bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract LB-062: Targeting of p32 in peritoneal carcinomatosis with intraperitoneal linTT1 peptide-guided pro-apoptotic nanoparticles
Authors: Teesalu Tambet , Hedi Hunt , Simón-Gracia Lorena , Tobi Allan , Sugahara Kazuki N. , Sharma Shweta , Ruoslahti Erkki
Published: July 2017

Gastrointestinal and gynecological malignancies disseminate loco-regionally in the peritoneal cavity - a condition known as peritoneal carcinomatosis (PC). Intraperitoneal (IP) administration can be used to improve therapeutic index of anticancer drugs used for PC treatment. Activity of IP anticancer drugs can be further potentiated by encapsulation in nanocarriers and/or affinity targeting with tumor-specific affinity ligands, such as tumor homing peptides. Here we evaluated a novel tumor penetrating peptide, linTT1 (AKRGARSTA), as a PC targeting ligand for nanoparticles. We first demonstrated that the primary homing receptor for linTT1, p32 (or gC1qR), is expressed on the cell surface of peritoneal carcinoma cell lines of gastric (MKN-45P), ovarian (SKOV-3), and colon (CT-26) origin, and that peritoneal tumors in mice and clinical peritoneal carcinoma explants express p32 protein accessible from the IP space. Iron oxide nanoworms (NWs) functionalized with the linTT1 peptide were taken up and routed to mitochondria in cultured PC cells. NWs functionalized with linTT1 peptide in tandem with a pro-apoptotic [D(KLAKLAK)2] peptide showed p32-dependent cytotoxicity in MKN-45P, SKOV-3, and CT-26 cells. Upon IP administration in mice bearing MKN-45P, SKOV-3, and CT-26 tumors, linTT1-functionalized NWs showed robust homing and penetration into malignant lesions, whereas only a background accumulation was seen in control tissues. In tumors, the linTT1-NW accumulation was seen predominantly in CD31-positive blood vessels, in LYVE-1-positive lymphatic structures, and in CD11b-positive tumor macrophages. Experimental therapy of mice bearing peritoneal MKN-45P xenografts and CT-26 syngeneic tumors with IP linTT1- D(KLAKLAK)2-NWs resulted in significant reduction of weight of peritoneal tumors and significant decrease in the number of metastatic tumor nodules, whereas treatment with untargeted D(KLAKLAK)2-NWs had no effect. Our data show that targeting of p32 with linTT1 tumor-penetrating peptide improves tumor selectivity and antitumor efficacy of IP pro-apoptotic NWs. P32-directed intraperitoneal targeting of other anticancer agents and nanoparticles using peptides and other affinity ligands may represent a general strategy to increase their therapeutic index.

Citation Format: Tambet Teesalu, Hunt Hedi, Lorena Simón-Gracia, Allan Tobi, Kazuki N. Sugahara, Shweta Sharma, Erkki Ruoslahti. Targeting of p32 in peritoneal carcinomatosis with intraperitoneal linTT1 peptide-guided pro-apoptotic nanoparticles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-062. doi:10.1158/1538-7445.AM2017-LB-062
Abstract LB-067: Design, synthesis and biological evaluation of novel selenocyanide histone deacetylase inhibitor as anti-triple negative breast cancer agents
Authors: Tang Chu , Du Yang , Tian Jie
Published: July 2017

Approximate 70-80% of breast cancers are estrogen receptor positive (ER+), and the ERα plays essential role in breast cancer growth. Therefore, many ERα ligands have been developed for hormone drugs, such as tamoxifen, which is the first line drug for the treatment of ER(+) breast cancer. Unfortunately, endocrine therapy is ineffective for triple-negative breast cancer (TNBC), which lacks of expression of ER, PR and HER-2, representing about 20% of breast cancers. Current treatment option for TNBC is still limited to cytotoxic chemotherapy, and histone deacetylase inhibitor (HDACi) was used as novel therapeutic strategy for TNBC. HDACi can induce functional ERα re-expression and re-sensitize cells of TNBC to estradiol activator and tamoxifen antagonist. More than ten clinical trials of HDACi are underway for the treatment of TNBC, and most of HDAC inhibitors have the hydroxamic acid moiety, a typical zinc-binding group. However, these inhibitors do not show significant anticancer effects on TNBC compared to SAHA, which is the first HDACi approved by FDA. Hydroxamic acids usually have pharmacokinetic and metabolic problems, and also SAHA shows considerable toxicity to healthy cells. Therefore, much effort has been undertaken to develop an “ideal HDACi”, more effective and less toxic. We recently found that zinc-binding group of HDACi is selenocyanide (named as SelA), which shows strong anti-HDAC1, HDAC6 and HDAC8. These three isoforms have been found to be critical for the invasion and migration of both ER(+) breast cancer and TNBC activities, with a nanomolar range of IC50, and demonstrate high selectivity for HDAC6; moreover, SelA also displays significant anti-proliferative effect on both ER(+) breast cancer and TNBC both in vitro and in vivo. In summary, selenocyanide compound represents a novel HDACi for the treatment of TNBC, and the structure-activity relation is pursuing.

Citation Format: Chu Tang, Yang Du, Jie Tian. Design, synthesis and biological evaluation of novel selenocyanide histone deacetylase inhibitor as anti-triple negative breast cancer agents [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-067. doi:10.1158/1538-7445.AM2017-LB-067
Abstract LB-069: In vivo delivery of asymmetric gene-silencing RNAs targeting CTNNB1 and PD-L1 show a broad spectrum of potent antitumor activities in preclinical cancer models
Authors: Li Youzhi , Gao Yuan , Wang Yuxin , Su Jie , Hsu Eric , Wybieralska Ewa , Huang Janet , Gada Keyur , Oishi Jun , Dai Xiaoshu , Koga Erina , Li Wei , Sun Xiangao , Brooks Emily , Li Chiang J.
Published: July 2017

RNAi (RNA interference) technology has the potential to target any genes causing disease, including conventionally “undruggable” targets in cancer. We previously discovered aiRNA (asymmetric interfering RNA), a next generation of gene-silencing technology with improved gene silencing efficiency and reduced off-target effects in comparison with siRNA. We have recently developed a nanoscale formulation that encapsulates therapeutic aiRNAs targeting CTNNB1 and PD-L1, named BBI-801. Here we investigate the in vivo delivery and antitumor activity of BBI-801 encapsulating aiRNAs targeting CTNNB1 and PD-L1. CTNNB1 encodes undruggable β-catenin which is a cancer stemness gene that is broadly implicated in multiple cancer types PD-L1 gene encodes a key immune checkpoint factor that mediates cancer immune evasion. In our in vivo studies, we have achieved prolong silencing of β-Catenin/PD-L1 mRNA and protein in a dose-dependent manner in a wide variety of murine tumor models, including subcutaneous human tumor xenografts, orthotopic human liver and lung tumors, as well as syngeneic mouse colorectal, breast and lung tumors. Our biodistribution analysis of fluorescence-labeled aiRNA demonstrated that the delivery of BBI-801 to xenograft tumors happens within 5 minutes of aiRNA administration and lasts at least 8 hours. In all the models we examined, significant tumor growth inhibition by BBI-801 was achieved not only in β-Catenin over-expressed colorectal tumor models, SW480 and APCmin, but also in the rest of β-Catenin normal-expressed tumor models. Finally, BBI-801 is well tolerated and no signs of toxicity were observed after repeated dosing. These exciting data support further investigation of the anti-tumor potential of BBI-801 as an anticancer therapeutic in variety of tumor indications.

Citation Format: Youzhi Li, Yuan Gao, Yuxin Wang, Jie Su, Eric Hsu, Ewa Wybieralska, Janet Huang, Keyur Gada, Jun Oishi, Xiaoshu Dai, Erina Koga, Wei Li, Xiangao Sun, Emily Brooks, Chiang J. Li. In vivo delivery of asymmetric gene-silencing RNAs targeting CTNNB1 and PD-L1 show a broad spectrum of potent antitumor activities in preclinical cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-069. doi:10.1158/1538-7445.AM2017-LB-069
Abstract LB-071: A facile strategy for exosome labeling and tracking
Authors: Kim Young , Lee Tae-Sup , Tung Ching H.
Published: July 2017

Exosomes are extracellular vesicles of endocytic origin with a size range of 40-150 nm and a lipid bilayer membrane. Though exosomes are known as dynamic mediators of intercellular communication, its characteristics and function have not been fully studied. In this report, we used a metabolic labeling method to prepare fluorescent exosomes to investigate the characteristics and the movement of exosomes derived from various breast cancer cells. MCF-7 and MDA-MB-231 cells were treated with three types of azido sugars, Ac4ManNAz, Ac4GalNAz, or Ac4GlcNAz (50 μM), for 3 days to produce the azide (-N3) containing exosomes through metabolic glycosylation. It is confirmed that the azido sugar decorated exosomes were able to maintain their original characteristics such as size, lipid bilayer morphology, and protein profile. The collected exosomes were labeled with Adibo-cy3 and Adibo-cy5.5 fluorescence dyes using copper-free click chemistry. The exosomes prepared with Ac4ManNAz have shown the highest labeling efficiency, in MCF-7 and MDA-MB-231 cells at 17.2% and 14.8%, respectively. To study their homing capability, the labeled exosomes from different origins were incubated with a panel of breast cancer cells, including MCF-7, MDA-MB-231, MDA-MB-468 and BT-549, and normal NIH/3T3 fibroblast cells for 24 hours. The cells were then evaluated by fluorescence microscopic imaging and flow cytometry. It was observed that exosomes from different origins have a different homing efficiency, suggesting that each exosome may have its unique navigation systems. Furthermore, the cells which have aggressive metastatic potential, such as MDA-MB-231, showed a higher uptake in all exosomes. Our development has demonstrated an effective labeling method that facilitates exosome research by providing a new way of quantification and tracking in vitro and potentially in vivo studies.

Citation Format: Young Kim, Tae-Sup Lee, Ching H. Tung. A facile strategy for exosome labeling and tracking [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-071. doi:10.1158/1538-7445.AM2017-LB-071
Abstract LB-097: DNA methylation at enhancers distinguishes distinct breast cancer lineages
Authors: Fleischer Thomas , Tekpli Xavier , Mathelier Anthony , Wang Shixiong , Nebdal Daniel , Dhakal Hari P. , Sandberg Kristine Kleivi , Schliting Ellen ,   Oslo Breast Cancer Research Consortium (OSBREAC), Børresen-Dale Anne-Lise , Borgen Elin , Naume Bjørn , Eskeland Ragnhild , Frigessi Arnoldo , Tost Jörg , Hurtado Antoni , Kristensen Vessela N.
Published: July 2017

Breast cancers exhibit genome-wide aberrant DNA methylation patterns. To investigate how these affect the transcriptome and which changes are linked to transformation or progression we applied genome-wide expression-methylation quantitative trait loci (emQTL) analysis between 5meCpG and gene expression. We find that on a whole genome scale, DNA methylation and gene expression have remarkably and reproducibly conserved patterns of association, both in cis and in trans, which lead to identify distinct transcriptional networks and specific disease cell lineages deviating from the normal tissue. In three breast cancer cohorts (n=104, n=253 and n=330), we invariably identify enhancers whose DNA methylation tethers the binding of three key transcription factors in breast cancer in a lineage specific manner. Our emQTL analysis also identifies tumor infiltrating immune cell signatures. Using ChromHMM segmentation and ChIP-seq associated TF binding regions, we identify enhancers and TF binding sites around emQTLs-CpGs. We functionally validate the genes associated with these CpGs using knock-down by siRNA and applying GRO-seq analysis after transcriptional stimulation with estrogen. DNA methylation at TF binding regions is considered an early event during normal breast cell transformation into estrogen dependent breast cancer. Two distinct key gene regulatory networks reported here are prominently altered by DNA methylation.

Citation Format: Thomas Fleischer, Xavier Tekpli, Anthony Mathelier, Shixiong Wang, Daniel Nebdal, Hari P. Dhakal, Kristine Kleivi Sandberg, Ellen Schliting, Oslo Breast Cancer Research Consortium (OSBREAC), Anne-Lise Børresen-Dale, Elin Borgen, Bjørn Naume, Ragnhild Eskeland, Arnoldo Frigessi, Jörg Tost, Antoni Hurtado, Vessela N. Kristensen. DNA methylation at enhancers distinguishes distinct breast cancer lineages [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-097. doi:10.1158/1538-7445.AM2017-LB-097
Abstract LB-098: Sequential azacitidine and histone deacetylase inhibition induces a potent antitumor response in Kras G12D mouse model of NSCLC
Authors: Topper Michael , Vaz Michelle , Chiappinelli Katherine , Shields Christina DeStefano , Wenzel Alyssa , Zahnow Cynthia , Strissel Pam , Strick Reiner , Baylin Stephen
Published: July 2017

Combination epigenetic treatment as a therapeutic approach holds much promise. However, to unlock the true potential of these combinatorial paradigms, further optimization is required. We have elucidated in our current study, a treatment schedule combining Azacitidine with Histone Deacetylase Inhibition (HDACi) which considers both schedule and isoform specificity. We have deployed a sequential schedule with HDACi administered post Azacitidine in a chronic low dose manner. This schedule takes advantage of two key parameters altered by Azacitidine: dsRNA induced immune signature and MYC depletion. In our system, HDACis amplify an existing immune signature and the MYC depleted environment acts as a potent sensitizer. HDACi induced augmentation of immune gene transcription seems driven predominantly through the inhibition of HDAC1/2 and HDAC6 isoforms, with broad spectrum HDACi inhibitors demonstrating the greatest potency. While the combination treatment induced perturbation of proliferation is driven by inhibition of HDAC1/2/3 isoforms. Applying this concept to a genetically engineered mouse model of NSCLC we observe a potent anti-tumor response as evidenced by a reduction in tumor burden, progression and proliferation. These phenotypic parameters are correlated with modification of both immune and proliferative gene signatures as well as alteration of key immune populations in the tumor microenvironment. We propose that this combinatorial alteration of both immune and proliferative parameters holds the promise to be a more robust treatment for NSCLC.

Note: This abstract was not presented at the meeting.

Citation Format: Michael Topper, Michelle Vaz, Katherine Chiappinelli, Christina DeStefano Shields, Alyssa Wenzel, Cynthia Zahnow, Pam Strissel, Reiner Strick, Stephen Baylin. Sequential azacitidine and histone deacetylase inhibition induces a potent antitumor response in Kras G12D mouse model of NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-098. doi:10.1158/1538-7445.AM2017-LB-098
Abstract LB-099: BET bromodomain proteins are essential for the oncogenic EWS-fusion driven Ewing Sarcoma
Authors: Gollavilli Paradesi N. , Pawar Aishwarya , Wilder-Romans Kari , Engelke Carl , Dommeti Vijaya L. , Krishnamurthy Pranathi M. , Nallasivam Archana , Apel Ingrid A. , Xu Tianlei , Qin Zhaohui S. , Feng Felix Y. , Asangani Irfan A.
Published: July 2017

Ewing sarcoma (EWS) is a lethal pediatric small, round, blue cell tumor defined by the characteristic fusion between EWSR1 and a member of the ETS family transcription factor, mostly FLI1 and ERG. Bromodomain and extra-terminal domain (BET) proteins play an essential role in transcription as an epigenetic reader of acetylated histones and transcription factors, and recent studies of inhibitors against these proteins have demonstrated therapeutic potential in various cancers. In this study, we investigated the importance of BET proteins BRD2, BRD3, and BRD4 in EWS-fusion driven transcription program required for maintenance and progression of EWS. Similar to EWS-FLI1 and EWS-ERG, knock-down of BET proteins severely impaired the proliferation and invasion of EWS cells. Gene expression profiling by RNA-Seq showed a common set of genes altered in EWS-FLI1 and BRD2/3/4 knockdown cells implicating a direct role of BET proteins in the transcriptional regulation of EWS-fusion targets. Importantly, BET inhibitor, JQ1, induces apoptosis in EWS cells through an MYC-independent mechanism, and without affecting the EWS-fusion levels. Rather, evidence suggested that BRD4 exists in a complex with EWS-ETS fusion proteins and that its inhibition abrogates the fusion transcriptional program. In vivo, JQ1 inhibited the metastases in chicken CAM model of EWS as well as displayed anti-tumor and anti-metastatic activity in mouse xenograft models of EWS. Together, these results indicate that BET proteins, especially BRD4 interacts with EWS-ETS fusion proteins and this interaction is necessary for the EWS-fusion mediated oncogenesis. Moreover, this study provides a clear rationale for the clinical utility of BET inhibitors in treating metastatic Ewing sarcoma patients.

Citation Format: Paradesi N. Gollavilli, Aishwarya Pawar, Kari Wilder-Romans, Carl Engelke, Vijaya L. Dommeti, Pranathi M. Krishnamurthy, Archana Nallasivam, Ingrid A. Apel, Tianlei Xu, Zhaohui S. Qin, Felix Y. Feng, Irfan A. Asangani. BET bromodomain proteins are essential for the oncogenic EWS-fusion driven Ewing Sarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-099. doi:10.1158/1538-7445.AM2017-LB-099
Abstract LB-109: PDeX (Patient Derived eXplant) models to determine the basis for response to targeted agents in prostate cancer
Authors: Shafi Ayesha A. , Schiewer Matthew J. , Leeuw Renee de , McCue Peter A. , Gomella Leonard G. , Lallas Costas D. , Trabulsi Edouard J. , Hickey Theresa , Shah Neelima , Cukierman Edna , Butler Lisa M. , Tilley Wayne , Raj Ganesh , Knudsen Karen E.
Published: July 2017

Prostate cancer (PCa) is the most common non-cutanenous cancer and the third leading cause of cancer-related death in American men. Androgen receptor (AR) is a hormone-activated transcription factor that plays an important role in both the development and progression of PCa. Androgen deprivation therapy is a common first-line therapy for disseminated disease. However, virtually all tumors become resistant to such therapy and the tumor recurs. Thus, there is a vital need for the development of novel, more effective drugs. One major hurdle in this aspect is the lack of adequate preclinical models. Current models do not effectively recapitulate the heterogeneity and the microenvironment of human PCa tumors, significantly hindering the ability to accurately predict therapeutic response. Our collaborative group has utilized and characterized a method to culture patient tumors ex vivo, termed Patient Derived eXplant (PDeX). This approach maintains the integrity of the native tumor microenvironment, tumor tissue morphology, and molecular signaling. Importantly, our PDeX model can be manipulated both chemically (drugs/compounds) and genetically (shRNA) in order to determine specific reactions and mechanisms of response on individual tumor growth. Furthermore, with this model we can quantitatively assess drug efficacy on numerous parameters (i.e. AR levels, Ki67 staining, apoptosis screening, and desmoplasmic indices). Data to be discussed will assess the variances in response to AR-directed therapeutics and underlying mechanisms of action, while also utilizing TME characteristics as a means to predict response to therapy. In addition, we can potentially identify clinically relevant subpopulations of patients and molecularly profile their cultured tissue to uncover new pathways for therapeutic intervention. Thus, the PDeX model allows for a comprehensive evaluation of individual tumors in their native microenvironment to ultimately develop more effective therapies. This study will have transformative clinical impact discerning novel metrics for the inclusion of precision medicine for advanced PCa.

Citation Format: Ayesha A. Shafi, Matthew J. Schiewer, Renee de Leeuw, Peter A. McCue, Leonard G. Gomella, Costas D. Lallas, Edouard J. Trabulsi, Theresa Hickey, Neelima Shah, Edna Cukierman, Lisa M. Butler, Wayne Tilley, Ganesh Raj, Karen E. Knudsen. PDeX (Patient Derived eXplant) models to determine the basis for response to targeted agents in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-109. doi:10.1158/1538-7445.AM2017-LB-109
Abstract LB-119: Targeting DNA-PK via small molecule inhibitors of the Ku-DNA interaction
Authors: Turchi John J. , Gavande Navnath , VanderVere-Carozza Pamela , Vernon Tyler , Pawelczak Katherine
Published: July 2017

DNA-PK, the DNA-dependent protein kinase, is a validated target for cancer therapeutics that drives the DNA damage response and plays a critical role in the nonhomologous end joining (NHEJ) DNA repair pathway.

Inhibition of DNA-PK activity can elicit anticancer activity and also sensitize cancer cells to DNA damaging therapy. NHEJ is responsible for the repair of DNA double strand breaks (DSB), particularly those induced by ionizing radiation (IR). The generation of DNA DSBs is the mechanism of clinical efficacy of radiation therapy and numerous DNA damaging chemotherapeutic drugs used to treat various cancers. Modulating the pathway responsible for repairing these breaks has been shown to have a profound impact on the efficacy of IR or chemotherapy in the clinic. We have taken a completely unique and novel approach to inhibiting DNA-PK that is based on extensive knowledge regarding DNA-PK kinase activation and affords considerable advantages to current approaches in DNA-PK inhibition. DNA-PK activation and NHEJ pathway engagement requires binding of the Ku70/80 heterodimer to DNA ends and we are targeting this protein-DNA interaction. We have discovered and developed a series of highly potent and selective DNA-PK inhibitors that act via blocking the binding of Ku70/80 to DNA ends. The lead compound from this series of molecules inhibits DNA-PK catalytic activity at nanomolar concentrations, has single-agent anticancer activity in cancer cell lines, and potentiates cellular sensitivity to IR treatment and DSB-producing chemotherapeutic agents. These data demonstrate the utility of inhibiting DNA-PK via targeting the Ku-DNA interaction.

Citation Format: John J. Turchi, Navnath Gavande, Pamela VanderVere-Carozza, Tyler Vernon, Katherine Pawelczak. Targeting DNA-PK via small molecule inhibitors of the Ku-DNA interaction [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-119. doi:10.1158/1538-7445.AM2017-LB-119
Abstract LB-147: EMT transcription factors induce tissue factor expression and pro-coagulant properties, supporting early metastasis of circulating tumor cells
Authors: Bourcy Morgane , Skrypek Nicolas , Thompson Erik W. , Berx Geert , Hollier Brett , Polette Myriam , Gilles Christine
Published: July 2017

The presence of circulating tumor cells (CTCs) expressing traits of epithelial-mesenchymal transition (EMT) in cancer patients is increasingly recognized. Recently, we identified a new mechanism by which EMT induces the expression of Tissue Factor (TF, a major cell-associated initiator of coagulation), triggering a local activation of the coagulation cascade that favors the early metastatic colonization of EMT-positive CTCs (Bourcy et al., Cancer Research, 2016). Strengthening the functional contribution of EMT to TF regulation and coagulation, we further accumulated evidence that EMT transcription factors regulate TF expression. Thus, silencing ZEB1 inhibited both EMT-associated TF expression and coagulant activity. EMT-positive cells also exhibited a higher survival/persistence in lungs of mice colonized after intravenous injection, which was diminished by silencing ZEB1. Inversely, triggering de novo expression of Snail in MDA-MB-468 increased TF, coagulant properties and early metastasis in mice. Using TF promoter reporter vectors (mutated at different potential ZEB1 and Snail transcription factors) and CHIP, we further identified a binding region for ZEB1 in the proximal TF promoter encompassing a MCAT box, suggesting that ZEB1 and YAP might interact to regulate TF expression. Ongoing experiments are being performed to verify this hypothesis. We also collected data suggesting that targeting this new EMT/TF axis with anti-EMT drugs may represent an important extension to global anticoagulant strategies against cancer.

Citation Format: Morgane Bourcy, Nicolas Skrypek, Erik W. Thompson, Geert Berx, Brett Hollier, Myriam Polette, Christine Gilles. EMT transcription factors induce tissue factor expression and pro-coagulant properties, supporting early metastasis of circulating tumor cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-147. doi:10.1158/1538-7445.AM2017-LB-147
Abstract LB-153: Lotus leaf and Cassia seed extracts, through activating Nrf2 pathway, suppress TPA-induced mouse skin cell transformation
Authors: Chan Yen-Fan , Lin Zi-Han , Chen Pei-Chun , Sung Ping-Hua , Su Zheng-Yuan
Published: July 2017

In traditional Chinese medicine, some Chinese herbs to be used as foods can protect and promote human health. Lotus (Nelumbo nucifera) leaves (LL) and Cassia (Cassia tora) seeds (CS) are often used as a food or an ingredient when cooking in Chinese region. LL and CS have been studied to exhibit some biological effects but there is no investigation to study their cancer chemopreventive potential. In this study, the extracts, including water extract (WE), water extraction residue ethanol extract (WREE) and ethanol extract (EE), of LL and CS were prepared. HepG2-C8 cell line, HepG2 cells stably transfected with Nrf2-ARE-luciferase plasmid, were used to screen out the extracts with cancer chemoprevetive potential. Our results showed that CS-WE, LL-WREE and LL-EE has better Nrf2-ARE-luciferase induction activity. Furthermore, we also found that these three extracts can inhibit 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced anchorage-independent cell growth of JB6 P+ cells while up-regulating Nrf2 and Nrf2 downstream antioxidant/detoxification enzymes. These results suggested that Chinese herbal Lotus leaves and Cassia seeds to be used as foods might inhibit carcinogenesis through the regulation of Nrf2 pathway.

Citation Format: Yen-Fan Chan, Zi-Han Lin, Pei-Chun Chen, Ping-Hua Sung, Zheng-Yuan Su. Lotus leaf and Cassia seed extracts, through activating Nrf2 pathway, suppress TPA-induced mouse skin cell transformation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-153. doi:10.1158/1538-7445.AM2017-LB-153
Abstract LB-165: Personalized prognostic prediction models for breast cancer recurrence and survival incorporating multidimensional data
Authors: Wu Xifeng , Ye Yuanqing , Barcenas Carlos H. , Chow Wong-Ho , Meng Qing H. , Gregor Mariana Chavez Mac , Hildebrandt Michelle , Zhao Hua , Gu Xiangjun , Deng Yang , Wagar Elizabeth A. , Esteva Francisco J. , Tripathy Debu , Hortobagyi Gabriel N.
Published: July 2017

Background: In this study, we developed integrative, personalized prognostic models for breast cancer recurrence and overall survival (OS) that consider receptor subtypes, epidemiological data, quality of life (QoL), and treatment.

Methods: 15,314 women with stage I to III invasive primary breast cancer treated at The University of Texas MD Anderson Cancer Center between 1997 and 2012 was used to generate prognostic models by Cox regression analysis including 10,809 women as discovery population (median follow-up: 6.09 years, 1,144 recurrence and 1,627 deaths) and 4,505 women as validation population (median follow-up: 7.95 years, 684 recurrence and 1,095 deaths). Model performance was assessed by calculating the area under the curve (AUC) and calibration analysis and compared with Nottingham Prognostic Index (NPI) and PREDICT.

Results: In addition to the known clinical/pathological variables, the model for recurrence included alcohol consumption while the model for OS included smoking status and physical component summary score. The AUCs for recurrence and OS were 0.813 and 0.810 in the discovery and 0.807 and 0.803 in the validation, respectively, compared to AUC of 0.761 and 0.753 in discovery and 0.777 and 0.751 in validation for NPI. Our model further showed better calibration compared to PREDICT. We also developed race-specific and receptor subtype-specific models with comparable AUC. Racial disparity was evident in the distributions of many risk factors and clinical presentation of the disease.

Conclusions: Our integrative prognostic models for breast cancer exhibit high discriminatory accuracy and excellent calibration and are the first to incorporate receptor subtype, epidemiological and QoL data.

Citation Format: Xifeng Wu, Yuanqing Ye, Carlos H. Barcenas, Wong-Ho Chow, Qing H. Meng, Mariana Chavez Mac Gregor, Michelle Hildebrandt, Hua Zhao, Xiangjun Gu, Yang Deng, Elizabeth A. Wagar, Francisco J. Esteva, Debu Tripathy, Gabriel N. Hortobagyi. Personalized prognostic prediction models for breast cancer recurrence and survival incorporating multidimensional data [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-165. doi:10.1158/1538-7445.AM2017-LB-165
Abstract LB-179: Next-generation epitope prediction using mass spectrometry and integrative genomics
Authors: Rooney Michael S. , Abelin Jenn , Sarkizova Siranush , Keskin Derin , Hartigan Christine , Zhang Wandi , Sidney John , Lane William , Stevens Jonathan , Zhang Guang L. , Clauser Karl , Hacohen Nir , Carr Steve , Wu Cathy
Published: July 2017

Personalized neoantigen therapies for cancer require accurate epitope selection. However, most Class I prediction algorithms in common use today are based on biochemical binding assays that are difficult to scale and do not address processing steps upstream of peptide-MHC binding. Here we present an alternative approach based on the LC-MS/MS identification of MHC Class I-bound peptides. While MS-based profiling is not new, we optimized the system for rule learning by focusing on cell lines expressing only a single HLA-A or HLA-B allele and by collecting parallel transcriptomic and proteomic measurements. Identifying over 24,000 peptides across 16 individual alleles, we were able to discover novel binding motifs, which were validated biochemically, and develop novel neural network algorithms. Furthermore, we systematically interrogated processing rules - discovering a novel motif conserved across multiple cell types - and developed a principled framework for integrating epitope cleavability, expression, and MHC binding potential into an overall ranking. Validating on external datasets, we saw a doubling in positive predictive value with respect to standard approaches. We thus demonstrate a scalable strategy for systematically learning the rules of endogenous antigen presentation that can be deployed for the optimal selection of patient-specific cancer neoantigens.

Citation Format: Michael S. Rooney, Jenn Abelin, Siranush Sarkizova, Derin Keskin, Christine Hartigan, Wandi Zhang, John Sidney, William Lane, Jonathan Stevens, Guang L. Zhang, Karl Clauser, Nir Hacohen, Steve Carr, Cathy Wu. Next-generation epitope prediction using mass spectrometry and integrative genomics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-179. doi:10.1158/1538-7445.AM2017-LB-179
Abstract LB-181: Cutaneous SCC may escape immune surveillance by secreting complement factor H
Authors: Loomis Ellise , Pulford Christopher , Uppalapati Chandana , Pascual Agnes , Montgomery McKale , Leyva Kathryn J. , Hull Elizabeth E.
Published: July 2017

Developing tumors evade elimination by the immune system using a variety of mechanisms. Evidence suggests that cutaneous squamous cell carcinomas (cSCCs) may evade immune system surveillance by secreting complement factor H (CFH), a regulatory protein of the complement system. As part of its normal function, CFH binds to glycosaminoglycans on the surface of host cells where it acts as a cofactor for Factor I mediated C3b cleavage and accelerates the decay of the C3-convertase C3bBb. This mechanism for protecting self-cells also involves shifting the immune response from a pro-inflammatory T-helper-1 cell to an anti-inflammatory regulatory T-cell response. Data presented here suggest that some cSCCs have the ability to upregulate expression of CFH and studies have shown that this could be in response to the pro-inflammatory cytokine interferon-γ. We suggest that, in our cSCC samples, a potential negative-feedback loop exists in which the initial immune response to the developing tumor triggers expression of an immunosuppressive molecule, allowing the cancer to create an environment conducive to evading immune surveillance mechanisms.

Note: This abstract was not presented at the meeting.

Citation Format: Ellise Loomis, Christopher Pulford, Chandana Uppalapati, Agnes Pascual, McKale Montgomery, Kathryn J. Leyva, Elizabeth E. Hull. Cutaneous SCC may escape immune surveillance by secreting complement factor H [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-181. doi:10.1158/1538-7445.AM2017-LB-181
Abstract LB-189: Blockade of stearoyl CoA desaturase 1 promotes immunogenic clearance of tumors
Authors: Roemeling Christina Anna Elizabeth Von , Caulfield Thomas , Qie Yaqing , Radisky Derek C. , Liu Xiujie , Chen Yuanxin , Knight Joshua , Copland John , Kim Betty
Published: July 2017

Metabolic reprogramming plays a critical role in carcinogenesis, in part due its ability to promote immune suppressive properties within tumors. Agents that specifically target crucial metabolic enzymes utilized by cancer are been actively investigated. However, it is unclear whether inhibition of fatty acid metabolism in tumors affects their immunogenicity. Here, we show for the first time that inhibition of stearoyl-CoA desaturase 1 (SCD1), a key enzyme involved in fatty-acid synthesis and a potential prognostic marker for human cancers, increases the immunogenicity of poorly immunogenic tumors. The enhanced immune activation is accompanied by upregulated endoplasmic reticulum (ER) stress and is dependent on the translocation of ER protein calreticulin to the tumor cell surface. Inhibition of SCD1 increased both recruitment and activation of immune cells in vivo, which when combined with PD-1 blockade resulted in potent and durable anti-tumor T cell responses. Together, our results indicate that inhibition of tumorigenic de novo lipogenesis represents a novel approach to enhance T cell based cancer immunotherapy.

Citation Format: Christina Anna Elizabeth Von Roemeling, Thomas Caulfield, Yaqing Qie, Derek C. Radisky, Xiujie Liu, Yuanxin Chen, Joshua Knight, John Copland, Betty Kim. Blockade of stearoyl CoA desaturase 1 promotes immunogenic clearance of tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-189. doi:10.1158/1538-7445.AM2017-LB-189
Abstract LB-206: Indicators of responsiveness to immune checkpoint inhibitors
Authors: Shields Bradley D. , Mahmoud Fade , Taylor Erin M. , Byrum Stephanie D. , Sengupta Deepanwita , Koss Brian , Baldini Giulia , Ransom Seth , Cline Kyle , Mackintosh Samuel , Edmondson Ricky , Shalin Sara C. , Tackett Alan J.
Published: July 2017

Modulation of the immune system can produce anti-tumor responses in various cancer types, including melanoma. Recently, immune checkpoint inhibitors, in single agent and combination regimens, have produced durable and long-lasting clinical responses in a subset of metastatic melanoma patients. These monoclonal antibodies, developed against CTLA-4 and PD-1, block immune-inhibitory receptors on activated T-cells, amplifying the immune response. However, even when using anti-CTLA-4 and anti-PD-1 in combination, approximately half of patients exhibit innate resistance and suffer from disease progression. Currently, it is impossible to predict therapeutic response. Here, we report the first proteomic and histone epigenetic analysis of patient metastatic melanoma tumors taken prior to immune checkpoint inhibitor therapy, which revealed specific biological signatures that can stratify metastatic melanoma patients as responders or non-responders. Furthermore, our findings provide the first evidence of epigenetically-driven epithelial-mesenchymal transition, a known mechanism of immune-escape, in non-responding melanoma tumors. We identified elevated histone H3 lysine (27) trimethylation (H3K27me3), decreased E-cadherin, and other protein features indicating a more mesenchymal phenotype in non-responding tumors. Furthermore, we show E-cadherin is transcriptionally regulated by the EZH2-catalyzed H3K27me3 epigenetic mark in non-responding tumors. The repressive epigenetic mark H3K27me3, has known roles in melanoma pathogenesis and progression, but not in response to immunotherapies. Here, we provide the first report of an epigenetic program directly linking elevated levels of H3K27me3 to non-responding tumors. Our results have broad implications for immune checkpoint inhibitor therapy in a variety of carcinomas as patient specific responsiveness can be predicted through readily assayable proteins and histone epigenetic marks, and specific pathways activated in non-responders have been identified for therapeutic development to enhance responsiveness.

Citation Format: Bradley D. Shields, Fade Mahmoud, Erin M. Taylor, Stephanie D. Byrum, Deepanwita Sengupta, Brian Koss, Giulia Baldini, Seth Ransom, Kyle Cline, Samuel Mackintosh, Ricky Edmondson, Sara C. Shalin, Alan J. Tackett. Indicators of responsiveness to immune checkpoint inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-206. doi:10.1158/1538-7445.AM2017-LB-206
Abstract LB-209: RON kinase: a target for treatment of cancer-induced bone destruction and osteoporosis
Authors: Andrade Kelsi , Fornetti Jaime , Zhao Ling , Miller Scott C. , Randall Lor R. , Anderson Neysi , Waltz Susan E. , McHale Mark , Welm Alana L.
Published: July 2017

Bone destruction occurs in aging and numerous diseases, including osteoporosis and cancer. Many cancer patients have bone osteolysis that is refractory to state-of-the-art treatments, which block osteoclast activity with bisphosphonates or by inhibiting the RANKL pathway. We previously showed that macrophage-stimulating protein (MSP) signaling, which is elevated in approximately 40% of breast cancers, promotes osteolytic bone metastasis, but it was unknown whether this was due to activation of the MSP signaling pathway in the tumor cells or in the bone microenvironment. Here we show that MSP signals through host expression of its receptor, RON tyrosine kinase, to directly activate osteoclasts by a previously undescribed pathway that is complementary to RANKL signaling and converges on SRC. Genetic or pharmacologic inhibition of RON kinase blocked cancer-mediated bone destruction and osteoporosis in several mouse models. Furthermore, the RON kinase inhibitor BMS-777607/ASLAN002 altered markers of bone turnover in a first-in-human clinical cancer study, indicating potential for normalizing bone loss in patients. These findings uncover a new therapeutic target for pathogenic bone loss and provide a rationale for treatment of bone destruction in various diseases with RON inhibitors.

Citation Format: Kelsi Andrade, Jaime Fornetti, Ling Zhao, Scott C. Miller, Lor R. Randall, Neysi Anderson, Susan E. Waltz, Mark McHale, Alana L. Welm. RON kinase: a target for treatment of cancer-induced bone destruction and osteoporosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-209. doi:10.1158/1538-7445.AM2017-LB-209
Abstract LB-211: Phenotypic change specific to tumor-infiltrating regulatory T cells by LFPRLR knockdown
Authors: Chen Kuan-Hui E. , Walker Ameae
Published: July 2017

The clinical relevance and prognostic significance of tumor-infiltrating Tregs in different types of cancers makes them appealing therapeutic targets. However, targeting all Tregs initiates autoimmune disease. In the current study, we have found that knockdown of the long form of the prolactin receptor (LFPRLR) inhibits the function of tumor Tregs with no functional change in peripheral Tregs. Knockdown of the LFPRLR was by splice modulating oligomer (SMO), tested in the syngeneic 4T1-Balb/c immune-competent breast cancer model. Similar effects would be predicted to occur in prostate and ovarian cancer. Knockdown reduced tumor output of CCL17, a chemokine regulated by the major LFPRLR signaling Jak2/Stat5 pathway. Reduced CCL17 output in turn resulted in impaired Treg recruitment into tumors, allowing enhanced CD4+ and CD8+ T cell activities within the tumor and reducing metastasis to distal organs. Also observed was a reduction in Tregs at metastatic sites. RNAseq transcriptomic analysis of LFPRLR SMO-treated tumor Tregs revealed that among immune-suppressive cytokines, expression of IL-10 and TGF-β was not affected, but EBI3, a component of IL-35, became undetectable. Of cytokines known to promote metastasis, IL-6, IL23a and IL34 were reduced. When tumor Tregs, isolated from LFPRLR SMO-treated animals, were co-cultured with 4T1 breast cancer cells, they failed to drive epithelial to mesenchymal transition, while tumor Tregs isolated from control SMO-treated animals did transform 4T1 cells into a more mesenchymal phenotype. Although tumor T regs were reduced by treatment, other major components of the tumor microenvironment, including B cells, CD8+ T cells, macrophages, NK T cells, dendritic cells, myeloid-derived suppressor cells, and fibroblasts were not changed by LFPRLR knockdown, while effector CD4+ T cells were increased and tumor endothelial cells were decreased. Although the population of CD8+ T cells was not changed, their activity was enhanced, as determined by their production of IL-2 and IFN-γ when stimulated. Examination of splenic Tregs from animals treated with LFPRLR- or control SMO for 28 days showed normal suppressive activity of anti-CD3-stimulated T cell proliferation. In conclusion, systemic LFPRLR knockdown has direct and indirect effects on tumor Tregs that modify their cytokine profile and reduce their suppressive capability and ability to drive epithelial to mesenchymal transition of tumor cells.

Citation Format: Kuan-Hui E. Chen, Ameae Walker. Phenotypic change specific to tumor-infiltrating regulatory T cells by LFPRLR knockdown [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-211. doi:10.1158/1538-7445.AM2017-LB-211
Abstract LB-212: Antioxidant therapy reprograms macrophages from protumor M2 to antitumor M1
Authors: Griess Brandon , Datta Kaustubh , Teoh-Fitzgerald Melissa
Published: July 2017

Macrophages (Mϕ) have high plasticity and can polarize to two extremes, pro-inflammatory M1 Mϕ and immuno-suppressive M2 Mϕ. In triple negative breast cancer, tumor-associated Mϕ (TAM) have a pro-tumor M2-like phenotype and are associated with decreased survival. Thus, it is vital to develop treatments to reprogram TAM away from protumor M2 Mϕ toward antitumor M1 Mϕ. A recent study reported a lipid peroxide scavenger selectively inhibits M2 Mϕ markers and cytokines. However, little is known about the differences in ROS metabolism between M1 Mϕ and M2 Mϕ. Our hypothesis is pro-tumorigenic M2 Mϕ possess a distinct profile of pro- and anti-oxidant enzymes, as well as a different sensitivity to ROS modulation versus the anti-tumor M1 Mϕ. Our results show M2 Mϕ, derived from primary human monocytes, have a significant 20-30% reduction in intracellular ROS levels versus M1 Mϕ by DCFH and DHE staining. Extracellular ROS synthesis was dramatically reduced by ~70% in M2 Mϕ, in part due to reduced mRNA expression of Nox2, Nox5, and their accessory protein CYBA in M2 Mϕ. Another contributing factor to lower ROS levels is that M2 Mϕ have significantly increased Catalase and Gpx4 mRNA expression, as well as increased Cu/ZnSOD and Gpx1 protein and activity. These data suggest M2 Mϕ have increased ROS metabolism versus M1 Mϕ, which may provide an advantage in the oxidative tumor microenvironment. Furthermore, EcSOD re-expression in MB231, a triple negative breast cancer cell line, inhibited the MB231-mediated increase in M2 Mϕ markers and decrease in M1 Mϕ markers. We moved forward utilizing Mn(III) meso-tetrakis(N-ethylpyridinium-2-yl)porphyrin (MnTE), a small molecule SOD mimetic, shown to have anti-tumor effects. MnTE treatment increased M1 Mϕ markers, IL-12b and CD86, while concurrently decreasing M2 Mϕ markers, IL-10, CD163, and CD206. MnTE also inhibited the ability of M2 Mϕ to inhibit T cell activation suggesting ROS is required for M2 Mϕ polarization and function. Increasing ROS levels by addition of exogenous H2O2, lead to increased M2 markers and decreased M1 markers, which implicates the oxidative tumor microenvironment in promoting a M2-like TAM phenotype. These studies provide the rationale for antioxidant treatment of breast cancer to reprogram TAM from pro-tumorigenic M2-like TAM phenotype to a more tumoricidal M1-like phenotype.

Citation Format: Brandon Griess, Kaustubh Datta, Melissa Teoh-Fitzgerald. Antioxidant therapy reprograms macrophages from protumor M2 to antitumor M1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-212. doi:10.1158/1538-7445.AM2017-LB-212