P04.18 Heterogeneity and plasticity of integrin α5β1 expression in glioblastoma stem cells

2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii22-ii22
Author(s):  
M Messé ◽  
C Bernhard ◽  
M Mercier ◽  
Q Fuchs ◽  
S Foppolo ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Metabolism ◽  
Cell Monolayer ◽  
Therapy Resistance ◽  
Molecular Heterogeneity ◽  
Integrin Expression ◽  
Glioma Stem Cell ◽  
Integrin Α5β1 ◽  
Α5β1 Integrin

Abstract BACKGROUND Glioblastoma (GBM) is the most frequent and deadliest type of central nervous system tumors. Despite the treatment by the Stupp protocol, almost all patients relapse and new therapeutic protocols have been unsuccessful for ameliorating patient survival. Molecular heterogeneity of GBM and existence of glioma stem cells (GSC) may be linked to therapy resistance and recurrence. We demonstrated earlier that α5β1 integrin is a GBM therapeutic target which participate to therapy resistance; a high expression in patient tumors is linked to a worse prognosis. Expression of α5β1 integrin is heterogeneous inter- and intra-tumorally. We particularly addressed the role of glioma stem cell plasticity in the modulation of the integrin expression. Stem cells reside in specific niches (perivascular or hypoxic niches) in the tumor and are at the origin of the more differentiated tumor cell bulk. Metabolism is known to change between the different GSC states and may be affected by or may affect the integrin expression. The aim of our work is therefore to consider the expression of the integrin α5β1 in relationship with GSC differentiation or in hypoxic environment and with cell metabolism. MATERIAL AND METHODS Ten different patient-derived glioma stem cell lines were investigated. Cell culture in stem cell medium (neurospheres) or differentiation medium (adherent cell monolayer) was made in normoxia (21% O2) or hypoxia (1%O2). Alternatively, chemically-induced hypoxia (cobalt chloride/desferoxiamine) was used. Integrin expression was kinetically checked at the mRNA (RT-qPCR) or protein (Western blot) levels. Cell metabolism was investigated with the Seahorse Xfp technology and by HRMAS-NMR. RESULTS No GSC lines (neurospheres) expressed the α5β1 integrin. Interestingly, only half of them did after differentiation suggesting a first level of heterogeneity. A second level of heterogeneity was observed in hypoxic conditions provoking induction of integrin α5β1 expression in only some non-differentiated GSC. Three categories of GSC were thus characterized: one able to express the integrin in hypoxia and after differentiation, one never expressing it and the third one only after differentiation. Cell metabolism differed between GSC before and after differentiation and in presence of integrin α5β1 antagonists. Specific glioma regulator network analysis revealed new targets to be inhibited concomitantly with the integrin. CONCLUSION Data suggest that α5β1 integrin expression may be induced by different signaling pathways. Molecular switches may occur either when stem cells differentiate to tumor cells but also directly in stem cells in hypoxic niches. Characterization of α5β1 integrin expression drivers may help to find new therapeutic targets but also to delineate subpopulation of patients who would benefit from an anti-integrin strategy.

scholarly journals P11.59 Integrin a5 heterogeneous expression in glioblastoma is related to glioma stem cell subpopulations

2019 ◽  
Vol 21 (Supplement_3) ◽  
pp. iii57-iii57
Author(s):  
M Dontenwill ◽  
M Mercier ◽  
G Gillmann ◽  
D Reita ◽  
I Lelong-Rebel ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Lines ◽  
Cell Populations ◽  
Glioma Stem Cells ◽  
Integrin Subunit ◽  
Glioma Stem Cell ◽  
Integrin Α5β1 ◽  
Heterogeneous Expression

Abstract BACKGROUND Glioblastoma (GBM) is the most aggressive primary brain tumor. Treatment failure and recurrence are explained in part by tumoral heterogeneity. Our previous results showed that the integrin α5β1 is implicated in GBM aggressiveness and represents a relevant therapeutic target. Recently, we observed intra- and inter-tumor heterogeneity of integrin α5β1 expression. Heterogeneity may be linked to different glioma stem cell populations. MATERIAL AND METHODS Ten glioma stem cell lines were grown as neurospheres in stem cell medium and their differentiation was induced by serum and/or ATRA. Two cell lines (NCH421k and NCH644) were selected and were modified by depletion (CrisprCas9) or transfection of the α5 integrin gene. Polyclonal lines and individual clones were analyzed phenotypically in vitro, before and after differentiation, and in vivo in orthotopic xenografts of 2x104 cells in nude mice. TCGA datasets were used to validate the heterogeneous expression of α5 integrin in GBM. RESULTS TCGA data validate that α5 integrin mRNA was only over-expressed in the mesenchymal subclass of GBM. Our results show that α5 integrin protein is not expressed in stem cell culture conditions. However, α5 integrin expression is induced after differentiation in only half of the cell lines supporting the notion of tumoral heterogeneity of glioma stem cells. Interestingly, single cell-derived clone evaluation showed that intra-tumoral stem cell heterogeneity also exists at the level of α5 protein expression. When glioma stem cells are programmed or transduced to express α5 integrin, differentiated cells became more aggressive. Notably, they acquired a fibronectin-dependent motility and a proliferative phenotype. Interestingly, integrin α5 remained expressed in secondary stem cells obtained after dedifferentiation. The in vivo assays suggested that glioma stem cells, programmed to express the integrin, were prone to form larger tumors. CONCLUSION Our data support the hypothesis that some glioma stem cells are programmed to express the α5 integrin subunit in their differentiated progeny to form a more aggressive tumor. They add new evidences that both cell populations may be considered for new therapeutic strategies against GBM.

scholarly journals Mitochondrial Dynamics in the Drosophila Ovary Regulates Germ Stem Cell Number, Cell Fate, and Female Fertility

2021 ◽  
Vol 8 ◽  
Author(s):  
Marcia Garcez ◽  
Joana Branco-Santos ◽  
Patricia C. Gracio ◽  
Catarina C. F. Homem
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Mitochondrial Dynamics ◽  
Tricarboxylic Acid Cycle ◽  
Cell Metabolism ◽  
Cell Number ◽  
Female Fertility ◽  
Mitochondrial Activity ◽  
Drosophila Ovary

The fate and proliferative capacity of stem cells have been shown to strongly depend on their metabolic state. Mitochondria are the powerhouses of the cell being responsible for energy production via oxidative phosphorylation (OxPhos) as well as for several other metabolic pathways. Mitochondrial activity strongly depends on their structural organization, with their size and shape being regulated by mitochondrial fusion and fission, a process known as mitochondrial dynamics. However, the significance of mitochondrial dynamics in the regulation of stem cell metabolism and fate remains elusive. Here, we characterize the role of mitochondria morphology in female germ stem cells (GSCs) and in their more differentiated lineage. Mitochondria are particularly important in the female GSC lineage. Not only do they provide these cells with their energy requirements to generate the oocyte but they are also the only mitochondria pool to be inherited by the offspring. We show that the undifferentiated GSCs predominantly have fissed mitochondria, whereas more differentiated germ cells have more fused mitochondria. By reducing the levels of mitochondrial dynamics regulators, we show that both fused and fissed mitochondria are required for the maintenance of a stable GSC pool. Surprisingly, we found that disrupting mitochondrial dynamics in the germline also strongly affects nurse cells morphology, impairing egg chamber development and female fertility. Interestingly, reducing the levels of key enzymes in the Tricarboxylic Acid Cycle (TCA), known to cause OxPhos reduction, also affects GSC number. This defect in GSC self-renewal capacity indicates that at least basal levels of TCA/OxPhos are required in GSCs. Our findings show that mitochondrial dynamics is essential for female GSC maintenance and female fertility, and that mitochondria fusion and fission events are dynamically regulated during GSC differentiation, possibly to modulate their metabolic profile.

scholarly journals Turning Cancer Stem Cells Inside Out: An Exploration of Glioma Stem Cell Signaling Pathways

2009 ◽  
Vol 284 (25) ◽  
pp. 16705-16709 ◽  
Author(s):  
Zhizhong Li ◽  
Hui Wang ◽  
Christine E. Eyler ◽  
Anita B. Hjelmeland ◽  
Jeremy N. Rich
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cancer Stem Cells ◽  
Cell Signaling ◽  
Signaling Pathways ◽  
Glioma Stem Cell ◽  
Inside Out ◽  
Cell Signaling Pathways

scholarly journals A Fast and Efficient Approach to Obtaining High-Purity Glioma Stem Cell Culture

2021 ◽  
Vol 12 ◽  
Author(s):  
Xin-Xin Han ◽  
Chunhui Cai ◽  
Li-Ming Yu ◽  
Min Wang ◽  
Dai-Yu Hu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Brain Tumor ◽  
Cancer Stem Cells ◽  
High Purity ◽  
Calcium Binding ◽  
Culture Conditions ◽  
Intermediate Filament Protein ◽  
Glioma Stem Cell ◽  
Efficient Approach

Glioma is the most common and malignant primary brain tumor. Patients with malignant glioma usually have a poor prognosis due to drug resistance and disease relapse. Cancer stem cells contribute to glioma initiation, progression, resistance, and relapse. Hence, quick identification and efficient understanding of glioma stem cells (GSCs) are of profound importance for therapeutic strategies and outcomes. Ideally, therapeutic approaches will only kill cancer stem cells without harming normal neural stem cells (NSCs) that can inhibit GSCs and are often beneficial. It is key to identify the differences between cancer stem cells and normal NSCs. However, reports detailing an efficient and uniform protocol are scarce, as are comparisons between normal neural and cancer stem cells. Here, we compared different protocols and developed a fast and efficient approach to obtaining high-purity glioma stem cell by tracking observation and optimizing culture conditions. We examined the proliferative and differentiative properties confirming the identities of the GSCs with relevant markers such as Ki67, SRY-box containing gene 2, an intermediate filament protein member nestin, glial fibrillary acidic protein, and s100 calcium-binding protein (s100-beta). Finally, we identified distinct expression differences between GSCs and normal NSCs including cyclin-dependent kinase 4 and tumor protein p53. This study comprehensively describes the features of GSCs, their properties, and regulatory genes with expression differences between them and normal stem cells. Effective approaches to quickly obtaining high-quality GSCs from patients should have the potential to not only help understand the diseases and the resistances but also enable target drug screening and personalized medicine for brain tumor treatment.

scholarly journals Stem cell-like breast cancer cells with acquired resistance to metformin are sensitive to inhibitors of NADH-dependent CtBP dimerization

2019 ◽  
Vol 40 (7) ◽  
pp. 871-882 ◽  
Author(s):  
Arindam Banerjee ◽  
Charles N Birts ◽  
Matthew Darley ◽  
Rachel Parker ◽  
Alex H Mirnezami ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Stem Cell ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Cyclic Peptide ◽  
Cell Metabolism ◽  
Acquired Resistance ◽  
Therapy Resistance ◽  
Cell Gene Expression

AbstractAltered flux through major metabolic pathways is a hallmark of cancer cells and provides opportunities for therapy. Stem cell-like cancer (SCLC) cells can cause metastasis and therapy resistance. They possess metabolic plasticity, theoretically enabling resistance to therapies targeting a specific metabolic state. The C-terminal binding protein (CtBP) transcriptional regulators are potential therapeutic targets in highly glycolytic cancer cells, as they are activated by the glycolytic coenzyme nicotinamide adenine dinucleotide (NADH). However, SCLC cells commonly exist in an oxidative state with low rates of glycolysis. Metformin inhibits complex I of the mitochondrial electron transport chain; it can kill oxidative SCLC cells and has anti-cancer activity in patients. SCLC cells can acquire resistance to metformin through increased glycolysis. Given the potential for long-term metformin therapy, we have studied acquired metformin resistance in cells from the claudin-low subtype of breast cancer. Cells cultured for 8 weeks in sub-IC50 metformin concentration proliferated comparably to untreated cells and exhibited higher rates of glucose uptake. SCLC cells were enriched in metformin-adapted cultures. These SCLC cells acquired sensitivity to multiple methods of inhibition of CtBP function, including a cyclic peptide inhibitor of NADH-induced CtBP dimerization. Single-cell mRNA sequencing identified a reprogramming of epithelial–mesenchymal and stem cell gene expression in the metformin-adapted SCLC cells. These SCLC cells demonstrated an acquired dependency on one of these genes, Tenascin C. Thus, in addition to acquisition of sensitivity to glycolysis-targeting therapeutic strategies, the reprograming of gene expression in the metformin-adapted SCLC cells renders them sensitive to potential therapeutic approaches not directly linked to cell metabolism.

Matrix Elasticity Affects Integrin Expression in Human Umbilical Cord-Derived Mesenchymal Stem Cells

2015 ◽  
Vol 815 ◽  
pp. 412-423
Author(s):  
Hong Wei Lv ◽  
Yin Zhang ◽  
Mei Yu Sun ◽  
Jia Hui Yang ◽  
Zhi Shen Chen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Umbilical Cord ◽  
Variable Stiffness ◽  
Cell Phenotype ◽  
Human Umbilical Cord ◽  
Β1 Integrin ◽  
Integrin Expression ◽  
Matrix Elasticity ◽  
Α5β1 Integrin

Mesenchymal stem cells (MSCs) are a powerful cellular alternative for regenerative medicine and tissue engineering applications due to their multipotency. It is becoming increasingly clear that elasticity of extracellular matrix (ECM) has a profound effect on cell phenotype including adhesion, proliferation and differentiation. Integrins are considered to be important mechanoreceptors in mechanotransduction. While numerous studies have focused on α2, β1 and β3 integrin involvement in substrate stiffness-driven commitment of bone marrow MSCs, comparatively little is known about the change of α5β1 integrin expression in human umbilical cord-derived mesenchymal stem cells (hUCMSCs) on substrates of variable stiffness. We plated hUCMSCs on fibronectin coated polyacrylamide hydrogels with elasticity corresponding to Young’s modulus ranging from 3 to 65 kPa. Our results showed that hUCMSCs displayed different morphologies on substrates of varying stiffness. Cells led to branched morphology similar to that of nerve cells when cultured on soft matrices, while cells became more spread and presented polygonal shapes on stiff substrates. Furthermore, hUCMSCs expressed α5 integrin both on soft substrates and stiff substrates, and the expression levels on the two substrates were similar. The total β1 integrin (including both active and inactive) was higher in hUCMSCs grown on the stiff substrate than that of grown on soft substrates, whereas the activated β1 integrin level on stiff substrates was distinctly lower than that of grown on soft substrates. In conclusion, α5β1 integrin expression in hUCMSCs is dependent on matrix elasticity. The results from this study will provide insight into the role of α5β1 integrin in matrix elasticity-regulated morphologies changes of stem cells and have implication for understanding the mechanism of physical induced lineage specification.

scholarly journals Cord blood stem cells revert glioma stem cell EMT by down regulating transcriptional activation of Sox2 and Twist1

Oncotarget ◽  
2011 ◽  
Vol 2 (12) ◽  
pp. 1028-1042 ◽  
Author(s):  
Kiran Kumar Velpula ◽  
Venkata Ramesh Dasari ◽  
Andrew J. Tsung ◽  
Dzung H. Dinh ◽  
Jasti S. Rao
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cord Blood ◽  
Transcriptional Activation ◽  
Glioma Stem Cell ◽  
Blood Stem Cells ◽  
Cord Blood Stem Cells

scholarly journals The spatial relationship between stem cells and their progeny in the basal layer of human epidermis: a new view based on whole-mount labelling and lineage analysis

Development ◽  
1999 ◽  
Vol 126 (11) ◽  
pp. 2409-2418 ◽  
Author(s):  
U.B. Jensen ◽  
S. Lowell ◽  
F.M. Watt
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
High Surface ◽  
Basal Layer ◽  
Spatial Relationship ◽  
Human Epidermis ◽  
Stem Cell Marker ◽  
Integrin Expression ◽  
Whole Mount ◽  
Beta1 Integrin

In order to examine the spatial organisation of stem cells and their progeny in human epidermis, we developed a method for whole-mount epidermal immunofluorescence labelling using high surface beta1 integrin expression as a stem cell marker. We confirmed that there are clusters of high beta1 integrin-expressing cells at the tips of the dermal papillae in epidermis from several body sites, whereas alpha6 integrin expression is more uniform. The majority of actively cycling cells detected by Ki67 or bromodeoxyuridine labelling were found in the beta1 integrin-dull, transit amplifying population and integrin-negative, keratin 10-positive cells left the basal layer exclusively from this compartment. When we examined p53-positive clones in sun-exposed epidermis, we found two types of clone that differed in size and position in a way that was consistent with the founder cell being a stem or transit amplifying cell. The patterning of the basal layer implies that transit amplifying cells migrate over the basement membrane away from the stem cell clusters. In support of this, isolated beta1 integrin-dull keratinocytes were more motile on type IV collagen than beta1 integrin-bright keratinocytes and EGFP-labelled stem cell clones in confluent cultured sheets were compact, whereas transit amplifying clones were dispersed. The combination of whole-mount labelling and lineage marking thus reveals features of epidermal organisation that were previously unrecognised.

STEM-19. NON-REDUNDANT, ISOFORM-SPECIFIC ROLES OF HDAC1 IN THE REGULATION OF THE GLIOMA STEM CELL PHENOTYPE

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi25-vi25
Author(s):  
Costanza Lo Cascio ◽  
James McNamara ◽  
Ernesto Luna Melendez ◽  
Erika Lewis ◽  
Matthew Dufault ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Histone Deacetylases ◽  
Target Genes ◽  
Tumor Grade ◽  
Cell Phenotype ◽  
Glioma Stem Cells ◽  
Normal Brain ◽  
Dependent Manner ◽  
Glioma Stem Cell

Abstract Glioblastoma (GBM) is characterized by an aberrant yet druggable epigenetic landscape. One major family of epigenetic regulators, the Histone Deacetylases (HDACs), are considered promising therapeutic targets for GBM due to their repressive influences on transcription. Although HDACs share redundant functions and common substrates, the unique isoform-specific roles of different HDACs in GBM remain unclear. There is a temporal and cell-type specific requirement of HDAC1 and 2 during normal brain development, with HDAC2 being indispensable in neural stem cells. Here, we specifically investigated the functional importance of HDAC1 in glioma stem cells, an HDAC isoform whose expression increases with brain tumor grade and is correlated with decreased survival. Using cell-based and biochemical assays, transcriptomic analyses and patient-derived xenograft models, we report that knockdown of HDAC1 alone has profound effects on the glioma stem cell (GSC) phenotype and survival in a p53-dependent manner. HDAC1 is the essential class I deacetylase in glioma stem cells, and its loss is not compensated for by its paralogue HDAC2 or other HDACs. Loss of HDAC1 expression significantly suppresses viability of GSCs harboring functional p53, and that HDAC2 expression is completely dispensable in GSCs. In addition, HDAC1 silencing but not HDAC2, stabilizes and acetylates p53 in GSCs, resulting in upregulation of key p53 target genes and induction of programmed cell death. Furthermore, ablation of HDAC1 function alone results in histone hyperacetylation and a collapse of the stemness state in GSCs. We demonstrate significant suppression in tumor growth upon targeting of HDAC1 and identify compensatory pathways that provide insights into combination therapies for GBM. Our study highlights the importance of HDAC1 in GBM and the need to develop isoform-specific HDAC inhibitor drugs.

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