A sphingosine kinase inhibitor induces cell death in temozolomide resistant glioblastoma cells

• Published in: Cancer chemotherapy and pharmacology 2009-10, Vol.64 (5), p.1053-1058
• Main Authors: Bektas, Meryem, Johnson, Stewart P., Poe, William E., Bigner, Darell D., Friedman, Henry S.
• Format: Article
• Language: English
• Subjects: Aniline Compounds - pharmacology; Antineoplastic agents; Antineoplastic Agents, Alkylating - pharmacology; Apoptosis - drug effects; Biological and medical sciences; Cancer Research; Caspase 3 - metabolism; Cell death; Cell Death - drug effects; Cell Line, Tumor; Cell Proliferation - drug effects; Dacarbazine - analogs & derivatives; Dacarbazine - pharmacology; Drug Resistance, Neoplasm; Enzyme Inhibitors - pharmacology; Flow Cytometry; Glioblastoma - drug therapy; Glioblastoma - pathology; Humans; Indicator Dilution Techniques; Medical sciences; Medicine; Medicine & Public Health; Neurology; Oligonucleotide Array Sequence Analysis; Oncology; Pharmacology. Drug treatments; Pharmacology/Toxicology; Phosphotransferases (Alcohol Group Acceptor) - antagonists & inhibitors; Reverse Transcriptase Polymerase Chain Reaction; Short Communication; Thiazoles - pharmacology; Tumors of the nervous system. Phacomatoses
• ISSN: 0344-5704; 1432-0843
• DOI: 10.1007/s00280-009-1063-0

Purpose Sphingosine kinase is an oncogene that is up-regulated in several solid tumors. The product of the sphingosine kinase activity, sphingosine-1-phosphate is a potent mitogen involved in diverse cell processes such as cell survival and migration. Current standard therapy in the treatment of glioblastoma multiforme (GBM) is a combination of surgery, radiation, and chemotherapy using the drug temozolomide (TMZ). However, virtually all tumors become resistant to TMZ. Therefore, new drug targets are necessary. In this study, we investigated whether inhibiting sphingosine kinase could induce cell death in TMZ-resistant GBM cells. Methods To study TMZ resistance in vitro, we have generated TMZ-resistant cell lines from established GBM cells. We used a potent inhibitor of sphingosine kinase to study its effect on colony formation and cell growth in GBM cells with a limited dilution and WST assay. Moreover, cell death was determined by measuring caspase-3 activity using flow cytometry. Results A sphingosine kinase inhibitor reduced cell colony formation and activated caspase-3 in both TMZ-sensitive and resistant GBM cells. Conclusion Addition of a sphingosine kinase inhibitor to the standard chemotherapy regimen against GBM may be beneficial.