bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 6506: SOS1 inhibition in combination with HER2 inhibition in models of HER2-driven cancer
Authors: Schenk Robyn L. , Kostyrko Kaja , Popow Johannes , Gewinner Christina , Baum Anke , Albrecht Christoph , Hinkel Melanie , Jacob Robin , Madensky Tom , Ruzicka Regina , Strauss Eva , Lyu Hengyu , Lopez Anastasia M. , Feng Ningping , Vellano Christopher P. , Marszalek Joseph R. , Heffernan Timothy P. , Pearson Mark , Hofmann Marco H.
Published: March 2024

Cancers driven by amplifications or mutations of the gene ERBB2 (coding for the receptor tyrosine kinase (RTK) HER2) have been the focus of HER2-targeting antibodies as well as small molecule inhibitors. Despite initial efficacy, resistance to these HER2-targeted therapies inevitably develops. One strategy to tackle this resistance is to identify rational combinations to address common pathways/factors that contribute to resistance. One such common mechanism of resistance is reactivation of the Mitogen-activated protein kinase (MAPK) pathway. SOS1 is a guanine nucleotide exchange factor (GEF) which regulates the MAPK pathway by catalyzing the exchange of RAS-GDP (inactive) to RAS-GTP (active). SOS1 is activated by multiple different RTKs - upon RTK-ligand binding, autophosphorylation of the RTK recruits the GRB2-SOS1 protein complex to the plasma membrane, enabling the complex to bind and activate RAS-GDP. Given SOS1’s role downstream of RTKs and upstream of the MAPK pathway, we sought to investigate the potential of a SOS1 inhibitor (SOS1i) in combination with a HER2 inhibitor (HER2i) in preclinical models of cancer driven by HER2 mutation or gene amplification. Using in vitro and in vivo models we found evidence of added benefit of SOS1i in combination with HER2i, as well as enhanced inhibition of MAPK signaling, as seen by decrease in ERK activation and expression of MAPK effector genes such as DUSP6. Taken together, we propose that SOS1 inhibition combined with HER2 inhibition may be a rational strategy for deeper and more prolonged responses to HER2 inhibitor treatment by preventing resistance via the MAPK pathway.

Citation Format: Robyn L. Schenk, Kaja Kostyrko, Johannes Popow, Christina Gewinner, Anke Baum, Christoph Albrecht, Melanie Hinkel, Robin Jacob, Tom Madensky, Regina Ruzicka, Eva Strauss, Hengyu Lyu, Anastasia M. Lopez, Ningping Feng, Christopher P. Vellano, Joseph R. Marszalek, Timothy P. Heffernan, Mark Pearson, Marco H. Hofmann. SOS1 inhibition in combination with HER2 inhibition in models of HER2-driven 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 6506.
Abstract 6525: Modulating the immune response in cholangiocarcinoma: Targeting sulfatase-2 for therapeutic intervention
Authors: Brooks Tayla R. , Campbell Nellie , Keim Melanie , Roberts Lewis R.
Published: March 2024

Cholangiocarcinoma (CCA) is an aggressive epithelial malignancy of the bile ducts. Recent reports have suggested a rise in the incidence of CCA globally. Current treatments for CCA have limited effectiveness, with only 20-30% response rates in patients with advanced cancer. Thus, there is a growing need to investigate new therapeutic targets for CCA. The tumor microenvironment (TME) is a potential target for novel therapies. The TME plays an important role in progression and metastasis of cancer through facilitating immune escape. Recent studies have demonstrated potential roles for heparan sulfate proteoglycans (HSPGs) in tumorigenesis. Sulfatase 2 (SULF2) is a heparan sulfate editing sulfatase that removes the 6-O sulfate moiety within the heparan sulfate (HS) chains and alters the affinity of HS chains for growth factors and cytokines and their receptors, thus modulating HSPG function in cell signaling pathways. HSPG specific sulfatases have been recently identified as a potential therapeutic target in CCA. We aimed to assess the effects of anti-Sulfatase-2 antibody on immune cells in the tumor microenvironment of syngeneic CCA xenografts in C57BL6 mice. Mice bearing syngeneic CCA xenografts were treated with an anti-sulf2 antibody, and the tumors compared to untreated control xenografts. After treatment, the tumors were harvested and analyzed by Cytometry by time of flight (Cytof) to identify changes in the types and numbers of immune cells in the tumor xenografts. Treatment with anti-sulf2 antibody resulted in a decrease in immunosuppressive cells such as tumor associated macrophages (TAMs) and myeloid derived suppressor cells (MDSC) compared to the control. There was also an increase in anti-tumor cells such as T-cells and NK cells, suggesting that suppressing sulf-2 in the microenvironment can shift the TME toward an anti-tumorigenic rather than a pro-tumorigenic environment. In summary, our work demonstrates the potential to target Sulfatase 2 as a therapeutic mechanism for immunomodulation of the tumor microenvironment. Future experiments to determine the relationship between specific clinical phenotypes and the number, activities and types of immune cells seen in the TME, and experiments in other hepatobiliary cancers models, such as hepatocellular carcinoma and gallbladder cancer, will be conducted.

Citation Format: Tayla R. Brooks, Nellie Campbell, Melanie Keim, Lewis R. Roberts. Modulating the immune response in cholangiocarcinoma: Targeting sulfatase-2 for therapeutic intervention [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 6525.
Abstract 6533: Pivotal role of specific LYVE1+ tissue resident macrophages in PDAC progression & immunotherapy resistance
Authors: Li Hong , Yan Jun
Published: March 2024

Pancreatic ductal adenocarcinoma (PDAC) is characterized by dense fibrotic stroma and abundant myeloid cell infiltration, which render it resistant to any therapeutic interventions, including immunocheckpoint blockade (ICB) therapy. Understanding the composition and function of myeloid cells within the PDAC microenvironment may help identify promising targets for PDAC immunotherapy. Tissue resident macrophages (TRMs) contribute to organogenesis and tissue regeneration and metabolism. In this study, we discovered a distinct population of pancreas TRMs that highly express lymphatic vessel hyaluronan receptor 1 (LYVE-1). Single cell RNAseq data reveal that LYVE-1+ TRM cluster in the pancreas expresses high levels of complement activation genes and transcription factors such as c-Maf and Stab1. RNAseq data also confirm that LYVE-1+ TRMs express enriched genes related to mannose binding, endocytosis, and glutathione metabolic process, while LYVE-1 negative macrophages express enriched genes related to antigen processing and presentation, T cell activation, and phagocytosis. Multiparameter flow cytometric analysis demonstrates that LYVE-1+ TRMs express M2-like markers, including increased CD163, CD206 and decreased MHC Class II molecule. During PDAC development and progression, LYVE-1+ TRMs expand and localize around the tumor border, promoting fibrotic stroma formation. Imaging mass cytometry (IMC) also reveals abundant infiltration of LYVE-1+CD14+CD68+ macrophages in human PDAC tumors and colocalized with collagen deposition. This subset of macrophages also highly express c-Maf. Through the use of Lys-Cre-c-Maf f/f mice, we demonstrate that depletion of c-Maf from myeloid cells significantly reduces LYVE-1+ TRMs and polarizes them to resemble an M1-like phenotype. In conclusion, our findings suggest that LYVE-1+ macrophages are a unique subset of myeloid cells within the pancreas and likely play a critical role in PDAC progression and immunotherapeutic resistance. Future work will focus on targeting LYVE1+ TRMs using various approaches, such as conditional knockout mice and small molecule inhibitors, to determine their therapeutic potential for PDAC treatment.

Presented by Dr. Hong Li

Citation Format: Hong Li, Jun Yan. Pivotal role of specific LYVE1+ tissue resident macrophages in PDAC progression & immunotherapy resistance [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 6533.
Abstract 6567: Affinity and cooperativity modulate ternary complex formation to drive degradation of SMARCA2
Authors: Archibeque Ivonne , Dellamaggiore Ken , Rex Karen , Ghimire-Rijal Sudipa , Choi Kaylee , Kate Smither , Amegadzie Albert , Chen Ning , Li Xiaofen , Wurz Ryan , Vaish Amit , Hughes Paul , Mohl Dane
Published: March 2024

Small molecules that hijack the ubiquitin-proteasome system to degrade target proteins have gained traction as tools for chemical biology and as promising clinical candidates. Targeted degradation strategies encompass relatively large hetero-bifunctional small molecules (hSMs) that are built from target and effector ligands joined by a linker to much smaller molecular glues that have limited affinity for the target or effector proteins outside of a ternary complex. There is good reason for medicinal chemists to move from linkered hSMs toward glue-like scaffolds. Molecular glues can be considerably smaller, e.g., the IMiDs, and thus are less likely to possess atoms and functional motifs that add up to poor permeability and higher protein binding.

Guided by the principle that hSMs with reduced molecular weight will have superior druglike properties, we have used SMARCA2, a potential therapeutic target in patients that have both copies of SMARCA4 inactivated, as a test of our own ability to drive rapid target degradation in relevant models. The hetero-bifunctional degraders that resulted from our work trade conventional linkers for chemical spacers that orient SMARCA2 and VHL to promote fortuitous protein-protein contacts in the ternary complex. Following in the footsteps of previously published works, we employed surface plasmon resonance (SPR), x-ray crystallography, and molecular modeling to understand the relationships between our cell-based metrics of degrader activity and the biophysical parameters that describe the ternary complex. Consequently, we found that cooperativity (α) and ternary complex affinity (KLPT) correlated well with both DC50 and initial rate of degradation. Within our series of novel SMARCA2 degraders, compound 1 exhibited exceptional cooperativity and ternary complex affinity, α = 12.8 and KLPT = 4.7 ± 1. The result of high cooperativity and enhanced affinity was rapid and near complete SMARCA2 degradation. Treatment of a cancer cell line with compound 1 resulted in 50% of SMARCA2 being degraded

in under 30 minutes, and greater than 90% degradation in 2 hours. Most importantly, the near complete degradation of SMARCA2 resulted in potent effects on SWI/SNF dependent transcription in vitro and in inhibition of tumor cell growth both in vitro and in vivo.

Citation Format: Ivonne Archibeque, Ken Dellamaggiore, Karen Rex, Sudipa Ghimire-Rijal, Kaylee Choi, Smither Kate, Albert Amegadzie, Ning Chen, Xiaofen Li, Ryan Wurz, Amit Vaish, Paul Hughes, Dane Mohl. Affinity and cooperativity modulate ternary complex formation to drive degradation of SMARCA2 [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 6567.
Abstract 6587: Discovery of molecular glue of FBXW7:MYC interaction using small molecule microarray
Authors: Guo Shenghao , Stilgenbauer Morgan , Wu Bocheng , Mankan Yatin , Koehler Angela N.
Published: March 2024

MYC deregulation is a key driver and feature of many human cancers. Yet, despite its importance in cancer progression, MYC is considered “undruggable” by small molecules due to its disordered conformation. Therefore, interfering with its interactions with protein partners to modulate MYC activity appears viable. FBXW7 is an E3 ligase, which serves as a constituent of the SCF (Skp1-Cul1-F box) ubiquitin ligase complex. It mediates the degradation of both c-Myc and Cyclin E through ubiquitin-dependent proteolysis. FBXW7 mutations are found in various human tumor types, establishing its role as a general human tumor suppressor. Specifically, FBXW7 down-regulation increases MYC level, and its expression correlates to lethal outcomes of breast epithelial cells, poor prognosis in glioblastoma, and T cell acute lymphoblastic leukemia remission. Therefore, our project aims to discover potent small molecule glues that would enhance the interaction between FBXW7 and MYC, leading to MYC degradation through proteolysis and eventually suppression of various cancers. Taking advantage of our high throughput screening technology, Small Molecule Microarrays (SMMs), we successfully identified 29 compounds that potently bind to both c-Myc and FBXW7 after screening our 65,000 ‘drug-like’ small molecule library. We then performed secondary assays using a mCherry-GFP MYC reporter cell line to identify our lead compound, KI-FBX-001, which decreases MYC’s expression:transcription ratio by over 50% compared to control. Additionally, this down-regulation can be rescued by protease inhibitor MG132, indicating that the effect is achieved via proteolysis. In vitro dose-response and time-course treatment revealed an optimal drugging concentration at 15uM in K562 cells, with inhibition reaching its peak at the 4-hour time point at over 60%. Using the Qiagen MYC reporter assay, the in vitro IC50 of KI-FBX-001 is found at 7.42uM. Beyond the protein level, the qPCR result also reveals a decrease in MYC mRNA level at over 70%. Surface Plasmon Resonance (SPR) is used to confirm direct binding between FBXW7 and KI-FBX-001, which showed promising binding with kd=0.17µM. Proximity Ligation Assay further confirms KI-FBX-001’s effect in enhancing FBXW7:MYC interaction in the cell. In summary, our findings proved that KI-FBX-001 is a promising molecular glue in the FBXW7:MYC interaction, and can effectively modulate the MYC level for future therapeutic purposes.

Citation Format: Shenghao Guo, Morgan Stilgenbauer, Bocheng Wu, Yatin Mankan, Angela N. Koehler. Discovery of molecular glue of FBXW7:MYC interaction using small molecule microarray [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 6587.
Abstract 6630: Non-cell-autonomous cancer progression from chromosomal instability
Authors: Li Jun , Hubisz Melissa , Earlie Ethan , Duran Mercedes , Hong Christy , Varela Austin , Lettera Emanuele , Deyell Matthew , Tavora Bernardo , Havel Jonathan , Su Phyu , Amin Amit Dipak , Budre Karolina , Kamiya Erina , Cavallo Julie-Ann , Garris Christopher , Powell Simon , Reis-Filho Jorge , Wen Hannah , Bettigole Sarah , Khan Atif , Izar Benjamin , Parkes Eileen , Laughney Ashley , Bakhoum Samuel
Published: March 2024

Chromosomal instability (CIN) is a driver of cancer metastasis, yet the extent to which this effect depends on the immune system remains unknown. Using ContactTracing—a newly developed, validated and benchmarked tool to infer the nature and conditional dependence of cell-cell interactions from single-cell transcriptomic data—we show that CIN-induced chronic activation of the cGAS-STING pathway promotes downstream signal re-wiring in cancer cells, leading to a pro-metastatic tumor microenvironment. This re-wiring is manifested by type I interferon tachyphylaxis selectively downstream of STING and a corresponding increase in cancer cell-derived endoplasmic reticulum (ER) stress response. Reversal of CIN, depletion of cancer cell STING or inhibition of ER stress response signaling abrogates CIN-dependent effects on the tumor microenvironment and suppresses metastasis in immune competent, but not severely immune compromised, settings. Treatment with STING inhibitors reduces CIN-driven metastasis in melanoma, breast and colorectal cancers in a manner dependent on tumor cell-intrinsic STING. Finally, we show that CIN and pervasive cGAS activation in micronuclei are associated with ER stress signaling, immune suppression and metastasis in human triple-negative breast cancer, highlighting a viable strategy to identify and therapeutically intervene in tumors spurred by CIN-induced inflammation.

Citation Format: Jun Li, Melissa Hubisz, Ethan Earlie, Mercedes Duran, Christy Hong, Austin Varela, Emanuele Lettera, Matthew Deyell, Bernardo Tavora, Jonathan Havel, Phyu Su, Amit Dipak Amin, Karolina Budre, Erina Kamiya, Julie-Ann Cavallo, Christopher Garris, Simon Powell, Jorge Reis-Filho, Hannah Wen, Sarah Bettigole, Atif Khan, Benjamin Izar, Eileen Parkes, Ashley Laughney, Samuel Bakhoum. Non-cell-autonomous cancer progression from chromosomal instability [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 6630.
Abstract 6651: Compromised TGFβ signaling and DNA repair primes immune poor tumors response to immune checkpoint blockade by activating NK cells
Authors: Moore Jade T. , Gkantalis Jim , Guix Ines , Barcellos-Hoff Mary Helen
Published: March 2024

We investigated the interplay between transforming growth factor beta (TGFβ) regulation of immunosuppressive signaling and immunogenic DNA repair. Loss of TGFβ signaling by cancer cells is accompanied by increased use of error-prone repair. We described a transcriptomic score, βAlt, that reports the TGFβ/DNA repair functional relationship. Pan-cancer analysis showed that high βAlt cancers (i.e., low TGFβ and high error-prone DNA repair) are sensitive to chemoradiation and have a greater fraction of genome altered compared to low βAlt cancers. Defective mismatch repair is associated with T cell infiltration and response to immune checkpoint blockade (ICB), hence we investigated the immune context of bAlt. Unsupervised clustering of RNAseq profiles 12 independent immunocompetent mouse tumor derived transplant (mTDT) tumors based on βAlt score indicated that high βAlt was associated with immune poor phenotype and lack of type I interferon signatures. A similar relationship was evident in the bladder, breast, and lung TCGA data. A high βAlt, immune poor mTDT in which T cells were only 20% of 10% CD45 were treated with monotherapy consisting of single fraction 10 Gy radiation, anti-PD-L1 or TGFβ inhibition, dual or triple treatment. Only monotherapy or combinations with radiation significantly increased survival. However, these ICB resistant tumors responded to triple treatment. Response was accompanied by increased tumor infiltrating CD45+ cells (P=0.02), circulating CD8 T cells (P<0.001) and natural killer (NK) cells (P<0.001). As NK cells tripled and TGFβ broadly impairs NK cell effector function, we depleted NK cells to test whether they were required for the response to triple treatment. NK depletion completely abrogated response (P<0.00001) indicating NK cells can provoke an ICB response in high βAlt immune poor tumors. Both mouse tumors and human cancers show that loss of TGFβ signaling resulting in error-prone DNA damage response is strongly associated with immune poor tumors and suggests that TGFβ inhibition can override NK cell dysfunction to create vulnerability to ICB.

Citation Format: Jade T. Moore, Jim Gkantalis, Ines Guix, Mary Helen Barcellos-Hoff. Compromised TGFβ signaling and DNA repair primes immune poor tumors response to immune checkpoint blockade by activating NK 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 6651.
Abstract 6690: Gut microbial metabolite butyrate facilitates antitumor efficacy of telomerase-specific oncolytic adenovirus via MHC-I and cGAS-STING pathway activation
Authors: Sakamoto Masaki
Published: March 2024

Introduction: Gut microbiota has been reported to have a potential to modulate tumor sensitivity to chemo- or immuno-therapies although the underlying mechanism is still unclear. Oncolytic virotherapy is a promising antitumor treatment that selectively induces oncolytic cell death in tumor cells. We have previously developed OBP-702, a telomerase-specific oncolytic adenovirus armed with the p53 tumor suppressor gene, highlighting potent antitumor effects across different cancer types. To explore the potential of gut microbial metabolites, particularly butyrate, in augmenting the antitumor efficacy of oncolytic virotherapy.

Materials and Methods: We assessed the synergistic antitumor effects of butyrate and OBP-702 in cytotoxic assay using two human (HCT116, SW48) and two murine (CT26, MC38) colorectal cancer cell lines in vitro, and the in vivo antitumor effects in subcutaneous tumor models using HCT116 and CT26. We explored underlying mechanisms of the synergistic effects, focusing on the influences of butylate on viral infectivity via Coxsackie-Adenovirus Receptor (CAR) and integrins, and antitumor immunity via tumor MHC-I expression and CD8-positive T cells.

Results: Butyrate and OBP-702 showed potent synergistic effects in all four cell lines in vitro, and the combination suppressed tumor growth significantly in HCT116 and CT26 subcutaneous tumors compared to each monotherapy. These synergistic effects were produced by butyrate increasing the potential of OBP-702 by enhancing viral infection efficiency via upregulating expressions of CAR and integrins on tumor cells. Butyrate also increased MHC-I expression on tumor cells by activating the cGAS-STING pathway, leading to increased CXCL10 expression, which led to activation of antitumor immunity through recruitment of CD8-positive T cells in tumor tissues. The synergistic effects of butyrate and OBP-702 were proved in an orthotopic colorectal tumor model with liver metastases using CT26 cells expressing luciferase, in which this combination not only reduced tumor growth, but also improved survival by activating antitumor immunity via CD8-positive T cells.

Conclusion: Butyrate and OBP-702 showed synergistic antitumor effects via activation of systemic antitumor immunity in addition to direct effects of butyrate on viral cytotoxic potential, which provides valuable insights into the development of innovative cancer treatment strategies.

Citation Format: Masaki Sakamoto. Gut microbial metabolite butyrate facilitates antitumor efficacy of telomerase-specific oncolytic adenovirus via MHC-I and cGAS-STING pathway activation [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 6690.
Abstract 6697: The role of microbiomes in pediatric cancer prevention: A survey of population awareness
Authors: Elmoneim Abeer Abd , Alshanqiti Mona Alhassan , Aljohani Yara Saad , Alomari Lubna Hosain
Published: March 2024

Background: Gut microbiome includes the genome of all gut microorganisms; it plays a crucial role in the body’s nutritional, metabolic, physiological, and immunological processes. Persistent imbalance of the gut microbial community is associated with the onset of metabolic and inflammatory disorders, including cancer. The environment has a major role in the great variability of microbiome composition among different people. This high heterogeneity between individuals may be a source of differences in susceptibility to disease. Dietary and lifestyle choices as well as social interactions play a significant role in makeup and function of the gut microbiota, which may affect microbiome-associated diseases. Therefore, strategies that might favorably modulate the gut microbiota to reduce the risk of cancer through diet and lifestyle changes are of great interest.

Aim: To detect and increase self-awareness about gut microbiota and its relation to diet and lifestyle habits.

Methods: A survey questionnaire is provided asking for microbiome knowledge and lifestyle habits and distributed among the population in Madina city in Saudi Arabia. Study population are the children aged 2-18 years. Data gathered from older children or the parents/guardian of young children.

Results: A profile involving each participant’ diet, physical activity, and sociodemographic characteristics through self- reporting questionnaire is obtained.

Discussion: Gut microbiota can regulate many functions of the tumor-bearing meta-organism, typically through immunomodulation. Known microbial mechanisms can alter non-hematopoietic and hematopoietic components of the gut epithelial barrier, modulate lymphoid organ activities, and regulate immune tone of the tumor microenvironment (TME).

Conclusion: Understanding information about microbiome and its role in causing diseases as well as each participant’ diet, physical activity and other sociodemographic characteristics help to raise participants’ awareness about the importance of taking care of their gut health.

Citation Format: Abeer Abd Elmoneim, Mona Alhassan Alshanqiti, Yara Saad Aljohani, Lubna Hosain Alomari. The role of microbiomes in pediatric cancer prevention: A survey of population awareness [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 6697.
Abstract 6728: Preclinical development of QL325, a novel T cell engager targeting CLEC12A-positive AML
Authors: Gu Shenda , Tran Hieu V. , Chen Shihao , Liu Ke , Zhang Xin , Jia Linchao , Ma Ruixue , Fu Jiayu
Published: March 2024

Despite advancement in targeted therapies, treatment options for patients with acute myeloid leukemia (AML) that provide a tolerable and durable response remain elusive. We have developed a CD3 bispecific antibody, QL325, targeting CLEC12A, a c-type lectin protein that is highly expressed on AML blasts. Normally, CLEC12A expression is mostly confined to the CD34+CD38- progenitor population and largely absent on normal and regenerating bone marrow stem cells. Our bispecific antibody is configured in a 2 + 1 format, with bivalent avidity binding to CLEC12A, monovalent low affinity binding to CD3, and an effector-null Fc for extending half-life. In our preclinical studies, QL325 induced CLEC12A -dependent activation and proliferation of T cells. Redirected T cell-dependent cytotoxicity mediated by QL325 was restricted to AML cancer cells expressing CLEC12A. QL325 demonstrated dose dependent suppression of tumor growth in xenograft models of AML, significantly more potent than a clinical benchmark antibody. In non-human primates, QL325 was tolerated up to 0.03 mg/kg for IV dosing and under 0.1 mg/kg for SC dosing, well above the predicted effective therapeutic dose. A phase 1 clinical trial is currently ongoing to determine the safety and early efficacy in patients with refractory or relapsed AML.

Citation Format: Shenda Gu, Hieu V. Tran, Shihao Chen, Ke Liu, Xin Zhang, Linchao Jia, Ruixue Ma, Jiayu Fu. Preclinical development of QL325, a novel T cell engager targeting CLEC12A-positive AML [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 6728.
Abstract 6741: Targeting glutamine metabolism potentiates antigen presentation in colorectal cancer
Authors: Yu Tao , Van der Jeught Kevin , Zhu Haiqi , Zhou Zhuolong , Sharma Samantha , Liu Sheng , So Ka Man , Eyvani Haniyeh , Wang Xiyu , Sandusky George E. , Liu Yunlong , Opyrchal Mateusz , Cao Sha , Wan Jun , Zhang Chi , Zhang Xinna
Published: March 2024

Colorectal cancer (CRC) ranks among the most prevalent cancers worldwide, causing substantial mortality. The urgent need for effective treatments has driven research into immune checkpoint blockade (ICB) therapies, which have demonstrated significant clinical benefits across various cancer types. Despite the success of ICB therapies, a significant proportion of CRC patients exhibit resistance to treatment, prompting the identification of mechanisms that hinder therapy resistance or enhance treatment response. CRC cells display remarkable adaptability, orchestrating metabolic changes that confer growth advantages, pro-tumor microenvironment, and therapeutic resistance. One such metabolic change occurs in glutamine metabolism. In this study, we found that colorectal tumors with high glutaminase (GLS) expression exhibit reduced T-cell infiltration and cytotoxicity, leading to poor clinical outcomes. To validate these findings, we applied the ovalbumin (OVA)/OT-I T cell-based cytotoxicity assay and the CRC patient-derived organoids (PDOs)/autologous T cell killing assay. Our results indicated that inhibition of GLS significantly enhanced T-cell cytotoxicity in vitro and ex vivo. Mechanistically, we elucidated that inhibition of GLS activated reactive oxygen species-related signaling pathways in tumor cells, thereby potentially increasing tumor immunogenicity by promoting antigen presentation. The combinational therapy of GLS inhibitor and ICB exhibited a superior tumor growth inhibitory effect in comparison with either of the monotherapies. These findings shed new light on clinical therapeutic strategies for CRC patients, offering a promising approach to enhance the efficacy of ICB therapy.

Citation Format: Tao Yu, Kevin Van der Jeught, Haiqi Zhu, Zhuolong Zhou, Samantha Sharma, Sheng Liu, Ka Man So, Haniyeh Eyvani, Xiyu Wang, George E. Sandusky, Yunlong Liu, Mateusz Opyrchal, Sha Cao, Jun Wan, Chi Zhang, Xinna Zhang. Targeting glutamine metabolism potentiates antigen presentation in colorectal 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 6741.
Abstract 6743: Identifying new cellular adjuvants for cancer vaccines and immunotherapies
Authors: Rucker Joseph , Nwogu Nnenna , Molino Nicholas M. , Snyder Ami , Sullivan Jonathan T. , Doranz Benjamin J.
Published: March 2024

Background: Cancer vaccines represent a promising strategy for antitumor immunotherapy. Despite considerable research efforts and progress, the effectiveness of cancer vaccines remains a challenge. This is primarily due to relatively low immune responses against tumors, stemming from issues of poor immunogenicity and the immunosuppressive microenvironment commonly found in many solid tumors. Use of an optimal adjuvant can augment immune responses against tumor antigens and guide them towards a specific adaptive immune enhancement. Dendritic cells (DCs) play a primary role in initiating immunes response to vaccines, often through activation of toll-like receptors (TLRs). Identifying novel immunomodulatory proteins that regulate DCs or TLR activation can identify novel adjuvant candidates with applications for cancer immunotherapy.

Methods: We constructed a Membrane Proteome Array (MPA) encompassing ~6,000 structurally intact human membrane proteins in their native conformation (94% of the entire membrane proteome) and used it to screen for cellular proteins that can modulate response to vaccination through DCs and TLRs. To identify proteins that interact with TLRs, the library was expressed in live TLR reporter cells, and these cells were tested for response to known activators. In addition, cells expressing the MPA were presented to DCs to identify membrane proteins that modulate DC activity. TLR-expressing cell activation was measuring using an NF-kB-activated luciferase reporter, while DC assays used upregulation of cell surface markers (CD80, CD83, and MHCII) to measure the activation of immature monocyte-derived dendritic cells.

Results: Screening of TLR2, TLR3, and TLR5 reporter cell lines identified both known and novel regulators of TLR activation. Activators common to several TLRs were identified as well as activators unique to individual TLRs. Screening of primary human DCs likewise identified known regulators of activation (for example CD40L) and several novel targets. Putative novel regulators of DC activation are being further investigated to determine their biological significance.

Conclusion: Discovering novel immunomodulatory targets and proteins that regulate DCs and TLR activation can identify novel adjuvant candidates with targeted immune outcomes, such as immune stimulating and anti-cancer responses. This study identified novel regulators of immune activation which are being further investigated as adjuvant candidates for cancer vaccines.

Citation Format: Joseph Rucker, Nnenna Nwogu, Nicholas M. Molino, Ami Snyder, Jonathan T. Sullivan, Benjamin J. Doranz. Identifying new cellular adjuvants for cancer vaccines and immunotherapies [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 6743.
Abstract 676: The integrated stress activator BTM-3566 overcomes therapeutic resistance in mantle cell lymphoma
Authors: Liu Yang , Lee Heng-Huan , McIntosh Joseph , Li Yijing , Zhang Tianci , Wang Wei , Kostura Matthew J. , Wang Michael
Published: March 2024

Successive generations of BTK inhibitors and CAR T-cell therapy have transformed the treatment of mantle cell lymphoma (MCL). However, treatment resistance has inevitably emerged, creating significant medical need. Recently a novel, clinical stage small molecule, BTM-3566, has been described that targets a mitochondrial process essential for Diffuse Large B-cell lymphoma (DLBCL) survival. BTM-3566 activates the mitochondrial protease OMA1, triggering the ATF4 integrated stress response (ISR). BTM-3566 has robust in vitro efficacy in DLBCL cell lines irrespective of genomic background and elicits complete tumor regression in multiple CDX and PDX mouse models of DLBCL. Based on the activity observed in DLBCL, we further explored the effectiveness of BTM-3566 in MCL models in vitro and in xenograft mouse models in vivo. BTM-3566 inhibited cell proliferation across a panel of MCL cell lines, irrespective of resistance status to ibrutinib and venetoclax (IC50s of 142.5-687.6 nM). Following a 24-hour treatment with BTM-3566, a dose-dependent increase in apoptosis was observed in four tested MCL cell lines—JeKo-1, JeKo-IBN-R, Mino, and Mino-VEN-R, as determined by increased caspase-3 activation and PARP cleavage. Similarly, western blot analysis revealed dose-dependent reductions in MCL-1 and c-MYC, accompanied by an increase in the transcription factor ATF4, indicative of activation of the stress response. We evaluated the in vivo efficacy of BTM-3566 in the JeKo-CDX mouse model. Daily oral administration of BTM-3566 at 10, 20 and 30 mg/kg (n = 5 for each group) in a 5-day on and 2-day off schedule resulted in tumor regression at all three doses (Treatment vs. Vehicle, p < 0.01). We expanded our investigation to PDX mouse models, including those derived from patients resistant to multiple therapies. Four PDX models encompassing naive, rituximab-resistant, BTKi-CAR T dual-resistant and BTKi-VEN-CAR T triple-resistant models were evaluated. BTM-3566 treatment results in nearly complete tumor growth inhibition associated with robust reductions in tumor burden in treated mice across all four PDX models (reduction in tumor weight at the study endpoint, p < 0.001). Notably, no toxicity was observed during the treatment period. In summary, BTM-3566 is effective in treating MCL in vitro and in vivo in preclinical studies.

Citation Format: Yang Liu, Heng-Huan Lee, Joseph McIntosh, Yijing Li, Tianci Zhang, Wei Wang, Matthew J. Kostura, Michael Wang. The integrated stress activator BTM-3566 overcomes therapeutic resistance in mantle cell lymphoma [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 676.
Abstract 6811: IL-9 enhances lung tumor growth through intrinsic and ARG1-dependent transcriptomic changes in interstitial macrophages
Authors: Cannon Anthony , Kaplan Mark H.
Published: March 2024

A defining characteristic of cancer is its ability to evade detection by immune cells through the generation of a myeloid cell-dependent immunosuppressive tumor microenvironment. Arginine is utilized by Arginase 1 (ARG1) or nitric oxide synthase in tumor-associated macrophages to respectively elicit pro-tumor or anti-tumor activity. The balance between these enzymes is regulated by extracellular cytokines including Interleukin 9 (IL-9), a pleiotropic cytokine that can be a positive or negative regulator of tumor growth. Our lab identified that IL-9 promotes tumor development in the lung by expanding interstitial macrophage populations and inducing ARG1. Lung tumor growth is attenuated in mice with myeloid cell deficiency of Arg1. Similarly, macrophage-targeting nanoparticles containing Arg1 siRNA can therapeutically reduce tumor burden and alter macrophage populations in the lung toward an immunostimulatory phenotype. However, an understanding of the mechanism by which IL-9R/ARG1+ interstitial macrophages drive tumor progression remains incomplete. Here, using a B16F10 lung metastasis model in mixed-bone marrow chimeric mice, we demonstrate that IL-9-responsive interstitial macrophages are intrinsically altered at the transcriptomic level toward an ARG1-dependent immunosuppressive phenotype. Furthermore, our research shows that the absence of IL-9 signaling or ARG1 expression in macrophages has a notable impact on the levels of arginine and its metabolites in the lung tissue and bronchoalveolar lavage fluid of tumor-bearing mice. These alterations subsequently lead to an enhanced anti-tumoral immune response, reflected by changes in Interferon-gamma expression in both lung macrophages and T cells. Thus, our work suggests that the IL-9R/ARG1/interstitial macrophage axis promotes lung tumor development by altering intrinsic arginine metabolism and reprogramming immune cell populations toward an immunosuppressive phenotype.

Citation Format: Anthony Cannon, Mark H. Kaplan. IL-9 enhances lung tumor growth through intrinsic and ARG1-dependent transcriptomic changes in interstitial macrophages [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 6811.
Abstract 6871: Tumor-infiltrating mregDC restrains anti-tumor immunity to promote cancer relapse in HCC
Authors: Zhang Zefan , Zhou Jian , Fan Jia , Zhong Yu , Wu Liang , Sun Yunfan
Published: March 2024

Background and aims: Cancer relapse is one of the major causes of mortality in patients after curative resection of primary tumors. Furthermore, significant proportion of patients with recurrent tumor lack of effective treatments, thus novel therapeutic strategies are urgently needed. Although there have been several single-cell studies of primary tumor, functional roles and mechanism of tumor-infiltrating immune cells, especially those of myeloid cells in tumor relapse have remained to be elucidated.

Methods: We analyzed the RNA profile of 16498 cells from 12 primary and 6 early-relapse HCC cases. Digital pathology, multiplex immunofluorescent staining and digital spatial profiling (DSP) of paired primary and relapsed tumors from 41 HCC patients were also performed as our validation set. The molecular mechanisms associated with DCs was further tested through ex vivo and in vivo experiments.

Results: We performed single-cell clustering and visualized 3 DC clusters (cDC1, cDC2, and DC3). Compared with the other two subsets, the enrichment of DC3 in relapsed HCC was correlated with a higher second recurrence rate. Deeper inspections of the signature genes indicated this subset as ‘mregDC’, a DC subset enriched in maturation and regulatory molecules. Our results demonstrated that mregDC recruited CD161+CD8+ T cells that had an innate-like, low-cytotoxic, and low-clonal-expansion phenotype. CD161+CD8+ T cells secreted large amounts of TNF to activate non-canonical NF-κB pathway via tumor necrosis factor receptor 2 (TNFR2) and promoted the differentiation of immature DC into mregDC. This positive feedback loop between mregDC and CD161+CD8+ T cells shaped a dysfunctional anti-tumor immunity, facilitating cancer relapse in HCC. In vivo assay further indicated that therapy combining anti-TNFR2 and PD-L1 antibodies significantly inhibited HCC tumor growth via impeding the infiltration of mregDC compared with anti-PD-L1 monotherapy. We also found mregDC recruited FCN1+ monocyte, a MDSC-like cell population to create an immunosuppressive niche of relapsed HCC.

Conclusions: We identified this population of mregDC with immunomodulatory function in recurrent HCC and demonstrated the role of these special DCs in shaping the immunosuppressive microenvironment of recurrent tumors. Our study suggests that mregDC may be a new target for the treatment of recurrent HCC in the future.

Citation Format: Zefan Zhang, Jian Zhou, Jia Fan, Yu Zhong, Liang Wu, Yunfan Sun. Tumor-infiltrating mregDC restrains anti-tumor immunity to promote cancer relapse in HCC [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 6871.
Abstract 6895: Application of MiniPDX® in clinical indication identification and anti-tumor drug development
Authors: Xie Bin , Chen Hongkui , Zhao Shizhu , Li Le , Xi Song , Di Yu , Liu Yang , Chen Xinlei , Gu Xiaorong , Bi Zhenle , Hu Kaimeng , Van Loc , Caggiula Josh , Tang Candice , Wen Danyi
Published: March 2024

MiniPDX® (Mini-patient-derived xenograft) is a novel, rapid (7~10days), and accurate method for drug sensitivity testing in vivo. It was referred as in vivo version of organoid assy. The testing material can be fresh patient tumor samples or tissues from established PDX models. We have systematically evaluated and compared the response rates of MiniPDX® assays and PDX assays pairwise in 26 PDX models across 3 types of cancers to 12 clinically relevant regimens for chemical and targeting drugs. The results demonstrate a high correlation between drug responses of the two assays, with sensitivity of 80% and specificity of 93%. More and more studies showed that MiniPDX® drug sensitivity test results were consistent with clinical responses in most patients, which indicated MiniPDX® models have great potential in guiding personalized medicine. LIDE has successfully conducted over 3,000 MiniPDX® tests for clinical precision medicine, covering more than 50 indications. The application of MiniPDX® extends beyond therapeutic selection, facilitating the prioritization of approved pharmacological interventions and informing the discovery pipeline for novel agents. Importantly, the MiniPDX® Mouse Trial using fresh tumor samples generated from the clinic is beneficial for determination of potential clinical indications. Only thousands of fresh cells leftover from MiniPDX® preparation are sufficient to get genomic and transcription data by OncoVee ® K-cell technology. The combination of MiniPDX® assay and omics data would be very useful for determination of potential biomarkers to distinguish responders and non-responders in population with certain indication(s) and leveraged for patient stratification and selection criteria in clinical trial design. In addition, we have developed a new version of MiniPDX® assay for immunotherapy (IO-FIVE, Immuno-Oncology Fast In Vivo Efficacy test) by using fresh patient cancer cells with autologous immune cells to maximally mimic human tumor microenvironment before seeding in immune-deficient mice. This assay allows for the tracking of cellular viability and phenotype pre- and post-treatment, thus providing a robust metric of in vivo immunotherapeutic efficacy within a fortnight.

Citation Format: Bin Xie, Hongkui Chen, Shizhu Zhao, Le Li, Song Xi, Yu Di, Yang Liu, Xinlei Chen, Xiaorong Gu, Zhenle Bi, Kaimeng Hu, Loc Van, Josh Caggiula, Candice Tang, Danyi Wen. Application of MiniPDX® in clinical indication identification and anti-tumor drug development [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 6895.
Abstract 6909: KRASG12C inhibitor resistance in patient-derived non-small cell lung cancer models
Authors: Rosen Joshua C. , Pham Nhu-An , Li Quan , Cao Pinjiang , Hueniken Katrina , Koga Takamasa , Radulovich Nikolina , Koers Alex , Niedbala Michael , Ross Sarah , Sacher Adrian , Tsao Ming-Sound
Published: March 2024

Introduction: One quarter of lung adenocarcinomas (LUAD) harbor KRAS-mutations, with KRASG12C accounting for the majority (40%). GDP-KRASG12C inhibitors (G12Ci) have been developed for this patient cohort, and two of these are approved for clinical use in the US. While response rates to G12Ci tested in clinical trials have been between 35-50%, studies have identified mechanisms of adaptive resistance to these novel agents, limiting their use as monotherapies. However, primary (intrinsic) resistance to these compounds has not been explored extensively. We leveraged our patient-derived xenograft (PDX) and xenograft-derived organoid (XDO) development programs to study primary resistance to the novel G12Ci, AZD4625.

Methods: Twelve KRASG12C PDX models were established which recapitulated patient tumor histology, and genomic, transcriptomic, and methylome profiles. From these 12 PDX, six long-term (passage >10) XDO were generated. PDX were treated with AZD4625 chronically for four weeks as well as in an acute dosing pharmacodynamic study, where tumors were harvested for further analysis.

Results: The AZD4625 drug screen in our PDX models reproduced the G12Ci response rate observed in clinical trials. Four of twelve tumor models reduced in size on treatment, while the remainder were considered resistant as these tumors increased in size on treatment. Sensitive tumors became necrotic while those resistant remained proliferative. XDO models recapitulated their originating PDX genomic alterations, histology, as well as responses to AZD4625. During the acute pharmacodynamic screen in our PDX models, we observed a decrease in pERK1/2 and pS6 protein expression in sensitive but not resistant models, despite acute DUSP6 gene expression decreases in every model. Global proteomic analysis highlighted differences between each model.

Conclusion: PDX and XDO are useful models to study resistance to this novel class of inhibitor, with the KRASG12C NSCLC PDX models exhibiting a treatment response rate that is similar to those observed in clinical trials. Global proteomics suggests uniqueness of each model in our cohort, hinting that a universal combination of specific targeted agents to treat KRASG12C LUAD tumors may be insufficient.

Citation Format: Joshua C. Rosen, Nhu-An Pham, Quan Li, Pinjiang Cao, Katrina Hueniken, Takamasa Koga, Nikolina Radulovich, Alex Koers, Michael Niedbala, Sarah Ross, Adrian Sacher, Ming-Sound Tsao. KRASG12C inhibitor resistance in patient-derived non-small cell lung cancer models [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 6909.