bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3851: An Aurora kinase inhibitor BPR6K471 inhibits tumor growth and reduces the cancer stem cell-like properties of small cell lung cancer
Authors: Chang Chun-Ping , Ke Yi-Yu , Lin Wen-Hsing , Jhuo Dai-Hui , Wang Wan-Ping , Tsai Chia-Hua , Chen Yen-Ting , Su Yu-Jie , Hung Ming-Chun , Wu Zhong-Wei , Kuo Po-Chu , Yeh Teng-Kuang , Chen Ching-Ping , Song Jen-Shin , Chen Chiun-Tong , Shih Chuan , Chi Ya-Hui
Published: August 2019

Small cell lung cancer (SCLC) is one the most aggressive tumors with poor survival rate. SCLC patients often present with metastasis at time of diagnosis, excluding surgery as a treatment option. While patients show high response rate to standard chemotherapy such as cisplatin/etoposide, they soon develop drug resistance and disease progression. Therefore, new therapeutic strategies are urgently needed for SCLC. Several characteristics of SCLC such as aggressiveness and drug resistance could attribute to the existence of a cancer stem cell (CSC) subpopulation in SCLC. The SCLC cell line NCI-H446 has been shown to present high degree of stemness and express stem cell markers including CD133, OCT4, MYC and Nestin. Here we develop a pyrimidine-based small molecule BPR6K471 which potently inhibits Aurora kinase activities in enzymatic- and cell- based assays. BPR6K471 efficiently (IC50 = 66 nM) inhibits proliferation of NCI-H446, and reduces the expression of stem-cell markers. In addition, intravenous injection of BPR6K471 inhibits >90 % progression of NCI-H446 in a mouse xenograft model. These results suggest that targeting Aurora kinases may be a potential therapeutic strategy to combat the CSC subpopulation in SCLC.

Citation Format: Chun-Ping Chang, Yi-Yu Ke, Wen-Hsing Lin, Dai-Hui Jhuo, Wan-Ping Wang, Chia-Hua Tsai, Yen-Ting Chen, Yu-Jie Su, Ming-Chun Hung, Zhong-Wei Wu, Po-Chu Kuo, Teng-Kuang Yeh, Ching-Ping Chen, Jen-Shin Song, Chiun-Tong Chen, Chuan Shih, Ya-Hui Chi. An Aurora kinase inhibitor BPR6K471 inhibits tumor growth and reduces the cancer stem cell-like properties of small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3851.
Abstract 3858: Inflammation and oncogene in hepatocellular carcinoma: Clinical relevance and experimental targeted therapy
Authors: Wang Wei , Cheng Jianwen , Qin Jiang-Jiang , Hu Bo , Nijampatnam Bhavitavya , Velu Sadanandan , Yang Xin-Rong , Fan Jia , Zhang Ruiwen
Published: August 2019

Hepatocellular carcinoma (HCC) poses a major public health problem worldwide and novel, effective therapeutic approaches for this devastating disease are urgently needed. The overexpression or activation of the MDM2 oncogene frequently occurs in HCC and is linked to cancer growth, poor survival, metastasis, and resistance to treatment. We have hypothesized that MDM2 is a promising therapeutic target for HCC therapy. We have recently discovered that the transcription factor NFAT1 upregulates MDM2 expression, promoting cancer cell growth, migration, invasion, and angiogenesis. The present study was designed to demonstrate the role of the NFAT1-MDM2 pathway in HCC progression and its value in developing HCC targeted therapy. We systemically investigated the expression and association of MDM2 and NFAT1 in 254 pairs of human HCC and matched non-cancerous tissue samples. High-throughput virtual and cell-based screenings were carried out for search for lead compounds targeting both NFAT1 and MDM2. The in vitro and in vivo anti-HCC activities and underlying mechanisms of action were further evaluated in HCC cell lines with various p53 backgrounds. Our results demonstrated that, compared with the non-malignant peritumoral tissues MDM2 and NFAT1 were overexpressed in HCC tissues, which were correlated with poor prognosis and increased metastasis. Based on molecular modeling study, Biacore assay, and pull-down assays, one of the lead compounds, named MA242, was identified as a potent and selective MDM2 and NFAT1 dual inhibitor. Mechanistically, M242 directly bound to MDM2 and NFAT1 proteins with high affinity and induced their protein degradation. MA242 also inhibited NFAT1-mediated MDM2 transcription. At cellular level, MA242 decreased cell proliferation, and induced apoptosis and G2/M phase arrest in various HCC cell lines, regardless of the p53 status. Furthermore, M242 inhibited the tumor growth and metastasis in orthotopic and patient-derived xenograft (PDX) models of HCC, without any obvious host toxicity. In conclusion, MDM2 and NFAT1 expression can serve as predictors of survival in patients with HCC. Dual MDM2 and NFAT1 inhibitors may represent a first-in-class clinical candidates for the treatment of HCC, including tumors lacking functional p53. This project is supported by NIH R01 CA186662 and R01 CA214019 and ACS RSG-15-009-01-CDD.

Citation Format: Wei Wang, Jianwen Cheng, Jiang-Jiang Qin, Bo Hu, Bhavitavya Nijampatnam, Sadanandan Velu, Xin-Rong Yang, Jia Fan, Ruiwen Zhang. Inflammation and oncogene in hepatocellular carcinoma: Clinical relevance and experimental targeted therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3858.
Abstract 3859: Targeting CDK9 and MCL-1 by a New CDK9/p-TEFB Inhibitor with and without 5-fluorouracil in esophageal adenocarcinoma
Authors: Tong zhimin , Mejia Alicia , Veeranki Omkara , Verma Anuj , Correa Arlene , Patel Viren , Dokey Rashmi , Solis Luisa , Mino Barbara , Kathkuda Riham , Canales Jaime , Lin Steven , Krishnan Sunil , Kopetz Scott , Blum Mariela , Ajani Jaffer , Hofstetter Wayne , Maru Dipen M
Published: August 2019

Background: CDK9 inhibitors are anti-tumorigenic against several solid tumors including esophageal adenocarcinoma (EAC). However, efficacy of CDK9 inhibitor as adjuvant to chemotherapy and target proteins shared between these two drugs are not known.

Methods: Efficacy of a new CDK9 inhibitor, BAY1143572 with and without 5-fluorouracil (5-FU) on tumor growth was tested in vitro and xenograft models of EAC. We tested effects of these agents on MCL-1 in vitro. We also analyzed a possible role of MCL-1 as a predictor of survival in patients with EAC.

Results: BAY1143572 had a dose-dependent anti-proliferative and pro-apoptotic effects in vitro. BAY1143572 and 5-FU had strong synergy in vitro. Median tumor volume of FLO1 or ESO26 xenografts in cohort treated with combination of two drugs was 82% or 55% smaller than the cohort treated with 5-FU alone, and 46 % or 33% smaller than the cohort treated with BAY114352 alone (p<0.05). BAY1143572 transcriptionally downregulated MCL-1 by inhibiting HIF-1α binding to the MCL-1 promoter. 5-FU enhanced BAY1143572 induced MCL-1 downregulation in vitro. Stable overexpression of MCL-1 reduced apoptosis by BAY1143572 and 5-FU. Higher tumor cell MCL-1 expression correlated with shorter overall survival in patients with EAC treated with chemoradiation and surgery.

Conclusion: CDK9 inhibitor and 5-FU are synergistic and MCL-1 is a target of CDK9 inhibitor in EAC.

Citation Format: zhimin Tong, Alicia Mejia, Omkara Veeranki, Anuj Verma, Arlene Correa, Viren Patel, Rashmi Dokey, Luisa Solis, Barbara Mino, Riham Kathkuda, Jaime Canales, Steven Lin, Sunil Krishnan, Scott Kopetz, Mariela Blum, Jaffer Ajani, Wayne Hofstetter, Dipen M Maru. Targeting CDK9 and MCL-1 by a New CDK9/p-TEFB Inhibitor with and without 5-fluorouracil in esophageal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3859.
Abstract 3863: Specifically targeting PDIA1 with indene inhibitors leads to bortezomib-potentiation in multiple myeloma
Authors: Robinson Reeder M. , Reyes Leticia , Duncan Ravyn , Dolloff Nathan
Published: August 2019

Protein disulfide isomerase (PDI) is an emerging therapeutic target in oncology. PDI inhibitors have demonstrated a unique propensity to overcome resistance to existing cancer therapies, although drug candidates have not yet progressed to the stage of clinical development. We recently reported the discovery of lead indene compound E64FC26 as a potent pan-PDI inhibitor that enhances the cytotoxic effects of proteasome inhibitors (PIs) in panels of Multiple Myeloma (MM) cells and MM mouse models [1]. An extensive medicinal chemistry program has led to the generation of a diverse library of indene-containing molecules with varying degrees of PI-potentiating activity. The results show detailed structure activity relationships (SAR) with a high degree of correlation between potency of PDIA1 inhibition and bortezomib (Btz) potentiation in MM cells. Inhibition of PDIA1 in MM leads to ER and oxidative stress characterized by the accumulation of misfolded poly-ubiquitinated proteins and the induction of UPR biomarkers ATF4, CHOP, and Nrf2. Furthermore, an advanced derivative, E64FC65, was identified as a PDIA1 selective inhibitor as it was significantly weaker against PDIA3, PDIA4, TXNDC5, PDIA6, and thioredoxin when compared to E64FC26 (Table 1). We purified the redox-active a and a’ thioredoxin-like domains of PDI and found that E64FC65 only inhibited the a domain while E64FC26 inhibited both a and a’ domains. The PDI isoform and domain selectivity of E64FC65 imparted increased anti-cancer activity while reducing toxicity against primary activated human T-cells. Additionally, E64FC65 exhibited improved pharmaceutical properties in ADME assays. This work shows the generation of a PDIA1 a domain specific indene inhibitor that potentiates Btz cytotoxicity in MM cells while abrogating toxicity in normal cells. E64FC65 is thus a favorable PDI inhibitor candidate for further development.

Citation Format: Reeder M. Robinson, Leticia Reyes, Ravyn Duncan, Nathan Dolloff. Specifically targeting PDIA1 with indene inhibitors leads to bortezomib-potentiation in multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3863.
Abstract 3881: Relating tumor drug concentrations to target effect with semi physiologic PK-PD modeling in drug development: An application using a novel dCK inhibitor
Authors: Poddar Soumya , Nikanjam Mina , Capparelli Edmund , Le Thuc , Wei Liu , Radu Caius
Published: August 2019

Introduction: Deoxycytidine kinase (dCK) is essential for DNA synthesis through salvage pathways and DI-87 is a novel dCK inhibitor in preclinical development. This study used PET imaging to measure dCK inhibition and pharmacokinetic-pharmacodynamic (PK-PD) modeling to relate tumor drug levels to tissue with dCK activity and tumor shrinkage.

Methods: Oral DI-87 was administered to NSG mice with plasma and tumor PK assessed over 24 hrs by mass spectrometry. NSG mice with CEM tumors were administered varying doses of DI-87 followed by the [18F]CFA PET probe and PET imaging. NSG mice with CEM tumors were administered thymidine and DI-87 concurrently and tumor growth monitored. PK-PD modeling was conducted with NONMEM (v. 7.3).

Results: DI-87 plasma concentrations peaked at 3 hr; tumor peak concentrations occurred later. Tumor concentrations were less than one third of plasma concentrations. Full dCK inhibition by PET imaging occurred between 10 and 25 mg/kg and decreasing doses led to faster recovery of activity. Full recovery of enzyme activity occurred by 36 hrs with full inhibition being maintained at the 12 hr time point at the 25 mg/kg dose. Maximal growth inhibition occurred with full dCK inhibition over the dosing range (25 mg/kg BID) when DI-87 was given in combination therapy with thymidine; thus increased doses led to more persistent dCK inhibition with predictable increased growth inhibition.

Conclusions: Combining PET probes with PK-PD modeling led to an optimized dosing schedule for combination therapy with DI-87.

Citation Format: Soumya Poddar, Mina Nikanjam, Edmund Capparelli, Thuc Le, Liu Wei, Caius Radu. Relating tumor drug concentrations to target effect with semi physiologic PK-PD modeling in drug development: An application using a novel dCK inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3881.
Abstract 391: Serine/threonine kinase LASK2 as a biomarker and therapeutic target for lung cancer
Authors: Daigo Yataro , Takano Atsushi , Nakamura Yusuke
Published: August 2019

Since the number of lung cancer patients responding well to standard chemotherapies is still small, further development of new anti-cancer drugs with minimum risk of adverse effects and highly sensitive cancer biomarkers for precision medicine is eagerly required. We have been developing new molecular therapies targeting oncogenic proteins with their companion diagnostics by screening system as follows; i) To identify overexpressed genes in 120 lung cancers by our original gene expression profile database, ii) To confirm the candidate genes for their low expression in 23 normal tissues, iii) To validate the clinicopathological significance of their protein expression by tissue microarray covering hundreds of non-small cell lung cancers (NSCLCs), iv) To verify whether they are essential for the growth/invasion of cancer cells by siRNAs. During this process, we selected dozens of druggable oncoproteins with various enzymatic activities, and detected higher expression of serine/threonine kinase LASK2 (lung cancer-associated kinase 2) in the majority of various types of lung cancers, but scarce expression in normal tissues except testis. We further observed much higher expression patterns of LASK2 in brain metastasis as well as advanced primary lung tumors, compared to those in earlier-stage primary lung tumors. Immunohistochemical analysis using tissue microarray showed that strong LASK2 positivity was an independent prognostic factor for NSCLC (P<0.0001). Suppression of LASK2 expression with its siRNAs inhibited growth of lung cancer cells, whereas enhanced cellular proliferation by exogenous expression of LASK2 in mammalian cells also supported its oncogenic function in vitro and in mice model. Invasion of mammalian cells transfected with LASK2-expression vector through Matrigel was significantly enhanced, compared to the control cells transfected with mock or LASK2-kinase dead vector, suggesting that LASK2 could also contribute to the highly malignant phenotype of lung-cancer cells. Induction of LASK2 appeared to activate oncogenic signals for lung cancer such as phosphorylation of MAPK and PCNA. Our data indicate that LASK2 is a promising diagnostic biomarker and therapeutic target for developing precision medicine of lung cancer.

Note: This abstract was not presented at the meeting.

Citation Format: Yataro Daigo, Atsushi Takano, Yusuke Nakamura. Serine/threonine kinase LASK2 as a biomarker and therapeutic target for lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 391.
Abstract 3911: Akt inhibitor SC66 promotes cell sensitivity to cisplatin in chemoresistant ovarian cancer cells through inhibition of COL11A1 expression
Authors: Wu Yi-Hui , Chou Cheng-Yang
Published: August 2019

Background and aims: Akt plays a central role in regulating cell growth and cell cycle progression and is regarded as a promising therapeutic target. We examined whether Akt inhibition by SC66 is therapeutically efficacious in the treatment of ovarian cancer as a single agent and in combination with chemotherapy drugs.

Methods: The expressions of phospho-Akt in ovarian cancer patients were evaluated by immunohistochemistry. Using eight human ovarian cancer cell lines, we determined the effect of SC66 by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, western blot, and apoptosis assays. We evaluated the association between phospho-Akt/mTOR, COL11A1 and SC66 sensitivity. We also determined the effect of SC66 on tumor growth using mice inoculated with human ovarian cancer cells.

Results: Elevated phospho-Akt levels in cancerous tissue were associated with short progression-free survival and overall survival. Cell sensitivity to SC66 was inversely correlated with phospho-Akt and COL11A1 expression levels as well as resistance to cisplatin or paclitaxel. SC66 inhibited phosphorylation of Akt and its downstream effectors 4E-BP1 and p70S6 kinase. SC66 also attenuated expression of TWIST1 and Mcl-1, factors important in cell invasiveness and anti-apoptosis, respectively. SC66 sensitized chemoresistant cells to cisplatin and paclitaxel treatment and promoted apoptosis. In addition, SC66 inhibited COL11A1 expression via decreased binding of CCAAT/enhancer-binding protein beta (c/EBPβ), reducing chemoresistance and decreasing binding of nuclear transcription factor Y (NF-YA) to COL11A1. A mouse xenograft experiment demonstrated that SC66 treatment caused a reduction in tumor formation and enhanced the therapeutic efficacy of cisplatin.

Conclusions: This study demonstrates the role of Akt in ovarian tumor progression and chemoresistance and supports the application of SC66 as a therapy for ovarian cancer.

Citation Format: Yi-Hui Wu, Cheng-Yang Chou. Akt inhibitor SC66 promotes cell sensitivity to cisplatin in chemoresistant ovarian cancer cells through inhibition of COL11A1 expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3911.
Abstract 3915: YH25248, a selective PI3K delta inhibitor, shows synergistic effect with an anti-PD-L1 antibody
Authors: Park Jinhwi , Kang Ho-Woong , Koo Hyun-Mo , Park Jongsuk , Kim Tae-Wang , Oh Se-Woong , Choi Soongyu
Published: August 2019

Phosphatidylinositol 3-kinase (PI3K) plays critical roles in numerous intracellular processes. Of the four known subtypes, PI3Kδ subtype is primarily expressed in immune cells and has been reported to promote B cell differentiation and regulatory T (Treg) cell activation. Treg cell-mediated immunosuppression is thought to be a major resistance mechanism for immune checkpoint inhibitors. We therefore hypothesized that an effective PI3Kδ inhibitor could enhance anti-cancer immunity when combined with immune checkpoint inhibitors. Through recent efforts, we have discovered YH25248, an oral PI3Kδ-specific inhibitor. YH25248 effectively inhibits PI3Kδ (IC50 = 10nM) showing more than 100-fold selectivity over α, β, and γ subtypes, and exhibited favorable kinase selectivity in 463 kinase panels. In cellular experiments, phospho-AKT was effectively blocked (IC50 = 7 nM), with basophil activation, a known PI3Kδ specific signal, was also inhibited. YH25248 reduced the activity of Treg cells (CD4+/CD25+) isolated from the splenocytes of CT26 tumor-bearing mice, while sparing conventional T cells (CD4+/CD25-). When YH25248 was orally administered (10 mg/kg) to mice, drug exposure in plasma was reasonable, with a half-life of 4.3 hours, while once-daily oral administration of YH25248 (10 ~ 60 mg/kg) significantly inhibited tumor growth of CT26 colon carcinomas in mouse. When the immune cells of tumors were analyzed by flow cytometry, the number of Treg cells was reduced, CD8 + T cells increased. In this model, YH25248 (30 mg/kg, QD) showed synergistic efficacy when combined with an anti-PD-L1 antibody (200 μg/mice, 10F.9G2 clone). In other syngeneic models using 4T1 or MC38 cells, YH25248 (30 mg/kg, QD) also exhibited similar synergistic efficacy in combination with the anti-PD-L1 antibody. In conclusion, YH25248 is a potent, selective, oral inhibitor of PI3Kδ that reduces tumor growth in syngeneic mouse tumor models by increasing the ratio of CD8+ to Treg cells. The combination of YH25248 and anti-PD-L1 antibody resulted in substantially greater tumor growth inhibition in several syngeneic models. These data support the promising potential of YH25248 for combination therapy with immune checkpoint inhibitors to increase therapeutic response rates.

Citation Format: Jinhwi Park, Ho-Woong Kang, Hyun-Mo Koo, Jongsuk Park, Tae-Wang Kim, Se-Woong Oh, Soongyu Choi. YH25248, a selective PI3K delta inhibitor, shows synergistic effect with an anti-PD-L1 antibody [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3915.
Abstract 3940: Acute total body ionizing radiation induces long-term adverse effects and immediate changes in cardiac protein oxidative carbonylation in the rat
Authors: Rosen Elliot T. , Kryndushkin Dmitry , Aryal Baikuntha , Gonzalez Yanira , Chehab Leena , Dickey Jennifer , Mog Steven , Rao V Ashutosh
Published: August 2019

Radiation-induced heart disease presents a significant challenge in the event of an accidental radiation exposure as well as to cancer patients who receive acute doses of irradiation as part of radiation therapy. We utilized the Wistar-Kyoto and spontaneously hypertensive rat model, previously shown to demonstrate drug-induced cardiomyopathy, to evaluate the acute and long-term effects of sub-lethal total body irradiation at two, four, and fifty-two weeks. We further examined irreversible oxidative protein carbonylation in the heart immediately following irradiation. Both males and females sustained reduced growth and anemic conditions over a one-year period as reflected by reduced body weight and low red blood cell count. Increased inflammation was detected by elevated IL-6 serum levels in males at four weeks. Serum cardiac troponin T and I analyses revealed indications of cardiomyopathy at earlier time points while more variability in the troponin levels was observed at one year. Echocardiography at two weeks following 5.0Gy treatment revealed hypertrophy and decrease in cardiac output in the short term, but significant differences were not observed at the one-year timepoint. Cardiac output was decreased in both males and females after two weeks, and statistically significant in females. Following irradiation, the heart tissue showed an increase in total protein carbonylation accompanied by DNA damage indicated by an increase in γ-H2AX. We present novel findings of several proteins that showed a marked change in carbonylation profile including those of mitochondrial origin. Overall, we present findings of acute oxidative protein, DNA damage, and long-term cardiomyopathy in the irradiated animals.

Citation Format: Elliot T. Rosen, Dmitry Kryndushkin, Baikuntha Aryal, Yanira Gonzalez, Leena Chehab, Jennifer Dickey, Steven Mog, V Ashutosh Rao. Acute total body ionizing radiation induces long-term adverse effects and immediate changes in cardiac protein oxidative carbonylation in the rat [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3940.
Abstract 3964: Chemotherapeutic drug-induced tumor neoantigen discovery
Authors: Rumble Julie M. , Mobley James L. , Jones Richard , Ford Michael , Pisano Michael
Published: August 2019

Checkpoint inhibitors have shown significant efficacy against a variety of cancers, changing the way many cancers are treated. However, only a subset of patients can benefit from these therapies currently, and finding ways to increase the number of patients who can is a primary interest. Tumor mutational burden is one biomarker for checkpoint inhibitor efficacy, which may point to effective strategies for increasing tumor response to therapy. Combination of checkpoint inhibitors with existing chemotherapy is being pursued in several clinical trials, and has been shown to have synergistic effects in a mouse tumor model. Chemotherapeutic drugs work in many ways to kill tumor cells, notably by attacking DNA and its replication machinery to prevent proliferation. These DNA-targeting drugs can cause mutations in cells that are not killed outright. We hypothesize that some chemotherapeutics can cause DNA mutations that are translated into proteins and peptides that make their way into the HLA class I peptide presentation pathway. If these neoantigens are seen by CD8+ T cells as foreign, T cells will attack these tumor cells. This could provide one mechanism of action for an increase in therapeutic efficacy in tumors treated with combinations of chemotherapeutics and checkpoint inhibitors. We test the ability of two drugs, SN-38 (an active metabolite of irinotecan) and oxaliplatin to induce neoantigens by sequencing peptides from class I molecules in a colon cancer cell line.

Citation Format: Julie M. Rumble, James L. Mobley, Richard Jones, Michael Ford, Michael Pisano. Chemotherapeutic drug-induced tumor neoantigen discovery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3964.
Abstract 397: SMARCA4 is a selective vulnerability in SMARCA2-deficient esophageal squamous cell carcinoma cell lines
Authors: Ehrenhöfer-Wölfer Katharina , Puchner Teresa , Blaha-Ostermann Silvia , Hörmann Alexandra , Sommergruber Wolfgang , Schweifer Norbert , Zichner Thomas , Schlattl Andreas , Neumüller Ralph A. , Koegl Manfred , Petronczki Mark P. , Pearson Mark , Wöhrle Simon
Published: August 2019

Esophageal squamous cell carcinoma (ESCC) is a highly prevalent tumor type with poor prognosis and limited treatment options. In this study, we aimed to discover potential novel drug targets using a pooled epigenome sgRNA viability screen in a panel of ESCC cell models. We identify the BAF chromatin remodeling helicase subunit SMARCA4/BRG1 as a novel dependency in a subset of ESCC cell lines. In line with the established synthetic lethal interaction of SMARCA4 and SMARCA2/BRM, the two mutual exclusive catalytic subunits of the BAF complex, SMARCA4-dependent cell lines display low or absent expression of SMARCA2. In rescue studies using SMARCA4 variants, we demonstrate that SMARCA4-dependency is linked to its ATPase/helicase activity, but not to bromodomain function. Similarly, ectopic expression of wild-type and bromodomain-mutant SMARCA2, but not a helicase-dead variant, rescues from loss of SMARCA4 in SMARCA2-low ESCC cells. SMARCA2-proficient ESCC cell models are rendered SMARCA4-dependent upon CRISPR/Cas9-mediated knock-out of SMARCA2. We further identify SMARCA4-dependent cell models from additional tumor types (colon, ovarian and pancreas carcinoma) with low or absent SMARCA2 expression. These findings expand the concept of SMARCA2/SMARCA4 paralog dependency and indicate pharmacological inhibition of SMARCA4 as a novel opportunity for targeted therapy of SMARCA2-deficient cancers.

Citation Format: Katharina Ehrenhöfer-Wölfer, Teresa Puchner, Silvia Blaha-Ostermann, Alexandra Hörmann, Wolfgang Sommergruber, Norbert Schweifer, Thomas Zichner, Andreas Schlattl, Ralph A. Neumüller, Manfred Koegl, Mark P. Petronczki, Mark Pearson, Simon Wöhrle. SMARCA4 is a selective vulnerability in SMARCA2-deficient esophageal squamous cell carcinoma cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 397.
Abstract 3974: In vivo CRISPR-Cas9 library screen for liver cancer therapeutic targets essential for T cell killing
Authors: Zhao Haixin , Geng Chenlu , Zhou Wenrong , Peng Zhengang , Ji Qunsheng , Cang Yong
Published: August 2019

T-cell checkpoint inhibition by antibodies blocking programmed cell death protein 1 (PD1) has been a major breakthrough in cancer therapeutic development. However, anti-PD1 drugs approved by FDA are ineffective in treating all cancer types or in all patients in a responsive cancer type. Therefore, it is important to stratify responsive patient population and identify synergistically effective combination therapies. Primary hepatocellular carcinoma (HCC) is a human malignancy with a high incidence, mortality and recurrence rate worldwide. We established a syngeneic mouse HCC model using a murine hepatoma cell line, Hepa1-6, which, interestingly, shrunk in volume shortly after reaching up to 400 mm3. The tumor failed to resume growth unless treated with anti-CD4/CD8 antibodies to deplete endogenous T cells, suggesting that an adaptive T cell immunity suppresses the late-stage tumor growth. To identify the genetic regulators of the cancer elimination, we employed CRISPR-Cas9 based genome-wide knockout screening strategy to identify the potential targets essential for cancer cell sensitivity to the T cell immunity. Mouse xenograft models derived from hepa1-6 cells infected with the library were treated with anti-CD4/CD8 antibodies or anti-mPD1 antibody. Deep sequencing of the tumors revealed T cell-dependent enrichment of guide RNAs targeting 241 genes with variable functions. We have performed a second round of in vivo screen with a CRISPR library focused on these candidate genes. We will discuss the technical challenges of the in vivo screen as well as the broad application of the technology for discovery of immune oncology targets.

Citation Format: Haixin Zhao, Chenlu Geng, Wenrong Zhou, Zhengang Peng, Qunsheng Ji, Yong Cang. In vivo CRISPR-Cas9 library screen for liver cancer therapeutic targets essential for T cell killing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3974.
Abstract 3983: An efficient new detection method of colorectal cancers from blood samples
Authors: Kim Joon , Kim Seon Hahn , Cho Kyung-Hwan , Kwon Yeongkeun , Kim Tae-Sung , Jung YouJin , Kim Hag Dong
Published: August 2019

Colorectal cancer incidence in Korea is known to be one of the highest in the world. However, the detection methods from patients’ blood samples show relatively inefficient. Ribosomal protein S3 (rpS3), a multifunctional protein with a DNA repair endonuclease activity, has been known to be overexpressed and secreted from cancer cells but not from normal cells. Western blotting using antibodies against rpS3 protein revealed that this protein is overexpressed from cancer tissues of colorectal cancer patients comparing to normal tissues from the same patients. However, other proteins including other ribosomal proteins did not show this phenomenon. We also tested the secretion level of the protein using newly developed S3-1 antibody in the serum samples from 50 colorectal cancer patients and 50 healthy people to test the possibility as a cancer marker. All the diagnosed blood samples which were randomly selected among subjects in National Biobank of Korea were collected and serum was acquired by centrifugation. Samples were analyzed by dot blotting and ELISA methods. The detection level of S3-1 from the serum of colorectal cancer patients showed significantly higher than that from healthy control group. Also more than 60% from colorectal cancer patients’ serum showed sensitivity signals with 90% specificity which are significantly better than those of CEA or CA19-9 showing a possibility as a novel colorectal cancer biomarker.

Citation Format: Joon Kim, Seon Hahn Kim, Kyung-Hwan Cho, Yeongkeun Kwon, Tae-Sung Kim, YouJin Jung, Hag Dong Kim. An efficient new detection method of colorectal cancers from blood samples [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3983.
Abstract 3993: Programmed cell death ligand-1 (PD-L1) and CD8 expression profiling identifies an immunologic subtype of pancreatic ductal adenocarcinomas with favorable survival
Authors: Ho Won Jin , Danilova Ludmila , Zhu Qingfeng , Vithayathil Teena , Jesus-Acosta Ana De , Azad Nilo , Laheru Daniel , Fertig Elana , Anders Robert , Jaffee Elizabeth , Yarchoan Mark
Published: August 2019

Unselected cases of pancreatic adenocarcinoma (PDAC) have not shown clinical benefit from single agent immune checkpoint therapy, but a subset of PDAC are known to upregulate pathways involved in acquired immune suppression. Further delineation of immunologic subtypes of PDAC is key to smarter trial designs and progress toward improved immunotherapy strategies. To accomplish this, we first employed clinical survival and RNA expression data from 155 patients in The Cancer Genome Atlas (TCGA) to investigate the relationship between immune modulating checkpoints and immune subset marker, CD8A, and their impact on survival in PDAC patients. Among the markers explored, overexpression of PD-L1 (HR=2.55, p=0.001) and IDO1 (HR=2.24, p<0.01) were individually associated with poor survival. PD-L1 expression was not significantly associated with stage or tumor mutational burden of the PDACs. While CD8A expression alone was not correlated with survival, stratifying the analysis based on PD-L1 and CD8 expression identified a subtype characterized by low PD-L1 and high CD8A with favorable survival (p=0.004). Similarly, the combination of low IDO1 and high CD8A expression was associated with favorable survival (p=0.038). We further extended these observations using an independent PDAC cohort of 33 patients from our institution via immunohistochemistry, again observing that low PD-L1 / high CD8 subtype associates with positive prognosis (p=0.021). Although PDAC is regarded as a poorly immunogenic cancer type, these findings infer that baseline T cell infiltration into PDAC is a feature of long term survival and highlights the importance of developing future immunotherapeutic strategies based on data-supported biomarkers to refine patient selection.

Citation Format: Won Jin Ho, Ludmila Danilova, Qingfeng Zhu, Teena Vithayathil, Ana De Jesus-Acosta, Nilo Azad, Daniel Laheru, Elana Fertig, Robert Anders, Elizabeth Jaffee, Mark Yarchoan. Programmed cell death ligand-1 (PD-L1) and CD8 expression profiling identifies an immunologic subtype of pancreatic ductal adenocarcinomas with favorable survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3993.
Abstract 3994: Genomic characterization of melanoma in the elderly reveals molecular drivers of progression and prognosis associated with immunotherapy response
Authors: Smith Stephen P. , Gaudy-Marqueste Caroline , Kumar Rajive , Marais Richard , Nagore Eduardo , Viros Amaya
Published: August 2019

Melanoma incidence and mortality particularly affects elderly patients. 85% of melanoma deaths occur in patients older than 60, and age is a powerful independent predictor of outcome. The genomic characteristics driving melanoma in the aged population have not been previously investigated.

We have undertaken a comprehensive genomic analysis of age-specific molecular characteristics in metastatic cutaneous melanoma and discovered a core set of 4 driver genes that when mutated in older patients is a powerful predictor of poor outcome. We validate these findings in international independent primary melanoma replication cohorts. This signature stratifies patient prognosis more accurately than the current staging guidelines from early to late stages, making it relevant to immediate clinical practice.

Checkpoint inhibitors are showing promising results in the adjuvant setting to treat early stage melanoma patients, and the cost burden to health care will limit access to these drugs. Importantly, elderly patients benefit from immune checkpoint inhibitor therapies, and there are currently no accepted predictors of response used to prioritize patients for these costly therapies in the adjuvant or advanced disease stages. Previous studies have shown a higher mutation burden and neo-antigen load are indicators of response.

Critically, we show elderly melanoma patients are the population subset most likely to present with a higher mutation burden, and our signature strongly correlates with melanomas of higher mutation burden and neo-antigen load. We validate these findings across multiple primary and metastatic melanoma cohorts. Finally, stratifying old patients by our 4-gene outcome signature is also associated with immunotherapy response in the metastatic stage. Our study demonstrates that stratifying patients by age will allow improved discrimination of prognosis and association with response to treatment.

Current selection of patients is based on AJCC stage alone, which means more patients have to be enrolled and more time is required to discriminate the effect of novel adjuvant immunotherapy strategies. Our work, validated across multiple cohorts, directly proposes enrolling patients with high genetic risk of poor outcome and improved rate of immunotherapy response using a simple 4-gene DNA signature that can be easily translated into clinical practice.

Citation Format: Stephen P. Smith, Caroline Gaudy-Marqueste, Rajive Kumar, Richard Marais, Eduardo Nagore, Amaya Viros. Genomic characterization of melanoma in the elderly reveals molecular drivers of progression and prognosis associated with immunotherapy response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3994.
Abstract 3996: Search for prognosis prediction factors in treatment selection for elderly patients with EGFR negative advanced stage non-small cell lung cancer patients
Authors: Kaneko Yoshiko , Mouri Takako , Tamiya Nobuyo , Yamada Tadaaki , Uchino Junji , Takayama Koichi
Published: August 2019

Introduction: Since 40% of Japanese lung cancer patients are older than 75 years old, it is necessary to consider a specific strategy to treat such elderly lung cancer patients. From that aspect, it is very important to define frail or vulnerable elder populations who have lots of heterogenic health background in treatment of lung cancer. In this study, we have tried to identify prediction factors which significantly correlates to overall survival (OS) of such elderly advanced lung cancer patients by using of patient status and laboratory data before treatment.

Objects and methods: Patients more than 75 years old who enrolled in this retrospective study were diagnosed as an advanced and EGFR negative non-small cell lung cancer during 2013-2017, and they were not available for any molecular targeted therapeutics. OS of best supportive care (BSC) cohort and chemotherapy with Docetaxel monotherapy and more cohort from those elderly patients were analyzed by Kaplan-Meier analysis.

Results: Clinical Question 1; What is a prediction factor for OS of BSC patients?

Answer 1; From analysis of 29 BSC patients (age 15-94 years old, median 82), it is revealed that low performance status (PS =0,1) stage at diagnosis (p=0.03) are significantly correlated to longer OS, and also hypoalbuminemia is significantly correlated to worse OS (11 wks vs 35 wks). Age at diagnosis did not correlate to duration of OS. ( more vs less than 80 years old:15 wks vs 37 wks, P=0.13)Clinical Question 2; Does chemotherapy significantly prolong OS of elderly patients?

Answer 2; Kaplan-Meier analysis of elderly patients (PS 0-2) less than 80 years old who were treated by chemotherapies at least with DOC monotherapy showed longer OS than that of 29 BSC patients ( 84 wk vs 15 wk, p=0.006). However, no significant difference to OS (p=0.378) has been observed to BSC patients in advanced stage with better PS (0-2). Multivariate analysis for OS indicated significant correlation of hypoalbuminemia (p=0.002), but no correlation of chemotherapy (p=0.202) has been observed.

Conclusion: 1, EGFR mutation-negative advanced NSCLC patients elder than 80 years old who were treated by chemotherapies did not showed significantly longer OS than that of BSC patients. 2, PS and hypoalbuminemia before treatment may be prediction factors for longer OS of elder lung cancer patients.

Citation Format: Yoshiko Kaneko, Takako Mouri, Nobuyo Tamiya, Tadaaki Yamada, Junji Uchino, Koichi Takayama. Search for prognosis prediction factors in treatment selection for elderly patients with EGFR negative advanced stage non-small cell lung cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3996.
Abstract 40: Biomaterials and systems biology to guide breast cancer drug screening
Authors: Schwartz Alyssa , Barney Lauren , Jansen Lauren , Hall Christopher , Meyer Aaron , Peyton Shelly R.
Published: August 2019

Improved in vitro models are needed to better understand cancer progression and bridge the gap between in vitro proof-of-concept studies, in vivo validation, and clinical application. Many methods exist to create biomaterial platforms, including hydrogels, which we use to study cells in contexts more akin to what they experience in vivo. Our lab has multiple approaches to create such biomaterials, based on combinations of poly(ethylene glycol) (PEG) with peptides and zwitterions. In this presentation, I will discuss our findings in using these cell culture environments to understand the role of the extracellular matrix (ECM) in controlling cancer cell innate drug response via adaptive signaling. Specifically, I will present data comparing the behavior of breast, prostate, and ovarian cancer cells to chemotherapy and targeted drugs when cultured as 3D spheroids, on 2D gels, and as a function of the stiffness of the tumor microenvironment. This approach uncovered that cells on 2D hydrogels and spheroids encapsulated in 3D hydrogels were less responsive to receptor tyrosine kinase (RTK)-targeting drugs sorafenib and lapatinib, but not cytotoxic drugs, compared to single cells in hydrogels and cells on plastic. We found that transcriptomic differences between these in vitro models and tumor xenografts did not reveal mechanisms of ECM-mediated resistance to sorafenib. However, a systems biology analysis of phospho-kinome data uncovered that variation in MEK phosphorylation was associated with RTK-targeted drug resistance. Using sorafenib as a model drug, we found that co-administration with a MEK inhibitor decreased ECM-mediated resistance in vitro and reduced in vivo tumor burden compared to sorafenib alone. In sum, we provide a novel strategy for identifying and overcoming ECM-mediated resistance mechanisms by performing drug screening, phospho-kinome analysis, and systems biology across multiple biomaterial environments. Our work suggests that different model systems are important for evaluating cell response to receptor tyrosine kinase inhibitors, whose efficacy depends on cell-ECM interactions.

Citation Format: Alyssa Schwartz, Lauren Barney, Lauren Jansen, Christopher Hall, Aaron Meyer, Shelly R. Peyton. Biomaterials and systems biology to guide breast cancer drug screening [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 40.
Abstract 400: Digital PCR combined with melting curve analysis for highly multiplexed genotyping
Authors: Tanaka Junko , Nakagawa Tatsuo , Shiratori Akiko , Shimazaki Yuzuru , Harada Kunio , Uematsu Chihiro , Kohara Yoshinobu , Takai Erina , Yachida Shinichi
Published: August 2019

Background

Digital PCR (dPCR) is a promising method for liquid biopsies and is able to quantify nucleic acids more sensitively than real-time PCR. However, dPCR has a large fluctuation in the fluorescence intensity of the droplets or wells due to insufficient PCR in the small partitions, limiting the multiplexing capability of using the fluorescence intensity. In this study, we propose a new measurement method that combines dPCR with melting curve analysis for highly multiplexed genotyping.

Methods

A sample is digitized into a silicon chip with up to ~104 wells in which asymmetric PCR was performed to obtain more single-stranded amplicons that are complimentary to molecular beacon probes. Fluorescence images were captured while controlling the temperature of the chip, and melting curve was measured for each well. Then, genotyping was performed by using the fluorescence intensity, dye color of the probe, and melting temperature (Tm). Because the Tm of the PCR products does not considerably depend on the amplification efficiency of PCR, genotyping accuracy is improved by using Tm values, enabling highly multiplexed genotyping.

Results

The concept was confirmed by measuring wildtype KRAS and its mutants, G12D, G12R, G12V, and G13D. The results showed that the peaks of the Tm distributions of the DNA groups were 69.2°C and 62.8°C for the wildtype and G13D with the first color dye (HEX), in addition to 66.9°C, 63.5°C, and 59.1°C for G12R, G12D, and G12V, respectively, with the second color dye (FAM). By combining the fluorescence intensities for HEX, FAM and the Tm values, the wildtype and mutant groups were clearly identified and able to be quantified. Furthermore, genotyping of cfDNA of pancreatic cancer patients was successfully performed by this method.

Conclusion

We have proposed a new measurement method that combines dPCR with melting curve analysis, and successfully performed the multiplexed genotyping assay. To our knowledge, this is the first demonstration of genotyping of five DNA groups with a single mutation of cancer-related genes by combining dPCR with melting curve analysis.

Citation Format: Junko Tanaka, Tatsuo Nakagawa, Akiko Shiratori, Yuzuru Shimazaki, Kunio Harada, Chihiro Uematsu, Yoshinobu Kohara, Erina Takai, Shinichi Yachida. Digital PCR combined with melting curve analysis for highly multiplexed genotyping [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 400.