tbuckley/cabot-search huggingface dataset:
Abstract 6997: Elucidating the tumorigenic properties of alveolar epithelial type 1 cells in EGFR-mediated LUAD tumorigenesis
Authors: Aaron M. Neely, Andrea Lanz, William Dean Wallace, Anthony W. Kim, Zea Borok, Crystal N. Marconett
Journal: Cancer Research (2024)

Abstract Originating from within the distal lung, lung adenocarcinoma (LUAD) is the most common pathologic subtype of non-small cell lung carcinoma (NSCLC) and encompasses an assortment of histologic presentations. Colocalized within the distal alveolar epithelium are two alveolar epithelial cell (AEC) subpopulations: alveolar epithelial type 1 (AT1) and alveolar epithelial type 2 (AT2) cells. We previously demonstrated that signatures unique to each AEC subpopulation were detected in LUAD tumors formed by oncogenic KRASG12D activation in mice and were associated with disparate survival outcomes, transcriptomic patterning, and histologic presentation. Epithelial growth factor receptor (EGFR) mutations are among the most frequent oncogenic drivers in thoracic oncology. Therefore, we set out to determine if EGFR oncogenic activation resulted in differential LUAD presentation and outcomes based on the cell of origin in which it was activated. To activate EGFR oncogenic mutations in AT1 or AT2 cells, we employed triple transgenic mouse models (AT1: Gramd2-CreERT2:EF1-LSL-tTA:TetO-EGFRdel20/T790 and AT2: Sftpc-CreERT2:EF1-LSL-tTA:TetO-EGFRdel20/T790), which allowed for EGFR activation in either Gramd2+ AT1 or Sftpc+ AT2 cells. Longitudinal analysis of hematoxylin and eosin-stained lungs over the course of 20 weeks was performed. Blinded pathology review demonstrated that EGFR oncogenic activation in Gramd2+ AT1 cells resulted in histologically defined LUAD with lepidic properties at early time points and solid adenocarcinoma properties at later time points. This differed from EGFR activation in Sftpc+ AT2 cells, which resulted in pre-carcinogenic atypical adenomatous hyperplasia (AAH) formation that did not progress to adenocarcinoma. While preliminary, our results suggest that cell of origin strongly influences EGFR-mediated lung oncogenesis and concomitant pathology and histologic presentation. This work may advance our understanding while informing patient stratification and treatment strategies for LUAD patients. Citation Format: Aaron M. Neely, Andrea Lanz, William Dean Wallace, Anthony W. Kim, Zea Borok, Crystal N. Marconett. Elucidating the tumorigenic properties of alveolar epithelial type 1 cells in EGFR-mediated LUAD tumorigenesis [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 6997.
Abstract 6986: Oncogenic CARD11 enhances marginal zone B cell survival by potentiating the non-canonical NF-κB pathway
Authors: Anushka Ghosh, Joel Pomerantz
Journal: Cancer Research (2024)

Abstract Dysregulation of antigen receptor-mediated signaling contributes to the oncogenesis of lymphoid malignancies. The activated B cell-like (ABC) subtype of Diffuse Large B cell Lymphoma (DLBCL) is characterized by receptor-independent constitutive activation of the canonical nuclear factor-kappaB (NF-κB) pathway, which is essential for the proliferation and survival of tumor cells. Caspase recruitment domain-containing protein 11 (CARD11) is a scaffolding protein that regulates B and T cell receptor signaling to canonical NF-κB activation downstream for adaptive immune response. Oncogenic gain-of-function (GOF) CARD11 mutations bypass normal pathway regulation and result in a hyperactive CARD11 that signals constitutively. Although present in ~10% of human ABC-DLBCL biopsies, we do not have a complete mechanistic understanding of how CARD11 GOF mutations drive abnormal B cell proliferation to cause lymphoma. We generated a mouse expressing the DLBCL-associated GOF mutation C49Y from the endogenous CARD11 locus. GOF CARD11 was sufficient to specifically drive B cell expansion in the mice with no significant effect on CD4+ or CD8+ T cells or NK cells. Quantification of splenic lymphocytes revealed that CARD11C49Y/C49Y mice had ~5-fold more splenic B cells when compared to CARD11+/+ mice and ~13-fold more marginal zone (MZ) B cells. CARD11C49Y/C49Y MZ B cells proliferated and survived much better than CARD11+/+ following stimulation with αIgM and importantly exhibited significant survivability prior to stimulation. Bulk mRNA sequencing revealed genes uniquely dysregulated in CARD11C49Y/C49Y MZ B cells including those associated with non-canonical NF-κB pathway signaling. CARD11C49Y/C49Y MZ B cells exhibited elevated levels of the p100 precursor NF-kB subunit leading to enhanced production of nuclear p52 following BAFF treatment. CARD11C49Y/C49Y MZ B cells also exhibited elevated levels of TRAF2, TRAF3 and cIAP1/2, components of a complex that degrades the NIK kinase that is responsible in normal cells for inducing p100 processing. Our results reveal an unexpected ability of CARD11 GOF mutants to potentiate the non-canonical NF-κB pathway through p100 accumulation, which likely contributes to the dysregulated B cell expansion observed in DLBCL cases that harbor CARD11 GOF variants. Citation Format: Anushka Ghosh, Joel Pomerantz. Oncogenic CARD11 enhances marginal zone B cell survival by potentiating the non-canonical NF-κB pathway [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 6986.
Abstract 557: Clofarabine inhibits U87MG glioblastoma cell line proliferation through CD99 signaling pathway
Authors: Camila Cristina de Souza, Roseli da Silva Soares, Antonio Marcondes Lerario, Suely Kazue Marie, Sueli Mieko Oba-Shinjo
Journal: Cancer Research (2024)

Abstract The present work aimed to test the efficacy of clofarabine in glioblastoma (GBM) cells that express high levels of CD99. GBMs are the most malignant with the poorest prognosis among tumors of the central nervous system. Patients have a median survival of 12 to 15 months despite surgical, radio, and chemotherapy. CD99 is a cell surface receptor overexpressed in several types of tumors, including GBMs, justifying the interest of studies in CD99 as a possible therapeutic target. Our group has previously demonstrated that knockout of CD99 in the U87MG GBM cell line promoted a decrease in cell adhesion, migration, and invasion. Clofarabine is a third-line drug used in the treatment of refractory/relapsed childhood acute lymphoblastic leukemia. It is a purine analog that is transported into intracellular space, phosphorylated, and incorporated into DNA chain, inhibiting DNA synthesis and ultimately inducing cell death by apoptosis. The clofarabine effect has also been demonstrated in cells from solid tumors, such as breast, gastric, and bladder. Clofarabine action on the proliferation of Ewing sarcoma cells in vitro and in vivo was proved to be by direct binding to CD99 and independent of the drug internalization. In addition, clofarabine also had an effect on cells from other tumor types that express CD99. The present work demonstrated the significant action of clofarabine on the high CD99-expressing U87MG cells by inhibiting cell proliferation, adhesion, and migration, and by inducing cell cycle arrest and apoptosis. U87MG cells knocked out for CD99 expression were more resistant to clofarabine action on proliferation. RNAseq analysis of U87MG cells treated with clofarabine and compared to control showed downregulated genes involved in cell cycle regulation and mitosis, while upregulated genes were enriched in extracellular proteins, cell adhesion, locomotion, p53 signaling pathway, and apoptosis. Our data indicates clofarabine as a potential CD99 inhibitor to treat GBM patients. Citation Format: Camila Cristina de Souza, Roseli da Silva Soares, Antonio Marcondes Lerario, Suely Kazue Marie, Sueli Mieko Oba-Shinjo. Clofarabine inhibits U87MG glioblastoma cell line proliferation through CD99 signaling pathway [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 557.
Abstract 4527: TNG348 is synergistic with PARP inhibitors in tumor models with elevated replication stress
Authors: Antoine Simoneau, Hsin-Jung Wu, Charlotte Pratt, Grace Comer, Shangtao Liu, Samuel Meier, Tenzing Khendu, Ashley Choi, Hongxiang Zhang, Binzhang Shen, Douglas Whittington, Sirimas Sudsakorn, Wenhai Zhang, Yi Yu, Yingnan Chen, Brian Haines, Adam Crystal, Jannik N. Andersen, John Maxwell, Scott Throner
Journal: Cancer Research (2024)

Abstract Defective maintenance of genomic integrity is a hallmark of cancer cells that can result from oncogene-induced replication stress and by loss of DNA repair mechanisms. DNA repair deficiencies and elevated replication stress present targetable vulnerabilities for cancer treatment. Notably, BRCA1/2 mutant and homologous recombination deficient (HRD) tumors cannot repair double-strand breaks by homologous recombination and rely on alternative pathways of DNA repair. PARP inhibitors (PARPi), which are a standard of care in many BRCA1/2 mutant tumors, cause synthetic lethality with BRCA1/2 mutation by inhibiting the DNA base excision repair pathway. Despite the clinical benefit of PARPi, they are not effective in every HRD tumor and the acquisition of PARPi resistance limits long-term response. TNG348, a selective allosteric inhibitor of the deubiquitinating enzyme USP1, was specifically designed to target HRD vulnerabilities through an alternative mechanism. We previously showed that the anti-tumor activity of USP1 inhibition results from disruption of the translesion synthesis DNA damage tolerance pathway, a mechanism of action that is functionally distinct from base excision repair targeted by PARPi. Our preclinical studies show that TNG348 is active in HRD models and strongly synergizes with PARP inhibitors to drive strong anti-tumor responses. We have identified replication stress as a predictive biomarker of TNG348 response using cell line profiling and genome-wide CRISPR screens. For example, overexpression of oncogenes known to induce replication stress sensitized to the TNG348 and PARPi combination both in vitro and in vivo. These data indicate that cancer-specific elevated DNA replication stress could contribute to tumor sensitivity to TNG348 and provide additional patient stratification strategies and opportunities for indication expansion. Citation Format: Antoine Simoneau, Hsin-Jung Wu, Charlotte Pratt, Grace Comer, Shangtao Liu, Samuel Meier, Tenzing Khendu, Ashley Choi, Hongxiang Zhang, Binzhang Shen, Douglas Whittington, Sirimas Sudsakorn, Wenhai Zhang, Yi Yu, Yingnan Chen, Brian Haines, Adam Crystal, Jannik N. Andersen, John Maxwell, Scott Throner. TNG348 is synergistic with PARP inhibitors in tumor models with elevated replication stress [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 4527.
Abstract 5546: CRISPR-based kinome screen identifies <i>Ikbkb</i> as a regulator of phagocytic evasion in hepatocellular carcinoma
Authors: Sze Man Chan, Terence Kin Wah Lee
Journal: Cancer Research (2024)

Abstract Hepatocellular carcinoma (HCC) is one of the most lethal and prevalent malignancies worldwide and is associated with poor prognosis. Recently, immune checkpoint inhibitors (ICIs) have revolutionized the oncology landscape by targeting genes critical for immune checkpoint pathways, leading to the immune evasion of cancer cells. Phagocytosis checkpoints have emerged as essential checkpoints for cancer immunotherapy by functioning as “don’t eat me” signal to suppress immune response. Given the druggable properties of protein kinases, together with recent reports showing the antitumor immunity of kinase inhibitors, we aimed to identify protein kinases critical for phagocytic evasion in HCC by transducing a lentiviral sgRNA expression plasmid containing 2,852 unique single-guide RNAs (sgRNAs) targeting the 713 mouse kinase gene in mouse HCC cells, RIL-175, and subsequently co-incubated with RAW 264.7 macrophages. Based on the deep sequencing analysis comparing the sgRNA distribution in RIL-175 with or without co-incubation, we identified the Ikbkb gene as top-sensitizing hit on this screen, with at least two-fold sgRNA reduction upon incubation with macrophages. To verify the phagocytic evasive role of Ikbkb in HCC, we have employed CRISPR/Cas9 knockout approach to delete Ikbkb in mouse HCC cell line, RIL-175 cells. The results showed that upon co-incubation with RAW 264.7 cells, the Ikbkb knockout cells exhibited increased phagocytosis, as confirmed by both flow cytometry analysis and microscopy observation. The analysis of the TCGA-LIHC cohort revealed that the expression level of Ikbkb was elevated and associated with unfavorable clinical outcomes. Notably, Ikbkb expression was found to be significantly correlated with established anti-phagocytic markers, including CD24, CD47, and CD274, further supporting their roles in the anti-phagocytic activities of HCC cells. In summary, we have uncovered IKBKB as a cancer-intrinsic regulator of phagocytosis, which has the potential to target IKBKB as a novel therapeutic strategy to enhance the efficacy of current ICI treatments for HCC patients. Citation Format: Sze Man Chan, Terence Kin Wah Lee. CRISPR-based kinome screen identifies Ikbkb as a regulator of phagocytic evasion in hepatocellular 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 5546.
Abstract 6971: The impact of lecithin retinol acyltransferase in squamous cell carcinoma: Tissue formation, cell mechanics, and gene transcription
Authors: Emily Peterson, Kuan-Che Feng, Jay Gao, Miriam Rafailovich, Marcia Simon
Journal: Cancer Research (2024)

Abstract Squamous cell carcinoma, along with several other cancers, has been found to lack expression of lecithin retinol acyltransferase (LRAT), a protein which catalyzes retinol esterification and thereby mediates retinoic acid biosynthesis. When expression of LRAT was reintroduced in squamous cell carcinoma, the protein promoted cell differentiation in addition to retinoid status normalization—whether this effect was dependent on the known enzymatic activity of LRAT in retinol esterification, versus another function, has not yet been established. Cell elasticity differences have also been reported between squamous cell carcinoma and normal keratinocytes. In this study, the role of LRAT expression and activity was evaluated in human squamous cell carcinoma cell line SCC13. LRAT was integrated into the genome of SCC13 via retroviral transduction, both as wild-type LRAT and LRAT with a cysteine-to-serine mutation at the active site for retinol esterification (C161-S). In these transformed cell lines, LRAT promoted formation of a cohesive sheet of tissue which remained intact after its removal from the tissue culture plastic surface, as evaluated at two weeks post-confluence. SCC13 alone produced tissue which easily fragmented during this scraping assay. In an evaluation of cell elasticity with shear modulation force microscopy, relative cell modulus measurements of pre-confluent SCC13 with LRAT expression were found to be significantly greater and consistent with the cell modulus of human keratinocytes (DO33). These effects persisted with mutation of the retinol esterification active site, suggesting that LRAT possesses an additional function which has yet to be described. Variation in transcription levels of multiple genes—urokinase-type plasminogen activator, plasminogen activator inhibitor 1, tissue inhibitor of metalloproteinases 1, and kallikrein 5—was also found based on LRAT expression and level of confluence. These findings suggest that the presence of LRAT influences tissue formation, cell elasticity, and gene transcription in SCC13. Citation Format: Emily Peterson, Kuan-Che Feng, Jay Gao, Miriam Rafailovich, Marcia Simon. The impact of lecithin retinol acyltransferase in squamous cell carcinoma: Tissue formation, cell mechanics, and gene transcription [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 6971.
Abstract 5540: Single cell multiomic analysis of human brain metastasis reveals conserved dormancy population
Authors: Remi Klotz, Yiru Wang, Anu Sunkara, Frank Attenelo, Min Yu
Journal: Cancer Research (2024)

Abstract This study explores the complex realm of brain metastasis, pivotal in crafting effective anti-tumor strategies. Leveraging single-cell multi-omics sequencing, we profiled the transcriptomes and chromatin accessibility landscapes of tumor cells and their surrounding microenvironment in human brain metastases that originated from across a spectrum of primary cancers. Our investigations have identified distinct, yet uniformly present, tumor cell subpopulations, each defined by unique gene expression patterns, chromatin accessibility, and the interactions between tumor and stromal cells. Notably, one such subpopulation exhibits a dormancy signature, characterized by enhanced interferon response, oxidative phosphorylation, and upregulated HLA class molecules, alongside alterations in circadian rhythms. Our trajectory analysis charts a course from these dormant cells to rapidly proliferating ones, with notable shifts in circadian rhythm genes, underscoring their potential role in brain metastasis. This aligns with recent findings that disruptions in circadian rhythms can modify stem cell characteristics in glioblastomas. This insight led us to focus on a specific circadian rhythm gene, highly active in the dormant cells and located on the HER2 amplicon—an area linked to high brain metastasis relapse rates in patients. We've developed inducible models for both overexpression and knockdown to scrutinize this gene's impact in her2 positive breast cancer cell lines, examining gene expression and proliferation in vitro. Complementing this, we are conducting spatial transcriptomic analysis to evaluate the microenvironmental regulation of tumor dormancy in human brain metastases. This multi-omics approach reveals a nuanced regulatory landscape of brain metastasis, highlighting a novel and often overlooked factor in metastasis progression and brain tumor relapse: the interplay between circadian rhythms and tumor dormancy. This discovery not only deepens our understanding of brain metastases but also opens potential new avenues for therapeutic interventions. Citation Format: Remi Klotz, Yiru Wang, Anu Sunkara, Frank Attenelo, Min Yu. Single cell multiomic analysis of human brain metastasis reveals conserved dormancy population [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 5540.
Abstract 5555: Lung squamous cancer cell mTORC2 signaling suppresses antitumor immunity by up-regulation of PSGL-1, a ligand of VISTA/PD-1H checkpoint receptor
Authors: Verra M. Ngwa, Yoonha Hwang, Deanna N. Edwards, Wenqiang Song, Jin Chen
Journal: Cancer Research (2024)

Abstract Lung squamous cell carcinoma (LUSC) represents 30% of non-small cell lung cancer (NSCLC) cases and has a high mortality rate with limited targeted therapies. Unlike lung adenocarcinoma (LUAD), which has seen advancements in targeted therapies, LUSC has not benefited from similar breakthroughs despite having similar genetic abnormalities. While immune checkpoint inhibitor therapies have shown promise in some LUSC patients, a significant portion does not respond effectively, leaving limited treatment options. In this study, we investigated vulnerabilities in NSCLC and found that a substantial number of LUSC patients have genetic alterations in the PI3K-mTORC2-AKT signaling pathway. By using CRISPR/CAS-9, we showed that disrupting mTORC2 function in LUSC cells reduced glycolysis and lactate secretion, which in turn reduced tumor growth in vivo. Remarkably, the loss of mTORC2 also enhanced the activity of CD4+ and CD8+ T cells within the tumors. To further understand the metabolic and immune changes associated with mTORC2 loss of function, we performed RNA sequencing comparing wild-type (WT) and mTORC2-deficient cells. Our results confirmed a link between mTORC2 and HIF-2α, while regulating PSGL-1, a ligand of the VISTA/PD-1H checkpoint receptor. Furthermore, introducing a stable, non-degradable form of HIF-2α in mTORC2-deficient tumor cells restored PSGL-1 expression in vitro and in vivo. These results suggest that the interaction between PSGL-1 and VISTA plays a role in suppressing the anti-tumor immune response in LUSC tumors. Indeed, anti-VISTA treatment inhibited the growth of LUSC WT tumors in vivo, suggesting that mTORC2 plays a role in regulating PSGL-1 expression in the tumor microenvironment. Together, these data demonstrate that targeting mTORC2 or inhibiting VISTA checkpoint receptor may serve as a potential therapeutic strategy for improving immunotherapy in LUSC. Citation Format: Verra M. Ngwa, Yoonha Hwang, Deanna N. Edwards, Wenqiang Song, Jin Chen. Lung squamous cancer cell mTORC2 signaling suppresses antitumor immunity by up-regulation of PSGL-1, a ligand of VISTA/PD-1H checkpoint receptor [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 5555.
Abstract 5577: TRPM8 mediated Ca2+ signaling as a therapeutic target in prostate cancer
Authors: Swapna Asuthkar, Kiran Velpula, Vander Don Griend
Journal: Cancer Research (2024)

Abstract Prostate cancer (PC) is a prevalent and deadly malignancy, necessitating the development of innovative therapeutic strategies. Transient receptor potential melastatin 8 (TRPM8), an ion channel highly expressed in prostate epithelium, has emerged as a potential target. Our preliminary studies demonstrate that TRPM8 plays a crucial role in PC progression. We observed an initial increase in TRPM8 mRNA expression during early-stage PC, followed by a decline in advanced and androgen-independent prostate cancer (AIPC) stages. Additionally, TRPM8 knockout mice exhibited elevated serum testosterone levels, heightened androgen receptor (AR) activity, and increased cell cycle, invasion, and adhesion-related effects. In xenograft models, TRPM8 demonstrated potent antitumor properties in both AR+ and AR- contexts. Our research suggests that TRPM8 activation on the plasma membrane promotes calcium influx and induces apoptosis in PC cells. Conversely, TRPM8 internalization correlates with PC pathogenesis. By exploring the effects of TRPM8 on PTEN-mediated cellular signaling, we aim to uncover novel insights into the molecular mechanisms underlying TRPM8's role in PC. This abstract underscores the potential of targeting TRPM8-mediated Ca2+ signaling as a promising therapeutic approach to combat PC progression, offering hope for improved patient outcomes. Citation Format: Swapna Asuthkar, Kiran Velpula, Vander Don Griend. TRPM8 mediated Ca2+ signaling as a therapeutic target in prostate 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 5577.