bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 5325: Cytokine CCL9, new downstream target of oncogene Kras to modulate acinar-to-ductal metaplasia during pancreatic cancer initiation
Authors: Liou Geou-Yarh (Stancy) , Messex Justin K. , Byrd Crystal J. 
Published: March 2024

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of cancer with a current five-year survival rate at 12% in the US, and is dominated by oncogenic Kras mutations. Accumulating evidence showed that PDAC can be originated from acinar-to-ductal metaplasia (ADM). In this process, pancreatic acini harboring oncogenic Kras mutations are transdifferentiated to a duct-like phenotype that further progresses to become pancreatic intraepithelial neoplasia (PanIN) lesions, giving rise to PDAC. Although ADM formation is commonly observed in KrasG12D transgenic mouse models of PDAC, the exact mechanisms of how oncogenic KrasG12D modulates this process remain unclear. Here, we unveil a new downstream target of oncogenic Kras, cytokine CCL9 during ADM formation. Either exogenously treating primary pancreatic acini with recombinant CCL9 or ectopically expressing CCL9 in primary pancreatic acini resulted in ADM formation in a 3D organoid culture system. Furthermore, knockdown of CCL9 in KrasG12D-expressed acini reduced KrasG12D-induced ADM. Higher levels of reactive oxygen species (ROS) were detected in the KrasG12D-expressed pancreatic acini, and knockdown of CCL9 in these acini decreased ROS levels. Overexpression of CCL9 in primary pancreatic acini elevated cellular ROS of pancreatic acinar cells. Furthermore, depletion of ROS in 3D organoid culture of CCL9-expressed acini reduced CCL9-induced ADM formation. In transgenic mice of p48cre:KrasG12D, blockade of CCL9 through its specific neutralizing antibody attenuated ADM formation as well as PanIN structures. Altogether, our results indicated oncogenic KrasG12D initiates PDAC through a new downstream target molecule, CCL9, to enhance ROS levels of pancreatic acinar cells.
Citation Format: Geou-Yarh (Stancy) Liou, Justin K. Messex, Crystal J. Byrd. Cytokine CCL9, new downstream target of oncogene Kras to modulate acinar-to-ductal metaplasia during pancreatic cancer initiation [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 5325.
Abstract 5451: FOXC2 influences EMT-induced stem cell properties through regulation of FABP4 in breast cancer
Authors: Demestichas Breanna R. , Shivakumar Vinita , Ramirez-Peña Esmeralda , Taube Joseph , Hollander Petra den , Mani Sendurai A. 
Published: March 2024

Abstract
Cancer stem cells (CSCs) pose a significant clinical challenge due to their inherent resistance to therapies and prevalence in cancer recurrence. CSCs have the ability for self-renewal and to adapt to different microenvironments during dissemination and seeding into distal organs, and these properties are critical in metastasis. We and others have shown that epithelial to mesenchymal transition (EMT) drives the acquisition of stem cell properties, particularly via the forkhead box protein C2 (FOXC2) transcription factor. FOXC2 is a master regulator of EMT and is necessary for the induction and maintenance of CSC properties. Importantly, FOXC2 is not expressed in most adult tissues except adipocytes, in which it dictates several aspects of lipid metabolism. Additionally, metabolic changes during EMT can equip cancer cells with enhanced survival mechanisms during tumor progression and metastasis. We hypothesized that FOXC2 regulates metabolism in EMT-induced cells, facilitating stem cell properties and metastatic competence.
To determine the downstream metabolic genes regulated by FOXC2 and that enhance stemness properties in cancer cells, we performed gene expression profiling and identified fatty acid binding protein 4 (FABP4), which is known to be involved in lipid metabolism, especially in adipocytes and macrophages. We demonstrate that inhibition of FOXC2 expression using shRNA in EMT-induced cells markedly reduces FABP4 expression. In agreement with this, we found that the overexpression of FOXC2 expression rescues the expression of FABP4. In addition, FOXC2 binds to the FABP4 promoter and regulates its expression suggesting that FABP4 is a direct target of FOXC2. We demonstrate that both lipid uptake and CSC formation is inhibited in a dose-dependent manner using a FABP4-specific small molecule inhibitor. Additional experiments are underway to assess the role of FABP4 in CSC formation in vivo and in contributions to metastasis, using our small molecule inhibitor in mouse models of metastatic breast cancer.
Overall, our data indicate that FABP4 is a key regulator of stemness in breast cancer cells and targeting the FOXC2—FABP4 axis may provide therapeutic benefits for breast cancer. This work also provides insights into the metabolic shifts that occur during EMT and CSC formation, which warrants further investigation into these mechanisms.
Citation Format: Breanna R. Demestichas, Vinita Shivakumar, Esmeralda Ramirez-Peña, Joseph Taube, Petra den Hollander, Sendurai A. Mani. FOXC2 influences EMT-induced stem cell properties through regulation of FABP4 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 5451.
Abstract 5512: Cerebral endothelial FAK paradoxically inhibits brain metastasis in vivo
Authors: Noda-Narita Shoko , Aiba Atsu 
Published: March 2024

Abstract
Introduction: In cancer metastasis in the trunk, the secreted proteins from tumors, such as VEGFs and TNF-α, activate focal adhesion kinase (FAK) in vascular endothelial cells (VECs). The activated FAK promotes VE-cadherin phosphorylation and the expression of cell adhesion molecules, and it facilitates the extravasation of cancer cells. In the cerebral blood vessels, the VECs maintain very strong cell adhesion supported by the surrounding pericytes and astrocytes. The strong barrier of cerebral VECs is called the blood-brain barrier (BBB) and is regulated differently from trunk VECs. Although the role of FAK in trunk metastasis is shown in many studies, its importance in brain metastasis is not verified. In this study, we focused on the role of the cerebral endothelial FAK and compared the role of FAK in brain metastasis with that in trunk metastasis.
Methods: We generated tamoxifen-inducible VEC-specific FAK knockout (FAK-cKO) mice (VEcad-CreERT2; Ptk2-flox/flox) and brain metastatic (BrM) cell lines of Ex3LL (murine lung cancer cell line). We intracardially injected BrM cells of Ex3LL into the FAK-cKO mice and analyzed the tumor development using in vivo bioluminescence imaging and a CUBIC tissue clearing system. We also analyzed the intracranially injected mice of the parental and BrM cell lines to evaluate the tumor angiogenesis, which is reported to be promoted by the endothelial FAK.
Results: Although FAK-cKO in VECs has been reported to inhibit lung metastasis, brain metastasis was accelerated in FAK-cKO mice compared with control mice. The number of brain metastatic sites increased in FAK-cKO mice, but there was no difference in the individual tumor size. It suggests that the brain metastasis was promoted by FAK-cKO, but that the proliferation of brain metastasis was not promoted by FAK-cKO. Blood vessel density was decreased with irregular shape in the brain tumors of FAK-cKO mice, suggesting that the angiogenesis was inhibited by FAK-cKO. It indicates that the angiogenic function of endothelial FAK in the brain vasculature was not different from that in the trunk.
Conclusion: FAK-cKO in VECs exacerbated the brain metastasis of the BrM cells although it has been reported to inhibit the metastasis in the trunk. FAK-cKO in VECs decreased tumor angiogenesis both in the brain and the trunk. It suggests that the regulatory mechanism of cell adhesion and the FAK function in the brain vasculature is partly different from that in the other organs in the body trunk. We need further investigation to elucidate the function of endothelial FAK in brain metastasis.
Citation Format: Shoko Noda-Narita, Atsu Aiba. Cerebral endothelial FAK paradoxically inhibits brain metastasis in vivo [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 5512.
Abstract 552: Non-canonical disulfide isomerases are strongly selective, understudied targets for cancer therapy
Authors: Law Mary E. , Dulloo Zaafir M. , Yaaghubi Elham , Alexandrow Grace M. , Forsyth Bianca , Su Hanyu , Castellano Ronald K. , Law Brian K. 
Published: March 2024

Abstract
A major challenge in cancer therapy is the identification of drug targets that are essential for cancer cells but not non-transformed cells. The Broad Institute’s Dependency Map (DepMap) evaluates whether knocking down or knocking out expression of specific genes is “strongly selective” against subsets of cancer cells, in contrast with genes that are “common essential.” Of the 22 human Protein Disulfide Isomerases (PDIs), only four, ERp44, TMX1, AGR2, and AGR3, were identified as strongly selective in the DepMap. Importantly, our team previously identified ERp44, AGR2, and AGR3 as targets of bicyclic thiosulfonate compounds termed Disulfide bond Disrupting Agents (DDAs). DDAs exhibit striking anti-cancer activity in xenograft tumor studies. DDA treatment of cancer cells blocks ERp44, AGR2, and AGR3 active site Cys residues, ablating their catalytic activity and binding to client proteins. Evaluation of cancer cell lines predicted to be sensitive to DDAs, based on their AGR2, AGR3, or ERp44 dependence, accurately predicts DDA sensitivity. Cell lines from a variety of tumor types exhibit AGR2, AGR3, or ERp44 dependencies. Our previous work identified HER-family members (i.e., EGFR, HER2, and HER3) and TRAIL receptors (Death Receptors 4 and 5) as important clients of DDA-sensitive PDIs in breast cancer cells, but it was unknown if these observations extend to other tumor types. Initial studies indicate that AGR2 DepMap dependencies are a strong predictor of sensitivity of cancer cells to DDAs, irrespective of their site of origin. It will be important in future studies to determine what the key client proteins for these DDA-sensitive PDIs are and whether they vary across tumor types.
Citation Format: Mary E. Law, Zaafir M. Dulloo, Elham Yaaghubi, Grace M. Alexandrow, Bianca Forsyth, Hanyu Su, Ronald K. Castellano, Brian K. Law. Non-canonical disulfide isomerases are strongly selective, understudied targets for cancer therapy [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 552.
Abstract 5529: Mimicking CAFs, pial cells support leptomeningeal metastasis
Authors: Snyder Jenna , Remsik Jan , Boire Adrienne 
Published: March 2024

Abstract
Leptomeningeal metastasis (LM), the spread of cancer into cerebrospinal fluid (CSF)-filled coverings of the brain and spinal cord, is a dismal complication of cancer leading to rapid neurologic disability and death. While a diverse array of primary tumors may result in LM, recent work from our laboratory (Chi Y et al 2020 Science) demonstrates a conserved transcriptional signature, independent of primary tumor, suggesting that tumor-microenvironmental interactions play a dominant role in this pathology. We have proteomically interrogated CSF collected from breast (n = 45), lung (n = 30), and melanoma (n = 27) patients with and without LM. We detect robust expression of inflammatory cytokines in all LM+ samples, 15 of these cytokines including IL8, IL6, and CXCL1 are conserved across tumor types in the presence of LM. Because cancer cells in the CSF do not express mRNA associated with these cytokines, we hypothesized that these inflammatory cytokines may originate from the microenvironment. Within the leptomeninges, LM cells adhere to and interact with the innermost layer of the meninges, the pia mater, which contains fibroblast-like cells. Co-culture of cancer cells with pial cells induced changes in the pial cell transcriptome and secretome, leading to increased IL8, IL6, and CXCL1 production. This communication between cancer cells and pial cells is preserved in the absence of direct cell-cell contact. These pial cells support cancer cell growth in vivo, as measured by co-implantation experiments. In addition, bulk RNA sequencing of mouse pial cells shows an inflammatory signature upregulated in the presence of LM. Taken together, these observations support a cancer-associated-fibroblast like role for pial cells in the setting of LM. Our work extends the CAF phenotype beyond classical fibroblasts to include pial cells, suggesting novel therapeutic opportunities within CNS malignancies.
Citation Format: Jenna Snyder, Jan Remsik, Adrienne Boire. Mimicking CAFs, pial cells support leptomeningeal 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 5529.
Abstract 5530: Metastasis founder cells activate immunsuppression early in human metastatic colonization
Authors: Guetter Severin , Koenig Courtney , Koerkel-Qu Huiqin , Markiewicz Aleksandra , Scheitler Sebastian , Katzer Marie , Berneburg Mark , Renner Philipp , Cucuruz Beatrix , Guttenberger Leonhard , Naimer Veronika , Weidele Kathrin , Treitschke Steffi , Werno Christian , Jaser Hanna , Bargmann Tonia , Braun Armin , Weber Florian , Limm Katharina , Rachel Reinhard , Baumann Felix , Schmidleithner Lisa , Schambeck Kathrin , Ulmer Anja , Haferkamp Sebastian , Klein Christoph , Werner-Klein Melanie 
Published: March 2024

Abstract
Metastatic dissemination occurs very early in melanoma, often before diagnosis, rendering prevention of metastasis formation an important therapeutic goal. However, the earliest steps of lethal metastasis in patients are incompletely understood. Therefore, in this study we searched for the earliest detectable disseminated cancer cells (DCC) in sentinel lymph node biopsies of 492 stage I-III melanoma patients. We used micromanipulator-assisted isolation and single-cell transcriptome analysis of these extremely rare DCC and identified melanoma -associated chondroitin sulfate proteoglycan (MCSP) expressing melanoma cells as strong candidates for metastasis founder cells in lymph nodes. Based on a median follow-up time of 6 years, their detection was the strongest predictor of systemic metastasis and death upon multivariable analysis. Single-cell transcriptome analysis revealed that melanoma DCC were exposed to CD8 T cell attack during the transition from single cells to metastasis-initiating clusters, activated the extracellular vesicular exosomal pathway, and expressed the immunomodulatory proteins CD155 and CD276, but rarely PD-L1. CD155- and CD276-positive extracellular vesicles from patient-derived DCC models showed an immunosuppressive activity on CD8 T cells. In conclusion, our data suggest that either direct targeting of metastasis-founder cell with MCSP or their immune escape mechanisms may be key to curing early-stage melanoma.
Citation Format: Severin Guetter, Courtney Koenig, Huiqin Koerkel-Qu, Aleksandra Markiewicz, Sebastian Scheitler, Marie Katzer, Mark Berneburg, Philipp Renner, Beatrix Cucuruz, Leonhard Guttenberger, Veronika Naimer, Kathrin Weidele, Steffi Treitschke, Christian Werno, Hanna Jaser, Tonia Bargmann, Armin Braun, Florian Weber, Katharina Limm, Reinhard Rachel, Felix Baumann, Lisa Schmidleithner, Kathrin Schambeck, Anja Ulmer, Sebastian Haferkamp, Christoph Klein, Melanie Werner-Klein. Metastasis founder cells activate immunsuppression early in human metastatic colonization [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 5530.
Abstract 554: Determining the role of PROX1 in prostate cancer neuroendocrine trans-differentiation
Authors: Raj Sonam , Capaldo Brian , Bowman Joel , White Margaret , Moore Xavier , Gryder Berkley , Alilin Aian N. , Takeda David , Kelly Kathleen 
Published: March 2024

Abstract
Nonbiased mutational screening to identify essential genes and pathways in cancer is a powerful approach for understanding underlying biology as well as the identification of potential therapeutic targets. Epigenetic (EPI) and transcriptional factors (TF) play an important role in the change of phenotype and lineage plasticity from adenocarcinoma to castration resistant prostate cancer (CRPC), double negative (DN) or treatment-induced neuroendocrine prostate cancer (NEPC). When RB1 loss occurs in combination with TP53 alterations, stemness and lineage plasticity increase with one consequence being differentiation to a neuroendocrine (NE) lineage. Here, we are identifying and testing the functional role of epigenetic and transcription factors required for the viability of CRPC, DN and NEPC relative to a matrix of genotypic and phenotypic characteristics. We applied CRISPR-CAS9 dropout screens in prostate organoids and cell lines to identify gene/s associated with CRPC, DN and NEPC viability. We successfully CRISPR-engineered LNCaP clones of single (LNCaP-TP53-SKO, LNCaP-RB1-SKO) and double (LNCaP-TP53-RB1-DKO) gene knockouts, which were subsequently characterized for immuno-phenotype and transcriptome. Our dropout screens, targeting all TFs and EPIs, identified 117 TF and 40 EPI genes responsible for the viability of DN, NEPC and LNCaP models. We found known genes such as FOXA1 and ASCL1, as well as novel genes including PROX1 and KLF3, which were validated through guide RNA competition assays. Our results showed PROX1 is essential for cell viability in a DN organoid model, and its expression is associated with increased aggressiveness, indicating PROX1 has role in stemness/lineage plasticity in treatment resistant adenocarcinoma. RNA-seq analysis following overexpression of PROX1 in the LNCaP-TP53-RB1 null adenocarcinoma model, with and without enzalutamide, identified pathways enriched for cell proliferation, differentiation, neuronal development, and prostate gland development. In summary, our study has suggested an important role for PROX1 in the growth and differentiation of poorly differentiated prostate cancer, which may lead to the identification of potential therapeutic targets.
Citation Format: Sonam Raj, Brian Capaldo, Joel Bowman, Margaret White, Xavier Moore, Berkley Gryder, Aian N. Alilin, David Takeda, Kathleen Kelly. Determining the role of PROX1 in prostate cancer neuroendocrine trans-differentiation [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 554.
Abstract 5557: Stem-like T cells maintain latent anticancer activity and underly therapy resistance
Authors: Tao Fang , McElroy Sara , Nemechek Jacqelyn , Pushel Irina , Szarejko John , Khanal Santosh , Bradley Todd , Myers Doug , Perry John M. 
Published: March 2024

Abstract
Pre-cancerous cells are normally recognized and eliminated by immune cells. Cancer progresses only when this immunosurveillance system fails. Although immunotherapy has driven the most significant and exciting advances in cancer treatment in modern times, current approaches are running into barriers. An emerging area of interest includes evidence for rare but highly potent stem cell-like T cells. Stem-like T cells combine long-term persistence and high potency with immunological memory. Our recent findings reveal insights into the nature and regulation of stem-like T cells and their potential anticancer activity. Minimal residual disease (MRD) underlies therapeutic resistance, dictates treatment escalation, and predicts patient outcomes. We have shown that the Wnt and PI3K pathways promote the transformation of hematopoietic stem cells (HSCs) into chemoresistant leukemia stem cells (LSCs), which form the root of leukemia initiation and post-treatment recurrence. High-throughput screening revealed that LSCs could be targeted by low dose anthracycline treatment. Mechanistically, low dose, but not high dose anthracyclines indirectly target LSCs by inhibiting their unique properties of immune escape, allowing for their elimination by CD8+ T cells. We employed single-cell genomic and proteomic analysis to investigate immunological changes during development of HSCs, LSCs, and their progeny in response to low dose anthracycline treatment. While leukemia progression results in exhaustion of differentiated CD8+ T cells, stem-like T cells accumulate. However, low dose anthracycline treatment reverses this imbalance. Comparing MRD+ and MRD- patient samples, we found that differential proportions of stem-like T cells persist in the bone marrow of leukemia patients. While T cells of MRD- patients recover following chemotherapy induction, T cell recovery is severely attenuated in MRD+ patients. Furthermore, failure of immunological recovery is driven at least partially by a lack of stem-like T cells in MRD+ leukemia patients. Overall, our studies have revealed that low dose anthracyclines, in contrast to high dose, induce opposing, dichotomous effects on LSCs vs. HSCs and stem-like vs. differentiated T cells.
Citation Format: Fang Tao, Sara McElroy, Jacqelyn Nemechek, Irina Pushel, John Szarejko, Santosh Khanal, Todd Bradley, Doug Myers, John M. Perry. Stem-like T cells maintain latent anticancer activity and underly therapy resistance [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 5557.