Parthenolide, An NF-κB Inhibitor, Suppresses Tumor Growth and Enhances Response to Chemotherapy in Gastric Cancer

Aim: This study evaluated the sesquiterpene lactone parthenolide, an inhibitor of transcription factor nuclear factor-kappaB (NF-kappa B), in the treatment of gastric cancer in vitro and in vivo. Materials and Methods: In vitro, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to evaluate the effect of parthenolide on growth inhibition and chemosensitization to antitumor drugs of three gastric cancer cell lines (MKN-28, MKN-45 and MKN-74). Microarray analysis was performed to identify genes which were up- or down-regulated on the treatment of parthenolide. The isobologram analysis was introduced to evaluate the synergic effect of parthenolide on antitumor drugs. In vivo, the effect of parthenolide was investigated in a mouse peritoneal dissemination model with and without chemotherapy. Results: Parthenolide significantly inhibited cell growth in three gastric cancer cell lines. The phosphorylation of NF-kappa B was down-regulated by the treatment of parthenolide. The synergic effect of parthenolide was confirmed in combination with paclitaxel and cisplatin. In the peritoneal dissemination model, parthenolide significantly suppressed the disseminated nodules as a single agent and also enhanced chemosensitivity to paclitaxel. Furthermore, the combined therapy of parthenolide and paclitaxel significantly contributed to prolonging the survival duration. Conclusion: The NF-kappa B inhibitor, parthenolide, may enhance chemosensitivity to paclitaxel in the treatment of patients with gastric cancer.