bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract LB-A10: ORIC-101 overcomes glucocorticoid-driven resistance to enzalutamide in castration-resistant prostate cancer
Authors: Zhou Haiying , Barkund Shravani , Pankov Aleksandr , Sinha Sharvani , Sutimantanapi Dena , Friedman Lori S. , Kabbarah Omar
Published: March 2020

Prostate cancer is the second leading cause of cancer-related death in men. Androgen deprivation is commonly used to treat hormone-sensitive prostate cancer, while second-generation antiandrogens, including enzalutamide and abiraterone, benefit patients with castration-resistant prostate cancer (CRPC). New therapeutic strategies are needed for patients who relapse with metastatic CRPC. The glucocorticoid receptor (GR) has been implicated as a major bypass mechanism to escape androgen blockade in patients with CRPC, indicating that GR-targeted therapies may provide an avenue to overcome therapeutic resistance in this clinical setting. We discovered a novel, selective, oral GR antagonist, ORIC-101, which fully reverses GR-driven resistance to enzalutamide in a dose-dependent manner in preclinical models. Specifically, we show that GR is widely expressed in prostate cancer cell lines, organoids, and tumor tissue, and that GR levels are upregulated upon enzalutamide treatment. We demonstrate in preclinical studies that physiological levels of glucocorticoids promote tumor cell growth, stimulate androgen-regulated gene expression, and drive resistance to enzalutamide. Importantly, these effects were completely reversed by ORIC-101, suggesting ORIC-101 overcomes GR-driven resistance to enzalutamide. To inform the clinical development of ORIC-101 in combination with enzalutamide, we identified FKBP5 and KLK3 as direct transcriptional targets of both androgen receptor and GR. We subsequently validated that secreted PSA, a product of the KLK3 gene, can be induced by glucocorticoids and this induction is fully inhibited by ORIC-101. These findings confirm that targeting GR may help overcome resistance to enzalutamide in CRPC, and that FKBP5 and KLK3 are rational PD biomarkers that may be used in clinical trials of ORIC-101, along with PSA.

Citation Format: Haiying Zhou, Shravani Barkund, Aleksandr Pankov, Sharvani Sinha, Dena Sutimantanapi, Lori S. Friedman, Omar Kabbarah. ORIC-101 overcomes glucocorticoid-driven resistance to enzalutamide in castration-resistant prostate cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr LB-A10. doi:10.1158/1535-7163.TARG-19-LB-A10
Abstract LB-A11: Quantitative and qualitative characterization of spontaneous resistance to targeted protein degradation
Authors: Brand Matthias , Winter Georg E.
Published: March 2020

Targeted protein degradation (TPD) by heterobifunctional small molecules commonly called PROTACs has recently emerged as a promising novel strategy in drug development. PROTACs hijack the endogenous cellular degradation machinery by recruiting E3 ubiquitin ligases to a protein of interest, resulting in its ubiquitination and degradation by the proteasome. The first two PROTACs have entered clinical investigation this year, but resistance mechanisms to this novel pharmacology are not yet thoroughly understood. Here, we set out to systematically quantify and characterize spontaneous resistance to TPD. For this, we made use of the well-characterized PROTACs dBET6 and ARV-771, that induce degradation of BET bromodomain proteins by recruitment of the E3 ligase CRBN or VHL, respectively. We estimated spontaneous resistance rates by exposing cells to lethal doses of drug and monitoring for the emergence of resistant clones. We detected important quantitative differences between the two PROTACs, with resistance rates to the VHL-based degrader ARV-771 being significantly lower than to dBET6. To characterize the mechanism of resistance, we implemented a customized hybrid-capture sequencing pipeline for known determinants of PROTAC sensitivity and applied it to drug-resistant cells, revealing several resistance-conferring mutations. Mapping of the mutations on crystal structures of the E3 ligase complexes highlighted their clustering at the drug binding pocket, as well as on important protein-protein interaction surfaces in the complex. The majority of identified mutations affected the hijiacked E3 ligase complex directly and not the general ubiquitination machinery, thereby not conferring cross-resistance to different PROTACS. This suggests combination treatment with degraders that exploit different E3 ligases as a viable strategy to limit emergence of PROTAC resistance.

Citation Format: Matthias Brand, Georg E. Winter. Quantitative and qualitative characterization of spontaneous resistance to targeted protein degradation [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr LB-A11. doi:10.1158/1535-7163.TARG-19-LB-A11
Abstract LB-B05: Characterization of a panel of 79 PDX-derived cell lines with a focus on the EGFR exon 20 insertion mutation-driven NSCLC model LXFE 2478
Authors: Kelter Gerhard , Peille Anne-Lise , Fehr Jutta , Klett Hagen , Maier Armin , Posch Markus , Metz Thomas M
Published: March 2020

Patient-derived tumor xenograft (PDX) models have become indispensable for the preclinical profiling of novel anti-cancer agents as they retain histological, molecular and pharmacological characteristics of the parental patient tumors and for many tumor types collectively replicate the diversity of patient tumors. To make PDX models available for in vitro assays, we have established a panel of 79 low passage cell lines derived from PDXs representing 15 different tumor histologies. Using, among others, the non-small cell lung cancer model LXFE_2478 which is driven by the exon 20 insertion EGFR mutation M766_A767insASV as an example, we demonstrate the following similarities of PDX models and the corresponding PDX-derived cell lines. (i) Subcutaneous xenografts established from PDX-derived cell lines mirror the histology of the corresponding PDX models and usually also patient tumors. (ii) For LXFE_2478 both the PDX model and the corresponding PDX-derived cell line express high levels of EGFR, suggesting that the oncogenic driver is still present. (iii) For LXFE_2478 the PDX and the PDX-derived cell line subcutaneously implanted in mice display comparable sensitivity to a variety of EGFR inhibitors and cytotoxics. (iv) For LXFE_2478 the sensitivity of the PDX-derived cell line to a variety of EGFR inhibitors in an in vitro 2D cell survival and proliferation assay in general corresponds to the EGFRi sensitivity of the corresponding PDX model in vivo. (v) For several additional PDX models representing various histotypes the sensitivity to first generation EGFR inhibitors of PDX-derived cell lines in the 2D assay is in line with the in vivo EGFR inhibitor sensitivity of the corresponding PDXs. In conclusion, at least for some mechanisms of action in vitro data obtained with PDX-derived cell lines can predict the in vivo behavior of the corresponding PDX model and can thereby accelerate, and reduce the costs of, the discovery of novel anticancer agents.

Citation Format: Gerhard Kelter, Anne-Lise Peille, Jutta Fehr, Hagen Klett, Armin Maier, Markus Posch, Thomas M Metz. Characterization of a panel of 79 PDX-derived cell lines with a focus on the EGFR exon 20 insertion mutation-driven NSCLC model LXFE 2478 [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr LB-B05. doi:10.1158/1535-7163.TARG-19-LB-B05
Abstract LB-B17: Uncovering novel cancer therapeutics using the Exoneural Medicines Platform: The role of innervation in cancer
Authors: Lou Shan , Fink Alexandria , Wang Jay , Turner Jesse , Thanawala Monica , Yuen Garmen , Lantermann Alexandra , Shu Jenny , Dai Hongyue , Huang Pearl , Hurov Jonathan
Published: March 2020

Peripheral nerves were first described as a component of tumors in the late 19th century. In the mid-20th century early preclinical studies indicated that tumor cells could recruit innervation from spinal cord ganglia and that stress promotes tumorigenesis. Within the last 10 years improvements in technologies allowing neuronal tracking and regulation of neuronal function have uncovered a role for both autonomic and sensory innervation in multiple tumor types. Initial studies have implicated this biology in prostate, pancreatic, gastric and breast cancer (among others) and point to a role for nerves in initiation, maintenance and metastasis of tumors. The stimulation of tumor cell growth by neural growth factors, the recruitment of neurites by tumor cells, the invasion and migration of tumor cells along nerves (perineural invasion), and the role of innervation in driving tumor angiogenesis are just a few examples of how peripheral nerves interact with the tumor microenvironment. Indeed, an argument could be made that innervation of tumors should be considered a hallmark of cancer. We describe here a biological platform that can define and decode the role of neural signaling in cancer. This platform, which we call Exoneural Medicines Platform ™, has 6 technical components: 1) co-culture models of primary neurons with both tumor and immune cells, 2) advanced imaging modalities to define the neural component of tumors, 3) AAV and transgenic tools that allow regulation of neurons proximal to tumors in vivo and in vitro, 4) neural-focused functional genomics, 5) neural-focused bioinformatics, and 6) a neuropharmacopeia compound library for probing relevant biological pathways and identification of advanced starting points for drug discovery. We show here how the platform is being employed to characterize this exciting new space in cancer biology and to identify new drivers of disease.

Citation Format: Shan Lou, Alexandria Fink, Jay Wang, Jesse Turner, Monica Thanawala, Garmen Yuen, Alexandra Lantermann, Jenny Shu, Hongyue Dai, Pearl Huang, Jonathan Hurov. Uncovering novel cancer therapeutics using the Exoneural Medicines Platform: The role of innervation in cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr LB-B17. doi:10.1158/1535-7163.TARG-19-LB-B17
Abstract LB-B19: Investigating the effect of pharmacogenetic variations on voriconazole levels in pediatric cancer patients
Authors: Saeed Dina , Shalaby Lobna , Nagy Mohamed , ElZeiny Ahmed , Mostafa Tarek M. , ElRakaiby Marwa T. , Nooh Mohammed M. , El-Haddad Alaa , Abbassi Maggie , Aziz Ramy K.
Published: March 2020

Background: Voriconazole is a second-generation triazole antifungal with broad-spectrum activity against Aspergillosis, metabolized mainly by CYP2C19 in the liver. Despite the use of weight-based dosing, plasma voriconazole blood levels show inter-individual variability, which is attributed to many factors such as weight, age, food, drug interactions, and CYP2C19 polymorphism. Voriconazole metabolism in pediatrics has been reported to be profoundly impacted by CYP2C19 genotypes. Aim: To evaluate the frequencies of CYP2C19 variant alleles (*2, *3, and *17), genotypes, and phenotypes in Egyptian pediatric cancer patients and to investigate the correlation between CYP2C19 genetic variability and other factors with voriconazole plasma levels. Methods: This study was conducted on 100 pediatric cancer patients with probable fungal infection treated with voriconazole. DNA was extracted from blood samples and analyzed by the TaqMan SNP genotyping assay. Identified genotypes were classified accordingly into various predicted phenotypes. Results: Voriconazole plasma levels widely varied, with only 49.5% reaching therapeutic levels. Frequencies of CYP2C19*2 and *17 allelic variants were 10.6 and 18.3%, respectively, while allele *3 was not detected in the study population. A significant correlation was found between plasma levels and CYP2C19 phenotypes: ultra-rapid metabolizers had significantly lower plasma levels (P=0.003) relative to the extensive metabolizer genotype. Conclusion: Determination of CYP2C19 genotype at initiation of therapy, followed by drug monitoring, would serve as a valuable tool for the optimization of voriconazole therapy for pediatric cancer patients. It would also be an essential step in the advancement of precision medicine to optimize therapeutic efficacy and minimize toxicity.

Citation Format: Dina Saeed, Lobna Shalaby, Mohamed Nagy, Ahmed ElZeiny, Tarek M. Mostafa, Marwa T. ElRakaiby, Mohammed M. Nooh, Alaa El-Haddad, Maggie Abbassi, Ramy K. Aziz. Investigating the effect of pharmacogenetic variations on voriconazole levels in pediatric cancer patients [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr LB-B19. doi:10.1158/1535-7163.TARG-19-LB-B19
Abstract LB-C10: Preclinical synergistic anti-tumor effect against multiple cancer types by EZH2 inhibitor EPZ-6438 plus imipridone ONC201 to mimic H3K27M mutation observed in DIPG tumors that respond to ONC201 in the clinic
Authors: Zhang Yiqun , Zhou Lanlan , Zhang Shengliang , Borsuk Robyn , Safran Howard P. , Seyhan Attila A. , El-Deiry Wafik S.
Published: March 2020

ONC201, the founding member of the imipridone class of small molecules, has broad spectrum anti-tumor activity and achieved tumor regressions and prolonged disease stability in clinical trials, especially in patients with histone H3 K27M mutated glioma. Levels of H3K27 dimethylation (H3K27me2) and trimethylation (H3K27me3) are reduced globally in H3 K27M patient samples. EZH2 is the catalytic component of the Polycomb Repressor Complex 2 (PRC2), a conserved multi-subunit that represses gene transcription by methylating lysine 27 on Histone H3 (H3K27). EZH2 is frequently overexpressed or mutated (activating) in numerous human malignancies and EZH2 inhibitors represent a promising therapeutic strategy. We hypothesized that cancer cells could be sensitized to ONC201 by EZH2 inhibition through suppression of H3K27 methylation that may mimic tumors such as DIPG with H3K27M mutations which are known to respond to ONC201 in the clinic and are defective in H3K27 methylation. We treated cancer cells from different tissue origins including breast cancer, pancreatic cancer, colorectal cancer, GBM, and DIPG with single agent ONC201, EZH2 inhibitor EPZ-6438 or the combination of ONC201 plus EPZ-6438. Cell viability was determined with the Cell Titer-Glo assay. Integrated stress response (ISR) activity widely observed in ONC201-treated tumor cells was evaluated using Western blot analysis of ATF4 and apoptosis by analysis of PARP cleavage. Our results demonstrate that ONC201 synergistically reduced cell viability, induced integrated stress response and apoptosis in combination with EZH2 inhibitor EPZ-6438. There was greater induction of ATF4 in combination therapy-treated tumor cells versus monotherapy. Intriguingly, U-251 GBM cells that were resistant to ONC201 under hypoxia could be sensitized to ONC201 by EZH2 inhibitor EPZ-6438. Our findings provide a preclinical rationale for developing ONC201 and EZH2 inhibitors as a novel synergistic combinatorial regimen with the potential for clinical translation in the treatment of several human malignancies including GBM, pancreatic cancer, colorectal cancer, and breast cancer.

Citation Format: Yiqun Zhang, Lanlan Zhou, Shengliang Zhang, Robyn Borsuk, Howard P. Safran, Attila A. Seyhan, Wafik S. El-Deiry. Preclinical synergistic anti-tumor effect against multiple cancer types by EZH2 inhibitor EPZ-6438 plus imipridone ONC201 to mimic H3K27M mutation observed in DIPG tumors that respond to ONC201 in the clinic [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr LB-C10. doi:10.1158/1535-7163.TARG-19-LB-C10
Abstract PL04-01: Background and use of circulating tumor-derived DNA and circulating tumor cells as biomarkers
Authors: Lolkema Martijn
Published: March 2020

The use of circulating biomarkers to assess malignant disease is an ever growing field of interest. Indeed, many studies have shown that mutations derived from tumors can be detected in plasma, and the use of novel sequencing techniques have given rise to many novel ways of probing blood samples for analytes that may reveal tumor characteristics. In my presentation I will present some crucial pieces of evidence that circulating tumor-derived DNA (ctDNA) may be used to detect minimal residual disease, track mutational evolution and may be used to monitor disease response to treatment. Indeed, ctDNA is one of the most promising analytes and has the potential to alter clinical practice in the foreseeable future. But to get there we need to have a basic understanding of the variables that determine the outcome of these tests. Pre-analytical conditions and proper controls for ctDNA quantification are crucial in the interpretation of the results. Seemingly trivial factors such as intrinsic variation of cfDNA may affect the way we can use this type of analyte. Moreover, I will give an overview of those tests that are about to become available in the coming years, including shallow whole genome sequencing, methylation specific sequencing and panel based sequencing of ctDNA. The second part of my presentation will deal with the first true circulating biomarker that has been the detection of Circulating Tumor Cells (CTCs) and still detecting CTCs is important for the oncology community. I will review the advances we made in this field and will dive a bit deeper into the reasons why we still should be looking at CTCs. In contrast to non-cellular analytes, CTCs can inform us on properties of cells as a whole. The technology development in this arena made enormous advances and the use of single cell sequencing techniques will revolutionize our understanding of intra-tumoral heterogeneity from relatively simple blood based tests. Moreover, the detection of CTCs has always been hampered by the relative low abundance of CTCs, however novel approaches such as leukapheresis to isolate CTCs may deliver on the promise characterization of CTCs holds to reveal the extent of tumor cell heterogeneity.

Citation Format: Martijn Lolkema. Background and use of circulating tumor-derived DNA and circulating tumor cells as biomarkers [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr PL04-01. doi:10.1158/1535-7163.TARG-19-PL04-01
Abstract A09: CD4 T cells mediated protumorigenic pathway in pancreatic cancer
Authors: Dey Prasenjit , Li Jun , Zhang Jianhua , Wang Huamin , Liao Wen-Ting , Bernard Vincent P , Genovese Giannicola , Maitra Anirban , Strom Anders , DePinho Ronald A.
Published: March 2020

A hallmark of pancreatic ductal adenocarcinoma (PDAC) is an exuberant stroma comprised of diverse cell types that enable or suppress tumor progression. This Kras*-driven heterotypic signaling circuit in the early and advance tumor microenvironment enables cooperative protumorigenic interactions in early steps of the neoplastic transformation process as well as in promoting growth of established tumors, providing novel therapeutic targets in the Kras* pathway for this intractable disease. Here, we explored the role of Kras* in protumorigenic signaling interactions between cancer cells and host cells in tumor microenvironment. Early-stage malignant lesions and advanced tumors show close proximity of Kras* expressing cancer cells and abundant invading TH2 (CD4+ Gata-3+) cells, which can produce IL-4 and IL-13. Single-cell analysis of low- and high-grade IPMN and PDAC patient samples revealed CD4+ T-cell infiltration and higher percentage of the CD4+ T cells are Gata3+ TH2 subtypes compared to T-bet+ TH1 cells. Similarly, imaging mass spectrometry analysis showed presence of CD4+ T cells in close proximity to cancer cells. Mechanistic studies identified Jak1-Stat6 as the primary signaling pathway downstream of IL-4/IL-13 activated IL-4 receptor complexes in cancer cells. Integrated transcriptomic and chromatin immunoprecipitation sequencing (ChIP-seq) profiling identified cMyc, specifically its upstream enhancer element, as a direct target of activated Stat6. Metabolomic analysis demonstrated that IL-4/13STAT6cMyc upregulation drives increased glycolysis along with upregulated expression of key glycolysis enzymes, forging a link between Kras*-driven glycolysis via paracrine activation of cMyc.

Citation Format: Prasenjit Dey, Jun Li, Jianhua Zhang, Huamin Wang, Wen-Ting Liao, Vincent P Bernard, Giannicola Genovese, Anirban Maitra, Anders Strom, Ronald A. DePinho. CD4 T cells mediated protumorigenic pathway in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr A09.
Abstract A16: A novel therapeutic approach to inhibit the bidirectional oncogenic crosstalk between pancreatic cancer cells and the surrounding stroma
Authors: Geleta Bekesho , Park Kyung Chan , Jansson Patric J. , Apte Minoti , Richardson Des R. , Kovacevic Zaklina
Published: March 2020

Background: Pancreatic cancer (PaCa) is a leading cause of cancer-related deaths and is projected to be the second most common cancer in a decade. It is characterized by a dense stroma surrounding tumor cells, known as desmoplasia that is stimulated by Sonic Hedgehog (SHH) released by PaCa cells. Stromal cells, in turn, release mitogenic substances such as hepatocyte growth factor (HGF) and Insulin-like growth factor receptor (IGF-1) by glioma-associated oncogene homolog 1 (GLI1) transcription factor that stimulate tumor growth, invasion, and resistance to therapy. We investigated the potential of targeting the metastasis suppressor gene N-myc downstream regulated gene 1 (NDRG1) to interrupt the oncogenic crosstalk between cancer associated human pancreatic stellate cells (PSCs) and PaCa cells.

Methods: We assessed novel thiosemicarbazone anti-cancer agents, Dp44mT and DpC, that upregulate NDRG1 and their effects on: (i) SHH production by PaCa cells and also HGF and IGF-1 production by PSCs; (ii) HGF and IGF-1 receptors and their downstream signaling in indirect 2D and direct 3D co-culture of PSCs and PaCa cells; (iii) GLI1 and its upstream mediators in PSCs; and (iv) proliferative and metastatic properties of PaCa cells co-cultured with PSCs.

Results: Dp44mT and DpC upregulated NDRG1 and reduced SHH production by PaCa. These agents also inhibited downstream HGF and IGF-1 signaling pathways in PaCa cells, leading to reduced metastatic potential in co-culture 2D and 3D models. Further, these agents also inhibited GLI1 levels and activation in PSCs, leading to reduced HGF and IGF-1 production by these stromal cells. NDRG1 overexpression alone had similar effects, while silencing NDRG1 further potentiated the oncogenic crosstalk between PaCa and PSC cells.

Conclusions: Novel agents targeting NDRG1 have the unique ability to block the oncogenic crosstalk between PaCa cells and the surrounding stroma. This presents a novel approach to PaCa treatment that can potentially overcome the major problems attributed to desmoplasia, including therapeutic resistance and metastasis.

Citation Format: Bekesho Geleta, Kyung Chan Park, Patric J. Jansson, Minoti Apte, Des R. Richardson, Zaklina Kovacevic. A novel therapeutic approach to inhibit the bidirectional oncogenic crosstalk between pancreatic cancer cells and the surrounding stroma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr A16.
Abstract A24: Gene expression along the glycolysis-cholesterol synthesis axis and outcome in pancreatic cancer
Authors: Karasinska Joanna M. , Topham James T. , Kalloger Steve E. , Jang Gun Ho , Denroche Robert E. , Culibrk Luka , Williamson Laura M. , Wong Hui-li , Lee Michael K.C. , O'Kane Grainne M. , Moore Richard A. , Mungall Andrew J. , Moore Malcolm J. , Warren Cassia , Metcalfe Andrew , Notta Faiyaz , Knox Jennifer J. , Gallinger Steven , Laskin Janessa , Marra Marco A. , Jones Steven J.M. , Renouf Daniel J. , Schaeffer David F.
Published: March 2020

Reprogramming of metabolic pathways allows cancer cells to survive and thrive in the tumor microenvironment. Glycolysis-inducing factors including oncogenic KRAS mutations, loss of function in TP53 and hypoxia are prevalent in PDAC. Cholesterol and its metabolites support tumor cell growth and the mevalonate pathway, which uses glycolysis products for de novo cholesterol synthesis, has been found to be upregulated in cancer. However, whether intertumoral heterogeneity in these metabolic networks influences outcome in pancreatic cancer has not been well established. We profiled the expression of glycolytic and cholesterogenic genes in 325 resected and metastatic pancreatic ductal adenocarcinoma (PDAC) tumors and identified four distinct subgroups: quiescent, glycolytic, cholesterogenic, and mixed. Glycolytic tumors were associated with the shortest median survival in resectable and metastatic disease settings. Patients with cholesterogenic tumors had the longest median survival. KRAS and MYC amplified tumors had higher expression of glycolytic genes than tumors with normal or lost copies of these oncogenes. The mitochondrial uptake of pyruvate, the end product of glycolysis, facilitates the generation of acetyl-CoA for cholesterol synthesis. PDAC tumors with a glycolytic gene signature had the lowest expression of mitochondrial pyruvate carriers MPC1 and MPC2. Glycolytic and cholesterogenic gene expression correlated with the expression of reported prognostic PDAC subtype classifier genes. Our results indicate that PDAC tumors have unique metabolic profiles that influence disease outcome and provide functional correlate to previously identified subtypes. The findings also raise the possibility of a shift in balance between the glycolytic and cholesterogenic pathways as a factor in PDAC progression and a potential target for therapy.

Citation Format: Joanna M. Karasinska, James T. Topham, Steve E. Kalloger, Gun Ho Jang, Robert E. Denroche, Luka Culibrk, Laura M. Williamson, Hui-li Wong, Michael K.C. Lee, Grainne M. O'Kane, Richard A. Moore, Andrew J. Mungall, Malcolm J. Moore, Cassia Warren, Andrew Metcalfe, Faiyaz Notta, Jennifer J. Knox, Steven Gallinger, Janessa Laskin, Marco A. Marra, Steven J.M. Jones, Daniel J. Renouf, David F. Schaeffer. Gene expression along the glycolysis-cholesterol synthesis axis and outcome in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr A24.
Abstract A29: Bicompartmental regulation of disease-related gene networks by histone deacetylase inhibition curbs pancreatic cancer progression
Authors: Liang Gaoyang , Hah Nasun , Shi Yu , Truitt Morgan L. , Antal Corina E. , Atkins Annette R. , Fraser Cory , Banayo Ester , Bashi Senada , Dai Yang , Sherman Mara , Liddle Christopher , Yu Ruth T. , Hunter Tony , Han Haiyong , Hoff Daniel D. Von , Downes Michael , Evans Ronald M.
Published: March 2020

A challenge for effective pancreatic ductal adenocarcinoma (PDAC) therapy is to target the aggressive neoplasm that is shrouded by the dense fibrotic stroma. Epigenetic modulation has the potential to regulate genes or gene networks causing disease phenotypes. Here we show that the HDAC inhibitor entinostat (Ent) provides therapeutic benefits by regulating the gene networks important for PDAC in both the stromal and epithelial compartments. While an HDAC inhibitor is anticipated to broadly open chromatin and activate genes, in stromal pancreatic stellate cells (PSCs), Ent unexpectedly restricts chromatin accessibility on and represses the gene networks essential for PSC activation, leading to proliferation arrest and reduced myofibroblast properties, including lower production of extracellular matrix and inflammatory and protumorigenic cytokines. Furthermore, Ent also attenuates the transcriptional responses of cancer-associated fibroblasts (CAFs) to injury-related cytokines from the tumor microenvironment including TGF-beta and TNF-alpha. In the neoplastic epithelium, Ent induces cytostasis and de novo vulnerability in DNA repair pathways by systematically suppressing cell cycle and DNA repair genes. Notably, the bicompartmental effects of Ent were found to arrest cancer progression, prolong survival, and synergize with DNA damage-inducing agent cisplatin in genetically engineered mouse model (GEMM) of PDAC. Overall, our study not only establishes Ent as a novel therapeutic agent for PDAC but also reveals the mechanisms underlying its benefits.

Citation Format: Gaoyang Liang, Nasun Hah, Yu Shi, Morgan L. Truitt, Corina E. Antal, Annette R. Atkins, Cory Fraser, Ester Banayo, Senada Bashi, Yang Dai, Mara Sherman, Christopher Liddle, Ruth T. Yu, Tony Hunter, Haiyong Han, Daniel D. Von Hoff, Michael Downes, Ronald M. Evans. Bicompartmental regulation of disease-related gene networks by histone deacetylase inhibition curbs pancreatic cancer progression [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr A29.
Abstract A42: Single-cell RNA-seq analysis of human pancreatic ductal adenocarcinoma identifies a novel cell type expressing the intestinal stem cell marker OLFM4
Authors: Rao Manisha , Nemajerova Alice , Li Jinyu , Gao Mei , Oh Ki , Moffit Richard , Kim Joseph , Georgakis George , Sasson Aaron , Bialkowkska Agnieszka , Powers Scott
Published: March 2020

Pancreatic ductal adenomcarcinoma (PDAC) is one of the most lethal forms of cancer with a 5-year survival rate of 8%. To determine the composition of different cell types in PDAC, we performed single-cell RNA-sequencing (scRNA-seq) analysis of two resected patient tumors. Nine distinct cell types were identified: (1) ductal carcinoma cells expressing mutant KRAS, (2) normal pancreatic islet cells, (3) B-lymphocytes, (4) macrophages, (5) mast cells, (6) nerve cells, (7-8) two types of cancer-associated fibroblasts (CAFs), and (9) a previously unidentified epithelial type with distinctly high expression of OLFM4 and CRISP3. Histologic analysis of human PDAC and chronic pancreatitis (CP) tissue sections confirmed the presence of this distinct cell type and furthermore demonstrated that it corresponded to inflamed/injured ducts and early pancreatic intraepithelial neoplasms (PanINs) but that actual PDACs did not express OLFM4. CRISP3 was not always expressed in this new cell type, but the expression of OLFM4 was always detected in these histologic structures. This distinct pancreatic epithelial cell type was also observed in mouse models for chronic pancreatitis and in mutant-KRAS induced PanINs. We hypothesize that inflammation-induced OLFM4 expression helps drive PanIN formation, and that its expression could be exploited for early PDAC detection. We are currently performing functional studies using organoids to address the role that OLFM4 might play in generation of this distinct cell type.

Citation Format: Manisha Rao, Alice Nemajerova, Jinyu Li, Mei Gao, Ki Oh, Richard Moffit, Joseph Kim, George Georgakis, Aaron Sasson, Agnieszka Bialkowkska, Scott Powers. Single-cell RNA-seq analysis of human pancreatic ductal adenocarcinoma identifies a novel cell type expressing the intestinal stem cell marker OLFM4 [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr A42.
Abstract A48: Genetic ablation of microRNA-21 profoundly remodels stroma and shortens survival of K-Ras-driven pancreatic cancer mouse models
Authors: Schipper Josh , Beddows Ian , Kiupel Matti , Conejo-Garcia Jose , Sempere Lorenzo
Published: March 2020

The tumor microenvironment of pancreatic cancer adenocarcinoma (PDAC) is highly desmoplastic with distinct tumor-restraining and tumor-promoting fibroblast subpopulations. Re-education rather than indiscriminate elimination of these fibroblasts has emerged as a new strategy for combination therapy. Here, we studied global loss of profibrotic noncoding regulatory microRNA-21 (miR-21) in K-Ras-driven genetically engineered mouse models of PDAC. We generated mouse strains carrying wild-type or knockout alleles of Mir-21 in a well-characterized K-Ras-driven, p53-deleted PDAC model (LSL-KrasG12D; p53lox/+;Pdx1-Cre, KPC). Even though miR-21 expression was upregulated in cancer cells and cancer-associated fibroblasts in KPC tumors, global loss of miR-21 activity did not inhibit tumor growth. Strikingly, loss of miR-21 accelerated tumor initiation via mucinous cystic neoplastic lesions and progression to locally advanced invasive carcinoma from which animals precipitously succumbed at an early age. We uncovered a cell-autonomous requirement of miR-21 activity for induction of tumor-restraining myofibroblasts, whose absence led to a profound remodeling of the stroma and massive infiltrate of tumor-permissive immune cells. Low miR-21 expression negatively correlated with a fibroblast gene expression signature and positively with an immune cell gene expression signature in TCGA PDAC data set (n = 156) mirroring findings in genetic models. In vitro and in vivo isograft experiments showed that miR-21 activity was dispensable for cancer cell growth but required for complete execution of TGF-b-mediated programs. Our results suggest that modulation of miR-21 activity may provide a novel therapeutic opportunity to affect the composition of fibroblast subpopulations and enhance current chemotherapy and/or immunotherapy treatments.

Citation Format: Josh Schipper, Ian Beddows, Matti Kiupel, Jose Conejo-Garcia, Lorenzo Sempere. Genetic ablation of microRNA-21 profoundly remodels stroma and shortens survival of K-Ras-driven pancreatic cancer mouse models [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr A48.
Abstract A51: Using single-cell gene expression profiles to determine the cellular landscape of pancreatic ductal adenocarcinoma
Authors: Sirihorachai Veerin R. , Kemp Samantha B. , Magliano Marina Pasca Di
Published: March 2020

A key feature of pancreatic cancer is the extensive fibroinflammatory stroma that constitutes the bulk of the tumor volume. The stroma includes fibroblasts, extracellular matrix, and abundant infiltrating immune cells. The latter are largely suppressive immune cells, including regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages. Data from our laboratory and many others show that immune cells are a key determinant of pancreatic cancer progression and metastasis. Previous data from the lab showed that the immune infiltration in the pancreas is regulated by signals deriving from oncogenic Kras-expressing epithelial cells. We tested the hypothesis that oncogenic Kras, through activation of its effector pathway MAPK/ERK, directly regulates the accumulation of suppressive myeloid and lymphoid cells at the premetastatic niche. We used a doxycycline-inducible, reversible iKras* cell line derived from genetically engineered mouse model to modulate expression of Kras in orthotopically implanted tumors. We used the 10X Genomics platform for single-cell RNAseq to distinguish populations of cells collected from the tumors in both the Kras-On and Kras-Off groups at single-cell resolution. Using the Seurat R package, we analyzed the data from the two groups using unsupervised clustering methods to define clusters of cells based on their gene expression data. We then broadly defined these populations using cell type-specific gene expression patterns. Our next step is to define subpopulations of cells on which we can perform differential expression analyses to determine the changes in gene expression between the Kras-On and Kras-Off groups.

Citation Format: Veerin R. Sirihorachai, Samantha B. Kemp, Marina Pasca Di Magliano. Using single-cell gene expression profiles to determine the cellular landscape of pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr A51.
Abstract B02: Tissue-specific innate lymphoid cells are novel targets for pancreatic cancer immunotherapy
Authors: Leung Joanne , Rojas Luis A , Ruan Jennifer , Zhao Julia , Gasmi Billel , Sethna Zachary , Ramnarain Anita , Bhanot Umesh , Askan Gokce , Gururajan Murali , Elyada Ela , Park Youngkyu , Tuveson David A. , Gonen Mithat , Leach Steven D. , Wolchok Jedd D. , DeMatteo Ronald P. , Merghoub Taha , Balachandran Vinod P. , Moral John Alec
Published: March 2020

Pancreatic ductal adenocarcinoma (PDAC) is the classic cold tumor, with few tumor-infiltrating activated CD8+ T cells, a major barrier to immunotherapy. Strategies to convert cold PDACs to hot can enable more effective immunotherapies. To identify targets that can convert cold PDACs to hot, we compared a large cohort of rare long-term PDAC survivors with hot tumors to short-term survivors with cold tumors. Surprisingly, hot PDACs were enriched not only in activated CD8+ T cells, but also in group-2 innate lymphoid cells (ILC2s), a class of largely tissue-resident, cytokine-producing innate lymphocyte that potentiates T cell immunity in local tissues. We identified that tumor ILC2s (TILC2s) infiltrate human and mouse PDACs, and TILC2 frequency and tumor expression of the ILC2-activating ligand interleukin (IL)-33 positively correlate with tumor immune cytolytic activity, and long-term patient survival. Using PDAC mouse models, we discovered that the IL33-ILC2 axis activates pancreatic tissue-specific antitumor T-cell immunity. Host IL33 deficiency attenuated TILC2 expansion and CD8+ T-cell activation, accelerating tumor growth in orthotopic PDACs but not heterotopic skin implanted PDACs where TILC2s lack the IL33 receptor. Acute ILC2 depletion partially phenocopied the tissue-specific phenotype of IL33 deficiency, with impaired rejection of immunogenic orthotopic but not heterotopic skin PDACs. Treatment with recombinant IL33 (rIL33), but not with the ILC1-activating ligand rIL18, increased TILC2 frequencies, activated CD8+ T cells, and abrogated orthotopic but not heterotopic PDAC establishment in >70% of mice. Taken together, these studies identify ILC2s as novel anticancer immune cells for PDAC immunotherapy. Strategies to activate tissue-specific ILC2s may be a promising immunotherapeutic approach for PDAC.

Citation Format: Joanne Leung, Luis A Rojas, Jennifer Ruan, Julia Zhao, Billel Gasmi, Zachary Sethna, Anita Ramnarain, Umesh Bhanot, Gokce Askan, Murali Gururajan, Ela Elyada, Youngkyu Park, David A. Tuveson, Mithat Gonen, Steven D. Leach, Jedd D. Wolchok, Ronald P. DeMatteo, Taha Merghoub, Vinod P. Balachandran, John Alec Moral. Tissue-specific innate lymphoid cells are novel targets for pancreatic cancer immunotherapy [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B02.
Abstract B03: Targeting tumor-intrinsic metabolic node in pancreatic cancer causes tumor regression, remodels extracellular matrix, and sensitizes to anti-PD1 therapy
Authors: Sharma Nikita S. , Gupta Vineet K. , Garrido Vanessa , Hadad Roey , Durden Brittany , Kesh Kousik , Ferrantella Anthony , Giri Bhuwan , Dudeja Vikas , Saluja Ashok , Banerjee Sulagna
Published: March 2020

Background: Pancreatic adenocarcinoma (PDAC) is an extremely immunosuppressive and heterogenous neoplasm for which immune checkpoint inhibitor therapy has not been very successful. Hexosamine biosynthesis pathway (HBP), a shunt pathway of glycolysis, is a metabolic node in cancer cells that can promote survival pathways on one hand and also influence the extracellular matrix in the tumor microenvironment. Our study aims to sensitize pancreatic cancer to anti PD-1 therapy by targeting the HBP pathway.

Methods: 6-Diazo-5-oxo L-norleucine or DON was used as a GFAT inhibitor. Tetracycline-inducible GFAT knockout cell lines were made using S2-VP10 as the parent cell line.

Results: High-dose monotherapy of DON (1mg/kg/3days a week) caused significant decrease in tumor volume in immunocompetent KPC mice along with significant reduction in metastasis and circulating tumor cells. Circulating tumor cells (CTCs) were also found to be significantly reduced in DON-treated mice as compared to control, leading to reduced metastasis. Combination of low-dose DON (0.5mg/kg/3 days a week) with low-dose anti PD-1 (100 μgX3 times) caused an impressive reduction in tumor volume along with an increase in survival in KPC tumor-bearing mice. Flow-based analysis of tumor cells show a significant influx of CD8+ T cells along with an increase in M1 polarization of macrophages. Survival study of CD8 knockout mice (CD8KO), orthotopically implanted with KPC and fibroblast cells, show that at low doses DON loses its anticancer effect in absence of CD8 as demonstrated by decrease in survival in CD8KO mice as compared to tumor-bearing wild-type mice.

Conclusion: Novel therapeutic strategies that can make PDAC more amenable to immune therapy are urgently needed. In this context, our study is extremely timely as it targets specific metabolic pathways in cancer cells to overcome immune resistance and sensitize the tumor to anti-PD1 therapy.

Citation Format: Nikita S. Sharma, Vineet K. Gupta, Vanessa Garrido, Roey Hadad, Brittany Durden, Kousik Kesh, Anthony Ferrantella, Bhuwan Giri, Vikas Dudeja, Ashok Saluja, Sulagna Banerjee. Targeting tumor-intrinsic metabolic node in pancreatic cancer causes tumor regression, remodels extracellular matrix, and sensitizes to anti-PD1 therapy [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B03.
Abstract B19: Targeting ATM to sensitize pancreatic cancer to immunotherapy and radiotherapy
Authors: Green Michael , Zhang Qiang , Lang Xueting , Lei Yu , Lawrence Theodore S. , Zou Weiping , Morgan Meredith A.
Published: March 2020

Combinatorial strategies are needed to overcome the resistance of pancreatic cancer to immune checkpoint blockade (ICB). DNA damage activates the innate immune response and improves ICB efficacy. We have studied the role of ATM, a core component of the DNA damage response, on pancreatic tumor immunogenicity in vitro and in vivo. Inhibition of ATM increased tumoral interferon signaling in a cGAS/STING-independent but TBK1 and SRC-dependent manner. The combination of ATM inhibition with radiation enhanced TBK1 activity, T1IFN production, and antigen presentation in vitro. Furthermore, ATM silencing enhanced T-cell trafficking in vivo and increased the sensitivity of pancreatic tumors to PD-L1 blocking antibody. The potential of ATM as a target for combinatorial strategy with ICB and radiation in pancreatic cancer will be discussed.

Citation Format: Michael Green, Qiang Zhang, Xueting Lang, Yu Lei, Theodore S. Lawrence, Weiping Zou, Meredith A. Morgan. Targeting ATM to sensitize pancreatic cancer to immunotherapy and radiotherapy [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B19.
Abstract B21: Pharmacologic activation of G protein-coupled estrogen receptor inhibits pancreatic ductal adenocarcinoma
Authors: Natale Christopher , Li Jinyang , Dentchev Tzvete , Capell Brian , Seykora John , Stanger Ben , Ridky Todd
Published: March 2020

LNS8801 is a novel, orally bioavailable, small-molecule agonist of the G Protein Coupled Estrogen Receptor (GPER) being developed for the treatment of pancreatic ductal adenocarcinoma (PDAC) and other advanced cancers. Women have a lower incidence and improved clinical outcomes for most cancer types, including PDAC. The mechanistic basis for this sex difference is unknown. We hypothesized that estrogen signaling may be responsible, despite the fact that PDAC lacks classic nuclear estrogen receptors. Here we used murine syngeneic tumor models and human xenografts to determine that agonizing GPER on tumor cells inhibits PDAC. Systemically administered GPER agonists were well tolerated, induced tumor regression, significantly prolonged survival, and markedly increased the efficacy of PD-1 targeted immune therapy. Complete responses, observed with the GPER agonist alone or in combination with PD-1 targeted immune therapy, were associated with durable immune memory that protected against tumor rechallenge. Activation of GPER depleted c-Myc and programmed death ligand 1 (PD-L1) and increased tumor cell immunogenicity. These data, coupled with the wide tissue distribution of GPER and previous work showing that GPER activation inhibits other cancer types, suggest that GPER agonists may be useful against a range of cancers that are not classically considered sex hormone responsive, and that arise in tissues outside of the reproductive system.

Citation Format: Christopher Natale, Jinyang Li, Tzvete Dentchev, Brian Capell, John Seykora, Ben Stanger, Todd Ridky. Pharmacologic activation of G protein-coupled estrogen receptor inhibits pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B21.