bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3587: Targeting cancer metabolism: A novel approach for improved radiotherapy
Authors: Taori Suchet , Naz Sarwat , Gamson Janet , Mathias Askale , Cook John , Mitchell James B.
Published: August 2019

One key distinguishing hallmark of cancer cells includes a deregulated cellular metabolism that can be reprogrammed to preferentially exhibit dependence on glycolysis over oxidative phosphorylation (OXPHOS) even in the presence of oxygen (commonly known as “Aerobic Glycolysis” or the Warburg Effect). The bi-directional conversion of glucose to lactate in the presence of oxygen is mainly driven by the activity of the lactate dehydrogenase enzyme (LDH), of which, its A isoform is highly overexpressed in a variety of tumors. In the present study we characterized two novel LDH inhibitors (NCI-006 and NCI-737) in combination with ionizing radiation (IR) for their anti-cancer and radio-sensitization effects across tumor types. This study primarily examined effects of this novel combination therapy in cell lines of Pancreatic (MiaPaca, Hs766T, Panc-1), Lung (H460, A549), Head and Neck (FaDU, UMSCC-1), and Prostate (DU145, PC3) origin. Our preliminary results indicated that targeting LDH in conjunction with IR can enhance radiosensitivity under both hypoxic and normoxic conditions across glycolytic tumor cell lines while not affecting non-glycolytic/normal cells (1522, skin fibroblast) in vitro. Further we established that this enhanced radiosensitivity could be attributed to reduced DNA repair as seen by enhanced expression of y-H2AX and reduced ATP generation. Our results also indicated that increased expression of lactate and glucose transporters, combined with cellular bioenergetics changes, leads to a reprogramming of cells to OXPHOS. Lastly, we found that inhibition of OXPHOS and NAD+ in conjunction with these novel LDH inhibitors promotes metabolic synthetic lethality in vitro. As cancer patients continue to receive radiation for local tumor control, we hope that future studies targeting cancer metabolic vulnerabilities in combination with IR in vivo will enhance the therapeutic ratio of radiotherapy.

*The LDH inhibitors used in this study were provided by the NCI Experimental Therapeutics (NExT) Program

Citation Format: Suchet Taori, Sarwat Naz, Janet Gamson, Askale Mathias, John Cook, James B. Mitchell. Targeting cancer metabolism: A novel approach for improved radiotherapy [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 3587.
Abstract 3594: GLUT1 as a metabolic target in glioblastoma therapy
Authors: Labak Collin M. , Guda Maheedhara R. , Jain Neha , Smith Chase P. , Cain Charles P. , Tsung Andrew J. , Velpula Kiran K.
Published: August 2019

Glioblastoma (GBM) is an aggressive diffuse glioma with poor prognosis due to lack of sound therapeutic options. As in many aggressive tumors, GBMs create a hypoxic microenvironment and switch to glycolytic metabolism from oxidative phosphorylation in what is known as the Warburg Effect. Here, we hypothesize that strategically inhibiting influx of glucose via targeting GLUT1 may reverse the Warburg Effect and selectively slow tumor progression. Nanostring data suggests an aberrant metabolic clincial profile in our cohort of GBM patients. Datamining studies and immunoblot analysis were conducted on these same human GBM specimens to demonstrate upregulated GLUT1. Mass spectrometric analysis was performed on GLUT1 precipitated from mesenchymal subtype patient-derived xenograft (PDX). Zonula Occludens adhesion studies were carried out to determine GLUT1 inhibition's effects on cell-cell adhesion structures. Finally, ATP, lactate release, and glucose uptake assays were performed on PDX and GLUT1-silenced PDX to demonstrate a normalized metabolic phenotype when GLUT1 is silenced. Our work suggests that GLUT1 overexpression plays a major role in the metabolic profile of mesenchymal subtype GBM, and that targeting its overexpression could prove effective in reversing the Warburg Effect in GBM cells and ultimately improving patient outcomes.

Citation Format: Collin M. Labak, Maheedhara R. Guda, Neha Jain, Chase P. Smith, Charles P. Cain, Andrew J. Tsung, Kiran K. Velpula. GLUT1 as a metabolic target in glioblastoma 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 3594.
Abstract 36: Application of patients derived organoids as co-clinical model
Authors: Cho Young-Won , Kim Hwang-Phill , Min Dong Wook , Lim Yoojoo , Song Sang-Hyun , Han Sae-Won , Kim Tae-You
Published: August 2019

Organoids are known to best in vitro model system which mostly mimic genetic, phenotypic feature of its origin. And it is expected and suitable to variable disease modeling and study. For cancer modeling using organoids as co-clinical model, our group derived organoids from 40 colorectal tumor including lymph node, terminal ileum metastatic tumor and ascites. Whole exome sequencing of matched tumor organoids and tissues was performed and their somatic mutation concordance was analyzed. As a results, Organoids reflect their genetic statues of the original tumor tissue and their phenotypic features are maintained. In order to prove the appliance of these organoids as a co-clinical model, clinical drugs on colorectal cancer such as 5-Fluorouracil, oxaliplatin, SN38 and cetuximab were tested. The drug results reflected the actual clinical outcome of the corresponding patients. To find the precise drug treatment option for conventional chemo-refractory patients, we performed 134 anti-cancer drug library screening. Organoids with specific mutations were sensitive to drugs which target these corresponding mutations. For instance, organoid with RNF43 mutation was sensitive to porcupine inhibitor which suppresses auto- and paracrine WNT- driven growth. In conclusion, we suggest that patient derived organoids can be applied in cancer treatment as a co-clinical model, due to their highly correlated genetic information and drug sensitivity with those of the patients themselves.

Citation Format: Young-Won Cho, Hwang-Phill Kim, Dong Wook Min, Yoojoo Lim, Sang-Hyun Song, Sae-Won Han, Tae-You Kim. Application of patients derived organoids as co-clinical model [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 36.
Abstract 3604: Synthetic lethality therapy for lung cancers with compromised glutathione homeostasis
Authors: Yan Xiang , Fang Bingliang
Published: August 2019

Glutathione (GSH)/GSH reductase (GSR) and thioredoxin/thioredoxin reductase (TXNRD) are two major compensating thiol-dependent antioxidant pathways that maintain protein dithiol/disulfide balance. We hypothesized that functional deficiency in one of these systems will render cells dependent on compensation by the other system for survival, providing a mechanism-based synthetic lethality approach for treatment of cancers. The human GSR gene is located on chromosome 8p12, a region frequently lost in human cancers. GSR deletion was detected in about 6% of lung adenocarcinomas in The Cancer Genome Atlas database. To test whether loss of GSR sensitizes cancer cells to TXNRD inhibition, we knocked out or knocked down the GSR gene in human lung cancer cells and evaluated their response to the TXNRD inhibitor auranofin. The results showed that GSR deficiency sensitized lung cancer cells to this agent. A correlation analysis of auranofin sensitivity and gene expression levels in a panel of 129 NSCLC cell lines revealed that auranofin sensitivity correlated with the expression levels of the GSR, glutamate-cysteine ligase catalytic subunit (GCLC), and NAD(P)H quinone dehydrogenase 1 (NQO1) genes. In NSCLC patient-derived xenografts with reduced expression of GSR and/or GCLC, growth was significantly suppressed by treatment with auranofin. Together, these results provide proof-of-concept evidence that cancers with compromised expression of enzymes required for GSH homeostasis or with chromosome 8p deletions that include the GSR gene may be targeted by a synthetic lethality strategy with TXNRD inhibitors.

Citation Format: Xiang Yan, Bingliang Fang. Synthetic lethality therapy for lung cancers with compromised glutathione homeostasis [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 3604.
Abstract 3605: O-linked N-acetylglucosamine transferase as a potential therapeutic target for metastatic gastric cancer
Authors: Hur Joon Young , Lee Jeeyun , Kim Kyoung-Mee , Byeon Sun-Ju , Lee Inkyoung , Kang Won Ki
Published: August 2019

Introduction

Many cancer types display elevated O-GlcNAcylation and aberrant expression of O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Here, we describe metabolic reprogramming linked to aberrant increased O-GlcNAcylation, and then inhibition of O-GlcNAcylation as a potential therapeutic target for gastric cancer (GC) treatment.

Methods

We utilized 17 established GC cell lines including 6 primary cell lines (AGS, OCUM-2M, MKN45, SNU1, SNU484, and SNU719), 4 metastatic cell lines (MKN1, MKN28, MKN74, and SNU216), 6 ascite cell lines (SNU5, SNU19, SNU601, SNU620, SNU638, and SNU668), and 1 pleural effusion cell line (KATO III). We collected 21 matched pairs of primary GC and normal gastric tissues and Patient-derived cells (PDCs) (N = 10) at the Samsung Medical Center. PDCs and all cells were grown in RPMI-1640 medium supplemented with 10% FBS. For immunoprecipitation, cells were transfected with pFlag-OGT or siOGT, washed with cold PBS, and lysed in a buffer. Protein extracts (300-500 μg) were incubated with protein G-agarose beads (sc-2002; Santa Cruz)

Results

Cell lines of primary, metastasis and ascites showed expression of O-GlcNAc and OGT. OGT expression is increased in tumor cell and ascites and western blot results showed that OGT expression is more increased in ascites than tumor cell. OGT knockdown inhibited MKN1 cell growth and colony formation. To determine the effect of OGT knockdown on tumor growth in vivo, BALB/c nude mice were injected subcutaneously in the bilateral flank with siC and siOGT transfected MKN1 cells (1 x 107 cells). OGT overexpression enhances O-GlcNAcylation of NFκB p65, c-Myc, and K-Ras. NFκB p65, c-Myc, and K-Ras immunoprecipitates obtained from the cellular extracts were analyzed by immunoblotting for O-GlcNAc. OGT knockdown inhibited PDC (collected from malignant ascites) cell growth. OGT knockdown inhibited GC PDC (1 x 104 cells) cell invasion. Targeting OGT with siRNA in xenograft models decreases the growth of tumors.

Conclusion

Depletion of OGT inhibits cancer cell proliferation and OGT knockdown significantly delays tumor growth in xenograft model. Future work will take advantage of approaches to explain the impact of O-GlcNAc modification on GC.

Citation Format: Joon Young Hur, Jeeyun Lee, Kyoung-Mee Kim, Sun-Ju Byeon, Inkyoung Lee, Won Ki Kang. O-linked N-acetylglucosamine transferase as a potential therapeutic target for metastatic gastric 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 3605.
Abstract 3621: Targeted hyaluronic acid nanoparticles improve treatment response in pancreatic cancer
Authors: Jajja Mohammad Raheel , Zhu Lei , Wang Dazhi , Staley Charles A. , El-Rayes Bassel , Kooby David A. , Yang Lily
Published: August 2019

Pancreatic cancer has poor response to chemotherapy with desmoplastic stroma identified as a delivery barrier. We have developed a nanoparticle (NP) drug system using an engineered ligand of receptor binding region of urokinase plasminogen activator (ATF) and the catalytic domain of metalloprotease (MMP14) carrying SN38 (CPT-11 analog). Hyaluronic acid (HA), a naturally occurring protein was chosen as the backbone to produce a biocompatible NP. HA can also bind to CD44, highly expressed in epithelial cancers. Dual uPAR, CD44 targeting allows for targeted delivery and facilitates receptor mediated endocytosis of NP-drug complex. MMP14 activity degrades extracellular matrix to deplete the stromal barrier. SN38 was encapsulated and recombinant ATFmmp14 conjugated to surface of self-assembled hyaluronic acid spheres (200nm) to form the complete particle (HANP). Cytotoxicity assays were conducted to determine IC50 in cell lines. Patient derived xenograft (PDX) model of a drug resistant pancreatic cancer was used for efficacy studies. Orthotopically implanted tumors were treated with HANP (10mg/kg SN38 dosage) weekly for 6 weeks via tail vein and overall survival compared to conventional therapy. HANP in-vitro cytotoxicity was greater than conventional Irinotecan (>80x) and liposomal irinotecan (>900x) in a PDX derived cell line (Table 1). In-vivo efficacy study demonstrated a significant improvement in survival of PDX bearing mice with HANP (n=9) (median survival 50 days), compared to FOLFIRINOX (n=9) and Gemcitabine-nab-Paclitaxel (n=9) (median survival 37 days each) and no treatment (n=13) (median survival 22 days). Combination of HANP with a modified-FOLFIRINOX regimen (n=9) led to median survival >72 days (p<0.001). HANP alone or in combination with a modified FOLFIRINOX led to significantly improved survival in a pancreatic cancer PDX model. Further studies are underway to evaluate preclinical PD/PK for eventual translation as targeted therapy for pancreatic cancer.

In-vitro cytoxicity assay for IC50 determinationDrugIC50 (uM)HANP0.01SN-380.012Irinotecan0.8Liposomal Irinotecan9

Citation Format: Mohammad Raheel Jajja, Lei Zhu, Dazhi Wang, Charles A. Staley, Bassel El-Rayes, David A. Kooby, Lily Yang. Targeted hyaluronic acid nanoparticles improve treatment response in pancreatic 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 3621.
Abstract 3626: Develop novel nanoparticle formulations of disulfiram copper for cancer therapy
Authors: Chen Wu , Yang Wen , Stewart Landon F. , Coombs David T. , Shen Jianzhong , Chen Pengyu , LI Feng
Published: August 2019

Despite remarkable progress in cancer treatment, drug resistance remains a significant issue for prostate cancer, breast cancer, and others. Disulfiram (DSF), an alcohol-aversion drug, has been repurposed for cancer treatment and overcome drug resistance. DSF and copper ions form a copper diethyldithiocarbamate (Cu-DSF) complex which has a potent anticancer activity. However, the poor aqueous solubility of Cu-DSF creates a significant formulation challenge, and there is no formulation available for clinical use. We developed a Stabilized Metal Ion Ligand Nanocomplex (SMILE) technology to prepare Cu-DSF nanoparticle (NP) formulations where in situ formed DSF-Cu NPs were stabilized by an optimal amount of stabilizers (e.g. poly(ethylene glycol)-poly(lactide)). The SMILE technology involves a novel formulation design and an innovative preparation process using a 3D-printed microfluidic device. After optimizing the protocol, we can prepare Cu-DSF NPs with size in the sub-100 nm range which are suitable for intravenous injection and can target solid tumors through enhanced permeability and retention (EPR) effects. Cu-DSF NPs prepared with SMILE method showed high drug loading efficiency (above 90%) and high drug concentration (at least 2 mg/mL). The drug concentration of Cu-DSF NPs developed in our study was much higher than those in micelle NP formulations prepared with the classical film-dispersion method. Since we used generally recognized as safe (GRAS) excipients approved by the US Food and Drug Administration (FDA) or other excipients with well-recognized safety profiles, the developed NP formulations will have less regulatory hurdle for FDA approval. Because of the novel preparation process and unique formulation design, the SMILE technology can produce Cu-DSF NPs on a large scale and thus paved the way for its mass production and commercialization. We also determined the anticancer effects of Cu-DSF NPs with multiple assays including MTT assay, colony-forming assay, calcein-AM/propidium iodide staining, and others. Cu-DSF NPs showed excellent anticancer activity against various prostate cancer and breast cancer cells as well as drug-resistant cancer cells. In summary, we developed a novel SMILE method to prepare Cu-DSF NP formulations which could address drug delivery and formulation challenges of DSF-based chemotherapy and facilitate the clinical translation.

Citation Format: Wu Chen, Wen Yang, Landon F. Stewart, David T. Coombs, Jianzhong Shen, Pengyu Chen, Feng LI. Develop novel nanoparticle formulations of disulfiram copper for cancer 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 3626.
Abstract 3629: Development of Combrestatin loaded vascular cell modified CLENS for targeting cellular models of tumor vascular endothelia in vitro
Authors: Sanghvi Kanchi S. , Campbell Robert , Yan Guang
Published: August 2019

Purpose: The American Cancer Society predicts that about 0.6 million people would die of cancer and about 1.7 million new cases will be diagnosed in the year 2018. One important goal of cancer treatment is to minimize uptake of the cytotoxic drug agent by normal tissues. CLENs (cell membrane lipid-extracted nanoliposomes) have been developed to enhance targeted delivery of drugs to cancer cells located in the tumor interstitial matrix environment. The purpose of this study was to evaluate the use of CLENs for tumor vascular targeting.

Methods: We expanded tumor endothelial cells derived from the pancreas followed by membrane extraction and the development of MS1-VEGF CLENs for vascular targeting. We evaluated the benefits of the additional inclusion of conventional liposome components (DOPC/Chol/DPPE-PEG5000) in various ratios, including the synthetic cationic lipid DOTAP (50 mol%), known for its vascular targeting characteristics when employed with conventional liposome components. We performed cellular uptake studies to determine relative level of selectivity in connection with the inclusion of LE (lipid extract) material. We determined also the effect of the additional inclusion of DOTAP in CLENs for targeting. We separated free drug from drug incorporated in CLENs using dialysis cassettes with MWCO of 10 kD. We evaluated the efficiency of Combrestatin A4 Phosphate (a microtubule-destabilizing agent) loading in CLENs by HPLC.

Results: The addition of (50 mol%) cationic lipid DOTAP content in CLENs increased the overall zeta potential of the preparation from -14.26 ± 3.65 mV to 10.24 ± 4.23 mV. The average particle size for MS1-VEGF CLENs was approximately 137 ± 7 nm. The cellular uptake studies revealed that CLENs consisting of 70 mol% LE demonstrated the greatest selectivity towards MS1 VEGF cells, when compared to minimal uptake observed for non-target human glioblastoma (U87-MG) cell control. However, the data suggest also an overwhelming cationic lipid effect when DOTAP was included in the CLENs. Where overall cellular uptake increased, the selectivity afforded by LE decreased. Preliminary drug loading studies (between 20 and 45%) suggested that LE inclusion in nanoliposomes influenced the capacity for drug loading.

Conclusion: The inclusion of MS1-VEGF lipid extract material in nanoliposomes improved vascular selectivity. The additional inclusion of DOTAP enhanced targeting, but the preference for target versus non-target cells had diminished. Additional studies are currently underway.

Citation Format: Kanchi S. Sanghvi, Robert Campbell, Guang Yan. Development of Combrestatin loaded vascular cell modified CLENS for targeting cellular models of tumor vascular endothelia in vitro [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 3629.
Abstract 365: Indotecan (LMP400), indimitecan (LMP776) and LMP744, a new class of non-camptothecin topoisomerase I inhibitors selective for schlafen11-positive and BRCA-deficient cells that synergize with olaparib
Authors: Marzi Laetitia , Szabova Ludmila , Ohler Zoe Weaver , Sharan Shyam , Beshiri Mike , Murai Junko , Kelly Kathy , Pommier Yves
Published: August 2019

To overcome the limitations of topoisomerase inhibitors, irinotecan and topotecan (chemical instability, drug efflux substrates, short half-life, dose-limiting bone marrow and gastrointestinal toxicity), we have developed the indenoisoquinolines (LMP400, LMP776 and LMP744). To rationally select patients for phase 2 clinical trials, we have taken two approaches. First, we mined the cancer cell lines genomic databases with CellMinerCDB and found that a dominant response determinant to the indenoisoquinolines is Schlafen 11 (SLFN11), a recently identified executor of cells undergoing replication stress. We validated this finding in isogenic cell lines. Second, because the major lesions generated by the trapping of TOP1 are replication-induced DNA double-strand breaks that are repaired by homologous recombination (HR), we determined whether the indenoisoquinolines exhibit a “synthetic lethality” in cells presenting BRCA1, BRCA2 or PALB2 deficiency. In addition, we tested wether this selectivity could be enhanced when combined with the PARP inhibitor, olaparib. Survival and cell cycle alterations were tested after treatment with the indenoisoquinolines as single agents in isogenic DT40, DLD1 and OVCAR cell lines, with BRCA1, BRCA2 or PALB2 deficiencies, and organoids cultured from patient-derived xenografts with BRCA2 loss, as well as in combination with olaparib. We found that BRCA1-, BRCA2- and PALB2-deficient cells are 3 to 5 times more sensitive to the indenoisoquinolines compared to isogenic cell lines. Moreover, combination treatments showed high synergy between all three indenoisoquinolines and olaparib. We also established the synergy between LMP400 (Indotecan) and olaparib in orthotopic allograft models derived from genetically engineered mouse models for serous epithelial ovarian cancer harboring BRCA1 loss. Better efficacy was observed with the combination over single agent treatments of LMP400 or olaparib. Our results provide a rationale for Phase 2 indenoisoquinoline clinical trials with the indenoisoquinolines in HR-deficient cancers as single agents and in combination with PARP inhibitors, and for measuring Schlafen 11 (SLFN11) as a clinical response determinant.

Citation Format: Laetitia Marzi, Ludmila Szabova, Zoe Weaver Ohler, Shyam Sharan, Mike Beshiri, Junko Murai, Kathy Kelly, Yves Pommier. Indotecan (LMP400), indimitecan (LMP776) and LMP744, a new class of non-camptothecin topoisomerase I inhibitors selective for schlafen11-positive and BRCA-deficient cells that synergize with olaparib [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 365.
Abstract 3653: Immunogenomic landscape of pediatric solid malignancies
Authors: Wei Jun S. , Brohl Andrew S. , Song Young K. , Najaraj Sushma , Gangalapudi Vineela , Walton Ashley , Wen Xinyu , Ladanyi Marc , Khan Javed
Published: August 2019

Malignancy remains the leading cause of disease-related death in children. To identify potential tumor-driving molecular targets and immunogenomic profiles in pediatric cancers, we performed RNA-seq analysis on a cohort of 792 pediatric solid malignant tumors across 14 different diagnoses in conjunction with additional 147 normal tissues for comparison. Sequencing data was analyzed for expressed mutations, fusion events, and expressional patterns, providing therapeutic targets and rich cancer biology for these childhood cancers. Furthermore, we describe immunogenomic features of the tumors including immune cell infiltrate, neoantigen expression, expression of immunomodulatory molecules, and T cell receptor repertoire. Across the cohort, we observed a striking correlation between the expressed neoantigen burden in tumors and enrichment of the effector immune signatures. Histology-specific immunogenomic patterns were also apparent. Several of the pediatric cancers such as alveolar soft part sarcoma and osteosarcoma exhibit rich immune cell infiltration and evidence for activated T cell activities, whereas others such as Ewing’s sarcoma and yolk sac tumors generally have a very low T cell infiltration. We demonstrate that RNA-seq is a powerful tool to identify clinically relevant and histology-specific recurrent mutations, novel oncogenic fusions, and translationally relevant immunogenomic patterns for pediatric cancers. This study also represents one of the largest of its type to date and provides a framework for future translational efforts in pediatric cancer.

Citation Format: Jun S. Wei, Andrew S. Brohl, Young K. Song, Sushma Najaraj, Vineela Gangalapudi, Ashley Walton, Xinyu Wen, Marc Ladanyi, Javed Khan. Immunogenomic landscape of pediatric solid malignancies [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 3653.
Abstract 3654: Recurrent deletions of 3q13.31 in human osteosarcoma commonly affect TUSC7 and LINC00901
Authors: Ameline Baptiste , Kovac Michal , Saba Karim H. , Barenboim Maxim , Nathrath Michaela , Nord Karolin H. , Baumhoer Daniel
Published: August 2019

Background: Osteosarcoma, the most common primary tumor of bone, generally harbors complex structural rearrangements. In this study, we identified frequent mono- and bi-allelic deletions of the two long non-coding RNAs TUSC7 and LINC00901, both located on the long arm of chromosome 3 (3q13.31). Their precise biological function remain largely unknown, although it was suggested that TUSC7 may participate in micro-RNA trapping and thereby could be involved in tumor suppressor gene regulation. Moreover, the presence of a TP53 responsive element upstream of their coding region suggests an involvement in the convoluted TP53 signaling pathway. Methods: Whole genome sequencing data (n=104) and Affymetrix Cytoscan arrays (n=52) were used to derive copy-number profiles of each tumor and interrogated for LINC00901 and TUSC7 deletions. These findings were validated in an independent set of 102 formalin-fixed and paraffin-embedded tissue samples using RNA in situ hybridization techniques. Results: Mono- and bi-allelic deletions were detected in 68 (43.5%) sequenced and array-profiled osteosarcomas. Of these, 34 tumors (50%) acquired deletions in both genes whilst additional focal deletions of TUSC7 and LINC00901 were acquired in 11 (16%) and 19 (28%), respectively. The four remaining cases (6%) revealed copy number losses within the intergenic region between TUSC7 and LINC00901. In addition, reduced amounts or complete losses of hybridisation signals were detected in similar proportions in the independent set of FFPE samples. Conclusions: We identified recurrent 3q13.31 deletions in 68/156 (43,5%) human osteosarcomas which seems remarkable in a tumor well known for its high amount of genomic complexity and intertumoral heterogeneity. TUSC7 and LINC00901 might act as downstream effectors of the TP53 pathway and could be functionally equivalent to TP53 inactivation in case of copy number loss. To further elucidate the consequences of 3q13.31 aberrations we aim to correlate our findings with transcriptome data which is currently ongoing.

Citation Format: Baptiste Ameline, Michal Kovac, Karim H. Saba, Maxim Barenboim, Michaela Nathrath, Karolin H. Nord, Daniel Baumhoer. Recurrent deletions of 3q13.31 in human osteosarcoma commonly affect TUSC7 and LINC00901 [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 3654.
Abstract 3658: Characterization of the role of L3MBTL3 in medulloblastoma tumorigenesis
Authors: Zhang Honglai , Fernandez Ester Calvo , Peabody Claire , Kuick Rork , Park Sung-Soo , Saunders Thomas , Camelo-Piragua Sandra , Rual Jean-Francois M.
Published: August 2019

Medulloblastoma is the most common malignant brain tumor of childhood. Therapeutic approaches to medulloblastoma have led to significant improvements but are achieved at a high cost to quality of life. The Notch pathway governs cell proliferation in many biological contexts, including medulloblastoma tumorigenesis. Using our proteomic platform, we discovered an interaction between RBPJ, a key co-factor of Notch for the mediation of Notch signals, and L3MBTL3, a methyllysine reader for which deletions are observed in medulloblastoma. We demonstrated that L3MBTL3 is part of a molecular mechanism linking the KDM1A demethylase to Notch signal modulation. We hypothesize that malfunction of this molecular mechanism may contribute to the previously suggested tumor suppressor role of L3MBTL3 in medulloblastoma. In a survival analysis using our L3mbtl3 KO mouse in combination with a genetically engineered mouse model of medulloblastoma, we validated our hypothesis that L3mbtl3 is a tumor suppressor in this disease context. Our discovery provides insights into the role of the L3MBTL3 in medulloblastoma that could be harnessed in the future for the therapeutic benefit of medulloblastoma patients.

Citation Format: Honglai Zhang, Ester Calvo Fernandez, Claire Peabody, Rork Kuick, Sung-Soo Park, Thomas Saunders, Sandra Camelo-Piragua, Jean-Francois M. Rual. Characterization of the role of L3MBTL3 in medulloblastoma tumorigenesis [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 3658.
Abstract 3674: Protein levels of Piwi-like 1 and -2 protein are prognostic factors for muscle invasive urothelial bladder cancer patients
Authors: Eckstein Markus , Jung Rudolf , Weigelt Katrin , Sikic Danijel , Stöhr Robert , Geppert Carol , Agaimy Abbas , Lieb Verena , Hartmann Arndt , Wullich Bernd , Wach Sven , Taubert Helge W.
Published: August 2019

The Piwi-like proteins are essential for stem-cell maintenance and self-renewal in all multicellular organisms. We analyzed the expression of Piwi-like 1 and Piwi-like 2 by immunohistochemistry (IHC) in 95 muscle invasive bladder cancer (MIBC) samples using tissue microarray. Application of an immunoreactive score (IRS) revealed 37 and 45 patients who were Piwi-like 1 and -2 positive (IRS>2). IHC results were correlated with clinico-pathological and survival data. The expression of both proteins was positively correlated with each other, lymph node metastasis and expression of CK20 and GATA 3. A negative correlation for both proteins was detected for disease-specific survival (DSS), recurrence, Ki67/MIB1 proliferation index, and CK5 expression. Detection of Piwi-like 1 protein positivity was associated with poor DSS (P=0.019; log rank test, Kaplan-Meier analysis), and in multivariate Cox’s analysis (adjusted to tumor stage and tumor grade), it was an independent prognostic factor for DSS (RR=2.16; P=0.011). Piwi-like 2 positivity was associated with DSS (P=0.008) and relapse-free survival (RFS; P=0.040), and in multivariate Cox’s analysis, Piwi-like 2 positivity was an independent prognostic factor for DSS (RR=2.46; P=0.004) and RFS (RR=3.0; P=0.003). Most interestingly, in the basal type patient subgroup (CK5+/CK20−), Piwi-like 2 positivity was associated with poorer DSS, OS and RFS (P<0.001, P<0.001 and P=0.006; log rank test). In multivariate analysis, Piwi-like 2 positivity was an independent prognostic factor for DSS (RR=10.49; P=0.001), OS (RR=5.71; P=0.001) and RFS (RR=6.35; P=0.016). In summary, Piwi-like 1 and -2 positivity are associated with clinico-pathological factors and survival. Therefore, both Piwi-like proteins are suggested as biomarkers for MIBC patients.

Citation Format: Markus Eckstein, Rudolf Jung, Katrin Weigelt, Danijel Sikic, Robert Stöhr, Carol Geppert, Abbas Agaimy, Verena Lieb, Arndt Hartmann, Bernd Wullich, Sven Wach, Helge W. Taubert. Protein levels of Piwi-like 1 and -2 protein are prognostic factors for muscle invasive urothelial bladder 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 3674.
Abstract 3691: XPC inhibits lung cancer cell dedifferentiation by suppressing Snail expression
Authors: Cai Shurui , Wu Dayong , Banerjee Ananya , Liu Lu , Han Chunhua , Cui Tiantian , Wang Qi-En
Published: August 2019

Lung cancer remains a leading cause of cancer-related deaths in the United States with unfavorable prognosis mainly due to tumor relapse and metastasis, which are recently believed to be caused by a specific population of cancer cells within tumor termed “cancer stem cells (CSCs)”. These cells share the common characteristic of self-renewal and differentiation as normal stem cell, but also show resistance to chemotherapy and radiation therapy. Thus, targeting CSC populations in lung tumors is critical to the prevention of tumor metastasis. Xeroderma pigmentosum group C (XPC) was first recognized as a DNA repair protein. As a DNA repair factor, XPC plays an important role in preventing carcinogenesis. However, it has also been reported that XPC insufficiency is associated with poor treatment outcomes for a variety of cancers, and low expression of XPC is correlated with poor prognosis of lung cancer patients, suggesting that XPC may suppress lung cancer progression. Here, we show that downregulation of XPC expanded lung CSCs characterized by CD133+, while overexpression of XPC limited this cell population, as well as reduced the tumorigenic potential of the lung cancer cell line. Furthermore, we found that XPC knockdown is able to promote the CD133--to-CD133+ cell conversion in A549 cells, indicating that XPC can inhibit lung cancer cell dedifferentiation. Mechanistic investigation demonstrated that XPC can suppress Snail expression by directly binding to the promoter region of the SNAI1 gene, leading to the enrichment of histone H3 trimethylation at serine 27 (H3K27me3) and loss of histone H3 acetylation at serine 27 (H3K27Ac) in this region. Given that Snail plays a critical role in the induction of epithelial-mesenchymal transition (EMT), which is a major mechanism for the acquisition of stem cell-like properties, we believe that XPC can limit the CSC population by inhibiting cancer cell dedifferentiation. In summary, we conclude that low expression of XPC in lung tumors can de-repress the expression of Snail, promote EMT, and increase the de novo production of CSCs, eventually facilitating lung tumor progression.

Citation Format: Shurui Cai, Dayong Wu, Ananya Banerjee, Lu Liu, Chunhua Han, Tiantian Cui, Qi-En Wang. XPC inhibits lung cancer cell dedifferentiation by suppressing Snail 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 3691.
Abstract 3723: Fatty acid synthase: A new therapeutic target for pancreatic cancer
Authors: Steen Travis Vander , Ding Li , Zhang Yu , Kemble George , Billadeau Daniel , Lupu Ruth
Published: August 2019

Pancreatic cancer is the fourth leading cause of cancer related deaths in the United States and continues to be hindered with limited treatment options. One of the current therapeutic regimens for pancreatic cancer often include the nucleoside analog gemcitabine (Gem), while it has been used for many years, the overall survival rate lingers around 6%. New therapies are needed to treat this disease. Fatty acid synthase (FASN) has received increased attention as a potential target for cancer therapy in the last decade. FASN is the key enzyme in the de novo synthesis of palmitate from malonyl-CoA. Palmitate is the precursor other long-chain fatty acids (FA). However, the precise mechanism by which pharmacological interference with endogenous FA biogenesis might facilitate apoptosis in tumor cells remains unresolved. We herein explored the molecular relationship between FASN activity, oxidative stress/redox balance, and the intrinsic apoptotic pathway in FASN overexpressing-dependent pancreatic cancer cells. About 68% of Pancreatic Ductal Carcinomas (PDA) expresses high levels of Fatty acid synthase (FASN), and its expression is correlated with disease free survival. A newly developed FASN inhibitor with excellent pharmaceutical properties was used for our studies TVB-3166 (in vitro) and TVB-3664 (in vivo) and ten different PDX derived cells were used for the studies. Pharmacological blockade of FASN activity significantly increased the NADPH/NADP+ ratio, promoted the production of reactive oxygen species (ROS). Accordingly, the inhibition of endogenous FA synthesis promoted mitochondrial membrane permeabilization, cytochrome c release, and apoptotic cell death. Each step of the FASN inhibition/BH3-only protein axis could be reversed with a ROS scavenger or the FASN end-product palmitate, thus confirming that the delineated pro-apoptotic cascade likely reflects on-target effects of FASN inhibition. Most importantly, the in vivo studies using PaCa-PDX reveal a significant decrease in tumor growth and furthermore a synergistic effect of between TVB-3664 and Gem. In conclusion, our findings uncover a novel FASN-dependent mitochondrial priming that links de novo FA biosynthesis with the intrinsic apoptotic threshold in cancer cells. The discovery that FASN-inhibited cancer cells exist in an apoptosis-prone state highly sensitive to BH3 mimetics warrants clinical exploration in FASN-overexpressing pancreatic cancer patients.

Citation Format: Travis Vander Steen, Li Ding, Yu Zhang, George Kemble, Daniel Billadeau, Ruth Lupu. Fatty acid synthase: A new therapeutic target for pancreatic 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 3723.
Abstract 3725: Numerical simulation of tumor treating fields effects on cell structures: Mechanism and signaling pathway candidates
Authors: Carlson Kristen W. , Paudel Nirmal , Tuszynski Jack A. , Bomzon Zeev
Published: August 2019

Tumor Treating Fields (TTFields) have become a fourth modality for cancer treatment. Mild electric fields (~1-4 V/cm) produce few side effects and significantly extend overall survival of glioblastoma patients, and TTFields are in clinical trials for a variety of tumor cell types. Our goal is to uncover TTFields’ mechanism and cell signaling pathways by numerically modeling their effects on sub-cellular structures, such as microtubules (MTs) and their interactions with motor proteins. METHODS: We have built finite element models in COMSOL Multiphysics (tm) of the MT and its micro-environment to test hypotheses on TTFields’ mechanism of action by predicting effects on sub-cellular structures. RESULTS: One model prediction is that current density induced in the MT counter-ion layer by TTFields essentially shunts electric current within them. The strongest current flows through the counter-ion layer surrounding the MT’s C-termini and energy density in this layer likely exceeds the level to disrupt motor protein ‘walk’ along the MT. The energy density is predicted at 10-20 Joules when both the field and the MTs are aligned with the cell axis. A second mechanism examined by our model is disruption of the ‘foot’ of kinesin, released from its C-terminus contact by ATP (10-19 Joules). The final phase of the walk is driven by thermal buffeting of the forward foot randomly positioning it near enough to the C-terminus for electrostatic forces to bind it. A stall force ~10-19 - 10-16 N from TTFields would prevent diffusion and disrupt the kinesin walk. A recent clinical study segregating patient cohorts treated vs. not treated with dexamethasone found overall survival indefinitely for the non-dexamethosone cohort, leading us to hypothesize that TTFields activate the intrinsic Bcl2-mediated apoptotic signaling pathway. Future modeling will seek to tie disruption of motor protein transport along MTs to activating intrinsic apoptosis, e.g. via failure to silence the G2 cell cycle checkpoint. CONCLUSION: Our modeling predicts that TTFields in cytosol induce electric currents along MTs that are strong enough to disrupt key cellular functions such as the kinesin walk and C-termini transitions, both of which are crucial for motor protein transport. Hence, TTFields disrupt the most delicate mechanisms involved in the carefully-orchestrated succession of steps in mitosis.

Citation Format: Kristen W. Carlson, Nirmal Paudel, Jack A. Tuszynski, Zeev Bomzon. Numerical simulation of tumor treating fields effects on cell structures: Mechanism and signaling pathway candidates [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 3725.
Abstract 373: Dysregulated RPB1 is a key driver of overgrowth and drug resistance in acute myeloid leukemia
Authors: Yu Qingfeng , Zheng Shu , Xu Ying , Xu Rongzhen
Published: August 2019

Acute myeloid leukemia (AML) is a group of highly aggressive malignancies with a 5-year overall survival (OS) of <40%. Cell overgrowth with apoptosis resistance is a hallmark of AML, but little is known about how it occurs. In this study, we show that dysregulated the largest subunit of RNA polymerase II (RPB1) encoded by POLR2A gene is critically involved in this hallmark in AML. qRT-PCR and RNA-seq results showed that POLR2A mRNA were significantly overexpressed in 76.87% (113/147) compared with normal hematopoietic cells(1.5526 versus 0.8447, P<0.001). Western blotting analysis revealed that RPB1 protein is also aberrantly activated in 68.14%(67/113) of AML patients but rare or even absent in normal hematopoietic cells, (0.7889 versus 0.0509, P<0.01). TCGA data analysis indicated that aberrant activation of POLR2A mRNA occurred predominantly in AML, CHOL and THYM, but not in most other types of cancers. Importantly, we observed that RPB1 expression levels were closely associated with tumor burden and poor prognosis. Notably, we found that POLR2A inhibition induced potent apoptosis and growth inhibition of refractory AML cells. Global transcriptomic analysis reveals that POLR2A knockout selectively depleted an array of AML-related oncogenic and anti-apoptosis genes such as c-MYC, RUNX2, MEIS1, FLT3, CDC25A and BCL-2. Conversely, enforced overexpression of RPB1 exhibits robust enrichment of oncogenes and anti-apoptosis genes, leading to cell overgrowth and drug resistance. Of particular interesting, targeting RPB1 by both genetic and pharmacological molecules could lead complete regression of refractory human AML in mouse models. In conclusion, our findings for the first time reveal that dysregulated RPB1 is a central oncogenic hub that drives overgrowth and drug resistance by coordinately hijacking an array of oncogenic genes and anti-apoptosis factors. Importantly, RPB1 is not absolutely required for the survival of normal hematopoietic cells, which is contrary to the commonly accepted belief that RPB1, the heart of the cellular transcription machinery, is required for all protein-coding genes. These data suggest that targeting RPB1 might be a potential therapeutics for treating refractory/relapse AML.

Note: This abstract was not presented at the meeting.

Citation Format: Qingfeng Yu, Shu Zheng, Ying Xu, Rongzhen Xu. Dysregulated RPB1 is a key driver of overgrowth and drug resistance in acute myeloid leukemia [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 373.
Abstract 3742: Exosome-mediated EGR1 transportation controls the radiation-induced abscopal effect in head and neck cancer
Authors: Akbor Mohammady , Lin Liang-Ting
Published: August 2019

Head and neck cancer (HNC) are one of the vital types of metastatic cancer, and radiotherapy (RT) is the convincing treatment regarding its location. RT can regulate cancer growth in not only directly irradiated cells but also non-irradiated remote cells by abscopal or bystander effects. It is evident that radiation-induced Early Growth Response 1 (EGR1) is involved in the control of such type cancer progression. Also, exosomes are established carriers for biological factors basically in cell communication. In this study, we would like to identify the EGR1 as a functional molecule that carried by the radiation-induced exosome to control the HNC growth to disclose the molecular mechanism of the abscopal effect. In this case, we used FaDu cell, a hypopharyngeal cancer, for in vitro experiments. Irradiation was given to the cells in a dose-dependent manner from 0 to 12 Gy followed by exosome isolation using miRCURY Exosome Cell Kit. Characterization of the isolated exosomes was performed by Nanoparticle Tracking Analysis (NTA) for vesicle sizes and concentration, and by transmembrane markers CD63 and CD9 through western blot. We treated unirradiated FaDu cells with isolated exosomes to address the phenotypic changes. MTT assay and colony-forming assay observed the cell viability and survival. Moreover, the expression of EGR1 in both radiation-induced exosome and the exosome-treated cells were determined by western blot. To validate the causal effect of exosomal transportation of EGR1, we assessed the viability changes in EGR1-silenced FaDu cells with exosome treatment. Our results indicated that the number of exosomes was increased while the amounts of protein in each isolated exosome were also increased in a radiation dose-dependent manner. CD63 and CD9 had been identified through western blotting. Moreover, the enhanced expression of EGR1 was observed in both radiation-induced exosomes and the cells treated with isolated exosomes. The possible abscopal effect was evident by the significant decrease of the viability of unirradiated FaDu cells treated with radiation-induced exosomes. Besides, elevated expression of EGR1 was noticed in the radiation-induced exosomes comparing to non-irradiated cohorts. Notably, EGR1-containing exosomes can suppress the proliferation of the unirradiated FaDu cells. Alternatively, radiation-induced EGR1-containing exosome failed to inhibit the proliferation of EGR1 knockdown FaDu cells. In conclusion, radiation-induced EGR1 via exosome transportation contributes to the mechanism of the abscopal effect for metastatic head and neck cancer.

Citation Format: Mohammady Akbor, Liang-Ting Lin. Exosome-mediated EGR1 transportation controls the radiation-induced abscopal effect in head and neck 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 3742.