bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 105: Gene expression heterogeneity reveals therapeutic targets and novel regulators of metastasis
Authors: Yang Dongbo , Dann Christopher , Valdespino Andrea , Robinson-Mailman Lydia , Chen Mengjie , Balázsi Gábor , Pott Sebastian , Rosner Marsha Rich 
Published: April 2023

Abstract
Tumor cell heterogeneity has been implicated in metastatic progression of solid tumors such as triple-negative breast cancer (TNBC), leading to resistance and recurrence. We hypothesize that genes with low cell-to-cell transcriptional variability are more effective therapeutic targets, and use of variability as a metric will identify new metastatic regulators. Using single cell RNA sequencing, we demonstrate that the metastasis suppressor Raf Kinase Inhibitory Protein (RKIP/PEBP1) reduced overall transcriptional heterogeneity in TNBC xenograft tumors including oxidative phosphorylation genes. Consistent with a dependence on respiratory genes, metformin inhibited growth of RKIP-expressing but not RKIP-deficient tumors. Among genes with reduced transcriptional variability and increased mean in response to RKIP, we identified KMT5C as a novel epigenetic metastasis suppressor in TNBC. Taken together, these results indicate that analysis of gene expression variability along with mean can lead to effective target selection and provides an alternative strategy for identifying novel regulators of metastasis.
Citation Format: Dongbo Yang, Christopher Dann, Andrea Valdespino, Lydia Robinson-Mailman, Mengjie Chen, Gábor Balázsi, Sebastian Pott, Marsha Rich Rosner. Gene expression heterogeneity reveals therapeutic targets and novel regulators of metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 105.
Abstract 1074: The potential of 18β-glycyrrhetinic acid benefit lenvatinib induced cytotoxicity on hepatocellular carcinoma
Authors: Pei-Wen Yeh , Liu Yu-Chiang , Chang Yuan , Chen Jiann-Hwa 
Published: April 2023

Abstract
Hepatocellular carcinoma (HCC) is usually caused by long-term inflammation such as infected by hepatitis B and C viruses. The current standard treatment methods of HCC has included with general surgery, radiation, etc. However, the recurrence rate remain high even after standard treatment, it is necessary to find a better treatment option to control the progression of HCC. Lenvatinib is a multi-endothelial angiogenesis factor inhibitor which is a first-line target drug for the treatment of advanced HCC. Some studies indicated that activation of the PI3K/AKT pathway could lead to the resistance effect of lenvatinib in HCC. 18β-glycyrrhetinic acid (18β-GA) is a hydrolyzed product of glycyrrhizic acid in the intestine. Studies reported that 18β-GA can effectively treat inflammatory diseases and may have antitumor potential. Some studies also indicated that 18β-GA can down-regulate the signaling transduction of PI3K/AKT pathway in various type of cancers. Therefore, in this study, we focused on exploring whether 18β-GA can be used as an adjuvant to downregulate PI3K/AKT signaling and thus enhance the efficacy of lenvatinib on HCC cells and animal model. Here, we used the MTT assay to investigate the cytotoxicity of HCC cells (Huh7 and Hep3B) after various dose of lenvatinib and (or) 18β-GA treatment. We also used combination index (CI) to evaluate the suitable combination condition. In our results, the CI value of lenvatinib 30 μM combined with 18β-GA 100 μM is smaller than 1, which indicated the synergistic effect of combination. We confirmed the superior extrinsic/intrinsic apoptosis induction ability was found in lenvatinib combined with 18β-GA as compared to single treatment. The activation of Fas/FasL pathway, Annexin V, cleaved caspase-3, -8 and -9 were used to confirm the apoptosis induction by lenvatinib combined with 18β-GA. Transwell invasion and wound healing assays results also indicated the invasion/migration suppression ability of lenvatinib combined with 18β-GA on HCC cells. The phosphorylation of AKT were markedly decreased by lenvatinib combined with 18β-GA in HCC cells. Hep3B bearing animal data proved the superior tumor control of lenvatinib combined with 18β-GA. Additionally, the liver function and normal tissue pathology may not affect by combination of lenvatinib and 18β-GA. To conclude, our result demonstrated that 18β-GA may sensitize HCC to lenvatinib via inactivation of PI3K/AKT signaling pathway and induction of extrinsic/intrinsic apoptosis signaling.
Citation Format: Yeh Pei-Wen, Yu-Chiang Liu, Yuan Chang, Jiann-Hwa Chen. The potential of 18β-glycyrrhetinic acid benefit lenvatinib induced cytotoxicity on hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1074.
Abstract 1095: Exploiting altered methionine metabolism to overcome treatment resistance in glioblastoma
Authors: Korimerla Navyateja , Romans Kari-Wilder , Kalev Peter , Kothari Ayesha , Qi Nathan , Evans Charles , Kachman Maureen , Hyer Marc L , Marjon Katya , Sleger Taryn , Wahl Daniel R 
Published: April 2023

Abstract
Glioblastoma (GBM) is the most aggressive adult brain tumor and is uniformly fatal due to resistance to standard therapies such as radiation (RT) and chemotherapy. Our group and others have identified altered metabolism as a key mediator of GBM RT resistance. Methionine is an essential sulfur-containing amino acid that cells use to synthesize antioxidants, polyamines and S-adenosyl methionine (SAM), which drives intracellular methylation reactions. Methionine uptake is dramatically elevated in GBM compared to normal brain, but what GBMs use this methionine for, and whether it governs GBM treatment resistance, is unknown. Here, we find that RT acutely increases the levels of numerous methionine-related metabolites in multiple RT-resistant GBM models. To interrogate metabolic pathway activity, we used 13C5 methionine stable isotope tracing to show that GBMs respond to RT by activating the conversion of methionine to SAM, which is dependent on signaling through the DNA damage response. We developed in vivo methionine stable isotope tracing techniques to confirm these findings in orthotopic PDX models of GBM. Blocking the conversion of methionine to SAM, through pharmacologic inhibition of methionine adenosyltransferase 2A (MAT2A), slowed the repair of RT-induced DNA damage and increased cell death in GBM models following RT. These effects were especially pronounced in GBM models lacking the methionine salvage enzyme methylthioadenosine phosphorylase (MTAP). Pharmacologic inhibition of MAT2A in flank and orthotopic in vivo GBM models depleted SAM levels and slowed tumor growth when combined with RT. Combining MAT2A inhibition with dietary methionine restriction and RT slowed GBM tumor growth even further. Together, our work demonstrates a new signaling link between DNA damage and methionine-driven SAM synthesis in GBM. Inhibiting SAM synthesis slows the repair of RT-induced DNA damage and augments RT efficacy. This therapeutic strategy may be especially effective in GBMs defective in methionine salvage and spare normal cortex in which methionine salvage is active.
Citation Format: Navyateja Korimerla, Kari-Wilder Romans, Peter Kalev, Ayesha Kothari, Nathan Qi, Charles Evans, Maureen Kachman, Marc L Hyer, Katya Marjon, Taryn Sleger, Daniel R Wahl. Exploiting altered methionine metabolism to overcome treatment resistance in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1095.
Abstract 1232: Gastroesophageal reflux disease promotes E-cadherin cleavage and activates EMT via APE1-redox function in esophageal adenocarcinoma
Authors: Lu Heng , Cao Longlong , Ballout Farah , Belkhiri Abbes , Peng Dunfa , Chen Lei , Soutto Mohammed , McDonald Oliver , Zaika Alexander , Que Jianwen , El-Rifai Wael 
Published: April 2023

Abstract
The incidence of esophageal adenocarcinoma (EAC) has increased rapidly over the past four decades. Chronic gastroesophageal reflux disease (GERD), where acidic bile salts (ABS) abnormally refluxate into the esophagus, is the leading risk factor for the development of a metaplastic condition known as Barrett’s esophagus (BE) and its progression to EAC. We used 3D organotypic culture, mouse and human tissue samples to assess the role of ABS in Epithelial-to-Mesenchymal Transition (EMT) in EAC. Analysis of public databases revealed significant enrichment of EMT signaling in EAC progression. RNA-seq analysis of EAC cells showed activation of EMT pathway in response to ABS exposure. ABS induced multiple characteristics of the EMT process, such as downregulation of E-cadherin, upregulation of Vimentin, activation of ß-catenin and EMT-transcription factors (EMT-TFs), cell morphological changes, and enhancement of cell migration and invasion capabilities. Mechanistically, we discovered that ABS induced E-cadherin cleavage via MMP14 proteolytic cascade. APE1 silencing, or APE1-redox-specific inhibitor (E3330), abrogated the ABS-induced EMT process and signaling by downregulating MMP14. Furthermore, APE1 and MMP14 co-expression levels were inversely correlated with E-cadherin expression in gastroesophageal junctions of human EAC tissues, and the L2-IL1ß transgenic mouse model of BE/EAC. EAC patients with high APE1 and EMT signatures had worse relapse free survival than those with low signature. In a summary, this study demonstrates the role of ABS in promoting EMT via the redox-sensitive signaling axis of APE1/MMP14/E-cadherin/ß-catenin. Pharmacological inhibition of APE1-redox function could be a potential therapeutic approach to effectively reduce the risk of Barrett’s carcinogenesis.
Citation Format: Heng Lu, Longlong Cao, Farah Ballout, Abbes Belkhiri, Dunfa Peng, Lei Chen, Mohammed Soutto, Oliver McDonald, Alexander Zaika, Jianwen Que, Wael El-Rifai. Gastroesophageal reflux disease promotes E-cadherin cleavage and activates EMT via APE1-redox function in esophageal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1232.
Abstract 1234: Tumor cell-intrinsic PD-L1 promotes epithelial-to-mesenchymal transition in non-small cell lung cancer in interferon-g-independent and dependent way
Authors: Jeong Hyein , Ahn Hyun Kyung , Kim Sehui , Jeon Yoon Kyung 
Published: April 2023

Abstract
The immune checkpoint molecule programmed cell death-ligand 1 (PD-L1, CD274) suppresses immunity when the cell surface PD-L1 is engaged by programmed death-1 (PD-1) on antitumor immune cells. Although PD-L1 has been established and targeted in cancer immunotherapy, the tumor-intrinsic role of PD-L1 is less appreciated in tumor biology and therapeutic development. In this study, we showed that PD-L1 facilitates epithelial-to-mesenchymal transition (EMT) in non-small cell lung cancer (NSCLC) cells by upregulating EMT transcription factors and mesenchymal markers, and downregulating epithelial marker. RNA-sequencing was performed on paired exogenously PD-L1-overexpressed A549 cells and wild-type cells, and PD-L1-depleted H460 cells and wild-type cells, and transcriptomic features associated with PD-L1 status were identified using Gene Set Enrichment Analysis (GSEA). In both the paired samples, PD-L1 expression was associated with EMT-related pathways. Subsequent in vitro experiment showed that exogenous overexpression of PD-L1 in A549 and H522 cells increased both mRNA and protein expression of Twist, Zeb1, Snail, Slug, Vimentin, Fibronectin, and N-Cadherin. Correspondingly, the transcription factors and mesenchymal markers were decreased in PD-L1-depleted H460 and H596 cells. Recombinant PD-1 treatment also increased the expression of EMT transcription factors and markers on A549 and H460 cells. Moreover, interferon-γ stimulation on tumor cells increased expression of EMT transcription factors and markers, which was suppressed by PD-L1-knockdown, suggesting that interferon-γ-induced PD-L1 contributes to EMT. Our findings suggest that PD-L1 facilitates NSCLC progression by promoting the EMT in interferon-γ-independent and dependent way, and this intrinsic PD-L1 function could be targeted for better clinical management of PD-L1-overexpressing NSCLCs.
Citation Format: Hyein Jeong, Hyun Kyung Ahn, Sehui Kim, Yoon Kyung Jeon. Tumor cell-intrinsic PD-L1 promotes epithelial-to-mesenchymal transition in non-small cell lung cancer in interferon-g-independent and dependent way [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1234.
Abstract 1246: Single-cell profiles of multiplexed in vivo models facilitate the characterization of phenotypic plasticity and invasion in glioblastoma
Authors: Hara Toshiro , Chanoch-Myers Rony , Greenwald Alissa , Bussema Lillian , Behnan Jinan , Galli Rossella , Wakimoto Hiroaki , Tirosh Itay , Suvà Mario 
Published: April 2023

Abstract
The lethality of glioblastoma and the failure of surgical treatment are in part attributable to the invasive properties of this cancer; however, our understanding of the cell-biological process is limited due to the complex representation of invasion phenotype in glioblastoma models. Here, to overcome this limitation, we developed an in vivo approach with human glioblastoma spheroid lines multiplexed for mouse intracranial xenografts. We validated this with 20 patient-derived models and identified, by 3’end single-cell RNA-sequencing (scRNA-seq) coupled with deconvolution analysis, in vivo models capable of infiltrating along the periphery of either neurons or blood vessels. We previously found that the diverse malignant cells in glioblastoma specimens exist in a limited set of four cellular states: neural progenitor-like (NPC-like), oligodendrocyte progenitor-like (OPC-like), astrocyte-like (AC-like), and mesenchymal-like (MES-like), with potential for state plasticity under the influence of tumor microenvironment. To determine whether or not the cell state heterogeneity is implicated in glioblastoma invasion, we profiled and characterized programs, states, and clonality of invading glioblastoma cells by comparing cells from the contralateral invasive edge to their counterparts residing at the original bulk tumor. This analysis showed evidence of a bi-directional state transitioning model for cells undergoing distinct environmental spaces. Exploration of cell state distribution at the primary tumors revealed that presence of an OPC-like state was significantly associated with invasion phenotype regardless of the infiltration routes. Our results suggest that cellular plasticity may be a prerequisite for the topographically diffusive nature of glioblastoma, urging further assessment by perturbing critical regulators of the cellular state programs. In conclusion, this work describes multiplexed in vivo models as an enabling platform for the rapid interrogation of patient-derived xenografts, coupling the molecularly measurable states with functional identity driving malignant phenotypes such as cancer invasion.
Citation Format: Toshiro Hara, Rony Chanoch-Myers, Alissa Greenwald, Lillian Bussema, Jinan Behnan, Rossella Galli, Hiroaki Wakimoto, Itay Tirosh, Mario Suvà. Single-cell profiles of multiplexed in vivo models facilitate the characterization of phenotypic plasticity and invasion in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1246.
Abstract 1256: Transglutaminase-2 is elevated in the invasive cell state and modulates the tumor immune microenvironment in cutaneous melanoma
Authors: Caksa Signe , Wilski Nicole A. , Kitterman Erica L. , Glasheen McKenna Q. , Heilizer Jacob S. , Purwin Timothy J. , Capparelli Claudia , Aplin Andrew E. 
Published: April 2023

Abstract
Cutaneous melanoma is the most fatal skin cancer; resistance to targeted therapies contributes to poor prognosis. In some cases, resistance arises from pre-existing tumor heterogeneity, which allows subpopulations of drug-tolerant cells with distinct transcriptional states to survive in the presence of drug. The loss of SOX10, a lineage-specific transcription factor, is known to drive melanoma phenotype switching from a proliferative to an invasive drug-tolerant state. Here, we found that knocking out SOX10 in human and mouse melanoma cell lines leads to the upregulation of transglutaminase-2 (TGM2), a calcium-dependent cross-linking enzyme. Analysis of publicly available bulk and single-cell RNA-sequencing data showed that TGM2 is highly expressed in the invasive cell state in melanoma cell lines and patient-derived melanoma cultures, respectively. Furthermore, knockdown of SOX10 in patient-derived melanoma cultures increases TGM2 mRNA expression. 3D spheroid assays and extracellular matrix production/remodeling assays showed that knockdown of TGM2 has no effect on the invasiveness of SOX10-deficient cells. However, we found that TGM2 is secreted by SOX10-deficient cells and hypothesized that it could modulate the tumor immune microenvironment (TIME) given that TGM2 has been associated with increased immune infiltration in melanoma patient samples. To investigate the effect of TGM2 on the TIME, we stably overexpressed TGM2/Tgm2 in syngeneic mouse melanoma cell lines and allowed tumors to grow in immune-competent C57BL/6 mice. As compared to empty vector, TGM2/Tgm2-overexpression led to an increase in the percentage and number of CD4+ T cells and B cells, and a decrease in the number of myeloid cells, in the tumor immune compartment by flow cytometry analysis. Future studies will assess which subsets of CD4+ T cells and B cells infiltrate TGM2/Tgm2-overexpressing tumors, how these changes to the TIME affect melanoma invasiveness, and if TGM2 expression affects response to targeted therapy in vivo. Overall, our data suggest that TGM2 is highly expressed in the invasive melanoma cell state, is regulated by the SOX10 transcription factor, and can modulate adaptive immune cells in the TIME.
Citation Format: Signe Caksa, Nicole A. Wilski, Erica L. Kitterman, McKenna Q. Glasheen, Jacob S. Heilizer, Timothy J. Purwin, Claudia Capparelli, Andrew E. Aplin. Transglutaminase-2 is elevated in the invasive cell state and modulates the tumor immune microenvironment in cutaneous melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1256.
Abstract 1280: Role of soluble mesothelin in peritoneal metastasis
Authors: Panchwagh Neel M. , Ewa Theressa , Avula Leela Rani , Joseph Sarah , Tai Chin-Hsien , Sevilla Samantha , Koparde Vishal , Zhang Xianyu , Alewine Christine 
Published: April 2023

Abstract
The cell-surface glycoprotein mesothelin (MSLN) is overexpressed in pancreatic adenocarcinoma (PDAC) and is positively correlated with tumor aggressiveness. MSLN knock-out (KO) PDAC cells have delayed growth of peritoneal metastases in mice. Complementation with wild-type MSLN rescued the phenotype, although complementation with MSLN containing a Y318A point mutation to ablate interaction with MSLN binding partner MUC-16 could not. Mature MSLN is shed into the tumor microenvironment to generate soluble MSLN (sMSLN). We hypothesized that sMSLN would promote peritoneal metastasis. We engineered MSLN C-terminal truncation mutants (∆599-WT and ∆599-Y318A) that lack the membrane attachment site and exist only in soluble form. Parent and MSLN KO PDAC cells were transduced with the vector constructs. These cells were injected into athymic nude mice and peritoneal tumor growth was measured 6 weeks later. MSLN KO cells complemented with ∆599-WT MSLN exhibited poor peritoneal tumor growth, while ∆599-Y318A resulted in growth rescue. We considered that sMSLN might exert a dominant negative effect because it competes for MUC-16 binding with membrane-bound MSLN but cannot facilitate cell-to-cell interaction. Expression of ∆599-WT inhibited tumor growth in parent cells, while ∆599-Y318A failed to do so. The activity of ∆599-Y318A in KO cells remained unexplained. We hypothesized that levels of mircoRNA-198, a purported tumor suppressor regulated by MSLN, might be altered by ∆599 expression and correlate with phenotype rescue. However, no change in microRNA-198 expression was observed in ∆599-expressing cells. We are continuing to investigate the mechanism for a novel activity of sMSLN that is unrelated to MUC-16 binding.
Citation Format: Neel M. Panchwagh, Theressa Ewa, Leela Rani Avula, Sarah Joseph, Chin-Hsien Tai, Samantha Sevilla, Vishal Koparde, Xianyu Zhang, Christine Alewine. Role of soluble mesothelin in peritoneal metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1280.