bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2737: Clinical and epidemiologic predictors of clonal immune responses in colorectal cancer
Authors: Gruber Stephen B. , Bonner Joseph D. , Lindsey Sidney S. , Tsai Ya-Yu , Sanz-Pamplona Rebeca , Alonso M. Henar , Melas Marilena , Rennert Hedy S. , McDonnell Kevin J. , Idos Gregory E. , Walker Christopher P. , Kast W. Martin , Da Silva Diane , Robins Harlan S. , Greenson Joel K. , Moreno Victor , Schmit Stephanie L. , Rennert Gad
Published: July 2021

The quantity and quality of immune responses in colorectal cancers (CRC) are widely variable and have important clinical, therapeutic, and prognostic implications. We studied clinical and epidemiologic factors that might influence T-cell quantity and clonality within colorectal adenocarcinomas to better understand the drivers of diverse immune responses. Incident cases of CRC from the Molecular Epidemiology of Colorectal Cancer Study (MECC) were interviewed, and 6,006 cases had complete epidemiologic data. Archived tumor blocks were retrieved from 3,865 (64.4%) cases, and all were reviewed by a single expert pathologist who quantified TILS/hpf. Sufficient tissue for macrodissection and measurement of TCR abundance and clonality using the immunoSEQ assay (Adaptive Biotechnologies) was available and completed for 2,750 cases. Logistic regression, negative binomial regression and linear regression models were used to evaluate potential associations between clinical and epidemiologic variables for: TILS/hpf, TCR abundance, and T-cell clonality. The stage distribution was representative of cancer incidence in the population, and the MSI-H phenotype was observed in 14.2% of cases. Clinical, pathologic, and epidemiologic variables including aspirin, alcohol, diet, hormone use, physical activity, smoking, and statins were assessed in relation to immune measures. Among other findings, >5 years of statins (p<0.001) and daily aspirin (p=0.037) were each strongly associated with T-cell clonality. Our study suggests that important parameters of the adaptive immune response may be mediated by modifiable factors. Mechanisms regulating immune responses in CRC may have implications for chemoprevention as well as immunotherapy.

Citation Format: Stephen B. Gruber, Joseph D. Bonner, Sidney S. Lindsey, Ya-Yu Tsai, Rebeca Sanz-Pamplona, M. Henar Alonso, Marilena Melas, Hedy S. Rennert, Kevin J. McDonnell, Gregory E. Idos, Christopher P. Walker, W. Martin Kast, Diane Da Silva, Harlan S. Robins, Joel K. Greenson, Victor Moreno, Stephanie L. Schmit, Gad Rennert. Clinical and epidemiologic predictors of clonal immune responses in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2737.
Abstract 2745: Murine high grade serous ovarian cancer (HGSOC) models replicate the human tumor microenvironment and suggest anti-tumor activities of macrophages after chemotherapy
Authors: Berlato Chiara , Heath Owen , Maniati Eleni , Gopinathan Ganga , Kotantaki Panoraia , Elorbany Samar , McDermott Jacqueline , Pegrum Colin , Szabova Ludmila , Perets Ruth , Drapkin Ronny , Bailey Peter , Annibaldi Alessandro , Barton Desmond P. , Balkwill Frances R.
Published: July 2021

The aim of this study is to characterize and validate similarities between the human tumor microenvironment (TME) and the TME of new HGSOC murine models and to use the models to analyze the role of tumor associated macrophages (TAMs) after chemotherapy. HGSOC has seen in the past decades only a modest reduction of mortality. This is in part due to the lack of suitable models, as the origin and mutation patterns of HGSOC were not previously understood. Despite recent advances with organoid models, murine models that represent the TME and in particular the complex interactions with the immune system are needed. We characterized the TME of six orthotopic, transplantable syngeneic murine HGSOC lines established from tumors in genetic models and compared these to patient biopsies. This analysis identified significant correlations between the transcriptome, host cell infiltrates, immune response, matrisome, vasculature and tissue modulus of mouse and human TMEs, with several stromal and malignant cell targets in common. However, each model also showed distinct differences and potential vulnerabilities that will enable us to study potential therapies. These models allowed us to extend our understanding of the role of TAMs following chemotherapy. Chemotherapy reduced the number and changed the phenotype of TAMs both in patient biopsies and in mouse models. Following chemotherapy, inflammasome activation in TAMs was also observed. Depletion of TAMs with CSFR1 inhibitors after carboplatin treatment reduced survival in a mouse model, suggesting that chemotherapy can activate sub-populations of macrophages to an anti-tumor phenotype that can sustain adaptive immunity. In conclusion, we have characterized murine transplantable models that share similarities with human HGSOC and have helped us elucidate the anti-tumor role of TAMs once activated by chemotherapy.

Citation Format: Chiara Berlato, Owen Heath, Eleni Maniati, Ganga Gopinathan, Panoraia Kotantaki, Samar Elorbany, Jacqueline McDermott, Colin Pegrum, Ludmila Szabova, Ruth Perets, Ronny Drapkin, Peter Bailey, Alessandro Annibaldi, Desmond P. Barton, Frances R. Balkwill. Murine high grade serous ovarian cancer (HGSOC) models replicate the human tumor microenvironment and suggest anti-tumor activities of macrophages after chemotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2745.
Abstract 2793: The role of IL-10 in obesity-induced T-cell polarization in the prostate tumor microenvironment
Authors: Kappel Margaret , Adkison Michael , De Angulo Alejandra , Travis Peyton , Harlow Brittany , Jolly Christopher , deGraffenried Linda
Published: July 2021

Background: Prostate cancer remains the second leading cause of cancer related deaths in men and obesity has been shown to severely impact its prognosis. Previous studies in our laboratory have shown that CD4+ T cells polarized under obese conditions are prostate cancer promoting and that this is due in part to suppression of IFNγ and induction of IL-6 in the T cells.

Objective: The goal of this study is to determine the role of IL-10 in mediating the impact of obese conditions on T cell phenotype.

Methods: A series of in vitro studies were conducted to evaluate the effects of obesity on T cell function and polarization. Splenic CD4+ T-cells from 10-week-old, male, C57BI/6 mice were isolated and stimulated with anti-CD3+/CD28+ antibodies under obese conditions. Gene expression was measured using qPCR and AKT phosphorylation was measured using Western blot analysis. In vivo T-cell function was compared between obese and non-obese male mice. Deletion assays were used to determine the role of IL-10 in mediating the effects observed on T cell phenotype in response to obese conditions.

Results: For both the in vitro and in vivo studies, obese conditions suppressed the expression of Th1 biomarkers (IFNγ, IL-2, and T-bet) and upregulated the expression of Th2 biomarkers (IL-6, IL-10, and GATA-3) in CD4+ T cells. Likewise, obese conditions in vitro and in vivo were associated with decreased AKT phosphorylation. Studies are on-going to determine whether inhibiting the IL-10 pathway restores proper T cell activation under obese conditions.

Conclusion: Obesity induces T cell dysfunction characterized by a Th1 to Th2 phenotypic shift, resulting in a pro-tumorigenic phenotype, potentially mediated by paracrine IL-10 signaling. These results are important in understanding the mechanisms by which obesity promotes a more aggressive disease, thereby identifying potential targets for improving outcomes. The results from these studies will provide a better understanding of the role of IL-10 as a novel target for preventing prostate cancer in obese subjects and improving overall survival.

Citation Format: Margaret Kappel, Michael Adkison, Alejandra De Angulo, Peyton Travis, Brittany Harlow, Christopher Jolly, Linda deGraffenried. The role of IL-10 in obesity-induced T-cell polarization in the prostate tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2793.
Abstract 2818: In vivo imaging of mitochondrial bioenergetics in lung cancer
Authors: Han Mingqi , Momcilovic Milica , Bushong Eric , Stiles Linsey , Shirihai Orian , Koehler Carla , Sadeghi Saman , Ellisman Mark , Shackelford David B.
Published: July 2021

Non-small cell lung cancer (NSCLC) is a histologically, genetically and metabolically heterogeneous disease. The mitochondria are essential regulators of cellular energy and metabolism and they play a critical role in sustaining growth and survival of lung tumor cells. However, our understanding of mitochondrial metabolism in cancer at an in vivo level has been limited thus leaving a large gap in our knowledge of how mitochondrial bioenergetics support tumor growth. To better study mitochondrial bioenergetics in lung tumors, we recently developed and validated a voltage sensitive, positron emission tomography (PET) tracer known as 4-[18F]fluorobenzyl triphenylphosphonium (18FBnTP) that we used to profile mitochondrial bioenergetics in autochthonous K-Ras driven mouse models of lung cancer (Momcilovic et al., (2019) Nature). The use of 18FBnTP PET imaging enabled us to functionally profile mitochondrial bioenergetics in live tumors and discover distinct functional mitochondrial heterogeneity conserved across different NSCLC tumor subtypes. In order to study mitochondria at the level of ultrastructure we coupled 18FBnTP PET with 3D serial block-face scanning electron microscopy (3D SBEM). By coupling these two techniques we are able to image and quantify mitochondria heterogeneity from whole tumors down to the ultrastructures of individual mitochondria within tumor cells. Our study reveals distinct organization of mitochondrial structure and function as lung tumors adapt during tumorigenesis. We anticipate that coupling 18FBnTP PET imaging with 3D SBEM will have dynamic applications beyond that of lung cancer and enrich our understanding how mitochondria impact human disease.

Citation Format: Mingqi Han, Milica Momcilovic, Eric Bushong, Linsey Stiles, Orian Shirihai, Carla Koehler, Saman Sadeghi, Mark Ellisman, David B. Shackelford. In vivo imaging of mitochondrial bioenergetics in lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2818.
Abstract 2827: Inactivating calcium-sensing receptor polymorphisms at rs1801725 are associated with increased risk of secondary malignancies
Authors: Beasley Heather K. , Actkins Ky'Era V. , Faucon Annika B. , Davis Lea K. , Sakwe Amos M.
Published: July 2021

The dysregulation of systemic calcium homeostasis during malignancy is common in most patients with high-grade tumors. The associated comorbidity is known as cancer-induced hypercalcemia (CIH) which affects up to 30% of cases, in the absence of metastasis. In the course of breast cancer progression, the secretion of parathyroid hormone-related protein (PTHrP) by tumor cells and the associated destruction of bone tissues, leads to a progressive increase in systemic calcium or CIH. The increase in circulating Ca2+ is sensed by the calcium-sensing receptor (CaSR), which plays a significant role in maintaining Ca2+ homeostasis. More than 200 mutations and single nucleotide polymorphisms (SNPs) in the CaSR gene have been described, including the A986S CaSR at rs1801725 and Q1011E CaSR at rs1801726 SNPs with reduced sensitivity to Ca2+. Interestingly, high circulating Ca2+ is associated with aggressive breast tumors in premenopausal women and larger tumors in postmenopausal women; however, the contribution of the CaSR in breast cancer progression remains poorly understood. Unlike SNPs at rs1801726, up to 20% of breast cancer patients with SNPs at rs1801725 may be predisposed to higher circulating Ca2+ in the course of their disease. Since breast cancer frequently metastasizes to Ca2+ rich skeletal tissues, we hypothesize that the development of CIH and subsequent desensitization of the CaSR by sustained high Ca2+ is critical for both the adaptation of TNBC cells to CIH in Ca2+ rich microenvironments and TNBC progression. Our preliminary data reveal that the expression level and mutational status of the CaSR is cell type-specific, and that sustained high Ca2+ desensitizes the receptor, but promotes tumor cell growth and motility. In addition, our preliminary data show that the A986S SNP is associated with hypercalcemia, secondary malignancy of bone and respiratory organs, and deficiency of humoral immunity. This study provides novel insights into not only the adaptation of TNBC cells to high circulating Ca2+, but also suggests that mutations of the CaSR at rs1801725 are predictive of the likelihood for metastasis to lungs and bone.

Citation Format: Heather K. Beasley, Ky'Era V. Actkins, Annika B. Faucon, Lea K. Davis, Amos M. Sakwe. Inactivating calcium-sensing receptor polymorphisms at rs1801725 are associated with increased risk of secondary malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2827.
Abstract 283: Target cell-derived, G401-CLENs for selective delivery of model therapeutics to rhabdoid tumors
Authors: Bourdeau Lindsay , Cruz Carlos , Williams Taylor
Published: July 2021

One of the rarest and most aggressive pediatric cancers to date is the malignant rhabdoid tumor (MRT), maintaining a survival rate of 16%. Considered a renal cancer, approximately 20-25 new cases are diagnosed in the USA each year, with the average age of diagnosis being about 11 months old. Conventional strategies for treating MRT are limited due to several factors including off-target associated toxicities, patient population, age, metastasis to brain tissue, and diminished survival rates. CLENs (cell membrane lipid-extracted nanoliposomes), a novel drug delivery system, was previously developed and evaluated for selective delivery of cytotoxic drug agents to breast cancer cells and compared to more conventional liposomes. The purpose of this investigation was to optimize and characterize G401-CLENs for selective targeting and delivery of model payloads to a cellular model of rhabdoid tumors. The MRT cell line (G-401 [G401] (ATCC® CRL-1441™) was cultured in McCoy's 5A Medium (ATCC® 30-2007™), supplemented by 10% FBS. The G401 cellular lipid materials (otherwise known as lipid extracts (LE)) were derived from G401 cells. Follow up studies include the incorporation of G401-LE in liposomes to form G401-CLENs. For development, special consideration was given to distinct determinants of targeting (i.e., particle size and zeta potential) and cellular uptake by G401-CLENs. Other analyses include a comparison of delivery of model and functional siRNA (BRD9 Silencer Select Pre-designed, siRNA ID s35295, Ambion) to G401 target cells using G401-CLENs, and conventional nano-preparations in vitro. G401-LE cell membrane components were extracted from rhabdoid G401 cells. On-going physiochemical characterization studies of G401-CLENs and functional in vitro and fluorescence microscopic analyses are currently underway.

Citation Format: Lindsay Bourdeau, Carlos Cruz, Taylor Williams. Target cell-derived, G401-CLENs for selective delivery of model therapeutics to rhabdoid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 283.
Abstract 2831: Exosome gene signatures characterize metastatic dynamicity
Authors: Gonda Amber , Shah Jay V. , Siebert Jake N. , Zhao Nanxia , Kwon Mi Jung , Moghe Prabhas V. , Francis Nicola , Ganapathy Vidya
Published: July 2021

Early diagnosis and effective tumor monitoring can significantly alter clinical outcomes of ovarian cancer patients. Innovative tools are needed to enhance the sensitivity and specificity of current monitoring modalities. Extracellular vesicles, or exosomes, have shown to be promising conduits of diagnostic biomarkers to aid in tumor detection as evidenced by Exosome Diagnostics' new ExoDx Prostate (IntelliScore) test that uses exosomal markers to differentiate between benign prostate disease and early cancer (Tutrone, R., Donovan, M.J., Torkler, P. et al. Clinical utility of the exosome based ExoDx Prostate(IntelliScore) EPI test in men presenting for initial Biopsy with a PSA 2-10 ng/mL. Prostate Cancer Prostatic Dis 23, 607-614 (2020)). The potential of these vesicles however goes beyond simple diagnostic power of cancer detection. Due to the onco-specific contents packaged and the minimally invasive, low risk accessibility, exosomes have the capacity to be used as longitudinal monitoring tools to characterize early molecular changes at all stages of the disease. We hypothesized that the dynamicity of ovarian tumors during progression and metastatic development is reflected in exosomes. In order to test this we isolated exosomes and used qPCR to analyze exosomal gene signatures from a mouse model of ovarian cancer. SKOV3 ovarian cancer tumor cells were injected into mice and allowed to grow for 3 weeks. Plasma was collected from mice at 5-7 day increments and exosomes were extracted. Multiple established metastatic genes in ovarian cancer were evaluated and 4 genes, Lox, THBS1, TIMP3, and β-actin, were found to be differentially expressed in correlation with 3 translationally pertinent assessments: presence or absence of tumors, levels of metastatic burden, and longitudinal tumor progression. Gene expression patterns were compared with exosomal gene signatures extracted from human ovarian patient plasma and found to express similar patterns. These results support the diagnostic potential of using exosomal genetic signatures to detect early metastatic development and to facilitate longitudinal tracking of tumor progression.

Citation Format: Amber Gonda, Jay V. Shah, Jake N. Siebert, Nanxia Zhao, Mi Jung Kwon, Prabhas V. Moghe, Nicola Francis, Vidya Ganapathy. Exosome gene signatures characterize metastatic dynamicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2831.
Abstract 2836: Effect of autophagy inhibition on epithelial mesenchymal transition in breast cancer cell lines
Authors: Rojas Guadalupe , Pazos Nidia , Maycotte Paola
Published: July 2021

The aim of our work is to evaluate potential undesirable effects of autophagy inhibition in breast cancer subtypes which are not sensitive to the inhibition of autophagy. Worldwide, BC is the most frequent cancer in women. Despite recent advances in diagnosis, molecular stratification and targeted therapy, BC is still the leading cause of cancer-related death in women. Thus, it is a public health issue that must be attended. In cancer, autophagy has a pro-tumorigenic role that helps tumor cells survive metabolic stress and growth factor deprivation, hypoxia, maintain tumor initiating cells, confer therapy resistance and modulate epithelial mesenchymal transition (EMT). Because tumor cells benefit from autophagy, it has been proposed that autophagy inhibition could be beneficial for cancer treatment. Nowadays, there are clinical trials where autophagy is being inhibited with promising results that encourage this approach. However, in these clinical trials, cancer types are not been stratified and autophagy is being inhibited in many solid tumor types. In this regard, there is also in vitro evidence in which autophagy inhibition in some cancer types induces EMT, which in the clinic could be detrimental for patients. This highlights the urgency for stratifying patients that will benefit the most from autophagy inhibition. In this work, autophagy inhibition in MCF7 ER+ cell line increased secretion, inflammation and EMT related pathways suggesting induction of malignancy. Autophagy inhibition induced changes in cell morphology in ER+ breast cancer cell lines (MCF7 and T47D) when evaluated by aspect ratio estimation changing from a cobblestone -like epithelial morphology to a fibroblast-like morphology. No changes in cell morphology were found in MCF10A and MDAMB231 cell lines. Changes in morphology were accompanied by a decrease in E-cadherin protein levels suggesting induction of EMT. Our results suggest that CQ treatment in ER+ BC cells could induce a malignant process related to EMT. Thus, ER+ BC patients may not benefit from autophagy inhibition. Nowadays, there are clinical trials where autophagy is being inhibited and no subtype stratification is being done, so we encourage to stratify patients to determine who will be benefited the most from autophagy inhibition and who will not.

Citation Format: Guadalupe Rojas, Nidia Pazos, Paola Maycotte. Effect of autophagy inhibition on epithelial mesenchymal transition in breast cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2836.
Abstract 2837: NR2F1 is a barrier to early dissemination of pre-malignant mammary cells
Authors: Sosa Maria Soledad , Rodriguez-Tirado Carolina , Kale Nupura , Carlini Maria , Shrivastava Nitisha , Khalil Bassem , Bravo-Cordero Javier , Alexander Melissa , Ji Jiayi
Published: July 2021

Cancer cells disseminate during very early and sometimes asymptomatic stages of tumor progression. Granted that biological barriers to tumorigenesis exist, there must also be limiting steps to early dissemination, all of which remain largely unknown. We report that the orphan nuclear receptor NR2F1/COUP-TF1 serves as a barrier to early dissemination. High-resolution intravital imaging revealed that loss of function of NR2F1 in HER2+ early cancer cells increased in vivo dissemination without accelerating mammary tumor formation. NR2F1 expression was positively regulated by the tumor suppressive MMK3/6-p38-MAPK pathway and downregulated by HER2 and Wnt4 oncogenic signaling. NR2F1 downregulation by HER2 in early cancer cells led to decreased E-cadherin expression and β-catenin membrane localization, disorganized laminin 5 deposition, and increased expression of CK14, TWIST1, ZEB1 and PRRX1. Our findings reveal the existence of an inhibitory mechanism of dissemination regulated by NR2F1 downstream of HER2 signaling.

Citation Format: Maria Soledad Sosa, Carolina Rodriguez-Tirado, Nupura Kale, Maria Carlini, Nitisha Shrivastava, Bassem Khalil, Javier Bravo-Cordero, Melissa Alexander, Jiayi Ji. NR2F1 is a barrier to early dissemination of pre-malignant mammary cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2837.
Abstract 2849: Shc1 as a potential metastasis driver gene of breast cancer
Authors: Majocha Megan , Hunter Kent , Ross Christina
Published: July 2021

In the US, women diagnosed with non-metastatic breast cancer have a 5-year survival rate of approximately 98.8%. However, if women develop metastases the survival rate drops to 27.4%, highlighting the need for a better understanding of the mechanisms that regulate and drive metastasis. Somatically acquired mutations that drive metastasis were originally hypothesized by Nowell in the 1970s; however, to date few candidate metastasis driver mutations have been identified and the role of these mutations in metastasis are not well-understood. Using the PyMT genetically engineered mouse model of luminal metastatic breast cancer, previous work by our group performed whole exome sequencing on pairs of matched primary tumor and metastatic tissues from 65 mice. Analysis of this sequencing data identified recurrent metastasis-specific mutations in members of the Ras signaling pathway. One of the members was the SHC Adaptor Protein 1 (Shc1). Five PyMT animals carried different nucleotide substitutions within the same proline 561 codon that falls within the SH2 domain, suggesting an activating role in metastasis. Furthermore, changing this proline mutation to another amino acid could induce a critical change to the Shc1 protein structure and its function. To investigate the role of Shc1 in breast cancer metastasis, CRISPR was performed engineer Shc1 P561 mutations for in vitro and in vivo assays using a series of mouse mammary cancer cell lines and allograft mouse models. Preliminary evidence suggests the P561 mutations have a role in metastasis. Future experiments will address the consequences of the P561 mutation on Shc1 binding partner interactions and downstream signaling and its effects on breast cancer metastasis.

Citation Format: Megan Majocha, Kent Hunter, Christina Ross. Shc1 as a potential metastasis driver gene of breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2849.
Abstract 2856: GLI3-mediated HH regulates prostate cancer progression
Authors: Duong Thu Minh , Burleson Marieke Oldenbroek , Deng J J. , Qin T , D Das , Sun L-z , Boyer T G.
Published: July 2021

Although prostate cancer patients initially respond to androgen deprivation therapy, they eventually progress to lethal castration resistant prostate cancer (CRPC), characterized by restoration of the androgen receptor (AR) signaling despite castrate levels of circulating androgens. Mechanisms proposed to underlie CRPC include AR crosstalk with alternative signaling pathways. Among these, the Sonic hedgehog (SHH)Hedgehog (HH) pathway, an essential signaling axis in prostate development and homeostasis, has been implicated in prostate cancerCRPC progression. SHH pathway is regulated by transcription factors and effectors Glioma-associated oncogene family zinc finger (GLI) proteins 1, 2, and 3. Previous studies reported that GLI1 and GLI2 drive androgen-independent growth of prostate cancer by upregulating androgen-stimulated genes. However, whether and how GLI3 plays a role in prostate cancer progression remains unclear. In the present study, we investigated the role of GLI3 in the progression of prostate cancer cells. Like GLI2, GLI3 is the a downstream transcriptional factor effector of the SHH signaling pathway that can exist as a full-length activator form or a cleaved repressor form. Our data showed an increase in GLI3 expression in prostate cancer cells growing under androgen deprived conditions. Thuserefore, we hypothesize that androgen deprivation leads to activation of the SHH signaling pathway which consequently activates GLI3 to promote androgen-independent growth of prostate cancer cells. We showed that knockdown of GLI3 repressed while overexpression of GLI3 promoted androgen-independent growth of prostate cancer cells. GLI3 knockdown also resulted in regression of castration-resistant outgrowth of xenograft tumors in mice. Additionally, transcriptomic analysis of GLI3 knockdown cells revealed that the SHH signaling pathway and epithelial mesenchymal transition (EMT) genes are altered suggesting that GLI3 regulates androgen-independent growth of prostate cancer cells through canonical SHH signaling pathway and likely contributes to prostate cancer metastasis. Lastly, our data demonstrated a physical and functional relationship between GLI3 and AR suggesting a functional crosstalk between SHH signaling and AR signaling pathways in advanced prostate cancer.

Citation Format: Thu Minh Duong, Marieke Oldenbroek Burleson, J J. Deng, T Qin, Das D, L-z Sun, T G. Boyer. GLI3-mediated HH regulates prostate cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2856.
Abstract 2862: BMP4 mediated suppression of cholesterol synthesis and breast cancer metastasis
Authors: Anderson Robin L. , Chi Lap Hing , Burrows Allan D. , Roslan Suraya , Redfern Andrew
Published: July 2021

Breast cancer affects one in seven women and kills more than 600,000 women each year. Compared to the 98.9% survival rate of patients with localized breast cancer, the five-year survival rate of patients with distant metastasis is only 28.1%. Using cDNA arrays and patient datasets, we found that a protein called bone morphogenetic protein 4 (BMP4) is downregulated in highly metastatic breast cancer cells and in high-grade breast tumors. BMP4 is a ligand in the TFGβ/BMP cytokine family and has the capacity to suppress TGFβ signaling through induction of SMAD6 and SMAD7. In several different preclinical metastasis models, we have shown that restored BMP4 expression in breast cancer cells with metastatic capacity does not alter primary tumor growth but results in significantly reduced metastasis to lung, liver and spine (p< 0.01), following primary tumor resection. MDA-MB-231HM cells with or without enforced BMP4 expression were recovered from primary mammary tumors and subjected to transcriptomic profiling by RNAseq. This analysis revealed that BMP4 suppressed multiple genes involved in the cholesterol biosynthesis pathway (p=2.56×10-7) and down-regulated cholesterol levels in the tumors (p=0.042). In a patient cohort of over 2000 predominantly luminal breast cancers, we found that stage, as measured by size and lymph node status, was not altered by statin use, however statin users had less high grade tumors and more luminal A tumors. In terms of recurrence, we found a marked risk reduction in patients with luminal B tumors (p=0.014) and particularly in Her2+ luminal B tumors (p=0.045). Lung, liver and brain metastases were most reduced in statin users. Current experiments involve testing a statin therapy, with the knowledge that statins are not effective in mice, but should inhibit cholesterol synthesis in human tumors in xenograft models. In addition, we are testing an inhibitor of the nuclear receptor RORγ that has been reported to activate cholesterol synthesis through SREBP2, a master regulator of cholesterol synthesis.

Citation Format: Robin L. Anderson, Lap Hing Chi, Allan D. Burrows, Suraya Roslan, Andrew Redfern. BMP4 mediated suppression of cholesterol synthesis and breast cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2862.
Abstract 2915: Synergistic, cytokine mediated stimulation (IL-1α/β + IL-6) of colon cancer cells reveals a novel mechanism of DNA damage facilitated by up-regulation of NOX1 and DUOX2
Authors: Meitzler Jennifer L. , Wu Yongzhong , Juhasz Agnes , Rapisarda Annamaria , Campbell Petreena , Diebold Becky A. , Antony Smitha , Jiang Guojian , Lu Jiamo , Mallick David J. , Konaté Mariam M. , Roy Krishnendu , Doroshow James H.
Published: July 2021

Inflammatory bowel diseases are states of long-term inflammation of the colon resulting from an interplay of environmental factors and dysregulated immune responses. As inflammatory exposure increases over the time frame of active disease, patients with these chronic conditions are at risk of developing colorectal cancers. Chronic inflammation is thought to contribute to cancer initiation through persistent release of reactive oxygen species (ROS), leading to genome damage. Accumulating evidence suggests inflammatory cells contribute to this process, as the secretion of cytokines and growth factors in response to gut inflammation also supports cancer cell progression. Specifically, IL-1 family members play a pivotal role in the pathogenesis of acute and chronic intestinal inflammation, regulating both innate and adaptive immune responses. To elucidate a direct link between IL-1 family cytokines, ROS generation and colorectal cancer, we observed that treatment of HT29 or T84 cells with IL-1α or IL-1β, in cooperation with IL-6, resulted in oxidant production through up-regulation of both NOX1 and DUOX2 enzymes. Up-regulation of the hydrogen peroxide generating DUOX2/DUOXA2 enzyme complex was directly associated with enhanced histone H2AX phosphorylation (γH2AX), a marker of DNA double strand breaks. Interestingly, this concentration and time-dependent induction of expression and oxidative response was absent in Caco2 cells and was not mediated by other IL-1 family members (IL-18, IL-33 or IL-37). Prior studies from our group have demonstrated significant up-regulation of DUOX2 and DUOXA2 in surgically resected colon cancer specimens compared with adjacent normal colonic epithelium. Future studies will focus on cytokine stimulation of colon organoids derived from patient tumor and adjacent non-malignant tissues to evaluate enzymatic expression and oxidant level changes in a novel patient-derived colon model system.

Citation Format: Jennifer L. Meitzler, Yongzhong Wu, Agnes Juhasz, Annamaria Rapisarda, Petreena Campbell, Becky A. Diebold, Smitha Antony, Guojian Jiang, Jiamo Lu, David J. Mallick, Mariam M. Konaté, Krishnendu Roy, James H. Doroshow. Synergistic, cytokine mediated stimulation (IL-1α/β + IL-6) of colon cancer cells reveals a novel mechanism of DNA damage facilitated by up-regulation of NOX1 and DUOX2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2915.
Abstract 2931: Pharmacological inhibition of 17β-hydroxysteroid dehydrogenase impairs endometrial cancer growth in an orthotopic xenograft mouse model
Authors: Xanthoulea Sofia , Konings Gonda , Saarinen Niina , Delvoux Bert , Kooreman Loes , Koskimies Pasi , Häkkinen Merja , Auriola Seppo , d'Avanzo Elisabetta , Walid Youssef , Verhaegen Frank , Lieuwes Natasja , Caiment Florian , Kruitwagen Roy , Romano Andrea
Published: July 2021

Endometrial cancer (EC) is the most common gynaecological tumor in developed countries and its incidence is increasing. Approximately 80% of newly diagnosed EC cases are estrogen-dependent. Type 1 17β-hydroxysteroid dehydrogenase (17β-HSD-1) is the enzyme that catalyzes the final step in estrogen biosynthesis by reducing the weak estrogen estrone (E1) to the potent estrogen 17β-estradiol (E2), and previous studies showed that this enzyme is implicated in the local E2 generation in EC. In the present study we employed a recently developed orthotopic and estrogen-dependent xenograft mouse model of EC to show that pharmacological inhibition of the 17β-HSD-1 enzyme inhibits disease development. Tumors were induced in one uterine horn of athymic nude mice by intra-uterine injection of the well-differentiated human endometrial adenocarcinoma Ishikawa cell line that was modified to express 17β-HSD-1 in levels comparable to humans and, in addition, the luciferase and green fluorescent protein reporter genes. After tumor engraftment, controlled estrogen exposure was achieved using subcutaneous MedRod implants that released either E1 or placebo. A subgroup of the E1 supplemented mice received daily gavage of FP4643, a well characterized 17β-HSD-1 inhibitor. Bioluminescence imaging (BLI) was used to measure tumor growth non-invasively. At sacrifice, mice receiving E1 and treated with the FP4643 inhibitor showed a significant reduction in tumor growth by approximately 65% compared to mice receiving E1 alone. Tumors exhibited metastatic spread to the peritoneum, to the lymphovascular space (LVI) and to the thoracic cavity. Metastatic spread and LVI were both reduced in the inhibitor treated group. Transcriptional profiling of tumors indicated that FP4643 treatment reduced the oncogenic potential at the mRNA level. In conclusion, we show that the FP4643 inhibition represents a potential promising novel endocrine treatment for EC

Citation Format: Sofia Xanthoulea, Gonda Konings, Niina Saarinen, Bert Delvoux, Loes Kooreman, Pasi Koskimies, Merja Häkkinen, Seppo Auriola, Elisabetta d'Avanzo, Youssef Walid, Frank Verhaegen, Natasja Lieuwes, Florian Caiment, Roy Kruitwagen, Andrea Romano. Pharmacological inhibition of 17β-hydroxysteroid dehydrogenase impairs endometrial cancer growth in an orthotopic xenograft mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2931.
Abstract 2936: Ago2 induces Kras signaling and promotes tumor progression in mouse models of lung adenocarcinoma
Authors: Tien Jean C. , Chugh Seema , Goodrum Andrew E. , Cheng Yunhui , Wang Lisha , Mannan Rahul , Wang Xiaoming , Dommeti Vijaya L. , Zhang Yuping , Xu Alice , Su Fengyu , Cao Xuhong , Shankar Sunita , Chinnaiyan Arul M.
Published: July 2021

Lung cancer is the deadliest malignancy in the United States. Non-small cell lung cancer (NSCLC) accounts for 85% of cases, and is frequently driven by activating mutations in the gene encoding the KRAS GTPase (e.g. KRASG12D). Our previous work demonstrated that Argonaute 2 (AGO2)—a component of the RNA induced silencing complex (RISC)—physically interacts with KRAS and stabilizes it at the protein level. In multiple cell lines, AGO2 knockdown reduces KRAS protein level and attenuates cell proliferation. We therefore hypothesized that AGO2 could promote KRASG12D-dependent NSCLC in vivo. To test the hypothesis, we evaluated the impact of Ago2 knockout in the KPC mouse model of NSCLC. In KPC mice, intratracheal delivery of adenoviral Cre drives lung-specific expression of a stop-floxed KRASG12D allele and biallelic ablation of p53. Simultaneous biallelic ablation of floxed Ago2 inhibited KPC lung nodule growth while reducing proliferative index and improving pathological grade. We next applied the KPHetC model, in which the clara cell-specific CCSP-driven Cre activates KRASG12D and ablates a single p53 allele. In these mice, Ago2 ablation also reduced tumor size and grade. In both models, Ago2 knockout inhibited ERK phosphorylation in tumor nodules, indicating impaired KRAS signaling. Furthermore, RNA-seq analysis of KPC nodules demonstrated broadly reduced expression of Kras-related genes. Taken together, our data demonstrate a novel pathogenic role for AGO2 in KRAS-dependent NSCLC. Given the prevalence of this malignancy and current difficulties in therapeutically targeting KRAS signaling, our work has future translational relevance.

Citation Format: Jean C. Tien, Seema Chugh, Andrew E. Goodrum, Yunhui Cheng, Lisha Wang, Rahul Mannan, Xiaoming Wang, Vijaya L. Dommeti, Yuping Zhang, Alice Xu, Fengyu Su, Xuhong Cao, Sunita Shankar, Arul M. Chinnaiyan. Ago2 induces Kras signaling and promotes tumor progression in mouse models of lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2936.
Abstract 2944: Altering RAS oncogenic activity defines unique oncogenic fates
Authors: Erdogan Ozgun , Pershing Nicole L. , Counter Christopher M.
Published: July 2021

RAS family oncogenes demonstrate a tropism of specific driver mutations towards different cancers and understanding the impact of individual RAS mutations on oncogenic activity, signaling, and tissue-specific cellular responses could inform on the origin of cancer as well as development of potential therapies. To genetically interrogate how each mutation could differentially alter RAS signaling output in vivo, we created a panel of mice whereby two very different oncogenic mutations, G12D and Q61R, were expressed from a Cre-inducible LSL-Kras allele encoded with native (nat) or common (com) codons to generate low or high levels of oncoprotein. We show that this panel leads to a stepwise increase in RAS activity (GTP loading) with comQ61R > comG12D > natQ61R > natG12D. Global activation of these alleles induced a restricted number of tumors, with increasing active Kras generally leading to a more severe disease and decreased survival. Histopathological analysis revealed that high oncogenic activity induces highly aggressive myeloproliferative disease while there is a shift to more solid tumors as the signaling is dampened. RNASeq revealed that low levels of active Kras induce transcriptional features of a plastic state while high levels have all the hallmarks of potent oncogenic activity and resultant oncogenic stress. Such findings are suggestive of potential unique vulnerabilities during tumor initiation driven by different RAS mutants that may find clinical utility in the treatment of early stage cancer to prevent recurrence.

Citation Format: Ozgun Erdogan, Nicole L. Pershing, Christopher M. Counter. Altering RAS oncogenic activity defines unique oncogenic fates [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2944.
Abstract 2960: A novel mouse model of pancreatic cancer reveals new insights into cell cycle deregulation
Authors: Adams Christina , Wang Lynn , Wang Tim S. , Miller Nichol , McMillan Elizabeth , Ramstetter Monica , Chionis John , Eisele Koleen , Almaden Jonathan , Affolter Timothy , Pillai Smitha , VanArsdale Todd , Dillon Chris , Dann Stephen G.
Published: July 2021

Overcoming checkpoints to cell cycle control is the basis for tumorigenesis and malignant growth. Therefore, models that recapitulate clinically relevant cell cycle deregulation enhance our understanding of defined tumors subsets. Specifically, pancreatic ductal adenocarcinomas (PDAs) frequently delete the 9p21 locus which contains the cyclin dependent kinase (CDK) inhibitors CDKN2A (p16, p14) and CDKN2B (p15), as well as methylthioadenosine phosphorylase (MTAP), a metabolic gene required for methionine salvage from methylthioadenosine. No model currently exists that accurately represents loss of the entire locus in a relevant disease context. Moreover, the contribution of MTAP to tumor progression remains largely unknown. Therefore, we have developed a novel genetically engineered mouse model (GEMM) of PDA which combines loss of the orthologous murine 9p21 region (4qC4) with activated KRAS [Pdx-Cre; LSL-KrasG12D; 9p21L/L (K9C)], which results in rapid adenocarcinoma formation and subsequent mortality in mice homozygous for 9p21 deletion. Single-cell RNA sequencing revealed a remarkable level of inter- and intra-tumoral heterogeneity, including a significant immune and stromal component that contribute to tumor growth and progression. Additionally, K9C derived cell lines are responsive to Pfizer's first-in class CDK2/4/6 selective inhibitor while displaying de novo resistance to CDK4/6 inhibitor Palbociclib. Allograft and single-cell RNA sequencing experiments corroborated these findings and implicate Myc in contributing to CDK2/4/6i sensitivity. Furthermore, phenotypic-based screens revealed synthetic-lethal hits with 9p21 loss, indicating ample opportunities for combination strategies in this select patient population. Thus, we show that the K9C model recapitulates salient aspects of PDA and is amenable to novel therapeutic intervention strategies that may aid in improving the outcomes of patients with this precise genetic background.

*All procedures performed on animals were in accordance with regulations and established guidelines and were reviewed and approved by an Institutional Animal Care and use committee

Citation Format: Christina Adams, Lynn Wang, Tim S. Wang, Nichol Miller, Elizabeth McMillan, Monica Ramstetter, John Chionis, Koleen Eisele, Jonathan Almaden, Timothy Affolter, Smitha Pillai, Todd VanArsdale, Chris Dillon, Stephen G. Dann. A novel mouse model of pancreatic cancer reveals new insights into cell cycle deregulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2960.
Abstract 2968: Organoid based functional genomics approach to identify treatment options for patients with rare cancers
Authors: Hopkins Benjamin David , Cavallo-Fleming Julie-Ann , Claridge Sally , De Boni Lamberto , Pauli Chantal
Published: July 2021

Rare cancers present a distinct challenge for the identification of effective therapeutic strategies. While these tumors make up 20% of total cancer cases in the United States, they are categorically defined as occurring in less than 6 of every 100,000 people, limiting the utility of traditional methods to study, and identify treatments for these cancers. Though there have been tremendous advances in cancer therapeutics, identification of treatments for rare tumors have lagged, leaving patients with rare tumors with worse 5 year survival rates than individuals diagnosed with common cancer types. The goal of precision oncology is to identify effective therapeutic strategies for each individual patient. With high throughput sequencing it is now possible to identify the genetic events that give rise to and sustain each individual tumor in clinically relevant time frames, however our capacity to leverage this information to identify effective therapeutic options remains limited. This gap in our capacity stems from a lack of clinically relevant approaches that would allow physicians to accurately gauge the impact of multiple therapeutic strategies and relate them to clinical responses. Through the establishment of an iterative Functional Genomics Pipeline which integrates the development and analysis of high-fidelity patient derived organoid models of rare cancers with personalized drug sensitivity testing, and comprehensive genomics our work suggests that personalized modeling could have clinical utility for the identification of treatment options for individual patients with rare cancers.

Citation Format: Benjamin David Hopkins, Julie-Ann Cavallo-Fleming, Sally Claridge, Lamberto De Boni, Chantal Pauli. Organoid based functional genomics approach to identify treatment options for patients with rare cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2968.