CSIG-30. miR-146a INHIBITS TUMORIGENESIS AND INDUCES TEMOZOLOMIDE SENSITIVITY VIA AFFECTING CANCER STEM CELL PROPERTIES IN GBM

Abstract BACKGROUND Glioblastomas (GBMs) are the most aggressive primary brain tumors, with an average survival time of less than 15 months. miRNAs are emerging as promising and novel biomarkers in GBM. The aims of this study are: 1) to investigate novel miRNAs biomarkers that affect tumorigenesis and therapeutic sensitivity, and 2) to study the underlying molecular mechanisms in GBM. METHODS Nanostring v3 was performed followed by univariable (UVA) and multivariable (MVA) analyses. Functional studies were conducted to define the role of miR-146a in GBM tumorigenesis and therapeutic response and the molecular mechanisms were investigated. RESULTS UVA analyses demonstrated that miR-146a is one of the top miRNAs that correlated with better prognosis in GBM patients (p=9.21E-05), which was independent of MGMT promoter methylation by MVA analyses (p< 0.001). miR-146a expression was significantly downregulated in recurrent GBM tumors compared with the paired primary GBM tumors (p=0.003). Overexpression of miR-146a significantly inhibited tumor cell growth and sensitized patient-derived primary GBM cells to temozolomide (TMZ) treatment in vitro, and showed statistically significant smaller tumor size (p< 0.01) and prolonged survival (p=0.001) in vivo. In addition, miR-146a is downregulated in glioma cancer stem cells, and overexpression of miR-146a significantly affected glioma cancer stem cell self-renewal. We also found that overexpression of miR-146a significantly inhibited the NF-κB, AKT, and ERK pathways. CONCLUSION Our data suggest, for the first time, that miR-146a predicts favorable prognosis for GBM patients and sensitizes primary GBM cells to TMZ treatment in vitro and in vivo through regulating glioma stem cells. Importantly, miR-146a may prove to be a master switch shutting off AKT, NF-κB, as well as other pathways and may overcome redundancies among these pathways leading to resistance. FUNDING: Bohnenn Fund (to PR), R01CA108633, R01CA169368, U10CA180850-01(NCI), Brain Tumor Funders Collaborative Grant, and The Ohio State University CCC (all to AC).

Download Full-text

Extracellular vesicles from human liver stem cells inhibit renal cancer stem cell‐derived tumor growth in vitro and in vivo

International Journal of Cancer ◽

10.1002/ijc.32925 ◽

2020 ◽

Vol 147 (6) ◽

pp. 1694-1706 ◽

Cited By ~ 4

Author(s):

Alessia Brossa ◽

Valentina Fonsato ◽

Cristina Grange ◽

Stefania Tritta ◽

Marta Tapparo ◽

...

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Cancer Stem Cell ◽

Tumor Growth ◽

Extracellular Vesicles ◽

Renal Cancer ◽

Human Liver ◽

Liver Stem Cells

Download Full-text

Pituitary Remodeling Throughout Life: Are Resident Stem Cells Involved?

Frontiers in Endocrinology ◽

10.3389/fendo.2020.604519 ◽

2021 ◽

Vol 11 ◽

Author(s):

Emma Laporte ◽

Annelies Vennekens ◽

Hugo Vankelecom

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Pituitary Gland ◽

Molecular Mechanisms ◽

Pituitary Function ◽

Cell Phenotype ◽

Cell Populations ◽

Cell Remodeling

The pituitary gland has the primordial ability to dynamically adapt its cell composition to changing hormonal needs of the organism throughout life. During the first weeks after birth, an impressive growth and maturation phase is occurring in the gland during which the distinct hormonal cell populations expand. During pubertal growth and development, growth hormone (GH) levels need to peak which requires an adaptive enterprise in the GH-producing somatotrope population. At aging, pituitary function wanes which is associated with organismal decay including the somatopause in which GH levels drop. In addition to these key time points of life, the pituitary’s endocrine cell landscape plastically adapts during specific (patho-)physiological conditions such as lactation (need for PRL) and stress (engagement of ACTH). Particular resilience is witnessed after physical injury in the (murine) gland, culminating in regeneration of destroyed cell populations. In many other tissues, adaptive and regenerative processes involve the local stem cells. Over the last 15 years, evidence has accumulated that the pituitary gland houses a resident stem cell compartment. Recent studies propose their involvement in at least some of the cell remodeling processes that occur in the postnatal pituitary but support is still fragmentary and not unequivocal. Many questions remain unsolved such as whether the stem cells are key players in the vivid neonatal growth phase and whether the decline in pituitary function at old age is associated with decreased stem cell fitness. Furthermore, the underlying molecular mechanisms of pituitary plasticity, in particular the stem cell-linked ones, are still largely unknown. Pituitary research heavily relies on transgenic in vivo mouse models. While having proven their value, answers to pituitary stem cell-focused questions may more diligently come from a novel powerful in vitro research model, termed organoids, which grow from pituitary stem cells and recapitulate stem cell phenotype and activation status. In this review, we describe pituitary plasticity conditions and summarize what is known on the involvement and phenotype of pituitary stem cells during these pituitary remodeling events.

Download Full-text

Epigenetic Mechanisms of Stem Cell Aging and Rejuvenation

Blood ◽

10.1182/blood.v124.21.sci-44.sci-44 ◽

2014 ◽

Vol 124 (21) ◽

pp. SCI-44-SCI-44

Author(s):

Thomas A. Rando

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Molecular Mechanisms ◽

Conflicts Of Interest ◽

Cell Aging ◽

Molecular Characteristics ◽

Molecular Features ◽

Functional Features

Abstract For most tissues, stem cell numbers decline negligibly with age; nevertheless, there is an age-dependent decline in stem cell functionality. Many molecular, biochemical, and functional features of stem cells have been characterized across a broad range of tissues, and these changes have been assumed to be largely irreversible and inevitable accompaniments of aging. However, in studies both in vivo and in vitro we have demonstrated a reversibility of the functional and, in some cases, molecular characteristics of aged stem cells. Supported by compelling data from studies of heterochronic parabiotic pairings of mice, it is clear that the aged phenotype can be modified when aged cells are exposed to a youthful systemic milieu. These findings challenge the fundamental tenet of aging as an irreversible process and raises the question of whether, or to what extent, the aged phenotype is epigenetically determined. We have begun to examine the epigenetic profiles of young, old, and “rejuvenated” old stem cells to attempt to define youthfulness and aging in epigenetic terms. To the extent that aging can be “reprogrammed” back to youthfulness in somatic tissues, it has parallels to the resetting of the aging clock that occurs with somatic cell nuclear transfer. Elucidating the underlying molecular features, both genetic and epigenetic, of aged stem cells will provide a framework for understanding the fundamental molecular mechanisms of aging and the mechanisms by which environmental influences, such as those that occur in the setting of heterochronic parabiosis, can reverse the mechanisms of aging. Disclosures No relevant conflicts of interest to declare.

Download Full-text

Regulation of sarcomagenesis by the empty spiracles homeobox genes EMX1 and EMX2

Cell Death and Disease ◽

10.1038/s41419-021-03801-w ◽

2021 ◽

Vol 12 (6) ◽

Author(s):

Manuel Pedro Jimenez-García ◽

Antonio Lucena-Cacace ◽

Daniel Otero-Albiol ◽

Amancio Carnero

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Transcription Factors ◽

Neural Crest ◽

Tumor Suppressors ◽

Homeobox Genes ◽

Neuronal Cell ◽

Cell Gene Expression

AbstractThe EMX (Empty Spiracles Homeobox) genes EMX1 and EMX2 are two homeodomain gene members of the EMX family of transcription factors involved in the regulation of various biological processes, such as cell proliferation, migration, and differentiation, during brain development and neural crest migration. They play a role in the specification of positional identity, the proliferation of neural stem cells, and the differentiation of certain neuronal cell phenotypes. In general, they act as transcription factors in early embryogenesis and neuroembryogenesis from metazoans to higher vertebrates. The EMX1 and EMX2’s potential as tumor suppressor genes has been suggested in some cancers. Our work showed that EMX1/EMX2 act as tumor suppressors in sarcomas by repressing the activity of stem cell regulatory genes (OCT4, SOX2, KLF4, MYC, NANOG, NES, and PROM1). EMX protein downregulation, therefore, induced the malignance and stemness of cells both in vitro and in vivo. In murine knockout (KO) models lacking Emx genes, 3MC-induced sarcomas were more aggressive and infiltrative, had a greater capacity for tumor self-renewal, and had higher stem cell gene expression and nestin expression than those in wild-type models. These results showing that EMX genes acted as stemness regulators were reproduced in different subtypes of sarcoma. Therefore, it is possible that the EMX genes could have a generalized behavior regulating proliferation of neural crest-derived progenitors. Together, these results indicate that the EMX1 and EMX2 genes negatively regulate these tumor-altering populations or cancer stem cells, acting as tumor suppressors in sarcoma.

Download Full-text

Expression Profile of New Marker Genes Involved in Differentiation of Canine Adipose-Derived Stem Cells into Osteoblasts

International Journal of Molecular Sciences ◽

10.3390/ijms22136663 ◽

2021 ◽

Vol 22 (13) ◽

pp. 6663

Author(s):

Maurycy Jankowski ◽

Mariusz Kaczmarek ◽

Grzegorz Wąsiatycz ◽

Claudia Dompe ◽

Paul Mozdziak ◽

...

Keyword(s):

Stem Cells ◽

In Vitro Culture ◽

Osteogenic Differentiation ◽

Molecular Mechanisms ◽

Marker Genes ◽

P Value ◽

Illumina Platform

Next-generation sequencing (RNAseq) analysis of gene expression changes during the long-term in vitro culture and osteogenic differentiation of ASCs remains to be important, as the analysis provides important clues toward employing stem cells as a therapeutic intervention. In this study, the cells were isolated from adipose tissue obtained during routine surgical procedures and subjected to 14-day in vitro culture and differentiation. The mRNA transcript levels were evaluated using the Illumina platform, resulting in the detection of 19,856 gene transcripts. The most differentially expressed genes (fold change >|2|, adjusted p value < 0.05), between day 1, day 14 and differentiated cell cultures were extracted and subjected to bioinformatical analysis based on the R programming language. The results of this study provide molecular insight into the processes that occur during long-term in vitro culture and osteogenic differentiation of ASCs, allowing the re-evaluation of the roles of some genes in MSC progression towards a range of lineages. The results improve the knowledge of the molecular mechanisms associated with long-term in vitro culture and differentiation of ASCs, as well as providing a point of reference for potential in vivo and clinical studies regarding these cells’ application in regenerative medicine.

Download Full-text

“Empowering” Cardiac Cells via Stem Cell Derived Mitochondrial Transplantation- Does Age Matter?

International Journal of Molecular Sciences ◽

10.3390/ijms22041824 ◽

2021 ◽

Vol 22 (4) ◽

pp. 1824

Author(s):

Matthias Mietsch ◽

Rabea Hinkel

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Treatment Strategies ◽

Cardiac Cells ◽

Aging Effects ◽

Beneficial Effects ◽

Micro Rnas ◽

New Treatment

With cardiovascular diseases affecting millions of patients, new treatment strategies are urgently needed. The use of stem cell based approaches has been investigated during the last decades and promising effects have been achieved. However, the beneficial effect of stem cells has been found to being partly due to paracrine functions by alterations of their microenvironment and so an interesting field of research, the “stem- less” approaches has emerged over the last years using or altering the microenvironment, for example, via deletion of senescent cells, application of micro RNAs or by modifying the cellular energy metabolism via targeting mitochondria. Using autologous muscle-derived mitochondria for transplantations into the affected tissues has resulted in promising reports of improvements of cardiac functions in vitro and in vivo. However, since the targeted treatment group represents mainly elderly or otherwise sick patients, it is unclear whether and to what extent autologous mitochondria would exert their beneficial effects in these cases. Stem cells might represent better sources for mitochondria and could enhance the effect of mitochondrial transplantations. Therefore in this review we aim to provide an overview on aging effects of stem cells and mitochondria which might be important for mitochondrial transplantation and to give an overview on the current state in this field together with considerations worthwhile for further investigations.

Download Full-text

Xenogenic Implantation of Equine Synovial Fluid-Derived Mesenchymal Stem Cells Leads to Articular Cartilage Regeneration

Stem Cells International ◽

10.1155/2018/1073705 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 10

Author(s):

Mohammed Zayed ◽

Steven Newby ◽

Nabil Misk ◽

Robert Donnell ◽

Madhu Dhar

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Stem Cell ◽

Articular Cartilage ◽

Synovial Fluid ◽

Cartilage Repair ◽

Cartilage Regeneration ◽

Large Animal

Horses are widely used as large animal preclinical models for cartilage repair studies, and hence, there is an interest in using equine synovial fluid-derived mesenchymal stem cells (SFMSCs) in research and clinical applications. Since, we have previously reported that similar to bone marrow-derived MSCs (BMMSCs), SFMSCs may also exhibit donor-to-donor variations in their stem cell properties; the current study was carried out as a proof-of-concept study, to compare the in vivo potential of equine BMMSCs and SFMSCs in articular cartilage repair. MSCs from these two sources were isolated from the same equine donor. In vitro analyses confirmed a significant increase in COMP expression in SFMSCs at day 14. The cells were then encapsulated in neutral agarose scaffold constructs and were implanted into two mm diameter full-thickness articular cartilage defect in trochlear grooves of the rat femur. MSCs were fluorescently labeled, and one week after treatment, the knee joints were evaluated for the presence of MSCs to the injured site and at 12 weeks were evaluated macroscopically, histologically, and then by immunofluorescence for healing of the defect. The macroscopic and histological evaluations showed better healing of the articular cartilage in the MSCs’ treated knee than in the control. Interestingly, SFMSC-treated knees showed a significantly higher Col II expression, suggesting the presence of hyaline cartilage in the healed defect. Data suggests that equine SFMSCs may be a viable option for treating osteochondral defects; however, their stem cell properties require prior testing before application.

Download Full-text

The Role of the Renin–Angiotensin System in the Cancer Stem Cell Niche

Journal of Histochemistry & Cytochemistry ◽

10.1369/00221554211026295 ◽

2021 ◽

pp. 002215542110262

Author(s):

Ethan J. Kilmister ◽

Swee T. Tan

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Signaling Pathways ◽

Renin Angiotensin System ◽

Epidemiological Data ◽

Malignant Cells ◽

Angiotensin System ◽

Renin Angiotensin

Cancer stem cells (CSCs) drive metastasis, treatment resistance, and tumor recurrence. CSCs reside within a niche, an anatomically distinct site within the tumor microenvironment (TME) that consists of malignant and non-malignant cells, including immune cells. The renin–angiotensin system (RAS), a critical regulator of stem cells and key developmental processes, plays a vital role in the TME. Non-malignant cells within the CSC niche and stem cell signaling pathways such as the Wnt, Hedgehog, and Notch pathways influence CSCs. Components of the RAS and cathepsins B and D that constitute bypass loops of the RAS are expressed on CSCs in many cancer types. There is extensive in vitro and in vivo evidence showing that RAS inhibition reduces tumor growth, cell proliferation, invasion, and metastasis. However, there is inconsistent epidemiological data on the effect of RAS inhibitors on cancer incidence and survival outcomes, attributed to different patient characteristics and methodologies used between studies. Further mechanistic studies are warranted to investigate the precise effects of the RAS on CSCs directly and/or the CSC niche. Targeting the RAS, its bypass loops, and convergent signaling pathways participating in the TME and other key stem cell pathways that regulate CSCs may be a novel approach to cancer treatment:

Download Full-text

Melatonin Reverses the Loss of Stemness Induced by TNF-α in Human Bone Marrow Mesenchymal Stem Cells through Upregulation of YAP Expression

Stem Cells International ◽

10.1155/2019/6568394 ◽

2019 ◽

Vol 2019 ◽

pp. 1-16 ◽

Cited By ~ 4

Author(s):

Xudong Wang ◽

Tongzhou Liang ◽

Jincheng Qiu ◽

Xianjian Qiu ◽

Bo Gao ◽

...

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Mesenchymal Stem Cells ◽

Stem Cell ◽

Molecular Mechanisms ◽

Inflammatory Factor ◽

Cell Transplant ◽

Alizarin Red ◽

Marrow Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are promising candidates for tissue regeneration and disease treatment. However, long-term in vitro culture results in loss of MSC stemness. The inflammation that occurs at stem cell transplant sites (such as that resulting from TNF-α) is a contributing factor for stem cell treatment failure. Currently, there is little evidence regarding the protective role of melatonin with regard to the negative effects of TNF-α on the stemness of MSCs. In this study, we report a melatonin-based method to reduce the inflammatory effects on the stemness of bone marrow mesenchymal stem cells (BMMSCs). The results of colony formation assays, Alizarin red staining, western blotting, and reverse transcription-polymerase chain reactions suggest that melatonin can reverse the inflammatory damage caused by TNF-α treatment in the third, seventh, and tenth generations of primary BMMSCs (vs. control and the TNF-α-treated group). Meanwhile, a detailed analysis of the molecular mechanisms showed that the melatonin receptor and YAP signaling pathway are closely related to the role that melatonin plays in negative inflammatory effects against BMMSCs. In addition, in vivo experiments showed that melatonin could reverse the damage caused by TNF-α on bone regeneration by BMMSCs in nude mice. Overall, our results suggest that melatonin can reverse the loss of stemness caused by inflammatory factor TNF-α in BMMSCs. Our results also provide a practical strategy for the application of BMMSCs in tissue engineering and cell therapy.

Download Full-text

Accept or Reject: The Role of Immune Tolerance in the Development of Stem Cell Therapies and Possible Future Approaches

Toxicologic Pathology ◽

10.1177/0192623320918241 ◽

2020 ◽

pp. 019262332091824

Author(s):

Richard Haworth ◽

Michaela Sharpe

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Embryonic Stem ◽

Immune Recognition ◽

Cell Of Origin ◽

In Vivo Models ◽

Cell Product ◽

A Cell

In 2011, Goldring and colleagues published a review article describing the potential safety issues of novel stem cell-derived treatments. Immunogenicity and immunotoxicity of the administered cell product were considered risks in the light of clinical experience of transplantation. The relative immunogenicity of mesenchymal stem cells, embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs) was being addressed through in vitro and in vivo models. But the question arose as to whether the implanted cells needed to be identical to the recipient in every respect, including epigenetically, to evade immune recognition? If so, this set a high bar which may preclude use of many cells derived from iPSCs which have vestiges of a fetal phenotype and epigenetic memory of their cell of origin. However, for autologous iPSCs, the immunogenicity reduces once the surface antigen expression profile becomes close to that of the parent somatic cells. Therefore, a cell product containing incompletely differentiated cells could be more immunogenic. The properties of the administered cells, the immune privilege of the administration site, and the host immune status influence graft success or failure. In addition, the various approaches available to characterize potential immunogenicity of a cell therapy will be discussed.

Download Full-text