RESUMO
<p><b>OBJECTIVE</b>To investigate the effect of small interfering RNA on cell proliferation and apoptosis in gastric cancer cell lines with high expression of RegIα.</p><p><b>METHODS</b>Total RNA was isolated from six gastric cancer cell lines,and the expression of RegI α mRNA was detected by RT-PCR. RegI α RNAi expression vector was constructed and stably transfected into MKN45 and AGS cells with high RegI α expression, empty-vector was used as control. RegI α mRNA and protein expression was measured by RT-PCR and Western blot respectively in stable transfected cell lines. Cell proliferation and apoptosis were detected with MTT assay and flow cytometry.</p><p><b>RESULT</b>RT-PCR results indicated that RegI α mRNA expression was significantly inhibited by RNAi in both cell lines compared with empty-vector. Western blot results showed that RegIα protein was down-regulated to (44 ± 4)% and (25 ± 4)% respectively in MKN45 and AGS cells compared to empty-vector. MTT results showed that cell growth was significantly inhibited in MKN45 and AGS cells. The apoptosis rate in MKN45 and AGS cells was remarkable increased compared to that of empty-vector (12.96 ± 0.50)% compared with (3.99 ± 0.30)% and (11.59 ± 1.10)% compared with (4.22 ± 0.40)% (P < 0.05).</p><p><b>CONCLUSION</b>Small interfering RNA of RegI α gene can efficiently down-regulate RegI α expression in MKN45 and AGS cell lines, and further inhibit cell growth and induce cell apoptosis.</p>