DDRE-13. PROSTAGLANDIN E RECEPTOR 3 (PTGER3) REGULATES RESISTANCE TO TUMOR TREATING FIELDS (TTFields) IN GLIOBLASTOMA CELLS

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi77-vi77
Author(s):  
Dongjiang Chen ◽  
Son Le ◽  
Tarun Hutchinson ◽  
David Tran
Keyword(s):  
Electric Fields ◽  
Nuclear Translocation ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Intermediate Frequency ◽  
Cell Surface Receptor ◽  
Tumor Control ◽  
Prostaglandin E ◽  
Relative Resistance

Abstract INTRODUCTION TTFields, a novel approved therapy for GBM, employ alternating intermediate-frequency electric fields to disrupt mitotic macromolecules leading to chromosome mis-segregation and apoptosis. The addition of TTFields significantly improves survival. However, most patients eventually develop resistance to TTFields through an unknown mechanism. METHODS Multiple human GBM cell lines were treated with TTFields continuously using Inovitro, an in vitro TTFields system, until cells with relative resistance to killing by TTFields emerged. Temporal gene expression profiles were analyzed using NETZEN, an innovative deep-learning and gene network-based ranking computational algorithm, to identify resistance pathways, followed by experimental validation. RESULTS PTGER3, a Gαi-protein-coupled cell surface receptor, is the top ranked master regulator in the predicted resistance program, which is upregulated in GBM cells within 24 hrs of exposure to TTFields and further reinforced as resistance sets in. Forced expression of PTGER3 in sensitive GBM cells confers relative resistance to TTFields, while PTGER3 depletion in resistant cells re-sensitizes them to TTFields. Most importantly, pharmacological inhibition of PTGER3 using either aspirin to reduce prostaglandin E production or PTGER3-specific inhibitors effectively prevent resistance from developing. Mechanistically, PTGER3 is rapidly translocated from the plasma membrane to the nucleus after TTFields exposure, where it interacts with ZNF488, a stemness transcription factor tightly linked to PTGER3 in our predicted network to initiate and maintain the resistance program. Indeed, TTFields resistance is associated with a transition to glioma stem cells (GSCs) as determined by increased neurosphere formation and orthotopic tumorigenesis in immunocompromised mice, and PTGER3 inhibition alone reverses the GSC transition leading to improved tumor control and survival. CONCLUSIONS PTGER3 is at the apex of a novel pathway that indispensably regulates TTFields resistance through a unique mechanism involving the physical nuclear translocation of this 7-transmembrane receptor. PTGER3 and its pathway are thus potential therapeutic targets to enhance therapeutic efficacy of TTFields.

scholarly journals DRES-06. PROSTAGLANDIN E RECEPTOR 3 MEDIATES RESISTANCE TO TUMOR TREATING FIELDS IN GLIOBLASTOMA CELLS

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi72-vi72
Author(s):  
Dongjiang Chen ◽  
Son Le ◽  
Nagheme Thomas ◽  
David Tran
Keyword(s):  
Electric Fields ◽  
Systems Approach ◽  
Expression Profiles ◽  
Critical Role ◽  
Gene Expression Profiles ◽  
Prolonged Treatment ◽  
Prostaglandin E ◽  
Tumor Treating Fields ◽  
Resistant Cells

Abstract OBJECTIVES Tumor Treating Fields (TTFields) are approved in combination with temozolomide for newly diagnosed glioblastoma (GBM). The addition of TTFields resulted in a significant improvement in overall survival. TTFields are low-intensity alternating electric fields that are thought to disturb mitotic macromolecules’ assembly. However, most GBM patients eventually develop resistance to TTFields. The mechanism of TTFields resistance remains largely unexplored. Understanding how GBM cells circumvent the biophysical forces of TTFields and their downstream effects will improve therapeutic efficacy of this novel anti-cancer treatment modality. METHODS A panel of GBM cell lines were treated continuously with TTFields at the clinically approved frequency of 200 kHz using an in vitro TTFields system until cells with relative resistance to the cytotoxic effects of TTFields. A systems approach aided by innovative network ranking computational algorithms were utilized to analyze global gene expression profiles and identify resistance pathways, which were subsequently validated experimentally. RESULTS TTFields-induced chromosomal instability such as the formation of cytoplasmic micronuclei is preserved in resistant cells, indicating that TTFields resistance is mediated through a non-biophysical mechanism. This acquired TTFields resistance phenotype is associated with a transition of GBM cells to a stem-like state as determined by a neurosphere assay. Using an innovative computational platform, we methodically dissected this stemness program in resistant cells. Mechanistically, Prostaglandin E Receptor 3 (PTGER3) is the top ranked master regulator responsible for resistance. PTGER3 is rapidly upregulated in GBM cells upon exposure to TTFields and further increases with prolonged treatment as resistance sets in. Pharmacological inhibition of PTGER3 either using aspirin to reduce prostaglandin E production or PTGER3-specific inhibitors resensitized cells to TTFields. CONCLUSIONS We have identified a novel pathway with PTGER3 at the apex that plays a critical role in TTFields resistance. This pathway is a potential therapeutic target to reduce resistance to TTFields therapy in GBM.

scholarly journals CSIG-15. INNOVATIVE COMPUTATIONAL PLATFORM ADDRESSES PROSTAGLANDIN E RECEPTOR 3 AS THE MASTER REGULATOR MEDIATING RESISTANCE TO TUMOR TREATING FIELDS IN GLIOBLASTOMA CELLS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii30-ii31
Author(s):  
Dongjiang Chen ◽  
Son Le ◽  
Tarun Hutchinson ◽  
David Tran
Keyword(s):  
Nuclear Translocation ◽  
Expression Profiles ◽  
Critical Role ◽  
Prolonged Treatment ◽  
Prostaglandin E ◽  
Tumor Treating Fields ◽  
Computational Platform ◽  
Resistant Cells

Abstract OBJECTIVES Tumor Treating Fields (TTFields) are approved in combination with temozolomide for newly diagnosed glioblastoma (GBM). TTFields are low-intensity alternating electric fields that are thought to disturb mitotic macromolecules’ assembly. The addition of TTFields resulted in a significant improvement in overall survival. However, most GBM patients eventually develop resistance to TTFields and the mechanism remains unexplored. METHODS Multiple GBM cell lines were treated continuously at clinically approved frequency of 200 kHz using an in vitro TTFields system until cells with relative resistance to the cytotoxic effects of TTFields. A systems approach aided by innovative network ranking computational algorithms were utilized to analyze global gene expression profiles and identify resistance pathways, which were subsequently validated experimentally. RESULTS TTFields-induced chromosomal instability is preserved in resistant cells, indicating that TTFields resistance is mediated through a non-biophysical mechanism. This acquired TTFields resistance phenotype is associated with a transition of GBM cells to a stem-like state as determined by a neurosphere assay, stemness markers such as CD44 and increased tumorigenesis when implanted into mouse brain. Using an innovative computational platform-NETZEN, we methodically dissected this stemness program in resistant cells. 3 networks were found disrupted and all play critical roles in GBM stemness. Mechanistically, Prostaglandin E Receptor 3 (PTGER3) is the top ranked regulator responsible for resistance. PTGER3 is rapidly upregulated both in vitro and in vivo upon exposure to TTFields and further increases with prolonged treatment as resistance sets in. Immunofluorescence staining shows PTGER3’s nuclear translocation along with Lamin A/C disruption in response to TTFields. Pharmacological inhibition of PTGER3 using aspirin or PTGER3-specific inhibitors resensitized or prevent cells becoming resistance to TTFields. CONCLUSIONS We have identified a novel regulator PTGER3 at the apex that plays a critical role in TTFields resistance. This is a potential therapeutic target to reduce resistance to TTFields therapy in GBM.

scholarly journals Transcriptome analysis of gravitational effects on mouse skeletal muscles under microgravity and artificial 1 g onboard environment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Risa Okada ◽  
Shin-ichiro Fujita ◽  
Riku Suzuki ◽  
Takuto Hayashi ◽  
Hirona Tsubouchi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Muscle Mass ◽  
Muscle Atrophy ◽  
Transcriptome Analysis ◽  
Fiber Type ◽  
Expression Profiles ◽  
Space Station ◽  
Gene Expression Profiles

AbstractSpaceflight causes a decrease in skeletal muscle mass and strength. We set two murine experimental groups in orbit for 35 days aboard the International Space Station, under artificial earth-gravity (artificial 1 g; AG) and microgravity (μg; MG), to investigate whether artificial 1 g exposure prevents muscle atrophy at the molecular level. Our main findings indicated that AG onboard environment prevented changes under microgravity in soleus muscle not only in muscle mass and fiber type composition but also in the alteration of gene expression profiles. In particular, transcriptome analysis suggested that AG condition could prevent the alterations of some atrophy-related genes. We further screened novel candidate genes to reveal the muscle atrophy mechanism from these gene expression profiles. We suggest the potential role of Cacng1 in the atrophy of myotubes using in vitro and in vivo gene transductions. This critical project may accelerate the elucidation of muscle atrophy mechanisms.

scholarly journals Discovery of novel mechanosensitive genes in vivo using mouse carotid artery endothelium exposed to disturbed flow

Blood ◽  
2010 ◽  
Vol 116 (15) ◽  
pp. e66-e73 ◽  
Author(s):  
Chih-Wen Ni ◽  
Haiwei Qiu ◽  
Amir Rezvan ◽  
Kihwan Kwon ◽  
Douglas Nam ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Ex Vivo ◽  
Expression Profiles ◽  
Quantitative Polymerase Chain Reaction ◽  
Gene Expression Profiles ◽  
Disturbed Flow ◽  
A Genome ◽  
Pattern Comparison

Abstract Recently, we showed that disturbed flow caused by a partial ligation of mouse carotid artery rapidly induces atherosclerosis. Here, we identified mechanosensitive genes in vivo through a genome-wide microarray study using mouse endothelial RNAs isolated from the flow-disturbed left and the undisturbed right common carotid artery. We found 62 and 523 genes that changed significantly by 12 hours and 48 hours after ligation, respectively. The results were validated by quantitative polymerase chain reaction for 44 of 46 tested genes. This array study discovered numerous novel mechanosensitive genes, including Lmo4, klk10, and dhh, while confirming well-known ones, such as Klf2, eNOS, and BMP4. Four genes were further validated for protein, including LMO4, which showed higher expression in mouse aortic arch and in human coronary endothelium in an asymmetric pattern. Comparison of in vivo, ex vivo, and in vitro endothelial gene expression profiles indicates that numerous in vivo mechanosensitive genes appear to be lost or dysregulated during culture. Gene ontology analyses show that disturbed flow regulates genes involved in cell proliferation and morphology by 12 hours, followed by inflammatory and immune responses by 48 hours. Determining the functional importance of these novel mechanosensitive genes may provide important insights into understanding vascular biology and atherosclerosis.

Simulated microgravity using the Random Positioning Machine inhibits differentiation and alters gene expression profiles of 2T3 preosteoblasts

2005 ◽  
Vol 288 (6) ◽  
pp. C1211-C1221 ◽  
Author(s):  
Steven J. Pardo ◽  
Mamta J. Patel ◽  
Michelle C. Sykes ◽  
Manu O. Platt ◽  
Nolan L. Boyd ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alkaline Phosphatase ◽  
Bone Loss ◽  
Simulated Microgravity ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Underlying Mechanism ◽  
Bone Biology ◽  
Random Positioning Machine

Exposure to microgravity causes bone loss in humans, and the underlying mechanism is thought to be at least partially due to a decrease in bone formation by osteoblasts. In the present study, we examined the hypothesis that microgravity changes osteoblast gene expression profiles, resulting in bone loss. For this study, we developed an in vitro system that simulates microgravity using the Random Positioning Machine (RPM) to study the effects of microgravity on 2T3 preosteoblast cells grown in gas-permeable culture disks. Exposure of 2T3 cells to simulated microgravity using the RPM for up to 9 days significantly inhibited alkaline phosphatase activity, recapitulating a bone loss response that occurs in real microgravity conditions without altering cell proliferation and shape. Next, we performed DNA microarray analysis to determine the gene expression profile of 2T3 cells exposed to 3 days of simulated microgravity. Among 10,000 genes examined using the microarray, 88 were downregulated and 52 were upregulated significantly more than twofold using simulated microgravity compared with the static 1-g condition. We then verified the microarray data for some of the genes relevant in bone biology using real-time PCR assays and immunoblotting. We confirmed that microgravity downregulated levels of alkaline phosphatase, runt-related transcription factor 2, osteomodulin, and parathyroid hormone receptor 1 mRNA; upregulated cathepsin K mRNA; and did not significantly affect bone morphogenic protein 4 and cystatin C protein levels. The identification of gravisensitive genes provides useful insight that may lead to further hypotheses regarding their roles in not only microgravity-induced bone loss but also the general patient population with similar pathological conditions, such as osteoporosis.

scholarly journals Recapitulating tumour microenvironment in chitosan–gelatin three-dimensional scaffolds: an improved in vitro tumour model

2012 ◽  
Vol 9 (77) ◽  
pp. 3288-3302 ◽  
Author(s):  
Neha Arya ◽  
Viren Sardana ◽  
Meera Saxena ◽  
Annapoorni Rangarajan ◽  
Dhirendra S. Katti
Keyword(s):  
Cancer Progression ◽  
Expression Profiles ◽  
Three Dimensional ◽  
Gene Expression Profiles ◽  
Petri Dish ◽  
Tumour Microenvironment ◽  
Two Dimensional ◽  
Tumour Model

Owing to the reduced co-relationship between conventional flat Petri dish culture (two-dimensional) and the tumour microenvironment, there has been a shift towards three-dimensional culture systems that show an improved analogy to the same. In this work, an extracellular matrix (ECM)-mimicking three-dimensional scaffold based on chitosan and gelatin was fabricated and explored for its potential as a tumour model for lung cancer. It was demonstrated that the chitosan–gelatin (CG) scaffolds supported the formation of tumoroids that were similar to tumours grown in vivo for factors involved in tumour-cell–ECM interaction, invasion and metastasis, and response to anti-cancer drugs. On the other hand, the two-dimensional Petri dish surfaces did not demonstrate gene-expression profiles similar to tumours grown in vivo . Further, the three-dimensional CG scaffolds supported the formation of tumoroids, using other types of cancer cells such as breast, cervix and bone, indicating a possible wider potential for in vitro tumoroid generation. Overall, the results demonstrated that CG scaffolds can be an improved in vitro tool to study cancer progression and drug screening for solid tumours.

Effects of MiR-451a on the Phagocytosis and Polarization of Macrophages

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 42-42
Author(s):  
Xiaoli Liu ◽  
Dongyue Zhang ◽  
Hao Wang ◽  
Qian Ren ◽  
Lina Wang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Conflicts Of Interest ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Microrna Expression ◽  
Differentially Expressed ◽  
Proliferation Capacity ◽  
Microrna Sequencing ◽  
Differentiation Marker

Macrophages are important member in tissue microenvironments and play diverse physiologic and pathologic roles. Leukemia associated macrophages (LAM) are a kind of specifically activated macrophages in leukemia microenvironment, which are different from M1, M2 and TAMs. We have reported the heterogeneities in gene expression profiles of LAMs. However, MicroRNA expression profiles of LAMs and regulatory mechanism are still unknown. Here, a MLL-AF9 induced mouse acute myeloid leukemia (AML) model was used, and LAMs in the spleen and bone marrow were sorted for microRNA sequencing. The microRNA expression profiles of LAMs in bone marrow and spleen in AML mice were different from macrophages from control mice. Based on the volcano plot, more than 100 microRNAs were differentially expressed in LAMs compared with macrophages in control mice. Next, five differentially expressed microRNAs were selected and verified by qRT-PCR in LAMs from spleen. The results showed that miR-451a and miR-155-5p in spleen LAMs were significantly upregulated in LAMs from spleen. Overexpression of miR-451a altered the morphology of macrophages, enhanced the phagocytic ability of macrophages, and promotes the expression of macrophage differentiation marker CD11b. Furthermore, overexpression of miR-451a had little effect on M0 macrophages, but increased the proliferation capacity of macrophages upon stimulation toward M1 or M2 phenotype. MiR-451a overexpressed-macrophages had higher level of iNOS when stimulated with LPS or IL-4 whereas there was no difference in the expression of IL-1β, IL-6, CD206 and Arg-1 between MiR-451a overexpressed-macrophages and control macrophage. Therefore, our data revealed the characteristics of the microRNA expression profile of LAMs for the first time, and verified the effect of miR-451a on macrophage in vitro. Disclosures No relevant conflicts of interest to declare.

JAK/STAT Inhibition Targets TP53 altered Primary Human Acute Myeloid Leukemia Stem Cells

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 27-28
Author(s):  
Marie Lue Antony ◽  
Klara Noble-Orcutt ◽  
Yoonku Lee ◽  
Oluwateniayo Ogunsan ◽  
Jeffrey Lee Jensen ◽  
...  
Keyword(s):  
Intracellular Signaling ◽  
Expression Profiles ◽  
Survival Rates ◽  
Gene Expression Profiles ◽  
Treatment Resistance ◽  
Cell Transplant ◽  
Hematopoietic Stem ◽  
Poor Risk ◽  
Molecular Features

In acute myeloid leukemia (AML), the impact of genetic drivers on response to therapy and long-term survival has been well characterized. AML with complex cytogenetics and TP53 alterations (TP53Alt) is a poor-risk AML subtype that is largely insensitive to chemotherapy, modern targeted agents, and hematopoietic stem cell transplant leading to survival rates 0-10% at 1 year. In contrast, AML with favorable risk molecular features is highly sensitive to chemotherapy and confers survival rates of 50-70%. AML with intermediate risk molecular features can be responsive to chemotherapy and can be cured with hematopoietic stem cell transplant leading to overall survival rates of 30-60%. Leukemia stem cells (LSCs), the cells that recapitulate and propagate leukemia, are central to leukemia progression and relapse. Given the differences in chemo-sensitivity and clinical behavior of genetic subgroups of AML, we asked whether LSCs from poor risk AMLs exhibit distinct signaling activation profiles. We assembled a panel of 23 primary human AML samples with intermediate- and poor- risk genetics and used CyTOF (mass cytometry) to quantitatively measure the levels of immunophenotypic proteins and intracellular signaling molecules in each sample, at the single-cell level. We gated on CD34+CD123+CD3-CD19- cells (LSCs) and measured the level of intracellular signaling molecules within the LSCs of each sample. Notably, the intracellular signaling activation state of LSCs from each AML subtype was distinct; NFkB, pERK, p4EBP1, and pSTAT3 were uniquely upregulated in complex cytogenetics and TP53Alt LSCs, relative to LSCs from intermediate risk AML, suggesting that these signaling pathways may be important for LSC function in this AML subtype. Given that TP53Alt independently confer treatment resistance in AML, we focused on this genetic subgroup. We compared the gene expression profiles of TP53Alt and TP53-wild-type AML samples from the BEAT AML dataset (Tyner et al. Nature 2018) and found that the gene expression profiles of TP53Alt samples are enriched for gene sets representing JAK/STAT signaling, consistent with our CyTOF data, which identified activation of STAT3 in TP53Alt LSCs. A recent drug screen in AML demonstrated that a JAK1/2 kinase inhibitor, AZD1480, can reduce the in vitro viability of TP53-deleted AML cell lines (Nechiporuk et al. Ca Discovery 2019), but these effects were not tested in primary AML samples or on LSCs. Since LSCs confer treatment resistance, we investigated the effect of the AZD1480 on the LSC population in TP53Alt primary human AML samples. AZD1480 treatment abolished all colony formation in primary human TP53Alt AML samples (n=7, 6 replicates per sample, p<0.01). Treatment of these samples in liquid cultures led to a 50% reduction in LSC frequency. We used CyTOF to profile the intracellular signaling states of in vitro treated samples and found that AZD1480 attenuated pSTAT3, pSTAT5, p4EBP1, and NFkB in the LSCs of these samples. The mTOR/4EBp1 and NF༆B pathways have been implicated as drivers of self-renewal and LSC function in AML. Our data suggest that JAK/STAT inhibition may target these pathways in TP53Alt LSCs. These data demonstrate the unique signaling states of TP53Alt LSCs, relative to other LSCs, and show that inhibition of the JAK/STAT pathway specifically targets LSCs within human TP53Alt AML. Figure Disclosures No relevant conflicts of interest to declare.

Abstract 15751: A New Role of Sox6 in Renin Regulation

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Jose Gomez ◽  
Eric Sum ◽  
Anna Keyte ◽  
Conrad Hodgkinson ◽  
Mary Hutson ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cell Fate ◽  
Kidney Development ◽  
Ex Vivo ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Renin Angiotensin System ◽  
Adult Kidney ◽  
Fold Reduction

Introduction: The renin-angiotensin system (RAS) is an important component of blood pressure regulation in mammals. Renin catalyzes the rate limiting step of RAS, is produced and stored by Juxtaglomerular (JG) cells in the kidney. However, the transcriptional mechanisms that govern the specification of renin expressing cells under normal or pathophysiological conditions remain poorly understood. During blood pressure changes the number of adult renal cells expressing renin increase through a process termed JG recruitment. We found that this process involves differentiation mesenchymal stromal-like cells (MSC) to renin expressing cells. Our aim in this study was to determine new regulators of renin cell fate during kidney development and JG recruitment. Methods: Gene expression profiles of MSC and JG cells were performed with Affymetrix Mouse 430 2.0 array. In vitro assays were performed in adult renal MSCs isolated from C57BL6 Ren1c YFP mice. Renin expression in vitro was induced by treatment with IBMX and Forskolin. MSC were transduced with lentivirus carrying vectors for Sox6, Sox6 shRNA or controls. Ex vivo analysis was performed in embryonic kidneys (14.5 dpc) isolated and transduced with Sox6 or scrambled shRNA, kidneys were then cultured for 4 days and the expression of Sox6 and Renin analyzed by IHC. Results: Data showed that the transcription factor Sox6 is expressed in renin producing cells in the developing kidney (n=4) and in the adult kidney after stimulation that promotes JG recruitment (n=3). Overexpression of Sox6 (n=3, P<0.05) enhanced differentiation of renal MSCs to renin producing cells in vitro , and Sox6 knockdown reduced differentiation of renal MSC to renin producing cells in vitro (6-fold, n=4, P<0.01). Furthermore, knockdown of Sox6 in an ex vivo model of kidney development resulted in a 5-fold reduction in renin expressing cells (n=4, P<0.05). Conclusion: These results support a novel role for Sox6 in the development of renin expressing cells. This may have implications for renal development and physiology, opening new possibilities of addressing questions regarding both developmental and physiological regulation of renin.

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