The Role of O6-Alkylguanine-DNA Alkyltransferase in Glioma in Resistance to Chloroethylnitrosoureas
Chloroethylnitrosoureas (CENUs) have been commonly used as chemotherapy for malignant gliomas . Based on the anticipated cytotoxic mechanisms of these agents, the results of a number of studies using cultured tumor cells have confirmed that a DNA repair enzyme, O6-alkylguanine-DNA alkyltransferase (AGT), affects the susceptibility of human tumor cells to CENUs [2,3]. A similar finding was also noted in rat and human glioma cell lines [4,5]. However, little is known about the contribution of AGT to the resistance to CENUs in clinically observed malignant gliomas. In this study, we investigated to what degree AGT influenced the mechanism of acquired resistance to CENUs in rat brain tumor cells, and evaluated the significance of this DNA repair enzyme in clinical resistance to CENUs by analyzing AGT activity measured in human malignant glioma surgical specimens.
KeywordsMalignant Glioma Human Glioma Cell Line 9LR12 Cell 9LR1 9LR3 Tumor Cell Strain
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