bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 170: Development of diacylglycerol kinase assays to facilitate isoform specific inhibitor discovery
Authors: AbdulSalam Safnas F. , Eason Mia M. , Fowle Holly A. , Stuart Anna L. , Horiuchi Kurumi Y.
Published: June 2022

Diacylglycerol (DAG) and phosphatidic acid (PA) are two key second messengers in signaling and metabolic pathways. Diacylglycerol kinase (DGK) phosphorylate DAG to produce PA, acting as a central switch between the various signal transduction pathways activated by these second messengers. Ten DGK isoforms (α, β, γ, δ, ε, ζ, η, θ, ι, and κ) have been identified and categorized into five classes based on their structural features. DGKα is highly expressed in several cancers including hepatoma, lymphoma and melanoma, and has been shown to promote cancer survival by positively regulating proliferative activity through several signaling pathways, attracting interest to DGKα as a potential therapeutic target. DGKα and ζ are expressed at high levels in T cells, and shown to promote T cell anergy, pointing to inhibition of these DGK isoforms as a means of enhancing T cell anti-tumor activity and restoring T cells function. Several DGK isoforms have also been implicated in disease contexts such as hypertension, autoimmunity, type II diabetes, epilepsy, and bipolar disorder. Current DGK inhibitor discovery efforts are focused on DGKα and ζ, but to our knowledge no compounds have proceeded to clinical trial-to date. To facilitate these efforts, we have developed a DGK screening panel including compound profiling assays for all DGK isoforms. This is an essential tool for identification of potent and isoform selective inhibitors towards therapeutically relevant DGK isoforms. Further, we present kinetic characterization of all isoforms and lipid substrate specificity studies of DGKs.

Citation Format: Safnas F. AbdulSalam, Mia M. Eason, Holly A. Fowle, Anna L. Stuart, Kurumi Y. Horiuchi. Development of diacylglycerol kinase assays to facilitate isoform specific inhibitor discovery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 170.
Abstract 1726: Novel, high-throughput multiplexed immunofluorescence staining method for assessing spatial relationships of immuno-oncology biomarkers in whole slide FFPE tissue
Authors: Schaefer Rachel , Liu Linying , McLane Michael , Perez Oscar , Circelli Jacob , Coltharp Carla , Zheng Yi
Published: June 2022

As cancer research has progressed, the role of the immune system in tumor development has been discovered to be increasingly more important. There is a need to explore the spatial relationships between tumor and immune cells in tissue to help better predict therapeutic treatment outcomes in patients in the growing field of immuno-oncology. We have developed a new single cell multiplexed immunofluorescence staining method along with our patented multi-spectral imaging (MSI) technology to allow scientists to detect up to six biomarkers simultaneously on one tissue section, which provides an end-to-end, fully automated workflow from staining to image analysis. In this study, we show a methodology that allows primary antibodies to be applied as a single cocktail in one incubation step followed by amplified detections using Opal fluorescent dye technology. Formalin-fixed paraffin-embedded (FFPE) samples were stained on the Leica BOND RX࣪ automated staining system using our new multiplex procedure and compared to 3,3′-Diaminobenzidine (DAB) chromogenic immunohistochemistry assay. Multispectral scans were acquired on the Akoya Vectra Polaris® imaging system with optimized acquisition parameters. Image analysis was performed with a phenotyping algorithm in inForm® analysis software and intensity analysis was performed in R using phenoptr and phenoptrReports. The six multiplexed biomarkers are shown to be comparable in staining patterns to their DAB counterparts. Whole slide image scans were successfully unmixed and treated as individual monoplexes, but combined at will to observe the spatial relationships. This easy-to-use staining method simplifies tissue-based multiplex immunofluorescence by providing primary antibody cocktailing and cyclic deposition of fluorescent Opal dyes while maintaining strong staining intensity and the ability to spectrally unmix different wavelengths from the image for visualization and spatial analysis. This novel method will provide researchers with a flexible and readily available solution for staining patient samples to investigate spatial phenotypic signatures, aiding in the development of targeted immune therapies.

Citation Format: Rachel Schaefer, Linying Liu, Michael McLane, Oscar Perez, Jacob Circelli, Carla Coltharp, Yi Zheng. Novel, high-throughput multiplexed immunofluorescence staining method for assessing spatial relationships of immuno-oncology biomarkers in whole slide FFPE tissue [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1726.
Abstract 1728: Single cell RNA-seq analysis reveals a role of pro-inflammatory tumor-associated macrophages in driving prostate cancer progression
Authors: Zhao Jimmy L. , Chan Joseph , Land Max , Smith Perianne , Gopalan Anuradha , Haffner Michael , Pe'er Dana , Sawyers Charles
Published: June 2022

Genomic amplification and increased expression of C-MYC are found in high-grade intraepithelial neoplasm (HGPIN) and primary prostate adenocarcinoma. What role C-MYC plays in the initiation and progression of prostate cancer remains unclear. A genetically engineered mouse model with a high level of human C-MYC protein expression under a probasin promoter (Hi-Myc model) was developed that captures prostate cancer progression from hyperplasia at 6-week-old, to HGPIN at 3-6 month-old, and ultimately to invasive adenocarcinoma at 8-month-old. Applying single-cell RNA sequencing (scRNA-seq) technology, we have carefully studied the temporal transcriptional change in MYC-expressing tumor-initiating cells and the tumor-infiltrating immune cells to understand the cell-intrinsic and -extrinsic mechanisms by which C-MYC promotes the transition from HGPIN to invasive prostate cancer. We have identified a particular type of luminal cells, Prom1+ L1 cells, as the likely tumor initiating cells in the Hi-Myc model. The MYC-expressing L1 tumor initiating cells were more abundant and cycling more often in the invasive cancer at 8-month-old, compared to the pre-invasive stage. Interestingly, significant infiltration of novel M1-like tumor-associated macrophages (TAMs) correlated with the histologic tumor progression from HGPIN to invasive cancer. Targeting TAMs with anti-CSF1R antibody delayed prostate cancer progression and invasion, which appears to be independent of CD8 T-cells. Mechanistically, TAMs expressed a high level of IL-1b, which stimulated Hi-Myc prostate cell proliferation in an organoid co-culture system. More importantly, depleting IL-1b with a neutralizing antibody slowed prostate cancer progression in Hi-Myc mice. Lastly, we found that increased macrophage gene expression was associated with higher Gleason scores and worse disease-free survival in a TCGA clinical patient cohort. In summary, we have identified a molecular mechanism involving pro-inflammatory TAMs and IL-1b in driving early prostate cancer progression in a MYC-driven prostate cancer model, opening a potential therapeutic avenue to target TAMs and pro-inflammatory cytokine in preventing early prostate cancer progression.

Citation Format: Jimmy L. Zhao, Joseph Chan, Max Land, Perianne Smith, Anuradha Gopalan, Michael Haffner, Dana Pe'er, Charles Sawyers. Single cell RNA-seq analysis reveals a role of pro-inflammatory tumor-associated macrophages in driving prostate cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1728.
Abstract 1758: The preclinical pharmacology of PRO1102, a novel exatecan-based HER2-directed antibody-drug conjugate with robust anti-tumor activity
Authors: Wang Lei , Liu Haidong , Shang Xiao , Han Tae H. , Zhao Baiteng
Published: June 2022

PRO1102 is an antibody-drug conjugate (ADC) directed toward HER2, a validated protein target that is overexpressed in multiple cancers, including breast and gastrointestinal cancer. PRO1102 is comprised of 1) trastuzumab, a clinically and commercially validated HER2-directed antibody, 2) a cleavable, hydrophilic linker, and 3) exatecan, a topoisomerase 1 inhibitor. The mechanism of action and the clinical potential of PRO1102 was evaluated in a series of experiments. PRO1102 maintained the same binding attributes of the parent antibody, trastuzumab, in vitro. In mouse xenograft studies, PRO1102 demonstrated robust anti-tumor activity across multiple HER2-expressing cell lines that was generally better than ADCs with alternative drug-linker technologies, such as those associated with monomethyl auristatin E, mertansine (DM1) and deruxtecan. In addition, PRO1102 retained activity in cancer cells with moderate and low HER2 expression, suggesting the potential to benefit a broader range of patients of HER2-expressing cancers. The pharmacokinetics of PRO1102 was evaluated in rats and PRO1102 was stable in circulation with disposition similar to the parent antibody. Tolerability was evaluated in mice and at PRO1102 dose levels associated with robust anti-tumor activity, PRO1102 was well tolerated. PRO1102 exhibits the attributes needed for an effective ADC with robust activity in a broad selection of HER2-expressing cancers.

Citation Format: Lei Wang, Haidong Liu, Xiao Shang, Tae H. Han, Baiteng Zhao. The preclinical pharmacology of PRO1102, a novel exatecan-based HER2-directed antibody-drug conjugate with robust anti-tumor activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1758.
Abstract 1781: Up284, a novel inhibitor to treat quadruple negative breast cancer
Authors: Karanam Balasubramanyam , Yates Clayton , Anchoori Ravi
Published: June 2022

Quadruple negative breast cancer (QNBC), lacking the expression of ER (estrogen receptor), PR (progesterone receptor), HER2 (human epidermal growth factor receptor 2) and AR (androgen receptor), is the breast cancer subtype with the worst prognosis, and QNBC disproportionately afflicts African Americans. It has no standard-of-care treatment targets and thus efficacious and safe treatments are urgently sought for this unmet medical need, and to address the disparity in breast cancer outcomes. The current proposal is motivated by data showing elevated expression of proteasome subunit RPN13 is associated with both African American race and lower survival in QNBC patients, that RPN13 selectively targeted by a small molecule Up284 developed by Up Therapeutics. Both triple negative breast cancer and QNBC cell lines show evidence of greater vulnerability to proteasome inhibitors. However, licensed 20S proteasome inhibitors, e.g. bortezomib, have proven ineffective against solid tumors, with emergence of resistance, and dose limiting toxicities including thrombocytopenia and neutropenia. Up284 has a target and structure designed to overcome the limitations of the licensed drugs with respect to drug resistance. Up284 blocks substrate recognition and deubiquitination rather than just one of the three 20S catalytic activities), poor activity against solid tumors (Up284 has a novel spiro structure with evidence of improved drug access to tumor as compared to peptide-based 20S inhibitors), key toxicities of thrombocytopenia and neutropenia (unlike 20S inhibitors, Up284 does not target the immunoproteasome expressed by hematopoietic cells and does not show these toxicities). Up284 shows broad anticancer activity in vitro, including against QNBC lines with a robust therapeutic index, a promising safety profile and pharmacodynamics, and the ability to control xenograft tumor. By inhibiting proteasome ubiquitin receptor RPN13 function and its associated deubiquitinase activity, Up284 triggers more rapid accumulation and increased molecular weight polyubiquinated protein aggregates than is induced by 20S inhibitors. These toxic misfolded protein aggregates produce an unresolved ER stress, activate the canonical Unfolded Protein Response (UPR) signaling cascade and more rapidly triggers apoptosis than 20S inhibitor. The safety parameters and promising efficacy of Up284 against breast cancer lines encourages us to validate Up284 efficacy in more QNBC lines and animal models. We discuss Up284 efficacy and pharmacological analysis in our presentation.

Citation Format: Balasubramanyam Karanam, Clayton Yates, Ravi Anchoori. Up284, a novel inhibitor to treat quadruple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1781.
Abstract 1862: Naphthoquinone analogues inhibit Wnt/β-catenin signaling and colorectal cancer tumorigenesis
Authors: Hoyle Rosalie G. , Morris Andrew , Pagare Piyusha , Zaman Shadid Uz , Ma Zhikun , Zhang Yan , Li Jiong
Published: June 2022

In this study, we performed a structure-activity-relationship study of seven previously identified chloro-naphthoquinone analogs and evaluated their abilities to inhibit the Wnt/β-catenin signaling pathway. The Wnt/β-catenin signaling pathway plays essential roles in colorectal cancer (CRC) initiation, proliferation, and development. While targeting the Wnt/β-catenin pathway has been validated as a very promising approach for CRC treatment, developing a therapeutic for inhibition of this elusive pathway has been very challenging for researchers. Of the seven chloro-naphthoquinone analogues, we found that two compounds, Compound 3 and Compound 6, significantly inhibited Wnt target gene transcription and Wnt-induced colorectal tumorigenesis in vitro. Chromatin immunoprecipitation binding assays and computational modeling analysis revealed that Compound 3 and Compound 6 inhibit the Wnt/β-catenin pathway through disruption of the TCF4-DNA binding, a crucial step for the activation of the Wnt/β-catenin signaling pathway. Lastly, using a patient-derived organoid model and xenograft mouse model, we showed that these compounds inhibit CRC tumorigenesis. Taken together, this study demonstrates a novel mechanism of action for these chloro-naphthoquinone analogs, which can be further explored in future drug design and discovery efforts for small molecules targeting the TCF family proteins for inhibition of the Wnt/β-catenin signaling pathway.

Citation Format: Rosalie G. Hoyle, Andrew Morris, Piyusha Pagare, Shadid Uz Zaman, Zhikun Ma, Yan Zhang, Jiong Li. Naphthoquinone analogues inhibit Wnt/β-catenin signaling and colorectal cancer tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1862.
Abstract 1864: Baicalein attenuates endometrial cancer growth by suppressing the ARF6
Authors: Mcglorthan Latoya , Syed Viqar
Published: June 2022

Using mass spectrometry-based proteomics, we have previously shown enhanced expression of the Adenosine diphosphate-Ribosylation Factor-6 (ARF6) in endometrial cancer cell lines compared to immortalized EM-E6/E7-TERT endometrial epithelial cells. ARFs belong to the RAS superfamily of small GTPases. ARF family proteins are activated by Guanine nucleotide Exchange Factors (GEFs) and inactivated by GTPase-Activating Proteins (GAPs). When active, they bind effectors, which mediate downstream functions. ARF6 localized on the plasma membrane plays a role in actin cytoskeleton dynamics and endocytic recycling. Dysregulation of expression and/or activity of ARF6 has been associated with enhanced cell migration, invasion, and proliferation in several types of cancer. Knockdown of ARF6 significantly inhibited the invasiveness of the cancer cells. There is a critical need for novel promising anticancer agents with lesser side effects and higher efficacy. Baicalein, extracted from the roots of the Chinese herb Huang Qin (Scutellaria baicalensis), showed a significant anticancer impact on many human cancers. However, the specific molecular mechanisms are still nebulous. Endometrial cancer cell lines were exposed to different concentrations of baicalein for 24 to 120 h. The effect on cell proliferation and invasion was determined utilizing MTS and Boyden chamber assays, respectively. The baicalein induced a dose and time-dependent reduction in cell viability. The invasiveness of cells was attenuated by baicalein. Furthermore, the anticancer effects were mediated by decreased ARF6, Rac1, and PAK1 expression in baicalein-treated cancer cells. In summary, the data reveal that suppression of ARF6 could reduce the invasive potential of endometrial cancer by modulating the major downstream effectors Rac1 and PAK1.

Citation Format: Latoya Mcglorthan, Viqar Syed. Baicalein attenuates endometrial cancer growth by suppressing the ARF6 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1864.
Abstract 195: A focused ultrasound blood brain barrier disruption model to test the influence of tight junction genes to treat brain tumors
Authors: Iyer Jayashree , Akkad Adam , Tang Nanyun , Peng Sen , Berens Michael , Zenhausern Frederic , Gu Jian
Published: June 2022

A major hindrance to advances in the care of patients with malignant gliomas is the presence of the blood brain barrier (BBB) and blood-brain tumor barrier (BBTB) that greatly restricts drug access from the plasma to the tumor cells. Bubble-assisted Focused Ultrasound (BAFUS) has proven effective in opening the BBB for treatment of glial tumors in adults and pediatric cases. BAFUS has been previously shown to disrupt noninvasively, selectively, and transiently the BBB in small animals in vivo. However, there is a lack of an in vitro preclinical model suitable for testing the genetic determinants of endothelial cell tight junction integrity and vulnerability to the physical disruption. Our BBB organ-on-chip platform will enable precision medicine of brain cancers through identifying patient-specific parameters by which to open the BBB allowing use of drugs and drug combinations otherwise unsuitable. We intend to sequence these in vitro models to verify that the genotype (alleles/SNPs) of tight junction proteins contribute to BBB structure and integrity. To initiate this effort, we report the development of an ultrasound transparent organ-on-chip model populated by iPSC-derived endothelial cells (iPSC-EC) co-cultured with astrocytes. Western blot, immunocytochemistry, permeability, and transelectrical endothelial resistance (TEER) studies all convey expression of key EC proteins and marked barrier integrity. Further benchmarking of device-ultrasound interactions, successful iPSC differentiation, tight junction formation, and fabrication of nanobubbles and their assistance in ultrasound BBB disruption will be presented. Efforts are underway to analyze nine characteristic BBB tight junction genes from WGS data to determine associations between iPSC-EC genotype and phenotype.

Citation Format: Jayashree Iyer, Adam Akkad, Nanyun Tang, Sen Peng, Michael Berens, Frederic Zenhausern, Jian Gu. A focused ultrasound blood brain barrier disruption model to test the influence of tight junction genes to treat brain tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 195.
Abstract 2035: Imaging mass cytometry identifies structural and cellular composition of the mouse tissue microenvironment
Authors: Raza Qanber , Cohen Michael , Kala Smriti , Lim Liang , Awong Geneve , Quong Andrew , Loh Christina
Published: June 2022

Imaging Mass Cytometry™ (IMC™) is a vital tool to deeply characterize the complexity and diversity of any tissue without disrupting spatial context. The Hyperion™ Imaging System utilizes IMC, based on CyTOF® technology, to simultaneously assess up to 40 individual structural and functional markers in tissues, providing unprecedented insight into the organization and function of tissue microenvironment. We have previously demonstrated the application of IMC in combination with Maxpar® panel kits to highlight cellular composition of human tissues. Here, we showcase the recently released Maxpar OnDemand Antibodies for IMC application on mouse tissue. We introduced 11 additional biomarkers to our existing mouse antibody catalog, providing the basis for the use of high-multiplex imaging in preclinical investigations. To demonstrate the IMC workflow on mouse tissue, we analyzed a normal mouse tissue microarray using IMC spatial proteomic analysis. Tissues were stained with a 20-marker panel designed to highlight tissue architecture and major immune lineage markers combined with our IMC Cell Segmentation Kit*. The IMC Cell Segmentation Kit facilitates identification of cellular borders using plasma membrane markers that lead to improved nucleus and plasma membrane demarcation. We generated a detailed spatial map of the heterogeneous tissue architecture and successfully identified immune, epithelial, and stromal cell populations in various mouse tissues. Additionally, we classified the activation state of immune cell populations, adhesion state of epithelial cells, and molecular composition of the extracellular matrix.Overall, this work demonstrates the capability of IMC to identify subcellular localization of cellular and structural markers in the mouse tissue microenvironment. Information gained from IMC studies will enable in-depth high-throughput phenotypic characterization of the tissue microenvironment in various mouse models of development and disease, and thus accelerate preclinical discoveries.

*The IMC Cell Segmentation Kit is part of the Innovative Solutions menu of custom-made reagents and workflows developed and tested by Fluidigm scientists to give faster access to new cutting-edge solutions for high-multiplex single-cell analysis. Innovative Solutions are not part of the Maxpar catalog.

For Research Use Only. Not for use in diagnostic procedures.

Citation Format: Qanber Raza, Michael Cohen, Smriti Kala, Liang Lim, Geneve Awong, Andrew Quong, Christina Loh. Imaging mass cytometry identifies structural and cellular composition of the mouse tissue microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2035.
Abstract 2044: The target antigen determines the mechanism of acquired resistance to T cell based therapies
Authors: Martínez-Sabadell Alex , Morancho Beatriz , Rius Irene , Escorihuela Marta , Luque Antonio , Chicote Irene , Palmer Hector García , Bacac Marina , Arribas Joaquin , Lahuerta Enrique Javier Arenas
Published: June 2022

Introduction: Immunotherapy has revolutionized the way many cancers are treated. Despite its success, cancer patients eventually progress due to the emergence of resistance. In this scenario, the selection of the tumor antigen is important and can be decisive in the success of the clinical response, particularly when resistance emerge. T cell bispecific antibodies (TCBs) are engineered molecules that include, within a single entity, binding sites to the T cell receptor and to a tumor-specific or a tumor-associated antigen. It is assumed that, as all TCBs have the same mechanism of action, mechanisms of resistance are independent of the tumor antigen.

Objective: This study was designed to identify the mechanisms that trigger the resistance against HER2 and CEACAM5 T cell bispecific antibodies. We assessed TCB sensitivity using in vitro and in vivo assays combining human cell lines or patient-derived models with human lymphocytes.

Material and Methods: Using gastric CEA+/HER2+ MKN45 cells as a model and TCBs directed against CEA or HER2, here we show for the first time that the mechanism of resistance to a T cell-based therapy is dependent on the tumor antigen.

Results: Acquired resistant models to a high-affinity CEA-targeted TCB exhibit a reduction of CEA antigen levels due to epigenetic transcriptional silencing, which is reversible upon 5-AZA treatment. In contrast, a HER2-TCB resistant model maintains HER2 levels as HER2 downregulation led to an impairment of proliferation. Furthermore, using this latter model, we identified that disruption of interferon- gamma signaling confers resistance to killing by active T lymphocytes.

Conclusions: Our results unveil different mechanisms of acquired resistance to TCBs depending on the selected antigen, which will help in the design of combinatorial strategies to increase the efficacy of cancer immunotherapies and to anticipate and overcome resistances.

Citation Format: Alex Martínez-Sabadell, Beatriz Morancho, Irene Rius, Marta Escorihuela, Antonio Luque, Irene Chicote, Hector García Palmer, Marina Bacac, Joaquin Arribas, Enrique Javier Arenas Lahuerta. The target antigen determines the mechanism of acquired resistance to T cell based therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2044.
Abstract 2056: PI3Kgamma inhibition reduces inflammation and promotes survival in cancer and SARS-CoV-2
Authors: Varner Judith A. , Ghebremedhin Anghesom
Published: June 2022

Solid tumors are characterized by extensive immune suppressive inflammation, vascular leak, fibrosis and organ damage. Similarly, SARS-CoV-2 infections induce aberrant pulmonary and systemic inflammation, vascular leak, coagulation, fibrosis and fatal organ damage. We previously demonstrated that macrophages in solid tumors strongly expressed phosphatidylinositol 3-kinase gamma (PI3Kγ), a signaling protein that coordinately controls granulocyte and monocyte trafficking to tumors as well as wound-healing-type macrophage transcription in cancer and fibrosis. We also observed that macrophages in COVID-19 lungs strongly expressed PI3Kγ. To identify therapeutic strategies to suppress COVID-19-associated inflammation, we characterized lung tissue of COVID-19 patients using multiplex immunohistochemistry and tissue transcriptomics. Lungs of deceased patients exhibited substantial infiltration by neutrophils and wound-healing macrophages, fibrosis and alveolar type II cell depletion. In animal models of lung inflammation, bacterial infections, viral infection and SARS-CoV-2 infection, PI3Kγ deletion or inhibition with the cancer therapeutic IPI-549 (eganelisib) suppressed pulmonary and systemic inflammation, reduced lung damage, and promoted survival. These studies demonstrate the essential role of PI3Kγ in inflammatory diseases as well as cancer and support the use of PI3Kγ inhibitors such as eganelisib to suppress inflammation and promote survival in pulmonary infections like SARS-CoV-2 and cancer.

Citation Format: Judith A. Varner, Anghesom Ghebremedhin. PI3Kgamma inhibition reduces inflammation and promotes survival in cancer and SARS-CoV-2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2056.
Abstract 2073: Childhood vaccine-specific CD4+T cell recall coordinates antitumor type I and II immunity
Authors: Brown Michael Clavon , Mckay Zachary P. , Yang Yuanfan , Bigner Darell D. , Nair Smita K. , Gromeier Matthias
Published: June 2022

A recombinant poliovirus (rPV) derived from the live-attenuated Sabin oral polio vaccine strain, is being tested in multi-institutional phase II clinical trials for recurrent glioblastoma (NCT04479241); unresectable, anti-PD-1 refractory melanoma (NCT04577807); and bladder cancer and head and neck squamous cell carcinomas (NCT04690699) in combination with PD-1/PD-L1 blockade. rPV capsid is identical to that of childhood polio vaccines, against which public health mandated vaccination is near universal. In non-vaccinated mice, rPV mediates antitumor efficacy in a replication-dependent manner via engaging innate inflammation and antitumor T cells. Accordingly, it was anticipated that pre-existing immunity to rPV impedes antitumor therapy.

Strikingly, despite curtailing intratumor viral replication, prior polio vaccination in mice substantially bolstered the antitumor efficacy of rPV relative to mice vaccinated with a control antigen (KLH). Intratumor recall responses induced by polio and tetanus antigens also delayed tumor growth. Recall antigen therapy was associated with marked intratumor influx of eosinophils, PD1 and Granzyme B expressing type 2 innate lymphoid cells (ILC2s), conventional CD4+ T cells, and increased expression of IFN-γ, TNF, and Granzyme B in tumor infiltrating T cells. The antitumor efficacy of polio recall antigen was mediated by CD4+ T cells, partially depended upon both CD8+ T cells and eosinophils, and was independent of B cells. Intratumor polio and tetanus recall antigen therapy bolstered the antitumor function of tumor-specific OT-I CD8+ T cells, indicating that intratumor CD4+ T cell recall provides help to antitumor CD8+ T cells. Recall antigen therapy complemented antitumor effects of immune checkpoint blockade and innate stimulating immunotherapy.

This work reveals that childhood vaccine-specific CD4+ T cells hold cancer immunotherapy potential and represent a novel mechanism to simultaneously engage both type I and II antitumor immunity.

Citation Format: Michael Clavon Brown, Zachary P. Mckay, Yuanfan Yang, Darell D. Bigner, Smita K. Nair, Matthias Gromeier. Childhood vaccine-specific CD4+T cell recall coordinates antitumor type I and II immunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2073.
Abstract 2134: Discovery and structure activity relationships of BAY 2666605: PDE3A-SLFN12 complex inducer for cancer therapy
Authors: Gradl Stefan
Published: June 2022

Velcrin compounds are small molecules which act as molecular glues to form a PDE3A-SLFN12 complex. This complex formation induces apoptosis in cancer cells expressing elevated levels of PDE3A and SLFN12 (de Waal et al., Nat Chem Biol 2016; Wu et al., J Bio Chem 2020). Unlike traditional targeted therapies that leverage dependencies created by genomic alterations in cancer cells, velcrins instead kill cancer cells by a gain-of-function mechanism dependent on stimulation of SLFN12 RNase activity by complex formation with PDE3A (Garvie et al., Nat Commun 2021).

Based on in-vivo tool compounds which were discovered by hit-to-lead optimization from a phenotypic screen (Lewis et al., ACS Med Chem Lett 2019), the team set out to optimize the properties of the tool compounds. While already showing excellent potency and in-vivo efficacy in various tumor models, the compounds were only approximately tenfold selective against PDE3A when compared to their cell killing activity. PDE3A/B activity most notably influences cardiohemodynamics and inhibition of PDE3A/B was to be reduced to generate a larger safety window. Co-crystallization of analogs with PDE3A showed the binding mode of the velcrin class and changes in the solvent exposed region of the PDE3A binders led to steep activity changes in complex formation and cell killing. Careful optimization of the ratio of cell killing to PDE3A activity while optimizing DMPK and safety pharmacology led to the discovery of BAY 2666605.

BAY 2666605 has recently entered a First-in-Human study (NCT04809805) in patients with advanced solid tumors that co-express PDE3A and SLFN12, including melanoma, ovarian cancer, and sarcoma. We will discuss the discovery and structure activity relationships of BAY 2666605.

Citation Format: Stefan Gradl. Discovery and structure activity relationships of BAY 2666605: PDE3A-SLFN12 complex inducer for cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2134.
Abstract 2153: ATR inhibition augments the efficacy of the lurbinectedin in small cell lung cancer
Authors: Schultz Christopher William , Zhang Yang , Fu Haiqing , Murai Yasuhisa , Wangsa Darawalee , Atkinson Devon , Saha Liton , Elenbaas Brian , Lee Chien-Fei , Zimmerman Astrid , Ried Thomas , Zenke Frank , Weaver Zoe , Elmeskini Rajaa , Pommier Yves , Thomas Anish
Published: June 2022

Small cell lung cancer (SCLC) is a recalcitrant disease with only a 9% five-year survival rate. SCLCs display intertumoral heterogeneity; high neuroendocrine (NE) tumors evolve with treatment and time in a largely MYC driven manner to a chemotherapy resistant non-NE state. Lurbinectedin, an RNA Pol-II inhibitor which causes DNA damage through binding ERCC5 was approved as second line therapy in 2020, with an overall response rate of 35% in patients with relapsed SCLC. However, these responses are short-lived and the majority of patient still succumb to their disease. A trial testing the combination of lurbinectedin and doxorubicin failed to improve survival compared with standard-of-care. We assessed lurbinectedin in combination with 43 other agents in SCLC cells. The top synergistic hit was the clinically relevant ATR inhibitor berzosertib which was 4-fold more synergistic than doxorubicin. Compared with lurbinectedin alone, the combination with berzosertib caused a 3.5-fold increase in DNA damage while significantly reducing the ability of cells to sense this damage by inhibiting γH2AX induction. This led to continued DNA replication even in the presence of lurbinectedin induced DNA damage, causing mitotic catastrophe and cell death. The combination was highly synergistic in 6 of 9 SCLC cell lines tested. Synergy was inversely correlated with p21 RNA and protein expression. The canonical role of p21 is to inhibit G1/S transition, and we found that thymidine induced G1 arrest inhibited synergy, while p21 knock-down increased the synergy. Interestingly, we observed synergy was inversely correlated with NE differentiation. In a high NE high p21 mouse model of SCLC, lurbinectedin alone was highly effective, with the combination showing little improvement. Conversely in a non-NE low p21 mouse model, lurbinectedin treatment alone was less effective, however the addition of berzosertib was synergistic and significantly improved efficacy. Overall, this work demonstrated berzosertib augments lurbinectedin efficacy in the recalcitrant non-NE SCLC subsets, and supported the development of a clinical trial testing lurbinectedin and berzosertib in SCLC patients NCT04802174.

Citation Format: Christopher William Schultz, Yang Zhang, Haiqing Fu, Yasuhisa Murai, Darawalee Wangsa, Devon Atkinson, Liton Saha, Brian Elenbaas, Chien-Fei Lee, Astrid Zimmerman, Thomas Ried, Frank Zenke, Zoe Weaver, Rajaa Elmeskini, Yves Pommier, Anish Thomas. ATR inhibition augments the efficacy of the lurbinectedin in small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2153.
Abstract 2174: Sirpiglenastat (DRP-104), a novel broad acting glutamine antagonist, has therapeutic potential in targeting KEAP1-mutant lung cancer
Authors: LeBoeuf Sarah , Pillai Ray , Huang Shih Ming , Karakousi Triantafyllia , Wu Warren , Sayin Volkan , Wild Robert , Papagiannakopoulos Thales
Published: June 2022

Treating KRAS mutant lung adenocarcinoma (LUAD) remains a major challenge for clinical oncology. Approximately 20% of KRASmutant LUAD tumors carry loss-of-function mutations in KEAP1, a negative regulator of NRF2, which is the master transcriptional regulator of the endogenous antioxidant response. Emerging clinical studies demonstrate that KEAP1-mutant tumors are refractory to standard-of-care chemotherapy, immunotherapy, radiation and more recently KRASG12C inhibitors. Using a genetically engineered mouse model of KRAS-driven LUAD we demonstrated that loss of Keap1 hyper-activates Nrf2 and accelerates KRAS-driven LUAD. We observe that the ability of KEAP1 mutant tumors to divert their metabolism towards antioxidant production comes with a cost, generating multiple metabolic vulnerabilities, including a dependency on glutamine metabolism that can be therapeutically exploited through the pharmacological inhibition of glutaminase and other glutamine metabolizing enzymes. Using sirpiglenastat (DRP-104), a novel broad acting glutamine antagonist which inhibits all glutamine-consuming reactions, we demonstrate robust anti-tumor efficacy in multiple mouse and human pre-clinical KEAP1-mutant NSCLC models. Furthermore, we have characterized the metabolic mechanisms underlying DRP-104 sensitivity. Our studies demonstrate that DRP-104 has a distinct and broader mechanism of action compared to glutaminase selective inhibition, suggesting broader inhibition of glutamine metabolism may be a more effective therapeutic approach against KEAP1-mutant tumors. We have recently demonstrated that KEAP1-mutant tumors evade anti-tumor immune responses and do not respond to immune checkpoint blockade, which is also supported by clinical observations. We are currently assessing whether DRP-104 is able to promote anti-tumor immune responses as a single agent or in combination with immune checkpoint blockade in KEAP1-mutant tumors. Our studies will provide a rationale for sub-stratification of KEAP1-mutant patients with hyperactivation of the NRF2 pathway, which is a genetic subset of NSCLC with great clinical need, as treatment candidates for sirpiglenastat. A first-in-human clinical trial of sirpiglenastat (DRP-104) is currently ongoing and will further explore this hypothesis in a LUAD cohort (NCT04471415).

Citation Format: Sarah LeBoeuf, Ray Pillai, Shih Ming Huang, Triantafyllia Karakousi, Warren Wu, Volkan Sayin, Robert Wild, Thales Papagiannakopoulos. Sirpiglenastat (DRP-104), a novel broad acting glutamine antagonist, has therapeutic potential in targeting KEAP1-mutant lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2174.
Abstract 2226: Using functional biomarkers to accurately predict advanced neoplasia in pancreatic cystic lesions
Authors: Caiazza Francesco , Lourenco Andre , Conroy Patricia , Hoffmann Thomas , Ivry Sam L. , York Tyler , Zhu Gina , Mustoe Audrey , O'Donoghue Anthony J. , Craik Charles S. , Kirkwood Kimberly
Published: June 2022

Background: The accurate identification of high-grade dysplasia (HGD) or invasive cancer (advanced neoplasia, AN) in pancreatic cystic lesions (PCLs) is needed to identify PCLs that warrant surgical intervention. Cytologic evaluation of cyst fluid is widely-used but has poor sensitivity. We previously found that activity of the lysosomal serine protease tripeptidyl peptidase 1 (TPP1) is associated with mucinous PCLs that harbor AN (AUC 0.72). We aimed to identify additional functional biomarkers that would improve performance of our classifier for dysplastic grade in mucinous PCLs.

Methods: We used a combination of global protease activity profiling and shotgun proteomics to identify differentiating markers between PCLs with low-grade dysplasia (LGD, n=3) and HGD (n=3). Candidate biomarkers were validated in an independent cohort of 28 clinically-annotated mucinous PCLs (HGD n=12, LGD n=16), by measuring both protein concentration (using ELISA) and enzymatic activity (using internally-quenched fluorescent substrates). We used a nested cross-validation approach to iteratively split our cohort into training and validation sets to predict HGD. Model accuracy was evaluated using area under the curve (AUC), sensitivity, specificity, and accuracy.

Results: We identified 8 proteins that were highly abundant in mucinous PCLs with HGD. Among these were the inflammatory enzymes myeloperoxidase (MPO) and neutrophil elastase (ELANE), suggesting that differential activity levels could be exploited that would minimize fluid requirements and cost. Among 28 mucinous PCLs, a composite score that included both activity and mass of MPO performed the best for HGD in mucinous cysts (AUC 0.955, sensitivity 98%, specificity 93%). ELANE activity (AUC 0.76, sensitivity 69%, specificity 59%) and TPP1 activity (AUC 0.765, sensitivity 71%, specificity 74%) had modest performance.

Conclusions: Our functional biomarkers accurately classified HGD among mucinous cysts. Functional biomarkers that require low sample volumes (<10μl) of cyst fluid have the potential to substantially improve clinical decision-making for patients with PCLs.

Citation Format: Francesco Caiazza, Andre Lourenco, Patricia Conroy, Thomas Hoffmann, Sam L. Ivry, Tyler York, Gina Zhu, Audrey Mustoe, Anthony J. O'Donoghue, Charles S. Craik, Kimberly Kirkwood. Using functional biomarkers to accurately predict advanced neoplasia in pancreatic cystic lesions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2226.
Abstract 2242: Impact of low-dose computed tomography screening for lung cancer at a community oncology clinic on stage of lung cancer diagnosis in the catchment area
Authors: Ellis Edgar T. , Bauer Michael A. , Beck Thaddeus , Bradford Daniel S. , Thompson Joanna , Kulik Margarete C. , Su Joseph L.
Published: June 2022

Introduction: Arkansas has the second-highest incidence of lung cancer in the U.S., with a largely rural and medically underserved population. Low-dose computed tomography (LDCT) is a well-established procedure for lung cancer screening in academic medical centers, but few local community oncology centers utilize this technology. Highlands Oncology Group (HOG), located in Northwest Arkansas (NWA), took the initiative to bring LDCT screening to a non-academic medical center and provide routine LDCT screening to a rural population. The objective of this study is to evaluate the benefits of free LDCT screening at a community oncology clinic.

Methods: The study compared for-fee and free periods of LDCT screening at HOG and their impact on identifying cancer in NWA. The study population was patients in HOG’s catchment area who fell into the risk categories set by the National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology to be eligible for screening between March 2013 and February 2020.

Results: A total of 5,402 eligible participants enrolled in the study. During ten months of for-fee screening (n=60), 3.3% of patients diagnosed had Stage I lung cancer, and 1.7% were diagnosed with Stages II-IV. During the first ten months of free screening (n=729), 3% of patients were diagnosed with Stage I lung cancer, 1.8% were diagnosed with Stages II-IV, and 1.1% were diagnosed with other cancers. Over the entire program until February 2020 (n=5,402), a total of 76 patients were diagnosed with Stage I lung cancer, 52 were diagnosed with Stage II-IV, and 35 were diagnosed with other cancers.

Conclusion: The result of this study suggests that eligible patients are more receptive to free lung cancer screening, even though most insurance coverage does not have a required co-pay for eligible patients. We also observed an increased diagnosis rate for early-stage lung cancers due to increased patient influx with free LDCT screening. The state central registry data showed a decline in distant lung cancer after the free LDCT screening offered in the northwestern counties in the HOG catchment area. At the same time, no such trend is visible for the entire state, suggesting a stage shift in lung cancer due to free LDCT screening.

Citation Format: Edgar T. Ellis, Michael A. Bauer, Thaddeus Beck, Daniel S. Bradford, Joanna Thompson, Margarete C. Kulik, Joseph L. Su. Impact of low-dose computed tomography screening for lung cancer at a community oncology clinic on stage of lung cancer diagnosis in the catchment area [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2242.
Abstract 2243: Diagnostic journey following a multi-cancer early detection test: A retrospective case series of gastrointestinal cancers in the PATHFINDER study
Authors: McDonnell Charles H. , Hudnut Andrew , Jacobs Debbie A. , Ogilvie Patrick D. , Bobolis Kristie A.
Published: June 2022

Introduction: Gastrointestinal (GI) cancers are common, but with the exception of colorectal cancer, are not amenable to population screening. A blood-based multi-cancer early detection (MCED) test is available for use as a complement to existing single cancer screening modalities, however experience deploying such tests is limited. PATHFINDER (NCT04241796; enrollment complete, n=6662) is an ongoing prospective study in asymptomatic adults ≥50 y that returns MCED test results (‘signal not detected’ or ‘signal detected’) with ≥1 cancer signal origin (CSO) prediction to direct diagnostic workup. To better understand challenges and opportunities following a signal detected result, GI case studies are presented.

Methods: Participants who were confirmed with a new Clinical Stage I/II GI cancer from the interim PATHFINDER data set (data cutoff Mar-19-2021) were included. Data were reviewed, and key diagnostic steps from signal detected (Day 1) to resolution were summarized.

Results: Individual 1 was a female >60 y without additional cancer risk factors (CSO=Colon/Rectum, Upper GI Tract). CT abdomen was performed, followed by colonoscopy then upper endoscopy. A 4.0 cm mass identified was further evaluated via endoscopic ultrasound with biopsy and confirmed a Clinical Stage I duodenal adenocarcinoma (Day 60), which was treated with surgery (Pathologic Stage III) and adjuvant chemotherapy. Patient tolerated the treatment and remains disease free. Individual 2 was a male former smoker >65 y with a history of hepatitis C (CSO=Liver/Bile-duct); CT confirmed cirrhotic liver with 6.4cm LI-RADS 5 mass at Day 57 (Clinical Stage Ib). Treatment was declined following surgical referral and participant died <9 months post-test result. Individual 3 was a male former smoker >70 y (CSO=Pancreas/Gallbladder, Lung). Work-up included metabolic panel, CA19-9, CT abdomen and chest, and PET-CT. A CT-guided core biopsy confirmed diagnosis of a Clinical Stage IIb resectable pancreatic adenocarcinoma on Day 38; surgery (Pathologic Stage IIa) and adjuvant chemotherapy followed; patient is disease free to date.

Conclusions: The MCED test detected cancer signals and predicted a GI CSO for three individuals with Clinical Stage I or II GI cancers for which there is currently no single early cancer screening method. All three achieved diagnostic resolution within 2 months and were provided treatment recommendations with curative intent.

Citation Format: Charles H. McDonnell III, Andrew Hudnut, Debbie A. Jacobs, Patrick D. Ogilvie, Kristie A. Bobolis. Diagnostic journey following a multi-cancer early detection test: A retrospective case series of gastrointestinal cancers in the PATHFINDER study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2243.