bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1740: Histone proteomic profiling of EMT-transformed MCF10A breast cells demonstrates a loss in novel histone arginine methylation sites via dual p53 and PTEN deletion
Authors: McGuinness Charlotte B. , Wilson Megan A. , Leonard Margaret V. , Ouzounova Maria , Korkaya Hasan , Shull Austin Y.
Published: March 2024

Metastatic potential of basal-like breast cancers typically is initiated by genetic alterations that lead to a process known as epithelial-mesenchymal transition (EMT). However, much is currently not understood regarding the role of epigenetic modifications that lead to invasive characteristics and EMT phenotype of metastatic breast cancers. Based on the previous notion connecting epigenetic changes to breast cancer metastasis, we performed DIA-based mass spectrometry of isolated histones from an isogenic panel of MCF10A breast cell lines where the tumor suppressor genes TP53 and PTEN were silenced and induced EMT. With this approach, we determined which histone modifications were differentially enriched in the non-EMT and EMT-induced MCF10A cell lines. From approximately 72 histone modifications identified and annotated from our mass spectrometry results, we were able to identify 5 histone events that were differentially enriched in our MCF10A cell line panel. Two events of note were histone H3 lysine-14 acetylation (H3K14ac) significantly increasing and histone H4 arginine 55 dimethylation (H4R55me2) significantly decreasing in our EMT-transformed MCF10A p53-/PTEN- cell lines when compared to the parental, non-tumorigenic MCF10A cell line, showing these events are differentially affected during the EMT process in breast cancer cells. Furthermore, significant arginine demethylation of H4R55me2 & H3.1R83me in the EMT-transformed MCF10A p53-/PTEN- cell lines corresponded with JMJD6, an established histone arginine demethylase, being overexpressed in basal-like breast cancer cell lines as well as basal-like breast cancer patients from The Cancer Genome Atlas (TCGA) and METABRIC datasets. Based on histone proteomic profiling of our isogenic cell line model, the loss of specific histone arginine methylation events corresponding with JMJD6 overexpression could highlight the potential for a targetable epigenetic mechanism in breast cancer metastasis.

Citation Format: Charlotte B. McGuinness, Megan A. Wilson, Margaret V. Leonard, Maria Ouzounova, Hasan Korkaya, Austin Y. Shull. Histone proteomic profiling of EMT-transformed MCF10A breast cells demonstrates a loss in novel histone arginine methylation sites via dual p53 and PTEN deletion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1740.
Abstract 1760: Mutational landscape of the canine acute myeloid leukemia exome
Authors: Harris Robert , Conaway Evan , Avery Anne
Published: March 2024

Over 21,000 newly diagnosed cases of human acute myeloid leukemia (hAML) and 10,000 hAML-related deaths are reported in the United States every year. hAML is considered a highly diverse aggressive hematopoietic malignancy, with over 16 recurrent gene rearrangements, 60 recurrent point mutations, and hundreds of rarely mutated genes. There are large ongoing multi-institutional studies devoted to advancing medical management for hAML by providing targeted therapeutics to patients based on their molecular characteristics. A preclinical spontaneous large animal model for testing novel therapies could accelerate the development of better treatments in people. Dogs spontaneously develop AML with similar clinical features and outcomes. As such, the dog may be a useful pre-clinical model, but little is known about the molecular landscape and/or drivers of canine AML (cAML). The goal of this work was to identify somatic mutation candidates in cAML and determine the overlapping features with hAML. We utilized whole exome sequencing at 300x coverage to identify candidate mutations in 51 cAML samples. Somatic variant calling was performed per the GATK best practice recommendations using Mutect2 and a reference panel of normals (n=77) and a variant call file of canine germline variants. We focused our analysis on novel variants predicted to have a moderate to high impact and that occurred in genes implicated in cancer. At least one variant was identified in genes involved in the RTK/RAS pathway (e.g. NRAS, KRAS, PTPN11, FLT3, KIT) in over 75% of cAML samples, a trend that is also found in people. Additionally, recurrent point mutations were predicted in NRAS and KRAS, and some of which, such as the codon changes G13R and Q61R/H in NRAS, were noted to be shared between hAML and cAML. Mutations in DNMT3A were uncommon (n=3/44) and NPM1 mutations were not identified in our cohort, both of which are common hAML-associated genes. However, mutations in other epigenetic modifiers, such as KDM5C and KDM6A, occurred at a high frequency. This data provides insight into the candidate mutations potentially driving cAML pathogenesis and highlights the overlapping molecular features with hAML.

Citation Format: Robert Harris, Evan Conaway, Anne Avery. Mutational landscape of the canine acute myeloid leukemia exome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1760.
Abstract 1762: Characterization of somatic copy number deletion of chromosome 22q in papillary thyroid carcinoma
Authors: Lee Olivia W. , Karyadi Danielle , Hartley Stephen , Zhou Weyin , Machiela Mitchell , Tronko Mykola , Bogdanova Tetiana , Zurnadzhy Liudmyla , Morton Lindsay , Chanock Stephen
Published: March 2024

Deletion in the long arm of chromosome 22 (22qDEL) is the most prevalent somatic copy number alteration (SCNA) observed in papillary thyroid carcinoma (PTC). Despite its recurrence, the specific characteristics and role of 22qDEL in PTC have not been fully studied. We conducted a pooled analysis of 22qDEL by integrating patient and clinical information and molecular profiles from 1,094 primary PTC tumors across four major published PTC genomic studies: The Cancer Genome Atlas (TCGA) PTC profile study, the National Cancer Institute (NCI) post-Chornobyl PTC study, the Memorial Sloan Kettering Cancer Center Integrated Mutation Profiling of Actionable Cancer Targets (MSKCC-IMPACT) PTC cases, and the Seoul National University (SNU) thyroid cancer profile study. The majority of PTC with 22qDEL demonstrated arm-level loss of heterozygosity (86%). Even in PTC cases with partial 22qDEL, we observed a loss across 70% of chromosome 22, encompassing regions 22q12 and 22q13, which harbors known cancer genes (NF2 and CHEK2). More than 90% of 22qDEL co-occurred with established oncogenic drivers of PTC, though a full assessment of PTC drivers was not available for all cases. 22qDEL occurred more frequently with RAS point mutations (50.4%) than other drivers (9.3%). A higher fraction of 22qDEL was clonal in RAS-driven PTCs (78.3%), suggesting 22qDEL occurs early in RAS-driven tumor development. We did not observe any association between 22qDEL and established PTC risk factors such as age, sex, and radiation, nor with clinical features including tumor size, multifocality, and metastasis (p-values>0.22). RNA sequencing gene expression analysis based on 22qDEL status revealed downregulation of most genes residing on chromosome 22q and significant differential expression activity of immune-related genes, further implicating a role of immune dysregulation in PTC. Our study suggests that 22qDEL may not act as a primary driver of PTC but plays an important role as a co-factor of RAS point mutations, which could further drive PTC development.

Citation Format: Olivia W. Lee, Danielle Karyadi, Stephen Hartley, Weyin Zhou, Mitchell Machiela, Mykola Tronko, Tetiana Bogdanova, Liudmyla Zurnadzhy, Lindsay Morton, Stephen Chanock. Characterization of somatic copy number deletion of chromosome 22q in papillary thyroid carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1762.
Abstract 1779: De novo purine pathway enzyme ATIC promotes tumor progression and modulates metabolic reprogramming in breast cancer
Authors: Murthy Divya , Attri Kuldeep S. , Park Jun Hyoung , Kaipparettu Benny A.
Published: March 2024

Breast cancer (BC), a complex and heterogeneous disease, poses a significant global health challenge with a pressing need for enhanced prognostic markers and therapeutic targets. This study focuses on 5-Aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (ATIC), an enzyme essential in de novo purine biosynthesis and previously implicated in myeloma and hepatocellular carcinoma progression. Leveraging publicly available datasets, including TCGA, METABRIC, and GENT2, we identified elevated ATIC expression in BC tissues compared to normal tissues. Notably, patients with elevated ATIC expression displayed significantly diminished overall survival rates, underscoring ATIC's potential as a prognostic marker. Functional assays involving ATIC downregulation in BC cell lines revealed suppressed cell growth, migration, and increased sensitivity to chemotherapeutic drug, Doxorubicin, implicating ATIC in BC progression. Further, RNA-sequencing analysis of ATIC knockdown (KD) BC cell lines revealed a positive correlation between ATIC expression and the activation of MYC and E2F-regulated pathways. The marked attenuation in cell growth and various tumor properties upon ATIC KD provides mechanistic insights into the role of ATIC in fueling BC progression, potentially through the modulation of MYC and E2F target gene expression. Gene Set Enrichment Analysis (GSEA) on differentially expressed genes identified between tumors with high ATIC expression and low ATIC expression in BC patients from the TCGA cohort revealed a notable enrichment of genes associated with MYC and E2F targets, providing additional support for the observed molecular associations in our experimental model. Intriguingly, ATIC KD in Triple Negative BC cell line unexpectedly led to an increase in fatty acid β-oxidation (FAO), uncovering a metabolic vulnerability in these cells. In conclusion, this study unravels the multifaceted role of ATIC in BC, demonstrating its influence on BC tumor progression and metabolism. The observed increase in FAO upon ATIC KD presents a novel metabolic vulnerability that could be explored for targeted therapeutic interventions in BC. This comprehensive analysis contributes valuable insights toward understanding ATIC as a potential therapeutic target and prognostic indicator in BC.

Citation Format: Divya Murthy, Kuldeep S. Attri, Jun Hyoung Park, Benny A. Kaipparettu. De novo purine pathway enzyme ATIC promotes tumor progression and modulates metabolic reprogramming in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1779.
Abstract 1781: Elucidation of glutathione related dipeptide metabolism in cancer
Authors: Alimohammadi Fatemeh , Hecht Fabio , Zocchi Marco , Tuttle Emily , Asantewaa Gloria , Scales TashJae , Ward Nathan , DeNicola Gina , Harris Isaac
Published: March 2024

There is a long-standing belief that supplementation with antioxidants could potentially treat diseases like cancer. Recent year studies showed, however, that they can behave like a double-edged sword and can also increase tumor proliferation and metastatic progression. The exact mechanism behind antioxidants' impact on tumors is poorly understood. Glutathione (GSH), the most abundant antioxidant in mammalian cells, is a tripeptide containing glutamate, cysteine, and glycine. GSH levels are reported to be significantly elevated within the extracellular space of the tumor. Our preliminary findings show that the breakdown of extracellular GSH can support tumor cell survival under cystine-free conditions. Extracellular GSH catabolism releases cysteinylglycine, which can enter the cell through a dipeptide transporter and be further broken down to supply cysteine and glycine to cells. Alternatively, cysteinylglycine can also be broken down extracellularly into cysteine and glycine, allowing for the uptake of these individual peptides. The molecular mechanisms surrounding the utilization of GSH-breakdown products by the tumor cell are largely unknown. We hypothesize that the proteins responsible for the supply of cysteinylglycine to the tumor cell are required for tumor growth and survival. To test this, we will use unbiased genetic and pharmacologic screening approaches to elucidate the proteins involved in cysteinylglycine processing. Preliminarily, we have found that inhibitors of dipeptidases prevent the ability of cysteinylglycine to support tumor cell survival under cystine starvation, suggesting that tumors require downstream utilization of GSH products. By identifying the mechanisms involved in cysteinylglycine breakdown and supply to tumor cells, we will potentially reveal novel therapeutic targets for cancer treatment, including those not relied upon by normal tissues. Further, our studies will potentially provide a better understanding of how antioxidants impact tumor growth and progression.

Citation Format: Fatemeh Alimohammadi, Fabio Hecht, Marco Zocchi, Emily Tuttle, Gloria Asantewaa, TashJae Scales, Nathan Ward, Gina DeNicola, Isaac Harris. Elucidation of glutathione related dipeptide metabolism in cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1781.
Abstract 1793: Transmembrane serine protease TMPRSS11B promotes tumorigenesis in lung squamous cell carcinoma through enhanced lactate export and modulation of the tumor microenvironment
Authors: Sunil Hari Shankar , Updegraff Barrett L. , Zhu Jingfei , Thomas Lisa , Evers Bret M. , Clemenceau Jean R. , Barnfather Isabel , Minna John D. , Deberardinis Ralph J. , Oliver Trudy G. , Hwang Tae Hyun , O'Donnell Kathryn A.
Published: March 2024

Lung cancer is the leading cause of cancer-related deaths worldwide. Existing therapeutic options have limited efficacy, underscoring the critical need for the identification of new actionable therapeutic targets. We previously identified the Transmembrane Serine Protease TMPRSS11B as a novel gene that promotes the transformation of human bronchial epithelial cells in vitro and induces tumorigenesis in vivo. TMPRSS11B promotes extracellular release of Basigin, an obligate chaperone of the lactate monocarboxylate transporters MCT1/4, enhancing lactate export and glycolytic metabolism, and thereby promoting tumorigenesis. Importantly, TMPRSS11B is frequently overexpressed in human lung squamous cell cancers (LSCC) and high expression is associated with poor patient survival. Moreover, as a cell surface protein and enzyme, TMPRSS11B represents a tractable target for therapeutic intervention. To investigate whether TMPRSS11B activity impacts the host immune system and the tumor microenvironment (TME), we evaluated the effect of Tmprss11b depletion in a syngeneic LSCC mouse model, KLN205. Tmprss11b loss of function in KLN205 LSCC cells significantly reduced tumor burden in immunocompetent mice and triggered an accumulation of CD4+ T cells. We are currently extending these studies by investigating the effect of Tmprss11b loss of function using CRISPR/Cas9 editing in the Rosa26LSL-Sox2-IRES-GFP; Nkx2-1 fl/fl; Lkb1fl/fl (SNL) mouse model of LSCC. Tumor burden analysis and pH-sensitive fluorescent imaging are ongoing to assess changes in lactate accumulation. Moreover, RNA FISH analysis and spatial transcriptomics revealed that Tmprss11b expression is highly enriched in lung squamous tumors compared to lung adenocarcinomas and normal lung in SNL mice. Spatial analysis of the transcriptome is currently ongoing to assess the effects of Tmprss11b expression on the TME. Collectively, these studies will elucidate the molecular mechanisms through which TMPRSS11B promotes tumor growth and alters the tumor microenvironment in LSCC.

Citation Format: Hari Shankar Sunil, Barrett L. Updegraff, Jingfei Zhu, Lisa Thomas, Bret M. Evers, Jean R. Clemenceau, Isabel Barnfather, John D. Minna, Ralph J. Deberardinis, Trudy G. Oliver, Tae Hyun Hwang, Kathryn A. O'Donnell. Transmembrane serine protease TMPRSS11B promotes tumorigenesis in lung squamous cell carcinoma through enhanced lactate export and modulation of the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1793.
Abstract 1799: Regulation of epidermal stem cell proliferation and adhesion by ACSS2
Authors: Chamberlain Nicholas K. , Bao Xiaomin
Published: March 2024

Acetyl-CoA Synthetase Short-Chain Family Member 2 (ACSS2) is an enzyme that converts acetate into acetyl-CoA, a crucial metabolite required for protein acetylation and lipogenesis. Acetyl-CoA is membrane-impermeable and must be synthesized in the compartment in which it will be used. Among ACSS enzymes, ACSS2 alone is found in the nucleocytoplasmic compartment rather than the mitochondria. This enzyme shows dynamic localization dependent on cell nutrient status, with nutrient stress promoting nuclear localization where ACSS2 activity promotes cell growth and survival. Emerging evidence suggests ACSS2 may also play roles in promoting metastasis, and has been proposed as a potential therapeutic target. However, the role of ACSS2 in controlling normal tissue homeostasis is understudied. Addressing this knowledge gap is critical to ensure safety and efficacy of cancer therapeutics. As 80% to 90% of human cancers originate from epithelial tissues, we have leveraged human epidermal stem cells to further interrogate the role of ACSS2. As progenitor keratinocytes differentiate, they detach from the basal lamina and migrate from the metabolically privileged basal layer to the more challenging environment at the surface of the epidermis. Using shRNA-mediated knockdown, we first found ACSS2 knockdown dramatically decreases progenitor keratinocyte clonogenicity, abolishing proliferative capacity. Analysis of RNA sequencing data following ACSS2 knockdown with five constructs showed significant increases in expression of genes related to cell adhesion, extracellular matrix organization, collagen catabolism, and cell migration, in addition to keratinocyte differentiation. Downregulated genes were associated with cell division, DNA repair, and DNA replication. Live cell imaging revealed knockdown cells show striking differences in cell adhesion compared to control. These results indicate a role for ACSS2 in regulating keratinocyte proliferation and adhesion during the maintenance of epidermal homeostasis.

Citation Format: Nicholas K. Chamberlain, Xiaomin Bao. Regulation of epidermal stem cell proliferation and adhesion by ACSS2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1799.
Abstract 1801: Rewiring of cortical glucose metabolism fuels human brain cancer growth
Authors: Scott Andrew J. , Mittal Anjali , Meghdadi Baharan , Palavalasa Sravya , Achreja Abhinav , O'Brien Alexandra , Kothari Ayesha , Zhou Weihua , Xu Jie , Lin Angelica , Wilder-Romans Kari , Edwards Donna M. , Tarnal Vijay , Qi Nathan , Lawrence Theodore S. , Venneti Sriram , Agar Nathalie Y. , Lyssiotis Costas A. , Al-Holou Wajd N. , Nagrath Deepak , Wahl Daniel R.
Published: March 2024

The brain avidly consumes glucose to fuel neurophysiology. Cancers of the brain, such as glioblastoma (GBM), lose aspects of normal biology and gain the ability to proliferate and invade healthy tissue. How brain cancers rewire glucose utilization to fuel these processes is poorly understood. Here we perform infusions of 13C-labeled glucose into patients and mice with brain cancer to define the metabolic fates of glucose-derived carbon in tumor and cortex. By combining these measurements with quantitative metabolic flux analysis, we find that human cortex funnels glucose-derived carbons towards physiologic processes including TCA cycle oxidation and neurotransmitter synthesis. In contrast, brain cancers downregulate these physiologic processes, scavenge alternative carbon sources from the environment, and instead use glucose-derived carbons to produce molecules needed for proliferation and invasion. Targeting this metabolic rewiring in mice through dietary modulation selectively alters GBM metabolism and slows tumor growth.

Citation Format: Andrew J. Scott, Anjali Mittal, Baharan Meghdadi, Sravya Palavalasa, Abhinav Achreja, Alexandra O'Brien, Ayesha Kothari, Weihua Zhou, Jie Xu, Angelica Lin, Kari Wilder-Romans, Donna M. Edwards, Vijay Tarnal, Nathan Qi, Theodore S. Lawrence, Sriram Venneti, Nathalie Y. Agar, Costas A. Lyssiotis, Wajd N. Al-Holou, Deepak Nagrath, Daniel R. Wahl. Rewiring of cortical glucose metabolism fuels human brain cancer growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1801.
Abstract 1813: Discovery, biomarker validation, and pre-clinical profiling of a novel PKMYT1 inhibitor
Authors: Brennan Alfie , Lanz Jan , Miller Daniel S. , Vipond Oliver , Harrison Noah , Aaronson James , Hercot Anna
Published: March 2024

Protein kinase membrane-associated tyrosine/threonine 1 (PKMYT1) is a negative regulator of CDK1 activity and has been identified as a putative synthetic lethal target in cancers which upregulate cyclin E (CCNE1). We used high-throughput virtual screening to identify inhibitors of PKMYT1 with high lipophilic ligand efficiency (LLE), which were rapidly optimized to potent leads with exceptional selectivity over a key off target, WEE1. Machine learning-driven optimization rapidly reduced mouse hepatocyte clearance to acceptable levels, delivering a compound with best-in-class potency, selectivity, and pharmacokinetic profiles in relevant animal models. Tool compounds from this series were used to validate a differentiated biomarker for sensitivity to PKMYT1 inhibition in cellular models, which could significantly expand the potential patient population. In vivo proof-of-concept studies are ongoing in a variety of cell line- and patient-derived xenograft models which represent the novel biomarker previously identified, to further validate our therapeutic strategy.

Citation Format: Alfie Brennan, Jan Lanz, Daniel S. Miller, Oliver Vipond, Noah Harrison, James Aaronson, Anna Hercot. Discovery, biomarker validation, and pre-clinical profiling of a novel PKMYT1 inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1813.
Abstract 1814: Development and evaluation of Hsp90β-selective inhibitors to overcome the safety challenges associated with pan-Hsp90 inhibitors
Authors: Mishra Sanket , Reynolds Tyelor , Blagg Brian
Published: March 2024

The 90 kD heat shock proteins (Hsp90) are molecular chaperones that are responsible for the folding of select proteins, many of which are directly associated with cancer progression. Consequently, inhibition of the Hsp90 protein folding machinery results in a combinatorial attack on numerous oncogenic pathways. More than 20 small-molecule inhibitors of Hsp90 have entered clinical trials for the treatment of cancer, all of which bind the Hsp90 N-terminus and exhibit pan-inhibitory activity against all four Hsp90 isoforms (Hsp90a, Hsp90β, Grp94 and TRAP-1). Most of these clinical trials have failed as pan-Inhibition of Hsp90 appears to be detrimental with toxicities reported alongside induction of the pro-survival heat shock response, which leads to additional dosing challenges/toxicities. The cytosolic Hsp90 isoforms Hsp90a and Hsp90β are the major contributors to cancer growth/survival. It has been established that inhibition of Hsp90a is associated with cardiac toxicity, retinal toxicity, and induction of the heat shock response. Therefore, the development of Hsp90β -selective inhibitors represents an alternative approach for the treatment of cancer with limited side effects. Towards this goal, Hsp90β-selective inhibitors that exhibit >150-fold selectivity over Hsp90a have been developed, which exhibit efficacy against select cancers while overcoming the safety challenges associated with previous Hsp90 inhibitors. The results from such studies will be presented.

Citation Format: Sanket Mishra, Tyelor Reynolds, Brian Blagg. Development and evaluation of Hsp90β-selective inhibitors to overcome the safety challenges associated with pan-Hsp90 inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1814.
Abstract 1821: Conessine inhibits cell proliferation, migration and invasion, and induces apoptosis in liver cancer cells
Authors: Li Chia-Yang , Lin Yu-Sheng
Published: March 2024

Cancer-related deaths from hepatocellular carcinoma (HCC) rank first worldwide. Although many attempts have been made to treat HCC, the survival rate remains unsatisfactory. Many plants from the family Apocynaceae, such as Holarrhena floribunda, contain conessine, a steroidal alkaloid. Several studies have indicated that conessine acts as an antihistamine with cancer therapy and antimicrobial resistance, but it hasn't been tested for its anti-cancer activity against liver cancer. Our study aimed to investigate the anticancer properties of conessine against liver cancer. We tested the effects of conessine on cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) markers using both Huh7 and Mahlavu cells. Our experimental results indicated that conessine inhibited cell proliferation, migration, motility, and invasion in Huh7 and Mahlavu cells. Results of Western blot analysis showed that conessine induced apoptosis and EMT in liver cancer cells. Taken together, our results demonstrated that conessine exhibits anticancer activity in liver cancer through suppressing cell proliferation, migration, and invasion, and inducing apoptosis, suggesting it may have benefits for liver cancer treatment.

Citation Format: Chia-Yang Li, Yu-Sheng Lin. Conessine inhibits cell proliferation, migration and invasion, and induces apoptosis in liver cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1821.
Abstract 1827: Exploring the feasibility and pharmacological mechanism of bufadienolides for the treatment of non-muscle invasive bladder cancer
Authors: Tu Chih-Chieh , Chen Mei-Chuan , Chen Chun-Han
Published: March 2024

The majority of diagnosed bladder cancer (BC) patients is presenting with non-muscle-invasive bladder cancer (NMIBC). Although NMIBC generally exhibits a favorable prognosis, a considerable number of patients suffer from short-term recurrence, and high risks of progression to the more aggressive muscle-invasive bladder cancer (MIBC). Therefore, there is an urgent need for innovative treatments to improve outcomes for patients with NMIBC. For centuries, traditional Chinese medicine (TCM) has played a significant role in Asian society, with ongoing research to investigate the intricate relationship between TCM and treatment of cancers. Bufadienolides, the principal active components in Chansu, are derived from the aqueous extract of the parotoid glands and the dried secretion of the Asiatic toad. Bufadienolides have been reported to demonstrate significant antitumor and anti-inflammatory activities. This study aims to evaluate the feasibility and elucidate the pharmacological mechanisms that underlie the anticancer effects of bufadienolides in NMIBC. Our experiments show that bufadienolides significantly decrease cell viability, induce cell-cycle arrest at the sub-G1 phase, and activate apoptosis in NMIBC cells (RT112 and RT4). Protein analysis reveals the activation of apoptosis-related proteins (PARP, caspase-3, -8, -9) by bufadienolides in NMIBC cells. In conclusion, our findings suggest that bufadienolides present promising potential as therapeutic agents for NMIBC treatment.

Citation Format: Chih-Chieh Tu, Mei-Chuan Chen, Chun-Han Chen. Exploring the feasibility and pharmacological mechanism of bufadienolides for the treatment of non-muscle invasive bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1827.
Abstract 1850: From proteomic analysis to early investigations of combining inhibitors targeting PCNA and histone deacetylase
Authors: Li Caroline M. , Garcia-Mansfield Krystine , Lingeman Robert G. , Gu Long , Hickey Robert J. , Pirrotte Patrick , Malkas Linda H.
Published: March 2024

Proteomic changes were investigated in a neuroblastoma cell line, SK-N-AS, treated with a small molecule inhibitor, AOH1996, designed to specifically bind proliferating cell nuclear antigen (PCNA) in cancer. PCNA is crucial to DNA replication, DNA repair, transcription, cell cycle control, and chromatin organization through interactions with different proteins. Pathway analysis of differential protein expressions between treated and untreated cells revealed less G2/M DNA damage checkpoint regulation and decreased assembly of RNA polymerase complex. Phosphoproteomic analysis by PTM Signature Enrichment Analysis (PTM-SEA) identified signatures of kinase activities, signaling pathways, and perturbations. Specifically, the histone deacetylase inhibitors belinostat and vorinostat were identified as enriched perturbation signatures. Both inhibitors were tested in combination with AOH1996 in SK-N-AS as well as cell lines derived from breast, lung, ovarian, and pancreatic cancer, revealing drug synergies at specific dose combinations. Western blot analysis showed that belinostat decreased protein expression of PCNA, suggestive of mechanistic synergies with AOH1996+belinostat combination therapies. Our proteomic analysis reveals a therapeutic potential of combining AOH1996 and histone deacetylase inhibitors for treating cancer with possibly lower drug dose and toxicities compared to single drug treatment.

Citation Format: Caroline M. Li, Krystine Garcia-Mansfield, Robert G. Lingeman, Long Gu, Robert J. Hickey, Patrick Pirrotte, Linda H. Malkas. From proteomic analysis to early investigations of combining inhibitors targeting PCNA and histone deacetylase [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1850.
Abstract 1857: Development of monoclonal antibodies against CD44v specifically expressed in cancers
Authors: Kato Yukinari , Suzuki Hiroyuki , Kaneko Mika K.
Published: March 2024

CD44 is a transmembrane glycoprotein that binds to the extracellular matrix including hyaluronic acid. Human CD44 has 19 exons, 10 of which are commonly present in all isoforms. CD44 standard isoform (CD44s) is composed of the common exons, and is expressed in many cell types. CD44 variants (CD44v) are produced by alternative splicing, in which the remaining nine variant exons are inserted into the CD44 standard isoform in various combinations. The CD44 isoforms have overlapping and unique functions. Both CD44s and CD44v harbor hyaluronan-binding motifs that promote interaction with the tumor microenvironment, which activate various signaling pathways in tumor cells. CD44v is mainly expressed in epithelial cells and is involved in cell adhesion, proliferation, and survival. Overexpression of CD44v is observed in many solid tumors and plays an important role in invasion, metastasis, and acquisition of stemness. In this study, we employed the Cell-Based Immunization and Screening method (CBIS method), and established highly sensitive anti-CD44 monoclonal antibodies (mAbs) using CD44v3-10-overexpressed cell lines as immunogens. After that, we determined the epitopes by enzyme-linked immunosorbent assay and investigated their applications. As a result, we successfully established eight mAbs against each CD44v (v3 to v10), which can be used for flow cytometry, western blotting, and immunohistochemistry. Furthermore, some of them exhibited cancer specificity against pancreatic cancers, colorectal cancers, gastric cancers, or oral cancers, indicating that established anti-CD44v mAbs are useful for the antibody therapies.

Citation Format: Yukinari Kato, Hiroyuki Suzuki, Mika K. Kaneko. Development of monoclonal antibodies against CD44v specifically expressed in cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1857.
Abstract 1903: Zenocutuzumab, a HER2xHER3 bispecific antibody, is effective in cancer models with high NRG1 expression
Authors: O'Connor Marie N. , Schackmann Ron C. , Odintsov Igor , Fatrai Szabolcs , Brinkman Arie B. , Walker Sidney , van Bueren Jeroen J. Lammerts , Geuijen Cecile A.
Published: March 2024

Neuregulin 1 (NRG1) is a ligand that binds to HER3, promotes HER2/HER3 dimerization and PI3K/AKT/mTOR signaling, and causes malignant transformation. Zenocutuzumab (Zeno, MCLA-128) is a humanized IgG1 bispecific antibody that docks on HER2, preventing heterodimerization with HER3, while also blocking NRG1 interaction with HER3, and potently inhibiting NRG1-induced HER2:HER3 proliferation and survival signaling of cancer cells. High NRG1 expression arising from autocrine signaling or gene amplification is associated with poor prognosis in certain cancers, and resistance to standard therapies. The clinical efficacy and safety of Zeno in patients with NRG1 fusion-driven cancer who were enrolled in the ongoing global multicenter eNRGy study and Early Access Program were recently presented. Treatment with Zeno led to durable responses across multiple different previously treated NRG1 fusion tumor types. Zeno utilizes the Merus Dock & Block® mechanism to inhibit HER2/HER3 dimerization and the NRG1/HER3 tumor-signaling pathway and is effective at high NRG1 concentrations. Here, we examined the efficacy of Zeno in preclinical models representing different tumor types expressing high NRG1 levels. Zeno treatment of the lung cancer cell line HCC95, which harbors an NRG1 gene amplification, effectively inhibited signaling pathways involved in the regulation of proliferation and survival, including the PI3K/AKT/mTOR pathway and inhibited cell proliferation. The anti-tumor efficacy of Zeno in vivo against a panel of 28 patient-derived xenograft (PDX) models representing different tumor types was examined. Zeno significantly inhibited tumor growth in seven high-NRG1-expressing PDX models. These results show that Zeno is effective in tumor cell killing in vitro and in vivo in high NRG1-expressing cancer models representing multiple different tumor types.

Citation Format: Marie N. O'Connor, Ron C. Schackmann, Igor Odintsov, Szabolcs Fatrai, Arie B. Brinkman, Sidney Walker, Jeroen J. Lammerts van Bueren, Cecile A. Geuijen. Zenocutuzumab, a HER2xHER3 bispecific antibody, is effective in cancer models with high NRG1 expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1903.
Abstract 1911: Dato-DXd mediates anti-tumor activity in preclinical TROP2-expressing intracranial tumor model
Authors: Jones Kristen Jones , Suksomboon Montira , rosenthal SaraAnn , Gordon Jacob , Reimer Corinne , Sung Matthew , Rane Chetan
Published: March 2024

Datopotamab deruxtecan (Dato-DXd) is an antibody-drug conjugate (ADC) consisting of a humanized anti-TROP2 monoclonal antibody linked to a potent DNA topoisomerase I (TOP1) inhibitor payload via a plasma-stable, tumor-selective, tetrapeptide-based cleavable linker. Dato-DXd is currently under clinical investigation for the treatment of patients with solid tumors including non-small cell lung cancer (NSCLC), hormone receptor positive (HR+ BC) and triple negative breast cancer (TNBC). Pharmacotherapy of brain tumors can be limiting due to restricted drug delivery across blood brain and blood tumor barrier. Enhertu®, that uses the same DXd ADC technology, has reported clinical activity in patients with brain metastases from HER2+ breast cancer, but very little information is available on what drives ADC biodistribution and activity in CNS-involved cancers. Here, we investigated whether systemically administered ADCs can penetrate the brain microenvironment and mediate anti-tumor activity in a preclinical model. Luciferase-tagged H1373 (TROP2-expressing NSCLC) tumor cells were intracranially implanted into NSG mice. Tumor-bearing mice were dosed with Dato-DXd or matched isotype Control IgG-ADC (DAR4) at 10mpk 7 days or 14 days post intracranial tumor implant. Dato-DXd inhibited intracranial tumor growth better than Control ADC (Day 7: 105% TGI vs 38% TGI; Day 14: 65% TGI vs <10% TGI, respectively, compared to Vehicle). Immunohistochemistry analysis of brain tissue validated localization of Dato-DXd in the tumor, suggesting Dato-DXd can distribute into the local tumor microenvironment in this preclinical tumor model. Additionally, treatment with Dato-DXd provided a significant survival benefit over Control ADC (Median survival of 63 days vs 43 days, P=0.0002). This preclinical study supports the inclusion of Dato-DXd in treatment of patients with CNS-involved tumors. Understanding the pharmacological determinants of Dato-DXd activity in the CNS will help outline strategies to implement Dato-DXd-based treatment of patients with CNS-involved tumors.

Citation Format: Kristen Jones Jones, Montira Suksomboon, SaraAnn rosenthal, Jacob Gordon, Corinne Reimer, Matthew Sung, Chetan Rane. Dato-DXd mediates anti-tumor activity in preclinical TROP2-expressing intracranial tumor model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1911.
Abstract 1916: Discovery of a novel Nectin4 IPSC-derived cell therapy for the treatment of solid tumors
Authors: Carton Jill M. , Dower Chris , Miller Michael , Wheeler John , Heron Sean , Millar Hillary J. , Walker David , Perry Daniel J. , Lebid Andriana , Cocka Luis , Kim Dae Hwan , Morse Barry , Gurung Buddha , Harris Maisha , Jethon Annalise , Naso Michael , Levitsky Hy
Published: March 2024

Century Therapeutics is developing a Nectin4-targeting IPSC-derived cell therapy for the treatment of Nectin4 expressing solid tumors. The Nectin proteins (Nectin1, Nectin2, Nectin3 and Nectin4) are members of the calcium independent immunoglobulin superfamily of cell adhesion molecules (CAMs) involved in adhesive processes that help in the growth and development of tissues. Nectin 1, 2 and 3 are normally found in adult tissue whereas Nectin4 is mainly found in normal placental and embryonic tissue. Nectin4 is also expressed in different types of cancer including urothelial, ovarian, lung and head/neck cancers. Nectin4 is established as a biomarker for worse prognosis in cancers and is linked with carcinogenesis and disease severity. These features establish Nectin4 as a promising target for anti-tumor drug development. Enfortumab vedotin, an antibody drug conjugate targeting Nectin4 positive tumors, has demonstrated benefit in clinical trials and is FDA approved for treatment of advanced bladder cancer. We have identified novel single-domain antibodies (VHH) that bind to multiple epitopes on Nectin4 extracellular domain. The VHH antibodies were engineered into chimeric antigen receptor (CAR) formats and characterized for expression, cell activation through antigen engagement, and cytotoxicity activity in primary T-cells. Selected binders demonstrated efficacy in multiple CAR formats in primary T-cells in a mouse xenograft model using OVCar-3 tumor cells. The lead CARs engineered into primary T-cells demonstrated tumor inhibition similar to a reference CAR using the ASG-5ME antibody (Enfortumab) as the Nectin4 binder. The CARs were engineered into our IPSC-derived iNK and iT cells and demonstrated cytotoxicity activity against a panel of cell lines with a range of cell surface expression of Nectin4. Based on these studies, Century Therapeutics is advancing the lead Nectin4 binder for development of an IPSC-derived cell therapy to treat Nectin4 positive solid tumors.

Citation Format: Jill M. Carton, Chris Dower, Michael Miller, John Wheeler, Sean Heron, Hillary J. Millar, David Walker, Daniel J. Perry, Andriana Lebid, Luis Cocka, Dae Hwan Kim, Barry Morse, Buddha Gurung, Maisha Harris, Annalise Jethon, Michael Naso, Hy Levitsky. Discovery of a novel Nectin4 IPSC-derived cell therapy for the treatment of solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1916.
Abstract 192: Orchestrating CDC42 turnover to regulate membrane protrusion and tumor metastasis
Authors: Hsieh Sen-Yung
Published: March 2024

F-actin cytoskeleton remodeling is essential for cell migration, organ development, and immune responses. CDC42, a factor orchestrating F-actin remodeling for membrane dynamics, switches between its inactive GDP- and active GTP-bound forms. However, the biological and clinical significance of the mechanisms regulating CDC42 protein turnover remains unclear. Here we show that KLHL23-mediated CDC42·GTP polyubiquitylation for degradation and RhoGDI-mediated CDC42·GDP sequestration away from the plasma membrane co-inactivate CDC42 in a spatiotemporal context, influencing membrane dynamics and homeostasis during migration. Via a functional genomic screen, we identified KLHL23 as a suppressor of tumor invasion. Decreased KLHL23 level was associated with tumor metastasis and poor clinical outcomes in patients with liver and pancreas cancers. KLHL23 functions as the E3 ligase responsible for CDC42 polyubiquitylation and degradation. KLHL23 shares with RhoGDI the switch II region of CDC42 for binding, enhancing selective targeting of CDC42·GTP and CDC42·GDP, respectively. KLHL23 depletion in cells leads to F-actin and membrane over-protrusion, as well as epithelial-mesenchymal transition and tumor metastasis. Fluorescence resonance energy transfer assays reveal that the KLHL23—CDC42·GTP interaction plays a primary role in quenching CDC42 activity during membrane protrusion-retraction, while the RhoGDI—CDC42·GDP interaction occurs lately. Our results demonstrate the spatiotemporal interplay between RhoGDI and KLHL23 in regulating CDC42 turnover for membrane dynamics. As KLHL23/RhoGDI—CDC42 axis dysregulation causes tumor metastasis, our findings open avenues for exploring novel therapeutics.

Citation Format: Sen-Yung Hsieh. Orchestrating CDC42 turnover to regulate membrane protrusion and tumor metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 192.
Abstract 200: OA inhibits the development of breast cancer through K1108 acetylation of Zeb1
Authors: Guo Min , Wang Yanjin , Shi Yi , Yang Shuang
Published: March 2024

Background:Olive oil has long been considered a healthier edible oil, rich in 75% oleic acid (OA) as its main component. OA is a monounsaturated fatty acid, and recent studies have shown that it is no longer limited to protecting cardiovascular and cerebrovascular systems, but can also reduce the risk of cancer. However, there is limited research on the specific mechanism. After fatty acid is ingested into the body, through fatty acids β-oxidation produces acetyl-CoA, which is a donor of protein acetylation. EMT is an important process to regulate tumor metastasis, and Zeb1 is one of the important EMT transcription factors. Therefore, we explored whether OA could inhibit the progress of breast cancer by affecting the acetylation modification of Zeb1.

Methods: Western blotting, CCK8 assay, and Transwell were used to test the impact of gradient doses of OA on breast cancer cells. Immunoprecipitation and Immunoprecipitation mass spectrum were used to determine the acetylation modification sites of Zeb1. Coimmunoprecipitation, IF, and pull-down were used to test and verify the acetylase and deacetylase of Zeb1. Knockdown endogenous ZEB1 and then reconstructed stable cell lines of Zeb1 wild-type (Zeb1K1108WT), acetylation activated (Zeb1K1108Q), and inactivated mutants (Zeb1K1108R) by lentivirus. Detection of Zeb1 acetylation in patient tissue samples and mouse models under OA treatment using Zeb1-specific acetylation-modified antibodies.

Results: OA inhibits the proliferation and migration of breast cancer cells in a concentration gradient-dependent manner, and inhibits the expression of Zeb1, N Cadherin, and upregulates E Cadherin. Among numerous fatty acids, only OA can promote the acetylation of Zeb1 by adjusting the ratio of acetyl-CoA and NAD+/NADH. K1108 is a biologically functional acetylation site of Zeb1, Zeb1K1108R exerts the cancer promoting function of Zeb1, while Zeb1K1108Q does not. OA can promote acetylation of Zeb1K1108WT, but cannot promote acetylation of Zeb1K1108R.

Conclusions: OA inhibits the development of breast cancer through K1108 acetylation of Zeb1. These results suggest that breast cancer may be ameliorated through dietary interventions.

Citation Format: Min Guo, Yanjin Wang, Yi Shi, Shuang Yang. OA inhibits the development of breast cancer through K1108 acetylation of Zeb1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 200.