Title :

Profound, durable and mgmt-independent sensitivity of glioblastoma cells to cyclin-dependent kinase inhibition

Author(s) :

Le Rhun, Emilie [Auteur]
Von Achenbach, Caroline [Auteur]
Lohmann, Birthe [Auteur]
Silginer, Manuela [Auteur]
Schneider, Hannah [Auteur]
Meetze, Kristan [Auteur]
Szabo, Emese [Auteur]
Weller, Michael [Auteur]

Journal title :

International journal of cancer

Abbreviated title :

Int. J. Cancer

Publication date :

2018-12-14

ISSN :

1097-0215

Keyword(s) :

glioma
senescence
chemotherapy
MGMT
resistance

HAL domain(s) :

Sciences du Vivant [q-bio]

English abstract : [en]

TG02 is a novel cyclin-dependent kinase (CDK) inhibitor and thought to act mainly via CDK-9 inhibition-dependent depletion of short-lived oncoproteins such as MCL-1 or c-MYC. We studied the activity of TG02 in 9 human ...
Show more >TG02 is a novel cyclin-dependent kinase (CDK) inhibitor and thought to act mainly via CDK-9 inhibition-dependent depletion of short-lived oncoproteins such as MCL-1 or c-MYC. We studied the activity of TG02 in 9 human long-term glioma cell lines (LTC) and 5 glioma-initiating cell lines (GIC) using various cell death assays in vitro and in the LN-229 LTC and ZH-161 GIC models in vivo. TG02 exhibits strong anti-tumor cell activity with EC50 concentrations in the nanomolar range. Median survival in the LN-229 and ZH-161 models was moderately prolonged by TG02. Neither constitutive CDK levels nor those of MCL-1 or c-MYC correlated with sensitivity to TG02. Cdk-9 or cdk-5 gene silencing alone did not fully reproduce the effects of TG02. C-myc gene silencing inhibited cell growth, but did not modulate TG02 activity. Electron microscopy revealed cell death to be essentially apoptotic. High concentrations of TG02 induced annexin V binding and minor caspase 3 cleavage, but the pan-caspase inhibitor, zVAD-fmk, or BCL-2 or MCL-1 gene transfer only moderately attenuated TG02-induced cell death, and caspase inhibition did not prevent loss of MCL-1 or c-MYC. TG02 activity was independent of O(6) -methylguanine DNA methyltransferase expression. Repetitive exposure to TG02 did not generate an acquired TG02 resistance phenotype, but accumulation of MCL-1, loss of c-MYC, or senescence. TG02 is a highly potent apoptosis-inducing agent in glioma cells in vitro. Caspase inhibition does not rescue TG02-treated cells and repetitive exposure fails to confer acquired resistance, supporting the clinical evaluation of TG02 in glioblastoma.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

INSERM
Université de Lille

Collections :

• Protéomique, Réponse Inflammatoire, Spectrométrie de Masse (PRISM) - U1192

Submission date :

2022-06-15T13:58:53Z