bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3847: Tumor stem cell derived asymmetric dimethylarginine drives immune evasion via functional modulation of macrophages
Authors: Chen Yiling , Lowery AKaychia T. , Becerril Andres , Laventure Zaida T. , Ferguson Shareda , Chen Kuan-Hui Ethan
Published: June 2022

Macrophages are the most abundant tumor infiltrating immune cells and perform diverse immune functions including phagocytosis and incitation of T cells to mount an immune attack against tumors. However, the macrophage plasticity can lead to different outcomes of tumor progression and the amino acid, arginine, plays a central role in macrophage dichotomy. The exact role of arginine on the management of macrophage polarization is not completely understood. We have discovered that a methylated arginine metabolite, asymmetric dimethylarginine (ADMA), serves as an important regulator of macrophage functions. Upon stimulation by ADMA, macrophages have reduced survival and show a delayed tumor-phagocytic capacity. Additionally, ADMA blocks the Nitric Oxide Synthase (NOS) but not the Arginase activity in macrophages leading to a tendency of M2-like phenotype polarization. ADMA has minor effect on tumor cell proliferation but significantly drives the epithelial to mesenchymal transition. Tumor cells, particularly the tumor stem cells, are the major sources of ADMA. Production and secretion of ADMA by tumor (stem) cells profoundly increase when co-cultured with activated T cells or treated with T cell associated inflammatory cytokine, interferon-gamma (IFN-r). IFN-r initiates autophagy of tumor (stem) cells and inhibition of autophagy reduces the output of ADMA by tumor (stem) cells. Similarly, IFN-r enhances the proteasomal degradation and inhibition of the proteasomal pathway also reduces the ADMA production induced by IFN-r. In summary, our work shows that tumor (stem) cells may escape from immune surveillance (such as their exposure to activated T lymphocytes or to cytotoxic cytokine, IFN-r) through the secretion of ADMA generated via both autophagic and proteasomal pathways.

Citation Format: Yiling Chen, AKaychia T. Lowery, Andres Becerril, Zaida T. Laventure, Shareda Ferguson, Kuan-Hui Ethan Chen. Tumor stem cell derived asymmetric dimethylarginine drives immune evasion via functional modulation of macrophages [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3847.
Abstract 3850: Supermeres are functional extracellular nanoparticles replete with cancer biomarkers and therapeutic targets
Authors: Zhang Qin , Jeppesen Dennis K. , Higginbotham James N. , Glass Sarah E. , Franklin Jeffrey L. , Coffey Robert J.
Published: June 2022

Cancer-derived extracellular vesicles, including exosomes, and exomere nanoparticles, are under intense investigation for cargo that may serve as clinical biomarkers and therapeutic targets. Here, we report the discovery of a new extracellular nanoparticle, termed supemeres. Supermeres are morphologically different from exomeres as determined by fluid-phase atomic force microscopy and display distinct uptake both in vitro and in vivo. In colorectal cancer (CRC) cell-derived supermeres, TGFBI is the most abundant protein and is linked to CRC progression and survival. Supermeres are enriched with cargo involved in multiple cancers including glycolytic enzymes, AGO2, shed MET and GPC1, and miR-1246. The majority of extracellular RNA is associated with supermeres rather than small extracellular vesicles and exomeres. Cancer-derived supermeres increase lactate secretion, transfer cetuximab-resistance, and decrease hepatic lipids and glycogen in vivo. This study identifies a distinct functional nanoparticle replete with potential cancer-related circulating biomarkers and therapeutic targets.

Citation Format: Qin Zhang, Dennis K. Jeppesen, James N. Higginbotham, Sarah E. Glass, Jeffrey L. Franklin, Robert J. Coffey. Supermeres are functional extracellular nanoparticles replete with cancer biomarkers and therapeutic targets [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3850.
Abstract 3853: Investigating PRL2/PTP4A2 as a new target for glioblastoma treatment
Authors: Chouleur Tiffanie , Derieppe Marie-Alix , Souleyreau Wilfried , Tremblay Michel L. , Bikfalvi Andreas
Published: June 2022

Glioblastoma (GBM) is the most aggressive primary brain tumor. The standard treatment consists in tumor resection followed by chemo- and radio- therapy. However, tumor recurrence still remains inevitable, and the average lifespan of patients is only 15 months. Over the past decades, targeted therapies such as anti-angiogenic therapy, were proposed but failed to improve overall survival. In this context, the identification of new therapeutic targets is fundamental to implement current treatments. Protein Tyrosine Phosphatases (PTPs) are known to be involved in oncogenesis in several types of cancer, including GBM. Oncogenic properties of PRL2 has been demonstrated in different tumors (e.g. leukemia, breast, lung and nasopharyngeal cancer), but no evidence of PRL2 involvement in GBM has been reported so far. The aim of this project is to understand the role of PRL2 in GBM development, in order to evaluate the potential of PRL2 inhibition as a new therapeutic strategy. Analysis of TCGA (The Cancer Genome Atlas) dataset revealed that PRL2 was a poor prognostic factor in gliomas, and its expression correlated GBM aggressiveness. PTP4A2 expression also correlated with expression of genes involved in immune responses, reactive oxygen species, actin cytoskeleton and trafficking. Thus, we oriented our work towards these directions. To study PRL2 effects both in brain tumor cells and microenvironment, we used spheroids of patient-derived GBM cells, in which PTP4A2 expression was modulated. In vitro assays showed that migration, invasion and adhesion abilities were increased in PTP4A2-KO cells but cell proliferation was not affected. Next, in orthotopic xenografts experiments, PRL2 over-expression promoted tumor growth and reduced mouse survival rate. In addition, to overcome PRLs functional compensation and to use a clinically relevant strategy, we targeted all PRLs (PRL1, 2 and 3) activity with an inhibitory compound. Inhibiting all PRLs drastically reduced viability of GBM cells. Our project aims at discovering how PRL2 is involved in the progression and tumor microenvironment of GBM. Our results indicate that PRL2 promotes GBM growth in response to microenvironmental pressure and its inhibition improves mouse outcomes. However, the precise mechanisms of this regulation are still under investigation. Targeting PRLs and particularly PRL2 open avenue for therapeutic strategy in GBM treatment.

Citation Format: Tiffanie Chouleur, Marie-Alix Derieppe, Wilfried Souleyreau, Michel L. Tremblay, Andreas Bikfalvi. Investigating PRL2/PTP4A2 as a new target for glioblastoma treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3853.
Abstract 3858: Peristalsis-like mechanical stimuli in the intestinal milieu promotes colorectal cancer invasion through GABAergic signaling changes in an organ-on-chip platform
Authors: Strelez Carly , Chilakala Sujatha , Ghaffarian Kimya , Yoon Ah Young , Katz Jonathan , Mumenthaler Shannon M.
Published: June 2022

Mechanical forces in the tumor microenvironmental milieu are often understudied due to a lack of relevant preclinical model systems. Here we describe a microfluidic organ-on-chip platform that incorporates tissue-tissue interfaces and physical forces to aid in the examination of colorectal cancer (CRC) progression. A major advantage of this model is the ability to mimic peristalsis, a physiological process occurring in the gut. Live-cell imaging with a 3D printed organ-on-chip cradle was used to quantify the number of CRC cells that have invaded from the epithelial channel into the vascular channel over time. We determined that peristalsis-like motions in our organ-on-chip model enhanced the invasion capacity of CRC cells, mimicking intravasation. We subsequently examined the effluent media in stretched compared to non-stretched conditions using mass spectrometry based metabolomics and discovered an increase in the secretion of gamma-aminobutyric acid (GABA) by CRC cells, implicating peristalsis-mediated tumor cell invasion with neurotransmitter release. Inhibitors targeting the GABA-A receptor reversed the observed tumor cell invasion phenotype when cells were subjected to peristalsis-like motions. Interestingly, even in the absence of peristalsis, tumor cell invasion was promoted when GABA agonists were introduced into the organ-on-chip system. This work reveals important interactions between CRC cells and their microenvironment, and that disrupting GABAergic signaling might be an approach to prevent or delay cancer progression.

Citation Format: Carly Strelez, Sujatha Chilakala, Kimya Ghaffarian, Ah Young Yoon, Jonathan Katz, Shannon M. Mumenthaler. Peristalsis-like mechanical stimuli in the intestinal milieu promotes colorectal cancer invasion through GABAergic signaling changes in an organ-on-chip platform [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3858.
Abstract 3866: Spatial multi-omics analysis targeting protein and RNA biomarkers on a single FFPE tissue section using an integrated staining workflow
Authors: Chatterjee Gourab , Vezeau Grace E. , Lazova Milena D. , Sismour Michael , Manesse Mael
Published: June 2022

Biomarker detection approaches capable of rapid identification, quantification, and spatial mapping of many cellular sub-types of the tumor environment in FFPE tissue sections are becoming increasingly valuable for investigating the highly complex biology of tumors and their respective microenvironments. Multiplexed immunofluorescence (mIF) enables simultaneous identification of multiple protein targets within their spatial context in FFPE tissues, thereby facilitating more in-depth analysis including cellular phenotyping. In parallel, spatial transcriptomic analysis can provide additional insights into cellular function. Multi-omics analyses combining protein and nucleic acid biomarkers on a single tissue section can provide a deeper understanding of the complex cellular interactions in the context of the tumor. In this study, we demonstrate the versatility of Ultivue InSituPlex technology (ISP) through an integrated workflow for co-detection of protein and RNA on a single tissue section.

FFPE tumor tissue samples were processed for protein and/or RNA detection on a single slide with an integrated workflow using ISP. Briefly, slides were stained for both protein and RNA targets using a Leica Biosystems BOND RX autostainer. Post-staining, the slides were imaged on ZEISS Axioscan.Z1 in five different fluorescent channels and evaluated using IndicaLabs HALO analysis software. In parallel, control serial sections were stained to perform comparative analyses.

Here we report an efficient and streamlined integrated workflow for co-detection of protein and RNA on a single section, powered by ISP technology. The protein and RNA targets were detected both sequentially (over different imaging rounds) with increased multiplexing capabilities, as well as concurrently (in the same imaging round) for a higher throughput solution, thereby demonstrating the flexibility of the workflow. Comparative analyses between the different workflows confirmed minimal effect on staining performance of individual biomarkers (both protein and RNA).

The gentle treatment of FFPE tissue sections through ISP technology preserves tissue integrity, and morphology enabling efficient detection of protein and RNA targets on a single section. The integrated workflows presented here demonstrate compatibility of the individual steps in the assay towards co-detection of protein and RNA targets with efficient sensitivity in terms of staining performance for individual biomarkers.

Citation Format: Gourab Chatterjee, Grace E. Vezeau, Milena D. Lazova, Michael Sismour, Mael Manesse. Spatial multi-omics analysis targeting protein and RNA biomarkers on a single FFPE tissue section using an integrated staining workflow [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3866.
Abstract 3896: Pimavanserin suppresses the growth of medulloblastoma by inhibiting Lyn/STAT3/MBSC signaling axis
Authors: Ramachandran Sharavan , Gaikwad Shreyas , Srivastava Sanjay K.
Published: June 2022

Medulloblastoma (MB) is one of the most frequently occurring malignant brain tumors in children, which accounts for 20% of all pediatric brain tumors and 40% of posterior fossa tumors. Despite advancements in the understanding of MB pathogenesis and identification of novel therapeutic targets, MB has emerged to be one of the most lethal pediatric diseases with peak incidences occurring in children aged between 5 and 7 years old. Numerous factors have been identified to hamper the management of several brain tumors including MB. However, the presence of medulloblastoma stem cells (MBSCs) and impermeability of drugs to cross the blood brain barrier (BBB) are identified as the major obstacles in MB management. MB is highly enriched with MBSCs, a subpopulation of MB cells that imparts therapy resistant, invasive and recurrent characteristics to MB. In our study, we evaluated the effects of Pimavanserin (PVT) in MB. Our results demonstrated that PVT treatment suppressed the proliferation of various MB cells by inducing apoptosis as shown by AnnexinV APC-PI assay. At molecular level, PVT inhibits Lyn/STAT3/MBSCs signaling axis. Additionally, chronic administration of PVT significantly suppressed the growth of subcutaneous and intracranial tumor xenografts without causing major side effects. Taken together, our study provides convincing evidence that PVT could serve as a novel treatment option for MB patients in the future. Ours is the first study to report to report the anti-cancer effects of PVT.

Citation Format: Sharavan Ramachandran, Shreyas Gaikwad, Sanjay K. Srivastava. Pimavanserin suppresses the growth of medulloblastoma by inhibiting Lyn/STAT3/MBSC signaling axis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3896.
Abstract 3906: Characterization of mTORC2 interactome reveals association with microtubules in glioblastoma and neuroblastoma cells
Authors: Pacharakullanon Narawit , Wongkongkathep Piriya , Tamanoi Fuyuhiko , Loo Joseph A. , Pisitkun Trairak , Chantaravisoot Naphat
Published: June 2022

The Mechanistic Target of Rapamycin Complex 2 (mTORC2) is a multiprotein complex representing one of the key players in the mTOR signaling pathway. This signal transduction is essential for the regulation of various cellular activities, including proper cell growth, proliferation, differentiation, survival, cell motility, and metabolism. Aberration of the mTOR cascade can be found in several types of disorders, including cancers and neurodegenerative diseases. It has been reported to correlate with acquired aggressive characteristics promoting metastasis, drug resistance, and recurrence in cancer cells and more progressive phenotypes in other diseased cells. More specifically, mTORC2 signaling promotes actin cytoskeleton reorganization, cell motility, cell survival, and has been recently reported to be responsible for DNA damage control. Unlike mTORC1 that has been more thoroughly studied, molecular mechanisms of mTORC2 are yet to be elaborated. Therefore, characterization of the mTORC2 signaling pathway will provide further information needed for better understandings of the biology of diseases. Previously, we have identified multiple cytoskeleton regulators, including actin-binding and microtubule-associated proteins as binding partners of mTORC2 in glioblastoma cells by affinity purification-mass spectrometry (AP-MS). In this work, we provided extensive characterization of mTORC2 interactome in both neuronal and non-neuronal cells focusing on microtubule-associated proteins. Interestingly, apart from many MAP proteins found in non-neuronal cells (glioblastoma), we identified Tau isoforms and their regulatory proteins such as Tau kinases from affinity-purified mTORC2 in neuroblastoma cells. The quantitative proteomic analyses of mTORC2-interacting proteins in various cellular conditions were performed to help determine the dynamics of the mTORC2-associated microtubule network. These novel protein-protein interactions acquired from this study suggested additional mTORC2 functions in different types of brain cells, which might also be beneficial to the understandings of neurodegenerative diseases in addition to cancers.

Citation Format: Narawit Pacharakullanon, Piriya Wongkongkathep, Fuyuhiko Tamanoi, Joseph A. Loo, Trairak Pisitkun, Naphat Chantaravisoot. Characterization of mTORC2 interactome reveals association with microtubules in glioblastoma and neuroblastoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3906.
Abstract 3913: Quantitative phosphoproteomic analysis of AXL signaling network in breast cancer
Authors: Wang Li , Pearson Nicole , Xiong Yuning , Renuse Santosh , Cheng Ran , Carter Jodi M. , Pandey Akhilesh , Wu Xinyan
Published: June 2022

Background: As a key receptor tyrosine kinase (RTK) regulating tumorigenesis, AXL is overexpressed in multiple different types of cancers. AXL can be activated by homodimerization after binding with its ligand, growth arrest specific 6 protein (Gas6) or by heterodimerization with other RTKs. AXL overexpression and/or activation have been reported to promote cancer cell proliferation, migration/invasion and to induce resistance to targeted therapy. However, the AXL downstream signaling network has not yet been fully elucidated.

Methods: We employed a CRISPR-CAS9-based knockout technology to create AXL inducible knockout cells in a human triple negative breast cancer (TNBC) cell line, HCC1395. In order to explore the downstream signaling events driven by AXL, we induced AXL knockout for 72 hours and used a 6-plex TMT-labeling-based quantitative proteomic approach to characterize the protein phosphorylation alterations induced by AXL knockout. IMAC and anti-phosphotyrosine antibody (pY1000)-based phosphopeptide enrichment methods were used to comprehensively quantify the phosphoproteome changes induced by AXL knockout.

Results: In this study, we identified 38,525 phospho serine/threonine sites and 1,427 phosphotyrosine sites. In response to AXL knockout, 1,581 phospho serine/threonine sites and 40 phosphotyrosine sites showed significant differences between AXL-KO and AXL-WT groups with >1.5-fold change and p<0.05 as the cutoff. Among them, 982 phosphoserine/threonine sites and 30 phosphotyrosine sites were decreased, while 599 phospho serine/threonine sites and 10 phosphotyrosine sites were increased in AXL-KO cells. Signaling pathway enrichment analysis revealed that suppressing AXL expression could inhibit multiple important cancer related signaling pathways, including cell cycle, focal adhesion, MAPK signaling pathway, p53 signaling pathway and mTOR signaling pathway.

Conclusion: Quantitative analysis of the phosphoproteome driven by AXL demonstrated that AXL plays a pivotal role in regulating canonical oncogenic signaling but also signaling pathways involved in RNA processing and DNA repair. Our data also suggest that targeting AXL could suppress these oncogenic signaling pathways and have therapeutic potential to improve clinical outcomes for patients with AXL overexpression.

Citation Format: Li Wang, Nicole Pearson, Yuning Xiong, Santosh Renuse, Ran Cheng, Jodi M. Carter, Akhilesh Pandey, Xinyan Wu. Quantitative phosphoproteomic analysis of AXL signaling network in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3913.
Abstract 394: Elevated aryl hydrocarbon receptor and leptin receptor expression correlates with prostate cancer progression and may be associated with obesity-associated leptin-mediated chemoresistance
Authors: Khamit-Kush Kofi Kyenku , Powell Joann B. , Handy Jeffrey A. , Bowen Nathan , Wu Daqing , Odero-Marah Valerie
Published: June 2022

The aryl hydrocarbon receptor (AhR) is a nuclear transcription factor and xenobiotic sensor reported to mediate diet-induced obesity and is upregulated in high-grade prostate cancer (PCa). Previously published data from our lab shows that AhR protein is overexpressed and constitutively active in castration-resistant prostate cancer cells. Physiologically relevant leptin concentration is proportional to BMI and it is secreted by adipose cells to inhibit hunger under normal circumstances. Our preliminary results suggest that obesity-associated leptin concentrations desensitize PCa cells to cancer drugs however, the underlying mechanisms must be elucidated and may require sustained AhR signaling. In this study, we conducted an integrative bioinformatics analysis to explore the role of AHR and LEPR in PCa, which revealed AHR and LEPR mRNA expression positively correlates in prostate cancer (P<0.05, Pearson: 0.68, R^2=0.46). The mRNA expression levels of AHR and LEPR in PCa tissue samples (i.e. solid tissue normal samples from individuals with cancer in TCGA, N=498) were analyzed using the cBioPortal and Xena online tools. We will further investigate if the decrease in drug response is seen in the presence of obesity-associated leptin concentrations. Further understanding of the potential interaction(s) between adipokines, AhR, and chemoresistance can promote improved treatments for patients with prostate cancer.

Citation Format: Kofi Kyenku Khamit-Kush, Joann B. Powell, Jeffrey A. Handy, Nathan Bowen, Daqing Wu, Valerie Odero-Marah. Elevated aryl hydrocarbon receptor and leptin receptor expression correlates with prostate cancer progression and may be associated with obesity-associated leptin-mediated chemoresistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 394.
Abstract 3980: Targeting Ewing sarcoma based on RNA expression
Authors: Smith Kaitlyn , Gandra Divya , McKinney Kimberly , Dykema Karl , Nagulapally Abhinav , Sholler Giselle S. , Oesterheld Javier , Trovillion Erin
Published: June 2022

Purpose: Ewing sarcoma (ES) is the second most common malignant bone sarcoma in children and young adults. Current treatment for Ewing sarcoma includes a combination of cytotoxic chemotherapeutic agents and local control with radiation and/or surgery. The survival rate of those with Ewing sarcoma has seen very little improvement over the past several decades and remains dismal for those with recurrent or metastatic disease. The purpose of this study is to identify novel agents currently available for use in Ewing sarcoma.

Methods: Novel targeted approaches for the treatment of ES were identified using RNA sequencing performed on 15 ES patient derived cell lines with bioinformatic analysis of gene expression. Targeted agents were tested on patient cell lines at escalating doses. At 48 hours cell viability was assessed with CellTiter-Glo 2.0 and analyzed with GraphPad Prism to determine the IC50. At 24- and 48-hours western blot analysis was performed to evaluate the effect on cell cycle and apoptosis. Combination studies with standard chemotherapy were performed to evaluate for synergy using SynergyFinder 2.0.

Results: RNA analysis identified HDAC2, ALK and JAK1 as a potential therapeutic targets. The pan-HDAC inhibitor, Panobinostat, was cytotoxic to all Ewing sarcoma cell lines tested with clinically relevant IC50s (≤200nM) and repressed expression of Cyclin D1 and pRB. ALK inhibition was cytotoxic at doses slightly higher than that of clinical relevance. HDAC and ALK expression levels correlated to cell sensitivity. JAK1 inhibition does not appear to have efficacy at clinically relevant dosing. Panobinostat synergizes with Doxorubicin at clinically relevant doses.

Conclusion: This work highlights that RNA expression may identify potential targets which could be effective in treating Ewing sarcoma or potentially improve the efficacy of standard of care drugs. HDAC and ALK inhibition show a decrease in cell viability in ES cell line models. Future studies of HDAC and ALK inhibitors will aim to determine efficacy in xenograft models.

Citation Format: Kaitlyn Smith, Divya Gandra, Kimberly McKinney, Karl Dykema, Abhinav Nagulapally, Giselle S. Sholler, Javier Oesterheld, Erin Trovillion. Targeting Ewing sarcoma based on RNA expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3980.
Abstract 399: The glucocorticoid receptor and β-catenin interact in prostate cancer cells and their co-inhibition attenuates stemness and docetaxel resistance
Authors: Martinez Shannalee R. , Elix Catherine C. , Ochoa Pedro T. , Sanchez-Hernandez Evelyn S. , Alkashgari Hossam R. , Ortiz-Hernandez Greisha L. , Zhang Lubo , Casiano Carlos A.
Published: June 2022

The efficacy of anti-androgen receptor (AR) therapies and taxane-based chemotherapy for the treatment of advanced prostate cancer (PCa) is hindered by the development of therapy resistance. Our previous studies demonstrated that docetaxel (DTX)-resistant PCa cells activates a transcriptomic program associated with stemness and display cancer stem cell (CSC) properties, consistent with the notion that CSCs within prostate tumors contribute to chemoresistance. Glucocorticoid receptor (GR) signaling is a critical mediator of resistance to AR-targeted therapy, and has been recently implicated in the development of PCa cell tumorsphere formation and chemoresistance. Like GR, β-catenin is overexpressed in metastatic and therapy-resistant tumors, and is considered a key regulator of cancer stemness and androgen-targeted therapy resistance. Given the structural and functional overlap between GR and AR, a known interacting partner of β-catenin, we hypothesized that GR also interacts with β-catenin to support stemness and chemoresistance in PCa cells. We observed that treatment with the glucocorticoid dexamethasone induces enhanced nuclear accumulation of both GR and β-catenin in DTX-resistant PCa cells compared to their DTX-sensitive counterparts. Knockdown studies revealed that GR and β-catenin do no regulate each other at the protein level. However, using whole cell and nuclear co-immunoprecipitation, we demonstrated the interaction between GR and β-catenin in both DTX-resistant and DTX-sensitive PC3, DU145, and 22RV1 cells. Pharmacological inhibition and RNA interference-mediated silencing of GR with concomitant inhibition of β-catenin enhanced DTX cytotoxicity in resistant PCa cells grown in both adherent and spheroid cultures, and decreased CD44+/CD24- cell populations in tumorspheres. These results indicate that both GR and β-catenin interact and influence stemness, and may be promising therapeutic targets to overcome PCa chemoresistance.

Citation Format: Shannalee R. Martinez, Catherine C. Elix, Pedro T. Ochoa, Evelyn S. Sanchez-Hernandez, Hossam R. Alkashgari, Greisha L. Ortiz-Hernandez, Lubo Zhang, Carlos A. Casiano. The glucocorticoid receptor and β-catenin interact in prostate cancer cells and their co-inhibition attenuates stemness and docetaxel resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 399.
Abstract 3990: MERTK is a potential therapeutic target in Ewing sarcoma
Authors: Smart Sherri K. , Yeung Tsz Y. , Wang Xiaodong , Frye Stephen V. , Earp H. Shelton , Graham Douglas K. , DeRyckere Deborah
Published: June 2022

Ewing sarcoma (EWS) is the second most common pediatric bone tumor, and outcomes remain poor in patients with advanced or relapsed disease. In addition, current treatments rely on multi-modal therapy that has significant short- and long-term side effects. New, less toxic and more effective treatments are urgently needed. One potential therapeutic target is the receptor tyrosine kinase MERTK. MERTK is overexpressed in numerous cancers where it promotes tumor cell survival, metastasis, and resistance to cytotoxic and targeted therapies. We demonstrated expression and phosphorylation of MERTK protein in 5 of 5 EWS family cell lines tested. Stimulation with the MERTK ligand GAS6 resulted in activation of downstream oncogenic signaling pathways, including JAK/STAT and MAPK/ERK. Moreover, publicly available data from CRISPR-based library screens suggest that EWS cell lines are particularly dependent on MERTK. Thus, therapeutic strategies targeting MERTK may be particularly effective for treatment of EWS. To explore the therapeutic impact of MERTK inhibition in various cancers, we developed MRX-2843, a first-in-class MERTK-selective tyrosine kinase inhibitor that is currently in clinical trials. Treatment with MRX-2843 decreased phosphorylation of MERTK in a dose dependent manner, with an IC50 of 123 nM (95% CI; 53-180 nM) in A673 cells, and reduced downstream STAT6 signaling. In addition, MRX-2843 had potent anti-tumor activity against all 5 EWS cell lines, leading to reduced expansion and decreased cell density in culture with IC50 values ranging from 178 - 297 nM. Of note, inhibition of MERTK phosphorylation correlated with anti-tumor activity in both the A673 and TC106 cell lines, implicating MERTK inhibition as a mechanism of MRX-2843 anti-tumor activity. Together these data validate MERTK as a promising therapeutic target in EWS and support development of MRX-2843 for treatment of EWS, with potential to directly inform and enable a clinical trial in pediatric patients and, ultimately, to improve both outcomes and quality of life for patients with this disease.

Citation Format: Sherri K. Smart, Tsz Y. Yeung, Xiaodong Wang, Stephen V. Frye, H. Shelton Earp, Douglas K. Graham, Deborah DeRyckere. MERTK is a potential therapeutic target in Ewing sarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3990.
Abstract 3995: Identification of perp as a tumor promoter in pancreatic cancer via the utilization of an aged model of cancer cachexia
Authors: Dasgupta Aneesha , Arneson-Wissink Paige C. , Schmitt Rebecca E. , Cho Dong Seong , Ducharme Alexandra M. , Hogenson Tara L. , Krueger Eugene W. , Bamlet William R. , Zhang Lizhi , Razidlo Gina , Fernandez-Zapico Martin E. , Doles Jason D.
Published: June 2022

Cachexia is a multifactorial syndrome characterized by extensive body weight, lean muscle and fat mass loss. Cachexia worsens cancer patient prognoses and contributes to poor chemotherapy tolerance and response rates. About 80% of pancreatic cancer patients suffer from cachexia and one-third die due to cachexia-related complications such as respiratory failure and cardiac arrest. Although there has been considerable research into cachexia mechanisms and interventions, there are, to date, no FDA-approved cachexia therapies. A major contributing factor could be the failure of animal models to accurately recapitulate the human condition. In this study, we generated an aged murine model of pancreatic cancer cachexia to compare cachexia progression in young versus aged tumor-bearing mice. Comparative transcriptomic analyses of the muscles identified 3-methyladenine (3-MA), a known autophagy inhibitor, as a candidate anti-wasting compound. In vitro analyses confirmed anti-wasting effects while in vivo analysis demonstrated that 3-MA could rescue muscle wasting and suppress tumor growth. Surprisingly, transcriptome analyses of 3MA-treated tumor cells did not reveal autophagy-related signatures but instead implicated Perp as a novel 3-MA target. Probing further, we 1) observed significantly higher expression of Perp in pancreatic cancer cell lines compared to control cells, 2) noted a survival disadvantage associated with elevated PERP in the TCGA database, 3) found that PERP knockdown in cancer cells led to reduced tumor proliferation, and 4) confirmed that 3-MA-associated Perp reduction inhibited tumor growth. Moreover, we also demonstrate that survival benefits associated with 3MA is independent of tumor progression. Finally, we queried Perp expression in human tumor samples and observed increased Perp expression in adenocarcinoma regions compared to tumor adjacent tissue. Taken together, we report a novel mechanism linking 3-MA to Perp inhibition, and further implicate Perp as a novel tumor promoting factor in pancreatic cancer.

Citation Format: Aneesha Dasgupta, Paige C. Arneson-Wissink, Rebecca E. Schmitt, Dong Seong Cho, Alexandra M. Ducharme, Tara L. Hogenson, Eugene W. Krueger, William R. Bamlet, Lizhi Zhang, Gina Razidlo, Martin E. Fernandez-Zapico, Jason D. Doles. Identification of perp as a tumor promoter in pancreatic cancer via the utilization of an aged model of cancer cachexia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3995.
Abstract 4017: Defining cell type-specific pathways in both cancer and tumor-microenvironment cells that impact survival of clear cell renal carcinoma patients
Authors: Strunilin Ilya , Wu Yige , Liu Ruiyang , Caravan Wagma , Chen Feng , Ding Li
Published: June 2022

Clear cell renal cell carcinoma (ccRCC) is the most common type of kidney cancer, with 5-year mortality of 25%. The molecular landscape of ccRCC has been elucidated by a number of next generation sequencing studies and complemented by recent global proteome and phosphoproteome results. However, a limitation of such studies is the mixture of signals from distinct cell populations, presenting challenges to subsequent interpretation. As a remedy, single nuclei RNA-seq (snRNA-seq) is able to dissect distinct cell populations and map their differential expression patterns. Using snRNA-seq from 30 ccRCC tumor samples, we identified distinct genetic pathways associated with survival in the TCGA patient cohort (525 patients) in multiple cell types, including immune and stromal components. Prognostic value of pathways was confirmed in an independent cohort with 130 patients. Multiple cancer cell-specific pathways were related to metabolism, suggesting that certain metabolites are less abundant in high-risk tumors. Using data from two independent large-scale metabolism ccRCC studies, we found metabolites’ levels changing in accordance with our predictions, when comparing low-risk to high-risk ccRCC tumors.

Citation Format: Ilya Strunilin, Yige Wu, Ruiyang Liu, Wagma Caravan, Feng Chen, Li Ding. Defining cell type-specific pathways in both cancer and tumor-microenvironment cells that impact survival of clear cell renal carcinoma patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4017.
Abstract 4018: Long-term response to Trastuzumab in patients with advanced gastric or gastroesophageal adenocarcinoma - A retrospective study
Authors: Porth Isabel , Weidner Philip , Lorenzen Sylvie , Weichert Wilko , Götze Thorsten Oliver , Perner Sven , Luley Kim , Hirsch Daniela , Hofheinz Ralf-Dieter , Peckys Diana B. , Mostajeran Zahra , de Jonge Niels , Gaiser Timo
Published: June 2022

Since 2010, Trastuzumab combined with chemotherapy is the standard treatment for patients with HER2 (ERBB2) positive advanced or metastatic gastric and gastroesophageal junction cancer (GGEJ). While few patients show long-term response to the treatment, most suffer from rapid disease progression. Several studies revealed that genomic alterations, gene expression changes and altered HER2 signaling activity contribute to impaired therapy response. However, the underlying mechanism remains unclear. The aim of this research project is to analyze differences between patients with long and short progression-free survival by utilizing combined genetic, histologic, clinical and gene expression data. We collected a retrospective German patient cohort (n=20) including patients with HER2 positive advanced GGEJ who received Trastuzumab combined with chemotherapy. Using archival samples that were obtained prior to Trastuzumab treatment, we created a dataset including clinical information, histologic assessment, immunostaining, target amplicon sequencing (TAS; 409 gene panel) and human transcriptome data using the Affymetrix platform. To analyze the TAS sequencing data, we generated an automated analysis pipeline, which detects single nucleotide variants (SNV) and copy number alterations (CNA). Information about genomic alteration will be correlated with pathway and gene set enrichment analysis (GSEA) from the Affymetrix data. Furthermore, the data will be supported by investigating the functional status of HER2 in patient samples via electron microscopy. The results of this study could give insights on how genetic and transcriptomic alterations are connected to long-term Trastuzumab therapy response in HER2 positive GGEJ patients. This could potentially support therapy decision in personalized medicine.

Citation Format: Isabel Porth, Philip Weidner, Sylvie Lorenzen, Wilko Weichert, Thorsten Oliver Götze, Sven Perner, Kim Luley, Daniela Hirsch, Ralf-Dieter Hofheinz, Diana B. Peckys, Zahra Mostajeran, Niels de Jonge, Timo Gaiser. Long-term response to Trastuzumab in patients with advanced gastric or gastroesophageal adenocarcinoma - A retrospective study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4018.
Abstract 4039: Cadmium modulates steatosis, fibrogenesis, and oncogenic signaling in hepatocellular carcinoma cells through activation of Notch/AKT/mTOR pathways
Authors: Niture Suryakant , Gadi Sashi , Lin Minghui , Qi Qi , Moore John T. , Kumar Deepak
Published: June 2022

Cadmium (Cd) is an environmental pollutant that increases hepatotoxicity and the risk of liver diseases. In the current study, we investigated the effect of a physiologically relevant, low concentration of Cd on the regulation of liver cancer cell proliferation, steatosis, and fibrogenic/oncogenic signaling. Exposure of Cd (1 to 10 nM) increased endogenous reactive oxygen species (ROS) production and enhanced cell proliferation in non-tumor derived HepaRG liver cells and in hepatocellular carcinoma (HCC) cell lines. Exposure of Cd increased Jagged1 expression and activated Notch signaling in HepaRG and HCC cell lines. Cd activated AKT/mTOR signaling by increasing phosphorylation of AKT-S473 and mTOR-S-4448 residues. Moreover, a low concentration of Cd also promoted cell steatosis and induced fibrogenic signaling in HCC cells. Similarly chronic exposure of HCC cells to a low concentration of Cd activated Notch and AKT/mTOR signaling. Further RNA seq data revealed that chronic Cd exposure modulate cell steatosis/fibrogenic gene expression that involved in fatty liver disease development. Cd induced the expression of pro-inflammatory cytokines TNFα and its downstream oncogenic protein Tumor Necrosis Factor-alpha (TNF-α)-Induced Protein 8 (TNFAIP8). Collectively our data suggest that a low concentration of Cd modulates cell steatosis and fibrogenic/oncogenic signaling in HCC by activation of Notch/AKT/mTOR pathways.

Citation Format: Suryakant Niture, Sashi Gadi, Minghui Lin, Qi Qi, John T. Moore, Deepak Kumar. Cadmium modulates steatosis, fibrogenesis, and oncogenic signaling in hepatocellular carcinoma cells through activation of Notch/AKT/mTOR pathways [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4039.
Abstract 4041: Use of Receptor Occupancy Assays on cells from Peripheral Blood as a Surrogate Model of the Tumor Microenvironment
Authors: Jones Nicholas , Ngo Brian , Fancke Benjamin , Limson Jessica , Davis Floyd
Published: June 2022

In the development of monoclonal antibodies for the treatment of solid tumors, monitoring receptor occupancy (RO) on peripheral blood lymphocytes can help illustrate potential therapeutic activity occurring in the tumor environment as an assessment of pharmacodynamics (PD). There is increased interest in using these PD assessments on cells from the periphery to assess the effectiveness and efficacy of investigational therapies. In this area of therapeutic development, much focus has been placed on checkpoint inhibitors proteins/receptors such as PD-1, PD-L1, TIM3, CTLA-4, TIGIT, and multiple others. These immune checkpoint inhibitors are suitable targets since they can be upregulated and/or modulated on exhausted T cells in cancer patients. Assessing the expression of these markers in the tumor itself would be an invasive process and provide little information to correlate with pharmacokinetic results throughout the course of a clinical trial to determine optimal dose selection. However, assessment of the receptor expression and occupancy in combination with pharmacokinetics can lead to a better understanding of drug levels required to achieve optimal therapeutic performance. Monitoring the expression and binding of these molecules by drug can determine specific treatment based on the ability of the patient’s own immune system to act, while providing information to identify therapeutic responses against cancer. This poster will present an example of one such RO assessment in its development and implementation.

Citation Format: Nicholas Jones, Brian Ngo, Benjamin Fancke, Jessica Limson, Floyd Davis. Use of Receptor Occupancy Assays on cells from Peripheral Blood as a Surrogate Model of the Tumor Microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4041.
Abstract 4049: Preclinical pharmacology profile of GTX-0196: A novel, potent and highly selective dihydroorotate dehydrogenase (DHODH) inhibitor for the treatment of hematologic malignancies
Authors: Kaptein Allard , Lain Sonia , Brunen Diede , van Wezel Edward , Barf Tjeerd
Published: June 2022

Dihydroorotate dehydrogenase (DHODH) is a key enzyme in the de novo pyrimidine synthesis [Löffler et al., 1997]. Initial clinical studies with the DHODH inhibitor brequinar in solid tumors showed limited efficacy due to dose limiting adverse effects [Peters et al, 2018]. Recently, there is renewed interest in the use of more potent and selective DHODH inhibitors for the treatment of myeloid and lymphoid malignancies [Sykes et al, 2016].

Here we report the identification of the novel potent and highly selective DHODH inhibitor GTX-0196, with excellent physicochemical properties. GTX-0196 exhibited a biochemical IC50 of 3.7 nM in a DHODH biochemical assay and an antiproliferative IC50 of 1.1 nM in the MOLM-13 cell line, with brequinar showing IC50 values of 6.9 and 50 nM, respectively. The activity in the MOLM-13 proliferation assay was uridine-dependent, indicating absence of general toxicity of the compound and confirming DHODH-mediated efficacy.

Profiling of GTX-0196 in the BioPrint panel (Eurofins/CEREP, at 10 µM), showed <50% inhibition for all 133 target proteins tested (GPCR’s, NR´s, kinases and other enzymes), illustrating the high selectivity for DHODH (> 2000-fold selectivity versus other targets tested). Furthermore, no inhibition was observed in a human CYP panel (1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1 and 3A4, at 30 µM) and in a panel of transporters (at 10 µM). High metabolic stability in human liver microsomes and hepatocytes was observed with t½ > 6h and 10h, respectively.

Compared to an earlier lead compound, GTX-0196 demonstrated enhanced potency and metabolic stability (particularly in preclinical species). Potent and efficacious inhibition of proliferation through DHODH was confirmed in a large number of solid tumor and hematologic malignancy cell lines, illustrating the broad potential use of this chemical series. Furthermore, tumor growth inhibition was observed in the MOLM-13 xenograft mouse model.

Due to its favorable properties, GTX-0196 has progressed towards IND-enabling studies. In parallel, we are exploring mono and combination therapy opportunities in hematological malignancies as well as combination therapy opportunities in solid tumors to investigate the full therapeutic potential in oncology for this optimized DHODH inhibitor.

Löffler et al. Mol. Cell. Biochem. 1997Peters GJ et al, Nucleosides, Nucleotides and Nucleic Acids 2018Sykes DB et al. Cell 2016

Citation Format: Allard Kaptein, Sonia Lain, Diede Brunen, Edward van Wezel, Tjeerd Barf. Preclinical pharmacology profile of GTX-0196: A novel, potent and highly selective dihydroorotate dehydrogenase (DHODH) inhibitor for the treatment of hematologic malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4049.
Abstract 4053: NGY-B is a novel inhibitor of MCT transporters blocking lactate and glucose metabolisms
Authors: Sharma Sambad , Goreczny Gregory , Bowman Nicole , Duffy Jennifer , Banerjee Daliya , Wijerathna Sanath , Dzuris John , Escobedo Jaime , Sandanayaka Vincent
Published: June 2022

Aberrant glycolytic flux and mitochondrial respiration are known to drive tumor progression and metastasis. Therefore, targeting metabolic alterations in cancer is critical for developing novel cancer therapeutics. We have developed NGY-B as a first-in-Class small molecule inhibitor of the lactate transporters, MCT1 and MCT4, that also decreases mitochondrial respiration. These transporters play a crucial role in regulating both glycolysis and oxidative phosphorylation in cancer cells. NGY-B treatment exhibited potent in vitro cytotoxicity in cancer cells with various levels of MCT1 and MCT4 expression. The on-target activity of NGY-B was validated by measuring intracellular and extracellular lactate levels. NGY-B blocks lactate import through MCT1 under high lactate conditions and lactate export through MCT4 in high glucose conditions. Seahorse and U-13C-glucose tracing analysis demonstrated NGY-B treatment modulates glycolysis and oxidative phosphorylation consistent with the lactate measurement data. Therefore, NGY-B is a novel inhibitor of MCT1/4 while also exhibiting inhibition of mitochondrial respiration.

Citation Format: Sambad Sharma, Gregory Goreczny, Nicole Bowman, Jennifer Duffy, Daliya Banerjee, Sanath Wijerathna, John Dzuris, Jaime Escobedo, Vincent Sandanayaka. NGY-B is a novel inhibitor of MCT transporters blocking lactate and glucose metabolisms [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4053.