Comparative analysis of the effects of a sphingosine kinase inhibitor to temozolomide and radiation treatment on glioblastoma cell lines

Abstract BACKGROUND Glioblastoma is the most aggressive brain tumor with poor prognosis despite the best available treatment. MicroRNAs (miRNAs) are emerging as promising, novel prognostic biomarkers and therapeutic targets in glioblastoma. In a previous study, we demonstrated that miR-4516 predicts poor prognosis and functions as an oncogene in glioblastoma. Aim of the current study is to examine the role miR-4516 in radiation resistance and identify downstream targets contributing to this phenotype METHODS Radiosensitization was evaluated by cell viability and clonogenic assays. Cell apoptosis was evaluated using flow cytometry and immunoblotting. Potential targets of miR-4516 were identified using bioinformatic analysis (Targetscan and miRDB) and confirmed by luciferase reporter assays. Results were validated using immunoblotting. miR-4516 expression in glioblastoma cell lines after radiation treatment was quantified by qRT-PCR. RESULTS Expression of miR-4516 was increased up to 15 fold following radiation treatment, peaking at around 15min-60 min in primary and established glioblastoma cell lines including GBM 08-387, GBM 30 and U87-MG. Furthermore, inhibition of miR-4516 sensitized GBM 08-387, GBM30 and U87-MG cells to radiation in comparison to control groups as determined by cell viability and clonogenic assays. Further, miR-4516 inhibition induced apoptosis in these cell lines following radiation treatment. While conducting mechanistic studies, we found that the tumor-promoting function of miR-4516 was, in part, mediated by inhibition of p21 and PTPN14, two direct targets of miR-4516 CONCLUSION Our data suggest that radiation induces the expression of miR-4516 in glioblastoma cell lines. This miRNA plays a critical role in radio-resistance and promotes aggressive phenotypes in glioblastoma and therefore, functional analyses of its target pathways may uncover novel therapeutically vulnerable target(s) in glioblastoma. FUNDING: R01CA108633, R01CA169368, RC2CA148190, U10CA180850-01(NCI), Brain Tumor Funders Collaborative Grant, and OSU-CCC (all to AC). The Ton and Patricia Bohnenn Fund for Neuro_Oncology Research (to PR).

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A sphingosine kinase inhibitor combined with temozolomide induces glioblastoma cell death through accumulation of dihydrosphingosine and dihydroceramide, endoplasmic reticulum stress and autophagy

Cell Death and Disease ◽

10.1038/cddis.2014.384 ◽

2014 ◽

Vol 5 (9) ◽

pp. e1425-e1425 ◽

Cited By ~ 41

Author(s):

J Noack ◽

J Choi ◽

K Richter ◽

A Kopp-Schneider ◽

A Régnier-Vigouroux

Keyword(s):

Endoplasmic Reticulum ◽

Cell Death ◽

Endoplasmic Reticulum Stress ◽

Kinase Inhibitor ◽

Sphingosine Kinase ◽

Glioblastoma Cell ◽

Sphingosine Kinase Inhibitor

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SRC Tyrosine Kinase Inhibitor and X-rays Combined Effect on Glioblastoma Cell Lines

International Journal of Molecular Sciences ◽

10.3390/ijms21113917 ◽

2020 ◽

Vol 21 (11) ◽

pp. 3917 ◽

Cited By ~ 3

Author(s):

Filippo Torrisi ◽

Luigi Minafra ◽

Francesco P. Cammarata ◽

Gaetano Savoca ◽

Marco Calvaruso ◽

...

Keyword(s):

Cell Lines ◽

Kinase Inhibitor ◽

Therapeutic Potential ◽

Glioblastoma Cell ◽

X Rays ◽

Inhibitor Molecule ◽

Src Tyrosine Kinase ◽

Treatment Regimens ◽

Hypoxic Conditions ◽

Glioblastoma Cell Lines

Glioblastoma (GBM) is one of the most lethal types of tumor due to its high recurrence level in spite of aggressive treatment regimens involving surgery, radiotherapy and chemotherapy. Hypoxia is a feature of GBM, involved in radioresistance, and is known to be at the origin of treatment failure. The aim of this work was to assess the therapeutic potential of a new targeted c-SRC inhibitor molecule, named Si306, in combination with X-rays on the human glioblastoma cell lines, comparing normoxia and hypoxia conditions. For this purpose, the dose modifying factor and oxygen enhancement ratio were calculated to evaluate the Si306 radiosensitizing effect. DNA damage and the repair capability were also studied from the kinetic of γ-H2AX immunodetection. Furthermore, motility processes being supposed to be triggered by hypoxia and irradiation, the role of c-SRC inhibition was also analyzed to evaluate the migration blockage by wound healing assay. Our results showed that inhibition of the c-SRC protein enhances the radiotherapy efficacy both in normoxic and hypoxic conditions. These data open new opportunities for GBM treatment combining radiotherapy with molecularly targeted drugs to overcome radioresistance.

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Sphingosine Kinase-1 Expression Correlates With Poor Survival of Patients With Glioblastoma Multiforme: Roles of Sphingosine Kinase Isoforms in Growth of Glioblastoma Cell Lines

Journal of Neuropathology & Experimental Neurology ◽

10.1097/01.jnen.0000175329.59092.2c ◽

2005 ◽

Vol 64 (8) ◽

pp. 695-705 ◽

Cited By ~ 220

Author(s):

James R Van Brocklyn ◽

Catherine A Jackson ◽

Dennis K Pearl ◽

Mark S Kotur ◽

Pamela J Snyder ◽

...

Keyword(s):

Glioblastoma Multiforme ◽

Cell Lines ◽

Sphingosine Kinase ◽

Glioblastoma Cell ◽

Sphingosine Kinase 1 ◽

Poor Survival ◽

Glioblastoma Cell Lines

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Combination MEK and mTOR inhibitor therapy is active in models of glioblastoma

Neuro-Oncology Advances ◽

10.1093/noajnl/vdaa138 ◽

2020 ◽

Vol 2 (1) ◽

Author(s):

Karisa C Schreck ◽

Amy N Allen ◽

Jiawan Wang ◽

Christine A Pratilas

Keyword(s):

Cell Lines ◽

Kinase Inhibitor ◽

De Novo ◽

Mek Inhibitor ◽

Glioblastoma Cell ◽

Mtor Inhibition ◽

Adaptive Resistance ◽

Downstream Signaling ◽

Induced Apoptosis ◽

Glioblastoma Cell Lines

Abstract Background RAS effector signaling pathways such as PI3K/mTOR and ERK are frequently dysregulated in glioblastoma. While small molecule targeted therapies against these pathways have appeared promising in preclinical studies, they have been disappointing in clinical trials due to toxicity and de novo and adaptive resistance. To identify predictors of glioblastoma sensitivity to dual pathway inhibition with mTORC1/2 and MEK inhibitors, we tested these agents, alone and in combination, in a cohort of genomically characterized glioblastoma cell lines. Methods Seven genomically characterized, patient-derived glioblastoma neurosphere cell lines were evaluated for their sensitivity to the dual mTORC1/2 kinase inhibitor sapanisertib (MLN0128, TAK-228) alone or in combination with the MEK1/2 inhibitor trametinib (GSK1120212), using assessment of proliferation and evaluation of the downstream signaling consequences of these inhibitors. Results Sapanisertib inhibited cell growth in neurosphere lines, but induced apoptosis only in a subset of lines, and did not completely inhibit downstream mTOR signaling via ribosomal protein S6 (RPS6). Growth sensitivity to MEK inhibitor monotherapy was observed in a subset of lines defined by loss of NF1, was predicted by an ERK-dependent expression signature, and was associated with effective phospho-RPS6 inhibition. In these lines, combined MEK/mTOR treatment further inhibited growth and induced apoptosis. Combined MEK and mTOR inhibition also led to modest antiproliferative effects in lines with intact NF1 and insensitivity to MEK inhibitor monotherapy. Conclusions These data demonstrate that combined MEK/mTOR inhibition is synergistic in glioblastoma cell lines and may be more potent in NF1-deficient glioblastoma.

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