bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 6644: A comprehensive in vitro and in vivo system to evaluate STING agonist efficacy in cancer therapeutics
Authors: Shi Xiaohe , Fan Feifei , Wei Ruicheng , Zuo Xiangyang , Lu Xiutao , Sun Quanhong 
Published: September 2020

Abstract
A number of stimulator of interferon genes protein (STING) agonists has recently been developed to treat cancer and infectious diseases. To investigate the binding of ligand to STING and subsequent activation of the STING pathway, we used the protein thermal shift assay, a high-throughput screening method for intermolecular interaction involving a protein of interest, to identify previously unknown compounds that bind to STING. To determine the functional consequence of ligand binding, we constructed IFN-β-Luc THP1 reporter cell line, to evaluate the pathway activation together with IFNβ secretion. In addition, we incubated human peripheral blood mononuclear cells (PBMCs) with STING agonist and measured phosphorylation of STING, phosphorylation of IRF3 and the secretion of cytokines such as IFN-β by ELISA or Luminex. To determine the in vivo therapeutic effects of STING agonists, we performed efficacy studies in syngeneic mouse models of melanoma (B16F10 cell line), colorectal cancer (CT-26 cell line) or breast cancer (4T1 cell line) with intratumoral delivery of test compounds. Test Treatment with STING agonists resulted in significant tumor growth inhibition as measured by tumor volume and significantly improved survival. Tumor-reactive IFN-γ secreting CD8+ T cells were harvested from spleens, purified by immunomagnetic sorting, and immediately used in ELISPOT assays using the mouse IFN-γ ELISPOT Kit. Tumor-infiltrating lymphocytes (TILs) have also been assessed in harvested melanoma (B16F10) tumors. We found that treatment with STING agonists resulted in increased CD69 percentage in CD8+ T cells in TILs, and decreased MHCII levels in macrophages and DCs in TILs.
In summary, we have established reporter-based in vitro assays and in vivo efficacy validation platforms, which can be used for STING agonists efficacy evaluation for cancer therapy and combination IO target therapy.
Citation Format: Xiaohe Shi, Feifei Fan, Ruicheng Wei, Xiangyang Zuo, Xiutao Lu, Quanhong Sun. A comprehensive in vitro and in vivo system to evaluate STING agonist efficacy in cancer therapeutics [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6644.
Abstract 6680: Inclusion of inhibitory neoantigens can abolish efficacy of otherwise protective therapeutic anti-tumor vaccines
Authors: DeVault Victoria L. , Starobinets Hanna , Adhikari Sanmit , Singh Simran , Rinaldi Stephanie , Classon Brendan , Flechtner Jessica B. , Lam Hubert 
Published: September 2020

Abstract
Identification of neoantigens that can elicit strong anti-tumor responses has become critical to vaccine design for cancer immunotherapy. Conventional methods for in silico neoantigen identification have yielded poor predictive value, highlighting the need for methods that identify bona fide neoantigen targets. The Genocea ATLAS™ platform uses autologous antigen presenting cells and T cells to identify pre-existing CD4+ and/or CD8+ T cell responses to patient-specific mutations and therefore selects confirmed neoantigens that can be used for vaccines and cell therapies. Screened neoantigens are characterized as stimulatory or inhibitory based on up- or downregulation of inflammatory cytokine secretion compared to baseline controls. In the mouse B16F10 melanoma model, therapeutic immunization with stimulatory neoantigen peptides arrested tumor growth whereas in contrast, inhibitory antigen immunization (henceforth referred to as inhibigens) resulted in accelerated tumor progression. The presence of an inhibigen in an otherwise protective vaccine formulation completely abolished protection. Global IFNγ responses to neoantigens were abrogated in these mice as measured by ELISpot suggesting that inhibigen pro-tumor responses can be immunodominant. Analysis of tumor-infiltrating lymphocytes (TILs) from mice immunized with ATLAS-identified neoantigen ± inhibigen peptide vaccines revealed significant alterations in the tumor microenvironment. Inclusion of inhibigens resulted in low T cell infiltration into tumors and increased expression of TIL inhibitory surface markers (e.g. PD-1, LAG-3). Immunological mechanisms of the inhibitory phenomenon are currently being explored. These data promote rational methods for neoantigen identification and highlight the potential advantages of excluding deleterious inhibigens from cancer vaccines and immunotherapies. GEN-009, a personalized cancer vaccine filtered for inclusion of only ATLAS-identified neoantigens (excluding inhibigens) is currently being evaluated in a Phase 1/2a clinical trial (NCT03633110).
Citation Format: Victoria L. DeVault, Hanna Starobinets, Sanmit Adhikari, Simran Singh, Stephanie Rinaldi, Brendan Classon, Jessica B. Flechtner, Hubert Lam. Inclusion of inhibitory neoantigens can abolish efficacy of otherwise protective therapeutic anti-tumor vaccines [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6680.
Abstract 684: Gastrointestinal/liver-targeted TLR7 agonist for treatment of colorectal and liver cancers
Authors: Miller Andrew T. , Rodrigo Evelyn , Corpuz Manny , Plouffe David , Wu Tom Y.-H. 
Published: September 2020

Abstract
Anti-PD1/L1 has become the backbone of immune therapy for many cancer types. However, the majority of patients do not respond due to a myriad of mechanisms affecting the tumor microenvironment, including low tumor mutational burden and low immune cell infiltrate. Innate immune agonists can potentially address both issues by increasing tumor antigen presentation and tumor microenvironment inflammation, thereby turning cold tumors hot. As clinical proof-of-concept, many intratumoral TLR/STING agonists have shown promising anti-tumor responses as single agents and in combination with checkpoint inhibitors; however, successful clinical applications have been limited to cutaneous-accessible tumor types. APR003 is an orally-administered GI/liver-targeted small molecule TLR7 agonist designed for the treatment of visceral colorectal and liver cancers. Studies in mice and monkeys demonstrate robust Type-1 Interferon pathway activation with good tolerability. APR003 is efficacious in several syngeneic orthotopic models of liver and colon cancer, both as single agent and in combination with anti-PDL1. Mechanistic studies show enhancement of CD103+ dendritic cells in tumor draining lymph nodes and tumor antigen-specific T cells in the tumor microenvironment. Pre-clinical pharmacology data will be presented.
Citation Format: Andrew T. Miller, Evelyn Rodrigo, Manny Corpuz, David Plouffe, Tom Y.-H. Wu. Gastrointestinal/liver-targeted TLR7 agonist for treatment of colorectal and liver cancers [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 684.
Abstract 694: PAWI-2 overcomes tumor stemness and drug resistance in pancreatic cancer stem cells
Authors: Cheng Jiongjia , Cashman John , Gomez-Galeno Jorge 
Published: September 2020

Abstract
Today, pancreatic cancer (PC) remains a major health problem in the US and soon will be the second most common cause of mortality due to cancer. However, most of the front-line PC chemotherapies cause serious side effects and a majority of patients with PC are often resistant to clinical therapies. The fact that cancer stem cells (CSCs) become enriched after anti-cancer therapy implicates CSCs as key contributors to tumor dormancy, metastasis, and relapse in PC. Given the important role of human pancreatic cancer stem cells (hPCSCs) in PC, development of a novel treatment strategy that targets hPCSCs or their extrinsic and intrinsic regulators could be of great clinical utility to treat PC. Herein, we used a highly validated hPCSCs model (FGβ3 cells) to test a novel compound (PAWI-2) to target CSCs. In this hPCSC model, integrin αvβ3 expression was shown to be a marker/functional contributor to CSC progression and drug resistance attributed to its ability to trigger anchorage-independent cell survival and tumor metastasis. Specifically, integrin αvβ3 recruits KRAS and RalB to tumor cell plasma membranes to activate NF-κB signaling that triggers dysregulated KRAS-RalB-NF-κB pathways. This was shown to be a pharmacological target to reverse CSC-like properties or re-sensitize drug resistance (e.g., EGFR inhibitors, erlotinib) of established FGβ3 tumors. Compared to parental FG cells, PAWI-2 showed greater potency to inhibit cell viability and self-renewal capacity of FGβ3 cells. PAWI-2 inhibited dysregulated integrin β3-KRAS-RalB-NF-κB signaling independent of KRAS and Ral. This is clinically relevant because &gt;90% of KRAS is activated by mutations in PC and RAS or Ral inhibitors have not proven effective clinically. PAWI-2 targeted downstream of KRAS signaling and was negatively regulated by other feedback mechanisms. This was further shown by genetic knockdown of key regulator and co-treatment of specific inhibitors. PAWI-2 overcomes erlotinib resistance in FGβ3 cells with greater potency than bortezomib. In the proposed mechanism of PAWI-2 action, key regulators link the inhibition of KRAS signaling and cell cycle arrest (G2/M). The great utility and pharmacological potency of PAWI-2 in FGβ3 cells (that possess stem-like properties) compared to FG cells provide a basis for further development. PAWI-2 as an efficient therapeutic to reverse tumor stemness and resensitize CSC tumors to drug inhibition.
This work was supported by Inception Award from California Institute for Regenerative Medicine (CIRM) (DISC1-10583; J.R. Cashman) and by funds from the Human BioMolecular Research Institute.
Citation Format: Jiongjia Cheng, John Cashman, Jorge Gomez-Galeno. PAWI-2 overcomes tumor stemness and drug resistance in pancreatic cancer stem cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 694.
Abstract 722: Urine for noninvasive liquid biopsy for germline and somatic mutations
Authors: Vowles James V. , Kim Amy K. , Hamilton James P. , Lin Selena Y. , Shieh Fwu-Shan , Luu Harry , Villafana Gabrielle , Hu Chi-Tan , Su Ying-Hsiu 
Published: September 2020

Abstract
Circulating tumor DNA (ctDNA) from blood and peripheral blood mononuclear cells (PBMCs) are used to determine comprehensive cancer genetics and germline genomics for precision medicine. To evaluate the use of urine samples as a noninvasive alternative to blood samples, we performed a comprehensive characterization of urine DNA as an alternative to PBMC DNA for germline genomics.
Whole genome sequencing (WGS) was performed in PBMC and total urine DNA in six normal subjects to compare the quality and comprehensiveness of the genomic data. There was no significant difference between the sequencing data obtained from PBMC and urine DNA upon comparing the variant calling, percent reads passing Phred score Q30 (p&gt;0.05, paired t-test), and coverage of human genome. Similar to plasma cfDNA, mononucleosomal-sized DNA was the most predominant species present in urine cfDNA. Samples from three hepatocellular carcinoma (HCC) patients were further analyzed for insert sizes by NGS, which demonstrated predominantly mononucleosomal-sized DNA fragments, with a series of peaks occurring with 10-bp periodicity, in both urine and plasma cfDNA. With shallow WGS, the genome coverage overlap was 53-61%, and by increasing the depth of coverage the overlap increased from 60% to 74%. Interestingly, 8-10% of the genome covered in plasma DNA was not detected in urine DNA, and 4-8% of the genome covered in urine DNA was not covered in plasma DNA.
Next, we compared the detectability of three HCC-associated genetic mutations in the matched urine and plasma DNA obtained from 76 HCC patients including mutations at TP53 codon 249 (TP53 249T), CTNNB1 exon 3 regions 32-37 (CTNNB1 32-37), and hTERT promoter region position 124 (hTERT 124). We observed higher levels of the TP53 mutation, similar levels of CTNNB1 mutation, and lower levels of the TERT mutation in urine cfDNA compared to plasma ctDNA. This suggests a potential for urine as a potential noninvasive source for ctDNA analysis, and a combination of both urine and plasma ctDNA may increase the overall sensitivity of ctDNA detection. In conclusion, our data suggest that (1) total urine DNA can replace PBMC DNA for providing comprehensive genomic sequencing data and (2) urine can complement blood for liver cancer liquid biopsy, precision medicine, and potential applications in other cancers.
Citation Format: James V. Vowles, Amy K. Kim, James P. Hamilton, Selena Y. Lin, Fwu-Shan Shieh, Harry Luu, Gabrielle Villafana, Chi-Tan Hu, Ying-Hsiu Su. Urine for noninvasive liquid biopsy for germline and somatic mutations [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 722.
Abstract 728: Early assessment of treatment effect in small cell lung cancer (SCLC) via ctDNA analysis
Authors: Jiang John , Ju Christine , Woestmann Corinna , Balasubramanyam Aarthi , Xi Liu , Yaung Stephanie J. , Gattam Sandeep , Hinzmann Bernd , Thomas Michael , Lasitschka Felix , Meister Michael , Schneider Marc , Herth Felix , Muley Thomas , Wehnl Birgit , Palma John 
Published: September 2020

Abstract
INTRODUCTION:
Quantifying circulating tumor DNA (ctDNA) is an emerging method to non-invasively assess treatment effect for solid tumors. A ctDNA-based method for disease monitoring for small cell lung cancer (SCLC) would be beneficial to disease management. By employing plasma taken during early treatment cycles and NGS, we tested whether early response assessed by ctDNA level could predict treatment effect.
METHODS:
Using a 197-gene NGS assay, the AVENIO ctDNA Surveillance Kit (for Research Use Only, not for use in diagnostic procedures), ctDNA levels were assessed in post-treatment plasma samples based on variants identified at baseline. Mutant allele concentration or mutant molecules per milliliter-of-plasma (MMPM) was utilized to quantify ctDNA over all variants of all sequenced genomic regions.
Samples collected from an observational German Lung Cancer Multi-Marker Study were analyzed retrospectively. In a cohort of 69 stage IV SCLC subjects, the association of survival with ctDNA-based monitoring classifier was evaluated in the first available post-treatment plasma sample after starting chemotherapy (median number of days after start of treatment = 25) by Kaplan-Meier methods and Cox proportional hazards model.
RESULTS:
The analysis demonstrated that subjects with mean MMPM less than the lower quartile (14.3) had longer progression free survival (PFS) compared to that of subjects with mean MMPM greater than or equal to the lower quartile (log-rank P = 0.0095; HR [95% CI] = 0.48 [0.27, 0.84]). The same classifier was applied for overall survival analysis, and subjects with mean MMPM less than the lower quartile had longer overall survival (OS) compared to that of subjects with mean MMPM greater than or equal to the lower quartile (log-rank P = 0.0095; HR [95% CI] = 0.46 [0.26, 0.84]).
CONCLUSIONS:
Changes in ctDNA levels in response to treatment may prove to be a valuable way of identifying subjects that either respond or fail to respond to therapy earlier than current standard of care methods such as computed tomography (CT) scan. Hypotheses will be validated in a separate cohort. Future prospective studies to confirm these results are needed.
Citation Format: John Jiang, Christine Ju, Corinna Woestmann, Aarthi Balasubramanyam, Liu Xi, Stephanie J. Yaung, Sandeep Gattam, Bernd Hinzmann, Michael Thomas, Felix Lasitschka, Michael Meister, Marc Schneider, Felix Herth, Thomas Muley, Birgit Wehnl, John Palma. Early assessment of treatment effect in small cell lung cancer (SCLC) via ctDNA analysis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 728.
Abstract 773: Tumor-derived Extracellular Vesicles (EVs) expressing TGFb as potential biomarkers for anti-TGFb antibody activity and drug activity in liquid biopsy
Authors: Nunes Manoel , Bernard Camille , Muzard Gaelle , Dos-Santos-Bele Wilson , Pollard Jack , Protopopov Alexei , Dib Colette 
Published: September 2020

Abstract
The field of liquid biopsies is of enormous interest in cancer using a noninvasive process. There are currently three major approaches: Circulating Cell Tumors (CTCs), circulating cell free DNA (cfDNA) and Extracellular Vesicles (EVs) such as exosomes, microvesicles and apoptotic bodies. The EVs are cell-derived small membrane vesicles secreted by cells that convey biological messages, either by surface-to-surface interaction or by shuttling bioactive molecules to a recipient cell's cytoplasm. The EVs released by cells harbor the cargos of their original cells and could be a good tool to follow drug activity.
We are developing anti-TGFβ antibody SAR439459 for the treatment of cancer (NCT03192345), and in this vitro study we explore the effect of anti-TGFβ antibody in EVs carrying TGFβ. The cargo of EVs were analyzed by an Elisa test for both latent and active free TGFβ and by miRNA expression.
Cell lines were selected based on their expression of TGFβ (A549, DU45, PC3, MCF7 and Caco2), treated for 72h and compared with respective untreated controls. The EVs were isolated from the supernatant and purified. Nanoparticle Tracking Analysis was used to quantify and determine size distribution of EVs. The expression of active free and latent TGFβ was done using Elisa tests. TGFβ antibody-coated magnetic beads were used to capture EVs, and miRNA expression sequencing was done using the Illumina NextSeq.
Anti-TGFβ treatment reduced notably the expression of latent TGFβ in the supernatant of cultured tumor cells; the active free TGFβ was very low expressed or not detected in the supernatants. EVs express both latent and active free TGFβ; the anti-TGFβ antibody treatment significantly reduced the active free TGFβ and altered miRNA expression in EVs. Finally, using TGFβ Antibody-coated magnetic beads, we demonstrate that intact EVs express TGFβ at their surface.
In conclusion, these results suggest that EVs express TGFβ at their surface and carry the active free TGFβ. Finally, the expression of active free TGFβ in EVs is decreased with anti-TGFβ antibody, suggesting that it might be a biomarker for monitoring anti-TGFβ antibody activity in patients by liquid biopsies.
Citation Format: Manoel Nunes, Camille Bernard, Gaelle Muzard, Wilson Dos-Santos-Bele, Jack Pollard, Alexei Protopopov, Colette Dib. Tumor-derived Extracellular Vesicles (EVs) expressing TGFb as potential biomarkers for anti-TGFb antibody activity and drug activity in liquid biopsy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 773.
Abstract 807: Predictive biomarkers for Bevacizumab activity in recurrent glioblastoma: A single institution study
Authors: Dragan Marcin , Carli Matthew , Malkin Mark , Yazbeck Victor 
Published: September 2020

Abstract
Glioblastoma Multiforme (GBM) is an aggressive type of astrocytoma and the most common malignant brain tumor in adults. Bevacizumab is a recombinant monoclonal antibody that targets VEGF-A. VEGF is regulated by the hypoxia-inducible-factor (HIF-1α) pathway, with the tumor suppressor gene TP53 as one of the key regulating factors. Our study examines the relevance of various genetic mutations of the HIF-1α pathway and their predictive significance in patients diagnosed with recurrent GBM and treated with bevacizumab. A total of 41 patients diagnosed with recurrent GBM and treated with Bevacizumab at Virginia Commonwealth University from January 1990 through November 2018 were included in our study. Our study cohort consists of 56.1% males and 43.9% females, with an average age of 59.9 (SD 12.1), and 68.3% were Caucasian. The majority (90%) of the cohort were classified as de novo cases of GBM. The overall survival (OS) was 172.5 days (95% CI: 122.0, 218.5), with a minimum of 11 days and maximum of 904 days measured from the date of the first bevacizumab treatment to the date of death. The majority of patients (70.7%) responded to treatment, with 61% exhibiting a partial response and 9.8% exhibiting a complete response. The median first response to treatment (FRT) was 34 days (95% CI: 21, 40), with a minimum of 2 days and maximum of 76. All patients died during the follow-up period. Survival analyses for OS, along with FRT, were both performed with Kaplan-Meier curves generated individually. We have examined the clinical characteristics of our study cohort and are currently examining the genetic characteristics of the tumors in our cohort. At the time of the conference we will have updated genomic and radiographic data in addition to the current detailed clinical data.
Citation Format: Marcin Dragan, Matthew Carli, Mark Malkin, Victor Yazbeck. Predictive biomarkers for Bevacizumab activity in recurrent glioblastoma: A single institution study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 807.