Glutathione S-Transferase Placental Form in Human and Rat Gliomas and Its Possible Role in Drug Resistance
Glutathione S-transferases (GSTs) are an important family of the detoxifying enzymes catalyzing the conjugation of glutathione to a wide variety of hydrophobic electrophilic substances . GSTs have various isoenzymes which have been studied extensively in rats . The isozyme, rat placental form (GST-P) has been shown to be a marker for preneoplastic or neoplastic lesions in chemical hepatocarcinogenesis , GST-P is well recognized to exist in normal rat astrocytes, and is regarded as a major form of isozymes expressed in rat brain . GST-P is expressed in GST-P-negative rat glioma cells after induction of benign transformation by dibutyryladenosine 3′,5′-cyclic monophosphate . The human placental form of GST (GST-π), which is closely related to GST-P immunologically, is also contained in normal human astrocytes. It may be that the GST-π; or GST-P contained in normal astrocytes is concerned with the detoxifying function against xenobiotics for the protection of neurons from their toxic effects. We have already demonstrated the expression of GST-π in human gliomas .
KeywordsGlioma Cell Human Glioma Preneoplastic Lesion Human Glioma Cell Line Anaplastic Glioma
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