Effects of primary microglia and astrocytes on neural stem cells in in vitro and in vivo models of ischemic stroke

Abstract Glioblastoma (GBM) is a malignant brain tumor with nearly universal recurrence. GBM cancer stem cells (CSCs), a subpopulation of radio- and chemo-resistant cancer cells capable of self-renewal, contribute to the high rate of recurrence. The anti-cancer agent, CBL0137, inhibits the FACT (facilitates chromatin transcription) complex leading to cancer cell specific cytotoxicity. Here, we show that CBL0137 sensitized GBM CSCs to radiotherapy using both in vitro and in vivo models. Treatment of CBL0137 combined with radiotherapy led to increased DNA damage in GBM patient specimens and failure to resolve the damage led to decreased cell viability. Using clonogenic assays, we confirmed that CBL0137 radiosensitized the CSCs. To validate that combination therapy impacted CSCs, we used an in vivo subcutaneous model and showed a decrease in the frequency of cancer stem cells present in tumors as well as decreased tumor volume. Using an orthotopic model of GBM, we confirmed that treatment with CBL0137 followed by radiotherapy led to significantly increased survival compared to either treatment alone. Radiotherapy remains a critical component of patient care for GBM, even though there exists a resistant subpopulation. Radio-sensitizing agents, including CBL0137, pose an exciting treatment paradigm to increase the efficacy of irradiation, especially by inclusively targeting CSCs.

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EXTH-07. TUMOR-HOMING INDUCED NEURAL STEM CELLS SECRETING A CYTOTOXIC PAYLOAD AS AN ADJUVANT TREATMENT FOR NON-SMALL CELL LUNG CANCER BRAIN METASTASES

Neuro-Oncology ◽

10.1093/neuonc/noaa215.361 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii88-ii88

Author(s):

Alison Mercer-Smith ◽

Wulin Jiang ◽

Alain Valdivia ◽

Juli Bago ◽

Scott Floyd ◽

...

Keyword(s):

Stem Cells ◽

Brain Metastases ◽

Neural Stem Cells ◽

Adjuvant Treatment ◽

Small Cell ◽

Small Cell Lung ◽

Tumor Homing ◽

Induced Neural Stem Cells

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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P-EP013. Superior migration propensity of dental pulp stem cells in in vitro and in vivo models of excitotoxic neurodegeneration

Clinical Neurophysiology ◽

10.1016/j.clinph.2021.02.176 ◽

2021 ◽

Vol 132 (8) ◽

pp. e82-e83

Author(s):

Sivapriya Senthilkumar ◽

Chaitra Venugopal ◽

K. Shobha ◽

Bindu M. Kutty ◽

Anandh Dhanushkodi

Keyword(s):

Stem Cells ◽

Dental Pulp ◽

Dental Pulp Stem Cells ◽

In Vivo Models ◽

Migration Propensity

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Immunosuppressants Affect Human Neural Stem Cells In Vitro but Not in an In Vivo Model of Spinal Cord Injury

Stem Cells Translational Medicine ◽

10.5966/sctm.2012-0175 ◽

2013 ◽

Vol 2 (10) ◽

pp. 731-744 ◽

Cited By ~ 21

Author(s):

Christopher J. Sontag ◽

Hal X. Nguyen ◽

Noriko Kamei ◽

Nobuko Uchida ◽

Aileen J. Anderson ◽

...

Keyword(s):

Spinal Cord ◽

Stem Cells ◽

Spinal Cord Injury ◽

Neural Stem Cells ◽

In Vivo Model ◽

Human Neural Stem Cells ◽

Cord Injury

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CBIO-13. THOC1 DRIVES GBM AGGRESSION THROUGH MODULATION OF R-LOOPS AND GENOMIC STABILITY

Neuro-Oncology ◽

10.1093/neuonc/noab196.113 ◽

2021 ◽

Vol 23 (Supplement_6) ◽

pp. vi29-vi30

Author(s):

Shreya Budhiraja ◽

Shivani Baisiwala ◽

Khizar Nandoliya ◽

Li Chen ◽

Crismita Dmello ◽

...

Keyword(s):

Stem Cells ◽

Dna Damage ◽

Neural Stem Cells ◽

Histone Deacetylase ◽

Genomic Stability ◽

Loop Formation ◽

Driver Genes ◽

A Genome

Abstract Glioblastoma (GBM) is the most aggressive and common type of adult malignant brain tumor, with a median survival of only 21 months. To identify which genes drive its highly aggressive phenotype, we performed a genome-wide CRISPR-Cas9 knockout screen. Results showed substantial enrichment of ~160 novel essential oncogenic driver genes and pathways, including a previously unstudied gene THOC1—involved in RNA processing—that showed significant elevations in expression at RNA and protein levels (p< 0.05) in GBM, as well as a significant survival benefit in patient datasets when downregulated (p< 0.05). Knocking out THOC1 resulted in cell death in multiple GBM patient-derived xenograft (PDX) lines and extended survival compared to the controls (p< 0.01) in vivo. Overexpression of THOC1 in neural stem cells resulted in transformation to a cancerous phenotype, as evidenced by sphere formation in a soft agar assay (p< 0.01) and in vivo tumor engraftment assays. Further investigation of THOC1 through immunoprecipitation in neural stem cells and multiple GBM lines showed significant interaction in GBM with histone deacetylase complex SIN3A, involved in recruiting major histone deacetylases in order to close the DNA and prevent the accumulation of R-loops, RNA:DNA hybrids that pose a threat to genomic stability. Additional investigation revealed that THOC1-knockdowns in vitro induced R-loop formation and DNA damage, while THOC1-overexpression in vitro resulted in an untenable decrease in R-loops and DNA damage, suggesting that the THOC1-SIN3A axis is elevated in GBM in order to prevent the accumulation of genotoxic R-loops. Additionally, histone deacetylase activity was shown to be elevated in THOC1-overexpression conditions and reduced in THOC1-knockdown conditions, confirming that the THOC1-SIN3A axis functions to prevent R-loop accumulation through the epigenetic regulation. In summary, our whole-genome CRISPR-Cas9 knockout screen has identified a promising therapeutic target for GBM—a disease desperately in need of therapeutic innovations.

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In Vivo Properties of In Vitro-Propagated Neural Stem Cells After Transplantation to the Neonatal and Adult Rat Brain

Stem Cells in the Nervous System: Functional and Clinical Implications - Research and Perspectives in Neurosciences ◽

10.1007/978-3-642-18883-1_9 ◽

2004 ◽

pp. 117-138

Author(s):

Ulrica Englund ◽

Anders Bjöklund

Keyword(s):

Stem Cells ◽

Neural Stem Cells ◽

Rat Brain ◽

Adult Rat ◽

Adult Rat Brain

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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.

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