bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3444: Role of AKR1C3 in converting reservoirs of DHEA-S into potent androgens that drive prostate cancer cell growth
Authors: Detlefsen Andrea J. , Duan Ling , Mesaros Clementina , Penning Trevor M. 
Published: April 2023

Abstract
Castration resistant prostate cancer (CRPC) treatment aims to stop a resurgence of androgen receptor (AR) signaling with a class of therapeutics known as androgen receptor signaling inhibitors (ARSI). Through inhibition of CYP17A1, Abiraterone (Abi) prevents an upstream step in androgen biosynthesis, while Enzalutamide (ENZ) acts as an AR antagonist. Despite the early success of ARSI, a subset of patients develop resistance and succumb to the disease. One major mode of resistance is thought to occur when steroidogenic enzymes that are upregulated in CRPC convert weaker circulating precursors to testosterone (T) and dihydrotestosterone (DHT) to restore AR signaling. In this study, we identify a mechanism driving intratumoral steroidogenesis that involves AKR1C3 (type 5 17β-hydroxysteroid dehydrogenase type 5). AKR1C3 is a major steroidogenic enzyme in the prostate that is involved in all androgen biosynthetic pathways to T and DHT, upregulated in CRPC patients, and is a component of Abi and ENZ drug resistance. Previously with Taplin et al. we observed in patients on Leuprolide that T was reduced to 5 ng/dL, and the addition of Abi lowered DHEA-S by 90% (from 230,000 ng/dL to 22,000 ng/dL). However, the DHEA-S that remained was 4,000x greater than circulating T, making it a reservoir for intratumoral steroidogenesis post Abi treatment. Here, we demonstrate that post-Abi concentrations of DHEA-S, and castrate levels of DHEA-S (post-leuprolide but pre-Abi treatment), which also corresponds to DHEA-S levels patients on ENZ are 1) converted to T in an AKR1C3-dependent manner in prostate cancer (PCa) cells, and 2) sufficient to stimulate AKR1C3-dependent cell growth. Our observations are consistent across both primary and metastatic PCa cell lines, CWR22PC and DuCaP, respectively. Androgen measurements were made using our highly sensitive and specific stable isotope dilution liquid chromatography tandem mass spectrometry (SID-LC-MS/MS) method. Additionally, we demonstrate AKR1C3-dependence using genetic and pharmacological approaches with an AKR1C3 stable knockdown for each cell line and two AKR1C3 competitive inhibitors. Taken together, we have identified a mechanism of resistance to ARSIs common to both primary and metastatic cell lines that operates through AKR1C3’s intratumoral conversion of DHEA-S to potent androgens that drive prostate cancer growth.
Citation Format: Andrea J. Detlefsen, Ling Duan, Clementina Mesaros, Trevor M. Penning. Role of AKR1C3 in converting reservoirs of DHEA-S into potent androgens that drive prostate cancer cell growth [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 3444.
Abstract 3465: HDAC8 regulates immune escape in melanoma through increased transcription of inhibitory cytokines that increase accumulation of myeloid-derived suppressor cells (MDSCs)
Authors: Zhang Chao , Emmons Michael , Bennett Richard , Licht Jonathan , Smalley Keiran 
Published: April 2023

Abstract
Immune checkpoint blockade leads to improved and durable responses in 30-40% of melanoma, yet nearly 1/3 of patients relapse from complete remission within 3 years. Recent studies from our group and others demonstrated that upfront use of targeted therapy leads to decreased immune infiltrate and confers resistance to immunotherapy. We have previously showed that HDAC8 reprograming cell transcriptional states leads to reduced recognition by immune system. However, it’s unclear how HDAC8 activity modulates the tumor immune microenvironment (TIME). In this study, we used integrated single cell RNA-seq, ATAC-seq and a novel BRAF-V600E; PTEN+/- melanoma genetically engineered mouse model (GEMM) to explore “cold” TIME modulated by HDAC8. Analysis of human melanoma cells overexpressing HDAC8 by ATAC-seq, ChIP-Seq and RNA-Seq showed that HDAC8 expression significantly increases chromatin accessibility, H3K27 promoter region acetylation and gene expression of IL-11. Increased IL-11 protein expression was confirmed by cytokine array in isogenic SM1 mouse melanoma cells expressing HDAC8.Overexpression of HDAC8 in the GEMM accelerated melanoma development and was associated with worse overall survival rate. Analysis of HDAC8 and control tumors by scRNA-seq and immunohistochemistry (IHC) showed that HDAC8 overexpressing tumors dramatically decreased CD4 and CD8 T cell infiltration and increased MDSCs and IL-11 expression. We next explored whether IL-11 drives the expansion and polarization of MDSCs and subsequent reduction in T cell infiltration and activation. A MDSCs polarization assay demonstrated that addition of IL-11 led to increased expansion and polarization of MDSCs from mouse bone marrow myeloid cells. A MDSCs suppression assay confirmed IL-11 induced MDSCs accumulation significantly reduced T cell proliferation and activation. We show for the first time that HDAC8 expression regulates immune escape by activating IL-11 expression and driving MDSCs expansion. Going forward, inhibition of HDAC8 activity is intriguing as a novel therapeutic strategy to reverse tumor derived immune suppression and to ultimately improve patient responses to immunotherapy.
Citation Format: Chao Zhang, Michael Emmons, Richard Bennett, Jonathan Licht, Keiran Smalley. HDAC8 regulates immune escape in melanoma through increased transcription of inhibitory cytokines that increase accumulation of myeloid-derived suppressor cells (MDSCs) [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 3465.
Abstract 3466: Microbial neoantigen vectors for cancer immunotherapy
Authors: Redenti Andrew A. , Danino Tal , Arpaia Nicholas 
Published: April 2023

Abstract
Cancers employ a variety of immunosuppressive and evasive mechanisms to avoid detection by the immune system and prevent tumor neoantigen-mediated elimination. In recent years, tumor-specific neoantigen vaccines have shown significant promise—promoting tumor regression and increasing survival benefit in certain malignancies by therapeutically directing the immune system to target previously protected tumor specific antigens. However, despite encouraging preclinical data, objective and durable responses have remained elusive—highlighting a requirement for improved therapeutic platforms that permit delivery and targeting of diverse sets of tumor antigens to enhance the efficacy of cancer vaccines. Through synthetic biology, we have engineered living microbial vectors harboring constructs encoding synthetic arrays of tumor-specific neoantigens that specifically colonize tumors following intravenous injection and deliver high levels of neoantigen cargo—both extracellularly (within the tumor microenvironment) and intracellularly (to the cytosol of tumor-resident phagocytes). These engineered vectors robustly activate innate immune cascades and effectively prime tumor neoantigen-directed T cell responses to promote tumor regression and survival in advanced murine solid tumor and lung metastasis models. Extensive remodeling of the tumor immune microenvironment accompanies therapeutic efficacy, with increased activation of tumor neoantigen-specific CD4+ and CD8+ T cells, broadened stimulation of tumor-infiltrating B and T cells, and reduced numbers of intratumoral myeloid cells exhibiting immunosuppressive phenotypes. This work provides a foundational platform for the development of a new class of next-generation tumor vaccines, leveraging the advantages of living medicines to deliver diverse arrays of tumor-specific neoantigens within the optimal immunostimulatory context to induce potent anti-tumor immunity.
Citation Format: Andrew A. Redenti, Tal Danino, Nicholas Arpaia. Microbial neoantigen vectors for cancer immunotherapy [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 3466.
Abstract 3487: An atlas of substrate specificities for the human tyrosine kinome
Authors: Johnson Jared L. , Yaron Tomer M. , Cantley Lewis C. , Yaffe Michael B. , Turk Benjamin E. , Huntsman Emily M. , Hornbeck Peter V. 
Published: April 2023

Abstract
Numerous physiological processes are governed by tyrosine phosphorylation. The protein tyrosine kinases that carry this out are dysregulated in a variety of cancers and are the targets of efficacious drugs. For most tyrosine kinases, we have a very limited understanding of their downstream signaling pathways and phosphorylation targets. Conversely, thousands of tyrosine phosphorylation events have so far been experimentally identified, and the overwhelming majority of these do not have an associated kinase. In this work, we have utilized peptide arrays to determine the substrate sequence specificity for the human tyrosine kinome, comprising 46 receptor tyrosine kinases, 32 nonreceptor tyrosine kinases, and 14 noncanonical tyrosine kinases. Nearly every kinase we profiled favored tyrosines that were positioned next to phosphorylated amino acids, indicating that PTM priming and crosstalk are general properties of the tyrosine kinome. Comparisons with C. elegans orthologs suggested that tyrosine kinase substrate motifs have remained conserved throughout metazoan evolution. When we computationally utilized our dataset to identify kinases for tyrosine substrates, our predictions were in strong accordance with published reports. When applied to high-throughput tyrosine phosphoproteomics datasets, we could decipher the kinases involved in cellular responses to growth factors, oncogenic mutations, and targeted inhibitors. Together, this work uncovers fundamental rules of substrate selection for nearly the entire human tyrosine kinome and provides a comprehensive resource for connecting tyrosine phosphorylation events with their kinases and signaling pathways.
Citation Format: Jared L. Johnson, Tomer M. Yaron, Lewis C. Cantley, Michael B. Yaffe, Benjamin E. Turk, Emily M. Huntsman, Peter V. Hornbeck. An atlas of substrate specificities for the human tyrosine kinome [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 3487.
Abstract 3495: A kinome-wide CRISPR screen identifies CK1α as a novel target to overcome enzalutamide resistance of prostate cancer
Authors: Liu Jinghui , Zhao Yue , Allison Derek , He Daheng , Li Lang , Liu Xiaoqi 
Published: April 2023

Abstract
Background: Androgen deprivation therapy is the first line of therapy for localized prostate cancer (PCa), but most patients will eventually develop castration-resistant PCa (CRPC). Enzalutamide (ENZA), a second-generation androgen receptor (AR) antagonist, has significantly increased CRPC patient survival. However, resistance remains a prominent obstacle in treatment, illustrating the urgent need to develop new approaches to increase ENZA efficacy.
Methods: A Kinome-wide CRISPR-Cas9 screen was used to identify the targets related to ENZA response. In vitro cell viability and in vivo cell line or patient-derived xenografts were used to verify inhibiting CK1α overcoming ENZA resistance. RNA sequencing was used to address the functions of CK1α in ENZA resistance. In vitro kinase assay was used to study ATM phosphorylation by CK1α. Immunohistochemistry, immunofluorescence, immunoblot and immunoprecipitation assays were used to study the functions of CK1α in regulation of ATM and DNA damage response signaling. Bioinformatics analysis was used to confirm these findings with clinical patients’ database.
Results: Utilizing a kinome-wide CRISPR-Cas9 knockout screen, we identified casein kinase 1 alpha (CK1α) as a novel therapeutic target to overcome ENZA resistance. Depletion or pharmacologic inhibition of CK1α with a novel compound in clinical trial significantly enhanced EZNA efficacy in ENZA resistant cell lines and patient-derived xenografts. Mechanistically, CK1α phosphorylates the serine residue S1270 and modulates the protein abundance of ataxia-telangiectasia mutated (ATM), which is a primary initiator of DNA double-strand break (DSB)-response signaling, and is compromised in ENZA-resistant cells and patients. Inhibition of CK1α stabilizes ATM, resulting in the restoration of DSB-response signaling, and thus increases ENZA-induced cell death and growth arrest in an ATM-dependent manner.
Conclusions: Our study details an innovative therapeutic approach for ENZA-resistant PCa and characterizes a novel perspective for the function of CK1α in the regulation of DNA damage response signaling through phosphorylation of ATM S1270.
Citation Format: Jinghui Liu, Yue Zhao, Derek Allison, Daheng He, Lang Li, Xiaoqi Liu. A kinome-wide CRISPR screen identifies CK1α as a novel target to overcome enzalutamide resistance of 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 3495.
Abstract 35: Development of novel human hepatocellular carcinoma models using genetically modified human hepatocytes in FSRG humanized liver mice
Authors: Carbonaro Marisa , Bonetti Ciro , Huang Hui , Wang Kehui , Desclaux Mathieu , Gong Guochun , Lin John C. , Daly Christopher , Thurston Gavin , Li Zhe 
Published: April 2023

Abstract
The incidence of liver cancer is growing worldwide, and it is estimated that by 2025, over 1 million individuals will be affected by liver cancer every year. Hepatocellular carcinoma (HCC) accounts for about 90% of primary liver cancer cases and is one of the leading causes of death from cancer worldwide. Establishing animal models that faithfully replicate the human disease is critical to improve our understanding of HCC pathogenesis and to test new therapeutic strategies. Here, we describe a novel human HCC model using genetically modified human hepatocytes in a humanized liver mouse. Primary human hepatocytes (PHH) were modified ex vivo through lentivirus or Lipid Nanoparticle (LNP)-mediated delivery of CRISPR/Cas9 components, resulting in over-expression of oncogenes or inactivation of tumor suppressor genes. These genetically engineered PHH were engrafted into the livers of FSRG (FAH−/−, SIRPahu/hu, RAG2−/−, IL2Rg−/−) mice, developed by Regeneron VelociGene technology, in which mouse liver parenchyma can be replaced with human hepatocytes. Tumor formation was validated in livers engrafted with human hepatocytes after different combinations of genetic modification, including over-expression of cMYC plus HRASv12, and cMYC over-expression together with p53 KO. Tumor progression could be monitored by measuring human Alpha Fetoprotein (AFP) in serum of engrafted mice. Liver tumors were positive for fumarylacetoacetate hydrolase (FAH) and human Asialoglycoprotein Receptor 1 (ASGR1), confirming their human origin, as well as the proliferation marker, Ki67, and Glypican-3 (GPC3), which is frequently over-expressed in HCC and a potential therapeutic target. In these studies, mice were engrafted with a mix of lentivirus-transduced and non-transduced hepatocytes, resulting in humanized livers with both normal and transformed human hepatocytes, providing an ideal system to recapitulate neoplastic transformation and clonal expansion of human hepatocytes carrying oncogenic mutations as well as to test the specificity of novel therapies. By combining genetic manipulation of human hepatocytes with the FSRG humanized liver mouse platform, we have established a flexible system to model clinically relevant combinations of HCC mutations for both new target discovery and therapeutic testing.
Citation Format: Marisa Carbonaro, Ciro Bonetti, Hui Huang, Kehui Wang, Mathieu Desclaux, Guochun Gong, John C. Lin, Christopher Daly, Gavin Thurston, Zhe Li. Development of novel human hepatocellular carcinoma models using genetically modified human hepatocytes in FSRG humanized liver mice [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 35.
Abstract 3515: Histone demethylase KDM5D drives sex-specific differences in colorectal cancer
Authors: Li Jiexi , Lan Zhengdao , Liao Wenting , Liu Jielin , Jiang Shan , Shim Hong Seok , Slotnik Max , LaBella Kyle A. , Hsu Wen-Hao , Shang Xiaoying , Spring Denise , Wang Y Alan , DePinho Ronald A. 
Published: April 2023

Abstract
Gender exerts a profound impact on cancer incidence, spectrum and outcomes, yet the molecular genetic bases of such sex differences are ill-defined and presumptively ascribed to X-chromosome genes and sex hormones. Such sex differences are particularly prominent in colorectal cancer (CRC) where men experience higher metastases and mortality. A murine CRC model, engineered with an inducible transgene encoding oncogenic mutant KRASG12D and conditional null alleles of Apc and Trp53 tumor suppressors (designated iKAP), revealed higher metastases and worse outcomes specifically in males with oncogenic mutant KRAS (KRAS*) CRC. Integrated cross-species molecular and transcriptomic analyses identified Y-chromosome gene histone demethylase KDM5D as a transcriptionally up-regulated gene driven by KRAS*-mediated activation of the STAT4 transcription factor. KDM5D-dependent chromatin mark and transcriptome changes showed repression of regulators of epithelial cell tight junction and MHC class I complex components. Deletion of KDM5D in iKAP cancer cells increased tight junction integrity, decreased cell invasiveness, and enhanced cancer cell killing by CD8+ T cells. Conversely, iAP mice engineered with a Kdm5d transgene to provide constitutive KDM5D expression specifically in iAP cancer cells exhibited an increased propensity for more invasive tumors in vivo. Thus, KRAS*-STAT4-mediated upregulation of Y chromosome KDM5D contributes significantly to the sex differences in KRAS* CRC via its disruption of cancer cell adhesion properties and tumor immunity, thus providing an actionable therapeutic strategy for metastasis risk reduction for men afflicted with KRAS* CRC.
Citation Format: Jiexi Li, Zhengdao Lan, Wenting Liao, Jielin Liu, Shan Jiang, Hong Seok Shim, Max Slotnik, Kyle A. LaBella, Wen-Hao Hsu, Xiaoying Shang, Denise Spring, Y Alan Wang, Ronald A. DePinho. Histone demethylase KDM5D drives sex-specific differences 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 3515.
Abstract 3795: Deciphering the in vivo roles of a novel long non-coding RNA in chronic lymphocytic leukemia and Richter syndrome
Authors: Mohapatra Swati , Knutsen Erik , Gagea Mihai Iurascu , Fabris Linda , Calin George Adrian 
Published: April 2023

Abstract
The ultraconserved regions (UCRs) are the genomic segments manifesting perfect conservation between the orthologous genomes of humans, rats, and mice that get transcribed into mono-exonic long non-coding RNAs (lncRNAs) known as transcribed ultraconserved regions (T-UCRs). Increasing evidence demonstrates the importance of T-UCRs in human cancers, however, their involvement in the pathogenesis of Chronic Lymphocytic Leukemia (CLL) is poorly understood. Our lab has recently identified a lncRNA transcribed from a UCR and named it TRUC-16 (Translational Regulatory UltraConserved gene affecting p16), which is overexpressed in CLL and correlates with treatment-free survival. We have developed a transgenic C57BL6 mouse model to overexpress TRUC-16 in B cells. We monitored the number and development of B cell subsets over time in peripheral blood and lymphoid organs (lymph nodes, spleen, and bone marrow), and performed immunophenotyping to assess clonality and proportion of the cells considered to be the origin for CLL (i.e. B1 cells and IgM memory B cells that are CD5+). We followed mice survival (n=10 for each gender) and performed necropsy with histopathologic and immunophenotypic analysis. If blood sampling suggests developing a CLL-like state, we will monitor for evolution to Richter Syndrome by flow cytometry analysis and biochemistry markers. We have validated the TRUC-16 overexpression specific to the B-cell compartment in the mice cohorts and have observed lymphoma in several organs. Interestingly, TRUC-16 overexpressing mice showed significantly higher splenic weights compared to controls. The mice were found to develop adulthood lymphoma that we are now analyzing molecularly and phenotypically. We are planning to further characterize the subtype of lymphoma by utilizing specific diagnostic markers through immunohistochemistry and flow cytometry. This is the first-ever transgenic mice modeling overexpression of UCR in the context of cancer. Validation of the functional correlation between the TRUC-16 phenotype and CLL patients’ clinical data will provide a valuable resource to pursue a multitude of preclinical studies to find targets that might help better understand the disease pathophysiology.
Citation Format: Swati Mohapatra, Erik Knutsen, Mihai Iurascu Gagea, Linda Fabris, George Adrian Calin. Deciphering the in vivo roles of a novel long non-coding RNA in chronic lymphocytic leukemia and Richter syndrome. [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 3795.