TRANSFECTION OF A T-CELL LINE WITH NEO INCREASES DEXAMETHASONE CYTOTOXICITY

Glucocorticoids (GC) are important therapeutic agents used in the treatment of lymphoid malignancies. GC-mediated cytotoxicity is preceded by the activation of a lysis mechanism induced by DNA nucleosomal cleavage. We have found that transfection of a relatively GC-resistant human T-cell leukemia line with the neo gene, and subsequent selection in geneticin (G418), is associated with enhanced GC-mediated DNA cleavage and cytotoxicity. The conversion of a GC-resistant clone to cells that are GC-sensitive may have implications for experiments involving G418 selection, as well as therapeutic implications in the development of certain types of GC-resistance. © 1990.