bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1377: Improved ctDNA detection in early stage non-small-cell lung cancer
Authors: Heider Katrin , Wan Jonathan C. , Gale Davina , Mouliere Florent C. , Qian Wendi , Kateb Angels , Doughton Gail , Ramenatte Nicola , Tysoe Ruth , Smith Christopher G. , Rassl Doris M. , Harden Susan , Rintoul Robert C. , Massie Charles , Rosenfeld Nitzan
Published: August 2019

Overall survival of non-small-cell lung cancer (NSCLC) patients remains poor as patients are frequently diagnosed at a late stage. The evaluation of circulating tumour DNA (ctDNA) has been shown to offer a non-invasive method for detection of cancer. However, detection rates of ctDNA in patients with early stage cancers, including NSCLC, have been limited due to sampling and sensitivity issues. We developed a novel algorithm for INtegration of VAriant Reads (INVAR), which uses sequencing data across hundreds to thousands of tumour-mutated loci to detect ctDNA in plasma samples at high sensitivity. We applied this to a cohort of stage I-III NSCLC patients recruited in the LUCID study. LUCID is a prospective and observational study of 100 stage I-IIIB NSCLC who are planning to undergo radical treatment (surgery or radiotherapy +/- chemotherapy) with curative intent. Plasma samples were collected before and after treatment with curative intent. We analysed a total of 50 patients using patient specific-sequencing panels and detected ctDNA in 78% of cases before treatment, at ctDNA fractions as low as 1.7x10-5. For 17 of those patients staging information was available. Here, we detected ctDNA in 50% of stage I patients (split evenly between stages IA and B) and 100% of stage II and III patients. We also applied INVAR to whole exome and shallow whole genome sequencing data from plasma samples, and showed that this algorithm can be used to detect low ctDNA fractions in such data. Our findings highlight an opportunity to improve ctDNA detection in early stage NSCLC by using patient specific sequencing information. Additionally, our algorithm has the potential to aid in longitudinal cancer monitoring and is applicable to a variety of sequencing data types. We aim to apply this approach to serial samples obtained through the LUCID study to investigate its application in the treatment management.

Citation Format: Katrin Heider, Jonathan C. Wan, Davina Gale, Florent C. Mouliere, Wendi Qian, Angels Kateb, Gail Doughton, Nicola Ramenatte, Ruth Tysoe, Christopher G. Smith, Doris M. Rassl, Susan Harden, Robert C. Rintoul, Charles Massie, Nitzan Rosenfeld. Improved ctDNA detection in early stage non-small-cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1377.
Abstract 138: TNBC induces immune suppressive tumor microenvironments through microRNAs
Authors: Guo Beichu , Kantono Melvin , Sun Wei
Published: August 2019

Metastatic breast cancer is the second leading cause of cancer-related deaths for US women. The triple negative breast cancer subtype (TNBC) is one of the major contributors to breast cancer mortality, among all types of breast cancer. There are no effective treatments available for metastatic tumors. Therefore, identifying and targeting novel tumorigenesis pathways will facilitate developing effective therapeutic approaches that could ultimately lead to effective treatment for breast cancer, particularly metastatic cancer and TNBC. Our results demonstrate that miR-146a promotes tumorigenesis and metastasis of breast cancer. We found that miR-146a was markedly overexpressed in TNBC cell lines. Notably, miR-146a deficiency in a spontaneous mammary tumor model leads to reduced tumor growth and metastasis. Notably, miR-146a shifts the polarization of macrophages into immunosuppressive phenotypes. Our studies suggest that miR-146a may contribute to tumor development through modulation of tumor microenvironments.

Note: This abstract was not presented at the meeting.

Citation Format: Beichu Guo, Melvin Kantono, Wei Sun. TNBC induces immune suppressive tumor microenvironments through microRNAs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 138.
Abstract 1418: Brother of regulator of imprinted sites (BORIS) inhibits cisplatin induced DNA damage in non-small-cell lung cancer
Authors: Song Yongfei , Li Chao , Fang Mengdie , Ren Juan , Fang Jianfei , Wang Xiaoju , Zhang Yanmei
Published: August 2019

Cisplatin (DDP) treatment is primary modality for non-small-cell lung cancer (NSCLC) chemotherapy. However, patients benefited from DDP treatment limitedly due to the DDP resistance. Brother of Regulator of Imprinted Sites (BORIS, CTCFL) is the paralogue of CCCTC-binding factor (CTCF) and expressed abnormally in most type of cancers and is potential tumor target for breast, cervical carcinoma and lung cancer. However, the funciton of BORIS on carcinoma is unrevealed. In our previous study, we found that BORIS suppressed apoptosis and resisted 5-FU (Fluorouracil) treatment in colorectal cancer. As either 5-FU or DDP induces DNA damage and apoptosis of carcinoma cells, BORIS perhaps resists DDP treatment too. Based on the prevalent expression of BORIS and the high incidence of DDP resistance in NSCLC, we proposed that BORIS contributed to DDP resistance by suppressing DNA damage in NSCLC. We collected RNA sequencing data of 156 NSCLC patients who received DDP chemotherapy from The Cancer Genome Atlas and analyzed the expressions of BORIS. We found high BORIS expression correlated with short survival in NSCLC patients who received DDP chemotherapy. BORIS expression declined from prospective to retrospective collected tissue which responded to DDP chemotherapy. It suggested the probability function of BORIS on DNA damage repair. In cell cultured lung cancer cell lines, BORIS was silenced or over-expressed including DDP resistant cell line. It indicated that A549/DDP (DDP resistant A549 cell line) expressed relative higher BORIS than A549 parental cells and BORISexpression levels correlated with cell viability. H1299 and A549/DDP expressed comparative BORIS and growed comparativly. H460 and A549 expressed relative lower BORIS levels and grew slower than H1299 and A549/DDP. BORIS knockdown inhibited the proliferation of NSCLC cells, enhanced the sensitivity of A549/DDP and H1299 to DDP treatment and induced DNA damage. Reversely DDP induced DNA damage was suppressed by BORIS over-expression. The excision repairing gene ERCC1, which is regulated by BORIS, might be the assistant for DDP resistance. Either high expression of BORIS or ERCC1 indicated short survival rates of NSCLC patients. Our data suggested that BORIS suppressed DNA damage and promoted the progression of NSCLC and DDP resistance, which indicated its potential in NSCLC prognosis and therapy.

Citation Format: Yongfei Song, Chao Li, Mengdie Fang, Juan Ren, Jianfei Fang, Xiaoju Wang, Yanmei Zhang. Brother of regulator of imprinted sites (BORIS) inhibits cisplatin induced DNA damage in non-small-cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1418.
Abstract 1435: An ultra-sensitive and high-throughput technology (imPACT) for the identification and isolation of intrinsic and emergent neoepitope-specific T cells from the peripheral blood and TILs of cancer patients
Authors: Peng Songming , Quach Boi , An Duo , Sandoval Salemiz , Bao Robert , Pan Zheng , Bethune Michael , Dalmas Olivier , Yi Michael , Meadows Corey , Heeringa Katherine , Guo Linlin , yuen Benjamin , Sorfleet John , Jacoby Kyle , Moot Robert , Lu William , Nguyen Diana , Sennino Barbara , Conroy Andrew , Purandare Bhamini , Litterman Adam , Mandl Stefanie , Franzusoff Alex
Published: August 2019

T cells capable of targeting neoepitopes (neoE) from tumor-specific mutations hold the potential to uniquely recognize and kill tumor cells. However, most cancer patients fail to mount a sufficient intrinsic T cell immune response to translate into clinical benefit. PACT Pharma has developed an ultra-sensitive and high-throughput technology (imPACT) for identifying and isolating neoE-specific T cells from peripheral blood. Whole exome sequencing of tumors and computational prediction identify patient-specific neoepitopes resulting from tumor-specific mutations. We then interrogate patient blood for neoE-specific T cells using human leukocyte antigen (HLA) protein-based reagents comprising a spectrum of human HLAs, thus enabling the evaluation of >99% of all individuals with cancer. We have identified and isolated neoE-specific T cells from the peripheral blood of >80% treatment-naive patients with bladder and colorectal cancers, melanoma and other solid tumors. Primary human T cells engineered with T cell receptor sequences (TCRs) cloned from the imPACT-isolated T cells gain the ability to kill cognate neoE-presenting tumor cells, thereby also confirming the specificity of the isolated TCR sequences to bind to the neoE target. This approach is also amenable to the longitudinal analysis of patients undergoing treatment for their cancers, to characterize the neoE-specific T cell populations likely to confer clinical benefit. In summary, the imPACT technology efficiently discovers potentially meaningful intrinsic neoE-specific TCRs from patients, enabling the development of personalized neoTCR-T cell therapies for the eradication of solid tumors.

Citation Format: Songming Peng, Boi Quach, Duo An, Salemiz Sandoval, Robert Bao, Zheng Pan, Michael Bethune, Olivier Dalmas, Michael Yi, Corey Meadows, Katherine Heeringa, Linlin Guo, Benjamin yuen, John Sorfleet, Kyle Jacoby, Robert Moot, William Lu, Diana Nguyen, Barbara Sennino, Andrew Conroy, Bhamini Purandare, Adam Litterman, Stefanie Mandl, Alex Franzusoff. An ultra-sensitive and high-throughput technology (imPACT) for the identification and isolation of intrinsic and emergent neoepitope-specific T cells from the peripheral blood and TILs of cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1435.
Abstract 1448: Lymphangiogenesis-inducing whole-cell vaccine against melanoma promotes broad tumor-specific T cell immunity and effective tumor control
Authors: Sasso Maria Stella , Hauert Sylvie , Briquez Priscilla S. , Wang Yue , Ishihara Jun , Hubbell Jeffrey A. , Swartz Melody A.
Published: August 2019

We recently reported that the growth of lymphatic vessels (lymphangiogenesis) in mouse melanomas dramatically enhances the efficacy of immunotherapy by promoting immune cell infiltration and broadening the anti-tumor T cell repertoire (Fankhauser et al, Sci. Trans. Med. 2017). Correlative evidence supporting such ‘lymphangiogenic potentiation’ was also seen in human melanoma patients, suggesting a possible immunotherapeutic use of the pro-lymphangiogenic growth factor VEGFC. On the other hand, tumor lymphangiogenesis is known to promote cancer cell dissemination and metastasis, raising concerns about the possibility of manipulating lymphatic vessels directly within the tumor site as a treatment strategy for cancer immunotherapy. Here, we sought to manipulate and exploit the immune-promoting functions of lymphatics remotely from the tumor by developing a lymphangiogenesis-inducing cancer vaccine that mimics the microenvironment of a lymphangiogenic tumor. Whole-cell vaccines were formulated using lethally irradiated B16F10 or B16F10-OVA mouse melanoma cells, either mock-transduced or genetically modified to overexpress VEGFC, and combined with topically retained immune adjuvants (ctrl-vax and VEGFC-vax, respectively). Upon intradermal injection, VEGFC-vax induced extensive local lymphatic growth and stimulated increased lymphatic transport from the vaccine site to the draining lymph nodes. Consistently with our previous study, VEGFC induced CCL21 upregulation and local recruitment of CCR7+ naïve T cells, which could undergo in situ priming in the vaccine site. Compared to ctrl-vax, VEGFC-vax elicited a robust T cell response directed against multiple mouse melanoma antigens, as assessed by ex vivo antigen stimulation and IFNγ ELISPOT. In a prophylactic vaccine setting, VEGFC-vax induced stronger tumor-specific T cell immunity and greater protection from tumor challenge compared to both ctrl-vax as well as a GM-CSF-secreting whole-cell vaccine. Overall this study provides a proof of concept for the use of VEGFC in cancer vaccines and characterizes a whole-cell lymphangiogenesis-inducing vaccine formulation with potential for clinical translation.

Citation Format: Maria Stella Sasso, Sylvie Hauert, Priscilla S. Briquez, Yue Wang, Jun Ishihara, Jeffrey A. Hubbell, Melody A. Swartz. Lymphangiogenesis-inducing whole-cell vaccine against melanoma promotes broad tumor-specific T cell immunity and effective tumor control [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1448.
Abstract 1453: Development of a novel PD-1 vaccine and in combination with two Chimeric HER-2 peptide vaccine provides synergistic inhibition of tumor growth in a syngeneic Balb/c model challenged with CT26/HER-2 carcinoma cell line
Authors: Bekaii-Saab Tanios , Overholser Jay , Yang Yuhong , Penichet Manuel , Kaumaya Pravin
Published: August 2019

Background: Therapeutic blockade of the signaling axis between PD-1 and its ligand programmed cell death ligand-1 (PD-L1) with monoclonal antibodies has shown remarkable clinical success in the treatment of cancer and demonstrated impressive activity across a broad set of cancer subtypes, even at advanced and metastatic stages of disease. Contrary to treatment with monoclonal antibodies, chimeric B-cell cancer vaccines have the advantage of producing a specific immune response that can potentially induce memory B & T cell responses, while reducing immune evasion and suppression.

Methods: We have translated two HER-2 combination peptide vaccines (B-Vaxx) to the clinic in a Phase 1/2b trial to safely deliver curative and transformative cancer immunotherapies to advanced cancer patients. We have created and established the development of a novel B-cell peptide vaccine (Key-Vaxx) with high immunogenicity that binds to human PD-1 and produces tumor inhibition in vivo in an animal model of colon cancer. Here, we describe the transferable CT-26-HER2 neu tumor model in Balb/c was used to test for synergistic effects of anti-PD1 immunization therapy in combination with anti-HER2 immunization therapy to determine whether this combination could increase immunogenicity, enhance anti-tumor responses and provide synergistic benefit in inhibiting tumor growth.

Results: We show robust HER-2 and PD-1 antibody responses in all vaccinated mice indicating that the combined vaccination is effective in reducing tumor growth in a Balb/c syngeneic model of colon carcinoma versus either the PD-1 vaccine or more importantly the positive control gold standard that is anti-mouse PD-1 monoclonal antibody. The vaccine combination was found to be safe and did not appear to exhibit toxicity or autoimmunity.

Conclusion: Development of a novel PD-1 vaccine in combination with two Chimeric HER-2 peptide vaccine provides synergistic inhibition of tumor growth with no evidence of toxicity or autoimmunity. A clinical trial with the combination is under planning.

Citation Format: Tanios Bekaii-Saab, Jay Overholser, Yuhong Yang, Manuel Penichet, Pravin Kaumaya. Development of a novel PD-1 vaccine and in combination with two Chimeric HER-2 peptide vaccine provides synergistic inhibition of tumor growth in a syngeneic Balb/c model challenged with CT26/HER-2 carcinoma cell line [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1453.
Abstract 1456: MEDI5395: A recombinant oncolytic virus with oncolytic and immune modulatory properties
Authors: Harper James A. , Burke Shannon , Leinster Andrew , Rath Nicola , Cheng Xing , Jin Hong , Wilkinson Robert W. , Carroll Danielle
Published: August 2019

MEDI5395 is a genetically modified attenuated Newcastle disease virus (NDV). A reverse genetic system has overcome environmental and regulatory concerns by uncoupling oncolytic potency from avian pathogenicity. MEDI5395 has the intrinsic ability to infect and kill tumor cells and has been inserted with a GM-CSF transgene to potentiate a stronger adaptive immune response. Described here is an extensive in vitro and in vivo pharmacology package that reveals the broad oncolytic activity and immune-modulatory properties of MEDI5395 in a variety of pre-clinical models.

In vitro, MEDI5395 lytic activity in human tumor cells is associated with elevated levels of tumor selective viral replication and expression of the GM-CSF transgene. MEDI5395 infection of immune cells indicated preferential uptake of virus and subsequent self-limiting replication in myeloid cells. Infected myeloid cells expressed cell surface activation markers (e.g. PD-L1) after 24 hours and were effective carriers of virus and mediated the transfer of infectious NDV particles to tumor cells resulting in death through oncolysis. Further mechanistic studies, indicated NDV-killed tumor cells released antigens that were capable of cross-presentation by dendritic cells driving activation of tumor antigen-specific autologous T cells.

In murine models, IV delivery of NDV leads to long lasting tumor selective replication and transgene expression. MEDI5395 administration results in significant anti-tumor activity, observed in patient-derived xenograft models, and in murine syngeneic cancer models. Together, the results suggest that MEDI5395 may act to positively transform the tumor microenvironment. This, coupled to its tumor-selective oncolytic capacity, further underscore NDV as a promising multimodal cancer therapeutic platform and why FTIH studies are planned to start in 2019.

Citation Format: James A. Harper, Shannon Burke, Andrew Leinster, Nicola Rath, Xing Cheng, Hong Jin, Robert W. Wilkinson, Danielle Carroll. MEDI5395: A recombinant oncolytic virus with oncolytic and immune modulatory properties [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1456.
Abstract 1457: Sustained persistence of IL-2 signaling enhances the antitumor effect of peptide vaccines
Authors: Kumai Takumi , Sultan Hussein , Harabuchi Yasuaki , Celis Esteban
Published: August 2019

Peptide vaccines can be a successful and cost-effective way of generating T-cell responses against defined tumor antigens, especially when combined with immune adjuvants such as poly-IC. However, strong immune adjuvants can induce a collateral increase in numbers of irrelevant, nonspecific T cells, which limits the effectiveness of the peptide vaccines. Here, we report that providing prolonged IL2 signaling in the form of either IL2/ anti-IL2 complexes or pegylated IL2 overcomes the competitive suppressive effect of irrelevant T cells, allowing the preferential expansion of antigen-specific T cells, and increasing the therapeutic effectiveness of the vaccines against established tumors. This vaccination strategy using peptides and sustained IL2 could be taken into the clinic for the treatment of cancer.

Citation Format: Takumi Kumai, Hussein Sultan, Yasuaki Harabuchi, Esteban Celis. Sustained persistence of IL-2 signaling enhances the antitumor effect of peptide vaccines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1457.
Abstract 1462: Novel oncolytic virus armed with interleukin-21 enhances immune oncotherapy
Authors: Zhang Rong , Wang Tingting , Qing Yun , Sun Shuaijun , Liu Meili , Hu Fang , Fu Jin
Published: August 2019

Oncolytic viruses have elucidated the broad anti-tumor properties through selectively destroying tumor cells, promoting tumor antigen release and inducing the activation of immune response. Vaccinia virus (VV) has been engineered for tumor selectivity by the deletion of two essential genes (DDvv), viral growth factor (VGF) and thymidine kinase (TK). However, it still has certain obstacles, such as spread of virus, tumor microenvironment barrier, immune cell infiltration and tumor infiltration lymphocytes (TILs) proliferation. In the present study, we engineered the novel oncolytic mV01 and hV01 viruses, recombinant DDvv viruses carrying human interleukin-21 (hIL-21) or mouse IL-21 (mIL-21), respectively. mV01 and hV01 exhibited potent inhibition of various tumor cells with IC50 < 0.5 MOI. When in combination with hNK cell, hV01 significantly enhanced the inhibition of cell proliferation in SK-HEP-1 cells and HepG2 cells as compared to mock virus. Animal studies showed that mV01 (i.t.) significantly reduced tumor burden in B16 C57/BL6 xenograph mice that were pre-treated with low dose cyclosporine A (i.p), compared to mock virus treatment. Simultaneously, mV01 regimens improved tumoral immune cell infiltration and TILs proliferation. Additionally, in HCT116 NCG xenograph mice, administration of hV01 (i.t.) exhibited significant inhibition of tumor growth (T/C < 40%) when in combination with hNK cells (i.v). Together, these data revealed that V01 is a promising candidate for tumor immunotherapy through viral oncolysis and anti-tumor immunity.

Citation Format: Rong Zhang, Tingting Wang, Yun Qing, Shuaijun Sun, Meili Liu, Fang Hu, Jin Fu. Novel oncolytic virus armed with interleukin-21 enhances immune oncotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1462.
Abstract 1464: Inhibition of p38 MAPK in dendritic cells enhances their antigen presentation and induces Th17 T cell differentiation
Authors: Luo Yan , Barath Shreeder , Bahr Deborah A. , Dutta Navnita , Raja Geraldine , Cannon Martin J. , Knutson Keith L.
Published: August 2019

Dendritic cells (DCs) are the most potent antigen-presenting cells which bridges innate and adaptive immunity, but how DC-derived signals regulate and induce T cell lineage choices remains unclear. The p38 MAPK pathway plays an essential role in regulating cellular processes such as cell differentiation, growth, and death. In this study, SB203580 was employed to selectively inhibit p38 pathway in bone marrow derived DCs (BMDCs) to investigate the effects of this pathway on the characteristic phenotype and function of DCs, especially the induction on T helper cell differentiation. We found that inhibition of p38 increased the proliferation of BMDCs, but did not alter their phagocytic ability. Also, inhibition of p38 enhanced the activation of BMDCs, as evidenced by the up-regulated expression of DCs-related surface markers including CD80, CD86 and MHCII. However, the secretion levels of IL-12 and IL-10 in BMDCs were reduced significantly, whereas the level of IL-6 was not influenced by the p38 inhibitor. In addition, we immunized the mice with BMDCs vaccines and studied the production of antigen-specific Th17 T cell in spleen. Our data demonstrated that p38-inhibited DCs vaccine could induce more antigen-specific Th17 T cells than regular DCs vaccine in vivo. Collectively, these results support the hypothesis that the p38 pathway plays a critical role in the immunologic activation of DCs. Our findings suggest that inhibition p38 pathway in DCs may be a new strategy for generating potent DC vaccines for cancer immunotherapy.

Citation Format: Yan Luo, Shreeder Barath, Deborah A. Bahr, Navnita Dutta, Geraldine Raja, Martin J. Cannon, Keith L. Knutson. Inhibition of p38 MAPK in dendritic cells enhances their antigen presentation and induces Th17 T cell differentiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1464.
Abstract 1490: Novel microbiome-derived peptides activate the host innate immune system by regulation of TLR signaling
Authors: Haria Dhwani , Kiefel Helena , Katlinskaya Yuliya , Jain Sunit , Weinmaier Thomas , Iwai Shoko , DeSantis Todd , Takeuchi Toshi , Dabbagh Karim , Graham Kareem
Published: August 2019

The gut microbiome is a key contributor to the maintenance of host physiology. At the same time, increasing evidence implicates microbiome dysbiosis as a key determinant of numerous metabolic and inflammatory disorders. It is, therefore, of paramount importance to understand the interactions between the host and gut microbiota. Second Genome has developed a proprietary, bioinformatics-driven discovery platform to identify novel microbiome-derived peptides with the potential to modulate host immune responses. We have leveraged this platform to evaluate immunomodulatory functions of novel, secreted peptides derived from gut-resident bacterial species Bifidobacterium longum and Bifidobacterium breve. Previously, the microbial genus Bifidobacterium (‘Bifido’) has been shown to be associated with enhanced dendritic cell functions and antitumor effects. Here, we identify Bifido-derived peptides that are putative agonists of certain murine and human Toll-like receptors (TLRs). These peptides induce secretion of pro-inflammatory cytokines such as TNF-α and IL-6 by in vitro-generated mouse dendritic cells and peritoneal macrophages in a TLR4 and CD14-dependent manner. One of the peptides, SG-A, also induces secretion of Th1-type cytokines and chemokines such as IL-21, GRO-α, and IP-10 by human monocytes and monocyte-derived dendritic cells. Moreover, in vivo administration of SG-A in mice elicited a systemic pro-inflammatory immune response in the absence of any secondary stimulus. Collectively, our results demonstrate the ability of a novel bacterial-derived peptide to engage the host innate immune system. Moreover, our findings validate the potential of the Second Genome discovery platform for identification of novel microbiome-derived agents that: i) have the ability to modulate host cell functions; and ii) may be developed into therapeutic agents for immune and inflammatory disorders.

Citation Format: Dhwani Haria, Helena Kiefel, Yuliya Katlinskaya, Sunit Jain, Thomas Weinmaier, Shoko Iwai, Todd DeSantis, Toshi Takeuchi, Karim Dabbagh, Kareem Graham. Novel microbiome-derived peptides activate the host innate immune system by regulation of TLR signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1490.
Abstract 1494: Galectin 9 associates with PDL1 expression and promotes gastric cancer cell invasion
Authors: Hill Charlotte , Cabrolier Camille , Cumsille Elisa , Arce Maximiliano , Pinto Mauricio P. , Bravo Maria Loreto , Muñoz Matias , Garrido Marcelo , Owen Gareth I.
Published: August 2019

Background: The development of immune checkpoint inhibitors (immunotherapy, such as anti-PD1) that induce a sustained T-cell immune response with anti-tumor activity has been a breakthrough in oncology practice. However, in gastric cancer (GC), sustained responses to anti PD-1 therapy are only observed in approximately 20% of patients. The expression of alternative immune checkpoints such as Galectin 9 (Gal-9) and Tim3 has been associated to anti-PD1 resistance in other cancer types. In search of the factors that render gastric tumors resistant to immunotherapy, we hypothesized that Gal-9 expression in gastric cancer cells may enhance metastasis and immunosuppression.

Methods: Bioinformatic analysis of gastric cancer data of patients with gastric adenocarcinoma from TCGA Database was performed. In vitro experiments with Gal-9 transfected gastric cancer cell line AGS were performed to elucidate Gal-9 gain of function effect on cell invasion and immune-suppressive proteins. Invasion assay using a matrigel coated transwell was performed within 24 hours of transfection. To determine changes in PDL1, E-Cadherin and N-Cadherin expression, cells were harvested 24h after transfection to analyze protein and mRNA levels through Western Blot and RT-PCR respectively.

Results: TCGA database analysis demonstrate that Gal-9 expression is significantly correlated to PDL-1 expression in gastric cancer; furthermore, it was also positively correlated to immune cell markers such as FOXP3. In accordance, in vitro analysis demonstrates that exogenous expression of GAL9 results in an increase in PDL-1 protein and greater invasive potential of the AGS cell line.

Conclusion: Taken together our results suggest that further studies should focus on the role played by Gal-9 is the establishment of an immune suppressive microenvironment in gastric tumors.

FONDECYT 1180241, 1180173. CONICYT FONDAP 15130011, IMII P09/016F

BMS CA209-8F3

Citation Format: Charlotte Hill, Camille Cabrolier, Elisa Cumsille, Maximiliano Arce, Mauricio P. Pinto, Maria Loreto Bravo, Matias Muñoz, Marcelo Garrido, Gareth I. Owen. Galectin 9 associates with PDL1 expression and promotes gastric cancer cell invasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1494.
Abstract 1495: Alternative humanized PD-1 mouse models provide more options for PD-1 antibody efficacy study in vivo
Authors: Lin Qing , Ma Huimin , Zhang Xiaoyu , Li Hengbin , Yang Wenjing , Yang Zhewei , Shen Xingchen , Ji Qunsheng
Published: August 2019

The Programmed Death-1 (PD-1) binding to its ligands PD-L1 and PD-L2 plays a critical role in suppression of T cell function and tumor immune evasion. Blocking antibodies against PD-1 have been shown to induce durable antitumor responses in multiple cancers in many clinical trials. So a well-characterized mouse model is essential for preclinical studies of antibodies that target human PD-1. Here we generated several humanized PD-1 knock-in mouse models, one expresses a hybrid PD1 protein by replacing the amino acids that involve in binding to PD-L1 (mostly IgV domain) with the human counterpart in both C57BL/6J and Balb/C genetic background, another one have both the IgV domain and signal peptide replaced by human counterpart. These mouse models were confirmed by PCR and southern blotting. And homozygous mouse models from these different strategies were also successfully generated and both of them could survive and the birth rate were very similar to heterozygous and wild type littermates. Staining for human and mouse PD-1 in stimulated CD8+ and CD4+ T cells indicate the up regulated expression of human PD-1 and absence of mouse PD-1 in these mouse model. Homozygous human PD-1 knock-in mice displayed normal development, and no obvious signs of autoimmunity for at least six months, whereas PD-1 knockout mice developed tissue-specific autoimmunity. With these human PD-1 knock-in mice engrafted with MC38 and treated with anti-human PD-1 antibodies, we confirmed the binding of anti-human antibody to chimeric PD-1 protein, and found anti-human PD-1 antibodies could significantly inhibit tumor growth in these models. Head to head comparison of these mice with current commercial available models for in vivo efficacy studies are undergoing and will reveal how the signal peptide effect the protein refolding or signaling transduction pathway for these ‘human-mouse’ chimeric proteins. In summary, these human PD-1 knock-in mouse models are functional and can be used to evaluate anti-human PD1 antibodies in vivo, we provide more options for antibodies which is targeting PD-1.

Citation Format: Qing Lin, Huimin Ma, Xiaoyu Zhang, Hengbin Li, Wenjing Yang, Zhewei Yang, Xingchen Shen, Qunsheng Ji. Alternative humanized PD-1 mouse models provide more options for PD-1 antibody efficacy study in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1495.
Abstract 15: Targeting vismodegib-resistant medulloblastoma using novel hedgehog pathway inhibitor and miR-29b mimic
Authors: Kumar Virender , Sethi Bharti , Kumar Vinod , Mcguire Timothy R. , Coulter Don W. , Mahato Ram I.
Published: August 2019

The purpose of this study to develop targeted liposomes of MDB5 and miR-29b combination for medulloblastoma (MB) treatment. Due to high heterogeneity and diverse genetic make-up, MB treatment is a challenge. Aberrant activation of hedgehog (Hh) pathway regulates cell growth, cancer stem cell (CSC) proliferation, and tumorigenicity in sonic Hh subgroup of MB. Further, Hh signaling regulates yes-associated protein 1 (YAP1) and glutaminolysis for energy need of tumor cells. GDC-0449 a smoothened receptors (SMO) antagonist treats (SHH)-MB initially, but resistance develops after repeated administration. Cholesterol potentiates Hh pathway independent of SHH by binding directly to the SMO. On the other hand, our RNA-seq and miRNA profiling confirmed downregulation of tumor suppressor miR-29b-3p in human MB samples. miR-29b control genes of apoptosis; p53, MDM2, AKT2, and cholesterol biosynthesis including HMGCR and SREBP1. We recently synthesized a potent GDC-0449 analog MDB5 (SMO inhibitors), which binds strongly to various Smo-mutants compared to GDC-0449. We found that a combination of MDB5 and miR-29b can treat MB synergistically. When we modified miR-29b backbone with 2-O’-methoxyethyl phosphorothioate (OMe-PS-miR-29b-3p), it showed enhanced stability in 50% serum. We designed a cationic lipid MDC2 for liposomal delivery of MDB5 and miR-29b1 simultaneously. Liposomes were prepared using film hydration technique and characterized for particle size and zeta potential, drug loading and release profile, miRNA complexation, stability, and transfection efficiency. These liposomes incorporated 88% MDB5 when the drug to phospholipid molar ratio was kept at 5%. Complete complexation was observed at N/P ratio of 3:1. These liposomes when loaded with green fluorescent protein (GFP) siRNA, resulted in 70% of signal silencing into DAOY MB cells (Shh driven). Liposomal MDB5 had higher cytotoxicity in DAOY cells compared to GDC-0449. Further, MDB5 and OMe-PS-miR-29b loaded liposomes resulted in higher, cytotoxicity and % of apoptosis, G0-G1 phase arrest, and decreased target gene expression in DAOY cells. Combination of drugs to simultaneously target multiple pathways related to Hh, glutaminolysis, cholesterol biosynthesis, and apoptosis has the potential to treat MB. Successful completion of this study will provide a nanomedicine for treating SHH-MB and other brain tumors.

Citation Format: Virender Kumar, Bharti Sethi, Vinod Kumar, Timothy R. Mcguire, Don W. Coulter, Ram I. Mahato. Targeting vismodegib-resistant medulloblastoma using novel hedgehog pathway inhibitor and miR-29b mimic [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 15.
Abstract 1505: Tumor associated antigen uptake tracking following immuno-radiotherapy
Authors: Christensen Esben , Ringgaard Lars , Brus Anja , Kjaer Andreas , Hansen Anders E. , Andresen Thomas L.
Published: August 2019

Immuno-radiotherapy is a promising strategy for generation of immunologic cancer recognition, rejection and induction of anti-cancer memory. Radiotherapy (RT) causes single or double strand DNA breaks in a dose dependent manner leading to immunogenic cell death of cancer cells and induction of type 1 interferons. Furthermore, RT increases MHCI expression on cancer cells and infiltration of cytotoxic T cells. Combined, these effects make RT a potent primer of anti-cancer immune responses. The most promising approaches in anti-cancer immunotherapy is to augment the adaptive immune response through danger associated molecular patterns signaling, including toll-like receptor (TLR) agonists. Optimally, these interventions should be given when tumor-associated antigen (TAA) uptake and presentation peaks. Previous studies on TAA uptake have mostly focused on in vitro or ex vivo assays to mimic the in vivo mechanisms. In the present study, we investigate the in vivokinetics of TAA uptake and trafficking using stably transfected mCherry-transfected B16F10 melanoma. B16F10 transfected with mCherry, a pH-stable fluorescent protein, allows tracking by e.g. flow cytometry in both cancer cells and phagocytosing populations. In vivo trafficking of mCherry fluorescence was investigated in mice treated with RT alone or in combination with TLR7 agonists given locally or systemically. Following treatment, TAA-uptake, -trafficking, and activation of relevant immune populations was evaluated in tumors or tumor draining lymph nodes (tdLNs). Increased TAA uptake was observed in MHCII high populations compared to MHCII low across all phagocytosing populations in tumors. The highest uptake (MFI of mCherry) was found in patrolling monocytes (CD11b+CD11c-Ly6c-CX3CR1high) and tumor-associated macrophages (CD11b+CD11c+CD64+). Interestingly, we exclusively found increased mCherry signal in resident cDC1s in tdLNs after treatment. RT led to a diminished population of migratory CD103+ cDC1s in tumors and we did not observe any increase in mCherry+ CD103+ cDC1s in tdLNs. We did not observe any mCherry signal in spleens - indicating that no cancer-specific immune response are mounted from the spleen. The results also indicate that TAA antigen is trafficked to tdLNs primarily by monocytes or by lymphatic drainage.

Citation Format: Esben Christensen, Lars Ringgaard, Anja Brus, Andreas Kjaer, Anders E. Hansen, Thomas L. Andresen. Tumor associated antigen uptake tracking following immuno-radiotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1505.
Abstract 1506: Lymph node metastasis in clinical breast cancer is significantly promoted by myeloid-derived lymphatic endothelial cell progenitors
Authors: Volk-Draper Lisa D. , Patel Radhika , Bhattarai Nihit , Yang Jie , Ran Sophia
Published: August 2019

Introduction: Lymph node (LN) metastasis, a key prognostic factor for poor survival of breast cancer (BC) patients, directly depends on tumor lymphangiogenesis. We previously showed in orthotopic BC models that lymphangiogenesis is strongly promoted by tumor-mobilized myeloid-derived lymphatic endothelial cell (LEC) progenitors (M-LECP) and that M-LECP density correlates with lymphatic metastasis. The goals of this study were to determine the blood levels of M-LECP, their tumor density and correlation with metastasis in clinical human BC.

Methods: Circulating CD14+ cells from BC patients (N=25) and healthy donors (N=24) were analyzed for expression of lymphatic-specific markers. Specimens from BC patients (N=104) along with normal mammary tissues (N=6) were co-stained with antibodies against myeloid and lymphatic markers including CD68, CD14, CD18 as well as LYVE1, podoplanin, and VEGFR-3. Sections were also double-stained to identify LYVE1+ cells expressing lymphoid, M2-type macrophage, and stem cell markers. Densities of tumor CD68+ macrophages, LYVE1+ vessels, and CD68+/LYVE1+ double-stained M-LECP were quantified and correlated with node status and other parameters. Pro-metastatic potential of experimentally produced mouse M-LECP was determined by injecting in vitro differentiated myeloid-lymphatic cells into mice bearing syngeneic EMT6 breast tumors.

Results: 92% of BC patients had monocytes expressing at least one lymphatic marker compared 2% of healthy donors. More than 70% of breast tumors contained M-LECP with density ranging from 2 to 50 cells per high-power field. Tumor-recruited M-LECP express specific markers of myeloid but not lymphoid lineages as well as M2-type, and stem cell markers. Tumors with high density (>20 cells/field) of M-LECP were significantly more likely to belong to aggressive sub-groups (HER2+ and TNBC) and present with lymph node metastasis (P-value <0.02).

Conclusion: These data show for the first time that human breast tumors recruit significant amount of immature myeloid cells with lymphatic phenotype and vessel-promoting properties. Such cells are largely absent from normal breast tissues. Statistical analyses show that M-LECP can significantly contribute to formation of new lymphatic vessels leading to increased nodal metastasis.

Citation Format: Lisa D. Volk-Draper, Radhika Patel, Nihit Bhattarai, Jie Yang, Sophia Ran. Lymph node metastasis in clinical breast cancer is significantly promoted by myeloid-derived lymphatic endothelial cell progenitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1506.
Abstract 1507: Transcriptional profiles of CD14+ cells in situ in melanoma tumors reveal plasticity and localization dependent function
Authors: Martinek Jan , Kim Kyung In , Wu Te-Chia , Wang Victor , Brookes Hannah M. , Sun Lili , Gulati Ananya , George Joshy , Henrich Philipp , Marches Florentina , Rongvaux Anthony , Chiorazzi Michael , Chuang Jeff , Robson Paul , Flavell Richard , Banchereau Jacques , Palucka Karolina
Published: August 2019

Mechanisms contributing to immunotherapy resistance in patients are the object of intense studies. Myeloid cells play a major role in tumors and include cells with different functions that can be grossly summarized as: (1) Antigen capture for presentation (dendritic cells, DCs) or for degradation (macrophages); (2) Tissue repair (macrophages) and (3) Effector function (mast cells, monocytes, granulocytes). However, the functional states of myeloid cells in human tumors are not completely understood. To study intact tumor microenvironments we have established a comprehensive approach for cellular and molecular analysis. Modular analysis of bulk RNAseq data of whole melanoma tissue sections stratified patient samples based on lymphocytic infiltrate but revealed inflammation and myeloid modules spread across samples. Polychromatic immunofluorescence and histocytometry showed that CD14+ cells represent the majority of the total tumor immune infiltrate. Furthermore, the majority of T cells present in melanoma tissue are in direct contact with CD14+ cells rather than melanoma cells. The distribution of CD14+ cells shows two distinct patterns: CD14+ cells within cancer nests (intratumoral) which are in close proximity to melanoma cells and are loaded with melanoma protein; CD14+ cells in the tissue surrounding cancer nests (stromal) which do not contain melanoma protein cargo and are organized in dense infiltrates. Using customized immunofluorescence-guided laser capture micro-dissection, we harvested CD14+ cells based on their tissue location and melanoma protein load for downstream analysis. We find that unsupervised clustering of transcriptomes groups cells by their tissue localization, i.e., intratumoral vs. stromal. Computational analysis, revealed distinct and replicable gene signatures associated with different pathways, in intratumoral and stromal CD14+ cells. Thus, the transcriptome differentiates the functional status of CD14+ cells related to their localization within tumor.

Citation Format: Jan Martinek, Kyung In Kim, Te-Chia Wu, Victor Wang, Hannah M. Brookes, Lili Sun, Ananya Gulati, Joshy George, Philipp Henrich, Florentina Marches, Anthony Rongvaux, Michael Chiorazzi, Jeff Chuang, Paul Robson, Richard Flavell, Jacques Banchereau, Karolina Palucka. Transcriptional profiles of CD14+ cells in situ in melanoma tumors reveal plasticity and localization dependent function [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1507.
Abstract 1517: Targeting M-MDSC intrinsic enhancer reprogramming enhances the efficacy of immune checkpoint therapy in hepatocellular carcinoma
Authors: Liu Man , Zhou Jingying , Cheng Alfred Sze Lok
Published: August 2019

Fibrous liver promotes an immunosuppressive environment to facilitate hepatocellular carcinoma (HCC) initiation. However, the underlying mechanisms of liver fibrosis-elicited immune evasion are poorly elucidated. Myeloid derived suppressor cells (MDSCs) play a key role in immunosuppression, leading to low responsiveness of immune checkpoint blockade (ICB). Emerging evidence highlights the pivotal role of enhancer remodeling in cell identity establishment and tumor immunity. Therefore, we aimed to determine whether enhancer remodeling participates in MDSC generation and aggressive HCC development in fibrous liver, and further explore the potential of enhancer inhibition in targeting MDSCs and improving efficacy of ICB in fibrotic HCC treatment.

By a mouse hepatoma cell Hepa1-6 orthotopic fibrotic HCC mouse model, we found that monocytic MDSC (M-MDSC) subset was also dramatically expanded in murine fibrous liver and positively correlated with increased hepatic tumorigenicity. Hepatic stellate cell (HSC), as key profibrogenic stromal cell, stimulated immunosuppressive M-MDSC generation from human peripheral blood mononuclear cells (PBMCs). Mechanistically, activated HSCs initiated p38 MAPK-mediated enhancer remodeling and triggered monocyte-to-M-MDSC identity shifting. Enhancer inhibition by a clinically-trialed drug iBET-762 disrupted HSC-M-MDSC crosstalk and abrogated M-MDSC generation and immunosuppressive functions. Notably, combination of iBET-762 with anti-PD-L1 antibody significantly induced tumor-infiltrating T lymphocytes, leading to tumor eradication and prolonged host survival in fibrosis-associated HCC model. As we also showed profound suppression of HCC patient-derived M-MDSCs by enhancer inhibition, our results delineate an enhancer deregulation mechanism for M-MDSC generation in fibrous liver environment, highlighting a promising therapeutic strategy of combined enhancer and immune-checkpoint targeting for desmoplastic tumors.

This project is supported by Collaborative Research Fund C4017-14G and the Focused Innovations Scheme 1907309.

Citation Format: Man Liu, Jingying Zhou, Alfred Sze Lok Cheng. Targeting M-MDSC intrinsic enhancer reprogramming enhances the efficacy of immune checkpoint therapy in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1517.