bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2892: Oncostatin M elicits cellular plasticity through cooperative STAT3-SMAD3 signaling
Authors: Bryson Benjamin L. , Junk Damian J. , Smigiel Jacob , Parameswaran Neetha , Doherty Mary R. , Bartel Courtney A. , Jackson Mark
Published: July 2017

Increasing evidence suggests that tumor cell plasticity promotes metastasis and tumor recurrence, resulting in cancer patient mortality. While it is clear that the tumor microenvironment (TME) contributes to tumor cell plasticity, the specific TME factors that actively generate tumor cell plasticity are largely unknown. Here, we identify TME cytokines that promote epithelial-mesenchymal plasticity, and acquisition of cancer stem-cell (CSC) properties. A screen of 27 TME cytokines identified multiple Interleukin-6 family members as inducers of mesenchymal/CSC properties, with Oncostatin M (OSM) being the most potent. Importantly, OSM induced plasticity was mediated by STAT3, but also dependent on TGF-β signaling and downstream SMAD3. Inhibition of functional TGF-β/SMAD signaling by expressing a dominant-negative TGF-β receptor, treating with a TGF-β receptor inhibitor, or suppressing SMAD3 expression using a SMAD3-shRNA prevented the OSM-induced mesenchymal/CSC properties. OSM-activated STAT3 binds to SMAD3 and promotes SMAD3 nuclear localization and binding to the SNAIL promoter, increasing transcription of the SNAIL gene. The epithelial-mesenchymal transition induced by the STAT3/SMAD3 axis results in a highly invasive and metastatic phenotype and the emergence of CSC properties, including therapeutic resistance. Importantly, maintenance of the OSM-induced mesenchymal/CSC state requires sustained exposure to the cytokine, as removal of OSM results in a marked phenotypic reversion. A high-throughput screen for small molecule inhibitors of the OSM-induced mesenchymal/CSC phenotype has been performed and are currently being confirmed. We propose that, targeted blockade of the STAT3/SMAD3 axis in tumor cells may represent a novel therapeutic approach to prevent the plasticity associated with metastasis and tumor recurrence.

Citation Format: Benjamin L. Bryson, Damian J. Junk, Jacob Smigiel, Neetha Parameswaran, Mary R. Doherty, Courtney A. Bartel, Mark Jackson. Oncostatin M elicits cellular plasticity through cooperative STAT3-SMAD3 signaling [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 2892. doi:10.1158/1538-7445.AM2017-2892
Abstract 2894: Epinephrine-induced gamma-secretase/Notch signaling in pancreatic cancer stem cells
Authors: Xu Xuemin , Hu Chen , Schuller Hildegard M.
Published: July 2017

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer deaths with 5-year survivals below 10%. Cancer stem cells represent a small population of cells in PDAC and are thought to drive the development, progression, metastasis and drug resistance of this cancer. The Notch pathway regulates the self-renewal of pancreatic cancer stem cells as well as angiogenesis and drug resistance. Gamma-secretase cleaves the Notch-1 receptor, resulting in release of the Notch intracellular domain (NICD) that then translocates to the nucleus and activates the transcription of target genes. Aberrant Notch signaling activated by γ-secretase activity is associated with progression, angiogenesis and drug resistance of PDAC and is being explored as a target for PDAC therapy. Smoking and psychological stress are risk factors for PDAC. However, the potential modulation of γ-secretase/Notch by these risk factors has not been investigated to date. Nicotine and psychological stress both cause hyperactivity of the sympathetic nervous system and adrenal glands, resulting in increased blood and organ levels of the stress neurotransmitters norepinephrine (NOR) and epinephrine (EPI), which are the physiological agonists of beta-adrenergic receptors (β-ARs). In turn, β-ARs are coupled to the stimulatory G-protein Gαs that stimulates the formation of intracellular cAMP, which activates multiple signaling pathways in a cell type-specific manner. Using spheroid formation assays and Western blotting, our data show, -for the first time,- that the stress neurotransmitter Epi significantly increases the self-renewal of pancreatic cancer stem cells by increasing the expression of the activated forms (c-terminal) of the γ-secretase component presenilin1 and of Notch1 (NICD). These responses were inhibited by the β-AR antagonist (beta-blocker) propranolol and by the inhibitory neurotransmitter γ-aminobutyric acid (GABA) that inhibits cAMP formation via activation of Gαi-coupled GABAB receptors. These findings suggest that the γ-sexretasesecretase/Notch pathway in pancreatic cancer stem cells is under regulatory control by neurotransmitters, with Epi as stimulator and GABA as inhibitor. These data could open up new avenues for the prevention and therapy of PDAC. Additional experiments are currently underway to further investigate mechanistic aspects of this novel concept. Supported by RO1CA042829 with NIH.

Note: This abstract was not presented at the meeting.

Citation Format: Xuemin Xu, Chen Hu, Hildegard M. Schuller. Epinephrine-induced gamma-secretase/Notch signaling in pancreatic cancer stem 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 2894. doi:10.1158/1538-7445.AM2017-2894
Abstract 29: Addition of Galunisertib to DC101 increased angiogenesis inhibition and tumor growth control in hepatocellular carcinoma (HCC)
Authors: Tijeras-Raballand Annemilai , Hobeika Christian , Payen Elise , Martinet Matthieu , Bonnin Philippe , Benhadji Karim A. , Eveno Clarisse , Pocard Marc , Faivre Sandrine , Raymond Eric , Gramont Armand de
Published: July 2017

Introduction: Galunisertib is a selective ATP-mimetic TGF-β receptor (TGFβR)-I inhibitor and DC101 is a rat antagonist antibody to mouse VEGFR-2 and is used to model VEGFR-2 blockade in murine tumor models. Ramucirumab and galunisertib being independently under clinical investigation in HCC patients, our study aimed at exploring the anti-tumoral potency of a combination of galunisertib and DC101 in an in vivo transgenic model of HCC.

Methods: Transgenic mice developing stage-defined HCC were treated for 8 weeks (W) from W8 to W16 with either vehicle, DC101 (40mg/kg, twice weekly, IP), galunisertib (100mg/kg, daily, oral gavage) or DC101 plus galunisertib. Tumor growth was evaluated by ultrasound (liver size) and by the number of macronodules at sacrifice. Angiogenesis was evaluated by doppler (blood flow in the coeliac trunk) and by CD31 staining.

Results: Liver size and the number of liver tumor macronodules were significantly lower in all treatment arms compared to placebo control at both the W12 intermediary sacrifice and W16 final sacrifice; the combination of galunisertib and DC101 showing increased tumor control at W16 (4,43±0,55 mean liver volume (in mm3) in the combination arm vs 5,22±0,86, 5,68±0,78, 7,09±1,54 in the DC101, galunisertib and placebo arms respectively). Angiogenesis assessed by measuring the mean blood flow in the coeliac trunk (TCm), decreased in all treatment arms compared to placebo. At W16, galunisetib potentiated the effect of DC101 with a TCm decrease of 66% compared to 59% and 10% in the DC101 and galunisertib, respectively. These results will be confirmed by the assessment of micronodules number on HPS section for tumor growth and CD31 staining for angiogenesis analysis (number of vessels and the vessel lumen area). The effects of the combination versus monotherapies will be evaluated on the immune landscape.

Conclusion: The combination of galunisertib and DC101 showed promising anti-tumor activities that were associated with decreased angiogenesis.

Citation Format: Annemilai Tijeras-Raballand, Christian Hobeika, Elise Payen, Matthieu Martinet, Philippe Bonnin, Karim A. Benhadji, Clarisse Eveno, Marc Pocard, Sandrine Faivre, Eric Raymond, Armand de Gramont. Addition of Galunisertib to DC101 increased angiogenesis inhibition and tumor growth control in hepatocellular carcinoma (HCC) [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 29. doi:10.1158/1538-7445.AM2017-29
Abstract 2913: Emergence of RAS or EGFR mutant clones affects duration of response to EGFR blockade in colorectal cancers
Authors: Arena Sabrina , Emburgh Beth Van , Siravegna Giulia , Lazzari Luca , Crisafulli Giovanni , Corti Giorgio , Mussolin Benedetta , Baldi Federica , Buscarino Michela , Bartolini Alice , Valtorta Emanuele , Vidal Joana , Bellosillo Beatriz , Germano Giovanni , Pietrantonio Filippo , Ponzetti Agostino , Albanell Joan , Siena Salvatore , Sartore-Bianchi Andrea , Nicolantonio Federica Di , Montagut Clara , Bardelli Alberto
Published: July 2017

Cetuximab and panitumumab are monoclonal anti-EGFR antibodies (moAbs) currently used for the treatment of advanced RAS wild type colorectal cancers (CRC). Emergence of acquired resistance invariably limits the efficacy of these agents, and the dynamics of clonal evolution during anti-EGFR blockade are poorly understood. At progression, RAS mutations represent the most common genetic alterations, while EGFR extracellular domain (ECD) mutations are acquired by a smaller cohort of patients. We found that the mutation profile correlates with the clinical outcome of patients; in particular those who develop RAS mutations upon EGFR blockade achieve reduced tumor shrinkage and shorter duration of response respect to patients in which EGFR ECD mutations emerge during therapy. We investigated in preclinical models the potential role of RAS and EGFR ECD mutations during the emergence of acquired resistance, by tracking the evolution of clones in a genetically barcoded population of CRC cells chronically treated with cetuximab. We observed that therapeutic (target therapy, chemotherapy) and environmental (reduced nutrient condition) pressures differentially shape the clonal composition of CRC cell populations, leading to the emergence of clones with the highest fitness in presence of the external pressure. In conclusion, a multistep clonal evolution process characterizes the development of drug resistance and is associated with the clinical outcome of CRC patients treated with anti-EGFR antibodies.

Citation Format: Sabrina Arena, Beth Van Emburgh, Giulia Siravegna, Luca Lazzari, Giovanni Crisafulli, Giorgio Corti, Benedetta Mussolin, Federica Baldi, Michela Buscarino, Alice Bartolini, Emanuele Valtorta, Joana Vidal, Beatriz Bellosillo, Giovanni Germano, Filippo Pietrantonio, Agostino Ponzetti, Joan Albanell, Salvatore Siena, Andrea Sartore-Bianchi, Federica Di Nicolantonio, Clara Montagut, Alberto Bardelli. Emergence of RAS or EGFR mutant clones affects duration of response to EGFR blockade in colorectal cancers [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 2913. doi:10.1158/1538-7445.AM2017-2913
Abstract 2921: Integrated exome- and single cell RNA-sequencing reveals a clone's genomic instability and multifaceted fitness
Authors: Andor Noemi , Maley Carlo C. , Ji Hanlee P.
Published: July 2017

DNA-damage therapy is the main line of defense against most cancers, especially at advanced stages of progression. DNA-damage therapy damages the cell’s DNA. We have identified that a cell’s cumulative extent of DNA damage - even when successfully repaired - is an indicator for future tolerance to new insults. This finding points to a quantitative measure of genomic instability as biomarker of sensitivity to DNA-damaging agents. However, quantifying genomic instability is difficult, especially because each individual tumor harbors clones with their own distinct genomic characteristics. Here we address the challenge of quantifying the complex phenotype of genomic instability across the clonal subpopulations that coexist within an individual tumor.

We identified coexisting clones from bulk-exome sequencing and calculated the copy number profile of each clone’s genome. We integrated mutations detected in both, single-cell RNA-sequencing (scRNA-seq) and exome sequencing, to assign single cells to clones. Because cells in G2/M phase of the cell cycle (further referred to as G2/M clones) have twice the ploidy compared to cells in other cell cycle phases, their presence represents an opportunity for validation. Using 15 gastric cancer cell lines - each sorted by cell cycle phase - we validated: i) clone-specific copy number and ii) assignment of single cells to clones. Here, the predicted size of G2/M clones is an indicator of how correct we quantify clone-specific copy number. The degree to which expression of cell cycle genes is exclusive to G2/M clones is an indicator as to how correct we assign single cells to clones. In addition to the dominant quiescent clone and the G2/M clone, we identified other discrete subclones in a subset of cell lines, suggesting that genetic intra-tumor heterogeneity is sometimes maintained in-vitro. This approach identified clone-specific markers that can be used for cytometry separation of cells of specific clonal subpopulations.

Overall, we demonstrate the power of combining exome sequencing and scRNA-seq to reveal how many clones are present in a tumor sample, how genomically unstable each clone is and how fit is each clone. When combined, these two techniques synergize into a powerful strategy to investigate the relationship between genomic instability, clone fitness and DNA-damage sensitivity.

Citation Format: Noemi Andor, Carlo C. Maley, Hanlee P. Ji. Integrated exome- and single cell RNA-sequencing reveals a clone's genomic instability and multifaceted fitness [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 2921. doi:10.1158/1538-7445.AM2017-2921
Abstract 2924: Circulating DNA demonstrates convergent evolution and common resistance mechanisms during treatment of colorectal cancer
Authors: Thierry Alain R. , Pastor Brice , Jiang Zhi-Qin Camilla , Katsiampoura anastasia , Parseghian Christine , Loree Jonathan , Overman Michael J. , Sanchez Cynthia , Messaoudi Safia El , Ychou Marc , Kopetz Scott
Published: July 2017

Malignant tumors shed cell free DNA into the blood stream. Analyzing this new biological source may have important implications in a shift towards personalized medicine for diagnosing and/or monitoring malignancies. We recently showed the first clinical validation and clinical utility of circulating DNA (cfDNA) analysis in oncology by testing RAS/BRAF hotspot mutations in plasma from metastatic colorectal cancer patients (mCRC) (Nat Med. 2014 Apr;20(4):430-5). In addition, liquid biopsies allow the tracking of clonal dynamics and detection of mutations during treatment. We evaluated under blinded conditions the ability of cfDNA to detect RAS/BRAF mutations in the plasma of 42 mCRC patients treated on a phase Ib/II trial of FOLFOX and dasatnib, with or without cetuximab. Prior to treatment, sequencing of archival tissue detected mutations in 25/42 patients (60%), while the cfDNA assay detected mutations in 37/42 patients (88%). Our cfDNA assay was able to detect mutations with allele frequencies as low as 0.01%. After exposure to treatment, 41/42 patients (98%) had a cfDNA detected RAS/BRAF mutation. Of 22 patients followed with serial measurements who were RAS/BRAF mutant at baseline, 11 (50%) developed a second mutation following treatment and 3 (14%) no longer had detectable levels of another mutant allele. Of RAS/BRAF wild type tumors at baseline, 4/5 (80%) developed new mutations. Patients may harbor mutations at very low frequency down to 0.01% before initiation or during treatment revealing the need of a high sensitive technique to detect mutant subclones. cfDNA quantitative measurements from this study closely mirrored changes in CEA and CT scan results, highlighting the importance of obtaining quantitative data beyond the mere presence of a mutation. Combined qualitative and quantitative cfDNA analysis allows tracking acquired resistance by studying the real-time clonal evolution of the tumor and might help physicians to adjust patient treatment. Our findings demonstrate the development of new RAS/BRAF mutations in patients regardless of whether they had pre-existing mutations in the pathway, demonstrating a convergent evolutionary pattern.

Note: This abstract was not presented at the meeting.

Citation Format: Alain R. Thierry, Brice Pastor, Zhi-Qin Camilla Jiang, anastasia Katsiampoura, Christine Parseghian, Jonathan Loree, Michael J. Overman, Cynthia Sanchez, Safia El Messaoudi, Marc Ychou, Scott Kopetz. Circulating DNA demonstrates convergent evolution and common resistance mechanisms during treatment of colorectal 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 2924. doi:10.1158/1538-7445.AM2017-2924
Abstract 2933: Involvement of CXCL12-CXCR7 axis in adipocyte-induced TNBC metastasis
Authors: Choi Hyeongjwa , Ignacio Rosa Mistica C. , Gibbs Carla R. , Lee Eunsook , Adunyah Samuel E. , Son Deok-Soo
Published: July 2017

Breast cancer (BC) is the most frequent tumor in women worldwide. Although its mortality has significantly decreased owing to advanced therapies, triple negative breast cancer (TNBC) is still difficult to treat because of lack of estrogen receptor, progesterone receptor and HER-2. TNBC accounts for 12-24% of total BC and contributes to the aggressiveness and poorer outcomes. The risk of BC increases significantly in obese women. Obesity is also associated with the worse clinical prognosis of BC. But the underlying mechanisms between obesity and BC, particularly TNBC, remain unclear. Therefore, we compare the molecular mechanisms by which human adipocyte conditioned media (CM) affect TNBC cells (BT549) and non-TNBC cells (MCF7A). Adipocyte CM had no effect on the proliferation of both TNBC and non-TNBC cells. However, adipocyte CM enhanced significantly migration in TNBC cells compared to non-TNBC cells. Next, we examined the signaling pathway by which adipocyte CM promote migration of TNBC cell. AKT and ERK were activated in both TNBC cells and non-TNBC cells. However, phospho-STAT3 was significantly increased in TNBC cells. Also, N-cadherin, a marker for epithelial to mesenchymal transition (EMT), was increased at the late time point in TNBC cells. Furthermore, CXCR7 was specifically increased in TNBC cells after treatment with adipocyte CM using a PCR array. CXCR7 is chemoattractive to CXCL12 which is highly expressed in the lung, the bone marrow, and the liver, common sites of BC metastasis. Taken together, the results indicate that adipocyte CM may promote metastasis of TNBC cells through the CXCL12-CXCR7 axis by activating STAT3.

Citation Format: Hyeongjwa Choi, Rosa Mistica C. Ignacio, Carla R. Gibbs, Eunsook Lee, Samuel E. Adunyah, Deok-Soo Son. Involvement of CXCL12-CXCR7 axis in adipocyte-induced TNBC metastasis [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 2933. doi:10.1158/1538-7445.AM2017-2933
Abstract 2943: MYC functions as a master switch for natural killer cell-mediated immune surveillance of lymphoid malignancies
Authors: Swaminathan Srividya , Mosley Adriane , Horton Crista , Liefwalker Daniel F. , Deutzmann Anja , Dhanasekaran Renumathy , Gouw Arvin , Gentles Andrew , Eilers Martin , Maecker Holden T. , Felsher Dean W.
Published: July 2017

The MYC oncogene drives the pathogenesis of many hematopoietic malignancies, including Burkitt’s lymphoma (BL) and Acute Lymphoblastic Leukemia (ALL). These malignancies are often “oncogene-addicted” to MYC. Using mass cytometry (CyTOF), we demonstrate that MYC-addicted T-ALL excludes specific immune subsets from the tumor microenvironment implicated in immune surveillance, including natural killer (NK) cells. MYC inhibition clears malignant lymphocytes from the spleen and restores the normal splenic NK composition. Concordantly, peripheral blood of T-ALL patients have reduced percentages of activated NK cells as compared to healthy individuals. We show that MYC excludes activated NK cells from sites of lymphomagenesis by suppressing ERK1/2-STAT1/2-Type I IFN signaling, in both murine and human lymphomas. Furthermore, MYC-associated BL patients with higher than median expression of STAT1/2, and cytotoxic NK cell genes, PRF1 and Granzymes, have favorable clinical outcomes. Hence, oncogenic MYC appears to causally and reversibly suppress NK-mediated immune surveillance during lymphomagenesis.

Citation Format: Srividya Swaminathan, Adriane Mosley, Crista Horton, Daniel F. Liefwalker, Anja Deutzmann, Renumathy Dhanasekaran, Arvin Gouw, Andrew Gentles, Martin Eilers, Holden T. Maecker, Dean W. Felsher. MYC functions as a master switch for natural killer cell-mediated immune surveillance of lymphoid malignancies [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 2943. doi:10.1158/1538-7445.AM2017-2943
Abstract 2944: miR-130a and -145 reprogram myeloid derived suppressor cells and enhance anti-tumor immunity
Authors: Ishii Hiroki , Vodnala Suman K. , Achyut Bhagelu R. , Hollander Christine M. , Lal Ashish , Yang Li
Published: July 2017

Myeloid derived suppressor cells (MDSCs) are increased in tumor bearing condition, and elicit immunosuppression via type 2 polarization. We have previously reported that TGF-β signaling in MDSCs is essential for tumor metastasis. TGFβR2, a receptor essential for TGF-β signaling, is elevated in MDSCs. Deletion of Tgfbr2 in MDSCs, the gene encoding TGFβR2, significantly decreased tumor metastasis. However, it is unclear how TGFβR2 is regulated in MDSCs. We identify microRNA-130a and -145, which directly target Tgfbr2 in MDSCs and inhibit the expression of TGF-β receptor II (TβRII). Both miRs levels were lower in MDSCs from advanced tumor bearing mice correlating to increased TβRII level. Overexpression of miR-130a or -145 in MDSCs shift their immunological phenotype from type 2 to type 1 polarization. Moreover, tumor metastasis was significantly suppressed in myeloid specific miR-130 transgenic mice. In pre-clinical mouse models, the number of lung metastasis was significantly decreased when mice were treated with combination therapy of miR-130a or -145 with paclitaxel when compared with miR-130a, -145, or paclitaxel alone. We proposed that reprogramming of MDSCs by miR-130a and -145 could be a novel strategy in therapeutic treatment for breast cancer metastasis.

Citation Format: Hiroki Ishii, Suman K. Vodnala, Bhagelu R. Achyut, Christine M. Hollander, Ashish Lal, Li Yang. miR-130a and -145 reprogram myeloid derived suppressor cells and enhance anti-tumor immunity [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 2944. doi:10.1158/1538-7445.AM2017-2944
Abstract 2948: A distinct CD8+ tumor infiltrating lymphocyte subset is associated with high TIL density, enhanced cytotoxicity and improved survival in patients with lung cancer
Authors: Ganesan Anusha Preethi , Wood Oliver , Garrido-Martin Eva , Chee Serena , Mellows Toby , Clarke James , Samaniego-Castruita Daniela , Singh Divya , Seumois Gregory , Altezani Aiman , Woo Edwin , Friedman Peter , Thomas Gareth , King Emma , Sanchez-Elsner Tilman , Vijayanand Pandurangan , Ottensmeier Christian H.
Published: July 2017

High tumor infiltrating lymphocyte (TIL) density predicts for good prognosis in several cancers and therapies that boost the anti-tumor responses of cytotoxic lymphocytes (CTLs) have shown promise in the clinic. However, clinical responses to currently available immunotherapeutic agents vary considerably, the molecular basis of which is unclear. We performed global transcriptional profiling of CTLs in tumors and adjacent non-tumor tissue from 36 patients with early stage lung cancer to define the molecular features associated with robustness and heterogeneity of anti-tumor immune responses. We observed major differences in the transcriptional program of tumor-infiltrating CTLs (CD8+ TILs) that is shared across tumor subtypes. Pathway analysis revealed enrichment of genes in cell cycle, TCR activation and co-stimulation pathways, indicating tumor-driven expansion of presumed tumor antigen-specific CTLs. We also observed marked heterogeneity in the expression of molecules associated with TCR activation and immune checkpoints, and their expression was positively correlated with the density of tumor-infiltrating CTLs. Interestingly, TILhigh tumors were also enriched for a distinct CD8+ tumor infiltrating lymphocyte subset that appeared to have enhanced cytotoxicity and independently predicted improved survival in patients with lung cancer. In summary, we define the molecular fingerprint of tumor-infiltrating CTLs and identify a number of novel targets that may be important in modulating the magnitude and specificity of anti-tumor immune responses in lung cancer.

Citation Format: Anusha Preethi Ganesan, Oliver Wood, Eva Garrido-Martin, Serena Chee, Toby Mellows, James Clarke, Daniela Samaniego-Castruita, Divya Singh, Gregory Seumois, Aiman Altezani, Edwin Woo, Peter Friedman, Gareth Thomas, Emma King, Tilman Sanchez-Elsner, Pandurangan Vijayanand, Christian H. Ottensmeier. A distinct CD8+ tumor infiltrating lymphocyte subset is associated with high TIL density, enhanced cytotoxicity and improved survival in patients with lung 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 2948. doi:10.1158/1538-7445.AM2017-2948
Abstract 2968: Examining the role of breast cancer Neuregulin1 and macrophage ErbB3 in intravasation
Authors: Cabrera Ramon , Chiang Serena , Segall Jeffrey
Published: July 2017

The purpose of our studies is to investigate the role of Neuregulin1 (NRG1) and ErbB3 signaling between breast cancer cells and macrophages in facilitating tumor cell intravasation. The interaction of breast cancer cells with other cell types within the tumor microenvironment plays an important role in metastasis. These interactions are thought to influence tumor cell invasion and intravasation, two important steps in the process of metastasis. Our studies are specifically interested in examining the signaling occurring between tumor cells and macrophages. Previous studies have established the presence of paracrine signaling between breast cancer cells and macrophages, where colony stimulating factor 1 (CSF-1) produced by the tumor cells stimulates the production of epidermal growth factor (EGF) by macrophages, leading to chemotactic invasion of the tumor cells. In addition to this paracrine loop signaling between tumor cells and macrophages, it has been seen that macrophage expression of ErbB3, a member of the EGFR family of receptor tyrosine kinases, may play a role in facilitating tumor cell invasion. In order to examine the effects of signaling between tumor cells and macrophages in intravasation, we utilize an in vitro transendothelial migration (iTEM) assay. This assay uses transwells coated with matrigel and endothelial cells in order to mimic the entry of tumor cells into blood vessels. We show that using an ErbB3 blocking antibody results in a significant reduction of macrophage-induced transendothelial migration of breast cancer cells. Additionally, reduction of expression of the ErbB3 receptor ligand Neuregulin1 in tumor cells yields a similar result. Stimulation of macrophages with NRG1 leads to increased expression of Jagged1 (JAG1), a ligand of the Notch receptor. Activation of the Notch receptor pathway has been shown to be involved in tumor cell invasion. Overall our studies look to further examine the interaction between tumor cells and macrophages, and these observations indicate that ErbB3, NRG1, and JAG1 could all serve as novel targets in metastasis and the tumor microenvironment.

Citation Format: Ramon Cabrera, Serena Chiang, Jeffrey Segall. Examining the role of breast cancer Neuregulin1 and macrophage ErbB3 in intravasation [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 2968. doi:10.1158/1538-7445.AM2017-2968
Abstract 2975: Collagen type XI alpha 1 confers cisplatin chemoresistance in ovarian cancer through inhibitor of apoptosis proteins (IAPs)
Authors: Rada Miran , Cha Jennifer , Sage Jessica , Orsulic Sandra , Cheon Dong-Joo
Published: July 2017

Ovarian cancer is the most lethal gynecological cancer, which affects one in 70 females in the United States during their lifetime. While cisplatin is the frontline treatment for ovarian cancer, chemoresistance severely limits the treatment success. The goal of this study is to identify novel therapeutic targets to overcome cisplatin resistance. We recently identified Collagen type XI alpha 1 (COL11A1) as a novel biomarker associated with cisplatin resistance in ovarian cancer. COL11A1 is a component of the tumor stroma and its expression is restricted to cancer-associated fibroblasts (CAFs) adjacent to tumor cells. We further showed that COL11A1 protects ovarian cancer cells from cisplatin-induced apoptosis, yet the underlying mechanism is largely unknown. To understand the molecular mechanism by which COL11A1 protects cancer cells from cisplatin-induced apoptosis, we overexpressed COL11A1 in ovarian cancer cells and performed RNA-Seq. Our RNA-Seq data revealed that COL11A1 did not change the levels of genes involved in cisplatin transport, inactivation, and DNA repair pathways in cancer cells, which are well-established mechanisms to confer cisplatin resistance. Rather, COL11A1 enhances the expression of the Inhibitors of Apoptosis Proteins (IAPs), including XIAP, BIRC2 (c-IAP1) and BIRC3 (c-IAP2). Using a full-length COL11A1 protein, genetic manipulation, and co-culture method, we confirmed that COL11A1 significantly increases the expression of IAPs upon cisplatin treatment. The inhibition of XIAP, BIRC2 and BIRC3 with an IAP antagonist BV6 attenuated the ability of COL11A1 to inhibit cisplatin-mediated apoptosis. Our data indicates that COL11A1 activates Akt, and Akt is known to phosphorylate XIAP at serine-87, which protects it from ubiquitination and degradation in response to cisplatin. Collectively, our data identify IAP as a mediator of COL11A1’s action in blocking cisplatin-induced apoptosis.

Note: This abstract was not presented at the meeting.

Citation Format: Miran Rada, Jennifer Cha, Jessica Sage, Sandra Orsulic, Dong-Joo Cheon. Collagen type XI alpha 1 confers cisplatin chemoresistance in ovarian cancer through inhibitor of apoptosis proteins (IAPs) [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 2975. doi:10.1158/1538-7445.AM2017-2975
Abstract 2983: Tumor induced stromal STAT1 deregulates mammary tissue homeostasis and accelerates breast cancer
Authors: Zellmer Victoria R. , Schnepp Patricia M. , Fracci Sarah L. , Tan Xuejuan , Howe Erin N. , Zhang Siyuan
Published: July 2017

The tumor microenvironment (TME) – the dynamic tissue space in which the tumor exists – plays a significant role in tumor initiation and is a key contributor in cancer progression. Little is known about the tumor-induced changes in the adjacent tissue stroma. Herein, we sought to explore tumor-induced changes in the TME at the morphological and molecular level to further characterize cancer progression. We show that tumor-adjacent mammary glands (TAGs) display altered branch morphology, increased expression of αSMA particularly in myofibroblasts, and an increased capacity to form mammospheres in 2D suspension culture. FACS analysis showed that TAGs contain an increased number of Lin-CD24+/CD49+ enriched mammary gland stem cell (MaSCs) population, suggesting deregulated tissue homeostasis in TAGs. We conducted comparative transcriptomics on TAGs and contralateral control glands. Meta-analysis on differentially expressed genes from our RNA-seq dataset plus two breast cancer stromal patient microarray datasets identified shared upregulation of STAT1, which we verified in tumor-adjacent tissues. Knockdown of STAT1 in caveolin-deficient mouse embryonic fibroblasts (CAFs) cocultured with human breast cancer cells altered cancer cell proliferation, further suggesting the role of STAT1 as a stromal contributor of tumorigenesis. Furthermore, in our proof-of-concept in vivo experiment, co-treatment with fludarabine, a FDA-approved STAT1 activation inhibitor and DNA synthesis inhibitor, in combination with doxorubicin, showed enhanced therapeutic efficacy in treating mouse mammary gland tumors. Our results demonstrate that stromal STAT1 expression could promote tumor progression and is a potential therapeutic target for breast cancer.

Citation Format: Victoria R. Zellmer, Patricia M. Schnepp, Sarah L. Fracci, Xuejuan Tan, Erin N. Howe, Siyuan Zhang. Tumor induced stromal STAT1 deregulates mammary tissue homeostasis and accelerates breast 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 2983. doi:10.1158/1538-7445.AM2017-2983
Abstract 2984: The chemokine CCL2/CCR2 signaling mediated fibroblasts-cancer cells crosstalk promotes basal like breast cancer progression
Authors: Yao Min , Fang Wei Bin , Fan Fang , Alvarez Nehemiah , Fields Patrick E. , Cheng Nikki
Published: July 2017

Cancer associated fibroblasts are the most abundant stromal cells in breast cancer, but their function in cancer progression has not been fully understood. We previously identified that the chemokine CCL2 was highly expressed in breast cancer associated fibroblasts, and high stromal CCl2 expression predicted poor outcome in basal like breast cancer. CCL2 is known to recruit monocyte/macrophage and promotes cancer progression. We previously found that recombinant CCL2 can directly signal to breast cancer cells and promote cell survival and invasion in vitro. In this study, we aimed to determine the functional importance of CCL2 signaling mediated fibroblast-cancer cell interactions in breast cancer progression. We used a fibroblast and cancer cell co-graft mouse model as the main functional assay. We generated primary fibroblasts from mouse mammary tumor and human breast cancer, and confirmed most of they expressed high level of CCL2. When co-grafted with the human basal breast cancer cell line MCF10A-CA1D into nude mice, fibroblasts enhanced xenograft growth. Stable knockdown of CCL2 expression from fibroblasts significantly reduced its ability in tumor growth promotion, while knockdown CCL2 from cancer cells did not. Decreased CCL2 production from fibroblasts resulted in increased apoptosis and autophagy in tumor samples. To determine the importance of direct CCL2 signaling to cancer cell, we generated the CCL2 receptor CCR2 mutant CA1D cancer cell lines by CRISPR-Cas9 targeting technology. Mutation of CCR2 in cancer cell significantly reduced tumor growth when co-grafted with CCL2 secreting fibroblasts. Lastly, we tested continuous delivery of CCL2 neutralizing antibody in the co-graft tumor model, but observed minimal therapeutic effect. Further examination of blood CCL2 level revealed an increased production of CCL2 from fibroblasts and mouse host after antibody treatment, which may contribute to the lack of therapeutic effect. In summary, our studies demonstrated the importance of CCL2/CCR2 signaling mediated fibroblasts-cancer cell interaction in basal like breast cancer progression. The CCL2 signaling pathway can be potentially served as therapeutic target, but requires development of efficient targeting strategy.

Citation Format: Min Yao, Wei Bin Fang, Fang Fan, Nehemiah Alvarez, Patrick E. Fields, Nikki Cheng. The chemokine CCL2/CCR2 signaling mediated fibroblasts-cancer cells crosstalk promotes basal like breast cancer progression [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 2984. doi:10.1158/1538-7445.AM2017-2984
Abstract 2989: Expression of immune checkpoints proteins and their prognostic relevance in prostate cancer
Authors: Hube-Magg Claudia , Schroeder Cornelia , Simon Ronald , Kluth Martina , Krech Till , Büscheck Franziska , Jacobsen Frank , Höflmayer Doris , Budäus Lars , Huland Hartwig , Graefen Markus , Sauter Guido , Schlomm Thorsten
Published: July 2017

Immune checkpoint proteins including programmed death ligand 1, 2 (PD-L1, PD-L2) and B7-H3 play important roles for immune evasion in many cancer types. PD-L1 is an established therapeutic target in lung cancer and in a growing number of other indications. The clinical success of PD-L1 inhibitors has accelerated the development of drugs also targeting PD-L2 and B7-H3. In prostate cancer, studies on the prevalence and clinical relevance of these proteins have been inconclusive. Here, we performed immunohistochemical analysis of PD-L1, PD-L2 and B7-H3 in our large prostate cancer prognosis tissue microarray (TMA) containing tissue samples from more than 17,000 patients. Normal prostate glands were negative for PD-L1 and B7-H3, but positive for PD-L2. We found that 47% of 12,808 interpretable cancers showed B7-H3 expression, and 92% of 9,463 cancers showed PD-L2 expression, while expression of PD-L1 was virtually absent (0.2% of 17,392 tumors) in epithelial cells. Stroma cells and immune cells were entirely negative for PD-L1 and B7-H3, while some faint staining of lymphocytes was occasionally observed for PD-L2. In cancers, PD-L2 and B7-H3 staining had different prognostic impact, which depended on the ERG status: B7-H3 expression was linked to young patient age, advanced stage, high Gleason grade, lymph node metastasis (p<0.0001 each), presence of PTEN deletion (p<0.0001), and poor prognosis in ERG negative cancers (p<0.0001), while PD-L2 expression was linked to beneficial tumor features and good prognosis exclusively in tumors with ERG fusion (p<0.0001). In a multivariate analysis including pT stage, Gleason grade, nodal stage, resection margin and preoperative PSA level, B7-H3 expression was an independent prognostic factor (p=0.0004). In summary, the results of our study identify a subset of young patients with ERG negative aggressive prostate cancers that might benefit from anti-B7-H3 therapy in the future. PD-L2 expression appears to protect tumors from progression and does not seem to be suitable as a potential target in prostate cancer. PD-L1 expression is extremely rare in this disease, suggesting that only few prostate cancer patients might benefit from PD-L1 inhibitors.

Citation Format: Claudia Hube-Magg, Cornelia Schroeder, Ronald Simon, Martina Kluth, Till Krech, Franziska Büscheck, Frank Jacobsen, Doris Höflmayer, Lars Budäus, Hartwig Huland, Markus Graefen, Guido Sauter, Thorsten Schlomm. Expression of immune checkpoints proteins and their prognostic relevance in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2989. doi:10.1158/1538-7445.AM2017-2989
Abstract 30: S100A11 is a prominent therapeutic target in malignant pleural mesothelioma
Authors: Sato Hiroki , Yamamoto Hiromasa , Namba Kei , Torigoe Hidejiro , Yoshioka Takahiro , Shien Kazuhiko , Soh Junichi , Toyooka Shinichi
Published: July 2017

[Background & Purpose] Malignant pleural mesothelioma (MPM) is an aggressive tumor arising from the mesothelial cells that show a serious malignancy in thoracic cavity with a median survival time of 9-12 months. The therapeutic approaches in clinical standard are limited to surgery and chemotherapy for early and advanced stages, respectively. The strategies unfortunately provide only palliation, thus further advanced approach is required. S100A11, a Ca2+-binding small protein with two EF-hands, is frequently upregulated in various human cancer tissues. It has been reported that S100A11 plays an important role in progression of many cancers derived from thyroid, ovarian and lung tissues, but its roles and signature in MPM are poorly understood. In this study, we investigated the impact of S100A11 in MPM cell lines and resected tumors.

[Material & Methods] We explored the expression of S100A11 in 7 MPM cell lines (HP-1, H28, MSTO-211H, H2052, H290, H2452, and YUMC44) and 2 normal mesothelial cell lines (Met-5A and LP-9). We analyzed the effect of S100A11 on cell proliferation, colony formation, migration, invasion and downstream signaling. The efficacy of anti-S100A11 antibody on cell proliferation and downstream signaling was also determined.

[Results] We found that S100A11 protein was consistently upregulated in 7 MPM cell lines at a significant level in comparison to 2 normal mesothelial cells. The same phenomenon was also confirmed in MPM tissue sections by immunohistochemistry, i.e., S100A11 was strongly stained at MPM cells, but not at surrounding normal lung cells. Specific knockdown of S100A11 by small interfering RNA turned the aggressive cells into the attenuated phenotypes for proliferation, invasion and migration. Those were notably observed in both 2 MPM cell lines (H2052 and H2452). Interestingly, we found that MPM cell lines but not normal cells actively secreted the S100A11 protein. To pursue this, we next tried to inhibit the function of the secreted S100A11. Administration of S100A11 neutralizing antibody significantly inhibited the proliferation of 4 MPM cell lines (H2052, H2452, H28, and H290). The antibody had no effect on the proliferation of only one MPM cell line, MSTO-211H, which showed no secretion of S100A11. Taken together, these results suggest that S100A11 secreted from MPM cells can be a prominent target for effective MPM therapy.

[Conclusion] Our results suggest that S100A11 is a possible therapeutic target in MPM.

Citation Format: Hiroki Sato, Hiromasa Yamamoto, Kei Namba, Hidejiro Torigoe, Takahiro Yoshioka, Kazuhiko Shien, Junichi Soh, Shinichi Toyooka. S100A11 is a prominent therapeutic target in malignant pleural mesothelioma [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 30. doi:10.1158/1538-7445.AM2017-30
Abstract 301: Prognostic value of metastatic tumoral caveolin-1 expression in patients with resected gastric cancer
Authors: Hong Jihyung , Sun Der Sheng , Hong Soon Auck , Won Hye Sung , Lee Han Hong , Kim Okran , Ko Yoon Ho
Published: July 2017

Background : Caveolin-1 (Cav-1), as the main component of caveolae, has complex roles in tumourigenesis and clinical outcomes in a variety of human malignancies. We investigated Cav-1 in primary and metastatic tumor of gastric cancer (GC) and its association with clinical outcomes.

Method : All specimens evaluated were obtained from 145 patients with GC who had undergone curative gastrectomy. The primary outcomes measured were the expression levels of Cav-1 by immunohistochemistry and its association with clinicopathologicalparameters and patient survival.

Results : Among the 145 patients, the frequency of high expression of stromal Cav-1 within primary tumor and tumoral Cav-1 protein in metastatic lymph node were 22.5% (18/145) and 16.6% (15/91). In the multivariate analysis tumoral Cav-1 protein in metastatic lymph node showed prognostic significance for relapse-free survival (RFS, HR, 3.934; 95% CI, 1.882-8.224; P<0.001) and cancer-specific survival outcome (CSS, HR, 3.985; 95% CI, 1.620 - 8.623; P = 0.002). In addition, it remained as a strong indicator of poor prognosis for RFS (HR, 3.137; 95% CI, 1.445 - 6.810; P = 0.004) and CSS (HR, 2.509; 95% CI, 1.079 - 5.838; P = 0.033).

Conclusions : High expression of tumoral Cav-1 protein in metastatic lymph node shows a strong negative association with the clinical outcomes in patients with curatively resected GC, suggesting that this protein have potential uses as novel prognostic markers.

Citation Format: Jihyung Hong, Der Sheng Sun, Soon Auck Hong, Hye Sung Won, Han Hong Lee, Okran Kim, Yoon Ho Ko. Prognostic value of metastatic tumoral caveolin-1 expression in patients with resected gastric 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 301. doi:10.1158/1538-7445.AM2017-301