Objective: To investigate modulation of decrease of intrinsic bcl-2 protein levels on programmed cell death of leukemia cells.
Method: Gene transfection procedure was applied to observe the effect of antisense RNA-mediated suppression of bcl-2 gene expression on programmed cell death of human T-lymphocytic leukemia cell line CEM.
Results: Temporary expression of antisense bcl-2 gene could effectively reduce levels of intrinsic bcl-2 protein of CEM cells and render it more sensitive to etoposide-induced cytotoxicity. Moreover, a great deal of apoptotic bodies and ladder DNA was always produced during etoposide-mediated killing of CEM and when CEM expressing bcl-2 antisense RNA served as target cells in particular, the amount of ladder DNA increased to around 40%.
Conclusion: Programmed cell death is one of the mechanisms by which etoposide kills leukemic cells and is modulated by cellular intrinsic bcl-2 protein.