bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3189: Pre-clinical evaluation of novel folate receptor 1 directed CAR T cells for high grade serous ovarian cancer
Authors: Herbel Christoph , Daigre Julie , Martinez-Osuna Manuel , Bethke Maria , Steiner Larissa , Brauner Janina , Kopatz Jens , Praveen Paurush , Eckardt Dominik , Bosio Andreas
Published: April 2023

Purpose: Treatment of ovarian cancer remains challenging. A high unmet clinical need for targeted, efficient, and persisting drugs still is a major issue for clinicians and patients diagnosed with ovarian cancer, particularly platinum-resistant and-refractory, recurrent disease. Genetically modified T cells expressing chimeric antigen receptors (CARs) have shown efficient, as well as persisting anti-tumor functionality in hematological malignancies. However, solid cancers have not yet been as efficiently treated with CAR T cells, potentially due to the lack of appropriate targets. Therefore, we thoroughly characterized FOLR1 as CAR T cell target for ovarian cancer, designed novel CAR T cells, and assessed these drug candidates preclinically in vitro and in vivo.

Experimental Design: We performed ultra-high content imaging on high-grade serous epithelial ovarian cancer as well as healthy tissue samples to profile the expression of the tumor-associated antigen FOLR1. Subsequently, we designed a series of CAR T cell candidates based on different monoclonal antibodies targeting FOLR1, in order to leverage on clinical experience with these binders, particularly safety aspects. The CAR designs differed in the VL-VH orientation and the spacer domain of the CAR construct. The preclinical assessment of various FOLR1-directed CAR T cell constructs was evaluated against various ovarian cancer cell lines in vitro and in vivo.

Results: In this study we show high and consistent expression of the tumor-associated antigen FOLR1 on primary ovarian cancer samples, namely high-grade serous ovarian cancer. Moreover, FOLR1 expression is low, restricted, and polarized in healthy tissues. We generated diverse FOLR1-specific CAR T cells and characterized their efficacy and specificity in vitro as well as in an ovarian cancer xenograft model. CAR T cells rapidly and efficiently eradicate xenograft tumors. This anti-tumor response is accompanied by CAR T cell expansion, FOLR1-dependent cytokine secretion, and infiltration of CAR T cells into the tumor.

Conclusions: These findings demonstrate the feasibility of a preclinical CAR T cell approach targeting FOLR1 as treatment option for ovarian cancer and potentially other FOLR1-expressing tumors.

Citation Format: Christoph Herbel, Julie Daigre, Manuel Martinez-Osuna, Maria Bethke, Larissa Steiner, Janina Brauner, Jens Kopatz, Paurush Praveen, Dominik Eckardt, Andreas Bosio. Pre-clinical evaluation of novel folate receptor 1 directed CAR T cells for high grade serous ovarian cancer [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 3189.
Abstract 3236: Optimizing mRNA vaccines and virus-mediated CAR T-cell therapy for immuno-oncology: Synthetic tools for gene modification
Authors: Yang Ming , Richardson Crystal , Rao Prassanna , Koole Cassandra , Karney Michael J. , Kumar Sumit
Published: April 2023

With the success of mRNA vaccines during the COVID-19 pandemic and CAR T-cell therapies in clinical trials, there is growing opportunity for immunotherapies in the treatment of many types of cancers. Lentiviral vectors have proven effective at delivery of genetic material or gene editing technology for ex vivo processing, but the benefits and promise of Adeno-associated virus (AAV) and mRNA tools for in vivo immunotherapy have garnered recent interest.

Here we describe complete synthetic solutions for immuno-oncology research programs using either mRNA-vaccines or virus-mediated cell and gene engineering. These solutions optimize workflows to minimize screening time while maximizing successful research results through: (1) Efficiency in lentiviral packaging with versatility in titer options for high-quality particles. (2) A high-throughput viral packaging process to enable rapid downstream screening. (3) Proprietary plasmid synthesis and preparation techniques to maintain ITR integrity through AAV packaging and improve gene delivery. (4) Rapid synthesis, in vitro transcription, and novel sequencing of mRNA constructs for complete characterization of critical components such as the polyA tail.

The reported research demonstrates a streamlined approach that improves data quality through innovative synthesis and sequencing methodologies as compared to current standard practices.

Citation Format: Ming Yang, Crystal Richardson, Prassanna Rao, Cassandra Koole, Michael J. Karney, Sumit Kumar. Optimizing mRNA vaccines and virus-mediated CAR T-cell therapy for immuno-oncology: Synthetic tools for gene modification [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 3236.
Abstract 3255: Investigate immune regulation and therapeutic efficacy via regorafenib combined with PD-L1 inhibitor in glioblastoma
Authors: Dong Dai-Cheng , Liu Yu-Chiang
Published: April 2023

Glioblastoma (GBM) is one of the most common aggressive primary brain tumors, with poor survival despite after surgery, radiation treatment, and chemotherapy. Regorafenib, a tyrosine kinase inhibitor used for cancer treatment, was known to effectively inhibit angiogenesis and attenuate the activity of oncogene receptor hormones. Currently, regorafenib has been approved to treat various cancer with significant improvement. Though regorafenib show potential to penetrate blood brain barrier, the role of regorafenib in glioblastoma has not been elucidated. With the finding of central nervous lymphatic system, immune checkpoint inhibitor (programmed cell death protein-1 and its ligand) therapy has ongoing with clinical trial in GBM. The PD-L1 on tumor cells may interact with the PD-1 on T cells, and therefore inhibited the proliferation of T cells proliferate and finally cause the immune escape of tumor. While the therapeutic efficacy of using immune checkpoint inhibitor alone is still not significant enough for GBM; thus, it is necessary to find other suitable drugs for combination. Moreover, patient with low PD-L1 expression may not be able to administrate with anti-PD-L1 therapy. Therefore, identifying suitable combination reagent to regulate PD-L1 expression and to enhance efficacy of anti-PD-L1 therapy is important. Our experiment aims to explore whether regorafenib can increase the transcription of PD-L1 via regulating β-catenin-related signal transduction, and thus enhancing the treatment efficacy of immune checkpoint inhibitor (anti-PD-L1) on GBM. Here, we used GL-261 animal model to prove the regulation of regorafenib combined with anti-PD-L1. According to our data, regorafenib can inhibit the proliferation and induce the apoptosis pattern in GBM cells. Further, regorafenib may induce PD-L1 expression via activating β-catenin-related signaling; and therefore, increasing the targeting efficacy of anti-PD-L1 in GBM. Not only induce PD-L1 expression, regorafenib combined with anti-PD-L1 may also induce the accumulation of active cytotoxicity T lymphocytes (CD8+IFN-γ+) and reduce the accumulation of immunosuppressive cells, such as regulatory T cells (CD11b+Gr-1+) and myeloid-derived suppressor cells (CD4+CD25+FOXP3+). In conclusion, our animal experiments suggested that regorafenib may effectively promote PD-L1 transcription in glioblastoma by up-regulating β-catenin-related signaling, thereby increasing the therapeutic target efficacy and effectiveness of immune checkpoint inhibitors.

Citation Format: Dai-Cheng Dong, Yu-Chiang Liu. Investigate immune regulation and therapeutic efficacy via regorafenib combined with PD-L1 inhibitor 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 3255.
Abstract 3378: Rapid and efficient sample preparations for cell free DNA
Authors: Zeng Zhiyang , Taft Andrew , Riemersma Kasen , Fitzgerald Connor , Scurria Mike , Hermanson Spenccer , Zhou Wenhui
Published: April 2023

The analysis of cell-free DNA (cfDNA) as a sensitive biomarker for cancer prognosis, diagnosis and monitoring resulted in a need for efficient and fast cfDNA isolation. The traditional cfDNA purification methods using chaotropic solvent to separate nucleic acids from plasma through column or magnetic bead purification processes are usually laborious and time consuming, involving multiple washing steps, and the residual organic solvent could be carried over to the elution solution that could cause downstream PCR inhibition. Herein, we developed a novel particle surface chemistry that can biochemically bind rapidly (<1min) and release nucleic acids rapidly (<1min) under different buffer conditions without needing chaotropic solvent. We further optimized the binding and elution buffer solutions that allow to isolate cfDNA from plasma within 5-10 minutes in the sample volumes from 1 ml to 4 ml. The real-time quantitative PCR indicated DNA extraction yields were comparable or slightly better than the traditional methods for both small and large volumes. The novel bead chemistry and the optimized binding and elution buffers are not only compatible to high throughput format but could also be applied to a variety sample types for rapid sample preparations.

Citation Format: Zhiyang Zeng, Andrew Taft, Kasen Riemersma, Connor Fitzgerald, Mike Scurria, Spenccer Hermanson, Wenhui Zhou. Rapid and efficient sample preparations for cell free DNA [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 3378.
Abstract 3409: Design and characterization of highly potent and selective CDK9 heterobifunctional degraders
Authors: Toure Mohammed A. , Motoyama Keisuke , Richters André , Koehler Angela N.
Published: April 2023

Cyclin-dependent kinase 9 (CDK9) has long been considered an attractive therapeutic target for modulating transcription in cancers of high unmet clinical need. CDK9 coordinates signaling events that regulate RNA polymerase II (Pol II) pause-release state and is considered an important co-factor for oncogenic transcription factors that drive transcription in an addictive manner. CDK9 modulation offers an approach for attenuating transcriptional dysregulation driven by amplified or overexpressed transcription factors, such as c-MYC. However, targeting CDK9 in the clinic has proven very challenging. This stems from the often highly intolerable cytotoxic effects likely due to off-target effects. Targeted protein degradation offers a novel approach for engineering enhanced selectivity and mitigating other liabilities of the conventional inhibition-driven approach that have been applied to date. Here, we present the design and characterization of a focused library of highly selective CDK9 degrader molecules with rapid kinetics and potency (half-degrading concentration of <1nM). We carry out transcriptional and phosphoproteomics profiling to comprehensively characterize the downstream effects and cellular adaptations resulting from CDK9 degradation. We gain new insights into adaptive responses to CDK9 modulation and the biological contexts most responsive for therapeutic application.

Citation Format: Mohammed A. Toure, Keisuke Motoyama, André Richters, Angela N. Koehler. Design and characterization of highly potent and selective CDK9 heterobifunctional degraders [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 3409.
Abstract 3450: Discovery and preclinical study of novel BTK degrader HZ-Q1070
Authors: Liu Xingguo , Zhou Yubo , Wu Yizhe , Luo Xiaomin , Xie Jiangfeng , Jin Xinxin , Li Jia , Zhou Xinglu
Published: April 2023

Introduction: Bruton's tyrosine kinase (BTK) is a clinical validated target for B cell lymphoma and autoimmune diseases. However, acquired resistance, which is the result of BTK C481S mutation, has been observed in patients. So reversible BTK inhibitors are developed to overcome acquired resistance of covalent BTK inhibitors. In order to achieve adequate efficacy, reversible BTK inhibitors require much higher exposure which may lead to higher risk of adverse effect. Proteolysis-targeting chimera (PROTAC) is a novel drug discovery strategy and achieve sustained target degradation though a catalytic mechanism of action. Comparing with traditional small molecule inhibitor, PROTAC has shown great advantages in overcoming acquired resistance, since potent and sustained active site occupation is no longer required. Here, we have identified a novel BTK-PROTAC HZ-Q1070 based on our DaTProD® platform, which is set up to promote the druggability research of PROTAC. After a series of evaluations, HZ-Q1070 has been validated as a promising pre-clinical candidate for further clinical development.

Results: 1. HZ-Q1070 can effectively degrade BTK in cancer cell lines with DC50 < 0.05 nM. In vitro cancer cell growth inhibition assay, it completely suppressed the cell proliferation of a panel of lymphoma cell lines with IC50 < 0.05 nM, such as Mino, OCI-ly10 and TMD8. 2. At the same time, HZ-Q1070 catalyzes the mutated BTK degradation (C481S/C481Y/C481F/T474M) and potently inhibits growth of BTK inhibitor-resistant tumor cell lines. 3. In proteomic analysis assay, HZ-Q1070 can selectively degrade BTK. 4. HZ-Q1070 has been engineered to avoid Aiolos and Ikaros degradation and therefore does not show IMiD activity. 5. Mechanistic investigation of indicates that HZ-Q1070 can function through the ubiquitin-proteasome system (UPS). 6. In the PK/PD experiments, HZ-Q1070 shows excellent pharmacokinetic properties and BTK degradation activity in vivo. 7. HZ-Q1070 demonstrates robust tumor growth inhibition in TMD8 and Mino xenograft mouse model. Doses as low as 3 mg/kg demonstrates a significant inhibitory effect.

Conclusion: In summary, HZ-Q1070 is a potent and highly selective BTK degrader against both BTK-WT and multiple BTK inhibitors-resistant mutations. In vivo, HZ-Q1070 exhibits excellent pharmacokinetic properties, BTK degradation activity and robust tumor growth inhibition in TMD8 and Mino mouse xenograft tumor model. These findings support further clinical development of HZ-Q1070 for the treatment of B cell malignancies.

Citation Format: Xingguo Liu, Yubo Zhou, Yizhe Wu, Xiaomin Luo, Jiangfeng Xie, Xinxin Jin, Jia Li, Xinglu Zhou. Discovery and preclinical study of novel BTK degrader HZ-Q1070 [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 3450.
Abstract 3451: XS-04: A first-in-class dual IRAK4/BTK inhibitor for the treatment of hematological malignancies
Authors: Zhao Chunyan , Wang Jianfei , Liu Aiguo , Gao Xin , Teng Yanfen , Liu Lei , Zhang Yang , Yu Xiaohong
Published: April 2023

Bruton's tyrosine kinase (BTK), a critical mediator of B-cell receptor (BCR) signaling, is a validated therapeutic target found across multiple B-cell cancers. Though initially responding to treatment with a BTK inhibitor, many patients with chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), or Waldenström macroglobulinemia (WM) eventually progressed and clinical responses to BTK inhibitors are often poor in diffuse large B-cell lymphoma (DLBCL) patients. These highlight the need to understand the resistance mechanisms and improve responses to BTK inhibitors. The serine/threonine protein kinase IRAK4 is a key modulator of MYD88, which is found to be mutated in various aggressive B-cell lymphomas, including DLBCL. As BCR signaling and MYD88 signaling converge downstream on NF-kB activation, which plays an essential role in proliferation and survival of lymphoma cells, blockade of the two signaling pathways presents a potential therapeutic strategy. Here, we investigated the pharmacokinetic properties and anti-tumor activity of XS-04, a first-in-class dual inhibitor targeting both IRAK4 and BTK, using preclinical models of DLBCL subtypes, including tumors resistant to BTK inhibitors. XS-04 showed potent inhibition of IRAK4 and BTK kinases, with IC50 values of 0.2 and 2.9 nM, respectively. Favorable pharmacokinetic properties were also seen across multiple non-clinical species. Using in vitro anti-proliferative assays, we found that XS-04 inhibited proliferation of various DLBCL cell lines with IC50s of 30 to 40 nM. Mechanistically, XS-04 suppressed NF-kB activity in DLBCL cells and in vivo xenograft tumors, as indicated by decreased phosphorylation of IkBa. Oral dosing of XS-04 in TMD8 xenograft model led to a dose-dependent inhibition of tumor growth, which was comparable to the inhibition shown by a combination of BTK and IRAK4 inhibitors. In addition, XS-04 treatment resulted in tumor regression in a patient-derived ibrutinib-resistant MCL xenograft model, without significant changes in body weight. XS-04, a first-in-class IRAK4/BTK dual inhibitor, shows broad anti-tumor activity across preclinical models of DLBCL subtypes, including tumors resistant to BTK inhibitors. These results support XS-04 as a therapeutic candidate for the treatment of hematological malignancies. An IND submission is planned for 2023.

Citation Format: Chunyan Zhao, Jianfei Wang, Aiguo Liu, Xin Gao, Yanfen Teng, Lei Liu, Yang Zhang, Xiaohong Yu. XS-04: A first-in-class dual IRAK4/BTK inhibitor for the treatment of hematological 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 3451.
Abstract 3529: EWSR1-WT1 isoform selectivity, DNA binding, and druggable targets: unpacking the biology of desmoplastic small round cell tumor
Authors: Magrath Justin W. , Goldberg Ilon A. , Hartono Alifiani B. , Lee Sean B.
Published: April 2023

Desmoplastic small round cell tumor (DSRCT) is a rare pediatric cancer caused by the EWSR1-WT1 fusion gene. No targeted therapies have been established and multimodal therapy is ineffective with a 5-year survival rate of 15-25%. Many questions about the biology of DSRCT remain unanswered including the critical genes regulated by the EWSR1-WT1 fusion gene, the role of the - and +KTS fusion gene isoforms produced by alternative splicing, and the relationship between EWSR1-WT1 binding and gene expression alterations. To address these questions, we established four doxycycline-inducible DSRCT cell lines that selectively knockdown the expression of EWSR1-WT1. RNA-seq analysis on these cell lines with or without EWSR1-WT1 knockdown identified commonly altered genes and pathways. To illuminate the role of the EWSR1-WT1 -KTS and +KTS isoforms, the -KTS, +KTS, or both isoforms were overexpressed in a mesothelial cell line, a hypothesized cell of origin for DSRCT. Remarkably, different gene expression alterations were observed between the -KTS and +KTS isoforms. While overexpression of the -KTS isoform upregulated 765 genes and downregulated 366 genes, overexpression of the +KTS isoform upregulated 203 genes and downregulated 25 genes. Gene set enrichment analysis showed EWSR1-WT1 regulated gene signatures are recapitulated by overexpression of the -KTS isoform or both +/-KTS isoforms, but not the +KTS isoform alone, suggesting the -KTS isoform predominantly regulates gene expression in DSRCT. To interrogate the influence of direct and indirect gene regulation by EWSR1-WT1, ChIP-seq and CUT&RUN data were integrated into our RNA-seq analysis. Across each of our four DSRCT cell lines, approximately 25% of EWSR1-WT1 bound peaks led to upregulation, 10% led to downregulation, and 65% led to no gene expression alteration. EWSR1-WT1 binding accounted for 33% of EWSR1-WT1 commonly upregulated genes but only 4.2% of commonly downregulated genes. Upregulated EWSR1-WT1 bound genes were more likely to be bound in the promoter or first intron and coincide with Znf263 or Hoxb4 motifs. To evaluate the functional role of EWSR1-WT1 targets in DSRCT biology, a screen of the 24 druggable EWSR1-WT1 targets was conducted and a number of novel and known target genes were identified as important for DSRCT survival. Current work is verifying these targets with gene knockdown and evaluating their function in vivo.

Citation Format: Justin W. Magrath, Ilon A. Goldberg, Alifiani B. Hartono, Sean B. Lee. EWSR1-WT1 isoform selectivity, DNA binding, and druggable targets: unpacking the biology of desmoplastic small round cell tumor. [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 3529.
Abstract 3558: Role of FLI portion of EWS::FLI in transcription regulation via modulation of chromatin 3D landscape in Ewing sarcoma
Authors: Bayanjargal Ariunaa , Taslim Cenny , Crow Jesse , Selich-Anderson Julia , Lessnick Stephen L.
Published: April 2023

Ewing sarcoma is an aggressive bone-associated tumor currently treated with dose-intense chemotherapy, radiation, and surgery and it affects adolescents and young adults. The hallmark of Ewing sarcoma is a translocated fusion transcription factor named EWS::FLI that drives the oncogenic process. We hypothesize that FLI portion of EWS::FLI containing a crucial alpha-helix plays a novel role in transcription regulation of thousands of genes by modulating chromatin looping. The hypothesis is based on recent evidences from our lab: an alpha-helix immediately downstream of DNA binding domain as an important player in regulating transcriptional activity and that EWS::FLI has a substantial role in shaping the chromatin landscape of Ewing sarcoma cells. The objective of this study is to elucidate the mechanism underlying transcriptional regulation by FLI. We utilized knockdown/rescue experiments in which EWS::FLI was depleted with shRNA and replaced with constructs containing the ETS DNA Binding Domain (DBD) alone or DBD+ (DBD and 4th alpha-helix). The binding pattern and transcriptional regulation were assessed with CUT&Tag and RNA-Seq respectively. The extent of roles each of these construct play in organization, structure, and function of chromatin are being assessed using Micro-C technique, a variation of Hi-C with improved resolution, higher signal-to-noise ratio and more information on chromatin domain boundaries and chromatin looping. The DNA binding and genomic localization of EWS::FLI was unaltered by the deletion surrounding the DNA binding domain (which contains a 4th alpha-helix) in A673 and TTC466 cells. Despite this similarity in genomic localization and binding, the transcriptional output driven by EWS::FLI was significantly diminished by the deletion. With this current study, we hope to understand if the flanking region neighboring the DNA binding domain contributes to the chromatin architecture remodeling function of EWS::FLI and whether this function could be attributed to the transcriptional output differences in the DBD and DBD+ conditions.

Citation Format: Ariunaa Bayanjargal, Cenny Taslim, Jesse Crow, Julia Selich-Anderson, Stephen L. Lessnick. Role of FLI portion of EWS::FLI in transcription regulation via modulation of chromatin 3D landscape in Ewing sarcoma. [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 3558.
Abstract 356: Targeting differential metabolism in an aged model of cancer cachexia
Authors: Dasgupta Aneesha , Schmitt Rebecca E. , Schneider Jessica Z. , Kono Tatsuyoshi , Lee Chih-Chun , Evans-Molina Carmella , Doles Jason D.
Published: April 2023

Cancer cachexia is a multifactorial syndrome entailing muscle and fat wasting, inflammation, and metabolic dysfunction. Pancreatic cancer has the highest incidence of cachexia at around 80%. However, there are no FDA approved therapy for cachexia in the clinic yet. This is mostly because of the failure of preclinical therapies to demonstrate success in the clinic. Most preclinical studies utilize 6-8 week old mice which roughly corresponds to a human age of ~ 20 years. However, the median age of diagnosis of pancreatic cancer is ~70 years. Given widespread physiology, microenvironment, and metabolism differences in young and aged skeletal muscle, we sought to study cancer cachexia in mice aged to >78 weeks, which corresponds to a human age of greater than 60 years. Our previously published study reported little difference in tumor growth or survival between the two cohorts, yet significant alterations in the muscle transcriptome. Building on this work, we show significant differences in the muscle metabolome of young/aged control and tumor bearing mice. Notably, histamine was higher in aged versus young control mice and even higher in the aged tumor-bearing cohort. We show higher activity of histamine decarboxylase (HDC), the enzyme that converts histidine to histamine in the muscles of aged tumor-bearing mice. Addition of cancer conditioned-media (CM) to C2C12 myotubes was able to induce histamine production and HDC activity in vitro, which demonstrates the ability of muscle cells to induce histamine independent of mast cells. We further show that addition of histamine to myotubes is sufficient to increase atrophy-associated markers. Inhibition of HDC activity by α-fluoromethylhistidine (FMH) in the in vitro model of cachexia protected against myotube thinning. Finally, we treated tumor-bearing aged mice with FMH and observed a) decreased histamine in the muscles 2) decreased HDC activity in the muscles 3) decreased muscle wasting, 4) decreased atrophy markers. Together, we present a novel wasting-associated metabolic pathway and corresponding therapeutic avenue for cancer cachexia that may have been overlooked if not for the use of a more-age-appropriate model of pancreatic cancer.

Citation Format: Aneesha Dasgupta, Rebecca E. Schmitt, Jessica Z. Schneider, Tatsuyoshi Kono, Chih-Chun Lee, Carmella Evans-Molina, Jason D. Doles. Targeting differential metabolism in an aged model of cancer cachexia [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 356.
Abstract 3602: The metastasis-suppressive function of intracellular galectin-3 in melanoma
Authors: Mohammed Norhan B. B. , Dimitroff Charles J.
Published: April 2023

Melanoma is a relatively rare skin cancer. However, it accounts for most of all skin cancer-related deaths worldwide. Once melanoma spreads to distant sites, it confers a poor prognosis characterized by resistance to therapy and high mortality rate. Hence, a favorable clinical outcome is strongly correlated with early diagnosis. Despite the ongoing research to identify novel diagnostic, prognostic, and therapeutic targets for metastatic melanoma (MM), a reliable serum marker to predict whether melanoma is vulnerable to metastasize or has already metastasized is still lacking. Galectin-3 (Gal-3), a ß-galactoside-binding protein, is widely expressed by many human epithelial and immune cells. High extracellular Gal-3 expression levels have been reported to be positively correlated with late-stage disease in melanoma patients, where it is theorized to bind surface glycosylated proteins to promote melanoma cell invasion and metastasis. Gal-3 is also expressed intracellularly where it participates in the regulation of many biological processes. However, intrinsic Gal-3 levels within the melanoma cell and its relationship to melanoma progression is still poorly understood. Using The Cancer Genome Atlas (TCGA) database, we analyzed the Gal-3 expression profiles of 471 tumor samples obtained from melanoma patients. To our surprise, TCGA data analysis has shown significantly higher expression of Gal-3 in primary melanoma samples compared to metastatic melanoma. We hypothesize that intracellular Gal-3 potentially negatively regulates primary melanoma progression to metastatic disease. Using several human melanoma cell lines silenced for Gal-3 expression, we investigated the corresponding malignancy-associated activities of these cells. Our results revealed that Gal-3 silencing in melanoma cells potentiated melanoma migration, invasion, and colony formation, compared with mock controls, suggesting that intracellular Gal-3 could interfere with melanoma metastatic activity. Moreover, loss of Gal-3 boosted the activation of the PI3K/AKT and MAPK signaling pathways and upregulated nuclear factor of activated T cells (NFAT1) expression and its pro-metastatic downstream target genes. Importantly, this study illuminates the apparent opposing roles of Gal-3 in melanoma progression, with intracellular Gal-3 potentially serving as a metastasis-suppressive molecule. Moreover, these studies reveal the potential of analyzing melanoma cell-intrinsic levels of Gal-3 to better predict metastatic potential and clinical outcome in melanoma patients.

Citation Format: Norhan B. B. Mohammed, Charles J. Dimitroff. The metastasis-suppressive function of intracellular galectin-3 in melanoma. [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 3602.
Abstract 3615: Targeting tumor-brain crosstalk in invasive brain metastases
Authors: Mourcos Caitlyn , Maritan Sarah M. , Annis Matthew G. , Kruck Georgia , Nowakowski Alexander , Lazaratos Anna-Maria , Petrecca Kevin , Siegel Peter
Published: April 2023

Background: An estimated 20-40% of cancer patients develop brain metastases (BrM), mostly those affected by lung cancer, breast cancer or melanoma. Unfortunately, these patients suffer from poor outcomes and diminished quality of life. Few BrM treatment options beyond local therapy exist and this is often a short-term solution as 60% of resected BrM recur within 1 year. Our group discovered that patient prognosis is linked to BrM invasiveness, with highly invasive (HI) BrM more likely to recur, compared to minimally invasive (MI) BrM. This has presented us the opportunity to investigate exploitable biological mechanisms driving HI BrM. For instance, invasive signaling can be driven by microenvironmental proteins such as growth and immunological factors (cytokines) secreted by surrounding brain or cancer cells, through inter-cellular or self-feeding autocrine loops.

Hypothesis: Considering the influence of secreted factors on cancer invasion and the brain microenvironment, I hypothesize that secretory profiling of BrM and brain parenchymal cells will be mechanistically insightful and help identify potential targetable drivers of BrM invasion.

Results: To identify BrM invasion-related tumor- and brain-derived factors, I performed human- and mouse-specific high throughput Enzyme-Linked Immunosorbent Assay (ELISA)-based screens on conditioned media from mouse brain slices harboring intracranial MI or HI BrM patient-derived xenografts (PDX). This secretome screen reveals distinct MI and HI secretory profiles for melanoma, breast cancer and lung cancer BrMs and several HI BrM-derived factors of interest have been identified. Such factors are important to investigate as possible drivers of invasiveness in BrM through functional studies.

Conclusion: BrM patients currently face a bleak prognosis, with few treatment options and a median survival of only 8-16 months. Considering the clinical availability of targeted therapies including inhibitors for growth factor-binding tyrosine kinases, antibody-drug conjugates, and immunotherapy, this project will help elucidate the cancer-brain crosstalk which may be exploited therapeutically with existing drugs in patients with frequently recurring HI BrM. ADDIN

Citation Format: Caitlyn Mourcos, Sarah M. Maritan, Matthew G. Annis, Georgia Kruck, Alexander Nowakowski, Anna-Maria Lazaratos, Kevin Petrecca, Peter Siegel. Targeting tumor-brain crosstalk in invasive brain metastases. [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 3615.
Abstract 3660: Bone mechanics influence cancer stem cell formation in osteosarcoma
Authors: Shoaib Zunaira , Tiffany Aleczandria S. , Harley Brendan , Irudayaraj Joseph , Fan Timothy M.
Published: April 2023

Osteosarcoma (OS) is the most common primary tumor of bone and is characterized by rapid bone remodeling accompanied by structural and mechanical heterogeneity across the tumor. Chemoresistance and recurrence of OS can be attributed to a subpopulation of OS cells known as cancer stem-like cells (OS-CSCs). It can be hypothesized that tumor niches possessing distinct structural and mechanical properties could be harboring different OS cell populations, and certain niches might be more conducive for OS-CSCs formation and maintenance.

To evaluate the presence of OS-CSCs, mineralized collagen scaffolds mimicking heterogenous bone niches with distinct structural and mechanical properties were fabricated by changing collagen content and pore alignment and were cultured with the highly metastatic human OS cell line 143B. Scaffolds with 47% collagen by weight but different pore alignment were chosen for further analysis because they possessed different stiffness and topographical properties. Cytoskeletal changes, epigenetic changes, chemoresistance and chemoresistance-related pathways, and the levels of stemness genes were assessed in the 3D scaffold cultures.

A consistent trend of OS-CSC phenotype was observed in the cell population grown in the softer bone niches (12 kPa) with aligned pores as compared to stiffer niche (31 kPa) with non-aligned pores. The cell population growing in softer, aligned scaffolds had a significantly higher expression of stemness genes (OCT4, NANOG, SOX2, ALDH1A1) and drug efflux gene ABCB1 and increased chemoresistance to doxorubicin and cisplatin. Epigenetic changes associated with cisplatin resistance in OS such as a decrease in methyl transferase EZH2 accompanied by the upregulation of LIF/Notch and PRKCA pathways was observed in cells grown in softer, aligned niches. Fluorescent imaging of actin organization showed rounder cells in the aligned niche indicative of the CSC phenotype, and stretched, elongated cells in the non-aligned niche indicative of a differentiated phenotype.

Our study showed that the mechanical and structural properties of bone niches influence the formation of distinct OS cell populations. A softer niche with an aligned structure is more conducive for maintaining OS-CSCs.

Citation Format: Zunaira Shoaib, Aleczandria S. Tiffany, Brendan Harley, Joseph Irudayaraj, Timothy M. Fan. Bone mechanics influence cancer stem cell formation in osteosarcoma. [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 3660.
Abstract 3681: c-MAF-driven metabolic reprogramming mediates H3K27 hyperacetylation to regulate super enhancer-associated genes
Authors: Chong Phyllis SY , Lim Sze Lynn Julia , Zhou Jianbiao , Leow Aaron Chung Yong , Chng Wee Joo
Published: April 2023

Overexpression of transcription factor c-MAF is found in about 50% of multiple myeloma cases, and associated with the prognostically unfavorable t(14;16) translocation subtype. Genetic alterations can modify the epigenome through metabolite availability that act as substrates in histone modifications, but how this translates into specificities in gene regulation is unclear. Here, we report a novel involvement of c-MAF in metabolically-driven histone acetylation, including the superenhancer mark H3K27ac, through altering acetyl-CoA metabolism. To sustain high levels of acetylation, c-MAF acquired the metabolic flexibility to utilize glutamine in addition to glucose, feeding into the tricarboxylic acid (TCA) cycle as acetyl-CoA sources. Loss-of-function studies indicated that c-MAF is important for citrate-derived acetyl-CoA and H3K27ac levels through metabolic enzymes citrate synthase (CS) and ATP-citrate lyase (ACLY). Furthermore, blocking citrate export from mitochondrial via CRISPR/Cas9 targeting of SLC25A1 reproduced the reductions in H3K27ac. Silencing of c-MAF also displayed defective mitochondrial oxidative phosphorylation attributed to reduced metabolic flux through TCA cycle and downregulation of electron transport chain complex I/II expression, without affecting mitochondrial DNA content. To identify c-MAF-regulated superenhancer genes, we overlapped our previously published H3K27ac ChIP-seq dataset on t(14;16) MM cell lines with c-MAF RNA-seq data. We found signal enrichment of H3K27ac at ZC3H3 locus responsible for its transcriptional upregulation, and knockdown of ZC3H3 inhibited cell growth specifically in the t(14;16) subtype. Altogether, we demonstrated a non-canonical c-MAF role in epigenetics that is connected to its altered metabolic state, and suggest metabolic disruptions as a new therapeutic direction in t(14;16) myeloma.

Citation Format: Phyllis SY Chong, Sze Lynn Julia Lim, Jianbiao Zhou, Aaron Chung Yong Leow, Wee Joo Chng. c-MAF-driven metabolic reprogramming mediates H3K27 hyperacetylation to regulate super enhancer-associated genes. [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 3681.
Abstract 3688: Exploring metabolic vulnerabilities of metastatic prostate cancer to bone
Authors: Mossa Federica , Robesti Daniele , Vellano Christopher , Titus Mark , Marszalek Joe , Frigo Daniel , Logothetis Christopher , Gujral Taranjit , Dondossola Eleonora
Published: April 2023

Currently, limited knowledge is available on subtype-specific metabolic features and their implications for treatment. Here, we investigated the metabolic determinants of the two major subtypes of castration-resistant prostate cancer (androgen receptor-expressing prostate cancer, ARPC; and aggressive variant prostate cancer, AVPC). Transcriptomic analyses revealed enrichment of gene sets involved in oxidative phosphorylation in ARPC tumor samples compared to AVPC. Unbiased screening of metabolic signaling pathways in PDX models by proteomic analyses further supported an enrichment of oxidative phosphorylation in ARPC compared to AVPC, and a skewing toward glycolysis by AVPC. Metabolic in vitro analyses showed that C4-2B cells depended on aerobic respiration, while PC3 cells relied more heavily on glycolysis, as further confirmed by pharmacological interference using IACS-010759, a clinical grade inhibitor of oxidative phosphorylation tested in patients. In vivo studies confirmed a significant reduction by IACS-010759 in C4-2B tumors implanted subcutaneously or in bone, and no effect in subcutaneous PC3 tumors. Unexpectedly, PC3 tumors in bone responded to IACS-010759, indicating a microenvironment-induced metabolic reprogramming. These results suggest that castration-resistant ARPC and AVPC exhibit different metabolic dependencies with aerobic respiration being a major driver of ARPC, while AVPC depends on glycolysis, but can undergo metabolic reprogramming in bone. Such metabolic vulnerabilities may be exploited to either introduce further lines of treatments or in combination with the existing therapies. These findings also underscore the important role that the tumor microenvironment can play in reprogramming prostate cancer metabolism and thus, influence the efficacy of metabolically targeted therapies.

Citation Format: Federica Mossa, Daniele Robesti, Christopher Vellano, Mark Titus, Joe Marszalek, Daniel Frigo, Christopher Logothetis, Taranjit Gujral, Eleonora Dondossola. Exploring metabolic vulnerabilities of metastatic prostate cancer to bone. [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 3688.
Abstract 370: Potential of inflammation pro-resolving lipid mediators in controlling cancer cachexia
Authors: Attaya Ahmed , Haak Victoria , Kelly Abigail , Yang Haixia , Rothenberger Eva , Freedman Steven D. , Serhan Charles N. , Panigrahy Dipak
Published: April 2023

Most people with advanced cancer exhibit cachexia, a syndrome of progressive weight loss that leads to the death of 20% of patients. The mechanisms underlying cachexia remain poorly understood and, as a result, no treatment has proven effective to date. Cachexia is characterized by systemic hyperinflammation, massive apoptotic cell death (“debris”), and skeletal muscle wasting. Here, we hypothesize that disrupted resolution of inflammation contributes to cancer cachexia, and pro-resolving lipid mediators, specifically novel specialized pro-resolving mediators (SPMs), could control cachexia. SPMs enhance resolution of inflammation by stimulating debris clearance, promoting tissue regeneration, and regulating major immune cell types. In testing our hypothesis, we profiled lipid mediators in a variety of metastatic cachexia models via metabololipidomics and investigated the changes of leukocytes, e.g., T lymphocyte, natural killer (NK), and macrophage cells, in various skeletal muscles (e.g., tibialis anterior and gastrocnemius). Dysregulation of SPMs was identified in different tissues in 5 cachexia models. The SPMs resolvin (RvD)2 and maresin (MaR)1 were reduced in the liver and spleen of colon cancer (CT26)-induced cachectic mice on day 35 post-tumor cell injection and RvD1, RvD2, lipoxin (LXA)4, and MaR1 were dysregulated in Lewis lung carcinoma (LLC)-induced cachectic mice on day 20. Chemotherapy was also found to dysregulate SPMs and induce cachexia in lymphoma (EL4) and ovarian cancer (ID8) mouse models. Ten days post-LLC tumor resection, the RvD1 receptor (ALX/FPR2) KO and RvE1 receptor (ChemR23/ERV) KO mice exhibited a 20-23% loss in body weight compared to WT mice. This shows that neutralizing the pro-resolving activity of RvD1 and RvE1 induces cancer cachexia. Moreover, RvD2 and PCTR (protectin conjugates in tissue regeneration)-2 prevented LLC- and B16F10 melanoma-induced cachexia at 15 ng/day. RvD4, RvD5, MCTR1, or MCTR2 inhibited inflammation-stimulated cytokine storm by counter-regulating the production of CCL3, CCL4, CXCL2, TNF-α, CCL2, G-CSF, and PAI-1. These results indicate that disrupted resolution of inflammation leads to the progression of cancer cachexia, and dysregulated SPMs are potential early markers for cachexia. This study provides a basis for the clinical translation of SPM-directed treatments as a new direction to potentially control cancer cachexia in humans.

Citation Format: Ahmed Attaya, Victoria Haak, Abigail Kelly, Haixia Yang, Eva Rothenberger, Steven D. Freedman, Charles N. Serhan, Dipak Panigrahy. Potential of inflammation pro-resolving lipid mediators in controlling cancer cachexia [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 370.
Abstract 3708: Platelet-derived microparticles modulate breast cancer malignant processes
Authors: Veilleux Vanessa , Pichaud Nicolas , Boudreau Luc H. , Robichaud Gilles A.
Published: April 2023

Breast cancer is one of the leading causes of morbidity and mortality among women, where metastasis accounts for the majority of deaths associated with this disease. Thus, the potential to effectively target tumor malignancy offers hope to mitigate disease progression and improve patient outcomes. It is well established that platelets promote multiple processes of metastasis cascade. Recently, platelets have received new attention for their impact in cancer through the production of platelet-derived microparticles (PMPs). Interestingly, PMPs allow intercellular exchange and trafficking of bioactive material through the internalization of these vesicles into recipient cells. As a result, the delivery of the intravesicular cargo can modulate signaling and activation processes of recipient cells. We recently identified a new subpopulation of these vesicles (termed mitoMPs) containing functional mitochondria. Given the predominant role of mitochondria in cancer malignancy, we believe that mitoMPs provide an important source of foreign mitochondria to support recipient breast cancer cells in malignancy and disease progression. We therefore set out to study the impact of mitoMPs on breast cancer metabolic and phenotypic processes involved in metastasis. Technically, PMPs were generated and purified from human blood platelets and co-incubated with various breast cell models (MB231, MCF7 and MCF10A). The physiological significance of mitoMPs in breast cancer disease was then assessed using various cellular and molecular assays. We demonstrate that the level of PMP internalization is highly dependent upon the type of breast cancer recipient cells. Furthermore, we show that the cargo of mitoMPs (notably mitochondria) is biologically active where recipient breast cancer cells acquired mitochondria-dependent functions, such as increased oxygen consumption rates and intracellular ATP production. Finally, we observe that mitoMPs promote malignant features such as cancer cell migration and invasion. Overall, we demonstrate that PMPs can modulate cancer cell activation and behaviour. These findings provide a better understanding of the extracellular tumor environment and the contribution of mitoMPs in supporting breast cancer cells through the metastatic landscape. The knowledge gained will further provide new avenues for therapeutic strategies in breast cancer patients.

Citation Format: Vanessa Veilleux, Nicolas Pichaud, Luc H. Boudreau, Gilles A. Robichaud. Platelet-derived microparticles modulate breast cancer malignant processes. [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 3708.