tbuckley/cabot-search huggingface dataset:
Abstract B048: Neutrophil extracellular traps-targeting DNase I enhances the therapeutic efficacy of CAR-T cell adoptive immunotherapy in a syngeneic murine metastasis model
Authors: Alexey Stepanov, Wenjian Wang, Yingqin Hou, Ivan Chernikov Ivan Chernikov, Reid Bissonnette, George Tetz, Grigory Borisenko, Dmitry Genkin
Journal: Cancer Research (2024)

Abstract In recent years, chimeric antigen receptor (CAR) T cell therapy has emerged as a promising approach for treating various malignancies, most notably in hematologic cancers. However, its efficacy in solid tumors is often hindered by an immunosuppressive tumor microenvironment (TME), which, in particular, is frequently characterized by the presence of tumor-associated cell-free DNA (cfDNA), especially in the form of neutrophil extracellular traps (NETs). In adoptive immunotherapies NETs, composed primarily of neutrophil-derived DNA, histones and neutrophil granule enzymes (e.g., MPO, NE), act as physical barriers and induce the secretion of immunosuppressive factors that impair CAR T cell function. This study investigates the potential of co-administration of deoxyribonuclease I (DNase I) with CAR T cells in a syngeneic B16 melanoma murine model of lung metastasis. Bioluminescent imaging of melanoma metastatic processes has shown that a single injection of DNase I (10 mg/kg) suppresses B16-EGFR lung metastasis at early stages in comparison to the vehicle control group but does not improve survival. However, co-administration of DNase I with murine EGFR-CAR T cells significantly suppresses tumor burden, decreases the number of metastatic foci, and substantially prolongs survival compared to the CAR T cell monotherapy group. Degrading of NETs [RB1] by DNase I increases the amount of tumor-infiltrating T and CAR T cells and reduces the immunosuppressive effects of the TME. This is reflected in the CD8 population of tumor-infiltrating CAR T cells from the DNase I treated group, which have lower expression of PD-1 and TIM-3 exhaustion markers. This research highlights the critical role of the NETs in modulating CAR T cell efficacy and provides a compelling rationale for incorporating DNase I as an adjunctive treatment to improve therapeutic responses in patients undergoing CAR T cell therapy. However, further clinical studies are warranted to validate these findings and explore the translational potential of this combinatorial approach in enhancing cancer treatment. [RB1]Again - this takes the emphasis and the reader away from NETs and into the cfDNA universe. Citation Format: Alexey Stepanov, Wenjian Wang, Yingqin Hou, Ivan Chernikov Ivan Chernikov, Reid Bissonnette, George Tetz, Grigory Borisenko, Dmitry Genkin. Neutrophil extracellular traps-targeting DNase I enhances the therapeutic efficacy of CAR-T cell adoptive immunotherapy in a syngeneic murine metastasis model [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B048.
Abstract B026: Pancreatic tumor extracellular vesicles induce perineural invasion in vitro via IL- 8/CCL2
Authors: Emory A Gregory, Isabel Powers, Inha Baek, Reagan Dugan, Azemat Jamshidi-Parsian, Robert J. Griffin, Younghye Song
Journal: Cancer Research (2024)

Abstract Pancreatic cancer (PDAC) remains a pre-eminent cause of cancer-related death with perineural invasion (PNI), i.e., cancer cell infiltration of nerves, contributing to high morbidity rates. Glial Schwann cells (SC) are activated by tumor signaling to produce chemical gradients, re-direct cancer cells, and accelerate PNI. Tumor extracellular vesicles (EV) have been implicated in cancer-nerve crosstalk; however, their role in activating SCs during PDAC PNI is unclear. In this study, we explored tumor EVs as initiators of SC-dependent PDAC PNI using tissue engineered modeling platforms. NanoSight Nanoparticle Tracking Analysis and Western blot confirmed the presence of non-contaminated EVs. Liquid chromatography-mass spectrometry characterized healthy (HPNE) and cancer cell (PANC-1) EV cargoes, and QIAGEN Ingenuity Pathway Analysis also exposed potential EV targets. SCs (sNF96.2) were embedded in an optimized decellularized nerve hydrogel and cultured with EVs ± cargo-function-blocking monoclonal antibody. SC phenotype was assessed using Luminex® multiplex assays and immunofluorescence. Subsequently, EV-treated SCs were co-cultured with healthy or cancer cells, and invasion was further probed using Transwell® assays. Proteins associated with IL-8 signaling were upregulated in tumor EVs versus healthy EVs. Tumor EVs significantly activated SCs to produce cytokines related to PNI, namely CCL2, in an IL-8-dependent manner. Tumor EV/IL-8-activated SCs facilitated significantly greater invasion in cancer cells compared to healthy cells, which was reduced by neutralizing IL-8 from tumor EVs or CCL2 in SC- conditioned media. These findings provide evidence of a potential mechanism in which PDAC EVs reprogram SCs to amplify PNI and necessitate further pre-clinical investigations with increased biodiversity targeting EVs for PDAC therapeutics. Citation Format: Emory A Gregory, Isabel Powers, Inha Baek, Reagan Dugan, Azemat Jamshidi-Parsian, Robert J. Griffin, Younghye Song. Pancreatic tumor extracellular vesicles induce perineural invasion in vitro via IL- 8/CCL2 [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B026.
Abstract B035: Reciprocal macrophage - T cell interactions regulate anti-tumor immunity
Authors: Meenakshi Sudhakaran, Sofia Lombardi, Sophie Ayma, Matthew F. Krummel, Kelly Kersten
Journal: Cancer Research (2024)

Abstract Cancer immunotherapy (including immune checkpoint blockade (ICB)) has shown great promise in the treatment of some solid cancers, but responses in breast cancer patients are limited. While breast cancer is generally considered poorly immunogenic, the abundance of CD8+ T cells correlates with clinical response. CD8+ T cells are critical mediators of anti-tumor immunity and the main target for ICB. However, the onset of terminal functional T cell exhaustion poses a major challenge. Although T cell exhaustion has been linked to persistent antigen exposure, it remains unclear how the immune composition of the breast tumor microenvironment (TME) contributes to this dysfunctional T cell state. Breast cancers are heavily infiltrated with tumor-associated macrophages (TAMs) and their abundance correlates with T cell exhaustion and poor prognosis. Previously, we discovered a spatiotemporal co-dependency between exhausted T cells (TEX) and TAMs in mouse models of melanoma and breast cancer. We showed that TEX actively recruit monocytes to the TME and shape their differentiation trajectory into TAMs. Reciprocally, these TAMs ‘capture’ T cells in long-lived synaptic interactions that contribute to functional T cell exhaustion. Our current work is focused on studying the TEX-derived chemokines that regulate these TAM – T cell interactions in the breast TME with the ultimate goal to alleviate immune evasion and improve responsiveness of breast cancer to immunotherapy. Citation Format: Meenakshi Sudhakaran, Sofia Lombardi, Sophie Ayma, Matthew F. Krummel, Kelly Kersten. Reciprocal macrophage - T cell interactions regulate anti-tumor immunity [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B035.
Abstract C003: Outer membrane vesicles from <i>Bacteroides fragilis</i> contain coding and non-coding small RNA species that modulate inflammatory signaling in intestinal epithelial cells
Authors: Aadil Sheikh, Colin Scano, Julia Xu, Tolulope Ojo, Jessica M. Conforti, Kayla L. Haberman, Bryan King, James Lotter, Alysia Martinez, Harry Ojeas, Michelle Pujol, Juli Watkins, Emily Lin, Bernd Zechmann, Amanda Sevcik, Christie Sayes, Elyssia S Gallagher, Joshua Mell, Garth Ehrlich, Joseph H Taube, K. Leigh Greathouse
Journal: Cancer Research (2024)

Abstract Alterations to the community structure and function of the microbiome are associated with changes to host physiology, including immune responses. However, the contribution of microbial-derived RNAs carried by outer membrane vesicles (OMVs) to host immune responses remains unclear. This paper investigates the role of OMVs and OMV-associated small RNA (sRNA) species from pathogenic and commensal Bacteroides fragilis (ETBF and NTBF respectively) in eliciting different immune responses in intestinal epithelial cells. To distinguish the differences in the sRNA profiles of both strains and their OMVs, small RNA-seq was conducted, and identified enrichment of discrete sRNA species in OMVs that were also differentially expressed between the two strains. To understand the effects of OMVs on pattern recognition receptors, Toll-like receptor (TLR) reporter cells were treated with OMVs, and activation of TLRs 2, 3, 4, and 7 were observed. Treatment of Caco-2 and HT29-MTX cells with OMVs demonstrated increased expression of IL-8. Surprisingly, we discovered that degradation of RNase-accessible RNAs within ETBF OMVs, but not NTBF OMVs, resulted in vesicles with enhanced capacity to stimulate IL-8 expression, indicating that these extravesicular RNAs exert an immunosuppressive effect. This suggests a dual role for OMV-associated RNAs in modulating host immune responses, with implications for both bacterial pathogenesis and therapeutic applications. Citation Format: Aadil Sheikh, Colin Scano, Julia Xu, Tolulope Ojo, Jessica M. Conforti, Kayla L. Haberman, Bryan King, James Lotter, Alysia Martinez, Harry Ojeas, Michelle Pujol, Juli Watkins, Emily Lin, Bernd Zechmann, Amanda Sevcik, Christie Sayes, Elyssia S Gallagher, Joshua Mell, Garth Ehrlich, Joseph H Taube, K. Leigh Greathouse. Outer membrane vesicles from Bacteroides fragilis contain coding and non-coding small RNA species that modulate inflammatory signaling in intestinal epithelial cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C003.
Abstract B036: WEE1 confers resistance to PD-1 blockade via hyperactivation of the AKT signaling pathway
Authors: Hyo-Jung Lee, Suyeon Kim, Eunho Cho, Tae Woo Kim
Journal: Cancer Research (2024)

Abstract Immune checkpoint blockade (ICB) has revolutionized cancer treatment, but resistance limits its clinical effectiveness. Therefore, understanding immune resistance mechanisms and identifying predictive markers are essential. Our transcriptomic analysis of PD-1 blockade-treated patients and non-responsive tumor models identifies WEE1 as a key resistance factor, promoting cancer stem cell (CSC)-like traits and immune resistance phenotypes including low T cell infiltrated into tumor and anti-apoptotic properties to cytotoxic T cells (CTLs). WEE1 drives AKT hyperactivation, enhancing expression of resistance factors such as CYCLIN A which contributes to CSC-like properties, and the anti-apoptotic molecule MCL-1, while also reducing T cell infiltration via CXCL10 downregulation. This signaling axis is conserved across various cancers. Notably, WEE1 inhibition sensitizes tumors to ICB by disrupting these refractory properties and reinvigorating antitumor immunity. These findings underscore the novel role of WEE1 in driving immune resistance and CSC-like characteristics, supporting the use of WEE1 inhibitors as a strategy to overcome resistance to anti-PD-1 therapy. Citation Format: Hyo-Jung Lee, Suyeon Kim, Eunho Cho, Tae Woo Kim. WEE1 confers resistance to PD-1 blockade via hyperactivation of the AKT signaling pathway [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B036.
Abstract C002: CKLF attracts CCR4-expressing CD4+ cells to foster immune repression and tumor aggressiveness in MYCN-driven neuroblastoma
Authors: Xiaodan Qin, Hui Feng, Andrew Lam, Xu Zhang, Satyaki Sengupta, Bryan Iorgulescu, Sanjukta Das, Zhenwei Zhou, Tao Zuo, Grace Meara, Madison Rager, Alexander Floru, Hongru Ni, Chinyere Kemet, Divya Veerapaneni, Daniel Kashy, Liang Lin, Kenneth Lloyd, Lauren Kwok, Kaylee Smith, Raghavendar Nagaraju, Rob Meijers, Craig Ceol, Ching-Ti Liu, Sanda Alexandrescu, Catherine J. Wu, Derin Keskin, Rani George
Journal: Cancer Research (2024)

Abstract Neuroblastoma, especially those with aberrant MYCN activation, often harbor an immunosuppressive microenvironment to fuel malignant growth and trigger treatment resistance. Despite this knowledge, there are no effective strategies to tackle this problem. Here we combined analyses of human neuroblastoma with live tracking and functional studies of the tumor microenvironment (TME) in zebrafish. We identified chemokine-like factor (CKLF) as a key driver of MYCN-mediated immunosuppression and neuroblastoma aggression. We showed that human MYCN-activated neuroblastoma upregulates and secretes CKLF, which is a reliable predictor of poor patient survival. Analysis of primary patient samples demonstrates a strong positive association between MYCN and CKLF expression in neuroblastoma cells together with the enrichment of FOXP3+ T cells in the TME. Taking advantage of in vivo zebrafish models of MYCN-driven neuroblastoma that resemble human high-risk disease, we demonstrated that cklf overexpression in zebrafish neural crest cells induces an immunosuppressive TME while promoting rapid tumor onset and progression. We also demonstrated that as early as the premalignant stage, tumor cells secrete CKLF to attract CCR4-expressing Cd4+ cells to induce immunosuppression and tumor aggression. Conversely, genetic depletion of cklf in tumor cells reduces the recruitment of Cd4+ cells to the TME while increasing cytotoxic Cd8+ and natural killer cells infiltration, inhibiting neuroblastoma development in zebrafish. Our work provides the first example that MYCN can activate CKLF to allure CD4+ immune cells to the TME and incite immunosuppression, positioning CKLF as a potential novel immunotherapeutic target for the treatment of MYCN-driven high-risk neuroblastoma. Citation Format: Xiaodan Qin, Hui Feng, Andrew Lam, Xu Zhang, Satyaki Sengupta, Bryan Iorgulescu, Sanjukta Das, Zhenwei Zhou, Tao Zuo, Grace Meara, Madison Rager, Alexander Floru, Hongru Ni, Chinyere Kemet, Divya Veerapaneni, Daniel Kashy, Liang Lin, Kenneth Lloyd, Lauren Kwok, Kaylee Smith, Raghavendar Nagaraju, Rob Meijers, Craig Ceol, Ching-Ti Liu, Sanda Alexandrescu, Catherine J. Wu, Derin Keskin, Rani George. CKLF attracts CCR4-expressing CD4+ cells to foster immune repression and tumor aggressiveness in MYCN-driven neuroblastoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C002.
Abstract B031: Lean adipocyte-derived lipid decreases metastatic potential of breast cancer cells
Authors: Abigail E. Jackson, Keren I Hilgendorf
Journal: Cancer Research (2024)

Abstract Obesity rates are increasing globally, making it of critical importance to study obesity-linked diseases. Breast cancer is the most common cancer in women, and obesity is associated with both increased incidence and metastatic progression of breast cancer. Metastasis formation depends on a cancer cell leaving the primary site, migrating through the bloodstream, and establishing new growth in a distant site. Both metastasizing cell-intrinsic and metastatic site-dependent factors can help to regulate the effectiveness of this process; however, it is unknown whether obesity-linked metastasis depends on changes to the metastasizing cell and/or changes to the distant metastatic site. This study aims to characterize how the lean versus obese tumor microenvironment impacts breast cancer metastasis and identify adipocyte-derived molecules that modulate the metastatic potential of breast cancer cells. We and others have shown that obesity leads to increased metastasis formation in mouse models of orthotopic breast cancer. However, my preliminary data show that an obese metastatic site is not sufficient to increase metastasis formation in an intravenous injection model of metastasis, emphasizing the importance of the primary tumor microenvironment in programming breast cancer cells for metastasis. Cancer cell stemness helps to mediate metastasis formation and can be assessed in vitro with the mammosphere assay. Importantly, my data demonstrate that a secreted lipid from lean, but not obese, adipocytes potently inhibits the ability of breast cancer cells to form mammospheres. Furthermore, this inhibition induces a G1/S cell cycle arrest. Together, these data suggest that lean adipocytes in the breast cancer tumor microenvironment act in a paracrine manner to decrease the metastatic potential of breast cancer cells. My work demonstrates the role of adipocytes in the regulation of metastasis in breast cancer and provides important insight into the role of the tumor microenvironment in mediating metastasis in lean versus obese conditions. Citation Format: Abigail E. Jackson, Keren I Hilgendorf. Lean adipocyte-derived lipid decreases metastatic potential of breast cancer cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B031.
Abstract B030: Productive T-cell-mediated immunoediting of developing sarcomas by distinct mechanisms
Authors: Brian G Hunt, Julie F. Cheung, Srividhya Venkatesan, Jennifer L. Loza, Kelli A. Connolly, Shudipto Wahed, Elaine Cheng, Ishan Bansal, Emily Borr, Wei Wei, Ivana William, Brittany Fitzgerald, Nikhil Joshi
Journal: Cancer Research (2024)

Abstract Immunoediting is the process where developing tumors are shaped by cells of the immune system. Tumors with low immunogenicity are likely to emerge after neoantigen-specific T cells eliminate the most immunogenic cell populations. However, direct interrogation of mechanisms by which this occurs has not possible due to the pre-emergent nature before the disease is verifiably established. By modifying a mouse model of soft-tissue sarcoma where emergent tumors are consistently edited, we developed a system to examine mechanisms underlying how T cells interact with pre-emergent tumor cell populations to suppress tumor emergence. This system involves production of neoantigen-expressing autochthonous tumors with a fluorescent reporter to define neoantigen-expression status of individual cells. Tumors emerge with lower penetrance and delayed onset in T cell-sufficient mice, while every tumor from T cell-deficient mice contain a significant fraction of neoantigen-negative tumor cells. Yet, ∼53% of T cell-sufficient mice never developed, which suggests that neoantigen silencing was necessary, but not sufficient for tumor emergence. Consistent with this, genetic removal of the neoantigen after malignant transformation shows that tumor development is only rescued when neoantigen loss occurs prior to the peak T cell response, occurring around 8 days post transformation. Moreover, clonality studies reveal the presence of T cells reduces the number clones that contribute to tumor emergence down to 1-2 clones per emerged tumor. Mechanistically, blockade of the T cell effector cytokine, IFNgamma, rescues the neoantigen-negative, but not neoantigen-expressing tumor cells, demonstrating that T cells control early tumors via at least two distinct mechanisms: IFNgamma-dependent suppression of neoantigen-negative tumors cells and IFNgamma-independent suppression of neoantigen-expressing cells. Thus, our findings support that neoantigen-negative cells are subjected to cytokine-mediated suppression from T cells responding to the neoantigen-positive population in the pre-emergent tumor microenvironment. This bystander suppression can prevent tumor emergence despite non-homogeneity in neoantigen expression. Citation Format: Brian G Hunt, Julie F. Cheung, Srividhya Venkatesan, Jennifer L. Loza, Kelli A. Connolly, Shudipto Wahed, Elaine Cheng, Ishan Bansal, Emily Borr, Wei Wei, Ivana William, Brittany Fitzgerald, Nikhil Joshi. Productive T-cell-mediated immunoediting of developing sarcomas by distinct mechanisms [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B030.
Abstract A030: Polycomb repressive complex 2 (PRC2) mediates the epigenetic regulation of cancer-associated fibroblasts in esophageal cancer
Authors: Karen J. Dunbar, Raul Navaridas Fernandez de Bobadil, Katherine M. Cunningham, Emily Esquea, Gizem Efe, Anil K. Rustgi
Journal: Cancer Research (2024)

Abstract Cancer-associated fibroblasts (CAFs) are a heterogenous cell population that can promote esophageal cancer progression through multiple molecular mechanisms including increased cancer cell proliferation and migration, immunosuppression, and therapeutic resistance. Despite the divergence of CAFs from normal fibroblasts with regards to phenotype and functions, CAFs rarely exhibit widespread genetic alterations. Instead, it is proposed that CAFs are regulated at the epigenetic level. Our objective is to delineate this epigenetic regulation of CAFs in esophageal cancer. Ultimately, we aim to identify the epigenetic regulatory complexes that mediate CAF heterogeneity and pro-tumorigenic functions. To this end, we completed RNA-seq and ATAC-seq on fibroblasts isolated from esophageal squamous cell carcinoma (ESCC), esophageal adenocarcinoma (EAC) and non-cancerous esophageal tissue. Enrichment analysis identified the polycomb repressive complex 2 (PRC2) as a potential regulator of ESCC and EAC CAFs. PRC2 catalyzes the methylation (mono-, di- or tri-) of lysine 27 on histone 3 (H3K27me1/2/3) resulting in transcriptional repression. Inhibition of two key proteins of PRC2 (EZH2 and SUZ12) through either pharmacological or genetic modulation, altered expression of multiple CAF phenotype related proteins and inhibited CAF functions including CAF proliferation. Ongoing studies, using co-cultures of fibroblasts and tumor cells, seek to identify if inhibition of PRC2 can prevent the initial transition of normal esophageal fibroblasts into CAFs. Importantly, we are conducting in vivo studies to determine if selective PRC2 inhibition in CAFs can inhibit esophageal tumor progression with specific focus on primary tumor growth and metastatic spread. In summary, initial studies have identify that PRC2 complex mediates CAF phenotype and functions, and we aim to establish the larger impact of these CAF specific effects on esophageal cancer. Citation Format: Karen J. Dunbar, Raul Navaridas Fernandez de Bobadil, Katherine M. Cunningham, Emily Esquea, Gizem Efe, Anil K. Rustgi. Polycomb repressive complex 2 (PRC2) mediates the epigenetic regulation of cancer-associated fibroblasts in esophageal cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A030.