bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2263: Complete remission of a patient with Merkel cell carcinoma treated with durvalumab
Authors: Sabbagh Saad , Dominguez Barbara , Sater Houssein Abdul
Published: April 2023

Merkel cell carcinoma (MCC) is a rare, cutaneous, neuroendocrine tumor that is highly aggressive. It is the second leading cause of death from skin cancer, after melanoma, despite accounting for less than 1% of malignant skin tumors. Due to the characteristic histopathological neuroendocrine features of the neoplasm, cases of MCC are often misdiagnosed as undifferentiated skin cancers or other tumors with small blue cell types. Clinical examination fails to establish the diagnosis in 99% of cases and pathological assessment by biopsy with immunohistochemistry is essential to confirm MCC diagnosis. Historically, cytotoxic chemotherapy combinations with platinum-based agents (Carboplatin or Cisplatin) plus Etoposide or Cyclophosphamide, Epirubicin, and Vincristine (CAV) agents were the primary systemic treatment for advanced cases. Despite available evidence sensitivity of MCC to chemotherapy, responses are not durable, and the literature is not supportive of combination chemotherapy (NCCN guidelines). The introduction of immunotherapy such as checkpoint inhibitors (ICI) particularly PD-1/PD-L1 blockers increased overall survival and achieved durable tumor regression in clinical trials leading to FDA approval in locally advanced and metastatic disease. Permbrluzimab and Avelumab are the only two FDA-approved ICIs as first-line standard-of-care treatments for MCC patients. What we are missing is data or trials examining the efficacy of other ICI such as Durvalumab, (anti-PD-L1) in MCC. We hereby report an unprecedented case of an 84-year-old female MCC patient with extensive axillary nodal involvement achieving complete remission after treatment with Durvalumab combined with Carboplatin and Etoposide.

Citation Format: Saad Sabbagh, Barbara Dominguez, Houssein Abdul Sater. Complete remission of a patient with Merkel cell carcinoma treated with durvalumab [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 2263.
Abstract 2316: Automating ctDNA liquid biopsy workflow for mutation testing: From sample extraction to dPCR analysis utilizing the Maxprep™ Liquid Handler, Maxwell® extraction system, and high-plex detection assays
Authors: Granitsiotis Michael , Gutierrez Kimberly , Horejsh Doug , Yue Monica
Published: April 2023

Liquid biopsies are a minimally-invasive sampling approach to overcome the heterogeneity of tumors and represent a valuable source of circulating tumor DNA (ctDNA) for oncological biomarker analysis. The use of ctDNA as a surrogate for tissue DNA is increasingly popular, and advances in the detection and characterization of ctDNA has enabled liquid biopsy assay integration into clinical utilization. However, an innate challenge with measurement of ctDNA is the requirement for highly sensitive quantitation to reliably detect rare genetic aberrations. Digital PCR has emerged as a powerful technology addressing the needs for next-generation analysis of liquid biopsies samples. Having reliable assays for analysis of key oncology targets help drive adoption of this technology into real-world applications. The exquisite sensitivity of digital PCR requires sample preparation methods that reduce variation, making automation of any manual steps highly desirable. Automation also provides flexibility to scale up as testing volumes increase while simultaneously decreasing overall complexity for the operator. Here we present an automated workflow for ctDNA extraction and analysis using the Maxprep™ Liquid Handler, Maxwell® extraction system (Promega Corporation), and a new, high-throughput digital PCR consumable, the Ruby Chip (Stilla Technologies). This ultra-sensitive detection for liquid biopsy samples was performed using a high-plex dPCR assay.

Citation Format: Michael Granitsiotis, Kimberly Gutierrez, Doug Horejsh, Monica Yue. Automating ctDNA liquid biopsy workflow for mutation testing: From sample extraction to dPCR analysis utilizing the Maxprep™ Liquid Handler, Maxwell® extraction system, and high-plex detection assays [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 2316.
Abstract 248: Using combinatorial barcoding to simultaneously profile the transcriptome and immune repertoire of 1 million T cells
Authors: Papalexi Efthymia , Kim Grace , Hariadi Bryan , Schroeder Sarah , Matulich Peter , Tran Vuong , Diaz Daniel , Roco Charles , Rosenberg Alexander
Published: April 2023

T cells are able to recognize and eliminate a wide variety of immunologic threats while maintaining self-tolerance. Pathogen recognition and clearance is ensured by a process called V(D)J recombination, during which a T cell obtains a unique set of V, D and J gene segments for all the chains (α and β or γ and δ) that make up its T cell receptor (TCR). Each recombined TCR detects a specific disease-associated antigen peptide, which triggers the appropriate adaptive immune response.

Understanding the relationship between TCR sequences (clonotypes) and T cell activation during disease pathogenesis and progression can assist in the development of next-generation therapeutics with more favorable and sustainable outcomes. Recent advances in single-cell sequencing allowed for simultaneous profiling of TCRs and full transcriptomes leading to the characterization of key T cell populations with pathogen recognition and disease clearance capabilities. Despite their success, these methods rely on microfluidics devices or plate-based protocols with limited sensitivity and throughput (1,000s-10,000s of cells) making the study of disease-relevant T cells time consuming and costly.

To overcome these limitations, we have extended our split pool combinatorial barcoding technology to simultaneously characterize the TCRs alongside the full transcriptomes of up to 1 million T cells. As a proof of concept experiment, we applied our method to primary T cells from 8 healthy human donors to characterize their TCR diversity. From the 920,000 T cells assayed we were able to recover TCR sequences from at least one chain in 88% of T cells (807,000 cells) and detected hundreds of thousands of unique alpha and beta chains across all donors. Furthermore we found that most of these chains represent rare clonotypes found in 1 or 2 cells. Lastly, we performed transcriptome-based clustering analyses to identify all major T cell subsets and discovered donor and subset-specific hyper-expanded clonotypes that could help us reconstruct each donor’s recent history of infection.

In summary, we report on the extension of our highly flexible and scalable combinatorial barcoding technology to allow researchers to profile up to 1 million of T cells in a single experiment and investigate their functional responses during infection, cancer, autoimmunity, or therapeutic interventions.

Citation Format: Efthymia Papalexi, Grace Kim, Bryan Hariadi, Sarah Schroeder, Peter Matulich, Vuong Tran, Daniel Diaz, Charles Roco, Alexander Rosenberg. Using combinatorial barcoding to simultaneously profile the transcriptome and immune repertoire of 1 million T cells [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 248.
Abstract 2501: A glioblastoma and blood-brain barrier in vitro model to assess the tumor microenvironment and temozolomide resistance
Authors: Lam Maxine S. , Aw Joey , Tan Damien , Vijayakumar Ragavi , Gordon Khloe S. , Birnbaum Michael E. , Sobota Radoslaw M. , Adriani Giulia , Pavesi Andrea
Published: April 2023

Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults with a dismal prognosis. Currently, Temozolomide (TMZ) and Bevacizumab are the main approved agents for primary and recurrent GBM, respectively. However, TMZ resistance is frequent and Bevacizumab does not improve overall survival. The heterogeneity of GBM and the presence of a highly selectively permeable blood-brain barrier (BBB) preclude the use of chemotherapeutics approved for other malignancies. Meanwhile, new therapy development is limited in part because most pre-clinical models do not recapitulate the key features of GBM that are relevant to therapy resistance and drug delivery. This is particularly important when validating immunotherapies such as engineered T cell therapy, which has shown some promise in the clinics. We therefore developed an in vitro 3D model that recapitulates the major features of the GBM tumor microenvironment (TME) that are involved in therapy resistance, including the dense tumor core and infiltrating invasive front observed in clinical tumors, surrounded by a perfusable BBB with a physiological permeability. With this model, we investigate the angiogenic nature of GBM, and the role of tumor organization and the TME in TMZ resistance and immunosuppression. We find that TMZ sensitivity decreases as complexity of tumor cell 3D organization increases, and identify pathways potentially associated with TMZ resistance and immunosuppression using proteomics and genomics approaches. Additionally, we find that tumor-associated vasculature has a higher permeability due to VEGFA from GBM tumors, which leads to the downregulation of endothelial junction proteins. Using an IL13Ra2-targetting chimeric antigen receptor (CAR) T cell as a model for engineered T cell therapy, we find that tumor-associated vasculature acts as a physical barrier to CAR-T cell extravasation, significantly impeding CAR-T cell efficacy. We then use the model to screen a CAR library to identify novel CAR combinations that can improve CAR-T cell extravasation and cytotoxicity in GBM.

Citation Format: Maxine S. Lam, Joey Aw, Damien Tan, Ragavi Vijayakumar, Khloe S. Gordon, Michael E. Birnbaum, Radoslaw M. Sobota, Giulia Adriani, Andrea Pavesi. A glioblastoma and blood-brain barrier in vitro model to assess the tumor microenvironment and temozolomide resistance [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 2501.
Abstract 2547: YAP1 associates with the EPHA3 receptor tyrosine kinase to promote prostate cancer progression
Authors: Al-Mathkour Marwah M. , Dwead Abdulrahman M. , Khazaw Kezhan , Cinar Bekir
Published: April 2023

Metastatic castration-resistant prostate cancer is lethal, and the mechanisms contributing to this deadly disease are largely unknown. The disparity in our knowledge poses a significant barrier to developing effective therapeutics against advanced prostate cancer in humans. Evidence suggests that the ephrin family of receptor tyrosine kinase signaling may play a critical role in the pathobiology of prostate cancer progression. However, the mechanism is elusive. Our initial study showed that YAP1, in concert with the TEAD1 transcription factor, regulated EPHA3 expression. However, the significance of EPHA3 signaling in prostate cancer remains elusive. Here we investigated the role of EPHA3 signaling in prostate cancer cells. We showed that the expression of EPHA3 correlated with YAP1 in prostate cancer clinical samples. We also showed that EPHA3 knockout reduced cell growth in 2D and 3D cultures. In addition, EPHA3 loss sensitized castration-resistant prostate cancer cells to enzalutamide. Moreover, EPHA3 knockout reduced the GTPase activity of RHOA compared to cells with EPHA3-WT, which coincided with reduced phospho-ERK1/2 levels. Consistently, EPHA3 knockout reduces phosphor-ERK1/2, similar to the inhibition of phospho-ERK1/2 by an inhibitor of ROCK1 (Rho-associated coiled-coil-containing protein kinase 1). Besides, EPHA3 knockout reduced the expression of EMT markers ZEB1/2 and the cancer stem cell marker CD44 compared to the wild type. Furthermore, the levels of EPAH3 transcripts were higher in high-grade PC of AA patients compared to other races. Finally, AA and Caucasian Americans (CA) PC cell lines differentially express the member of ephrin-A and ephrin-B receptors. These observations suggest that the YAP1-EPHA3 signaling is a viable therapeutic target for patients with advanced prostate cancer.

Citation Format: Marwah M. Al-Mathkour, Abdulrahman M. Dwead, Kezhan Khazaw, Bekir Cinar. YAP1 associates with the EPHA3 receptor tyrosine kinase to promote prostate cancer progression [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 2547.
Abstract 2552: A novel RIP1-mediated canonical WNT signaling pathway promoting colorectal cancer metastasis
Authors: Park Jong Kuk , Kang A-Ram , Kwon Jin-Hee
Published: April 2023

RIP1 (receptor interacting protein kinase 1) is an important component of TNF-α signaling that contributes to various pathological effects. We herein reveal new potential roles of RIP1 in controlling WNT/β-catenin canonical signaling to enhance metastasis of colorectal cancer (CRC). Firstly, we show that WNT3A treatment sequentially increases the expression levels of RIP1 and β-catenin. Immunohistochemical analyses of human CRC tissue arrays consisting of normal, primary cancer, and metastatic cancer indicate that elevated RIP1 expression might be related to β-catenin expression, carcinogenesis, and metastasis. Intravenous injection of RIP1 over-expressed CRC cells to mice demonstrates that RIP1 may promote metastasis. Immunoprecipitation (IP) results indicate that WNT3A treatment induces direct binding between RIP1 and β-catenin, and that this stabilizes the β-catenin protein in a manner that depends on the regulation of RIP1 ubiquitination via down-regulation of the E3 ligase, cIAP1/2. Elimination of cIAP1/2 expression and inhibition of its ubiquitinase activity enhances WNT3A-induced RIP1 and β-catenin protein expression and binding, and this stimulates endothelial-mesenchymal transition (EMT) induction to enhance the migration/invasion of CRC cells in vitro. The results of an in vitro binding assay and IP of exogenous RIP1-containing CRC cells additionally verify the direct binding of RIP1 and β-catenin. Finally, RIP1 expression can destroy the β-catenin-β-TrCP complex. Taken together, these results suggest a novel EMT-enhancing role of RIP1 in the WNT pathway and suggest a new canonical WNT3A-RIP1-β-catenin pathway that contributes to CRC malignancy by promoting EMT.

Citation Format: Jong Kuk Park, A-Ram Kang, Jin-Hee Kwon. A novel RIP1-mediated canonical WNT signaling pathway promoting colorectal cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2552.
Abstract 2634: AMB302/GR1017, an antibody-drug conjugate (ADC) with topoisomerase 1 inhibitor shows therapeutic potency in orthotopic glioblastoma PDX and bladder cancer models with FGFR3-TACC3 fusion
Authors: Min Byeongkwi , Shi Lily , Kim Hye Jin , Kim Sangwoo , Fan Beibei , Lv Cao , Sun Yajun , Her Nam-Gu , Song Paul , Qin Gang , Nam Do-Hyun
Published: April 2023

Background: FGFR3-TACC3 (F3-T3) fusion leads to FGFR3 kinase activation constitutively and acts as a driver mutation in several solid tumors. AMB302/GR1017 is a novel FGFR3 targeting ADC that was developed using the intelligent Ligase-Dependent Conjugation (iLDC) technologies from GeneQuantum (GQ) that provide high homogeneity, excellent druggability and high linker stability, and contains a topoisomerase 1 inhibitor as a payload. Based on the preclinical characterization, AMB302/GR1017 shows impressive anti-tumor activities against glioblastoma (GBM) and bladder cancer (BC) models with either FGFR3 amplification or F3-T3 fusion, and demonstrates the potential as a first-in-class FGFR3 ADC against FGFR3 active solid tumor indications.

Methods: in vitro anti-tumor effects and mechanism of action for AMB302/GR1017 were assessed on patients-derived cells with F3-T3 using a 3D-spheroid high throughput assay. in vivo anti-tumor effect of AMB302/GR1017 were assessed on F3-T3 fusion GBM orthotopic PDX model and several FGFR3+ or F3-T3 fusion BC models

Results: AMB302/GR1017 was generated by linking FGFR3 targeting antibody (AimedBio) with TopoIx (GQ), a next generation Topoisomerase 1 inhibitor via a cleavable linker using the iLDC technologies. In a 3D-spheroid high throughput assay system, AMB302/GR1017 showed significant anti-tumor activity against glioblastoma patients-derived cells (PDCs) in F3-T3 dependent manner, which is superior to chemical conjugate applying the same antibody and Dxd payload. Also, AMB302/GR1017 prolonged the survival of GBM orthotopic PDX models with F3-T3 fusion by 200 % and achieved complete tumor regression in RT112 BC model with F3-T3 fusion. AMB302/GR1017 treatments were well-tolerated up to 200 mg/kg in a mouse safety study.

Conclusion: AMB302/GR1017 showed robust anti-tumor efficacies in F3-T3 fusion and FGFR3 overexpression models derived from GBM and BC in vitro and in vivo. In addition, AMB302/GR1017 was well tolerated with no adverse effects in rodent model. Our data suggest AMB302/GR1017 has a potential therapeutic option as a first-in-class FGFR3 targeting ADC for GBM, BC, and other solid tumors with FGFR3 overexpression or alterations.

Citation Format: Byeongkwi Min, Lily Shi, Hye Jin Kim, Sangwoo Kim, Beibei Fan, Cao Lv, Yajun Sun, Nam-Gu Her, Paul Song, Gang Qin, Do-Hyun Nam. AMB302/GR1017, an antibody-drug conjugate (ADC) with topoisomerase 1 inhibitor shows therapeutic potency in orthotopic glioblastoma PDX and bladder cancer models with FGFR3-TACC3 fusion [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 2634.
Abstract 2829: Acetyl-CoA Acetyltransferase 2 confers radioresistance by inhibiting ferroptosis and enhancing the phosphorylation of AKT-S473 in esophageal squamous cell carcinoma
Authors: Jinghua Heng , Enmin Li , Liyan Xu
Published: April 2023

Purpose: The overall efficacy of patients with esophageal squamous cell carcinoma (ESCC) is not high due to the lack of markers to evaluate concurrent chemoradiotherapy (CCRT) resistance, which is dominated by radiotherapy. The aim of this study is to identify a radioresistant protein from proteomics and explore its molecular mechanism.

Methods and Materials: The proteomic data of pre-treatment biopsy tissues of 18 ESCC patients with CCRT (complete response CR group, n = 8; incomplete response <CR group, n = 10) was collected, combined with PXD021701 to explore the radioresistant candidate. Subsequently, immunohistochemistry of 126 paraffin embedded biopsies was used for validation. The ESCC cell models with overexpression, knockdown or knockout of Acetyl-CoA Acetyltransferase 2 (ACAT2) were applied for exploring its effects on radioresistance using clonogenic assay underwent ionizing radiation (IR). ROS, C11-BODIPY, Fer-1 (ferrostatin inhibitor) and western blotting analysis were employed to reveal the potential mechanism ACAT2 triggered after IR.

Results: Enrichment analysis of differentially expressed proteins (<CR vs. CR) showed that the pathways of CCRT resistance molecules in ESCC were related to lipid metabolism, while the sensitive ones were mainly aggregated to immunity pathways. ACAT2 was selected from proteomics and verified as a risk factor of overall survival and a radioresistant factor among ESCC patients with CCRT or radiotherapy by immunohistochemistry. ACAT2 overexpression conferred ESCC cell resistance to IR treatment, whereas the ACAT2 knockdown or knockout ones were sensitive to IR. ACAT2 knockout cells were prone to produce ROS and enhance lipid peroxidation after IR, which was rescued by Fer-1. ACAT2 knockout also inhibited GPX4 and phosphorylation of AKT-S473 site after IR.

Conclusion: ACAT2 is negatively associated with the response of radiotherapy and prognosis of ESCC patients, suggesting ACAT2 as an effective therapy target to enhance radiosensitivity of ESCC. This work was supported by the National Natural Science Foundation of China (82273108 and 82173034), the Innovative Team Grant of Guangdong Department of Education (2021KCXTD005), the Science and Technology Special Fund project of Guangdong Province in 2021 (No. 210729156901797) and the 2020 Li Ka Shing Foundation Cross-Disciplinary Research Grant (2020LKSFG07B)

Citation Format: Heng Jinghua, Li Enmin, Xu Liyan. Acetyl-CoA Acetyltransferase 2 confers radioresistance by inhibiting ferroptosis and enhancing the phosphorylation of AKT-S473 in esophageal squamous cell carcinoma [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 2829.
Abstract 3014: Association between HLA-KIR allele interaction combinations and density of T-cell subsets in colorectal cancer
Authors: Thomas Claire Elizabeth , Huyghe Jeroen , Ugai Tomotaka , Yin Hang , Takashima Yasutoshi , Buchanan Daniel D. , Qu Conghui , Hsu Li , Costa Andressa Dias , Gallinger Stephen , Grant Robert , Thomas Sushma , Ogino Shuji , Phipps Amanda I. , Nowak Jonathan , Peters Ulrike
Published: April 2023

Background: Germline genetic factors central to immunity, such as human leukocyte antigen (HLA) variants, have been associated with several immune-related phenotypes such as response to immune checkpoint inhibitors. However, HLA and killer-cell immunoglobulin-like (KIR) gene combinations, which may modulate immune function, have not been studied in relation to T-cell density in cancer.

Methods: This study was conducted within 3 well characterized epidemiologic studies that collected colorectal tumor tissue blocks (N=484). We profiled the in-situ T cell landscape of CRC using digital imaging, machine learning, and a customized 9-plex multiplexed immunofluorescence panel with antibodies directed against CD3, CD4, CD8, CD45RA, CD45RO, FOXP3, and MKI67. HLA and KIR variants were imputed from genome-wide array datasets through SNP2HLA and KIR*IMP methods. We used multivariable ordinal logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between HLA-KIR activation/inhibition ligand combinations with quartile of T cell densities in CRC adjusting for age, sex, GWAS panel, and the first two principal components of ancestry.

Results: Presence of KIR2DL2+HLAC1+ and KIR2DS2+HLAC1+ combinations were associated with lower odds of greater CD3+CD8+ T-cell density quartile, however these findings were not statistically significant [OR = 0.73, 95% CI (0.52, 1.02), p-value = 0.067; OR = 0.74 95% CI (0.53, 1.04), p-value= 0.082, respectively]. There was no association between HLA-KIR combinations and CD3+CD4+ T-cell density quartile. Further results will examine HLA and KIR genes individually, as well as additional combination variables and more specific T-cell density subsets.

Conclusions: Further investigation is needed to determine if germline genetics related to immune profile plays a role in T-cell densities in CRC.

Citation Format: Claire Elizabeth Thomas, Jeroen Huyghe, Tomotaka Ugai, Hang Yin, Yasutoshi Takashima, Daniel D. Buchanan, Conghui Qu, Li Hsu, Andressa Dias Costa, Stephen Gallinger, Robert Grant, Sushma Thomas, Shuji Ogino, Amanda I. Phipps, Jonathan Nowak, Ulrike Peters. Association between HLA-KIR allele interaction combinations and density of T-cell subsets in colorectal 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 3014.
Abstract 3105: Design principle of heparanase inhibitors: A combined in vitro and in silico study
Authors: Zhang Yuzhao , Xiong Meijun , Chen Zixin , Seabra Gustavo , Liu Jun , Li Chenglong , Cui Lina
Published: April 2023

Heparanase (HPSE) is an endo-β-D-glucuronidase and the only known enzyme responsible for the cleavage of heparan sulfate (HS) side chains from heparan sulfate proteoglycans (HSPGs). The enzymatic activity of HPSE mediates ECM remodeling, regulates growth factors, and modulates related signaling pathways, thus HPSE has emerged as a novel therapeutic target for various diseases, including most types of cancers. In the last two decades, a number of HPSE inhibitors have been reported by several labs worldwide, with most of them belonging to the heparan sulfate mimics category. So far, few of the small molecule HPSE inhibitors have progressed into clinical trials and none has gained approval by regulatory agencies, leaving a blank in HPSE drug discovery. Here we present the discovery of a novel HPSE small molecule inhibitor by high-throughput screening using an ultrasensitive HPSE enzymatic detecting probe developed in our lab and provide the mechanisms of action behind the small molecule’s HPSE inhibitory activity. By doing a series of molecular dynamics (MD) simulations, we discovered the binding profiles on the derivatives of the lead compound. We summarized the essential structural features of the lead compound to provide insights into the design of future HPSE small molecule inhibitors.

Citation Format: Yuzhao Zhang, Meijun Xiong, Zixin Chen, Gustavo Seabra, Jun Liu, Chenglong Li, Lina Cui. Design principle of heparanase inhibitors: A combined in vitro and in silico study [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 3105.
Abstract 3246: Targeting Syk reprograms tumor-associated macrophages and enhances responses to immune checkpoint blockade and radiation therapy in high-risk neuroblastoma
Authors: Rohila Deepak , Park In Hwan , Pham Timothy , Jones Riley , Tamayo Pablo , Yu Alice , Sharabi Andrew , Joshi Shweta
Published: April 2023

Neuroblastoma (NB) is the most common extracranial solid malignancy in children. As leading regulators of inflammation and tumor progression, tumor associated macrophages (TAMs) have gained major interest as immunotherapeutic targets in NB. Hence targeting or “re-educating” tumorigenic macrophages towards an immunostimulatory phenotype might improve responses to immunotherapy in this childhood cancer. Spleen tyrosine kinase (Syk) has recently been identified by our group as a novel immune-oncology target. We found that Syk is abundantly present in TAMs infiltrated in MYCN and non-MYCN amplified neuroblastoma tumors. Furthermore, genetic deletion or pharmacological inhibition of Syk markedly impaired neuroblastoma tumor growth. This effect was facilitated by macrophages that became immunogenic in the absence of Syk, skewing the suppressive tumor microenvironment towards immunostimulation and activating antitumor immune responses. Moreover, combining Syk inhibitor, R788 along with anti-PDL1 mAb and radiation provided a synergistic effect leading to complete tumor regression and durable anti-tumor immunity in aggressive MYCN-and non-MYCN-driven murine neuroblastoma tumor models. Collectively, our findings demonstrate the importance of Syk inhibitor, R788, in enhancing the anti-tumor immune responses in NB and support the clinical evaluation of R788 either alone or together with radiation and immune check point inhibitors as a potential treatment strategy for NB.

Citation Format: Deepak Rohila, In Hwan Park, Timothy Pham, Riley Jones, Pablo Tamayo, Alice Yu, Andrew Sharabi, Shweta Joshi. Targeting Syk reprograms tumor-associated macrophages and enhances responses to immune checkpoint blockade and radiation therapy in high-risk neuroblastoma [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 3246.
Abstract 3305: Clinical significance of circZKSCAN1 RNA in human hepatocellular carcinoma
Authors: Bang Minji , Kim Gyeonghwa , Hwangbo Eun , Jeon Mi Yeon , Hur Keun
Published: April 2023

Circular RNAs (CircRNAs) are type of noncoding RNAs without 5’ caps and 3’ tails that has been created by back splicing of mRNA. Recently, circRNAs are identified in many types of cancers, and its function has been elucidated as multiple miRNAs sponge. Hepatocellular carcinoma (HCC) is the most common type of malignancies. The incidence and mortality of HCC have been on the rise in recent years. Thus, it is necessary to identify further molecular mechanisms of HCC initiation and progression. In this study, we aim to investigate the clinical relevance of circRNAs encoded by the ZKSCAN1 (Zinc finger protein with KRAB and SCAN domains 1) gene in HCC.We analyzed clinical specimens from 100 pairs of HCC and corresponding normal liver (NL) tissues. Total RNAs were isolated from clinical tissues using qiagen kit. CircRNAs (circZKSCAN1) derived from ZKSCAN1 gene. The expression levels were determined by quantitative real-time PCR (qRT-PCR), and its expression was normalized with GAPDH. In addition, we analyzed the correlation between circZKSCAN1 expression and various clinicopathological features of HCC patients.CircZKSCAN1 expression was significantly down-regulated in HCC tissues compared to corresponding NL tissues (P<0.001). In HCC patients, circZKSCAN1 expression was gradually suppressed according to state of malignant progression (P<0.010). Further correlation analysis showed that circZKSCAN1 expression was significantly associated with T-stage (P=0.009), TNM stage (P=0.002), BCLC stage (P=0.0467), and survival (P<0.001).Conclusively, we have determined clinical significances of circZKSCAN1 expression in HCC, which may provide clinical evidence for the potential of circZKSCAN1 as novel markers for diagnosis and predicting prognosis in HCC patients.

Citation Format: Minji Bang, Gyeonghwa Kim, Eun Hwangbo, Mi Yeon Jeon, Keun Hur. Clinical significance of circZKSCAN1 RNA in human hepatocellular carcinoma [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 3305.
Abstract 336: Role of ST6GAL1 sialyltransferase in early stages of pancreatic cancer development
Authors: Bellis Susan L. , Chakraborty Asmi , Bhalerao Nikita , Marciel Michael , Hwang Jihye , Silva Austin
Published: April 2023

Increased cell surface sialylation is a prevalent feature of tumor cells. The addition of sialic acid (a negatively-charged sugar) to select surface receptors modulates the structure and function of these receptors, leading to changes in intracellular signaling and gene expression. Increased tumor cell sialylation occurs, in part, through the upregulation of sialyltransferases such as ST6GAL1, an enzyme that adds an α2-6 linked sialic acid to N-glycosylated proteins. ST6GAL1 is overexpressed in numerous malignancies, including pancreatic ductal adenocarcinoma (PDAC), and high expression correlates with a poor prognosis. Our group has shown that ST6GAL1 plays a causal role in promoting PDAC initiation and progression in tumor xenograft and genetically-engineered mouse (GEM) models. As one example, we developed a GEM model with conditional ST6GAL1 expression in the pancreas and crossed this line to the “KC” PDAC model, which expresses oncogenic Kras (KrasG12D). Mice with dual expression of ST6GAL1 and KrasG12D (”KSC” mice) exhibit greatly accelerated PDAC initiation, progression, and mortality when compared with KC mice. In light of ST6GAL1's known role in conferring progenitor-like cell characteristics, we postulated that ST6GAL1 activity contributes to PDAC initiation by fostering acinar to ductal metaplasia (ADM). During ADM, pancreatic acinar cells de-differentiate into ductal-like, progenitor cells and acquire greater proliferative potential as well as apoptosis resistance. Cells undergoing ADM are particularly vulnerable to Kras-dependent transformation. Using a variety of approaches and model systems including GEM organoids, 3D acinar cultures, acinar-like cell lines, and an in vivo assay for ADM, we uncovered a novel function for ST6GAL1 in promoting ADM. We further determined that high ST6GAL1 activity in acinar cells cooperates with KrasG12D to drive neoplasia. Finally, our studies suggest that the tumor-promoting effects of ST6GAL1 are mediated, at least in part, by ST6GAL1-mediated sialylation of EGFR. These collective results highlight a novel glycosylation-dependent mechanism involved in early stages of PDAC development.

Citation Format: Susan L. Bellis, Asmi Chakraborty, Nikita Bhalerao, Michael Marciel, Jihye Hwang, Austin Silva. Role of ST6GAL1 sialyltransferase in early stages of pancreatic cancer development [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 336.
Abstract 3557: Stage-restricted osteoblasts specify signatures of osteosarcoma molecular subtypes
Authors: Tao Jianning , Fan g , Torres Haydee
Published: April 2023

A challenging question in osteosarcoma research is the identity of the cell of origin, and its contribution to the molecular subtypes and signatures. We examine the potential of stage restricted osteoblasts to induce fully penetrant osteosarcoma using osteoblast stage specific Cre mice to mutate Trp53. We identified three molecularly distinct subtypes of osteosarcoma induced by the same driver mutation. Our results suggest that the three subtypes arise from different subpopulations of osteoblasts. Despite histologic identity as one entry osteosarcoma, these subtypes are separable based on molecular signatures and specific signaling pathways. These studies point to the cell of origin as a determinant of osteosarcoma molecular subtypes. Our studies may provide insights for understanding osteosarcoma heterogeneity and improving treatment of the disease.

Citation Format: Jianning Tao, g Fan, Haydee Torres. Stage-restricted osteoblasts specify signatures of osteosarcoma molecular subtypes. [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 3557.
Abstract 3596: EMG1 is an rRNA-modifying protein that contributes to breast cancer progression
Authors: Elhamamsy Amr R. , Alsheikh Heba A. , Samant Rajeev S. , Shevde Lalita A.
Published: April 2023

The ribosome, a multi-subunit RNA-protein complex, is essential for translation in all cells. Variation in ribosome composition and characteristics has been observed between cell types and under different metabolic conditions; this phenomenon is referred to as "ribosome heterogeneity." Ribosome heterogeneity has been linked to carcinogenesis and cancer progression. One of the major layers of ribosome heterogeneity is the diverse rRNA modifications. To study the impact of rRNA modifications on cancer, we performed a systematic literature search and identified 22 rRNA modifying proteins (RRMPs) that are involved in mediating different modifications of rRNA. We next examined the RRMPs' expression levels and frequency of mutation in different cancer types, with a focus on breast cancer. We see that most malignancies show alterations in RRMPs' expression levels and frequent mutations. Our analysis of gene expression patterns and clinical outcomes in breast cancer has shown that several RRPMs are strongly linked to an aggressive phenotype and a poor prognosis. Our analysis also revealed that EMG1, a N1-specific psuedouridine methyltransferase, is a RRMP with potential roles in cancer progression and metastasis. Our findings pave the way for further research into the role of RRMPs in different cancers as well as the development of therapies that specifically target RRMPs involved in cancer progression.

Citation Format: Amr R. Elhamamsy, Heba A. Alsheikh, Rajeev S. Samant, Lalita A. Shevde. EMG1 is an rRNA-modifying protein that contributes to breast cancer progression. [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 3596.
Abstract 3689: Uncovering the metabolic vulnerabilities in activated B cell diffuse large B cell lymphoma
Authors: Singh Satishkumar , Choueiry Fouad , Sircar Anuvrat , Epperla Narendranath , Zhu Jiangjiang , Sehgal Lalit
Published: April 2023

DLBCL is the most common B cell malignancy in adults accounting for 30-40% of non-Hodgkin lymphoma. Only 60% of these cases are curable, with activated B cell DLBCL (ABC-DLBCL) having inferior outcomes than the germinal center (GCB) DLBCL. The use of ibrutinib to treat non-responsive/relapsed ABC-DLBCL cases has significantly improved the treatment of this disease. However, in more than 40% of ABC-DLBCL cases, the disease progresses or develops resistance to ibrutinib. Thus, there is an urgent unmet need to understand the molecular basis of resistance mechanisms and identify novel therapeutic regimens to treat IR DLBCL. Utilizing high throughput metabolomics, we identified cysteine-methionine metabolism and alanine, aspartate, and glutamate metabolism to be deregulated in IR cells. We further identified interleukin four induced 1 (IL4I1), an L-amino acid oxidase that partakes in cysteine and methionine metabolism by contributing to the methionine salvage pathway. The amino acid cysteine contributes to cancer metabolic remodeling by a), in its free form, in redox control, as a component of the antioxidant glutathione or its involvement in protein s-cysteinylation, b), as a substrate for the production of hydrogen sulfide (H2S), which feeds the mitochondrial electron transfer chain and mediates persulphidation of ATPase and glycolytic enzymes, thereby stimulating cellular bioenergetics; and, c), as a carbon source for epigenetic regulation, biomass production, and energy production. Consistent with this, we show that loss of IL4I1 expression induced aberrant cysteine and methionine metabolism accompanied by metabolic reprogramming to OXPHOS, which collectively enabled increased drug tolerance of DLBCL. This adaptive metabolic mechanism exhibited increased cysteine and cystathionine intracellular levels in IR-DLBCL lacking IL4I1 expression. As cysteine and glutathione are scavengers of free radicals (mainly reactive oxygen species (ROS)), they can nullify the effects of the majority of oxidative or alkylating drugs used in cancer therapy, affording a vital resistance mechanism and disruption of cysteine homeostasis appears to be promising strategy for induction of cancer cell death and provide therapeutic approaches to treat Ibrutinib-resistant-ABC- DLBCL for improved patient care.

Citation Format: Satishkumar Singh, Fouad Choueiry, Anuvrat Sircar, Narendranath Epperla, Jiangjiang Zhu, Lalit Sehgal. Uncovering the metabolic vulnerabilities in activated B cell diffuse large B cell lymphoma. [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 3689.
Abstract 3930: MCT1 as a potential target in the progression of oral premalignant dysplasia to invasive squamous cell carcinoma
Authors: Wong Ethan J. , Khammanivong Ali , Maisuria Ravi , Dickerson Erin B. , Gopalakrishnan Raj
Published: April 2023

Introduction: Most oral squamous cell carcinomas (OSCC) progress through clinically identifiable stages, starting from premalignant epithelial dysplasia to early invasive OSCC. How cells transform from premalignant dysplasia to early invasive OSCC is unknown. High monocarboxylate transporter 1 (MCT1; SLC16A1) expression is correlated with poor outcomes in OSCC patients, where it is thought to promote tumor growth by supporting metabolic coupling between cancer cells and tumor stroma. Because expression of MCT1 is markedly increased in OSCC patients, we sought to determine if MCT1 played a role in the progression of oral dysplasia in early invasive OSCC.

Methods: Immunohistochemistry (IHC) was used to evaluate changes in the levels of MCT1 expression across adjacent normal, dysplasia, and OSCC tissues to identify expression patterns during cancer progression. Genetic knockout (KO) of SLC16A1 via CRISPR/Cas9 and pharmacological blockade by the MCT1 inhibitor AZD3965 were used on OSCC (TR146) and dysplastic (DOK) cell lines. KO was confirmed by qRT-PCR and immunoblotting. MCT1-KO and AZD3965-treated cells were assayed for changes in cell invasion using Matrigel-coated transwell assays. Correlative changes in gene expression based on MCT1 staining and disease progression were also observed in adjacent normal, dysplasia, and OSCC regions in each tissue section using Nanostring GeoMx Digital Spatial Profiler.

Results: Expression of MCT1 was directly correlated to the progression of disease from dysplasia to early superficially invasive OSCC relative to normal adjacent epithelium. KO of MCT1 significantly decreased the invasion of dysplastic and OSCC cell lines compared to the wild-type (parental) controls. AZD3965 also decreased invasion in the parental dysplastic and OSCC lines. To identify progressive changes in gene expression across normal, dysplasia, and early invasive OSCC, transcripts for cancer-related genes were quantified in the epithelial and stromal compartments from patient samples. Compared to the normal epithelium, upregulation in gene expression, including SLC16A1, was observed in the cell cycle and metabolic pathways in OSCC tissues.

Conclusions: Our data suggest that MCT1 plays a key role in breaching of the basement membrane and facilitating tumor cell migration and invasion. Targeting MCT1 in oral dysplasia may prevent progression to OSCC in oral cancer patients.

Citation Format: Ethan J. Wong, Ali Khammanivong, Ravi Maisuria, Erin B. Dickerson, Raj Gopalakrishnan. MCT1 as a potential target in the progression of oral premalignant dysplasia to invasive squamous cell carcinoma. [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 3930.
Abstract 3989: EVI1 oncogenic role in non-canonical AR driven lethal prostate cancer
Authors: Gulla Surendra , Bard Jonathan E. , VanderWeele David J. , Kelly Kathleen , Adelaiye-Ogala Remi
Published: April 2023

Background: Androgen receptor (AR) remains active in castration-resistant prostate cancer (CRPC), and AR cistrome can become extensively reprogrammed with disease progression. Recent findings from our group and others have shown an association with non-canonical AR signature with resistance to enzalutamide. However, the complete mechanism is not fully revealed. EVI1 belongs to the zinc-finger transcription factor family, and overexpression of EVI1 is associated with poor patient outcomes. However, its role in the context of resistance to AR-targeted therapy remains unclear. Our preliminary data from ChIP-seq and GSEA analysis shows a significant enrichment of EVI1 target gene-set captured from annotated enzalutamide-resistant AR binding sites.

Hypothesis: EVI1 cooperates in regulating the non-canonical AR activity associated with resistance to AR targeted therapy and blocking EVI1 may overcome resistance to target therapy.

Methods: Using a PDX model of advanced enzalutamide-resistant CRPC, we performed single-cell ATAC-seq + gene expression multi-omic assay. Next, we determined the enrichment of canonical vs. non-canonical AR signatures across cell populations. Using motif analysis and transcription factor foot printing, we determine EVI1 (MECOM) motif z score and enrichment.

Results: Our findings demonstrate enrichment of non-canonical AR signatures in distinct population of cells following exposure to enzalutamide. In addition, the subpopulation of cells enriched for non-canonical AR cistrome also exhibited high EVI1 (MECOM) motif z-scores.

Conclusion: Our data suggests a potential link between EVI1 and non-canonical AR signaling. Ongoing mechanistic studies will provide insight mechanism by which EVI1 controls non canonical AR activity and its vulnerabilities.

Citation Format: Surendra Gulla, Jonathan E. Bard, David J. VanderWeele, Kathleen Kelly, Remi Adelaiye-Ogala. EVI1 oncogenic role in non-canonical AR driven lethal prostate 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 3989.