M-ds-P21 induces cell apoptosis in bladder cancer T24 cells through P53 independent pathway.

Objectives: To investigate the effect of M-ds-P21 on the apoptosis of bladder cancer T24 cells and its potential mechanism.

Materials And Methods: Effect of M-ds-P21 on T24 cells were assessed by cell morphology and Western blot. Apoptosis was quantified by Annexin-V flow-cytometry analysis. To uncover the role of P53 in M-ds-P21-mediated apoptosis of T24 cells, we knocked down P53 before treating cells with M-ds-P21, and then assayed P21 and apoptosis-related protein by Western blot. To uncover the mechanism by which M-ds-P21 played stronger effect than ds-P21, we performed confocal microscope analyses.

Results: Both M-ds-P21 and ds-P21 treatment changed the cell morphology, leading to cell apoptosis after 3 days. Apoptosis induced by M-ds-P21 and ds-P21 treatment is not P53-dependent but caspase-dependent. Compared with ds-P21, M-ds-P21 significantly increased the bioavailability of ds-RNA in T24 cells.

Conclusions: M-ds-P21 treatment induces more apoptotic population than ds-P21 does. The mechanism for stronger effect of M-ds-P21 is partly due to the enhanced bioavailability of ds-RNA in human bladder cancer T24 cells, and not P53-dependent but caspase-dependent.