bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3075: Different roles of EPAC1 and EPAC2 in ovarian cancer: Implications for precision targeting in cancer therapy
Authors: Gao Zhengyin , Yuan Wanjun , Lee Leo T.O. 
Published: March 2024

Abstract
There are two distinct functional isoforms of Exchange proteins directly activated by cAMP (EPACs), EPAC1 and EPAC2, which exhibit fundamental distinctions in structure, expression patterns, signaling specificity, and subcellular localization. This diversity suggests that EPAC1 and EPAC2 can operate independently, synergistically, or antagonistically, contributing to the wide range of reported functions and impacts in different cancers and studies. We compared the function of EPAC1 and EPAC2 in ovarian cancer using in vitro and in vivo models and further explored the underlying mechanism in the regulation of metabolism reprogramming. Selective inhibition of EPAC1 and EPAC2 markedly reduced proliferation in ovarian cancer cell lines, leading to cell death and cycle arrest. RNA-seq analysis indicated different downstream signaling pathways triggered by EPAC1 and EPAC2, with EPAC2 specifically linked to functions in energy metabolism. Treatment with an antagonist or knockdown of EPAC2 resulted in attenuation of both glycolysis and oxidative phosphorylation (OXPHOS), while EPAC1 did not induce such effects. Furthermore, inhibition of EPAC2 induced mitochondrial dysfunction, manifested by reduced ATP production, decreased mitochondrial membrane potential, and increased burden of reactive oxygen species (ROS). Our data also revealed that EPAC2 governs the MAPK pathway and mediates the mitochondrial unfolded protein response (UPRmt) in ovarian cancer cells. By delineating the distinctions between EPAC1 and EPAC2 within ovarian cancer cells, this project revised the prevailing understanding of EPACs and suggests the potential for precise targeting of EPAC isoforms as a viable strategy in cancer therapy.
Citation Format: Zhengyin Gao, Wanjun Yuan, Leo T.O. Lee. Different roles of EPAC1 and EPAC2 in ovarian cancer: Implications for precision targeting in cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3075.
Abstract 3095: A high-throughput phenotypic screen to identify small molecule inhibitors of Werner helicase
Authors: Moomau Christine A. , Lu Yipin , Zhang Xiaobin , Zhai Xiang , Gu Lina , Sheng Qing , Li Fang , Chen Yaoyu 
Published: March 2024

Abstract
Werner helicase (WRN) is a RecQ DNA helicase involved in genome maintenance and DNA damage repair. It has recently been shown to be essential to cancer cells with high microsatellite instability (MSI-H). In MSI-H cancer cells, WRN depletion was shown to induce DNA damage and disrupt mitoses, resulting in a distinct phenotype of enlarged and fragmented nuclei. Here, we present a high-throughput phenotypic screen to identify compounds that selectively induce enlarged nuclei in MSI-H cancer cells. In HCT116, an MSI-H colorectal cancer cell line, approximately 40% of cells exhibited enlarged nuclei when WRN was depleted using siRNA. In contrast, fewer than 10% of control cells displayed this phenotype. In HT29, a microsatellite stable (MSS) cancer cell line, no such difference in nuclear morphology was observed, suggesting that the phenotype is specific to MSI-H cells. We used high content imaging to screen our in-house diversity library of approximately 175,000 compounds in 384-well format. 4,260 compounds induced enlarged nuclei in HCT116 cells, a 2.4% hit rate. After re-screening hits in HCT116 along with two additional MSI-H cancer cell lines, SW48 and SNU-407, and counter-screening in HT29 cells, 144 hits were confirmed to specifically enlarge nuclei in MSI-H but not MSS cells. Using the ADP-Glo Kinase Assay, two of these compounds were confirmed to inhibit WRN ATPase activity, suggesting WRN inhibition as a potential mechanism for their specific effects in MSI-H cells. This screen will also identify compounds which selectively kill MSI-H cells through mechanisms beyond direct inhibition of WRN, including interaction with WRN complex members or other members of DNA damage repair pathways. Validation studies including the assessment of cell viability and DNA damage in a panel of MSI-H and MSS cell lines will be performed. Our study proposes a phenotypic screening strategy for identifying small molecules with the potential to target WRN and uncover additional novel mechanisms for treating MSI-H cancers.
Citation Format: Christine A. Moomau, Yipin Lu, Xiaobin Zhang, Xiang Zhai, Lina Gu, Qing Sheng, Fang Li, Yaoyu Chen. A high-throughput phenotypic screen to identify small molecule inhibitors of Werner helicase [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3095.
Abstract 3109: Development of novel mono and bivalent nanobodies against EGFR for targeted cancer therapy
Authors: Cortes Diana C. Aguilar , Heitrich Mauro O. , Fernandez Marisa M. , Werbajh Santiago , Canziani Gabriela , Zylberman Vanesa , Malchiod Emilio L. , Podhajcer Osvaldo L. , Vinzón Sabrina E. 
Published: March 2024

Abstract
Introduction: The epidermal growth factor receptor (EGFR) plays a central role in the tumorigenesis of various solid tumors, rendering it a noteworthy target for cancer therapy. Nanobodies (Nbs) offer an appealing therapeutic approach due to their low immunogenicity, rapid clearance, and high targeting specificity. The aim of this study is to isolate, design, and characterize Nbs directed against EGFR.
Methods: The Nb library was constructed following llama immunization with cells overexpressing EGFR. After three rounds of panning the phage-display library (both in solid phase and solution), individual clones were screened for EGFR reactivity using ELISA against Virus-Like Particles. Positive clones were sequenced, cloned into an expression vector, and then purified by immobilized metal affinity chromatography (IMAC). The Nbs were characterized through immunofluorescence (IF), flow cytometry (FACS), and surface plasmon resonance (SPR). The most promising candidates were used to design bivalent constructs, which were subsequently characterized by SPR and in a cell proliferation assay.
Results: We successfully constructed an EGFR-targeted Nb library, which allowed the selection of multiple EGFR-specific Nbs following the optimization of the panning strategy. Two of the candidates exhibit strong binding to native EGFR in cells and outperform the gold standard anti-EGFR Nb 7D12. They demonstrate enhanced binding parameters in surface plasmon resonance (SPR) assays, with fast association and slow dissociation rates. The homo/heterodimeric bivalent constructs show improved affinity and the ability to inhibit cancer cell proliferation.
Conclusion: We were able to develop novel mono and bivalent nanobodies with enhanced binding properties which can be used for targeted cancer therapy.
Citation Format: Diana C. Aguilar Cortes, Mauro O. Heitrich, Marisa M. Fernandez, Santiago Werbajh, Gabriela Canziani, Vanesa Zylberman, Emilio L. Malchiod, Osvaldo L. Podhajcer, Sabrina E. Vinzón. Development of novel mono and bivalent nanobodies against EGFR for targeted cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3109.
Abstract 3113: Development of HTS enzymatic assays for WRN helicase and exonuclease functions
Authors: Pham Ha , Ali Mahbbat , Martinez Anibal Ramos , Lowery Robert 
Published: March 2024

Abstract
WRN, a double strand break repair enzyme with ATP-dependent DNA-helicase and 3’- &gt;5’ exonuclease activities, is under intense focus as a therapeutic target because of its synthetic lethality in tumors with microsatellite instability. To accelerate discovery of WRN inhibitors, we developed and validated homogenous, fluorescence-based high throughput assays for WRN helicase and exonuclease enzymatic activities using the Transcreener HTS Assay platform, which relies on highly selective antibodies to detect nucleotides in a homogenous (mix-and-read) format with far red fluorescent readouts. We produced the WRN helicase domain (aa 500-946, N-terminal 6xHis) in BaV-infected insect cells and optimized detection of its dsDNA-dependent ATPase activity using the Transcreener ADP2 Assay in FP, TR-FRET, and FI detection modes. Optimal reaction conditions included 50 μM ATP (approximate Km) and saturating concentration (100 nM) of a 3’ flapped duplex DNA oligomer; these conditions yielded a good signal with 250 pM WRN, a kcat of 300 min−1, and a Z’ of 0.85. An IC50 of 35 nM was determined for the probe inhibitor NSC-617145, and a 1,280 compound pilot screen (Tocris 2.0 Micro) identified multiple hits that were confirmed in dose response experiments. We produced the WRN 3’-5’ exonuclease domain (aa 1-133-6xHis) in E. coli and used the Transcreener dAMP Exonuclease Assay to allow direct, FP-based detection of dAMP monomers released from a 52 bp dsDNA oligomer with a 5’ overhang. With saturating DNA present (1 μM), the assay produced a good signal with 1 nM enzyme; the Z’ value was 0.89. There are no published inhibitors for the WRN exonuclease, but suramin inhibited with an IC50 of approximately 100 nM. These assays allow sensitive, robust, quantitative detection of WRN ATPase and exonuclease activities using an extensively validated HTS platform; they should be valuable tools for screening and optimizing small molecules targeting specific WRN functions.
Citation Format: Ha Pham, Mahbbat Ali, Anibal Ramos Martinez, Robert Lowery. Development of HTS enzymatic assays for WRN helicase and exonuclease functions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3113.
Abstract 3133: A novel bispecific antibody-drug conjugate targeting HER2 and Trop-2 displays potent antitumor activity in a variety of tumor models with promising preclinical characteristics
Authors: Zhong Haihong (Helen) , Xiong Yan , Huang Han , Pan Yuming , Wang Na , Sun Bin , Liu Shen , Yuan Wei , Liu Dingguo , Fang Jan , Bao Haifeng 
Published: March 2024

Abstract
Antibody-drug conjugates (ADCs) have exhibited considerable advancements in cancer therapy, though their efficacy is often confined to specific patient subsets or results in modest clinical responses due to low and heterogenous expression of drug targets in tumors. Targeting more than one tumor-associated antigens (TAAs) represents a new strategy to broaden treatment applicability and minimize on-target toxicity of ADC. Our analysis of co-expression of HER2 and Trop-2, two clinically validated ADC targets, in tumors of various histological malignancies manifests the great potential for an ADC simultaneously targeting these two antigens. We describe here a novel bispecific ADC (BIO-201) designed to co-target HER2 and Trop-2. This compound comprises a bispecific anti-HER2/Trop-2 antibody conjugated with a novel topoisomerase I inhibitor via a cleavable linker. BIO-201 demonstrates increased or comparable cell binding and internalization compared to parental antibodies. In in vitro cytotoxicity assays, BIO-201 effectively kills cancer cells with an IC50 in the sub nM range, irrespective of whether they co-express HER2 and Trop-2 or express only one antigen. Co-culture studies reveal that BIO-201 possesses a good bystander killing effect on drug target-negative tumor cells. In vivo studies further demonstrate the superior anti-tumor activity of BIO-201 in various tumor xenograft models, including those expressing different levels of HER2 and/or Trop-2, as well as models resistant to HER-2-targeting therapies. Moreover, BIO-201 exhibits favorable plasma stability, preclinical pharmacokinetics (PK), and toxicity profiles. In conclusion, these findings suggest that the anti-HER2/Trop-2 bispecific ADC, BIO-201, holds significant promise as an effective therapy for a diverse range of cancers, especially those expressing heterogenous levels of HER2 or Trop-2, and has the potential to benefit a broad patient population.
Citation Format: Haihong (Helen) Zhong, Yan Xiong, Han Huang, Yuming Pan, Na Wang, Bin Sun, Shen Liu, Wei Yuan, Dingguo Liu, Jan Fang, Haifeng Bao. A novel bispecific antibody-drug conjugate targeting HER2 and Trop-2 displays potent antitumor activity in a variety of tumor models with promising preclinical characteristics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3133.
Abstract 3274: Trefoil factor 1 suppresses stemness and enhances chemosensitivity of pancreatic cancer
Authors: Yamaguchi Junpei , Kokuryo Toshio , Yokoyama Yukihiro , Sunagawa Masaki , Baba Taisuke , Ebata Tomoki 
Published: March 2024

Abstract
Background and Aims: Pancreatic cancer is one of the most lethal malignancies, partly due to resistance to conventional chemotherapy. The chemoresistance of malignant tumors is associated with epithelial-mesenchymal transition (EMT) and the stemness of cancer cells. The aim of this study is to investigate the availability and functional mechanisms of trefoil factor family 1 (TFF1), a tumor-suppressive protein in pancreatic carcinogenesis, to treat pancreatic cancer.
Methods: To investigate the role of endogenous TFF1 in human and mice, specimens of human pancreatic cancer and genetically engineered mouse model of pancreatic cancer (KPC/TFF1KO; Pdx1-Cre/LSL-KRASG12D/LSL-p53R172H/TFF1−/−) were analyzed by immunohistochemistry (IHC). To explore the efficacy of extracellular administration of TFF1, recombinant and chemically synthesized TFF1 were administered to pancreatic cancer cell lines, a xenograft mouse model and a transgenic mouse model.
Results: The deficiency of TFF1 was associated with increased EMT markers of cancer cells (Snail and Zeb1) in mouse models of pancreatic cancer, KPC. Analysis of the survival of patients who underwent chemotherapy for recurrent pancreatic cancer revealed that the expression of TFF1 in cancer cells was associated with better survival. Also, in the mouse model of pancreatic cancer, KPC mice showed improved survival when treated with gemcitabine, the KPC/TFF1KO mice did not. Pancreatic cancer cell lines were administered with gemcitabine and/or chemically synthesized TFF1, revealing that addition of TFF1 downregulated gemcitabine-induced EMT markers (Snail, Slug, ZEB1, and αSMA), Wnt pathway activation (β-catenin, TCF7, and EPHB3). In addition, TFF1 inhibited the expression of cancer stemness markers (CD133 and NANOG3) and the ability to form tumor sphere. Importantly, TFF1 accelerated the apoptosis of cancer cells induced by gemcitabine in vitro. In vivo, combined treatment of gemcitabine and subcutaneous administration of TFF1 arrested tumor growth in xenograft mouse model. Also, KPC mice with combined treatment showed the better survival rather than gemcitabine-alone treatment, with lower expression of CD133, high expression of ZEB1, and lower nuclear translocation of β-catenin.
Conclusion: These results indicate that TFF1 can contribute to establishing a novel strategy to treat pancreatic cancer patients by enhancing chemosensitivity.
Citation Format: Junpei Yamaguchi, Toshio Kokuryo, Yukihiro Yokoyama, Masaki Sunagawa, Taisuke Baba, Tomoki Ebata. Trefoil factor 1 suppresses stemness and enhances chemosensitivity of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3274.
Abstract 3279: MUC1 is necessary for the inflammatory memory response to osimertinib resistance in NSCLC cells
Authors: Haratake Naoki , Bhattacharya Atrayee , Nakashoji Ayako , Ozawa Hiroki , Shimokawa Mototsugu , Kufe Donald 
Published: March 2024

Abstract
Emergence of resistance is an invariable outcome in cancer progression that may involve memory of cancer cells to treatment. The oncogenic MUC1-C protein confers pleotropic resistance of cancer cells to diverse cytotoxic and targeted agents by unclear mechanisms. We demonstrate that MUC1-C regulates the interferon (IFN) type I/II pathways in H1975 non-small cell lung cancer (NSCLC) cells selected for osimertinib resistance (H1975-OR). Targeting MUC1-C in H1975-OR cells suppressed STAT1 and inflammatory IFN signaling in association with reversing the osimertinib-resistant phenotype. Studies of H1975-OR cells selected for growth in the absence of osimertinib demonstrate that revertant H1975-RT cells retain MUC1-C-dependent memory necessary for recalling osimertinib resistance. Mechanistically, osimertinib treatment of H1975-RT cells activates the MUC1 gene at a (i) promoter-like signature (PLS) by MUC1-C and STAT1, and (ii) proximal enhancer-like signature (pELS) by PBAF and JUN/AP-1. Targeting MUC1-C in osimertinib-treated H1975-RT and MGH170 NSCLC MET-amplified cells isolated from a patient refractory to osimertinib treatment suppressed induction of STAT1 and downstream IFN-stimulated genes (ISGs) encoding MX1, OAS1 and ISG15. Targeting MUC1-C, STAT1, PBRM1/PBAF and JUN/AP-1 further confirmed their dependencies for reemergence of osimertinib resistance in H1975-RT and MGH170 cells. In support of these results, high MUC1-C protein expression analyzed by IHC is associated with shorter progression free survival for patients treated with osimertinib. These findings and the demonstration that MUC1-C is upregulated in NSCLC cells from patients refractory to osimertinib indicate that MUC1-C drives osimertinib resistance in NSCLC cells by promoting an inflammatory memory response.
Citation Format: Naoki Haratake, Atrayee Bhattacharya, Ayako Nakashoji, Hiroki Ozawa, Mototsugu Shimokawa, Donald Kufe. MUC1 is necessary for the inflammatory memory response to osimertinib resistance in NSCLC cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3279.
Abstract 3289: APOBEC3A drives tumor evolution through activation of ERVs in non small cell lung cancer
Authors: Isozaki Hideko , Sakhtemani Ramin , Nikpour Naveed , Monroe Susanna , Lawrence Michael , Hata Aaron 
Published: March 2024

Abstract
Acquired drug resistance to even the most effective anti-cancer targeted therapies remains an unsolved clinical problem. Although many drivers of acquired drug resistance have been identified, the underlying molecular mechanisms shaping tumor evolution during treatment are incompletely understood. We recently demonstrated that lung cancer targeted therapies commonly used in the clinic induce the expression of cytidine deaminase APOBEC3A (A3A), leading to sustained mutagenesis in drug-tolerant cancer cells persisting during therapy. Preventing therapy-induced A3A mutagenesis by gene deletion decreased the chromosomal aberration events and delayed the emergence of drug resistance. Thus, inhibition of A3A may represent a potential therapeutic strategy to prevent acquired resistance. Understanding the regulatory mechanisms of A3A may provide alternative approaches to inhibit A3A mutagenesis. Using a panel drug screen, we found that DNA methyltransferase (DNMT) inhibitor remarkably induces A3A in non-small cell lung cancer cells. RNA-seq profiling revealed that targeted therapy as well as DNMT inhibitor treatment activate expression of distinct classes non-coding repetitive RNA elements, including endogenous retrovirus (ERVs), in drug-tolerant persister cells. Activation of intracellular viral sensing pathways by introduction of exogenous nucleic acids mimicking viral elements induced A3A expression. While the transcription factor NFkB was acutely activated by targeted therapy, TBK1-IRF3 signaling was activated at later time points. These findings suggest that reactivation of ERVs may underlie A3A mutagenic activity and tumor evolution during targeted therapy.
Citation Format: Hideko Isozaki, Ramin Sakhtemani, Naveed Nikpour, Susanna Monroe, Michael Lawrence, Aaron Hata. APOBEC3A drives tumor evolution through activation of ERVs in non small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3289.
Abstract 3313: Discovery of a potent, selective, and orally available small molecule for disruption of the SOS1-RAS interaction
Authors: Ki Dong Hyuk , Yu Hana , Kim Donggeon , Jeon Yeejin , Jo Seongin , Nam Joonwoo , Kim Eun-Jung , Kim Sungeun , Choi Hunmi , Kim Jieun , Yu Jihyun , Choi Sungpil , Han Wooseok 
Published: March 2024

Abstract
KRAS mutations represent one of the most common genetic alterations in many cancers including non-small cell lung cancer (NSCLC), pancreatic ductal adenocarcinoma (PDAC), and colorectal cancer (CRC). While Sotorasib and Adagrasib, KRAS G12C inhibitors, have received approval, they exhibit limited responsiveness in clinical trials and are not applicable to various other KRAS mutation types. SOS1 (Son of Sevenless 1) functions as a guanine nucleotide exchange factor (GEF) on RAS, facilitating the transition of inactive GDP-bound RAS to its active GTP-bound state. In addition, SOS1 plays a pivotal role in negative feedback by actively contributing to the reactivation of ERK during treatment with inhibitors targeting the RTK/RAS/MAPK pathway. Inhibiting SOS1, which impedes the reactivation of ERK, has the potential to enhance the effectiveness of inhibitors targeting the RTK/RAS/MAPK signaling cascade and prevent the emergence of resistance mechanisms via H-RAS and N-RAS bypass pathways. Therefore, combining the inhibition of SOS1 with inhibitors targeting the RTK/RAS/MAPK pathway may enhance outcomes and mitigate relapse associated with observed resistances. Here, we present the discovery of a potent, selective, and orally bioavailable small molecule SOS1 inhibitor that effectively disrupts the interaction between SOS1 and RAS. It has demonstrated remarkable synergy effects with RTK/RAS/MAPK pathway inhibitors, significantly impeding the growth of tumors carrying KRAS or EGFR mutations in vivo. Overall, our development candidate has demonstrated significant therapeutic potential in combination with inhibitors targeting the RTK/RAS/MAPK pathway for cancers bearing activating mutations in this pathway.
Citation Format: Dong Hyuk Ki, Hana Yu, Donggeon Kim, Yeejin Jeon, Seongin Jo, Joonwoo Nam, Eun-Jung Kim, Sungeun Kim, Hunmi Choi, Jieun Kim, Jihyun Yu, Sungpil Choi, Wooseok Han. Discovery of a potent, selective, and orally available small molecule for disruption of the SOS1-RAS interaction [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3313.