bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1232: Synergistic roles played by autophagy and Hsp70 in cancer cell survival
Authors: Sannino Sara , Brodsky Jeffrey L. 
Published: September 2020

Abstract
To avoid cell death, cancer cells adapt to extreme conditions. Chaperone upregulation, modulation of the unfolded protein response (UPR), and induction of protein degradation pathways are critical for cancer cell survival and metastasis in some cancers. Thus, it is not surprising that the molecular chaperone Hsp70 is upregulated in many cancers. For example, increased Hsp70 abundance correlates with metastasis formation and poor prognosis in breast cancer patients. We previously demonstrated that inhibition of Hsp70, by treating cells with a specific inhibitor known as MAL3-101, induces rhabdomyosarcoma cancer cell death due to induction of a UPR-mediated apoptotic response (Sabinis et al., 2016). Moreover, by taking advantage of a MAL3-101-resistant cell line, we established that protein degradation pathways act as a compensatory mechanism in MAL3-101 resistant rhabdomyosarcoma cells. In particular, we found that autophagy inhibition re-sensitized resistant cells to Hsp70 inhibition, suggesting that autophagy is a key compensatory mechanism for Hsp70 inhibition. Autophagy was further induced by MAL3-101 treatment in these cells, as evidenced by both autophagy related gene mRNA and protein accumulation as well as by autophagic-like structures detected by electron microscopy (Sannino et al., 2018). These data highlight a pro-survival role for autophagy induction upon exposure to an Hsp70 inhibitor in cancer, and provide a link between Hsp70, proteasome activity, the UPR, and autophagy in rhabdomyosarcoma. We next asked if other cancers might be dependent on Hsp70 activity and investigated the benefit of combined treatment with autophagy and/or proteasome inhibitors together with MAL3-101 in breast cancer cells. Our recent studies suggest that diverse breast cancer cell lines are either sensitive or resistant to Hsp70 inhibition. MAL3-101 resistant breast cancer cells have higher autophagy levels compared to MAL3-101 sensitive lines. Moreover, autophagy is upregulated upon Hsp70 inhibition in resistant breast cancer cells, again highlighting the potential benefit of combined treatment with autophagy and Hsp70 inhibitors. Overall, our work positions autophagy as a critical compensatory mechanism when molecular chaperone function is overwhelmed and misfolded proteins accumulate in cancer cells. Further investigations will reveal the potential for Hsp70 inhibitors and the role of protein degradation pathways in vivo in breast cancer.
Citation Format: Sara Sannino, Jeffrey L. Brodsky. Synergistic roles played by autophagy and Hsp70 in cancer cell survival [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1232.
Abstract 1251: Epigenetics in early onset colorectal cancer (EOCRC)
Authors: Riggins Karen , Musher Benjamin , Scheurer Michael , Yang Li , Castro Patricia , Zarrin-Khameh Neda , Shen Lanlan 
Published: September 2020

Abstract
Colorectal cancer (CRC) incidence rates have increased among young adults while the rates have decreased among older adults over 50 years of age. While the etiology of the growing prevalence of young adults with newly diagnosed CRC is unknown, there has been growing interest in the roles implicated for diabetes, obesity, environmental changes, and epigenetics. Among the epigenetic marks implicated in EOCRC, the most widely studied are the global DNA hypomethylation. Using mouse studies, our group has demonstrated that DNA methylation as an epigenetic mechanism to control gene expression is essential to postnatal development. We have discovered a key set of genes that undergo epigenetic changes in colonic epithelial stem cells, and these changes are stable over a lifetime. We have shown that the gut microbiome influences this process. Importantly, perturbation of established intestinal DNA methylation leads to accelerated intestinal tumor development. To translate our mechanistic studies in the animal model to humans, we have confirmed these CpG loci that are concordant between the two species (i.e. homologous regions and/or conserved CpG islands). Here, we hypothesize that the dysregulation of developmentally programmed intestinal DNA methylation is associated with enhanced susceptibility to colon cancer in young adult. We have identified a population of patients within the Harris Health and Baylor College of Medicine system under the age of 50 with mismatch repair stable colorectal adenocarcinoma. Patient characteristics including age, sex, race, and primary tumor profile (stage at diagnosis, histology, and RAS status) have been defined. Using a panel of 6 genes and bisulfite pyrosequencing for quantitative assessment of DNA methylation, we compared the level of methylation in EOCRC tumors to paired normal adjacent tissues as well as normal adult tissue (age 50 or greater) to traditional CRC tumors. Our preliminary data suggest hypermethylation patterns are distinct in patients of EOCRC relative to traditional CRC. Our ultimate goal is to better understand the etiology of EOCRC in order to devise better prevention and treatment strategies for EOCRC.
Citation Format: Karen Riggins, Benjamin Musher, Michael Scheurer, Li Yang, Patricia Castro, Neda Zarrin-Khameh, Lanlan Shen. Epigenetics in early onset colorectal cancer (EOCRC) [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1251.
Abstract 1274: Metformin, not γ-tocotrienol, increases gene methylation and decreases expression of genes responsible for cell signal transduction in prostate cancer cells
Authors: Moore Christine Ann , Lightner Janet , Duffourc Michelle , Krishnan Koyamangalath 
Published: September 2020

Abstract
Metformin and γ-tocotrienol (GT3) are promising chemopreventative agents with studies showing improved patient outcomes with metformin use in several cancer types, including prostate cancer. However, the cellular mechanisms underlying the improved survival rates in cancer patients treated with these drugs are incompletely understood. Inhibition of mammalian target of rapamycin (mTOR), alteration of p-c-JUN and p-ERK signaling pathways and inhibition of mitochondrial complex 1 have all been implicated as part of metformin's anti-tumorigenesis activities. More recently, metformin was shown to influence the activity of epigenetic modifying enzymes resulting in genome-wide alterations in DNA methylation patterns in breast cancer cell lines. In this study, we investigated whether GT3 and metformin treatment would alter methylation pathways in prostate cancer cells.The prostate cancer cell line PC-3 (androgen independent) and normal prostate control cell line RWPE-1 were treated with varying concentrations of either GT3, metformin, the methylation inhibitor azacitidine, or metformin plus azacitidine for 6 hours. Genomic DNA was isolated, and methylation assessed using the Illumina Infinium methylation EPIC BeadChip array. Analysis revealed treatment of PC-3 cells with metformin promoted hypermethylation of CC2D2B, GHDC, LINC01377, PLPP2, and PTK2 and decreased methylation of TSPY4 as compared to normal prostate controls. qRT-PCR experiments confirmed decreased expression of PTK2 mRNA, consistent with hypermethylation of PTK2. In contrast, GT3 did not affect methylation of any identifiable recognizable genes. This study suggests metformin, but not GT3, may inhibit prostate cancer proliferation partially through epigenetic changes which disrupt downstream focal adhesion kinase (FAK) signaling pathways. Metformin is a promising chemopreventive agent; studies investigating the impact of metformin on cellular adhesion and FAK pathways are ongoing in our laboratory.
Citation Format: Christine Ann Moore, Janet Lightner, Michelle Duffourc, Koyamangalath Krishnan. Metformin, not γ-tocotrienol, increases gene methylation and decreases expression of genes responsible for cell signal transduction in prostate cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1274.
Abstract 1324: Genomic and clinical characteristics of MET exon14 alterations in 26,391 Chinese cancer patients
Authors: Liu Sisi , Song Danni , Tong Xiaoling , Wu Xue , Wang Xiaonan , Shao Yang Washington 
Published: September 2020

Abstract
Background: Alterations in MET exon 14 (METex14) and its flanking intronic regions have been identified in a variety of cancers, and suggested to cause enhanced MET activity and oncogenesis. Clinical evidences suggested that patients with METex14 alterations often benefit from MET inhibitors such as crizotinib. Given the unique mutation profiles of Chinese lung cancer patients, it is necessary to investigate the prevalence of METex14 alterations in a large cohort of cancer patients.
Patients and methods: Cases carrying METex14 alterations were screened from 26,391 Chinese cancer patients, and the clinicopathologic and molecular characteristics of the cohort were reviewed. PD-L1 immunohistochemistry and the treatment response to MET inhibitors were also analyzed for cases with such information available.
Results: Compared to Western cancer population (3~7%), the frequency of METex14 alterations is much lower in Chinese cancer patients (0.7%, n=184) and in Chinese lung cancer patients (1.1%, n=175). Seventy-eight distinct METex14 alterations were detected, with majority of alterations are base substitutions at splice donor site (42%) and insertion/deletions (indels) in intron 13 (28%). Concurrent MET copy gain and non-exon14 MET mutations were found in 4% and 11% of cases, respectively. Other driver alterations, such as EGFR copy gain (11%) and mutations (8%), KRAS (5%) and PIK3CA (5%), appeared in a mutually exclusive pattern. In 71 patients sequenced by 425-gene panel, gene copy gains were prevalent in MDM2 (24%), CDK4 (14%), MCL1 (13%), TERT (13%), MYC (11%), CD274 (7%) and CDK6 (6%). Female patients contain much less TP53 mutations than male patients (65% vs. 24%, FDR = 0.01). Of 9 tissue specimens having PD-L1 immunohistochemistry (IHC) results, 5 of them (55.5%) were found PD-L1 positive, indicating the option for immunotherapy. In 14 patients who received crizotinib-treatment, the median progression free survival (mPFS) was 7 months with the longest PFS of 17 months. Upon resistance to crizotinib, two patients acquired secondary mutations in MET and one patient acquired BRAF p.K601E that can be a novel resistance mechanism to crizotinib treatment.
Conclusion: Chinese cancer patients have a relatively lower frequency of METex14 alterations compared to Western patients, and these patients can be potentially treated by immunotherapy and crizotinib.
Citation Format: Sisi Liu, Danni Song, Xiaoling Tong, Xue Wu, Xiaonan Wang, Yang Washington Shao. Genomic and clinical characteristics of MET exon14 alterations in 26,391 Chinese cancer patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1324.
Abstract 133: Micro-environment on demand (MOD): A versatile technology for cognate T-cell receptor - neoantigen discovery
Authors: Srinivasan Maithreyan , Madrigal Justin , Schoepp Nathan , Cole Russell 
Published: September 2020

Abstract
NCI estimates that cancer will be the leading cause of death in 2030, worldwide. Checkpoint inhibitors and adoptive cell therapies (ACTs) cost up to ~$2 million/patient and have shown durable responses in a few patients while many patients experience life-threatening side-effects. So, there is a critical need to identify cost-effective therapies to treat cancer with minimal to no side-effects. Deep mapping of cancer antigens and their cognate immune cells is one approach that has the potential for a more universal/targeted treatment. However, systematic methods do not exist to identify cancer antigens and their cognate immune cells functionally and link phenotypic readouts to antigen and immune cell DNA sequences. Here we present a single cell handling and analysis platform based on Printed Droplet Microfluidics, a new droplet microfluidic technology that enables the precise construction of cell-cell interaction experiments with single cell resolution, followed by functional and genomic analysis. At the core of the technology is a fluorescence-activated flow sorter repurposed to deterministically sort and merge droplets containing single cells, beads, reagents, and drugs, collect and assay merged droplets and resort assay-positive droplets for downstream genomic analyses. The selectivity of the sorting/merging technology enables both the construction of experiments with up to one million precise cell combinations and the performance of flexible multi-step molecular biology workflows. We will show proof-of-concept for the MOD platform that integrates three technologies after fluorescently labeled single-cells are encapsulated in droplets - droplet-based cell-sorting and merging, single-cell-based cytokine assays and selective sequencing of T-cell receptor variable regions based on cytokine signals. The technology has the potential to rapidly accelerate the rate of immunotherapy discovery by enabling a larger number of experiments to be performed with higher precision, more modes of analysis, and less starting material than competing bulk technologies.
Citation Format: Maithreyan Srinivasan, Justin Madrigal, Nathan Schoepp, Russell Cole. Micro-environment on demand (MOD): A versatile technology for cognate T-cell receptor - neoantigen discovery [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 133.
Abstract 1374: Preclinical investigation of ATR inhibition alone and in combination with PARP inhibition in high risk neuroblastoma
Authors: Southgate Harriet E. , Chen Lindi , Curtin Nicola J. , Tweddle Deborah A. 
Published: September 2020

Abstract
Background:Neuroblastoma (NB) is the commonest extra-cranial malignant solid tumour of childhood and one of the most difficult to cure. DNA damage response (DDR) defects are frequently observed in high risk NB including allelic loss and loss of function mutations in key DDR genes, oncogene induced replication stress (RS) and cell cycle checkpoint dysfunction. Cancer cells with defective cell cycle checkpoint signalling and/or increased oncogene-driven RS are acutely dependent on the DNA damage sensor kinase ATR. This study aims to identify features of NB cell lines leading to ATR inhibitor sensitivity. As PARP inhibition causes RS through unrepaired single strand DNA breaks progressing to replication, we hypothesise that ATR inhibition will increase PARP inhibitor cytotoxicity.
Aims: 1) To determine which molecular features lead to sensitivity to VE-821 (ATR inhibitor) in cell lines derived from high-risk NB tumours. 2) To assess synergism between PARP inhibition with olaparib and ATR inhibition in high risk NB cell lines and to measure RS.
Materials and Methods: Cell proliferation in response to 72 hours treatment with VE-821 was assessed by XTT assay (Roche) in a panel of 11 NB cell lines and the effect of ATR inhibition on olaparib growth inhibition in 4 cell lines: SHSY5Y, SKNAS, NGP and N20_R1. CHK1S345 and H2AXS129 phosphorylation was assessed using Western blotting to determine ATR activity and RS respectively. RS was also measured by γH2AX foci formation using immunofluorescent microscopy.
Results: VE-821 caused significantly more growth inhibition in MYCN amplified cell lines and cell lines with low ATM protein expression by XTT assay (p&lt;0.05 Mann-Whitney U test). Olaparib (5 µM) treatment increased CHK1S345 and H2AXS129 phosphorylation after 24 hours treatment in all cell lines. H2AXS129 phosphorylation and foci number was further increased with the addition of VE-821 (1 µM). ATR inhibition prevented CHK1S345 phosphorylation. In cell proliferation assays, combination index analysis (Calcusyn) showed that ATR inhibition by VE-821 is synergistic with olaparib at sub lethal concentrations (&lt;1 µM) (CI value 0.04-0.89).
Conclusion: MCYN amplification and low ATM protein expression are determinants of ATRi sensitivity in NB cell lines. ATR inhibition by VE-821 is synergistic with olaparib at sub lethal concentrations (&lt;1 µM) and further increases the replication stress caused by PARP inhibition.
Citation Format: Harriet E. Southgate, Lindi Chen, Nicola J. Curtin, Deborah A. Tweddle. Preclinical investigation of ATR inhibition alone and in combination with PARP inhibition in high risk neuroblastoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1374.
Abstract 1378: Targeting the metabolic-epigenetic axis to sensitize HR-proficient ovarian cancer to PARP inhibitors
Authors: Dahl Erika S. , Leon Kelly E. , Chen Chi-Wei , Jia Qingyuan , Buj Raquel , Snyder Nathaniel W. , Aird Katherine M. 
Published: September 2020

Abstract
Overexpression of the oncogene cyclin E1 is considered one of the initiating factors in fallopian tube transformation and ovarian tumorigenesis. Patients with high cyclin E1 expression have worse overall survival than patients with low expression. Cyclin E1 overexpression increases expression of DNA damage response (DDR) genes in order to tolerate DNA damage and bypass senescence, a state of cell cycle arrest. However, the mechanism by which cyclin E1-high cells transcriptionally increase DDR gene expression to bypass senescence remains unclear. We found that cyclin E1 overexpression alters the metabolic-epigenetic axis through wildtype isocitrate dehydrogenase I (wtIDH1), a TCA cycle enzyme. Upregulation of wtIDH1 in cyclin E1-high cells increased the transcription of multiple DDR genes related to homologous recombination (HR), including BRCA1, BRCA2, and RAD51. Published data from our lab demonstrates that wtIDH1 primarily converts isocitrate to alpha-ketoglutarate (αKG) in cyclin E1-high ovarian cancer cells, and suppression of wtIDH1 and αKG pools induces senescence through increased repressive histone marks. Our current data suggest that wtIDH1 is both necessary and sufficient for HR gene expression in cyclin E1-high cells in part through modulation of histone methylation. Functionally, inhibition of wtIDH1 in cyclin E1-high fallopian tube cells induced senescence via decreased HR and marked accumulation of DNA damage. Cyclin E1-high ovarian cancer tumors are HR-proficient and resistant to emerging poly(ADP-ribose) polymerase (PARP) inhibitors. Interestingly, inhibition of both wtIDH1 and PARP in combination increased apoptosis of cyclin E1-high ovarian cancer cells in vitro, suggesting this may be a novel therapy for HR-proficient ovarian cancers. Together, our data suggest that wtIDH1-mediated metabolism affects the epigenome in cyclin E1-high cells, which contributes to both fallopian tube transformation and HR-proficiency. Targeting wtIDH1 with current FDA-approved inhibitors may therefore be a rational therapeutic strategy for cyclin E1-high ovarian cancer patients.
Citation Format: Erika S. Dahl, Kelly E. Leon, Chi-Wei Chen, Qingyuan Jia, Raquel Buj, Nathaniel W. Snyder, Katherine M. Aird. Targeting the metabolic-epigenetic axis to sensitize HR-proficient ovarian cancer to PARP inhibitors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1378.
Abstract 1389: Exploiting inherent DNA damage repair defects in IDH1/2 mutated gliomas with the CNS penetrant PARP inhibitor, pamiparib
Authors: Hong Christopher , Sule Amrita , Beckta Jason , Sundaram Ranjini , Bindra Ranjit 
Published: September 2020

Abstract
Our group recently demonstrated that IDH1/2 mutated gliomas exhibit intrinsic homologous recombination (HR) defects mediated by the oncometabolite, 2HG. These defects render IDH1/2 mutated cells exquisitely sensitive to PARP inhibitors (PARPi's), which suggests a novel therapeutic strategy. Here, we studied the potential in vitro and in vivo efficacy of a CNS penetrant PARPi, pamiparib, in combination with radiation therapy (RT) and temozolomide (TMZ) against IDH1/2 mutated gliomas. Our central hypothesis is that multi-modality therapy using agents that are active against 2HG producing cells will increase efficacy, while allowing lower doses of RT and TMZ as a means to mitigate normal tissue toxicity. We performed a comprehensive series of DNA repair functional studies, short and long term viability assays, as well as in vivo studies, using engineered and patient-derived IDH1/2 mutant glioma models. We tested unique combinations of pamiparib, TMZ and RT in these experiments. In vitro short term viability assays and long-term clonogenic survival assays in model IDH1 wild-type (WT) and R132H mutated glioma cells demonstrated that the mutation confers enhanced TMZ sensitivity (IC50 602 vs. 9.5 uM, respectively). A similar differential sensitivity was observed with RT. We also demonstrated significant, mutant IDH1 selective pamiparib sensitivity in vitro (IC50 0.67 vs. 141 uM). Western blot analysis of PARylation, a functional readout of PARPi activity, confirmed PARylation inhibition by pamiparib in a dose dependent manner. Subsequently, we demonstrated synergistic interactions between TMZ and RT combined with pamiparib, particularly at low doses of both DNA damaging agents, in an IDH1 selective manner. Finally, we demonstrated the activity of PARPi's against IDH1 mutant tumors in vivo, including pharmacodynamic and pharmacokinetic properties of pamiparib on target activity within the brain. Pamiparib is a promising, CNS penetrant PARP inhibitor that may selectively target IDH1/2 mutated gliomas, based on intrinsic HR defects associated with these tumors. Pamiparib appears to act synergistically with TMZ and RT, which are the backbone of GBM therapies. These data lay the groundwork for a future trial testing “trimodality therapy” (i.e., pamiparib, RT and TMZ) against IDH1/2 mutant gliomas.
Citation Format: Christopher Hong, Amrita Sule, Jason Beckta, Ranjini Sundaram, Ranjit Bindra. Exploiting inherent DNA damage repair defects in IDH1/2 mutated gliomas with the CNS penetrant PARP inhibitor, pamiparib [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1389.