Paclitaxel combined with harmine inhibits the migration and invasion of gastric cancer cells through downregulation of cyclooxygenase-2 expression.

Cyclooxygenase-2 (COX-2) has a critical role in the invasiveness and metastasis of gastric cancer. In addition, paclitaxel (PTX) and harmine (HM) were reported to be potential therapeutic drug candidates for cancer therapy; however, the synergistic antitumor effect of PTX and HM combined treatment on the human gastric cancer cells remains to be elucidated. The aim of the present study was to evaluate the effects of PTX and/or HM on the cell migration and invasion in two human gastric cancer cell lines, SGC-7901 and MKN-45. MTT assay was used to detect the growth inhibition induced by PTX and HM. The Transwell assay was employed to assess the effects of PTX and HM on the cell migration and invasion. The expression levels of COX-2 and matrix metalloproteinase-9 (MMP-9) were analyzed by western blot analysis. The results demonstrated that PTX and HM inhibited cell proliferation in a dose-dependent manner. Individually PTX and HM were able to inhibit the migration and invasion of two human gastric cancer cells; however, the combination of PTX and HM exerted synergistic effects on migration and invasion inhibition, with downregulation of COX-2 and matrix metalloproteinase (MMP)-9. In conclusion, the results of the present study indicated that combination chemotherapy using PTX with HM exerted an antitumor effect, which may be implicated for the treatment of gastric cancer. Of note, the combination of the two drugs inhibited migration and invasion more effectively compared with each drug alone, the mechanism of which proceeded via the downregulation of COX-2 expression.