- •A MGMT negative and TMZ-resistant glioma cell line (U87/TR) was established.
- •U87/TR displayed cell cycle arrest and EMT-like changes.
- •Akt and Wnt/β-catenin pathways were response for TMZ-resistance and EMT.
- •Phosphorylated PRAS40 and inactivated mTOR contributed to cell cycle arrest.
Glioblastoma is one of the most lethal cancers in central nervous system, and some individual cells that cannot be isolated for surgical resection and also show treatment-resistance induce poor prognosis. Hence, in order to research these cells, we treated temozolomide (TMZ)-sensitive U87MG cells with 400 μM TMZ in culture media for over 6 months and established TMZ-resistant cell line designated as U87/TR. We detected the MGMT status through pyrosequencing and western blotting, and we also assessed the proliferation, migration, EMT-like changes and possible activated signaling pathways in U87/TR cells. Our results demonstrated that U87/TR was MGMT negative, which indicated that MGMT made no contribution for TMZ-resistance of U87/TR. And U87/TR cells displayed cell cycle arrest, higher capacity for migration and EMT-like changes including both phenotype and characteristic proteins. We also revealed that both β-catenin and the phosphorylation level of Akt and PRAS40 were increased in U87/TR, while we did not observe the phosphorylation of mTOR in U87/TR. It indicated that activation of Akt and Wnt/β-catenin pathways may be response for the chemo-resistance and increased invasion of U87/TR cells, and the phosphorylation of PRAS40 and inactivated mTOR may be related to cell cycle arrest in U87/TR cells.
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Published online: May 31, 2016
Accepted: May 30, 2016
Received in revised form: May 5, 2016
Received: April 6, 2016
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