bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4038: ABM-1310, A novel BRAF Inhibitor, combined with EGFR and MEK inhibitors, inhibits colorectal tumor growth and increases overall survival in vivo
Authors: Hu Yong , Chen Chen , Huang Charles , Xu Min , Chen Youqin , Zhao Xiyuan , Zhao Li
Published: September 2020

Colorectal cancer (CRC) is a cancer that starts in the colon or the rectum, and the current treatment mainly relies on chemotherapies. For example, ERBITUX® /cetuximab is an FDA approved targetedtherapy drug to treat CRC with wild-type KRAS, the 11% low response rate limits its clinical application. BRAF inhibitors have been widely used clinically for melanoma and lung cancer, however, they have dismally low response rate at only approximately 5% of colorectal cancer patients with BRAFv600 mutation.

Here, we report that ABM-1310, a novel small molecule inhibitor of BRAF (specifically inhibit BRAFv600 mutant), has shown good potency in colon cancer xenograft models, when combined with a MEK inhibitor and EGFR antibody. In the HT-29 xenograft subcutaneous model, 10 to 25mg/kg/day oral dose of ABM-1310 combined with cetuximab (0.1mg/dose, twice a week) and 3 mg/kg/day of Binimetinib (MEK inhibitor) significantly inhibited HT-29 tumor growth with TGI of 85% to 92% after 34-days treatment. As a monotherapy or combined with cetuximab alone, ABM-1310 also brought the TGI of 74% and 82% at 25mg/kg/day, which indicates ABM-1310 played a key role in tumor growth inhibition in the combinations. Beside with Binimetinib, we also tested combination of ABM-1310 with other different MEK inhibitors in this model.

ABM-1310 is highly water-soluble small molecule with high cell permeability and blood brain barrier penetration. ABM-1310 shown good efficacy in melanoma A375 (luciferase labelled cells) in the subcutaneous/intracranial/intracardiac xenograft models (brain metastasis models). In the HT-29 colon intracranial model, ABM-1310 also demonstrated significant tumor inhibition effect and increased animal overall survival. Compared with vehicle or marketed BRAF inhibitor vemurafenib, the median survival time of ABM-1310 group was >90 days vs 51 days (vemurafenib) and 38 days (vehicle), respectively.

In Summary, ABM-1310, as a novel small molecule BRAF inhibitor, combined with EGFR and MEK inhibitors, has shown strong anti-tumor effect in preclinical in vivo models of colon cancer with BRAFv600 mutation, especially with brain metastasis.

Citation Format: Yong Hu, Chen Chen, Charles Huang, Min Xu, Youqin Chen, Xiyuan Zhao, Li Zhao. ABM-1310, A novel BRAF Inhibitor, combined with EGFR and MEK inhibitors, inhibits colorectal tumor growth and increases overall survival in vivo [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4038.
Abstract 4059: CRISPR-EXO - genetic deletion tool for treating chronic myelogenous leukemia
Authors: Lainšček Duško , Forstnerič Vida , Malenšek Špela , Skrbinek Mojca , Sever Matjaž , Jerala Roman
Published: September 2020

Chronic myeloid leukemia (CML) is a myeloproliferative neoplastic disease, occurring in 1 to 2 cases per 100.000 adults, which accounts for ~ 15 % of newly diagnosed leukemias in adult patients. The diagnosis is based upon the genetic translocation between the t(9;22)(q34;q11.2), resulting in the formation of Philadelphia fusion chromosome, coding for BCR-ABL1 oncoprotein. The life-long treatment relies on tyrosine kinase inhibitors (TKIs). In nearly in 2 % patients develop point mutations, leading to resistance to TKIs treatment. New solutions for treating cancer with genetic etiology are considered. CRISPR/Cas system, composed of guide RNA, targeting endonuclease Cas9 to specific target genomic region has been used before to mediate breakage of Philadelphia chromosome at the site of oncogenic translocation. We present a strategy to couple Cas9 to the exonuclease to promote large deletions at the cancer-specific target genomic site. Cotransfection with EXOIII exhibited the best increase in deletion formation of all tested exonucleases. To further improve the rate of genetic lesion formation, Cas9 and EXOIII were connected via coiled-coil heterodimer forming peptides, bringing the two enzymes into close proximity (CRISPR-EXO). This resulted in a potent increase of deletion formation compared to the standard CRISPR/Cas, cotransfection and genetic fusion. We performed an animal study for the use of the CRISPR-EXO system as a potential anti-cancer therapeutic tool. In case of the CRISPR-EXO system, we showed a significant increase in cell death due to higher genome editing in the BCR-ABL1 region. These findings were confirmed also in an animal cancer model, where animals with tumors, electroporated with CRISPR-EXO system showed improved survival and drastic reduction in tumor size.CRISPR-EXO upgraded CRISPR system based on tethering Cas9 protein to exonuclease EXOIII by heterodimeric coiled-coil forming peptides, resulted in highly efficient editing of BCR-ABL1 fusion gene, leading to enhanced death of CML cancer cells.

Citation Format: Duško Lainšček, Vida Forstnerič, Špela Malenšek, Mojca Skrbinek, Matjaž Sever, Roman Jerala. CRISPR-EXO - genetic deletion tool for treating chronic myelogenous leukemia [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4059.
Abstract 4070: Development of MAEGI as a new class of immune gene therapy for cancer treatment
Authors: Chen Sidi
Published: September 2020

Current major types of immunotherapy include checkpoint blockade, adoptive cell transfer, human recombinant cytokines, and cancer vaccines. However, immunotherapy has met challenges in immunologically cold tumors. These challenges urge for new types of immunotherapies that are more potent and potentially less toxic. Recently, we have developed CRISPRa-mediated Multiplexed Activation of Endogenous Genes as an Immunotherapy (MAEGI) (Wang et al. 2019 Nature Immunology, in press). The CRISPR activation (CRISPRa) system uses a catalytically inactive Cas9 (dCas9), enabling simple and flexible gene expression regulation through dCas9-transcriptional activators paired with single guide RNAs (sgRNAs). This enables precise targeting of large gene pools of endogenous genes in a flexible manner. We demonstrate that MAEGI has therapeutic efficacy across three tumor types. Mechanistically, our preliminary work showed that MAEGI treatment elicits anti-tumor immune responses by recruiting effector T cells and remodeling the tumor microenvironment. We will perform advanced development, characterization and optimization of MAEGI, as a novel immune-gene therapy approach to elicit a potent and specific immune response to tumors based on their unique genetic composition.

Citation Format: Sidi Chen. Development of MAEGI as a new class of immune gene therapy for cancer treatment [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4070.
Abstract 4140: Dissecting the structural basis for rational inhibitor design: Crystal and solution structures of human oncoprotein Musashi-2 N-terminal RNA recognition motif 1
Authors: Lan Lan , Xing Minli , Kashipathy Maithri , Douglas Justin , Gao Philip , Battaile Kevin , Hanzlik Robert , Lovell Scott , Xu Liang
Published: September 2020

RNA-binding proteins (RBPs) are key regulators of cellular functions, especially in post-transcriptional regulations. Dysregulation of RBPs is implicated in many diseases including cancer. One of the RBPs that is overexpressed in a variety of human cancer is Musashi-2 (MSI2). Elevated MSI2 expression is associated with ectopic oncogenic pathways including but not limited to NUMB/Notch, PTEN/mTOR, TGF-β/SMAD3, making MSI2 a promising therapeutic target for cancer. Protein structure is critical for drug discovery and structure-based rational design. Both MSI1 and MSI2 proteins contain two N-terminal RNA recognition motifs and play roles in post-transcriptional regulation of target mRNAs. We have identified several inhibitors of MSI1, all of which bind to MSI2 as well. In order to design MSI2 specific inhibitors and compare the differences of binding mode of the inhibitors, we set out to solve the structure of MSI2-RRM1, the key motif that is responsible for the binding. Here we report the crystal structure and the first NMR solution structure of MSI2-RRM1, and compare these to the structures of MSI1-RBD1 and other RNA binding proteins. A high degree of structural similarity was observed between the crystal and solution NMR structures. MSI2-RRM1 shows a highly similar overall folding topology to MSI1-RBD1 and other RNA binding proteins. The structural information of MSI2-RRM1 will be helpful for understanding MSI2-RNA interaction and for guiding rational design of MSI2 specific inhibitors.

Citation Format: Lan Lan, Minli Xing, Maithri Kashipathy, Justin Douglas, Philip Gao, Kevin Battaile, Robert Hanzlik, Scott Lovell, Liang Xu. Dissecting the structural basis for rational inhibitor design: Crystal and solution structures of human oncoprotein Musashi-2 N-terminal RNA recognition motif 1 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4140.
Abstract 4145: Performance of IntelliPlexTM companion diagnostics application in cancer management
Authors: Felicioni Lara , Buttitta Fiamma , Marchetti Antonio , Hu ShianPin , Chao ChenHung , Liang WenKai , Hu JuiYu , Palmer Stuart , Huang ChinShiou
Published: September 2020

Background: Cancer is a group of various diseases with diverse causes which lead to the uncontrolled growth of abnormal cells. Understanding the genetic alteration in genes associated with cancer optimizes therapy outcomes by tailoring treatment based on each patient genetic basis. Molecular profiling is therefore a crucial tool for precision medicine to improve cancer management.

Method: The IntelliPlexTM system, based on πCodeTM technology, provides a multiplexing solution for molecular profiling in just one reaction. PlexBio developed several single target gene assays utilizing DNA samples derived from formalin-fixed paraffin-embedded (FFPE) tumor tissues. The IntelliPlex EGFR Mutation kit is intended for detection of 40 mutations in the EGFR gene. The IntelliPlex BRAF V600 Mutation Kit is designed for identification of 7 nucleotide changes. The IntelliPlex KRAS Mutation Plus kit targets 25 single nucleotide changes in the KRAS gene and the IntelliPlex NRAS Mutation qualitative detects 33 single nucleotide changes in the NRAS gene. All IntelliPlex assays analyze the mutational status of each target in less than 5 hours (nucleic acid extraction not included) and allow high-throughput screening of up to 94 samples in parallel with minimal hands-on time. The performance of IntelliPlex system was evaluated on archived FFPE DNA specimens by comparing the results of the respective IntelliPlex assay with results previously obtained using the indicated commercially available molecular assays. All tests were conducted in a hospital lab located in Italy.

Results: Among 76 FFPE DNA specimens tested, the overall agreement between IntelliPlex system and the comparison method was found to be 93.4%. The individual concordance for each assay kit is 90.0%, 95.8%, 93.8%, and 93.8% for EGFR, KRAS Plus, NRAS and BRAF, respectively.

Conclusion: PlexBio's IntelliPlexTM system, a multiplex detection platform, is suitable to support precision medicine in cancer management. The system offers a rapid and cost-effective way to analyze patient specimens with high sensitivity and specificity in a clinical environment.

Citation Format: Lara Felicioni, Fiamma Buttitta, Antonio Marchetti, ShianPin Hu, ChenHung Chao, WenKai Liang, JuiYu Hu, Stuart Palmer, ChinShiou Huang. Performance of IntelliPlexTM companion diagnostics application in cancer management [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4145.
Abstract 4195: Steviol induces pancreatic cancer cell death via targeting glucose metabolism and protein translation pathways
Authors: Kumari Sonam , Khan Sheema , Sikander Mohammed , Malik Shabnam , Chauhan Subhash C. , Jaggi Meena
Published: September 2020

Background Pancreatic cancer is one of the deadliest malignancies, and fourth leading cause of cancer-related deaths in the United States. Aberrant glucose metabolism in cancer cells leads to enhanced tumor growth and aggressiveness. Herein, we have identified an important constituent, steviol from the plant Stevia rebaudiana, which inhibits pancreatic cancer cells via modulation of glucose metabolism and protein translation.

Methods Glucose and Lactate assays were performed in pancreatic cancer cells (HPAF-II and AsPC1) using kits purchased from Cayman Chemical. The effect of steviol on the growth, colonization and invasion of pancreatic cancer cells was determined by using in vitro functional assays for cell viability (MTT and xCELLigence), migration (Boyden chambers), invasion (Matrigel) and colonogenicity. The cell cycle study was performed using propidium iodide and analysis done through ModFit software. Immunoblotting was performed to analyze the expression of key proteins associated with translation machinery and apoptotic signaling pathways.

Results Our results demonstrate that steviol inhibits proliferation and invasion of pancreatic cancer cells and modulates their glucose uptake and lactate secretion. Steviol treatment regulates the expression of proteins that control the translation machinery in a cell, which include mTOR, 4EBP1, eIF4E, eIF4B and eIF4G. Treatment of cells with steviol was observed to modulate cell cycle regulatory proteins, including p18, p21 and Cyclin D1 and block the cell cycle progression at G1 phase This followed the activation of apoptosis as indicated by upregulation of apoptotic protein, Bax and PARP cleavage.

Conclusion: These results suggest that steviol suppresses pancreatic cancer growth and progression by regulating the glucose metabolism and protein translation. This prospects steviol as a promising therapeutic modality for pancreatic cancer prevention and treatment alone or in combination with other existing chemotherapeutic drugs.

Citation Format: Sonam Kumari, Sheema Khan, Mohammed Sikander, Shabnam Malik, Subhash C. Chauhan, Meena Jaggi. Steviol induces pancreatic cancer cell death via targeting glucose metabolism and protein translation pathways [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4195.
Abstract 4217: Synergy of tyrosine kinase inhibitor HQP1351 and MDM2-P53 antagonist, APG-115, in preclinical models of FLT3 mutant and TP53 wild-type acute myeloid leukemia
Authors: Fang Douglas D. , Tang Qiuqiong , Wang Qixin , Li Na , Fang Xu , Gu Jiaxing , Kong Yanhui , Rong Tao , Wang Guangfeng , Yang Dajun , Zhai Yifan
Published: September 2020

HQP1351 is a novel, orally bioavailable multi-kinase inhibitor targeting BCR-ABL, KIT, and FLT3. Currently, HQP1351 is in phase II clinical trials in relapsed and refractory chronic myeloid leukemia (CML) patients by targeting BCR-ABL. Besides, HQP1351 inhibits both wild-type and mutant FLT3 in kinase binding assay. APG-115 is another clinical stage, small molecule MDM2 antagonist. In the present study, we explored the antitumor effect of the combination of HQP1351 and APG-115, and the molecular mechanism in FLT3-ITD and TP53 wild-type acute myeloid leukemia (AML) in the preclinical setting. First, the effect of HQP1351 as single agent on cell viability in FLT3-ITD mutant and TP53 wild-type human AML cell lines, including MV-4-11 and MOLM-13. Second, antitumor activity of the combination was investigated in systemic and subcutaneous xenograft models in NOD/SCID mice derived from these cells. The results showed that HQP1351 alone exhibited potent antiproliferative activity in both cell lines in vitro, with nanomolar IC50 values. The activity was enhanced in the combination treatment with APG-115. In vivo, HQP1351 single agent demonstrated significant antitumor activity evidenced by a markedly reduction of tumor burden (i.e., CD45+ human tumor cells) in systemic MOLM-13 xenograft model. Treatment with HQP1351 at 3, 10 and 30 mg/kg significantly prolonged mice survival with median survival of 20.5 days, 26.0 days and 35 days, respectively, compared with 18 days in the control group. In subcutaneous MV-4-11 xenograft model, treatment with HQP1351 or APG-115 single agents achieved T/C values of 28.6% and 59.6%, respectively. The combination achieved synergistic antitumor activity with a T/C value of 13.4%. The benefit of the combination was also demonstrated in systemic MOLM-13 xenograft model. Mechanistically, the combined treatment synergistically downregulated p-FLT3, p-ERK, p-STAT5 and anti-apoptotic protein MCL-1, and thus enhanced antitumor effect. Taken together, our data provide scientific rationale for clinical development of the combination of HQP1351 and APG-115 in FLT3-ITD mutant and TP53 wild-type AML patients.

Citation Format: Douglas D. Fang, Qiuqiong Tang, Qixin Wang, Na Li, Xu Fang, Jiaxing Gu, Yanhui Kong, Tao Rong, Guangfeng Wang, Dajun Yang, Yifan Zhai. Synergy of tyrosine kinase inhibitor HQP1351 and MDM2-P53 antagonist, APG-115, in preclinical models of FLT3 mutant and TP53 wild-type acute myeloid leukemia [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4217.
Abstract 4257: Detection of bone marrow metastases: Comparison of functional magnetic resonance imaging with bone marrow biopsy and aspiration
Authors: Zhao Hui , Wang Zhiyu , Li Yue Hua
Published: September 2020

Bone marrow metastases are frequently detected by unilateral bone marrow biopsy and aspiration (BMBA), which is invasive. In this study, the value of functional magnetic resonance imaging (MRI) of pelvis was compared with BMBA and its clinical implication was evaluated. Cancer patients with bone metastasis and CT scan of pelvis showed no bone metastasis at the site of BMBA were included. BMBA was performed after MRI scan. Apparent Diffusion Coefficient (ADC), volume transfer constant (Ktrans), Pure diffusion coefficient (D), Pseudo diffusion coefficient (D*) and Perfusion fraction (f) were detected. The sensitivity, specificity and accuracy of MRI was calculate. An internal cross-validation via bootstrap was conducted for MRI performance in terms of the area under the curve (AUC). 28 oncological patients (11 breast cancer, 8 lung cancer, 5 prostatic cancer; 4 other cancers ) were enrolled. 16 patients were confirmed bone marrow metastases by BMBA. The sensitivity, specificity and accuracy of MRI was 93%, 50% and 75%. The ROC of Ktrans was 78%, which was the best. MRI can be used as a supplement to BMBA to diagnose bone marrow metastasis.

Citation Format: Hui Zhao, Zhiyu Wang, Yue Hua Li. Detection of bone marrow metastases: Comparison of functional magnetic resonance imaging with bone marrow biopsy and aspiration [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4257.
Abstract 4327: Progranulin (GP88) is an independent prognostic factor for prostate cancer patients
Authors: Taubert Helge W. , Abdulrahman Amer , Eckstein Markus , Jung Rudolf , Guzman Juan , Weigelt Katrin , Serrero Ginette , Yue Binbin , Geppert Carol , Stöhr Robert , Hartmann Arndt , Wullich Bernd , Wach Sven
Published: September 2020

Prostate cancer, is still a major cause of morbidity and mortality among men worldwide. The expression of the survival and proliferation factor progranulin (GP88) has not yet been comprehensively studied in PCa tumors. The aim of this study was to characterize GP88 protein expression in PCa by immunohistochemistry and to correlate the findings to the clinico-pathological data and prognosis. Immunohistochemical staining for GP88 was performed by TMA with samples from 442 PCa patients using an immunoreactive score (IRS). Altogether, 233 cases (52.7%) with negative GP88 staining (IRS<2) and 209 cases (47.3%) with positive GP88 staining (IRS≥2) were analyzed. A significant positive correlation was found for the GP88 IRS with the PSA value at prostatectomy and the cytoplasmic cytokeratin 20 IRS, whereas it was negatively associated with follow-up times. The association of GP88 staining with prognosis was further studied by survival analysis (Kaplan-Meier, univariate and multivariate Cox's regression analysis). Increased GP88 protein expression appeared as independent prognostic factor for overall, disease-specific and relapse-free survival in all PCa patients. Interestingly, in the subgroup of younger PCa patients (≤65 years), GP88 positivity was associated with a 3.8-fold (P=0.004), a 6.0-fold (P=0.008) and a 3.7-fold (P=0.003) increased risk for death, disease-specific death and occurrence of a relapse, respectively. This finding gains impact against the background of increasing numbers of PCa cases among younger men below 65 years of age. Summarizing, GP88 protein positivity appears to be an independent prognostic factor for PCa patients.

Citation Format: Helge W. Taubert, Amer Abdulrahman, Markus Eckstein, Rudolf Jung, Juan Guzman, Katrin Weigelt, Ginette Serrero, Binbin Yue, Carol Geppert, Robert Stöhr, Arndt Hartmann, Bernd Wullich, Sven Wach. Progranulin (GP88) is an independent prognostic factor for prostate cancer patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4327.
Abstract 4443: Inhibition of PGE2/EP4 pathway by ONO-4578/BMS-986310, a novel EP4 antagonist, promotes T cell activation and myeloid cell differentiation to dendritic cells
Authors: Kotani Tohru , Takano Hirotsugu , Yoshida Tomoko , Hamasaki Ryota , Kohanbash Gary , Takeda Kazuhiko , Okada Hideho
Published: September 2020

Prostaglandin E2 (PGE2) contributes to immunosuppression in the tumor microenvironment through one or more of its receptors (EP1-EP4), especially EP4 which is expressed at high levels on myeloid cells. ONO-4578/BMS-986310 is a novel EP4-selective antagonist that potently inhibits the PGE2-induced cAMP production in CHO cells expressing mouse and human EP4 receptors with single-digit nM IC50. Furthermore, ONO-4578/BMS-986310 shows excellent pharmacokinetic properties after oral dosing in mouse. ONO-4578/ BMS-986310 reverses PGE2-mediated suppression of T cell activation and promotes DC differentiation in vitro. Moreover, treatment with ONO-4578/BMS-986310 inhibits growth of CT26 and MC38 tumors in syngeneic mouse. The anti-tumor effect of ONO-4578/BMS-986310 is abrogated in immuno-deficient mice bearing CT26 tumors indicating that such effect is immune-mediated. ONO-4578/BMS-986310 treatment significantly prolongs survival of mice with highly aggressive SB28 gliomas in the brain. Flow cytometric analysis reveals that ONO-4578/BMS-986310 reduces infiltration of M2 macrophages in MC38 tumors compared with control mice. Microarray analysis of MC38 tumor tissues demonstrates up-regulation of cytotoxic T lymphocytes, natural killer cells and innate immunity-related genes after treatment with ONO-4578/BMS-986310. Finally, a combination of ONO-4578/BMS-986310 and anti-PD-1 antibody results in enhanced anti-tumor effects in GL261 and MC38 tumor-bearing mice compared with anti-PD-1 monotherapy.Our data demonstrate that ONO-4578/BMS-986310 promotes anti-tumor immunity and may be useful in the treatment of cancer patients. ONO-4578/BMS-986310 is being evaluated as monotherapy and in combination with nivolumab in an ongoing Ph1/1b clinical trials in patients with advanced solid tumors (NCT03155061, NCT03661632).

Citation Format: Tohru Kotani, Hirotsugu Takano, Tomoko Yoshida, Ryota Hamasaki, Gary Kohanbash, Kazuhiko Takeda, Hideho Okada. Inhibition of PGE2/EP4 pathway by ONO-4578/BMS-986310, a novel EP4 antagonist, promotes T cell activation and myeloid cell differentiation to dendritic cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4443.
Abstract 4541: QL315, A CD3 bispecific antibody redirecting T cell activation to the tumor stroma antigen LRRC15
Authors: Jin Monica , Kurtzman Aaron , Prior Weiwei W. , Chan Allan , McClain Anna , Gu Shenda , Tang Irene , Cai Zijie , Schwimmer Lauren , Tran Hieu , Chen Shihao
Published: September 2020

Leucine-rich repeat containing 15 (LRRC15) antigen is highly expressed on both stromal fibroblasts of multiple solid tumors and on cancer cells of mesenchymal origin. As its expression is very low in normal tissues, targeting LRRC15 has shown therapeutic potential as an antibody-drug conjugate (Demetri, ASCO 2019), which could lead to significant tumor inhibition by solely targeting stromal LRRC15 expression. In this study, we have developed and rank ordered an array of IgG-based CD3 bispecific molecules based on biophysical and biologic attributes and anti-cancer efficiency through T-cell engagement and redirection/activation against LRRC15-expressing tumors. The selected lead, QL315, robustly and conditionally induced T cell activation and proliferation only in the presence of LRRC15-expressing cancer cells with an EC50 in a picomolar range in vitro but not in the coculture with LRRC15-negative cancer cells. Moreover, QL315 strongly induced tumor cell lysis in vitro and led to significant tumor regression and T cell expansion in a mouse xenograft model. Importantly, toxicologic evaluation of QL315 in cynomolgus monkeys showed antibody-like stability and half-life, and good tolerability with no changes of circulating blood cell homeostasis and organ damage. At highest levels, liver enzymes, as well as cytokine release, were transiently elevated but returned to normal within one week of treatment. In conclusion, these data demonstrate drug-like properties, promising anti-tumor capability and good tolerability of the anti-LRRC15/CD3 bispecific antibody, QL315, indicating its potential as a therapeutic option in the treatment of solid tumors of diverse origin by targeting either tumor stromal micro environment or patient cancers expressing LRRC15.

Citation Format: Monica Jin, Aaron Kurtzman, Weiwei W. Prior, Allan Chan, Anna McClain, Shenda Gu, Irene Tang, Zijie Cai, Lauren Schwimmer, Hieu Tran, Shihao Chen. QL315, A CD3 bispecific antibody redirecting T cell activation to the tumor stroma antigen LRRC15 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4541.
Abstract 4549: Evaluation of GUCY2c-CD3 bispecific targeting GI cancers in an orthotopic colorectal tumor model
Authors: Yao Johnny , Mathur Divya , Yang Sharon , Conant Roger , Kearney Jessica , Buklan Vlad , Golas Jonathan , Rosfjord Edward
Published: September 2020

GUCY2c is a tumor target expressed in >90% of colorectal cancer (CRC). It is also expressed on the apical side of intestinal epithelial tight junctions, where it regulates intestinal fluidity. PF-07062119, a GUCY2c-CD3 bispecific antibody that recruits T cells to GUCY2c expressing gastrointestinal tumors, has shown anti-tumor efficacy in several subcutaneous colorectal cancer models without any signs of intestinal toxicity. Here we describe the effects of PF-07062119 in an intestinal orthotopic xenograft model, created surgically in NSG mice using LS1034 CRC cells expressing luciferase. To establish this model, LS1034-luc tumor fragments were sutured onto the cecum proximal to the colon. Tumor growth was monitored through detection of luciferin bioluminescence. PF-07062119 was administered at 0.03, 0.1 and 0.3 mg/kg iv weekly, along with an adoptive transfer of 2x106 human T cells the day after bispecific compound dosing. At 0.3 mg/kg dose, the bioluminescence signal was significantly reduced compared with the isotype control group. Necropsies at the end of study revealed complete tumor clearance, or residual calcified or fibrotic tissues, at the tumor implant site in all animals of the 0.3 mg/kg group, compared with tumor presence in 9 of 9 animals and liver metastases in 2 of 9 animals in the isotype control group. The average tumor weight of 0.1 mg/kg dose group decreased relative to the control group, but the difference did not reach statistical significance. The results of histological examination indicate enhanced T cell infiltration in the tumor tissues compared with the normal intestinal tissues in PF-07062119 treated animals. No body weight loss or other clinical signs were observed in all groups. These results demonstrate that PF-07062119 can eliminate LS1034 orthotopic tumors and potential metastasis with no observable toxicities. This supports our hypothesis that apical restriction of GUCY2c expression in normal intestine creates tumor-vs-normal differential for selective targeting of GUCY2c positive tumors, and the GUCY2c-CD3 bispecific antibody redirects T cells to lyse the CRC tumor cells.

Citation Format: Johnny Yao, Divya Mathur, Sharon Yang, Roger Conant, Jessica Kearney, Vlad Buklan, Jonathan Golas, Edward Rosfjord. Evaluation of GUCY2c-CD3 bispecific targeting GI cancers in an orthotopic colorectal tumor model [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4549.
Abstract 4597: 5-Hydroxymethylcytosine signatures in cell-free DNA as a potential biomarker for colorectal cancer andprecancerous adenoma
Authors: Xiao Zewen , Wu Jiayan , Wu Chunlong , Li Man , Sun Fuming , Zheng Lu , Liu Gaojing , Li Xiaoling , Yun Zhiyuan , Tang Jiebing , Yu Yang , Luo Shengnan , Sun Wenji , Feng Xiaohong , Cheng Qian , Tao Xue , Bai Jian , Wu Lin , Wu Shuangxiu , Tao Ji
Published: September 2020

Colorectal cancer (CRC) is a serious malignancy with the third incidence and second mortality throughout the world. 5-Hydroxymethylcytosine (5hmC) signatures in circulating cell-free DNA (cfDNA) is an important epigenetic mark linked with human cancer pathogenesis. Here we explored the genome-wide 5-hydroxymethylcytosine profiling in the plasma cfDNA and tissue genomic DNA (gDNA) acquired from 101 samples (63 from plasma and 38 from tissues), collected from 21 CRC patients, 21 precancerous adenoma (AD) patients and 21 healthy control individuals (HC). 5hmC modifications exhibited distinct features in promoter and gene body regions in all 5 groups (3 groups from plasma and 2 groups from tissues), which offered a global overview of epigenetic changes of colon pathogenic statuses between early stage CRC and AD. Adenoma showed an independent property in the 5hmC profiles compared to cancer and healthy control. The 5hmC signatures in tumor were more comprehensive and could be divided into two clusters, one was similar to the healthy individuals and the other was similar to the AD patients. The results indicated that the candidate biomarkers to distinguish colorectal cancer from the blood-test population should be generated in two ways, one focused on the differential 5hmC features between CRC patients and healthy individuals; the other should detect the adenoma and tumor patients more extensive according to their precise pathological diagnosis and clinical information. Candidate cfDNA 5hmC biomarkers were further identified in the differential 5hmC modification regions between CRC and HC with a higher sensitivity than the classical CEA marker in non-invasive blood-based diagnosis. We suggested that the differentially enriched 5hmC regions in cfDNA were potential biomarkers to track colorectal cancer, even precancerous adenoma, with further large-scale follow-up studies.

Citation Format: Zewen Xiao, Jiayan Wu, Chunlong Wu, Man Li, Fuming Sun, Lu Zheng, Gaojing Liu, Xiaoling Li, Zhiyuan Yun, Jiebing Tang, Yang Yu, Shengnan Luo, Wenji Sun, Xiaohong Feng, Qian Cheng, Xue Tao, Jian Bai, Lin Wu, Shuangxiu Wu, Ji Tao. 5-Hydroxymethylcytosine signatures in cell-free DNA as a potential biomarker for colorectal cancer andprecancerous adenoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4597.
Abstract 4611: A multicenter clinical study of stool DNA test of methylated syndecan-2 for colorectal cancer detection
Authors: Wang Jianping , Liu Side , Wang Hui , Zheng Lei , Zhou Changchun , Li Guoxin , Huang Rongkang , Wang Huaiming , Li Chujun , Fan Xinjuan , Fu Xinhui , Wang Xinying , Guo Hongliang , Guan Jie , Sun Yanlai , Song Xilin , Li Zengjun , Mu Dianbin , Sun Jujie , Liu Xianglin , Qi Yan , Niu Feng , Chen Chunhua , Wu Xiaolin , Wang Xianshu , Song Xianrang , Zou Hongzhi
Published: September 2020

Study purpose: Previously, we had a pilot study to evaluate the feasibility of a stool DNA test of methylated Syndycan-2 (SDC2) for colorectal cancer (CRC) detection. The purpose of this continuing investigation was to assess the performance of this test in a multicenter hospital-based setting.

Methods: Each participant was required to undergo both a stool DNA test and a reference colonoscopy. The stool DNA test assesses the methylation status of a single target of SDC2 gene. Results of real-time methylation-specific PCR were dichotomized as positive and negative by a prespecified cut-off value. The main evaluation indexes were sensitivity, specificity, and kappa value, which was used to assess the diagnostic consistency between stool DNA test and colonoscopy. Tests were performed in blinded fashion and processed independently of the colonoscopic results.

Results: Among the 1110 participants from three hospitals included for analysis, 359 and 38 had CRC and advanced adenomas, respectively, according to colonoscopy findings. The sensitivity of the stool DNA test was 83.8% for CRC and 42.1% for advanced adenomas. For CRC at early stage confined to bowel wall (I to II), the sensitivity was 87.0%. Detection rate for CRC did not vary significantly according to age, tumor location, differentiation, and TNM stage, except for gender (P=0.041). The specificity of the stool DNA test was 98.0% among participants with nonadvanced colorectal neoplasia, non-neoplastic disorders, or negative results on colonoscopy. Diagnostic consistency for CRC assessed by kappa value was 0.84, indicating that the agreement in outcome between the stool DNA test and colonoscopy was excellent.

Conclusion: Noninvasive stool DNA test using methylated SDC2 as a molecular marker was a sensitive and accurate method for CRC detection.

Citation Format: Jianping Wang, Side Liu, Hui Wang, Lei Zheng, Changchun Zhou, Guoxin Li, Rongkang Huang, Huaiming Wang, Chujun Li, Xinjuan Fan, Xinhui Fu, Xinying Wang, Hongliang Guo, Jie Guan, Yanlai Sun, Xilin Song, Zengjun Li, Dianbin Mu, Jujie Sun, Xianglin Liu, Yan Qi, Feng Niu, Chunhua Chen, Xiaolin Wu, Xianshu Wang, Xianrang Song, Hongzhi Zou. A multicenter clinical study of stool DNA test of methylated syndecan-2 for colorectal cancer detection [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4611.
Abstract 4614: Genome-wide association analysis of pro-inflammatory cytokines and gene-lifestyle interaction for invasive breast cancer risk: The WHI Database for Genotypes and Phenotypes Study
Authors: Jung Su Yon , Scott Peter , Han Sihao , Pellegrini Matteo , Papp Jeanette , Sobel Eric , Yu Herbert , Zhang Zuo-Feng
Published: September 2020

Purpose: Pro-inflammatory biomarkers and their genetic variants may interact with obesity and obesity-related lifestyle factors, influencing breast cancer risk in postmenopausal women, but the interrelated metabolic pathways are incompletely understood.

Methods: We used data from the Women's Health Initiative Database for Genotypes and Phenotypes Study including 16,088 postmenopausal women, a population highly susceptible to obesity and increased risk for breast cancer. We conducted a genome-wide association (GWA) analysis in two steps: 1) with six GWA substudies, GWA meta-analysis of pro-inflammatory cytokines (Interleukin-6 [IL-6] and C-reactive protein [CRP]) for their gene-lifestyle interactions and 2) test for the association between identified single-nucleotide polymorphisms (SNPs) at the genome-wide level and breast cancer risk.

Results: In women overall and stratified by obesity status (body mass index, waist circumference, and waist-to-hip circumference) and obesity-related lifestyle factors (physical activity and high fat-diet), 88 loci were associated with pro-inflammatory phenotypes at genome-wide significance: 3 associated with IL-6 (1 index SNP in MAPK1 and 1 independent SNP in DEC1); 85 with CRP (3 index SNPs in CRP/CRPP1/HNF1A and 2 SNPs in APOE/APOC1, independently). Of those, 27 loci had significantly increased risk for breast cancer.

Conclusions: We found a number of novel genetic markers in relation to pro-inflammatory phenotypes, which interacted with obesity and related lifestyle factors. A substantial proportion of those SNPs' susceptibility influences breast cancer risk in the identical subgroup populations. Our findings may contribute to improved prediction accuracy for cancer and suggest intervention strategies for women who carry the risk genotypes, eventually reducing breast cancer risk.

Citation Format: Su Yon Jung, Peter Scott, Sihao Han, Matteo Pellegrini, Jeanette Papp, Eric Sobel, Herbert Yu, Zuo-Feng Zhang. Genome-wide association analysis of pro-inflammatory cytokines and gene-lifestyle interaction for invasive breast cancer risk: The WHI Database for Genotypes and Phenotypes Study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4614.
Abstract 4642: Effects of soy protein diet on plasma isoflavones levels in obese DMBA-induced mammary tumor rat model
Authors: Hakkak Reza , Korourian Soheila
Published: September 2020

Obesity epidemic in the US and world grows as the number of overweight and obese adults continues to rise. Obese women have higher mortality rates from all cancers including breast cancer. Several studies have reported the protective effects of soy intake on breast cancer development, while other studies report the adverse effects of soy protein diet on breast cancer development. Soybeans contain isoflavones genistein, daidzein and glycitein, known as isoflavonoids, which are structurally similar to mammalian estrogens, have estrogenic properties and are potential anticarcinogens. Gut flora metabolizes daidzein into equol, a non-steroidal estrogen and has cancer chemopreventive property. The objective of this study was to determine the effects of obesity and a high isoflavones soy protein diet on plasma isoflavones; genistein, daidzein, glycitein, equol and O-Desmethylangolensin (O-MDA) levels using 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary tumor model. Five-week-old female Zucker rats (45 obese fa/fa and 54 lean) were used. After one week of acclimation (age 42 days), rats were randomly assigned to the following diet groups; 1) Lean, casein; 2) Obese, casein; 3) Lean, soy and 4) Obese, soy. Rats had ad lib access to water and diet with either casein or soy protein isolate as source of protein. All rats were orally gavaged at age 50 days with 65 mg/kg DMBA. Rats were weighed and palpated twice weekly and sacrificed 21 weeks post-DMBA treatment. Plasma was collected to measure genistein, daidzein, glycitein, equol and O-MDA levels using liquid chromatography−tandem mass spectrometry (LC-MS/MS). At end of the experiment, 69% of the Lean casein rats developed mammary tumors compared to 50% in lean soy group (p= 0.176). In the obese group, 76% of the soy-fed rats developed mammary tumors compared to 15% (P<0.001) of obese casein- fed rats. Plasma daidzein and genistein concentration were not significantly different in lean vs obese soy-fed rats. However, O-MDA and equol concentration were significantly lower (P<0.05) in obese soy-fed rats compared to lean soy rats. These data suggests that obese rats fed soy protein diet containing high isoflavone levels promoted DMBA-induced mammary tumor development compared to a casein-based diet. Also, obese soy-fed rats exhibited significantly lower plasma equol concentrations than those observed in lean soy-fed rats and this reduction may aid in explaining soy's impaired cancer chemopreventative effects in obese breast cancer model.

Citation Format: Reza Hakkak, Soheila Korourian. Effects of soy protein diet on plasma isoflavones levels in obese DMBA-induced mammary tumor rat model [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4642.
Abstract 466: Epigenetic drug profiling in diffuse intrinsic pontine glioma
Authors: Tolson Hannah
Published: September 2020

Diffuse Intrinsic Pontine Glioma (DIPG) is a highly aggressive and universally fatal form of childhood brain cancer. As prognosis has improved little over the last 40 years, exploring alternate drug therapies remains paramount. Roughly 80% of DIPG patients harbor mutations that result in the substitution of a lysine for a methionine at position 27 of histone variants 3.1 and 3.3 (H3.1K27M and H3.3K27M). This hallmark mutation causes global epigenetic changes in DIPG patients by dysregulating methylation and acetylation of histones, thus making the epigenome a potential therapeutic target. We explored vulnerabilities in 10 DIPG models (8 of which were H3.3K27M and 2 of which were H3.1K27M) to HDAC inhibitors (TSA and Panobinostat) and an LSD1 inhibitor (SP2577) both alone and in combination using drug dose response assays. As expected, Panobinostat showed high potency in each DIPG cell line, with 7 of the 9 lines having IC50 values less than 10 nM. In contrast, all 10 lines had no response to SP2577 apart from cytotoxic reactions in higher concentration ranges. SP2577 will thus be interesting to test in combination with Panobinostat with the intention of increasing its sensitivity. We also evaluated the efficacy of epigenetic drugs when used in combination with drugs targeting transcriptional pathways including TGN1076, a novel reversible CDK7 inhibitor. We found that TGN1076 shows marginal synergy with TSA, an HDAC inhibitor, and good synergy with JQ1, a BET inhibitor in the cell line DIPG6. Though equilibrating the epigenome remains a necessary objective in DIPG research, elucidating the mechanisms underlying extreme epigenetic shifts could provide important insight into disease pathogenesis. For this reason, we also focused on the histone methyltransferase protein PRC2 which is commonly implicated in epigenetic dysregulation in DIPG. Because the catalytic subunit of PRC2, EZH1/2, is allosterically regulated by another subunit, EED, in a “write and read mechanism,” we are testing the efficacy of the drug EED226 which binds to EED and modulates the function of PRC2. Analyzing the effects of this drug alone and in combination will provide a novel approach to managing PRC2 dysregulation and will potentially reveal future therapeutic strategies. Through screening novel drugs and testing their efficacies in combination with drugs that are commercially available, we intend to provide future therapeutic options for DIPG patients.

Citation Format: Hannah Tolson. Epigenetic drug profiling in diffuse intrinsic pontine glioma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 466.
Abstract 4689: Co-treatment of MEKi and BRD4 inhibitors lead to synergistic repression of MYC-associated enhancer RNAs
Authors: Azofeifa Joseph , Basken Joel , Lai Maria , Langendorf Ryan , Norris Laura , Read Tim , Robbins-Pianka Adam
Published: September 2020

Recent evidence suggests that co-treatment with BRD4 and MEK inhibitors can lead to synergistic suppression of MAPK signaling, however, little is known about the mechanism of action of this synergy. In a triple negative breast cancer cell line model, we harvested nascent RNA at 45 minutes following repression of BRD4 and MEK via a variant of the precision run-on followed by sequencing (PRO-seq) assay. We noted dose-dependent repression of enhancer RNAs over MYC binding sites as well as enhancer RNAs upstream known ERK targets such as DUSP6. Using new machine learning techniques, we were able to link synergy-specific enhancer RNAs to their target genes. This work will inform on new methods for patient stratification and biomarker selection of the BETi and MEKi treatment regimes.

Citation Format: Joseph Azofeifa, Joel Basken, Maria Lai, Ryan Langendorf, Laura Norris, Tim Read, Adam Robbins-Pianka. Co-treatment of MEKi and BRD4 inhibitors lead to synergistic repression of MYC-associated enhancer RNAs [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4689.