bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract IA005: Risk prediction in colorectal cancer screening: Reflections on the current status
Authors: Schoen Robert E.
Published: December 2022

Colorectal cancer screening is an effective means of reducing colorectal cancer incidence and mortality. However, the testing we have, though effective, is costly and inefficient, with the majority of people undergoing an expensive, negative screening examination such as colonoscopy. Risk prediction is a potential means to tailor screening and personalize care to risk. Individuals could be directed to a less invasive test (FIT or blood testing) as opposed to a more invasive test (colonoscopy), or to other adjustments such as modifying the starting age for screening. The polygenic risk score is an objective, reproducible risk assessment tool, that has promise, but its utility and possible application in clinical practice will require considerably more investigation. Other challenges include determining the “threshold“ for assignment to a low risk as opposed to a high risk screening strategy, and ensuring that risk assessment does not deter subsequent screening behavior.

Citation Format: Robert E. Schoen. Risk prediction in colorectal cancer screening: Reflections on the current status [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr IA005.
Abstract IA006: The effect of ancestry and the genomics of colorectal cancer: Implications on incidence and outcomes
Authors: Myer Parvathi A.
Published: December 2022

Blacks have a higher incidence of colorectal cancer (CRC) and worse survival rates when compared to Whites. Comprehensive genomic profiling was performed in 46,140 colorectal adenocarcinoma cases. Ancestry-informative markers identified 5,301 patients of African descent (AFR) and 33,770 patients of European descent (EUR). AFR were younger, had fewer MSI-H tumors, and had significantly more frequent alterations in KRAS, APC, and PIK3CA. AFR had increased frequency of KRAS mutations specifically KRAS G12D and KRAS G13. There were no differences in rates of actionable kinase driver alterations (HER2, MET, NTRK, ALK, ROS1, RET). In patients with young onset CRC (<50 years), AFR and EUR had similar frequency of MSI-H and TMB-H tumors, and strikingly different trends in APC mutations by age, as well as differences in MAPK pathway alterations. These findings inform treatment decisions, impact prognosis, and underscore the need for model systems representative of our diverse US population. Further studies are needed to investigate the role of colon polyps and the effect of genomics, ancestry and social determinants of health on CRC incidence and outcomes.

Citation Format: Parvathi A. Myer. The effect of ancestry and the genomics of colorectal cancer: Implications on incidence and outcomes [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr IA006.
Abstract IA008: Modeling immune-epithelial interactions in health and disease using human intestinal enteroid co-cultures
Authors: Zachos Nicholas C.
Published: December 2022

Human intestinal enteroids derived from Lgr5+ actively dividing adult stem cells offer a relevant ex vivo system to study biological processes of the human small intestine and colon. While these primary cultures recreate cellular and functional features of the intestinal epithelium of the small intestine (enteroids) or colon (colonoids), they are limited by the lack of associated cell types, including immunological cells, nerves, stromal cells that help maintain tissue homeostasis and respond to external challenges. In the gut, innate immune cells interact with the epithelium by conducting lumial surveillance, support barrier function, and deploy effector functions in response to injury/damage. We have established a co-culture system of enteroid/colonoid monolayers and underlying macrophages and polymorphonuclear neutrophils to recapitulate the cellular framework of the human intestinal epithelial niche. Human intestinal enteroids can generated from biopsies or resected tissue from any segment of the human intestine/colon and maintained in long-term cultures in a basement membrane-rich matrix supplemented with growth factor-conditioned media necessary to maintain intestinal stem cell homeostasis. Immune cells are isolated from fresh human whole blood or frozen peripheral blood mononuclear cells (PBMC) and co-cultured with human intestinal enteroids/colonoids grown as confluent monolayers on permeable supports (e.g., Transwells). This configuration allows for controlled access to the apical side of the epithelium to mimic the gut luminal environment as well as the basolateral side occupied by immune cells to mimic the mucosal environment. Enteroid-immune co-cultures enable multiple outcome measures, including transepithelial resistance, production of cytokines/chemokines, phenotypic analysis of immune cells, tissue immunofluorescence imaging, protein or mRNA expression, antigen or microbe uptake, and other cellular functions.

Citation Format: Nicholas C. Zachos. Modeling immune-epithelial interactions in health and disease using human intestinal enteroid co-cultures [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr IA008.
Abstract IA016: Stem cells, therapy resistance and metastasis in colorectal cancer
Authors: Batlle Eduard
Published: December 2022

The Cancer Stem Cell (CSC) concept states that tumor growth, analogous to the renewal of healthy tissues, is fueled by small numbers of dedicated stem cells. It provides attractive explanations for the clinical behavior of cancers and inspires treatment strategies that specifically target CSCs, the 'beating heart' of the tumor. Over the past years, an avalanche of studies has identified CSCs by expression of individual marker genes but the nature and features of these cells remain largely uncharacterized. As a case of example, LGR5 has been established as a bonafide marker of CSCs in gastrointestinal tumors. Many CRCs contain abundant LGR5+ cells yet clonal analysis suggests that only a small proportion of these cells function as CSCs. It is also known that many CRCs contain few or no LGR5+ cells, yet these tumors may still exhibit a hierarchical organization. Here, I will discuss our recent work on the functional states adopted by LGR5+ cells during CRC progression and the role of this cell population in chemotherapy resistance and metastatic dissemination.

Citation Format: Eduard Batlle. Stem cells, therapy resistance and metastasis in colorectal cancer [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr IA016.
Abstract IA017: Microbiota drivers of colorectal cancer and their translation to prevention
Authors: Sears Cynthia L.
Published: December 2022

Abundant data support that the microbiota, both communities and individual pathogenic bacteria, promote the development of colorectal cancer (CRC). More limited data support that CRC is initiated by specific bacteria or communities. This talk will focus on bacterial contributors to CRC pathogenesis, potential mechanisms, gaps in knowledge and potential approaches to enabling use of the colon microbiota and its members to advance CRC prevention. Improved approaches to prevention are particularly key to identify those at risk for early onset CRC that represents a global change in CRC epidemiology.

Citation Format: Cynthia L. Sears. Microbiota drivers of colorectal cancer and their translation to prevention [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr IA017.
Abstract IA019: Molecular pathological epidemiology of tumor microbiota and immunity can give etiologic insights
Authors: Ogino Shuji
Published: December 2022

This lecture discusses the integration of tumor microbiology and immunology into evolving/expanding molecular pathological epidemiology (MPE) research framework (Ogino et al. Gut 2011; Ogino et al. Annu Rev Pathol 2019; Inamura et al. Gut 2022; etc.), which will open new opportunities. Neoplasms represent heterogeneous pathological processes due to interactive influences of the exposome (including the microbiome), the immune system, and neoplastic cells. Hence cancers should be regarded as not only microenvironmental diseases but also environmental and systemic diseases (Inamura et al. Gut 2022). To address this complexity, we investigate influences of exposures on microbial-tumor-immune interactions in tumor microenvironment. Colorectal cancer (CRC) provides an ideal model, as the colorectum is the most microbial rich organ and there are many established or putative risk factors for CRC. In our proof-of-principle studies that used the Nurses’ Health Study and Health Professionals Follow-up Study along with tumor tissue biobanks having 1700 CRC cases, we can provide evidence for influences of prudent diets (Mehta et al. JAMA Oncol 2017), inflammatory diets (Liu et al. Clin Gastroenterol Hepatol 2018), and western diets (Arima et al. Gastroenterology 2022) on developments of cancer subtypes with intratumor bacteria such as Fusobacterium nucleatum and pks+ Escherichia coli. We have also gain insights into interactions between microbes and immune cells. We have discovered an inverse relationship between F. nucleatum and T cell infiltrates (Mima et al. JAMA Oncol 2015), especially CD3+CD4+CD45RO+ memory helper T cells (Borowsky et al. Clin Cancer Res 2021). In situ spatial single cell analyses using multispectral fluorescence imaging and machine learning can shed light on the roles of microbes as well as various immune cell infiltrates in CRC (Vayrynen et al. Cancer Immunol Res 2021; Vayrynen et al. J. ImmunoTher Cancer 2021; Vayrynen et al. Cancer Immunol Res 2022; Akimoto et al. Front Immunol 2022). The integrative MPE approach is also expected to advance research on early-onset cancers (Akimoto et al. Nat Rev Clin Oncol 2021; Ugai et al. Nat Rev Clin Oncol, in press). Our new research paradigm to integrate microbial and immune assays on archival tumor tissue in large-scale population studies can provide not only etiological insights but also possible paths for precision medicine and prevention.

Citation Format: Shuji Ogino. Molecular pathological epidemiology of tumor microbiota and immunity can give etiologic insights [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr IA019.
Abstract IA020: The gut microbiome in colorectal cancer
Authors: Atreya Chloe E.
Published: December 2022

The gut microbiome plays important roles in colorectal cancer (CRC) initiation, treatment, and survivorship. This talk will highlight preliminary results from two pilot studies: Gut microbiome & Oral fluoropyrimidines (GO) and Lifestyle and Outcome in Gastrointestinal Cancer (LOGIC). GO investigated the impact of oral fluoropyrimidines (e.g., capecitabine) on gut microbes via longitudinal stool sampling. Despite marked inter- and intra-individual differences in diversity and community structure, we detected multiple consistent taxonomic differences. LOGIC asked: how do diet and lifestyle, measured by the American Cancer Society (ACS) score, correlate with gut microbiota characteristics in CRC survivors? We found that components of the ACS score related to fruit and vegetable consumption, but not the overall ACS score, significantly associated with variations in microbial community structures, diversity, and differences in abundance of microorganisms at various taxonomic levels. Practical considerations influencing the design of follow-up studies in progress will be discussed.

Citation Format: Chloe E. Atreya. The gut microbiome in colorectal cancer [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr IA020.
Abstract PR010: Inhibition of HGF maturation overcomes cetuximab resistance in colorectal cancer
Authors: Graves-Deal Ramona , Jones Vivian T. , Bogatcheva Galina T. , Cao Zheng , Harmych Sarah J. , Damalanka Vishnu , Klampfer Lidija , Coffey Robert J. , Janetka James W. , Singh Bhuminder
Published: December 2022

We have previously identified that activation of receptor tyrosine kinases (RTKs), MET and RON contributed to resistance to the EGF receptor (EGFR)-directed therapeutic antibody, cetuximab. These findings originated from our in vitro 3D type I collagen cultures of human colorectal cancer (CRC) cell line HCA-7 derivatives CC, SC, and CC-CR. CC are sensitive to cetuximab, while SC and CC-CR are resistant. Both de novo and acquired modes of cetuximab resistance in SC and CC-CR, respectively, could be overcome by crizotinib, a multi-RTK inhibitor that also targets MET and RON. Conversely, exogenous administration of MET ligand, HGF could transiently induce cetuximab resistance which could be further overcome by crizotinib addition. HGF/HGFL are synthesized as inactive precursors and require cleavage by proteases (HGFA, Matriptase, and Hepsin) to be biologically active. To inhibit HGF/HGFL cleavage in cetuximab-resistant cells, we employed inhibitors of HGF/HGFL proteases (ZFH7116 and VD2173) and were able to overcome both de novo and acquired cetuximab resistance. A survey of TCGA datasets indicated that HGF/HGFL were overexpressed in several CRC CMS subtypes. We next expressed human HGF in cetuximab-sensitive CC cells and observed that HGF overexpression imparts cetuximab resistance. Moreover, cetuximab resistance induced by HGF overexpression could be overcome by the downstream MET inhibition (with crizotinib), and we are now testing if the upstream inhibition of HGF proteases (with ZFH7116/VD2173) also overcomes cetuximab resistance. Combined these results indicate that inhibition of HGF cleavage and maturation may be a novel way to overcome resistance to EGFR-targeted therapies in CRC.

Citation Format: Ramona Graves-Deal, Vivian T. Jones, Galina T. Bogatcheva, Zheng Cao, Sarah J. Harmych, Vishnu Damalanka, Lidija Klampfer, Robert J. Coffey, James W. Janetka, Bhuminder Singh. Inhibition of HGF maturation overcomes cetuximab resistance in colorectal cancer [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr PR010.
Abstract PR011: Histone demethylase KDM5D drives sex-specific differences in colorectal cancer
Authors: Li Jiexi , Lan Zhengdao , Liao Wenting , Horner James W. , Liu Jielin , Jiang Shan , Shim Hong S. , Slotnik Max , LaBella Kyle A. , Hsu Wen-Hao , Spring Denise J. , Wang Y. Alan , DePinho Ronald A.
Published: December 2022

Gender exerts a profound impact on cancer incidence, spectrum and outcomes, yet the molecular genetic bases of such sex differences are ill-defined and presumptively ascribed to X-chromosome genes and sex hormones. Such sex differences are particularly prominent in colorectal cancer (CRC) where men experience higher metastases and mortality. A murine CRC model, engineered with an inducible oncogenic Kras transgene (KRAS*) and conditional null alleles of Apc and Trp53 tumor suppressors (designated iKAP), revealed higher metastases and worse outcomes specifically in males with KRAS* CRC. Integrated cross-species molecular and transcriptomic analyses identified Y-chromosome gene histone demethylase KDM5D as a transcriptionally up-regulated gene driven by KRAS*-mediated activation of the STAT4 transcription factor. KDM5D-dependent chromatin mark and transcriptome changes showed repression of regulators of epithelial cell tight junction and MHC class I complex components. Deletion of KDM5D in iKAP cancer cells increased tight junction integrity, decreased cell invasiveness, and enhanced cancer cell killing by CD8+ T cells. Conversely, iAP mice engineered with a Kdm5d transgene to provide constitutive KDM5D expression specifically in iAP cancer cells exhibited an increased propensity for more invasive tumors in vivo. Thus, KRAS*-STAT4-mediated upregulation of Y chromosome KDM5D contributes significantly to the sex differences in KRAS* CRC via its disruption of cancer cell adhesion properties and tumor immunity, thus providing an actionable therapeutic strategy for metastasis risk reduction for men afflicted with KRAS* CRC.

Citation Format: Jiexi Li, Zhengdao Lan, Wenting Liao, James W. Horner, Jielin Liu, Shan Jiang, Hong S. Shim, Max Slotnik, Kyle A. LaBella, Wen-Hao Hsu, Denise J. Spring, Y. Alan Wang, Ronald A. DePinho. Histone demethylase KDM5D drives sex-specific differences in colorectal cancer [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr PR011.
Abstract A09: Immune checkpoint inhibitor-induced polyarthritis: a case series
Authors: Smith-Uffen Megan , Tselios Konstantinos
Published: December 2022

Background. Immune checkpoint inhibitors (ICIs) have revolutionized cancer care. However, their mechanism of action also results in the uncontrolled collateral of ICI-related adverse events (ICI-AEs). Polyarthritis is a rare ICI-AE. Here we describe two cases of ICI-induced polyarthritis, induced by nivolumab/ipilimumab and sasanlimab for melanoma and urothelial cancer, respectively. Methods/Results. A 64-year-old male received combination immunotherapy with nivolumab and ipilimumab for metastatic melanoma. Within one month of his second cycle of nivolumab alone, he developed polyarthritis of the small joints of the hands bilaterally, as well as the shoulders and knees; active synovitis; and erosive arthropathy on radiographic findings. He was successfully treated with prednisone at 20mg daily, gradually tapered over several months. A 43-year-old male with high-grade non-invasive urothelial cell carcinoma received two cycles of adjuvant sasanlimab. Within two months of his second treatment, he developed a large-joint polyarthritis involving the bilateral knees, ankles, elbows, and the cervical spine. His symptoms resolved with prednisone, initiated at 50mg daily with a recommended slow taper, however resurfaced five days after he abruptly ceased treatment. He was subsequently started on methotrexate in combination with prednisone. Both patients had a past medical history of non-rheumatological autoimmune disease, developed symptoms within 8 weeks of ICI, had elevated inflammatory markers and negative autoantibodies. Neither had to discontinue their cancer therapy and indeed both had a good tumour responses to their ICI. Both of our patients were initially well-managed prednisone. However, our second patient relapsed after abrupt cessation of his prednisone and required a combination of methotrexate with prednisone to control his symptoms. Conclusions. These cases add to the literature on ICI-induced polyarthritis, a rare ICI-AE. Clinical manifestations most commonly resemble rheumatoid arthritis, with bilateral inflammation of the small joints. Time to onset tends to be <12 weeks after ICI exposure, and repeated ICI exposure is a risk factor. Most patients have no personal or family history of autoimmune disease, negative autoantibodies, and can be managed well with glucocorticoids. As ICIs become more widely used, rheumatologists and oncologists alike should familiarise themselves with their adverse effects. More research is needed to understand the epidemiology, clinical presentation, and treatment of these adverse events.

Citation Format: Megan Smith-Uffen, Konstantinos Tselios. Immune checkpoint inhibitor-induced polyarthritis: a case series [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr A09.
Abstract A10: In vivo CRISPR screen reveals how to drive therapeutic T cell function to solid tumors
Authors: Hong Yeonsun , Kim Minsoo
Published: December 2022

Chimeric antigen receptor (CAR)-T cell therapy is emerging as a promising option for cancer immunotherapy. Although CAR-T cell therapy has excellent efficacy in the treatment of hematologic malignancies, it has largely failed in patients with solid tumors due to several problems, such as homing and trafficking. Here, we performed an in vivo targeted CRISPR-Cas9 screens to identify a molecular regulator of off-target trafficking of CAR-T cells, and identified ST3 b-galactoside a-2,3-sialyltransferase1 (St3gal1) as a major negative factor of CAR-T cells migration. Analysis of Maackia amurensis lectin-II immunoprecipitates revealed that CD18 in activated CD8+ T cells is the glycoproteins bearing the St3gal1-specific α2,3-sialylated glycans. Overexpression of St3gal1 in activated T cells induced glycosylation of lymphocyte function-associated antigen-1 (LFA-1), which inhibited endocytic recycling of LFA-1, leading to the nonspecific accumulation of T cells in the lungs. We checked that the expression of St3gal1 increased, and that of bII-spectrin, a key LFA-1 associated cytoskeleton molecule, decreased as T cells were activated. Engineered CAR-T cells with enhanced bII-spectrin expression showed decreased St3gal1 expression and induced a significant reduction in tumor growth in mice through improved tumor-specific homing. In addition, the expression level of bII-spectrinin anti-CD19 CAR-T cells injected in patients with large B-cell lymphomas correlated positively with patient response to treatment but negatively with systemic toxicity. Our findings suggest that St3gal1-bII-spectrin axis controls tissue-specific migration of therapeutic T cells delivered intravenously, which can improve tumor-specific homing of CAR-T cells in cancer immunotherapy.

Citation Format: Yeonsun Hong, Minsoo Kim. In vivo CRISPR screen reveals how to drive therapeutic T cell function to solid tumors [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr A10.
Abstract A15: Interaction between cancer-associated fibroblasts and apoptotic cancer cells inhibits the migration and invasion of lung cancer cells and cancer-associated fibroblasts preventing the development of metastasis
Authors: Kim Hee Ja , Yang Kyungwon , Kim Kiyoon , Kang Jihee Lee
Published: December 2022

The interplay between apoptotic cancer cells and the tumor microenvironment (TME) modulates cancer progression and metastasis. Cancer-associated fibroblasts (CAFs) play a crucial role in promoting these events through paracrine communication. In the present study, we investigated how the interaction of CAFs with apoptotic lung cancer cells modulates migration and invasion of cancer cells and CAFs. CAFs isolated from the lung tumors of Kras-mutant (KrasLA1) mice and ultraviolet-irradiated apoptotic cancer cells, including 344SQ (murine), A549 and HCT116 cells (human), were used for Transwell migration and invasion assays. Western blotting, real-time quantitative PCR, immunofluorescence staining, cytokine array, ELISA, and flow cytometry were used to assess TGFβ1 signaling pathways, CAF activation markers, Notch1 signaling pathways and phagocytosis. For in vivo study, apoptotic 344SQ cells with or without the Notch1 inhibitor LY3039478 were injected following subcutaneously injection of 344SQ cells into syngeneic (129/Sv) mice. In addition, conditioned medium (CM) derived from CAFs with or without neutralizing mouse anti-WISP-1 antibody or isotype IgG was administered via intratumoral injection. Interaction of lung CAFs and apoptotic cancer cells suppressed TGFb1-induced migration and invasion of cancer cells and CAFs. Enhanced secretion of Wnt-induced signaling protein 1 (WISP-1) by CAFs exposed to apoptotic 344SQ cells (ApoSQ) was required for these anti-migration and -invasion effects. Pharmacologic inhibition of Notch1 activation or siRNA-mediated Notch1 silencing prevented WISP-1 production by CAFs and reversed the anti-migration and -invasion effects. In addition, a single injection of ApoSQ enhanced WISP-1 production, suppressed expression of CAF activation markers in isolated Thy1+ CAFs, and inhibited lung metastasis in syngeneic immunocompetent mice via Notch1 signaling. Treatment with ApoSQ-exposed CAF CM suppressed lung metastasis, whereas WISP-1-immunodepleted ApoSQ-exposed CAF CM reversed the anti-metastatic effect.

Citation Format: Hee Ja Kim, Kyungwon Yang, Kiyoon Kim, Jihee Lee Kang. Interaction between cancer-associated fibroblasts and apoptotic cancer cells inhibits the migration and invasion of lung cancer cells and cancer-associated fibroblasts preventing the development of metastasis [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr A15.
Abstract A16: RIG-I-mediated cell death pathways activated by PAMP RNA in hepatic tumor cells
Authors: Ulloa Brittany , Gale Michael
Published: December 2022

Most malignant cells are poorly immunogenic and fail to elicit an effective antitumor response. However, some viral infections of cancer cells can trigger intracellular innate immune defenses that initiate cancer cell death, known as “oncolytic signaling.” Our lab has identified a viral pathogen associated molecular pattern (PAMP) RNA motif from the hepatitis C virus (HCV) genome that is recognized by the pathogen recognition receptor, retinoic acid-inducible gene I (RIG-I), to induce innate immune signaling when delivered to cells in a liposomal formulation. We found that PAMP RNA can direct RIG-I-dependent signaling to drive cell death in tumor cells, indicating that PAMP activation of the RIG-I pathway has applications for oncolytic destruction of tumors. However, the exact cell death pathways that are activated by PAMP are not clearly defined. We hypothesize that PAMP activates a RIG-I-mediated form of apoptosis and that cancer cells are more susceptible than non-cancer cells to death by this apoptotic pathway. In vitro studies using CRISPR knockout cell lines confirmed that PAMP-induced cell death signaling requires RIG-I, mitochondrial antiviral-signaling protein (MAVS), and interferon regulatory factor 3 (IRF3). Further, our analyses show that PAMP-induced cell death is regulated by type 1 interferon, and that cell death outcomes can be blocked by treatment of cells with caspase inhibitor. Thus, PAMP-induced RIG-I signaling triggers cell death through linkage with caspase signaling. This research will define cell death pathways activated by PAMP and RIG-I signaling by interrogating multiple cell death programs and will reveal the potential of designing antitumor therapeutics leveraging PAMP.

Citation Format: Brittany Ulloa, Michael Gale. RIG-I-mediated cell death pathways activated by PAMP RNA in hepatic tumor cells [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr A16.
Abstract A21: Virtual clinical trials: a tool for identifying patients who benefit from treatment beyond progression with pembrolizumab in NSCLC
Authors: Qi Timothy , Cao Yanguang
Published: December 2022

Background: Enrolling patients in immunotherapy clinical trials is becoming increasingly competitive. Virtual clinical trials can help investigators answer key questions despite this. For example, pembrolizumab is the recommended first-line treatment for non-small cell lung cancer (NSCLC) with no driver alterations and PD-L1 Tumor Proportion Score (TPS) ≥ 50%. Salvage therapies for relapsed/refractory patients are limited. Retrospective studies suggest a subset of patients may benefit from pembrolizumab treatment beyond progression (TBP); these results have not been validated in a prospective study. Methods: We constructed digital twins of patients and enrolled them in virtual clinical trials to identify the best salvage therapy after progressive disease (PD) on pembrolizumab. Response dynamics were evaluated at the lesion level to represent patients who experience systemic PD while individual lesions are still shrinking. With > 25,000 radiographic lesion measurements from > 500 patients, we simulated responses to pembrolizumab, chemotherapy, and PD on pembrolizumab followed by either pembrolizumab TBP or salvage chemotherapy. We then assessed combination pembrolizumab and chemotherapy to explore a possible mechanism of intrapatient drug synergy called lesion-level independent action (LLIA).Results: Switching all progressors to salvage chemotherapy was suboptimal. Virtual trials identified a subset of patients with fewer baseline lesions who experienced longer progression-free survival (PFS) and disease control on pembrolizumab TBP. Combination therapy under LLIA but not patient-level independent action (PLIA) yielded longer PFS.Conclusions: Pembrolizumab TBP may benefit a subset of patients with PD-L1-high, driver alteration-free NSCLC, but prospective studies are warranted. LLIA may be an important consideration for future clinical investigation.

Citation Format: Timothy Qi, Yanguang Cao. Virtual clinical trials: a tool for identifying patients who benefit from treatment beyond progression with pembrolizumab in NSCLC [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr A21.
Abstract A32: GIGA-564, a third generation anti-CTLA-4 with minimal ability to block CTLA-4 binding to B7 ligands, has enhanced efficacy but reduced toxicity compared to ipilimumab in pre-clinical models
Authors: Stone Erica L , Carter Kyle P , Wagner Ellen K , Asensio Michael A , Benzie Emily , Chiang Yao Yuan , Coles Garry L , Edgar Chelsea , Gautam Bishal K , Gras Ashley , Leong Jackson , Leong Renee , Manickam Vishal A , Mizrahi Rena A , Niedecken Ariel R , Saini Jasmeen , Sandhu Savreet K , Simons Jan Fredrick , Stadtmiller Kacy , Tinsley Brendan , Tracy LaRee , Wayham Nicholas P , Lim Yoong Wearn , Adler Adam S , Johnson David S
Published: December 2022

Anti-CTLA-4 antibodies such as ipilimumab were among the first immuno-oncology agents to show significantly improved outcomes for patients. However, existing anti-CTLA-4 therapies fail to induce a response in a majority of patients and can induce severe, immune-related adverse events. It has been assumed that checkpoint inhibition, i.e., blocking the interaction between CTLA-4 and its ligands, is the primary mechanism of action for ipilimumab. Here we present evidence that checkpoint inhibition may not be the primary mechanism of action for efficacy of anti-CTLA-4 antibodies. Instead, the primary mechanism for efficacy may be FcR-mediated Treg depletion in the tumor microenvironment. First, we identified a monoclonal antibody (mAb), GIGA-564, that binds to CTLA-4 at an epitope that differs from ipilimumab’s by only a few amino acids, yet has limited checkpoint inhibitor activity. Surprisingly, GIGA-564 has superior anti-tumor activity compared to ipilimumab in a murine model. GIGA-564 also induces less Treg proliferation and has increased ability to induce in vitro FcR signaling and in vivo depletion of intratumoral Tregs. Further experiments showed that the enhanced FcR activity of GIGA-564 likely contributes to its enhanced anti-tumor activity. Importantly, we also showed that GIGA-564 was associated with lower toxicity in murine models. Our work suggests that new anti-CTLA-4 drugs should be optimized for Treg depletion rather than checkpoint inhibition.

Citation Format: Erica L Stone, Kyle P Carter, Ellen K Wagner, Michael A Asensio, Emily Benzie, Yao Yuan Chiang, Garry L Coles, Chelsea Edgar, Bishal K Gautam, Ashley Gras, Jackson Leong, Renee Leong, Vishal A Manickam, Rena A Mizrahi, Ariel R Niedecken, Jasmeen Saini, Savreet K Sandhu, Jan Fredrick Simons, Kacy Stadtmiller, Brendan Tinsley, LaRee Tracy, Nicholas P Wayham, Yoong Wearn Lim, Adam S Adler, David S Johnson. GIGA-564, a third generation anti-CTLA-4 with minimal ability to block CTLA-4 binding to B7 ligands, has enhanced efficacy but reduced toxicity compared to ipilimumab in pre-clinical models [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr A32.
Abstract A34: Therapeutic induction of High Endothelial Venules in cancer generates TCF1+ lymphocyte niches
Authors: Vella Gerlanda , Hua Yichao , Rambow Florian , Allen Elizabeth , Martinez Asier Antoranz , Merchiers Pascal , Bosisio Francesca , Floris Giuseppe , Takeda Akira , Jalkanen Sirpa , Hollmén Maija , Marine Jean-Christophe , Schlenner Susan , Bergers Gabriele
Published: December 2022

The lack of T-cell infiltrates is a major obstacle to effective immunotherapy in cancer. Conversely, the formation of tumor-associated tertiary-lymphoid-like structures (TA-TLS), which are the local site of humoral and cellular immune responses against cancers, are associated with good prognosis and have recently been detected in Immune Checkpoint Blockade (ICB)-responding patients. However, how these lymphoid aggregates develop remains poorly understood. By employing scRNA sequencing, endothelial fate mapping, and multiplex immunohistochemistry, we demonstrate that antiangiogenic immune-modulating therapies evoke the transition of postcapillary venules into inflamed high endothelial venules (HEV), which predominantly generate permissive TA-TLS-like lymphocyte niches. These HEV+ immune niches entail PD1neg and PD1+TCF1+CD8+ progenitor cells that differentiate into cytotoxic TCF1neg TIM3+ PD1+ CD8 effector cells and migrate into the tumor core. Congruently, TU-HEV signatures correlate with response to ICB therapies in several human tumor types. In line with these observations, TU-HEVs require continuous CD8 and NK cell-derived lymphotoxin signals revealing that tumor-HEV maintenance is actively sculpted by the immune system through a feed-forward loop.

Citation Format: Gerlanda Vella, Yichao Hua, Florian Rambow, Elizabeth Allen, Asier Antoranz Martinez, Pascal Merchiers, Francesca Bosisio, Giuseppe Floris, Akira Takeda, Sirpa Jalkanen, Maija Hollmén, Jean-Christophe Marine, Susan Schlenner, Gabriele Bergers. Therapeutic induction of High Endothelial Venules in cancer generates TCF1+ lymphocyte niches [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr A34.
Abstract A46: Neoantigen-driven B and T follicular helper cell collaboration promotes anti-tumor CD8 T cell responses
Authors: Cui Can , Craft Joseph , Joshi Nikhil S.
Published: December 2022

CD4 T follicular helper (TFH) cells and B cells are essential components of germinal center (GC) response, but the importance and mechanisms of TFH-B cell collaborations in malignancy are unclear. The presence of TFH, B cells and GC has been associated with favorable clinical outcomes and improved therapeutic responses to checkpoint blockade immunotherapy in numerous types of solid tumors. We found enrichment of TFH cell transcriptional signature correlates with prolonged survival in lung adenocarcinoma (LUAD) individuals. To further investigate if and how TFH-B cell interactions elicit protective anti-tumor responses, we developed the KP-HELLO murine lung adenocarcinoma model, in which tumor cells expressed B-cell- and T-cell-recognized neoantigens (HEL, LCMV GP33-43/FLAG/GP61-80, and codon-Optimized mScarlet). Collaborations between tumor-specific TFH and B cells, as well as interleukin (IL)-21 primarily produced by TFH cells, are necessary for tumor control and effector CD8 T cell function. Development of TFH cells and IL-21 production requires B cells and B cell-recognized neoantigens. We demonstrated that tumor neoantigens can educate the differentiation of tumor-specific CD4 T cells and regulate their fate by facilitating their interactions with tumor-specific B cells, which in turn promote anti-tumor immunity by enhancing CD8 T cell effector functions.

Citation Format: Can Cui, Joseph Craft, Nikhil S. Joshi. Neoantigen-driven B and T follicular helper cell collaboration promotes anti-tumor CD8 T cell responses [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr A46.
Abstract A52: PD-1High CAR T cells exhibit superior homing, retention, and function in solid tumors
Authors: Sailer Cooper , Hong Yeonsun , Reagan Patrick , Kim Minsoo
Published: December 2022

Chimeric antigen receptor (CAR)-T cell has emerged a promising treatment option for several cancers, with six FDA-approved therapies for hematologic malignancies. However, patients with solid tumors largely fail to respond to CAR T cell therapy due to T cell exhaustion, associated with impaired CAR T cell functions and strong immunosuppressive microenvironment at the tumor site. There are currently no FDA-approved CAR T cell therapies for solid tumors, which make up the vast majority of cancer cases. Here, we found that both murine and human CAR T cells manufactured ex vivo displayed phenotypic signs of terminal exhaustion and developed heterogeneous expression levels of PD-1 (i.e. PD1high and PD1low CAR T cells). Surprisingly, PD1high CAR T cells outperformed PD1low CAR T cells in multiple T cell function and anti-cancer activity assays both in vitro and in vivo, where PD1high CAR T cells exhibited heightened target tumor-cell killing and engagement, and also increased homing and retention within tumors. We show that the increased retention of PD1high cells in the tumor is independent of the PD1/PD-L1 signaling axis. The superior anti-cancer function of PD1high CAR T cells was closely associated with the elevated production of interferon gamma (IFNg) in PD1high cells. We further revealed that IFNg secreted from PD1high CAR T cells played an important role in actively regulating the tumor microenvironment by inducing ICAM-1 expression. In conclusion, our data identifies PD1high CAR T cell as a subset of clinically manufactured CAR T cells with improved anti-cancer functions. Our data supports the emerging notion that CAR T cells may interact differently between solid and liquid cancers, and suggests a unique T cell phenotype may be required to maximize solid tumor adoptive cell transfer therapies.

Citation Format: Cooper Sailer, Yeonsun Hong, Patrick Reagan, Minsoo Kim. PD-1High CAR T cells exhibit superior homing, retention, and function in solid tumors [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr A52.
Abstract A67: CD40 agonism inhibits tumor growth in murine hormone receptor positive breast cancer via CD8 T cells
Authors: Zhang Jennifer , Lanchoney Olivia , Joshi Nikhil , Markosyan Nune , Vonderheide Robert
Published: December 2022

Breast cancer is the second most common malignancy affecting women and accounts for 15% of cancer-related mortality globally. Over 70% of breast cancers are hormone receptor (HR) positive (estrogen receptor and/or progesterone receptor positive) and human epidermal growth factor receptor 2 negative (HER2-). HR+HER2- breast cancers are poorly responsive to chemotherapy and recurrence and mortality remain high for patients with locally advanced disease. Thus, more therapeutic strategies are needed. Dendritic cell (DC) activation is an important pathway for T cell priming and subsequent improvements in immunosurveillance. In this study, we determined the ability of DC-targeted therapy with agonistic CD40 antibody to restore anti-tumor immunologic function in a murine orthotopic HR+HER2- breast cancer model. The Brpkp110 cell line was injected orthotopically into the abdominal mammary glands of 8 to 10-week-old C57BL/6 mice. Tumor-bearing mice treated with agonistic CD40 antibody (FGK4.5, 100 ug intraperitoneal) demonstrated decreased tumor growth and increased intratumoral CD8 T cells at 2 weeks. Both intratumoral DCs and tumor-associated macrophages in mice treated with agonistic CD40 were found to upregulate PD-L1 and CD40. CD8 T cell depletion abrogated the anti-tumor effect of agonistic CD40. Our data suggest that agonistic CD40 therapy may be a viable strategy for tumor inhibition and activation of anti-tumor immunity in HR+HER2- breast cancer.

Citation Format: Jennifer Zhang, Olivia Lanchoney, Nikhil Joshi, Nune Markosyan, Robert Vonderheide. CD40 agonism inhibits tumor growth in murine hormone receptor positive breast cancer via CD8 T cells [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr A67.
Abstract B58: B cells modulate T cell infiltration in a preclinical model of HPV+ oropharyngeal cancer
Authors: Dorta-Estremera Stephanie M , Ortíz Jorge R Galán , del Valle Kamila A Andino , Rosario Abelardo A Perez , Rivera Jennifer Díaz , Castañón Daniel
Published: December 2022

Programmed Death-1 (PD-1) blockade has been FDA approved to treat head and neck squamous cell carcinoma (HNSCC), however, less than 30% of patients respond. Among the different immune cells present within tumors, B cells also infiltrate HPV+ HNSCC and different B cell subsets may exert opposite functions in tumor development. Therefore, fine regulation of anti-tumor and tumor-promoting B cell subsets is necessary to promote an effective anti-tumor response and therefore prevent tumor progression. However, the role of B cells during PD-1 blockade in HPV+ oropharyngeal cancer needs to be better defined. By using the preclinical mouse model for HPV+ oropharyngeal cancer (named mEER), we have determined that tongue-implanted tumors are sensitive to anti-PD-1, where around 50% of the mice clear the tumors, whereas flank-implanted tumors are completely resistant to these treatments. By using this in vivo model, we characterized B cells within tumors and during anti-PD-1 therapy by flow cytometry and determined whether B cell deficiency (µMt) affected tumor growth. We determined that tongue-implanted tumors (sensitive) contained high infiltration of CD8+ T cells and low infiltration of B cells whereas flank-implanted tumors contained (resistant) high frequency of B cells compared to T cells. Interestingly, when we compared tongue tumor-bearing mice treated with anti-PD-1, we observed that tumors that responded to the therapy contained more T cells and B cells than the ones that did not respond. B cell-deficient mice showed a slower tumor growth rate and longer survival compared to wild-type (WT) mice, however, treatment with PD-1 blockade did not affect tumor growth when comparing WT vs. µMt. B cell deficiency increased CD8+ T cell infiltration however, PD-1 blockade also increased regulatory T cells. Our data suggest that B cells modulate T cell infiltration and therefore affect tumor development. Also, PD-1 blockade affects different regulatory immune cell types, therefore, affecting its efficacy. Identification of B cell subsets and their functions within tumors may better predict responsiveness to PD-1 blockade in HPV+ HNSCC patients.

Citation Format: Stephanie M Dorta-Estremera, Jorge R Galán Ortíz, Kamila A Andino del Valle, Abelardo A Perez Rosario, Jennifer Díaz Rivera, Daniel Castañón. B cells modulate T cell infiltration in a preclinical model of HPV+ oropharyngeal cancer [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr B58.
Abstract B66: Superiority of dual IDO1/TDO2 inhibition versus IDO1 selective inhibition in reducing immunosuppressive KYN levels in tumors co-expressing IDO1 and TDO2
Authors: Lotz-Jenne Carina , Cren Sylvaine , Joesch Christoph , Ackerknecht Sabine , Brandes Jennifer , Moebs Claire , Hartl Dominik , Hartrampf Felix , Guerry Philippe , Pothier Julien , Chavanton-Arpel Alexia
Published: December 2022

Indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO2) catalyze the oxidation of L-Tryptophan (TRP) leading to the formation of immunosuppressive kynurenine (KYN) pathway metabolites. According to TCGA, a substantial fraction of different tumor types express both IDO1 and TDO2. In 82 tumor samples (GBM, hepatocellular carcinoma, NSCLC, and ovarian cancer) analyzed for IDO1/TDO2 RNA expression (RNA sequencing) and TRP metabolite content (LC-MS/MS), we found TDO2 highly expressed in hepatocellular carcinoma and to lower levels in NSCLC and ovarian cancer. IDO1 was found to be expressed in NSCLC and ovarian cancer but at higher levels and its expression was correlating with KYN levels. Immunosuppressive properties of KYN and downstream metabolites are mediated through T cell apoptosis and regulatory T cell (Treg) induction. In our hands, KYN at concentrations ≥ 50uM was shown to be immunosuppressive, notably inducing T cell apoptosis. According to our and published data, such high KYN concentrations (≥ 50uM) can be found in a subset of human tumors. As outlined, both IDO1 and TDO2 can contribute to high KYN levels in tumors. Hence, dual IDO1/TDO2 inhibition should be superior in decreasing tumor KYN levels and levering immunosuppression as compared to IDO1 selective inhibition. In this regard, we have generated potent dual IDO1/TDO2 inhibitors inhibiting IDO1 and TDO2 enzyme activity in cellular assays in vitro. To proof the concept of superiority in vivo, we established a dual IDO1/TDO2 expressing human tumor model (LOVO+IFNg) in the mouse and showed that the oral administration of a dual IDO1/TDO2 inhibitor as compared to an IDO1 selective inhibitor showed enhanced KYN/TRP modulation in the tumor. Lead compounds with favorable drug-like properties are currently investigated for pre-clinical development.

Citation Format: Carina Lotz-Jenne, Sylvaine Cren, Christoph Joesch, Sabine Ackerknecht, Jennifer Brandes, Claire Moebs, Dominik Hartl, Felix Hartrampf, Philippe Guerry, Julien Pothier, Alexia Chavanton-Arpel. Superiority of dual IDO1/TDO2 inhibition versus IDO1 selective inhibition in reducing immunosuppressive KYN levels in tumors co-expressing IDO1 and TDO2 [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr B66.