RESUMEN
Objective To study the pathogenic molecular mechanism of H.pylori through analyzing its effect of on MMP-9 expression. Methods BGC-823 cells were cocultured with ATCC49503(CagA +)and HP 030811 (CagA -) H.pylori strains respectively, then the total cellelar RNA was extracted. The MMP-9 mRNA expression in BGC-823 cells, 9 cases of H.pylori-positive and 9 cases of H.pylori-negative gastric ulcer biopsy tissues was detected by RT-PCR. The MMP-9 protein expression on the paraffin-imbedded tissue sections of 17 cases of H.pylori-positive and 14 cases of H.pylori-negative gastric ulcer tissues was detected with immunohistochemical technique, and was quantified by image quantitative analysis. Results H.pylori induced MMP-9 expression in BGC-823, and the level of MMP-9 expression induced by CagA -postive H.pylori strain was higher than that by CagA -negative one. MMP-9 expression level was higher in the H.pylori-positive gastric ulcer tissues than that in the H.pylori-negative ones. Conclusion H.pylori-induced MMP-9 expression may play an important role in gastric ulcer formation and gastric carcinogenesis.