bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 4699: Pan-cancer single-cell analysis reveals the interactions of SPP1+MMP12+ macrophages with metastasis-initiating cells that drives metastasis
Authors: Zhang Baifeng , Lai-wan Kwong Dora , Guan Xin-Yuan 
Published: April 2023

Abstract
Advanced understanding of cancer immunology has contributed to a significant decline in cancer deaths in the past few decades. However, there are still vast majority of patients with no effective response for current immunotherapy drugs because of some innate immune cells, particularly macrophages and neutrophils, promoting all steps of malignant progression to metastasis. Therefore, the development of new strategies against these pro-metastatic non-tumor components in the tumor microenvironment is in need. Tumor-associated macrophage (TAMs), as the critical component of tumor microenvironment (TME), display diverse and even opposing function phenotypes, but without systematic investigation on their ubiquitous characteristics across different cancer types. Here, we perform pan-cancer analysis on 92 samples across 6 solid cancer types to profile the TME of normal, primary tumor, metastatic lymph node and distant metastasis at single-cell resolution, illustrating the commonalities/plasticity of heterogenous TAMs. We uncover 21 distinct subtypes of TAMs with varying abundance and biological function in different tissue microenvironment, providing evidence for the plasticity of TAMs. In particular, the enrichment of SPP1+MMP12+ macrophages in the TME of lymph node metastasis, likely interacting with metastasis-initiating cells (MICs), is associated with promoting malignant progression to metastasis and survival stratifications. Multi-color immunofluorescence (mIF) staining for relevant markers is being performed in mouse models and clinical samples for comprehensive validation. Our study comprehensively describes the characteristics and dynamics of TAMs and highlights their heterogeneity and plasticity depending on their surrounding microenvironment.
Citation Format: Baifeng Zhang, Dora Lai-wan Kwong, Xin-Yuan Guan. Pan-cancer single-cell analysis reveals the interactions of SPP1+MMP12+ macrophages with metastasis-initiating cells that drives metastasis. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4699.
Abstract 4710: Novel 3D cytotoxicity assay to assess the impact of chimeric antigen receptor (CAR) domain design on the tumor infiltration and cytotoxicity efficacy of CAR T-cell therapies for solid tumors
Authors: Johnston Adrian , Wan Zeqi , Chen Tina , Lim Yeongseo , Lee Cameron , Du Wenxuan , Philip Jude , Wirtz Denis 
Published: April 2023

Abstract
CAR T-cell therapy is a popular topic of discussion in and out of the scientific community. Already with multiple therapies FDA-approved for certain blood cancers, focus has rightly shifted toward FDA approval for solid tumor indications. Yet, advancing past clinical trials to FDA approval has yet to occur and has proved challenging. Of course, multiple factors are at play as to why, but we aim to use-in house expertise to elucidate one, namely CAR T-cell tumor infiltration and tissue migration and surveillance efficacy. Migration is a central parameter ignored in traditional 2D cytotoxicity assays, but there is no tumor cell killing by T cells if there is no T cell migration. We developed a novel first-of-its-kind organoid-based 3D cytotoxicity assay using multicompartment organoids and the most abundant extracellular matrix protein in human organs, collagen. We suspend solid tumor organoids in the center of CAR T-cell/collagen gel mixtures that are solidified then imaged in intervals in the span of two weeks by live-cell time-lapse reflection/fluorescence confocal microscopy, after which standard luciferase-based readouts of quantitative specific lysis is determined. Our assay allows high-resolution tracking of CAR T-cell 3D movements through collagen fibers surrounding solid tumor organoids to determine their random and directional migration as well as their surveillance and infiltration of solid tumor organoids. We will describe the differences between currently in clinical trial mesothelin-specific CAR T-cell therapies that differ in their scFv, hinge, transmembrane, and costimulatory domains; and comparing alongside the traditional 2D luciferase-based cytotoxicity assay, we will underline how 3D migration and infiltration around and into mesothelin-expressing ovarian cancer cell organoids allow the determination of CAR T-cell therapy efficacy of different CAR T clones in a lab’s arsenal for a given solid tumor through migration, infiltration, and subsequent cytotoxic capacity that is absent in traditional 2D cytotoxicity assays. CAR T-cell therapy vector design and cloning can thus be tuned for optimal migration and infiltration using our novel 3D cytotoxicity assay.
Citation Format: Adrian Johnston, Zeqi Wan, Tina Chen, Yeongseo Lim, Cameron Lee, Wenxuan Du, Jude Philip, Denis Wirtz. Novel 3D cytotoxicity assay to assess the impact of chimeric antigen receptor (CAR) domain design on the tumor infiltration and cytotoxicity efficacy of CAR T-cell therapies for solid tumors. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4710.
Abstract 4734: BRD8-driven EP400 complex hijacks H2AZ to maintain proliferation in glioblastoma
Authors: Sun Sherine Xueqin , Klingbeil Olaf , Vakoc Christopher , Mills Alea 
Published: April 2023

Abstract
Glioblastoma (GBM) is the most notorious primary brain tumor. The median survival of GBM patients is only about one year and about 95% patients succumb after five years. This gloomy picture has not been improved for decades, even with extensive treatments including surgery, radiotherapy, and chemotherapy. Hence, a better understanding of the mechanisms underlying GBM development may provide new therapeutic opportunities. Primary GBM generally harbors a low mutational load when compared to other human cancers. Even P53—the guardian of the genome that is essentially disabled in nearly all human cancers, remains unmutated in about 71% of GBM cases. Moreover, these P53 wildtype GBM cases are as aggressive as those with P53 mutations. To explore the mechanism by which P53 wildtype GBM thrive in the presence of intact P53, we performed CRISPR screens in a panel of human cancer cell lines using an sgRNA library specifically targeting the functional domains of ~200 chromatin regulators. We discovered that BRD8’s bromodomain—a druggable domain as shown by the tremendous success in preclinical and clinical trial in diverse cancers—is a vulnerability specifically in P53 wildtype GBM cases. Our mechanistic studies demonstrate that BRD8 functions through the EP400 chromatin remodeling complex and hijacks the histone variant H2AZ at P53 target loci, enforcing a compact chromatin state that blocks P53’s accessibility to its targets. We show that targeting the BRD8 bromodomain releases H2AZ, opens up chromatin, engages P53-mediated transactivation, and triggers growth arrest. Consistent with these findings, BRD8 is highly expressed with H2AZ in patient-derived proliferating GBM cells, and is inversely correlated with the expression of P53 targets. Our work solves a long-standing mystery in P53 wildtype GBM, and presents a promising therapeutic target for the majority of GBM patients.
Citation Format: Sherine Xueqin Sun, Olaf Klingbeil, Christopher Vakoc, Alea Mills. BRD8-driven EP400 complex hijacks H2AZ to maintain proliferation in glioblastoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4734.
Abstract 477: Discovery of RGT-018: A potent, selective and orally bioavailable SOS1 inhibitor for mutant KRAS-driven cancers
Authors: Xiao Fei , Wang Kailiang , Wang Xinjuan , Li Huijuan , Hu Zhilong , Huang Wei , Ren Xiaoming , Feng Teng , Yao Lili , Lin Jing , Li Chunlai , Mei Liufeng , Zhang Zhuanzhuan , Liu Yangyang , Chen Xi , Zhu Xiaotian , Zhong Wenge , Xie Zhi 
Published: April 2023

Abstract
Background: KRAS is the most frequently mutated oncogene with high prevalence in non-small cell lung cancers (NSCLC), colorectal cancers (CRC), and pancreatic cancers (PAC). FDA currently approved sotorasib provides breakthrough therapy for cancer patients with KRASG12C mutation, however there is still high unmet medical need for new agents that target a broader KRAS mutated tumors. A new opportunity emerges to develop a pan KRAS inhibitor by suppressing the upstream guanine nucleotide exchange factor (GEF) protein son of sevenless 1 (SOS1). SOS1 is a key activator of KRAS and facilitates the conversion of GDP-bound KRAS (off) state to GTP-bound KRAS (on) state. Binding to its catalytic domain, small molecule SOS1 inhibitor prevents KRAS activation and suppresses cancer cell proliferation.
Material and Methods: Regor’s unique Computer Accelerated Rational Design (CARD) technology platform was applied to identify potent and selective SOS1 inhibitors. Biochemical assays and cellular assays were utilized to drive the structure-activity relationship (SAR). In vitro and in vivo target engagement were confirmed. In vivo efficacy study data were generated using lung and pancreatic cancer xenograft mouse models with KRAS mutation.
Results: In vitro, RGT-018 blocked the interaction of KRAS::SOS1 with high selectivity, and inhibited proliferation of a broad spectrum of mutant KRAS-driven cancer cells as a single agent. Robust anti-proliferation activity was observed when RGT-018 was combined with MEK, KRASG12C, EGFR or CDK2/4/6 inhibitors in vitro. Oral administration of RGT-018 inhibited tumor growth and suppressed KRAS signaling pathway activation in tumor xenografts. Furthermore, combination with MEK or KRASG12C inhibitors led to profound tumor regression.
Conclusions: The pharmacological properties of RGT-018 represent an attractive drug candidate with oral bioavailability for combination with targeted agents to treat a broader patient population driven by mutant KRAS.
Citation Format: Fei Xiao, Kailiang Wang, Xinjuan Wang, Huijuan Li, Zhilong Hu, Wei Huang, Xiaoming Ren, Teng Feng, Lili Yao, Jing Lin, Chunlai Li, Liufeng Mei, Zhuanzhuan Zhang, Yangyang Liu, Xi Chen, Xiaotian Zhu, Wenge Zhong, Zhi Xie. Discovery of RGT-018: A potent, selective and orally bioavailable SOS1 inhibitor for mutant KRAS-driven cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 477.
Abstract 4781: New generation of fluorescent probes for cell-based measurements of caspase activation and mitochondrial superoxide
Authors: Mandavilli Bhaskar S. , Beacham Daniel , Hu Yi Zhen , Yang Jongtae , Chen Aimei 
Published: April 2023

Abstract
Cell health and stress readouts are critical indicators of altered or impaired function in normal and diseased states of cells, and work has been underway to develop improved small molecule sensor dyes compatible with traditional imaging and High Content Analysis (HCA) interrogation of apoptotic and mitochondrial stress pathways.
The CellEvent™ Caspase Green dye effectively reports caspase activation, but suffers complications in assay configuration when attempting to multiplex with the Green Fluorescent Protein (GFP), calcein, or other 488 laser line tools in fluorescence microscopy. Here, we describe the testing and functional characterization of a new candidate molecule for measuring apoptosis in living cells. Our sensor is comprised of a fluorogenic reporter dye that is liberated from a DEVD peptide substrate by caspase activation, but operates in the Texas Red, 590nm excitation band, with an emission peak near 610 nm, permitting easy multiplex with GFP or calcein stained neurons in both traditional and HCA microscopy configurations. Similarly, mitochondrial superoxide accompanying cell stress is probed in microscopy with the MitoSOX™ Red Mitochondrial Superoxide Indicator dye, which localizes to mitochondria and reports superoxide generation, ignoring other Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS). This dye has an unusually long Stokes’ shift, requiring specialized microscopy and HCA filters that excite at 405nm, and capture emission at 610nm for specific superoxide detection. This unconventional spectroscopic profile prevents the dye’s use on many imaging platforms and promotes phototoxicity. To this end, our team has produced a dye with the same level of specificity for superoxide that will operate in one of the traditional fluorescence microscopy channels. Our candidate dye, here named MitoSOX™ Green Mitochondrial Superoxide Indicator also localizes to mitochondria of live cells and selectively reports superoxide generation, while ignoring other ROS and RNS species in ex vivo testing. With an Excitation/Emission profile in the GFP/FITC microscopy channel, a series of comparative studies in immortalized and neural cells are shown, highlighting photostability, specificity and signal amplitude from the dye. These reagents are research use only, not for diagnostic purposes
Citation Format: Bhaskar S. Mandavilli, Daniel Beacham, Yi Zhen Hu, Jongtae Yang, Aimei Chen. New generation of fluorescent probes for cell-based measurements of caspase activation and mitochondrial superoxide. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4781.
Abstract 4786: Imipridones induce lipid peroxidation and oxidative stress in gastrointestinal malignancies
Authors: Cruz Arielle De La , Srinivasan Praveen R. , George Andrew , Prabhu Varun V. , Pinho-Schwermann Maximilian P. , El-Deiry Wafik S. 
Published: April 2023

Abstract
Colorectal and pancreatic cancer collectively comprise 20% of all cancer-related deaths in the United States. Despite therapeutic advancements, the current standard of care often results in significant toxicity. Therefore, there is an urgent need to develop more efficacious novel therapies. The imipridones, ONC201/TIC10, ONC206, and ONC212, are novel small-molecules that bind mitochondrial ClpP and induce activation of the integrated stress response (ISR), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) signaling, and oxidative stress. Each has previously demonstrated antitumor effects in a variety of preclinical in vitro and in vivo cancer subtypes, including colorectal cancer, with limited toxicity. Reactive oxidation species (ROS) are natural biproducts of cellular oxidative metabolism and play important roles in the modulation of cell death pathways, differentiation, and immune response. Using varying doses of ONC201, ONC206, and ONC212, we observed increased lipid peroxidation in several colorectal and pancreatic cancer cell lines using the C-11 BODIPY assay which measures lipid-specific peroxides. Lipid peroxidation was reversed by the ferroptosis inhibitor liproxstatin-1, suggesting that in addition to inducing apoptosis, imipridones may be involved in ferroptosis induction. Future directions include mechanistic work, investigation of the effect of imipridone-induced lipid peroxidation on immune cell cytotoxicity, and understanding the relative importance of lipid peroxidation in the clinical efficacy of imipridones.
Citation Format: Arielle De La Cruz, Praveen R. Srinivasan, Andrew George, Varun V. Prabhu, Maximilian P. Pinho-Schwermann, Wafik S. El-Deiry. Imipridones induce lipid peroxidation and oxidative stress in gastrointestinal malignancies. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4786.
Abstract 4787: The cancer targeting synergy of tertbutylhydroquinone and a manganese porphyrin
Authors: LaMorte Joseph P. , Tamarin Sandra , Lalo Margueritte , Sokoloski David J. , Paul Jared J. , Eggler Aimee L. 
Published: April 2023

Abstract
Cancer cells utilize high basal levels of reactive oxygen species (ROS) to create conditions that facilitate rapid cell proliferation. This creates an Achilles heel, making cancer cells more susceptible than normal cells to cell death caused by a bolus dose of ROS. The common food preservative, tert-butylhydroquinone (tBHQ), generates ROS intracellularly via redox cycling. Herein, we tested the effect of combining tBHQ with a manganese porphyrin, compounds originally designed as super oxide dismutase mimetics which can also generate ROS intracellularly in cancer cells and have radioprotective effects under clinical investigation. We find that the combination treatment of tBHQ and the commercially available Mn(III) tetrakis(1-methyl-4-pyridyl)porphyrin pentachloride (MnTMPyP) is much more toxic to leukemic Jurkat lymphocytes than either compound alone, e.g., lowering the LC50 of tBHQ by two orders of magnitude to 1.0 μM. MnTMPyP acts as a catalyst to oxidize tBHQ, shown by UV-Vis spectroscopy. Flow cytometry analysis revealed that while 5 μM tBHQ decreases cell viability by less than 10% in 4 hours, the combination of 5 μM tBHQ and 12 μM MnTMPyP decreases viability by 60%, primarily by apoptosis. A clinically tested manganese porphyrin, Mn(III) meso-tetrakis(N-n-butoxyethylpyridinium-2-yl)porphyrin (Mn2BuOE), was as effective and more potent than MnTMPyP. We evaluated the cancer-targeting effect of tBHQ and Mn2BuOE in both Jurkats and a matched primary CD4 T cell line. The combination treatment induced significantly more cell death in cancerous Jurkats than in the normal CD4 cells. With the promise Mn2BuOE shows in pre-clinical studies and early clinical trials as adjunctive to radiotherapy, and the wide use of tBHQ in prepared food, the results shown here in CD4 cells suggest their combination may be an effective therapy to target cancer cells.
Citation Format: Joseph P. LaMorte, Sandra Tamarin, Margueritte Lalo, David J. Sokoloski, Jared J. Paul, Aimee L. Eggler. The cancer targeting synergy of tertbutylhydroquinone and a manganese porphyrin. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4787.
Abstract 4790: Oxidation in the nucleotide pool as a novel targetable vulnerability in pancreatic ductal adenocarcinoma
Authors: Mateo-Victoriano Beatriz , Zhang Ling , Samaranayake Govindi J. , Due Cassie , Troccoli Clara , Zaias Julia , Nagathihalli Nagaraj , VanSaun Michael , Mohsen Michael G. , Kool Eric T. , Rai Priyamvada 
Published: April 2023

Abstract
Oncogenic RAS signaling is mediated by reactive oxygen species (ROS) signaling. However, oncogenic ROS also evoke tumor suppressive damage, necessitating adaptive redox protective mechanisms. We previously reported that MTH1, the main mammalian 8-oxodGTPase, comprises one such critical adaptation. High MTH1 expression significantly correlates with poor disease-free survival in several KRAS-driven tumors. We have shown in RAS-driven xenograft cancer models that MTH1 is critical for the maintenance of ROS-driven signaling and prevention of DNA damage-induced senescence. However, how MTH1 loss affects KRAS-driven spontaneous tumor formation is unknown. We focused on pancreatic ductal adenocarcinoma (PDAC) due to the high prevalence of driving oncogenic KRASG12D mutations, and the lack of MTH1 studies. Therefore, we depleted MTH1 via shRNA in MIA PacCa-2 and SU.86.86 cell lines and generated novel MTH1-null Pdx1Cre; LSL-KrasG12D/+; LSL-Trp53R172H/+ (KPC), Ptf1acre/+;LSL-KrasG12D/+;Tgfbr2flox/flox (PKT) and corresponding MTH1-wildtype strains. We found MTH1 knockdown significantly reduced growth of KRAS-driven PDAC cells, and that germline MTH1 deficiency reduced tumor burden in the short latency PKT but not the long latency KPC animals. The PKT tumors exhibited higher overall 8-oxodGTPase activity and reduced total 8-oxo-dGTPase activity in the MTH1-deficient background, unlike KPC tumors. This finding suggests that in aggressive KRAS-driven tumors, redundant 8-oxodGTPase activity cannot compensate for MTH1 loss to prevent oncogenic stress-induced tumor suppression. Additionally, both MTH1-depleted PDAC cell lines and the smaller MTH1-null PKT tumors had decreased EGFR expression, suggesting MTH1 loss compromises this ROS-driven pathway. RNA-seq analysis revealed MTH1 deficiency altered MDSC gene expression in the PKT model, suggesting better anti-tumor response through improved immune infiltration in a typically immunologically cold tumor. Our results indicate MTH1 targeting could benefit aggressive PDAC stages. We further show PDAC tumors possess redundancy in MTH1 8-oxodGTPase function, which needs to be better understood in order to therapeutically leverage current MTH1 inhibitors, which do not target this redundancy.
Citation Format: Beatriz Mateo-Victoriano, Ling Zhang, Govindi J. Samaranayake, Cassie Due, Clara Troccoli, Julia Zaias, Nagaraj Nagathihalli, Michael VanSaun, Michael G. Mohsen, Eric T. Kool, Priyamvada Rai. Oxidation in the nucleotide pool as a novel targetable vulnerability in pancreatic ductal adenocarcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4790.