scholarly journals STEM-25. HDAC1 IS ESSENTIAL FOR GLIOMA STEM CELL SURVIVAL

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi239-vi239
Author(s):  
Costanza Lo Cascio ◽  
James McNamara ◽  
Ernesto Luna Melendez ◽  
Shwetal Mehta

Abstract OLIG2 is a central nervous system-specific transcription factor that is expressed in almost all diffuse gliomas. It is also one of the key core transcription factors that can reprogram differentiated glioma cells to highly tumorigenic glioma stem-like cells (GSCs). We have previously shown that expression of OLIG2 is critical for glioma growth both in a genetically relevant mouse model as well as in patient-derived xenograft models. Our work suggests that a small molecule inhibitor of OLIG2 could serve as a highly targeted therapy for high-grade glioma; however, transcription factors are generally very difficult to target because their interactions with DNA and co-regulatory proteins involve large and complex surface area contacts. Our laboratory has shown that OLIG2 functions are regulated through interactions with distinct co-regulator proteins in normal neural stem cells. However, there are currently no reports on interactors that promote the proto-oncogenic functions of OLIG2 in malignant glioma. In this study, we employed two independent proteomics screens identify tumor-specific, druggable OLIG2 co-regulators as possible surrogate targets to suppress OLIG2 function in glioma. These screens led to the identification of a novel OLIG2 partner protein: Histone Deacetylase 1 (HDAC1). We confirmed that this interaction occurs in both murine and human glioma models. Although HDACs are ubiquitously expressed and are known to be functionally redundant, we show that ablation of HDAC1 alone significantly decreases the stemness and proliferation capacity of patient-derived GSCs in a p53-dependent manner, while having a minimal impact on normal human neural stem cells and astrocytes. Furthermore, we demonstrate that knockdown of HDAC1, in combination with ionizing radiation treatment, significantly alters the growth pattern of intracranial tumors in vivo. We demonstrate that HDAC1 function is critical for GSC growth and provide a strong rationale for targeting the OLIG2-HDAC1 interaction in malignant glioma.

2020 ◽  
Author(s):  
Bharath Sunchu ◽  
Nicole Lee ◽  
Roberto Carlos Segura ◽  
Clemens Cabernard

Metazoan cells accurately attach to, congress and segregate chromosomes during mitosis Additionally, hybrid cells derived through fertilization or somatic cell fusion also employ mechanisms to recognize and separate chromosomes of different origin. The underlying mechanisms are mostly unknown but could prevent aneuploidy and tumor formation. Here, we acutely induce fusion betweenDrosophilaneural stem cells (neuroblasts) and differentiating ganglion mother cells (GMCs)in vivoto define how epigenetically distinct chromatin is recognized and segregated. We find that Nb-GMC hybrid cells align both endogenous (neuroblast-origin) and ectopic (GMC-origin) chromosomes at the metaphase plate through centrosome derived dual spindles. Mixing of endogenous and ectopic chromatin is prevented through an asymmetric, microtubule-dependent chromatin capture mechanism during interphase and physical boundaries imposed by nuclear envelopes. Although hybrid cells fail to accurately segregate ectopic chromatin, manifested in lagging chromosomes and chromosome bridges, transplanted brain tissue containing hybrid cells neither reduce the lifespan nor form visible tumors in host flies. We conclude that fly neural stem cells utilize asymmetric centrosome activity in interphase to capture and physically separate epigenetically distinct chromatin in a microtubule-dependent manner. We propose a novel chromosome recognition and separation mechanism that could also inform biased chromatid segregation observed in flies and vertebrates.


Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1043 ◽  
Author(s):  
Phil Jun Kang ◽  
Daryeon Son ◽  
Tae Hee Ko ◽  
Wonjun Hong ◽  
Wonjin Yun ◽  
...  

Human neural stem cells (NSCs) hold enormous promise for neurological disorders, typically requiring their expandable and differentiable properties for regeneration of damaged neural tissues. Despite the therapeutic potential of induced NSCs (iNSCs), a major challenge for clinical feasibility is the presence of integrated transgenes in the host genome, contributing to the risk for undesired genotoxicity and tumorigenesis. Here, we describe the advanced transgene-free generation of iNSCs from human urine-derived cells (HUCs) by combining a cocktail of defined small molecules with self-replicable mRNA delivery. The established iNSCs were completely transgene-free in their cytosol and genome and further resembled human embryonic stem cell-derived NSCs in the morphology, biological characteristics, global gene expression, and potential to differentiate into functional neurons, astrocytes, and oligodendrocytes. Moreover, iNSC colonies were observed within eight days under optimized conditions, and no teratomas formed in vivo, implying the absence of pluripotent cells. This study proposes an approach to generate transplantable iNSCs that can be broadly applied for neurological disorders in a safe, efficient, and patient-specific manner.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Georgina Navoly ◽  
Conor J. McCann

AbstractEnteric neural stem cells (ENSC) have been identified as a possible treatment for enteric neuropathies. After in vivo transplantation, ENSC and their derivatives have been shown to engraft within colonic tissue, migrate and populate endogenous ganglia, and functionally integrate with the enteric nervous system. However, the mechanisms underlying the integration of donor ENSC, in recipient tissues, remain unclear. Therefore, we aimed to examine ENSC integration using an adapted ex vivo organotypic culture system. Donor ENSC were obtained from Wnt1cre/+;R26RYFP/YFP mice allowing specific labelling, selection and fate-mapping of cells. YFP+ neurospheres were transplanted to C57BL6/J (6–8-week-old) colonic tissue and maintained in organotypic culture for up to 21 days. We analysed and quantified donor cell integration within recipient tissues at 7, 14 and 21 days, along with assessing the structural and molecular consequences of ENSC integration. We found that organotypically cultured tissues were well preserved up to 21-days in ex vivo culture, which allowed for assessment of donor cell integration after transplantation. Donor ENSC-derived cells integrated across the colonic wall in a dynamic fashion, across a three-week period. Following transplantation, donor cells displayed two integrative patterns; longitudinal migration and medial invasion which allowed donor cells to populate colonic tissue. Moreover, significant remodelling of the intestinal ECM and musculature occurred upon transplantation, to facilitate donor cell integration within endogenous enteric ganglia. These results provide critical evidence on the timescale and mechanisms, which regulate donor ENSC integration, within recipient gut tissue, which are important considerations in the future clinical translation of stem cell therapies for enteric disease.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Manuel Pedro Jimenez-García ◽  
Antonio Lucena-Cacace ◽  
Daniel Otero-Albiol ◽  
Amancio Carnero

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.


2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Xiaoxiong Wang ◽  
Heping Wang ◽  
Jiajun Xu ◽  
Xu Hou ◽  
Haoqiang Zhan ◽  
...  

AbstractHigh-grade glioma is the most common and aggressive primary brain tumor in adults with poor therapeutic efficiency and survival prognosis. Cell division cycle associated 8 (CDCA8) has been well known as a cell cycle regulator and tumor promotor in various malignant tumors. However, its biological role in glioma still remains unclear. Our results showed that high level of CDCA8 was significantly correlated with advanced WHO grade and poor overall survival and disease-free survival prognosis. In vitro and in vivo investigations demonstrated that CDCA8 promoted the glioma malignancy by promoting cell proliferation, cell migration, and inhibiting cell apoptosis. Moreover, we found its synergetic biological protein—E2F1 by the gene microarray chip. In this study, we revealed that CDCA8 synergized with E2F1 facilitated the proliferation and migration of glioma. In conclusion, our study provides a novel promising therapeutic targets and prognostic biomarkers for malignant glioma treatment.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii88-ii88
Author(s):  
Alison Mercer-Smith ◽  
Wulin Jiang ◽  
Alain Valdivia ◽  
Juli Bago ◽  
Scott Floyd ◽  
...  

Abstract INTRODUCTION Non-small cell lung cancer (NSCLC) is the most common cancer to form brain metastases. Radiation treatment is standard-of-care, but recurrence is still observed in 40% of patients. An adjuvant treatment is desperately needed to track down and kill tumor remnants after radiation. Tumoritropic neural stem cells (NSCs) that can home to and deliver a cytotoxic payload offer potential as such an adjuvant treatment. Here we show the transdifferentiation of human fibroblasts into tumor-homing induced neural stem cells (hiNSCs) that secrete the cytotoxic protein TRAIL (hiNSC-TRAIL) and explore the use of hiNSC-TRAIL to treat NSCLC brain metastases. METHODS To determine the migratory capacity of hiNSCs, hiNSCs were infused intracerebroventricularly (ICV) into mice bearing established bilateral NSCLC H460 brain tumors. hiNSC accumulation at tumor foci was monitored using bioluminescent imaging and post-mortem fluorescent analysis. To determine synergistic effects of radiation with TRAIL on NSCLC, we performed in vitro co-culture assays and isobologram analysis. In vivo, efficacy was determined by tracking the progression and survival of mice bearing intracranial H460 treated with hiNSC-TRAIL alone or in combination with 2 Gy radiation. RESULTS/CONCLUSION Following ICV infusion, hiNSCs persisted in the brain for > 1 week and migrated from the ventricles to colocalize with bilateral tumor foci. In vitro, viability assays and isobologram analysis revealed the combination treatment of hiNSC-TRAIL and 2 Gy radiation induced synergistic killing (combination index=0.64). In vivo, hiNSC-TRAIL/radiation combination therapy reduced tumor volumes > 90% compared to control-treated animals while radiation-only and hiNSC-TRAIL-only treated mice showed 21% and 52% reduced volumes, respectively. Dual-treatment extended survival 40%, increasing survival from a median of 20 days in controls to 28 days in the treatment group. These results suggest hiNSC-TRAIL can improve radiation therapy for NSCLC brain metastases and could potentially improve outcomes for patients suffering from this aggressive form of cancer.


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