Abstract: AIM: To understand the role of aspirin inthe prevention and cure of prostatie carcinoma, and the effects of Aspirin on the promoter actr of humanMMP-9 gene were studied.METHODS: DU145 cells were cultured and subcultured. Different concentrations of Aspirin (10, 5, 2.5, 1, 0.5, 0.1 and 0.2 mmol·L^-1)were added into the plates to co-incubated with the cell MTT method was used to detect cytotoxicity of Aspirin af-ter 24, 48 and 72 hours. Cells were transient transfected with PCAT 1.28, PCAT 0.65, PCAT 0.54 and PCAT0.52 containing^-1 28 kb, 0.65 kb, 0.54 kb, 0.52kb of 5 flanked sequence of human MMP-9 gene, fused to CAT reporter gene by CAT-ELISA.RESULTS: Aspirin (< 1 mmol·L^-1) had no cytotoxicity of DU145 cells (P> 0.05). CAT expression of PCAT 1.28 and PCAT 0.65are 2 and 1.6 times as high as the control groups. CAT expression of PCAT 1.28, PCAT 0.65 and PCAT 0.54were 2.5, 2.2 and 1.3 times as high as the contre groups. Aspirin inhibited the promoter activities of PCAT 1.28, PCAT 0.65. And the inhibition of Aspirin was reversed by PMA.CONCLUSION: Aspirin can inhibit the expression of human MMP-9 gene in the tramscriptional level and can inhibit the formation and development of prostatic carcinoma.

Key words: MMP-9, DU145, promoter, aspirin, transcriptional regulation