side effects, given that survivin is essential for normal cells. Our results cast doubt on the efficacy of inhibitors of survivin expression in NB and call for targeting survivin by alternative approaches, such as inhibiting protein-protein interactions of survivin.

Citation Format: Carmen Dorneburg, Volker Rasche, Andre Lechel, Sarah-Fee Katz, Klaus-Michael Debatin, Christian Beltinger. Marked decrease of BIRC5/Survivin by haploinsufficiency does not inhibit neuroblastoma in transgenic mice: Implications for survivin as a therapeutic target in neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4136.
Abstract 4145: Characterization of the ODZ receptor family in neuroblastoma
Authors: Andonova Teodora , Kogner Per , Johnsen John Inge , Wickström Malin
Published: August 2018

Neuroblastoma is the most common extracranial solid tumor of childhood, causing 6% of all childhood cancers but 9% of deaths from malignant tumors in children. It is a tumor with highly heterogeneous clinical behavior, believed to originate from undifferentiated neural crest cells that form the sympathetic nervous system. Neuritogenesis is the process during embryonic development when neural crest cells migrate and differentiate into multiple cell types. The Rho/Rac signaling cascade is fundamental for this process. We performed whole genome sequencing of 40 neuroblastoma tumor samples, 32.5% of the samples contained a mutation in a gene associated with Rho/Rac signaling. The most frequently mutated receptor family among the Rho/Rac associated genes was the tenuerins (ODZ1-4). The ODZ genes were mutated in three out of 40 patients, i.e. 7.5%. The ODZ proteins are not fully characterized, however it is known they are highly expressed during the development of the central nervous system and play role in differentiation of the drosophila fly.

Evidence suggests a function for dysregulated expression of the ODZs in human tumors, but investigations of a deeper cellular and molecular understanding in neuroblastoma are missing. The aim of this study is to investigate the ODZ receptors to determine the role and function of these proteins in neuroblastoma tumor development, progression and metastasis. When investigated in publically available and validated neuroblastoma cohorts, low expression levels of ODZ1, ODZ2 and ODZ3 were associated with poor overall survival, while low ODZ4 expression correlated with high overall survival. Our data demonstrated that the ODZ receptors were differently expressed in neuroblastoma cell lines. Preliminary results also showed that siRNA knockdown of ODZ4 in a neuroblastoma cell line led to a 50% decrease in cell viability compared to control, together with morphological changes such as more neurite extensions, suggesting that an inhibition of ODZ4 may result in differentiation. Knockout of the four different ODZ transcripts also showed that the ODZ receptors might have compensatory mechanisms for each other. Our data suggest that activity of the ODZ receptors may be important for neuroblastoma development and that manipulation could offer a possible therapy for neuroblastoma.

Citation Format: Teodora Andonova, Per Kogner, John Inge Johnsen, Malin Wickström. Characterization of the ODZ receptor family in neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4145.
Abstract 4148: Role of the photoreceptor gene, CRX (cone-rod homeobox) in pathogenesis of non-WNT, non-SHH medulloblastoma
Authors: Masurkar Shalaka , Moiyadi Aliasagar , Sridhar Epari , Jalali Rakesh , Shirsat Neelam
Published: August 2018

Central nervous system (CNS) tumours are the second most common cancers diagnosed in children after leukemia and continue to be the leading cause of cancer-related mortality in children. Medulloblastoma (MB) is a highly malignant primary brain tumour that occurs in posterior fossa region of the brain. The current standard treatment regimen includes surgical resection, craniospinal irradiation and adjuvant chemotherapy. Although this has resulted in significant increase in survival, approximately one-third of medulloblastoma patients still die because of the disease. Genome-wide gene expression profiling studies have identified four molecularly distinct subgroups of medulloblastoma namely WNT, SHH, Group 3, and Group 4. Among the four subgroups, Group 3 patients exhibit highest incidence of metastasis and worst overall survival rates. Molecular mechanism underlying the pathogenesis of Group 3 medulloblastomas is not understood. Group 3 tumors often express retina photoreceptor-specific genes like CRX (Cone Rod Homeobox) which is a homeodomain transcription factor and it is essential for the normal development and maintenance of cones and rods cells of the retina. We have noted that this expression is also retained by the medulloblastoma cell lines like D425, D283 and D341 which have characteristics of Group 3 tumours. Downregulation of CRX in these cell lines brought about inhibition of cell proliferation and anchorage-independent growth as studied by soft agar colony formation assay. CRX gene, therefore, seems to act as an oncogene similar to OTX2, another homeobox gene overexpressed in medulloblastomas. Transcriptome profiling and CHIP-seq analysis is being carried out to identify genes regulated by CRX transcription factor to delineate the molecular mechanism underlying the oncogenic role of CRX in medulloblastoma pathogenesis.

Citation Format: Shalaka Masurkar, Aliasagar Moiyadi, Epari Sridhar, Rakesh Jalali, Neelam Shirsat. Role of the photoreceptor gene, CRX (cone-rod homeobox) in pathogenesis of non-WNT, non-SHH medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4148.
Abstract 4152: Synergistic gold nanostar-mediated photothermal and immunotherapy for cancer metastasis treatment
Authors: Liu Yang , Maccarini Paolo , Palmer Gregory M. , Inman Brant A. , Vo-Dinh Tuan
Published: August 2018

Cancer has become a severe thread to human health resulting in more than eight million deaths each year. Cancer metastasis is the main mechanism in more than 90 percent of cancer deaths. However, current therapeutic options including chemotherapy and radiation therapy have limited therapeutic effects to treat cancer metastasis. Therefore, there is an urgent need to develop novel methods for cancer treatment. Our group has developed a unique method to synthesize star-shaped gold nanoparticles, gold nanostars (GNS), without using toxic surfactant, which is very suitable for in vivo applications. The synthesized GNS has tip-enhanced plasmonics and tunable strong in the near-infrared “tissue optical window”, enabling it a superior photon-to-heat nanotransducer. The GNS nanoparticles accumulate preferably into tumor with enhanced permeability and retention (EPR) effect after intravenous administration. We have applied GNS for photothermal therapy with 808 nm laser to specifically ablate tumor. Here we report a new cancer treatment method by combing nanophotothermal therapy and anti-PD-L1 immunotherapy. Immunogenic cell death is often insufficient to trigger effective anti-cancer immunity due to the presence of immunosuppressive factors occurring in the tumor microenvironment such as hypoxia, impaired leukocyte trafficking and inhibitory immune checkpoint signaling. The GNS-mediated photothermal ablation can reduce hypoxia and improve leukocyte trafficking to the tumor. In addition, the administration of anti-PD-L1 antibody reverses another critical immunosuppression factor. Experiment results using a mouse bladder cancer model demonstrated that the combined photothermal and immunotherapy have synergistic effect and can not only eradicate primary tumors with laser treatment but also distant metastasis without laser treatment. Furthermore, delayed rechallenge in the cured mice didn't result in new tumor generation, indicating that our combined therapy induced memorized immune response against cancer. The combined GNS-mediated photothermal therapy and anti-PD-L1 immunotherapy has promise to improve therapeutic effect on not only primary tumor but also cancer metastasis.

Citation Format: Yang Liu, Paolo Maccarini, Gregory M. Palmer, Brant A. Inman, Tuan Vo-Dinh. Synergistic gold nanostar-mediated photothermal and immunotherapy for cancer metastasis treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4152.
Abstract 4155: USP11 regulates UV-induced DNA damage repair and cell survival associated with skin cancer
Authors: Shah Palak , Qiang Lei , Yang Seungwon , Soltani Keyoumars , He Yu-Ying
Published: August 2018

UV radiation is a major risk factor for skin cancer, the most common cancer in the United States. UV exposure leads to DNA damage by formation of dimers between adjacent pyrimidine bases. The nucleotide excision repair (NER) process is responsible for removal of UV-induced DNA damage. When the damage is left unrepaired due to inefficient NER in disorders like xeroderma pigmentosum, it leads to skin tumorigenesis. Although the main players of the NER pathway have been characterized, the molecular regulation of the pathway is less understood. Understanding the regulation, particularly post-translational regulation, of the NER pathway has the potential to yield modulators of NER efficiency to prevent skin cancer. We found that chronic UV irradiation led to down-regulation of ubiquitin specific peptidase 11 (USP11) in mouse skin tissue. We also found that USP11 is decreased in skin tumors in mice and humans. Moreover, high-throughput proteomics analysis had predicted that USP11 may interact with NER factor XPC. Hence, we undertook this study to determine the role of USP11 in NER and cellular response to UV. We found that USP11 promoted the NER pathway by regulating XPC activity. USP11 promoted XPC deubiquitination and retention at the DNA damage sites. We also found that USP11 interaction with ubiquitinated XPC was enhanced post-UV irradiation, and that USP11 was recruited to the chromatin post-UV damage. Further, squamous cell carcinoma cells showed reduced survival with inhibition of USP11 after UV exposure. Our findings indicate that USP11 plays an important role in maintaining NER capacity, and suggest that USP11 acts as a tumor suppressor via its role in DNA repair.

Citation Format: Palak Shah, Lei Qiang, Seungwon Yang, Keyoumars Soltani, Yu-Ying He. USP11 regulates UV-induced DNA damage repair and cell survival associated with skin cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4155.
Abstract 4156: Inhibition of NF-kB improves sensitivity to radiation and EGFR inhibitor and decreases radiation-induced lung toxicity in lung cancer
Authors: Wang Wei , Wang Rong , Peng Shunli , Li Qi , Zhang Xiaojuan , Ma Yueyun
Published: August 2018

Combination with EGFR-TKIs and radiation seems to be a good strategy against lung cancer, since radiation could enhance EGFR expression. However, the results of clinical trials were controversial. MET activation was involved in resistance to both radiation and EGFR inhibitor, while NF-kB was reported to closely relate to HGF/MET signaling axis. Furthermore, NF-κB has been proved to play a role in bleomycin-induced pulmonary fibrosis, which could be ameliorated by IKKB inhibitor (IMD-0354). Therefore, we evaluated the influence of NF-kB/MET inhibition to the sensitivity of radiation and EGFR-TKIs in lung cancer cells in vitro and in vivo. we also examined the role of NF-κB in radiation-induced lung toxicity. Our data showed that radiation enhanced activation and expression of MET and EGFR, whereas only activation of MET could be reversed by IMD-0354 and p65 depletion, suggesting that radiation-induced MET activation was mediated by NF-kB signaling. Furthermore, NF-kB inhibition increased radiation-induced DNA damage and apoptosis in lung cancer cells. On the other hand, radiation decreased sensitivity to EGFR inhibitor in EGFR mutant lung cancer cells, while inhibition of NF-kB or MET overcame the resistance. Importantly, IMD-0354 increased sensitivity to radiation, EGFR-TKIs, or their combination in mouse xenograft tumors by arresting cell proliferation and inducing cell apoptosis. Interestingly, IMD-0354 significantly reduced the lung toxicity in a mouse model of radiation-induced pneumonia and lung fibrosis. Our preclinical findings indicated that inhibition of NF-kB/MET could improve sensitivity to radiation and EGFR inhibitor and decrease radiation-induced lung toxicity in lung cancer.

Citation Format: Wei Wang, Rong Wang, Shunli Peng, Qi Li, Xiaojuan Zhang, Yueyun Ma. Inhibition of NF-kB improves sensitivity to radiation and EGFR inhibitor and decreases radiation-induced lung toxicity in lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4156.
Abstract 416: Impact of virus integration into the genomes of hepatocellular carcinoma patients with prior hepatitis B virus infection
Authors: Midorikawa Yutaka , Tatsuno Kenji , Yamamoto Shogo , Nagae Genta , Koike Kazuhiko , Moriyama Mitsuhiko , Takayama Tadatoshi , Moriya Kyoji , Aburatani Hiroyuki
Published: August 2018

It has been elucidated that hepatitis B virus (HBV) DNA is frequently integrated to some cancer related genes such as TERT or KMT2B in patients with chronic HBV infection. On the other hand, it has not yet become clear of the integration of HBV to the genome of patients with prior infection with HBV. To identify the integration sites of HBV, we performed next generation of target capture technology for hepatocellular carcinoma samples obtained from 73 HBc antibody positive patients but negative for HBs antigen nor hepatitis C antibody (HCV) (Group 1; prior infection), 78 HBs antigen positive patients (Group 2; positive control), and 33 patients without any antigens nor antibodies for HBV (Group 3; negative control). Among these patients, overall HBV integration in Group 2 (54 patients, 69.2%) was significantly frequent compared with that in Group 1 (12, 16.4%) (P < 0.001), and was not detected in any patients of Group 3. On the other hand, HBV integration occurred in the known driver genes; TERT in seven (9.5%) and 12 (15.3%) patients (P = 0.332), MLL4 in two (3.5%) and four (5.1%) patients (P = 682), and CCNE1 in 0 and one (1.2%) patient (P = 1.000) in Group 1 and 2, respectively. Notably, integration of any driver genes was not observed in 56 patients with prior infection with HBV who were positive for HCV infection.Taken together, despite the disappearance of HBV, the frequency of driver events by HBV integration in patients with prior HBV infection is similar to those with chronic HBV infection, and patients with prior HBV infection are still at the risk of hepatocellular carcinoma.

Citation Format: Yutaka Midorikawa, Kenji Tatsuno, Shogo Yamamoto, Genta Nagae, Kazuhiko Koike, Mitsuhiko Moriyama, Tadatoshi Takayama, Kyoji Moriya, Hiroyuki Aburatani. Impact of virus integration into the genomes of hepatocellular carcinoma patients with prior hepatitis B virus infection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 416.
Abstract 4163: Space radiation-induced persistent DNA damage and alterations in cytoskeletal remodeling pathways affect intestinal epithelial cell migration in mice
Authors: Kumar Santosh , Suman Shubhankar , Fornace Albert , Datta Kamal
Published: August 2018

Lombardi Comprehensive Cancer Center, and Department of Biochemistry and Molecular & Cellular Biology Georgetown University, Washington, DC 20057, USA.

Heavy ion space radiation is considered as a risk factor of gastrointestinal (GI) cancer and perturbed intestinal epithelial cell (IEC) migration has been implicated in GI carcinogenesis. The purpose of the current study was to assess rate of IEC migration as well as dissect key IEC migration signaling events after exposure to heavy ion 56Fe irradiation and compare the results to sham- and γ-irradiation. Male C57BL/6J mice were exposed to 0.5 Gy of either γ or 56Fe radiation and control mice were sham irradiated. IEC migration distance was measured 7 and 60 d after exposure using BrdU pulse labeling. We also analyzed cell polarity, microtubule dynamics, and adhesion dynamics using immunoblots and immunofluorescence. Measure of IEC migration rate showed a greater decrease after 56Fe relative to γ radiation at both the time points. At the molecular level, compared to sham and γ radiation, 56Fe radiation exhibited significantly greater impairment of cell adhesion dynamics evidenced by altered integrins and Rock1 as well as cytoskeletal dynamics evidenced by altered MLCK expression. Similarly, perturbed cell polarity, tight junction, and microtubule dynamics was revealed by the deregulation of Par3, Claudin1, Scribble, Occludin, ZO-1, phospho-Tau and MAP1B. Also, the Wnt/β-catenin and EphB/EphrinB pathways critical for IEC migration consistently showed greater deregulation at both the time points tested after 56Fe radiation relative to γ -rays. Taken together, our molecular findings correlate with the BrdU pulse labeling data, and demonstrate greater effects of heavy ion 56Fe on IEC migration relative to γ -rays. In summary, our results have demonstrated for the first time that radiation can disrupt cell migration dynamics through alteration of signaling molecules involved in crucial cellular processes and these results have implications for heavy ion space radiation-induced gastrointestinal homeostatic deregulation and carcinogenesis.

Citation Format: Santosh Kumar, Shubhankar Suman, Albert Fornace, Kamal Datta. Space radiation-induced persistent DNA damage and alterations in cytoskeletal remodeling pathways affect intestinal epithelial cell migration in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4163.
Abstract 4164: Fasting protects mice from lethal radiation by promoting small intestinal stem cell survival
Authors: Bonilla Marimar de la Cruz , Stemler Kristina M. , Fujimoto Tara N. , Jeter-Jones Sabrina , Molkentine Jessica M. , Torres Gabriela M. Asencio , Taniguchi Cullen M. , Piwnica-Worms Helen
Published: August 2018

Pancreatic cancer is the fourth leading cause of cancer-related deaths in the US. Surgical resection is the only potentially curative treatment; however, only 15%-20% of patients present with tumors that can be resected. There is no consensus regarding standard of care in unresectable cases, however many academic centers use stereotactic body radiotherapy (SBRT) to give tumor-directed radiotherapy (RT). Unfortunately, even this conformal technique can still cause severe gastrointestinal (GI) toxic effects caused by the proximity of the pancreatic head to the duodenum. Protecting the intestine from the toxic effects of radiation may enable dose escalation that could achieve more effective local control of disease. We and others have previously shown that a prolonged fast of 24 hours protects mice from lethal doses of etoposide. In this study, we extend and build on our previous finding to demonstrate that a similar 24 hour fast also protects from lethal doses of total abdominal radiation. Histologic analyses, using the Withers-Elkind microcolony assay, show that fasting protected small intestinal (SI) stem cells from radiation damage and promoted early regeneration. To show a proof-of-principle for the use of this radioporotective maneuver in cancer therapy, we developed an orthotopic model of pancreatic cancer using KPC tumor cells syngeneic to C57BL/6. Here, we show that fasting-mediated intestinal protection enabled dose escalated SBRT for treatment of these orthotopic tumors. RT with fasting radioprotection delayed tumor growth and improved survival compared to controls. Given this robust phenotype, we developed a 3D culture ex vivo assay using intestinal stem cell enriched epithelial spheroid cultures. We modified these intestinal spheroids with a bioluminescent reporter and used these cells to develop a modified clonogenic assay for 3D culture that can be used to identify novel radioprotectors, such as a fasting mimetic. Taken together, these results suggest that fasting protects small intestinal stem cells sufficiently to allow animals to receive potentially curative doses of abdominal radiation that would other wise be lethal. Future work will aim to identifying the mechanism by which fasting confers intestinal protection and drug candidates that can be used to mimic this fasting-mediated protection.

Citation Format: Marimar de la Cruz Bonilla, Kristina M. Stemler, Tara N. Fujimoto, Sabrina Jeter-Jones, Jessica M. Molkentine, Gabriela M. Asencio Torres, Cullen M. Taniguchi, Helen Piwnica-Worms. Fasting protects mice from lethal radiation by promoting small intestinal stem cell survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4164.