QIAO Min1, XIANG Tingª²Xiu2, WANG Piª²Long3, HUANG Aiª²Long4

    1Department of Digestive Diseases, First Affiliated Hospital, 2Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing University of Medical Science, Chongqing 400016,China

    ¡¾Abstract¡¿AIM: To investigate the inhibitory effect of siRNA targeting COXª²2 on the growth of gastric carcinoma cells of well, moderate or poor differentiation (MKNª²28, SGCª²7901, BGCª²823) and related mechanism. METHODS: siRNA targeting COXª²2 gene was designed, siRNAª²COXª²2 vector was constructed and transfected into gastric carcinoma cells to induce RNA interference. The changes of COXª²2 were detected with RTª²PCR and Western blotting.Cell viability was detected by MTT. Cell apoptosis was judged by TUNEL and electromicroscopy, and expressions of Bax and Bclª²2 were tested by Western blot. RESULTS: Both COXª²2 expression and cell growth were inhibited in SGCª²7901 and BGCª²823 after transfection of siRNAª²COXª²2 vector into the cells. But, in MKNª²28 ,only COXª²2 expression decreased. The obvious cell apoptosis both in SGCª²7901 and BGCª²823 was observed. Bax was upª²regulated and Bclª²2 was downª²regulated in SGCª²7901 and BGCª²823. In contrast, there were almost no changes in control group in vitro. CONCLUSION: RNA interference inhibits the growth of gastric carcinoma cells, which may be related to downª²regulation of COXª²2 and induction of cell apoptosis. The inhibitory effect of RNAi was relatively strong in SGCª²7901, which indicated that the effect of siRNA was dependent on the differentiation degree of gastric carcinoma cells. ......