Large-scale assessment of the gliomasphere model system

Laks, Dan R.; Crisman, Thomas J.; Shih, Michelle Y. S.; Mottahedeh, Jack; Gao, Fuying; Sperry, Jantzen; Garrett, Matthew C.; Yong, William H.; Cloughesy, Timothy F.; Liau, Linda M.; Lai, Albert; Coppola, Giovanni; Kornblum, Harley I.

doi:10.1093/neuonc/now045

Cited by 88 publications

(86 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…But that study has used a small sample size to assess the possible association between the neurosphere formation and clinical outcome of the tumor. A recent study on the relationship between gene expressions based on The Cancer Genome Atlas (TCGA) classification and gliomaspheres has shown that gliomasphere system retains the important expression profiles and molecular pathways, thus can be used to study the important genes associated with glioma malignancy (12). One of the aims of our study was to determine whether GSCs can be isolated and grown from both LGG and HGG, especially low grade, as there were no extensive studies that focused on such population in LGGs (18).…”

Section: Discussionmentioning

confidence: 99%

In vitro neurosphere formation correlates with poor survival in glioma

et al. 2018

View full text Add to dashboard Cite

Sphere formation is an indicator of tumor aggressiveness independent of the tumor grade; however, its relation to progression‐free survival (PFS) is less known. This study was designed to assess the neurosphere forming ability among low grade glioma (LGG) and high‐grade glioma (HGG), its stem cell marker expression, and correlation to PFS. Tumor samples of 140 patients, including (LGG; n = 67) and (HGG; n = 73) were analyzed. We used sphere forming assay, immunofluorescence, and immunohistochemistry to characterize the tumors. Our study shows that, irrespective of the pathological sub type, both LGG and HGG formed neurospheres in vitro under conventional sphere forming conditions. However, the number of neurospheres formed from tumor tissues were significantly higher in HGG compared to LGG (P < 0.0001). Different grades of glioma were further characterized for the expression of stem cell marker proteins and lineage markers. When neurospheres were analyzed, CD133 positive cells were identified in addition to CD15 and nestin positive cells in both LGG and HGG. When these neurospheres were subjected to differentiation, cells positive for GFAP and β‐tubulin III were observed. Expression of stem cell markers and β‐tubulin III were prominent in HGG compared to LGG, whereas GFAP expression was higher in LGG than in HGG. Kaplan–Meier survival analysis demonstrated that neurosphere forming ability was significantly associated with shorter PFS (P < 0.05) in both LGG and HGG. Our results supports earlier studies that neurosphere formation may serve as a definitive indicator of stem cell population within the tumor and thus a better predictor of PFS than the tumor grades alone. © 2018 IUBMB Life, 71(1):244–253, 2019

show abstract

Section: Discussionmentioning

confidence: 99%

In vitro neurosphere formation correlates with poor survival in glioma

et al. 2018

View full text Add to dashboard Cite

show abstract

“…TCGA classification, EGFR amplification, EGFR v3 status, and doubling time (proliferation rate) were determined as previously described (Laks, et al, 2016)(29). …”

Section: Methodsmentioning

confidence: 99%

Inhibition of Nucleotide Synthesis Targets Brain Tumor Stem Cells in a Subset of Glioblastoma

Laks

Crisman

et al. 2016

Molecular Cancer Therapeutics

Self Cite

View full text Add to dashboard Cite

Inhibition of both the de novo (DNP) and salvage (NSP) pathways of nucleoside synthesis has been demonstrated to impair leukemia cells. We endeavored to determine if this approach would be efficacious in glioblastoma (GBM). To diminish nucleoside biosynthesis, we utilized compound DI-39 that selectively targets NSP, in combination with thymidine (dT) that selectively targets DNP. We employed in vitro and ex vivo models to determine the effects of pre-treatment with dT +DI-39 on brain tumor stem cells (BTSC). Here, we demonstrate that this combinatorial therapy elicits a differential response across a spectrum of human patient derived GBM cultures. As determined by apoptotic markers, most cultures were relatively resistant to treatment, although a subset was highly sensitive. Sensitivity was unrelated to S-phase delay and to DNA damage induced by treatment. Bioinformatics analysis indicated that response across cultures was associated with the transcription factor PAX3 (associated with resistance) and with canonical pathways including the nucleotide excision repair pathway, PTEN (associated with resistance), PI3K/AKT (associated with sensitivity), and ErbB2-ErbB3. Our in vitro assays demonstrated that, in sensitive cultures, clonal sphere formation was reduced upon removal from pre-treatment. In contrast, in a resistant culture, clonal sphere formation was slightly increased upon removal from pre-treatment. Moreover, in an intracranial xenograft model, pre-treatment of a sensitive culture caused significantly smaller and fewer tumors. In a resistant culture, tumors were equivalent irrespective of pre-treatment. These results indicate that, in the subset of sensitive GBM, BTSC are targeted by inhibition of pyrimidine synthesis.

show abstract

“…Primary human glioma cell lines were established at UCLA as described (Hemmati et al, PNAS 2003 (7); Characteristics of specific gliomasphere lines can be found in Laks et al, Neuro-Oncology 2016 (13)). The GL261 murine glioma cell line was a kind gift of Dr. William H. McBride (Department of Radiation Oncology at UCLA).…”

Section: Cell Culturementioning

confidence: 99%

The Dopamine Receptor Antagonist TFP Prevents Phenotype Conversion and Improves Survival in Mouse Models of Glioblastoma

Bhat¹,

Saki²,

Vlashi³

et al. 2019

Preprint

Self Cite

View full text Add to dashboard Cite

Glioblastoma (GBM) is the deadliest adult brain cancer and all patients ultimately succumb to the disease. Radiation therapy (RT) provides survival benefit of 6 months over surgery alone but these results have not improved in decades. We report that radiation induces a glioma-initiating cell phenotype and we have identified trifluoperazine (TFP) as a compound that interferes with this phenotype conversion. TFP caused loss of radiation-induced Nanog mRNA expression, activation of GSK3 with consecutive post-translational reduction in p-Akt, Sox2and -catenin protein levels. TFP did not alter the intrinsic radiation sensitivity of glioma-initiating cells (GICs). Continuous treatment with TFP and a single dose of radiation reduced the number of GICs in vivo and prolonged survival in syngeneic and patient-derived orthotopic xenograft (PDOX) mouse models of GBM. Our findings suggest that combination of a dopamine receptor antagonist with radiation enhances the efficacy of RT in GBM by preventing radiationinduced phenotype conversion of radiosensitive non-GICs into treatment resistant, induced GICs. SignificanceGBM is the most common and most deadly adult brain cancer. The current standard-of-care is surgery followed by RT and temozolomide, which results in a median survival time of only 15 months. The efficacy of chemotherapies and targeted therapies in GBM is very limited because most of these drugs do not pass the blood-brain-barrier. Ultimately, all patients succumb to the disease.Our study describes radiation-induced cellular plasticity as a novel resistance mechanism in GBM. We identified a dopamine receptor antagonist as a readily available, FDA-approved drug known to penetrate the blood-brain-barrier which prevents phenotype conversion of glioma cells into glioma-initiating cells and prologs survival in mouse models of GBM, thus suggesting that it will improve the efficacy of RT without increasing toxicity.

show abstract

Large-scale assessment of the gliomasphere model system

Abstract: This comprehensive assessment reveals advantages and limitations of using gliomaspheres to model GBM biology, and provides a novel strategy for selecting genes for future study.

Cited by 88 publications

References 33 publications

In vitro neurosphere formation correlates with poor survival in glioma

In vitro neurosphere formation correlates with poor survival in glioma

Inhibition of Nucleotide Synthesis Targets Brain Tumor Stem Cells in a Subset of Glioblastoma

The Dopamine Receptor Antagonist TFP Prevents Phenotype Conversion and Improves Survival in Mouse Models of Glioblastoma

Contact Info

Product

Resources

About