bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5393: Characterization of small ubiquitin-like modifier (SUMO) protein complex expression in human cancer cells to identify novel therapeutic targets
Authors: Salih Mohammed Abdullah Mohammed , Williamson Ritchie , Kantamneni Sriharsha
Published: March 2024

SUMOylation is a post-translational modification where a number of small ubiquitin-like modifier proteins (SUMO) are conjugated to lysine residues of the target proteins and contribute to various cellular functions essential for cancer cell survival and proliferation. The unique behaviors, phenotypic and molecular adaptations found in the naked-mole rat (NMR) suggest a high stability and effective functioning of the molecular machinery that counteracts damage accumulation in its genome. NMR can reach 32 years, shows no signs of ageing, and possesses a very efficient mechanism of resistance to cancer. This study aims to investigate the regulation of SUMOylation machinery between NMR tissues in comparison to human cancer cells, to find novel targets for cancer therapy. Gene expression of SUMO isoforms between NMR and humans, were investigated through qRT-PCR. The data suggests a significant low expression level for most SUMO machinery (except PIAS4) in NMR brain and intestine tissues compared to MCF-7, DLD-1, SH-SY5Y, and MCF-10A cells. Western blotting analysis also revealed high protein expression of PIAS4 in NMR compared to SENP1 and Ubc9. Also, SUMO machinery expression levels from NMR are recapitulated in cancer cells either silencing (hUBE2I: shRNA, hSENP1: shRNA) or overexpression (Myc/hPIAS4: Exp). Further, cytotoxicity assay was analyzed in relevance to Doxorubicin in MCF-7, 5-Fluorouracil in DLD-1 and Methotrexate in SH-SY5. The functional assays such as clonogenic and invasion assays were performed including apoptotic mechanisms (Bcl-2, and BID). In conclusion, the data revealed important differences in SUMOylation machinery between NMR and human cancer cells, which provides a future therapeutic path for cancer treatment.

Citation Format: Mohammed Abdullah Mohammed Salih, Ritchie Williamson, Sriharsha Kantamneni. Characterization of small ubiquitin-like modifier (SUMO) protein complex expression in human cancer cells to identify novel therapeutic targets [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 5393.
Abstract 5395: The influence of hyperthermia on epigenetic signaling in dysbiotic tumor vasculature
Authors: Kristian Hailey , Jenkins Samir , Griffin Robert , Dings Ruud Petrus
Published: March 2024

The overall use of antibiotics has increased significantly in recent years. Although they resolve infections, oral antibiotics (ABX) severely alter the gut microbiota, disrupting commensal bacteria crucial for maintenance of various homeostatic processes. ABX-induced microbial imbalance, or dysbiosis, has systemic and long-lasting deleterious effects on the host. For example, we and others have shown that distal, non-GI tract solid tumors show accelerated progression during dysbiosis due to vascular immune suppression. Localized hyperthermia has been increasingly recognized to elicit various cellular responses, yet the epigenetic effects of hyperthermia on the tumor vasculature during ABX-induced dysbiosis are unknown. The balance of histone acetylation and deacetylation plays a critical role in the regulation of gene expression and thereby cellular processes. Therefore, we assessed which histone deacetylases (HDACs) are expressed and their abundance in endothelial cells of various sources with or without dysbiotic stress and/or hyperthermia to understand the utility of thermal medicine to promote normal functioning of the vasculature in dysbiotic patients. We found that HDAC expression levels differed among endothelial origins and that hyperthermia (60 min of either 41.5 °C or 43 °C) influenced the HDAC levels differentially. Especially HDAC 2, 3 and 8 were inhibited by hyperthermia. Additionally, we found that the vasculature receptors for endogenous HDAC inhibitors, GPR41, GPR43, and GPR109a are less abundant intrinsically on dysbiotic than orthobiotic tumor endothelial cells and that hyperthermia increased this expression. Although further studies are warranted, these results demonstrate that hyperthermia exerts epigenetic effects and is capable of overcoming the dysbiosis-induced phenotype. Since anti-cancer treatment with HDAC inhibitors has shown promise in the clinic but is hindered by systemic toxicities, localized hyperthermia may become a viable alternative in the future.

Citation Format: Hailey Kristian, Samir Jenkins, Robert Griffin, Ruud Petrus Dings. The influence of hyperthermia on epigenetic signaling in dysbiotic tumor vasculature [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 5395.
Abstract 5400: CD160 regulates angiogenesis in activated human endothelial cells
Authors: Aziz Abdel-ilah , Mocquery-Corre Maxence , Jean Chloé , Oumeslakht Loubna , Chazée Lise , Thevenard-Devy Jessica , Fatimy Rachid El , Bensussan Armand , Mkaddem Sanae Ben , Devy Jérôme
Published: March 2024

Angiogenesis, the process of forming new blood vessels from pre-existing ones, plays a pivotal role in various physiological and pathological conditions. CD160, a cell surface receptor known for its modulatory function in the immune response, has recently garnered attention as a surface marker for activated endothelial cells. In this study, we investigate the anti-angiogenic effects of a novel anti-CD160 antibody. Using the tube formation assay, we evaluated the novel anti-CD160 antibody's ability to inhibit neovascularization potential in activated Human umbilical vein endothelial cells (HUVEC) in vitro. Our results revealed a significant reduction in total tube length, the number of branches, and closed networks, indicating the antibody's efficacy in impeding neovascularization. In addition, we explored the molecular mechanisms underlying CD160's anti-angiogenic properties, showing its ability to selectively decrease fibroblast growth factor-2-induced angiogenesis. Furthermore, we assessed the safety profile of our new anti-CD160 antibody by examining its impact on endothelial cell apoptosis. Encouragingly, our findings demonstrated no induction of apoptosis, suggesting the antibody's selective targeting of angiogenic processes without compromising endothelial cell viability, thus supporting CD160's vascular normalization properties. In conclusion, our research provides compelling evidence for the anti-angiogenic effects of the CD160 antibody, as evidenced by its inhibition of tube formation without inducing apoptosis in activated endothelial cells. These findings hold promising therapeutic implications for targeting angiogenesis in various pathological conditions, warranting further exploration for potential clinical applications.

Keywords: CD160, Angiogenesis, Endothelial cells. HUVECs.

Citation Format: Abdel-ilah Aziz, Maxence Mocquery-Corre, Chloé Jean, Loubna Oumeslakht, Lise Chazée, Jessica Thevenard-Devy, Rachid El Fatimy, Armand Bensussan, Sanae Ben Mkaddem, Jérôme Devy. CD160 regulates angiogenesis in activated human endothelial cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5400.
Abstract 542: Development of novel syngeneic tumor models with intrinsic or extrinsic resistance mechanisms to PD-1 blockade
Authors: Wang Xiaomin , Zhang Ziwei , Liu Longzhou , Zhang Xue , Wang Dong , Xu Nengwei , Qiang Xiangnan , Gu Qingyang , Xiang Jian , Zhang Zhixiang
Published: March 2024

Programmed cell death-1 (PD-1) blockade has demonstrated remarkable clinical efficacy across various tumor types. However, the current PD-1 blockade monotherapy benefits only a small proportion of patients, and primary or acquired resistance can ultimately lead to cancer progression in clinical settings. Understanding the underlying mechanisms of resistance is both necessary and urgent to enhance clinical outcomes. Increasing evidence suggests that resistance to PD-1 therapy can arise from both tumor-cell-intrinsic and tumor-cell-extrinsic factors. Loss-of-function mutations in the antigen presentation pathway and downstream elements represent intrinsic mechanisms, while tumor-infiltrating immunosuppressive cells such as regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs), and tumor-associated macrophages (TAMs) contribute to immune tolerance as extrinsic factors. Currently, the rational design of combination therapies based on these resistance mechanisms remains to be achieved.

In this study, we developed two types of anti-PD-1 antibody-resistant models based on the intrinsic anti-PD-1 treatment-sensitive MC38 models. These models include genetically engineered resistant models with B2M or STK11 knockout (KO) and induced resistant models through in vivo progressive drug selection. STK11 KO mutations resulted in reduced expression of PD-L1 on tumor cells and a lower infiltration of CD8+ cytotoxic T lymphocytes in the tumor microenvironment, while B2M KO led to a lack of antigen presentation on the tumor cell surface, blocking the binding of the anti-PD-1 antibody. In terms of the induced anti-PD-1 resistant models, a higher proportion of immunosuppressive cells, including Tregs, MDSCs, and TAMs, were observed in the tumor microenvironment compared to the parental counterparts, contributing to immune escape from PD-1 blockade. These models simulate extrinsic and intrinsic mechanism-based anti-PD-1 resistance, allowing for the identification of combination therapies to overcome resistance to anti-PD-1.

Our study enhances our understanding of the biological basis of anti-PD-1 resistance and supports the discovery of mechanistically-designed combination therapies to overcome resistance to anti-PD-1 therapy, potentially broadening its clinical applicability.

Citation Format: Xiaomin Wang, Ziwei Zhang, Longzhou Liu, Xue Zhang, Dong Wang, Nengwei Xu, Xiangnan Qiang, Qingyang Gu, Jian Xiang, Zhixiang Zhang. Development of novel syngeneic tumor models with intrinsic or extrinsic resistance mechanisms to PD-1 blockade [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 542.
Abstract 5433: Functional involvement of ribosomal protein L9 to colorectal cancer stemness
Authors: Jeon Eun-Hye , Park Keun Uk , Ryoo Hun-Mo , Hwang Ilseon , Lee Yun-Han
Published: March 2024

We have previously demonstrated that targeting of ribosomal protein L9 (RPL9) suppresses the growth of colorectal cancer (CRC) via the inactivation of Id-1/NF-κB signaling axis which is known to augment tumor stemness. Thus we aimed in this study to investigate whether the function of RPL9 was associated with CRC stemness properties. It was initially evidenced that inhibition of RPL9 expression reduces the migration and invasion abilities of HT29 parental cell population. We have then sorted out CD133+ cancer stem cells (CSCs) from HT-29 parental cell culture and treated RPL9-specific siRNAs to the isolated CSCs to observe the effect of RPL9 targeting on stemness. As results, knockdown of RPL9 significantly suppressed the proliferation potential and sphere forming capacity of CD133+ HT29 CSCs accompanying with the reduction in CD133 and Id-1 levels. Reflecting these molecular alterations, targeting RPL9 also inhibited the abilities of migration and invasion in CD133+ HT29 CSCs population. Taken together, these findings suggest that RPL9 could be a therapeutic target for both primary CRC treatment and the prevention of metastasis and/or recurrence.

Citation Format: Eun-Hye Jeon, Keun Uk Park, Hun-Mo Ryoo, Ilseon Hwang, Yun-Han Lee. Functional involvement of ribosomal protein L9 to colorectal cancer stemness [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 5433.
Abstract 5489: The spatial landscape of early-stage lung adenocarcinoma
Authors: Kim Junbum , Ravichandran Hiranmayi , Yoffe Liron , Binder Bhavneet , McGraw Timothy , Altorki Nasser K. , Mittel Vivek , Elemento Olivier
Published: March 2024

Cellular and molecular basis of ground-glass opacities (GGO), which has been used as a screening indicator for lung cancer, remains a gray area. Our aim was to investigate the tumor-immune microenvironment (TIME) in a cohort of early-stage lung adenocarcinomas (LUAD) through imaging mass cytometry, enabling us to examine the TME spatial composition of nodules at single-cell resolution. We collected 354 imaging mass cytometry (IMC) regions of interest (ROI) from 135 early-stage lung adenocarcinoma patients to investigate the spatial and molecular profiles of early stage LUAD. Specifically, we gathered 27 solid (S), 39 part-solid (PS), 74 pure non-solid (PNS) patients and 89 matched adjacent-normal cases to profile the phenotype of 2.24 million cells across the two IMC panels to characterize the cellular and molecular composition of GGO nodules. Comparing progression from adjacent normal, pure non-solid, part-solid, to solid, we observed consistent reduction in RAGE+ AT1 cells (p*<1.6E-7) and a reciprocal increase in SFTPC+ AT2 cells (p*<1.3E-8) and PanCK+Ki67+ proliferative epithelial cells (p*<2.8E-7). We also report fibrogenesis and an increase in immune cell populations such as regulatory (p*<1.4E-5), CD4 (p*<0.0024), CD8 T (p*<0.017) cells, B (p*<5.5E-9) cells, and macrophages. Spatially, we quantify an upregulation of tumor-tumor and tumor-fibroblast interaction, and a downregulation of tumor-immune interaction. We believe this evidence suggests the role of fibroblasts as liner for tumors, barricading immune infiltration and harvesting uninterrupted tumorigenesis. In summary, we performed a highly multiplexed IMC data to analyze the TIME spatial profiles of GGO nodules in early-stage LUAD at a single-cell level. Spatial analysis of this integrated multidimensional omics dataset provides insight into the pivotal role of fibroblasts in early-stage LUAD in immune suppression, evasion, tumorigenesis, and potentially metastasis.

Citation Format: Junbum Kim, Hiranmayi Ravichandran, Liron Yoffe, Bhavneet Binder, Timothy McGraw, Nasser K. Altorki, Vivek Mittel, Olivier Elemento. The spatial landscape of early-stage lung adenocarcinoma [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 5489.
Abstract 5490: Spatial profiling of inflamed tumor microenvironment of clear cell renal cell carcinoma
Authors: Pellinen Teijo , Luomala Lassi , Mattila Kalle , Säilä Jenni , Hemmes Annabrita , Valimaki Katja , Bruck Oscar , Paavolainen Lassi , Nisen Harry , Järvinen Petrus , Kallioniemi Olli , Vainio Paula , Jaakkola Panu , Mirtti Tuomas
Published: March 2024

Clear cell renal cell carcinoma (ccRCC) presents a distinctive tumor microenvironment (TME) characterized by extensive vascularization and immune infiltration. This unique TME makes ccRCC an attractive target for anti-angiogenesis and immune checkpoint blockade (ICB). To better understand the complexity of ccRCC and the associated cell types and states involved in disease progression, we conducted high-throughput single-cell immunofluorescence imaging on tissue sections from 437 localized tumors that were surgically resected. These samples included regions from the tumor center, tumor edge, and adjacent benign areas (TMA cores, n=1859). Our primary focus was on tumors with elevated immune cell enrichment (CD45high), as these tumors are known to be aggressive and may respond well to immunotherapy. Our study reveals the intricate interactions between tumor, vascular, stromal, and immune cells within ccRCC. We find that CD45high tumors, upon losing epithelial marker expression, acquire tumor cell PD-L1 and mesenchymal markers such as Fibroblast activation protein (FAP). This shift is indicative of the epithelial-mesenchymal transition (EMT) process. These CD45high and EMThigh tumors are enriched with changes in TME, including elevated FAP+ cancer-associated fibroblasts (CAFs) and subsets of immune suppressive T cells and macrophages. We report that ccRCC patients with high tumor PD-L1 expression or abundant FAP+ CAFs are associated with earlier metastasis and, in sunitinib-treated patients, shorter progression-free survival. This study illuminates the intricate connection between immune cell infiltration, stromal biology, and EMT in ccRCC, offering a deeper understanding of the disease's complex biology and potentially guiding future therapeutic approaches and strategies.

Citation Format: Teijo Pellinen, Lassi Luomala, Kalle Mattila, Jenni Säilä, Annabrita Hemmes, Katja Valimaki, Oscar Bruck, Lassi Paavolainen, Harry Nisen, Petrus Järvinen, Olli Kallioniemi, Paula Vainio, Panu Jaakkola, Tuomas Mirtti. Spatial profiling of inflamed tumor microenvironment of clear cell renal cell 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 5490.
Abstract 5516: Aberrant activation and perpetuation of lung wound response facilitates osteosarcoma metastasis
Authors: Reinecke James Brandon , Gross Amy C. , Cam Maren , Garcia Leyre Jimenez , Cannon Matthew V. , Roberts Ryan D.
Published: March 2024

Introduction: The mechanisms that allow tumor cells to integrate with unfamiliar parenchymal cells within hostile distant tissues during metastatic colonization remain poorly defined. Nowhere are these mechanisms more important than in osteosarcoma-a pediatric bone tumor where metastases cause nearly all osteosarcoma related deaths and occur almost exclusively in the lung. The purpose of this study was to define the cellular and molecular events that facilitate osteosarcoma lung colonization to devise novel therapeutic strategies that prevent and treat metastasis.

Experimental Approach: We generated experimental lung metastases using a panel of immunocompetent murine and human xenograft osteosarcoma models. A combination of immunohistochemistry, single cell RNA sequencing, and spatial transcriptomics were used to define the metastatic niche. Relevant findings were validated in human primary tumor, lung metastasis, and normal lung tissue specimens.

Results: Disseminated osteosarcoma cells physically associate with alveolar epithelial cells and trigger changes in surrounding epithelial cells that are characteristic of the aberrant, non-resolving wound response seen in non-malignant lung diseases such as idiopathic pulmonary fibrosis (IPF). This process drives the accumulation of fibrotic epithelial cells and scar-associated macrophages confined within a dense fibronectin-based matrix. Anti-fibrotic tyrosine kinase inhibitors used to treat patients with IPF (nintedanib) prevent the observed fibrogenic changes and inhibit metastatic colonization. Epithelial-osteosarcoma paracrine signaling is dominated by an inflammatory cytokine milieu that facilitates this transition towards fibrosis. Blocking one of the dominant paracrine signals with a recombinant IL1 receptor antagonist (anakinra) has similar effects on both fibrosis and metastatic colonization.

Conclusions: Our study demonstrates that tumor interactions with host stromal cells are critical for metastasis. Metastatic colonization requires transformation of the local lung microenvironment into a fibrotic, non-resolving, cytokine-rich, wound-like state that is both provoked and sustained by tumor-epithelial interactions. These insights have identified several potential therapeutic approaches to prevent metastatic colonization and treat established metastases.

Citation Format: James Brandon Reinecke, Amy C. Gross, Maren Cam, Leyre Jimenez Garcia, Matthew V. Cannon, Ryan D. Roberts. Aberrant activation and perpetuation of lung wound response facilitates osteosarcoma 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 5516.
Abstract 5535: Intracellular negative regulators of RTK-Ras-ERK signaling alter breast cancer perception of metastatic niche-derived growth factors
Authors: Murthy Vaibhav , Erdem Cemal , Copperman Jeremy , Birtwistle Marc , Davies Alexander
Published: March 2024

Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype that commonly metastasizes to distant organs, such as the lung, resulting in the poor clinical outcomes. TNBC cells commonly overexpress epidermal growth factor receptor (EGFR), a receptor tyrosine kinase (RTK) which when bound by microenvironmental growth factors, results in the activation of downstream effector kinases ERK-AKT and initiates transcriptional programs that control cell fate. Tumor cells, however, simultaneously receive many growth factor inputs from their respective microenvironments, many of which stimulate RTKs other than EGFR, that converge at ERK and AKT resulting in different transcriptional and cell fate outputs. This raises questions as to how tumor cells perceive, decode, and respond to a complex set of microenvironmental signals and what the relevance of this process may be for disease pathogenesis and treatment. To this end, our study aimed to determine how disseminated breast cancer cells perceive and respond to a complex growth factor milieu upon seeding and engraftment in the lung. Using live-cell microscopy techniques and TNBC cells carrying biosensors for ERK and Akt signaling pathways, we monitored the dynamic signaling behaviors of single tumor cells, in real-time, as they adapted to the environment in living human lung tissue. Strikingly, we found that individual disseminated tumor cells are less responsive to growth factors once seeded in the lung, as compared to outside this tissue, despite the presence of RTK stimulating ligands. We showed that partial activation of EGFR is necessary for complete activation of ERK signaling by other growth factor-RTK pairs, and expression of downstream ERK target genes, whereas AKT signaling was unaffected. Using quantitative modeling and experimentation, we showed that reshaping of ERK signaling response dynamics occurred via dysregulation of negative regulators that are dominantly controlled by EGFR signaling. Together, these results provide novel insight into how tumor cells perceive and respond to complex microenvironmental signals, which has important implications for drug targeting strategies.

Citation Format: Vaibhav Murthy, Cemal Erdem, Jeremy Copperman, Marc Birtwistle, Alexander Davies. Intracellular negative regulators of RTK-Ras-ERK signaling alter breast cancer perception of metastatic niche-derived growth factors [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 5535.
Abstract 5567: Breast cancer cell alteration of immune cell transcriptome through indirect communication
Authors: Kennard Jacob , Norek Karen , Fuh Kenneth , Shepherd Robert D. , Rinker Kristina D. , Kharenko Olesya A.
Published: March 2024

Crosstalk between tumor and non-tumor cells plays an important role in cancer progression and metastasis often leading to a modification of non-malignant cells into pro-oncogenic phenotypes. Understanding this process is important for diagnostic and therapeutic advances. We previously reported clinical validation results for a new way to detect early-stage breast cancer using a panel of RNA biomarkers from whole blood and a machine learning software-powered testing system. Recently, we showed that immune cells undergo transcriptomic and functional changes upon direct contact with breast cancer cells. Here, we report results from investigation of indirect communication between breast cancer and immune cells leading to cancer-driven immune cell transformation and activation of multiple oncogenic pathways. To characterize these modifications, we performed RNAseq and pathway analysis on a human monocytic cell line, THP1, exposed to media from triple negative breast cancer (TNBC) cells (MDA-MB-231) in culture. Our results demonstrate that 24 hours of THP1 cell exposure to soluble factors secreted by tumor cells leads to significant gene modulation, with over 1,100 differentially expressed genes (|Fold Change|>2; p<0.05). KEGG and Reactome enrichment analysis revealed overlap of multiple pathways between THP1 cells exposed to direct and indirect cancer cell contact conditions, such as cytokine-cytokine receptor interaction, JAK-STAT signaling pathways and others. TNF, NMP1, STING1 and TGM2 were identified as key upstream regulators potentially driving this transformation in both direct and indirect contact conditions. The S100 pathway, which we previously found to be activated by fluid shear stress in MDA-MB-231 cells was also activated in THP1 cells upon both direct and indirect contact. The observed gene expression changes in THP1 cells exposed to media from MDA-MB-231 suggests that indirect intercellular communication alone can transmit an oncogenic signal. These results support a role for secreted factors from breast cancer cells in transforming immune cells and modulating the gene expression markers detected by our blood test, expanding the potential for leveraging this type of tumor education response in advancing cancer detection and treatment.

Citation Format: Jacob Kennard, Karen Norek, Kenneth Fuh, Robert D. Shepherd, Kristina D. Rinker, Olesya A. Kharenko. Breast cancer cell alteration of immune cell transcriptome through indirect communication [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 5567.
Abstract 559: Investigating DDX3X as a target to improve outcomes in Black and Native American endometrial cancer patients
Authors: Lausen James D. , Benbrook Doris M.
Published: March 2024

Introduction: The goal of this project was to identify and test a new molecular target that will help reduce the worse outcomes of endometrial cancer, especially in Black and Native American patients. Endometrial cancer is rapidly on the rise in the developed world. It has overtaken many other types of cancer in both incidence and mortality. Black populations are disproportionately impacted by endometrial cancer, both in Oklahoma and across the United States. In Oklahoma specifically, Native Americans are the most heavily impacted group.

Methods: Machine learning techniques were used to analyze comprehensive metabolic panel (CMP) data from electronic medical record of patients in the University of Oklahoma (OU) network of hospitals and clinics. This data was broken down by endometrial cancer status, race, and age. Plasma samples of endometrial cancer patients were collected from the OU Health Sciences Center Biobank. These samples were analyzed by mass spectrometry. Endometrial cancer cell lines Ishikawa (low-grade) and ARK-1 and ARK-4 (high grade) were cultured in EMEM. For treating the cells, we used RK-33, a small molecule inhibitor of DDX3X. MTT assays were performed in 96-well plates at increasing concentrations of RK-33 for 48 hours. Western blots were used to determine effect of the drug on cellular DDX3X and yH2AX protein levels.

Results: Machine learning analysis EMR data revealed a difference between races in albumin levels of women with endometrial cancer. Black and Native American patients had lower albumin, which is known to correlate to worse outcomes. IPA analysis of plasma proteomics revealed several proteins that were differentially expressed between races. Among these was DDX3X, the X-linked form of DDX3, a DEAD-box RNA helicase which is involved in DNA damage repair. Patient data indicated that patients with high DDX3X expression tended to have lower survival rates. MTT analysis determined that Ishikawa has a lower IC50 than the high-grade cell lines, but all responded. Western blotting confirmed that treatment with RK-33 reduced the amount of DDX3X in the cells and increased y-H2AX, indicating more DNA damage.

Conclusions: This study demonstrates that DDX3X is a valid molecular target in endometrial cancer. The differential expression across race groups indicates that Black and Native Americans may stand to benefit the most from a novel drug targeting this difference. Because DDX3X is involved in DNA damage repair, combining the treatment with a DNA-damaging drug may increase response to the drug as well.

Citation Format: James D. Lausen, Doris M. Benbrook. Investigating DDX3X as a target to improve outcomes in Black and Native American endometrial cancer patients [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 559.
Abstract 5590: Engineered destabilized 3’UTR of TEAD1 therapeutically inhibits and degrades TEAD1 mRNA and YAP1 interactors across multiple cancers
Authors: Awah Chidiebere U.
Published: March 2024

The hippo pathway mediated by TEAD1 is overexpressed and oncogenic in multiple cancers. We report here the development of engineered destabilized 3’UTR of TEAD1 which overwrote and degraded oncogenic TEAD1 in ethnically diverse breast cancers, prostate cancers, ovarian cancers, and pancreatic cancer. We validated the destabilization and degradation of TEAD1 on the transcript and protein levels. This led to the loss of cancer cell size causing severe shrinkage as hippo pathway controls cells size , impaired cancer cell migration abilities and loss of cancer cell viability. These properties are titratable and specific demonstrating the specific engagement of the engineered destabilized 3’UTR of TEAD1 with oncogenic TEAD1 mRNA in destabilizing and degrading it. In a dose dependent titration analysis, we determined the IC50 of the engineered destabilized 3’UTR of TEAD1 across many cancers. IC50 dose dependent titration comparison with the engineered destabilized 3’UTR of TEAD1 constructs and chemotherapies (DNA damaging agents, microtubules inhibiting drugs, alkylating agents) as well as immune checkpoint inhibitor. We found evidence that suggests that the engineered destabilized 3’UTR of TEAD1 is superior. Mechanistically, the loss of TEAD1 led to the loss of TEAD2,3 and YAP1 and FOSL1 , JUN and c-MYC.

Citation Format: Chidiebere U. Awah. Engineered destabilized 3’UTR of TEAD1 therapeutically inhibits and degrades TEAD1 mRNA and YAP1 interactors across multiple cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5590.
Abstract 5593: METTL3-NUP93 axis as a novel therapeutic target in castration-resistant prostate cancer (CRPC)
Authors: Lee Jihoon , Zhang Zhao , Hong Juyeong , Xu Kexin
Published: March 2024

Androgens and androgen receptor (AR) are the key factors driving the development and progression of prostate cancer. Extensive studies confirm both androgens and AR are required for normal growth and development of the prostate gland, and also in prostate cancer pathogenesis and androgen-independent cancer progression. Therefore, androgen deprivation therapies or targeting AR function have always been the mainstay of therapeutic strategy against advanced prostate cancers. However, the current therapeutic strategies are temporally effective in suppressing prostate tumors, and eventually develop metastatic disease. Nuclear pore complex (NPC) is a large complex composed of approximately 30 different proteins termed nucleoporins (NUPs), which serve as the structural and functional units for macromolecules shuttling including proteins and messenger RNAs (mRNAs) between nucleus and cytoplasm. Abnormal expression or genetic alterations of NUP genes has been indicated to involve in the progression of prostate cancer, but the underlying molecular mechanisms are poorly understood. We recently found that the m6A methyltransferase METTL3 directly interacts with nucleoporin 93 (NUP93), one of the NPC components in multiple prostate cancer cells, which seems to be more robust in the castration-resistant prostate cancer (CRPC) cell lines. Disruption of METTL3-NUP93 axis abrogated proliferation and oncogenic phenotypes of CRPC cells, suggesting that the METTL3-NUP93 axis may play an important role in prostate cancer progression to castration resistance. Most importantly, a subgroup of mRNAs regulated through METTL3-NUP93 axis encode cholesterol biosynthesis enzymes that trigger the activation of persistent AR signaling in CRPC. Therefore, Our current findings suggest that inhibition of METTL3-NUP93 axis may represent a promising therapeutic strategy for CRPC, the lethal form of the disease.

Citation Format: Jihoon Lee, Zhao Zhang, Juyeong Hong, Kexin Xu. METTL3-NUP93 axis as a novel therapeutic target in castration-resistant prostate cancer (CRPC) [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 5593.
Abstract 5609: A WRN screening cascade to facilitate novel drug discovery
Authors: Wang Aicheng , Mao Kejun , Li Tao , Guan Lizhao , Chen Yuhong , Dai Haiting , Wu Xian , Lv Jiabao , Wang Xu , Huang Cong , Bing Tiejun
Published: March 2024

Human RecQ deconjugating enzyme WRN is involved in DNA replication, DNA repair, recombination, transcription and telomere stabilization[1]. It plays a key role in nucleic acid metabolism as well. WRN defects lead to premature aging, type II diabetes, osteoporosis, atherosclerosis and cancer[2]. Hence it is of great interest of both pharmaceutical and academic field to develop the WRN inhibitors. Here we constructed an integrated experimental cascade, which contains both in vitro and in vivo assays, to conduct the high throughput hit-to-lead compound screen. WRN proteins of different length have been successfully purified and utilized to develop multiple biochemical assays such as unwinding assay and ATPase assay. We have also validated different cellular assays, including proliferation and immunofluorescence, to assess the cytotoxicity and the influence of downstream biomarkers of WRN inhibitors. A WRN knock-out cell line has been generated to better appreciate the inhibition mechanism. In addition, we have generated a WRN-HiBiT knock-in cell line to evaluate WRN degraders or target-compound interactions. Lastly, multiple CDX models utilizing different MSI or MSS cell lines have been validated to help determine the efficacy of WRN inhibitors thus shed light on the drug indications. Together our WRN screening cascade can provide comprehensive compound evaluation across in vitro and in vivo platforms, thus serve as an efficient screening platform for new drug discovery.

[1] Kitano K. Structural mechanisms of human RecQ helicases WRN and BLM. Front Genet. 2014 Oct 29;5:366.

[2]Hussain M, Krishnamurthy S, Patel J, Kim E, Baptiste BA, Croteau DL, Bohr VA. Skin Abnormalities in Disorders with DNA Repair Defects, Premature Aging, and Mitochondrial Dysfunction. J Invest Dermatol. 2021 Apr;141(4S):968-975.

Citation Format: Aicheng Wang, Kejun Mao, Tao Li, Lizhao Guan, Yuhong Chen, Haiting Dai, Xian Wu, Jiabao Lv, Xu Wang, Cong Huang, Tiejun Bing. A WRN screening cascade to facilitate novel drug discovery [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 5609.
Abstract 5681: Identification of dysregulated miRNAs involved in TNBC progression
Authors: Lee Minyoung , Kim Yesol , Son Dasom , Lim Sera , Park Jong Hoon
Published: March 2024

Triple negative breast cancer (TNBC) is the most aggressive type of all breast cancer subtypes. Although various studies have been performed to identify prognostic and therapeutic targets for TNBC, the TNBC specific biomarkers have not yet been elucidated. Herein, we identified dysregulated miRNAs in TNBC via analysis of miRNA microarray in breast cancer tissues and found the oncogenic RNA (miR-374a-5p) and tumor suppressive miRNAs (miR-320c, miR-371b-5p). These miRNAs were closely related to overall survival of TNBC patients and status and involved in TNBC progression or drug responsiveness. Collectively, these results suggest that dysregulated miRNAs might serve as potential prognostic marker or therapeutic target for TNBC.

Citation Format: Minyoung Lee, Yesol Kim, Dasom Son, Sera Lim, Jong Hoon Park. Identification of dysregulated miRNAs involved in TNBC progression [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 5681.
Abstract 5692: Posttranscriptional molecular network facilitates KRAS-linked tumorigenesis via XRN1-miR-21 signaling in pancreatic cancers
Authors: Seo Yoona , Oh Seung Eon , Kim Jong Heon
Published: March 2024

Aberrant expression of mutant KRAS and miRNA-21 (miR-21) are commonly attribute to malignancy and tumorigenic progression of pancreatic cancers. However, few studies have explored the molecular mechanism linking these two prognostic factors. In this study, we explored the underlying molecular bridge between KRAS and miR-21 regulation in pancreatic cancer. Functional integrative analysis of KRAS, an essential oncogenic driver in pancreatic cancer progression, and together with miR-21 revealed XRN1, a 5′-3′ exoribonuclease, as RNA-linked top-scored molecule with a strong survival correlation and malignancy in pancreatic cancer patients. Depletion of XRN1 led to severe reduction in mature miR-21 expression, while unaltered precursor miR-21 levels; indicating that the XRN1 is critical in miR-21 maturation at post-Drosha step in conjunction with Dicer. Moreover, miR-21 sensor-based experiment also confirmed the critical role of XRN1 on miR-21 biogenesis. Depletion experiments showed that XRN1 positively regulates proliferation and self-renewal capacity of pancreatic cancer cells via its 5′-3′ exoribonuclease activity and concomitantly elevated the expression of PTEN and PDCD4 which are the key miR-21 cellular downstream targets. shRNA-mediated XRN1 depletion also yielded smaller tumor volume and longer survival in pancreatic cancer xenografts and syngeneic model demonstrating the therapeutic potential of targeting XRN1. Subsequent silencing of KRAS reduced XRN1 expression in pancreatic cancer cells, suggesting that KRAS plays a key role in this XRN1-miR-21 axis. Furthermore, drug-resistant pancreatic cells showed elevated expression of both KRAS and XRN1-miR-21 indicating that this axis is also associated with drug sensitivity. In sum, these results suggest that a novel KRAS-XRN1 posttranscriptional regulatory axis plays a pivotal role in tumor progression by mediating miR-21-directed signaling, and thus may suggest a novel targeting strategy for pancreatic cancer therapeutics.

Significance: This study identifies molecular regulatory interplay between KRAS and XRN1-miR-21 signaling in pancreatic cancers, elucidates how KRAS-XRN1 modulates tumorigenesis via miR-21, and demonstrates that targeting this signaling can contribute to therapeutic strategies for pancreatic cancers. [Y. Seo and S. E. Oh contributed equally to this work.]

Citation Format: Yoona Seo, Seung Eon Oh, Jong Heon Kim. Posttranscriptional molecular network facilitates KRAS-linked tumorigenesis via XRN1-miR-21 signaling in pancreatic cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5692.
Abstract 5798: Preclinical safety assessment for specificity of biotherapeutics using the membrane proteome array
Authors: Raghavan Kristopher S. , Sullivan Jonathan T. , Navia Carmen , Fong Rachel H. , Doranz Benjamin J.
Published: March 2024

Rigorous specificity analysis is critical for the development of antibody-based therapies, as even minimal off-target binding can lead to toxicity and clinical failures. Long believed to be exquisitely specific, recent preclinical data and our own work indicate that monoclonal antibodies (MAbs) frequently (~25%) display cross-reactivity. In many cases, off-target interactions occur with unrelated proteins that cannot be predicted by protein sequence homology. Cross-reactivity can lead to serious or even life-threatening consequences especially when MAbs are configured as bispecifics, antibody-drug conjugates (ADC) or CAR-T cell therapies, and IND applications for biotherapeutics require cross-reactivity assessment to prevent adverse events. Tissue cross-reactivity (TCR) studies have traditionally been used to screen for off-target binding, however, with poor predictive value for in vivo safety and toxicity. We developed the Membrane Proteome Array (MPA) platform to de-risk MAb-based therapeutics by testing for specificity across 6,000 human membrane proteins expressed in unfixed cells. The MPA assesses binding interactions by high-throughput flow cytometry allowing for high sensitivity detection and rapid analysis. All targets identified on the MPA screen are validated by secondary titration analysis. In contrast to TCR studies, proteins in the MPA exist in their native conformations and are not altered by fixation. Recently, we used the MPA to select a lead antibody candidate targeting the oncotherapeutic target Claudin 6 (CLDN6). Through MPA screening, we successfully identified a lead candidate devoid of cross-reactivity against other CLDN family members or any other membrane protein across the human genome. The MPA has also been used to rapidly evaluate the specificity of novel CAR-T cell therapies for cancer and autoimmunity. The MPA has been used for lead selection and data from the MPA has been accepted by the FDA as a part of IND applications for antibody-based therapies. The MPA is currently under consideration for being developed as an FDA-qualified Drug Development Tool.

Citation Format: Kristopher S. Raghavan, Jonathan T. Sullivan, Carmen Navia, Rachel H. Fong, Benjamin J. Doranz. Preclinical safety assessment for specificity of biotherapeutics using the membrane proteome array [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 5798.
Abstract 5803: Tumor treating fields alter PDGFR-β localization in immortalized human pericytes in an in vitro model of the blood-brain barrier
Authors: Salvador Ellaine , Koeppl Theresa , Kessler Almuth F. , Burek Malgorzata , Ernestus Ralf-Ingo , Löhr Mario , Hagemann Carsten
Published: March 2024

Background: Tumor Treating Fields (TTFields) are alternating electric fields of intermediate frequency (100-500 kHz) and low intensity (1-3 V/cm). TTFields at 200 kHz, together with adjuvant chemotherapy, increased progression-free and overall survival of newly diagnosed Isocitrate dehydrogenase (IDH) wildtype and IDH mutant glioblastoma (GBM, WHO CNS 2016) patients in a randomized controlled trial and were therefore approved for the treatment of these patients. We recently demonstrated that TTFields at lower frequencies transiently increase the permeability of blood-brain barrier (BBB) models of murine and human origin by delocalizing junctional proteins such as claudin-5, ZO-1, and occludin in endothelial cells. The interaction between pericytes and endothelial cells contributes to the rigorous integrity of the BBB and is driven by endothelial cells releasing the platelet-derived growth factor β-subunit (PDGF-β), which binds to the receptor PDGFR-β on the surface of pericytes. Here, we investigated the effects of TTFields on pericytes in a human cell-based in vitro BBB model in order to gain a better understanding of the effects of TTFields on BBB integrity.

Methods: We prepared an in vitro BBB model composed of human brain microvascular endothelial cells and human pericytes. The model was subjected to TTFields at 100-300 kHz for 24 to 72 h. Afterwards, pericytes were incubated with Alexa Fluor 488-labeled anti-PDGFR-β antibody in order to visualize PDGFR-β localization and cell morphology under the microscope. To make sure that no cell loss occurred due to TTFields treatment, the nuclei of pericytes were counted.

Results: TTFields treatment altered the distribution of PDGFR-β staining after treatment, with fewer, less distinct and more punctate PDGFR-β foci. These changes were most prominent after 72 h of TTFields treatment at 300 kHz. We also observed larger nuclei in the pericytes after treatment but no significant loss of cells could be observed as per the nuclei count.

Conclusion: Together with the previously observed delocalization of tight junctional proteins in endothelial cells, the altered distribution of PDGFR-β pericytes could reveal new mechanistic insights into the effects of TTFields on BBB integrity.

Citation Format: Ellaine Salvador, Theresa Koeppl, Almuth F. Kessler, Malgorzata Burek, Ralf-Ingo Ernestus, Mario Löhr, Carsten Hagemann. Tumor treating fields alter PDGFR-β localization in immortalized human pericytes in an in vitro model of the blood-brain barrier [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 5803.
Abstract 5813: AI-driven identification and validation of novel synthetic lethal gene pairs through deep mining of cancer dependency data
Authors: Miller Daniel S. , Vipond Oliver , Brennan Alfie , Hercot Anna
Published: March 2024

The targeting of synthetic lethal (SL) gene pairs is emerging as a new paradigm in precision oncology, with the potential to deliver treatments with higher efficacy and fewer side-effects. However, existing approaches have focused on a few well-validated pairs, and there is a clear need to expand the toolbox of potential SL targets. We have performed deep mining of cancer dependency data using a suite of machine learning tools and AI algorithms underpinned by robust statistical analysis to identify the next generation of SL gene pairs.

To ensure robust, high confidence validation of multiple SL pairs simultaneously, we have used three cell lines and orthogonal assay formats. This has led to the confirmation of new druggable SL genes suitable for clinical development. We have identified the cancer subtypes with the strongest evidence of SL vulnerabilities and quantified patient populations who would most benefit from novel therapeutic agents. For one gene pair, we have generated novel best-in-class inhibitors of the target of interest, with exceptional selectivity over the SL partner, and used these chemical tools to validate the SL relationship in 2D and 3D models.

Citation Format: Daniel S. Miller, Oliver Vipond, Alfie Brennan, Anna Hercot. AI-driven identification and validation of novel synthetic lethal gene pairs through deep mining of cancer dependency data [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 5813.