A unique human T-leukemia cell line highly sensitive to dexamethasone-induced lysis is described. The cell line designated Be13 is killed readily within 24 hr by 10-9 m dexamethasone. No lysis is induced by nonglucocorticoid steroids. The lysis is mediated via specific cytoplasmic receptors and is efficiently blocked by the antagonist cortexolone. The inhibiting effect of actinomycin D and cycloheximide on the lytic process suggests the involvement of gene activation and destruction of the cells by an “autolytic protein.” Kinetic studies imply that the lytic process is induced during a distinct phase of the cell cycle. Dexamethasone, however, does not cause an arrest in a distinct phase of the cell cycle. The Be13 cell is a unique human cell line killed directly by glucocorticoids, and it may serve as a suitable in vitro model for studying the lytic effect of glucocorticoids on the proliferating compartment of human leukemias.
This work was supported also by the Samuel Wang award granted by the Israel Cancer Research Fund.