bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 6223: Combination of BCL-2/BCL-xL dual inhibitor APG-1252 and chemotherapeutics overcomes resistance to osimertinib in EGFR mutant NSCLC in preclinical models
Authors: Tao Ran , Wang Guangfeng , Fang Douglas D. , Zhai Guoqin , Li Yuanbao , Lv Jing , Wu Miaoyi , Ge Yangfeng , Zhang Feifei , Wen Danyi , Yang Dajun , Zhai Yifan
Published: September 2020

Osimertinib (AZD9291) is the first-line treatment for EGFR-mutated NSCLC; however, the majority of patients inevitably develop resistance due to de novo genomic abnormalities, such as C797S mutation, EGFR exon 20 insertion, MET amplification and other unknown mechanisms. Hence, effective therapies to overcome acquired resistance are urgently needed. Inhibition of BCL-2/BCL-xL has been reported to enhance apoptosis in EGFR-TKI resistant cells with low sensitivity to EGFR inhibition. In this study, we evaluated whether the combination of a dual BCL-2/BCL-xL inhibitor APG-1252 and chemotherapeutics could overcome osimertinib resistance in preclinical xenograft models.

First, EGFR C797S mutation was introduced to human NCI-H1975 NSCLC cells to construct an NCI-H1975-C797S resistant cell line using CRISPR technology. NCI-H1975-C797S derived-xenografts were treated with APG-1252, cisplatin/docetaxel or their combinations.

Combination therapy with APG-1252 and cisplatin or docetaxel exhibited synergistic antitumor activity. APG-1252 plus docetaxel combination achieved 100% tumor partial regression (PR). Similar results were demonstrated in a patient-derived xenograft (PDX) tumor model derived from an osimertinib-resistant NSCLC patient harboring 19del-T790M-C797S mutations. Furthermore, the combinations also exhibited enhanced antitumor activity in an osimertinib-resistant PDX model that the resistant mechanism remained unknown.

In summary, our results suggest that the combination treatment with APG-1252 and chemotherapeutics can overcome acquired resistance to osimertinib and the combination deserves further clinical evaluations.

Citation Format: Ran Tao, Guangfeng Wang, Douglas D. Fang, Guoqin Zhai, Yuanbao Li, Jing Lv, Miaoyi Wu, Yangfeng Ge, Feifei Zhang, Danyi Wen, Dajun Yang, Yifan Zhai. Combination of BCL-2/BCL-xL dual inhibitor APG-1252 and chemotherapeutics overcomes resistance to osimertinib in EGFR mutant NSCLC in preclinical models [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 6223.
Abstract 6252: Development and validation of an LC/MS/MS method for the determination of celastrol in rat plasma and its application to the pharmacokinetic evaluation of celastrol-encapsulated silk fibroin nanoparticles
Authors: Zhan Shuyu , Paik Amy , Onyeabor Felicia , Ding Baoyue , Prabhu Sunil , Wang Jeffrey
Published: September 2020

Celastrol (CL), a compound isolated from Tripterygium wilfordii, possesses various bioactivities such as anti-tumor, anti-inflammatory and anti-obesity effects. Many new drug delivery systems of CL have been designed to overcome its poor water solubility and low bioavailability. However, few studies are available concerning its in vivo pharmacokinetics. In this study, a simple and sensitive LC-MS/MS method was developed and validated to determine CL in rat plasma using 18α-glycyrrhetinic acid as the internal standard. The separation of CL was performed on a Phenomenex Gemini C18 column (150 mm × 2 mm, 5 µm) following sample preparation using liquid-liquid extraction with the optimized extraction solvent of tert-butyl methyl ether and a small plasma sample volume of 50 μL. The analyte was quantitated under positive electrospray ionization and multiple reactions monitoring mode. The assay exhibited a good linearity in the concentration range of 0.5-500 ng/mL. The lower limit of quantification (LLOQ) was 0.5 ng/mL. The method was fully validated to meet the requirements for bioassay with accuracy of 91.1-110.0%, precision (RSD %) of less than 9.1 %, extraction recovery of 63.5-74.7%, and matrix effect of 87.3-101.2%. The developed method was successfully applied to the pharmacokinetic evaluation of CL-encapsulated silk fibroin nanoparticles (CL-SFNP). The results show, after intravenous (IV) and oral (PO) administration of equivalent CL (1 mg/kg and 3 mg/kg, respectively) in rats, the AUC values of CL were 8646.1±1998.9 ng/mL·h after IV dosing and 1065.5±494.6 ng/mL·h after PO dosing for CL-SFNP, which were significantly (P<0.05) higher than those for pure CL (4697.7±723.0 ng/mL·h and 441.9±82.6 ng/mL·h, respectively). The dose-normalized oral bioavailability of CL significantly (P<0.05) increased from 3.1% for pure CL to 7.6% for CL-SFNP.

Citation Format: Shuyu Zhan, Amy Paik, Felicia Onyeabor, Baoyue Ding, Sunil Prabhu, Jeffrey Wang. Development and validation of an LC/MS/MS method for the determination of celastrol in rat plasma and its application to the pharmacokinetic evaluation of celastrol-encapsulated silk fibroin nanoparticles [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 6252.
Abstract 6362: TH1901, a novel curcumin-peptide conjugate for the treatment of Sortilin-positive (SORT1+) cancer
Authors: Annabi Borhane , Demeule Michel , Currie Jean-Christophe , Larocque Alain , Zgheib Alain , Marsolais Christian , Béliveau Richard
Published: September 2020

Rational: Phytochemicals are compounds found in plant foods that can help prevent the occurrence of chronic diseases like cancer. Several studies, over the last decade on the impact of phytochemicals in cancer treatment, have provided experimental evidence that curcumin contains antiproliferative, antiangiogenic, and apoptotic properties. Further evidence suggested that curcumin also suppresses tumor/colon cancer cell progression and angiogenesis by stimulating apoptosis and regulating immune response. Increased expression of the scavenging receptor Sortilin (SORT1), has been clinically observed in numerous invasive tumor biopsies.

Procedures: In light of this, we developed a peptide conjugation platform and a new SORT1 receptor-mediated strategy to increase cell targeting selectivity and cell delivery of anticancer agents. As a proof-of-concept for phytochemicals, curcumin was conjugated to a SORT1-binding proprietary peptide (TH19P01). Curcumin-TH19P01 conjugate (TH1901) and unconjugated curcumin were tested on the proliferation of various cancer cells.

Results: TH1901 showed a stronger anti-proliferation activity against cancer cells, with IC50 values up to 100-fold greater when compared to unconjugated curcumin. In addition, higher accumulation of fluorescence was detected for TH1901 indicating a more efficient cell internalization and release of curcumin from the conjugate. TH1901 uptake was reduced in the presence of SORT1 ligands neurotensin and progranulin as well as of free peptide confirming a preferential SORT1-mediated uptake of TH1901 in ES-2 ovarian cancer cells. Fluorescence microscopy showed that, in contrast to unconjugated curcumin, TH1901 induced cell apoptosis, and showed a stronger effect than unconjugated curcumin on TNF-alpha-induced intracellular signaling pathways involved in pro-inflammation processes. Interestingly, conjugation of curcumin also increased its in vitro stability in solution. In vivo, intraperitoneal administration of TH1901 (60 mg/kg/twice a week) inhibited growth of SORT1+ HT-29 colorectal cancer cell subcutaneous xenograft tumors, whereas at an equivalent dose unconjugated curcumin (15 mg/kg/twice a week) had no effect.

Conclusion: Overall, these proof-of-concept experiments support the future development of this flexible and innovative platform to generate novel anticancer treatments.

Citation Format: Borhane Annabi, Michel Demeule, Jean-Christophe Currie, Alain Larocque, Alain Zgheib, Christian Marsolais, Richard Béliveau. TH1901, a novel curcumin-peptide conjugate for the treatment of Sortilin-positive (SORT1+) cancer [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 6362.
Abstract 6375: Development of novel Pt-based drugs using Deferasirox as ligand to diminish systemic toxicity and resistance induced by CisPt
Authors: Delgado Yamixa , Pandrala Mallesh , Perez Daraishka , Velazquez Eddian , Vega Jaisy , Milian Melissa , Torres Anamaris
Published: September 2020

Today, CisPt is one of the most successful chemotherapeutic metallodrugs. Unfortunately, the use of CisPt is restricted by the dose-limiting toxic effects and the acquired resistance, especially in lung cancer. As an alternatively, FDA-approved drugs for different diseases which target cancer metabolic pathways, are considered an attractive strategy to diminish systemic toxic effects. In the same way, the mechanistic pathways activated/inactivated by this drug could potentially overcome the acquired resistance induced by CisPt. For this reason in our approach, we incorporated deferasirox (Def), a clinical drug for iron (Fe) overload, as the ligand in the development of novel Pt complexes. In cancer progression, Fe plays a key role as a nutrient for cell growth and energy production. In consequence, we have synthesized and characterized our first library of three Pt-Def complexes: Pt(Def-COOH), Pt(Def-CONH2), Pt(Def-COOCH3). In this strategy, we have modified the OH of the carboxylic group of the Def to see the effects in the metabolic pathways. Viability assay results showed that Pt(Def-CONH2) induced a dramatic decrease in the IC50 in non-small lung adenocarcinoma cells after 24 h of incubation compared to CisPt, Def and Def-CONH2. Gene expression studies were conducted for cell growth, resistance and metastases related genes, where Pt(Def-CONH2) showed a significant downregulation of all of them. In addition, insight into target sites and metabolic pathways (apoptosis, caspase 3, ROS, cell cycle) inhibited or activated was garnered. This study will afford the optimization of the rationale to fine tune the structure of novel potential drugs.

Citation Format: Yamixa Delgado, Mallesh Pandrala, Daraishka Perez, Eddian Velazquez, Jaisy Vega, Melissa Milian, Anamaris Torres. Development of novel Pt-based drugs using Deferasirox as ligand to diminish systemic toxicity and resistance induced by CisPt [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 6375.
Abstract 6380: Suppression of the solar ultraviolet-induced skin carcinogenesis by TOPK inhibitor HI-TOPK-032
Authors: Roh Eunmiri , Han Yaping , Reddy Kanamata , Zykova Tatyana A. , Lee Mee Hyun , Yao Ke , Bai Ruihua , Curiel-Lewandrowski Clara , Dong Zigang
Published: September 2020

Non-melanoma skin cancer (NMSC) such as cutaneous squamous cell carcinoma (cSCC) is caused by solar ultraviolet (SUV) exposure and is the most common cancer in the United States. T-LAK cell-originated protein kinase (TOPK), a serine-threonine kinase is activated by SUV irradiation and involved in skin carcinogenesis. Strategies with research focusing on the TOPK signaling pathway and targeted therapy in skin carcinogenesis may helpful for the discovery of additional treatments against skin cancer. In this study, we found that TOPK can directly bind to and phosphorylate c-Jun (as one of the core member of AP-1) at Ser63 and Ser73 after SSL exposure in a JNKs-independent manner. TOPK knocking down, or HI-TOPK-032 (TOPK specific inhibitor) attenuated colony formation and cell proliferation of skin cancer cells. Phosphorylated levels of c-Jun were overexpressed in human AK and cSCC compared to normal skin tissues, and HI-TOPK-032 inhibited the phosphorylation of c-Jun in SCC cell line in a dose-dependent manner. Furthermore, HI-TOPK-032 decreased SSL-induced AP-1 transactivation activity. Moreover, acute SSL-induced inflammation was attenuated by the topical application of HI-TOPK-032 in SKH1 hairless mice. Importantly, HI-TOPK-032 suppressed chronic SSL-induced skin carcinogenesis and c-Jun phosphorylation levels in SKH1 hairless mice. Our results demonstrate that TOPK can phosphorylate and activate c-Jun at Ser63 and Ser73 in the process of skin carcinogenesis and HI-TOPK-032 could be used as a potential chemopreventive drug against cSCC development.

Citation Format: Eunmiri Roh, Yaping Han, Kanamata Reddy, Tatyana A. Zykova, Mee Hyun Lee, Ke Yao, Ruihua Bai, Clara Curiel-Lewandrowski, Zigang Dong. Suppression of the solar ultraviolet-induced skin carcinogenesis by TOPK inhibitor HI-TOPK-032 [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 6380.
Abstract 6414: Using 3D models to test the efficacy of targeting cancer-associated fibroblast exosomes to overcome chemoresistance in pancreatic cancer
Authors: Eun Chae Young , DeKalb Charlene , Xiao Weikun , Zhang Xinyu , Hill Reginald
Published: September 2020

Exosomes play a critical role in promoting proliferation and survival of cancer cells. These extracellular vesicles that range in size from 30-100nm in diameter are released by many different cell types and contain proteins, nucleic acids, and micro RNAs that can modify the content and state of recipient cells. Our previous studies have shown that cancer-associated fibroblasts (CAFs), which make up the bulk of pancreatic ductal adenocarcinoma (PDAC) tumors, hypersecrete exosomes upon chemotherapy treatment. When these exosomes were taken up by surrounding cancer cells, we observed more cell proliferation and drug resistance. Considering these findings, there is clearly a need of therapeutic strategies that target exosome biogenesis and secretion. Here, we investigate the effectiveness of several compounds, including farnesyl transferase inhibitors, imidazoles, and nonsteroidal anti-inflammatory drugs (NSAIDs), in blocking exosome secretion and suppressing chemoresistance in PDAC CAF and cancer cell lines. We observed decrease in exosome secretion upon ketoconazole, tipifarnib, and neticonazole treatment, using GW4869 (a neutral sphingomyelinase inhibitor) as our control. Furthermore, we established a 3D organoid model from our PDAC mouse models to better understand the impact of these drugs on exosome secretion in tumors with different genetic alterations. Together, our 2D and 3D models illuminate the potential for pharmacological targeting of exosome secretion as a treatment option that can improve the current standard-of-care treatment in PDAC.

Citation Format: Chae Young Eun, Charlene DeKalb, Weikun Xiao, Xinyu Zhang, Reginald Hill. Using 3D models to test the efficacy of targeting cancer-associated fibroblast exosomes to overcome chemoresistance in pancreatic cancer [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 6414.
Abstract 6433: Dual targeting MYC G-quadruplex and topoisomerase I: Lead discovery indenoisoquinolines for cancer therapy
Authors: Wang Kaibo
Published: September 2020

G-quadruplexes are noncanonical four-stranded DNA or RNA secondary structures that have emerged as novel therapeutic targets. MYC is one of the most important oncogenes and is overexpressed in a number of human cancers. The G-quadruplex formed in the MYC oncogene promoter (MycG4) is a transcriptional silencer and amenable to small molecule targeting. Indenoisoquinolines are human topoisomerase I inhibitors with improved physicochemical and biological properties as compared to the clinically used camptothecin anticancer drugs. Three indenoisoquinolines, indotecan (LMP400), indimitecan (LMP776), and LMP744, have entered phase I clinical trials in adults with relapsed solid tumors and lymphomas. However, some indenoisoquinolines showed potent anticancer activity without being strong topoisomerase I inhibition activity, suggesting additional mechanisms of action. Herein, we demonstrate that a large number of anticancer indenoisoquinolines strongly bind and stabilize MycG4 in vitro, using fluorescence, nuclear magnetic resonance (NMR), and circular dichroism (CD) spectroscopy, as well as gel electromobility shift assay (EMSA). In addition, MycG4-interactive indenoisoquinolines lower MYC mRNA and protein levels in vivo, as shown by western blotting and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) experiments. These results indicate that targeting the MYC promoter G4 to downregulate MYC is a likely mechanism of action for the anticancer activities of these particular indenoisoquinolines. In addition, structure-activity-relationships of MycG4 recognition by indenoisoquinolines were investigated and elucidated the essential structural requirements for strong binding. The analysis of indenoisoquinoline derivatives for their MYC inhibitory, topoisomerase I inhibitory, and anticancer activity led to the discovery of a synergistic effect of MYC inhibition and topoisomerase I inhibition on anticancer activity. In conclusion, our result reveals MYC downregulation by MycG4 binding as a new mechanism of action for anticancer indenoisoquinolines. Moreover, we suggest dual targeting of MycG4 and topoisomerase I as a novel strategy for cancer therapy.

Citation Format: Kaibo Wang. Dual targeting MYC G-quadruplex and topoisomerase I: Lead discovery indenoisoquinolines for cancer therapy [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 6433.
Abstract 6448: Oral cancer pain mediators released in exosomes are oncogenes with potential to shape the microenvironment and induce neuronal sensitivity
Authors: Bhattacharya Aditi , Dubeykoskaya Zinaida , Nguyen Huu Tu , Dolgalev Igor , Veeramachaneni Ratna , Schmidt Brian L. , Albertson Donna G.
Published: September 2020

Oral cancer patients suffer severe chronic and mechanically-induced pain at the site of the cancer. Patients with metastatic (N+) cancers report greater pain. Cancer pain is attributed to cancer-derived mediators that sensitize neurons and is associated with increased neuronal density. To identify cancer derived mediators of pain and metastasis, we queried an RNA-seq dataset of 19 cancers and 5 normal tissues for genes overexpressed in N+ cancers from patients who reported high pain on the UCSF Oral Cancer Pain Questionnaire (UCSFOCPQ). The 40 candidate pain mediator genes are enriched for functions in extracellular matrix organization and angiogenesis, and are reported to have oncogenic and neuronal functions. Differentially expressed genes encoding neurotrophic and axon guidance molecules were also identified. The pain and metastasis genes encode secreted or membrane proteins. Most of the pain and metastasis genes have been reported in exosomes. A role for exosomes in induction of cancer pain was demonstrated using a mouse paw withdrawal assay. Intraplantar injection of HSC-3 oral tongue cancer cell line conditioned media induced mechanical allodynia and thermal hyperalgesia. By contrast, when conditioned medium depleted of exosomes and extracellular vesicles (EVs) by size exclusion chromatography was injected into the paw, nociceptive behavioral responses to mechanical or thermal stimuli were reduced or abolished, respectively. Nociceptive responses to these stimuli were restored by reconstitution of the EV depleted media with the EV fraction. In conclusion, functional analysis of genes overexpressed in painful N+ cancers highlighted the composition of the N+ oral cancer microenvironment for promotion of angiogenesis and axonogenesis. Preclinical studies implicated cancer-derived exosomes in induction of pain. The autocrine and paracrine actions of identified pain and metastasis genes, as well as communication via exosomes, are potential therapeutic targets for stopping cancer and alleviating pain.

Citation Format: Aditi Bhattacharya, Zinaida Dubeykoskaya, Huu Tu Nguyen, Igor Dolgalev, Ratna Veeramachaneni, Brian L. Schmidt, Donna G. Albertson. Oral cancer pain mediators released in exosomes are oncogenes with potential to shape the microenvironment and induce neuronal sensitivity [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 6448.
Abstract 6461: HER2 positive DCIS increases short term risk of ipsilateral invasive ductal carcinoma in breast conserving surgery patients
Authors: O'Keefe Thomas , Blair Sarah , Hosseini Ava , Harismendy Olivier , Wallace Anne
Published: September 2020

Purpose: The impact of HER2 status in ductal carcinoma in situ (DCIS) lesions on the risk of progression to invasive ductal carcinoma (IDC) has been debated with reports of both increased and decreased risk of development of invasive breast cancer in HER2 positive patients. We aim to use a large national database to elucidate the effect of HER2 positivity on ipsilateral IDC (iIDC) development.

Methods: We performed survival analyses on patient-level data using the US National Cancer Institute's Surveillance, Epidemiology, and End Results program to identify patients diagnosed with DCIS who underwent lumpectomy and had known HER2, estrogen and progesterone receptor statuses, grade, comedonecrosis, age, tumor size, and radiation therapy (RT). Competing risks analysis was performed.

Results: 1,540 patients meeting inclusion criteria were identified. Median age at diagnosis was 60 with median follow-up time of 44.5 months. 22 (1.4%) patients developed iIDC and 27 (1.8%) developed ipsilateral in situ or contralateral disease. 1,035 (67.2%) patients were HER2 negative and 417 (27.1%) were HER2 positive. The estimated cumulative incidence of iIDC at 5 years was 1.9% for all patients, 1.2% (95% CI 0.6-2.1%) for HER2 negative patients, and 4.0% (95% CI 2.9-5.4%) for HER2 positive patients. On competing risks regression, two factors were significant for iIDC: RT within 20 months (HR=0.02, p=0.0002) and HER2 positivity (HR=2.81, p=0.046).

Conclusions: HER2 may serve as a prognostic factor for consideration in decision making in patients for whom it is available, and in our analysis was the only lesion-related factor to significantly relate to iIDC development.

Citation Format: Thomas O'Keefe, Sarah Blair, Ava Hosseini, Olivier Harismendy, Anne Wallace. HER2 positive DCIS increases short term risk of ipsilateral invasive ductal carcinoma in breast conserving surgery 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 6461.
Abstract 6472: Clonal lineage and somatic hypermutation analysis of chronic lymphocytic leukemia by long-amplicon IGH chain sequencing
Authors: Chang Jayde , Davis Zadie , Quest Graeme , Feilloter Harriet , Toro Michelle , Lowman Geoffrey , Pickle Loni , Hyland Fiona , Looney Timothy
Published: September 2020

Background: Current next-generation sequencing (NGS) approaches for analyzing SHM commonly rely on multiplex primers targeting the framework 1 (FR1) or leader region of the IGH variable gene in combination with joining gene primers to amplify rearranged IGH chains from gDNA template. Limitations include the potential for joining gene mutations to interfere with primer binding and an inability to evaluate isotype. Here we present a method for translational research investigations of IGH chain SHM employing multiplex FR1 and isotype (constant gene) specific primers (Oncomine IGH-LR assay primers) to amplify IGH chains from RNA template. We evaluated performance by comparing SHM values obtained from NGS of RNA from 54 CLL samples amplified using Oncomine IGH-LR primers to values obtained by Sanger sequencing or NGS of RNA amplified using FR1 or leader region/J gene primers.

Methods: IGH chains from 54 CLL samples derived from two separate sequencing sites (Site 1: 24 samples, Site 2: 30 samples) were amplified from peripheral blood using Oncomine IGH-LR assay followed by sequencing via the Ion Gene Studio S5. Clonotyping, clonal lineage identification and somatic hypermutation analysis was performed by Ion Reporter via comparison to the IMGT reference database. Oncomine IGH-LR assay SHM values were compared to those obtained via NGS-based sequencing utilizing FR1/J gene primers (Site 1) or Sanger sequencing utilizing IGH-leader or FR1 and joining gene primers (Site 2).

Results: IGHV SHM values were highly concordant between NGS approaches (Spearman cor =.957, Site 1) and between Sanger sequencing and NGS approaches (Spearman cor = .849, Site 2). Sequence data obtained using Oncomine IGH-LR assay enables more in-depth clonal lineage analysis, including evaluation of isotype representation and subclonal evolution.

Conclusions: These results support the robustness and reliability of multiplex FR1 and constant gene based IGH chain amplification for the translational research characterization of somatic hypermutation in CLL and other B cell neoplasms.

Citation Format: Jayde Chang, Zadie Davis, Graeme Quest, Harriet Feilloter, Michelle Toro, Geoffrey Lowman, Loni Pickle, Fiona Hyland, Timothy Looney. Clonal lineage and somatic hypermutation analysis of chronic lymphocytic leukemia by long-amplicon IGH chain sequencing [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 6472.
Abstract 659: Synergistic antitumor activity of futibatinib (TAS-120), a FGFR1-4 inhibitor, and PI3K pathway inhibitors
Authors: Miura Akihiro , Sootome Hiroshi , Komori Toshiharu , Ochiiwa Hiroaki , Hirai Hiroshi
Published: September 2020

Background: Futibatinib, a selective irreversible small-molecule fibroblast growth factor receptor (FGFR) 1–4 inhibitor is currently being investigated in phase 2 studies in patients with various FGFR-deregulated cancers. FGFRs use the PI3K pathway to promote cell growth and survival, suggesting that a combination of futibatinib with PI3K pathway inhibitors may result in synergistic activity. Therefore, we investigated the antitumor effects of futibatinib plus PI3K pathway inhibitors, everolimus (mTOR inhibitor) or MK2206 (AKT inhibitor).

Methods: Human endometrial FGFR2-N549K-mutated AN3CA cancer cells were treated with futibatinib plus either everolimus or MK2206 or with each agent alone. AKT, ERK, mTOR, and S6 phosphorylation, cell viability, and apoptosis (via caspase-3/7 activity) were assessed. Cell growth inhibition was measured and combination indices (CIs) determined using CalcuSyn software; a CI<0.9 indicates synergy. Antitumor activity of futibatinib plus everolimus in ANC3A xenografts was evaluated by assessing relative tumor volume (RTV).

Results: In ANC3A cells, the combination of futibatinib with MK2206 inhibited AKT phosphorylation; futibatinib plus either MK2206 or everolimus inhibited mTOR phosphorylation to a greater degree than monotherapy. Apoptosis induction by caspase-3/7 was readily detected with futibatinib plus MK2206, but low to no activity was observed with either agent alone. A synergistic effect on cell growth inhibition was observed for futibatinib plus everolimus (CI=0.26) or MK2206 (CI=0.14). In AN3CA xenografts, there was a significant (P<0.05) decrease in RTV with futibatinib plus everolimus vs monotherapy (Table).

Table.Relative tumor volume in AN3CA mouse xenografts treated with futibatinib or everolimus or combination therapyTreatment (mg/kg/d)Relative tumor volumeDay 0Day 3Day 6Day 10Day 15Control14.657.8116.4937.77Futibatinib (15)a13.084.516.8412.59Futibatinib (50)a12.292.703.154.76Everolimus (2)a12.664.046.3410.24Futibatinib + Everolimus (15 + 2)b11.841.921.681.91Futibatinib + Everolimus (50 + 2)b11.501.310.840.72aDays 1–14 (oral);bDays 1–14 + Days 1–14 (both oral).

Conclusions: The combination of futibatinib plus a PI3K pathway inhibitor resulted in synergistic antitumor effects. These data are encouraging and can serve as a basis for investigating the combination of PI3K pathway inhibitors with futibatinib.

Citation Format: Akihiro Miura, Hiroshi Sootome, Toshiharu Komori, Hiroaki Ochiiwa, Hiroshi Hirai. Synergistic antitumor activity of futibatinib (TAS-120), a FGFR1-4 inhibitor, and PI3K pathway inhibitors [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 659.
Abstract 6636: Therapy with BXCL701 (B), a DPP8, DPP9, DPPIV and FAP inhibitor, in combination with anti-PD1 antibody (PD1) in a syngeneic murine pancreatic ductal adenocarcinoma (PDAC) model improves treatment outcomes and induces intratumoral NK cell infiltrates and a marked reduction in tumor stromal fibrosis
Authors: Wang Shangzi , Fitzgerald Allison , Ajina Reham , Jablonsk Sandra A. , Weiner Louis M. , MacDougall John , Agarwal Veena , O'Neill Vince J.
Published: September 2020

PDAC is typically resistant to chemotherapy and immunotherapy; therefore, novel strategies are needed to enhance therapeutic response. BXCL701 is a well-studied inhibitor of dipeptidyl peptidases 4, 8, 9, and Fibroblast Activation Protein, and has been postulated to work through cytokine induction and macrophage pyroptosis. We examined the effects of BXCL701 and/or PD1 therapy in murine models of PDAC. In the mT3-2D PDAC model, combination therapy of established (~75mm3) sc tumors reduced tumor growth to a greater extent (PBS: 1349±230 mm3 on day 42 vs B + PD1: 355±161mm3, p<0.0001) following a 28-day treatment program of PBS, B (1mg/kg by daily oral gavage), PD1 (10mg/kg ip weekly) or the combination of B + PD1. Treatment with either B or PD1 alone had minimal anti-tumor effects. B + PD1 therapy was accompanied by significant tumor infiltration of NK cells by IHC, flow cytometry and Nanostring analysis. A dramatic reduction of tumor stromal fibrosis by Masson's trichrome staining was found in tumors treated with B alone or B + PD1. These findings suggest that the combination of BXCL701 with anti-PD1 antibody therapy can exert anti-tumor effects associated with increased intratumoral NK cell content and the loss of fibrosis that may facilitate immunotherapy efficacy.

Citation Format: Shangzi Wang, Allison Fitzgerald, Reham Ajina, Sandra A. Jablonsk, Louis M. Weiner, John MacDougall, Veena Agarwal, Vince J. O'Neill. Therapy with BXCL701 (B), a DPP8, DPP9, DPPIV and FAP inhibitor, in combination with anti-PD1 antibody (PD1) in a syngeneic murine pancreatic ductal adenocarcinoma (PDAC) model improves treatment outcomes and induces intratumoral NK cell infiltrates and a marked reduction in tumor stromal fibrosis [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 6636.
Abstract 6697: DT095895, a selective EP4 receptor antagonist with monotherapy efficacy in syngeneic mouse model(s) and best-in-class properties
Authors: Blayo Anne-Laure , Deshons Laurène , Dumont Alexia , Franchet Christel , Halter Célia , Herbin Ludovic , Hommet Gaël , Mayer Stanislas , Bessede Alban , Nafia Imane , Sidhoum Marjorie , Leroy Xavier , Schann Stephan
Published: September 2020

Elevated levels of Prostaglandin E2 (PGE2), an eicosanoid notably synthesized by the cyclooxygenase-2 (COX-2), exert strong immunosuppressive effects in the tumor microenvironment. COX-2-positive solid tumors have the ability to use this pathway as a resistance mechanism, especially to escape from the host immune system, thus limiting the anti-tumor effects of immune checkpoint inhibitors (ICI). These immunosuppressive effects are largely mediated by the EP4 receptor, expressed on multiple immune cells. A novel series of EP4 receptor antagonists has been developed, with improved pharmacokinetic properties when compared to the EP4 receptor antagonists currently being evaluated in clinical trials. An intensive lead optimization program led to the identification of DT095895, a small molecule development candidate with a “best-in class” potential. Its preclinical package will be presented in the poster. DT095895 was assessed in multiple syngeneic mouse tumor models selected for their COX-2 expression profile. Efficacy was seen both in a monotherapy setting, as well as in combination with ICI. Additionally, a specific biomarker program was implemented and validated in order to show target engagement. A phospho-flow murine whole blood assay was set up to assess the ability of DT095895 to inhibit CREB phosphorylation induced by a selective EP4 receptor agonist in CD3+ cells. This biomarker was further developed for human whole blood to support Phase 1 and clinical trials studies. In conclusion, DT095895 is a selective EP4 receptor antagonist and demonstrates strong anti-tumor effects in multiple syngeneic mouse tumor models, both as a monotherapy and in combination with ICI, through the inhibition of the PGE2-induced immunosuppression. DT095895 progresses in regulatory development.

Citation Format: Anne-Laure Blayo, Laurène Deshons, Alexia Dumont, Christel Franchet, Célia Halter, Ludovic Herbin, Gaël Hommet, Stanislas Mayer, Alban Bessede, Imane Nafia, Marjorie Sidhoum, Xavier Leroy, Stephan Schann. DT095895, a selective EP4 receptor antagonist with monotherapy efficacy in syngeneic mouse model(s) and best-in-class properties [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 6697.
Abstract CT231: Clinical study of the safety and tolerability of laser interstitial thermal therapy and avelumab for recurrent glioblastoma
Authors: Hormigo Adilia , Mandeli John , Ghatan Saadi , Hadjipanayis Constantinos , Yong Raymond , Kim-Schulze Seunghee , Gnjatic Sacha
Published: September 2020

Background: Glioblastoma (GBM) is a fatal disease with no standard care for disease progression and as other cancers is known to evade the immune system. Avelumab is a human IgG1 antibody that binds PD-L1 and blocks the interaction between PD-L1 and its receptors PD-1 and B7-1. Consequently, the suppressive effect on T cell function is inhibited and anti-tumor CD8+ T cells cytotoxicity is restored.Laser Interstitial Thermal Therapy (LITT) is a minimally invasive technique that allows the delivery of light energy causing disruption of the blood-brain barrier and hyperthermia of a brain lesion, initiating a cascade of events leading to coagulative necrosis and potentially triggering immunogenic death of cancer cells. It is hypothesized that avelumab combined with MRI-guided LITT has acceptable safety, tolerability and will generate robust immunomodulation and clinical activity to treat brain cancer. Methods: This phase 1 study is enrolling adult patients with first recurrence of GBM. The study follows a 3+3 design exploring safety and tolerability in part A, Avelumab alone and part B, Avelumab combined with LITT (NCT03341806). Objective response will be determined by iRANO criteria and secondary objectives include PFS and OS. Avelumab is administered intravenously within a week of LITT and every two weeks thereafter until disease progression or intolerable toxicity. Tissue immune biomarkers, signature of plasma analytes, and circulating cellular signature profiling are assessed. Part A and B completed enrollment with no serious infusion or immune-related adverse events. The study will proceed with an expansion cohort on January 2020. A Simon minimax two-stage design will be used for efficacy. The first stage consists of the 6 subjects evaluable from the safety cohorts in Part 1B together with the first 8 subjects in the expansion cohort (total of 14 subjects).

Citation Format: Adilia Hormigo, John Mandeli, Saadi Ghatan, Constantinos Hadjipanayis, Raymond Yong, Seunghee Kim-Schulze, Sacha Gnjatic. Clinical study of the safety and tolerability of laser interstitial thermal therapy and avelumab for recurrent glioblastoma [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 CT231.
Abstract CT284: Phase 3 KEYNOTE-937: Adjuvant pembrolizumab versus placebo in patients with hepatocellular carcinoma and complete radiologic response after surgical resection or local ablation
Authors: Zhu Andrew , Kudo Masatoshi , Vogel Arndt , Yau Thomas , Zhou Jian , Kim Eunhee , Malhotra Usha , Siegel Abby B. , Cheng Ann-Lii
Published: September 2020

Background: For patients with hepatocellular carcinoma (HCC) who are undergoing potentially curative surgical resection or local ablation, 5-year recurrence rates are up to 50%-80%; there is no standard of care for adjuvant treatment. The programmed death 1 inhibitor pembrolizumab is approved for the treatment of patients with HCC previously treated with sorafenib. There is no direct evidence of benefit with pembrolizumab in the HCC adjuvant setting, but a favorable benefit/risk profile is anticipated based on data from other indications. KEYNOTE-937 (NCT03867084) is a randomized, double-blind, phase 3 trial to examine the safety and efficacy of adjuvant pembrolizumab versus placebo in patients with complete radiologic response after surgical resection or local ablation of HCC. Methods: Eligible patients are aged ≥18 years and have confirmed HCC, complete radiologic response after complete resection or local ablation, Eastern Cooperative Oncology Group performance status of 0, and class A Child-Pugh score. Patients with past or ongoing HCV or controlled HBV are eligible if they meet certain criteria. Patients (N~950) will be randomly assigned 1:1 to receive pembrolizumab 200 mg or placebo every 3 weeks and stratified by geographic region, prior local therapy (resection vs ablation), recurrence risk, and alpha-fetoprotein level at diagnosis. Treatment will continue for up to 17 cycles (~1 year) or until documented disease recurrence, unacceptable toxicity, or investigator/patient decision to withdraw. Dual primary end points are recurrence free survival (RFS) and overall survival. Secondary end points are safety, tolerability, and quality of life. Exploratory end points include distant metastases-free survival (DMFS); time to recurrence (TTR); and genomic, metabolic, and/or proteomic biomarkers. RFS, DMFS, and TTR will be assessed radiographically by the investigator and/or by subsequent biopsy and confirmed by blinded independent central review. Adverse events (AEs), graded per National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0, will be recorded up to 30 days after last dose (90 days for serious AEs).

Citation Format: Andrew Zhu, Masatoshi Kudo, Arndt Vogel, Thomas Yau, Jian Zhou, Eunhee Kim, Usha Malhotra, Abby B. Siegel, Ann-Lii Cheng. Phase 3 KEYNOTE-937: Adjuvant pembrolizumab versus placebo in patients with hepatocellular carcinoma and complete radiologic response after surgical resection or local ablation [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 CT284.
Abstract CT406: Patients with cancer appear more vulnerable to SARS-COV-2: A multi-center study during the COVID-19 outbreak
Authors: Dai Meng-Yuan , Liu Dian-bo , Liu Miao , Zhou Fu-Xiang , Li Gui-Ling , Chen Zhen , Zhang Zhi-An , Md Hua-You , Wu Meng , Zheng Qi-Chao , Xiong Yong , Xiong Hui-Hua , Wang Chun , Chen Chang-Chun , Xiong Fei , Zhang Yan , Peng Ya-Qin , Ge Si-Ping , Zhen Bo , Yu Ting-Ting , Wang Ling , Wang Hua , Liu Yu , Chen Ye-Shan , Mei Jun-Hua , Gao Xiao-Jia , Li Zhu-Yan , Gan Li-Juan , He Can , Li Zhen , Shi Yu-Ying , Qi Yu-Wen , Yang Jing , Tenen Daniel G. , Chai Li , Mucci Lorelei Ann , Santillana Mauricio , Cai Hongbing
Published: September 2020

The novel COVID-19 outbreak has affected more than 200 countries and territories as of March 2020. Given that patients with cancer are generally more vulnerable to infections, systematic analysis of diverse cohorts of patients with cancer affected by COVID-19 are needed. We performed a multi-center study including 105 cancer patients and 536 age-matched non-cancer patients confirmed with COVID-19. Our results showed COVID-19 patients with cancer had higher risks in all severe outcomes. Patients with hematological cancer, lung cancer, or with metastatic cancer (stage IV) had the highest frequency of severe events. Non-metastatic cancer patients experienced similar frequencies of severe conditions to those observed in patients without cancer. Patients who received surgery had higher risks of having severe events, while patients with only radiotherapy did not demonstrate significant differences in severe events when compared to patients without cancer. These findings indicate that cancer patients appear more vulnerable to SARS-COV-2 outbreak. Since this is the first large cohort study on this topic, our report will provide the much-needed information that will benefit global cancer patients. As such, we believe it is extremely important that our study be disseminated widely to alert clinicians and patients.

Citation Format: Meng-Yuan Dai, Dian-bo Liu, Miao Liu, Fu-Xiang Zhou, Gui-Ling Li, Zhen Chen, Zhi-An Zhang, Hua-You Md, Meng Wu, Qi-Chao Zheng, Yong Xiong, Hui-Hua Xiong, Chun Wang, Chang-Chun Chen, Fei Xiong, Yan Zhang, Ya-Qin Peng, Si-Ping Ge, Bo Zhen, Ting-Ting Yu, Ling Wang, Hua Wang, Yu Liu, Ye-Shan Chen, Jun-Hua Mei, Xiao-Jia Gao, Zhu-Yan Li, Li-Juan Gan, Can He, Zhen Li, Yu-Ying Shi, Yu-Wen Qi, Jing Yang, Daniel G. Tenen, Li Chai, Lorelei Ann Mucci, Mauricio Santillana, Hongbing Cai. Patients with cancer appear more vulnerable to SARS-COV-2: A multi-center study during the COVID-19 outbreak [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 CT406.
Abstract LB-080: USP18 modulates the ISGylome, immune signaling and sensitizes tumor cells to irradiation and CTL recognition
Authors: Pinto-Fernandez Adan , Greenwood Helene , Salio Mariolina , Chen Jianzhou , Partridge Thomas , Vere George , Scott Hannah C. , Damianou Andreas , Borrow Persephone , Muschel Ruth , Cerundolo Vincenzo , Kessler Benedikt M.
Published: September 2020

The innate immune response plays a critical role in modulating the efficacy of and mechanisms conferring resistance to immune checkpoint blockade (ICB) therapies in humans. A major negative regulator of the Interferon (IFN) stimulated gene (ISG) pathway, is the ubiquitin-specific protease 18 (USP18). USP18 is the predominant human deubiquitylating enzyme that processes Interferon Stimulated Gene 15 ISG15, a ubiquitin-like protein that covalently modifies protein substrates, a tightly regulated process in the context of innate immunity. In this study, using advanced mass spectrometry and chemical biology tools, we defined the USP18 Interactome and ISG15ylome in chronic myeloid leukemia (CML)-derived cells (HAP1) treated with Interferon alpha (IFNα). Novel ISG15ylation targets were characterized that reduce the sensing of innate ligands and secretion of cytokines. In addition, we show that USP18 deletion leads to enhanced ISG15ylation profiles. Furthermore, we demonstrate that CML USP18-/- cells are more antigenic, leading to increased activation of cytotoxic T lymphocytes (CTLs), and are more susceptible to irradiation. Our results reinforce the role of USP18 as a key “brake” for inflammatory signals in tumor cells. As USP18 expression is upregulated in lung, breast and colon cancers, USP18 pharmacological inhibition may reflect a target opportunity in cancer immunotherapy.

Citation Format: Adan Pinto-Fernandez, Helene Greenwood, Mariolina Salio, Jianzhou Chen, Thomas Partridge, George Vere, Hannah C. Scott, Andreas Damianou, Persephone Borrow, Ruth Muschel, Vincenzo Cerundolo, Benedikt M. Kessler. USP18 modulates the ISGylome, immune signaling and sensitizes tumor cells to irradiation and CTL recognition [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 LB-080.
Abstract LB-187: Enhanced mapping of N6-methyladenosine (m6A) RNA modification sites with m6A-eCLIP
Authors: Rabano Ines , Shishkin Alexander A. , Shen Kylie , Foster Heather M. , Chu Peter , Van Nostrand Eric L. , Yeo Gene W.
Published: September 2020

N6-methyladenosine (m6A) is the most prevalent epitranscriptomic RNA modification found in eukaryotes and has been shown to regulate many stages of RNA biology including splicing, secondary/tertiary structure, localization, stability, and translation. Adenosine modifications are actively added, recognized, and removed by a series of “writer”, “reader”, and “eraser” proteins, making m6A a dynamic and reversible system for regulating RNAs. Further, there are now clear links between m6A writer, reader, and eraser proteins as well as m6A state of specific mRNAs to cancer pathogenesis, indicating that both global and specific dysregulation of m6A can have targeted effects that lead to disease. Thus, there is a need for methods to robustly profile m6A-modification states in both cell lines as well as tissues, and in normal as well as diseased or modified states. Advancements in high-throughput sequencing have led to the development of methods to map m6A transcriptome-wide, but there remains a need for improved methods that are scalable across conditions and treatments and with low abundance samples, such as blood or patient tissue. To address this need, we adapted enhanced crosslinking and immunoprecipitation (eCLIP) to create an optimized protocol for profiling m6A modification sites with 20-50-fold less starting RNA material (m6A-eCLIP). Using m6A-eCLIP, we recover traditional m6A motif enrichment and positioning enrichment at stop codons, validating the accuracy of the approach. Further, the improved handling and efficiency enabled us to profile m6A status across cell types and tissues, showing that m6A-eCLIP can be a robust method that is widely applicable for epitranscriptomic profiling across a range of conditions.

Citation Format: Ines Rabano, Alexander A. Shishkin, Kylie Shen, Heather M. Foster, Peter Chu, Eric L. Van Nostrand, Gene W. Yeo. Enhanced mapping of N6-methyladenosine (m6A) RNA modification sites with m6A-eCLIP [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 LB-187.