bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2295: Influence of endocrine therapy on the ratio of androgen receptor (AR) to estrogen receptor (ER) positive circulating epithelial tumor cells (CETCs) in breast cancer
Authors: Pizon Monika , Schott Dorothea , Lux Daniel , Pachmann Ulrich , Pachmann Katharina
Published: August 2019

Background: The androgen receptor (AR) is expressed in the majority of breast cancers and across the main breast cancer subtypes. Despite the high frequency of AR expression in breast cancer its appraisal remains controversial because its role is complex, dependent on the hormonal milieu. The aim of the current study was to investigate the frequency of AR and ER positive CETCs in breast cancer patients.

Material and Methods: The number of vital CETCs was determined from blood of 66 patients suffering from breast cancer and the expression of AR and ER on these cells was investigated using the maintrac method.

Results: Numbers of CETCs/ml blood were significantly higher in patients with advanced disease as compared to patients with early stage disease. The fraction of AR positive CETCs was significantly higher than the fraction of ER positive CETCs (90% vs. 50%; p<0.001). Patients with positive lymph nodes had less AR positive CETCs as compared to patients with negative lymph node status. The AR:ER ratio was higher in patients receiving tamoxifen therapy as compared to patients without tamoxifen therapy whereas treatment with aromatase inhibitor had no influence on AR:ER ratio.

Conclusions: The ratio of AR to ER positive CETCs, obviously, is influenced by endocrine therapy, more specifically therapy with tamoxifen. Since AR expression seems to be responsible to resistance to endocrine therapy this may provide a new biomarker to select patients who might benefit from combination treatment of ER and AR inhibitors.

Note: This abstract was not presented at the meeting.

Citation Format: Monika Pizon, Dorothea Schott, Daniel Lux, Ulrich Pachmann, Katharina Pachmann. Influence of endocrine therapy on the ratio of androgen receptor (AR) to estrogen receptor (ER) positive circulating epithelial tumor cells (CETCs) in breast 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 2295.
Abstract 2296: Validation of a novel one-step digital PCR platform with precision circulating cell-free DNA standards
Authors: Dueck Megan E. , Lin Robert , Anfora Andrew , Zayac Andrew , Gallagher Steve , Clement Omo , Ruminsky-Lowe Dana , Hung Paul
Published: August 2019

In this study we demonstrate precision quantification of Seraseq ctDNA EGFR T790M mutation mix at AF0.1% (mutant/wild-type ratio) using a novel one-step digital PCR (dPCR) platform. This novel yet simple workflow has the potential to make cancer liquid biopsy a clinical application. EGFR is an important drug target for the treatment of non-small cell lung carcinoma (NSCLC). During the treatment of NSCLC with tyrosine kinase inhibitors (TKIs), there is typically a significant response initially, followed by a secondary mutation as the carcinoma develops resistance. Early detection of cancer can better inform patient treatment and guide drug selection. One key EGFR mutation that leads to TKI resistance is the T790M mutation. Only a few clinical assays have been approved as companion diagnostics in patient biopsies (FFPE or plasma), while a larger number of laboratory developed assays (LDTs) under CLIA/CAP guidance are finding routine use in cancer disease diagnosis or treatment monitoring. Herein we describe the validation of a novel, fully integrated dPCR platform for the detection and absolute quantification of EGFR T790M. The integrated dPCR platform consists of a patented micro-molded plastic consumable and a fully-integrated instrument combining consumable sample loading, thermal cycling and 5-color fluorescence detection. The platform was designed to have a simplified, single-step workflow and provide results in less than one hour. In addition, developments in the micro-molded plastic consumable allow for near-zero dead volume. The novel integrated instrument is 100% dry and contamination-free, making it attractive for the transition to clinical applications. Seraseq ctDNA EGFR T790M mutation mix AF1% and AF0.1% reference standards in combination with a commercially available EGFR T790M dPCR assay were used to validate the novel integrated platform. In conclusion, we highlight the capability to precisely quantify samples as low as 0.1% T790M EGFR in a background of wild-type EGFR with high reproducibility and high accuracy.

Citation Format: Megan E. Dueck, Robert Lin, Andrew Anfora, Andrew Zayac, Steve Gallagher, Omo Clement, Dana Ruminsky-Lowe, Paul Hung. Validation of a novel one-step digital PCR platform with precision circulating cell-free DNA standards [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 2296.
Abstract 2297: Anti-labyrinthin monoclonal antibody reduces human adenocarcinoma circulating tumor cells in the blood of patient-derived xenograft models and inhibits the growth of adenocarcinoma cell cultures
Authors: Saleev Natalia , Blondheim-Shraga Netta R. , Solomonov Evgeny , Shapira Shiran , Haviv Izhak , Stemmer Solomon M. , Slor Hanoch
Published: August 2019

Labyrinthin is a 255-amino acid protein antigen that is expressed on the cell-surface of most adenocarcinoma tumors and is not expressed on the surface of most normal cells, which makes it an attractive candidate for targeted therapy. Originally, labyrinthin had been deduced to be a product of a large deletion in the gene coding for junctate. We found that the junctate gene in labyrinthin-expressing adenocarcinoma cells does not have any deletion, and we propose that the labyrinthin protein is a splice variant of the junctate gene. This study aimed to determine the effects of an anti-labyrinthin monoclonal antibody, on adenocarcinoma cells in vitro and on patient-derived xenograft (PDX) models in vivo. Lung, breast and colorectal adenocarcinoma cell lines, as well as a primary-cell culture of a colorectal adenocarcinoma patient, were assessed for cell surface expression of labyrinthin. The cells were then incubated in the presence of the anti-labyrinthin antibody and growth rate was monitored by live imaging methods. Untreated primary-cell cultures of the colorectal adenocarcinoma patient were also grafted to immunodeficient mice to produce PDX tumors. When establishment of palpable tumors was observed, the mice were injected with the antibody. Peripheral blood was sampled from the mice and circulating tumor cells (CTCs) were quantified by flow cytometry. A significant reduction of approximately 60% was detected in the number of CTCs in the peripheral blood of the antibody-treated PDX mice compared to untreated control PDX mice. Additionally, a significant reduction was measured in the growth-rate of cultured primary cells and in lung, breast and colorectal adenocarcinoma cell lines in the presence of the antibody. We conclude that the anti-labyrinthin antibody has an inhibitory effect on the formation of adenocarcinoma CTCs in vivo as well as on the growth rate of cultured adenocarcinoma tumor cells.

Citation Format: Natalia Saleev, Netta R. Blondheim-Shraga, Evgeny Solomonov, Shiran Shapira, Izhak Haviv, Solomon M. Stemmer, Hanoch Slor. Anti-labyrinthin monoclonal antibody reduces human adenocarcinoma circulating tumor cells in the blood of patient-derived xenograft models and inhibits the growth of adenocarcinoma cell cultures [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 2297.
Abstract 2311: Analysis of glypican 3-targeted chimeric antigen receptor T cells in hepatocellular carcinoma cell and mouse models
Authors: Li Dan , Li Nan , Zhang Yifan , Fu Haiying , Duan Zhijian , Hummer Alissa , Yang Hongjia , Torres Madeline B. , Luo Xiaoling , Su Ling , Zhu Hu , Kramer Josh , Chen Jinqiu , Wu Xiaolin , Hall Matthew , Wang Qun , Hewitt Stephen , Greten Tim , Ho Mitchell
Published: August 2019

Background: Glypican-3 (GPC3) is a cell surface protein that is highly expressed in hepatocellular carcinoma (HCC).

Methods and Results: In this report, we analyzed two chimeric antigen receptors (CARs) targeting GPC3, CAR (HN3) recognizes the N-lobe of GPC3 while CAR (hYP7) targets the C-lobe that is close to the cell surface. In a real-time cell cytolytic assay, we found that CAR (hYP7) T cells showed higher cytolytic activity than CAR(HN3) T cells at an E:T ratio of 2:1 when co-cultured with HepG2 cells for up to 140 hours. The Luminex analysis showed that CAR (hYP7) T cells produced significantly more Th1/Th2 cytokines and chemokines than CAR (HN3) T cells following exposure to Hep3B and HepG2 cells. In the Hep3B peritoneal dissemination xenograft mouse model, a single intraperitoneal infusion of CAR (hYP7) cells exhibited sustainable antitumor efficacy, and all of the mice survived without recurrence 10 weeks post treatment. Strikingly, we demonstrated that single injection of CAR (hYP7) T cells derived from either healthy donor or HCC patient significantly regressed tumor growth in the orthotopic HCC mouse model. Using a highly sensitive droplet digital PCR (ddPCR), we detected high frequencies of CAR T cells in the spleen and tumor microenvironment of mice in the CAR (hYP7) group. By contrast, CD19 CAR T cells showed no sign of gene integration in either tissue. More importantly, we found that CD8+ CAR (hYP7) T cells recovered from mouse spleens exhibited much higher lytic activity against HCC cells than CD4+ CAR (hYP7) T cells. Finally, we found that the GPC3-targeted CAR T cells downregulated the Wnt signaling in HCC cells.

Conclusion: The hYP7 antibody-derived GPC3-specific CAR is a promising therapeutic that could be tested for the treatment of advanced stage liver cancer.

Citation Format: Dan Li, Nan Li, Yifan Zhang, Haiying Fu, Zhijian Duan, Alissa Hummer, Hongjia Yang, Madeline B. Torres, Xiaoling Luo, Ling Su, Hu Zhu, Josh Kramer, Jinqiu Chen, Xiaolin Wu, Matthew Hall, Qun Wang, Stephen Hewitt, Tim Greten, Mitchell Ho. Analysis of glypican 3-targeted chimeric antigen receptor T cells in hepatocellular carcinoma cell and mouse models [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 2311.
Abstract 2335: Breast cancer cell-derived DNA activates STING pathway in macrophages
Authors: LIM GaYoung , Ka Na-Lee , Lee Mi-Ock
Published: August 2019

Cell-free DNA (cfDNA) has been studied to be a diagnostic and prognosic marker. In breast cancer, however, there have been few studies on the biological role of cfDNA in the tumor microenvironment. Thus, investigating a role of cfDNA released from cancer cells to the tumor microenvironment is important in order to understand cancer biology. In this study, we showed that free DNA was a mediator that elicited inflammation and activated stimulator of interferon genes (STING) signaling, an essential pathway in cytosolic DNA-associated innate immune reponses in breast cancer. First, we found that mRNA levels of pro-inflammatory cytokines were increased in THP-1 macrophage cells co-cultured with MDA-MB-231 breast cancer cells. Second, the amount of free double strand DNA derived from MDA-MB-231 cells culture media was much more than THP-1 cells. Third, there was little induction of STING pathway in response to exogenous DNA in MDA-MB-231 cells, suggesting that cancer cells may not be sensitive to exogenous DNA for activating STING pathway. In contrast, STING pathway was activated in response to exogenous DNA in THP-1 cells. Taken together, cancer cell-derived DNA could be a factor to induce inflammation through activating STING pathway in tumor-associated macrophages.

Citation Format: GaYoung LIM, Na-Lee Ka, Mi-Ock Lee. Breast cancer cell-derived DNA activates STING pathway in macrophages [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 2335.
Abstract 2336: Clinical-pathological characterization of the immunomodulator subgroup of triple negative breast cancer as a promising step in the selection of patients in personalized immunotherapies
Authors: Bautista Ruben R. , Rodríguez Oscar Gerardo A. , Miranda Alfredo H. , Dehesa Alejandro Z.
Published: August 2019

Introduction: Triple Negative Breast Cancer (CMTN) represents 23.1% of breast cancer cases in Mexico, is defined as a tumor that is absent of hormone receptors (estrogen and progesterone) and low HER2 overexpression and clinically is characterized by its agressive tumoral behavior.

Lehmann et al. described an immunomodulatory (IM) group which is composed of genes for immune antigens and transduction pathways of immune signals and cytokines. Recent studies have shown that patients with the IM phenotype have a better prognosis. So it is important to continue with the description of this subgroup as the first step for personalized therapies in this heterogeneous tumor.

Methodology: Retrospective clinical study, patients with diagnosis of CMTN, attended at the National Cancer Institute of Mexico (Total: 69 patients) were included. Following, the extraction of RNA from the primary tumor tissue of CMTN paraffin blocks was performed to subsequently generate labeled cDNA for hybridization in Affymetrix® Human Gene 2.0 microarrays, to later carry out the scanning and analysis of the data. For the analysis of microarrays we used the free software R and Bioconductor.65. And then the classification of patients using the platform "TNBCtype (http://cbc.mc.vanderbilt.edu/tnbc/)". And finally the analysis of survival, univariate and multivariate through SPSS.

Results: We observed some clinical variables with statistical difference such as radiotherapy (p<0.001), metastasis to lung (p=0.009), liver (p=0.013), and central nervous system (p=0.0029), as well as the Lehmann classifier showed significant difference between patients classified as IM vs. No IM (p=0.04).

Conclusions: the IM classifier could not only serve as an excellent prognostic classification in CMTN but as a predictor of immunological treatments.

Citation Format: Ruben R. Bautista, Oscar Gerardo A. Rodríguez, Alfredo H. Miranda, Alejandro Z. Dehesa. Clinical-pathological characterization of the immunomodulator subgroup of triple negative breast cancer as a promising step in the selection of patients in personalized immunotherapies [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 2336.
Abstract 2340: Differentiation of pro- and anti-inflammatory features of monocyte-derived dendritic cells
Authors: Bakke Ragnhild Maukon , Azeem Waqas , Appel Silke , Kalland Karl-Henning , Oyan Anne Margrete
Published: August 2019

Background: Dendritic cells (DCs) are the most potent antigen-presenting cells of the immune system and are consequently exploited in cancer immunotherapy in order to present tumor-associated antigens to lymphocytes. The ability of tumor cells to induce tolerogenic DCs and avoid the immune system challenges DC-based immunotherapies. Utilizing buffycoats of healthy blood donors we have investigated the activation of gene expression programs conventionally associated with either pro- or anti-inflammatory features of monocyte-derived DCs.

Methodology: Following isolation of monocytes from buffycoats, various culture conditions were tested to generate immature DCs and to mature and activate them in vitro. Genome-wide gene expression, secretion of cytokines and tryptophan metabolites, surface expression of maturation and activation markers, and functional abilities were analyzed. Specifically, beta-catenin and indoleamine 2,3-dioxigenase 1 (IDO-1) activation were examined using both agonists and inhibitors of those pathways.

Results: A considerable variability among buffycoats of different healthy blood donors was observed regarding DC yield and cytokine secretion. Induction time to generate immature DCs with interleukin-4 and granulocyte-macrophage colony-stimulating factor affected DC differentiation. Several maturation conditions induced strong IDO-1 expression. Activation of beta-catenin during DC maturation induced anti-inflammatory features that could be competed by adding beta-catenin inhibitors during cultivation of the cells. Pro- and anti-inflammatory features often co-existed in mature DCs.

Conclusions: Beta-catenin and IDO-1 activation are prevalent according to different conditions of monocyte-derived DC maturation and associated with anti-inflammatory features. Both pathways can be inhibited by specific antagonists. More robust pro-inflammatory DC generation is desirable for more effective cancer immunotherapy.

Citation Format: Ragnhild Maukon Bakke, Waqas Azeem, Silke Appel, Karl-Henning Kalland, Anne Margrete Oyan. Differentiation of pro- and anti-inflammatory features of monocyte-derived dendritic cells [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 2340.
Abstract 2347: NOD-like receptor NLRP12 suppresses hepatocellular carcinoma via regulation of JNK signaling
Authors: Zaki Hasan
Published: August 2019

Hepatocellular carcinoma (HCC) is a deadly human cancer associated with chronic inflammation. The cytosolic pathogen sensor NLRP12, a member of NOD-like receptor, has emerged as a negative regulator of inflammation, but its role in HCC is unknown. Here we investigated the role of NLRP12 in HCC using mouse models of HCC induced by carcinogen diethylnitrosamine (DEN) or DEN plus hepatotoxin carbon tetrachloride (CCl4). Livers collected from wild-type and Nlrp12-/- mice at 10 and 5.5 months following DEN or DEN plus CCl4 treatment, respectively, were examined for tumor burden, histopathological changes, expression of inflammatory and tumor-promoting genes, and activation of signaling pathways. Primary hepatocytes from healthy mice were isolated, cultured, and used to assess cell signaling, apoptosis, and proliferation. Cancer genomics database analysis showed that NLRP12 expression is significantly reduced in human HCC and 2-3% HCC patients carry mutations in NLRP12. Nlrp12-/- mice were highly susceptible to DEN or DEN plus CCl4-induced HCC with increased inflammation, hepatocyte proliferation, and tumor burden. Consistently, Nlrp12-/- tumors showed higher expression of proto-oncogenes cJun and cMyc and downregulation of tumor suppressor p21. Interestingly, antibiotics treatment dramatically diminished tumorigenesis in Nlrp12-/- mouse livers. Signaling pathway analyses demonstrated higher JNK activation in Nlrp12-/- HCC and cultured hepatocytes during stimulation with microbial pattern molecules. Inhibition of JNK activation or NLRP12 overexpression reduced proliferative and inflammatory responses of Nlrp12-/- hepatocytes. In summary, this study demonstrated for the first time that NLRP12 negatively regulates HCC pathogenesis via downregulation of JNK-dependent inflammation and proliferation of hepatocytes.

Citation Format: Hasan Zaki. NOD-like receptor NLRP12 suppresses hepatocellular carcinoma via regulation of JNK 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 2347.
Abstract 2362: NF-κB (p65) mediates interleukin-1 (IL-1) repression of androgen receptor (AR) in AR+prostate cancer (PCa) cell lines
Authors: Thomas-Jardin Shayna Elizabeth , Dahl Haley , Bautista Monica , Ha Freedom , Jacob Joan , Nawas Afshan Fathima , Kanshwala Mohammed , Xing Chao , Delk Nikki
Published: August 2019

Inflammation promotes cancer initiation and progression. The Nuclear Factor Kappa-Light-Chain-Enhancer of Activated B cells (NF-κB) family of transcription factor proteins, p65 (RelA), RelB, c-Rel, p105/p50 (NF-κB1), and p100/52 (NF-κB2), form homo- and heterodimeric complexes that mediate inflammatory cytokine signaling. We previously reported that the inflammatory cytokines, interleukin-1 alpha (IL-1α) and IL-1 beta (IL-1β), repress androgen receptor (AR) levels and activity in AR+ prostate cancer (PCa) cell lines. AR drives PCa tumorigenicity and, thus, AR is a therapeutic target. Our data suggests that IL-1 selects for ARlow/-PCa cell subpopulations that can evade AR-targeting therapy. Using RNA sequencing, we identified an IL-1-regulated gene signature predicted to supported AR-independent tumorigenicity in PCa cells. Pathway analysis of the RNA sequencing data predicted that AR is a target molecule of p65 (RELA). p50:p65 heterodimers are known to mediate IL-1 signaling, therefore, we investigated if NF-κB (p50:p65) signaling mediates IL-1 repression of AR. We found that siRNA silencing of p65 is sufficient to attenuate IL-1 repression of AR mRNA and protein levels and AR activity in AR+ PCa cell lines, while siRNA silencing of p50 had no effect on IL-1 repression of AR. Our data suggests that p65 represses AR levels, directly or indirectly, in response to IL-1. Thus, therapeutic inhibition of p65 activity could prevent the accumulation of inflammation-induced treatment-resistance ARlow/- PCa cell subpopulations.

Citation Format: Shayna Elizabeth Thomas-Jardin, Haley Dahl, Monica Bautista, Freedom Ha, Joan Jacob, Afshan Fathima Nawas, Mohammed Kanshwala, Chao Xing, Nikki Delk. NF-κB (p65) mediates interleukin-1 (IL-1) repression of androgen receptor (AR) in AR+prostate cancer (PCa) cell lines [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 2362.
Abstract 2365: Selective Stat3 inhibition in the tumor microenvironment restricts gastrointestinal tumor growth
Authors: Alorro Mariah Grace , Masson Frederick , Eissmann Moritz , Ernst Matthias
Published: August 2019

The transcription factor Stat3 plays essential roles in biological processes involving development, immunity and inflammation. Stat3 is known to regulate the expression of a large repertoire of genes which when deregulated, as in the context of tumorigenesis, can lead to the development of some of the well-known hallmarks of cancer, such as resistance to cell death and sustained proliferation. Indeed the aberrant activation of Stat3 has been characterized across a number of different cancers including gastrointestinal cancers, presenting Stat3 and its signalling pathway a promising therapeutic target. Although intrinsic Stat3 signalling in tumor cells is well characterized, the effect(s) of Stat3 signalling among the infiltrating cells of the tumor microenvironment is still poorly understood. With this project we aim to elucidate the role of Stat3 in the non-tumoral compartment, and explore the therapeutic value of Stat3 inhibition for gastric and colon cancer.

We generated the CAGsrtTA3;STAT3.1348 (shStat3) mouse that utilizes short-hairpin RNAi technology allowing for conditional and reversible Stat3 reduction. To study the effects of systemic Stat3 inhibition, the shStat3 was crossed with the gp130F/F mutant mouse that spontaneously develops gastric cancer. To assess the effects of Stat3 suppression in the non-tumoral compartment alone, the shStat3 mice were sub-cutaneously injected with MC38 murine colon cancer cells. Tumors and other tissues of these mice were excised and analysed.

We found that shStat3-mediated systemic Stat3 suppression resulted in significant tumor reduction in the gp130F/F gastric cancer mice. Similarly, isolated Stat3 reduction in the non-tumoral compartment of the shStat3 mice, restricted the growth of Stat3-proficient MC38 tumor allografts. Immunophenotyping of excised tumors highlighted an increase of a monocytic Ly6C+Ly6G- myeloid population.

Our data provides evidence for the therapeutic value of specific Stat3 targeting in gastrointestinal cancers. Interestingly, we have shown that Stat3 suppression in the non-tumoral compartment alone was enough to result in significant tumor reduction, indicating a prominent role of Stat3 in creating a pro-tumorigenic microenvironment. We have also identified a monocytic population as candidate cell type that drives this Stat3 suppression mediated anti-tumor effect.

Citation Format: Mariah Grace Alorro, Frederick Masson, Moritz Eissmann, Matthias Ernst. Selective Stat3 inhibition in the tumor microenvironment restricts gastrointestinal tumor growth [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 2365.
Abstract 2375: Developing double knock-in models of human immune checkpoint targets (dKI HuGEMM) for efficacy assessment of combinatorial therapeutic antibodies
Authors: Zheng Lei , He Daniel Xianfei , Sun Ruilin , An Annie Xiaoyu , Fei Jian , Li Henry Qixiang , Ouyang Davy Xuesong
Published: August 2019

Immune checkpoint inhibitors (ICIs), i.e. PD1, PDL1 and CTLA4 therapeutic antibodies, have led to long-term survival in many late stage solid tumor patients. Despite their revolutionary clinical impact, the overall response rate is still low. One major roadblock is that compensatory immune inhibitory pathways are turned on to protect tumor cells from being attacked by T cells. Various combinatory ICI treatments have now been investigated in clinical trials to tackle this challenge. We have previously reported the development of immune checkpoint target humanized mice (HuGEMM) through CRISPR-Cas9 knock-in. We have generated PD1 and CTLA4 HuGEMM mice and used them for efficacy assessment of corresponding therapeutic antibodies. We have also generated human PDL1 expressing MC38 cells and PDL1 HuGEMM, and demonstrated robust efficacy of several PDL1 therapeutic antibodies. Here we report the establishment of double knock-in (dKI) mice of ICI targets, i.e., PD1/PDL1 and PD1/CTLA4 dKI HuGEMM, and use them as tools to test immunotherapies with PD1/PDL1 and PD1/CTLA4 combos. Similar to clinical benefit of PD1 and CTLA4 combo shown in the melanoma and NSCLC patients, we found combined treatment of Nivolumab and Ipilimumab antibody leads to 103% TGI in the corresponding PD1/CTLA4 dKI-HuGEMM, with complete tumor remission in 80% of treated mice. These mice remained disease free throughout a tumor re-challenge study for over 40 days. We have also developed PD1/PDL1 dKI HuGEMM and tested combined treatment of Atezolizumab and Nivolumab. Interestingly, we observed improved efficacy in the combo treatment group despite the two ICIs are thought to target the same PD1/PDL1 axis. Monotherapies may not fully release the PD1/PDL1 blockade due to complicity of multiple compatible ligands & receptors, including PDL2 and B7-1. We have also tested PD1/OX40 combo treatment with dKI HuGEMM, which is reported separately. Taken together, Our dKI HuGEMM models offer robust tests on ICI combinations, as well as combos of ICIs with other anti-tumor therapeutic modalities.

Citation Format: Lei Zheng, Daniel Xianfei He, Ruilin Sun, Annie Xiaoyu An, Jian Fei, Henry Qixiang Li, Davy Xuesong Ouyang. Developing double knock-in models of human immune checkpoint targets (dKI HuGEMM) for efficacy assessment of combinatorial therapeutic antibodies [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 2375.
Abstract 2393: Bridging MOA-based reporter bioassays with PBMC based ADCC for immunotherapy drug development
Authors: Cong Mei , Stecha Pete , paguio Aileen , binkowski brock , Cheng Zhi-Jie , Fan Frank
Published: August 2019

Having a functional bioassay that is MOA-based, accurate, precise, robust and reproducible is critical for the development of antibody-based biologics. We have developed reporter bioassays that meet these criteria for a broad range of antibody modalities including Fc effector function, immune checkpoint modulation, bispecific antibody engagement, cytokine modulation, and others. Here we will present the latest technology advancements and bridging of the PBMC based ADCC cell killing assay with reporter based ADCC Bioassay.

Citation Format: Mei Cong, Pete Stecha, Aileen paguio, brock binkowski, Zhi-Jie Cheng, Frank Fan. Bridging MOA-based reporter bioassays with PBMC based ADCC for immunotherapy drug development [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 2393.
Abstract 2394: Discovery of small anti-PD-L1 peptides for cancer immunotherapy
Authors: Liu Hao , Zhao Zhen , Li Yuanke , Cheng Kun
Published: August 2019

Immunotherapy using checkpoint inhibitors, especially PD-1/PD-L1 inhibitors, has now evolved into the most promising therapy for cancer patients. However, most of these inhibitors are monoclonal antibodies, and their large size may limit their tumor penetration, leading to suboptimal efficacy. As a result, there has been a growing interest in developing low-molecular-weight checkpoint inhibitors. Using a phage display peptide library, we discover small peptide-based anti-PD-L1 inhibitors to block the PD-1/PD-L1 interaction. These peptides exhibit high affinity and specificity to human PD-L1 as well as PD-L1-positive human cancer cells. Molecular docking studies indicate that the CLP002 peptide specifically binds to PD-L1 at the residues where PD-L1 interacts with PD-1. Compared to anti-PD-L1 antibody, the anti-PD-L1 peptides exhibited better tumor penetration in a 3D tumor spheroid model. The CLP002 peptide restores proliferation and prevents apoptosis of T cells that are co-cultured with cancer cells. The CLP002 peptide also inhibits tumor growth and increases survival of CT26 tumor-bearing mice, suggesting that the CLP002 peptide represents a promising low-molecular-weight checkpoint inhibitor for cancer immunotherapy.

Citation Format: Hao Liu, Zhen Zhao, Yuanke Li, Kun Cheng. Discovery of small anti-PD-L1 peptides for cancer immunotherapy [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 2394.
Abstract 2416: Vitamin D concentration and the risks of Barrett’s esophagus and esophageal adenocarcinoma: A Mendelian randomization study
Authors: Dong Jing , Thrift Aaron
Published: August 2019

Background Epidemiological studies on circulating concentrations of 25 hydroxy vitamin D (25(OH)D) and risks of esophageal adenocarcinoma (EAC) have shown conflicting results. Here we conducted a Mendelian randomization (MR) study to determine the associations between circulating concentrations of 25 hydroxy vitamin D (25(OH)D) and risks of EAC and its precursor, Barrett’s esophagus (BE).

Methods We conducted a MR study using a two-sample (summary data) approach. Six single-nucleotide polymorphisms (SNPs) (rs3755967, rs10741657, rs12785878, rs10745742, rs8018720 and rs17216707) associated with circulating 25(OH)D concentrations were used as instrumental variables. Data from 6,167 BE patients, 4,112 EAC patients and 17,159 control participants were from studies participating in the Barrett’s and Esophageal Adenocarcinoma Consortium (BEACON), as well as studies from Bonn, Germany, and Cambridge and Oxford, United Kingdom. Analyses were performed separately for BE and EAC.

Results Overall, we found no evidence for an association between genetically estimated 25(OH)D concentrations and the risk of BE or EAC. The odds ratio (OR) per standard deviation unit increase in genetically estimated 25(OH)D concentrations for BE risk estimated by combining the individual SNP association using inverse variance weighting was 1.21 (95% confidence interval, CI, 0.77-1.92; P = 0.41). The OR for EAC risk estimated by combining the individual SNP association using inverse variance weighting was 0.68 (95% CI, 0.39-1.19; P = 0.18).

Conclusions This Mendelian randomization study found that genetically estimated low 25(OH)D concentrations were not associated with increased risks of BE or EAC.

Citation Format: Jing Dong, Aaron Thrift. Vitamin D concentration and the risks of Barrett’s esophagus and esophageal adenocarcinoma: A Mendelian randomization study [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 2416.
Abstract 2430: Assessing patient navigation and support services at FQHCs
Authors: Aponte-Soto Lisa
Published: August 2019

Cancer is the leading cause of morbidity and mortality for Latinx followed by African Americans (CDC, 2017). Screening can increase the rate of early detection and treatment success. However, the rates of compliance for screening are typically lower among Latinx, which may contribute to decreased diagnosis and increased risk of disease in comparison to their Euro-American counterparts (ACS, 2015). Access to screening services and ability to pay are among the commonly cited barriers for screening compliance. The IDPH recommends incorporating patient navigator (PN) models in community health clinics and communitywide events to increase health literacy, knowledge, and delivery, and quality of care including compliance with screening methods. The University of Illinois (UI) Cancer Center (UICC) works in partnership with the UI Health Mile Square Health Center (MSHC) to implement a bilingual, bicultural PN model for conducting comprehensive cancer prevention and screening services among Latinx, African Americans, and underserved communities in Chicago. A mixed methods approach was used to evaluate the patients’ perceptions and experiences with patient navigator encounters and support services. The authors conducted a semi-structured interviews and abstracted data from patient records. Provider interviews were conducted to understand provider knowledge and attitudes of navigator services. Navigator interviews captured benefits and challenges of incorporating navigation services at the clinics. Data were entered in REDCap and analyzed using Dedoose v. 8.0.42. This paper validates the implementation of PN models at federally qualified health centers (FQHCs) as an asset to patients and providers in facilitating health education, increasing patient screening compliance, and improving access to health care services. Comprehensive cancer screening maximizes resources and improves the quality of life and health outcomes of underserved Latinx and African American patients who are navigated to services. PN-provider partnerships are introduced as a hallmark of the program’s success in identifying at-risk patients and navigating them to appropriate and timely medical screening, diagnostic, and treatment services. Future directions for incorporating and evaluating culturally responsive, bilingual, bicultural PN models at FQHCs, community clinics, and school based clinics are shared to inform public policy for rapid cycle monitoring of protective health cancer interventions and early detection services for Latinx and African American patients in Chicago.

Citation Format: Lisa Aponte-Soto. Assessing patient navigation and support services at FQHCs [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 2430.
Abstract 2432: Prevalence of depression and other chronic diseases among uninsured cancer survivors: A free clinic study
Authors: Mirza Sayeef , Rahman Shams , Macdonald Madeline , Towne Alexandra , Robinson Katherine , Todd Amber , Wang Wei , Wathington Deanna
Published: August 2019

Introduction: Free clinics play an important role in providing health care services to the poor and uninsured. Limited data exist on chronic disease burden and patient characteristics of cancer survivors outside the network of insured health systems. In this study we describe characteristics of cancer patients utilizing free clinics for chronic disease management and mental health services in order to evaluate associations between chronic conditions.

Methods: Nine free clinics in the Tampa Bay area were included in this study. A retrospective review of patient charts from 01/01/2016 to 12/31/2017 was conducted. Data on patient characteristics and prevalence of chronic diseases were abstracted through an online questionnaire using Redcap software. Patients with a documented history of cancer were considered cancer survivors. Chi-square test was used to compare patient characteristics and p-values were reported. Logistic regressions were used to examine associations between diseases and socio-demographic factors. Odds ratios (OR) and 95% confidence intervals (CI) were reported.

Results: From 2016 to 2017, 208 cancer survivors were managed in nine free clinics. The average age was 54 years and 138 (66%) were women. The prevalence of depression was 11.14%. The prevalence of depression was higher among women (12.7%) compared to men (8.8%), p-value 0.001. The prevalence was significantly highest among patients who were 18-44 years, non-Hispanics, white race, unemployed and considered low-income. In univariate analyses, the prevalence of depression was significantly associated with cancer (OR 2.12; 95%CI: 1.23-3.67), diabetes (OR 1.59; 95%CI: 1.21-2.08), cerebrovascular accident (OR 3.25; 95%CI: 1.71-6.21), cardiovascular disease (OR 2.10; 95%CI: 1.26-3.51), hypertension (OR 1.96; 95%CI: 1.58-2.43), and hyperlipidemia (OR 2.30; 95%CI: 1.79-2.94). Unemployment, lower income level, and higher BMI were also factors positively associated with the prevalence of depression. Additional relationships and multivariate analyses are available.

Conclusion: Despite having access to limited resources, free clinics receive mainly poor, women, middle-aged, and uninsured patients. Comorbidities such as cancer and other chronic conditions are often directly associated with depression among patients managed in free clinics. Mental health support is critically needed in free clinics, especially for those who are cancer survivors.

Citation Format: Sayeef Mirza, Shams Rahman, Madeline Macdonald, Alexandra Towne, Katherine Robinson, Amber Todd, Wei Wang, Deanna Wathington. Prevalence of depression and other chronic diseases among uninsured cancer survivors: A free clinic study [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 2432.
Abstract 2437: Microfluidic device integrated with lipid nanoprobe for extracellular vesicle isolation toward non-invasive cancer diagnosis
Authors: Zheng Siyang , Wan Yuan , Maurer Mackenzie , Xia Yi-Qiu , Hao Si-Jie , Zhang Wen-Long , Yee Nelson S.
Published: August 2019

Extracellular vesicles (EVs) can mediate intercellular communication by transferring cargo proteins and nucleic acids between cells. Recently, they have been demonstrated for potential value in cancer diagnostics and treatment monitoring. However, relevant clinical translation is mainly limited by technical challenges in EV isolation. We previously reported lipid nanoprobes, which is a nanomaterial system of labeling probe and capture probe. The labeling probe is constructed with a lipid molecule as the active component to label EVs rapidly and spontaneously with high efficiency, while the capture probe can isolate labeled EVs magnetically. Herein, we report on the development of a microfluidic device with integrated lipid nanoprobe for on-chip EV isolation towards instrument development for clinical translation. The nanostructured substrate of the device is integrated with a micromixer for one-step isolation of EVs from 1-ml plasma. We validated the device with plasma collected from pancreatic cancer patients, followed by DNA mutation detection of EV cargo. Size-tunable nanostructures are fabricated by patterning high-resolution iron thin films on fused silica substrates. By judicious thermal annealing, homogeneously dispersed iron nanoparticles are formed by fission and fusion on the substrate, which are served as a mask for silica dry-etching. Subsequently, selected lipid nanoprobes, which can instantaneously insert into lipid bilayers of EVs, are grafted onto the nanostructured substrate in a micromixer. This platform is verified first to isolate cultured cancer cell-derived EVs spiked-in plasma samples that emulated clinical samples. This platform is further applied to isolate EVs from pancreatic cancer patients’ plasma and identified KRASmutations in EV DNA with highly sensitive droplet digital PCR. Together, this platform enables rapid and efficient isolation of EVs from plasma specimens, and thus, holds great potential in clinical translation.

Citation Format: Siyang Zheng, Yuan Wan, Mackenzie Maurer, Yi-Qiu Xia, Si-Jie Hao, Wen-Long Zhang, Nelson S. Yee. Microfluidic device integrated with lipid nanoprobe for extracellular vesicle isolation toward non-invasive cancer diagnosis [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 2437.
Abstract 2439: A semi-supervised deconvolution method for quantifying the composition and activity of tumor-infiltrating cell types
Authors: Chang Wennan , Wan Changlin , Sun Yifan , Han Yan , Qi Siyuan , Lu Xiongbin , Cao Sha , Zhang Chi
Published: August 2019

Tumor microenvironment (TME) plays a key role in tumorigenesis, disease progression and the acquirement of drug resistance. An accurate assessment of TME cellular compositions may not only shed light on how TME interacts with cancer cells, but also bring new insights for translational researchers in studying the non-responding mechanism of immunotherapy. Traditional deconvolution methods infer the relative proportions of predefined cell types based on a tissue omics data through either regression- or enrichment- based approaches. However, there are several challenges that remain unsolved in the current formulations, including (1) identifying the Immune/Stromal (I/S) cell types that truly exists in a TME, (2) identifying the marker genes for each cell type that are specifically expressed by one or a few I/S cell types in a TME, (3) co-linearity among to-be-assessed I/S proportions due to their co-infiltration. We have developed a novel semi-supervised deconvolution method namely ICTD (Inference of Cell types and Deconvolution), addressing the three challenges via (i) developing a Bi-Cross Validation (BCV) based matrix rank test to assess the significance level of the existence of cell types and signature genes, (ii) utilizing a constrained Non-negative Matrix Factorization (NMF) to eliminate the effect of co-linearity. We validated ICTD on bulk tumor datasets simulated using single-cell RNA-seq data. Our analysis suggested that ICTD has a largely improved prediction accuracy of TME compositions comparing to existing methods, and particularly, it is capable of identifying novel or sub-cell types. We applied our method to TCGA and other gene expression data of breast and prostate cancer. Subsets of CD8+ T cells with varied cytotoxicity levels and subtypes of fibroblast cells were identified. Moreover, integrated with an analysis of an independent single-cell and cell line gene expression dataset, we identified genes specifically expressed by cancer cells that are associated with decreased T cell cytotoxicity level.

Citation Format: Wennan Chang, Changlin Wan, Yifan Sun, Yan Han, Siyuan Qi, Xiongbin Lu, Sha Cao, Chi Zhang. A semi-supervised deconvolution method for quantifying the composition and activity of tumor-infiltrating cell types [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 2439.
Abstract 244: Inhibition of atypical PKC signaling enhances the sensitivity of glioblastoma cells towards Temozolomide therapy
Authors: Dey Avijit , Patel Rekha , Smalley Tracess , Ratnayake Wishrawana Sarathi , Islam Anisul , Acevedo-Duncan Mildred
Published: August 2019

Glioblastoma is a highly aggressive brain cancer which has a mean survival rate of only 12 months. Current treatment options of glioblastoma include chemotherapy and limited surgical resection. Temozolomide (TMZ) is the current therapeutic choice for chemotherapy but has severe limitations due to development of resistance that occurs by genetic modification and constitutive activation of several other pathways. Therefore, to overcome Temozolomide resistance and to prevent recurrence of the disease a more effective therapeutic approach is required. One of the signaling pathways that contribute to the aggressive behavior of glioma cells is the activation of PKC signaling. Of the various PKC isoforms, the atypical PKCs, PKC ζ and ι were found to be over-expressed in glioblastoma tissue samples compared with normal brain tissue and high atypical PKC levels were correlated with increased cellular proliferation and invasiveness of glioma cells. [4-(5-amino-4-carbamoylimidazol-1-yl)-2, 3-dihydroxycyclopentyl] methyl dihydrogen phosphate also known as ICA-1 was used as a specific inhibitor of PKC-ι and [8-hydroxynaphthalene-1,3,6-trisulfonic acid] also known as ζ-Stat was used as a specific inhibitor of PKC- ζ. T98G and U87 glioblastoma cells were treated with ICA-1 monotherapy (7.5µM), ζ-stat monotherapy (10 µM), TMZ monotherapy at varying doses, TMZ combined with ICA-1 (7.5µM) and TMZ combined with ζ-stat (10 µM) for five consecutive days and analyzed for cell viability by WST assay. Results exhibited that ICA (7.5µM) when combined with TMZ showed significantly increased cytotoxicity compared to TMZ monotherapy. Annexin-V/PI assay revealed that combination treatment with TMZ and ICA nucleotide (7.5µM) significantly increased the number of dead cells and the number of cells undergoing late apoptosis when compared to TMZ monotherapy. This study offers the first evidence for the novel combination of ICA-1 with TMZ to induce robust apoptosis in a Caspase-3 mediated mechanism. Scratch assay results also showed that inhibition of PKC-ζ by ζ-Stat lead to decreased invasion compared to control. Our studies suggest that atypical PKCs particularly PKC-ι might be an important therapeutic target in the treatment of glioblastoma.

Citation Format: Avijit Dey, Rekha Patel, Tracess Smalley, Wishrawana Sarathi Ratnayake, Anisul Islam, Mildred Acevedo-Duncan. Inhibition of atypical PKC signaling enhances the sensitivity of glioblastoma cells towards Temozolomide therapy [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 244.