bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1660: Humanization of patient derived xenograft (PDX) cancer model mice with peripheral blood mononuclear cells (PBMCs)
Authors: Norum Jens Henrik , Josefsen Dag , Kvalheim Gunnar , Engebråten Olav , Sørlie Therese , Mælandsmo Gunhild M. 
Published: July 2017

Abstract
Immunocompetent transgenic mouse models have for decades served as valuable tools to address the effect of oncogenes and tumor suppressors. Immunodeficient mice have been used to establish patient derived xenograft (PDX) models harboring human tumors. These types of models have been used to study cancer initiation and progression as well as preclinical evaluation of anticancer drugs. One major limiting factor for both these model systems is the immune system; the PDX models lack an immune system and the immune system in immunocompetent mouse models display differences compared to the human immune system. Thus, in cancer research there is a need for preclinical models to study the influence of human immune cells on tumor progression and response to cancer therapies. We have established and optimized protocols for intravenous (IV) or intraperitoneal (IP) injections of isolated human PBMCs, to generate humanized mice harboring human immune cells. Our protocols do not require irradiation or busulfan pretreatment of the animals. Flow cytometry analyses showed that mainly T helper cells, CD4+, and cytotoxic T cells, CD8+, were present in the humanized mice. Immunohistochemistry (IHC) analyses of humanized PDX cancer model mice showed that human lymphocytes were present in the tumor periphery and some very few cells within the tumor, in addition to the human leukocytes in the liver and spleen. The growth rates of the PDX tumors were not affected by the humanization. Our protocols require minimal preparations of the animals and generate humanized PDX mice harboring human lymphocytes locating in close proximity of, as well as inside the PDX tumors. The model systems are suitable for preclinical studies of human, adaptive immune responses in tumor progression and cancer therapies.
Citation Format: Jens Henrik Norum, Dag Josefsen, Gunnar Kvalheim, Olav Engebråten, Therese Sørlie, Gunhild M. Mælandsmo. Humanization of patient derived xenograft (PDX) cancer model mice with peripheral blood mononuclear cells (PBMCs) [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 1660. doi:10.1158/1538-7445.AM2017-1660
Abstract 1665: MuScreenTM : A well-characterized syngeneic model platform for rapid in vivo screening
Authors: Zhang Lan , Mao Binchen , Shi Qian 
Published: July 2017

Abstract
Background: Syngeneic tumor models, many shelved for decades, have been revived as effective models for immunotherapy, accompanying the clinical success of the immuno-checkpoint inhibitors (e.g. anti-CTLA4, anti-PD1, anti-PD-L1 antibodies). In vitro cell-based screens that are frequently used in oncology to quickly identify responsive cells and assess PD effects, often fail in immuno-oncology, due to immunotherapeutics targeting the complex host immune system. Alternatively, an in vivo screen with a panel of models addresses many of these questions, e.g. PD and efficacy, but may be cost prohibitive.
Material and methods: Leveraging in-house detailed profiling data on our syngeneic models, including efficacy benchmarking with anti PD-1, PD-L1, CTLA-4, OX-40, GITR , LAG3 and TIM3 antibodies, RNAseq data on tumor samples, and FACS analysis on both baseline and post-treatment tumor samples, we created a new in vivo screening tool for immune-oncology: MuScreen. MuScreen includes up to 20 well-characterized syngeneic models in a 3 month screening run. Both PD and efficacy may be determined in the run, allowing researchers to make decisions based on results observed from a large dataset. To address the cost issue, test agents from multiple clients are pooled together for each run (sharing vehicle and other common groups) providing a significant reduction in the number of animals used and the associated costs.
Results: CrownBio has established the largest collection of syngeneic models with well-characterized immunotherapy data. With the three MuScreen runs, we have generated new data on common IO agents (e.g. aPD-1 antibody) and combinations treatments, with FACS analysis, IHC, and efficacy data. Based on these data, a bioinformatics
analyses were further explored to identify the makers/pathways that could be correlated with the efficacy or PD effect of the tested IO treatment.
Conclusions: MuScreen, the first in vivo screening tool for cancer immunotherapeutics, provides detailed response data on a panel of syngeneic models, and may help on biomarker discovery in a cost and time efficient manner.
Citation Format: Lan Zhang, Binchen Mao, Qian Shi. MuScreenTM : A well-characterized syngeneic model platform for rapid in vivo screening [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 1665. doi:10.1158/1538-7445.AM2017-1665
Abstract 1666: Immune consequences of penfluridol treatment associated with inhibition of glioblastoma tumor growth
Authors: Ranjan Alok , Gupta Nehal , Ramachandran Sharavan , Wright Stephen , Srivastava Sanjay 
Published: July 2017

Abstract
Glioblastoma is the most common and lethal brain tumor associated with only 12% median survival rate of patients. Despite the development of advanced surgical, radiation or use of combinations of anti-cancer drugs, treatment for glioblastoma patients is still a challenge. The major contributing factor in glioblastoma progression and resistive nature is its ability to evade the immune surveillance. Hence, modulating the immune system in glioblastoma tumors could be an important strategy for anticancer therapeutics. Penfluridol, an antipsychotic drug has been shown to have anti-cancer properties in our recently published studies. The present study evaluates the immune response of penfluridol in glioblastoma tumors. Our results demonstrated that penfluridol treatment significantly suppressed glioblastoma tumor growth. Our current results demonstrated about 72% suppression of myeloid derived suppressor cells (MDSCs) with penfluridol treatment in mouse bearing U87MG glioblastoma tumors. MDSCs are known to increase regulatory T cells (Treg), which are immunosuppressive in nature and suppresses M1 macrophages that are tumor suppressive in nature. Our results also showed suppression of regulatory T cells as well as elevation of M1 macrophages with penfluridol treatment by 58% and 57% respectively. Decrease in CCL4 as well as IFNγ with penfluridol treatment was also observed indicating decrease in overall tumor inflammation. This is the first report demonstrating immune modulations by penfluridol treatment associated with glioblastoma tumor growth suppression prompting further investigation to establish penfluridol as a treatment option for glioblastoma patients. [Studies supported in part by R01 grant CA129038, awarded by National Cancer Institute, NIH]
Citation Format: Alok Ranjan, Nehal Gupta, Sharavan Ramachandran, Stephen Wright, Sanjay Srivastava. Immune consequences of penfluridol treatment associated with inhibition of glioblastoma tumor growth [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 1666. doi:10.1158/1538-7445.AM2017-1666
Abstract 1667: Identifying intrinsic regulators of PD-L1 expression in cancer cells: A genome-scale CRISPR knock-out approach
Authors: Mann Jacqueline E. , Ludwig Megan L. , Hoesli Rebecca C. , Kulkarni Aditi , Patel Simmy , Kafelghazal Judy , Nesvizhskii Alexey , Brenner J Chad 
Published: July 2017

Abstract
Head and Neck Squamous Cell Carcinoma (HNSCC) is the sixth most common cancer in the United States and affects 600,000 people each year worldwide. With a five-year survival rate of only 50% and a recent rise in HPV-associated HNSCCs, improved treatment protocols are urgently needed. Evidence of immunosuppression is often reported in HNSCC, making immunotherapy an attractive strategy for the management of this disease. The immune checkpoint inhibitor Pembrolizumab was recently approved for the treatment of metastatic and recurrent HNSCC, but only 18% of initial participants in a trial of Pembrolizumab responded, and it remains difficult to predict patients likely to experience benefit. To increase the number of patients that respond to immune checkpoint inhibition, we sought to identify targetable genetic factors modulating PD-L1, a molecule that serves to dampen the anti-tumor immune response. We show that several HNSCC models exhibit mild (2-4 fold) induction of PD-L1 expression following treatment with interferon-γ (adaptive expression), and recent reports suggest that common oncogenic pathways, including the EGFR and PI3K pathways, may provide a novel strategy to regulate PD-L1 expression. To this end, we developed a high throughput screen to identify targetable pathways that may be used to regulate PD-L1 expression in patients with specific genetic lesions. We have employed a Genome-scale CRISPR Knock-Out (GeCKO) screening technique in HNSCC cell lines and selected for genetic knockouts exhibiting altered PD-L1 expression. Stable knockout pools with representation of approximately 300 gRNAs per target gene (&gt;20,000 target genes in the library) were expanded and serially sorted to create stable sub-populations with enhanced PD-L1 expression. These sub-populations were sequenced to identify gRNAs whose knockout causes a change in PD-L1 expression (e.g. genes that repress or enhance PD-L1 expression). We expect that these large-scale screens, when performed over multiple HNSCC cell lines with diverse genetic lesions, will identify patterns of targetable regulators that may ultimately be manipulated in combination with PD-1/PD-L1 inhibitors.
Citation Format: Jacqueline E. Mann, Megan L. Ludwig, Rebecca C. Hoesli, Aditi Kulkarni, Simmy Patel, Judy Kafelghazal, Alexey Nesvizhskii, J Chad Brenner. Identifying intrinsic regulators of PD-L1 expression in cancer cells: A genome-scale CRISPR knock-out approach [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 1667. doi:10.1158/1538-7445.AM2017-1667
Abstract 1669: Multiplex immunohistochemical staining of PD-L1, PD-1, CD3, CD4, CD8, CD68, FoxP3, and Ki-67 and image analysis of tumor and invasive margin in human FFPE NSCLC tissue
Authors: Dauffenbach Lisa M. , Sia Gela C. , Zheng Jianping , Jun Natalia , Olsen Eric P. , Kerfoot Christopher A. 
Published: July 2017

Abstract
Evaluating the density of immune cell subtypes and their relative spatial positioning in cancers has become an important tool in understanding response to immune checkpoint inhibitors. The purpose of this study was to investigate protein expression of PD-L1, PD-1, CD3, CD4, CD8, CD68, FoxP3, and Ki-67 with four multiplex immunohistochemical assays (Ki-67+CD8, CD3+CD4+Ki-67, FoxP3+PD-1+CD8, and CD68+PD-L1+CD3) using DAB, red, and green chromogens within formalin-fixed, paraffin embedded non-small cell lung (NSCLC) tissues. The Ki-67+CD8 multiplex was developed to evaluate the density of cytotoxic T cells and the percentage that are proliferating. The CD3+CD4+Ki-67 multiplex characterizes the frequency of CD4+ T cells and evaluate proliferation in this subset. The FoxP3+PD-1+CD8 multiplex evaluates the regulatory T cell subset and evaluates PD-1 expression. The CD68+PD-L1+CD3 multiplex characterizes PD-L1 expression on macrophages and T cells. Cell densities were evaluated in the center of tumor and invasive margin regions, and image analysis was performed to quantitate each stain as a single agent and co-expression within each multiplex assay.
Citation Format: Lisa M. Dauffenbach, Gela C. Sia, Jianping Zheng, Natalia Jun, Eric P. Olsen, Christopher A. Kerfoot. Multiplex immunohistochemical staining of PD-L1, PD-1, CD3, CD4, CD8, CD68, FoxP3, and Ki-67 and image analysis of tumor and invasive margin in human FFPE NSCLC tissue [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 1669. doi:10.1158/1538-7445.AM2017-1669
Abstract 1676: EZH2 inhibitors in immunotherapy of melanoma
Authors: Hersey Peter , Gallagher Stuart , Tiffen Jessamy , Shklovskaya Elena , Wilson Stephen , Filipp Fabian 
Published: July 2017

Abstract
EZH2 contains the catalytic subunit of the PRC2 complex, which plays a role in maintenance of stem cell- like state of cancer cells and in the progression of melanoma. Our previous studies have shown that hyperactivation of EZH2 by somatic mutations or copy number gain occurs in 20% of melanoma patients and impacts overall survival. Elevated activity of EZH2 in cancer can be targeted by small molecule drugs (e.g. GSK126) and is associated with sensitivity to apoptotic cell death. Transcriptomic profiling showed that several well-known tumor suppressors such as BOK, NDRG1 and RASSF5 are down-regulated in cells with abnormalities in EZH2, which can be reversed by inhibitor treatment. By using our in vitro EZH2 drug targeting assay we validated genes associated with immune recognition and MHC class II antigen presentation such as HLA A and B,DR and CD74 (HLA DR invariant chain). In addition, ChIP-Seq studies identified adhesion molecules, chemokine ligands, and receptors involved in traffic of lymphocytes to tumors as well as the function of NK cells. Treatment of melanoma with EZH2 inhibitors showed increased killing by NK cells suggesting that an immunosuppressive effect of EZH2 involving both innate and adaptive immunity. In a mouse model of subcutaneous B16 melanoma, a course of daily treatment with an EZH2 inhibitor did not change tumour growth or immune responses in immunosufficient mice but caused a transient 9-fold increase in circulating Ly6G+ [granulocytic] myeloid-derived suppressor cells [MDSCs] suggesting the effect of EZH2 modifiers on the myeloid compartment. In summary, patients with somatic activation of EZH2 may benefit from treatment combinations that include inhibitors of EZH2. Supported by NHMRC program grant 633004, Sydney medical school foundation and Cancer Institute NSW. F.V.F. is grateful for the support of grants CA154887 from the National Institutes of Health, National Cancer Institute and CRCC CRN-17-427258.
Citation Format: Peter Hersey, Stuart Gallagher, Jessamy Tiffen, Elena Shklovskaya, Stephen Wilson, Fabian Filipp. EZH2 inhibitors in immunotherapy of melanoma [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 1676. doi:10.1158/1538-7445.AM2017-1676
Abstract 1678: A flow-based immunoprofiling strategy for interrogating system-wide leukocyte composition in response to glioblastoma
Authors: Baker Gregory J. , Thiagarajan P.S. , Palaniappan Sucheendra K. , Davis Stephanie H. , Moore Jodene K. , Sorger Peter K. 
Published: July 2017

Abstract
Glioblastoma (GBM) is a deadly brain cancer that suppresses cellular immunity through the production of anti-inflammatory cytokines/catabolites, expression of immune checkpoint molecules, and induction of tolerogenic immune cell subsets. While preclinical models have shown each of these mechanisms to negatively impact survival outcome, it remains unclear how these distinct processes manifest themselves within the context of a coordinated immune system and whether additional immunosuppressive mechanisms exist. To address these questions, we have developed an extensible in vivo screening platform to holistically determine how GBM affects cellular immune organization. The method allows for temporal assessment of leukocyte population dynamics in response to tumor progression. Leukocytes derived from lymphoid tissues of tumor-bearing mice are isolated and immunolabeled with a 12-color optimized immunofluorescence panel (OMIP) targeting several major leukocyte lineages. Single-cell data is acquired by flow cytometry and is clustered in an unsupervised manner based on cell-surface protein expression. A vector-based classification system is then used to map phenotypically distinct clusters onto known immune cell lineages. The platform allows for the extraction of immune signatures whose divergence from tumor-naïve standards may be quantified and statistically analyzed; such signatures may also be correlated with response/resistance to therapy. The approach has been validated on orthotopic GL261 glioma in syngeneic C57BL6/J mice, yet it is readily amenable to the study of diverse model systems, including de novo tumors driven by clinically-relevant oncogenes. Alternative flow cytometry antibody panels may easily be substituted to probe more specific immune cell subsets of interest. Systems biology approaches applied to the field of tumor-induced immunosuppression hold promise in identifying novel network-level immune signatures, facilitating a better understanding of immunotherapeutic drug action, and driving next generation high-dimensional biomarker discovery.
Citation Format: Gregory J. Baker, P.S. Thiagarajan, Sucheendra K. Palaniappan, Stephanie H. Davis, Jodene K. Moore, Peter K. Sorger. A flow-based immunoprofiling strategy for interrogating system-wide leukocyte composition in response to glioblastoma [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 1678. doi:10.1158/1538-7445.AM2017-1678
Abstract 1679: BET inhibitors suppress PD-L1 expression in pancreatic stellate cells
Authors: Ebine Kazumi , DeCant Brian T. , Collier Katharine A. , Pham Thao N. , Kumar Krishan , Munshi Hidayatullah G. 
Published: July 2017

Abstract
Single agent treatment with T-cell checkpoint inhibitors has not been effective in pancreatic ductal adenocarcinoma (PDAC) patients. The PDAC stroma, which can account for as much as 80-90% of the tumor mass, can act as a physical and an immunologic barrier to T-cell-mediated therapies. Transgenic mouse models have shown that ablation of pancreatic stellate cells (PSCs), key regulators of fibrosis in vivo, can sensitize PDAC tumors to immune checkpoint therapies. Recently, inhibitors targeting bromodomains and extra-terminal (BET) proteins, a number of which are currently being evaluated in clinical trials for solid tumors, were shown to induce stellate cells to become quiescent and decrease collagen production. The BET family of proteins binds to acetylation motifs present in histones and enables recruitment of transcription factors and other chromatin regulators during RNA transcription. We have found that PSCs express significantly increased PD-L1 levels compared to pancreatic cancer cell lines. We show that BET inhibitors, and in particular specific knockdown of BRD4 protein, decrease basal and IFN-γ-mediated PD-L1 expression in primary stellate cells. We also show that, in contrast to a recent report using cancer cells, c-MYC does not mediate basal or IFN-γ-mediated PD-L1 expression in stellate cells. Instead, we show that the IFN-γ-mediated PD-L1 expression is regulated by IRF1, suggesting cross talk between BRD4 and IRF1 in the regulation of PD-L1 expression. Ongoing in vivo experiments will evaluate the role of BET inhibitors in the regulation of PD-L1 in mouse models of pancreatic cancer.
Citation Format: Kazumi Ebine, Brian T. DeCant, Katharine A. Collier, Thao N. Pham, Krishan Kumar, Hidayatullah G. Munshi. BET inhibitors suppress PD-L1 expression in pancreatic stellate 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 1679. doi:10.1158/1538-7445.AM2017-1679
Abstract 1681A: Overcoming pd1 targeting antibody resistance using combination strategies
Authors: Mirjolet Jean-François , Ramelet Maxime , France Damien 
Published: July 2017

Abstract
PD-1 targeting antibodies (nivolumab, pembrolizumab) are now approved in various tumor types either as second line treatment (locally advanced or metastatic urothelial carcinoma, advanced renal cell carcinoma, recurrent or metastatic head and neck squamous cell carcinoma, classical Hodgkin lymphoma) or even as first line therapy (metastatic melanoma, metastatic non-small cell lung cancer). Despite an increase in response rate as well as survival, there is still issue with resistance to PD-1 targeting therapies. Selection biomarkers as well as response biomarkers are still under intensive research. In addition, combination strategies are needed to increase response rate and overcome resistance.
Combination strategies were therefore tested in one well characterized syngeneic mouse model, i.e. EMT-6 breast carcinoma. The model is known to be highly sensitive to CTLA-4 targeting antibody (optimum tumor to control ratio (T/C) of 3%), a moderate responder to PD-1 targeting treatment (best T/C of 54%) and a well immune infiltrated tumor. Antibodies targeting co-stimulatory receptor such as OX40, GITR and 4-1BB as well as co-inhibitory receptor such as Tim3 were combined to anti-PD-1 antibody. In all cases, combination arm produces better therapeutic activity when compared to single treatment alone. Moreover, both strategies, meaning combination of two antibodies targeting co-inhibitory receptors (PD-1 + Tim3) and combination targeting one co-inhibitory (i.e. PD-1) and one co-stimulatory receptors (OX40, GITR or 4-1BB) worked. Detailed results will be presented including response rate, immune infiltrates and cytokines profiles in order to rationally choose the best therapeutic treatment.
Citation Format: Jean-François Mirjolet, Maxime Ramelet, Damien France. Overcoming pd1 targeting antibody resistance using combination strategies [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 1681A. doi:10.1158/1538-7445.AM2017-1681A