Objective: To investigate celecoxib-induced apoptosis of acute promyelocytic leukemia cell line MR2 and related mechanism.
Methods: MR2 cells were treated with celecoxib at different concentrations (0, 20, 40, 80, 120 and 160 micromol/L). The proliferation of MR2 cells was observed by MTT assay and apoptosis was detected by DNA fragmentation analysis and flow cytometry with Annexin V-FITCïPI staining. The expression of survivin and PML/RARalpha mRNA was examined by RT-PCR and nested-PCR, and the protein expression of caspase-3, 9 and PARP was analyzed by Western-blot.
Results: After treatment with celecoxib the viability of MR2 cells decreased markedly in a dose- and time-dependent manner, and a DNA ladder pattern of internucleosomal fragmentation was observed. The translocation of phosphatidylserine at the outer surface of the cell plasma membrane was induced by celecoxib and its level increased following the augmentation of the drug concentration. The expression of survivin mRNA decreased dramatically while no significant change with PML/RARalpha. Treatment with celecoxib for 24 h resulted in the activation of caspase-3 and 9, cleavage of PARP.
Conclusion: Celecoxib could inhibit MR2 cell proliferation by inducing apoptosis, which might be mediated by the caspase-3 and 9 activation and PARP cleavage. Moreover, the down-regulation of survivin may play a certain role in apoptosis of MR2 cells induced by celecoxib.