| 1. |
- Huang, Miller, et al.
(författare)
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Engineering Genetic Predisposition in Human Neuroepithelial Stem Cells Recapitulates Medulloblastoma Tumorigenesis
- 2019
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Ingår i: Cell Stem Cell. - : CELL PRESS. - 1934-5909 .- 1875-9777. ; 25:3, s. 433-
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Tidskriftsartikel (refereegranskat)abstract
- Human neural stem cell cultures provide progenitor cells that are potential cells of origin for brain cancers. However, the extent to which genetic predisposition to tumor formation can be faithfully captured in stem cell lines is uncertain. Here, we evaluated neuroepithelial stem (NES) cells, representative of cerebellar progenitors. We transduced NES cells with MYCN, observing medulloblastoma upon orthotopic implantation in mice. Significantly, transcriptomes and patterns of DNA methylation from xenograft tumors were globally more representative of human medulloblastoma compared to a MYCN-driven genetically engineered mouse model. Orthotopic transplantation of NES cells generated from Gorlin syndrome patients, who are predis- posed to medulloblastoma due to germline-mutated PTCH1, also generated medulloblastoma. We engineered candidate cooperating mutations in Gorlin NES cells, with mutation of DDX3X or loss of GSE1 both accelerating tumorigenesis. These findings demonstrate that human NES cells provide a potent experimental resource for dissecting genetic causation in medulloblastoma.
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| 2. |
- Ilkhanizadeh, Shirin, et al.
(författare)
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Live Detection of Neural Progenitors and Glioblastoma Cells by an Oligothiophene Derivative
- 2023
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Ingår i: ACS Applied Bio Materials. - : American Chemical Society (ACS). - 2576-6422. ; 6:9, s. 3790-3797
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Tidskriftsartikel (refereegranskat)abstract
- There is an urgent need for simple and non-invasive identification of live neural stem/progenitor cells (NSPCs) in the developing and adult brain as well as in disease, such as in brain tumors, due to the potential clinical importance in prognosis, diagnosis, and treatment of diseases of the nervous system. Here, we report a luminescent conjugated oligothiophene (LCO), named p-HTMI, for non-invasive and non-amplified real-time detection of live human patient-derived glioblastoma (GBM) stem cell-like cells and NSPCs. While p-HTMI stained only a small fraction of other cell types investigated, the mere addition of p-HTMI to the cell culture resulted in efficient detection of NSPCs or GBM cells from rodents and humans within minutes. p-HTMI is functionalized with a methylated imidazole moiety resembling the side chain of histidine/histamine, and non-methylated analogues were not functional. Cell sorting experiments of human GBM cells demonstrated that p-HTMI labeled the same cell population as CD271, a proposed marker for stem cell-like cells and rapidly migrating cells in glioblastoma. Our results suggest that the LCO p-HTMI is a versatile tool for immediate and selective detection of neural and glioma stem and progenitor cells.
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| 3. |
- Ilkhanizadeh, Shirin
(författare)
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Microenvironmental control and molecular detection of neural stem cell state and fate
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Neural stem cell growth and specialization is dependent on microenvironmental cues, such as growth factors, oxygen levels and substrate stiffness. Together these cues define the genetic and epigenetic program of neural stem cells. In our studies we have manipulated these cues in order to achieve better control of neural stem cell state and fate. In addition, we introduce a novel way of detecting neural stem cells and cancer stem cells in culture. Luminescent conjugated oligothiophenes (LCO) are short polymers, which cross the cell membrane and generate luminescence in the range of wavelengths of ordinary fluorescent probes. In paper I we present a novel LCO, p- HTMI, for detection of live neural stem cells but not differentiated cells. p-HTMI represents a new generation of molecular probes for immediate and non-invasive live detection of specific cell types. In paper II we show that the NADH-sensitive transcriptional co-repressor, CtBP, controls a switch between neuronal and nonneuronal cell fates in oxygen and BMP rich environments. CtBP molecularly integrates microenvironmental levels of BMP and oxygen through Notch mediated regulation of anti- and pro-neural genes. Furthermore, we manipulated growth factor presentation in the stem cell microenvironment through inkjet printing technology. In paper III, we show that inkjet printed macromolecules remained biologically active when printed on hydrogels and control the differentiation of neural stem cells. Finally, in paper IV we demonstrate that soft substrates with brain-like stiffness promote the maturation of neurons. This defines substrate stiffness as a crucial parameter in neuronal differentiation of neural stem cells.
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| 4. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 5. |
- Sabelström, H., et al.
(författare)
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Driving Neuronal Differentiation through Reversal of an ERK1/2-miR-124-SOX9 Axis Abrogates Glioblastoma Aggressiveness
- 2019
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Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 28:8, s. 11-2079
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Tidskriftsartikel (refereegranskat)abstract
- Identifying cellular programs that drive cancers to be stem-like and treatment resistant is critical to improving outcomes in patients. Here, we demonstrate that constitutive extracellular signal-regulated kinase 1/2 (ERK1/2) activation sustains a stem-like state in glioblastoma (GBM), the most common primary malignant brain tumor. Pharmacological inhibition of ERK1/2 activation restores neurogenesis during murine astrocytoma formation, inducing neuronal differentiation in tumorspheres. Constitutive ERK1/2 activation globally regulates miRNA expression in murine and human GBMs, while neuronal differentiation of GBM tumorspheres following the inhibition of ERK1/2 activation requires the functional expression of miR-124 and the depletion of its target gene SOX9. Overexpression of miR124 depletes SOX9 in vivo and promotes a stem-like-to-neuronal transition, with reduced tumorigenicity and increased radiation sensitivity. Providing a rationale for reports demonstrating miR-124-induced abrogation of GBM aggressiveness, we conclude that reversal of an ERK1/2-miR-124-SOX9 axis induces a neuronal phenotype and that enforcing neuronal differentiation represents a therapeutic strategy to improve outcomes in GBM. Sabelström et al. show that the loss of neurogenesis is reversible during neural stem cell-derived glioma formation. Pharmacological inhibition of ERK1/2 globally regulates miRNAs and induces neuronal differentiation, a process that is dependent on the modulation of an miR-124-SOX9 axis in glioblastoma (GBM) cells. The overexpression of miR-124 induces neuronal differentiation that abrogates GBM aggressiveness.
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