bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 252: How the gatekeeper helix of the thioesterase domain of fatty acid synthase controls substrate recognition and initiation of cleavage of the proper substrate
Authors: Fromm Joseph , Teriete Peter , Cieplak Piotr , Misson Laetitia , Burkart Michael , Cosford Nicholas 
Published: September 2020

Abstract
Since the initiation of multiple clinical trials of two chemically distinct small molecule fatty acid synthase (FASN) inhibitors for the treatment of Non-Alcoholic SteatoHepatitis (NASH), breast cancer, colon cancer, and non-small cell lung cancer, FASN has garnered a resurgent interest as a therapeutic target. However, little effort has been made to better understand this target to improve upon previous drug discovery efforts. Using both computational modelling and enzymatic analysis, we have identified specific residues from the thioesterase (TE) domain of FASN that are crucial for the enzymatic function of FASN-TE while independent of the catalytic triad. Introduction of point mutations to these residues hinder the protein's ability to cleave the proper substrate of FASN, effectively disrupting the de novo synthesis of fatty acids. We propose a mechanism-of-action by which FASN-TE measures and initiates the cleavage of the proper substrate of FASN and have shown that interfering with the residues involved in this mechanism cripples the activity of the protein. Building upon these findings regarding the substrate selection mechanism of FASN-TE will allow for the enhanced design and development of the next generation of potent and selective inhibitors of FASN for the treatment of a variety of cancer types and other metabolic diseases.
Citation Format: Joseph Fromm, Peter Teriete, Piotr Cieplak, Laetitia Misson, Michael Burkart, Nicholas Cosford. How the gatekeeper helix of the thioesterase domain of fatty acid synthase controls substrate recognition and initiation of cleavage of the proper substrate [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 252.
Abstract 2539: Mutant TP53 action in lung dictated by the cell microenvironment
Authors: Yin Christopher , Gao Li , Villalona-Calero Miguel A. , Duan Wenrui 
Published: September 2020

Abstract
TP53 is a well-known tumor suppressor protein involved in many anti-tumor processes such as apoptosis, DNA repair, and cell cycle arrest. Codon 273 is one of the most frequently mutated sites among all p53 mutant types in human lung cancer. Recently, it has been discovered that TP53 and its mutants influence the expression of cancer-relevant microRNAs and vice-versa. Although many experiments have been performed on cell lines, far fewer experiments were geared toward how TP53 mutations affect miRNA expression in complex, in vivo settings. In addition to this, there are competing viewpoints on how TP53-273H could interact with wild type TP53. To investigate the mechanism involved in the oncogenic potential of mutant TP53 protein in vivo, TP53+/+/TG273H transgenic mice were bred into p53 null background. At the age of 5-6 weeks, TP53−/−; TP53−/-/TG273H; TP53+/+; and TP53+/+/TG273H mice were used to evaluate the expression of micro RNAs (miRNAs) as well as TP53 downstream genes. Based on the nanoString miRNA analysis, TP53−/- 273H mice exhibits decreased expression of miR-205, 206, and 1274a when compared against TP53−/− mice. However, TP53+/+ 273H mice resulted in increased expression of these miRNAs when compared against wild-type mice without mutant TP53 (TP53+/+). When comparing p53−/− knockout mice with wild-type mice, miRNAs 205, 206, and 1274a all increased at least 3-fold compared to wild-type. TP53−/− 273H mice exhibited widespread decrease of miRNA expression levels when compared against TP53+/+ 273H mice. The results suggest that the biological function of the TP53-273H is dictated by the cell microenvironment, especially the presence/absence of the wild type TP53 through dominant-negative effects in lung tissues. Mutant TP53-273H exerts oncogenic/tumor suppressor effects through specific miRNAs and their target gene networks.
Citation Format: Christopher Yin, Li Gao, Miguel A. Villalona-Calero, Wenrui Duan. Mutant TP53 action in lung dictated by the cell microenvironment [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2539.
Abstract 2569: Uncovering metabolic bottlenecks in KEAP1 mutant lung cancer
Authors: LeBoeuf Sarah E. , Wu Warren , Karakousi Triantafyllia , Wild Robert , Papagiannakopoulos Thales 
Published: September 2020

Abstract
During tumorigenesis cancer cells continuously encountermetabolic bottlenecks as a result of accelerated growth, overall increased metabolic demand and increased oxidative stress due to the formation of reactive oxygen species. We use a combination of genetically-engineered mouse models, an accelerated CRISPR/Cas9-based experimentalplatformand biochemical approaches to identify metabolic liabilities that can be exploited using novel targeted therapies.Lung cancer, the leading cause of cancer-related deaths worldwide,is the most common cancer type to acquire mutually exclusive gain-of-function mutations in the anti-oxidant transcription factor NRF2or loss-of-function mutations in its negative regulator KEAP1. Loss of Keap1activates Nrf2, increases antioxidant production and dramatically accelerates KRAS-driven lung cancer. Our data are in line with mounting evidence demonstrating that antioxidants promote cancer progression. Our studies focus on elucidating the mechanisms underlying novel metabolic dependencies in KEAP1mutant tumors and explore the therapeutic potential of targeting metabolism in highly relevant pre-clinical mouse and human lung cancer models. We observe that the ability of KEAP1mutant tumors to divert their metabolism towards antioxidant production comes with a cost, generating multiple metabolic vulnerabilities, including a dependency on glutamine metabolism that can be therapeutically exploited using DRP-104, a novel broad acting glutamine antagonist which inhibits all glutamine-consuming reactions. In addition, we have extended our findings to demonstrate that cancers with high antioxidant capacity exhibit a general dependency on exogenous non-essential amino acids (NEAAs) that is driven by the Nrf2-dependent secretion of glutamate through system xc-(XCT), which limits intracellular glutamate pools that are required for NEAA synthesis. This dependency can be therapeutically targeted by dietary restriction or enzymatic depletion of individual NEAAs. Importantly, limiting endogenous glutamate levels by glutaminase inhibition can sensitize tumors without alterations in Keap1/Nrf2 pathway to dietary restriction of NEAAs. Our findings identify a metabolic strategy to therapeutically target cancers with genetic or pharmacologic activation of the Nrf2 antioxidant response pathway by restricting exogenous sources of NEAAs.
Citation Format: Sarah E. LeBoeuf, Warren Wu, Triantafyllia Karakousi, Robert Wild, Thales Papagiannakopoulos. Uncovering metabolic bottlenecks in KEAP1 mutant lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2569.
Abstract 2618: Tumor multicomponent targeting nanoparticle for synergistic killing of drug resistant renal cell carcinoma
Authors: Vanamala Kushal , Sau Samaresh , Naik Shivani , Rishi Arun K. , Iyer Arun 
Published: September 2020

Abstract
Targeted therapy in renal cell carcinoma (RCC) has limited clinical response due to the development of drug resistance. Drug resistance can be acquired through multiple pathways including, impairment of apoptosis, overexpression of hypoxia promoting carbonic anhydrase 9 (CA9), and infiltration of folate receptor (FR) positive tumorigenic macrophages. Our hypothesis was to overcome the drug resistance by developing a tumor stimuli-responsive nanoparticle (NP) that can carry combination drugs, such as Cabozantinib (CB) and CFM 4.16 in RCC. The rationale of choosing the CB in combination with CFM4.16 was to induce synergistic anti-RCC effect by modulating the multiple tumor survival pathways, such as caspase 3, Akt/p-Akt, MET. One of the major challenges of the CB and CFM4.16 combination therapy is their poor water solubility and limited targetability to cancer. Thus, we came up with a smart strategy of developing dual folate receptor (FR) and carbonic anhydrase-9 (CA9) biomarker directed nanoparticles that can target the tumor stroma and hypoxia of RCC, respectively. In this proof of concept study, we synthesized SMA-TPGS and SMA polymer (PL) comprising of FR and CA9 dual targeting ligand, namely, FR-CA9-OL using reagent free ‘click' chemistry. FR-CA9-PL was encapsulated either with CFM4.16 or with CB to obtain nanoparticles, called FR-CA9-C4.16 and FR-CA9-CB respectively. The nanoparticles were prepared by using a co-solvent dialysis method that resulted in small-particle size with a range of 80-100 nm diameter, narrow polydispersity index of ∼ 0.15 and high drug loading of 30% (wt./wt.). The homogenous and high drug loading characteristics of nanoparticles are optimal for penetrating hypoxia of RCC. The IC50 of FR-CA9-C4.16 was improved by 60-fold as compared to CFM4.16 treatment and IC50 of FR-CA9-CB is improved by 16-fold compared to CB treatment in aggressive Everolimus-resistant (Evr-res) A498 RCC cells. The combination of FR-CA9-C4.16 with FR-CA9-CB demonstrated synergistic killing of Evr-res-A498 with CI value 0.1-0.5. The signature characteristic and superior anticancer effect of nanoparticles in Evr-resistant RCC provide a worthwhile strategy for overcoming drug resistance in RCC.
Citation Format: Kushal Vanamala, Samaresh Sau, Shivani Naik, Arun K. Rishi, Arun Iyer. Tumor multicomponent targeting nanoparticle for synergistic killing of drug resistant renal cell carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2618.
Abstract 2646: CD39+PD-1+CD8+ T cells mediate metastatic dormancy in breast cancer
Authors: de Lara Paulino Tallón , Cuadrado Héctor Castañón , Vermeer Marijne , Núñez Nicolás , Urdínez Joaquín , Cecconi Virginia , Attar Farkhondeh Movahedian , Glarner Isabelle , Hiltbrunner Stefanie , Tugues Sonia , Becher Burkhard , van den Broek Maries 
Published: September 2020

Abstract
Although metastatic disease can be present already at diagnosis, in some patients it appears months or years after resection of the primary tumor. This is thought to be due to the ability of some tumor cells to remain dormant after metastatic seeding. It is not known how dormancy is controlled, but there is evidence for tumor cell-intrinsic and -extrinsic mechanisms including immune defense.
Here we found in preclinical models of breast cancer that metastatic dormancy was fully controlled by T cells. Through high-parametric single-cell mapping, we identified a discrete population of CD39+PD-1+CD8+ T cells present both in primary tumors and in spontaneous dormant metastasis, whereas this population is hardly found in aggressively metastasizing tumors. Surprisingly, despite expressing many exhaustion markers, this population was rich in effector molecules and cytokines that induced dormancy in tumor cells. Of note, the adoptive transfer of purified CD39+PD-1+CD8+ T cells prevented metastatic outgrowth.
Thus, we discovered that primary breast tumors prime CD39+PD-1+CD8+ T cells that induce metastatic dormancy in distal disseminated tumor cells in the lungs.
Citation Format: Paulino Tallón de Lara, Héctor Castañón Cuadrado, Marijne Vermeer, Nicolás Núñez, Joaquín Urdínez, Virginia Cecconi, Farkhondeh Movahedian Attar, Isabelle Glarner, Stefanie Hiltbrunner, Sonia Tugues, Burkhard Becher, Maries van den Broek. CD39+PD-1+CD8+ T cells mediate metastatic dormancy in breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2646.
Abstract 2656: Myeloid derived Wnt5a influences the immune-dynamics of melanoma tumor microenvironment
Authors: Douglass Stephen , Fane Mitchell , Sanseviero Emilio , Gabrilovich Dmitry , Weeraratna Ashani 
Published: September 2020

Abstract
Despite breakthroughs in targeted therapies and immunotherapies, over 75% of patients either do not respond to therapy, or relapse. This may be due in part to changes in their tumor microenvironment (TME). Wnt5A is a glycoprotein that has been shown to influence melanoma phenotype, promoting a slow-cycling, but more invasive cancer. Wnt5A was thought to be produced from tumor cells and fibroblasts in the TME. However, our data now suggest that unique pathologically induced myeloid derived suppressor cells (MDSCs) produce a major proportion of Wnt5A in the TME which is taken up by melanoma cells to increase invasiveness. This finding highlights the diverse roles that MDSCs play in melanoma, going beyond immunosuppression. We created novel transgenic animals with MDSC specific knockdown of Wnt5A and demonstrate a clear decrease in the Wnt5A expression within the TME. Wnt5A deficient MDSCs caused an increase in CD8+ T-cells in peripheral blood and decreased tumoral MDSCs and Tregs. Tumor infiltrating lymphocytes also had significantly decreased PD-1 expression suggesting a less exhausted phenotype, and increased ratios of effector T-cells to immunosuppressive cells resulting in a more immunogenic TME. Wnt5A promotes a switch from proliferative to an invasive melanoma cell state. Myeloid specific Wnt5A knockdown caused decreased lung metastasis and significantly increased tumor growth in vivo, with the lack of MDSC infiltration negatively correlating to tumor volume. Tumor infiltrating MDSCs from control animals had a strong positive correlation with Tregs, whereas, this was completely ablated in animals with Wnt5A-negative MDSCs. Overall, our data suggests that while MDSCs contribute to an immunosuppressive and less immunogenic environment, they may have an additional function as the major source of Wnt5A in the tumor microenvironment. These two functions likely synergize to drive a highly metastatic and therapy-resistant phenotype altering immunogenicity.
Citation Format: Stephen Douglass, Mitchell Fane, Emilio Sanseviero, Dmitry Gabrilovich, Ashani Weeraratna. Myeloid derived Wnt5a influences the immune-dynamics of melanoma tumor microenvironment [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2656.
Abstract 2713: Elucidation of bone metastasis using a caudal artery injection mouse model and Akaluc-AkaLumine near-infrared bioluminescence technology
Authors: Kuchimaru Takahiro , Minegishi Misa , Kizaka-Kondoh Shinae 
Published: September 2020

Abstract
Bone is one of the most common sites of metastasis for various primary tumors including breast, prostate and lung cancers. We have addressed molecular basis underlying bone metastasis using newly developed murine model of bone metastasis and near-infrared bioluminescence technologies. Our new murine model overcomes several limitations in the current standard model by intra-cardiac (IC) injection of cancer cells [1]. We found that the caudal artery is a new pathway to predominantly deliver cancer cells to the bone marrow of hind limbs in mice. Intra-caudal arterial (CA) injection is technically as easy as tail vein injection [2]. In addition, CA injection delivered cancer cells &gt;10-fold more efficiently than IC injection. This accelerated the development of bone metastasis in hind limbs with wide variety of cell lines. We have combined the CA injection model with near-infrared bioluminescence imaging. Bioluminescence imaging (BLI) with firefly luciferases and its natural substrate D-luciferin has been indispensable to noninvasively monitor metastasis development in mice. To improve deep-tissue imaging, synthetic luciferin AkaLumine has successfully extended the wavelength of firefly bioluminescence to the near-infrared region where tissue is more transparent to light [3]. More recently, our collaborators created an engineered luciferase Akaluc that displays high catalytic activity in reaction with AkaLumine [4]. AkaLumine-Akaluc bioluminescence imaging (AkaBLI) is capable of noninvasive visualization of single cancer cells deep inside mice. Combining the CA injection model with AkaBLI technology is a powerful tool for elucidating the mechanism of bone metastasis in small animals. References [1] Kuchimaru et al. Nat Commun 2018, 9, 2918 [2] http://sites.google.com/view/takahirokuchimaru/protocol [3] Kuchimaru et al. Nat Commun 2016, 7, 11856 [4] Iwano et al. Science 2018, 359, 935
Citation Format: Takahiro Kuchimaru, Misa Minegishi, Shinae Kizaka-Kondoh. Elucidation of bone metastasis using a caudal artery injection mouse model and Akaluc-AkaLumine near-infrared bioluminescence technology [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2713.
Abstract 2726: Nuclear checkpoints for melanoma and breast cancer lung metastasis
Authors: Roncato Francesco , Regev Ofer , Levi Nehora , Feigelson Sara W. , Gerlitz Gabi , Alon Ronen 
Published: September 2020

Abstract
Introduction
Metastasis involves cancer cell intravasation and extravasation from blood vessels at target organs. The mechanisms by which the nuclei of metastatic tumor cells squeeze through different vascular and epithelial barriers are poorly understood. The nuclear lamina attaches chromatin domains to the nuclear periphery and controls the mechanical properties of the nucleus and its crosstalk with the cell cytoskeleton. A-type lamins, lamin A and its splice variant lamin C, are key nuclear lamina proteins that control nucleus stiffness and regulate chromatin conformation. Reduced lamin A was reported in some aggressive cancers.
Results and Discussion
Using a new in vitro transendothelial migration (TEM) assay we found that melanoma and breast cancer cells slowly squeeze their nuclei and complete TEM through endothelial junctions irrespective of their relative lamin A/C levels, suggesting that lamin A/C dependent nuclear stiffening is not a rate-limiting step for cancer cell squeezing through endothelial cells in vitro. In contrast, reduced lamin A/C enhanced cancer cell squeezing through rigid pores. Tumor emigration analysis across blood vessels in vivo was performed by new 3D imaging of fluorescently labeled cancer cells with high and low lamin A/C levels. This imaging was based on light sheet microscopy of lipid-cleared lungs of recipient mice in situ labeled with anti-vascular CD31 mAb. Using this technology, we found that reduced lamin A/C expression did not enhance the emigration of circulating murine melanoma and breast cancer cells across lung capillaries in vivo. Lower lamin A/C levels reduced the constitutive, transcriptionally repressed, heterochromatin in both melanoma and breast cancer cells. Decreased lamin A/C expression did not enhance however, nuclear rupture in the tumor cells that entered the lung parenchyma. The outcomes of the epigenetic and mechanical changes resulting of lamin A/C suppression on tumor growth and metastasis are under current investigation.
Conclusions
Our results suggest that subsets of tumor cells may benefit from reducing their nuclear content of lamin A/C mainly at the level of rigid barrier crossing (e.g. dense interstitial spaces), but not at the level of extravasation or post extravasation survival at target organs. How alterations in lamin A/C content contribute to tumor heterogeneity and metastatic potential of singular cancer cells remains an open question.
Citation Format: Francesco Roncato, Ofer Regev, Nehora Levi, Sara W. Feigelson, Gabi Gerlitz, Ronen Alon. Nuclear checkpoints for melanoma and breast cancer lung metastasis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2726.
Abstract 2730: BCL6 promotes ovarian cancer metastasis
Authors: Nguyen Duc Ngoc Hong , Walker David F. , Frank David A. , Walker Sarah R. 
Published: September 2020

Abstract
Ovarian cancer remains a deadly disease with the five-year survival rate for ovarian cancer patients at about 50%. Ovarian spheroids, clusters of 3D growing cells, are thought to promote ovarian cancer metastasis and serve as a reserve of cancer cells that are not responsive to chemotherapy. Understanding genes associated with spheroid growth and metastasis may identify pathways to target for ovarian cancer therapy. We have found that the transcriptional modulator BCL6 is active in ovarian spheroids. BCL6 is a highly-conserved oncogene originally found to drive malignant transformation in B-cell lymphoma. Although BCL6 is thought to be a transcriptional repressor, we and others have found that it also upregulates genes. Little is known about the role of BCL6 in ovarian cancer. Using the Cancer Genome Atlas (TCGA) data and CBioPortal, we found that BCL6 is amplified in about 20% of high-grade serous ovarian cancer patients. In addition, analysis of nuclear extracts from a number of ovarian cancer cell lines demonstrated that BCL6 is overexpressed in many ovarian cancer cell lines. To assess transcriptional activity, we used a BCL6-responsive reporter and we found that BCL6 was active in most of these cell lines. Having demonstrated that BCL6 is active in ovarian cancer cells, we wanted to determine if BCL6 affected the viability of these cells. Therefore, we transfected ovarian cancer cells with siRNA to BCL6, measured their viability, and found that BCL6 is important for ovarian cancer cell survival. Recognizing that spheroids occur in advanced ovarian cancer, we analyzed the effects of BCL6 in 3D formation using micropatterned plates and discovered that BCL6 is also important for 3D spheroid formation. A major problem in advanced ovarian cancer is metastasis; therefore, we wanted to determine if BCL6 plays a role in promoting metastasis. We overexpressed BCL6 or downregulated BCL6 with siRNA and performed a mesothelial clearance assay to assess the early steps in ovarian cancer metastasis. While overexpressing BCL6 enhanced mesothelial clearance by the ovarian spheroids, reducing BCL6 expression also reduced mesothelial clearance. This suggested that BCL6 promotes ovarian cancer metastasis. We are currently in the process of identifying BCL6 target genes that are involved in metastasis. Taken together, our data suggests that BCL6 is an important transcriptional modulator in ovarian cancer and that targeting BCL6 in the future may be a useful strategy to treat metastatic ovarian cancer.
Citation Format: Duc Ngoc Hong Nguyen, David F. Walker, David A. Frank, Sarah R. Walker. BCL6 promotes ovarian cancer metastasis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2730.