bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 5597: Genomic profiling of syngeneic mouse cell lines and in vitro screen of the models against checkpoint inhibitors and target agents for preclinical application
Authors: Xing Frank , Qian Wubin , Dong Chunlan , Xu Xiaoxi , Guo Sheng , Shi Qian 
Published: July 2017

Abstract
Cancer immunotherapy has provided substantial clinical benefit in a significant number of patients with advanced diseases. In pre-clinical studies, CrownBio has developed a large collection of syngeneic models to facilitate in vivo efficacy testing of immune-oncology agents in mice (MuScreenTM). To combine the ostensibly separate therapeutic strategies of activating immune cells against and targeting the unique genetic characteristics of a tumor model, we sought to thoroughly characterize the mutation profiles of these syngeneic mouse cell lines and examine drug response profiles of these cell line models. The goal of this work was to provide an in vitro system in evaluating combination effectiveness when targeting both immune checkpoint markers and oncogenic targets in preclinical studies.
To this end, we investigated mutation and gene expression profiles of 18 mouse cancer cell lines out of the panel of 23 syngeneic mouse models included in the MuScreenTM for 50 well defined cancer-related mutations among 30,690 variants in exonic regions called by RNAseq (Illumina HiSeq X10). The somatic mutations revealed through the bioinformatics analysis include ALK (3 - frequency, same for the rest), BRAF (4), BRCA1 (7), BRCA2 (12), EGFR (3), ERBB2 (6), EGFR3 (2), FBXW7 (10), FLT3 (12), HRAS (1), KRAS (8), NRAS (1), PDGFRA (11), PTCH1 (9), PIK3CA (2), PTEN (6), RET (3), SETD2 (5), SMAD4 (3), SMO (13), TRP53 (13), TSC1 (3), and TSC2 (10). All of these oncogenic alterations are clinically actionable (Cancer Discovery 2, 82-93, 2012). The same set of genes was also subject to mRNA expression change analysis.
We screened the 18 mouse cell lines with a few selected target therapy agents, and performed combination assays of these agents together with check point inhibitors such as aPD1, aPDL1, in a co-culture system with mouse T cells. An IncuCyte real-time imaging platform was used to distinguish activities on T cells and tumor cells. The results and the implications will be discussed.
Citation Format: Frank Xing, Wubin Qian, Chunlan Dong, Xiaoxi Xu, Sheng Guo, Qian Shi. Genomic profiling of syngeneic mouse cell lines and in vitro screen of the models against checkpoint inhibitors and target agents for preclinical application [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 5597. doi:10.1158/1538-7445.AM2017-5597
Abstract 56: Antibody-drug conjugates containing glucuronide-tubulysin payloads display activity in MDR+ and heterogeneous tumor models
Authors: Burke Patrick J. , Hamilton Joseph Z. , Hunter Joshua H. , Cochran Julia H. , Pires Thomas A. , Leiske Christopher I. , Emmerton Kim K. , Senter Peter D. , Lyon Robert P. , Jeffrey Scott C. 
Published: July 2017

Abstract
While antibody-drug conjugates (ADCs) find increasing application in cancer treatment regimens, de novo or treatment-emergent resistance mechanisms could impair clinical benefit. Two resistance mechanisms that emerge under continuous ADC exposure in vitro include upregulation of transporters that confer multidrug resistance (MDR+) and loss of cognate antigen expression. New technologies that circumvent these resistance mechanisms may serve to extend the utility of next generation ADCs. Recently, we developed the quaternary ammonium linker system to expand the scope of conjugatable payloads to include tertiary amine-containing compounds and applied the linker to tubulysins, a highly potent class of microtubule disrupting agents that maintain activity in MDR+ cell lines. Quaternary ammonium-linked glucuronide-tubulysin drug-linkers were synthesized and evaluated as ADCs. The resulting conjugates were potent and immunologically specific across a panel of cancer cell lines, including those displaying the MDR phenotype. The ADCs also demonstrate potent bystander activity in a co-culture model containing a mixture of antigen-positive and -negative cell lines. Incorporation of a PEG12 side chain in the linker enabled loading at 8-drugs/Ab for increased in vivo potency while maintaining suitable ADC pharmacokinetic properties. In vivo, the glucuronide-tubulysin conjugates displayed activity in MDR+ xenograft models and bystander activity in an admixed Ag+/Ag- heterogeneous tumor model. Thus, the glucuronide-tubulysin drug-linkers represent a promising new payload for ADCs, combining conjugate potency in the presence of the MDR phenotype with robust activity in models of tumor antigen heterogeneity.
Citation Format: Patrick J. Burke, Joseph Z. Hamilton, Joshua H. Hunter, Julia H. Cochran, Thomas A. Pires, Christopher I. Leiske, Kim K. Emmerton, Peter D. Senter, Robert P. Lyon, Scott C. Jeffrey. Antibody-drug conjugates containing glucuronide-tubulysin payloads display activity in MDR+ and heterogeneous tumor 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 56. doi:10.1158/1538-7445.AM2017-56
Abstract 5637: An oral Androgen Receptor PROTAC degrader for prostate cancer
Authors: Neklesa Taavi K. , Snyder Lawrence B. , Bookbinder Mark , Chen Xin , Crew Andrew P. , Crews Craig M. , Dong Hanqing , Gordon Deborah , Macaluso Jennifer , Raina Kanak , Rossi AnnMarie , Taylor Ian , Vitale Nicholas , Wang Jing , Willard Ryan R. , Zimmermann Kurt 
Published: July 2017

Abstract
The Androgen Receptor (AR) remains the principal driver of castration-resistant prostate cancer during the transition from a localized to metastatic disease. Most patients initially respond to inhibitors of the AR pathway, but the response is often short-lived. The majority of patients progressing on enzalutamide or abiraterone exhibit genetic alterations in the AR locus, either in the form of amplifications or point mutations in the AR gene. Given these mechanisms of resistance, our goal is to eliminate the AR protein using the PROteolysis TArgeting Chimera (PROTAC) technology. Further, we sought to make an orally bioavailable AR PROTAC. Medicinal chemistry efforts yielded a small molecule AR PROTAC that simultaneously binds E3-ubiquitin ligase and AR, thus leading to ubiquitination and degradation of AR. This molecule has been characterized in in vitro and in vivo preclinical studies. Our lead oral AR PROTAC degrades approximately 98% of total AR in all cell lines tested, with 50% degradation concentration (DC50) &lt; 1 nM. AR degradation suppresses the expression of AR-target gene PSA, inhibits cell proliferation, and induces potent apoptosis in VCaP cells. No activity is observed in AR-null cell lines, such as PC-3. While enzalutamide loses its activity in the presence of elevated androgens, AR PROTAC maintains its antiproliferative activity. Further, AR PROTAC is able to degrade all clinically relevant mutant AR proteins. A robust oral bioavailability is observed across multiple species and overall ADME properties are encouraging. Approximately 95% AR degradation is observed in AR-amplified VCaP xenografts at doses as low as 10 mg/kg. Congruent with AR degradation, a dose responsive tumor growth inhibition is observed in AR-dependent xenograft studies. In summary, we report the first orally bioavailable AR PROTAC that robustly degrades AR in vitro and in vivo.
Citation Format: Taavi K. Neklesa, Lawrence B. Snyder, Mark Bookbinder, Xin Chen, Andrew P. Crew, Craig M. Crews, Hanqing Dong, Deborah Gordon, Jennifer Macaluso, Kanak Raina, AnnMarie Rossi, Ian Taylor, Nicholas Vitale, Jing Wang, Ryan R. Willard, Kurt Zimmermann. An oral Androgen Receptor PROTAC degrader for 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 5637. doi:10.1158/1538-7445.AM2017-5637
Abstract 5705: Analytical validation of Guardant360 v2.10
Authors: Vowles James , Odegaard Justin , Mortimer Stefanie , Fairclough Stephen , Sikora Marcin , Abdueva Diana , Mokhtari Reza , Baca Arthur , Talasaz AmirAli 
Published: July 2017

Abstract
Guardant360 is a cell-free circulating tumor DNA (ctDNA) test that genotypes all guideline-recommended solid tumor somatic genomic treatment targets from a single non-invasive blood draw. The new version, v2.10, was redesigned to enhance sensitivity and specificity across 73 cancer-related genes. It detects all four major variant classes (single nucleotide variants, SNVs, in all 73 genes; indels in 23 genes; gene amplifications, CNAs, in 18 genes; and fusions in 6 genes).
Analytical performance was assessed throughout the reportable range via multiple serial dilution studies of orthogonally-characterized contrived and patient samples. Analytical specificity was assessed by calculating the false positive rate in pre-characterized healthy donor sample mixtures serially diluted. Positive predictive value (PPV) was estimated as a function of allelic fraction/copy number from pre-characterized samples and prevalence-adjusted using a cohort of 2,585 consecutive clinical samples. Confirmation was performed using ddPCR.
Analytical specificity was 100% for SNVs, fusions, and CNAs and 96% for indels across 25 defined samples. Relative to Guardant360v2.9, v2.10 demonstrated 20-50% increase in fusion molecule recovery. Retrospective in silico analysis of 2,585 consecutive clinical samples demonstrated a 15% increase in actionable fusion detection, a 6%-15% increase in actionable indel detection (excluding newly reportable indels), and a 3%-6% increase in actionable SNV detection.
AlterationsReportable Range95% Limit of DetectionAllelic Fraction / Copy NumberAnalytical SensitivityAllelic Fraction / Copy numberPPVSNVs≥0.04%0.25%≥0.25%&gt;99.9%≥0.25%98.7%0.05–0.25%63.8%&lt;0.25%92.3%Indels≥0.02%0.2%≥0.25%&gt;99.9%≥0.25%98.4%0.05–0.25%67.8%&lt;0.25%88.5%Fusions≥0.04%0.4%≥0.3%100%any100%&lt;0.3%83.0%CNAs≥2.12 copies2.24-2.93 copies2.3 copies95.0%any100%
Guardant360 analytical performance characteristics based on standard cfDNA input (30ng). Analytical sensitivity/limit of detection estimates are provided for clinically actionable variants and may vary by sequence context and cfDNA input. PPV is estimated across entire reportable panel space (PPV was 100% for clinically actionable variants).
Conclusion: Guardant360 v2.10 comprehensively detects all adult solid tumor guideline-recommended somatic genomic variants with unparalleled sensitivity, accuracy, and specificity.
Citation Format: James Vowles, Justin Odegaard, Stefanie Mortimer, Stephen Fairclough, Marcin Sikora, Diana Abdueva, Reza Mokhtari, Arthur Baca, AmirAli Talasaz. Analytical validation of Guardant360 v2.10 [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 5705. doi:10.1158/1538-7445.AM2017-5705
Abstract 5782: A novel method for high-throughput drug screening in 3D tumor organoids
Authors: Phan Nhan , Huang Jessica , Eisenberg David , Memarzadeh Sanaz , Soragni Alice 
Published: July 2017

Abstract
3D tumor organoids are pivotal tools to study tumor development, propagation and invasive properties (Tanner and Gottesman, 2015). They closely recapitulate many characteristics of the tumor of origin in terms of structure, heterogeneity, complexity and response to drug treatment. As such, they are considered an accurate pre-clinical model for drug discovery and development (Nyga et al, 2011; Tanner and Gottesman, 2015; Shroyer, 2016). Nevertheless, reliable methods to perform high-throughput drug screenings using tumor organoids are limited and require extensive manipulation such as sample transfer from plate to plate. In addition, thick 3D matrix supports may hinder drug penetration.
Here we introduce a robust method to generate, treat and assay 3D tumor organoids in standard, uncoated 96- or 384-well plates. By plating cells around the rim of the wells we generate an ultrathin layer of Matrigel that allows penetration of small molecules and bulkier peptide drugs. Media change is easily performed from the center of the well without perturbing the organoids. After a 2-day treatment course, organoids are released by dispase treatment and assayed in the same well by performing a CellTiter-Glo assay (Promega). The method exhibits low plate-to-plate, experiment-to-experiment and operator-to-operator variability.
In addition, it can be extended to patient-derived tumor organoids (PDTO) generated from primary tumors. We show how PDTO from high-grade serous ovarian carcinoma (HGSOC) specimens are generated with a success rate &gt;95%. Given the low number of cells required and high assay sensitivity, we can seed 200 wells from 1Mio cells derived from a tumor biopsy, and test over 60 different drugs/concentrations in triplicates. Moreover, we show how drug combination studies are feasible and allow assessing treatment synergies. As an example, we combined a peptidic inhibitor of p53 aggregation, ReACp53 (Soragni et al, 2016), with carboplatin in PDTO HGSOC established from a panel of patients harboring different p53 mutations. Drug interaction studies are performed across a range of ReACp53 and carboplatin concentrations and cell viability assessed at day 2 is used to compute drug-response curves, EC50 values and combination indexes.
In conclusion, we are introducing an inexpensive, robust, easily automated method to perform high-throughput drug screenings in 3D organoids and PDTO and demonstrate its utility in determining drug sensitivities and optimizing multi-drug combinations in vitro.
Citation Format: Nhan Phan, Jessica Huang, David Eisenberg, Sanaz Memarzadeh, Alice Soragni. A novel method for high-throughput drug screening in 3D tumor organoids [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 5782. doi:10.1158/1538-7445.AM2017-5782
Abstract 5891: DCIS to invasive progression in breast cancer is delayed by restoring CCN5
Authors: Sarkar Sandipto , Ghosh Arnab , Maity Gargi , Banerjee Snigdha , Banerjee Sushanta 
Published: July 2017

Abstract
Malignant progression of breast cancer from pre-invasive to invasive lesions remains a mechanistically unknown event and a major challenge in medical research. By revealing the mechanism of action, our new and substantially different approach aims to demonstrate that CCN5/WISP2 might play a role in negative regulation of progression of pre-invasive lesion ductal carcinoma in-situ (DCIS) to invasive carcinoma (IC). DCIS to IC transition results primarily from the loss of the myoepithelial cell (MEC) layer surrounding the breast ducts & lobules and basement membrane (BM) degradation followed by invasion of cancer cells into the surrounding stromal tissue and vasculature. It has been recently discovered that CCN5, a matricellular protein, is highly expressed in DCIS patient specimens and facilitates regression of aggressive phenotypes. Our in-vitro studies with myoepithelial cell lines (MECs) indicate that CCN5 may prevent the DCIS to IC transition through the protection of the MEC layer. CCN5 performs it’s protective role by regulating sonic hedgehog (SHh) expression in MECs. It has been previously shown in separate studies that Neuropilin1 (Nrp1) positively regulates expression of SHh and Nrp1 is exclusively expressed in MEC layer in breast tissues. An extension of our studies indicate that CCN5 might regulate the integrity of the mammary ductal architecture by protecting the MEC layer through a novel Nrp1-SHh signaling axis. Collectively, our studies indicate that regulating CCN5 expression level in breast cancer tissues might help us controlling the rate of progression of the disease from DCIS to an invasive stage.
Citation Format: Sandipto Sarkar, Arnab Ghosh, Gargi Maity, Snigdha Banerjee, Sushanta Banerjee. DCIS to invasive progression in breast cancer is delayed by restoring CCN5 [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 5891. doi:10.1158/1538-7445.AM2017-5891
Abstract 5924: Necrotic cells promote microglia infiltration in glioblastoma through regulating MCP-1 and MIP-3α expression
Authors: Jung Yieun , Ahn So-Hee , Park Hyunju , Lim Jiwoo , Kang Jihee Lee , Choi Youn-Hee , Kim Eun Ju 
Published: July 2017

Abstract
Glioblastoma multiform (GBM), a grade IV astrocytoma, is most lethal and common adult primary intracranial tumor. GBM is characterized by diffuse infiltration into normal brain parenchyma, rapid growth and the presence of necrosis and microglia/macrophage infiltration. Among these properties of GBM, necrosis has been implicated to be a strong predictor of poor prognosis; however, the effect of necrosis on GBM progression is poorly understood at present. In this study, we examined the effect of necrosis on glioblastoma cells by exploring molecular mechanisms underlying gene expression and chemokine expression. Data obtaining from chemokine array and ELISA showed that CRT-MG human gliomablastoma cells secreted several chemokines including MCP-1 and MIP-3α in response to necrotic cells. Expression levels of mRNA and protein of MCP-1 and MIP-3α were also increased by treatment with necrotic cells in CRT-MG in a dose-dependent manner. Necrotic cells induced NF-κB/AP-1 activation and their binding to the MCP-1 and MIP-3α promoter, leading to enhanced MCP-1 and MIP-3α production in GBM cells. Finally, transwell migration assay showed that incubation with necrotic cells significantly enhanced the migration of microglia. Our data demonstrate that when GBM cells are exposed to and stimulated by necrotic cells, the expression and secretion of MCP-1 and MIP-3α are enhanced in GBM cells and microglia infiltration/migration to the tumor site are facilitated.
Citation Format: Yieun Jung, So-Hee Ahn, Hyunju Park, Jiwoo Lim, Jihee Lee Kang, Youn-Hee Choi, Eun Ju Kim. Necrotic cells promote microglia infiltration in glioblastoma through regulating MCP-1 and MIP-3α expression [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 5924. doi:10.1158/1538-7445.AM2017-5924
Abstract 634: RNAi-mediated β-catenin inhibition promotes T-cell infiltration and anti-tumor activity in combination with immune checkpoint blockade
Authors: Ganesh Shanthi , Shui Serena , Wang Weimin , Brown Bob D. , Abrams Marc 
Published: July 2017

Abstract
Recent research strongly suggests an important role for Wnt/β-catenin signaling in mediating cancer immune evasion and resistance to immune checkpoint therapy, including anti-PD-1, anti-PD-L1, and anti CTLA-4 antibodies. The mechanism by which Wnt/β-catenin signaling causes checkpoint resistance is believed to involve blocking of specific cytokines which trigger immune cell recruitment to the tumor, resulting in the phenomenon of T-cell exclusion and rendering the tumor to a non-inflamed state. Inhibition of β-catenin may be an effective strategy for increasing the low response rate to these effective medicines in numerous cancer populations. DCR-BCAT is a potent and specific chemically-optimized RNA interference (RNAi) trigger targeting CTNNB1, the gene which encodes β-catenin, formulated in a tumor-selective EnCore lipid nanoparticle. In syngeneic mouse tumor models, β-catenin inhibition promoted T-cell infiltration and significantly improved the sensitivity of the tumors to checkpoint inhibition. The combination of DCR-BCAT and IO therapy yielded significant tumor growth inhibition compared to monotherapy in B16F10 melanoma, 4T1 mammary carcinoma, Neuro2A neuroblastoma and Renca renal adenocarcinoma. Importantly, a significant increase in CD8+ T-cells after DCR-BCAT monotherapy was observed in all models evaluated, including genetically-driven spontaneous MMTV-Wnt1 tumors. These data support clinical development of these combination approaches for this first-in-class RNAi therapeutic.
Citation Format: Shanthi Ganesh, Serena Shui, Weimin Wang, Bob D. Brown, Marc Abrams. RNAi-mediated β-catenin inhibition promotes T-cell infiltration and anti-tumor activity in combination with immune checkpoint blockade [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 634. doi:10.1158/1538-7445.AM2017-634
Abstract 639: Morphological changes in mitochondria induced by CD137 (4-1BB) co-stimulation on CD8 T cells
Authors: Labiano Sara , Teijeira Álvaro , Azpilikueta Arantza , Aznar Ángela , Bolaños Elixabet , Melero Ignacio 
Published: July 2017

Abstract
Metabolism has emerged as a fundamental biological process in the control of immunological functions of T cells, playing essential roles in survival and differentiation of these immune cells. Mitochondria are key organelles in controlling these processes by performing fundamental steps in aerobic respiration, fatty acid metabolism and in the control of apoptosis. Recently, Carl June and colleagues showed that CARs engineered with the cytoplasmic tail of 4-1BB were able to promote oxidative phosphorylation in T cells as a result of enhanced mitochondrial biogenesis. CD137 (4-1BB) is an immunostimulatory receptor of the TNFR family expressed on the surface of antigen-activated T cells. Treatment with agonist monoclonal antibodies targeting 4-1BB is showing promising results for immunotherapy of cancer.
In this work, we observed that stimulation of 4-1BB with agonistic mAbs was able to raise the mitochondrial membrane potential on human CD8 T cells. 4-1BB co-stimulated CD8 T cells showed enlarged mitochondria (up to 3μm diameter) with a round shape when observed by confocal or transmission electron microscopy. We observed that CD8 T cells from DLNs (drainig lymph nodes) of tumors in mice treated with agonistic anti-4-1BB antibodies also contained enlarged mitochondria.
By double fluorescence labeling of mitochondria prior and after activation, we could ascertain that enlarged mitochondria were a product of preexisting mitochondria rather than de novo generated organelles. This observation prompted us to study the regulation of mitochondrial dynamics by 4-1BB receptor. 4-1BB stimulation induced an increase in expression of the mitochondrial fusion protein OPA-1. By Super-resolution microscopy with AiryScan detectors we observed more pronounced co-localization of OPA-1 with mitochondrial membrane in 4-1BB co-stimulated T cells than in T cells activated only by CD3 crosslinking.
Our results indicate an important role of 4-1BB in the regulation of mitochondrial morphology and performance in such a way that can be relevant for various T cell functions.
Citation Format: Sara Labiano, Álvaro Teijeira, Arantza Azpilikueta, Ángela Aznar, Elixabet Bolaños, Ignacio Melero. Morphological changes in mitochondria induced by CD137 (4-1BB) co-stimulation on CD8 T 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 639. doi:10.1158/1538-7445.AM2017-639