bluuebunny/crossref_metadata_2025 huggingface dataset:
Big Data-Enabled Analysis of DRGs-Based Payment on Stroke Patients in Jiaozuo, China
Authors: Qiao Dawei , Zhang Yanru , Rehman Ateeq ur , Khosravi Mohammad R.
Published: December 2020

Stroke is the first leading cause of mortality in China with annual 2 million deaths. According to the National Health Commission of the People’s Republic of China, the annual in-hospital costs for the stroke patients in China reach ¥20.71 billion. Moreover, multivariate stepwise linear regression is a prevalent big data analysis tool employing the statistical significance to determine the explanatory variables. In light of this fact, this paper aims to analyze the pertinent influence factors of diagnosis related groups- (DRGs-) based stroke patients on the in-hospital costs in Jiaozuo city of Henan province, China, to provide the theoretical guidance for medical payment and medical resource allocation in Jiaozuo city of Henan province, China. All medical data records of 3,590 stroke patients were from the First Affiliated Hospital of Henan Polytechnic University between 1 January 2019 and 31 December 2019, which is a Class A tertiary comprehensive hospital in Jiaozuo city. By using the classical statistical and multivariate linear regression analysis of big data related algorithms, this study is conducted to investigate the influence factors of the stroke patients on in-hospital costs, such as age, gender, length of stay (LoS), and outcomes. The essential findings of this paper are shown as follows: (1) age, LoS, and outcomes have significant effects on the in-hospital costs of stroke patients; (2) gender is not a statistically significant influence factor on the in-hospital costs of the stroke patients; (3) DRGs classification of the stroke patients manifests not only a reduced mean LoS but also a peculiar shape of the distribution of LoS.
Potential Therapeutic Role of Purinergic Receptors in Cardiovascular Disease Mediated by SARS-CoV-2
Authors: dos Anjos Fernanda , Simões Júlia Leão Batista , Assmann Charles Elias , Carvalho Fabiano Barbosa , Bagatini Margarete Dulce
Published: December 2020

Novel coronavirus disease 2019 (COVID-19) causes pulmonary and cardiovascular disorders and has become a worldwide emergency. Myocardial injury can be caused by direct or indirect damage, particularly mediated by a cytokine storm, a disordered immune response that can cause myocarditis, abnormal coagulation, arrhythmia, acute coronary syndrome, and myocardial infarction. The present review focuses on the mechanisms of this viral infection, cardiac biomarkers, consequences, and the possible therapeutic role of purinergic and adenosinergic signalling systems. In particular, we focus on the interaction of the extracellular nucleotide adenosine triphosphate (ATP) with its receptors P2X1, P2X4, P2X7, P2Y1, and P2Y2 and of adenosine (Ado) with A2A and A3 receptors, as well as their roles in host immune responses. We suggest that receptors of purinergic signalling could be ideal candidates for pharmacological targeting to protect against myocardial injury caused by a cytokine storm in COVID-19, in order to reduce systemic inflammatory damage to cells and tissues, preventing the progression of the disease by modulating the immune response and improving patient quality of life.
Numerical Simulation and Experimental Studies of Karst Caves Collapse Mechanism in Fractured-Vuggy Reservoirs
Authors: Guo Liwen , Wang Shuoliang , Sun Liming , Kang Zhihong , Zhao Chenjun
Published: December 2020

Karst cave collapse usually occurs during the process of drilling and reservoir development. Karst cave collapse increases drilling risk and seriously affects oil production. In order to reveal the collapse mechanism of karst caves in fractured-vuggy reservoirs in Tahe oil field, rock mechanic experiments and numerical simulation studies were conducted. In rock mechanic experiments, three types of rock mechanics tests (uniaxial compression, triaxial compression, and Brazilian splitting) were carried out to obtain the basic rock mechanics parameters. In numerical simulation studies, the collapse conditions of a single karst cave and a cave system were studied. Numerical simulation results indicate that for a single karst cave, the size and geometrical features of karst caves are the main factors influencing collapse condition. For a cave system, a combination pattern and distance between caves are two main factors affecting collapse condition. In order to facilitate the application of these research results, the authors present formulas for calculating the critical conditions of karst cave collapse by means of multivariate linear regression method. The calculation formulas and prediction chart were verified as consistent with actual field results. The research results in this paper have great theoretical and practical value for revealing the mechanism of karst cave collapse in fractured-vuggy carbonate reservoirs.
Evidence of Second Canal between Permanent Mandibular Central and Lateral Incisors in China; a Systematic Review on CBCT Studies
Authors: Aung Nyan M. , Myint Kyaw K.
Published: December 2020

Introduction. Evidence of second canal in permanent mandibular incisors is frequently questioned in dentistry. The difference in evidence between the two teeth is an interesting argument across different countries and ethnicities. So the aim of the systematic review was to investigate the evidence of second canal between permanent mandibular central and lateral incisors in China. Materials and Methods. The papers were selected from the electronic databases and hand searching according to inclusion and exclusion criteria. All qualified studies were judged by the reviewers. The selected studies were checked with Joanna Briggs Institute Critical Appraisal tool for prevalence studies. Finally, three studies were selected for the review and meta-analyses. The proportion of the second canal with its confidence interval and forest plot for the meta-analyses were calculated. Results. The evidences of second canal in permanent mandibular central and lateral incisors in China were 5.6% and 14.1%. Only one study reported bilateral symmetry of the second canal as 58.7% and 76.1% in the two types of teeth. Out of all canal anatomies, Vertucci’s type ΙΙΙ was dominant comprising 4.1% and 11.2% together with other second-canal types comprising 1.4% and 3% in permanent mandibular central and lateral incisors. When the proportions were meta-analyzed, mandibular central incisors had been less numerous OR = 0.35 [0.31, 0.40], 0.33[0.28, 0.39], and 0.42 [0.22, 0.79] in the evidence of second canal, of Type ΙΙΙ, and of other types except Type ΙΙΙ than mandibular lateral incisors in China. Out of all second-canal anatomies, Type ΙΙΙ presented 72.5% and 78.9% along with other second-canal types comprising 24.3% and 21.1% in the two teeth in China. Discussion. There was the evidence of second canal which deviated toward the permanent mandibular lateral incisor also in case of bilateral symmetry, the prevalence of Vertucci’s Type ΙΙΙ, and other second-canal types out of all canal anatomies.
A Framework for Detecting Vehicle Occupancy Based on the Occupant Labeling Method
Authors: Lee Jooyoung , Byun Jihye , Lim Jaedeok , Lee Jaeyun
Published: December 2020

High-occupancy vehicle (HOV) lanes or congestion toll discount policies are in place to encourage multipassenger vehicles. However, vehicle occupancy detection, essential for implementing such policies, is based on a labor-intensive manual method. To solve this problem, several studies and some companies have tried to develop an automated detection system. Due to the difficulties of the image treatment process, those systems had limitations. This study overcomes these limits and proposes an overall framework for an algorithm that effectively detects occupants in vehicles using photographic data. Particularly, we apply a new data labeling method that enables highly accurate occupant detection even with a small amount of data. The new labeling method directly labels the number of occupants instead of performing face or human labeling. The human labeling, used in existing research, and occupant labeling, this study suggested, are compared to verify the contribution of this labeling method. As a result, the presented model’s detection accuracy is 99% for the binary case (2 or 3 occupants or not) and 91% for the counting case (the exact number of occupants), which is higher than the previously studied models’ accuracy. Basically, this system is developed for the two-sided camera, left and right, but only a single side, right, can detect the occupancy. The single side image accuracy is 99% for the binary case and 87% for the counting case. These rates of detection are also better than existing labeling.
Chemometrics-Enabled Raman Spectrometric Qualitative Determination and Assessment of Biochemical Alterations during Early Prostate Cancer Proliferation in Model Tissue
Authors: Githaiga John I. , Angeyo Hudson K. , Kaduki Kenneth A. , Bulimo Wallace D.
Published: December 2020

The use of Raman spectroscopy combined with multivariate chemometrics for disease diagnosis has attracted great attention from researchers in recent years. This is because it is a noninvasive and nondestructive detection approach with enhanced sensitivity. However, a major challenge when analyzing spectra from biological samples has been the detection of subtle biochemical alterations buried in background and fluorescence noise. This work reports a qualitative chemometrics-assisted investigation of subtle biochemical alterations associated with prostate malignancy in model biological tissue (metastatic androgen insensitive (PC3) and immortalized normal (PNT1a) prostate cell lines). Raman spectra were acquired from PC3 and PNT1a cells at various stages of growth, and their biochemical alterations were determined from difference spectra between the two cell lines (for prominent alterations) and principal component analysis (PCA) (for subtle alterations). The Raman difference spectra were computed by subtracting the normalized mean spectral intensities of PNT1a cells from the normalized mean spectral intensities of PC3 cells. These difference spectra revealed prominent biochemical alterations associated with the malignant PC3 cells at 566 ± 0.70 cm−1, 630 cm−1, 1370 ± 0.86 cm−1, and 1618 ± 1.73 cm−1 bands. The band intensity ratios at 566 ± 0.70 cm−1 and 630 cm−1 suggested that prostate malignancy can be associated with an increase in relative amounts of nucleic acids and lipids, respectively, whereas those at 1370 ± 0.86 cm−1 and 1618 ± 1.73 cm−1 suggested that prostate malignancy can be associated with a decrease in relative amounts of saccharides and tryptophan, respectively. In the analysis using PCA, intermediate-order and high-order principal components (PCs) were used to extract the subtle biochemical fingerprints associated with the cell lines. This revealed subtle biochemical differences at 1076 cm−1, (1232, 1234 cm−1), (1276, 1278 cm−1), (1330, 1333 cm−1), (1434, 1442 cm−1), and (1471, 1479 cm−1). The band intensity ratios at 1076 cm−1 and 1232 cm−1 suggested that prostate malignancy can be associated with an increase in subtle amounts of nucleic acids and amide III components, respectively. The method reported here has demonstrated that subtle biochemical alterations can be extracted from Raman spectra of normal and malignant cell lines. The identified subtle bands could play an important role in quantitative monitoring of early biomarker alterations associated with prostate cancer proliferation.
Numerical Study on the Flow Mechanism of Compressor Rotor Blade Vibration under Different Inlet Probe Configurations
Authors: Yang Rongfei , Wang Guoliang , Liu Haixu , Xiang Honghui , Gao Jie
Published: December 2020

In the performance test of a compressor, the overstrain alarm of a rotor blade occurred and it was thought to be caused by a large-sized inlet probe. To explain and further avoid the occurrence of this phenomenon, the influences of probe strut configuration on the vibration strain of the compressor rotor blade and the corresponding flow mechanism are studied by using a one-way fluid-structure coupling calculation method. Firstly, the probe strut is simplified as a cylinder with a diameter of 10 mm and located upstream of the inlet stator with the strut wake impinging on the stator blade according to the compressor test. Then, the three scenarios are considered: moving the strut away from the stator blade in axial direction, shifting the strut half of the stator pitch circumferentially, and reducing the strut diameter. The analysis results show that the characteristics of blade vibration are determined by the excitation force on the rotor blade. Under the interaction between the large-sized strut and the compressor, in addition to the excitation force with the strut passing frequency, a force with a lower frequency, namely, the strut-wake-induced frequency, is also observed. The amplitude of the excitation force on the rotor blade depends on the probe configuration. When one of the excitation force frequencies is close to a natural frequency of the rotor blade, the blade resonates, and the amplitude of blade strain varies with the amplitude of the excitation force. In order to reduce the adverse effect of upstream strut wake on the compressor rotor blade vibration, the inlet probe strut should be designed with a smaller diameter and be placed further upstream of the stator in such a way that the strut wake vortex passes through the midpassage of the following stator.
Abstract IA02: Regulating amino acid metabolism can improve response to immunotherapy
Authors: Erez Ayelet , Ruppin Eytan
Published: December 2020

Aberrant expression of urea cycle enzymes occurs in multiple types of cancer. We have previously demonstrated that the urea cycle enzyme ASS1 is downregulated in different tumor types to increase the availability of its substrate aspartate for pyrimidine synthesis, supporting cell proliferation. Therapeutically, we demonstrated that high pyrimidine to purine ratio improves response to immunotherapy. Interestingly, in several prevalent types of cancer ASS1 expression is upregulated for a yet unknown metabolic benefit that associates with poor patients’ prognosis. We now find that ASS1 expression in cancer provides a survival advantage in nutrient deficiency states by generating NO that activates gluconeogenesis. The increase in gluconeogenic flux increases serine levels and leads to a nucleotide imbalance promoting pyrimidine to purine transversion mutations. Consequently, cancers with high ASS1 expression are less immunogenic. Reversing the nucleotide imbalance to favor pyrimidines leads to better response to immunotherapy. Our data establish ASS1 expression as a metabolic survival mechanism under nutrient deprivation that may also serve as a strong determinant of the immune response. Importantly, our findings suggest that we can metabolically regulate tumor mutations to improve patients’ responsiveness to immunotherapy.

Citation Format: Ayelet Erez, Eytan Ruppin. Regulating amino acid metabolism can improve response to immunotherapy [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr IA02.
Abstract IA05: Viral Mimicry in Pancreatic Cancer
Authors: Espinet Elisa , Trumpp Andreas
Published: December 2020

With an overall survival rate of about 8% after five years, ductal adenocarcinoma of the pancreas (PDAC) is one of the cancers with the worst prognosis (Cancer Research UK and American Cancer Society). A hallmark of PDAC is the immense contribution of desmoplastic stroma to the total tumour mass. Typically, epithelial PDAC cells represent only a minority of cells within the tumour (as low as 10%). The excessive stromal presence represents a major technical challenge when aiming to interrogate the specific molecular signals contributed by the neoplastic epithelial cell compartment from data generated using bulk tumour samples. To address this, we FACS-purified epithelial cells from PDAC and, as controls, healthy human pancreas and performed genome-wide transcriptome and DNA methylome analyses. Clustering based on DNA methylation revealed two distinct groups of PDAC with different methylation levels at genomic regions encoding repeat elements. Methylationlow tumours showed higher expression of endogenous retroviral (ERV) transcripts and a strong engagement of the dsRNA sensing machinery. This results in the cell intrinsic activation of an interferon response signature (IFNsign), leading to the reprogramming of stromal cells towards a pro-tumourigenic microenvironment and poor patient outcome. Methylationlow/IFNsignhigh and Methylationhigh/IFNsignlow PDAC cells harboured distinct lineage traits specific for normal ductal or acinar pancreatic epithelial cells at the methylation and transcriptional level. Moreover, ductal-cell-derived KrasG12D/Trp53-/- mutant mouse PDACs showed higher expression of IFNsign compared to tumors initiated by the same genetic drivers in acinar cells. Collectively, our data point to two distinct origins and etiology of human PDACs, with the aggressive Methylationhigh/IFNsignlow tumour subtype potentially targetable by agents blocking cell intrinsic IFN-signaling.

Citation Format: Elisa Espinet, Andreas Trumpp. Viral Mimicry in Pancreatic Cancer [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr IA05.
Abstract IA08: Metabolic compartmentalization in the regulation of chromatin modification
Authors: Wellen Kathryn
Published: December 2020

Metabolic processes are compartmentalized within cells. Many chromatin modifying enzymes utilize metabolites as substrates, and localized metabolite production may play important roles in the regulation of the epigenome. A number of metabolic enzymes have been detected and shown to be dynamically regulated within the nucleus. For example, nuclear localization and phosphorylation of the enzyme ATP-citrate lyase (ACLY) plays a key role in supplying acetyl-CoA for histone acetylation during DNA double strand break repair. A major barrier to understanding metabolic regulation of chromatin modification is the lack of methodology to reliably measure nuclear metabolite levels. In this talk, I will discuss efforts to quantify subcellular acyl-CoA levels, as well as insights into the regulation of nuclear metabolite pools emerging from this work.

Citation Format: Kathryn Wellen. Metabolic compartmentalization in the regulation of chromatin modification [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr IA08.
Abstract IA15: Metabolic coordination of cancer cell fate
Authors: Finley Lydia
Published: December 2020

Increasing evidence demonstrates that intracellular metabolic pathways can be critical drivers of tumor progression. Metabolites provide the biomass required for cancer cell proliferation and contribute to antioxidant defenses that promote survival and metastatic dissemination. Moreover, oncogenic mutations in several metabolic enzymes lead to accumulation of pathological levels of metabolites that interfere with histone and DNA demethylation and impose a block to differentiation. However, absent these mutations, whether the metabolic profile of cancer cells contributes to the establishment or maintenance of malignant cell identity remains poorly understood. Combining in vitro culture of cancer cells with mouse models of tumor progression, we aim to define the metabolic changes driven by common oncogenes and tumor suppressors and elucidate how these metabolic alterations affect cancer-associated phenotypes. In particular, we focus on how metabolic alterations influence regulation of the chromatin landscape and differentiation programs that antagonize tumor progression. These studies will provide insight into the mechanisms through which tumor cells evade differentiation and sustain malignancy.

Citation Format: Lydia Finley. Metabolic coordination of cancer cell fate [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr IA15.
Abstract IA19: Dietary Control of Stem Cells in Physiology and Disease
Authors: Yilmaz Omer H.
Published: December 2020

Organismal diet has a profound impact on tissue homeostasis and health in mammals. Adult stem cells mediate many aspects of tissue adaptation by balancing self-renewal and differentiation divisions to alter tissue composition in response to the environment. Because somatic stem cells may respond to organismal physiology to orchestrate tissue remodeling and some cancers are understood to arise from transformed stem cells, these findings raise the possibility that organismal diet, stem cell function, and cancer initiation are interconnected. Here I will present work from my group that describes our emerging view of how diet, metabolites and nutrient-sensing pathways instruct mammalian intestinal stem cell fate in homeostasis, adaptation to diet and diseases such as cancer.

Citation Format: Omer H. Yilmaz. Dietary Control of Stem Cells in Physiology and Disease [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr IA19.
Abstract IA21: Metabolic phenotypes and liabilities in human cancer
Authors: DeBerardinis Ralph J.
Published: December 2020

Metabolic reprogramming in cancer arises from a complex, incompletely-defined combination of factors intrinsic and extrinsic to malignant cells. In some cases, reprogrammed pathways contribute to the process of transformation, and in many others they enable cancer progression by supporting cell survival and excessive growth. The clinical relevance of cancer metabolism is emphasized by the fact that numerous imaging modalities and therapeutic strategies in cancer capitalize on the altered metabolic states present in tumors. Recent work has emphasized that metabolic phenotypes and liabilities evolve as cancer progresses, such that pathways required for cancer initiation may be dispensable in more advanced stages, and vice versa. A key challenge is to define metabolic properties that support key aspects of cancer progression, particularly metastasis and acquired therapy resistance, which account for the majority of cancer-related deaths. Because these processes are difficult to model in culture, we have developed clinical approaches to study cancer metabolism in vivo, in patients, and to uses these approaches to identify features that drive cancer progression. I will discuss approaches using metabolomics and intra-operative infusions with 13C-labeled nutrients to assess metabolic pathway utilization in human tumors. We use this approach to characterize metabolic heterogeneity among tumors arising in different organs, to identify areas of regional metabolic heterogeneity within solid tumors and to predict which activities support cancer progression. Our work to this point demonstrates marked diversity of fuel preferences in primary tumors and unexpected roles of particular pathways in cancer cell biology.

Citation Format: Ralph J. DeBerardinis. Metabolic phenotypes and liabilities in human cancer [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr IA21.
Abstract PO-015: Hypermethylated genes in leiomyosarcoma can be targeted through guadecitabine treatment
Authors: Hasan Nesrin , De Carvalho Fischer Cynthia , Sharma Anup , Ahuja Nita
Published: December 2020

Leiomyosarcomas (LMS) are aggressive mesenchymal tumors of smooth muscle origin. Understanding the molecular alterations associated with LMS is needed to identify potential therapeutic targets. Epigenetic alterations such as hypermethylation of gene promoter regions with associated transcriptional silencing is a hallmark of most cancers. Epigenetic reprograming is fundamentally linked to tumor initiation, progression and metastasis. Frequent epigenetic alterations have been observed in LMS. Epigenetic drugs such as DNA methyltransferase inhibitors (DNMTi) have been used to reverse aberrant DNA methylation and restore expression of silenced genes. Our previous studies using DNMTi, including guadecitabine, have shown that DNMTi treatment has anti-proliferative and pro-apoptotic effects in in vitro and in vivo models of LMS. Our goal was to characterize the methylation changes following guadecitabine treatment of the leiomyosarcoma cell line SK-UT1. SK-UT1 cells were treated with guadecitabine (0.05 µM-0.1 µM) and methylation was determined using Illumina 450K platform. We filtered the promoter CpG island regions that respond to guadecitabine treatment and were associated with decreased methylation compared to untreated SK-UT1 control (p≤0.05, Δβ≥0.15). In order to assess the relevance of these differentially methylated regions, we compared them to the methylation and expression profiles of LMS patient samples (GSE68312). We focused on the genes that have decreased expression and are associated with increased methylation of the promoter CpG island regions in the patient LMS samples. In conclusion, treatment of SK-UT1 cell line with guadecitabine resulted in decrease of methylation of a subset of promoter CpG island regions that were differentially hypermethylated in LMS patient samples. Further studies are needed to explore the effect of differential methylation on gene expression in guadecitabine treated SK-UT1 cell line. Understanding the effect of DNMTi on LMS is needed to identify potential therapeutic applications targeting the epigenetic pathways. Funding supported by Astex Pharmaceuticals.

Citation Format: Nesrin Hasan, Cynthia De Carvalho Fischer, Anup Sharma, Nita Ahuja. Hypermethylated genes in leiomyosarcoma can be targeted through guadecitabine treatment [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr PO-015.
Abstract PO-016: Modulating cancer stem cell pathways to enhance systemic therapeutic efficacy
Authors: Sadhukhan Pritam , Shibata Masahiro , Ugurlu M. Talha , Goldberg Rachel , Hoque Mohammad O.
Published: December 2020

Chemoresistance and poor immune sensitivity are one of the major challenges to treat different cancer types including lung, bladder and head & neck. Different epigenetic regulators and cancer stem cells (CSCs) regulatory pathways play a critical role in the development of therapeutic resistance. Prolonged chemotherapy treatment enriches CSCs in the tumor microenvironment and in a previous study we have shown that inhibition of the CSCs regulatory pathway/s combined with chemotherapy decreased CSC properties and efficiently inhibit tumor growth in patient-derived xenografts (PDXs) models. The purpose of this study is to determine the chemo and immunotherapeutic efficacy in combination with several CSC pathway/s modulatory agent/agents to treat different solid tumors. To identify relevant CSC regulating pathways, we tested the therapeutic efficacy of different agents such as 5-Azacytidine (DNA methyltransferase 1 inhibitor), Vismodegib (SMO inhibitor), Romidepsin (HDAC1 inhibitor), Olaparib (PARP1 inhibitor), and GSK343 (EZH2 inhibitor) using different bladder and head & neck cancer cell lines and also determined the numerous CSCs properties. Our data indicate that in vitro treatment with these potential therapeutic agents decreases cell viability, sphere formation and wound healing that suggest that, these drugs may be effective in reducing CSCs population when combined with chemo and/or immunotherapy. Our immunoblotting experiments indicate reduced expression of some CSCs markers and factors such as such as NANOG, OCT4, CD133 and CD24. Interestingly, after treating the cells with some of these agents and array analysis, we have found differential expression of some of the key genes regulating the immunogenic response. Further, to confirm the array-based data, selected candidate immune-associated genes were analyzed by qRT-PCR. Moreover, our preliminary data suggest that combination treatment with epigenetic drugs and an immune agent may effectively reduce tumor growth in vivo compared to either of these drugs. In conclusion, although comprehensive mechanistic studies are ongoing, our initial results highlight the importance of considering combination of epigenetic and immune therapy for patients with diverse cancer types that respond poorly to immune and chemotherapy.

Citation Format: Pritam Sadhukhan, Masahiro Shibata, M. Talha Ugurlu, Rachel Goldberg, Mohammad O. Hoque. Modulating cancer stem cell pathways to enhance systemic therapeutic efficacy [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr PO-016.
Abstract PO-020: Targeting metabolism to improve response to immune-checkpoint inhibition in melanoma
Authors: Tiersma Jiske F. , Evers Bernard , Bakker Barbara M. , de Jong Steven , Jalving Mathilde
Published: December 2020

Immune checkpoint inhibitors improve long term survival of advanced melanoma patients, however, 40-50% of patients do not benefit. Reprogrammed tumor metabolism may hinder immune cell function. We aimed to reverse metabolic reprogramming in melanoma cells by inhibiting pyruvate dehydrogenase (PDK), thereby reducing lactate secretion, while preserving or enhancing immune cell activity. In addition, we strived to elucidate metabolic vulnerabilities arising during PDK inhibitor treatment by co-treating cells with other metabolically targeted inhibitors. We treated a panel of melanoma cell lines with genetic backgrounds similar to those most frequently found in the clinic with PDK inhibitor dichloroacetate (DCA) to determine effects on viability, expression of metabolic proteins and oxygen consumption/lactate secretion. IC50 values for DCA were 14.9 ± 1.0 for A375, 13.3 ± 0.6 for MeWo, 20.0 ± 1.4 for SK-MEL-28 and 27.3 ± 1.7 mM for SK-MEL-2 cells. PDK inhibition decreased expression of the phosphorylated (inactive) form of PDH (pPDH) in melanoma cells. DCA treatment led to an up to threefold increase in the oxygen consumption rate:extracellular acidification rate (OCR:ECAR) ratio in melanoma cells. Growth inhibition of DCA synergized with other metabolic inhibitors CB-839 (glutaminase inhibitor) and metformin. The combination index (CI) was less than 0.5, indicating strong synergy, for DCA with CB-839 or DCA with metformin in several models. DCA at concentrations affecting OCR:ECAR ratio of melanoma cells (7 mM) had only minimal effects on proliferation of activated T cells and peripheral blood mononuclear cells (PBMCs). Interestingly, the interferon-γ level as a marker of cytotoxicity was increased by DCA in culture media of both T cells and PBMCs. We conclude that PDK inhibition through DCA reverses metabolic programming in melanoma cells. Also, DCA toxicity was enhanced by other metabolic inhibitors, showing that DCA treatment leads to dependency on other metabolic pathways. DCA treatment was non-toxic to immune cells and even enhanced cytotoxicity. Therefore, DCA may be a valuable tool in improving response to immunotherapy in melanoma patients.

Citation Format: Jiske F. Tiersma, Bernard Evers, Barbara M. Bakker, Steven de Jong, Mathilde Jalving. Targeting metabolism to improve response to immune-checkpoint inhibition in melanoma [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr PO-020.
Abstract PO-021: Cell identity determines TCA cycle dynamics
Authors: Arnold Paige K. , Jackson Benjamin T. , Alibeckoff Sydney , Drill Esther , Sullivan Lucas B. , Finley Lydia W.S.
Published: December 2020

Cells utilize diverse metabolic strategies to support cell type-specific bioenergetic requirements. The enzymes that mediate cellular metabolic processes have been well studied. However, how cells coordinate these factors into metabolic networks remains poorly understood. Here we use measurements of gene dependency across hundreds of cancer cell lines to cluster metabolic genes into co-dependent modules. These analyses identified two distinct tricarboxylic acid (TCA) cycle modules with specific genetic dependencies. Isotope tracing combined with genetic manipulation of TCA cycle modules revealed that both normal stem cells and cancer cells can engage two different modes of TCA cycle metabolism. Enforcing self-renewal or differentiation induced preferential use of one TCA cycle module over another, indicating that TCA cycle dynamics are determined by cell state. In turn, the mode of TCA cycle metabolism employed by cells dictated nutrient dependencies, enabling cell-type specific responses to nutrient deprivation. Collectively, these studies reveal that TCA cycle behavior is dynamic and can be rerouted to confer a selective advantage to cells under different nutrient conditions.

Citation Format: Paige K. Arnold, Benjamin T. Jackson, Sydney Alibeckoff, Esther Drill, Lucas B. Sullivan, Lydia W.S. Finley. Cell identity determines TCA cycle dynamics [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr PO-021.
Abstract PO-022: The NKX3.1 homeoprotein functions in the mitochondria to protect against oxidative stress-dependent prostate tumorigenesis
Authors: Papachristodoulou Alexandros , Panja Sukanya , Mitrofanova Antonina , Dutta Aditya , Abate-Shen Cory
Published: December 2020

The NKX3.1 homeobox gene is a key regulator of prostate differentiation, whose loss-of-function predisposes to prostate cancer. Here, we uncover an unexpected role for NKX3.1 in mitochondrial function and bioenergetics that regulates cancer initiation under conditions of oxidative stress. To investigate whether NKX3.1 plays a direct functional role in protection against oxidative stress, we studied the consequences of its loss- or gain-of-function in tumorigenic and non-tumorigenic human prostate cells, mutant mice, and primary human prostate cultures. Utilizing redox compounds to exogenously induce and study oxidative stress responses in our models, we show that NKX3.1 localizes to the mitochondria to protect against oxidative stress, while its loss-of-function leads to deregulation of mitochondrial-encoded oxidative phosphorylation genes, elevated reactive oxygen species, and accelerated prostate cancer initiation. Importantly, our studies reveal that cells lacking NKX3.1 have impaired intracellular energetics under oxidative stress, warranting further investigation into the role of NKX3.1 loss in cancer metabolism. These observations uncover a novel function for a tissue-specific differentiation regulator in mitochondria and demonstrate its functional relevance for suppressing prostate cancer initiation.

Citation Format: Alexandros Papachristodoulou, Sukanya Panja, Antonina Mitrofanova, Aditya Dutta, Cory Abate-Shen. The NKX3.1 homeoprotein functions in the mitochondria to protect against oxidative stress-dependent prostate tumorigenesis [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr PO-022.
Abstract PO-025: Mitochondrial elongation through Drp1 deletion increases CD8 T cell oxidative phosphorylation and memory formation
Authors: Gonzales Marissa A. , Bullock Timothy NJ
Published: December 2020

Despite the positive effects of tumor infiltrating lymphocytes (TIL) seen in patients with melanoma and other tumor types, TIL often fail to completely control disease progression even with immune responses enhanced by checkpoint blockade or other immunotherapy. These TIL exhibit characteristics of exhaustion such as poor proliferation, poor effector function, and an increase in inhibitory receptor expression. By flow cytometry, we find that TIL have lower mitochondrial mass as well as lower mitochondrial membrane potential when compared to functional effector T-cells. During the activation and differentiation of T cells, the metabolic demands fluctuate between the necessity for glycolysis or oxidative phosphorylation (OXPHOS), which is supported by shifting of the mitochondrial network state. Using mice lacking Drp1, a mitochondrial fission protein, in T cells as a model of elongated mitochondria, we see increased spare respiratory capacity and OXPHOS as compared to WT T cells with fission capability. We find that these mice are more likely to generate memory precursor CD8 T cells as represented by KLRG1 lo and CD127 hi during a primary response to anti-CD40, PolyI:C, and ovalbumin protein. As indicated by the increase in memory precursors, we find that Drp1 −/− T cells form more memory than WT animals after a 28-day rest period. At this time, mice were challenged with an adenovirus expressing ovalbumin to elicit a recall response. This recall response of CD8 T cells is greater in animals lacking Drp1 in the T cells. In addition to the increase in T cell numbers, we anticipate an increase in the metabolic and possibly cytokine function of these cells, which is still under investigation. We aim to exploit mitochondrial dynamics to enforce elongation of the mitochondrial network of TIL in order to improve TIL functions and have begun investigations into mitochondrial elongation in T cells in mice bearing B16OVA melanoma tumors.

Citation Format: Marissa A. Gonzales, Timothy NJ Bullock. Mitochondrial elongation through Drp1 deletion increases CD8 T cell oxidative phosphorylation and memory formation [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr PO-025.
Abstract PO-026: Analysis of metabolic adaptations in HeLa cells as a function of energy status using a novel, direct ATP chelation methodology
Authors: Brown Ashley P. , Muhammad Taha , Martinez Selina , Korch Shaleen B. , Norris Jeffrey
Published: December 2020

Introduction: Since pioneering studies by Otto Warburg demonstrated that cancer cells had markedly reduced oxidative phosphorylation under conditions of high oxygen tension (Warburg Effect/aerobic glycolysis), metabolic reprogramming has become a well-recognized hallmark of cancer. While numerous discoveries have revealed highly specific metabolic differences between cancer cells, utilization of aerobic glycolysis as the primary means of ATP generation remains one of the most common metabolic alterations observed across a range of cancers. Gain-of-function mutations in p53 (mutp53) occur with a frequency of greater than 50% in many types of cancers and promote aerobic glycolysis by activation of glycolysis and inhibition of the tricarboxylic acid cycle. However, the manner by which these mutp53 regulates metabolic shifts in response to energy strain is only beginning to be elucidated. Hypothesis: Increased energy demand by cells caused by direct chelation of ATP by the novel, synthetic ATP-binding protein DX will be met by increases primarily in oxygen consumption. Methods: A cationic lipid mixture was complexed with active, purified DX protein to generate a DX/lipid complex. HeLa cells were incubated with the DX/lipid complex to allow efficient delivery of DX into the cytoplasm of the HeLa cells. The XF Real-Time ATP Rate Assay using Seahorse XF label-free technology was used to measure the rate of ATP production following DX expression and estimate the relative contributions of glycolysis and oxidative phosphorylation to the total ATP production rate. Results: HeLa cells transfected with DX had reduced viability, altered morphology, and decreased bioavailable intracellular ATP following DX expression. Unexpectedly, in response to DX expression and reduction in ATP, total ATP production rates in HeLa cells significantly decreased over time. Importantly, this drop in total ATP production was associated with a metabolic pathway utilization shift. Conclusion: The synthetically derived DX protein is a tool that allows for direct control of the ATP levels in cancer cells and has the potential to reveal novel metabolic adaptive responses to energy stress. Following regulated ATP reduction in HeLa cells, changes observed in the OXPHOS/glycolytic balance represent an overall cellular metabolic shift.

Citation Format: Ashley P. Brown, Taha Muhammad, Selina Martinez, Shaleen B. Korch, Jeffrey Norris. Analysis of metabolic adaptations in HeLa cells as a function of energy status using a novel, direct ATP chelation methodology [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr PO-026.
Abstract PO-031: MetMap: A map of metastatic potential of human cancer cell lines
Authors: Jin Xin , Demere Zelalem , Nair Karthik , Ali Ahmed , Ferraro Gino B. , Natoli Ted , Deik Amy , Petronio Lia , Tang Andrew A. , Zhu Cong , Wang Li , Rosenberg Danny , Mangena Vamsi , Roth Jennifer , Chung Kwanghun , Jain Rakesh K. , Clish Clary B. , Vander Heiden Matthew G. , Golub Todd R.
Published: December 2020

Most deaths from cancer are explained by metastasis, and yet large-scale metastasis research has been impractical due to the complexity of in vivo models. Here, we introduce an in vivo barcoding strategy capable of determining the metastatic potential of human cancer cell lines in murine xenografts at scale. We validated the robustness, scalability and reproducibility of the method, and applied it to 500 cell lines spanning 21 solid cancer types. We created a first-generation Metastasis Map (MetMap) that reveals organ-specific patterns of metastasis and allows relating those patterns to clinical and genomic features. We demonstrated the utility of MetMap by exploring the molecular basis of breast cancers capable of metastasizing to the brain – a principal cause of death in these patients. We found that breast cancers capable of metastasizing to the brain had unexpected evidence of altered lipid metabolism. Perturbing lipid metabolism curbed brain metastasis development, suggesting a therapeutic strategy to combat the disease and demonstrating the utility of MetMap as a public resource to support metastasis research.

Citation Format: Xin Jin, Zelalem Demere, Karthik Nair, Ahmed Ali, Gino B. Ferraro, Ted Natoli, Amy Deik, Lia Petronio, Andrew A. Tang, Cong Zhu, Li Wang, Danny Rosenberg, Vamsi Mangena, Jennifer Roth, Kwanghun Chung, Rakesh K. Jain, Clary B. Clish, Matthew G. Vander Heiden, Todd R. Golub. MetMap: A map of metastatic potential of human cancer cell lines [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr PO-031.
Abstract PO-051: Metabolic alterations reveal epigenetic vulnerabilities in breast cancer
Authors: Deblois Genevieve
Published: December 2020

Tumor progression and therapeutic resistance in cancer are characterized by changes in cell identity, which is regulated in part by the epigenetic landscape of the cells. Alterations in metabolic profiles can contribute to changes in cell fate during tumor progression through remodelling of chromatin landscapes. We show that chemoresistance in triple-negative breast cancer is characterized by altered cellular metabolism, impacting the levels of metabolites required for DNA and histone methylation. Using models of chemotherapy resistance breast cancer, we have identified metabolic and epigenetic dependencies specific to drug-resistant breast cancer cells. We show that the remodelling of epigenetic states upon chemotherapy-induced metabolic stress can contribute to drug resistance in breast cancer cells by enabling the maintenance of transposable element repression and preventing the induction of cytotoxic stress-induced viral mimicry. While these metabolic and epigenetic changes contribute to the enhanced tumorigenic fitness of chemo resistant breast cancer, they reveal epigenetic vulnerabilities that can be therapeutically targeted in drug-resistant tumors.

Citation Format: Genevieve Deblois. Metabolic alterations reveal epigenetic vulnerabilities in breast cancer [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr PO-051.
Abstract PR02: Integrated metabolic and epigenomic reprograming by H3K27M mutations in diffuse intrinsic pontine gliomas
Authors: Chung Chan , Sweha Stefan , Pratt Drew , Tamrazi Benita , Panwalkar Pooja , Banda Adam , Bayliss Jill , Hawes Debra , Yang Fusheng , Lee Ho-Joon , Shan Mengrou , Cieslik Marcin , Qin Tingting , Werner Christian , Wahl Daniel , Lyssiotis Costas , Yadav Viveka Nand , Koschmann Carl , Chinnaiyan Arul , Blüml Stefan , Judkins Alexander , Venneti Sriram
Published: December 2020

H3K27M-midline gliomas are fatal tumors that mainly harbor H3.3K27M mutations resulting in global H3K27me3 reduction that impacts neuroglial-differentiation. However, the exact mechanisms by which H3.3K27M mutations promote cancer are poorly understood. Metabolic reprogramming is a hallmark of cancer and we hypothesized that H3.3K27M mutations can reprogram metabolism to support uncontrolled growth. We demonstrate that H3.3K27M-mutant cells show elevated levels of critical enzymes related to glycolysis and TCA cycle metabolism including hexokinase-2, isocitrate dehydrogenase (IDH)-1 and glutamate dehydrogenase. H3.3K27M cells also demonstrated enhanced glycolysis, glutamine and TCA-cycle metabolism accompanied by increased alpha-ketoglutarate (α-KG) production. Mutant IDH (mIDH)1/2 converts α-KG to D-2-hydroxyglutarate (D-2HG). D-2HG increases H3K27me3 by inhibiting α-KG’s function to drive H3K27-demethylases. We discovered that H3.3K27M cells use α-KG in an opposing manner to maintain low H3K27me3. Inhibiting enzymes related to α-KG generation including hexokinase-2, glutamate-dehydrogenase and wild type-IDH1 increased global H3K27me3, altered chromatin accessibility at neuroglial-differentiation factors, lowered tumor cell proliferation, and increased overall survival in vivo in two independent H3.3K27M animal models (p< 0.0001). H3K27M and mIDH1 were mutually exclusive in-patient tumor samples and D-2HG treatment or forced-mIDH1 expression in H3.3K27M cells increased global H3K27me3 and cell death. Finally, H3.3K27M and mIDH1 were synthetic lethal in vitro. Our data suggest that H3.3K27M and mIDH1 hijack a critical and conserved metabolic pathway in opposing manners to regulate global H3K27me3. These results have implications for understanding the pathogenesis of fatal H3K27M-gliomas and for developing therapeutic strategies by disruption of an integrated metabolic/epigenetic-axis.

Citation Format: Chan Chung, Stefan Sweha, Drew Pratt, Benita Tamrazi, Pooja Panwalkar, Adam Banda, Jill Bayliss, Debra Hawes, Fusheng Yang, Ho-Joon Lee, Mengrou Shan, Marcin Cieslik, Tingting Qin, Christian Werner, Daniel Wahl, Costas Lyssiotis, Viveka Nand Yadav, Carl Koschmann, Arul Chinnaiyan, Stefan Blüml, Alexander Judkins, Sriram Venneti. Integrated metabolic and epigenomic reprograming by H3K27M mutations in diffuse intrinsic pontine gliomas [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr PR02.