tbuckley/cabot-search huggingface dataset:
Abstract 5018: Dissecting antigen-specific T-cell response in a novel mouse model of colon cancer
Authors: Mary C. Beytagh, Peter M. Westcott, Olivia C. Smith, Jatin Roper, Omer Yilmaz, Tyler E. Jacks
Journal: Cancer Research (2017)

Abstract Immune checkpoint blockade therapies, which unleash the immune system’s ability to recognize and eliminate cancer cells, are currently among the most promising treatments for cancer. Antibodies that block the immune inhibitory receptors CTLA4 and PD1 have shown clinical success, with objective response rates over 20% and some durable responses exceeding 10 years. However, some cancers, such as colorectal cancer (CRC), have proven particularly refractory to immunotherapy. Although it is appreciated that the colon is an immunosuppressive environment, the mechanism and extent of immune suppression remains unclear. Studies of human CRC tumors have shown that T cell infiltration is an important predictor of clinical outcome, yet current mouse models of CRC are not particularly well suited to the mechanistic study of T cell responses against tumor-specific antigens. Syngeneic cell line transplants, by far the most widely used models to study adaptive immune response in CRC, are characterized by a highly complex tumor antigen landscape, and have not employed orthotopic transplant into the colon. In order to track highly specific T cell responses in CRC, we have employed a novel colon organoid-based system, in which transformed organoids expressing model antigens are orthotopically transplanted into the wall of the colon via colonscopy-guided injection, a method pioneered in the lab of Omer Yilmaz. Organoids were harvested from VillinCreER; Apcfl/fl mice and grown in the presence of Wnt ligand; addition of tamoxifen and removal of Wnt from the media facilitated expression of the colon-specifc Cre, deletion of Apc, and selection of transformed organoids capable of growing in the absence of Wnt. To induce expression of model antigens, organoids were infected with a lentiviral vector that, in addition to the fluorescent reporter FusionRed, expressed the T cell antigens SIYRYYGL and two antigens from ovalbumin - SIINFEKL and OVA323-339 - fused to the C-terminus of luciferase (FRLucOS), enabling us to monitor antigen expression in vivo. Organoids were then sorted and injected into the wall of the colon. Previous work by Michael DuPage, in which he expressed the LucOS construct in an autochthonous lung cancer and sarcoma mouse model, provided key insights into the dynamic nature of T cell response against cancer cells. The novel model system described here provides a powerful new tool to dissect antitumor T cell responses in the poorly understood context of CRC. Citation Format: Mary C. Beytagh, Peter M. Westcott, Olivia C. Smith, Jatin Roper, Omer Yilmaz, Tyler E. Jacks. Dissecting antigen-specific T-cell response in a novel mouse model of colon 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 5018. doi:10.1158/1538-7445.AM2017-5018
Abstract 4866: CD47 promotes metastasis and proliferation of colorectal cancer via MAPK/ERK pathway
Authors: Tuo Hu, Yu-feng Chen, Chi Zhou, Jia Ke, Hua-shan Liu, Xiao-bin Zheng, Jian-ping Wang, Xiao-jian Wu, Xian-rui Wu, Ping Lan
Journal: Cancer Research (2017)

Abstract Background and Aim: A number of studies demonstrated that CD47 was overexpressed in several kinds of tumors including colorectal cancer (CRC). Furthermore, the level of CD47 was positively correlated with tumor proliferation, stemness and metastasis. The aim of this study is to evaluate the role of CD47 in the metastasis and proliferation in CRC. Methods: We used the data from GEO database GSE8671 to analyze the expression level of CD47 and its relationship with prognosis in CRC. The expression levels of CD47 in normal and CRC tissues from our hospital were detected using quantitative RT-PCR and western blot. CD47 was downregulated or overexpressed via lentiviral vector system. Then the RTCA assay and migration assay were carried out to investigate the function of CD47 in cell proliferation and migration. Western blot for cancer related pathways was performed to find out the downstream signaling pathways of CD47. Results: Increased expression of CD47 was found in CRC tissues. Inhibition of CD47 expression in HCT116 by ShRNA attenuated the capacity of cell proliferation and migration. On the other hand, overexpression of CD47 in DLD1 increased the capacity for cell proliferation and migration. CD47 induced cell proliferation and migration was found to be associated with the activation of MAPK/ERK pathway. Conclusions: High expression of CD47 was found to be associated with the proliferation and metastasis in CRC via the activation of MAPK/ERK signaling pathway. These findings provide an SIRPα-independent mechanism for CD47 in the progression of CRC, which may find a novel therapy target for the precise treatment of CRC. Citation Format: Tuo Hu, Yu-feng Chen, Chi Zhou, Jia Ke, Hua-shan Liu, Xiao-bin Zheng, Jian-ping Wang, Xiao-jian Wu, Xian-rui Wu, Ping Lan. CD47 promotes metastasis and proliferation of colorectal cancer via MAPK/ERK pathway [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 4866. doi:10.1158/1538-7445.AM2017-4866
Abstract 3976: Resolving cellular complexity in renal cell carcinoma with droplet-based single cell transcriptomics
Authors: Siva Vijayakumar, Mohan Bolisetty, Santosh Sivajothi, Paul Robson
Journal: Cancer Research (2017)

Abstract Purpose: The development, growth, invasion and metastasis of cancer is supported and sustained by complex tissue microenvironments. Interactions between the stromal cells, cancer cells and immune cells through autocrine and paracrine signaling, influences many stages of cancer progression. Furthermore, understanding the identity of the tumor infiltrated immune cell populations is known to predict survival outcomes. Kidney cancer is the 12th most prevalent cancer in the world and is predicted to affect 62,700 new cases in 2016 in the United States alone (American Cancer Society). Existing studies on renal cell carcinoma utilizing bulk profiling methods have been unable to deconvolute the role of the various cell types in promoting the progression this cancer type. Method: Single cell transcriptomics of primary tumors is a powerful approach to study not only the cancer cells but also the cells of the microenvironment. We profiled the various cell types that comprise primary renal cell carcinoma using the Chromium Single Cell 3’ system (10X Genomics). Results: With this single cell approach, we have generated thousands of single cell transcriptomes leading to the identification of numerous cell types and cell states in renal cell carcinoma and matched normal kidney. The microenvironment of renal cell carcinoma tumors contains a heterogeneous mix of stromal, immune and kidney cell types. Compared with the matched normal, the tumors are heavily infiltrated with lymphocytes, mast cells and cells of the myeloid lineage. We identified pathways enriched in specific cell types that illuminate potential mechanisms underlying the cell-cell interactions between cancer cells, stromal cells, and the infiltrating immune cells thus highlighting potentially new targeting strategies for the treatment of this disease. In addition, the single cell data described here will be used to deconvolute existing and new bulk analyses of renal cell carcinoma patients and to establish targeted antibody panels for use in flow and imaging mass cytometry. We anticipate both will lead to better patient stratification to inform patient-specific treatment regimes. Conclusion: Droplet-based single cell transcriptomics can successfully identify the numerous cell types that comprise a tumor, providing a foundation of knowledge to inform biomarker selection and provide insight into novel treatment strategies. This approach reflects a more comprehensive view of renal tumors that is often masked by bulk profiling analyses. Citation Format: Siva Vijayakumar, Mohan Bolisetty, Santosh Sivajothi, Paul Robson. Resolving cellular complexity in renal cell carcinoma with droplet-based single cell transcriptomics [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 3976. doi:10.1158/1538-7445.AM2017-3976
Abstract 2150: Oncogenic role of GAEC1 and its potential modulation with p53 in pathogenesis of colon cancer
Authors: Riajul Wahab, Farhadul Islam, Vinod Gopalan, Alfred King-Yin Lam
Journal: Cancer Research (2017)

Abstract Introduction: GAEC1 (Gene amplified in esophageal cancer 1), is frequently amplified and overexpressed in colon cancer tissues. In the present study, we aimed to unveil the oncogenic potential of GAEC1 in carcinogenesis of colon cancer by studying the underlying cellular functions and molecular interactions by in vitro and in vivo experiments. Method: Transient overexpression of GAEC1 with pcDNA3.1-GAEC1 and silencing with GAEC1-siRNA was performed and several downstream assays were done such as migration, clonogenic and apoptotic assay. Analysis of cell kinetics was done using flow cytometry and cell counting kit-8 was used for cell proliferation assay. Immunofluorescence and Western blot assay were used to determine the expression of different target proteins. Co-immunoprecipitation was used to confirm the protein-protein interaction. For xenotransplantation the severely combined immunodeficient (SCID) mice (4 groups, 6 in each group) were injected subcutaneously with GAEC1 shRNA and control shRNA transfected (stable) SW480 and SW48 colon cancer cells. Result: The overexpression of GAEC1 increased cell proliferation, migration, reduced apoptosis in colon cancer cells. Also, these cells showed cell cycle arrest at the synthetic phase, activation of Bcl-2, K-ras, pAKT proteins as well as inhibition of p53, PUMA, p21 and BAX proteins. Conversely, knockdown of GAEC1 reduced cell proliferation, migration, decreased the phosphorylation of AKT, and induced apoptosis, G2/M phase arrest and cleavage of poly (ADP-ribose) polymerase (PARP). Co-immunoprecipitation revealed GAEC1’s interaction with p53. In addition ectopic over expression and silencing of GAEC1 lead to reciprocal effects of p53 protein expression. Moreover, knockdown of GAEC1 reduced the nuclear translocation of murine double minute 2 protein (mdm2) indicating that GAEC1 is responsible for the degradation of p53 through the direct interaction between mdm2-p53 in nucleus. Furthermore, our in vivo data demonstrate that the loss of GAEC1 inhibits the tumor formation in xenograft model. Conclusion: Collectively our study demonstrates that GAEC1 exhibits the oncogenic role in colon cancer by reducing expression of p53 through protein-protein interaction which leads to the inhibition of PUMA, p21, BAX, and activation of Bcl-2, K-ras and pAKT protein expression. Note: This abstract was not presented at the meeting. Citation Format: Riajul Wahab, Farhadul Islam, Vinod Gopalan, Alfred King-Yin Lam. Oncogenic role of GAEC1 and its potential modulation with p53 in pathogenesis of colon 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 2150. doi:10.1158/1538-7445.AM2017-2150
Abstract 304: CLIC1 membrane insertion is a pivotal regulator of glioblastoma stem cell G1-S transition by promoting an increase of chloride permeability
Authors: Ivan Verduci, Valentina Carlini, Federica M. Raciti, Matteo Conti, Federica Barbieri, Tullio Florio, Michele Mazzanti
Journal: Cancer Research (2017)

Abstract Glioblastoma (GBM) is the most aggressive and lethal brain tumor and, despite aggressive surgery and adjuvant radiotherapy and/or chemotherapy, the prognosis remains invariantly poor. As for most of solid and hematological malignancies, it was demonstrated that the bulk of tumor cells in GBM is generated by a rare fraction of self-renewing, multipotent cancer stem cells (CSCs) and the persistence of CSCs within the tumor mass is considered the main determinant of GBM development, progression, recurrence and radio- or chemoresistance. Thus, one of the main goals of current research is to identify specific biological mechanisms or intracellular pathways of CSCs whose pharmacological targeting might affect their survival and proliferation. In particular, little is known about the possibility that the molecular mechanisms underlying cell-cycle control in GBM CSCs are endowed with specific and unique features as compared with normal cells. Our study is based on the observation that GBM cells express higher levels of chloride intracellular channel 1 (CLIC1) as compared to nonmalignant brain cells and that in CSCs CLIC1 is mainly localized in the membrane forming an active channel. Conversely, in physiological conditions CLIC1 is mainly a cytoplasmic protein only transiently translocating to the membrane. We recently showed that the different level of activity of CLIC1 in CSCs and normal mesenchymal stem cells confers CLIC1-targeting drugs (for example the biguanide metformin) selective cytotoxicity toward tumor cells. Here we report, that in response to stress conditions, CLIC1 increases the probability to modify its structure going from a cytoplasmic hydrophilic form to a transmembrane conformation. Once in the membrane, CLIC1 acts as a chloride permeability, participating, together with NADPH oxidase, to the generation of a chronic state of oxidative stress that favor the transition between G1 and S phase. The peculiarity of CLIC1 exposure on the external face of the GMB CSC plasma membrane support the idea that this protein could represent a main determinant of the cell cycle progression in this tumor cell subpopulation and thus an accessible and relevant pharmacological target to eradicate CSCs in GBM. Note: This abstract was not presented at the meeting. Citation Format: Ivan Verduci, Valentina Carlini, Federica M. Raciti, Matteo Conti, Federica Barbieri, Tullio Florio, Michele Mazzanti. CLIC1 membrane insertion is a pivotal regulator of glioblastoma stem cell G1-S transition by promoting an increase of chloride permeability [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 304. doi:10.1158/1538-7445.AM2017-304
Abstract 5633: Unique modulation of estrogen-induced apoptosis with structural analogues of endoxifen in long-term estrogen-deprived (LTED) breast cancer cells
Authors: Balkees Abderrahman, Sean W. Fanning, Daniela Quintana Rincon, Geoffrey Greene, Philipp Y. Maximov, V. Craig Jordan
Journal: Cancer Research (2017)

Abstract Endoxifen, a non-steroidal anti-estrogen is the active hydroxylated metabolite of N-desmethyltamoxifen. The structure is based on a synthetic triphenylethylene-type angular estrogen. Endoxifen is in clinical trials as a therapeutic agent to treat aromatase resistant breast cancer. Paradoxically, LTED breast cancer is known to respond to synthetic and natural estrogens through estrogen-induced apoptosis. A series of synthetic endoxifen analogs, were used to modulate estrogen-induced apoptosis in LTED breast cancer cells (MCF7:5C). X-ray crystallography was performed on endoxifen, bisphenol, and diethylstillbestrol (DES), bound to the ligand-binding domain (LBD) of the human estrogen receptor (ER). Cellular studies established that (MCF-7:5C) of estrogen-induced apoptosis was dependent on the LBD of the ER. Similarly, endoxifen blocked estrogen-induced apoptosis in a concentration and time-dependent manner. Apoptosis triggered by DES was blocked by endoxifen and was ER-dependent. X-ray crystallography of both endoxifen and DES illustrate the two extremes of estrogen-induced apoptosis, which is dependent upon the closure of helix 12 over the LBD to generate estrogenic activity. Despite the fact that bisphenol, an analog of endoxifen without the anti-estrogenic monomethylamino ethyl side chain, is an estrogen that causes breast cancer cell replication; bisphenol initially inhibits estrogen-induced apoptosis, but triggers estrogen-induced apoptosis itself after 7 days of treatment of LTED breast cancer cells. X-ray crystallography demonstrates that bisphenol can produce a unique complex with the ER:LBD, which is similar to the DES:LBD estrogenic complex. In both cases, the ligands are sealed into the LBD by helix 12. This delay in apoptosis caused by an analog of endoxifen, that is an angular estrogen, possess unique biological features. We hypothesize that in LTED cells the complex passes through an anti-estrogenic conformation to evolve into an estrogenic complex with helix 12 sealing the LBD. We describe a unique property of a ligand:receptor complex. For the first time we demonstrate that a ligand:receptor complex is slowly activated from an antagonist to an agonist complex over a period of days. Citation Format: Balkees Abderrahman, Sean W. Fanning, Daniela Quintana Rincon, Geoffrey Greene, Philipp Y. Maximov, V. Craig Jordan. Unique modulation of estrogen-induced apoptosis with structural analogues of endoxifen in long-term estrogen-deprived (LTED) breast cancer 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 5633. doi:10.1158/1538-7445.AM2017-5633
Abstract 5793: Comparison of EMT biomarker expression in 2D monolayer and 3D spheroid cultures in a prostate cancer cell model
Authors: Jen Carlstrom, Jeanine M. Hinterneder, Lindsay Nelson, Stephen Hurt
Journal: Cancer Research (2017)

Abstract The purpose of this study was to examine the induction of epithelial to mesenchymal transition (EMT) in a prostate cancer cell line by measuring classical biomarker expression in three-dimensional (3D) spheroid cultures compared to traditional 2D monolayers in an effort to develop a more biologically relevant assay. Using Ultra-Low Attachment (ULA) microplates, we grew spheroids from a human prostate cancer cell line (DU 145). Numerous studies have implicated a role for EMT in carcinoma invasion and metastasis. EMT is characterized by rearrangement of the extracellular matrix (ECM) and differential regulation of ECM proteins. We induced EMT using TGF-beta and phorbol-12-myristate-13-acetate (PMA) and compared expression levels of specific biomarkers, such as E-cadherin, fibronectin, and IL-6, using AlphaLISA and LANCE (TR-FRET) assay technologies. We confirmed that treatment of DU 145 cells with TGF-beta is sufficient for inducing changes in both EMT biomarker expression and characteristic cellular morphology in monolayer cultures. However, in 3D spheroid cultures, we observed only a partial EMT response to the same TGF-beta treatment as demonstrated by changes in the expected biomarker expression pattern. Using the small molecule, PMA, we see significant differences in the levels of IL-6 secretion after EMT induction between cells grown in monolayer and those grown in spheroids. Cellular proliferation, growth and vitality were assessed using ATPlite luminescence assays and confocal microscopy of live-stained cells with a high content imaging system. Though we observe increased proliferation in monolayer cultures compared to 3D spheroids, the changes observed in protein expression patterns cannot be sufficiently explained by differences in cell number or viability. These data illustrate the differences in protein expression levels and in cellular tolerance for compound treatment between a human prostate cancer cell line grown in monolayers and those same cells grown in 3D spheroids. Citation Format: Jen Carlstrom, Jeanine M. Hinterneder, Lindsay Nelson, Stephen Hurt. Comparison of EMT biomarker expression in 2D monolayer and 3D spheroid cultures in a prostate cancer cell model [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 5793. doi:10.1158/1538-7445.AM2017-5793
Abstract 352: The role of p62 (SQTSM1) in the transforming growth factor β signaling pathway
Authors: Evelyn Ng, Adrian Gunaratne, John Di Guglielmo
Journal: Cancer Research (2017)

Abstract Transforming growth factor beta (TGFβ) is a cytokine that regulates many cellular processes, including cellular adhesion, proliferation and apoptosis. Its canonical downstream effectors include Smad2/3 proteins, which are phosphorylated and then translocate to the nucleus to alter gene transcriptional programs and promote processes such as epithelial-to-mesenchymal transition (EMT). Previous studies in our lab have shown that atypical Protein Kinase C (aPKC) isoforms associate with TGFβ receptors and modulate receptor trafficking and signal transduction. An aPKC-associated protein, p62 (SQSTM1) has been implicated in TGFβ-dependent EMT, however the mechanisms remain unclear.Here, we investigate the localization of p62 and its potential roles in modulating TGFβ signaling via knockdown and overexpression studies. Using antibody feeding and immunofluorescence microscopy, we support previous findings showing that p62 localizes to late endosomes. In addition, using a co-immunoprecipitation approach, we observed that p62 may associate with TGFβ type II receptor. To explore the functional role of p62 in TGFβ signaling, we conducted protein silencing using siRNA. We observed TGFβ-independent decreases in E-cadherin expression. However these changes were independent of the phosphorylation status or nuclear translocation of Smad2.P62 also plays an important role in autophagy by targeting proteins for degradation. Recently, prolonged TGFβ stimulation has been shown to induce cellular autophagy. Therefore, it is in our interest to characterize the relationship between TGFβ-dependent EMT and autophagy, and to determine whether p62 has a regulatory role between these two processes. Citation Format: Evelyn Ng, Adrian Gunaratne, John Di Guglielmo. The role of p62 (SQTSM1) in the transforming growth factor β signaling pathway [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 352. doi:10.1158/1538-7445.AM2017-352
Association Between Extending CareFirst’s Medical Home Program to Medicare Patients and Quality of Care, Utilization, and Spending
Authors: G. Greg Peterson, Kristin Lowe Geonnotti, Lauren Hula, Timothy Day, Laura Blue, Keith Kranker, Boyd Gilman, Kate Stewart, Sheila Hoag, Lorenzo Moreno
Journal: JAMA Internal Medicine (2017)

CareFirst, the largest commercial insurer in the mid-Atlantic Region of the United States, runs a medical home program focusing on financial incentives for primary care practices and care coordination for high-risk patients. From 2013 to 2015, CareFirst extended the program to Medicare fee-for-service (FFS) beneficiaries in participating practices. If the model extension improved quality while reducing spending, the Centers for Medicare and Medicaid Services could expand the program to Medicare beneficiaries broadly.