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.

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 The Diverse Roles of the Global Transcriptional Regulator PhoP in the Lifecycle of Yersinia pestis

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1039
Author(s):  
Hana S. Fukuto ◽  
Gloria I. Viboud ◽  
Viveka Vadyvaloo
Keyword(s):  
Yersinia Pestis ◽  
Current Knowledge ◽  
Response Regulator ◽  
Expression Profiles ◽  
Critical Role ◽  
Gene Expression Profiles ◽  
Acanthamoeba Castellanii ◽  
Wide Range

Yersinia pestis, the causative agent of plague, has a complex infectious cycle that alternates between mammalian hosts (rodents and humans) and insect vectors (fleas). Consequently, it must adapt to a wide range of host environments to achieve successful propagation. Y. pestis PhoP is a response regulator of the PhoP/PhoQ two-component signal transduction system that plays a critical role in the pathogen’s adaptation to hostile conditions. PhoP is activated in response to various host-associated stress signals detected by the sensor kinase PhoQ and mediates changes in global gene expression profiles that lead to cellular responses. Y. pestis PhoP is required for resistance to antimicrobial peptides, as well as growth under low Mg2+ and other stress conditions, and controls a number of metabolic pathways, including an alternate carbon catabolism. Loss of phoP function in Y. pestis causes severe defects in survival inside mammalian macrophages and neutrophils in vitro, and a mild attenuation in murine plague models in vivo, suggesting its role in pathogenesis. A Y. pestisphoP mutant also exhibits reduced ability to form biofilm and to block fleas in vivo, indicating that the gene is also important for establishing a transmissible infection in this vector. Additionally, phoP promotes the survival of Y. pestis inside the soil-dwelling amoeba Acanthamoeba castellanii, a potential reservoir while the pathogen is quiescent. In this review, we summarize our current knowledge on the mechanisms of PhoP-mediated gene regulation in Y. pestis and examine the significance of the roles played by the PhoP regulon at each stage of the Y. pestis life cycle.

scholarly journals The Erythroid Phenotype of EKLF-Null Mice: Defects in Hemoglobin Metabolism and Membrane Stability

2005 ◽  
Vol 25 (12) ◽  
pp. 5205-5214 ◽  
Author(s):  
Roy Drissen ◽  
Marieke von Lindern ◽  
Andrea Kolbus ◽  
Siska Driegen ◽  
Peter Steinlein ◽  
...  
Keyword(s):  
Blood Cells ◽  
Target Genes ◽  
Expression Profiles ◽  
Critical Role ◽  
Gene Expression Profiles ◽  
Erythroid Differentiation ◽  
Membrane Stability ◽  
Erythroid Progenitors ◽  
Hemoglobin Metabolism

ABSTRACT Development of red blood cells requires the correct regulation of cellular processes including changes in cell morphology, globin expression and heme synthesis. Transcription factors such as erythroid Krüppel-like factor EKLF (Klf1) play a critical role in erythropoiesis. Mice lacking EKLF die around embryonic day 14 because of defective definitive erythropoiesis, partly caused by a deficit in β-globin expression. To identify additional target genes, we analyzed the phenotype and gene expression profiles of wild-type and EKLF null primary erythroid progenitors that were differentiated synchronously in vitro. We show that EKLF is dispensable for expansion of erythroid progenitors, but required for the last steps of erythroid differentiation. We identify EKLF-dependent genes involved in hemoglobin metabolism and membrane stability. Strikingly, expression of these genes is also EKLF-dependent in primitive, yolk sac-derived, blood cells. Consistent with lack of upregulation of these genes we find previously undetected morphological abnormalities in EKLF-null primitive cells. Our data provide an explanation for the hitherto unexplained severity of the EKLF null phenotype in erythropoiesis.

UBE2L6 is Involved in Cisplatin Resistance by Regulating the Transcription of ABCB6

2020 ◽  
Vol 20 (12) ◽  
pp. 1487-1496 ◽  
Author(s):  
Midori Murakami ◽  
Hiroto Izumi ◽  
Tomoko Kurita ◽  
Chiho Koi ◽  
Yasuo Morimoto ◽  
...  
Keyword(s):  
Gene Expression ◽  
Promoter Activity ◽  
Anticancer Agent ◽  
Cisplatin Resistance ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Molecular Target ◽  
Transcriptional Level ◽  
And Control ◽  
Resistant Cells

Background: Cisplatin is an important anticancer agent in cancer chemotherapy, but when resistant cells appear, treatment becomes difficult, and the prognosis is poor. Objective: In this study, we investigated the gene expression profile in cisplatin sensitive and resistant cells, and identified the genes involved in cisplatin resistance. Methods: Comparison of gene expression profiles revealed that UBE2L6 mRNA is highly expressed in resistant cells. To elucidate whether UBE2L6 is involved in the acquisition of cisplatin resistance, UBE2L6- overexpressing cells established from cisplatin-sensitive cells and UBE2L6-silenced cells developed from cisplatin- resistant cells were generated, and the sensitivity of cisplatin was examined. Results: The sensitivity of the UBE2L6-overexpressing cells did not change compared with the control cells, but the UBE2L6-silenced cells were sensitized to cisplatin. To elucidate the mechanism of UBE2L6 in cisplatin resistance, we compared the gene expression profiles of UBE2L6-silenced cells and control cells and found that the level of ABCB6 mRNA involved in cisplatin resistance was decreased. Moreover, ABCB6 promoter activity was partially suppressed in UBE2L6-silenced cells. Conclusion: These results suggest that cisplatin-resistant cells have upregulated UBE2L6 expression and contribute to cisplatin resistance by regulating ABCB6 expression at the transcriptional level. UBE2L6 might be a molecular target that overcomes cisplatin resistance.

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.

The characteristics of mesenteric adipose tissue attached to different intestinal segments and their roles in immune regulation

2022 ◽  
Author(s):  
Haowei Zhang ◽  
Yujin Ding ◽  
Qin Zeng ◽  
Dandan Wang ◽  
Ganglei Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Immune Regulation ◽  
Expression Profiles ◽  
Critical Role ◽  
Gene Expression Profiles ◽  
Rna Seq ◽  
Mesenteric Adipose Tissue ◽  
Cell Components ◽  
Subsequent Effect

Background: Mesenteric adipose tissue (MAT) plays a critical role in the intestinal physiological ecosystems. Small and large intestines have evidently intrinsic and distinct characteristics. However, whether there exist any mesenteric differences adjacent to the small and large intestines (SMAT and LMAT) has not been properly characterized. We studied the important facets of these differences, such as morphology, gene expression, cell components and immune regulation of MATs, to characterize the mesenteric differences. Methods: The SMAT and LMAT of mice were utilized for comparison of tissue morphology. Paired mesenteric samples were analyzed by RNA-seq to clarify gene expression profiles. MAT partial excision models were constructed to illustrate the immune regulation roles of MATs, and 16S-seq was applied to detect the subsequent effect on microbiota. Results: Our data show that different segments of mesenteries have different morphological structures. SMAT not only has smaller adipocytes but also contains more fat-associated lymphoid clusters than LMAT. The gene expression profile is also discrepant between these two MATs in mice. B-cell markers were abundantly expressed in SMAT, while development-related genes were highly expressed in LMAT. Adipose-derived stem cells of LMAT exhibited higher adipogenic potential and lower proliferation rates than those of SMAT. In addition, SMAT and LMAT play different roles in immune regulation and subsequently affect microbiota components. Finally, our data clarified the described differences between SMAT and LMAT in humans. Conclusions: There were significant differences in cell morphology, gene expression profiles, cell components, biological characteristics, and immune and microbiota regulation roles between regional MATs.

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