bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 938: Characterization of a murine pancreatic ductal adenocarcinoma (PDAC) model with tamoxifen inducible pancreas-specific blockade of transforming growth factor-β (TGF-β) signaling with KrasG12D expression
Authors: Pandey Sanjay , Bell Brett , Chavez Claudia G. , Koba Wade , Savage Talicia , Asp Patrik , Basu Indranil , Guha Chandan
Published: June 2022

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a five-year overall survival of less than 10%. The lack of effective therapeutic strategies for PDAC necessitates the development of models to better understand the disease. Transforming growth factor-β (TGFβ)-SMAD4 signaling plays a critical role in PDAC development with more than half of all patients either have mutated SMAD4 (loss of function) or altered type II TGF TGFβ -receptor (Tgfbr2) gene. Here we present a murine model of PDAC with Tamoxifen induced conditional deletion of the TGFβ-receptor 2 (Tgfbr2) gene and expression of an activating KrasG12D mutation in pancreatic acinar cells. LSL-KrasG12D/+; Tgfbriifl/fl; Ptf1a-CreER mice were generated by crossing Ptf1aCre-ERTM mice with LSL-KrasG12D mice in which expression of KrasG12D is restrained by a lox-stop-lox cassette until Cre activation by tamoxifen injection. These mice were then bred with Tgfbr2fl/fl mice with loxP sites flanking exon 4 of the Tgfbr2 allele to block TGFβ-SMAD4 signaling. 18Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography was performed to detect tumors and measure their metabolic volumes and standard uptake values over time. This model showed a latency of approximately 16-20 weeks following 5 i.p. injections of tamoxifen (~75 mg/kg in corn oil). Follow-up on the survival of the mice post tamoxifen injections showed the median survival of 252 days in male and 234 days in female mice. Histological evaluation showed multifocal nodules of neoplasia composed of tubules and acini with cuboidal to polygonal cells. Carcinoma cells were positive for cytokeratin 19 and for mucins identified by Alcian blue staining, both confirming the ductal phenotype of these tumors. Picrosirius red staining demonstrated dense stromal desmoplasia which recapitulates human disease. Flow cytometric evolution of the immune microenvironment was also done to evaluate the infiltration of immune cells. Additional characterization of our novel mouse model of pancreatic cancer is underway to understand PDAC progression and develop effective therapeutic approaches.

Citation Format: Sanjay Pandey, Brett Bell, Claudia G. Chavez, Wade Koba, Talicia Savage, Patrik Asp, Indranil Basu, Chandan Guha. Characterization of a murine pancreatic ductal adenocarcinoma (PDAC) model with tamoxifen inducible pancreas-specific blockade of transforming growth factor-β (TGF-β) signaling with KrasG12D expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 938.
Abstract 956: Role of E-cadherin in progression of invasive breast lobular carcinoma
Authors: Savariau Laura , Tasdemir Nilgun , Elangovan Ashuvinee , Ding Kai , Tallapaneni Pooja Sree , Hooda Jagmohan , Atkinson Jennifer M. , Lee Adrian V. , Oesterreich Steffi
Published: June 2022

Invasive lobular carcinoma (ILC) is the second most frequently diagnosed histologic subtype of invasive breast cancer following invasive ductal carcinoma (IDC) and accounts for 15% of all cases. The hallmark of ILC is the genetic loss of E-cadherin (CDH1) causing the disruption of adherens junctions and resulting in discohesive, linear growth of ILC cells in tissues. Beyond its effects on this unique histology, there is limited data on the role of E-cadherin loss in ILC metastasis. Therefore, we generated three ILC cell lines (MDA-MB-134, SUM44PE and BCK4) with inducible E-cadherin overexpression. Using immunoblotting and immunofluorescence microscopy we confirmed E-cadherin expression, re-expression of other adherens junction proteins including α and β-catenin, and re-localization of cytoplasmic p120-catenin to the membrane. Successful cell adhesion to E-cadherin coated plates suggested formation of functional junctions. E-cadherin expression had no effect on 2D growth but did diminish cell growth in ultra-low attachment (ULA) conditions consistent with its previously described role in anoikis. We confirmed increased cell death of MM134 with E-cadherin overexpression compared to control cells when grown in ULA. Overexpression of E-cadherin failed to rescue poor migratory and invasive ability of ILC cell lines as measured by transwell assays. However, E-cadherin expression in SUM44PE lead to decreased haptotaxis to collagen I, and altered morphology from loose grape-like structure to tight sphere-like formation when embedded in collagen I.In vivo analyses revealed reduced primary tumor formation in E-cadherin-overexpression SUM44PE cells after mammary fat pad injection. Additional studies aimed at understanding E-cadherin’s effect on in vivo metastasis are ongoing.Collectively, our studies using novel cell line models will lead to an improved understanding of the hallmark loss of E-cadherin and disease mechanisms in ILC, which we hope will ultimately enable the development of more effective therapies and improve the outcome of patients with this understudied histological subtype of breast cancer.

Citation Format: Laura Savariau, Nilgun Tasdemir, Ashuvinee Elangovan, Kai Ding, Pooja Sree Tallapaneni, Jagmohan Hooda, Jennifer M. Atkinson, Adrian V. Lee, Steffi Oesterreich. Role of E-cadherin in progression of invasive breast lobular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 956.
Abstract 96: A novel virus-drug combination to enhance oncolysis in colorectal cancer (crc)
Authors: Chavez Valery A. , Bustamante Floritza , Murray Abner , Saluja Ashok , Merchan Jaime
Published: June 2022

Background: While advances in immune and targeted therapies improve outcomes in selected cancers, only a minority of colorectal cancer (CRC) patients benefit from them. Oncolytic viruses (OVs) represent novel cancer biotherapies, and among them, the oncolytic measles virus (MV) has demonstrated safety and antitumor activity in early clinical studies. MV alone does is not associated with cancer cures. Triptolide, a diterpenoid epoxide extracted from the thunder god vine (Tripterygium wilfordii), has been reported to have potent antitumor effects via multiple mechanisms, including anti-proliferative, pro-apoptotic, antiangiogenic, and induction of ER stress. The effects of triptolide on viral colon cancer oncolysis have not been previously investigated.

Objectives: To characterize the in vitro and in vivo mechanisms of novel stromal retargeted oncolytic MVs and improve efficacy by combining MVs with triptolide.

Methods: The in vitro effects of triptolide alone, MV-GFP (Edmonston strain of Measles virus expressing eGFP, for human cancer cells), MV-m-uPA (MV retargeted against the murine uPA receptor, for murine cancer cells), or virus-triptolide combinations on tumor cell cytotoxicity were assessed by cell count (Vi cell counter) or xCelligence assays, on HT-29, HCT116, SW620, CT26, and MC38 cells. Molecular and mechanistic characterization of Triptolide’s effects alone and combination with MV in HT29 cells will be analyzed by the (Reverse Phase Protein Array (RPPA) and validated by western blot analysis (experiment undergoing). In vivo effects (tumor progression and survival) of minnelide (M) (water-soluble version of Triptolide) alone and in combination with Measles Virus were assessed in Balb/C mice bearing CT26.

Results: While MV and T had dose-dependent cytotoxic activity as single agents, significant augmentation of MV oncolysis was induced by co-treatment with triptolide. In vivo experiments showed similar effects observed in vitro, with potent antitumor activity of triptolide and enhanced in vivo antitumor activity when minnelide was combined with MV vectors.

Conclusions: our results strongly suggest that triptolide or minnelide enhances measles virus oncolysis in vitro and in vivo models of colorectal cancer. In vitro and in vivo mechanistic studies are underway to characterize the molecular mechanisms by which triptolide enhances MV oncolysis and will be presented at the meeting.

Citation Format: Valery A. Chavez, Floritza Bustamante, Abner Murray, Ashok Saluja, Jaime Merchan. A novel virus-drug combination to enhance oncolysis in colorectal cancer (crc) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 96.
Abstract 966: All stressed out: Phenoytpe plasticity and therapy resistance in melanoma
Authors: Giles Jasmin , Biancaniello Maria , Fane Mitchell , Alicea Gretchen , Kossenkov Andrew , Kaur Amanpreet , Rebecca Vito , Xu Xiaowei , Herlyn Meenhard , Murphy Maureen , Weeraratna Ashani , Webster Marie R.
Published: June 2022

Metastatic melanoma is an aggressive disease. Despite recent improvements in therapy, drug resistant populations emerge even in drug-sensitive tumors. The ability to adapt to multiple types of stress contributes to tumor progression and therapy resistance. We have found a subset of melanoma cells with high Wnt5A and wild type p53 expression can transition to a slow-cycling state, rendering them resistant to most targeted therapy. Multiple types of stress, including DNA damage, targeted therapy, and aging increase Wnt5A and p53 in these metastatic cells. Inhibiting p53 blocks the slow cycling phenotype and promotes sensitivity to targeted therapy. A single dose of a p53 inhibitor at the commencement of BRAF/MEKi therapy was sufficient to prolong sensitivity to BRAF/MEKi therapy in Yumm1.7 derived tumors grown in aged mice (> 52 weeks). Upon analysis of PDX tumors with WTp53, treated with BRAF/MEKi combination or BRAFi therapy, we observed an increase in p53 positive cells as well as an increase in Wnt5A expression, further linking Wnt5A and p53 with resistance to targeted therapy. These data suggest that melanoma cells require p53 to survive multiple types of stress and that taking the paradoxical approach of inhibiting rather than activating WTp53 may sensitize previously resistant metastatic melanoma cells to therapy by temporarily driving them into a rapidly cycling state. WTp53 is typically thought of as a tumor suppressor due to its ability to regulate cell proliferation, stress response, and cell death. However, in metastatic melanoma cells, p53 promotes the expression of EDIL3, FAP, MMP3, and netrin G1, which are associated with poor prognosis, increased angiogenesis, and metastasis in multiple types of cancer. These data suggest that p53, typically thought of as a tumor suppressor, may be promoting the survival of a subset of highly resistant metastatic cells.

Citation Format: Jasmin Giles, Maria Biancaniello, Mitchell Fane, Gretchen Alicea, Andrew Kossenkov, Amanpreet Kaur, Vito Rebecca, Xiaowei Xu, Meenhard Herlyn, Maureen Murphy, Ashani Weeraratna, Marie R. Webster. All stressed out: Phenoytpe plasticity and therapy resistance in melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 966.
Abstract 968: Loss of glutathione peroxidase 2 promotes epithelial to mesenchymal transition and breast cancer metastasis
Authors: Ren Zuen , Liang Huizhi , Dharmaratne Malindrie , Morales-Gallego Miriam , Fard Atefeh Taherian , Mar Jessica , Suyama Kimita , Benard Outhiriaradjou , Prystowsky Michael B. , Norton Larry , Hazan Rachel B.
Published: June 2022

The processes regulating tumor metastasis are multivariate and complex. Redox regulation of the tumor phenotype by GPx2 knockdown (KD) in breast cancer led us to uncover dramatic effects on spontaneous metastasis. Analysis of single cell RNA sequencing (scRNAseq) data from GPx2 KD tumor and control tumor, revealed that both tumors were comprised of several luminal-like tumor cell clusters and one mesenchymal-like cell cluster (cluster 3). Notably, GPx2 KD promoted a significant increase in the size of mesenchymal cells (cluster 3) relative to control, which might be due to the stimulation of epithelial-to-mesenchymal transition (EMT) in response to GPx2 loss. In support of this view, GPx2 KD stimulated an increase in mRNA expression of basal/mesenchymal (KRT5, KRT14, KRT17, Vimentin, Twist1, Twist2, CDH2) genes and a decrease in mRNA expression of epithelial/luminal (Cldn7 and Epcam) genes, especially in cluster 3. Moreover, GPx2 KD upregulated mRNA expression of basal/mesenchymal (Twist2, CDH2, and KRT14) genes in most luminal-like clusters expressing epithelial/luminal (Epcam, Cldn3/7, CDH1, KRT8/18) genes, implying these clusters may be undergoing EMT transition in a hybrid epithelial/mesenchymal state in response to GPx2 loss. Validation of these data in cell lines and tumors showed that GPx2 KD dramatically enhanced EMT via activation of ROS/HIF1α-mediated signaling. Importantly, these effects were reversed by GPx2 re-expression or HIF1α inhibition, which was capable of suppressing EMT and metastasis. Collectively, these results indicate that GPx2 loss promotes breast cancer metastasis by stimulating EMT due to HIF1α signaling, highlighting the impact of GPx2 and HIF1 on therapeutic intervention in metastasis.

Citation Format: Zuen Ren, Huizhi Liang, Malindrie Dharmaratne, Miriam Morales-Gallego, Atefeh Taherian Fard, Jessica Mar, Kimita Suyama, Outhiriaradjou Benard, Michael B. Prystowsky, Larry Norton, Rachel B. Hazan. Loss of glutathione peroxidase 2 promotes epithelial to mesenchymal transition and breast cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 968.
Abstract 97: Mechanisms of action and regulation of the progranulin/EphA2 axis in mesothelioma
Authors: Ventura Elisa , Buraschi Simone , Williams Stephen J. , Belfiore Antonino , Iozzo Renato V. , Giordano Antonio , Morrione Andrea
Published: June 2022

Mesothelioma is an aggressive tumor with very poor prognosis. The limited availability of therapeutic options for mesothelioma patients suggests the need for a better understanding of mesothelioma biology and the identification of novel therapeutic targets. Progranulin is a pluripotent growth factor whose dysregulation is implicated in several human pathologies including cancer. The pro-tumorigenic activity of progranulin depends on the activation of its functional receptor EphA2. Indeed, in bladder cancer, progranulin promotes EphA2 phosphorylation at Ser897 and triggers EphA2 oncogenic action resulting in increased tumor cell migration, invasion and in vivo tumor growth. Both progranulin and EphA2 are expressed in mesothelioma, with progranulin promoting tumor angiogenesis in a VEGF-independent manner and EphA2 being often mutated or overexpressed. However, in mesothelioma, the potential functional interaction between progranulin and EphA2 is unexplored. Using a panel of mesothelioma cell lines covering all mesothelioma subtypes, we observed increased levels of phosphorylated EphA2 at Ser897 when compared to immortalized normal mesothelial cells, and the levels of phosphorylation positively correlated with progranulin expression. Progranulin-dependent activation of EphA2 in mesothelioma cells promoted the activation of the MAPK and AKT pathways and ERK1/2-dependent EphA2 phosphorylation at Ser897. Transient depletion of progranulin by siRNA approaches as well as GRN gene knock-out by CRISP/Cas9 strategies in mesothelioma cells reduced the activation of the AKT signaling pathway and inhibited the migratory and invasive capabilities of progranulin-depleted cells when compared to parental cells, suggesting that the progranulin/EphA2 axis is oncogenic in mesothelioma. However, EphA2 genetic ablation resulted in an increased basal activation of AKT and MAPK and in progranulin-evoked EphA2-independet AKT/MAPK activation, indicating that alternative membrane receptors might compensate for EphA2 loss and sustain progranulin action in mesothelioma. Using several pharmacological and genetic approaches, we uncovered a role for EGFR and FAK in compensating for EphA2 loss by triggering progranulin-dependent oncogenic signaling in mesothelioma, highlighting a complex functional cross-talk between EphA2, EGFR and FAK in mediating progranulin-dependent tumorigenesis. Thus, these results suggest the need for combinatorial therapeutic approaches to blunt progranulin oncogenic action in mesothelioma.

Citation Format: Elisa Ventura, Simone Buraschi, Stephen J. Williams, Antonino Belfiore, Renato V. Iozzo, Antonio Giordano, Andrea Morrione. Mechanisms of action and regulation of the progranulin/EphA2 axis in mesothelioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 97.
Abstract 972: MMR-deficiency is the most prominent genetic feature of prostate cancer metastases organotropism
Authors: Vis Daniel , Palit Sander , Corradi Marie , Lolkema Martijn , Mehra Niven , Cuppen Edwin , Wessels Lodewyk FA , Bernards Rene , Zwart Wilbert , van der Heijden Michiel S. , Bergman Andries M.
Published: June 2022

Prostate cancer (PCa) is the most prevalent, non-cutaneous, cancer in men in the Western world. Disease confined to the prostate can be cured, but metastatic disease cannot. PCa metastases are found in bone, lymph-nodes, liver and other visceral organs (visceral), in decreasing order of frequency. After an initial response to androgen receptor directed therapy, metastatic disease will inevitably recur as metastatic castration resistant prostate cancer (mCRPC), which is hallmarked by high morbidity and mortality. Since it is previously established, that the site of metastasis correlates with prostate cancer survival, we need a better understanding of metastatic organotropism. Therefore, we took advantage of the largest Whole Genome Sequencing (HiSeq X Ten system using the paired-end sequencing protocol) data set of mCRPC metastases to date. Molecular profiling of 326 metastases (Bone: 105, Lymph-node: 149, Liver: 49, Visceral: 23) revealed genetic determinants associated with organ-specific metastasis. First, we assessed differential occurrence of mutations in genes associated with targetable pathways. RB1 alteration were enriched in liver (35%) and in visceral metastases (30%), while lower rates were found in bone (10%) and lymph-nodes (13%)(Fisher exact test, p: 0.012). Analysis of aggregated pathway alteration data revealed a trend for increased frequency of alterations in the DNA repair and PI3K pathways in lymph node vs. bone metastases (p: 0.066 and 0.066, respectively). Next, we explored differential tumor mutational burden (TMB) between the sites. A higher TMB was observed in liver and visceral metastases compared to bone and lymph node metastases, while there was no difference between liver and visceral. The increased TMB in liver and visceral samples was associated with an MMR-deficiency mutational signature. Alterations in MSH6, MLH1 and POLD3 characterized a significant proportion of high TMB liver metastases, whereas high TMB visceral metastases predominantly showed MSH2 and POLD1 alterations.In conclusion: Our findings implicate high TMB/MMR-deficiency is a characteristic feature of liver and visceral PCa metastases, potentially impacting disease progression. Moreover, since response to immune check-point inhibitors is associated with high TMB, our findings might direct choice of therapy.

Citation Format: Daniel Vis, Sander Palit, Marie Corradi, Martijn Lolkema, Niven Mehra, Edwin Cuppen, Lodewyk FA Wessels, Rene Bernards, Wilbert Zwart, Michiel S. van der Heijden, Andries M. Bergman. MMR-deficiency is the most prominent genetic feature of prostate cancer metastases organotropism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 972.
Abstract 982: A new transcriptional metastatic signature predicts survival in clear cell renal cell carcinoma
Authors: Alchahin Adele Mirna , Mei Shenglin , Tsea Ioanna , Hirz Taghreed , Kfoury Youmna , Dahl Douglas , Wu Chin-Lee , Subtelny Alexander O. , WU Shulin , Scadden David T. , Shin John H. , Saylor Philip J. , Sykes David B. , Kharchenko Peter V. , Baryawno Ninib
Published: June 2022

Introduction: Renal cell carcinoma, particularly the clear cell histological subtype (ccRCC), is the most common kidney cancer in adults, accounting for 75-85% of all cases. When it is localized to the kidney, it is often cured with surgical resection or thermal ablation. One quarter of the patients have evidence of metastatic disease at the time of diagnosis, and in this setting ccRCC still is a highly lethal disease with few effective treatment options. In this study we used single-cell RNA-sequencing to characterize tumor cell clonality, metastatic signatures and the tumor microenvironment in ccRCC at the single-cell level.

Methodological approach: Here we took advantage of fresh patient samples that included treatment-naive primary tumor tissue, matched adjacent normal kidney tissue, as well as tumor samples collected from patients with bone metastases. We used single cell RNA sequencing (10X Genomics, Chromium 3’ v2 kit, 10x Genomics), that was analyzed with PAGODA and CONOS.

Summary of new unpublished data: Our analysis revealed a distinct transcriptional signature that predicts metastatic potential and patient survival was disclosed through the single-cell analysis. In-depth exploration of the supporting stromal cells displayed a phenotype of vascular remodeling within the endothelial cells. The fibroblasts showed a proliferative signature that was associated with poor survival. An in silico cell-to-cell interaction analysis highlighted the CXCL9/CXCL10-CXCR3 axis and the CD70-CD27 axis as potential therapeutic targets.

Conclusions: Our discoveries in ccRCC provide complementary biological insights, specifically in the interplay between tumor cells and their microenvironment in ccRCC. We demonstrate important biological insights into ccRCC biology including: (1) identification of a distinct metastatic signature that predicts survival outcome, (2) discovery of a proximal tubule cell population that may represent the ccRCC cell of origin, and (3) a detailed exploration in the immunosuppressive environment and the stromal alterations in treatment-naïve patients. In addition, we stress potential therapeutic targets for further evaluation in preclinical models.

Citation Format: Adele Mirna Alchahin, Shenglin Mei, Ioanna Tsea, Taghreed Hirz, Youmna Kfoury, Douglas Dahl, Chin-Lee Wu, Alexander O. Subtelny, Shulin WU, David T. Scadden, John H. Shin, Philip J. Saylor, David B. Sykes, Peter V. Kharchenko, Ninib Baryawno. A new transcriptional metastatic signature predicts survival in clear cell renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 982.
Abstract 998: Extracellular proximity labeling (ePL) as a tool to identify protein-protein interactions in the tumor microenvironment
Authors: Gurung Sadeechya
Published: June 2022

The extracellular matrix (ECM) is a dynamic niche that is extensively reshaped in the development of the tumor microenvironment (TME). Our current understanding of ECM function and dynamics is largely informed by identification of protein-protein interactions (PPIs) using co-immunoprecipitation (co-IP) techniques that may miss transient and weak/unstable interactions. Recent advances in proximity labeling techniques have greatly expanded the interactome networks of numerous intracellular proteins, however these tools have yet to be extended to study PPIs in the ECM. We have recently optimized a systematic approach to identify PPIs in the ECM using fusion constructs of the biotinylating enzymes, BioID2 and TurboID, with the widely expressed matrix regulator TIMP2. BioID2 and TurboID offer differing reaction kinetics that may provide complimentary information on extracellular PPIs (ePPIs). Matrix metalloproteinases (MMPs) and their endogenous inhibitors, tissue inhibitors of metalloproteinases (TIMPs) are crucial regulators of ECM structure and composition. TIMPs are widely expressed multifunctional proteins that serve to promote ECM homeostasis that is often perturbed in many cancers and chronic disorders. Although biochemical data suggests that TIMPs are promiscuous proteins, the TIMP interactome is poorly defined. We have optimized a protocol for the identification of ePPIs for the TIMP family of proteins. Fusion constructs equipped with a promiscuous biotin ligase (BioID2/TurboID) fused to the N- or C-terminal of full length TIMP2 were packaged into retroviral vectors for cellular delivery. Cells were exposed to the extracellular proximity labelling (ePL) fusion proteins and processed in our optimized analysis pipeline. ePPIs were identified via streptavidin pulldown and proteomic techniques. We present our optimized ePL pipeline and show that this technique is an effective tool for the identification of novel ePPIs for multiple extracellular targets.

Citation Format: Sadeechya Gurung. Extracellular proximity labeling (ePL) as a tool to identify protein-protein interactions in the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 998.
Abstract CT035: Safety, preliminary efficacy and pharmacodynamic (PD) analysis of maveropepimut-S, intermittent low-dose cyclophosphamide and pembrolizumab in patients with advanced, metastatic bladder cancer
Authors: Rixe Olivier , Castonguay Vincent , Conter Henry , Chalas Eva , Desai Pratibha , Squillante Christian , MacDonald Lisa A. , Conlon Rebekah , Bramhecha Yogesh , Hirsch Heather , Graff Jeremy R. , Fiset Stephan
Published: June 2022

Background: Maveropepimut-S (MVP-S) is a novel immunotherapeutic that educates a specific CD8 T cell response to the cancer antigen, survivin, to orchestrate immune-mediated elimination of survivin-expressing cancer cells. Specifically, MVP-S is a lipid-in-oil formulation of the DPX delivery platform, incorporating five survivin-specific immunogenic peptides, the innate immune stimulant, polydIdC, and a CD4 T cell helper peptide. In prior clinical studies, MVP-S and intermittent low-dose cyclophosphamide (CPA) elicited confirmed clinical responses (both partial and complete by RECISTv1.1) and induced a robust, durable survivin-specific CD8 T cell response. Moreover, the combination with pembrolizumab appeared to be well tolerated in solid tumors and lymphomas. The purpose of this phase 2 study is to explore whether this combination may be safe and effective in advanced, metastatic bladder cancer patients, both naïve to, and previously treated with, immune checkpoint inhibitors.

Results: Seventeen (17) subjects were treated with the combination of MVP-S, CPA and pembrolizumab. Subjects received an average of 3 prior lines of therapy with 13/17 (76.4%) having previously received an anti-PD1/L1. Seven subjects progressed on or after anti-PD1/L1 as last line of therapy prior to entering the trial. The combination was well-tolerated, with majority of AEs being grade 1 or grade 2. Five (5) out of 17 subjects showed response: 3 subjects with PR (unconfirmed) and 2 with CR (confirmed). Three of these, including the 2 CRs, had progressed on anti-PD-1/L1. Long-term clinical benefit has been observed in several subjects (one patient is still on treatment after 17 months) and coincides with an increase in detectable survivin-specific T cells in peripheral blood.

Conclusion: Preliminary data suggest that MVP-S/CPA and pembrolizumab is a well-tolerated combination and shows encouraging preliminary clinical activity in the treatment of advanced or metastatic bladder cancer patients, including patients who have progressed on prior anti-PD-1/L1 therapy.

Citation Format: Olivier Rixe, Vincent Castonguay, Henry Conter, Eva Chalas, Pratibha Desai, Christian Squillante, Lisa A. MacDonald, Rebekah Conlon, Yogesh Bramhecha, Heather Hirsch, Jeremy R. Graff, Stephan Fiset. Safety, preliminary efficacy and pharmacodynamic (PD) analysis of maveropepimut-S, intermittent low-dose cyclophosphamide and pembrolizumab in patients with advanced, metastatic bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT035.
Abstract CT206: EVT801, a novel selective VEGFR-3 inhibitor targeting tumor angiogenesis, started enrollment for its phase I first-in-human study
Authors: Gomez roca Carlos , Cassier Philippe , Mandron Marie , Estrabaut Myriam , Delesque-Touchard Nathalie , Smith Adam C. , Klawitter Amy , Gentry Leesa , Fons Pierre , Paillasse Michael R. , Davenne Lise , Fitzgerald Michael , Garner James , Delord Jean-Pierre
Published: June 2022

Introduction: EVT801 is a highly selective, orally available VEGFR3 inhibitor that strongly inhibits angiogenesis without inducing hypoxia, considered one of the main causes of cancer-associated immunosuppression. EVT801 has shown compelling single agent efficacy in multiple in vivo models. In addition, combination of EVT801 and Immune Checkpoint Therapy (ICT) agents shows additive effects, and thus holds promise for combination treatment without induction of hypoxia-induced-immunosuppression. A phase I clinical trial is underway.

Methods: The phase I trial will consist of two sequential stages. During the first stage, EVT801 will be administered to patients with advanced solid tumors in a multiple ascending dose study using an accelerated 3+3 design (1 patient per dose until grade 2 toxicities are observed) in up to 48 patients in 8 dose levels. The primary objective is to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). Stage 2 will focus on validation of this RP2D in two 6-patient cohorts diagnosed with soft tissue sarcoma or renal cell carcinoma. These patients will participate in intensive analyses involving several biomarkers to better understand the pharmacological activity of the drug. A potential third stage, consisting of a multiple ascending dose evaluation of the combination of EVT801 with immuno-oncology drugs, may be added to the ongoing trial, pending further technical discussions with physicians and regulators. In addition to conventional measures of safety, tolerability, efficacy, and pharmacokinetics, the phase I study will employ a rich suite of histological, immunological, and radiological biomarkers to provide early insights into the activity of EVT801.

Citation Format: Carlos Gomez roca, Philippe Cassier, Marie Mandron, Myriam Estrabaut, Nathalie Delesque-Touchard, Adam C. Smith, Amy Klawitter, Leesa Gentry, Pierre Fons, Michael R. Paillasse, Lise Davenne, Michael Fitzgerald, James Garner, Jean-Pierre Delord. EVT801, a novel selective VEGFR-3 inhibitor targeting tumor angiogenesis, started enrollment for its phase I first-in-human study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT206.
Abstract CT233: A phase 3, single-arm study of CG0070 in subjects with non-muscle invasive bladder cancer (NMIBC) unresponsive to Bacillus Calmette-Guerin (BCG)
Authors: Uchio Ed , Lamm Donald , Shore Neil , Bivalacqua Trinity , Kamat Ashish , Tyson Mark , Anderson Paul , Grandi Paola , Burke James
Published: June 2022

IntroductionCG0070 is a serotype 5 adenovirus engineered to express GM-CSF and replicate in cells with mutated or deficient RB, with response rates (RR) of approximately 45% observed in patients with recurrent NMIBC after BCG (J Urol. 2012;188:2391-7; Urol Oncol. 2018;36(10):440-7). This single arm phase 3 study (NCT04452591) was launched to confirm the clinical activity of CG0070 in patients with BCG Unresponsive NMIBC.Methods110 patients with BCG-unresponsive CIS with or without concurrent Ta or T1 disease will be treated with intravesical (IVe) CG0070 at a dose of 1x1012 vp. CG0070 will be administered as follows: induction weekly x 6 followed by weekly x 3 maintenance instillations at months 3, 6, 9, 12, and 18. Patients with persistent CIS or HG Ta at 3 months (m) may receive re-induction with weekly x 6 CG0070. Assessment of response will include q 3 m cystoscopy with biopsy of areas suspicious for disease, urine cytology, CTU/MRU, and mandatory bladder mapping at 12 m. Detection of high grade disease within the bladder will be enumerated as recurrence or non-response.ResultsThe primary endpoint of the study is CR at any time on study as assessed by biopsy (directed to cystoscopic abnormalities and mandatory mapping at 12 m), urine cytology, and radiography, as above. Secondary endpoints include CR at 12 m, duration of response, progression free survival, cystectomy free survival and safety. Correlative assessments include changes in the tumor immune microenvironment, systemic immune induction as reflected in the peripheral blood and urine, as well as viral replication and transgene expression. Baseline expression of coxsackie adenovirus receptor, E2F transcription factor as well as anti-adenovirus antibody titer will be correlated with tumor response.ConclusionThe study an ongoing trial, currently enrolling in the United States, Japan, South Korea, Australia, and Taiwan.Refs. Burke JM, Lamm DL, Meng MV, Nemunaitis JJ, Stephenson JJ, Arseneau JC, Aimi J, Lerner S, Yeung AW, Kazarian T, Maslyar DJ, McKiernan JM. A first in human phase 1 study of CG0070, a GM-CSF expressing oncolytic adenovirus, for the treatment of nonmuscle invasive bladder cancer.

Citation Format: Ed Uchio, Donald Lamm, Neil Shore, Trinity Bivalacqua, Ashish Kamat, Mark Tyson, Paul Anderson, Paola Grandi, James Burke. A phase 3, single-arm study of CG0070 in subjects with non-muscle invasive bladder cancer (NMIBC) unresponsive to Bacillus Calmette-Guerin (BCG) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT233.
Abstract CT512: A technology-based intervention using computers and mobile devices: To improve symptom experience of Asian American breast cancer survivors
Authors: Im Eun-Ok , Kim Gayeong , Jin Ruiqi , Choi Mi-Yong , Paul Sudeshna , Chee Wonshik
Published: June 2022

Purpose: Especially with the COVID19 pandemic, the necessity of technology-based interventions using computers and mobile devices has increased in cancer survivorship management including symptom management. However, little is known about the effectiveness of a technology-based intervention in improving symptom experience of racial/ethnic minorities including Asian American breast cancer survivors. The purpose of this study was to examine the efficacy of a technology-based intervention in improving symptom experience of Asian American breast cancer survivors.

Methods: This study was conducted as a part of an ongoing randomized clinical trial among 199 Asian American breast cancer survivors. The technology-based intervention included three sub-ethnic specific social media sites, interactive online educational sessions, and online resources. Both groups (intervention and control groups) used the American Cancer Society’s website on breast cancer, and only the intervention group used the technology-based intervention. Only the data collected using the questionnaire on background characteristics and health/disease status and the Memorial Symptom Assessment Scale-Short Form (MSAS) were analyzed for this study. The data were analyzed using separate intent-to-treat growth curve models.

Results: While both groups reported decreases in symptom scores from the pre-test to post 3-months (p<.01), the intervention group had larger decreases in symptom scores compared with the control group (p<.01). There existed significant group * time interactive effects on the Global Distress Index (β = - 0.234), the Physical Symptom Distress scores (β = -0.266), the psychological symptom distress scores (β = - 0.212c), the total number of symptoms (β = -0.261), and the total symptom distress scores ( β = -0.261).

Conclusions: The findings of this study clearly indicated symptom improvement among Asian American breast cancer survivors by a technology-based intervention using computers and mobile devices. Further studies with diverse racial/ethnic minorities are warranted to confirm the effectiveness of technology-based interventions in improving symptom experience of cancer survivors across different types of cancer.

Citation Format: Eun-Ok Im, Gayeong Kim, Ruiqi Jin, Mi-Yong Choi, Sudeshna Paul, Wonshik Chee. A technology-based intervention using computers and mobile devices: To improve symptom experience of Asian American breast cancer survivors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT512.
Abstract CT529: A Phase 1b Study of CG0070 combined with nivolumab in cisplatin ineligible patients with muscle invasive bladder cancer
Authors: Li Roger , Sexton Wade , Spiess Phillipe , Gilbert Scott , Pow-Sang Julio , Zhang Jingsong , Borjas Gustavo , Grandi Paola , Burke James , Jain Rohit , Conejo-Garcia Jose
Published: June 2022

Background: Up to 50% of patients with muscle invasive bladder cancer (MIBC) are unable to receive neoadjuvant chemotherapy, creating an unmet clinical need for alternative systemic treatment. Results from recent neoadjuvant immune checkpoint blockade (ICB) studies signal pCR rates between 31-42%. However, there was a clear dichotomy in response between patients with high vs. low pre-treatment lymphocytic infiltration. In tumors exhibiting immune excluded or immune desert phenotypes, therapeutic strategies to attract CD8+ T cells infiltration prior to ICB may be beneficial. CG0070 is an oncolytic adenovirus designed to preferentially replicate through a transcriptionally regulated promoter that is up-regulated in RB-pathway-defective cells (>70% of MIBC). In addition, CG0070 expresses GM-CSF to attract antigen presenting cells to the tumor microenvironment. We hypothesize that combination therapy using intravesical CG0070 and systemic Nivolumab is 1) safe and 2) can enhance local and systemic treatment response in the neoadjuvant setting against MIBC.

Methods: This is a phase Ib trial evaluating 2 doses of nivolumab (4 weeks apart) with 6 weekly intravesical CG0070 followed by cystectomy. Dose-limiting toxicities (DLTs) will be assessed in 6 DLT-evaluable patients in a safety lead-in phase. The combination would be declared tolerable if the incidence of DLTs is <33%, and the study expanded to 30 patients. Key eligibility: cT2-T4aN0-1M0 stage, no autoimmume disease within 2 years, and no concurrent invasive upper tract carcinoma or other active cancer. The primary objective is to evaluate the safety of combination therapy according to CTCAE v5.0. The secondary objective is to assess the changes in the lymphocytic infiltration following combination therapy and to assess the antitumor efficacy of combination therapy. Exploratory endpoints include assessing the predictive value of E2F expression, tumor mutational burden, immune infiltration, and various peripheral blood for treatment response. Study Progress: Study is actively accruing. Clinical trial information: NCT04610671. An update on the study will be provided at the time of presentation.

Citation Format: Roger Li, Wade Sexton, Phillipe Spiess, Scott Gilbert, Julio Pow-Sang, Jingsong Zhang, Gustavo Borjas, Paola Grandi, James Burke, Rohit Jain, Jose Conejo-Garcia. A Phase 1b Study of CG0070 combined with nivolumab in cisplatin ineligible patients with muscle invasive bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT529.
Abstract CT531: A 16-week circuit interval-based exercise intervention reduces systemic inflammation in obese, sedentary cancer survivors
Authors: Kang Dong-Woo , Christopher Cami N. , Normann Amber J. , Norris Mary K. , Dieli-Conwright Christina M.
Published: June 2022

Introduction: Obesity and a lack of physical activity lead to systemic and chronic inflammation among cancer survivors, which are highly associated with various comorbidities (e.g., type 2 diabetes, hypertension, and metabolic syndrome) and poor oncologic prognosis. Exercise, optimized to benefit physiological responses, can be an effective strategy to reduce systemic inflammation. The objective of the study was to investigate the effects of a 16-week circuit, interval-based exercise training program on proinflammatory cytokines in cancer survivors who are obese and sedentary.

Methods: This study was a single center, pilot randomized controlled trial in 90 survivors of breast, prostate, and colorectal cancers who were sedentary (<60 mins of exercise per week) and overweight/obese (body mass index > 25.0 kg/m2). Participants were randomly assigned to either the exercise group (n=60) or the usual care group (n=30). The exercise intervention was moderate to vigorous intensity aerobic (65-85% of VO2max) and resistance (65-85% of 1-repetition maximum) exercise training in a supervised, circuit, interval-based format performed thrice-weekly for 16 weeks. Blood samples were obtained at baseline and post-intervention to measure serum levels of proinflammatory cytokines, including interleukin (IL)-6, IL-8, tumor necrosis factor-α (TNF-α), and high-sensitive c-reactive protein (hsCRP). Paired t-test and repeated measure ANOVA were used to determine the between-group differences.

Results: Participants were aged 63.2±10.8 years and diagnosed with breast (35%), prostate (30%), and colorectal (35%) cancers. 55% were female and mean BMI was 34.7±5.9. 75% completed chemotherapy and/or radiation therapy. Retention and adherence rates to the exercise intervention was high (100% and 92%, respectively). Compared to usual care, circuit, interval-based exercise significantly reduced IL-6 (between group mean difference, -1.2 pg/mL; p<0.001), IL-8 (-2.4; p<0.001), TNF-α (-1.9 pg/mg; p<0.001), and hsCRP (-0.8 mg/L; p=0.02).

Conclusions: A 16-week circuit, interval-based aerobic and resistance exercise training program induced a reduction in systemic levels of proinflammatory cytokines among sedentary and obese breast, prostate, and colorectal cancer survivors. Our findings suggest that combined aerobic and resistance exercise may be an effective strategy to offset elevated systemic inflammation associated with obesity and sedentary behavior in cancer survivors.

Citation Format: Dong-Woo Kang, Cami N. Christopher, Amber J. Normann, Mary K. Norris, Christina M. Dieli-Conwright. A 16-week circuit interval-based exercise intervention reduces systemic inflammation in obese, sedentary cancer survivors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT531.
Abstract LB002: Development of fully human anti-CD19 &CD22 bispecific tandem CAR-T for the treatment of resistant or relapsed B cell malignancies
Authors: Nguyen Jenna , Zhang Gening , Zhang Keming , Jiang Ning , Feng Ryan , Wong Jeffrey , Luu Annie , Chen Yan , Zhao Kehao
Published: June 2022

Background: CD19 CAR-T has revolutionized the cancer immunotherapy for B cell malignancies. However, 40-50% patients have relapsed post current CD19 monospecific CAR-T treatment within 24 months. It has been shown that the resistance mechanism relates to either lack of persistency of the CAR-T in patients or due to CD19 target escape during treatment. CD19 and CD22 are co-expressed on B cells during B cell maturation and on most B cell malignancies. We have developed a fully human anti-CD19 and CD22 bispecific tandem CAR, aiming to overcome CD19 target escape mechanism and be more persistent with improved production process.

Methods: Utilizing mRNADis࣪ mRNA display and live cell selections, we have discovered a set of human anti-CD19 and anti-CD22 scFvs with a broad affinity range and broad epitope coverage. We have generated EPC-001, an optimal CD19/CD22 bispecific tandem CAR-T candidate, by precise engineering of multiple pairs of CD19/CD22 tandem scFvs with monospecific and bispecific target binding properties, linker length and scFv orientation.

Results: EPC-001 demonstrated both mono-specific and bivalent CD19 and CD22 target cell engagement, which led to CAR-T cell mediated cytotoxic cancer cell killing, cytokine release and CAR-T proliferation. EPC-001 showed improved Tscm and Tcm early phenotype and demonstrated potent anti-tumor activity in Raji-luciferase disseminated animal model, as well as persistent CAR-T activity when mice re-challenged with additional tumor cells. Furthermore, we have developed CD19 and CD22 knockout Raji animal models and demonstrated the in vivo mechanism of EPC-001 in overcoming CD19 or CD22 target escape resistance mechanism.

Conclusion: EPC-001 is a promising candidate that potentially prevents target escape by bivalent targeting of CD19 and CD22 simultaneously and overcome target escape with mono-specific engagement and CAR activation. EPC-001 has been advanced into clinic for proof of concept in investigator-initiated trial to treat CD19 CAR-T resistant/relapsed patients.

Citation Format: Jenna Nguyen, Gening Zhang, Keming Zhang, Ning Jiang, Ryan Feng, Jeffrey Wong, Annie Luu, Yan Chen, Kehao Zhao. Development of fully human anti-CD19 &CD22 bispecific tandem CAR-T for the treatment of resistant or relapsed B cell malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB002.