Abstract: Objective    To invesigate the inhibitory effect of paclitaxel combined with miR-200b mimics on proliferation and invasion of human gastric cancer cell line SGC-7901 in vitro. Methods     Human gastric cancer SGC-7901 cells were treated with 50nmol/L paclitaxel alone or combined with transfecting miR-200b mimics. We use the flow cytometry technology, the cell cloning, Transwell assay and wound healing test to observe the change on the the cell cycle, the percentage of cell apoptotic cells, the proliferation ability and the invasive ability. We also discussed the possible mechanism by detecting the level of certain protein using western-blot. Results   The experiments shows that the group treated both with paclitaxel and miR-200b mimics had significantly higher cell apoptotic rate(P<0.001) and lower percentage of cell cloning（P<0.001）, less trans-membrane cell number(P<0.001)，lower migrating rate after 48 h(P<0.001) than the group treated with paclitaxel alone. While there is no significant in the percentage of cells blocked at G2/M phase. As western-blot showed, the level of E2F3 reduced (P<0.001) affter transfecting the miR-200b mimics. Conclusion    MiR-200b may enhance the inhibitory effect of paclitaxel on cell proliferation and invasion of human gastric cancer cell line SGC-7901 by lowering the level of E2F3.

Key words: stomach neoplasms, adenocarcinoma, Proliferation, Paclitaxel, microRNA-200b