bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3024: CD4+ outperform CD8+ central memory-derived CAR T cells, mediating persistent antitumor responses and long-term eradication of glioblastoma
Authors: Wang Dongrui , Starr Renate , Aguilar Brenda , Brito Alfonso , Chang Brenda , Sarkissian Aniee , Badie Behnam , Barish Michael E. , Forman Stephen J. , Brown Christine E. 
Published: July 2017

Abstract
Purpose: To compare antitumor effector function mediated by CD4+ and CD8+ chimeric antigen receptor (CAR)-T cells targeting IL13 receptor α2 (IL13Rα2) for treatment of glioblastoma (GBM).
Experimental Design: CD4+ and CD8+ IL13Rα2-specific CAR-T cells, derived from enriched central memory T cells (Tcm), were evaluated for their antitumor potential both in vitro by recursive challenge with GBM cells and in vivo in established orthotopic GBM xenograft models. Further, GBM-stimulated CD4+ and CD8+ CAR-T cells were examined for their exhaustion- and memory-associated phenotypes at transcriptional and protein levels, which would account for their differential antitumor activity.
Results: While CD8+ CAR-T cells mediated robust short-term cytolytic effector function, they became rapidly exhausted and lost antitumor potential after repeated stimulation with tumor cells. CD4+ CAR-T cells, by contrast, persisted and retained effector potency even after repetitive tumor challenge. CD4-mediated cytotoxicity acted through the granzyme B/perforin pathway and was independent of the CD8+ cells. Activated CD4+ CAR-T cells augmented the proliferation of CD8+ cells, but failed to protect the CD8+ cells against stimulation-induced exhaustion. In NSG mice bearing GBM xenografts, CD4+ CAR-T cell treatment led to long-term tumor-free survival, while CD8+ CAR-T cell treated mice showed short-term tumor regression followed by antigen-positive relapse and associated T cell exhaustion. Upon GBM stimulation, CD4+ cells expressed less co-inhibitory receptors and more memory-associated markers than the CD8+ T cell subset. Further, a comprehensive transcriptional analysis revealed that when activated, CD4+ cells retained expression of genes involved in survival- and self-renewal-related pathways, indicating a less exhausted status and a better functional persistence in comparison to the CD8+ cells.
Conclusion: We observed a superior anti-GBM activity mediated by CD4+ CAR-T cells over the CD8+ subset, featured by their ability to maintain long-term immune response and reduce stimulation-induced exhaustion. It is thus inferred that the frequency of CD4+ cells could be an important criteria for evaluating the efficacy of CAR-T cells as immunotherapeutic products.
Citation Format: Dongrui Wang, Renate Starr, Brenda Aguilar, Alfonso Brito, Brenda Chang, Aniee Sarkissian, Behnam Badie, Michael E. Barish, Stephen J. Forman, Christine E. Brown. CD4+ outperform CD8+ central memory-derived CAR T cells, mediating persistent antitumor responses and long-term eradication of 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 3024. doi:10.1158/1538-7445.AM2017-3024
Abstract 3027: Dissecting mechanisms of anti-PD-1 therapy with massively parallel single-cell RNA-sequencing
Authors: Miller Brian C. , Wadsworth Marc H. , Bi Kevin , Hughes Travis K. , Manguso Robert , Sharpe Arlene H. , Shalek Alex K. , Haining Nicholas 
Published: July 2017

Abstract
Anti-PD-1 therapy is an important new treatment option for many different types of malignancies, but overall response rates are less than 40%. Limited understanding of how anti-PD-1 treatment changes the tumor immune microenvironment is a barrier to identifying rational combination therapies and understanding mechanisms of immunotherapy resistance. To overcome this barrier, we set out to understand the mechanisms by which anti-PD-1 therapy augments the anti-tumor immune response using single-cell genomics. We have developed a massively parallel single-cell RNA-sequencing platform (“Seq-Well”) that uses a fabricated chip with nearly 100,000 nanowells into which barcoded beads and individual cells are distributed prior to lysis and RNA capture. We used this platform to comprehensively define the global expression profile of all major immune lineages in the tumor microenvironment in a mouse tumor model of immunotherapy. Mice were implanted with the B16F10 melanoma transplantable model of cancer and treated with anti-PD-1 or control antibodies. Tumors were harvested and CD45+ tumor-infiltrating leukocytes isolated by FACS. In a single experiment we were able to sequence the transcriptomes of over 600 individual cells, allowing us to clearly distinguish different immune lineages within the tumor microenvironment. We detect two transcriptionally distinct populations of CD8+ T cells, one that is highly proliferative (as marked by Ki-67), and one that has higher expression of cytotoxic markers (i.e. perforin). The Ki-67hi population is enriched for a gene expression signature from terminally exhausted CD8+ T cells in chronic viral infection, suggesting that this is a more exhausted subset. Treatment with anti-PD-1 globally alters the tumor microenvironment, including enriching for CD8+ T cells in the Prfhi subpopulation compared with the Ki-67hi more terminally exhausted population. Studies to understand changes in the immune infiltrate of immunotherapy resistant tumors are currently ongoing. In conclusion, massively parallel single-cell RNA-sequencing allows us to dissect the mechanisms by which checkpoint blockade controls tumor growth, revealing shifts in the differentiation state of exhausted CD8+ T cells induced by checkpoint blockade.
Citation Format: Brian C. Miller, Marc H. Wadsworth, Kevin Bi, Travis K. Hughes, Robert Manguso, Arlene H. Sharpe, Alex K. Shalek, Nicholas Haining. Dissecting mechanisms of anti-PD-1 therapy with massively parallel single-cell RNA-sequencing [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 3027. doi:10.1158/1538-7445.AM2017-3027
Abstract 3029: An in vivo role for Argonaute 2 in KRAS driven pancreatic cancer
Authors: Shankar Sunita , Tien Jean , Dommeti Vijaya L. , Zelenka-Wang Sylvia , Apel Ingrid A. , Shi Jiaqi , Kumar-Sinha Chandan , Chinnaiyan Arul M. 
Published: July 2017

Abstract
Oncogenic mutations in RAS provide a compelling yet intractable therapeutic target. Using co-immunoprecipitation mass spectrometry, we recently identified an interaction between RAS and Argonaute 2 (AGO2), the core component of the RNA silencing machinery exerting translational control of mRNA transcripts. RAS and AGO2 co-sediment and co-localize in intracellular endomembrane bound organelles. The AGO2 N-terminal domain directly binds the KRAS Switch II region, irrespective of GDP/GTP bound to RAS. Functionally, we observed that AGO2 was required for maximal oncogenic KRAS levels and AGO2 knock-down attenuates cell proliferation in mutant KRAS-dependent cells. Intriguingly, AGO2 mediated microRNA processing (RISC activity) was attenuated in cancer cells expressing mutant KRAS compared to those expressing wild type RAS. Yet, these initial investigations using cell line models do not reveal a clear role for AGO2 in KRAS driven oncogenesis. Therefore, we probed the role of AGO2 in the well-established pancreatic ductal adenocarcinoma (PDAC) mouse model driven by oncogenic KRAS.
Towards this end, we generated LSL-KrasG12D; Pft1a Cre; AGO2flox/flox (KCA) mice. Preliminary analysis (8-10 weeks of age) suggests that compared to LSL-KRASG12D (KC) mice, homozygous loss of AGO2 results in increased KRAS driven Acinar to Ductal Metaplasia (ADM) phenotype considered as precursors of PanIN (pancreatic intraepithelial neoplasia) and PDAC. This mirrors the phenotype of loss of Dicer in the same model further reinforcing a role for microRNAs in restraining KRAS oncogenic programs. Yet unlike Dicer, loss of AGO2 alone did not cause any gross or histological changes in the development of the mouse pancreata. In an effort to understand the underlying mechanisms that are regulated by AGO2, we also studied the activated levels of a variety of signaling molecules in pancreata obtained from different genotypes. Primary analysis indicates that wild type RAS levels are elevated during AGO2 loss and has a bearing on PDAC initiation. Using both Western blot and Immunohistochemical analyses, we demonstrate a previously unknown and critical role for AGO2 in KRAS-MAPK signaling pathway.
Citation Format: Sunita Shankar, Jean Tien, Vijaya L. Dommeti, Sylvia Zelenka-Wang, Ingrid A. Apel, Jiaqi Shi, Chandan Kumar-Sinha, Arul M. Chinnaiyan. An in vivo role for Argonaute 2 in KRAS driven pancreatic 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 3029. doi:10.1158/1538-7445.AM2017-3029
Abstract 3032: Direct regulation of alternative splicing by Smad3 through PCBP1 is essential to the tumor-promoting role of transforming growth factor beta1
Authors: Tripathi Veenu , Sixt Katherine M. , Xu Xuan , Zhang Ying E. 
Published: July 2017

Abstract
In advanced stages of cancers, TGF- β promotes tumor progression in conjunction with inputs from receptor tyrosine kinase pathways. However, the mechanisms that underpin the signaling cooperation and convert TGF- β from a potent growth inhibitor to a tumor promoter are not fully understood. In this work we report that TGF- β directly regulates alternative splicing of cancer stem cell marker CD44 through a phosphorylated T179 of SMAD3-mediated interaction with RNA-binding protein PCBP1. We show that TGF- β and EGF respectively induce SMAD3 and PCBP1 to colocalize in SC35 positive nuclear speckles, and the two proteins interact in the variable exon region of CD44 pre-mRNA to inhibit spliceosome assembly in favor of expressing the mesenchymal isoform CD44s over the epithelial isoform CD44E. We further show that the SMAD3-mediated alternative splicing is essential to the tumor-promoting role of TGF- β and has a global influence on protein products of genes instrumental to epithelial to mesenchymal transition and metastasis.
Citation Format: Veenu Tripathi, Katherine M. Sixt, Xuan Xu, Ying E. Zhang. Direct regulation of alternative splicing by Smad3 through PCBP1 is essential to the tumor-promoting role of transforming growth factor beta1 [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 3032. doi:10.1158/1538-7445.AM2017-3032
Abstract 3034: A programmed ribosomal frameshifting defect potentiates the transforming activity of the JAK2-V617F mutation
Authors: Khan Yousuf A. , Sulima Sergey O. , Kendra Joe , Advani Vivek M. , Jones John E. , Briggs Joseph , Keersmaecker Kim de , Dinman Jonathan D. 
Published: July 2017

Abstract
The JAK-STAT pathway is one of the major mechanisms through which cellular proliferation, differentiation, migration, survival and apoptosis are regulated in response to external stimuli. Promiscuous activation of this pathway is a major driver in the pathogenesis of myeloproliferative neoplasms, often characterized by clonal expansion of mature myeloid cells. The JAK2-V617F allele is the most common and well characterized mutation linked to this class of leukemias. A change of G to T at nucleotide 1849 of the coding sequence (CDS) results in substitution of valine to phenylalanine at codon 617. JAK2-V617F mutant cells have strongly increased activation of JAK-STAT signaling, which can partially be explained by its ability abolish inhibition of kinase activity and increase the Km of the enzyme. It is however unclear if these effects are sufficient to explain the strong activation of the JAK-STAT pathway induced by the V617F mutation. Here, we demonstrate that this mutation destabilizes a programmed -1 ribosomal frameshift (-1 PRF) signal in the JAK2 mRNA, leading to decreased rates of -1 PRF promoted by this element. There is an inverse relationship between -1 PRF and mRNA stability. Thus, decreased -1 PRF results in increased abundance of the JAK2 mRNA and increased JAK2 protein expression. Prior studies established that elevated expression levels of JAK proteins are sufficient to transform cells in vitro, suggesting that -1 PRF may normally help to limit JAK2 expression. Silent protein coding changes in the -1 PRF signal slippery sequence ablating JAK2 frameshifting also increased JAK2 expression and phenocopied the transforming activity of JAK2-V617F in cell culture. Further, the combination of the V617F and slippery site mutations conferred an additive effect on cellular transformation. The presence at least three additional -1 PRF signals in the JAK2 mRNA suggests that -1 PRF plays a significant role in controlling JAK2 expression.
Citation Format: Yousuf A. Khan, Sergey O. Sulima, Joe Kendra, Vivek M. Advani, John E. Jones, Joseph Briggs, Kim de Keersmaecker, Jonathan D. Dinman. A programmed ribosomal frameshifting defect potentiates the transforming activity of the JAK2-V617F mutation [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 3034. doi:10.1158/1538-7445.AM2017-3034
Abstract 3050: Polymorphisms in the arntl2 promoter affect breast cancer metastasis susceptibility
Authors: Ha Ngoc-Han , Hunter Kent 
Published: July 2017

Abstract
Breast cancer mortality is primarily due to metastatic lesions rather than primary tumors, yet relatively little is known regarding the mechanisms of metastatic breast cancer, making it difficult to identify patients who are at risk for metastatic disease. Our hypothesis suggests that inherited germline mutations contribute to metastatic disease and that these single nucleotide polymorphisms (SNPs) could be used to predict outcome in breast cancer patients. To investigate the effect of inherited SNPs on metastasis, we used a mouse genetics approach comparing strains with high (FVB) and low (MOLF) metastatic phenotypes and identified Arntl2, a circadian rhythm transcription factor, as a gene whose differential expression predicted outcome in breast cancer patients. To identify SNP differences in Arntl2 between MOLF and FVB, we performed whole genome sequencing of MOLF and compared it to the FVB genome. Overlapping the data with DNase hypersensitivity sites revealed 10 SNPs in the predicted promoter of Arntl2. To test the causative role of the SNPs on Arntl2 expression in vivo, metastatic cell lines were engineered using the CRISPR-Cas9 approach to specifically replace the FVB Arntl2 promoter with that of MOLF. In agreement with our hypothesis, substitution of the MOLF promoter reduced Arntl2 transcript levels and subsequently decreased lung metastases in orthotopic implantation assays. In vitro pulldown experiments with strain-specific promoter probes revealed potential differential binding of chromatin modifier proteins, demonstrating the significance of the SNPs in regulating Arntl2 transcription. Finally, analysis of SNPs associated with Arntl2 expression in a cohort of Chinese breast cancer patients revealed significant correlation of Arntl2 expression with overall survival, validating this gene as a marker in humans. Since Arntl2 is a transcription factor, current studies are focused on identifying Arntl2-regulated genes to investigate downstream pathways involved in metastasis. This study has important implications regarding the role of circadian rhythm in cancer progression and provides a potential mechanism to explain the increased risk of breast cancers in nightshift workers. Furthermore, this provides the first evidence that transcriptional control elements can be engineered using CRISPR-Cas9 to establish the causative role of SNPs in inherited susceptibility to cancer metastasis.
Citation Format: Ngoc-Han Ha, Kent Hunter. Polymorphisms in the arntl2 promoter affect breast cancer metastasis susceptibility [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 3050. doi:10.1158/1538-7445.AM2017-3050
Abstract 3051: Mechanism of early dissemination and metastasis in Her2+ mammary cancer
Authors: Harper Kathryn , Sosa Maria Soledad , Entenberg David , Hosseini Hedayatollah , Cheung Julie , Nobre Rita , Avivar-Valderas Alvaro , Nagi Chandandaneep , Girnius Nomeda , Davis Roger , Farias Eduardo , Condeelis John , Klein Christoph A. , Aguirre-Ghiso Julio A. 
Published: July 2017

Abstract
Metastasis is the leading cause of cancer related deaths and these lesions develop from disseminated cancer cells (DCC) that can remain dormant. Metastasis initiating cells are thought to originate from a subpopulation present in progressed invasive tumors. However, DCCs detected in patients before the manifestation of breast cancer metastasis contain fewer genetic abnormalities than primary tumors or than DCCs from patients with metastases. These findings and those in pancreatic cancer and melanoma models argued that dissemination might occur during early stages of tumor evolution. Yet, the mechanisms that might allow early-disseminated cancer cells (eDCC) to complete all steps of metastasis were unknown. Here we show that in early lesions (EL), before any overt primary tumor (PT) masses are detected, there is a sub-population of Her2+/P-p38lo/P-ATF2lo/TWISThi/E-cadherinlo early cancer cells that are invasive and disseminate to target organs. Intra-vital imaging and organoid studies of early lesions revealed that Her2+ eDCC precursors locally invaded, intravasated and lodged in target organs. Her2+ eDCCs activated a Wnt-dependent EMT-like dissemination program but without complete loss of epithelial phenotype that was reversed by Her2 or Wnt inhibition. Surprisingly, while the majority of eDCCs are TWISThi/E-cadherinlo and dormant, they eventually initiate metastasis. Our work identifies a mechanism for early dissemination whereby Her2 aberrantly activates a program similar to mammary ductal branching that spawns eDCCs capable of forming metastasis after a dormancy phase.
Citation Format: Kathryn Harper, Maria Soledad Sosa, David Entenberg, Hedayatollah Hosseini, Julie Cheung, Rita Nobre, Alvaro Avivar-Valderas, Chandandaneep Nagi, Nomeda Girnius, Roger Davis, Eduardo Farias, John Condeelis, Christoph A. Klein, Julio A. Aguirre-Ghiso. Mechanism of early dissemination and metastasis in Her2+ mammary 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 3051. doi:10.1158/1538-7445.AM2017-3051
Abstract 3052: Defining the role of EMT in breast cancer dormancy and metastasis in vivo
Authors: Jung Hae-Yun , Yeung Kay T. , Lee Tiffany , Tsai Jeff H. , Yang Jing 
Published: July 2017

Abstract
Breast cancer patients can develop metastases from dormant tumor cells years after primary tumor resection and treatment. Despite the clinical significance of metastatic latency, the exact cellular and molecular events regulating tumor dormancy remains largely unknown due to challenges in detecting single dormant tumor cells in vivo and characterizing the dormant tumor microenvironment. A developmental program termed Epithelial Mesenchymal Transition (EMT) has been shown to play an important role in tumor cell dissemination, tumor dormancy, and chemoresistance. During EMT, stationary epithelial cells lose their epithelial characteristics, including adherent junctions and apical-basal polarity, and acquire mesenchymal shape and properties. These cells gain the ability to migrate into the circulation, lodge into a distant organ, and form dormant tumor niches. We have previously shown that reversal of EMT is a key driving force in dormant tumor cell proliferation and macrometastasis formation in a skin carcinoma mouse model. Here, we present a novel metastatic breast cancer mouse model in which HER2-driven primary breast tumor cells are labelled with red fluorescent protein with inducible EMT transcription factor TWIST1. We established this mouse model by crossing the TetON-TWIST1 mice with the MMTV-rtTA mice to generate the MMTV-rtTA/TetON-TWIST1 double transgenic mice. To generate HER2-driven breast tumors in these mice, we administered concentrated lentivirus that expresses both the HER2 gene and the tdTomato fluorescent marker under one promoter via intraductal injection. This allows for rapid and synchronized development of primary tumors which recapitulate the formation of sporadic human breast cancer which arises in single cells in otherwise normally developed breast tissue. TWIST1 expression in the luminal layer of the mammary gland was then induced via oral doxycycline. Upon expression of TWIST1, Her2-driven breast tumor cells were found in circulation and in the lungs as micrometastases. We determined that disseminated breast tumor cells mostly remained in dormancy until TWIST expression was switched off by doxycycline withdrawal. We showed that tumor dormancy is partly due to the inability to reverse EMT and regain proliferative capacity. Lastly, using our mouse model to track disseminated breast cancer cells, we will characterize the associated dormant residing niche to further our understanding of tumor dormancy in connection with EMT and immune escape.
Citation Format: Hae-Yun Jung, Kay T. Yeung, Tiffany Lee, Jeff H. Tsai, Jing Yang. Defining the role of EMT in breast cancer dormancy and metastasis in vivo [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 3052. doi:10.1158/1538-7445.AM2017-3052
Abstract 3053: Stability and stemness of the hybrid epithelial-mesenchymal phenotype
Authors: Jolly Mohit Kumar , Jia Dongya , Tripathi Satyendra C. , Mooney Steve , Celiktas Muge , Hanash Samir M. , Mani Sendurai A. , Pienta Kenneth J. , Ben-Jacob Eshel , Levine Herbert 
Published: July 2017

Abstract
Transitions between epithelial and mesenchymal phenotypes – EMT and MET – are hallmarks of cellular plasticity during embryonic development and cancer metastasis. During these transitions, cells can also adopt a hybrid epithelial/mesenchymal (hybrid E/M) phenotype enabling them to migrate collectively as observed during gastrulation, wound healing, and clusters of Circulating Tumor Cells (CTCs). The hybrid E/M phenotype has largely been tacitly assumed to be 'metastable', i.e. transient state. Here, we integrate mathematical modeling with in vitro experiments to identify certain 'phenotypic stability factors' (PSFs) - GRHL2, OVOL2 and ΔNP63α that can stabilize a hybrid E/M phenotype. We show that H1975 (NSCLC cell line) cells can display a hybrid E/M phenotype stably and migrate collectively, a behavior that is impaired by knockdown of GRHL2 or OVOL2. Further, our computational model predicts that these PSFs can also associate hybrid E/M phenotype with high tumor-initiating potential, a prediction strengthened by the observation that the higher levels of one or more of these PSFs may predict poor patient outcome. Overall, our results suggest that a hybrid E/M phenotype need not be 'metastable', and bolster the notion that a hybrid E/M phenotype, but not necessarily full EMT, associates with aggressive tumor progression.
Citation Format: Mohit Kumar Jolly, Dongya Jia, Satyendra C. Tripathi, Steve Mooney, Muge Celiktas, Samir M. Hanash, Sendurai A. Mani, Kenneth J. Pienta, Eshel Ben-Jacob, Herbert Levine. Stability and stemness of the hybrid epithelial-mesenchymal phenotype [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 3053. doi:10.1158/1538-7445.AM2017-3053